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>

drivers/usb/host/ohci-hcd.c

@@ -1052,6 +1052,11 @@ MODULE_LICENSE ("GPL");
 #define SSB_OHCI_DRIVER		ssb_ohci_driver
 #endif
 
+#ifdef CONFIG_MFD_SM501
+#include "ohci-sm501.c"
+#define PLATFORM_DRIVER		ohci_hcd_sm501_driver
+#endif
+
 #if	!defined(PCI_DRIVER) &&		\
 	!defined(PLATFORM_DRIVER) &&	\
 	!defined(OF_PLATFORM_DRIVER) &&	\

drivers/usb/host/ohci-sm501.c

+/*
+ * 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",
+	},
+};