Commit 38461c5c authored by Thierry Reding's avatar Thierry Reding Committed by Wim Van Sebroeck
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[WATCHDOG] Add support for the Avionic Design Xanthos watchdog timer.



This patch adds support for the watchdog timer on Avionic Design Xanthos
boards.
Signed-off-by: default avatarThierry Reding <thierry.reding@avionic-design.de>
Acked-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent 851b147e
......@@ -282,6 +282,13 @@ config NUC900_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called nuc900_wdt.
config ADX_WATCHDOG
tristate "Avionic Design Xanthos watchdog"
depends on ARCH_PXA_ADX
help
Say Y here if you want support for the watchdog timer on Avionic
Design Xanthos boards.
# AVR32 Architecture
config AT32AP700X_WDT
......
......@@ -45,6 +45,7 @@ obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o
obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o
obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
obj-$(CONFIG_ADX_WATCHDOG) += adx_wdt.o
# AVR32 Architecture
obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
......
/*
* Copyright (C) 2008-2009 Avionic Design GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
#define WATCHDOG_NAME "adx-wdt"
/* register offsets */
#define ADX_WDT_CONTROL 0x00
#define ADX_WDT_CONTROL_ENABLE (1 << 0)
#define ADX_WDT_CONTROL_nRESET (1 << 1)
#define ADX_WDT_TIMEOUT 0x08
static struct platform_device *adx_wdt_dev;
static unsigned long driver_open;
#define WDT_STATE_STOP 0
#define WDT_STATE_START 1
struct adx_wdt {
void __iomem *base;
unsigned long timeout;
unsigned int state;
unsigned int wake;
spinlock_t lock;
};
static struct watchdog_info adx_wdt_info = {
.identity = "Avionic Design Xanthos Watchdog",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
};
static void adx_wdt_start_locked(struct adx_wdt *wdt)
{
u32 ctrl;
ctrl = readl(wdt->base + ADX_WDT_CONTROL);
ctrl |= ADX_WDT_CONTROL_ENABLE;
writel(ctrl, wdt->base + ADX_WDT_CONTROL);
wdt->state = WDT_STATE_START;
}
static void adx_wdt_start(struct adx_wdt *wdt)
{
unsigned long flags;
spin_lock_irqsave(&wdt->lock, flags);
adx_wdt_start_locked(wdt);
spin_unlock_irqrestore(&wdt->lock, flags);
}
static void adx_wdt_stop_locked(struct adx_wdt *wdt)
{
u32 ctrl;
ctrl = readl(wdt->base + ADX_WDT_CONTROL);
ctrl &= ~ADX_WDT_CONTROL_ENABLE;
writel(ctrl, wdt->base + ADX_WDT_CONTROL);
wdt->state = WDT_STATE_STOP;
}
static void adx_wdt_stop(struct adx_wdt *wdt)
{
unsigned long flags;
spin_lock_irqsave(&wdt->lock, flags);
adx_wdt_stop_locked(wdt);
spin_unlock_irqrestore(&wdt->lock, flags);
}
static void adx_wdt_set_timeout(struct adx_wdt *wdt, unsigned long seconds)
{
unsigned long timeout = seconds * 1000;
unsigned long flags;
unsigned int state;
spin_lock_irqsave(&wdt->lock, flags);
state = wdt->state;
adx_wdt_stop_locked(wdt);
writel(timeout, wdt->base + ADX_WDT_TIMEOUT);
if (state == WDT_STATE_START)
adx_wdt_start_locked(wdt);
wdt->timeout = timeout;
spin_unlock_irqrestore(&wdt->lock, flags);
}
static void adx_wdt_get_timeout(struct adx_wdt *wdt, unsigned long *seconds)
{
*seconds = wdt->timeout / 1000;
}
static void adx_wdt_keepalive(struct adx_wdt *wdt)
{
unsigned long flags;
spin_lock_irqsave(&wdt->lock, flags);
writel(wdt->timeout, wdt->base + ADX_WDT_TIMEOUT);
spin_unlock_irqrestore(&wdt->lock, flags);
}
static int adx_wdt_open(struct inode *inode, struct file *file)
{
struct adx_wdt *wdt = platform_get_drvdata(adx_wdt_dev);
if (test_and_set_bit(0, &driver_open))
return -EBUSY;
file->private_data = wdt;
adx_wdt_set_timeout(wdt, 30);
adx_wdt_start(wdt);
return nonseekable_open(inode, file);
}
static int adx_wdt_release(struct inode *inode, struct file *file)
{
struct adx_wdt *wdt = file->private_data;
adx_wdt_stop(wdt);
clear_bit(0, &driver_open);
return 0;
}
static long adx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct adx_wdt *wdt = file->private_data;
void __user *argp = (void __user *)arg;
unsigned long __user *p = argp;
unsigned long seconds = 0;
unsigned int options;
long ret = -EINVAL;
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &adx_wdt_info, sizeof(adx_wdt_info)))
return -EFAULT;
else
return 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
adx_wdt_keepalive(wdt);
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(seconds, p))
return -EFAULT;
adx_wdt_set_timeout(wdt, seconds);
/* fallthrough */
case WDIOC_GETTIMEOUT:
adx_wdt_get_timeout(wdt, &seconds);
return put_user(seconds, p);
case WDIOC_SETOPTIONS:
if (copy_from_user(&options, argp, sizeof(options)))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
adx_wdt_stop(wdt);
ret = 0;
}
if (options & WDIOS_ENABLECARD) {
adx_wdt_start(wdt);
ret = 0;
}
return ret;
default:
break;
}
return -ENOTTY;
}
static ssize_t adx_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
struct adx_wdt *wdt = file->private_data;
if (len)
adx_wdt_keepalive(wdt);
return len;
}
static const struct file_operations adx_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.open = adx_wdt_open,
.release = adx_wdt_release,
.unlocked_ioctl = adx_wdt_ioctl,
.write = adx_wdt_write,
};
static struct miscdevice adx_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &adx_wdt_fops,
};
static int __devinit adx_wdt_probe(struct platform_device *pdev)
{
struct resource *res;
struct adx_wdt *wdt;
int ret = 0;
u32 ctrl;
wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt) {
dev_err(&pdev->dev, "cannot allocate WDT structure\n");
return -ENOMEM;
}
spin_lock_init(&wdt->lock);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "cannot obtain I/O memory region\n");
return -ENXIO;
}
res = devm_request_mem_region(&pdev->dev, res->start,
res->end - res->start + 1, res->name);
if (!res) {
dev_err(&pdev->dev, "cannot request I/O memory region\n");
return -ENXIO;
}
wdt->base = devm_ioremap_nocache(&pdev->dev, res->start,
res->end - res->start + 1);
if (!wdt->base) {
dev_err(&pdev->dev, "cannot remap I/O memory region\n");
return -ENXIO;
}
/* disable watchdog and reboot on timeout */
ctrl = readl(wdt->base + ADX_WDT_CONTROL);
ctrl &= ~ADX_WDT_CONTROL_ENABLE;
ctrl &= ~ADX_WDT_CONTROL_nRESET;
writel(ctrl, wdt->base + ADX_WDT_CONTROL);
platform_set_drvdata(pdev, wdt);
adx_wdt_dev = pdev;
ret = misc_register(&adx_wdt_miscdev);
if (ret) {
dev_err(&pdev->dev, "cannot register miscdev on minor %d "
"(err=%d)\n", WATCHDOG_MINOR, ret);
return ret;
}
return 0;
}
static int __devexit adx_wdt_remove(struct platform_device *pdev)
{
struct adx_wdt *wdt = platform_get_drvdata(pdev);
misc_deregister(&adx_wdt_miscdev);
adx_wdt_stop(wdt);
platform_set_drvdata(pdev, NULL);
return 0;
}
static void adx_wdt_shutdown(struct platform_device *pdev)
{
struct adx_wdt *wdt = platform_get_drvdata(pdev);
adx_wdt_stop(wdt);
}
#ifdef CONFIG_PM
static int adx_wdt_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct adx_wdt *wdt = platform_get_drvdata(pdev);
wdt->wake = (wdt->state == WDT_STATE_START) ? 1 : 0;
adx_wdt_stop(wdt);
return 0;
}
static int adx_wdt_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct adx_wdt *wdt = platform_get_drvdata(pdev);
if (wdt->wake)
adx_wdt_start(wdt);
return 0;
}
static struct dev_pm_ops adx_wdt_pm_ops = {
.suspend = adx_wdt_suspend,
.resume = adx_wdt_resume,
};
# define ADX_WDT_PM_OPS (&adx_wdt_pm_ops)
#else
# define ADX_WDT_PM_OPS NULL
#endif
static struct platform_driver adx_wdt_driver = {
.probe = adx_wdt_probe,
.remove = __devexit_p(adx_wdt_remove),
.shutdown = adx_wdt_shutdown,
.driver = {
.name = WATCHDOG_NAME,
.owner = THIS_MODULE,
.pm = ADX_WDT_PM_OPS,
},
};
static int __init adx_wdt_init(void)
{
return platform_driver_register(&adx_wdt_driver);
}
static void __exit adx_wdt_exit(void)
{
platform_driver_unregister(&adx_wdt_driver);
}
module_init(adx_wdt_init);
module_exit(adx_wdt_exit);
MODULE_DESCRIPTION("Avionic Design Xanthos Watchdog Driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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