From b5c5353d417580f7a6ac21a0954f1c500a5cc4f5 Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Sun, 21 Oct 2012 01:01:12 -0600 Subject: [PATCH] ARM: OMAP1: create read_reset_sources() function (for initial use by watchdog) On OMAP1, the existing OMAP watchdog driver reads a register directly from a non-watchdog IP block. It also does not convert the register's contents into the standard WDIOF_* bits expected from the GETBOOTSTATUS ioctl(). To move towards fixing these problems, create an function in arch/arm/mach-omap1 to return the reset source data. A subsequent patch will provide this function to the watchdog driver via platform_data. In the long term, the best approach would be to move this function to a new OMAP1 driver that handles access to the OMAP1 Clock Generation and Reset Management IP block. Then no platform_data would be needed. Signed-off-by: Paul Walmsley --- arch/arm/mach-omap1/common.h | 2 ++ arch/arm/mach-omap1/reset.c | 38 ++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/arch/arm/mach-omap1/common.h b/arch/arm/mach-omap1/common.h index c2552b24f9f2..e4efac9839a8 100644 --- a/arch/arm/mach-omap1/common.h +++ b/arch/arm/mach-omap1/common.h @@ -90,4 +90,6 @@ extern int ocpi_enable(void); static inline int ocpi_enable(void) { return 0; } #endif +extern int omap1_get_reset_sources(void); + #endif /* __ARCH_ARM_MACH_OMAP1_COMMON_H */ diff --git a/arch/arm/mach-omap1/reset.c b/arch/arm/mach-omap1/reset.c index b17709103866..a0a9f97772ea 100644 --- a/arch/arm/mach-omap1/reset.c +++ b/arch/arm/mach-omap1/reset.c @@ -10,6 +10,19 @@ #include "common.h" +/* ARM_SYSST bit shifts related to SoC reset sources */ +#define ARM_SYSST_POR_SHIFT 5 +#define ARM_SYSST_EXT_RST_SHIFT 4 +#define ARM_SYSST_ARM_WDRST_SHIFT 2 +#define ARM_SYSST_GLOB_SWRST_SHIFT 1 + +/* Standardized reset source bits (across all OMAP SoCs) */ +#define OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT 0 +#define OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT 1 +#define OMAP_MPU_WD_RST_SRC_ID_SHIFT 3 +#define OMAP_EXTWARM_RST_SRC_ID_SHIFT 5 + + void omap1_restart(char mode, const char *cmd) { /* @@ -23,3 +36,28 @@ void omap1_restart(char mode, const char *cmd) omap_writew(1, ARM_RSTCT1); } + +/** + * omap1_get_reset_sources - return the source of the SoC's last reset + * + * Returns bits that represent the last reset source for the SoC. The + * format is standardized across OMAPs for use by the OMAP watchdog. + */ +int omap1_get_reset_sources(void) +{ + int ret = 0; + u16 rs; + + rs = __raw_readw(ARM_SYSST); + + if (rs & (1 << ARM_SYSST_POR_SHIFT)) + ret |= 1 << OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT; + if (rs & (1 << ARM_SYSST_EXT_RST_SHIFT)) + ret |= 1 << OMAP_EXTWARM_RST_SRC_ID_SHIFT; + if (rs & (1 << ARM_SYSST_ARM_WDRST_SHIFT)) + ret |= 1 << OMAP_MPU_WD_RST_SRC_ID_SHIFT; + if (rs & (1 << ARM_SYSST_GLOB_SWRST_SHIFT)) + ret |= 1 << OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT; + + return ret; +} -- 2.20.1