linux/drivers/usb/host/ohci-pxa27x.c
Alan Stern e872154921 USB: don't explicitly reenable root-hub status interrupts
This patch (as1069b) 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>
2008-04-24 21:16:53 -07:00

379 lines
8.3 KiB
C

/*
* 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 pxa27x
*
* 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 pxa27x from ohci-lh7a404.c
* by Nick Bane <nick@cecomputing.co.uk> 26-8-2004
*
* This file is licenced under the GPL.
*/
#include <linux/device.h>
#include <linux/signal.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <asm/mach-types.h>
#include <asm/hardware.h>
#include <asm/arch/pxa-regs.h>
#include <asm/arch/ohci.h>
#define PXA_UHC_MAX_PORTNUM 3
#define UHCRHPS(x) __REG2( 0x4C000050, (x)<<2 )
static struct clk *usb_clk;
/*
PMM_NPS_MODE -- PMM Non-power switching mode
Ports are powered continuously.
PMM_GLOBAL_MODE -- PMM global switching mode
All ports are powered at the same time.
PMM_PERPORT_MODE -- PMM per port switching mode
Ports are powered individually.
*/
static int pxa27x_ohci_select_pmm( int mode )
{
switch ( mode ) {
case PMM_NPS_MODE:
UHCRHDA |= RH_A_NPS;
break;
case PMM_GLOBAL_MODE:
UHCRHDA &= ~(RH_A_NPS & RH_A_PSM);
break;
case PMM_PERPORT_MODE:
UHCRHDA &= ~(RH_A_NPS);
UHCRHDA |= RH_A_PSM;
/* Set port power control mask bits, only 3 ports. */
UHCRHDB |= (0x7<<17);
break;
default:
printk( KERN_ERR
"Invalid mode %d, set to non-power switch mode.\n",
mode );
UHCRHDA |= RH_A_NPS;
}
return 0;
}
extern int usb_disabled(void);
/*-------------------------------------------------------------------------*/
static int pxa27x_start_hc(struct device *dev)
{
int retval = 0;
struct pxaohci_platform_data *inf;
inf = dev->platform_data;
clk_enable(usb_clk);
UHCHR |= UHCHR_FHR;
udelay(11);
UHCHR &= ~UHCHR_FHR;
UHCHR |= UHCHR_FSBIR;
while (UHCHR & UHCHR_FSBIR)
cpu_relax();
if (inf->init)
retval = inf->init(dev);
if (retval < 0)
return retval;
UHCHR &= ~UHCHR_SSE;
UHCHIE = (UHCHIE_UPRIE | UHCHIE_RWIE);
/* Clear any OTG Pin Hold */
if (PSSR & PSSR_OTGPH)
PSSR |= PSSR_OTGPH;
return 0;
}
static void pxa27x_stop_hc(struct device *dev)
{
struct pxaohci_platform_data *inf;
inf = dev->platform_data;
if (inf->exit)
inf->exit(dev);
UHCHR |= UHCHR_FHR;
udelay(11);
UHCHR &= ~UHCHR_FHR;
UHCCOMS |= 1;
udelay(10);
clk_disable(usb_clk);
}
/*-------------------------------------------------------------------------*/
/* configure so an HC device and id are always provided */
/* always called with process context; sleeping is OK */
/**
* usb_hcd_pxa27x_probe - initialize pxa27x-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.
*
*/
int usb_hcd_pxa27x_probe (const struct hc_driver *driver, struct platform_device *pdev)
{
int retval;
struct usb_hcd *hcd;
struct pxaohci_platform_data *inf;
inf = pdev->dev.platform_data;
if (!inf)
return -ENODEV;
if (pdev->resource[1].flags != IORESOURCE_IRQ) {
pr_debug ("resource[1] is not IORESOURCE_IRQ");
return -ENOMEM;
}
usb_clk = clk_get(&pdev->dev, "USBCLK");
if (IS_ERR(usb_clk))
return PTR_ERR(usb_clk);
hcd = usb_create_hcd (driver, &pdev->dev, "pxa27x");
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");
retval = -EBUSY;
goto err1;
}
hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
if (!hcd->regs) {
pr_debug("ioremap failed");
retval = -ENOMEM;
goto err2;
}
if ((retval = pxa27x_start_hc(&pdev->dev)) < 0) {
pr_debug("pxa27x_start_hc failed");
goto err3;
}
/* Select Power Management Mode */
pxa27x_ohci_select_pmm(inf->port_mode);
if (inf->power_budget)
hcd->power_budget = inf->power_budget;
ohci_hcd_init(hcd_to_ohci(hcd));
retval = usb_add_hcd(hcd, pdev->resource[1].start, IRQF_DISABLED);
if (retval == 0)
return retval;
pxa27x_stop_hc(&pdev->dev);
err3:
iounmap(hcd->regs);
err2:
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
err1:
usb_put_hcd(hcd);
clk_put(usb_clk);
return retval;
}
/* may be called without controller electrically present */
/* may be called with controller, bus, and devices active */
/**
* usb_hcd_pxa27x_remove - shutdown processing for pxa27x-based HCDs
* @dev: USB Host Controller being removed
* Context: !in_interrupt()
*
* Reverses the effect of usb_hcd_pxa27x_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_pxa27x_remove (struct usb_hcd *hcd, struct platform_device *pdev)
{
usb_remove_hcd(hcd);
pxa27x_stop_hc(&pdev->dev);
iounmap(hcd->regs);
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
usb_put_hcd(hcd);
clk_put(usb_clk);
}
/*-------------------------------------------------------------------------*/
static int __devinit
ohci_pxa27x_start (struct usb_hcd *hcd)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
int ret;
ohci_dbg (ohci, "ohci_pxa27x_start, ohci:%p", ohci);
/* The value of NDP in roothub_a is incorrect on this hardware */
ohci->num_ports = 3;
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_pxa27x_hc_driver = {
.description = hcd_name,
.product_desc = "PXA27x OHCI",
.hcd_priv_size = sizeof(struct ohci_hcd),
/*
* generic hardware linkage
*/
.irq = ohci_irq,
.flags = HCD_USB11 | HCD_MEMORY,
/*
* basic lifecycle operations
*/
.start = ohci_pxa27x_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_pxa27x_drv_probe(struct platform_device *pdev)
{
pr_debug ("In ohci_hcd_pxa27x_drv_probe");
if (usb_disabled())
return -ENODEV;
return usb_hcd_pxa27x_probe(&ohci_pxa27x_hc_driver, pdev);
}
static int ohci_hcd_pxa27x_drv_remove(struct platform_device *pdev)
{
struct usb_hcd *hcd = platform_get_drvdata(pdev);
usb_hcd_pxa27x_remove(hcd, pdev);
platform_set_drvdata(pdev, NULL);
return 0;
}
#ifdef CONFIG_PM
static int ohci_hcd_pxa27x_drv_suspend(struct platform_device *pdev, pm_message_t state)
{
struct usb_hcd *hcd = platform_get_drvdata(pdev);
struct ohci_hcd *ohci = hcd_to_ohci(hcd);
if (time_before(jiffies, ohci->next_statechange))
msleep(5);
ohci->next_statechange = jiffies;
pxa27x_stop_hc(&pdev->dev);
hcd->state = HC_STATE_SUSPENDED;
return 0;
}
static int ohci_hcd_pxa27x_drv_resume(struct platform_device *pdev)
{
struct usb_hcd *hcd = platform_get_drvdata(pdev);
struct ohci_hcd *ohci = hcd_to_ohci(hcd);
int status;
if (time_before(jiffies, ohci->next_statechange))
msleep(5);
ohci->next_statechange = jiffies;
if ((status = pxa27x_start_hc(&pdev->dev)) < 0)
return status;
ohci_finish_controller_resume(hcd);
return 0;
}
#endif
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:pxa27x-ohci");
static struct platform_driver ohci_hcd_pxa27x_driver = {
.probe = ohci_hcd_pxa27x_drv_probe,
.remove = ohci_hcd_pxa27x_drv_remove,
.shutdown = usb_hcd_platform_shutdown,
#ifdef CONFIG_PM
.suspend = ohci_hcd_pxa27x_drv_suspend,
.resume = ohci_hcd_pxa27x_drv_resume,
#endif
.driver = {
.name = "pxa27x-ohci",
.owner = THIS_MODULE,
},
};