diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/watchdog/mpc5200_wdt.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/drivers/char/watchdog/mpc5200_wdt.c b/drivers/char/watchdog/mpc5200_wdt.c index cc3299c03683..564143d40610 100644 --- a/drivers/char/watchdog/mpc5200_wdt.c +++ b/drivers/char/watchdog/mpc5200_wdt.c @@ -3,6 +3,7 @@ #include <linux/miscdevice.h> #include <linux/watchdog.h> #include <linux/io.h> +#include <linux/spinlock.h> #include <asm/of_platform.h> #include <asm/uaccess.h> #include <asm/mpc52xx.h> @@ -19,8 +20,11 @@ struct mpc5200_wdt { struct miscdevice miscdev; struct resource mem; struct mpc52xx_gpt __iomem *regs; + spinlock_t io_lock; }; +/* is_active stores wether or not the /dev/watchdog device is opened */ +static unsigned long is_active; /* misc devices don't provide a way, to get back to 'dev' or 'miscdev' from * file operations, which sucks. But there can be max 1 watchdog anyway, so... @@ -47,24 +51,31 @@ static int mpc5200_wdt_get_timeout(struct mpc5200_wdt *wdt) /* 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; } @@ -91,11 +102,17 @@ static int mpc5200_wdt_ioctl(struct inode *inode, struct file *file, switch (cmd) { case WDIOC_GETSUPPORT: - ret = copy_to_user(data, &mpc5200_wdt_info, sizeof(mpc5200_wdt_info)); + ret = copy_to_user(data, &mpc5200_wdt_info, + sizeof(mpc5200_wdt_info)); if (ret) ret = -EFAULT; break; + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + ret = put_user(0, data); + break; + case WDIOC_KEEPALIVE: mpc5200_wdt_ping(wdt); break; @@ -112,15 +129,23 @@ static int mpc5200_wdt_ioctl(struct inode *inode, struct file *file, timeout = mpc5200_wdt_get_timeout(wdt); ret = put_user(timeout, data); break; + + default: + ret = -ENOTTY; } return ret; } static int mpc5200_wdt_open(struct inode *inode, struct file *file) { + /* /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); file->private_data = wdt_global; - return 0; + return nonseekable_open(inode, file); } static int mpc5200_wdt_release(struct inode *inode, struct file *file) { @@ -129,6 +154,7 @@ static int mpc5200_wdt_release(struct inode *inode, struct file *file) mpc5200_wdt_stop(wdt); wdt->count = 0; /* == disabled */ #endif + clear_bit(0, &is_active); return 0; } @@ -173,6 +199,7 @@ static int mpc5200_wdt_probe(struct of_device *op, const struct of_device_id *ma } dev_set_drvdata(&op->dev, wdt); + spin_lock_init(&wdt->io_lock); wdt->miscdev = (struct miscdevice) { .minor = WATCHDOG_MINOR, @@ -256,3 +283,4 @@ module_exit(mpc5200_wdt_exit); MODULE_AUTHOR("Domen Puncer <domen.puncer@telargo.com>"); MODULE_LICENSE("Dual BSD/GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |