[PATCH] USB: add support for OCHI on AT91rm9200

This adds support for OHCI on AT91rm9200 based boards.

Possibly of interest here is the way this uses <linux/clk.h> to
gate clocks on/off during system pm state transitions.  That's
typical for non-PCI systems.  Some can go further; Mini-A host
side connectors enable ID-pin sensing.

From: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/Kconfig

@@ -23,6 +23,7 @@ config USB_ARCH_HAS_OHCI
 	default y if ARCH_LH7A404
 	default y if ARCH_S3C2410
 	default y if PXA27x
+	default y if ARCH_AT91RM9200
 	# PPC:
 	default y if STB03xxx
 	default y if PPC_MPC52xx

drivers/usb/Makefile

@@ -15,6 +15,7 @@ obj-$(CONFIG_USB_OHCI_HCD)	+= host/
 obj-$(CONFIG_USB_UHCI_HCD)	+= host/
 obj-$(CONFIG_USB_SL811_HCD)	+= host/
 obj-$(CONFIG_ETRAX_USB_HOST)	+= host/
+obj-$(CONFIG_USB_OHCI_AT91)	+= host/
 
 obj-$(CONFIG_USB_ACM)		+= class/
 obj-$(CONFIG_USB_PRINTER)	+= class/

drivers/usb/host/ohci-at91.c

+/*
+ * OHCI HCD (Host Controller Driver) for USB.
+ *
+ *  Copyright (C) 2004 SAN People (Pty) Ltd.
+ *  Copyright (C) 2005 Thibaut VARENE <varenet@parisc-linux.org>
+ *
+ * AT91RM9200 Bus Glue
+ *
+ * Based on fragments of 2.4 driver by Rick Bronson.
+ * Based on ohci-omap.c
+ *
+ * This file is licenced under the GPL.
+ */
+
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+
+#include <asm/mach-types.h>
+#include <asm/hardware.h>
+#include <asm/arch/board.h>
+
+#ifndef CONFIG_ARCH_AT91RM9200
+#error "This file is AT91RM9200 bus glue.  CONFIG_ARCH_AT91RM9200 must be defined."
+#endif
+
+/* interface and function clocks */
+static struct clk *iclk, *fclk;
+
+extern int usb_disabled(void);
+
+/*-------------------------------------------------------------------------*/
+
+static void at91_start_hc(struct platform_device *pdev)
+{
+	struct usb_hcd *hcd = platform_get_drvdata(pdev);
+	struct ohci_regs __iomem *regs = hcd->regs;
+
+	dev_dbg(&pdev->dev, "starting AT91RM9200 OHCI USB Controller\n");
+
+	/*
+	 * Start the USB clocks.
+	 */
+	clk_enable(iclk);
+	clk_enable(fclk);
+
+	/*
+	 * The USB host controller must remain in reset.
+	 */
+	writel(0, &regs->control);
+}
+
+static void at91_stop_hc(struct platform_device *pdev)
+{
+	struct usb_hcd *hcd = platform_get_drvdata(pdev);
+	struct ohci_regs __iomem *regs = hcd->regs;
+
+	dev_dbg(&pdev->dev, "stopping AT91RM9200 OHCI USB Controller\n");
+
+	/*
+	 * Put the USB host controller into reset.
+	 */
+	writel(0, &regs->control);
+
+	/*
+	 * Stop the USB clocks.
+	 */
+	clk_disable(fclk);
+	clk_disable(iclk);
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+static int usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
+
+/* configure so an HC device and id are always provided */
+/* always called with process context; sleeping is OK */
+
+
+/**
+ * usb_hcd_at91_probe - initialize AT91RM9200-based HCDs
+ * Context: !in_interrupt()
+ *
+ * Allocates basic resources for this USB host controller, and
+ * then invokes the start() method for the HCD associated with it
+ * through the hotplug entry's driver_data.
+ *
+ * Store this function in the HCD's struct pci_driver as probe().
+ */
+int usb_hcd_at91_probe (const struct hc_driver *driver, struct platform_device *pdev)
+{
+	int retval;
+	struct usb_hcd *hcd = NULL;
+
+	if (pdev->num_resources != 2) {
+		pr_debug("hcd probe: invalid num_resources");
+		return -ENODEV;
+	}
+
+	if ((pdev->resource[0].flags != IORESOURCE_MEM) || (pdev->resource[1].flags != IORESOURCE_IRQ)) {
+		pr_debug("hcd probe: invalid resource type\n");
+		return -ENODEV;
+	}
+
+	hcd = usb_create_hcd(driver, &pdev->dev, "at91rm9200");
+	if (!hcd)
+		return -ENOMEM;
+	hcd->rsrc_start = pdev->resource[0].start;
+	hcd->rsrc_len = pdev->resource[0].end - pdev->resource[0].start + 1;
+
+	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
+		pr_debug("request_mem_region failed\n");
+		retval = -EBUSY;
+		goto err1;
+	}
+
+	hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
+	if (!hcd->regs) {
+		pr_debug("ioremap failed\n");
+		retval = -EIO;
+		goto err2;
+	}
+
+	iclk = clk_get(&pdev->dev, "ohci_clk");
+	fclk = clk_get(&pdev->dev, "uhpck");
+
+	at91_start_hc(pdev);
+	ohci_hcd_init(hcd_to_ohci(hcd));
+
+	retval = usb_add_hcd(hcd, pdev->resource[1].start, SA_INTERRUPT);
+	if (retval == 0)
+		return retval;
+
+	/* Error handling */
+	at91_stop_hc(pdev);
+
+	clk_put(fclk);
+	clk_put(iclk);
+
+	iounmap(hcd->regs);
+
+ err2:
+	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+
+ err1:
+	usb_put_hcd(hcd);
+	return retval;
+}
+
+
+/* may be called without controller electrically present */
+/* may be called with controller, bus, and devices active */
+
+/**
+ * usb_hcd_at91_remove - shutdown processing for AT91RM9200-based HCDs
+ * @dev: USB Host Controller being removed
+ * Context: !in_interrupt()
+ *
+ * Reverses the effect of usb_hcd_at91_probe(), first invoking
+ * the HCD's stop() method.  It is always called from a thread
+ * context, normally "rmmod", "apmd", or something similar.
+ *
+ */
+static int usb_hcd_at91_remove (struct usb_hcd *hcd, struct platform_device *pdev)
+{
+	usb_remove_hcd(hcd);
+	at91_stop_hc(pdev);
+	iounmap(hcd->regs);
+ 	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+
+ 	clk_put(fclk);
+ 	clk_put(iclk);
+ 	fclk = iclk = NULL;
+
+	dev_set_drvdata(&pdev->dev, NULL);
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int __devinit
+ohci_at91_start (struct usb_hcd *hcd)
+{
+//	struct at91_ohci_data	*board = hcd->self.controller->platform_data;
+	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
+	int			ret;
+
+	if ((ret = ohci_init(ohci)) < 0)
+		return ret;
+
+	if ((ret = ohci_run(ohci)) < 0) {
+		err("can't start %s", hcd->self.bus_name);
+		ohci_stop(hcd);
+		return ret;
+	}
+//	hcd->self.root_hub->maxchild = board->ports;
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static const struct hc_driver ohci_at91_hc_driver = {
+	.description =		hcd_name,
+	.product_desc =		"AT91RM9200 OHCI",
+	.hcd_priv_size =	sizeof(struct ohci_hcd),
+
+	/*
+	 * generic hardware linkage
+	 */
+	.irq =			ohci_irq,
+	.flags =		HCD_USB11 | HCD_MEMORY,
+
+	/*
+	 * basic lifecycle operations
+	 */
+	.start =		ohci_at91_start,
+	.stop =			ohci_stop,
+
+	/*
+	 * managing i/o requests and associated device resources
+	 */
+	.urb_enqueue =		ohci_urb_enqueue,
+	.urb_dequeue =		ohci_urb_dequeue,
+	.endpoint_disable =	ohci_endpoint_disable,
+
+	/*
+	 * scheduling support
+	 */
+	.get_frame_number =	ohci_get_frame,
+
+	/*
+	 * root hub support
+	 */
+	.hub_status_data =	ohci_hub_status_data,
+	.hub_control =		ohci_hub_control,
+
+#ifdef CONFIG_PM
+	.hub_suspend =		ohci_hub_suspend,
+	.hub_resume =		ohci_hub_resume,
+#endif
+	.start_port_reset =	ohci_start_port_reset,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int ohci_hcd_at91_drv_probe(struct platform_device *dev)
+{
+	return usb_hcd_at91_probe(&ohci_at91_hc_driver, dev);
+}
+
+static int ohci_hcd_at91_drv_remove(struct platform_device *dev)
+{
+	return usb_hcd_at91_remove(platform_get_drvdata(dev), dev);
+}
+
+#ifdef CONFIG_PM
+static int ohci_hcd_at91_drv_suspend(struct platform_device *dev, u32 state, u32 level)
+{
+	printk("%s(%s:%d): not implemented yet\n",
+		__func__, __FILE__, __LINE__);
+
+	clk_disable(fclk);
+
+	return 0;
+}
+
+static int ohci_hcd_at91_drv_resume(struct platform_device *dev, u32 state)
+{
+	printk("%s(%s:%d): not implemented yet\n",
+		__func__, __FILE__, __LINE__);
+
+	clk_enable(fclk);
+
+	return 0;
+}
+#else
+#define ohci_hcd_at91_drv_suspend NULL
+#define ohci_hcd_at91_drv_resume  NULL
+#endif
+
+static struct platform_driver ohci_hcd_at91_driver = {
+	.probe		= ohci_hcd_at91_drv_probe,
+	.remove		= ohci_hcd_at91_drv_remove,
+	.suspend	= ohci_hcd_at91_drv_suspend,
+	.resume		= ohci_hcd_at91_drv_resume,
+	.driver		= {
+		.name	= "at91rm9200-ohci",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init ohci_hcd_at91_init (void)
+{
+	if (usb_disabled())
+		return -ENODEV;
+
+	return platform_driver_register(&ohci_hcd_at91_driver);
+}
+
+static void __exit ohci_hcd_at91_cleanup (void)
+{
+	platform_driver_unregister(&ohci_hcd_at91_driver);
+}
+
+module_init (ohci_hcd_at91_init);
+module_exit (ohci_hcd_at91_cleanup);

drivers/usb/host/ohci-hcd.c

@@ -905,6 +905,10 @@ MODULE_LICENSE ("GPL");
 #include "ohci-ppc-soc.c"
 #endif
 
+#ifdef CONFIG_ARCH_AT91RM9200
+#include "ohci-at91.c"
+#endif
+
 #if !(defined(CONFIG_PCI) \
       || defined(CONFIG_SA1111) \
       || defined(CONFIG_ARCH_S3C2410) \
@@ -913,6 +917,7 @@ MODULE_LICENSE ("GPL");
       || defined (CONFIG_PXA27x) \
       || defined (CONFIG_SOC_AU1X00) \
       || defined (CONFIG_USB_OHCI_HCD_PPC_SOC) \
+      || defined (CONFIG_ARCH_AT91RM9200) \
 	)
 #error "missing bus glue for ohci-hcd"
 #endif