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linux/drivers/usb/host/ohci-sa1111.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

270 lines
6.5 KiB
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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
*
* SA1111 Bus Glue
*
* Written by Christopher Hoover <ch@hpl.hp.com>
* Based on fragments of previous driver by Russell King et al.
*
* This file is licenced under the GPL.
*/
#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <mach/assabet.h>
#include <mach/badge4.h>
#include <asm/hardware/sa1111.h>
#ifndef CONFIG_SA1111
#error "This file is SA-1111 bus glue. CONFIG_SA1111 must be defined."
#endif
extern int usb_disabled(void);
/*-------------------------------------------------------------------------*/
static void sa1111_start_hc(struct sa1111_dev *dev)
{
unsigned int usb_rst = 0;
printk(KERN_DEBUG __FILE__
": starting SA-1111 OHCI USB Controller\n");
#ifdef CONFIG_SA1100_BADGE4
if (machine_is_badge4()) {
badge4_set_5V(BADGE4_5V_USB, 1);
}
#endif
if (machine_is_xp860() ||
machine_has_neponset() ||
machine_is_pfs168() ||
machine_is_badge4())
usb_rst = USB_RESET_PWRSENSELOW | USB_RESET_PWRCTRLLOW;
/*
* Configure the power sense and control lines. Place the USB
* host controller in reset.
*/
sa1111_writel(usb_rst | USB_RESET_FORCEIFRESET | USB_RESET_FORCEHCRESET,
dev->mapbase + SA1111_USB_RESET);
/*
* Now, carefully enable the USB clock, and take
* the USB host controller out of reset.
*/
sa1111_enable_device(dev);
udelay(11);
sa1111_writel(usb_rst, dev->mapbase + SA1111_USB_RESET);
}
static void sa1111_stop_hc(struct sa1111_dev *dev)
{
unsigned int usb_rst;
printk(KERN_DEBUG __FILE__
": stopping SA-1111 OHCI USB Controller\n");
/*
* Put the USB host controller into reset.
*/
usb_rst = sa1111_readl(dev->mapbase + SA1111_USB_RESET);
sa1111_writel(usb_rst | USB_RESET_FORCEIFRESET | USB_RESET_FORCEHCRESET,
dev->mapbase + SA1111_USB_RESET);
/*
* Stop the USB clock.
*/
sa1111_disable_device(dev);
#ifdef CONFIG_SA1100_BADGE4
if (machine_is_badge4()) {
/* Disable power to the USB bus */
badge4_set_5V(BADGE4_5V_USB, 0);
}
#endif
}
/*-------------------------------------------------------------------------*/
#if 0
static void dump_hci_status(struct usb_hcd *hcd, const char *label)
{
unsigned long status = sa1111_readl(hcd->regs + SA1111_USB_STATUS);
dbg ("%s USB_STATUS = { %s%s%s%s%s}", label,
((status & USB_STATUS_IRQHCIRMTWKUP) ? "IRQHCIRMTWKUP " : ""),
((status & USB_STATUS_IRQHCIBUFFACC) ? "IRQHCIBUFFACC " : ""),
((status & USB_STATUS_NIRQHCIM) ? "" : "IRQHCIM "),
((status & USB_STATUS_NHCIMFCLR) ? "" : "HCIMFCLR "),
((status & USB_STATUS_USBPWRSENSE) ? "USBPWRSENSE " : ""));
}
#endif
/*-------------------------------------------------------------------------*/
/* configure so an HC device and id are always provided */
/* always called with process context; sleeping is OK */
/**
* usb_hcd_sa1111_probe - initialize SA-1111-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_sa1111_probe (const struct hc_driver *driver,
struct sa1111_dev *dev)
{
struct usb_hcd *hcd;
int retval;
hcd = usb_create_hcd (driver, &dev->dev, "sa1111");
if (!hcd)
return -ENOMEM;
hcd->rsrc_start = dev->res.start;
hcd->rsrc_len = dev->res.end - dev->res.start + 1;
if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
dbg("request_mem_region failed");
retval = -EBUSY;
goto err1;
}
hcd->regs = dev->mapbase;
sa1111_start_hc(dev);
ohci_hcd_init(hcd_to_ohci(hcd));
retval = usb_add_hcd(hcd, dev->irq[1], IRQF_DISABLED);
if (retval == 0)
return retval;
sa1111_stop_hc(dev);
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_sa1111_remove - shutdown processing for SA-1111-based HCDs
* @dev: USB Host Controller being removed
* Context: !in_interrupt()
*
* Reverses the effect of usb_hcd_sa1111_probe(), first invoking
* the HCD's stop() method. It is always called from a thread
* context, normally "rmmod", "apmd", or something similar.
*
*/
void usb_hcd_sa1111_remove (struct usb_hcd *hcd, struct sa1111_dev *dev)
{
usb_remove_hcd(hcd);
sa1111_stop_hc(dev);
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
usb_put_hcd(hcd);
}
/*-------------------------------------------------------------------------*/
static int __devinit
ohci_sa1111_start (struct usb_hcd *hcd)
{
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;
}
return 0;
}
/*-------------------------------------------------------------------------*/
static const struct hc_driver ohci_sa1111_hc_driver = {
.description = hcd_name,
.product_desc = "SA-1111 OHCI",
.hcd_priv_size = sizeof(struct ohci_hcd),
/*
* generic hardware linkage
*/
.irq = ohci_irq,
.flags = HCD_USB11 | HCD_MEMORY,
/*
* basic lifecycle operations
*/
.start = ohci_sa1111_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
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
#endif
.start_port_reset = ohci_start_port_reset,
};
/*-------------------------------------------------------------------------*/
static int ohci_hcd_sa1111_drv_probe(struct sa1111_dev *dev)
{
int ret;
if (usb_disabled())
return -ENODEV;
ret = usb_hcd_sa1111_probe(&ohci_sa1111_hc_driver, dev);
return ret;
}
static int ohci_hcd_sa1111_drv_remove(struct sa1111_dev *dev)
{
struct usb_hcd *hcd = sa1111_get_drvdata(dev);
usb_hcd_sa1111_remove(hcd, dev);
return 0;
}
static struct sa1111_driver ohci_hcd_sa1111_driver = {
.drv = {
.name = "sa1111-ohci",
},
.devid = SA1111_DEVID_USB,
.probe = ohci_hcd_sa1111_drv_probe,
.remove = ohci_hcd_sa1111_drv_remove,
};
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