diff options
Diffstat (limited to 'drivers/watchdog/at91rm9200_wdt.c')
| -rw-r--r-- | drivers/watchdog/at91rm9200_wdt.c | 61 |
1 files changed, 54 insertions, 7 deletions
diff --git a/drivers/watchdog/at91rm9200_wdt.c b/drivers/watchdog/at91rm9200_wdt.c index d244112d5b6f..41cecb55766c 100644 --- a/drivers/watchdog/at91rm9200_wdt.c +++ b/drivers/watchdog/at91rm9200_wdt.c @@ -12,27 +12,32 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/bitops.h> +#include <linux/delay.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/io.h> #include <linux/kernel.h> +#include <linux/mfd/syscon.h> +#include <linux/mfd/syscon/atmel-st.h> #include <linux/miscdevice.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/regmap.h> #include <linux/types.h> #include <linux/watchdog.h> #include <linux/uaccess.h> #include <linux/of.h> #include <linux/of_device.h> -#include <mach/at91_st.h> #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=" @@ -50,12 +55,33 @@ 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. */ 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 +89,9 @@ 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 +99,7 @@ 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); } /* ......................................................................... */ @@ -203,16 +229,32 @@ 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; + 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; @@ -220,8 +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; @@ -267,7 +314,7 @@ 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 +343,4 @@ 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"); |