USB: at91: Add USB EHCI driver for at91sam9g45 series

Add host USB High speed driver for at91sam9g45 series.
The host driver is an EHCI with its companion OHCI. EHCI is
handled by the new ehci-atmel.c whereas the OHCI is always
handled by ohci-at91.c.

Signed-off-by: Nicolas Ferre <[e-mail]>
Acked-by: David Brownell <[e-mail]>

drivers/usb/Kconfig

···
 	default y if SOC_AU1200
 	default y if ARCH_IXP4XX
 	default y if ARCH_W90X900
+	default y if ARCH_AT91SAM9G45
 	default PCI
 
 # ARM SA1111 chips have a non-PCI based "OHCI-compatible" USB host interface.

drivers/usb/host/ehci-atmel.c

···
+/*
+ * Driver for EHCI UHP on Atmel chips
+ *
+ *  Copyright (C) 2009 Atmel Corporation,
+ *                     Nicolas Ferre <[e-mail]>
+ *
+ *  Based on various ehci-*.c drivers
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive for
+ * more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+
+/* interface and function clocks */
+static struct clk *iclk, *fclk;
+static int clocked;
+
+/*-------------------------------------------------------------------------*/
+
+static void atmel_start_clock(void)
+{
+	clk_enable(iclk);
+	clk_enable(fclk);
+	clocked = 1;
+}
+
+static void atmel_stop_clock(void)
+{
+	clk_disable(fclk);
+	clk_disable(iclk);
+	clocked = 0;
+}
+
+static void atmel_start_ehci(struct platform_device *pdev)
+{
+	dev_dbg(&pdev->dev, "start\n");
+	atmel_start_clock();
+}
+
+static void atmel_stop_ehci(struct platform_device *pdev)
+{
+	dev_dbg(&pdev->dev, "stop\n");
+	atmel_stop_clock();
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int ehci_atmel_setup(struct usb_hcd *hcd)
+{
+	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+	int retval = 0;
+
+	/* registers start at offset 0x0 */
+	ehci->caps = hcd->regs;
+	ehci->regs = hcd->regs +
+		HC_LENGTH(ehci_readl(ehci, &ehci->caps->hc_capbase));
+	dbg_hcs_params(ehci, "reset");
+	dbg_hcc_params(ehci, "reset");
+
+	/* cache this readonly data; minimize chip reads */
+	ehci->hcs_params = ehci_readl(ehci, &ehci->caps->hcs_params);
+
+	retval = ehci_halt(ehci);
+	if (retval)
+		return retval;
+
+	/* data structure init */
+	retval = ehci_init(hcd);
+	if (retval)
+		return retval;
+
+	ehci->sbrn = 0x20;
+
+	ehci_reset(ehci);
+	ehci_port_power(ehci, 0);
+
+	return retval;
+}
+
+static const struct hc_driver ehci_atmel_hc_driver = {
+	.description		= hcd_name,
+	.product_desc		= "Atmel EHCI UHP HS",
+	.hcd_priv_size		= sizeof(struct ehci_hcd),
+
+	/* generic hardware linkage */
+	.irq			= ehci_irq,
+	.flags			= HCD_MEMORY | HCD_USB2,
+
+	/* basic lifecycle operations */
+	.reset			= ehci_atmel_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,
+
+	/* 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,
+};
+
+static int __init ehci_atmel_drv_probe(struct platform_device *pdev)
+{
+	struct usb_hcd *hcd;
+	const struct hc_driver *driver = &ehci_atmel_hc_driver;
+	struct resource *res;
+	int irq;
+	int retval;
+
+	if (usb_disabled())
+		return -ENODEV;
+
+	pr_debug("Initializing Atmel-SoC USB Host Controller\n");
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_err(&pdev->dev,
+			"Found HC with no IRQ. Check %s setup!\n",
+			dev_name(&pdev->dev));
+		retval = -ENODEV;
+		goto fail_create_hcd;
+	}
+
+	hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
+	if (!hcd) {
+		retval = -ENOMEM;
+		goto fail_create_hcd;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev,
+			"Found HC with no register addr. Check %s setup!\n",
+			dev_name(&pdev->dev));
+		retval = -ENODEV;
+		goto fail_request_resource;
+	}
+	hcd->rsrc_start = res->start;
+	hcd->rsrc_len = res->end - res->start + 1;
+
+	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len,
+				driver->description)) {
+		dev_dbg(&pdev->dev, "controller already in use\n");
+		retval = -EBUSY;
+		goto fail_request_resource;
+	}
+
+	hcd->regs = ioremap_nocache(hcd->rsrc_start, hcd->rsrc_len);
+	if (hcd->regs == NULL) {
+		dev_dbg(&pdev->dev, "error mapping memory\n");
+		retval = -EFAULT;
+		goto fail_ioremap;
+	}
+
+	iclk = clk_get(&pdev->dev, "ehci_clk");
+	if (IS_ERR(iclk)) {
+		dev_err(&pdev->dev, "Error getting interface clock\n");
+		retval = -ENOENT;
+		goto fail_get_iclk;
+	}
+	fclk = clk_get(&pdev->dev, "uhpck");
+	if (IS_ERR(fclk)) {
+		dev_err(&pdev->dev, "Error getting function clock\n");
+		retval = -ENOENT;
+		goto fail_get_fclk;
+	}
+
+	atmel_start_ehci(pdev);
+
+	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
+	if (retval)
+		goto fail_add_hcd;
+
+	return retval;
+
+fail_add_hcd:
+	atmel_stop_ehci(pdev);
+	clk_put(fclk);
+fail_get_fclk:
+	clk_put(iclk);
+fail_get_iclk:
+	iounmap(hcd->regs);
+fail_ioremap:
+	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+fail_request_resource:
+	usb_put_hcd(hcd);
+fail_create_hcd:
+	dev_err(&pdev->dev, "init %s fail, %d\n",
+		dev_name(&pdev->dev), retval);
+
+	return retval;
+}
+
+static int __exit ehci_atmel_drv_remove(struct platform_device *pdev)
+{
+	struct usb_hcd *hcd = platform_get_drvdata(pdev);
+
+	ehci_shutdown(hcd);
+	usb_remove_hcd(hcd);
+	iounmap(hcd->regs);
+	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+	usb_put_hcd(hcd);
+
+	atmel_stop_ehci(pdev);
+	clk_put(fclk);
+	clk_put(iclk);
+	fclk = iclk = NULL;
+
+	return 0;
+}
+
+static struct platform_driver ehci_atmel_driver = {
+	.probe		= ehci_atmel_drv_probe,
+	.remove		= __exit_p(ehci_atmel_drv_remove),
+	.shutdown	= usb_hcd_platform_shutdown,
+	.driver.name	= "atmel-ehci",
+};

drivers/usb/host/ehci-hcd.c

···
 #define	PLATFORM_DRIVER		ehci_hcd_w90x900_driver
 #endif
 
+#ifdef CONFIG_ARCH_AT91
+#include "ehci-atmel.c"
+#define	PLATFORM_DRIVER		ehci_atmel_driver
+#endif
+
 #if !defined(PCI_DRIVER) && !defined(PLATFORM_DRIVER) && \
     !defined(PS3_SYSTEM_BUS_DRIVER) && !defined(OF_PLATFORM_DRIVER)
 #error "missing bus glue for ehci-hcd"