[PATCH] watchdog_dev: Use device tree alias for naming watchdogs

From: Justin Chen
Date: Fri Aug 28 2015 - 17:58:55 EST


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

Signed-off-by: Justin Chen <justinpopo6@xxxxxxxxx>
---
drivers/watchdog/watchdog_dev.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 6aaefba..52b1f0b 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -41,6 +41,7 @@
#include <linux/miscdevice.h> /* For handling misc devices */
#include <linux/init.h> /* For __init/__exit/... */
#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
+#include <linux/of.h>

#include "watchdog_core.h"

@@ -522,7 +523,13 @@ static struct miscdevice watchdog_miscdev = {

int watchdog_dev_register(struct watchdog_device *watchdog)
{
- int err, devno;
+ int err, devno, ret;
+
+ if (watchdog->parent) {
+ ret = of_alias_get_id(watchdog->parent->of_node, "watchdog");
+ if (ret >= 0)
+ watchdog->id = ret;
+ }

if (watchdog->id == 0) {
old_wdd = watchdog;
--
2.1.0

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