From 8432f9e5e82a13b82a76171c89b0858e855c9da5 Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Thu, 12 Mar 2015 13:07:27 +0100 Subject: watchdog: at91rm9200: use the system timer syscon Use a syscon regmap to access the system timer registers. Also, rename the driver atmel_st_watchdog to stop conflicting with at91sam9_wdt.c Signed-off-by: Alexandre Belloni Reviewed-by: Guenter Roeck Signed-off-by: Nicolas Ferre --- drivers/watchdog/Kconfig | 2 +- drivers/watchdog/at91rm9200_wdt.c | 29 ++++++++++++++++++++++------- 2 files changed, 23 insertions(+), 8 deletions(-) (limited to 'drivers/watchdog') diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 16f202350997..ce4f3a7f95fd 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -154,7 +154,7 @@ config ARM_SP805_WATCHDOG config AT91RM9200_WATCHDOG tristate "AT91RM9200 watchdog" - depends on SOC_AT91RM9200 + depends on SOC_AT91RM9200 && MFD_SYSCON help Watchdog timer embedded into AT91RM9200 chips. This will reboot your system when the timeout is reached. diff --git a/drivers/watchdog/at91rm9200_wdt.c b/drivers/watchdog/at91rm9200_wdt.c index d244112d5b6f..e6fa87d85de3 100644 --- a/drivers/watchdog/at91rm9200_wdt.c +++ b/drivers/watchdog/at91rm9200_wdt.c @@ -17,22 +17,25 @@ #include #include #include +#include +#include #include #include #include #include +#include #include #include #include #include #include -#include #define WDT_DEFAULT_TIME 5 /* seconds */ #define WDT_MAX_TIME 256 /* seconds */ static int wdt_time = WDT_DEFAULT_TIME; static bool nowayout = WATCHDOG_NOWAYOUT; +static struct regmap *regmap_st; module_param(wdt_time, int, 0); MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default=" @@ -55,7 +58,7 @@ static unsigned long at91wdt_busy; */ static inline void at91_wdt_stop(void) { - at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN); + regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN); } /* @@ -63,9 +66,9 @@ static inline void at91_wdt_stop(void) */ static inline void at91_wdt_start(void) { - at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN | + regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN | (((65536 * wdt_time) >> 8) & AT91_ST_WDV)); - at91_st_write(AT91_ST_CR, AT91_ST_WDRST); + regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST); } /* @@ -73,7 +76,7 @@ static inline void at91_wdt_start(void) */ static inline void at91_wdt_reload(void) { - at91_st_write(AT91_ST_CR, AT91_ST_WDRST); + regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST); } /* ......................................................................... */ @@ -203,12 +206,24 @@ static struct miscdevice at91wdt_miscdev = { static int at91wdt_probe(struct platform_device *pdev) { + struct device *dev = &pdev->dev; + struct device *parent; int res; if (at91wdt_miscdev.parent) return -EBUSY; at91wdt_miscdev.parent = &pdev->dev; + parent = dev->parent; + if (!parent) { + dev_err(dev, "no parent\n"); + return -ENODEV; + } + + regmap_st = syscon_node_to_regmap(parent->of_node); + if (!regmap_st) + return -ENODEV; + res = misc_register(&at91wdt_miscdev); if (res) return res; @@ -267,7 +282,7 @@ static struct platform_driver at91wdt_driver = { .suspend = at91wdt_suspend, .resume = at91wdt_resume, .driver = { - .name = "at91_wdt", + .name = "atmel_st_watchdog", .of_match_table = at91_wdt_dt_ids, }, }; @@ -296,4 +311,4 @@ module_exit(at91_wdt_exit); MODULE_AUTHOR("Andrew Victor"); MODULE_DESCRIPTION("Watchdog driver for Atmel AT91RM9200"); MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:at91_wdt"); +MODULE_ALIAS("platform:atmel_st_watchdog"); -- cgit v1.2.3 From 9ab45f3fb2bebd048ffa2692e8f7cc89f3d379d4 Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Thu, 12 Mar 2015 13:07:28 +0100 Subject: watchdog: at91rm9200: implement restart handler Restarting the at91rm9200 is done through programming the watchdog and waiting for it to reset. Signed-off-by: Alexandre Belloni Reviewed-by: Guenter Roeck Signed-off-by: Nicolas Ferre --- drivers/watchdog/at91rm9200_wdt.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'drivers/watchdog') diff --git a/drivers/watchdog/at91rm9200_wdt.c b/drivers/watchdog/at91rm9200_wdt.c index e6fa87d85de3..41cecb55766c 100644 --- a/drivers/watchdog/at91rm9200_wdt.c +++ b/drivers/watchdog/at91rm9200_wdt.c @@ -12,6 +12,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include +#include #include #include #include @@ -23,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -53,6 +55,27 @@ static unsigned long at91wdt_busy; /* ......................................................................... */ +static int at91rm9200_restart(struct notifier_block *this, + unsigned long mode, void *cmd) +{ + /* + * Perform a hardware reset with the use of the Watchdog timer. + */ + regmap_write(regmap_st, AT91_ST_WDMR, + AT91_ST_RSTEN | AT91_ST_EXTEN | 1); + regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST); + + mdelay(2000); + + pr_emerg("Unable to restart system\n"); + return NOTIFY_DONE; +} + +static struct notifier_block at91rm9200_restart_nb = { + .notifier_call = at91rm9200_restart, + .priority = 192, +}; + /* * Disable the watchdog. */ @@ -228,6 +251,10 @@ static int at91wdt_probe(struct platform_device *pdev) if (res) return res; + res = register_restart_handler(&at91rm9200_restart_nb); + if (res) + dev_warn(dev, "failed to register restart handler\n"); + pr_info("AT91 Watchdog Timer enabled (%d seconds%s)\n", wdt_time, nowayout ? ", nowayout" : ""); return 0; @@ -235,8 +262,13 @@ static int at91wdt_probe(struct platform_device *pdev) static int at91wdt_remove(struct platform_device *pdev) { + struct device *dev = &pdev->dev; int res; + res = unregister_restart_handler(&at91rm9200_restart_nb); + if (res) + dev_warn(dev, "failed to unregister restart handler\n"); + res = misc_deregister(&at91wdt_miscdev); if (!res) at91wdt_miscdev.parent = NULL; -- cgit v1.2.3