usb: ohci-sm501 driver

usb: ohci-sm501 driver V2

This patch adds sm501 ohci support. It's all very straightforward with the
exception of dma_declare_coherent_memory() and HCD_LOCAL_MEM. Together they
are used to ensure that usb data is allocated using dma_alloc_coherent(),
and that only valid dma memory is used to allocate from. This driver is
a platform device, and the mfd driver sm501.c is already creating one
usb host controller instance per sm501.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 264 insertions, 0 deletions

diff --git a/drivers/usb/host/ohci-sm501.c b/drivers/usb/host/ohci-sm501.c
new file mode 100644
index 000000000000..a97070142869
--- /dev/null
+++ b/drivers/usb/host/ohci-sm501.c
@@ -0,0 +1,264 @@
+/*
+ * OHCI HCD (Host Controller Driver) for USB.
+ *
+ * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
+ * (C) Copyright 2000-2005 David Brownell
+ * (C) Copyright 2002 Hewlett-Packard Company
+ * (C) Copyright 2008 Magnus Damm
+ *
+ * SM501 Bus Glue - based on ohci-omap.c
+ *
+ * This file is licenced under the GPL.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/sm501.h>
+#include <linux/sm501-regs.h>
+
+static int ohci_sm501_init(struct usb_hcd *hcd)
+{
+        return ohci_init(hcd_to_ohci(hcd));
+}
+
+static int ohci_sm501_start(struct usb_hcd *hcd)
+{
+        struct device *dev = hcd->self.controller;
+        int ret;
+
+        ret = ohci_run(hcd_to_ohci(hcd));
+        if (ret < 0) {
+                dev_err(dev, "can't start %s", hcd->self.bus_name);
+                ohci_stop(hcd);
+        }
+
+        return ret;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static const struct hc_driver ohci_sm501_hc_driver = {
+        .description =          hcd_name,
+        .product_desc =         "SM501 OHCI",
+        .hcd_priv_size =        sizeof(struct ohci_hcd),
+
+        /*
+         * generic hardware linkage
+         */
+        .irq =                  ohci_irq,
+        .flags =                HCD_USB11 | HCD_MEMORY | HCD_LOCAL_MEM,
+
+        /*
+         * basic lifecycle operations
+         */
+        .reset =                ohci_sm501_init,
+        .start =                ohci_sm501_start,
+        .stop =                 ohci_stop,
+        .shutdown =             ohci_shutdown,
+
+        /*
+         * 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,
+        .hub_irq_enable =       ohci_rhsc_enable,
+#ifdef  CONFIG_PM
+        .bus_suspend =          ohci_bus_suspend,
+        .bus_resume =           ohci_bus_resume,
+#endif
+        .start_port_reset =     ohci_start_port_reset,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int ohci_hcd_sm501_drv_probe(struct platform_device *pdev)
+{
+        const struct hc_driver *driver = &ohci_sm501_hc_driver;
+        struct device *dev = &pdev->dev;
+        struct resource *res, *mem;
+        int retval, irq;
+        struct usb_hcd *hcd = 0;
+
+        irq = retval = platform_get_irq(pdev, 0);
+        if (retval < 0)
+                goto err0;
+
+        mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+        if (mem == NULL) {
+                dev_err(dev, "no resource definition for memory\n");
+                retval = -ENOENT;
+                goto err0;
+        }
+
+        if (!request_mem_region(mem->start, mem->end - mem->start + 1,
+                                pdev->name)) {
+                dev_err(dev, "request_mem_region failed\n");
+                retval = -EBUSY;
+                goto err0;
+        }
+
+        /* The sm501 chip is equipped with local memory that may be used
+         * by on-chip devices such as the video controller and the usb host.
+         * This driver uses dma_declare_coherent_memory() to make sure
+         * usb allocations with dma_alloc_coherent() allocate from
+         * this local memory. The dma_handle returned by dma_alloc_coherent()
+         * will be an offset starting from 0 for the first local memory byte.
+         *
+         * So as long as data is allocated using dma_alloc_coherent() all is
+         * fine. This is however not always the case - buffers may be allocated
+         * using kmalloc() - so the usb core needs to be told that it must copy
+         * data into our local memory if the buffers happen to be placed in
+         * regular memory. The HCD_LOCAL_MEM flag does just that.
+         */
+
+        if (!dma_declare_coherent_memory(dev, mem->start,
+                                         mem->start - mem->parent->start,
+                                         (mem->end - mem->start) + 1,
+                                         DMA_MEMORY_MAP |
+                                         DMA_MEMORY_EXCLUSIVE)) {
+                dev_err(dev, "cannot declare coherent memory\n");
+                retval = -ENXIO;
+                goto err1;
+        }
+
+        /* allocate, reserve and remap resources for registers */
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (res == NULL) {
+                dev_err(dev, "no resource definition for registers\n");
+                retval = -ENOENT;
+                goto err2;
+        }
+
+        hcd = usb_create_hcd(driver, &pdev->dev, pdev->dev.bus_id);
+        if (!hcd) {
+                retval = -ENOMEM;
+                goto err2;
+        }
+
+        hcd->rsrc_start = res->start;
+        hcd->rsrc_len = res->end - res->start + 1;
+
+        if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, pdev->name)) {
+                dev_err(dev, "request_mem_region failed\n");
+                retval = -EBUSY;
+                goto err3;
+        }
+
+        hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
+        if (hcd->regs == NULL) {
+                dev_err(dev, "cannot remap registers\n");
+                retval = -ENXIO;
+                goto err4;
+        }
+
+        ohci_hcd_init(hcd_to_ohci(hcd));
+
+        retval = usb_add_hcd(hcd, irq, IRQF_DISABLED | IRQF_SHARED);
+        if (retval)
+                goto err4;
+
+        /* enable power and unmask interrupts */
+
+        sm501_unit_power(dev->parent, SM501_GATE_USB_HOST, 1);
+        sm501_modify_reg(dev->parent, SM501_IRQ_MASK, 1 << 6, 0);
+
+        return 0;
+err4:
+        release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+err3:
+        usb_put_hcd(hcd);
+err2:
+        dma_release_declared_memory(dev);
+err1:
+        release_mem_region(mem->start, mem->end - mem->start + 1);
+err0:
+        return retval;
+}
+
+static int ohci_hcd_sm501_drv_remove(struct platform_device *pdev)
+{
+        struct usb_hcd *hcd = platform_get_drvdata(pdev);
+        struct resource *mem;
+
+        usb_remove_hcd(hcd);
+        release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+        usb_put_hcd(hcd);
+        dma_release_declared_memory(&pdev->dev);
+        mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+        release_mem_region(mem->start, mem->end - mem->start + 1);
+
+        /* mask interrupts and disable power */
+
+        sm501_modify_reg(pdev->dev.parent, SM501_IRQ_MASK, 0, 1 << 6);
+        sm501_unit_power(pdev->dev.parent, SM501_GATE_USB_HOST, 0);
+
+        platform_set_drvdata(pdev, NULL);
+        return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+#ifdef CONFIG_PM
+static int ohci_sm501_suspend(struct platform_device *pdev, pm_message_t msg)
+{
+        struct device *dev = &pdev->dev;
+        struct ohci_hcd *ohci = hcd_to_ohci(platform_get_drvdata(pdev));
+
+        if (time_before(jiffies, ohci->next_statechange))
+                msleep(5);
+        ohci->next_statechange = jiffies;
+
+        sm501_unit_power(dev->parent, SM501_GATE_USB_HOST, 0);
+        ohci_to_hcd(ohci)->state = HC_STATE_SUSPENDED;
+        dev->power.power_state = PMSG_SUSPEND;
+        return 0;
+}
+
+static int ohci_sm501_resume(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct ohci_hcd *ohci = hcd_to_ohci(platform_get_drvdata(pdev));
+
+        if (time_before(jiffies, ohci->next_statechange))
+                msleep(5);
+        ohci->next_statechange = jiffies;
+
+        sm501_unit_power(dev->parent, SM501_GATE_USB_HOST, 1);
+        dev->power.power_state = PMSG_ON;
+        usb_hcd_resume_root_hub(platform_get_drvdata(pdev));
+        return 0;
+}
+#endif
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * Driver definition to register with the SM501 bus
+ */
+static struct platform_driver ohci_hcd_sm501_driver = {
+        .probe          = ohci_hcd_sm501_drv_probe,
+        .remove         = ohci_hcd_sm501_drv_remove,
+        .shutdown       = usb_hcd_platform_shutdown,
+#ifdef  CONFIG_PM
+        .suspend        = ohci_sm501_suspend,
+        .resume         = ohci_sm501_resume,
+#endif
+        .driver         = {
+                .owner  = THIS_MODULE,
+                .name   = "sm501-usb",
+        },
+};