[U-Boot] [PATCH] bcm2835_wdt: support for the BCM2835/2836 watchdog

["Brüns, Stefan" <Stefan.Bruens@rwth-aachen.de>]

On Freitag, 27. Januar 2017 10:59:05 CET Paolo Pisati wrote:
> Signed-off-by: Paolo Pisati <p.pisati@gmail.com>
> ---
>  arch/arm/mach-bcm283x/reset.c  | 21 ++++++++++++++++++---
>  board/raspberrypi/rpi/rpi.c    |  4 ++++
>  drivers/watchdog/Makefile      |  1 +
>  drivers/watchdog/bcm2835_wdt.c | 34 ++++++++++++++++++++++++++++++++++
>  include/configs/rpi.h          |  3 +++
>  scripts/config_whitelist.txt   |  1 +
>  6 files changed, 61 insertions(+), 3 deletions(-)
>  create mode 100644 drivers/watchdog/bcm2835_wdt.c
> 
> diff --git a/arch/arm/mach-bcm283x/reset.c b/arch/arm/mach-bcm283x/reset.c
> index 685815c..b62cb8a 100644
> --- a/arch/arm/mach-bcm283x/reset.c
> +++ b/arch/arm/mach-bcm283x/reset.c
> @@ -21,18 +21,33 @@
>   */
>  #define BCM2835_WDOG_RSTS_RASPBERRYPI_HALT	0x555
> 
> +/* max ticks timeout */
> +#define BCM2835_WDOG_MAX_TIMEOUT	0x000fffff
> +
> +#ifdef CONFIG_BCM2835_WDT
> +extern void hw_watchdog_disable(void);
> +#else
> +void hw_watchdog_disable(void) {}
> +#endif
> +
>  __efi_runtime_data struct bcm2835_wdog_regs *wdog_regs =
>  	(struct bcm2835_wdog_regs *)BCM2835_WDOG_PHYSADDR;
> 
> -void __efi_runtime reset_cpu(ulong addr)
> +void __efi_runtime reset_cpu(ulong ticks)
>  {
> -	uint32_t rstc;
> +	uint32_t rstc, timeout;
> +
> +	if (ticks == 0) {
> +		hw_watchdog_disable();
> +		timeout = RESET_TIMEOUT;

This is wrong. The efi runtime reset function calls this as reset_cpu(0), and 
then tries to call hw_watchdog_disable, which is not marked as __efi_runtime.

Actually, I can see no reason the watchdog setup piggybacks on the reset_cpu 
funtion.

> +	} else
> +		timeout = ticks & BCM2835_WDOG_MAX_TIMEOUT;
> 
>  	rstc = readl(&wdog_regs->rstc);
>  	rstc &= ~BCM2835_WDOG_RSTC_WRCFG_MASK;
>  	rstc |= BCM2835_WDOG_RSTC_WRCFG_FULL_RESET;
> 
> -	writel(BCM2835_WDOG_PASSWORD | RESET_TIMEOUT, &wdog_regs->wdog);
> +	writel(BCM2835_WDOG_PASSWORD | timeout, &wdog_regs->wdog);
>  	writel(BCM2835_WDOG_PASSWORD | rstc, &wdog_regs->rstc);
>  }
> 
> diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c
> index 22e87a2..106e518 100644
> --- a/board/raspberrypi/rpi/rpi.c
> +++ b/board/raspberrypi/rpi/rpi.c
[...]
> --- a/scripts/config_whitelist.txt
> +++ b/scripts/config_whitelist.txt
> @@ -294,6 +294,7 @@ CONFIG_BCH_CONST_M
>  CONFIG_BCH_CONST_PARAMS
>  CONFIG_BCH_CONST_T
>  CONFIG_BCM2835_GPIO
> +CONFIG_BCM2835_WDT
>  CONFIG_BCM283X_MU_SERIAL
>  CONFIG_BCM_SF2_ETH
>  CONFIG_BCM_SF2_ETH_DEFAULT_PORT

I think the rule is no new CONFIG_xxx options, but appropriate options in 
KConfig.

Kind regards,

Stefan