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| author | Wim Van Sebroeck <wim@iguana.be> | 2007-07-03 17:59:04 +0000 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@iguana.be> | 2007-07-05 05:37:29 +0000 |
| commit | e75e657756554676f13070266bedbd75d404a0f8 (patch) | |
| tree | e7ae23553be788b00dc59c89a0b8dec22fe0d94b /drivers/char | |
| parent | 28401140a27b7ebc5a686dbfc345e3724d274738 (diff) | |
| download | linux-e75e657756554676f13070266bedbd75d404a0f8.tar.gz linux-e75e657756554676f13070266bedbd75d404a0f8.tar.bz2 linux-e75e657756554676f13070266bedbd75d404a0f8.zip | |
[WATCHDOG] at32ap700x_wdt.c - Add spinlock support
Add spinlock support so that forked children can't
do different io stuff at the same time.
Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/watchdog/at32ap700x_wdt.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/char/watchdog/at32ap700x_wdt.c b/drivers/char/watchdog/at32ap700x_wdt.c index fcd55c600b87..75e852e954e7 100644 --- a/drivers/char/watchdog/at32ap700x_wdt.c +++ b/drivers/char/watchdog/at32ap700x_wdt.c @@ -18,6 +18,7 @@ #include <linux/watchdog.h> #include <linux/uaccess.h> #include <linux/io.h> +#include <linux/spinlock.h> #define TIMEOUT_MIN 1 #define TIMEOUT_MAX 2 @@ -53,6 +54,7 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" struct wdt_at32ap700x { void __iomem *regs; + spinlock_t io_lock; int timeout; int users; struct miscdevice miscdev; @@ -66,9 +68,11 @@ static char expect_release; */ static inline void at32_wdt_stop(void) { + spin_lock(&wdt->io_lock); unsigned long psel = wdt_readl(wdt, CTRL) & WDT_BF(CTRL_PSEL, 0x0f); wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0x55)); wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0xaa)); + spin_unlock(&wdt->io_lock); } /* @@ -79,12 +83,14 @@ static inline void at32_wdt_start(void) /* 0xf is 2^16 divider = 2 sec, 0xe is 2^15 divider = 1 sec */ unsigned long psel = (wdt->timeout > 1) ? 0xf : 0xe; + spin_lock(&wdt->io_lock); wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN) | WDT_BF(CTRL_PSEL, psel) | WDT_BF(CTRL_KEY, 0x55)); wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN) | WDT_BF(CTRL_PSEL, psel) | WDT_BF(CTRL_KEY, 0xaa)); + spin_unlock(&wdt->io_lock); } /* @@ -92,7 +98,9 @@ static inline void at32_wdt_start(void) */ static inline void at32_wdt_pat(void) { + spin_lock(&wdt->io_lock); wdt_writel(wdt, CLR, 0x42); + spin_unlock(&wdt->io_lock); } /* @@ -272,6 +280,7 @@ static int __init at32_wdt_probe(struct platform_device *pdev) dev_dbg(&pdev->dev, "could not map I/O memory\n"); goto err_free; } + spin_lock_init(&wdt->io_lock); wdt->users = 0; wdt->miscdev.minor = WATCHDOG_MINOR; wdt->miscdev.name = "watchdog"; |