From 565ac44593d17bdfc9f595614b56bb335a9b8d6f Mon Sep 17 00:00:00 2001 From: Andrew Victor Date: Wed, 2 Apr 2008 21:52:19 +0100 Subject: [ARM] 4907/1: [AT91] SAM9/CAP9 reset reason The Reset controller on the SAM9/CAP9 processors will store the reason for the last system reset. On startup, display this information (wakeup signal, RTT alarm, watchdog reset, user reset, etc) Based on patch from David Brownell. Signed-off-by: Andrew Victor Signed-off-by: Russell King --- arch/arm/mach-at91/pm.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) (limited to 'arch/arm/mach-at91') diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c index 77d9669810ed..39733b6992aa 100644 --- a/arch/arm/mach-at91/pm.c +++ b/arch/arm/mach-at91/pm.c @@ -83,6 +83,79 @@ static inline void sdram_selfrefresh_enable(void) #endif +/* + * Show the reason for the previous system reset. + */ +#if defined(AT91_SHDWC) + +#include +#include + +static void __init show_reset_status(void) +{ + static char reset[] __initdata = "reset"; + + static char general[] __initdata = "general"; + static char wakeup[] __initdata = "wakeup"; + static char watchdog[] __initdata = "watchdog"; + static char software[] __initdata = "software"; + static char user[] __initdata = "user"; + static char unknown[] __initdata = "unknown"; + + static char signal[] __initdata = "signal"; + static char rtc[] __initdata = "rtc"; + static char rtt[] __initdata = "rtt"; + static char restore[] __initdata = "power-restored"; + + char *reason, *r2 = reset; + u32 reset_type, wake_type; + + reset_type = at91_sys_read(AT91_RSTC_SR) & AT91_RSTC_RSTTYP; + wake_type = at91_sys_read(AT91_SHDW_SR); + + switch (reset_type) { + case AT91_RSTC_RSTTYP_GENERAL: + reason = general; + break; + case AT91_RSTC_RSTTYP_WAKEUP: + /* board-specific code enabled the wakeup sources */ + reason = wakeup; + + /* "wakeup signal" */ + if (wake_type & AT91_SHDW_WAKEUP0) + r2 = signal; + else { + r2 = reason; + if (wake_type & AT91_SHDW_RTTWK) /* rtt wakeup */ + reason = rtt; + else if (wake_type & AT91_SHDW_RTCWK) /* rtc wakeup */ + reason = rtc; + else if (wake_type == 0) /* power-restored wakeup */ + reason = restore; + else /* unknown wakeup */ + reason = unknown; + } + break; + case AT91_RSTC_RSTTYP_WATCHDOG: + reason = watchdog; + break; + case AT91_RSTC_RSTTYP_SOFTWARE: + reason = software; + break; + case AT91_RSTC_RSTTYP_USER: + reason = user; + break; + default: + reason = unknown; + break; + } + pr_info("AT91: Starting after %s %s\n", reason, r2); +} +#else +static void __init show_reset_status(void) {} +#endif + + static int at91_pm_valid_state(suspend_state_t state) { switch (state) { @@ -294,6 +367,7 @@ static int __init at91_pm_init(void) suspend_set_ops(&at91_pm_ops); + show_reset_status(); return 0; } arch_initcall(at91_pm_init); -- cgit v1.2.3