usb: add host support for the tilegx architecture

This change adds OHCI and EHCI support for the tilegx's on-chip
USB hardware.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

drivers/usb/host/ehci-tilegx.c

@@ -0,0 +1,214 @@
+/*
+ * Copyright 2012 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+/*
+ * Tilera TILE-Gx USB EHCI host controller driver.
+ */
+
+#include <linux/irq.h>
+#include <linux/platform_device.h>
+#include <linux/usb/tilegx.h>
+#include <linux/usb.h>
+
+#include <asm/homecache.h>
+
+#include <gxio/iorpc_usb_host.h>
+#include <gxio/usb_host.h>
+
+static void tilegx_start_ehc(void)
+{
+}
+
+static void tilegx_stop_ehc(void)
+{
+}
+
+static int tilegx_ehci_setup(struct usb_hcd *hcd)
+{
+	int ret = ehci_init(hcd);
+
+	/*
+	 * Some drivers do:
+	 *
+	 *   struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+	 *   ehci->need_io_watchdog = 0;
+	 *
+	 * here, but since this is a new driver we're going to leave the
+	 * watchdog enabled.  Later we may try to turn it off and see
+	 * whether we run into any problems.
+	 */
+
+	return ret;
+}
+
+static const struct hc_driver ehci_tilegx_hc_driver = {
+	.description		= hcd_name,
+	.product_desc		= "Tile-Gx EHCI",
+	.hcd_priv_size		= sizeof(struct ehci_hcd),
+
+	/*
+	 * Generic hardware linkage.
+	 */
+	.irq			= ehci_irq,
+	.flags			= HCD_MEMORY | HCD_USB2,
+
+	/*
+	 * Basic lifecycle operations.
+	 */
+	.reset			= tilegx_ehci_setup,
+	.start			= ehci_run,
+	.stop			= ehci_stop,
+	.shutdown		= ehci_shutdown,
+
+	/*
+	 * Managing I/O requests and associated device resources.
+	 */
+	.urb_enqueue		= ehci_urb_enqueue,
+	.urb_dequeue		= ehci_urb_dequeue,
+	.endpoint_disable	= ehci_endpoint_disable,
+	.endpoint_reset		= ehci_endpoint_reset,
+
+	/*
+	 * Scheduling support.
+	 */
+	.get_frame_number	= ehci_get_frame,
+
+	/*
+	 * Root hub support.
+	 */
+	.hub_status_data	= ehci_hub_status_data,
+	.hub_control		= ehci_hub_control,
+	.bus_suspend		= ehci_bus_suspend,
+	.bus_resume		= ehci_bus_resume,
+	.relinquish_port	= ehci_relinquish_port,
+	.port_handed_over	= ehci_port_handed_over,
+
+	.clear_tt_buffer_complete	= ehci_clear_tt_buffer_complete,
+};
+
+static int ehci_hcd_tilegx_drv_probe(struct platform_device *pdev)
+{
+	struct usb_hcd *hcd;
+	struct ehci_hcd *ehci;
+	struct tilegx_usb_platform_data *pdata = pdev->dev.platform_data;
+	pte_t pte = { 0 };
+	int my_cpu = smp_processor_id();
+	int ret;
+
+	if (usb_disabled())
+		return -ENODEV;
+
+	/*
+	 * Try to initialize our GXIO context; if we can't, the device
+	 * doesn't exist.
+	 */
+	if (gxio_usb_host_init(&pdata->usb_ctx, pdata->dev_index, 1) != 0)
+		return -ENXIO;
+
+	hcd = usb_create_hcd(&ehci_tilegx_hc_driver, &pdev->dev,
+			     dev_name(&pdev->dev));
+	if (!hcd)
+		return -ENOMEM;
+
+	/*
+	 * We don't use rsrc_start to map in our registers, but seems like
+	 * we ought to set it to something, so we use the register VA.
+	 */
+	hcd->rsrc_start =
+		(ulong) gxio_usb_host_get_reg_start(&pdata->usb_ctx);
+	hcd->rsrc_len = gxio_usb_host_get_reg_len(&pdata->usb_ctx);
+	hcd->regs = gxio_usb_host_get_reg_start(&pdata->usb_ctx);
+
+	tilegx_start_ehc();
+
+	ehci = hcd_to_ehci(hcd);
+	ehci->caps = hcd->regs;
+	ehci->regs =
+		hcd->regs + HC_LENGTH(ehci, readl(&ehci->caps->hc_capbase));
+	/* cache this readonly data; minimize chip reads */
+	ehci->hcs_params = readl(&ehci->caps->hcs_params);
+
+	/* Create our IRQs and register them. */
+	pdata->irq = create_irq();
+	if (pdata->irq < 0) {
+		ret = -ENXIO;
+		goto err_no_irq;
+	}
+
+	tile_irq_activate(pdata->irq, TILE_IRQ_PERCPU);
+
+	/* Configure interrupts. */
+	ret = gxio_usb_host_cfg_interrupt(&pdata->usb_ctx,
+					  cpu_x(my_cpu), cpu_y(my_cpu),
+					  KERNEL_PL, pdata->irq);
+	if (ret) {
+		ret = -ENXIO;
+		goto err_have_irq;
+	}
+
+	/* Register all of our memory. */
+	pte = pte_set_home(pte, PAGE_HOME_HASH);
+	ret = gxio_usb_host_register_client_memory(&pdata->usb_ctx, pte, 0);
+	if (ret) {
+		ret = -ENXIO;
+		goto err_have_irq;
+	}
+
+	ret = usb_add_hcd(hcd, pdata->irq, IRQF_SHARED);
+	if (ret == 0) {
+		platform_set_drvdata(pdev, hcd);
+		return ret;
+	}
+
+err_have_irq:
+	destroy_irq(pdata->irq);
+err_no_irq:
+	tilegx_stop_ehc();
+	usb_put_hcd(hcd);
+	gxio_usb_host_destroy(&pdata->usb_ctx);
+	return ret;
+}
+
+static int ehci_hcd_tilegx_drv_remove(struct platform_device *pdev)
+{
+	struct usb_hcd *hcd = platform_get_drvdata(pdev);
+	struct tilegx_usb_platform_data *pdata = pdev->dev.platform_data;
+
+	usb_remove_hcd(hcd);
+	usb_put_hcd(hcd);
+	tilegx_stop_ehc();
+	gxio_usb_host_destroy(&pdata->usb_ctx);
+	destroy_irq(pdata->irq);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static void ehci_hcd_tilegx_drv_shutdown(struct platform_device *pdev)
+{
+	usb_hcd_platform_shutdown(pdev);
+	ehci_hcd_tilegx_drv_remove(pdev);
+}
+
+static struct platform_driver ehci_hcd_tilegx_driver = {
+	.probe		= ehci_hcd_tilegx_drv_probe,
+	.remove		= ehci_hcd_tilegx_drv_remove,
+	.shutdown	= ehci_hcd_tilegx_drv_shutdown,
+	.driver = {
+		.name	= "tilegx-ehci",
+		.owner	= THIS_MODULE,
+	}
+};
+
+MODULE_ALIAS("platform:tilegx-ehci");