watchdog: shwdt: driver model conversion.

This is a long overdue driver model conversion for the shwdt watchdog
driver. This is the initial conversion, more incremental changes to
follow.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Paul Mundt 2010-05-25 18:31:12 +09:00
parent b1fa888e01
commit 8f5585ec3d

View File

@ -19,6 +19,7 @@
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
@ -28,11 +29,12 @@
#include <linux/ioport.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <asm/watchdog.h>
#define PFX "shwdt: "
#define DRV_NAME "sh-wdt"
/*
* Default clock division ratio is 5.25 msecs. For an additional table of
@ -62,31 +64,36 @@
* misses its deadline, the kernel timer will allow the WDT to overflow.
*/
static int clock_division_ratio = WTCSR_CKS_4096;
#define next_ping_period(cks) msecs_to_jiffies(cks - 4)
static void sh_wdt_ping(unsigned long data);
static unsigned long shwdt_is_open;
static const struct watchdog_info sh_wdt_info;
static char shwdt_expect_close;
static DEFINE_TIMER(timer, sh_wdt_ping, 0, 0);
static unsigned long next_heartbeat;
static struct platform_device *sh_wdt_dev;
static DEFINE_SPINLOCK(shwdt_lock);
#define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat */
static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
static int nowayout = WATCHDOG_NOWAYOUT;
static unsigned long next_heartbeat;
static void sh_wdt_start(void)
struct sh_wdt {
void __iomem *base;
struct device *dev;
struct timer_list timer;
unsigned long enabled;
char expect_close;
};
static void sh_wdt_start(struct sh_wdt *wdt)
{
__u8 csr;
unsigned long flags;
u8 csr;
spin_lock_irqsave(&shwdt_lock, flags);
next_heartbeat = jiffies + (heartbeat * HZ);
mod_timer(&timer, next_ping_period(clock_division_ratio));
mod_timer(&wdt->timer, next_ping_period(clock_division_ratio));
csr = sh_wdt_read_csr();
csr |= WTCSR_WT | clock_division_ratio;
@ -115,22 +122,23 @@ static void sh_wdt_start(void)
spin_unlock_irqrestore(&shwdt_lock, flags);
}
static void sh_wdt_stop(void)
static void sh_wdt_stop(struct sh_wdt *wdt)
{
__u8 csr;
unsigned long flags;
u8 csr;
spin_lock_irqsave(&shwdt_lock, flags);
del_timer(&timer);
del_timer(&wdt->timer);
csr = sh_wdt_read_csr();
csr &= ~WTCSR_TME;
sh_wdt_write_csr(csr);
spin_unlock_irqrestore(&shwdt_lock, flags);
}
static inline void sh_wdt_keepalive(void)
static inline void sh_wdt_keepalive(struct sh_wdt *wdt)
{
unsigned long flags;
@ -154,11 +162,12 @@ static int sh_wdt_set_heartbeat(int t)
static void sh_wdt_ping(unsigned long data)
{
struct sh_wdt *wdt = (struct sh_wdt *)data;
unsigned long flags;
spin_lock_irqsave(&shwdt_lock, flags);
if (time_before(jiffies, next_heartbeat)) {
__u8 csr;
u8 csr;
csr = sh_wdt_read_csr();
csr &= ~WTCSR_IOVF;
@ -166,37 +175,43 @@ static void sh_wdt_ping(unsigned long data)
sh_wdt_write_cnt(0);
mod_timer(&timer, next_ping_period(clock_division_ratio));
mod_timer(&wdt->timer, next_ping_period(clock_division_ratio));
} else
printk(KERN_WARNING PFX "Heartbeat lost! Will not ping "
"the watchdog\n");
dev_warn(wdt->dev, "Heartbeat lost! Will not ping "
"the watchdog\n");
spin_unlock_irqrestore(&shwdt_lock, flags);
}
static int sh_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &shwdt_is_open))
struct sh_wdt *wdt = platform_get_drvdata(sh_wdt_dev);
if (test_and_set_bit(0, &wdt->enabled))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
sh_wdt_start();
file->private_data = wdt;
sh_wdt_start(wdt);
return nonseekable_open(inode, file);
}
static int sh_wdt_close(struct inode *inode, struct file *file)
{
if (shwdt_expect_close == 42) {
sh_wdt_stop();
struct sh_wdt *wdt = file->private_data;
if (wdt->expect_close == 42) {
sh_wdt_stop(wdt);
} else {
printk(KERN_CRIT PFX "Unexpected close, not "
"stopping watchdog!\n");
sh_wdt_keepalive();
dev_crit(wdt->dev, "Unexpected close, not "
"stopping watchdog!\n");
sh_wdt_keepalive(wdt);
}
clear_bit(0, &shwdt_is_open);
shwdt_expect_close = 0;
clear_bit(0, &wdt->enabled);
wdt->expect_close = 0;
return 0;
}
@ -204,21 +219,23 @@ static int sh_wdt_close(struct inode *inode, struct file *file)
static ssize_t sh_wdt_write(struct file *file, const char *buf,
size_t count, loff_t *ppos)
{
struct sh_wdt *wdt = file->private_data;
if (count) {
if (!nowayout) {
size_t i;
shwdt_expect_close = 0;
wdt->expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
shwdt_expect_close = 42;
wdt->expect_close = 42;
}
}
sh_wdt_keepalive();
sh_wdt_keepalive(wdt);
}
return count;
@ -227,6 +244,7 @@ static ssize_t sh_wdt_write(struct file *file, const char *buf,
static long sh_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct sh_wdt *wdt = file->private_data;
int new_heartbeat;
int options, retval = -EINVAL;
@ -242,18 +260,18 @@ static long sh_wdt_ioctl(struct file *file, unsigned int cmd,
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
sh_wdt_stop();
sh_wdt_stop(wdt);
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
sh_wdt_start();
sh_wdt_start(wdt);
retval = 0;
}
return retval;
case WDIOC_KEEPALIVE:
sh_wdt_keepalive();
sh_wdt_keepalive(wdt);
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_heartbeat, (int *)arg))
@ -262,7 +280,7 @@ static long sh_wdt_ioctl(struct file *file, unsigned int cmd,
if (sh_wdt_set_heartbeat(new_heartbeat))
return -EINVAL;
sh_wdt_keepalive();
sh_wdt_keepalive(wdt);
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(heartbeat, (int *)arg);
@ -275,8 +293,10 @@ static long sh_wdt_ioctl(struct file *file, unsigned int cmd,
static int sh_wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
struct sh_wdt *wdt = platform_get_drvdata(sh_wdt_dev);
if (code == SYS_DOWN || code == SYS_HALT)
sh_wdt_stop();
sh_wdt_stop(wdt);
return NOTIFY_DONE;
}
@ -307,56 +327,148 @@ static struct miscdevice sh_wdt_miscdev = {
.fops = &sh_wdt_fops,
};
static int __devinit sh_wdt_probe(struct platform_device *pdev)
{
struct sh_wdt *wdt;
struct resource *res;
int rc;
/*
* As this driver only covers the global watchdog case, reject
* any attempts to register per-CPU watchdogs.
*/
if (pdev->id != -1)
return -EINVAL;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (unlikely(!res))
return -EINVAL;
if (!devm_request_mem_region(&pdev->dev, res->start,
resource_size(res), DRV_NAME))
return -EBUSY;
wdt = devm_kzalloc(&pdev->dev, sizeof(struct sh_wdt), GFP_KERNEL);
if (unlikely(!wdt)) {
rc = -ENOMEM;
goto out_release;
}
wdt->dev = &pdev->dev;
wdt->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (unlikely(!wdt->base)) {
rc = -ENXIO;
goto out_err;
}
rc = register_reboot_notifier(&sh_wdt_notifier);
if (unlikely(rc)) {
dev_err(&pdev->dev,
"Can't register reboot notifier (err=%d)\n", rc);
goto out_unmap;
}
sh_wdt_miscdev.parent = wdt->dev;
rc = misc_register(&sh_wdt_miscdev);
if (unlikely(rc)) {
dev_err(&pdev->dev,
"Can't register miscdev on minor=%d (err=%d)\n",
sh_wdt_miscdev.minor, rc);
goto out_unreg;
}
init_timer(&wdt->timer);
wdt->timer.function = sh_wdt_ping;
wdt->timer.data = (unsigned long)wdt;
wdt->timer.expires = next_ping_period(clock_division_ratio);
platform_set_drvdata(pdev, wdt);
sh_wdt_dev = pdev;
dev_info(&pdev->dev, "initialized.\n");
return 0;
out_unreg:
unregister_reboot_notifier(&sh_wdt_notifier);
out_unmap:
devm_iounmap(&pdev->dev, wdt->base);
out_err:
devm_kfree(&pdev->dev, wdt);
out_release:
devm_release_mem_region(&pdev->dev, res->start, resource_size(res));
return rc;
}
static int __devexit sh_wdt_remove(struct platform_device *pdev)
{
struct sh_wdt *wdt = platform_get_drvdata(pdev);
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
platform_set_drvdata(pdev, NULL);
misc_deregister(&sh_wdt_miscdev);
sh_wdt_dev = NULL;
unregister_reboot_notifier(&sh_wdt_notifier);
devm_release_mem_region(&pdev->dev, res->start, resource_size(res));
devm_iounmap(&pdev->dev, wdt->base);
devm_kfree(&pdev->dev, wdt);
return 0;
}
static struct platform_driver sh_wdt_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
.probe = sh_wdt_probe,
.remove = __devexit_p(sh_wdt_remove),
};
static int __init sh_wdt_init(void)
{
int rc;
if (clock_division_ratio < 0x5 || clock_division_ratio > 0x7) {
if (unlikely(clock_division_ratio < 0x5 ||
clock_division_ratio > 0x7)) {
clock_division_ratio = WTCSR_CKS_4096;
printk(KERN_INFO PFX
"clock_division_ratio value must be 0x5<=x<=0x7, using %d\n",
clock_division_ratio);
pr_info("%s: divisor must be 0x5<=x<=0x7, using %d\n",
DRV_NAME, clock_division_ratio);
}
rc = sh_wdt_set_heartbeat(heartbeat);
if (unlikely(rc)) {
heartbeat = WATCHDOG_HEARTBEAT;
printk(KERN_INFO PFX
"heartbeat value must be 1<=x<=3600, using %d\n",
heartbeat);
pr_info("%s: heartbeat value must be 1<=x<=3600, using %d\n",
DRV_NAME, heartbeat);
}
rc = register_reboot_notifier(&sh_wdt_notifier);
if (unlikely(rc)) {
printk(KERN_ERR PFX
"Can't register reboot notifier (err=%d)\n", rc);
return rc;
}
pr_info("%s: configured with heartbeat=%d sec (nowayout=%d)\n",
DRV_NAME, heartbeat, nowayout);
rc = misc_register(&sh_wdt_miscdev);
if (unlikely(rc)) {
printk(KERN_ERR PFX
"Can't register miscdev on minor=%d (err=%d)\n",
sh_wdt_miscdev.minor, rc);
unregister_reboot_notifier(&sh_wdt_notifier);
return rc;
}
printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
heartbeat, nowayout);
return 0;
return platform_driver_register(&sh_wdt_driver);
}
static void __exit sh_wdt_exit(void)
{
misc_deregister(&sh_wdt_miscdev);
unregister_reboot_notifier(&sh_wdt_notifier);
platform_driver_unregister(&sh_wdt_driver);
}
module_init(sh_wdt_init);
module_exit(sh_wdt_exit);
MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
MODULE_DESCRIPTION("SuperH watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
module_param(clock_division_ratio, int, 0);
@ -373,6 +485,3 @@ module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
module_init(sh_wdt_init);
module_exit(sh_wdt_exit);