kernel-ark/drivers/usb/host/pci-quirks.c
Roel Kluin 6e14bda1b1 USB: count reaches -1, tested 0
With a postfix decrement count will reach -1 rather than 0,
so the warning will not be issued.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24 16:20:29 -07:00

356 lines
9.9 KiB
C

/*
* This file contains code to reset and initialize USB host controllers.
* Some of it includes work-arounds for PCI hardware and BIOS quirks.
* It may need to run early during booting -- before USB would normally
* initialize -- to ensure that Linux doesn't use any legacy modes.
*
* Copyright (c) 1999 Martin Mares <mj@ucw.cz>
* (and others)
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/acpi.h>
#include "pci-quirks.h"
#define UHCI_USBLEGSUP 0xc0 /* legacy support */
#define UHCI_USBCMD 0 /* command register */
#define UHCI_USBINTR 4 /* interrupt register */
#define UHCI_USBLEGSUP_RWC 0x8f00 /* the R/WC bits */
#define UHCI_USBLEGSUP_RO 0x5040 /* R/O and reserved bits */
#define UHCI_USBCMD_RUN 0x0001 /* RUN/STOP bit */
#define UHCI_USBCMD_HCRESET 0x0002 /* Host Controller reset */
#define UHCI_USBCMD_EGSM 0x0008 /* Global Suspend Mode */
#define UHCI_USBCMD_CONFIGURE 0x0040 /* Config Flag */
#define UHCI_USBINTR_RESUME 0x0002 /* Resume interrupt enable */
#define OHCI_CONTROL 0x04
#define OHCI_CMDSTATUS 0x08
#define OHCI_INTRSTATUS 0x0c
#define OHCI_INTRENABLE 0x10
#define OHCI_INTRDISABLE 0x14
#define OHCI_OCR (1 << 3) /* ownership change request */
#define OHCI_CTRL_RWC (1 << 9) /* remote wakeup connected */
#define OHCI_CTRL_IR (1 << 8) /* interrupt routing */
#define OHCI_INTR_OC (1 << 30) /* ownership change */
#define EHCI_HCC_PARAMS 0x08 /* extended capabilities */
#define EHCI_USBCMD 0 /* command register */
#define EHCI_USBCMD_RUN (1 << 0) /* RUN/STOP bit */
#define EHCI_USBSTS 4 /* status register */
#define EHCI_USBSTS_HALTED (1 << 12) /* HCHalted bit */
#define EHCI_USBINTR 8 /* interrupt register */
#define EHCI_CONFIGFLAG 0x40 /* configured flag register */
#define EHCI_USBLEGSUP 0 /* legacy support register */
#define EHCI_USBLEGSUP_BIOS (1 << 16) /* BIOS semaphore */
#define EHCI_USBLEGSUP_OS (1 << 24) /* OS semaphore */
#define EHCI_USBLEGCTLSTS 4 /* legacy control/status */
#define EHCI_USBLEGCTLSTS_SOOE (1 << 13) /* SMI on ownership change */
/*
* Make sure the controller is completely inactive, unable to
* generate interrupts or do DMA.
*/
void uhci_reset_hc(struct pci_dev *pdev, unsigned long base)
{
/* Turn off PIRQ enable and SMI enable. (This also turns off the
* BIOS's USB Legacy Support.) Turn off all the R/WC bits too.
*/
pci_write_config_word(pdev, UHCI_USBLEGSUP, UHCI_USBLEGSUP_RWC);
/* Reset the HC - this will force us to get a
* new notification of any already connected
* ports due to the virtual disconnect that it
* implies.
*/
outw(UHCI_USBCMD_HCRESET, base + UHCI_USBCMD);
mb();
udelay(5);
if (inw(base + UHCI_USBCMD) & UHCI_USBCMD_HCRESET)
dev_warn(&pdev->dev, "HCRESET not completed yet!\n");
/* Just to be safe, disable interrupt requests and
* make sure the controller is stopped.
*/
outw(0, base + UHCI_USBINTR);
outw(0, base + UHCI_USBCMD);
}
EXPORT_SYMBOL_GPL(uhci_reset_hc);
/*
* Initialize a controller that was newly discovered or has just been
* resumed. In either case we can't be sure of its previous state.
*
* Returns: 1 if the controller was reset, 0 otherwise.
*/
int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base)
{
u16 legsup;
unsigned int cmd, intr;
/*
* When restarting a suspended controller, we expect all the
* settings to be the same as we left them:
*
* PIRQ and SMI disabled, no R/W bits set in USBLEGSUP;
* Controller is stopped and configured with EGSM set;
* No interrupts enabled except possibly Resume Detect.
*
* If any of these conditions are violated we do a complete reset.
*/
pci_read_config_word(pdev, UHCI_USBLEGSUP, &legsup);
if (legsup & ~(UHCI_USBLEGSUP_RO | UHCI_USBLEGSUP_RWC)) {
dev_dbg(&pdev->dev, "%s: legsup = 0x%04x\n",
__func__, legsup);
goto reset_needed;
}
cmd = inw(base + UHCI_USBCMD);
if ((cmd & UHCI_USBCMD_RUN) || !(cmd & UHCI_USBCMD_CONFIGURE) ||
!(cmd & UHCI_USBCMD_EGSM)) {
dev_dbg(&pdev->dev, "%s: cmd = 0x%04x\n",
__func__, cmd);
goto reset_needed;
}
intr = inw(base + UHCI_USBINTR);
if (intr & (~UHCI_USBINTR_RESUME)) {
dev_dbg(&pdev->dev, "%s: intr = 0x%04x\n",
__func__, intr);
goto reset_needed;
}
return 0;
reset_needed:
dev_dbg(&pdev->dev, "Performing full reset\n");
uhci_reset_hc(pdev, base);
return 1;
}
EXPORT_SYMBOL_GPL(uhci_check_and_reset_hc);
static inline int io_type_enabled(struct pci_dev *pdev, unsigned int mask)
{
u16 cmd;
return !pci_read_config_word(pdev, PCI_COMMAND, &cmd) && (cmd & mask);
}
#define pio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_IO)
#define mmio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_MEMORY)
static void __devinit quirk_usb_handoff_uhci(struct pci_dev *pdev)
{
unsigned long base = 0;
int i;
if (!pio_enabled(pdev))
return;
for (i = 0; i < PCI_ROM_RESOURCE; i++)
if ((pci_resource_flags(pdev, i) & IORESOURCE_IO)) {
base = pci_resource_start(pdev, i);
break;
}
if (base)
uhci_check_and_reset_hc(pdev, base);
}
static int __devinit mmio_resource_enabled(struct pci_dev *pdev, int idx)
{
return pci_resource_start(pdev, idx) && mmio_enabled(pdev);
}
static void __devinit quirk_usb_handoff_ohci(struct pci_dev *pdev)
{
void __iomem *base;
if (!mmio_resource_enabled(pdev, 0))
return;
base = pci_ioremap_bar(pdev, 0);
if (base == NULL)
return;
/* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
#ifndef __hppa__
{
u32 control = readl(base + OHCI_CONTROL);
if (control & OHCI_CTRL_IR) {
int wait_time = 500; /* arbitrary; 5 seconds */
writel(OHCI_INTR_OC, base + OHCI_INTRENABLE);
writel(OHCI_OCR, base + OHCI_CMDSTATUS);
while (wait_time > 0 &&
readl(base + OHCI_CONTROL) & OHCI_CTRL_IR) {
wait_time -= 10;
msleep(10);
}
if (wait_time <= 0)
dev_warn(&pdev->dev, "OHCI: BIOS handoff failed"
" (BIOS bug?) %08x\n",
readl(base + OHCI_CONTROL));
/* reset controller, preserving RWC */
writel(control & OHCI_CTRL_RWC, base + OHCI_CONTROL);
}
}
#endif
/*
* disable interrupts
*/
writel(~(u32)0, base + OHCI_INTRDISABLE);
writel(~(u32)0, base + OHCI_INTRSTATUS);
iounmap(base);
}
static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
{
int wait_time, delta;
void __iomem *base, *op_reg_base;
u32 hcc_params, val;
u8 offset, cap_length;
int count = 256/4;
int tried_handoff = 0;
if (!mmio_resource_enabled(pdev, 0))
return;
base = pci_ioremap_bar(pdev, 0);
if (base == NULL)
return;
cap_length = readb(base);
op_reg_base = base + cap_length;
/* EHCI 0.96 and later may have "extended capabilities"
* spec section 5.1 explains the bios handoff, e.g. for
* booting from USB disk or using a usb keyboard
*/
hcc_params = readl(base + EHCI_HCC_PARAMS);
offset = (hcc_params >> 8) & 0xff;
while (offset && --count) {
u32 cap;
int msec;
pci_read_config_dword(pdev, offset, &cap);
switch (cap & 0xff) {
case 1: /* BIOS/SMM/... handoff support */
if ((cap & EHCI_USBLEGSUP_BIOS)) {
dev_dbg(&pdev->dev, "EHCI: BIOS handoff\n");
#if 0
/* aleksey_gorelov@phoenix.com reports that some systems need SMI forced on,
* but that seems dubious in general (the BIOS left it off intentionally)
* and is known to prevent some systems from booting. so we won't do this
* unless maybe we can determine when we're on a system that needs SMI forced.
*/
/* BIOS workaround (?): be sure the
* pre-Linux code receives the SMI
*/
pci_read_config_dword(pdev,
offset + EHCI_USBLEGCTLSTS,
&val);
pci_write_config_dword(pdev,
offset + EHCI_USBLEGCTLSTS,
val | EHCI_USBLEGCTLSTS_SOOE);
#endif
/* some systems get upset if this semaphore is
* set for any other reason than forcing a BIOS
* handoff..
*/
pci_write_config_byte(pdev, offset + 3, 1);
}
/* if boot firmware now owns EHCI, spin till
* it hands it over.
*/
msec = 1000;
while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
tried_handoff = 1;
msleep(10);
msec -= 10;
pci_read_config_dword(pdev, offset, &cap);
}
if (cap & EHCI_USBLEGSUP_BIOS) {
/* well, possibly buggy BIOS... try to shut
* it down, and hope nothing goes too wrong
*/
dev_warn(&pdev->dev, "EHCI: BIOS handoff failed"
" (BIOS bug?) %08x\n", cap);
pci_write_config_byte(pdev, offset + 2, 0);
}
/* just in case, always disable EHCI SMIs */
pci_write_config_dword(pdev,
offset + EHCI_USBLEGCTLSTS,
0);
/* If the BIOS ever owned the controller then we
* can't expect any power sessions to remain intact.
*/
if (tried_handoff)
writel(0, op_reg_base + EHCI_CONFIGFLAG);
break;
case 0: /* illegal reserved capability */
cap = 0;
/* FALLTHROUGH */
default:
dev_warn(&pdev->dev, "EHCI: unrecognized capability "
"%02x\n", cap & 0xff);
break;
}
offset = (cap >> 8) & 0xff;
}
if (!count)
dev_printk(KERN_DEBUG, &pdev->dev, "EHCI: capability loop?\n");
/*
* halt EHCI & disable its interrupts in any case
*/
val = readl(op_reg_base + EHCI_USBSTS);
if ((val & EHCI_USBSTS_HALTED) == 0) {
val = readl(op_reg_base + EHCI_USBCMD);
val &= ~EHCI_USBCMD_RUN;
writel(val, op_reg_base + EHCI_USBCMD);
wait_time = 2000;
delta = 100;
do {
writel(0x3f, op_reg_base + EHCI_USBSTS);
udelay(delta);
wait_time -= delta;
val = readl(op_reg_base + EHCI_USBSTS);
if ((val == ~(u32)0) || (val & EHCI_USBSTS_HALTED)) {
break;
}
} while (wait_time > 0);
}
writel(0, op_reg_base + EHCI_USBINTR);
writel(0x3f, op_reg_base + EHCI_USBSTS);
iounmap(base);
return;
}
static void __devinit quirk_usb_early_handoff(struct pci_dev *pdev)
{
if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
quirk_usb_handoff_uhci(pdev);
else if (pdev->class == PCI_CLASS_SERIAL_USB_OHCI)
quirk_usb_handoff_ohci(pdev);
else if (pdev->class == PCI_CLASS_SERIAL_USB_EHCI)
quirk_usb_disable_ehci(pdev);
}
DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, quirk_usb_early_handoff);