From 75932094601b404fc9ef28f7b6c0aa83dd619af0 Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Tue, 12 Feb 2013 15:11:19 +0000 Subject: mfd: ab8500-sysctrl: Add new reset function Add a new reset function which uses the AB WD with 0 timeout. Signed-off-by: Lee Jones Acked-by: Samuel Ortiz --- drivers/mfd/ab8500-sysctrl.c | 63 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) (limited to 'drivers/mfd/ab8500-sysctrl.c') diff --git a/drivers/mfd/ab8500-sysctrl.c b/drivers/mfd/ab8500-sysctrl.c index 6ac63a05893c..f43c42b9f32c 100644 --- a/drivers/mfd/ab8500-sysctrl.c +++ b/drivers/mfd/ab8500-sysctrl.c @@ -15,6 +15,12 @@ #include #include +/* RtcCtrl bits */ +#define AB8500_ALARM_MIN_LOW 0x08 +#define AB8500_ALARM_MIN_MID 0x09 +#define RTC_CTRL 0x0B +#define RTC_ALARM_ENABLE 0x4 + static struct device *sysctrl_dev; void ab8500_power_off(void) @@ -79,6 +85,63 @@ shutdown: } } +/* + * Use the AB WD to reset the platform. It will perform a hard + * reset instead of a soft reset. Write the reset reason to + * the AB before reset, which can be read upon restart. + */ +void ab8500_restart(char mode, const char *cmd) +{ + struct ab8500_platform_data *plat; + struct ab8500_sysctrl_platform_data *pdata; + u16 reason = 0; + u8 val; + + if (sysctrl_dev == NULL) { + pr_err("%s: sysctrl not initialized\n", __func__); + return; + } + + plat = dev_get_platdata(sysctrl_dev->parent); + pdata = plat->sysctrl; + if (pdata->reboot_reason_code) + reason = pdata->reboot_reason_code(cmd); + else + pr_warn("[%s] No reboot reason set. Default reason %d\n", + __func__, reason); + + /* + * Disable RTC alarm, just a precaution so that no alarm + * is running when WD reset is executed. + */ + abx500_get_register_interruptible(sysctrl_dev, AB8500_RTC, + RTC_CTRL , &val); + abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC, + RTC_CTRL , (val & ~RTC_ALARM_ENABLE)); + + /* + * Android is not using the RTC alarm registers during reboot + * so we borrow them for writing the reason of reset + */ + + /* reason[8 LSB] */ + val = reason & 0xFF; + abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC, + AB8500_ALARM_MIN_LOW , val); + + /* reason[8 MSB] */ + val = (reason>>8) & 0xFF; + abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC, + AB8500_ALARM_MIN_MID , val); + + /* Setting WD timeout to 0 */ + ab8500_sysctrl_write(AB8500_MAINWDOGTIMER, 0xFF, 0x0); + + /* Setting the parameters to AB8500 WD*/ + ab8500_sysctrl_write(AB8500_MAINWDOGCTRL, 0xFF, (AB8500_ENABLE_WD | + AB8500_WD_RESTART_ON_EXPIRE | AB8500_KICK_WD)); +} + static inline bool valid_bank(u8 bank) { return ((bank == AB8500_SYS_CTRL1_BLOCK) || -- cgit v1.2.3