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linux/drivers/usb/host/ohci-au1xxx.c
Alan Stern b5fb454f69 USB: automatically enable RHSC interrupts 
This patch (as1069c) changes the way OHCI root-hub status-change
interrupts are enabled.  Currently a special HCD method,
hub_irq_enable(), is called when the hub driver is finished using a
root hub.  This approach turns out to be subject to races, resulting
in unnecessary polling.

The patch does away with the method entirely.  Instead, the driver
automatically enables the RHSC interrupt when no more status changes
are present.  This scheme is safe with controllers using
level-triggered semantics for their interrupt flags.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-21 10:26:38 -07:00

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/*
* OHCI HCD (Host Controller Driver) for USB.
*
* (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
* (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
* (C) Copyright 2002 Hewlett-Packard Company
*
* Bus Glue for AMD Alchemy Au1xxx
*
* Written by Christopher Hoover <ch@hpl.hp.com>
* Based on fragments of previous driver by Russell King et al.
*
* Modified for LH7A404 from ohci-sa1111.c
* by Durgesh Pattamatta <pattamattad@sharpsec.com>
* Modified for AMD Alchemy Au1xxx
* by Matt Porter <mporter@kernel.crashing.org>
*
* This file is licenced under the GPL.
*/
#include <linux/platform_device.h>
#include <linux/signal.h>
#include <asm/mach-au1x00/au1000.h>
#ifndef CONFIG_SOC_AU1200
#define USBH_ENABLE_BE (1<<0)
#define USBH_ENABLE_C (1<<1)
#define USBH_ENABLE_E (1<<2)
#define USBH_ENABLE_CE (1<<3)
#define USBH_ENABLE_RD (1<<4)
#ifdef __LITTLE_ENDIAN
#define USBH_ENABLE_INIT (USBH_ENABLE_CE | USBH_ENABLE_E | USBH_ENABLE_C)
#elif __BIG_ENDIAN
#define USBH_ENABLE_INIT (USBH_ENABLE_CE | USBH_ENABLE_E | USBH_ENABLE_C | \
USBH_ENABLE_BE)
#else
#error not byte order defined
#endif
#else /* Au1200 */
#define USB_HOST_CONFIG (USB_MSR_BASE + USB_MSR_MCFG)
#define USB_MCFG_PFEN (1<<31)
#define USB_MCFG_RDCOMB (1<<30)
#define USB_MCFG_SSDEN (1<<23)
#define USB_MCFG_OHCCLKEN (1<<16)
#ifdef CONFIG_DMA_COHERENT
#define USB_MCFG_UCAM (1<<7)
#else
#define USB_MCFG_UCAM (0)
#endif
#define USB_MCFG_OBMEN (1<<1)
#define USB_MCFG_OMEMEN (1<<0)
#define USBH_ENABLE_CE USB_MCFG_OHCCLKEN
#define USBH_ENABLE_INIT (USB_MCFG_PFEN | USB_MCFG_RDCOMB | \
USBH_ENABLE_CE | USB_MCFG_SSDEN | \
USB_MCFG_UCAM | \
USB_MCFG_OBMEN | USB_MCFG_OMEMEN)
#define USBH_DISABLE (USB_MCFG_OBMEN | USB_MCFG_OMEMEN)
#endif /* Au1200 */
extern int usb_disabled(void);
static void au1xxx_start_ohc(void)
{
/* enable host controller */
#ifndef CONFIG_SOC_AU1200
au_writel(USBH_ENABLE_CE, USB_HOST_CONFIG);
au_sync();
udelay(1000);
au_writel(au_readl(USB_HOST_CONFIG) | USBH_ENABLE_INIT, USB_HOST_CONFIG);
au_sync();
udelay(1000);
/* wait for reset complete (read register twice; see au1500 errata) */
while (au_readl(USB_HOST_CONFIG),
!(au_readl(USB_HOST_CONFIG) & USBH_ENABLE_RD))
udelay(1000);
#else /* Au1200 */
au_writel(au_readl(USB_HOST_CONFIG) | USBH_ENABLE_CE, USB_HOST_CONFIG);
au_sync();
udelay(1000);
au_writel(au_readl(USB_HOST_CONFIG) | USBH_ENABLE_INIT, USB_HOST_CONFIG);
au_sync();
udelay(2000);
#endif /* Au1200 */
}
static void au1xxx_stop_ohc(void)
{
#ifdef CONFIG_SOC_AU1200
/* Disable mem */
au_writel(au_readl(USB_HOST_CONFIG) & ~USBH_DISABLE, USB_HOST_CONFIG);
au_sync();
udelay(1000);
#endif
/* Disable clock */
au_writel(au_readl(USB_HOST_CONFIG) & ~USBH_ENABLE_CE, USB_HOST_CONFIG);
au_sync();
}
static int __devinit ohci_au1xxx_start(struct usb_hcd *hcd)
{
struct ohci_hcd *ohci = hcd_to_ohci(hcd);
int ret;
ohci_dbg(ohci, "ohci_au1xxx_start, ohci:%p", ohci);
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;
}
return 0;
}
static const struct hc_driver ohci_au1xxx_hc_driver = {
.description = hcd_name,
.product_desc = "Au1xxx OHCI",
.hcd_priv_size = sizeof(struct ohci_hcd),
/*
* generic hardware linkage
*/
.irq = ohci_irq,
.flags = HCD_USB11 | HCD_MEMORY,
/*
* basic lifecycle operations
*/
.start = ohci_au1xxx_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,
#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_au1xxx_drv_probe(struct platform_device *pdev)
{
int ret;
struct usb_hcd *hcd;
if (usb_disabled())
return -ENODEV;
#if defined(CONFIG_SOC_AU1200) && defined(CONFIG_DMA_COHERENT)
/* Au1200 AB USB does not support coherent memory */
if (!(read_c0_prid() & 0xff)) {
printk(KERN_INFO "%s: this is chip revision AB !!\n",
pdev->name);
printk(KERN_INFO "%s: update your board or re-configure "
"the kernel\n", pdev->name);
return -ENODEV;
}
#endif
if (pdev->resource[1].flags != IORESOURCE_IRQ) {
pr_debug("resource[1] is not IORESOURCE_IRQ\n");
return -ENOMEM;
}
hcd = usb_create_hcd(&ohci_au1xxx_hc_driver, &pdev->dev, "au1xxx");
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");
ret = -EBUSY;
goto err1;
}
hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
if (!hcd->regs) {
pr_debug("ioremap failed\n");
ret = -ENOMEM;
goto err2;
}
au1xxx_start_ohc();
ohci_hcd_init(hcd_to_ohci(hcd));
ret = usb_add_hcd(hcd, pdev->resource[1].start,
IRQF_DISABLED | IRQF_SHARED);
if (ret == 0) {
platform_set_drvdata(pdev, hcd);
return ret;
}
au1xxx_stop_ohc();
iounmap(hcd->regs);
err2:
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
err1:
usb_put_hcd(hcd);
return ret;
}
static int ohci_hcd_au1xxx_drv_remove(struct platform_device *pdev)
{
struct usb_hcd *hcd = platform_get_drvdata(pdev);
usb_remove_hcd(hcd);
au1xxx_stop_ohc();
iounmap(hcd->regs);
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
usb_put_hcd(hcd);
platform_set_drvdata(pdev, NULL);
return 0;
}
#ifdef CONFIG_PM
static int ohci_hcd_au1xxx_drv_suspend(struct platform_device *pdev,
pm_message_t message)
{
struct usb_hcd *hcd = platform_get_drvdata(pdev);
struct ohci_hcd *ohci = hcd_to_ohci(hcd);
unsigned long flags;
int rc;
rc = 0;
/* Root hub was already suspended. Disable irq emission and
* mark HW unaccessible, bail out if RH has been resumed. Use
* the spinlock to properly synchronize with possible pending
* RH suspend or resume activity.
*
* This is still racy as hcd->state is manipulated outside of
* any locks =P But that will be a different fix.
*/
spin_lock_irqsave(&ohci->lock, flags);
if (hcd->state != HC_STATE_SUSPENDED) {
rc = -EINVAL;
goto bail;
}
ohci_writel(ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
(void)ohci_readl(ohci, &ohci->regs->intrdisable);
/* make sure snapshot being resumed re-enumerates everything */
if (message.event == PM_EVENT_PRETHAW)
ohci_usb_reset(ohci);
clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
au1xxx_stop_ohc();
bail:
spin_unlock_irqrestore(&ohci->lock, flags);
return rc;
}
static int ohci_hcd_au1xxx_drv_resume(struct platform_device *pdev)
{
struct usb_hcd *hcd = platform_get_drvdata(pdev);
au1xxx_start_ohc();
set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
ohci_finish_controller_resume(hcd);
return 0;
}
#else
#define ohci_hcd_au1xxx_drv_suspend NULL
#define ohci_hcd_au1xxx_drv_resume NULL
#endif
static struct platform_driver ohci_hcd_au1xxx_driver = {
.probe = ohci_hcd_au1xxx_drv_probe,
.remove = ohci_hcd_au1xxx_drv_remove,
.shutdown = usb_hcd_platform_shutdown,
.suspend = ohci_hcd_au1xxx_drv_suspend,
.resume = ohci_hcd_au1xxx_drv_resume,
.driver = {
.name = "au1xxx-ohci",
.owner = THIS_MODULE,
},
};
MODULE_ALIAS("platform:au1xxx-ohci");
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