Merge branch 'i2c/for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang: - if a host can be a client, too, the I2C core can now use it to emulate SMBus HostNotify support (STM32 and R-Car added this so far) - also for client mode, a testunit has been added. It can create rare situations on the bus, so host controllers can be tested - a binding has been added to mark the bus as "single-master". This allows for better timeout detections - new driver for Mellanox Bluefield - massive refactoring of the Tegra driver - EEPROMs recognized by the at24 driver can now have custom names - rest is driver updates * 'i2c/for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (80 commits) Documentation: i2c: add testunit docs to index i2c: tegra: Improve driver module description i2c: tegra: Clean up whitespaces, newlines and indentation i2c: tegra: Clean up and improve comments i2c: tegra: Clean up printk messages i2c: tegra: Clean up variable names i2c: tegra: Improve formatting of variables i2c: tegra: Check errors for both positive and negative values i2c: tegra: Factor out hardware initialization into separate function i2c: tegra: Factor out register polling into separate function i2c: tegra: Factor out packet header setup from tegra_i2c_xfer_msg() i2c: tegra: Factor out error recovery from tegra_i2c_xfer_msg() i2c: tegra: Rename wait/poll functions i2c: tegra: Remove "dma" variable from tegra_i2c_xfer_msg() i2c: tegra: Remove redundant check in tegra_i2c_issue_bus_clear() i2c: tegra: Remove likely/unlikely from the code i2c: tegra: Remove outdated barrier() i2c: tegra: Clean up variable types i2c: tegra: Reorder location of functions in the code i2c: tegra: Clean up probe function ...
2020-10-21 10:54:05 -07:00
parent ed7cfefe44 40daf09a30
commit b5df4b5c28
41 changed files with 4020 additions and 931 deletions
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -101,7 +101,6 @@ source "drivers/i2c/busses/Kconfig"
 config I2C_STUB
 	tristate "I2C/SMBus Test Stub"
 	depends on m
-	default 'n'
 	help
 	  This module may be useful to developers of SMBus client drivers,
 	  especially for certain kinds of sensor chips.
@@ -126,6 +125,14 @@ config I2C_SLAVE_EEPROM
 	  This backend makes Linux behave like an I2C EEPROM. Please read
 	  Documentation/i2c/slave-eeprom-backend.rst for further details.

+config I2C_SLAVE_TESTUNIT
+	tristate "I2C eeprom testunit driver"
+	help
+	  This backend can be used to trigger test cases for I2C bus masters
+	  which require a remote device with certain capabilities, e.g.
+	  multi-master, SMBus Host Notify, etc. Please read
+	  Documentation/i2c/slave-testunit-backend.rst for further details.
+
 endif

 config I2C_DEBUG_CORE
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -16,5 +16,6 @@ obj-$(CONFIG_I2C_MUX)		+= i2c-mux.o
 obj-y				+= algos/ busses/ muxes/
 obj-$(CONFIG_I2C_STUB)		+= i2c-stub.o
 obj-$(CONFIG_I2C_SLAVE_EEPROM)	+= i2c-slave-eeprom.o
+obj-$(CONFIG_I2C_SLAVE_TESTUNIT)	+= i2c-slave-testunit.o

 ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -147,6 +147,7 @@ config I2C_I801
 	    Tiger Lake (PCH)
 	    Jasper Lake (SOC)
 	    Emmitsburg (PCH)
+	    Alder Lake (PCH)

 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-i801.
@@ -730,6 +731,19 @@ config I2C_LPC2K
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-lpc2k.

+config I2C_MLXBF
+        tristate "Mellanox BlueField I2C controller"
+        depends on ARM64
+        help
+          Enabling this option will add I2C SMBus support for Mellanox BlueField
+          system.
+
+          This driver can also be built as a module. If so, the module will be
+          called i2c-mlxbf.
+
+          This driver implements an I2C SMBus host controller and enables both
+          master and slave functions.
+
 config I2C_MESON
 	tristate "Amlogic Meson I2C controller"
 	depends on ARCH_MESON || COMPILE_TEST
@@ -840,7 +854,6 @@ config I2C_PASEMI
 config I2C_PCA_PLATFORM
 	tristate "PCA9564/PCA9665 as platform device"
 	select I2C_ALGOPCA
-	default n
 	help
 	  This driver supports a memory mapped Philips PCA9564/PCA9665
 	  parallel bus to I2C bus controller.
@@ -1026,6 +1039,7 @@ config I2C_STM32F7
 	tristate "STMicroelectronics STM32F7 I2C support"
 	depends on ARCH_STM32 || COMPILE_TEST
 	select I2C_SLAVE
+	select I2C_SMBUS
 	help
 	  Enable this option to add support for STM32 I2C controller embedded
 	  in STM32F7 SoCs.
@@ -1181,6 +1195,8 @@ config I2C_RCAR
 	tristate "Renesas R-Car I2C Controller"
 	depends on ARCH_RENESAS || COMPILE_TEST
 	select I2C_SLAVE
+	select I2C_SMBUS
+	select RESET_CONTROLLER if ARCH_RCAR_GEN3
 	help
 	  If you say yes to this option, support will be included for the
 	  R-Car I2C controller.
@@ -1240,7 +1256,6 @@ config I2C_TAOS_EVM
 	depends on TTY
 	select SERIO
 	select SERIO_SERPORT
-	default n
 	help
 	  This supports TAOS evaluation modules on serial port. In order to
 	  use this driver, you will need the inputattach tool, which is part
@@ -1324,7 +1339,6 @@ config I2C_PCA_ISA
 	tristate "PCA9564/PCA9665 on an ISA bus"
 	depends on ISA
 	select I2C_ALGOPCA
-	default n
 	help
 	  This driver supports ISA boards using the Philips PCA9564/PCA9665
 	  parallel bus to I2C bus controller.
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -140,6 +140,7 @@ obj-$(CONFIG_I2C_BRCMSTB)	+= i2c-brcmstb.o
 obj-$(CONFIG_I2C_CROS_EC_TUNNEL)	+= i2c-cros-ec-tunnel.o
 obj-$(CONFIG_I2C_ELEKTOR)	+= i2c-elektor.o
 obj-$(CONFIG_I2C_ICY)		+= i2c-icy.o
+obj-$(CONFIG_I2C_MLXBF)		+= i2c-mlxbf.o
 obj-$(CONFIG_I2C_MLXCPLD)	+= i2c-mlxcpld.o
 obj-$(CONFIG_I2C_OPAL)		+= i2c-opal.o
 obj-$(CONFIG_I2C_PCA_ISA)	+= i2c-pca-isa.o
--- a/drivers/i2c/busses/i2c-amd-mp2-plat.c
+++ b/drivers/i2c/busses/i2c-amd-mp2-plat.c
@@ -155,7 +155,7 @@ static int i2c_amd_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 	struct amd_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
 	int i;
 	struct i2c_msg *pmsg;
-	int err;
+	int err = 0;

 	/* the adapter might have been deleted while waiting for the bus lock */
 	if (unlikely(!i2c_dev->common.mp2_dev))
--- a/drivers/i2c/busses/i2c-bcm2835.c
+++ b/drivers/i2c/busses/i2c-bcm2835.c
@@ -421,11 +421,9 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
 		return PTR_ERR(i2c_dev->regs);

 	mclk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(mclk)) {
-		if (PTR_ERR(mclk) != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "Could not get clock\n");
-		return PTR_ERR(mclk);
-	}
+	if (IS_ERR(mclk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(mclk),
+				     "Could not get clock\n");

 	i2c_dev->bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev);

--- a/drivers/i2c/busses/i2c-efm32.c
+++ b/drivers/i2c/busses/i2c-efm32.c
@@ -332,21 +332,15 @@ static int efm32_i2c_probe(struct platform_device *pdev)
 		return ret;
 	}

-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(&pdev->dev, "failed to determine base address\n");
-		return -ENODEV;
-	}
+	ddata->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(ddata->base))
+		return PTR_ERR(ddata->base);

 	if (resource_size(res) < 0x42) {
 		dev_err(&pdev->dev, "memory resource too small\n");
 		return -EINVAL;
 	}

-	ddata->base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(ddata->base))
-		return PTR_ERR(ddata->base);
-
 	ret = platform_get_irq(pdev, 0);
 	if (ret <= 0) {
 		if (!ret)
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -71,6 +71,7 @@
 * Tiger Lake-H (PCH)		0x43a3	32	hard	yes	yes	yes
 * Jasper Lake (SOC)		0x4da3	32	hard	yes	yes	yes
 * Comet Lake-V (PCH)		0xa3a3	32	hard	yes	yes	yes
+ * Alder Lake-S (PCH)		0x7aa3	32	hard	yes	yes	yes
 *
 * Features supported by this driver:
 * Software PEC				no
@@ -228,6 +229,7 @@
 #define PCI_DEVICE_ID_INTEL_ELKHART_LAKE_SMBUS		0x4b23
 #define PCI_DEVICE_ID_INTEL_JASPER_LAKE_SMBUS		0x4da3
 #define PCI_DEVICE_ID_INTEL_BROXTON_SMBUS		0x5ad4
+#define PCI_DEVICE_ID_INTEL_ALDER_LAKE_S_SMBUS		0x7aa3
 #define PCI_DEVICE_ID_INTEL_LYNXPOINT_SMBUS		0x8c22
 #define PCI_DEVICE_ID_INTEL_WILDCATPOINT_SMBUS		0x8ca2
 #define PCI_DEVICE_ID_INTEL_WELLSBURG_SMBUS		0x8d22
@@ -1081,6 +1083,7 @@ static const struct pci_device_id i801_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_TIGERLAKE_LP_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_TIGERLAKE_H_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_JASPER_LAKE_SMBUS) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ALDER_LAKE_S_SMBUS) },
 	{ 0, }
 };

@@ -1274,6 +1277,7 @@ static const struct {
 	/*
 	 * Additional individual entries were added after verification.
 	 */
+	{ "Latitude 5480",      0x29 },
 	{ "Vostro V131",        0x1d },
 };

@@ -1767,6 +1771,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	case PCI_DEVICE_ID_INTEL_TIGERLAKE_H_SMBUS:
 	case PCI_DEVICE_ID_INTEL_JASPER_LAKE_SMBUS:
 	case PCI_DEVICE_ID_INTEL_EBG_SMBUS:
+	case PCI_DEVICE_ID_INTEL_ALDER_LAKE_S_SMBUS:
 		priv->features |= FEATURE_BLOCK_PROC;
 		priv->features |= FEATURE_I2C_BLOCK_READ;
 		priv->features |= FEATURE_IRQ;
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -1159,11 +1159,9 @@ static int i2c_imx_probe(struct platform_device *pdev)

 	/* Get I2C clock */
 	i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(i2c_imx->clk)) {
-		if (PTR_ERR(i2c_imx->clk) != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "can't get I2C clock\n");
-		return PTR_ERR(i2c_imx->clk);
-	}
+	if (IS_ERR(i2c_imx->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(i2c_imx->clk),
+				     "can't get I2C clock\n");

 	ret = clk_prepare_enable(i2c_imx->clk);
 	if (ret) {
@@ -1171,14 +1169,6 @@ static int i2c_imx_probe(struct platform_device *pdev)
 		return ret;
 	}

-	/* Request IRQ */
-	ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, IRQF_SHARED,
-				pdev->name, i2c_imx);
-	if (ret) {
-		dev_err(&pdev->dev, "can't claim irq %d\n", irq);
-		goto clk_disable;
-	}
-
 	/* Init queue */
 	init_waitqueue_head(&i2c_imx->queue);

@@ -1197,6 +1187,14 @@ static int i2c_imx_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto rpm_disable;

+	/* Request IRQ */
+	ret = request_threaded_irq(irq, i2c_imx_isr, NULL, IRQF_SHARED,
+				   pdev->name, i2c_imx);
+	if (ret) {
+		dev_err(&pdev->dev, "can't claim irq %d\n", irq);
+		goto rpm_disable;
+	}
+
 	/* Set up clock divider */
 	i2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ;
 	ret = of_property_read_u32(pdev->dev.of_node,
@@ -1239,13 +1237,12 @@ static int i2c_imx_probe(struct platform_device *pdev)

 clk_notifier_unregister:
 	clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
+	free_irq(irq, i2c_imx);
 rpm_disable:
 	pm_runtime_put_noidle(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
-
-clk_disable:
 	clk_disable_unprepare(i2c_imx->clk);
 	return ret;
 }
@@ -1253,7 +1250,7 @@ clk_disable:
 static int i2c_imx_remove(struct platform_device *pdev)
 {
 	struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
-	int ret;
+	int irq, ret;

 	ret = pm_runtime_get_sync(&pdev->dev);
 	if (ret < 0)
@@ -1273,6 +1270,9 @@ static int i2c_imx_remove(struct platform_device *pdev)
 	imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);

 	clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
+	irq = platform_get_irq(pdev, 0);
+	if (irq >= 0)
+		free_irq(irq, i2c_imx);
 	clk_disable_unprepare(i2c_imx->clk);

 	pm_runtime_put_noidle(&pdev->dev);
--- a/drivers/i2c/busses/i2c-ismt.c
+++ b/drivers/i2c/busses/i2c-ismt.c
@@ -77,6 +77,7 @@
 #define PCI_DEVICE_ID_INTEL_S1200_SMT1	0x0c5a
 #define PCI_DEVICE_ID_INTEL_CDF_SMT	0x18ac
 #define PCI_DEVICE_ID_INTEL_DNV_SMT	0x19ac
+#define PCI_DEVICE_ID_INTEL_EBG_SMT	0x1bff
 #define PCI_DEVICE_ID_INTEL_AVOTON_SMT	0x1f15

 #define ISMT_DESC_ENTRIES	2	/* number of descriptor entries */
@@ -176,14 +177,12 @@ struct ismt_priv {
 	u8 buffer[I2C_SMBUS_BLOCK_MAX + 16];	/* temp R/W data buffer */
 };

-/**
- * ismt_ids - PCI device IDs supported by this driver
- */
 static const struct pci_device_id ismt_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT0) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT1) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CDF_SMT) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_DNV_SMT) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_EBG_SMT) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_AVOTON_SMT) },
 	{ 0, }
 };
@@ -197,6 +196,8 @@ MODULE_PARM_DESC(bus_speed, "Bus Speed in kHz (0 = BIOS default)");

 /**
 * __ismt_desc_dump() - dump the contents of a specific descriptor
+ * @dev: the iSMT device
+ * @desc: the iSMT hardware descriptor
 */
 static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
 {
@@ -628,11 +629,6 @@ static u32 ismt_func(struct i2c_adapter *adap)
 	       I2C_FUNC_SMBUS_PEC;
 }

-/**
- * smbus_algorithm - the adapter algorithm and supported functionality
- * @smbus_xfer: the adapter algorithm
- * @functionality: functionality supported by the adapter
- */
 static const struct i2c_algorithm smbus_algorithm = {
 	.smbus_xfer	= ismt_access,
 	.functionality	= ismt_func,
--- a/drivers/i2c/busses/i2c-jz4780.c
+++ b/drivers/i2c/busses/i2c-jz4780.c
@@ -752,6 +752,7 @@ static const struct ingenic_i2c_config x1000_i2c_config = {
 };

 static const struct of_device_id jz4780_i2c_of_matches[] = {
+	{ .compatible = "ingenic,jz4770-i2c", .data = &jz4780_i2c_config },
 	{ .compatible = "ingenic,jz4780-i2c", .data = &jz4780_i2c_config },
 	{ .compatible = "ingenic,x1000-i2c", .data = &x1000_i2c_config },
 	{ /* sentinel */ }
@@ -856,7 +857,7 @@ static struct platform_driver jz4780_i2c_driver = {
 	.remove		= jz4780_i2c_remove,
 	.driver		= {
 		.name	= "jz4780-i2c",
-		.of_match_table = of_match_ptr(jz4780_i2c_of_matches),
+		.of_match_table = jz4780_i2c_of_matches,
 	},
 };

--- a/drivers/i2c/busses/i2c-mlxbf.c
+++ b/drivers/i2c/busses/i2c-mlxbf.c
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -496,11 +496,10 @@ static irqreturn_t
 mv64xxx_i2c_intr(int irq, void *dev_id)
 {
 	struct mv64xxx_i2c_data	*drv_data = dev_id;
-	unsigned long	flags;
 	u32		status;
 	irqreturn_t	rc = IRQ_NONE;

-	spin_lock_irqsave(&drv_data->lock, flags);
+	spin_lock(&drv_data->lock);

 	if (drv_data->offload_enabled)
 		rc = mv64xxx_i2c_intr_offload(drv_data);
@@ -517,7 +516,7 @@ mv64xxx_i2c_intr(int irq, void *dev_id)

 		rc = IRQ_HANDLED;
 	}
-	spin_unlock_irqrestore(&drv_data->lock, flags);
+	spin_unlock(&drv_data->lock);

 	return rc;
 }
--- a/drivers/i2c/busses/i2c-nvidia-gpu.c
+++ b/drivers/i2c/busses/i2c-nvidia-gpu.c
@@ -125,8 +125,7 @@ static int gpu_i2c_read(struct gpu_i2c_dev *i2cd, u8 *data, u16 len)
 		put_unaligned_be16(val, data);
 		break;
 	case 3:
-		put_unaligned_be16(val >> 8, data);
-		data[2] = val;
+		put_unaligned_be24(val, data);
 		break;
 	case 4:
 		put_unaligned_be32(val, data);
--- a/drivers/i2c/busses/i2c-owl.c
+++ b/drivers/i2c/busses/i2c-owl.c
@@ -165,10 +165,9 @@ static irqreturn_t owl_i2c_interrupt(int irq, void *_dev)
 {
 	struct owl_i2c_dev *i2c_dev = _dev;
 	struct i2c_msg *msg = i2c_dev->msg;
-	unsigned long flags;
 	unsigned int stat, fifostat;

-	spin_lock_irqsave(&i2c_dev->lock, flags);
+	spin_lock(&i2c_dev->lock);

 	i2c_dev->err = 0;

@@ -214,7 +213,7 @@ stop:
 			   OWL_I2C_STAT_IRQP, true);

 	complete_all(&i2c_dev->msg_complete);
-	spin_unlock_irqrestore(&i2c_dev->lock, flags);
+	spin_unlock(&i2c_dev->lock);

 	return IRQ_HANDLED;
 }
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -210,9 +210,8 @@ static irqreturn_t geni_i2c_irq(int irq, void *dev)
 	u32 dma;
 	u32 val;
 	struct i2c_msg *cur;
-	unsigned long flags;

-	spin_lock_irqsave(&gi2c->lock, flags);
+	spin_lock(&gi2c->lock);
 	m_stat = readl_relaxed(base + SE_GENI_M_IRQ_STATUS);
 	rx_st = readl_relaxed(base + SE_GENI_RX_FIFO_STATUS);
 	dm_tx_st = readl_relaxed(base + SE_DMA_TX_IRQ_STAT);
@@ -294,7 +293,7 @@ static irqreturn_t geni_i2c_irq(int irq, void *dev)
 	    dm_rx_st & RX_DMA_DONE || dm_rx_st & RX_RESET_DONE)
 		complete(&gi2c->done);

-	spin_unlock_irqrestore(&gi2c->lock, flags);
+	spin_unlock(&gi2c->lock);

 	return IRQ_HANDLED;
 }
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -19,7 +19,9 @@
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
@@ -105,10 +107,11 @@
 #define ID_ARBLOST	(1 << 3)
 #define ID_NACK		(1 << 4)
 /* persistent flags */
+#define ID_P_HOST_NOTIFY	BIT(28)
 #define ID_P_REP_AFTER_RD	BIT(29)
 #define ID_P_NO_RXDMA		BIT(30) /* HW forbids RXDMA sometimes */
 #define ID_P_PM_BLOCKED		BIT(31)
-#define ID_P_MASK		GENMASK(31, 29)
+#define ID_P_MASK		GENMASK(31, 28)

 enum rcar_i2c_type {
 	I2C_RCAR_GEN1,
@@ -140,14 +143,13 @@ struct rcar_i2c_priv {

 	struct reset_control *rstc;
 	int irq;
+
+	struct i2c_client *host_notify_client;
 };

 #define rcar_i2c_priv_to_dev(p)		((p)->adap.dev.parent)
 #define rcar_i2c_is_recv(p)		((p)->msg->flags & I2C_M_RD)

-#define LOOP_TIMEOUT	1024
-
-
 static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val)
 {
 	writel(val, priv->io + reg);
@@ -221,18 +223,18 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv)

 static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
 {
-	int i;
+	int ret;
+	u32 val;

-	for (i = 0; i < LOOP_TIMEOUT; i++) {
-		/* make sure that bus is not busy */
-		if (!(rcar_i2c_read(priv, ICMCR) & FSDA))
-			return 0;
-		udelay(1);
+	ret = readl_poll_timeout(priv->io + ICMCR, val, !(val & FSDA), 10,
+				 priv->adap.timeout);
+	if (ret) {
+		/* Waiting did not help, try to recover */
+		priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;
+		ret = i2c_recover_bus(&priv->adap);
 	}

-	/* Waiting did not help, try to recover */
-	priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;
-	return i2c_recover_bus(&priv->adap);
+	return ret;
 }

 static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv)
@@ -760,20 +762,14 @@ static void rcar_i2c_release_dma(struct rcar_i2c_priv *priv)
 /* I2C is a special case, we need to poll the status of a reset */
 static int rcar_i2c_do_reset(struct rcar_i2c_priv *priv)
 {
-	int i, ret;
+	int ret;

 	ret = reset_control_reset(priv->rstc);
 	if (ret)
 		return ret;

-	for (i = 0; i < LOOP_TIMEOUT; i++) {
-		ret = reset_control_status(priv->rstc);
-		if (ret == 0)
-			return 0;
-		udelay(1);
-	}
-
-	return -ETIMEDOUT;
+	return read_poll_timeout_atomic(reset_control_status, ret, ret == 0, 1,
+					100, false, priv->rstc);
 }

 static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
@@ -884,14 +880,21 @@ static int rcar_unreg_slave(struct i2c_client *slave)

 static u32 rcar_i2c_func(struct i2c_adapter *adap)
 {
+	struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+
 	/*
 	 * This HW can't do:
 	 * I2C_SMBUS_QUICK (setting FSB during START didn't work)
 	 * I2C_M_NOSTART (automatically sends address after START)
 	 * I2C_M_IGNORE_NAK (automatically sends STOP after NAK)
 	 */
-	return I2C_FUNC_I2C | I2C_FUNC_SLAVE |
-		(I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+	u32 func = I2C_FUNC_I2C | I2C_FUNC_SLAVE |
+		   (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+
+	if (priv->flags & ID_P_HOST_NOTIFY)
+		func |= I2C_FUNC_SMBUS_HOST_NOTIFY;
+
+	return func;
 }

 static const struct i2c_algorithm rcar_i2c_algo = {
@@ -991,6 +994,8 @@ static int rcar_i2c_probe(struct platform_device *pdev)
 	else
 		pm_runtime_put(dev);

+	if (of_property_read_bool(dev->of_node, "smbus"))
+		priv->flags |= ID_P_HOST_NOTIFY;

 	priv->irq = platform_get_irq(pdev, 0);
 	ret = devm_request_irq(dev, priv->irq, rcar_i2c_irq, 0, dev_name(dev), priv);
@@ -1005,10 +1010,20 @@ static int rcar_i2c_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto out_pm_disable;

+	if (priv->flags & ID_P_HOST_NOTIFY) {
+		priv->host_notify_client = i2c_new_slave_host_notify_device(adap);
+		if (IS_ERR(priv->host_notify_client)) {
+			ret = PTR_ERR(priv->host_notify_client);
+			goto out_del_device;
+		}
+	}
+
 	dev_info(dev, "probed\n");

 	return 0;

+ out_del_device:
+	i2c_del_adapter(&priv->adap);
 out_pm_put:
 	pm_runtime_put(dev);
 out_pm_disable:
@@ -1021,6 +1036,8 @@ static int rcar_i2c_remove(struct platform_device *pdev)
 	struct rcar_i2c_priv *priv = platform_get_drvdata(pdev);
 	struct device *dev = &pdev->dev;

+	if (priv->host_notify_client)
+		i2c_free_slave_host_notify_device(priv->host_notify_client);
 	i2c_del_adapter(&priv->adap);
 	rcar_i2c_release_dma(priv);
 	if (priv->flags & ID_P_PM_BLOCKED)
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -1312,18 +1312,13 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
 		i2c->pclk = devm_clk_get(&pdev->dev, "pclk");
 	}

-	if (IS_ERR(i2c->clk)) {
-		ret = PTR_ERR(i2c->clk);
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "Can't get bus clk: %d\n", ret);
-		return ret;
-	}
-	if (IS_ERR(i2c->pclk)) {
-		ret = PTR_ERR(i2c->pclk);
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "Can't get periph clk: %d\n", ret);
-		return ret;
-	}
+	if (IS_ERR(i2c->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(i2c->clk),
+				     "Can't get bus clk\n");
+
+	if (IS_ERR(i2c->pclk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(i2c->pclk),
+				     "Can't get periph clk\n");

 	ret = clk_prepare(i2c->clk);
 	if (ret < 0) {
--- a/drivers/i2c/busses/i2c-stm32.c
+++ b/drivers/i2c/busses/i2c-stm32.c
@@ -26,8 +26,9 @@ struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
 	dma->chan_tx = dma_request_chan(dev, "tx");
 	if (IS_ERR(dma->chan_tx)) {
 		ret = PTR_ERR(dma->chan_tx);
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "can't request DMA tx channel\n");
+		if (ret != -ENODEV)
+			ret = dev_err_probe(dev, ret,
+					    "can't request DMA tx channel\n");
 		goto fail_al;
 	}

@@ -46,8 +47,9 @@ struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
 	dma->chan_rx = dma_request_chan(dev, "rx");
 	if (IS_ERR(dma->chan_rx)) {
 		ret = PTR_ERR(dma->chan_rx);
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "can't request DMA rx channel\n");
+		if (ret != -ENODEV)
+			ret = dev_err_probe(dev, ret,
+					    "can't request DMA rx channel\n");

 		goto fail_tx;
 	}
@@ -76,8 +78,6 @@ fail_tx:
 	dma_release_channel(dma->chan_tx);
 fail_al:
 	devm_kfree(dev, dma);
-	if (ret != -EPROBE_DEFER)
-		dev_info(dev, "can't use DMA\n");

 	return ERR_PTR(ret);
 }
--- a/drivers/i2c/busses/i2c-stm32f4.c
+++ b/drivers/i2c/busses/i2c-stm32f4.c
@@ -797,10 +797,8 @@ static int stm32f4_i2c_probe(struct platform_device *pdev)

 	rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 	if (IS_ERR(rst)) {
-		ret = PTR_ERR(rst);
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "Error: Missing reset ctrl\n");
-
+		ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
+				    "Error: Missing reset ctrl\n");
 		goto clk_free;
 	}
 	reset_control_assert(rst);
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -18,6 +18,7 @@
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
@@ -50,6 +51,7 @@

 /* STM32F7 I2C control 1 */
 #define STM32F7_I2C_CR1_PECEN			BIT(23)
+#define STM32F7_I2C_CR1_SMBHEN			BIT(20)
 #define STM32F7_I2C_CR1_WUPEN			BIT(18)
 #define STM32F7_I2C_CR1_SBC			BIT(16)
 #define STM32F7_I2C_CR1_RXDMAEN			BIT(15)
@@ -150,7 +152,12 @@

 #define STM32F7_I2C_MAX_LEN			0xff
 #define STM32F7_I2C_DMA_LEN_MIN			0x16
-#define STM32F7_I2C_MAX_SLAVE			0x2
+enum {
+	STM32F7_SLAVE_HOSTNOTIFY,
+	STM32F7_SLAVE_7_10_BITS_ADDR,
+	STM32F7_SLAVE_7_BITS_ADDR,
+	STM32F7_I2C_MAX_SLAVE
+};

 #define STM32F7_I2C_DNF_DEFAULT			0
 #define STM32F7_I2C_DNF_MAX			16
@@ -301,6 +308,8 @@ struct stm32f7_i2c_msg {
 * @fmp_creg: register address for clearing Fast Mode Plus bits
 * @fmp_mask: mask for Fast Mode Plus bits in set register
 * @wakeup_src: boolean to know if the device is a wakeup source
+ * @smbus_mode: states that the controller is configured in SMBus mode
+ * @host_notify_client: SMBus host-notify client
 */
 struct stm32f7_i2c_dev {
 	struct i2c_adapter adap;
@@ -327,6 +336,8 @@ struct stm32f7_i2c_dev {
 	u32 fmp_creg;
 	u32 fmp_mask;
 	bool wakeup_src;
+	bool smbus_mode;
+	struct i2c_client *host_notify_client;
 };

 /*
@@ -1321,11 +1332,20 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
 	int i;

 	/*
-	 * slave[0] supports 7-bit and 10-bit slave address
-	 * slave[1] supports 7-bit slave address only
+	 * slave[STM32F7_SLAVE_HOSTNOTIFY] support only SMBus Host address (0x8)
+	 * slave[STM32F7_SLAVE_7_10_BITS_ADDR] supports 7-bit and 10-bit slave address
+	 * slave[STM32F7_SLAVE_7_BITS_ADDR] supports 7-bit slave address only
 	 */
-	for (i = STM32F7_I2C_MAX_SLAVE - 1; i >= 0; i--) {
-		if (i == 1 && (slave->flags & I2C_CLIENT_TEN))
+	if (i2c_dev->smbus_mode && (slave->addr == 0x08)) {
+		if (i2c_dev->slave[STM32F7_SLAVE_HOSTNOTIFY])
+			goto fail;
+		*id = STM32F7_SLAVE_HOSTNOTIFY;
+		return 0;
+	}
+
+	for (i = STM32F7_I2C_MAX_SLAVE - 1; i > STM32F7_SLAVE_HOSTNOTIFY; i--) {
+		if ((i == STM32F7_SLAVE_7_BITS_ADDR) &&
+		    (slave->flags & I2C_CLIENT_TEN))
 			continue;
 		if (!i2c_dev->slave[i]) {
 			*id = i;
@@ -1333,6 +1353,7 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
 		}
 	}

+fail:
 	dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr);

 	return -EINVAL;
@@ -1776,7 +1797,13 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
 		stm32f7_i2c_enable_wakeup(i2c_dev, true);

-	if (id == 0) {
+	switch (id) {
+	case 0:
+		/* Slave SMBus Host */
+		i2c_dev->slave[id] = slave;
+		break;
+
+	case 1:
 		/* Configure Own Address 1 */
 		oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
 		oar1 &= ~STM32F7_I2C_OAR1_MASK;
@@ -1789,7 +1816,9 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
 		oar1 |= STM32F7_I2C_OAR1_OA1EN;
 		i2c_dev->slave[id] = slave;
 		writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1);
-	} else if (id == 1) {
+		break;
+
+	case 2:
 		/* Configure Own Address 2 */
 		oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
 		oar2 &= ~STM32F7_I2C_OAR2_MASK;
@@ -1802,7 +1831,10 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
 		oar2 |= STM32F7_I2C_OAR2_OA2EN;
 		i2c_dev->slave[id] = slave;
 		writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2);
-	} else {
+		break;
+
+	default:
+		dev_err(dev, "I2C slave id not supported\n");
 		ret = -ENODEV;
 		goto pm_free;
 	}
@@ -1843,10 +1875,10 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
 	if (ret < 0)
 		return ret;

-	if (id == 0) {
+	if (id == 1) {
 		mask = STM32F7_I2C_OAR1_OA1EN;
 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask);
-	} else {
+	} else if (id == 2) {
 		mask = STM32F7_I2C_OAR2_OA2EN;
 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask);
 	}
@@ -1911,14 +1943,51 @@ static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
 					  &i2c_dev->fmp_mask);
 }

+static int stm32f7_i2c_enable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
+{
+	struct i2c_adapter *adap = &i2c_dev->adap;
+	void __iomem *base = i2c_dev->base;
+	struct i2c_client *client;
+
+	client = i2c_new_slave_host_notify_device(adap);
+	if (IS_ERR(client))
+		return PTR_ERR(client);
+
+	i2c_dev->host_notify_client = client;
+
+	/* Enable SMBus Host address */
+	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_SMBHEN);
+
+	return 0;
+}
+
+static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
+{
+	void __iomem *base = i2c_dev->base;
+
+	if (i2c_dev->host_notify_client) {
+		/* Disable SMBus Host address */
+		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1,
+				     STM32F7_I2C_CR1_SMBHEN);
+		i2c_free_slave_host_notify_device(i2c_dev->host_notify_client);
+	}
+}
+
 static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
-		I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
-		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
-		I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
-		I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
-		I2C_FUNC_SMBUS_I2C_BLOCK;
+	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+
+	u32 func = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
+		   I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+		   I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+		   I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
+		   I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
+		   I2C_FUNC_SMBUS_I2C_BLOCK;
+
+	if (i2c_dev->smbus_mode)
+		func |= I2C_FUNC_SMBUS_HOST_NOTIFY;
+
+	return func;
 }

 static const struct i2c_algorithm stm32f7_i2c_algo = {
@@ -1968,11 +2037,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
 						    "wakeup-source");

 	i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(i2c_dev->clk)) {
-		if (PTR_ERR(i2c_dev->clk) != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "Failed to get controller clock\n");
-		return PTR_ERR(i2c_dev->clk);
-	}
+	if (IS_ERR(i2c_dev->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(i2c_dev->clk),
+				     "Failed to get controller clock\n");

 	ret = clk_prepare_enable(i2c_dev->clk);
 	if (ret) {
@@ -1982,10 +2049,8 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)

 	rst = devm_reset_control_get(&pdev->dev, NULL);
 	if (IS_ERR(rst)) {
-		ret = PTR_ERR(rst);
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "Error: Missing reset ctrl\n");
-
+		ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
+				    "Error: Missing reset ctrl\n");
 		goto clk_free;
 	}
 	reset_control_assert(rst);
@@ -2052,14 +2117,13 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
 	i2c_dev->dma = stm32_i2c_dma_request(i2c_dev->dev, phy_addr,
 					     STM32F7_I2C_TXDR,
 					     STM32F7_I2C_RXDR);
-	if (PTR_ERR(i2c_dev->dma) == -ENODEV)
-		i2c_dev->dma = NULL;
-	else if (IS_ERR(i2c_dev->dma)) {
+	if (IS_ERR(i2c_dev->dma)) {
 		ret = PTR_ERR(i2c_dev->dma);
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev,
-				"Failed to request dma error %i\n", ret);
-		goto fmp_clear;
+		/* DMA support is optional, only report other errors */
+		if (ret != -ENODEV)
+			goto fmp_clear;
+		dev_dbg(i2c_dev->dev, "No DMA option: fallback using interrupts\n");
+		i2c_dev->dma = NULL;
 	}

 	if (i2c_dev->wakeup_src) {
@@ -2084,10 +2148,22 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)

 	stm32f7_i2c_hw_config(i2c_dev);

+	i2c_dev->smbus_mode = of_property_read_bool(pdev->dev.of_node, "smbus");
+
 	ret = i2c_add_adapter(adap);
 	if (ret)
 		goto pm_disable;

+	if (i2c_dev->smbus_mode) {
+		ret = stm32f7_i2c_enable_smbus_host(i2c_dev);
+		if (ret) {
+			dev_err(i2c_dev->dev,
+				"failed to enable SMBus Host-Notify protocol (%d)\n",
+				ret);
+			goto i2c_adapter_remove;
+		}
+	}
+
 	dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr);

 	pm_runtime_mark_last_busy(i2c_dev->dev);
@@ -2095,6 +2171,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)

 	return 0;

+i2c_adapter_remove:
+	i2c_del_adapter(adap);
+
 pm_disable:
 	pm_runtime_put_noidle(i2c_dev->dev);
 	pm_runtime_disable(i2c_dev->dev);
@@ -2126,6 +2205,8 @@ static int stm32f7_i2c_remove(struct platform_device *pdev)
 {
 	struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);

+	stm32f7_i2c_disable_smbus_host(i2c_dev);
+
 	i2c_del_adapter(&i2c_dev->adap);
 	pm_runtime_get_sync(i2c_dev->dev);

--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -46,34 +46,36 @@ enum xiic_endian {

 /**
 * struct xiic_i2c - Internal representation of the XIIC I2C bus
- * @dev:	Pointer to device structure
- * @base:	Memory base of the HW registers
- * @wait:	Wait queue for callers
- * @adap:	Kernel adapter representation
- * @tx_msg:	Messages from above to be sent
- * @lock:	Mutual exclusion
- * @tx_pos:	Current pos in TX message
- * @nmsgs:	Number of messages in tx_msg
- * @state:	See STATE_
- * @rx_msg:	Current RX message
- * @rx_pos:	Position within current RX message
+ * @dev: Pointer to device structure
+ * @base: Memory base of the HW registers
+ * @wait: Wait queue for callers
+ * @adap: Kernel adapter representation
+ * @tx_msg: Messages from above to be sent
+ * @lock: Mutual exclusion
+ * @tx_pos: Current pos in TX message
+ * @nmsgs: Number of messages in tx_msg
+ * @rx_msg: Current RX message
+ * @rx_pos: Position within current RX message
 * @endianness: big/little-endian byte order
- * @clk:	Pointer to AXI4-lite input clock
+ * @clk: Pointer to AXI4-lite input clock
+ * @state: See STATE_
+ * @singlemaster: Indicates bus is single master
 */
 struct xiic_i2c {
-	struct device		*dev;
-	void __iomem		*base;
-	wait_queue_head_t	wait;
-	struct i2c_adapter	adap;
-	struct i2c_msg		*tx_msg;
-	struct mutex		lock;
-	unsigned int		tx_pos;
-	unsigned int		nmsgs;
-	enum xilinx_i2c_state	state;
-	struct i2c_msg		*rx_msg;
-	int			rx_pos;
-	enum xiic_endian	endianness;
+	struct device *dev;
+	void __iomem *base;
+	wait_queue_head_t wait;
+	struct i2c_adapter adap;
+	struct i2c_msg *tx_msg;
+	struct mutex lock;
+	unsigned int tx_pos;
+	unsigned int nmsgs;
+	struct i2c_msg *rx_msg;
+	int rx_pos;
+	enum xiic_endian endianness;
 	struct clk *clk;
+	enum xilinx_i2c_state state;
+	bool singlemaster;
 };


@@ -526,6 +528,15 @@ static int xiic_busy(struct xiic_i2c *i2c)
 	if (i2c->tx_msg)
 		return -EBUSY;

+	/* In single master mode bus can only be busy, when in use by this
+	 * driver. If the register indicates bus being busy for some reason we
+	 * should ignore it, since bus will never be released and i2c will be
+	 * stuck forever.
+	 */
+	if (i2c->singlemaster) {
+		return 0;
+	}
+
 	/* for instance if previous transfer was terminated due to TX error
 	 * it might be that the bus is on it's way to become available
 	 * give it at most 3 ms to wake
@@ -811,6 +822,9 @@ static int xiic_i2c_probe(struct platform_device *pdev)
 		goto err_clk_dis;
 	}

+	i2c->singlemaster =
+		of_property_read_bool(pdev->dev.of_node, "single-master");
+
 	/*
 	 * Detect endianness
 	 * Try to reset the TX FIFO. Then check the EMPTY flag. If it is not
--- a/drivers/i2c/i2c-slave-testunit.c
+++ b/drivers/i2c/i2c-slave-testunit.c
@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * I2C slave mode testunit
+ *
+ * Copyright (C) 2020 by Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
+ * Copyright (C) 2020 by Renesas Electronics Corporation
+ */
+
+#include <linux/bitops.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h> /* FIXME: is system_long_wq the best choice? */
+
+#define TU_CUR_VERSION 0x01
+
+enum testunit_cmds {
+	TU_CMD_READ_BYTES = 1,	/* save 0 for ABORT, RESET or similar */
+	TU_CMD_HOST_NOTIFY,
+	TU_NUM_CMDS
+};
+
+enum testunit_regs {
+	TU_REG_CMD,
+	TU_REG_DATAL,
+	TU_REG_DATAH,
+	TU_REG_DELAY,
+	TU_NUM_REGS
+};
+
+enum testunit_flags {
+	TU_FLAG_IN_PROCESS,
+};
+
+struct testunit_data {
+	unsigned long flags;
+	u8 regs[TU_NUM_REGS];
+	u8 reg_idx;
+	struct i2c_client *client;
+	struct delayed_work worker;
+};
+
+static void i2c_slave_testunit_work(struct work_struct *work)
+{
+	struct testunit_data *tu = container_of(work, struct testunit_data, worker.work);
+	struct i2c_msg msg;
+	u8 msgbuf[256];
+	int ret = 0;
+
+	msg.addr = I2C_CLIENT_END;
+	msg.buf = msgbuf;
+
+	switch (tu->regs[TU_REG_CMD]) {
+	case TU_CMD_READ_BYTES:
+		msg.addr = tu->regs[TU_REG_DATAL];
+		msg.flags = I2C_M_RD;
+		msg.len = tu->regs[TU_REG_DATAH];
+		break;
+
+	case TU_CMD_HOST_NOTIFY:
+		msg.addr = 0x08;
+		msg.flags = 0;
+		msg.len = 3;
+		msgbuf[0] = tu->client->addr;
+		msgbuf[1] = tu->regs[TU_REG_DATAL];
+		msgbuf[2] = tu->regs[TU_REG_DATAH];
+		break;
+
+	default:
+		break;
+	}
+
+	if (msg.addr != I2C_CLIENT_END) {
+		ret = i2c_transfer(tu->client->adapter, &msg, 1);
+		/* convert '0 msgs transferred' to errno */
+		ret = (ret == 0) ? -EIO : ret;
+	}
+
+	if (ret < 0)
+		dev_err(&tu->client->dev, "CMD%02X failed (%d)\n", tu->regs[TU_REG_CMD], ret);
+
+	clear_bit(TU_FLAG_IN_PROCESS, &tu->flags);
+}
+
+static int i2c_slave_testunit_slave_cb(struct i2c_client *client,
+				     enum i2c_slave_event event, u8 *val)
+{
+	struct testunit_data *tu = i2c_get_clientdata(client);
+	int ret = 0;
+
+	switch (event) {
+	case I2C_SLAVE_WRITE_RECEIVED:
+		if (test_bit(TU_FLAG_IN_PROCESS, &tu->flags))
+			return -EBUSY;
+
+		if (tu->reg_idx < TU_NUM_REGS)
+			tu->regs[tu->reg_idx] = *val;
+		else
+			ret = -EMSGSIZE;
+
+		if (tu->reg_idx <= TU_NUM_REGS)
+			tu->reg_idx++;
+
+		/* TU_REG_CMD always written at this point */
+		if (tu->regs[TU_REG_CMD] >= TU_NUM_CMDS)
+			ret = -EINVAL;
+
+		break;
+
+	case I2C_SLAVE_STOP:
+		if (tu->reg_idx == TU_NUM_REGS) {
+			set_bit(TU_FLAG_IN_PROCESS, &tu->flags);
+			queue_delayed_work(system_long_wq, &tu->worker,
+					   msecs_to_jiffies(10 * tu->regs[TU_REG_DELAY]));
+		}
+		fallthrough;
+
+	case I2C_SLAVE_WRITE_REQUESTED:
+		tu->reg_idx = 0;
+		break;
+
+	case I2C_SLAVE_READ_REQUESTED:
+	case I2C_SLAVE_READ_PROCESSED:
+		*val = TU_CUR_VERSION;
+		break;
+	}
+
+	return ret;
+}
+
+static int i2c_slave_testunit_probe(struct i2c_client *client)
+{
+	struct testunit_data *tu;
+
+	tu = devm_kzalloc(&client->dev, sizeof(struct testunit_data), GFP_KERNEL);
+	if (!tu)
+		return -ENOMEM;
+
+	tu->client = client;
+	i2c_set_clientdata(client, tu);
+	INIT_DELAYED_WORK(&tu->worker, i2c_slave_testunit_work);
+
+	return i2c_slave_register(client, i2c_slave_testunit_slave_cb);
+};
+
+static int i2c_slave_testunit_remove(struct i2c_client *client)
+{
+	struct testunit_data *tu = i2c_get_clientdata(client);
+
+	cancel_delayed_work_sync(&tu->worker);
+	i2c_slave_unregister(client);
+	return 0;
+}
+
+static const struct i2c_device_id i2c_slave_testunit_id[] = {
+	{ "slave-testunit", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, i2c_slave_testunit_id);
+
+static struct i2c_driver i2c_slave_testunit_driver = {
+	.driver = {
+		.name = "i2c-slave-testunit",
+	},
+	.probe_new = i2c_slave_testunit_probe,
+	.remove = i2c_slave_testunit_remove,
+	.id_table = i2c_slave_testunit_id,
+};
+module_i2c_driver(i2c_slave_testunit_driver);
+
+MODULE_AUTHOR("Wolfram Sang <wsa@sang-engineering.com>");
+MODULE_DESCRIPTION("I2C slave mode test unit");
+MODULE_LICENSE("GPL v2");
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -197,6 +197,113 @@ EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert);

 module_i2c_driver(smbalert_driver);

+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+#define SMBUS_HOST_NOTIFY_LEN	3
+struct i2c_slave_host_notify_status {
+	u8 index;
+	u8 addr;
+};
+
+static int i2c_slave_host_notify_cb(struct i2c_client *client,
+				    enum i2c_slave_event event, u8 *val)
+{
+	struct i2c_slave_host_notify_status *status = client->dev.platform_data;
+
+	switch (event) {
+	case I2C_SLAVE_WRITE_RECEIVED:
+		/* We only retrieve the first byte received (addr)
+		 * since there is currently no support to retrieve the data
+		 * parameter from the client.
+		 */
+		if (status->index == 0)
+			status->addr = *val;
+		if (status->index < U8_MAX)
+			status->index++;
+		break;
+	case I2C_SLAVE_STOP:
+		if (status->index == SMBUS_HOST_NOTIFY_LEN)
+			i2c_handle_smbus_host_notify(client->adapter,
+						     status->addr);
+		fallthrough;
+	case I2C_SLAVE_WRITE_REQUESTED:
+		status->index = 0;
+		break;
+	case I2C_SLAVE_READ_REQUESTED:
+	case I2C_SLAVE_READ_PROCESSED:
+		*val = 0xff;
+		break;
+	}
+
+	return 0;
+}
+
+/**
+ * i2c_new_slave_host_notify_device - get a client for SMBus host-notify support
+ * @adapter: the target adapter
+ * Context: can sleep
+ *
+ * Setup handling of the SMBus host-notify protocol on a given I2C bus segment.
+ *
+ * Handling is done by creating a device and its callback and handling data
+ * received via the SMBus host-notify address (0x8)
+ *
+ * This returns the client, which should be ultimately freed using
+ * i2c_free_slave_host_notify_device(); or an ERRPTR to indicate an error.
+ */
+struct i2c_client *i2c_new_slave_host_notify_device(struct i2c_adapter *adapter)
+{
+	struct i2c_board_info host_notify_board_info = {
+		I2C_BOARD_INFO("smbus_host_notify", 0x08),
+		.flags  = I2C_CLIENT_SLAVE,
+	};
+	struct i2c_slave_host_notify_status *status;
+	struct i2c_client *client;
+	int ret;
+
+	status = kzalloc(sizeof(struct i2c_slave_host_notify_status),
+			 GFP_KERNEL);
+	if (!status)
+		return ERR_PTR(-ENOMEM);
+
+	host_notify_board_info.platform_data = status;
+
+	client = i2c_new_client_device(adapter, &host_notify_board_info);
+	if (IS_ERR(client)) {
+		kfree(status);
+		return client;
+	}
+
+	ret = i2c_slave_register(client, i2c_slave_host_notify_cb);
+	if (ret) {
+		i2c_unregister_device(client);
+		kfree(status);
+		return ERR_PTR(ret);
+	}
+
+	return client;
+}
+EXPORT_SYMBOL_GPL(i2c_new_slave_host_notify_device);
+
+/**
+ * i2c_free_slave_host_notify_device - free the client for SMBus host-notify
+ * support
+ * @client: the client to free
+ * Context: can sleep
+ *
+ * Free the i2c_client allocated via i2c_new_slave_host_notify_device
+ */
+void i2c_free_slave_host_notify_device(struct i2c_client *client)
+{
+	if (IS_ERR_OR_NULL(client))
+		return;
+
+	i2c_slave_unregister(client);
+	kfree(client->dev.platform_data);
+	i2c_unregister_device(client);
+}
+EXPORT_SYMBOL_GPL(i2c_free_slave_host_notify_device);
+#endif
+
 /*
 * SPD is not part of SMBus but we include it here for convenience as the
 * target systems are the same.
--- a/drivers/i2c/muxes/i2c-mux-gpmux.c
+++ b/drivers/i2c/muxes/i2c-mux-gpmux.c
@@ -85,18 +85,14 @@ static int i2c_mux_probe(struct platform_device *pdev)
 		return -ENOMEM;

 	mux->control = devm_mux_control_get(dev, NULL);
-	if (IS_ERR(mux->control)) {
-		if (PTR_ERR(mux->control) != -EPROBE_DEFER)
-			dev_err(dev, "failed to get control-mux\n");
-		return PTR_ERR(mux->control);
-	}
+	if (IS_ERR(mux->control))
+		return dev_err_probe(dev, PTR_ERR(mux->control),
+				     "failed to get control-mux\n");

 	parent = mux_parent_adapter(dev);
-	if (IS_ERR(parent)) {
-		if (PTR_ERR(parent) != -EPROBE_DEFER)
-			dev_err(dev, "failed to get i2c-parent adapter\n");
-		return PTR_ERR(parent);
-	}
+	if (IS_ERR(parent))
+		return dev_err_probe(dev, PTR_ERR(parent),
+				     "failed to get i2c-parent adapter\n");

 	children = of_get_child_count(np);

--- a/drivers/i2c/muxes/i2c-mux-reg.c
+++ b/drivers/i2c/muxes/i2c-mux-reg.c
@@ -171,13 +171,9 @@ static int i2c_mux_reg_probe(struct platform_device *pdev)
 			sizeof(mux->data));
 	} else {
 		ret = i2c_mux_reg_probe_dt(mux, pdev);
-		if (ret == -EPROBE_DEFER)
-			return ret;
-
-		if (ret < 0) {
-			dev_err(&pdev->dev, "Error parsing device tree");
-			return ret;
-		}
+		if (ret < 0)
+			return dev_err_probe(&pdev->dev, ret,
+					     "Error parsing device tree");
 	}

 	parent = i2c_get_adapter(mux->data.parent);