From 2ccd4510bd74d01ad20b276f0e2e51ced0c475a8 Mon Sep 17 00:00:00 2001 From: Steffen Trumtrar Date: Mon, 11 Feb 2013 11:42:05 +0100 Subject: [PATCH] ARM i.MX28: change default watchdog reset method The default setting for the imx28 watchdog is to do a power-off reset. If the SoC is only powered via battery, then the watchdog powers the chip down, though. According to the datasheet it should still be possible to execute a proper POR with battery power, but testing showed otherwise. When the watchdog power-off reset is disabled, a software reset is executed instead. This works with and without battery power. Signed-off-by: Steffen Trumtrar Signed-off-by: Sascha Hauer --- arch/arm/mach-mxs/soc-imx28.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/arm/mach-mxs/soc-imx28.c b/arch/arm/mach-mxs/soc-imx28.c index a181b759c..a5f3d685d 100644 --- a/arch/arm/mach-mxs/soc-imx28.c +++ b/arch/arm/mach-mxs/soc-imx28.c @@ -21,6 +21,7 @@ #define HW_CLKCTRL_RESET 0x1e0 # define HW_CLKCTRL_RESET_CHIP (1 << 1) +#define HW_CLKCTRL_WDOG_POR_DISABLE (1 << 5) /* Reset the full i.MX28 SoC via a chipset feature */ void __noreturn reset_cpu(unsigned long addr) @@ -35,3 +36,14 @@ void __noreturn reset_cpu(unsigned long addr) /*NOTREACHED*/ } EXPORT_SYMBOL(reset_cpu); + +static int imx28_init(void) +{ + /* + * The default setting for the WDT is to do a POR. If the SoC is only + * powered via battery, then a WDT reset powers the chip down instead + * of resetting it. Use a software reset only. + */ + writel(HW_CLKCTRL_WDOG_POR_DISABLE, IMX_CCM_BASE + HW_CLKCTRL_RESET); +} +postcore_initcall(imx28_init);