From 9dd4e173f71d5ac6ea37f7dbf49af6e5cd44f9fb Mon Sep 17 00:00:00 2001 From: Justin Chen Date: Wed, 2 Sep 2015 11:00:17 -0700 Subject: [PATCH] watchdog: watchdog_dev: Use device tree alias for naming watchdogs Currently there is no way to easily differentiate multiple watchdog devices. The watchdogs are named by the order they are probed. 1st probed watchdog: /dev/watchdog0 2nd probed watchdog: /dev/watchdog1 ... This change uses the alias of the watchdog device node for the name of the watchdog. aliases { watchdog0 = "/...../...." watchdog3 = "/..../....." watchdog2 = "/..../....." ... } This will translate to... /dev/watchdog0 /dev/watchdog3 /dev/watchdog2 v2 Assign alias number to id in watchdog_core instead of watchdog_dev. If failed to get id, fallback to original ida_simple_get call. Signed-off-by: Justin Chen Reviewed-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/watchdog_core.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c index 1a8059455413..873f13972cf4 100644 --- a/drivers/watchdog/watchdog_core.c +++ b/drivers/watchdog/watchdog_core.c @@ -139,7 +139,7 @@ EXPORT_SYMBOL_GPL(watchdog_init_timeout); static int __watchdog_register_device(struct watchdog_device *wdd) { - int ret, id, devno; + int ret, id = -1, devno; if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL) return -EINVAL; @@ -157,7 +157,18 @@ static int __watchdog_register_device(struct watchdog_device *wdd) */ mutex_init(&wdd->lock); - id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL); + + /* Use alias for watchdog id if possible */ + if (wdd->parent) { + ret = of_alias_get_id(wdd->parent->of_node, "watchdog"); + if (ret >= 0) + id = ida_simple_get(&watchdog_ida, ret, + ret + 1, GFP_KERNEL); + } + + if (id < 0) + id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL); + if (id < 0) return id; wdd->id = id; -- 2.20.1