watchdog: wdt-uclass.c: handle all DM watchdogs in watchdog_reset()

A board can have and make use of more than one watchdog device, say
one built into the SOC and an external gpio-petted one. Having
wdt-uclass only handle the first is both a little arbitrary and
unexpected.

So change initr_watchdog() so we visit (probe) all DM watchdog
devices, and call the init_watchdog_dev helper for each.

Similarly let watchdog_reset() loop over the whole uclass - each
having their own ratelimiting metadata, and a separate "is this device
running" flag.

This gets rid of the watchdog_dev member of struct global_data.  We
do, however, still need the GD_FLG_WDT_READY set in
initr_watchdog(). This is because watchdog_reset() can get called
before DM is ready, and I don't think we can call uclass_get() that
early.

The current code just returns 0 if "getting" the first device fails -
that can of course happen because there are no devices, but it could
also happen if its ->probe call failed. In keeping with that, continue
with the handling of the remaining devices even if one fails to
probe. This is also why we cannot use uclass_probe_all().

If desired, it's possible to later add a per-device "u-boot,autostart"
boolean property, so that one can do CONFIG_WATCHDOG_AUTOSTART
per-device.

Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>

diff --git a/drivers/watchdog/wdt-uclass.c b/drivers/watchdog/wdt-uclass.c
index 5b1c0df..7570710 100644 (file)
--- a/drivers/watchdog/wdt-uclass.c
+++ b/drivers/watchdog/wdt-uclass.c
@@ -61,20 +61,24 @@ static void init_watchdog_dev(struct udevice *dev)
 
 int initr_watchdog(void)
 {
-       /*
-        * Init watchdog: This will call the probe function of the
-        * watchdog driver, enabling the use of the device
-        */
-       if (uclass_get_device_by_seq(UCLASS_WDT, 0,
-                                    (struct udevice **)&gd->watchdog_dev)) {
-               debug("WDT:   Not found by seq!\n");
-               if (uclass_get_device(UCLASS_WDT, 0,
-                                     (struct udevice **)&gd->watchdog_dev)) {
-                       printf("WDT:   Not found!\n");
-                       return 0;
+       struct udevice *dev;
+       struct uclass *uc;
+       int ret;
+
+       ret = uclass_get(UCLASS_WDT, &uc);
+       if (ret) {
+               log_debug("Error getting UCLASS_WDT: %d\n", ret);
+               return 0;
+       }
+
+       uclass_foreach_dev(dev, uc) {
+               ret = device_probe(dev);
+               if (ret) {
+                       log_debug("Error probing %s: %d\n", dev->name, ret);
+                       continue;
                }
+               init_watchdog_dev(dev);
        }
-       init_watchdog_dev(gd->watchdog_dev);
 
        gd->flags |= GD_FLG_WDT_READY;
        return 0;
@@ -182,22 +186,34 @@ void watchdog_reset(void)
 {
        struct wdt_priv *priv;
        struct udevice *dev;
+       struct uclass *uc;
        ulong now;
 
        /* Exit if GD is not ready or watchdog is not initialized yet */
        if (!gd || !(gd->flags & GD_FLG_WDT_READY))
                return;
 
-       dev = gd->watchdog_dev;
-       priv = dev_get_uclass_priv(dev);
-       if (!priv->running)
+       if (uclass_get(UCLASS_WDT, &uc))
                return;
 
-       /* Do not reset the watchdog too often */
-       now = get_timer(0);
-       if (time_after_eq(now, priv->next_reset)) {
-               priv->next_reset = now + priv->reset_period;
-               wdt_reset(dev);
+       /*
+        * All devices bound to the wdt uclass should have been probed
+        * in initr_watchdog(). But just in case something went wrong,
+        * check device_active() before accessing the uclass private
+        * data.
+        */
+       uclass_foreach_dev(dev, uc) {
+               if (!device_active(dev))
+                       continue;
+               priv = dev_get_uclass_priv(dev);
+               if (!priv->running)
+                       continue;
+               /* Do not reset the watchdog too often */
+               now = get_timer(0);
+               if (time_after_eq(now, priv->next_reset)) {
+                       priv->next_reset = now + priv->reset_period;
+                       wdt_reset(dev);
+               }
        }
 }
 #endif

diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index a4cf7fd..16fd305 100644 (file)
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -447,12 +447,6 @@ struct global_data {
         */
        fdt_addr_t translation_offset;
 #endif
-#if CONFIG_IS_ENABLED(WDT)
-       /**
-        * @watchdog_dev: watchdog device
-        */
-       struct udevice *watchdog_dev;
-#endif
 #ifdef CONFIG_GENERATE_ACPI_TABLE
        /**
         * @acpi_ctx: ACPI context pointer