[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: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 306 insertions, 0 deletions

diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
new file mode 100644
index 000000000000..980030d684d5
--- /dev/null
+++ b/drivers/usb/host/ohci-at91.c
@@ -0,0 +1,306 @@
+/*
+ * 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);