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linux-next/drivers/usb/host/ohci-s3c2410.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

504 lines
11 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
*
* USB Bus Glue for Samsung S3C2410
*
* Written by Christopher Hoover <ch@hpl.hp.com>
* Based on fragments of previous driver by Rusell King et al.
*
* Modified for S3C2410 from ohci-sa1111.c, ohci-omap.c and ohci-lh7a40.c
* by Ben Dooks, <ben@simtec.co.uk>
* Copyright (C) 2004 Simtec Electronics
*
* Thanks to basprog@mail.ru for updates to newer kernels
*
* This file is licenced under the GPL.
*/
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <asm/hardware.h>
#include <asm/arch/usb-control.h>
#define valid_port(idx) ((idx) == 1 || (idx) == 2)
/* clock device associated with the hcd */
static struct clk *clk;
static struct clk *usb_clk;
/* forward definitions */
static void s3c2410_hcd_oc(struct s3c2410_hcd_info *info, int port_oc);
/* conversion functions */
static struct s3c2410_hcd_info *to_s3c2410_info(struct usb_hcd *hcd)
{
return hcd->self.controller->platform_data;
}
static void s3c2410_start_hc(struct platform_device *dev, struct usb_hcd *hcd)
{
struct s3c2410_hcd_info *info = dev->dev.platform_data;
dev_dbg(&dev->dev, "s3c2410_start_hc:\n");
clk_enable(usb_clk);
mdelay(2); /* let the bus clock stabilise */
clk_enable(clk);
if (info != NULL) {
info->hcd = hcd;
info->report_oc = s3c2410_hcd_oc;
if (info->enable_oc != NULL) {
(info->enable_oc)(info, 1);
}
}
}
static void s3c2410_stop_hc(struct platform_device *dev)
{
struct s3c2410_hcd_info *info = dev->dev.platform_data;
dev_dbg(&dev->dev, "s3c2410_stop_hc:\n");
if (info != NULL) {
info->report_oc = NULL;
info->hcd = NULL;
if (info->enable_oc != NULL) {
(info->enable_oc)(info, 0);
}
}
clk_disable(clk);
clk_disable(usb_clk);
}
/* ohci_s3c2410_hub_status_data
*
* update the status data from the hub with anything that
* has been detected by our system
*/
static int
ohci_s3c2410_hub_status_data (struct usb_hcd *hcd, char *buf)
{
struct s3c2410_hcd_info *info = to_s3c2410_info(hcd);
struct s3c2410_hcd_port *port;
int orig;
int portno;
orig = ohci_hub_status_data (hcd, buf);
if (info == NULL)
return orig;
port = &info->port[0];
/* mark any changed port as changed */
for (portno = 0; portno < 2; port++, portno++) {
if (port->oc_changed == 1 &&
port->flags & S3C_HCDFLG_USED) {
dev_dbg(hcd->self.controller,
"oc change on port %d\n", portno);
if (orig < 1)
orig = 1;
buf[0] |= 1<<(portno+1);
}
}
return orig;
}
/* s3c2410_usb_set_power
*
* configure the power on a port, by calling the platform device
* routine registered with the platform device
*/
static void s3c2410_usb_set_power(struct s3c2410_hcd_info *info,
int port, int to)
{
if (info == NULL)
return;
if (info->power_control != NULL) {
info->port[port-1].power = to;
(info->power_control)(port-1, to);
}
}
/* ohci_s3c2410_hub_control
*
* look at control requests to the hub, and see if we need
* to take any action or over-ride the results from the
* request.
*/
static int ohci_s3c2410_hub_control (
struct usb_hcd *hcd,
u16 typeReq,
u16 wValue,
u16 wIndex,
char *buf,
u16 wLength)
{
struct s3c2410_hcd_info *info = to_s3c2410_info(hcd);
struct usb_hub_descriptor *desc;
int ret = -EINVAL;
u32 *data = (u32 *)buf;
dev_dbg(hcd->self.controller,
"s3c2410_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
hcd, typeReq, wValue, wIndex, buf, wLength);
/* if we are only an humble host without any special capabilities
* process the request straight away and exit */
if (info == NULL) {
ret = ohci_hub_control(hcd, typeReq, wValue,
wIndex, buf, wLength);
goto out;
}
/* check the request to see if it needs handling */
switch (typeReq) {
case SetPortFeature:
if (wValue == USB_PORT_FEAT_POWER) {
dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
s3c2410_usb_set_power(info, wIndex, 1);
goto out;
}
break;
case ClearPortFeature:
switch (wValue) {
case USB_PORT_FEAT_C_OVER_CURRENT:
dev_dbg(hcd->self.controller,
"ClearPortFeature: C_OVER_CURRENT\n");
if (valid_port(wIndex)) {
info->port[wIndex-1].oc_changed = 0;
info->port[wIndex-1].oc_status = 0;
}
goto out;
case USB_PORT_FEAT_OVER_CURRENT:
dev_dbg(hcd->self.controller,
"ClearPortFeature: OVER_CURRENT\n");
if (valid_port(wIndex)) {
info->port[wIndex-1].oc_status = 0;
}
goto out;
case USB_PORT_FEAT_POWER:
dev_dbg(hcd->self.controller,
"ClearPortFeature: POWER\n");
if (valid_port(wIndex)) {
s3c2410_usb_set_power(info, wIndex, 0);
return 0;
}
}
break;
}
ret = ohci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength);
if (ret)
goto out;
switch (typeReq) {
case GetHubDescriptor:
/* update the hub's descriptor */
desc = (struct usb_hub_descriptor *)buf;
if (info->power_control == NULL)
return ret;
dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
desc->wHubCharacteristics);
/* remove the old configurations for power-switching, and
* over-current protection, and insert our new configuration
*/
desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
desc->wHubCharacteristics |= cpu_to_le16(0x0001);
if (info->enable_oc) {
desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
desc->wHubCharacteristics |= cpu_to_le16(0x0008|0x0001);
}
dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
desc->wHubCharacteristics);
return ret;
case GetPortStatus:
/* check port status */
dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);
if (valid_port(wIndex)) {
if (info->port[wIndex-1].oc_changed) {
*data |= cpu_to_le32(RH_PS_OCIC);
}
if (info->port[wIndex-1].oc_status) {
*data |= cpu_to_le32(RH_PS_POCI);
}
}
}
out:
return ret;
}
/* s3c2410_hcd_oc
*
* handle an over-current report
*/
static void s3c2410_hcd_oc(struct s3c2410_hcd_info *info, int port_oc)
{
struct s3c2410_hcd_port *port;
struct usb_hcd *hcd;
unsigned long flags;
int portno;
if (info == NULL)
return;
port = &info->port[0];
hcd = info->hcd;
local_irq_save(flags);
for (portno = 0; portno < 2; port++, portno++) {
if (port_oc & (1<<portno) &&
port->flags & S3C_HCDFLG_USED) {
port->oc_status = 1;
port->oc_changed = 1;
/* ok, once over-current is detected,
the port needs to be powered down */
s3c2410_usb_set_power(info, portno+1, 0);
}
}
local_irq_restore(flags);
}
/* may be called without controller electrically present */
/* may be called with controller, bus, and devices active */
/*
* usb_hcd_s3c2410_remove - shutdown processing for HCD
* @dev: USB Host Controller being removed
* Context: !in_interrupt()
*
* Reverses the effect of usb_hcd_3c2410_probe(), first invoking
* the HCD's stop() method. It is always called from a thread
* context, normally "rmmod", "apmd", or something similar.
*
*/
static void
usb_hcd_s3c2410_remove (struct usb_hcd *hcd, struct platform_device *dev)
{
usb_remove_hcd(hcd);
s3c2410_stop_hc(dev);
iounmap(hcd->regs);
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
usb_put_hcd(hcd);
}
/**
* usb_hcd_s3c2410_probe - initialize S3C2410-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.
*
*/
static int usb_hcd_s3c2410_probe (const struct hc_driver *driver,
struct platform_device *dev)
{
struct usb_hcd *hcd = NULL;
int retval;
s3c2410_usb_set_power(dev->dev.platform_data, 1, 1);
s3c2410_usb_set_power(dev->dev.platform_data, 2, 1);
hcd = usb_create_hcd(driver, &dev->dev, "s3c24xx");
if (hcd == NULL)
return -ENOMEM;
hcd->rsrc_start = dev->resource[0].start;
hcd->rsrc_len = dev->resource[0].end - dev->resource[0].start + 1;
if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
dev_err(&dev->dev, "request_mem_region failed\n");
retval = -EBUSY;
goto err_put;
}
clk = clk_get(&dev->dev, "usb-host");
if (IS_ERR(clk)) {
dev_err(&dev->dev, "cannot get usb-host clock\n");
retval = -ENOENT;
goto err_mem;
}
usb_clk = clk_get(&dev->dev, "usb-bus-host");
if (IS_ERR(usb_clk)) {
dev_err(&dev->dev, "cannot get usb-host clock\n");
retval = -ENOENT;
goto err_clk;
}
s3c2410_start_hc(dev, hcd);
hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
if (!hcd->regs) {
dev_err(&dev->dev, "ioremap failed\n");
retval = -ENOMEM;
goto err_ioremap;
}
ohci_hcd_init(hcd_to_ohci(hcd));
retval = usb_add_hcd(hcd, dev->resource[1].start, IRQF_DISABLED);
if (retval != 0)
goto err_ioremap;
return 0;
err_ioremap:
s3c2410_stop_hc(dev);
iounmap(hcd->regs);
clk_put(usb_clk);
err_clk:
clk_put(clk);
err_mem:
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
err_put:
usb_put_hcd(hcd);
return retval;
}
/*-------------------------------------------------------------------------*/
static int
ohci_s3c2410_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_s3c2410_hc_driver = {
.description = hcd_name,
.product_desc = "S3C24XX OHCI",
.hcd_priv_size = sizeof(struct ohci_hcd),
/*
* generic hardware linkage
*/
.irq = ohci_irq,
.flags = HCD_USB11 | HCD_MEMORY,
/*
* basic lifecycle operations
*/
.start = ohci_s3c2410_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_s3c2410_hub_status_data,
.hub_control = ohci_s3c2410_hub_control,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
#endif
.start_port_reset = ohci_start_port_reset,
};
/* device driver */
static int ohci_hcd_s3c2410_drv_probe(struct platform_device *pdev)
{
return usb_hcd_s3c2410_probe(&ohci_s3c2410_hc_driver, pdev);
}
static int ohci_hcd_s3c2410_drv_remove(struct platform_device *pdev)
{
struct usb_hcd *hcd = platform_get_drvdata(pdev);
usb_hcd_s3c2410_remove(hcd, pdev);
return 0;
}
static struct platform_driver ohci_hcd_s3c2410_driver = {
.probe = ohci_hcd_s3c2410_drv_probe,
.remove = ohci_hcd_s3c2410_drv_remove,
.shutdown = usb_hcd_platform_shutdown,
/*.suspend = ohci_hcd_s3c2410_drv_suspend, */
/*.resume = ohci_hcd_s3c2410_drv_resume, */
.driver = {
.owner = THIS_MODULE,
.name = "s3c2410-ohci",
},
};
MODULE_ALIAS("platform:s3c2410-ohci");