From af4bb822bc65efb087cd36b83789f22161a6515b Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Wed, 17 Aug 2005 09:03:23 +0200 Subject: [PATCH] [WATCHDOG] s3c2410 watchdog power management Patch from Dimitry Andric , updated by Ben Dooks . Patch is against 2.6.11-mm2 Add power management support to the s3c2410 watchdog, so that it is shut-down over suspend, and re-initialised on resume. Also add Dimitry to the list of authors. Signed-off-by: Dimitry Andric Signed-off-by: Ben Dooks Signed-off-by: Wim Van Sebroeck --- drivers/char/watchdog/s3c2410_wdt.c | 51 +++++++++++++++++++++++++++-- 1 file changed, 48 insertions(+), 3 deletions(-) diff --git a/drivers/char/watchdog/s3c2410_wdt.c b/drivers/char/watchdog/s3c2410_wdt.c index f85ac898a49a..522435782e73 100644 --- a/drivers/char/watchdog/s3c2410_wdt.c +++ b/drivers/char/watchdog/s3c2410_wdt.c @@ -27,7 +27,9 @@ * Fixed tmr_count / wdt_count confusion * Added configurable debug * - * 11-Jan-2004 BJD Fixed divide-by-2 in timeout code + * 11-Jan-2005 BJD Fixed divide-by-2 in timeout code + * + * 25-Jan-2005 DA Added suspend/resume support * * 10-Mar-2005 LCVR Changed S3C2410_VA to S3C24XX_VA */ @@ -479,15 +481,57 @@ static int s3c2410wdt_remove(struct device *dev) return 0; } +#ifdef CONFIG_PM + +static unsigned long wtcon_save; +static unsigned long wtdat_save; + +static int s3c2410wdt_suspend(struct device *dev, u32 state, u32 level) +{ + if (level == SUSPEND_POWER_DOWN) { + /* Save watchdog state, and turn it off. */ + wtcon_save = readl(wdt_base + S3C2410_WTCON); + wtdat_save = readl(wdt_base + S3C2410_WTDAT); + + /* Note that WTCNT doesn't need to be saved. */ + s3c2410wdt_stop(); + } + + return 0; +} + +static int s3c2410wdt_resume(struct device *dev, u32 level) +{ + if (level == RESUME_POWER_ON) { + /* Restore watchdog state. */ + + writel(wtdat_save, wdt_base + S3C2410_WTDAT); + writel(wtdat_save, wdt_base + S3C2410_WTCNT); /* Reset count */ + writel(wtcon_save, wdt_base + S3C2410_WTCON); + + printk(KERN_INFO PFX "watchdog %sabled\n", + (wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis"); + } + + return 0; +} + +#else +#define s3c2410wdt_suspend NULL +#define s3c2410wdt_resume NULL +#endif /* CONFIG_PM */ + + static struct device_driver s3c2410wdt_driver = { .name = "s3c2410-wdt", .bus = &platform_bus_type, .probe = s3c2410wdt_probe, .remove = s3c2410wdt_remove, + .suspend = s3c2410wdt_suspend, + .resume = s3c2410wdt_resume, }; - static char banner[] __initdata = KERN_INFO "S3C2410 Watchdog Timer, (c) 2004 Simtec Electronics\n"; static int __init watchdog_init(void) @@ -505,7 +549,8 @@ static void __exit watchdog_exit(void) module_init(watchdog_init); module_exit(watchdog_exit); -MODULE_AUTHOR("Ben Dooks "); +MODULE_AUTHOR("Ben Dooks , " + "Dimitry Andric "); MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);