[U-Boot] [PATCH] ls102xa: Fix reset hang

[Sinan Akman]

   Hi Fabio

On 02/10/15 09:25 AM, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam at 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.
>
> Reported-by: Sinan Akman <sinan at writeme.com>
> Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
> ---
>   arch/arm/cpu/armv7/ls102xa/cpu.c | 21 +++++++++++++++++++++
>   drivers/watchdog/Makefile        |  2 +-
>   2 files changed, 22 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/cpu/armv7/ls102xa/cpu.c b/arch/arm/cpu/armv7/ls102xa/cpu.c
> index 8dd95d9..0de6f19 100644
> --- a/arch/arm/cpu/armv7/ls102xa/cpu.c
> +++ b/arch/arm/cpu/armv7/ls102xa/cpu.c
> @@ -13,6 +13,7 @@
>   #include <tsec.h>
>   #include <netdev.h>
>   #include <fsl_esdhc.h>
> +#include <config.h>
>   
>   #include "fsl_epu.h"
>   
> @@ -354,3 +355,23 @@ void smp_kick_all_cpus(void)
>   	asm volatile("sev");
>   }
>   #endif
> +
> +struct watchdog_regs {
> +	u16	wcr;	/* Control */
> +	u16	wsr;	/* Service */
> +	u16	wrsr;	/* Reset Status */
> +};
> +
> +#define WCR_SRS		(1 << 4)
> +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

    Tested-by: Sinan Akman <sinan at writeme.com>

    Regards
    Sinan Akman