[PATCH 4/4] watchdog: Automatically register device with sysreset

[Heinrich Schuchardt]

On 8/22/21 22:41, Samuel Holland wrote:
> Add an option to automatically register the first watchdog device with
> the wdt_reboot driver for use with sysreset. This allows sysreset to be
> a drop-in replacement for platform-specific watchdog reset code, without
> needing any device tree changes.
> 
> Signed-off-by: Samuel Holland <samuel at sholland.org>
> ---
> 
>   drivers/sysreset/Kconfig             |  7 +++++++
>   drivers/sysreset/sysreset_watchdog.c | 24 ++++++++++++++++++++++++
>   drivers/watchdog/wdt-uclass.c        |  5 +++++
>   include/sysreset.h                   | 14 ++++++++++++++
>   4 files changed, 50 insertions(+)
> 
> diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
> index fdc858ccbac..49354b1b27a 100644
> --- a/drivers/sysreset/Kconfig
> +++ b/drivers/sysreset/Kconfig
> @@ -119,6 +119,13 @@ config SYSRESET_WATCHDOG
>   	help
>   	  Reboot support for generic watchdog reset.
>   
> +config SYSRESET_WATCHDOG_AUTO
> +	bool "Automatically register first watchdog with sysreset"
> +	depends on SYSRESET_WATCHDOG
> +	help
> +	  If enabled, the first watchdog (as selected by the watchdog uclass)
> +	  will automatically be registered with the watchdog reboot driver.
> +
>   config SYSRESET_RESETCTL
>   	bool "Enable support for reset controller reboot driver"
>   	select DM_RESET
> diff --git a/drivers/sysreset/sysreset_watchdog.c b/drivers/sysreset/sysreset_watchdog.c
> index b723f5647cd..35efcac59dd 100644
> --- a/drivers/sysreset/sysreset_watchdog.c
> +++ b/drivers/sysreset/sysreset_watchdog.c
> @@ -5,7 +5,9 @@
>   
>   #include <common.h>
>   #include <dm.h>
> +#include <dm/device-internal.h>
>   #include <errno.h>
> +#include <malloc.h>
>   #include <sysreset.h>
>   #include <wdt.h>
>   
> @@ -57,3 +59,25 @@ U_BOOT_DRIVER(wdt_reboot) = {
>   	.plat_auto	= sizeof(struct wdt_reboot_plat),
>   	.ops = &wdt_reboot_ops,
>   };
> +
> +#if IS_ENABLED(CONFIG_SYSRESET_WATCHDOG_AUTO)
> +int sysreset_register_wdt(struct udevice *dev)
> +{
> +	struct wdt_reboot_plat *plat = malloc(sizeof(*plat));
> +	int ret;
> +
> +	if (!plat)
> +		return -ENOMEM;
> +
> +	plat->wdt = dev;
> +
> +	ret = device_bind(dev, DM_DRIVER_GET(wdt_reboot),
> +			  dev->name, plat, ofnode_null(), NULL);
> +	if (ret) {
> +		free(plat);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +#endif
> diff --git a/drivers/watchdog/wdt-uclass.c b/drivers/watchdog/wdt-uclass.c
> index 17334dbda6c..3170ef9d945 100644
> --- a/drivers/watchdog/wdt-uclass.c
> +++ b/drivers/watchdog/wdt-uclass.c
> @@ -10,6 +10,7 @@
>   #include <errno.h>
>   #include <hang.h>
>   #include <log.h>
> +#include <sysreset.h>
>   #include <time.h>
>   #include <wdt.h>
>   #include <asm/global_data.h>
> @@ -53,6 +54,10 @@ int initr_watchdog(void)

This function has been changed in upstream:
@@ -44,6 +45,10 @@ static void init_watchdog_dev(struct udevice *dev)

>   						    4 * reset_period) / 4;
>   	}
>   
> +	ret = sysreset_register_wdt(gd->watchdog_dev);

ret = sysreset_register_wdt(dev);

I applied the following series to enable testing on the sandbox:

   [PATCH 0/2] sandbox: enable testing SYSRESET_WATCHDOG
   https://lists.denx.de/pipermail/u-boot/2021-October/465270.html

I found no issues.

Please, resend the rebased series.

Best regards

Heinrich

> +	if (ret)
> +		printf("WDT:   Failed to register sysreset\n");
> +
>   	if (!IS_ENABLED(CONFIG_WATCHDOG_AUTOSTART)) {
>   		printf("WDT:   Not starting\n");
>   		return 0;
> diff --git a/include/sysreset.h b/include/sysreset.h
> index 701e4f5c86e..ad45fe0db28 100644
> --- a/include/sysreset.h
> +++ b/include/sysreset.h
> @@ -118,4 +118,18 @@ void sysreset_walk_halt(enum sysreset_t type);
>    */
>   void reset_cpu(void);
>   
> +/**
> + * sysreset_register_wdt() - register a watchdog for use with sysreset
> + *
> + * This registers the given watchdog timer to be used to reset the system.
> + *
> + * @dev:	WDT device
> + * @return:	0 if OK, -errno if error
> + */
> +#if IS_ENABLED(CONFIG_SYSRESET_WATCHDOG_AUTO)
> +int sysreset_register_wdt(struct udevice *dev);
> +#else
> +static inline int sysreset_register_wdt(struct udevice *dev) { return 0; }
> +#endif
> +
>   #endif
>