Merge tag 'tty-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here is the big set of TTY / Serial patches for 5.7-rc1

  Lots of console fixups and reworking in here, serial core tweaks
  (doesn't that ever get old, why are we still creating new serial
  devices?), serial driver updates, line-protocol driver updates, and
  some vt cleanups and fixes included in here as well.

  All have been in linux-next with no reported issues"

* tag 'tty-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (161 commits)
  serial: 8250: Optimize irq enable after console write
  serial: 8250: Fix rs485 delay after console write
  vt: vt_ioctl: fix use-after-free in vt_in_use()
  vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual console
  tty: serial: make SERIAL_SPRD depend on COMMON_CLK
  tty: serial: fsl_lpuart: fix return value checking
  tty: serial: fsl_lpuart: move dma_request_chan()
  ARM: dts: tango4: Make /serial compatible with ns16550a
  ARM: dts: mmp*: Make the serial ports compatible with xscale-uart
  ARM: dts: mmp*: Fix serial port names
  ARM: dts: mmp2-brownstone: Don't redeclare phandle references
  ARM: dts: pxa*: Make the serial ports compatible with xscale-uart
  ARM: dts: pxa*: Fix serial port names
  ARM: dts: pxa*: Don't redeclare phandle references
  serial: omap: drop unused dt-bindings header
  serial: 8250: 8250_omap: Add DMA support for UARTs on K3 SoCs
  serial: 8250: 8250_omap: Work around errata causing spurious IRQs with DMA
  serial: 8250: 8250_omap: Extend driver data to pass FIFO trigger info
  serial: 8250: 8250_omap: Move locking out from __dma_rx_do_complete()
  serial: 8250: 8250_omap: Account for data in flight during DMA teardown
  ...

drivers/tty/serial/8250/8250.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  *  Driver for 8250/16550-type serial ports
  *
@@ -156,7 +156,9 @@ void serial8250_rpm_put(struct uart_8250_port *p);
 void serial8250_rpm_get_tx(struct uart_8250_port *p);
 void serial8250_rpm_put_tx(struct uart_8250_port *p);
 
-int serial8250_em485_init(struct uart_8250_port *p);
+int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485);
+void serial8250_em485_start_tx(struct uart_8250_port *p);
+void serial8250_em485_stop_tx(struct uart_8250_port *p);
 void serial8250_em485_destroy(struct uart_8250_port *p);
 
 /* MCR <-> TIOCM conversion */

drivers/tty/serial/8250/8250_bcm2835aux.c

@@ -6,6 +6,10 @@
  *
  * Based on 8250_lpc18xx.c:
  * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
+ *
+ * The bcm2835aux is capable of RTS auto flow-control, but this driver doesn't
+ * take advantage of it yet.  When adding support, be sure not to enable it
+ * simultaneously to rs485.
  */
 
 #include <linux/clk.h>
@@ -16,16 +20,64 @@
 
 #include "8250.h"
 
+#define BCM2835_AUX_UART_CNTL		8
+#define BCM2835_AUX_UART_CNTL_RXEN	0x01 /* Receiver enable */
+#define BCM2835_AUX_UART_CNTL_TXEN	0x02 /* Transmitter enable */
+#define BCM2835_AUX_UART_CNTL_AUTORTS	0x04 /* RTS set by RX fill level */
+#define BCM2835_AUX_UART_CNTL_AUTOCTS	0x08 /* CTS stops transmitter */
+#define BCM2835_AUX_UART_CNTL_RTS3	0x00 /* RTS set until 3 chars left */
+#define BCM2835_AUX_UART_CNTL_RTS2	0x10 /* RTS set until 2 chars left */
+#define BCM2835_AUX_UART_CNTL_RTS1	0x20 /* RTS set until 1 chars left */
+#define BCM2835_AUX_UART_CNTL_RTS4	0x30 /* RTS set until 4 chars left */
+#define BCM2835_AUX_UART_CNTL_RTSINV	0x40 /* Invert auto RTS polarity */
+#define BCM2835_AUX_UART_CNTL_CTSINV	0x80 /* Invert auto CTS polarity */
+
 /**
  * struct bcm2835aux_data - driver private data of BCM2835 auxiliary UART
  * @clk: clock producer of the port's uartclk
  * @line: index of the port's serial8250_ports[] entry
+ * @cntl: cached copy of CNTL register
  */
 struct bcm2835aux_data {
 	struct clk *clk;
 	int line;
+	u32 cntl;
 };
 
+static void bcm2835aux_rs485_start_tx(struct uart_8250_port *up)
+{
+	if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) {
+		struct bcm2835aux_data *data = dev_get_drvdata(up->port.dev);
+
+		data->cntl &= ~BCM2835_AUX_UART_CNTL_RXEN;
+		serial_out(up, BCM2835_AUX_UART_CNTL, data->cntl);
+	}
+
+	/*
+	 * On the bcm2835aux, the MCR register contains no other
+	 * flags besides RTS.  So no need for a read-modify-write.
+	 */
+	if (up->port.rs485.flags & SER_RS485_RTS_ON_SEND)
+		serial8250_out_MCR(up, 0);
+	else
+		serial8250_out_MCR(up, UART_MCR_RTS);
+}
+
+static void bcm2835aux_rs485_stop_tx(struct uart_8250_port *up)
+{
+	if (up->port.rs485.flags & SER_RS485_RTS_AFTER_SEND)
+		serial8250_out_MCR(up, 0);
+	else
+		serial8250_out_MCR(up, UART_MCR_RTS);
+
+	if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) {
+		struct bcm2835aux_data *data = dev_get_drvdata(up->port.dev);
+
+		data->cntl |= BCM2835_AUX_UART_CNTL_RXEN;
+		serial_out(up, BCM2835_AUX_UART_CNTL, data->cntl);
+	}
+}
+
 static int bcm2835aux_serial_probe(struct platform_device *pdev)
 {
 	struct uart_8250_port up = { };
@@ -47,6 +99,14 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
 	up.port.fifosize = 8;
 	up.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE |
 			UPF_SKIP_TEST | UPF_IOREMAP;
+	up.port.rs485_config = serial8250_em485_config;
+	up.rs485_start_tx = bcm2835aux_rs485_start_tx;
+	up.rs485_stop_tx = bcm2835aux_rs485_stop_tx;
+
+	/* initialize cached copy with power-on reset value */
+	data->cntl = BCM2835_AUX_UART_CNTL_RXEN | BCM2835_AUX_UART_CNTL_TXEN;
+
+	platform_set_drvdata(pdev, data);
 
 	/* get the clock - this also enables the HW */
 	data->clk = devm_clk_get(&pdev->dev, NULL);
@@ -102,8 +162,6 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
 	}
 	data->line = ret;
 
-	platform_set_drvdata(pdev, data);
-
 	return 0;
 
 dis_clk:
@@ -137,6 +195,24 @@ static struct platform_driver bcm2835aux_serial_driver = {
 };
 module_platform_driver(bcm2835aux_serial_driver);
 
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+
+static int __init early_bcm2835aux_setup(struct earlycon_device *device,
+					const char *options)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->port.iotype = UPIO_MEM32;
+	device->port.regshift = 2;
+
+	return early_serial8250_setup(device, NULL);
+}
+
+OF_EARLYCON_DECLARE(bcm2835aux, "brcm,bcm2835-aux-uart",
+		    early_bcm2835aux_setup);
+#endif
+
 MODULE_DESCRIPTION("BCM2835 auxiliar UART driver");
 MODULE_AUTHOR("Martin Sperl <kernel@martin.sperl.org>");
 MODULE_LICENSE("GPL v2");

drivers/tty/serial/8250/8250_core.c

@@ -608,6 +608,14 @@ static int univ8250_console_setup(struct console *co, char *options)
 	return retval;
 }
 
+static int univ8250_console_exit(struct console *co)
+{
+	struct uart_port *port;
+
+	port = &serial8250_ports[co->index].port;
+	return serial8250_console_exit(port);
+}
+
 /**
  *	univ8250_console_match - non-standard console matching
  *	@co:	  registering console
@@ -666,6 +674,7 @@ static struct console univ8250_console = {
 	.write		= univ8250_console_write,
 	.device		= uart_console_device,
 	.setup		= univ8250_console_setup,
+	.exit		= univ8250_console_exit,
 	.match		= univ8250_console_match,
 	.flags		= CON_PRINTBUFFER | CON_ANYTIME,
 	.index		= -1,
@@ -1007,14 +1016,18 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 		uart->port.unthrottle	= up->port.unthrottle;
 		uart->port.rs485_config	= up->port.rs485_config;
 		uart->port.rs485	= up->port.rs485;
+		uart->rs485_start_tx	= up->rs485_start_tx;
+		uart->rs485_stop_tx	= up->rs485_stop_tx;
 		uart->dma		= up->dma;
 
 		/* Take tx_loadsz from fifosize if it wasn't set separately */
 		if (uart->port.fifosize && !uart->tx_loadsz)
 			uart->tx_loadsz = uart->port.fifosize;
 
-		if (up->port.dev)
+		if (up->port.dev) {
 			uart->port.dev = up->port.dev;
+			uart_get_rs485_mode(uart->port.dev, &uart->port.rs485);
+		}
 
 		if (up->port.flags & UPF_FIXED_TYPE)
 			uart->port.type = up->port.type;

drivers/tty/serial/8250/8250_dwlib.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /* Synopsys DesignWare 8250 library header file. */
 
 #include <linux/types.h>

drivers/tty/serial/8250/8250_exar.c

@@ -135,7 +135,7 @@ struct exar8250 {
 	unsigned int		nr;
 	struct exar8250_board	*board;
 	void __iomem		*virt;
-	int			line[0];
+	int			line[];
 };
 
 static void exar_pm(struct uart_port *port, unsigned int state, unsigned int old)

drivers/tty/serial/8250/8250_lpss.c

@@ -156,6 +156,11 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 	return 0;
 }
 
+static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
+{
+	return 0;
+}
+
 #ifdef CONFIG_SERIAL_8250_DMA
 static const struct dw_dma_platform_data qrk_serial_dma_pdata = {
 	.nr_channels = 2,
@@ -356,6 +361,7 @@ static const struct lpss8250_board byt_board = {
 static const struct lpss8250_board ehl_board = {
 	.freq = 200000000,
 	.base_baud = 12500000,
+	.setup = ehl_serial_setup,
 };
 
 static const struct lpss8250_board qrk_board = {

drivers/tty/serial/8250/8250_mtk.c

@@ -32,6 +32,7 @@
 #define MTK_UART_RXTRI_AD	0x14	/* RX Trigger address */
 #define MTK_UART_FRACDIV_L	0x15	/* Fractional divider LSB address */
 #define MTK_UART_FRACDIV_M	0x16	/* Fractional divider MSB address */
+#define MTK_UART_DEBUG0	0x18
 #define MTK_UART_IER_XOFFI	0x20	/* Enable XOFF character interrupt */
 #define MTK_UART_IER_RTSI	0x40	/* Enable RTS Modem status interrupt */
 #define MTK_UART_IER_CTSI	0x80	/* Enable CTS Modem status interrupt */
@@ -388,9 +389,18 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
 static int __maybe_unused mtk8250_runtime_suspend(struct device *dev)
 {
 	struct mtk8250_data *data = dev_get_drvdata(dev);
+	struct uart_8250_port *up = serial8250_get_port(data->line);
 
-	clk_disable_unprepare(data->uart_clk);
-	clk_disable_unprepare(data->bus_clk);
+	/* wait until UART in idle status */
+	while
+		(serial_in(up, MTK_UART_DEBUG0));
+
+	if (data->clk_count == 0U) {
+		dev_dbg(dev, "%s clock count is 0\n", __func__);
+	} else {
+		clk_disable_unprepare(data->bus_clk);
+		data->clk_count--;
+	}
 
 	return 0;
 }
@@ -400,16 +410,16 @@ static int __maybe_unused mtk8250_runtime_resume(struct device *dev)
 	struct mtk8250_data *data = dev_get_drvdata(dev);
 	int err;
 
-	err = clk_prepare_enable(data->uart_clk);
-	if (err) {
-		dev_warn(dev, "Can't enable clock\n");
-		return err;
-	}
-
-	err = clk_prepare_enable(data->bus_clk);
-	if (err) {
-		dev_warn(dev, "Can't enable bus clock\n");
-		return err;
+	if (data->clk_count > 0U) {
+		dev_dbg(dev, "%s clock count is %d\n", __func__,
+			data->clk_count);
+	} else {
+		err = clk_prepare_enable(data->bus_clk);
+		if (err) {
+			dev_warn(dev, "Can't enable bus clock\n");
+			return err;
+		}
+		data->clk_count++;
 	}
 
 	return 0;
@@ -419,12 +429,14 @@ static void
 mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
 {
 	if (!state)
-		pm_runtime_get_sync(port->dev);
+		if (!mtk8250_runtime_resume(port->dev))
+			pm_runtime_get_sync(port->dev);
 
 	serial8250_do_pm(port, state, old);
 
 	if (state)
-		pm_runtime_put_sync_suspend(port->dev);
+		if (!pm_runtime_put_sync_suspend(port->dev))
+			mtk8250_runtime_suspend(port->dev);
 }
 
 #ifdef CONFIG_SERIAL_8250_DMA
@@ -501,6 +513,8 @@ static int mtk8250_probe(struct platform_device *pdev)
 	if (!data)
 		return -ENOMEM;
 
+	data->clk_count = 0;
+
 	if (pdev->dev.of_node) {
 		err = mtk8250_probe_of(pdev, &uart.port, data);
 		if (err)
@@ -533,6 +547,7 @@ static int mtk8250_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, data);
 
+	pm_runtime_enable(&pdev->dev);
 	err = mtk8250_runtime_resume(&pdev->dev);
 	if (err)
 		return err;
@@ -541,9 +556,6 @@ static int mtk8250_probe(struct platform_device *pdev)
 	if (data->line < 0)
 		return data->line;
 
-	pm_runtime_set_active(&pdev->dev);
-	pm_runtime_enable(&pdev->dev);
-
 	data->rx_wakeup_irq = platform_get_irq_optional(pdev, 1);
 
 	return 0;
@@ -556,11 +568,13 @@ static int mtk8250_remove(struct platform_device *pdev)
 	pm_runtime_get_sync(&pdev->dev);
 
 	serial8250_unregister_port(data->line);
-	mtk8250_runtime_suspend(&pdev->dev);
 
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
 
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		mtk8250_runtime_suspend(&pdev->dev);
+
 	return 0;
 }
 

drivers/tty/serial/8250/8250_of.c

@@ -7,7 +7,6 @@
 #include <linux/console.h>
 #include <linux/module.h>
 #include <linux/slab.h>
-#include <linux/delay.h>
 #include <linux/serial_core.h>
 #include <linux/serial_reg.h>
 #include <linux/of_address.h>
@@ -26,67 +25,16 @@ struct of_serial_info {
 	int line;
 };
 
-#ifdef CONFIG_ARCH_TEGRA
-static void tegra_serial_handle_break(struct uart_port *p)
-{
-	unsigned int status, tmout = 10000;
-
-	do {
-		status = p->serial_in(p, UART_LSR);
-		if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
-			status = p->serial_in(p, UART_RX);
-		else
-			break;
-		if (--tmout == 0)
-			break;
-		udelay(1);
-	} while (1);
-}
-#else
-static inline void tegra_serial_handle_break(struct uart_port *port)
-{
-}
-#endif
-
-static int of_8250_rs485_config(struct uart_port *port,
-				  struct serial_rs485 *rs485)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	/* Clamp the delays to [0, 100ms] */
-	rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
-	rs485->delay_rts_after_send  = min(rs485->delay_rts_after_send, 100U);
-
-	port->rs485 = *rs485;
-
-	/*
-	 * Both serial8250_em485_init and serial8250_em485_destroy
-	 * are idempotent
-	 */
-	if (rs485->flags & SER_RS485_ENABLED) {
-		int ret = serial8250_em485_init(up);
-
-		if (ret) {
-			rs485->flags &= ~SER_RS485_ENABLED;
-			port->rs485.flags &= ~SER_RS485_ENABLED;
-		}
-		return ret;
-	}
-
-	serial8250_em485_destroy(up);
-
-	return 0;
-}
-
 /*
  * Fill a struct uart_port for a given device node
  */
 static int of_platform_serial_setup(struct platform_device *ofdev,
-			int type, struct uart_port *port,
+			int type, struct uart_8250_port *up,
 			struct of_serial_info *info)
 {
 	struct resource resource;
 	struct device_node *np = ofdev->dev.of_node;
+	struct uart_port *port = &up->port;
 	u32 clk, spd, prop;
 	int ret, irq;
 
@@ -207,13 +155,11 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 		port->flags |= UPF_SKIP_TEST;
 
 	port->dev = &ofdev->dev;
-	port->rs485_config = of_8250_rs485_config;
+	port->rs485_config = serial8250_em485_config;
+	up->rs485_start_tx = serial8250_em485_start_tx;
+	up->rs485_stop_tx = serial8250_em485_stop_tx;
 
 	switch (type) {
-	case PORT_TEGRA:
-		port->handle_break = tegra_serial_handle_break;
-		break;
-
 	case PORT_RT2880:
 		port->iotype = UPIO_AU;
 		break;
@@ -258,7 +204,7 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
 		return -ENOMEM;
 
 	memset(&port8250, 0, sizeof(port8250));
-	ret = of_platform_serial_setup(ofdev, port_type, &port8250.port, info);
+	ret = of_platform_serial_setup(ofdev, port_type, &port8250, info);
 	if (ret)
 		goto err_free;
 
@@ -358,7 +304,6 @@ static const struct of_device_id of_platform_serial_table[] = {
 	{ .compatible = "ns16550",  .data = (void *)PORT_16550, },
 	{ .compatible = "ns16750",  .data = (void *)PORT_16750, },
 	{ .compatible = "ns16850",  .data = (void *)PORT_16850, },
-	{ .compatible = "nvidia,tegra20-uart", .data = (void *)PORT_TEGRA, },
 	{ .compatible = "nxp,lpc3220-uart", .data = (void *)PORT_LPC3220, },
 	{ .compatible = "ralink,rt2880-uart", .data = (void *)PORT_RT2880, },
 	{ .compatible = "intel,xscale-uart", .data = (void *)PORT_XSCALE, },

drivers/tty/serial/8250/8250_omap.c

@@ -40,6 +40,7 @@
  * The same errata is applicable to AM335x and DRA7x processors too.
  */
 #define UART_ERRATA_CLOCK_DISABLE	(1 << 3)
+#define	UART_HAS_EFR2			BIT(4)
 
 #define OMAP_UART_FCR_RX_TRIG		6
 #define OMAP_UART_FCR_TX_TRIG		4
@@ -93,6 +94,10 @@
 #define OMAP_UART_REV_52 0x0502
 #define OMAP_UART_REV_63 0x0603
 
+/* Enhanced features register 2 */
+#define UART_OMAP_EFR2			0x23
+#define UART_OMAP_EFR2_TIMEOUT_BEHAVE	BIT(6)
+
 struct omap8250_priv {
 	int line;
 	u8 habit;
@@ -105,6 +110,8 @@ struct omap8250_priv {
 	u8 delayed_restore;
 	u16 quot;
 
+	u8 tx_trigger;
+	u8 rx_trigger;
 	bool is_suspending;
 	int wakeirq;
 	int wakeups_enabled;
@@ -118,6 +125,17 @@ struct omap8250_priv {
 	bool throttled;
 };
 
+struct omap8250_dma_params {
+	u32 rx_size;
+	u8 rx_trigger;
+	u8 tx_trigger;
+};
+
+struct omap8250_platdata {
+	struct omap8250_dma_params *dma_params;
+	u8 habit;
+};
+
 #ifdef CONFIG_SERIAL_8250_DMA
 static void omap_8250_rx_dma_flush(struct uart_8250_port *p);
 #else
@@ -295,8 +313,8 @@ static void omap8250_restore_regs(struct uart_8250_port *up)
 	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_RESTORE(16) |
 			OMAP_UART_TCR_HALT(52));
 	serial_out(up, UART_TI752_TLR,
-		   TRIGGER_TLR_MASK(TX_TRIGGER) << UART_TI752_TLR_TX |
-		   TRIGGER_TLR_MASK(RX_TRIGGER) << UART_TI752_TLR_RX);
+		   TRIGGER_TLR_MASK(priv->tx_trigger) << UART_TI752_TLR_TX |
+		   TRIGGER_TLR_MASK(priv->rx_trigger) << UART_TI752_TLR_RX);
 
 	serial_out(up, UART_LCR, 0);
 
@@ -435,8 +453,8 @@ static void omap_8250_set_termios(struct uart_port *port,
 	 * This is because threshold and trigger values are the same.
 	 */
 	up->fcr = UART_FCR_ENABLE_FIFO;
-	up->fcr |= TRIGGER_FCR_MASK(TX_TRIGGER) << OMAP_UART_FCR_TX_TRIG;
-	up->fcr |= TRIGGER_FCR_MASK(RX_TRIGGER) << OMAP_UART_FCR_RX_TRIG;
+	up->fcr |= TRIGGER_FCR_MASK(priv->tx_trigger) << OMAP_UART_FCR_TX_TRIG;
+	up->fcr |= TRIGGER_FCR_MASK(priv->rx_trigger) << OMAP_UART_FCR_RX_TRIG;
 
 	priv->scr = OMAP_UART_SCR_RX_TRIG_GRANU1_MASK | OMAP_UART_SCR_TX_EMPTY |
 		OMAP_UART_SCR_TX_TRIG_GRANU1_MASK;
@@ -651,7 +669,7 @@ static int omap_8250_startup(struct uart_port *port)
 		priv->wer |= OMAP_UART_TX_WAKEUP_EN;
 	serial_out(up, UART_OMAP_WER, priv->wer);
 
-	if (up->dma)
+	if (up->dma && !(priv->habit & UART_HAS_EFR2))
 		up->dma->rx_dma(up);
 
 	pm_runtime_mark_last_busy(port->dev);
@@ -676,6 +694,8 @@ static void omap_8250_shutdown(struct uart_port *port)
 	pm_runtime_get_sync(port->dev);
 
 	serial_out(up, UART_OMAP_WER, 0);
+	if (priv->habit & UART_HAS_EFR2)
+		serial_out(up, UART_OMAP_EFR2, 0x0);
 
 	up->ier = 0;
 	serial_out(up, UART_IER, 0);
@@ -699,14 +719,12 @@ static void omap_8250_shutdown(struct uart_port *port)
 static void omap_8250_throttle(struct uart_port *port)
 {
 	struct omap8250_priv *priv = port->private_data;
-	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned long flags;
 
 	pm_runtime_get_sync(port->dev);
 
 	spin_lock_irqsave(&port->lock, flags);
-	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
-	serial_out(up, UART_IER, up->ier);
+	port->ops->stop_rx(port);
 	priv->throttled = true;
 	spin_unlock_irqrestore(&port->lock, flags);
 
@@ -714,36 +732,6 @@ static void omap_8250_throttle(struct uart_port *port)
 	pm_runtime_put_autosuspend(port->dev);
 }
 
-static int omap_8250_rs485_config(struct uart_port *port,
-				  struct serial_rs485 *rs485)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	/* Clamp the delays to [0, 100ms] */
-	rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
-	rs485->delay_rts_after_send  = min(rs485->delay_rts_after_send, 100U);
-
-	port->rs485 = *rs485;
-
-	/*
-	 * Both serial8250_em485_init and serial8250_em485_destroy
-	 * are idempotent
-	 */
-	if (rs485->flags & SER_RS485_ENABLED) {
-		int ret = serial8250_em485_init(up);
-
-		if (ret) {
-			rs485->flags &= ~SER_RS485_ENABLED;
-			port->rs485.flags &= ~SER_RS485_ENABLED;
-		}
-		return ret;
-	}
-
-	serial8250_em485_destroy(up);
-
-	return 0;
-}
-
 static void omap_8250_unthrottle(struct uart_port *port)
 {
 	struct omap8250_priv *priv = port->private_data;
@@ -757,6 +745,7 @@ static void omap_8250_unthrottle(struct uart_port *port)
 	if (up->dma)
 		up->dma->rx_dma(up);
 	up->ier |= UART_IER_RLSI | UART_IER_RDI;
+	port->read_status_mask |= UART_LSR_DR;
 	serial_out(up, UART_IER, up->ier);
 	spin_unlock_irqrestore(&port->lock, flags);
 
@@ -767,32 +756,50 @@ static void omap_8250_unthrottle(struct uart_port *port)
 #ifdef CONFIG_SERIAL_8250_DMA
 static int omap_8250_rx_dma(struct uart_8250_port *p);
 
+/* Must be called while priv->rx_dma_lock is held */
 static void __dma_rx_do_complete(struct uart_8250_port *p)
 {
-	struct omap8250_priv	*priv = p->port.private_data;
 	struct uart_8250_dma    *dma = p->dma;
 	struct tty_port         *tty_port = &p->port.state->port;
+	struct dma_chan		*rxchan = dma->rxchan;
+	dma_cookie_t		cookie;
 	struct dma_tx_state     state;
 	int                     count;
-	unsigned long		flags;
 	int			ret;
 
-	spin_lock_irqsave(&priv->rx_dma_lock, flags);
-
 	if (!dma->rx_running)
-		goto unlock;
+		goto out;
 
+	cookie = dma->rx_cookie;
 	dma->rx_running = 0;
-	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+	dmaengine_tx_status(rxchan, cookie, &state);
 
-	count = dma->rx_size - state.residue;
+	count = dma->rx_size - state.residue + state.in_flight_bytes;
+	if (count < dma->rx_size) {
+		dmaengine_terminate_async(rxchan);
 
+		/*
+		 * Poll for teardown to complete which guarantees in
+		 * flight data is drained.
+		 */
+		if (state.in_flight_bytes) {
+			int poll_count = 25;
+
+			while (dmaengine_tx_status(rxchan, cookie, NULL) &&
+			       poll_count--)
+				cpu_relax();
+
+			if (!poll_count)
+				dev_err(p->port.dev, "teardown incomplete\n");
+		}
+	}
+	if (!count)
+		goto out;
 	ret = tty_insert_flip_string(tty_port, dma->rx_buf, count);
 
 	p->port.icount.rx += ret;
 	p->port.icount.buf_overrun += count - ret;
-unlock:
-	spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
+out:
 
 	tty_flip_buffer_push(tty_port);
 }
@@ -818,8 +825,12 @@ static void __dma_rx_complete(void *param)
 		return;
 	}
 	__dma_rx_do_complete(p);
-	if (!priv->throttled)
-		omap_8250_rx_dma(p);
+	if (!priv->throttled) {
+		p->ier |= UART_IER_RLSI | UART_IER_RDI;
+		serial_out(p, UART_IER, p->ier);
+		if (!(priv->habit & UART_HAS_EFR2))
+			omap_8250_rx_dma(p);
+	}
 
 	spin_unlock_irqrestore(&p->port.lock, flags);
 }
@@ -845,10 +856,8 @@ static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
 		if (WARN_ON_ONCE(ret))
 			priv->rx_dma_broken = true;
 	}
-	spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
-
 	__dma_rx_do_complete(p);
-	dmaengine_terminate_all(dma->rxchan);
+	spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
 }
 
 static int omap_8250_rx_dma(struct uart_8250_port *p)
@@ -864,8 +873,20 @@ static int omap_8250_rx_dma(struct uart_8250_port *p)
 
 	spin_lock_irqsave(&priv->rx_dma_lock, flags);
 
-	if (dma->rx_running)
+	if (dma->rx_running) {
+		enum dma_status state;
+
+		state = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, NULL);
+		if (state == DMA_COMPLETE) {
+			/*
+			 * Disable RX interrupts to allow RX DMA completion
+			 * callback to run.
+			 */
+			p->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
+			serial_out(p, UART_IER, p->ier);
+		}
 		goto out;
+	}
 
 	desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
 					   dma->rx_size, DMA_DEV_TO_MEM,
@@ -1036,6 +1057,46 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir)
 	return omap_8250_rx_dma(up);
 }
 
+static unsigned char omap_8250_handle_rx_dma(struct uart_8250_port *up,
+					     u8 iir, unsigned char status)
+{
+	if ((status & (UART_LSR_DR | UART_LSR_BI)) &&
+	    (iir & UART_IIR_RDI)) {
+		if (handle_rx_dma(up, iir)) {
+			status = serial8250_rx_chars(up, status);
+			omap_8250_rx_dma(up);
+		}
+	}
+
+	return status;
+}
+
+static void am654_8250_handle_rx_dma(struct uart_8250_port *up, u8 iir,
+				     unsigned char status)
+{
+	/*
+	 * Queue a new transfer if FIFO has data.
+	 */
+	if ((status & (UART_LSR_DR | UART_LSR_BI)) &&
+	    (up->ier & UART_IER_RDI)) {
+		omap_8250_rx_dma(up);
+		serial_out(up, UART_OMAP_EFR2, UART_OMAP_EFR2_TIMEOUT_BEHAVE);
+	} else if ((iir & 0x3f) == UART_IIR_RX_TIMEOUT) {
+		/*
+		 * Disable RX timeout, read IIR to clear
+		 * current timeout condition, clear EFR2 to
+		 * periodic timeouts, re-enable interrupts.
+		 */
+		up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
+		serial_out(up, UART_IER, up->ier);
+		omap_8250_rx_dma_flush(up);
+		serial_in(up, UART_IIR);
+		serial_out(up, UART_OMAP_EFR2, 0x0);
+		up->ier |= UART_IER_RLSI | UART_IER_RDI;
+		serial_out(up, UART_IER, up->ier);
+	}
+}
+
 /*
  * This is mostly serial8250_handle_irq(). We have a slightly different DMA
  * hoook for RX/TX and need different logic for them in the ISR. Therefore we
@@ -1044,6 +1105,7 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir)
 static int omap_8250_dma_handle_irq(struct uart_port *port)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
+	struct omap8250_priv *priv = up->port.private_data;
 	unsigned char status;
 	unsigned long flags;
 	u8 iir;
@@ -1053,19 +1115,18 @@ static int omap_8250_dma_handle_irq(struct uart_port *port)
 	iir = serial_port_in(port, UART_IIR);
 	if (iir & UART_IIR_NO_INT) {
 		serial8250_rpm_put(up);
-		return 0;
+		return IRQ_HANDLED;
 	}
 
 	spin_lock_irqsave(&port->lock, flags);
 
 	status = serial_port_in(port, UART_LSR);
 
-	if (status & (UART_LSR_DR | UART_LSR_BI)) {
-		if (handle_rx_dma(up, iir)) {
-			status = serial8250_rx_chars(up, status);
-			omap_8250_rx_dma(up);
-		}
-	}
+	if (priv->habit & UART_HAS_EFR2)
+		am654_8250_handle_rx_dma(up, iir, status);
+	else
+		status = omap_8250_handle_rx_dma(up, iir, status);
+
 	serial8250_modem_status(up);
 	if (status & UART_LSR_THRE && up->dma->tx_err) {
 		if (uart_tx_stopped(&up->port) ||
@@ -1107,18 +1168,41 @@ static int omap8250_no_handle_irq(struct uart_port *port)
 	return 0;
 }
 
-static const u8 omap4_habit = UART_ERRATA_CLOCK_DISABLE;
-static const u8 am3352_habit = OMAP_DMA_TX_KICK | UART_ERRATA_CLOCK_DISABLE;
-static const u8 dra742_habit = UART_ERRATA_CLOCK_DISABLE;
+static struct omap8250_dma_params am654_dma = {
+	.rx_size = SZ_2K,
+	.rx_trigger = 1,
+	.tx_trigger = TX_TRIGGER,
+};
+
+static struct omap8250_dma_params am33xx_dma = {
+	.rx_size = RX_TRIGGER,
+	.rx_trigger = RX_TRIGGER,
+	.tx_trigger = TX_TRIGGER,
+};
+
+static struct omap8250_platdata am654_platdata = {
+	.dma_params	= &am654_dma,
+	.habit		= UART_HAS_EFR2,
+};
+
+static struct omap8250_platdata am33xx_platdata = {
+	.dma_params	= &am33xx_dma,
+	.habit		= OMAP_DMA_TX_KICK | UART_ERRATA_CLOCK_DISABLE,
+};
+
+static struct omap8250_platdata omap4_platdata = {
+	.dma_params	= &am33xx_dma,
+	.habit		= UART_ERRATA_CLOCK_DISABLE,
+};
 
 static const struct of_device_id omap8250_dt_ids[] = {
-	{ .compatible = "ti,am654-uart" },
+	{ .compatible = "ti,am654-uart", .data = &am654_platdata, },
 	{ .compatible = "ti,omap2-uart" },
 	{ .compatible = "ti,omap3-uart" },
-	{ .compatible = "ti,omap4-uart", .data = &omap4_habit, },
-	{ .compatible = "ti,am3352-uart", .data = &am3352_habit, },
-	{ .compatible = "ti,am4372-uart", .data = &am3352_habit, },
-	{ .compatible = "ti,dra742-uart", .data = &dra742_habit, },
+	{ .compatible = "ti,omap4-uart", .data = &omap4_platdata, },
+	{ .compatible = "ti,am3352-uart", .data = &am33xx_platdata, },
+	{ .compatible = "ti,am4372-uart", .data = &am33xx_platdata, },
+	{ .compatible = "ti,dra742-uart", .data = &omap4_platdata, },
 	{},
 };
 MODULE_DEVICE_TABLE(of, omap8250_dt_ids);
@@ -1129,10 +1213,10 @@ static int omap8250_probe(struct platform_device *pdev)
 	struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	struct device_node *np = pdev->dev.of_node;
 	struct omap8250_priv *priv;
+	const struct omap8250_platdata *pdata;
 	struct uart_8250_port up;
 	int ret;
 	void __iomem *membase;
-	const struct of_device_id *id;
 
 	if (!regs || !irq) {
 		dev_err(&pdev->dev, "missing registers or irq\n");
@@ -1187,7 +1271,9 @@ static int omap8250_probe(struct platform_device *pdev)
 	up.port.shutdown = omap_8250_shutdown;
 	up.port.throttle = omap_8250_throttle;
 	up.port.unthrottle = omap_8250_unthrottle;
-	up.port.rs485_config = omap_8250_rs485_config;
+	up.port.rs485_config = serial8250_em485_config;
+	up.rs485_start_tx = serial8250_em485_start_tx;
+	up.rs485_stop_tx = serial8250_em485_stop_tx;
 	up.port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
 
 	ret = of_alias_get_id(np, "serial");
@@ -1211,9 +1297,9 @@ static int omap8250_probe(struct platform_device *pdev)
 
 	priv->wakeirq = irq_of_parse_and_map(np, 1);
 
-	id = of_match_device(of_match_ptr(omap8250_dt_ids), &pdev->dev);
-	if (id && id->data)
-		priv->habit |= *(u8 *)id->data;
+	pdata = of_device_get_match_data(&pdev->dev);
+	if (pdata)
+		priv->habit |= pdata->habit;
 
 	if (!up.port.uartclk) {
 		up.port.uartclk = DEFAULT_CLK_SPEED;
@@ -1230,6 +1316,7 @@ static int omap8250_probe(struct platform_device *pdev)
 	spin_lock_init(&priv->rx_dma_lock);
 
 	device_init_wakeup(&pdev->dev, true);
+	pm_runtime_enable(&pdev->dev);
 	pm_runtime_use_autosuspend(&pdev->dev);
 
 	/*
@@ -1243,12 +1330,13 @@ static int omap8250_probe(struct platform_device *pdev)
 		pm_runtime_set_autosuspend_delay(&pdev->dev, -1);
 
 	pm_runtime_irq_safe(&pdev->dev);
-	pm_runtime_enable(&pdev->dev);
 
 	pm_runtime_get_sync(&pdev->dev);
 
 	omap_serial_fill_features_erratas(&up, priv);
 	up.port.handle_irq = omap8250_no_handle_irq;
+	priv->rx_trigger = RX_TRIGGER;
+	priv->tx_trigger = TX_TRIGGER;
 #ifdef CONFIG_SERIAL_8250_DMA
 	/*
 	 * Oh DMA support. If there are no DMA properties in the DT then
@@ -1260,13 +1348,26 @@ static int omap8250_probe(struct platform_device *pdev)
 	 */
 	ret = of_property_count_strings(np, "dma-names");
 	if (ret == 2) {
+		struct omap8250_dma_params *dma_params = NULL;
+
 		up.dma = &priv->omap8250_dma;
-		priv->omap8250_dma.fn = the_no_dma_filter_fn;
-		priv->omap8250_dma.tx_dma = omap_8250_tx_dma;
-		priv->omap8250_dma.rx_dma = omap_8250_rx_dma;
-		priv->omap8250_dma.rx_size = RX_TRIGGER;
-		priv->omap8250_dma.rxconf.src_maxburst = RX_TRIGGER;
-		priv->omap8250_dma.txconf.dst_maxburst = TX_TRIGGER;
+		up.dma->fn = the_no_dma_filter_fn;
+		up.dma->tx_dma = omap_8250_tx_dma;
+		up.dma->rx_dma = omap_8250_rx_dma;
+		if (pdata)
+			dma_params = pdata->dma_params;
+
+		if (dma_params) {
+			up.dma->rx_size = dma_params->rx_size;
+			up.dma->rxconf.src_maxburst = dma_params->rx_trigger;
+			up.dma->txconf.dst_maxburst = dma_params->tx_trigger;
+			priv->rx_trigger = dma_params->rx_trigger;
+			priv->tx_trigger = dma_params->tx_trigger;
+		} else {
+			up.dma->rx_size = RX_TRIGGER;
+			up.dma->rxconf.src_maxburst = RX_TRIGGER;
+			up.dma->txconf.dst_maxburst = TX_TRIGGER;
+		}
 	}
 #endif
 	ret = serial8250_register_8250_port(&up);
@@ -1464,7 +1565,7 @@ static int omap8250_runtime_resume(struct device *dev)
 	if (omap8250_lost_context(up))
 		omap8250_restore_regs(up);
 
-	if (up->dma && up->dma->rxchan)
+	if (up->dma && up->dma->rxchan && !(priv->habit & UART_HAS_EFR2))
 		omap_8250_rx_dma(up);
 
 	priv->latency = priv->calc_latency;

drivers/tty/serial/8250/8250_pci.c

@@ -53,7 +53,7 @@ struct serial_private {
 	unsigned int		nr;
 	struct pci_serial_quirk	*quirk;
 	const struct pciserial_board *board;
-	int			line[0];
+	int			line[];
 };
 
 static const struct pci_device_id pci_use_msi[] = {

drivers/tty/serial/8250/8250_port.c

@@ -557,17 +557,6 @@ static void serial8250_clear_fifos(struct uart_8250_port *p)
 	}
 }
 
-static inline void serial8250_em485_rts_after_send(struct uart_8250_port *p)
-{
-	unsigned char mcr = serial8250_in_MCR(p);
-
-	if (p->port.rs485.flags & SER_RS485_RTS_AFTER_SEND)
-		mcr |= UART_MCR_RTS;
-	else
-		mcr &= ~UART_MCR_RTS;
-	serial8250_out_MCR(p, mcr);
-}
-
 static enum hrtimer_restart serial8250_em485_handle_start_tx(struct hrtimer *t);
 static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t);
 
@@ -615,7 +604,7 @@ EXPORT_SYMBOL_GPL(serial8250_rpm_put);
  *
  *	Return 0 - success, -errno - otherwise
  */
-int serial8250_em485_init(struct uart_8250_port *p)
+static int serial8250_em485_init(struct uart_8250_port *p)
 {
 	if (p->em485)
 		return 0;
@@ -632,11 +621,12 @@ int serial8250_em485_init(struct uart_8250_port *p)
 	p->em485->start_tx_timer.function = &serial8250_em485_handle_start_tx;
 	p->em485->port = p;
 	p->em485->active_timer = NULL;
-	serial8250_em485_rts_after_send(p);
+	p->em485->tx_stopped = true;
+
+	p->rs485_stop_tx(p);
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(serial8250_em485_init);
 
 /**
  *	serial8250_em485_destroy() - put uart_8250_port into normal state
@@ -664,6 +654,52 @@ void serial8250_em485_destroy(struct uart_8250_port *p)
 }
 EXPORT_SYMBOL_GPL(serial8250_em485_destroy);
 
+/**
+ * serial8250_em485_config() - generic ->rs485_config() callback
+ * @port: uart port
+ * @rs485: rs485 settings
+ *
+ * Generic callback usable by 8250 uart drivers to activate rs485 settings
+ * if the uart is incapable of driving RTS as a Transmit Enable signal in
+ * hardware, relying on software emulation instead.
+ */
+int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	/* pick sane settings if the user hasn't */
+	if (!!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
+	    !!(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
+		rs485->flags |= SER_RS485_RTS_ON_SEND;
+		rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
+	}
+
+	/* clamp the delays to [0, 100ms] */
+	rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
+	rs485->delay_rts_after_send  = min(rs485->delay_rts_after_send, 100U);
+
+	memset(rs485->padding, 0, sizeof(rs485->padding));
+	port->rs485 = *rs485;
+
+	/*
+	 * Both serial8250_em485_init() and serial8250_em485_destroy()
+	 * are idempotent.
+	 */
+	if (rs485->flags & SER_RS485_ENABLED) {
+		int ret = serial8250_em485_init(up);
+
+		if (ret) {
+			rs485->flags &= ~SER_RS485_ENABLED;
+			port->rs485.flags &= ~SER_RS485_ENABLED;
+		}
+		return ret;
+	}
+
+	serial8250_em485_destroy(up);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(serial8250_em485_config);
+
 /*
  * These two wrappers ensure that enable_runtime_pm_tx() can be called more than
  * once and disable_runtime_pm_tx() will still disable RPM because the fifo is
@@ -1318,8 +1354,8 @@ out_lock:
 		fintek_8250_probe(up);
 
 	if (up->capabilities != old_capabilities) {
-		pr_warn("%s: detected caps %08x should be %08x\n",
-			port->name, old_capabilities, up->capabilities);
+		dev_warn(port->dev, "detected caps %08x should be %08x\n",
+			 old_capabilities, up->capabilities);
 	}
 out:
 	DEBUG_AUTOCONF("iir=%d ", scratch);
@@ -1394,9 +1430,21 @@ static void serial8250_stop_rx(struct uart_port *port)
 	serial8250_rpm_put(up);
 }
 
-static void __do_stop_tx_rs485(struct uart_8250_port *p)
+/**
+ * serial8250_em485_stop_tx() - generic ->rs485_stop_tx() callback
+ * @up: uart 8250 port
+ *
+ * Generic callback usable by 8250 uart drivers to stop rs485 transmission.
+ */
+void serial8250_em485_stop_tx(struct uart_8250_port *p)
 {
-	serial8250_em485_rts_after_send(p);
+	unsigned char mcr = serial8250_in_MCR(p);
+
+	if (p->port.rs485.flags & SER_RS485_RTS_AFTER_SEND)
+		mcr |= UART_MCR_RTS;
+	else
+		mcr &= ~UART_MCR_RTS;
+	serial8250_out_MCR(p, mcr);
 
 	/*
 	 * Empty the RX FIFO, we are not interested in anything
@@ -1410,6 +1458,8 @@ static void __do_stop_tx_rs485(struct uart_8250_port *p)
 		serial_port_out(&p->port, UART_IER, p->ier);
 	}
 }
+EXPORT_SYMBOL_GPL(serial8250_em485_stop_tx);
+
 static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t)
 {
 	struct uart_8250_em485 *em485;
@@ -1422,8 +1472,9 @@ static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t)
 	serial8250_rpm_get(p);
 	spin_lock_irqsave(&p->port.lock, flags);
 	if (em485->active_timer == &em485->stop_tx_timer) {
-		__do_stop_tx_rs485(p);
+		p->rs485_stop_tx(p);
 		em485->active_timer = NULL;
+		em485->tx_stopped = true;
 	}
 	spin_unlock_irqrestore(&p->port.lock, flags);
 	serial8250_rpm_put(p);
@@ -1444,7 +1495,7 @@ static void __stop_tx_rs485(struct uart_8250_port *p)
 	struct uart_8250_em485 *em485 = p->em485;
 
 	/*
-	 * __do_stop_tx_rs485 is going to set RTS according to config
+	 * rs485_stop_tx() is going to set RTS according to config
 	 * AND flush RX FIFO if required.
 	 */
 	if (p->port.rs485.delay_rts_after_send > 0) {
@@ -1452,7 +1503,9 @@ static void __stop_tx_rs485(struct uart_8250_port *p)
 		start_hrtimer_ms(&em485->stop_tx_timer,
 				   p->port.rs485.delay_rts_after_send);
 	} else {
-		__do_stop_tx_rs485(p);
+		p->rs485_stop_tx(p);
+		em485->active_timer = NULL;
+		em485->tx_stopped = true;
 	}
 }
 
@@ -1477,8 +1530,6 @@ static inline void __stop_tx(struct uart_8250_port *p)
 		if ((lsr & BOTH_EMPTY) != BOTH_EMPTY)
 			return;
 
-		em485->active_timer = NULL;
-
 		__stop_tx_rs485(p);
 	}
 	__do_stop_tx(p);
@@ -1528,25 +1579,42 @@ static inline void __start_tx(struct uart_port *port)
 	}
 }
 
-static inline void start_tx_rs485(struct uart_port *port)
+/**
+ * serial8250_em485_start_tx() - generic ->rs485_start_tx() callback
+ * @up: uart 8250 port
+ *
+ * Generic callback usable by 8250 uart drivers to start rs485 transmission.
+ * Assumes that setting the RTS bit in the MCR register means RTS is high.
+ * (Some chips use inverse semantics.)  Further assumes that reception is
+ * stoppable by disabling the UART_IER_RDI interrupt.  (Some chips set the
+ * UART_LSR_DR bit even when UART_IER_RDI is disabled, foiling this approach.)
+ */
+void serial8250_em485_start_tx(struct uart_8250_port *up)
 {
-	struct uart_8250_port *up = up_to_u8250p(port);
-	struct uart_8250_em485 *em485 = up->em485;
-	unsigned char mcr;
+	unsigned char mcr = serial8250_in_MCR(up);
 
 	if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
 		serial8250_stop_rx(&up->port);
 
+	if (up->port.rs485.flags & SER_RS485_RTS_ON_SEND)
+		mcr |= UART_MCR_RTS;
+	else
+		mcr &= ~UART_MCR_RTS;
+	serial8250_out_MCR(up, mcr);
+}
+EXPORT_SYMBOL_GPL(serial8250_em485_start_tx);
+
+static inline void start_tx_rs485(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct uart_8250_em485 *em485 = up->em485;
+
 	em485->active_timer = NULL;
 
-	mcr = serial8250_in_MCR(up);
-	if (!!(up->port.rs485.flags & SER_RS485_RTS_ON_SEND) !=
-	    !!(mcr & UART_MCR_RTS)) {
-		if (up->port.rs485.flags & SER_RS485_RTS_ON_SEND)
-			mcr |= UART_MCR_RTS;
-		else
-			mcr &= ~UART_MCR_RTS;
-		serial8250_out_MCR(up, mcr);
+	if (em485->tx_stopped) {
+		em485->tx_stopped = false;
+
+		up->rs485_start_tx(up);
 
 		if (up->port.rs485.delay_rts_before_send > 0) {
 			em485->active_timer = &em485->start_tx_timer;
@@ -1683,7 +1751,7 @@ void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr)
 		lsr &= port->read_status_mask;
 
 		if (lsr & UART_LSR_BI) {
-			pr_debug("%s: handling break\n", __func__);
+			dev_dbg(port->dev, "handling break\n");
 			flag = TTY_BREAK;
 		} else if (lsr & UART_LSR_PE)
 			flag = TTY_PARITY;
@@ -1815,6 +1883,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
 	unsigned char status;
 	unsigned long flags;
 	struct uart_8250_port *up = up_to_u8250p(port);
+	bool skip_rx = false;
 
 	if (iir & UART_IIR_NO_INT)
 		return 0;
@@ -1823,7 +1892,20 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
 
 	status = serial_port_in(port, UART_LSR);
 
-	if (status & (UART_LSR_DR | UART_LSR_BI)) {
+	/*
+	 * If port is stopped and there are no error conditions in the
+	 * FIFO, then don't drain the FIFO, as this may lead to TTY buffer
+	 * overflow. Not servicing, RX FIFO would trigger auto HW flow
+	 * control when FIFO occupancy reaches preset threshold, thus
+	 * halting RX. This only works when auto HW flow control is
+	 * available.
+	 */
+	if (!(status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS)) &&
+	    (port->status & (UPSTAT_AUTOCTS | UPSTAT_AUTORTS)) &&
+	    !(port->read_status_mask & UART_LSR_DR))
+		skip_rx = true;
+
+	if (status & (UART_LSR_DR | UART_LSR_BI) && !skip_rx) {
 		if (!up->dma || handle_rx_dma(up, iir))
 			status = serial8250_rx_chars(up, status);
 	}
@@ -1924,6 +2006,13 @@ void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
 	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned char mcr;
 
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		if (serial8250_in_MCR(up) & UART_MCR_RTS)
+			mctrl |= TIOCM_RTS;
+		else
+			mctrl &= ~TIOCM_RTS;
+	}
+
 	mcr = serial8250_TIOCM_to_MCR(mctrl);
 
 	mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
@@ -2134,7 +2223,7 @@ int serial8250_do_startup(struct uart_port *port)
 	 */
 	if (!(port->flags & UPF_BUGGY_UART) &&
 	    (serial_port_in(port, UART_LSR) == 0xff)) {
-		pr_info_ratelimited("%s: LSR safety check engaged!\n", port->name);
+		dev_info_ratelimited(port->dev, "LSR safety check engaged!\n");
 		retval = -ENODEV;
 		goto out;
 	}
@@ -2166,8 +2255,7 @@ int serial8250_do_startup(struct uart_port *port)
 	     (port->type == PORT_ALTR_16550_F128)) && (port->fifosize > 1)) {
 		/* Bounds checking of TX threshold (valid 0 to fifosize-2) */
 		if ((up->tx_loadsz < 2) || (up->tx_loadsz > port->fifosize)) {
-			pr_err("%s TX FIFO Threshold errors, skipping\n",
-			       port->name);
+			dev_err(port->dev, "TX FIFO Threshold errors, skipping\n");
 		} else {
 			serial_port_out(port, UART_ALTR_AFR,
 					UART_ALTR_EN_TXFIFO_LW);
@@ -2268,8 +2356,7 @@ int serial8250_do_startup(struct uart_port *port)
 	if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
 		if (!(up->bugs & UART_BUG_TXEN)) {
 			up->bugs |= UART_BUG_TXEN;
-			pr_debug("%s - enabling bad tx status workarounds\n",
-				 port->name);
+			dev_dbg(port->dev, "enabling bad tx status workarounds\n");
 		}
 	} else {
 		up->bugs &= ~UART_BUG_TXEN;
@@ -2294,10 +2381,14 @@ dont_test_tx_en:
 	 * Request DMA channels for both RX and TX.
 	 */
 	if (up->dma) {
-		retval = serial8250_request_dma(up);
-		if (retval) {
-			pr_warn_ratelimited("%s - failed to request DMA\n",
-					    port->name);
+		const char *msg = NULL;
+
+		if (uart_console(port))
+			msg = "forbid DMA for kernel console";
+		else if (serial8250_request_dma(up))
+			msg = "failed to request DMA";
+		if (msg) {
+			dev_warn_ratelimited(port->dev, "%s\n", msg);
 			up->dma = NULL;
 		}
 	}
@@ -2880,7 +2971,7 @@ static int do_serial8250_get_rxtrig(struct tty_port *port)
 	return rxtrig_bytes;
 }
 
-static ssize_t serial8250_get_attr_rx_trig_bytes(struct device *dev,
+static ssize_t rx_trig_bytes_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct tty_port *port = dev_get_drvdata(dev);
@@ -2926,7 +3017,7 @@ static int do_serial8250_set_rxtrig(struct tty_port *port, unsigned char bytes)
 	return ret;
 }
 
-static ssize_t serial8250_set_attr_rx_trig_bytes(struct device *dev,
+static ssize_t rx_trig_bytes_store(struct device *dev,
 	struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct tty_port *port = dev_get_drvdata(dev);
@@ -2947,18 +3038,16 @@ static ssize_t serial8250_set_attr_rx_trig_bytes(struct device *dev,
 	return count;
 }
 
-static DEVICE_ATTR(rx_trig_bytes, S_IRUSR | S_IWUSR | S_IRGRP,
-		   serial8250_get_attr_rx_trig_bytes,
-		   serial8250_set_attr_rx_trig_bytes);
+static DEVICE_ATTR_RW(rx_trig_bytes);
 
 static struct attribute *serial8250_dev_attrs[] = {
 	&dev_attr_rx_trig_bytes.attr,
-	NULL,
-	};
+	NULL
+};
 
 static struct attribute_group serial8250_dev_attr_group = {
 	.attrs = serial8250_dev_attrs,
-	};
+};
 
 static void register_dev_spec_attr_grp(struct uart_8250_port *up)
 {
@@ -2987,6 +3076,9 @@ static void serial8250_config_port(struct uart_port *port, int flags)
 	if (flags & UART_CONFIG_TYPE)
 		autoconfig(up);
 
+	if (port->rs485.flags & SER_RS485_ENABLED)
+		port->rs485_config(port, &port->rs485);
+
 	/* if access method is AU, it is a 16550 with a quirk */
 	if (port->type == PORT_16550A && port->iotype == UPIO_AU)
 		up->bugs |= UART_BUG_NOMSR;
@@ -3127,10 +3219,14 @@ static void serial8250_console_restore(struct uart_8250_port *up)
  *	any possible real use of the port...
  *
  *	The console_lock must be held when we get here.
+ *
+ *	Doing runtime PM is really a bad idea for the kernel console.
+ *	Thus, we assume the function is called when device is powered up.
  */
 void serial8250_console_write(struct uart_8250_port *up, const char *s,
 			      unsigned int count)
 {
+	struct uart_8250_em485 *em485 = up->em485;
 	struct uart_port *port = &up->port;
 	unsigned long flags;
 	unsigned int ier;
@@ -3138,8 +3234,6 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 
 	touch_nmi_watchdog();
 
-	serial8250_rpm_get(up);
-
 	if (oops_in_progress)
 		locked = spin_trylock_irqsave(&port->lock, flags);
 	else
@@ -3161,6 +3255,12 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 		up->canary = 0;
 	}
 
+	if (em485) {
+		if (em485->tx_stopped)
+			up->rs485_start_tx(up);
+		mdelay(port->rs485.delay_rts_before_send);
+	}
+
 	uart_console_write(port, s, count, serial8250_console_putchar);
 
 	/*
@@ -3168,6 +3268,13 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 	 *	and restore the IER
 	 */
 	wait_for_xmitr(up, BOTH_EMPTY);
+
+	if (em485) {
+		mdelay(port->rs485.delay_rts_after_send);
+		if (em485->tx_stopped)
+			up->rs485_stop_tx(up);
+	}
+
 	serial_port_out(port, UART_IER, ier);
 
 	/*
@@ -3182,7 +3289,6 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 
 	if (locked)
 		spin_unlock_irqrestore(&port->lock, flags);
-	serial8250_rpm_put(up);
 }
 
 static unsigned int probe_baud(struct uart_port *port)
@@ -3206,6 +3312,7 @@ int serial8250_console_setup(struct uart_port *port, char *options, bool probe)
 	int bits = 8;
 	int parity = 'n';
 	int flow = 'n';
+	int ret;
 
 	if (!port->iobase && !port->membase)
 		return -ENODEV;
@@ -3215,7 +3322,22 @@ int serial8250_console_setup(struct uart_port *port, char *options, bool probe)
 	else if (probe)
 		baud = probe_baud(port);
 
-	return uart_set_options(port, port->cons, baud, parity, bits, flow);
+	ret = uart_set_options(port, port->cons, baud, parity, bits, flow);
+	if (ret)
+		return ret;
+
+	if (port->dev)
+		pm_runtime_get_sync(port->dev);
+
+	return 0;
+}
+
+int serial8250_console_exit(struct uart_port *port)
+{
+	if (port->dev)
+		pm_runtime_put_sync(port->dev);
+
+	return 0;
 }
 
 #endif /* CONFIG_SERIAL_8250_CONSOLE */

drivers/tty/serial/8250/8250_pxa.c

@@ -123,7 +123,7 @@ static int serial_pxa_probe(struct platform_device *pdev)
 	uart.port.regshift = 2;
 	uart.port.irq = irqres->start;
 	uart.port.fifosize = 64;
-	uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST;
+	uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST | UPF_FIXED_TYPE;
 	uart.port.dev = &pdev->dev;
 	uart.port.uartclk = clk_get_rate(data->clk);
 	uart.port.pm = serial_pxa_pm;

drivers/tty/serial/8250/8250_tegra.c

@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Serial Port driver for Tegra devices
+ *
+ *  Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved.
+ */
+
+#include <linux/acpi.h>
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+
+#include "8250.h"
+
+struct tegra_uart {
+	struct clk *clk;
+	struct reset_control *rst;
+	int line;
+};
+
+static void tegra_uart_handle_break(struct uart_port *p)
+{
+	unsigned int status, tmout = 10000;
+
+	do {
+		status = p->serial_in(p, UART_LSR);
+		if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
+			status = p->serial_in(p, UART_RX);
+		else
+			break;
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while (1);
+}
+
+static int tegra_uart_probe(struct platform_device *pdev)
+{
+	struct uart_8250_port port8250;
+	struct tegra_uart *uart;
+	struct uart_port *port;
+	struct resource *res;
+	int ret;
+
+	uart = devm_kzalloc(&pdev->dev, sizeof(*uart), GFP_KERNEL);
+	if (!uart)
+		return -ENOMEM;
+
+	memset(&port8250, 0, sizeof(port8250));
+
+	port = &port8250.port;
+	spin_lock_init(&port->lock);
+
+	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT |
+		      UPF_FIXED_TYPE;
+	port->iotype = UPIO_MEM32;
+	port->regshift = 2;
+	port->type = PORT_TEGRA;
+	port->irqflags |= IRQF_SHARED;
+	port->dev = &pdev->dev;
+	port->handle_break = tegra_uart_handle_break;
+
+	ret = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (ret >= 0)
+		port->line = ret;
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+
+	port->irq = ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	port->membase = devm_ioremap(&pdev->dev, res->start,
+				     resource_size(res));
+	if (!port->membase)
+		return -ENOMEM;
+
+	port->mapbase = res->start;
+	port->mapsize = resource_size(res);
+
+	uart->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
+	if (IS_ERR(uart->rst))
+		return PTR_ERR(uart->rst);
+
+	if (device_property_read_u32(&pdev->dev, "clock-frequency",
+				     &port->uartclk)) {
+		uart->clk = devm_clk_get(&pdev->dev, NULL);
+		if (IS_ERR(uart->clk)) {
+			dev_err(&pdev->dev, "failed to get clock!\n");
+			return -ENODEV;
+		}
+
+		ret = clk_prepare_enable(uart->clk);
+		if (ret < 0)
+			return ret;
+
+		port->uartclk = clk_get_rate(uart->clk);
+	}
+
+	ret = reset_control_deassert(uart->rst);
+	if (ret)
+		goto err_clkdisable;
+
+	ret = serial8250_register_8250_port(&port8250);
+	if (ret < 0)
+		goto err_clkdisable;
+
+	platform_set_drvdata(pdev, uart);
+	uart->line = ret;
+
+	return 0;
+
+err_clkdisable:
+	clk_disable_unprepare(uart->clk);
+
+	return ret;
+}
+
+static int tegra_uart_remove(struct platform_device *pdev)
+{
+	struct tegra_uart *uart = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(uart->line);
+	reset_control_assert(uart->rst);
+	clk_disable_unprepare(uart->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tegra_uart_suspend(struct device *dev)
+{
+	struct tegra_uart *uart = dev_get_drvdata(dev);
+	struct uart_8250_port *port8250 = serial8250_get_port(uart->line);
+	struct uart_port *port = &port8250->port;
+
+	serial8250_suspend_port(uart->line);
+
+	if (!uart_console(port) || console_suspend_enabled)
+		clk_disable_unprepare(uart->clk);
+
+	return 0;
+}
+
+static int tegra_uart_resume(struct device *dev)
+{
+	struct tegra_uart *uart = dev_get_drvdata(dev);
+	struct uart_8250_port *port8250 = serial8250_get_port(uart->line);
+	struct uart_port *port = &port8250->port;
+
+	if (!uart_console(port) || console_suspend_enabled)
+		clk_prepare_enable(uart->clk);
+
+	serial8250_resume_port(uart->line);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(tegra_uart_pm_ops, tegra_uart_suspend,
+			 tegra_uart_resume);
+
+static const struct of_device_id tegra_uart_of_match[] = {
+	{ .compatible = "nvidia,tegra20-uart", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tegra_uart_of_match);
+
+static const struct acpi_device_id tegra_uart_acpi_match[] = {
+	{ "NVDA0100", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, tegra_uart_acpi_match);
+
+static struct platform_driver tegra_uart_driver = {
+	.driver = {
+		.name = "tegra-uart",
+		.pm = &tegra_uart_pm_ops,
+		.of_match_table = tegra_uart_of_match,
+		.acpi_match_table = ACPI_PTR(tegra_uart_acpi_match),
+	},
+	.probe = tegra_uart_probe,
+	.remove = tegra_uart_remove,
+};
+
+module_platform_driver(tegra_uart_driver);
+
+MODULE_AUTHOR("Jeff Brasen <jbrasen@nvidia.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra 8250 Driver");
+MODULE_LICENSE("GPL v2");

drivers/tty/serial/8250/Kconfig

@@ -500,6 +500,15 @@ config SERIAL_8250_PXA
 	  applicable to both devicetree and legacy boards, and early console is
 	  part of its support.
 
+config SERIAL_8250_TEGRA
+	tristate "8250 support for Tegra serial ports"
+	default SERIAL_8250
+	depends on SERIAL_8250
+	depends on ARCH_TEGRA || COMPILE_TEST
+	help
+	  Select this option if you have machine with an NVIDIA Tegra SoC and
+	  wish to enable 8250 serial driver for the Tegra serial interfaces.
+
 config SERIAL_OF_PLATFORM
 	tristate "Devicetree based probing for 8250 ports"
 	depends on SERIAL_8250 && OF

drivers/tty/serial/8250/Makefile

@@ -37,6 +37,7 @@ obj-$(CONFIG_SERIAL_8250_INGENIC)	+= 8250_ingenic.o
 obj-$(CONFIG_SERIAL_8250_LPSS)		+= 8250_lpss.o
 obj-$(CONFIG_SERIAL_8250_MID)		+= 8250_mid.o
 obj-$(CONFIG_SERIAL_8250_PXA)		+= 8250_pxa.o
+obj-$(CONFIG_SERIAL_8250_TEGRA)		+= 8250_tegra.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM)	+= 8250_of.o
 
 CFLAGS_8250_ingenic.o += -I$(srctree)/scripts/dtc/libfdt

drivers/tty/serial/Kconfig

@@ -260,15 +260,6 @@ config SERIAL_SAMSUNG_UARTS
 	help
 	  Select the number of available UART ports for the Samsung S3C
 	  serial driver
-	
-config SERIAL_SAMSUNG_DEBUG
-	bool "Samsung SoC serial debug"
-	depends on SERIAL_SAMSUNG && DEBUG_LL
-	help
-	  Add support for debugging the serial driver. Since this is
-	  generally being used as a console, we use our own output
-	  routines that go via the low-level debug printascii()
-	  function.
 
 config SERIAL_SAMSUNG_CONSOLE
 	bool "Support for console on Samsung SoC serial port"
@@ -1111,7 +1102,7 @@ config SERIAL_SC16IS7XX_SPI
 	help
 	  Enable SC16IS7xx driver on SPI bus,
 	  If required say y, and say n to spi if not required,
-	  This is additional support to exsisting driver.
+	  This is additional support to existing driver.
 	  You must select at least one bus for the driver to be built.
 
 config SERIAL_TIMBERDALE
@@ -1279,6 +1270,7 @@ config SERIAL_AR933X
 	tristate "AR933X serial port support"
 	depends on HAVE_CLK && ATH79
 	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO if GPIOLIB
 	help
 	  If you have an Atheros AR933X SOC based board and want to use the
 	  built-in UART of the SoC, say Y to this option.
@@ -1452,8 +1444,8 @@ config SERIAL_MEN_Z135
 
 config SERIAL_SPRD
 	tristate "Support for Spreadtrum serial"
-	depends on ARCH_SPRD
 	select SERIAL_CORE
+	depends on COMMON_CLK
 	help
 	  This enables the driver for the Spreadtrum's serial.
 

drivers/tty/serial/ar933x_uart.c

@@ -13,6 +13,7 @@
 #include <linux/console.h>
 #include <linux/sysrq.h>
 #include <linux/delay.h>
+#include <linux/gpio/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
@@ -29,6 +30,8 @@
 
 #include <asm/mach-ath79/ar933x_uart.h>
 
+#include "serial_mctrl_gpio.h"
+
 #define DRIVER_NAME "ar933x-uart"
 
 #define AR933X_UART_MAX_SCALE	0xff
@@ -47,6 +50,8 @@ struct ar933x_uart_port {
 	unsigned int		min_baud;
 	unsigned int		max_baud;
 	struct clk		*clk;
+	struct mctrl_gpios	*gpios;
+	struct gpio_desc	*rts_gpiod;
 };
 
 static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up,
@@ -100,6 +105,18 @@ static inline void ar933x_uart_stop_tx_interrupt(struct ar933x_uart_port *up)
 	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
 }
 
+static inline void ar933x_uart_start_rx_interrupt(struct ar933x_uart_port *up)
+{
+	up->ier |= AR933X_UART_INT_RX_VALID;
+	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+}
+
+static inline void ar933x_uart_stop_rx_interrupt(struct ar933x_uart_port *up)
+{
+	up->ier &= ~AR933X_UART_INT_RX_VALID;
+	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+}
+
 static inline void ar933x_uart_putc(struct ar933x_uart_port *up, int ch)
 {
 	unsigned int rdata;
@@ -125,11 +142,21 @@ static unsigned int ar933x_uart_tx_empty(struct uart_port *port)
 
 static unsigned int ar933x_uart_get_mctrl(struct uart_port *port)
 {
-	return TIOCM_CAR;
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+	int ret = TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+
+	mctrl_gpio_get(up->gpios, &ret);
+
+	return ret;
 }
 
 static void ar933x_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+
+	mctrl_gpio_set(up->gpios, mctrl);
 }
 
 static void ar933x_uart_start_tx(struct uart_port *port)
@@ -140,6 +167,37 @@ static void ar933x_uart_start_tx(struct uart_port *port)
 	ar933x_uart_start_tx_interrupt(up);
 }
 
+static void ar933x_uart_wait_tx_complete(struct ar933x_uart_port *up)
+{
+	unsigned int status;
+	unsigned int timeout = 60000;
+
+	/* Wait up to 60ms for the character(s) to be sent. */
+	do {
+		status = ar933x_uart_read(up, AR933X_UART_CS_REG);
+		if (--timeout == 0)
+			break;
+		udelay(1);
+	} while (status & AR933X_UART_CS_TX_BUSY);
+
+	if (timeout == 0)
+		dev_err(up->port.dev, "waiting for TX timed out\n");
+}
+
+static void ar933x_uart_rx_flush(struct ar933x_uart_port *up)
+{
+	unsigned int status;
+
+	/* clear RX_VALID interrupt */
+	ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_RX_VALID);
+
+	/* remove characters from the RX FIFO */
+	do {
+		ar933x_uart_write(up, AR933X_UART_DATA_REG, AR933X_UART_DATA_RX_CSR);
+		status = ar933x_uart_read(up, AR933X_UART_DATA_REG);
+	} while (status & AR933X_UART_DATA_RX_CSR);
+}
+
 static void ar933x_uart_stop_tx(struct uart_port *port)
 {
 	struct ar933x_uart_port *up =
@@ -153,8 +211,7 @@ static void ar933x_uart_stop_rx(struct uart_port *port)
 	struct ar933x_uart_port *up =
 		container_of(port, struct ar933x_uart_port, port);
 
-	up->ier &= ~AR933X_UART_INT_RX_VALID;
-	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+	ar933x_uart_stop_rx_interrupt(up);
 }
 
 static void ar933x_uart_break_ctl(struct uart_port *port, int break_state)
@@ -336,11 +393,20 @@ static void ar933x_uart_rx_chars(struct ar933x_uart_port *up)
 static void ar933x_uart_tx_chars(struct ar933x_uart_port *up)
 {
 	struct circ_buf *xmit = &up->port.state->xmit;
+	struct serial_rs485 *rs485conf = &up->port.rs485;
 	int count;
+	bool half_duplex_send = false;
 
 	if (uart_tx_stopped(&up->port))
 		return;
 
+	if ((rs485conf->flags & SER_RS485_ENABLED) &&
+	    (up->port.x_char || !uart_circ_empty(xmit))) {
+		ar933x_uart_stop_rx_interrupt(up);
+		gpiod_set_value(up->rts_gpiod, !!(rs485conf->flags & SER_RS485_RTS_ON_SEND));
+		half_duplex_send = true;
+	}
+
 	count = up->port.fifosize;
 	do {
 		unsigned int rdata;
@@ -368,8 +434,14 @@ static void ar933x_uart_tx_chars(struct ar933x_uart_port *up)
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(&up->port);
 
-	if (!uart_circ_empty(xmit))
+	if (!uart_circ_empty(xmit)) {
 		ar933x_uart_start_tx_interrupt(up);
+	} else if (half_duplex_send) {
+		ar933x_uart_wait_tx_complete(up);
+		ar933x_uart_rx_flush(up);
+		ar933x_uart_start_rx_interrupt(up);
+		gpiod_set_value(up->rts_gpiod, !!(rs485conf->flags & SER_RS485_RTS_AFTER_SEND));
+	}
 }
 
 static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id)
@@ -427,8 +499,7 @@ static int ar933x_uart_startup(struct uart_port *port)
 		AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE);
 
 	/* Enable RX interrupts */
-	up->ier = AR933X_UART_INT_RX_VALID;
-	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+	ar933x_uart_start_rx_interrupt(up);
 
 	spin_unlock_irqrestore(&up->port.lock, flags);
 
@@ -511,6 +582,21 @@ static const struct uart_ops ar933x_uart_ops = {
 	.verify_port	= ar933x_uart_verify_port,
 };
 
+static int ar933x_config_rs485(struct uart_port *port,
+				struct serial_rs485 *rs485conf)
+{
+	struct ar933x_uart_port *up =
+		container_of(port, struct ar933x_uart_port, port);
+
+	if ((rs485conf->flags & SER_RS485_ENABLED) &&
+	    !up->rts_gpiod) {
+		dev_err(port->dev, "RS485 needs rts-gpio\n");
+		return 1;
+	}
+	port->rs485 = *rs485conf;
+	return 0;
+}
+
 #ifdef CONFIG_SERIAL_AR933X_CONSOLE
 static struct ar933x_uart_port *
 ar933x_console_ports[CONFIG_SERIAL_AR933X_NR_UARTS];
@@ -680,6 +766,8 @@ static int ar933x_uart_probe(struct platform_device *pdev)
 		goto err_disable_clk;
 	}
 
+	uart_get_rs485_mode(&pdev->dev, &port->rs485);
+
 	port->mapbase = mem_res->start;
 	port->line = id;
 	port->irq = irq_res->start;
@@ -690,6 +778,7 @@ static int ar933x_uart_probe(struct platform_device *pdev)
 	port->regshift = 2;
 	port->fifosize = AR933X_UART_FIFO_SIZE;
 	port->ops = &ar933x_uart_ops;
+	port->rs485_config = ar933x_config_rs485;
 
 	baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1);
 	up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD);
@@ -697,6 +786,18 @@ static int ar933x_uart_probe(struct platform_device *pdev)
 	baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);
 	up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD);
 
+	up->gpios = mctrl_gpio_init(port, 0);
+	if (IS_ERR(up->gpios) && PTR_ERR(up->gpios) != -ENOSYS)
+		return PTR_ERR(up->gpios);
+
+	up->rts_gpiod = mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS);
+
+	if ((port->rs485.flags & SER_RS485_ENABLED) &&
+	    !up->rts_gpiod) {
+		dev_err(&pdev->dev, "lacking rts-gpio, disabling RS485\n");
+		port->rs485.flags &= ~SER_RS485_ENABLED;
+	}
+
 #ifdef CONFIG_SERIAL_AR933X_CONSOLE
 	ar933x_console_ports[up->port.line] = up;
 #endif

drivers/tty/serial/atmel_serial.c

@@ -20,15 +20,12 @@
 #include <linux/platform_device.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
-#include <linux/of_gpio.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
 #include <linux/atmel_pdc.h>
 #include <linux/uaccess.h>
 #include <linux/platform_data/atmel.h>
 #include <linux/timer.h>
-#include <linux/gpio.h>
-#include <linux/gpio/consumer.h>
 #include <linux/err.h>
 #include <linux/irq.h>
 #include <linux/suspend.h>
@@ -2679,18 +2676,8 @@ static struct console atmel_console = {
 
 #define ATMEL_CONSOLE_DEVICE	(&atmel_console)
 
-static inline bool atmel_is_console_port(struct uart_port *port)
-{
-	return port->cons && port->cons->index == port->line;
-}
-
 #else
 #define ATMEL_CONSOLE_DEVICE	NULL
-
-static inline bool atmel_is_console_port(struct uart_port *port)
-{
-	return false;
-}
 #endif
 
 static struct uart_driver atmel_uart = {
@@ -2719,14 +2706,14 @@ static int atmel_serial_suspend(struct platform_device *pdev,
 	struct uart_port *port = platform_get_drvdata(pdev);
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 
-	if (atmel_is_console_port(port) && console_suspend_enabled) {
+	if (uart_console(port) && console_suspend_enabled) {
 		/* Drain the TX shifter */
 		while (!(atmel_uart_readl(port, ATMEL_US_CSR) &
 			 ATMEL_US_TXEMPTY))
 			cpu_relax();
 	}
 
-	if (atmel_is_console_port(port) && !console_suspend_enabled) {
+	if (uart_console(port) && !console_suspend_enabled) {
 		/* Cache register values as we won't get a full shutdown/startup
 		 * cycle
 		 */
@@ -2762,7 +2749,7 @@ static int atmel_serial_resume(struct platform_device *pdev)
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 	unsigned long flags;
 
-	if (atmel_is_console_port(port) && !console_suspend_enabled) {
+	if (uart_console(port) && !console_suspend_enabled) {
 		atmel_uart_writel(port, ATMEL_US_MR, atmel_port->cache.mr);
 		atmel_uart_writel(port, ATMEL_US_IER, atmel_port->cache.imr);
 		atmel_uart_writel(port, ATMEL_US_BRGR, atmel_port->cache.brgr);
@@ -2916,7 +2903,7 @@ static int atmel_serial_probe(struct platform_device *pdev)
 		goto err_add_port;
 
 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
-	if (atmel_is_console_port(&atmel_port->uart)
+	if (uart_console(&atmel_port->uart)
 			&& ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
 		/*
 		 * The serial core enabled the clock for us, so undo
@@ -2959,7 +2946,7 @@ err_add_port:
 	kfree(atmel_port->rx_ring.buf);
 	atmel_port->rx_ring.buf = NULL;
 err_alloc_ring:
-	if (!atmel_is_console_port(&atmel_port->uart)) {
+	if (!uart_console(&atmel_port->uart)) {
 		clk_put(atmel_port->clk);
 		atmel_port->clk = NULL;
 	}

drivers/tty/serial/atmel_serial.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * include/linux/atmel_serial.h
  *

drivers/tty/serial/cpm_uart/cpm_uart.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  *  Driver for CPM (SCC/SMC) serial ports
  *
@@ -13,6 +13,8 @@
 #include <linux/platform_device.h>
 #include <linux/fs_uart_pd.h>
 
+struct gpio_desc;
+
 #if defined(CONFIG_CPM2)
 #include "cpm_uart_cpm2.h"
 #elif defined(CONFIG_CPM1)
@@ -80,7 +82,7 @@ struct uart_cpm_port {
 	int			wait_closing;
 	/* value to combine with opcode to form cpm command */
 	u32			command;
-	int			gpios[NUM_GPIOS];
+	struct gpio_desc	*gpios[NUM_GPIOS];
 };
 
 extern int cpm_uart_nr;

drivers/tty/serial/cpm_uart/cpm_uart_core.c

@@ -30,8 +30,7 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
-#include <linux/gpio.h>
-#include <linux/of_gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/clk.h>
 
 #include <asm/io.h>
@@ -88,11 +87,11 @@ static void cpm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 	struct uart_cpm_port *pinfo =
 		container_of(port, struct uart_cpm_port, port);
 
-	if (pinfo->gpios[GPIO_RTS] >= 0)
-		gpio_set_value(pinfo->gpios[GPIO_RTS], !(mctrl & TIOCM_RTS));
+	if (pinfo->gpios[GPIO_RTS])
+		gpiod_set_value(pinfo->gpios[GPIO_RTS], !(mctrl & TIOCM_RTS));
 
-	if (pinfo->gpios[GPIO_DTR] >= 0)
-		gpio_set_value(pinfo->gpios[GPIO_DTR], !(mctrl & TIOCM_DTR));
+	if (pinfo->gpios[GPIO_DTR])
+		gpiod_set_value(pinfo->gpios[GPIO_DTR], !(mctrl & TIOCM_DTR));
 }
 
 static unsigned int cpm_uart_get_mctrl(struct uart_port *port)
@@ -101,23 +100,23 @@ static unsigned int cpm_uart_get_mctrl(struct uart_port *port)
 		container_of(port, struct uart_cpm_port, port);
 	unsigned int mctrl = TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
 
-	if (pinfo->gpios[GPIO_CTS] >= 0) {
-		if (gpio_get_value(pinfo->gpios[GPIO_CTS]))
+	if (pinfo->gpios[GPIO_CTS]) {
+		if (gpiod_get_value(pinfo->gpios[GPIO_CTS]))
 			mctrl &= ~TIOCM_CTS;
 	}
 
-	if (pinfo->gpios[GPIO_DSR] >= 0) {
-		if (gpio_get_value(pinfo->gpios[GPIO_DSR]))
+	if (pinfo->gpios[GPIO_DSR]) {
+		if (gpiod_get_value(pinfo->gpios[GPIO_DSR]))
 			mctrl &= ~TIOCM_DSR;
 	}
 
-	if (pinfo->gpios[GPIO_DCD] >= 0) {
-		if (gpio_get_value(pinfo->gpios[GPIO_DCD]))
+	if (pinfo->gpios[GPIO_DCD]) {
+		if (gpiod_get_value(pinfo->gpios[GPIO_DCD]))
 			mctrl &= ~TIOCM_CAR;
 	}
 
-	if (pinfo->gpios[GPIO_RI] >= 0) {
-		if (!gpio_get_value(pinfo->gpios[GPIO_RI]))
+	if (pinfo->gpios[GPIO_RI]) {
+		if (!gpiod_get_value(pinfo->gpios[GPIO_RI]))
 			mctrl |= TIOCM_RNG;
 	}
 
@@ -1139,6 +1138,7 @@ static int cpm_uart_init_port(struct device_node *np,
 {
 	const u32 *data;
 	void __iomem *mem, *pram;
+	struct device *dev = pinfo->port.dev;
 	int len;
 	int ret;
 	int i;
@@ -1211,29 +1211,23 @@ static int cpm_uart_init_port(struct device_node *np,
 	}
 
 	for (i = 0; i < NUM_GPIOS; i++) {
-		int gpio;
+		struct gpio_desc *gpiod;
 
-		pinfo->gpios[i] = -1;
+		pinfo->gpios[i] = NULL;
 
-		gpio = of_get_gpio(np, i);
+		gpiod = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
 
-		if (gpio_is_valid(gpio)) {
-			ret = gpio_request(gpio, "cpm_uart");
-			if (ret) {
-				pr_err("can't request gpio #%d: %d\n", i, ret);
-				continue;
-			}
+		if (gpiod) {
 			if (i == GPIO_RTS || i == GPIO_DTR)
-				ret = gpio_direction_output(gpio, 0);
+				ret = gpiod_direction_output(gpiod, 0);
 			else
-				ret = gpio_direction_input(gpio);
+				ret = gpiod_direction_input(gpiod);
 			if (ret) {
 				pr_err("can't set direction for gpio #%d: %d\n",
 					i, ret);
-				gpio_free(gpio);
 				continue;
 			}
-			pinfo->gpios[i] = gpio;
+			pinfo->gpios[i] = gpiod;
 		}
 	}
 

drivers/tty/serial/earlycon.c

@@ -170,6 +170,7 @@ static int __init register_earlycon(char *buf, const struct earlycon_id *match)
 int __init setup_earlycon(char *buf)
 {
 	const struct earlycon_id **p_match;
+	bool empty_compatible = true;
 
 	if (!buf || !buf[0])
 		return -EINVAL;
@@ -177,6 +178,7 @@ int __init setup_earlycon(char *buf)
 	if (early_con.flags & CON_ENABLED)
 		return -EALREADY;
 
+again:
 	for (p_match = __earlycon_table; p_match < __earlycon_table_end;
 	     p_match++) {
 		const struct earlycon_id *match = *p_match;
@@ -185,6 +187,10 @@ int __init setup_earlycon(char *buf)
 		if (strncmp(buf, match->name, len))
 			continue;
 
+		/* prefer entries with empty compatible */
+		if (empty_compatible && *match->compatible)
+			continue;
+
 		if (buf[len]) {
 			if (buf[len] != ',')
 				continue;
@@ -195,6 +201,11 @@ int __init setup_earlycon(char *buf)
 		return register_earlycon(buf, match);
 	}
 
+	if (empty_compatible) {
+		empty_compatible = false;
+		goto again;
+	}
+
 	return -ENOENT;
 }
 

drivers/tty/serial/efm32-uart.c

@@ -200,7 +200,7 @@ static void efm32_uart_rx_chars(struct efm32_uart_port *efm_port)
 		/*
 		 * This is a reserved bit and I only saw it read as 0. But to be
 		 * sure not to be confused too much by new devices adhere to the
-		 * warning in the reference manual that reserverd bits might
+		 * warning in the reference manual that reserved bits might
 		 * read as 1 in the future.
 		 */
 		rxdata &= ~SW_UARTn_RXDATAX_BERR;

drivers/tty/serial/fsl_lpuart.c

@@ -234,6 +234,7 @@ static DEFINE_IDA(fsl_lpuart_ida);
 enum lpuart_type {
 	VF610_LPUART,
 	LS1021A_LPUART,
+	LS1028A_LPUART,
 	IMX7ULP_LPUART,
 	IMX8QXP_LPUART,
 };
@@ -278,11 +279,16 @@ static const struct lpuart_soc_data vf_data = {
 	.iotype = UPIO_MEM,
 };
 
-static const struct lpuart_soc_data ls_data = {
+static const struct lpuart_soc_data ls1021a_data = {
 	.devtype = LS1021A_LPUART,
 	.iotype = UPIO_MEM32BE,
 };
 
+static const struct lpuart_soc_data ls1028a_data = {
+	.devtype = LS1028A_LPUART,
+	.iotype = UPIO_MEM32,
+};
+
 static struct lpuart_soc_data imx7ulp_data = {
 	.devtype = IMX7ULP_LPUART,
 	.iotype = UPIO_MEM32,
@@ -297,7 +303,8 @@ static struct lpuart_soc_data imx8qxp_data = {
 
 static const struct of_device_id lpuart_dt_ids[] = {
 	{ .compatible = "fsl,vf610-lpuart",	.data = &vf_data, },
-	{ .compatible = "fsl,ls1021a-lpuart",	.data = &ls_data, },
+	{ .compatible = "fsl,ls1021a-lpuart",	.data = &ls1021a_data, },
+	{ .compatible = "fsl,ls1028a-lpuart",	.data = &ls1028a_data, },
 	{ .compatible = "fsl,imx7ulp-lpuart",	.data = &imx7ulp_data, },
 	{ .compatible = "fsl,imx8qxp-lpuart",	.data = &imx8qxp_data, },
 	{ /* sentinel */ }
@@ -307,6 +314,11 @@ MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
 /* Forward declare this for the dma callbacks*/
 static void lpuart_dma_tx_complete(void *arg);
 
+static inline bool is_ls1028a_lpuart(struct lpuart_port *sport)
+{
+	return sport->devtype == LS1028A_LPUART;
+}
+
 static inline bool is_imx8qxp_lpuart(struct lpuart_port *sport)
 {
 	return sport->devtype == IMX8QXP_LPUART;
@@ -409,6 +421,7 @@ static void lpuart_dma_tx(struct lpuart_port *sport)
 	struct circ_buf *xmit = &sport->port.state->xmit;
 	struct scatterlist *sgl = sport->tx_sgl;
 	struct device *dev = sport->port.dev;
+	struct dma_chan *chan = sport->dma_tx_chan;
 	int ret;
 
 	if (sport->dma_tx_in_progress)
@@ -427,17 +440,19 @@ static void lpuart_dma_tx(struct lpuart_port *sport)
 		sg_set_buf(sgl + 1, xmit->buf, xmit->head);
 	}
 
-	ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
+	ret = dma_map_sg(chan->device->dev, sgl, sport->dma_tx_nents,
+			 DMA_TO_DEVICE);
 	if (!ret) {
 		dev_err(dev, "DMA mapping error for TX.\n");
 		return;
 	}
 
-	sport->dma_tx_desc = dmaengine_prep_slave_sg(sport->dma_tx_chan, sgl,
+	sport->dma_tx_desc = dmaengine_prep_slave_sg(chan, sgl,
 					ret, DMA_MEM_TO_DEV,
 					DMA_PREP_INTERRUPT);
 	if (!sport->dma_tx_desc) {
-		dma_unmap_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
+		dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents,
+			      DMA_TO_DEVICE);
 		dev_err(dev, "Cannot prepare TX slave DMA!\n");
 		return;
 	}
@@ -446,7 +461,7 @@ static void lpuart_dma_tx(struct lpuart_port *sport)
 	sport->dma_tx_desc->callback_param = sport;
 	sport->dma_tx_in_progress = true;
 	sport->dma_tx_cookie = dmaengine_submit(sport->dma_tx_desc);
-	dma_async_issue_pending(sport->dma_tx_chan);
+	dma_async_issue_pending(chan);
 }
 
 static bool lpuart_stopped_or_empty(struct uart_port *port)
@@ -459,11 +474,13 @@ static void lpuart_dma_tx_complete(void *arg)
 	struct lpuart_port *sport = arg;
 	struct scatterlist *sgl = &sport->tx_sgl[0];
 	struct circ_buf *xmit = &sport->port.state->xmit;
+	struct dma_chan *chan = sport->dma_tx_chan;
 	unsigned long flags;
 
 	spin_lock_irqsave(&sport->port.lock, flags);
 
-	dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
+	dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents,
+		     DMA_TO_DEVICE);
 
 	xmit->tail = (xmit->tail + sport->dma_tx_bytes) & (UART_XMIT_SIZE - 1);
 
@@ -529,15 +546,16 @@ static bool lpuart_is_32(struct lpuart_port *sport)
 static void lpuart_flush_buffer(struct uart_port *port)
 {
 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	struct dma_chan *chan = sport->dma_tx_chan;
 	u32 val;
 
 	if (sport->lpuart_dma_tx_use) {
 		if (sport->dma_tx_in_progress) {
-			dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
+			dma_unmap_sg(chan->device->dev, &sport->tx_sgl[0],
 				sport->dma_tx_nents, DMA_TO_DEVICE);
 			sport->dma_tx_in_progress = false;
 		}
-		dmaengine_terminate_all(sport->dma_tx_chan);
+		dmaengine_terminate_all(chan);
 	}
 
 	if (lpuart_is_32(sport)) {
@@ -993,6 +1011,7 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
 	struct tty_port *port = &sport->port.state->port;
 	struct dma_tx_state state;
 	enum dma_status dmastat;
+	struct dma_chan *chan = sport->dma_rx_chan;
 	struct circ_buf *ring = &sport->rx_ring;
 	unsigned long flags;
 	int count = 0;
@@ -1053,10 +1072,7 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
 
 	spin_lock_irqsave(&sport->port.lock, flags);
 
-	dmastat = dmaengine_tx_status(sport->dma_rx_chan,
-				sport->dma_rx_cookie,
-				&state);
-
+	dmastat = dmaengine_tx_status(chan, sport->dma_rx_cookie, &state);
 	if (dmastat == DMA_ERROR) {
 		dev_err(sport->port.dev, "Rx DMA transfer failed!\n");
 		spin_unlock_irqrestore(&sport->port.lock, flags);
@@ -1064,7 +1080,8 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
 	}
 
 	/* CPU claims ownership of RX DMA buffer */
-	dma_sync_sg_for_cpu(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
+	dma_sync_sg_for_cpu(chan->device->dev, &sport->rx_sgl, 1,
+			    DMA_FROM_DEVICE);
 
 	/*
 	 * ring->head points to the end of data already written by the DMA.
@@ -1106,7 +1123,7 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
 		sport->port.icount.rx += count;
 	}
 
-	dma_sync_sg_for_device(sport->port.dev, &sport->rx_sgl, 1,
+	dma_sync_sg_for_device(chan->device->dev, &sport->rx_sgl, 1,
 			       DMA_FROM_DEVICE);
 
 	spin_unlock_irqrestore(&sport->port.lock, flags);
@@ -1138,6 +1155,7 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
 	struct tty_port *port = &sport->port.state->port;
 	struct tty_struct *tty = port->tty;
 	struct ktermios *termios = &tty->termios;
+	struct dma_chan *chan = sport->dma_rx_chan;
 
 	baud = tty_get_baud_rate(tty);
 
@@ -1159,7 +1177,8 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
 		return -ENOMEM;
 
 	sg_init_one(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len);
-	nent = dma_map_sg(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
+	nent = dma_map_sg(chan->device->dev, &sport->rx_sgl, 1,
+			  DMA_FROM_DEVICE);
 
 	if (!nent) {
 		dev_err(sport->port.dev, "DMA Rx mapping error\n");
@@ -1170,7 +1189,7 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
 	dma_rx_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 	dma_rx_sconfig.src_maxburst = 1;
 	dma_rx_sconfig.direction = DMA_DEV_TO_MEM;
-	ret = dmaengine_slave_config(sport->dma_rx_chan, &dma_rx_sconfig);
+	ret = dmaengine_slave_config(chan, &dma_rx_sconfig);
 
 	if (ret < 0) {
 		dev_err(sport->port.dev,
@@ -1178,7 +1197,7 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
 		return ret;
 	}
 
-	sport->dma_rx_desc = dmaengine_prep_dma_cyclic(sport->dma_rx_chan,
+	sport->dma_rx_desc = dmaengine_prep_dma_cyclic(chan,
 				 sg_dma_address(&sport->rx_sgl),
 				 sport->rx_sgl.length,
 				 sport->rx_sgl.length / 2,
@@ -1192,7 +1211,7 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
 	sport->dma_rx_desc->callback = lpuart_dma_rx_complete;
 	sport->dma_rx_desc->callback_param = sport;
 	sport->dma_rx_cookie = dmaengine_submit(sport->dma_rx_desc);
-	dma_async_issue_pending(sport->dma_rx_chan);
+	dma_async_issue_pending(chan);
 
 	if (lpuart_is_32(sport)) {
 		unsigned long temp = lpuart32_read(&sport->port, UARTBAUD);
@@ -1210,11 +1229,12 @@ static void lpuart_dma_rx_free(struct uart_port *port)
 {
 	struct lpuart_port *sport = container_of(port,
 					struct lpuart_port, port);
+	struct dma_chan *chan = sport->dma_rx_chan;
 
-	if (sport->dma_rx_chan)
-		dmaengine_terminate_all(sport->dma_rx_chan);
+	if (chan)
+		dmaengine_terminate_all(chan);
 
-	dma_unmap_sg(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
+	dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
 	kfree(sport->rx_ring.buf);
 	sport->rx_ring.tail = 0;
 	sport->rx_ring.head = 0;
@@ -1490,39 +1510,77 @@ static void rx_dma_timer_init(struct lpuart_port *sport)
 	add_timer(&sport->lpuart_timer);
 }
 
+static void lpuart_request_dma(struct lpuart_port *sport)
+{
+	sport->dma_tx_chan = dma_request_chan(sport->port.dev, "tx");
+	if (IS_ERR(sport->dma_tx_chan)) {
+		dev_info_once(sport->port.dev,
+			      "DMA tx channel request failed, operating without tx DMA (%ld)\n",
+			      PTR_ERR(sport->dma_tx_chan));
+		sport->dma_tx_chan = NULL;
+	}
+
+	sport->dma_rx_chan = dma_request_chan(sport->port.dev, "rx");
+	if (IS_ERR(sport->dma_rx_chan)) {
+		dev_info_once(sport->port.dev,
+			      "DMA rx channel request failed, operating without rx DMA (%ld)\n",
+			      PTR_ERR(sport->dma_rx_chan));
+		sport->dma_rx_chan = NULL;
+	}
+}
+
 static void lpuart_tx_dma_startup(struct lpuart_port *sport)
 {
 	u32 uartbaud;
+	int ret;
 
-	if (sport->dma_tx_chan && !lpuart_dma_tx_request(&sport->port)) {
-		init_waitqueue_head(&sport->dma_wait);
-		sport->lpuart_dma_tx_use = true;
-		if (lpuart_is_32(sport)) {
-			uartbaud = lpuart32_read(&sport->port, UARTBAUD);
-			lpuart32_write(&sport->port,
-				       uartbaud | UARTBAUD_TDMAE, UARTBAUD);
-		} else {
-			writeb(readb(sport->port.membase + UARTCR5) |
-				UARTCR5_TDMAS, sport->port.membase + UARTCR5);
-		}
+	if (!sport->dma_tx_chan)
+		goto err;
+
+	ret = lpuart_dma_tx_request(&sport->port);
+	if (ret)
+		goto err;
+
+	init_waitqueue_head(&sport->dma_wait);
+	sport->lpuart_dma_tx_use = true;
+	if (lpuart_is_32(sport)) {
+		uartbaud = lpuart32_read(&sport->port, UARTBAUD);
+		lpuart32_write(&sport->port,
+			       uartbaud | UARTBAUD_TDMAE, UARTBAUD);
 	} else {
-		sport->lpuart_dma_tx_use = false;
+		writeb(readb(sport->port.membase + UARTCR5) |
+		       UARTCR5_TDMAS, sport->port.membase + UARTCR5);
 	}
+
+	return;
+
+err:
+	sport->lpuart_dma_tx_use = false;
 }
 
 static void lpuart_rx_dma_startup(struct lpuart_port *sport)
 {
-	if (sport->dma_rx_chan && !lpuart_start_rx_dma(sport)) {
-		/* set Rx DMA timeout */
-		sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT);
-		if (!sport->dma_rx_timeout)
-			sport->dma_rx_timeout = 1;
+	int ret;
 
-		sport->lpuart_dma_rx_use = true;
-		rx_dma_timer_init(sport);
-	} else {
-		sport->lpuart_dma_rx_use = false;
-	}
+	if (!sport->dma_rx_chan)
+		goto err;
+
+	ret = lpuart_start_rx_dma(sport);
+	if (ret)
+		goto err;
+
+	/* set Rx DMA timeout */
+	sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT);
+	if (!sport->dma_rx_timeout)
+		sport->dma_rx_timeout = 1;
+
+	sport->lpuart_dma_rx_use = true;
+	rx_dma_timer_init(sport);
+
+	return;
+
+err:
+	sport->lpuart_dma_rx_use = false;
 }
 
 static int lpuart_startup(struct uart_port *port)
@@ -1541,6 +1599,8 @@ static int lpuart_startup(struct uart_port *port)
 	sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_RXSIZE_OFF) &
 					    UARTPFIFO_FIFOSIZE_MASK);
 
+	lpuart_request_dma(sport);
+
 	spin_lock_irqsave(&sport->port.lock, flags);
 
 	lpuart_setup_watermark_enable(sport);
@@ -1587,11 +1647,23 @@ static int lpuart32_startup(struct uart_port *port)
 	sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_RXSIZE_OFF) &
 					    UARTFIFO_FIFOSIZE_MASK);
 
+	/*
+	 * The LS1028A has a fixed length of 16 words. Although it supports the
+	 * RX/TXSIZE fields their encoding is different. Eg the reference manual
+	 * states 0b101 is 16 words.
+	 */
+	if (is_ls1028a_lpuart(sport)) {
+		sport->rxfifo_size = 16;
+		sport->txfifo_size = 16;
+		sport->port.fifosize = sport->txfifo_size;
+	}
+
+	lpuart_request_dma(sport);
+
 	spin_lock_irqsave(&sport->port.lock, flags);
 
 	lpuart32_setup_watermark_enable(sport);
 
-
 	lpuart_rx_dma_startup(sport);
 	lpuart_tx_dma_startup(sport);
 
@@ -1615,6 +1687,11 @@ static void lpuart_dma_shutdown(struct lpuart_port *sport)
 			dmaengine_terminate_all(sport->dma_tx_chan);
 		}
 	}
+
+	if (sport->dma_tx_chan)
+		dma_release_channel(sport->dma_tx_chan);
+	if (sport->dma_rx_chan)
+		dma_release_channel(sport->dma_rx_chan);
 }
 
 static void lpuart_shutdown(struct uart_port *port)
@@ -1811,11 +1888,12 @@ lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
 	spin_unlock_irqrestore(&sport->port.lock, flags);
 }
 
-static void
-lpuart32_serial_setbrg(struct lpuart_port *sport, unsigned int baudrate)
+static void __lpuart32_serial_setbrg(struct uart_port *port,
+				     unsigned int baudrate, bool use_rx_dma,
+				     bool use_tx_dma)
 {
 	u32 sbr, osr, baud_diff, tmp_osr, tmp_sbr, tmp_diff, tmp;
-	u32 clk = sport->port.uartclk;
+	u32 clk = port->uartclk;
 
 	/*
 	 * The idea is to use the best OSR (over-sampling rate) possible.
@@ -1861,10 +1939,10 @@ lpuart32_serial_setbrg(struct lpuart_port *sport, unsigned int baudrate)
 
 	/* handle buadrate outside acceptable rate */
 	if (baud_diff > ((baudrate / 100) * 3))
-		dev_warn(sport->port.dev,
+		dev_warn(port->dev,
 			 "unacceptable baud rate difference of more than 3%%\n");
 
-	tmp = lpuart32_read(&sport->port, UARTBAUD);
+	tmp = lpuart32_read(port, UARTBAUD);
 
 	if ((osr > 3) && (osr < 8))
 		tmp |= UARTBAUD_BOTHEDGE;
@@ -1875,14 +1953,23 @@ lpuart32_serial_setbrg(struct lpuart_port *sport, unsigned int baudrate)
 	tmp &= ~UARTBAUD_SBR_MASK;
 	tmp |= sbr & UARTBAUD_SBR_MASK;
 
-	if (!sport->lpuart_dma_rx_use)
+	if (!use_rx_dma)
 		tmp &= ~UARTBAUD_RDMAE;
-	if (!sport->lpuart_dma_tx_use)
+	if (!use_tx_dma)
 		tmp &= ~UARTBAUD_TDMAE;
 
-	lpuart32_write(&sport->port, tmp, UARTBAUD);
+	lpuart32_write(port, tmp, UARTBAUD);
 }
 
+static void lpuart32_serial_setbrg(struct lpuart_port *sport,
+				   unsigned int baudrate)
+{
+	__lpuart32_serial_setbrg(&sport->port, baudrate,
+				 sport->lpuart_dma_rx_use,
+				 sport->lpuart_dma_tx_use);
+}
+
+
 static void
 lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
 		   struct ktermios *old)
@@ -2376,6 +2463,30 @@ static int __init lpuart32_early_console_setup(struct earlycon_device *device,
 	return 0;
 }
 
+static int __init ls1028a_early_console_setup(struct earlycon_device *device,
+					      const char *opt)
+{
+	u32 cr;
+
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->port.iotype = UPIO_MEM32;
+	device->con->write = lpuart32_early_write;
+
+	/* set the baudrate */
+	if (device->port.uartclk && device->baud)
+		__lpuart32_serial_setbrg(&device->port, device->baud,
+					 false, false);
+
+	/* enable transmitter */
+	cr = lpuart32_read(&device->port, UARTCTRL);
+	cr |= UARTCTRL_TE;
+	lpuart32_write(&device->port, cr, UARTCTRL);
+
+	return 0;
+}
+
 static int __init lpuart32_imx_early_console_setup(struct earlycon_device *device,
 						   const char *opt)
 {
@@ -2390,6 +2501,7 @@ static int __init lpuart32_imx_early_console_setup(struct earlycon_device *devic
 }
 OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup);
 OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup);
+OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1028a-lpuart", ls1028a_early_console_setup);
 OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart", lpuart32_imx_early_console_setup);
 EARLYCON_DECLARE(lpuart, lpuart_early_console_setup);
 EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup);
@@ -2520,16 +2632,6 @@ static int lpuart_probe(struct platform_device *pdev)
 
 	sport->port.rs485_config(&sport->port, &sport->port.rs485);
 
-	sport->dma_tx_chan = dma_request_slave_channel(sport->port.dev, "tx");
-	if (!sport->dma_tx_chan)
-		dev_info(sport->port.dev, "DMA tx channel request failed, "
-				"operating without tx DMA\n");
-
-	sport->dma_rx_chan = dma_request_slave_channel(sport->port.dev, "rx");
-	if (!sport->dma_rx_chan)
-		dev_info(sport->port.dev, "DMA rx channel request failed, "
-				"operating without rx DMA\n");
-
 	return 0;
 
 failed_attach_port:

drivers/tty/serial/icom.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * icom.h
  *

drivers/tty/serial/ifx6x60.c

@@ -39,7 +39,7 @@
 #include <linux/fs.h>
 #include <linux/ip.h>
 #include <linux/dmapool.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/sched.h>
 #include <linux/time.h>
 #include <linux/wait.h>
@@ -61,7 +61,6 @@
 #define IFX_SPI_HEADER_F		(-2)
 
 #define PO_POST_DELAY		200
-#define IFX_MDM_RST_PMU	4
 
 /* forward reference */
 static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev);
@@ -81,7 +80,7 @@ static struct notifier_block ifx_modem_reboot_notifier_block = {
 
 static int ifx_modem_power_off(struct ifx_spi_device *ifx_dev)
 {
-	gpio_set_value(IFX_MDM_RST_PMU, 1);
+	gpiod_set_value(ifx_dev->gpio.pmu_reset, 1);
 	msleep(PO_POST_DELAY);
 
 	return 0;
@@ -107,7 +106,7 @@ static int ifx_modem_reboot_callback(struct notifier_block *nfb,
  */
 static inline void mrdy_set_high(struct ifx_spi_device *ifx)
 {
-	gpio_set_value(ifx->gpio.mrdy, 1);
+	gpiod_set_value(ifx->gpio.mrdy, 1);
 }
 
 /**
@@ -117,7 +116,7 @@ static inline void mrdy_set_high(struct ifx_spi_device *ifx)
  */
 static inline void mrdy_set_low(struct ifx_spi_device *ifx)
 {
-	gpio_set_value(ifx->gpio.mrdy, 0);
+	gpiod_set_value(ifx->gpio.mrdy, 0);
 }
 
 /**
@@ -244,7 +243,7 @@ static inline void swap_buf_32(unsigned char *buf, int len, void *end)
  */
 static void mrdy_assert(struct ifx_spi_device *ifx_dev)
 {
-	int val = gpio_get_value(ifx_dev->gpio.srdy);
+	int val = gpiod_get_value(ifx_dev->gpio.srdy);
 	if (!val) {
 		if (!test_and_set_bit(IFX_SPI_STATE_TIMER_PENDING,
 				      &ifx_dev->flags)) {
@@ -691,7 +690,7 @@ complete_exit:
 	clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &(ifx_dev->flags));
 
 	queue_length = kfifo_len(&ifx_dev->tx_fifo);
-	srdy = gpio_get_value(ifx_dev->gpio.srdy);
+	srdy = gpiod_get_value(ifx_dev->gpio.srdy);
 	if (!srdy)
 		ifx_spi_power_state_clear(ifx_dev, IFX_SPI_POWER_SRDY);
 
@@ -898,7 +897,7 @@ static irqreturn_t ifx_spi_srdy_interrupt(int irq, void *dev)
 static irqreturn_t ifx_spi_reset_interrupt(int irq, void *dev)
 {
 	struct ifx_spi_device *ifx_dev = dev;
-	int val = gpio_get_value(ifx_dev->gpio.reset_out);
+	int val = gpiod_get_value(ifx_dev->gpio.reset_out);
 	int solreset = test_bit(MR_START, &ifx_dev->mdm_reset_state);
 
 	if (val == 0) {
@@ -954,14 +953,14 @@ static int ifx_spi_reset(struct ifx_spi_device *ifx_dev)
 	 * to reset properly
 	 */
 	set_bit(MR_START, &ifx_dev->mdm_reset_state);
-	gpio_set_value(ifx_dev->gpio.po, 0);
-	gpio_set_value(ifx_dev->gpio.reset, 0);
+	gpiod_set_value(ifx_dev->gpio.po, 0);
+	gpiod_set_value(ifx_dev->gpio.reset, 0);
 	msleep(25);
-	gpio_set_value(ifx_dev->gpio.reset, 1);
+	gpiod_set_value(ifx_dev->gpio.reset, 1);
 	msleep(1);
-	gpio_set_value(ifx_dev->gpio.po, 1);
+	gpiod_set_value(ifx_dev->gpio.po, 1);
 	msleep(1);
-	gpio_set_value(ifx_dev->gpio.po, 0);
+	gpiod_set_value(ifx_dev->gpio.po, 0);
 	ret = wait_event_timeout(ifx_dev->mdm_reset_wait,
 				 test_bit(MR_COMPLETE,
 					  &ifx_dev->mdm_reset_state),
@@ -992,22 +991,23 @@ static int ifx_spi_spi_probe(struct spi_device *spi)
 	int srdy;
 	struct ifx_modem_platform_data *pl_data;
 	struct ifx_spi_device *ifx_dev;
+	struct device *dev = &spi->dev;
 
 	if (saved_ifx_dev) {
-		dev_dbg(&spi->dev, "ignoring subsequent detection");
+		dev_dbg(dev, "ignoring subsequent detection");
 		return -ENODEV;
 	}
 
-	pl_data = dev_get_platdata(&spi->dev);
+	pl_data = dev_get_platdata(dev);
 	if (!pl_data) {
-		dev_err(&spi->dev, "missing platform data!");
+		dev_err(dev, "missing platform data!");
 		return -ENODEV;
 	}
 
 	/* initialize structure to hold our device variables */
 	ifx_dev = kzalloc(sizeof(struct ifx_spi_device), GFP_KERNEL);
 	if (!ifx_dev) {
-		dev_err(&spi->dev, "spi device allocation failed");
+		dev_err(dev, "spi device allocation failed");
 		return -ENOMEM;
 	}
 	saved_ifx_dev = ifx_dev;
@@ -1026,7 +1026,7 @@ static int ifx_spi_spi_probe(struct spi_device *spi)
 	spi->bits_per_word = spi_bpw;
 	ret = spi_setup(spi);
 	if (ret) {
-		dev_err(&spi->dev, "SPI setup wasn't successful %d", ret);
+		dev_err(dev, "SPI setup wasn't successful %d", ret);
 		kfree(ifx_dev);
 		return -ENODEV;
 	}
@@ -1049,7 +1049,7 @@ static int ifx_spi_spi_probe(struct spi_device *spi)
 				&ifx_dev->tx_bus,
 				GFP_KERNEL);
 	if (!ifx_dev->tx_buffer) {
-		dev_err(&spi->dev, "DMA-TX buffer allocation failed");
+		dev_err(dev, "DMA-TX buffer allocation failed");
 		ret = -ENOMEM;
 		goto error_ret;
 	}
@@ -1058,7 +1058,7 @@ static int ifx_spi_spi_probe(struct spi_device *spi)
 				&ifx_dev->rx_bus,
 				GFP_KERNEL);
 	if (!ifx_dev->rx_buffer) {
-		dev_err(&spi->dev, "DMA-RX buffer allocation failed");
+		dev_err(dev, "DMA-RX buffer allocation failed");
 		ret = -ENOMEM;
 		goto error_ret;
 	}
@@ -1075,122 +1075,83 @@ static int ifx_spi_spi_probe(struct spi_device *spi)
 	/* create our tty port */
 	ret = ifx_spi_create_port(ifx_dev);
 	if (ret != 0) {
-		dev_err(&spi->dev, "create default tty port failed");
+		dev_err(dev, "create default tty port failed");
 		goto error_ret;
 	}
 
-	ifx_dev->gpio.reset = pl_data->rst_pmu;
-	ifx_dev->gpio.po = pl_data->pwr_on;
-	ifx_dev->gpio.mrdy = pl_data->mrdy;
-	ifx_dev->gpio.srdy = pl_data->srdy;
-	ifx_dev->gpio.reset_out = pl_data->rst_out;
-
-	dev_info(&spi->dev, "gpios %d, %d, %d, %d, %d",
-		 ifx_dev->gpio.reset, ifx_dev->gpio.po, ifx_dev->gpio.mrdy,
-		 ifx_dev->gpio.srdy, ifx_dev->gpio.reset_out);
-
-	/* Configure gpios */
-	ret = gpio_request(ifx_dev->gpio.reset, "ifxModem");
-	if (ret < 0) {
-		dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET)",
-			ifx_dev->gpio.reset);
+	ifx_dev->gpio.reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ifx_dev->gpio.reset)) {
+		dev_err(dev, "could not obtain reset GPIO\n");
+		ret = PTR_ERR(ifx_dev->gpio.reset);
 		goto error_ret;
 	}
-	ret += gpio_direction_output(ifx_dev->gpio.reset, 0);
-	ret += gpio_export(ifx_dev->gpio.reset, 1);
-	if (ret) {
-		dev_err(&spi->dev, "Unable to configure GPIO%d (RESET)",
-			ifx_dev->gpio.reset);
-		ret = -EBUSY;
-		goto error_ret2;
+	gpiod_set_consumer_name(ifx_dev->gpio.reset, "ifxModem reset");
+	ifx_dev->gpio.po = devm_gpiod_get(dev, "power", GPIOD_OUT_LOW);
+	if (IS_ERR(ifx_dev->gpio.po)) {
+		dev_err(dev, "could not obtain power GPIO\n");
+		ret = PTR_ERR(ifx_dev->gpio.po);
+		goto error_ret;
 	}
+	gpiod_set_consumer_name(ifx_dev->gpio.po, "ifxModem power");
+	ifx_dev->gpio.mrdy = devm_gpiod_get(dev, "mrdy", GPIOD_OUT_LOW);
+	if (IS_ERR(ifx_dev->gpio.mrdy)) {
+		dev_err(dev, "could not obtain mrdy GPIO\n");
+		ret = PTR_ERR(ifx_dev->gpio.mrdy);
+		goto error_ret;
+	}
+	gpiod_set_consumer_name(ifx_dev->gpio.mrdy, "ifxModem mrdy");
+	ifx_dev->gpio.srdy = devm_gpiod_get(dev, "srdy", GPIOD_IN);
+	if (IS_ERR(ifx_dev->gpio.srdy)) {
+		dev_err(dev, "could not obtain srdy GPIO\n");
+		ret = PTR_ERR(ifx_dev->gpio.srdy);
+		goto error_ret;
+	}
+	gpiod_set_consumer_name(ifx_dev->gpio.srdy, "ifxModem srdy");
+	ifx_dev->gpio.reset_out = devm_gpiod_get(dev, "rst_out", GPIOD_IN);
+	if (IS_ERR(ifx_dev->gpio.reset_out)) {
+		dev_err(dev, "could not obtain rst_out GPIO\n");
+		ret = PTR_ERR(ifx_dev->gpio.reset_out);
+		goto error_ret;
+	}
+	gpiod_set_consumer_name(ifx_dev->gpio.reset_out, "ifxModem reset out");
+	ifx_dev->gpio.pmu_reset = devm_gpiod_get(dev, "pmu_reset", GPIOD_ASIS);
+	if (IS_ERR(ifx_dev->gpio.pmu_reset)) {
+		dev_err(dev, "could not obtain pmu_reset GPIO\n");
+		ret = PTR_ERR(ifx_dev->gpio.pmu_reset);
+		goto error_ret;
+	}
+	gpiod_set_consumer_name(ifx_dev->gpio.pmu_reset, "ifxModem PMU reset");
 
-	ret = gpio_request(ifx_dev->gpio.po, "ifxModem");
-	ret += gpio_direction_output(ifx_dev->gpio.po, 0);
-	ret += gpio_export(ifx_dev->gpio.po, 1);
-	if (ret) {
-		dev_err(&spi->dev, "Unable to configure GPIO%d (ON)",
-			ifx_dev->gpio.po);
-		ret = -EBUSY;
-		goto error_ret3;
-	}
-
-	ret = gpio_request(ifx_dev->gpio.mrdy, "ifxModem");
-	if (ret < 0) {
-		dev_err(&spi->dev, "Unable to allocate GPIO%d (MRDY)",
-			ifx_dev->gpio.mrdy);
-		goto error_ret3;
-	}
-	ret += gpio_export(ifx_dev->gpio.mrdy, 1);
-	ret += gpio_direction_output(ifx_dev->gpio.mrdy, 0);
-	if (ret) {
-		dev_err(&spi->dev, "Unable to configure GPIO%d (MRDY)",
-			ifx_dev->gpio.mrdy);
-		ret = -EBUSY;
-		goto error_ret4;
-	}
-
-	ret = gpio_request(ifx_dev->gpio.srdy, "ifxModem");
-	if (ret < 0) {
-		dev_err(&spi->dev, "Unable to allocate GPIO%d (SRDY)",
-			ifx_dev->gpio.srdy);
-		ret = -EBUSY;
-		goto error_ret4;
-	}
-	ret += gpio_export(ifx_dev->gpio.srdy, 1);
-	ret += gpio_direction_input(ifx_dev->gpio.srdy);
-	if (ret) {
-		dev_err(&spi->dev, "Unable to configure GPIO%d (SRDY)",
-			ifx_dev->gpio.srdy);
-		ret = -EBUSY;
-		goto error_ret5;
-	}
-
-	ret = gpio_request(ifx_dev->gpio.reset_out, "ifxModem");
-	if (ret < 0) {
-		dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET_OUT)",
-			ifx_dev->gpio.reset_out);
-		goto error_ret5;
-	}
-	ret += gpio_export(ifx_dev->gpio.reset_out, 1);
-	ret += gpio_direction_input(ifx_dev->gpio.reset_out);
-	if (ret) {
-		dev_err(&spi->dev, "Unable to configure GPIO%d (RESET_OUT)",
-			ifx_dev->gpio.reset_out);
-		ret = -EBUSY;
-		goto error_ret6;
-	}
-
-	ret = request_irq(gpio_to_irq(ifx_dev->gpio.reset_out),
+	ret = request_irq(gpiod_to_irq(ifx_dev->gpio.reset_out),
 			  ifx_spi_reset_interrupt,
 			  IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING, DRVNAME,
 			  ifx_dev);
 	if (ret) {
-		dev_err(&spi->dev, "Unable to get irq %x\n",
-			gpio_to_irq(ifx_dev->gpio.reset_out));
-		goto error_ret6;
+		dev_err(dev, "Unable to get irq %x\n",
+			gpiod_to_irq(ifx_dev->gpio.reset_out));
+		goto error_ret;
 	}
 
 	ret = ifx_spi_reset(ifx_dev);
 
-	ret = request_irq(gpio_to_irq(ifx_dev->gpio.srdy),
+	ret = request_irq(gpiod_to_irq(ifx_dev->gpio.srdy),
 			  ifx_spi_srdy_interrupt, IRQF_TRIGGER_RISING, DRVNAME,
 			  ifx_dev);
 	if (ret) {
-		dev_err(&spi->dev, "Unable to get irq %x",
-			gpio_to_irq(ifx_dev->gpio.srdy));
-		goto error_ret7;
+		dev_err(dev, "Unable to get irq %x",
+			gpiod_to_irq(ifx_dev->gpio.srdy));
+		goto error_ret2;
 	}
 
 	/* set pm runtime power state and register with power system */
-	pm_runtime_set_active(&spi->dev);
-	pm_runtime_enable(&spi->dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
 
 	/* handle case that modem is already signaling SRDY */
 	/* no outgoing tty open at this point, this just satisfies the
 	 * modem's read and should reset communication properly
 	 */
-	srdy = gpio_get_value(ifx_dev->gpio.srdy);
+	srdy = gpiod_get_value(ifx_dev->gpio.srdy);
 
 	if (srdy) {
 		mrdy_assert(ifx_dev);
@@ -1199,18 +1160,8 @@ static int ifx_spi_spi_probe(struct spi_device *spi)
 		mrdy_set_low(ifx_dev);
 	return 0;
 
-error_ret7:
-	free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), ifx_dev);
-error_ret6:
-	gpio_free(ifx_dev->gpio.srdy);
-error_ret5:
-	gpio_free(ifx_dev->gpio.mrdy);
-error_ret4:
-	gpio_free(ifx_dev->gpio.reset);
-error_ret3:
-	gpio_free(ifx_dev->gpio.po);
 error_ret2:
-	gpio_free(ifx_dev->gpio.reset_out);
+	free_irq(gpiod_to_irq(ifx_dev->gpio.reset_out), ifx_dev);
 error_ret:
 	ifx_spi_free_device(ifx_dev);
 	saved_ifx_dev = NULL;
@@ -1234,14 +1185,8 @@ static int ifx_spi_spi_remove(struct spi_device *spi)
 	pm_runtime_disable(&spi->dev);
 
 	/* free irq */
-	free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), ifx_dev);
-	free_irq(gpio_to_irq(ifx_dev->gpio.srdy), ifx_dev);
-
-	gpio_free(ifx_dev->gpio.srdy);
-	gpio_free(ifx_dev->gpio.mrdy);
-	gpio_free(ifx_dev->gpio.reset);
-	gpio_free(ifx_dev->gpio.po);
-	gpio_free(ifx_dev->gpio.reset_out);
+	free_irq(gpiod_to_irq(ifx_dev->gpio.reset_out), ifx_dev);
+	free_irq(gpiod_to_irq(ifx_dev->gpio.srdy), ifx_dev);
 
 	/* free allocations */
 	ifx_spi_free_device(ifx_dev);

drivers/tty/serial/ifx6x60.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /****************************************************************************
  *
  * Driver for the IFX spi modem.
@@ -10,6 +10,8 @@
 #ifndef _IFX6X60_H
 #define _IFX6X60_H
 
+struct gpio_desc;
+
 #define DRVNAME				"ifx6x60"
 #define TTYNAME				"ttyIFX"
 
@@ -94,11 +96,12 @@ struct ifx_spi_device {
 
 	struct {
 		/* gpio lines */
-		unsigned short srdy;		/* slave-ready gpio */
-		unsigned short mrdy;		/* master-ready gpio */
-		unsigned short reset;		/* modem-reset gpio */
-		unsigned short po;		/* modem-on gpio */
-		unsigned short reset_out;	/* modem-in-reset gpio */
+		struct gpio_desc *srdy;		/* slave-ready gpio */
+		struct gpio_desc *mrdy;		/* master-ready gpio */
+		struct gpio_desc *reset;	/* modem-reset gpio */
+		struct gpio_desc *po;		/* modem-on gpio */
+		struct gpio_desc *reset_out;	/* modem-in-reset gpio */
+		struct gpio_desc *pmu_reset;	/* PMU reset gpio */
 		/* state/stats */
 		int unack_srdy_int_nb;
 	} gpio;

drivers/tty/serial/imx.c

@@ -195,6 +195,8 @@ struct imx_port {
 	unsigned int		have_rtscts:1;
 	unsigned int		have_rtsgpio:1;
 	unsigned int		dte_mode:1;
+	unsigned int		inverted_tx:1;
+	unsigned int		inverted_rx:1;
 	struct clk		*clk_ipg;
 	struct clk		*clk_per;
 	const struct imx_uart_data *devdata;
@@ -1335,7 +1337,7 @@ static int imx_uart_startup(struct uart_port *port)
 	int retval, i;
 	unsigned long flags;
 	int dma_is_inited = 0;
-	u32 ucr1, ucr2, ucr4;
+	u32 ucr1, ucr2, ucr3, ucr4;
 
 	retval = clk_prepare_enable(sport->clk_per);
 	if (retval)
@@ -1387,11 +1389,29 @@ static int imx_uart_startup(struct uart_port *port)
 
 	imx_uart_writel(sport, ucr1, UCR1);
 
-	ucr4 = imx_uart_readl(sport, UCR4) & ~UCR4_OREN;
+	ucr4 = imx_uart_readl(sport, UCR4) & ~(UCR4_OREN | UCR4_INVR);
 	if (!sport->dma_is_enabled)
 		ucr4 |= UCR4_OREN;
+	if (sport->inverted_rx)
+		ucr4 |= UCR4_INVR;
 	imx_uart_writel(sport, ucr4, UCR4);
 
+	ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_INVT;
+	/*
+	 * configure tx polarity before enabling tx
+	 */
+	if (sport->inverted_tx)
+		ucr3 |= UCR3_INVT;
+
+	if (!imx_uart_is_imx1(sport)) {
+		ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
+
+		if (sport->dte_mode)
+			/* disable broken interrupts */
+			ucr3 &= ~(UCR3_RI | UCR3_DCD);
+	}
+	imx_uart_writel(sport, ucr3, UCR3);
+
 	ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
 	ucr2 |= (UCR2_RXEN | UCR2_TXEN);
 	if (!sport->have_rtscts)
@@ -1404,20 +1424,6 @@ static int imx_uart_startup(struct uart_port *port)
 		ucr2 &= ~UCR2_RTSEN;
 	imx_uart_writel(sport, ucr2, UCR2);
 
-	if (!imx_uart_is_imx1(sport)) {
-		u32 ucr3;
-
-		ucr3 = imx_uart_readl(sport, UCR3);
-
-		ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
-
-		if (sport->dte_mode)
-			/* disable broken interrupts */
-			ucr3 &= ~(UCR3_RI | UCR3_DCD);
-
-		imx_uart_writel(sport, ucr3, UCR3);
-	}
-
 	/*
 	 * Enable modem status interrupts
 	 */
@@ -2184,6 +2190,12 @@ static int imx_uart_probe_dt(struct imx_port *sport,
 	if (of_get_property(np, "rts-gpios", NULL))
 		sport->have_rtsgpio = 1;
 
+	if (of_get_property(np, "fsl,inverted-tx", NULL))
+		sport->inverted_tx = 1;
+
+	if (of_get_property(np, "fsl,inverted-rx", NULL))
+		sport->inverted_rx = 1;
+
 	return 0;
 }
 #else

drivers/tty/serial/jsm/jsm.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /************************************************************************
  * Copyright 2003 Digi International (www.digi.com)
  *

drivers/tty/serial/kgdboc.c

@@ -169,15 +169,13 @@ static int configure_kgdboc(void)
 	if (!p)
 		goto noconfig;
 
-	cons = console_drivers;
-	while (cons) {
+	for_each_console(cons) {
 		int idx;
 		if (cons->device && cons->device(cons, &idx) == p &&
 		    idx == tty_line) {
 			kgdboc_io_ops.is_console = 1;
 			break;
 		}
-		cons = cons->next;
 	}
 
 	kgdb_tty_driver = p;

drivers/tty/serial/lantiq.c

@@ -11,7 +11,6 @@
 #include <linux/clk.h>
 #include <linux/console.h>
 #include <linux/device.h>
-#include <linux/gpio.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/ioport.h>

drivers/tty/serial/omap-serial.c

@@ -37,8 +37,6 @@
 #include <linux/of_gpio.h>
 #include <linux/platform_data/serial-omap.h>
 
-#include <dt-bindings/gpio/gpio.h>
-
 #define OMAP_MAX_HSUART_PORTS	10
 
 #define UART_BUILD_REVISION(x, y)	(((x) << 8) | (y))

drivers/tty/serial/pch_uart.c

@@ -310,32 +310,32 @@ static ssize_t port_show_regs(struct file *file, char __user *user_buf,
 	if (!buf)
 		return 0;
 
-	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
 			"PCH EG20T port[%d] regs:\n", priv->port.line);
 
-	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
 			"=================================\n");
-	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
 			"IER: \t0x%02x\n", ioread8(priv->membase + UART_IER));
-	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
 			"IIR: \t0x%02x\n", ioread8(priv->membase + UART_IIR));
-	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
 			"LCR: \t0x%02x\n", ioread8(priv->membase + UART_LCR));
-	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
 			"MCR: \t0x%02x\n", ioread8(priv->membase + UART_MCR));
-	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
 			"LSR: \t0x%02x\n", ioread8(priv->membase + UART_LSR));
-	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
 			"MSR: \t0x%02x\n", ioread8(priv->membase + UART_MSR));
-	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
 			"BRCSR: \t0x%02x\n",
 			ioread8(priv->membase + PCH_UART_BRCSR));
 
 	lcr = ioread8(priv->membase + UART_LCR);
 	iowrite8(PCH_UART_LCR_DLAB, priv->membase + UART_LCR);
-	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
 			"DLL: \t0x%02x\n", ioread8(priv->membase + UART_DLL));
-	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
 			"DLM: \t0x%02x\n", ioread8(priv->membase + UART_DLM));
 	iowrite8(lcr, priv->membase + UART_LCR);
 

drivers/tty/serial/pic32_uart.c

@@ -768,11 +768,6 @@ static int __init pic32_console_init(void)
 }
 console_initcall(pic32_console_init);
 
-static inline bool is_pic32_console_port(struct uart_port *port)
-{
-	return port->cons && port->cons->index == port->line;
-}
-
 /*
  * Late console initialization.
  */
@@ -873,8 +868,7 @@ static int pic32_uart_probe(struct platform_device *pdev)
 	}
 
 #ifdef CONFIG_SERIAL_PIC32_CONSOLE
-	if (is_pic32_console_port(port) &&
-	    (pic32_console.flags & CON_ENABLED)) {
+	if (uart_console(port) && (pic32_console.flags & CON_ENABLED)) {
 		/* The peripheral clock has been enabled by console_setup,
 		 * so disable it till the port is used.
 		 */

drivers/tty/serial/pic32_uart.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * PIC32 Integrated Serial Driver.
  *

drivers/tty/serial/qcom_geni_serial.c

@@ -21,6 +21,7 @@
 
 /* UART specific GENI registers */
 #define SE_UART_LOOPBACK_CFG		0x22c
+#define SE_UART_IO_MACRO_CTRL		0x240
 #define SE_UART_TX_TRANS_CFG		0x25c
 #define SE_UART_TX_WORD_LEN		0x268
 #define SE_UART_TX_STOP_BIT_LEN		0x26c
@@ -95,6 +96,12 @@
 #define CTS_RTS_SORTED	BIT(1)
 #define RX_TX_CTS_RTS_SORTED	(RX_TX_SORTED | CTS_RTS_SORTED)
 
+/* UART pin swap value */
+#define DEFAULT_IO_MACRO_IO0_IO1_MASK		GENMASK(3, 0)
+#define IO_MACRO_IO0_SEL		0x3
+#define DEFAULT_IO_MACRO_IO2_IO3_MASK		GENMASK(15, 4)
+#define IO_MACRO_IO2_IO3_SWAP		0x4640
+
 #ifdef CONFIG_CONSOLE_POLL
 #define CONSOLE_RX_BYTES_PW 1
 #else
@@ -113,12 +120,14 @@ struct qcom_geni_serial_port {
 	unsigned int baud;
 	unsigned int tx_bytes_pw;
 	unsigned int rx_bytes_pw;
-	u32 *rx_fifo;
+	void *rx_fifo;
 	u32 loopback;
 	bool brk;
 
 	unsigned int tx_remaining;
 	int wakeup_irq;
+	bool rx_tx_swap;
+	bool cts_rts_swap;
 };
 
 static const struct uart_ops qcom_geni_console_pops;
@@ -505,7 +514,6 @@ static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
 
 static int handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop)
 {
-	unsigned char *buf;
 	struct tty_port *tport;
 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
 	u32 num_bytes_pw = port->tx_fifo_width / BITS_PER_BYTE;
@@ -517,8 +525,7 @@ static int handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop)
 	if (drop)
 		return 0;
 
-	buf = (unsigned char *)port->rx_fifo;
-	ret = tty_insert_flip_string(tport, buf, bytes);
+	ret = tty_insert_flip_string(tport, port->rx_fifo, bytes);
 	if (ret != bytes) {
 		dev_err(uport->dev, "%s:Unable to push data ret %d_bytes %d\n",
 				__func__, ret, bytes);
@@ -818,17 +825,7 @@ static void get_tx_fifo_size(struct qcom_geni_serial_port *port)
 
 static void qcom_geni_serial_shutdown(struct uart_port *uport)
 {
-	unsigned long flags;
-
-	/* Stop the console before stopping the current tx */
-	if (uart_console(uport))
-		console_stop(uport->cons);
-
 	disable_irq(uport->irq);
-	spin_lock_irqsave(&uport->lock, flags);
-	qcom_geni_serial_stop_tx(uport);
-	qcom_geni_serial_stop_rx(uport);
-	spin_unlock_irqrestore(&uport->lock, flags);
 }
 
 static int qcom_geni_serial_port_setup(struct uart_port *uport)
@@ -836,6 +833,7 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport)
 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
 	u32 rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;
 	u32 proto;
+	u32 pin_swap;
 
 	if (uart_console(uport)) {
 		port->tx_bytes_pw = 1;
@@ -856,6 +854,20 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport)
 	get_tx_fifo_size(port);
 
 	writel(rxstale, uport->membase + SE_UART_RX_STALE_CNT);
+
+	pin_swap = readl(uport->membase + SE_UART_IO_MACRO_CTRL);
+	if (port->rx_tx_swap) {
+		pin_swap &= ~DEFAULT_IO_MACRO_IO2_IO3_MASK;
+		pin_swap |= IO_MACRO_IO2_IO3_SWAP;
+	}
+	if (port->cts_rts_swap) {
+		pin_swap &= ~DEFAULT_IO_MACRO_IO0_IO1_MASK;
+		pin_swap |= IO_MACRO_IO0_SEL;
+	}
+	/* Configure this register if RX-TX, CTS-RTS pins are swapped */
+	if (port->rx_tx_swap || port->cts_rts_swap)
+		writel(pin_swap, uport->membase + SE_UART_IO_MACRO_CTRL);
+
 	/*
 	 * Make an unconditional cancel on the main sequencer to reset
 	 * it else we could end up in data loss scenarios.
@@ -868,12 +880,6 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport)
 						false, false, true);
 	geni_se_init(&port->se, UART_RX_WM, port->rx_fifo_depth - 2);
 	geni_se_select_mode(&port->se, GENI_SE_FIFO);
-	if (!uart_console(uport)) {
-		port->rx_fifo = devm_kcalloc(uport->dev,
-			port->rx_fifo_depth, sizeof(u32), GFP_KERNEL);
-		if (!port->rx_fifo)
-			return -ENOMEM;
-	}
 	port->setup = true;
 
 	return 0;
@@ -1284,6 +1290,13 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
 	port->rx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
 	port->tx_fifo_width = DEF_FIFO_WIDTH_BITS;
 
+	if (!console) {
+		port->rx_fifo = devm_kcalloc(uport->dev,
+			port->rx_fifo_depth, sizeof(u32), GFP_KERNEL);
+		if (!port->rx_fifo)
+			return -ENOMEM;
+	}
+
 	port->name = devm_kasprintf(uport->dev, GFP_KERNEL,
 			"qcom_geni_serial_%s%d",
 			uart_console(uport) ? "console" : "uart", uport->line);
@@ -1299,6 +1312,12 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
 	if (!console)
 		port->wakeup_irq = platform_get_irq_optional(pdev, 1);
 
+	if (of_property_read_bool(pdev->dev.of_node, "rx-tx-swap"))
+		port->rx_tx_swap = true;
+
+	if (of_property_read_bool(pdev->dev.of_node, "cts-rts-swap"))
+		port->cts_rts_swap = true;
+
 	uport->private_data = drv;
 	platform_set_drvdata(pdev, port);
 	port->handle_rx = console ? handle_rx_console : handle_rx_uart;

drivers/tty/serial/sc16is7xx.c

@@ -329,7 +329,7 @@ struct sc16is7xx_port {
 	struct task_struct		*kworker_task;
 	struct kthread_work		irq_work;
 	struct mutex			efr_lock;
-	struct sc16is7xx_one		p[0];
+	struct sc16is7xx_one		p[];
 };
 
 static unsigned long sc16is7xx_lines;

drivers/tty/serial/serial_core.c

@@ -20,6 +20,7 @@
 #include <linux/device.h>
 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
 #include <linux/serial_core.h>
+#include <linux/sysrq.h>
 #include <linux/delay.h>
 #include <linux/mutex.h>
 #include <linux/security.h>
@@ -40,6 +41,8 @@ static struct lock_class_key port_lock_key;
 
 #define HIGH_BITS_OFFSET	((sizeof(long)-sizeof(int))*8)
 
+#define SYSRQ_TIMEOUT	(HZ * 5)
+
 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
 					struct ktermios *old_termios);
 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
@@ -1908,6 +1911,24 @@ static int uart_proc_show(struct seq_file *m, void *v)
 }
 #endif
 
+static inline bool uart_console_enabled(struct uart_port *port)
+{
+	return uart_console(port) && (port->cons->flags & CON_ENABLED);
+}
+
+/*
+ * Ensure that the serial console lock is initialised early.
+ * If this port is a console, then the spinlock is already initialised.
+ */
+static inline void uart_port_spin_lock_init(struct uart_port *port)
+{
+	if (uart_console(port))
+		return;
+
+	spin_lock_init(&port->lock);
+	lockdep_set_class(&port->lock, &port_lock_key);
+}
+
 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
 /**
  *	uart_console_write - write a console message to a serial port
@@ -2060,16 +2081,7 @@ uart_set_options(struct uart_port *port, struct console *co,
 	struct ktermios termios;
 	static struct ktermios dummy;
 
-	/*
-	 * Ensure that the serial console lock is initialised
-	 * early.
-	 * If this port is a console, then the spinlock is already
-	 * initialised.
-	 */
-	if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
-		spin_lock_init(&port->lock);
-		lockdep_set_class(&port->lock, &port_lock_key);
-	}
+	uart_port_spin_lock_init(port);
 
 	memset(&termios, 0, sizeof(struct ktermios));
 
@@ -2605,7 +2617,7 @@ struct tty_driver *uart_console_device(struct console *co, int *index)
 }
 EXPORT_SYMBOL_GPL(uart_console_device);
 
-static ssize_t uart_get_attr_uartclk(struct device *dev,
+static ssize_t uartclk_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2615,7 +2627,7 @@ static ssize_t uart_get_attr_uartclk(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
 }
 
-static ssize_t uart_get_attr_type(struct device *dev,
+static ssize_t type_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2624,7 +2636,8 @@ static ssize_t uart_get_attr_type(struct device *dev,
 	uart_get_info(port, &tmp);
 	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
 }
-static ssize_t uart_get_attr_line(struct device *dev,
+
+static ssize_t line_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2634,7 +2647,7 @@ static ssize_t uart_get_attr_line(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
 }
 
-static ssize_t uart_get_attr_port(struct device *dev,
+static ssize_t port_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2648,7 +2661,7 @@ static ssize_t uart_get_attr_port(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
 }
 
-static ssize_t uart_get_attr_irq(struct device *dev,
+static ssize_t irq_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2658,7 +2671,7 @@ static ssize_t uart_get_attr_irq(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
 }
 
-static ssize_t uart_get_attr_flags(struct device *dev,
+static ssize_t flags_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2668,7 +2681,7 @@ static ssize_t uart_get_attr_flags(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
 }
 
-static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
+static ssize_t xmit_fifo_size_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2678,8 +2691,7 @@ static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
 }
 
-
-static ssize_t uart_get_attr_close_delay(struct device *dev,
+static ssize_t close_delay_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2689,8 +2701,7 @@ static ssize_t uart_get_attr_close_delay(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
 }
 
-
-static ssize_t uart_get_attr_closing_wait(struct device *dev,
+static ssize_t closing_wait_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2700,7 +2711,7 @@ static ssize_t uart_get_attr_closing_wait(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
 }
 
-static ssize_t uart_get_attr_custom_divisor(struct device *dev,
+static ssize_t custom_divisor_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2710,7 +2721,7 @@ static ssize_t uart_get_attr_custom_divisor(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
 }
 
-static ssize_t uart_get_attr_io_type(struct device *dev,
+static ssize_t io_type_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2720,7 +2731,7 @@ static ssize_t uart_get_attr_io_type(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
 }
 
-static ssize_t uart_get_attr_iomem_base(struct device *dev,
+static ssize_t iomem_base_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2730,7 +2741,7 @@ static ssize_t uart_get_attr_iomem_base(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
 }
 
-static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
+static ssize_t iomem_reg_shift_show(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
 	struct serial_struct tmp;
@@ -2740,40 +2751,92 @@ static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
 }
 
-static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
-static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
-static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
-static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
-static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
-static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
-static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
-static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
-static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
-static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
-static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
-static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
-static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
+static ssize_t console_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct tty_port *port = dev_get_drvdata(dev);
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport;
+	bool console = false;
+
+	mutex_lock(&port->mutex);
+	uport = uart_port_check(state);
+	if (uport)
+		console = uart_console_enabled(uport);
+	mutex_unlock(&port->mutex);
+
+	return sprintf(buf, "%c\n", console ? 'Y' : 'N');
+}
+
+static ssize_t console_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct tty_port *port = dev_get_drvdata(dev);
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport;
+	bool oldconsole, newconsole;
+	int ret;
+
+	ret = kstrtobool(buf, &newconsole);
+	if (ret)
+		return ret;
+
+	mutex_lock(&port->mutex);
+	uport = uart_port_check(state);
+	if (uport) {
+		oldconsole = uart_console_enabled(uport);
+		if (oldconsole && !newconsole) {
+			ret = unregister_console(uport->cons);
+		} else if (!oldconsole && newconsole) {
+			if (uart_console(uport))
+				register_console(uport->cons);
+			else
+				ret = -ENOENT;
+		}
+	} else {
+		ret = -ENXIO;
+	}
+	mutex_unlock(&port->mutex);
+
+	return ret < 0 ? ret : count;
+}
+
+static DEVICE_ATTR_RO(uartclk);
+static DEVICE_ATTR_RO(type);
+static DEVICE_ATTR_RO(line);
+static DEVICE_ATTR_RO(port);
+static DEVICE_ATTR_RO(irq);
+static DEVICE_ATTR_RO(flags);
+static DEVICE_ATTR_RO(xmit_fifo_size);
+static DEVICE_ATTR_RO(close_delay);
+static DEVICE_ATTR_RO(closing_wait);
+static DEVICE_ATTR_RO(custom_divisor);
+static DEVICE_ATTR_RO(io_type);
+static DEVICE_ATTR_RO(iomem_base);
+static DEVICE_ATTR_RO(iomem_reg_shift);
+static DEVICE_ATTR_RW(console);
 
 static struct attribute *tty_dev_attrs[] = {
+	&dev_attr_uartclk.attr,
 	&dev_attr_type.attr,
 	&dev_attr_line.attr,
 	&dev_attr_port.attr,
 	&dev_attr_irq.attr,
 	&dev_attr_flags.attr,
 	&dev_attr_xmit_fifo_size.attr,
-	&dev_attr_uartclk.attr,
 	&dev_attr_close_delay.attr,
 	&dev_attr_closing_wait.attr,
 	&dev_attr_custom_divisor.attr,
 	&dev_attr_io_type.attr,
 	&dev_attr_iomem_base.attr,
 	&dev_attr_iomem_reg_shift.attr,
-	NULL,
-	};
+	&dev_attr_console.attr,
+	NULL
+};
 
 static const struct attribute_group tty_dev_attr_group = {
 	.attrs = tty_dev_attrs,
-	};
+};
 
 /**
  *	uart_add_one_port - attach a driver-defined port structure
@@ -2824,14 +2887,8 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
 		goto out;
 	}
 
-	/*
-	 * If this port is a console, then the spinlock is already
-	 * initialised.
-	 */
-	if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
-		spin_lock_init(&uport->lock);
-		lockdep_set_class(&uport->lock, &port_lock_key);
-	}
+	uart_port_spin_lock_init(uport);
+
 	if (uport->cons && uport->dev)
 		of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
 
@@ -3082,6 +3139,60 @@ void uart_insert_char(struct uart_port *port, unsigned int status,
 }
 EXPORT_SYMBOL_GPL(uart_insert_char);
 
+#ifdef CONFIG_MAGIC_SYSRQ_SERIAL
+static const char sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE;
+
+static void uart_sysrq_on(struct work_struct *w)
+{
+	int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
+
+	sysrq_toggle_support(1);
+	pr_info("SysRq is enabled by magic sequence '%*pE' on serial\n",
+		sysrq_toggle_seq_len, sysrq_toggle_seq);
+}
+static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on);
+
+/**
+ *	uart_try_toggle_sysrq - Enables SysRq from serial line
+ *	@port: uart_port structure where char(s) after BREAK met
+ *	@ch: new character in the sequence after received BREAK
+ *
+ *	Enables magic SysRq when the required sequence is met on port
+ *	(see CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE).
+ *
+ *	Returns false if @ch is out of enabling sequence and should be
+ *	handled some other way, true if @ch was consumed.
+ */
+static bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch)
+{
+	int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq);
+
+	if (!sysrq_toggle_seq_len)
+		return false;
+
+	BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX);
+	if (sysrq_toggle_seq[port->sysrq_seq] != ch) {
+		port->sysrq_seq = 0;
+		return false;
+	}
+
+	if (++port->sysrq_seq < sysrq_toggle_seq_len) {
+		port->sysrq = jiffies + SYSRQ_TIMEOUT;
+		return true;
+	}
+
+	schedule_work(&sysrq_enable_work);
+
+	port->sysrq = 0;
+	return true;
+}
+#else
+static inline bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch)
+{
+	return false;
+}
+#endif
+
 int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 {
 	if (!IS_ENABLED(CONFIG_MAGIC_SYSRQ_SERIAL))
@@ -3091,9 +3202,13 @@ int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 		return 0;
 
 	if (ch && time_before(jiffies, port->sysrq)) {
-		handle_sysrq(ch);
-		port->sysrq = 0;
-		return 1;
+		if (sysrq_mask()) {
+			handle_sysrq(ch);
+			port->sysrq = 0;
+			return 1;
+		}
+		if (uart_try_toggle_sysrq(port, ch))
+			return 1;
 	}
 	port->sysrq = 0;
 
@@ -3110,9 +3225,13 @@ int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
 		return 0;
 
 	if (ch && time_before(jiffies, port->sysrq)) {
-		port->sysrq_ch = ch;
-		port->sysrq = 0;
-		return 1;
+		if (sysrq_mask()) {
+			port->sysrq_ch = ch;
+			port->sysrq = 0;
+			return 1;
+		}
+		if (uart_try_toggle_sysrq(port, ch))
+			return 1;
 	}
 	port->sysrq = 0;
 
@@ -3120,22 +3239,19 @@ int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
 }
 EXPORT_SYMBOL_GPL(uart_prepare_sysrq_char);
 
-void uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
+void uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long flags)
+__releases(&port->lock)
 {
-	int sysrq_ch;
+	if (port->has_sysrq) {
+		int sysrq_ch = port->sysrq_ch;
 
-	if (!port->has_sysrq) {
-		spin_unlock_irqrestore(&port->lock, irqflags);
-		return;
+		port->sysrq_ch = 0;
+		spin_unlock_irqrestore(&port->lock, flags);
+		if (sysrq_ch)
+			handle_sysrq(sysrq_ch);
+	} else {
+		spin_unlock_irqrestore(&port->lock, flags);
 	}
-
-	sysrq_ch = port->sysrq_ch;
-	port->sysrq_ch = 0;
-
-	spin_unlock_irqrestore(&port->lock, irqflags);
-
-	if (sysrq_ch)
-		handle_sysrq(sysrq_ch);
 }
 EXPORT_SYMBOL_GPL(uart_unlock_and_check_sysrq);
 
@@ -3149,14 +3265,12 @@ int uart_handle_break(struct uart_port *port)
 	if (port->handle_break)
 		port->handle_break(port);
 
-	if (port->has_sysrq) {
-		if (port->cons && port->cons->index == port->line) {
-			if (!port->sysrq) {
-				port->sysrq = jiffies + HZ*5;
-				return 1;
-			}
-			port->sysrq = 0;
+	if (port->has_sysrq && uart_console(port)) {
+		if (!port->sysrq) {
+			port->sysrq = jiffies + SYSRQ_TIMEOUT;
+			return 1;
 		}
+		port->sysrq = 0;
 	}
 
 	if (port->flags & UPF_SAK)

drivers/tty/serial/serial_mctrl_gpio.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Helpers for controlling modem lines via GPIO
  *

drivers/tty/serial/sifive.c

@@ -618,10 +618,10 @@ static void sifive_serial_shutdown(struct uart_port *port)
  *
  * On the V0 SoC, the UART IP block is derived from the CPU clock source
  * after a synchronous divide-by-two divider, so any CPU clock rate change
- * requires the UART baud rate to be updated.  This presumably could corrupt any
- * serial word currently being transmitted or received.  It would probably
- * be better to stop receives and transmits, then complete the baud rate
- * change, then re-enable them.
+ * requires the UART baud rate to be updated.  This presumably corrupts any
+ * serial word currently being transmitted or received.  In order to avoid
+ * corrupting the output data stream, we drain the transmit queue before
+ * allowing the clock's rate to be changed.
  */
 static int sifive_serial_clk_notifier(struct notifier_block *nb,
 				      unsigned long event, void *data)
@@ -629,6 +629,26 @@ static int sifive_serial_clk_notifier(struct notifier_block *nb,
 	struct clk_notifier_data *cnd = data;
 	struct sifive_serial_port *ssp = notifier_to_sifive_serial_port(nb);
 
+	if (event == PRE_RATE_CHANGE) {
+		/*
+		 * The TX watermark is always set to 1 by this driver, which
+		 * means that the TX busy bit will lower when there are 0 bytes
+		 * left in the TX queue -- in other words, when the TX FIFO is
+		 * empty.
+		 */
+		__ssp_wait_for_xmitr(ssp);
+		/*
+		 * On the cycle the TX FIFO goes empty there is still a full
+		 * UART frame left to be transmitted in the shift register.
+		 * The UART provides no way for software to directly determine
+		 * when that last frame has been transmitted, so we just sleep
+		 * here instead.  As we're not tracking the number of stop bits
+		 * they're just worst cased here.  The rest of the serial
+		 * framing parameters aren't configurable by software.
+		 */
+		udelay(DIV_ROUND_UP(12 * 1000 * 1000, ssp->baud_rate));
+	}
+
 	if (event == POST_RATE_CHANGE && ssp->clkin_rate != cnd->new_rate) {
 		ssp->clkin_rate = cnd->new_rate;
 		__ssp_update_div(ssp);
@@ -709,6 +729,29 @@ static const char *sifive_serial_type(struct uart_port *port)
 	return port->type == PORT_SIFIVE_V0 ? "SiFive UART v0" : NULL;
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+static int sifive_serial_poll_get_char(struct uart_port *port)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+	char is_empty, ch;
+
+	ch = __ssp_receive_char(ssp, &is_empty);
+	if (is_empty)
+		return NO_POLL_CHAR;
+
+	return ch;
+}
+
+static void sifive_serial_poll_put_char(struct uart_port *port,
+					unsigned char c)
+{
+	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
+
+	__ssp_wait_for_xmitr(ssp);
+	__ssp_transmit_char(ssp, c);
+}
+#endif /* CONFIG_CONSOLE_POLL */
+
 /*
  * Early console support
  */
@@ -877,6 +920,10 @@ static const struct uart_ops sifive_serial_uops = {
 	.request_port	= sifive_serial_request_port,
 	.config_port	= sifive_serial_config_port,
 	.verify_port	= sifive_serial_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= sifive_serial_poll_get_char,
+	.poll_put_char	= sifive_serial_poll_put_char,
+#endif
 };
 
 static struct uart_driver sifive_serial_uart_driver = {

drivers/tty/serial/sirfsoc_uart.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Drivers for CSR SiRFprimaII onboard UARTs.
  *

drivers/tty/serial/sprd_serial.c

@@ -1013,7 +1013,7 @@ static void sprd_console_write(struct console *co, const char *s,
 		spin_unlock_irqrestore(&port->lock, flags);
 }
 
-static int __init sprd_console_setup(struct console *co, char *options)
+static int sprd_console_setup(struct console *co, char *options)
 {
 	struct sprd_uart_port *sprd_uart_port;
 	int baud = 115200;
@@ -1102,29 +1102,6 @@ static struct uart_driver sprd_uart_driver = {
 	.cons = SPRD_CONSOLE,
 };
 
-static int sprd_probe_dt_alias(int index, struct device *dev)
-{
-	struct device_node *np;
-	int ret = index;
-
-	if (!IS_ENABLED(CONFIG_OF))
-		return ret;
-
-	np = dev->of_node;
-	if (!np)
-		return ret;
-
-	ret = of_alias_get_id(np, "serial");
-	if (ret < 0)
-		ret = index;
-	else if (ret >= ARRAY_SIZE(sprd_port) || sprd_port[ret] != NULL) {
-		dev_warn(dev, "requested serial port %d not available.\n", ret);
-		ret = index;
-	}
-
-	return ret;
-}
-
 static int sprd_remove(struct platform_device *dev)
 {
 	struct sprd_uart_port *sup = platform_get_drvdata(dev);
@@ -1132,14 +1109,13 @@ static int sprd_remove(struct platform_device *dev)
 	if (sup) {
 		uart_remove_one_port(&sprd_uart_driver, &sup->port);
 		sprd_port[sup->port.line] = NULL;
+		sprd_rx_free_buf(sup);
 		sprd_ports_num--;
 	}
 
 	if (!sprd_ports_num)
 		uart_unregister_driver(&sprd_uart_driver);
 
-	sprd_rx_free_buf(sup);
-
 	return 0;
 }
 
@@ -1147,7 +1123,8 @@ static bool sprd_uart_is_console(struct uart_port *uport)
 {
 	struct console *cons = sprd_uart_driver.cons;
 
-	if (cons && cons->index >= 0 && cons->index == uport->line)
+	if ((cons && cons->index >= 0 && cons->index == uport->line) ||
+	    of_console_check(uport->dev->of_node, SPRD_TTY_NAME, uport->line))
 		return true;
 
 	return false;
@@ -1203,14 +1180,11 @@ static int sprd_probe(struct platform_device *pdev)
 	int index;
 	int ret;
 
-	for (index = 0; index < ARRAY_SIZE(sprd_port); index++)
-		if (sprd_port[index] == NULL)
-			break;
-
-	if (index == ARRAY_SIZE(sprd_port))
-		return -EBUSY;
-
-	index = sprd_probe_dt_alias(index, &pdev->dev);
+	index = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (index < 0 || index >= ARRAY_SIZE(sprd_port)) {
+		dev_err(&pdev->dev, "got a wrong serial alias id %d\n", index);
+		return -EINVAL;
+	}
 
 	sprd_port[index] = devm_kzalloc(&pdev->dev, sizeof(*sprd_port[index]),
 					GFP_KERNEL);
@@ -1262,10 +1236,8 @@ static int sprd_probe(struct platform_device *pdev)
 	sprd_ports_num++;
 
 	ret = uart_add_one_port(&sprd_uart_driver, up);
-	if (ret) {
-		sprd_port[index] = NULL;
+	if (ret)
 		sprd_remove(pdev);
-	}
 
 	platform_set_drvdata(pdev, up);
 

drivers/tty/serial/stm32-usart.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (C) Maxime Coquelin 2015
  * Copyright (C) STMicroelectronics SA 2017

drivers/tty/serial/timbuart.h

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * timbuart.c timberdale FPGA GPIO driver
  * Copyright (c) 2009 Intel Corporation

drivers/tty/serial/xilinx_uartps.c

@@ -650,8 +650,8 @@ static unsigned int cdns_uart_tx_empty(struct uart_port *port)
 	unsigned int status;
 
 	status = readl(port->membase + CDNS_UART_SR) &
-				CDNS_UART_SR_TXEMPTY;
-	return status ? TIOCSER_TEMT : 0;
+		       (CDNS_UART_SR_TXEMPTY | CDNS_UART_SR_TACTIVE);
+	return (status == CDNS_UART_SR_TXEMPTY) ? TIOCSER_TEMT : 0;
 }
 
 /**
@@ -693,20 +693,8 @@ static void cdns_uart_set_termios(struct uart_port *port,
 	u32 cval = 0;
 	unsigned int baud, minbaud, maxbaud;
 	unsigned long flags;
-	unsigned int ctrl_reg, mode_reg, val;
-	int err;
+	unsigned int ctrl_reg, mode_reg;
 
-	/* Wait for the transmit FIFO to empty before making changes */
-	if (!(readl(port->membase + CDNS_UART_CR) &
-				CDNS_UART_CR_TX_DIS)) {
-		err = readl_poll_timeout(port->membase + CDNS_UART_SR,
-					 val, (val & CDNS_UART_SR_TXEMPTY),
-					 1000, TX_TIMEOUT);
-		if (err) {
-			dev_err(port->dev, "timed out waiting for tx empty");
-			return;
-		}
-	}
 	spin_lock_irqsave(&port->lock, flags);
 
 	/* Disable the TX and RX to set baud rate */