From: Fabio Estevam fabio.estevam@freescale.com
Since commit 623d96e89aca6("imx: wdog: correct wcr register settings") issuing a 'reset' command causes the system to hang.
Unlike i.MX and Vybrid, the watchdog controller on LS102x is big-endian.
This means that the watchdog on LS1021 has been working by accident as it does not use the big-endian accessors in drivers/watchdog/imx_watchdog.c. Commit 623d96e89aca6("imx: wdog: correct wcr register settings") only revelead the endianness problem on LS102x.
In order to fix the reset hang, introduce a reset_cpu() implementation that is specific for ls102x, which accesses the watchdog WCR register in big-endian format. All that is required to reset LS102x is to clear the SRS bit.
This approach is a temporary workaround to avoid a regression for LS102x in the 2015.10 release. The proper fix is to make the watchdog driver endian-aware, so that it can work for i.MX, Vybrid and LS102x.
Reported-by: Sinan Akman sinan@writeme.com Tested-by: Sinan Akman sinan@writeme.com Reviewed-by: Wolfgang Denk wd@denx.de Signed-off-by: Fabio Estevam fabio.estevam@freescale.com --- Changes since v2: - Explain that this a temporary workaround (Tom) Changes since v1: - Do not add duplicate wdog struct (Wolfgang)
arch/arm/cpu/armv7/ls102xa/cpu.c | 15 +++++++++++++++ drivers/watchdog/Makefile | 2 +- 2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/arch/arm/cpu/armv7/ls102xa/cpu.c b/arch/arm/cpu/armv7/ls102xa/cpu.c index 8dd95d9..e2eb5f3 100644 --- a/arch/arm/cpu/armv7/ls102xa/cpu.c +++ b/arch/arm/cpu/armv7/ls102xa/cpu.c @@ -13,6 +13,8 @@ #include <tsec.h> #include <netdev.h> #include <fsl_esdhc.h> +#include <config.h> +#include <fsl_wdog.h>
#include "fsl_epu.h"
@@ -354,3 +356,16 @@ void smp_kick_all_cpus(void) asm volatile("sev"); } #endif + +void reset_cpu(ulong addr) +{ + struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR; + + clrbits_be16(&wdog->wcr, WCR_SRS); + + while (1) { + /* + * Let the watchdog trigger + */ + } +} diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 9e9cb55..a007ae8 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -7,7 +7,7 @@
obj-$(CONFIG_AT91SAM9_WATCHDOG) += at91sam9_wdt.o obj-$(CONFIG_FTWDT010_WATCHDOG) += ftwdt010_wdt.o -ifneq (,$(filter $(SOC), mx31 mx35 mx5 mx6 mx7 vf610 ls102xa)) +ifneq (,$(filter $(SOC), mx31 mx35 mx5 mx6 mx7 vf610)) obj-y += imx_watchdog.o endif obj-$(CONFIG_S5P) += s5p_wdt.o