[PATCH 3/3] mpc52xx/wdt: WDT uses GPT api
Albrecht Dreß
albrecht.dress at arcor.de
Wed Nov 11 06:43:00 EST 2009
Use the MPC5200 GPT api for the WDT which drastically simplifies this file.
Signed-off-by: Albrecht Dreß <albrecht.dress at arcor.de>
---
drivers/watchdog/mpc5200_wdt.c | 246 +++++++++++-----------------------------
1 files changed, 65 insertions(+), 181 deletions(-)
diff --git a/drivers/watchdog/mpc5200_wdt.c b/drivers/watchdog/mpc5200_wdt.c
index fa9c47c..5bb553c 100644
--- a/drivers/watchdog/mpc5200_wdt.c
+++ b/drivers/watchdog/mpc5200_wdt.c
@@ -2,25 +2,16 @@
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
-#include <linux/io.h>
-#include <linux/spinlock.h>
#include <linux/of_platform.h>
#include <linux/uaccess.h>
#include <asm/mpc52xx.h>
-#define GPT_MODE_WDT (1 << 15)
-#define GPT_MODE_CE (1 << 12)
-#define GPT_MODE_MS_TIMER (0x4)
-
+#define WDT_IDENTITY "mpc5200 watchdog on GPT0"
struct mpc5200_wdt {
- unsigned count; /* timer ticks before watchdog kicks in */
- long ipb_freq;
- struct miscdevice miscdev;
- struct resource mem;
- struct mpc52xx_gpt __iomem *regs;
- spinlock_t io_lock;
+ int timeout;
+ struct mpc52xx_gpt_priv *timer;
};
/* is_active stores wether or not the /dev/watchdog device is opened */
@@ -32,80 +23,33 @@ static unsigned long is_active;
static struct mpc5200_wdt *wdt_global;
-/* helper to calculate timeout in timer counts */
-static void mpc5200_wdt_set_timeout(struct mpc5200_wdt *wdt, int timeout)
-{
- /* use biggest prescaler of 64k */
- wdt->count = (wdt->ipb_freq + 0xffff) / 0x10000 * timeout;
-
- if (wdt->count > 0xffff)
- wdt->count = 0xffff;
-}
-/* return timeout in seconds (calculated from timer count) */
-static int mpc5200_wdt_get_timeout(struct mpc5200_wdt *wdt)
-{
- return wdt->count * 0x10000 / wdt->ipb_freq;
-}
-
-
-/* watchdog operations */
-static int mpc5200_wdt_start(struct mpc5200_wdt *wdt)
-{
- spin_lock(&wdt->io_lock);
- /* disable */
- out_be32(&wdt->regs->mode, 0);
- /* set timeout, with maximum prescaler */
- out_be32(&wdt->regs->count, 0x0 | wdt->count);
- /* enable watchdog */
- out_be32(&wdt->regs->mode, GPT_MODE_CE | GPT_MODE_WDT |
- GPT_MODE_MS_TIMER);
- spin_unlock(&wdt->io_lock);
-
- return 0;
-}
-static int mpc5200_wdt_ping(struct mpc5200_wdt *wdt)
-{
- spin_lock(&wdt->io_lock);
- /* writing A5 to OCPW resets the watchdog */
- out_be32(&wdt->regs->mode, 0xA5000000 |
- (0xffffff & in_be32(&wdt->regs->mode)));
- spin_unlock(&wdt->io_lock);
- return 0;
-}
-static int mpc5200_wdt_stop(struct mpc5200_wdt *wdt)
-{
- spin_lock(&wdt->io_lock);
- /* disable */
- out_be32(&wdt->regs->mode, 0);
- spin_unlock(&wdt->io_lock);
- return 0;
-}
-
-
/* file operations */
static ssize_t mpc5200_wdt_write(struct file *file, const char __user *data,
- size_t len, loff_t *ppos)
+ size_t len, loff_t *ppos)
{
struct mpc5200_wdt *wdt = file->private_data;
- mpc5200_wdt_ping(wdt);
+ mpc52xx_gpt_wdt_ping(wdt->timer);
return 0;
}
+
static struct watchdog_info mpc5200_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
- .identity = "mpc5200 watchdog on GPT0",
+ .identity = WDT_IDENTITY,
};
+
static long mpc5200_wdt_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
+ unsigned long arg)
{
struct mpc5200_wdt *wdt = file->private_data;
int __user *data = (int __user *)arg;
int timeout;
+ u64 real_timeout;
int ret = 0;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user(data, &mpc5200_wdt_info,
- sizeof(mpc5200_wdt_info));
+ sizeof(mpc5200_wdt_info));
if (ret)
ret = -EFAULT;
break;
@@ -116,19 +60,23 @@ static long mpc5200_wdt_ioctl(struct file *file, unsigned int cmd,
break;
case WDIOC_KEEPALIVE:
- mpc5200_wdt_ping(wdt);
+ mpc52xx_gpt_wdt_ping(wdt->timer);
break;
case WDIOC_SETTIMEOUT:
ret = get_user(timeout, data);
if (ret)
break;
- mpc5200_wdt_set_timeout(wdt, timeout);
- mpc5200_wdt_start(wdt);
+ ret = mpc52xx_gpt_wdt_start(wdt->timer, timeout);
+ if (ret)
+ break;
+ wdt->timeout = timeout;
/* fall through and return the timeout */
case WDIOC_GETTIMEOUT:
- timeout = mpc5200_wdt_get_timeout(wdt);
+ real_timeout = mpc52xx_gpt_timer_period(wdt->timer);
+ do_div(real_timeout, 1000000000);
+ timeout = (int) real_timeout;
ret = put_user(timeout, data);
break;
@@ -140,154 +88,90 @@ static long mpc5200_wdt_ioctl(struct file *file, unsigned int cmd,
static int mpc5200_wdt_open(struct inode *inode, struct file *file)
{
+ int ret;
+
/* /dev/watchdog can only be opened once */
if (test_and_set_bit(0, &is_active))
return -EBUSY;
/* Set and activate the watchdog */
- mpc5200_wdt_set_timeout(wdt_global, 30);
- mpc5200_wdt_start(wdt_global);
+ ret = mpc52xx_gpt_wdt_start(wdt_global->timer, 30);
+ if (ret) {
+ clear_bit(0, &is_active);
+ return ret;
+ }
+ wdt_global->timeout = 30;
+
file->private_data = wdt_global;
return nonseekable_open(inode, file);
}
+
static int mpc5200_wdt_release(struct inode *inode, struct file *file)
{
-#if WATCHDOG_NOWAYOUT == 0
+#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
struct mpc5200_wdt *wdt = file->private_data;
- mpc5200_wdt_stop(wdt);
- wdt->count = 0; /* == disabled */
+ mpc52xx_gpt_wdt_stop(wdt->timer);
+ wdt->timeout = 0; /* == disabled */
#endif
clear_bit(0, &is_active);
return 0;
}
static const struct file_operations mpc5200_wdt_fops = {
- .owner = THIS_MODULE,
- .write = mpc5200_wdt_write,
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = mpc5200_wdt_write,
.unlocked_ioctl = mpc5200_wdt_ioctl,
- .open = mpc5200_wdt_open,
- .release = mpc5200_wdt_release,
+ .open = mpc5200_wdt_open,
+ .release = mpc5200_wdt_release,
+};
+
+static struct miscdevice mpc5200_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &mpc5200_wdt_fops,
};
/* module operations */
-static int mpc5200_wdt_probe(struct of_device *op,
- const struct of_device_id *match)
+static int __init mpc5200_wdt_init(void)
{
- struct mpc5200_wdt *wdt;
int err;
- const void *has_wdt;
- int size;
+ struct mpc52xx_gpt_priv *timer;
- has_wdt = of_get_property(op->node, "has-wdt", NULL);
- if (!has_wdt)
- has_wdt = of_get_property(op->node, "fsl,has-wdt", NULL);
- if (!has_wdt)
+ /* grab the watchdog-capable gpt */
+ timer = mpc52xx_gpt_wdt_probe();
+ if (!timer) {
+ pr_err(WDT_IDENTITY ": probing failed\n");
return -ENODEV;
+ }
- wdt = kzalloc(sizeof(*wdt), GFP_KERNEL);
- if (!wdt)
+ wdt_global = kzalloc(sizeof(struct mpc5200_wdt), GFP_KERNEL);
+ if (!wdt_global) {
+ mpc52xx_gpt_wdt_release(timer);
return -ENOMEM;
-
- wdt->ipb_freq = mpc5xxx_get_bus_frequency(op->node);
-
- err = of_address_to_resource(op->node, 0, &wdt->mem);
- if (err)
- goto out_free;
- size = wdt->mem.end - wdt->mem.start + 1;
- if (!request_mem_region(wdt->mem.start, size, "mpc5200_wdt")) {
- err = -ENODEV;
- goto out_free;
- }
- wdt->regs = ioremap(wdt->mem.start, size);
- if (!wdt->regs) {
- err = -ENODEV;
- goto out_release;
}
-
- dev_set_drvdata(&op->dev, wdt);
- spin_lock_init(&wdt->io_lock);
-
- wdt->miscdev = (struct miscdevice) {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &mpc5200_wdt_fops,
- .parent = &op->dev,
- };
- wdt_global = wdt;
- err = misc_register(&wdt->miscdev);
+ wdt_global->timer = timer;
+ err = misc_register(&mpc5200_wdt_miscdev);
if (!err)
- return 0;
-
- iounmap(wdt->regs);
-out_release:
- release_mem_region(wdt->mem.start, size);
-out_free:
- kfree(wdt);
+ pr_info(WDT_IDENTITY ": registered\n");
+ else {
+ mpc52xx_gpt_wdt_release(timer);
+ kfree(wdt_global);
+ }
return err;
}
-static int mpc5200_wdt_remove(struct of_device *op)
-{
- struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
-
- mpc5200_wdt_stop(wdt);
- misc_deregister(&wdt->miscdev);
- iounmap(wdt->regs);
- release_mem_region(wdt->mem.start, wdt->mem.end - wdt->mem.start + 1);
- kfree(wdt);
-
- return 0;
-}
-static int mpc5200_wdt_suspend(struct of_device *op, pm_message_t state)
-{
- struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
- mpc5200_wdt_stop(wdt);
- return 0;
-}
-static int mpc5200_wdt_resume(struct of_device *op)
-{
- struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
- if (wdt->count)
- mpc5200_wdt_start(wdt);
- return 0;
-}
-static int mpc5200_wdt_shutdown(struct of_device *op)
-{
- struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev);
- mpc5200_wdt_stop(wdt);
- return 0;
-}
-
-static struct of_device_id mpc5200_wdt_match[] = {
- { .compatible = "mpc5200-gpt", },
- { .compatible = "fsl,mpc5200-gpt", },
- {},
-};
-static struct of_platform_driver mpc5200_wdt_driver = {
- .owner = THIS_MODULE,
- .name = "mpc5200-gpt-wdt",
- .match_table = mpc5200_wdt_match,
- .probe = mpc5200_wdt_probe,
- .remove = mpc5200_wdt_remove,
- .suspend = mpc5200_wdt_suspend,
- .resume = mpc5200_wdt_resume,
- .shutdown = mpc5200_wdt_shutdown,
-};
-
-
-static int __init mpc5200_wdt_init(void)
-{
- return of_register_platform_driver(&mpc5200_wdt_driver);
-}
-
static void __exit mpc5200_wdt_exit(void)
{
- of_unregister_platform_driver(&mpc5200_wdt_driver);
+ mpc52xx_gpt_wdt_release(wdt_global->timer);
+ misc_deregister(&mpc5200_wdt_miscdev);
+ kfree(wdt_global);
}
module_init(mpc5200_wdt_init);
module_exit(mpc5200_wdt_exit);
-MODULE_AUTHOR("Domen Puncer <domen.puncer at telargo.com>");
+MODULE_AUTHOR("Domen Puncer <domen.puncer at telargo.com>, "
+ "Albrecht Dreß <albrecht.dress at arcor.de>");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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