linux-kernel - [PATCH/RFC v5 1/4] leds: Improve and export led_update

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-id: <1408542118-32723-2-git-send-email-j.anaszewski@samsung.com>
Date:	Wed, 20 Aug 2014 15:41:55 +0200
From:	Jacek Anaszewski <j.anaszewski@...sung.com>
To:	linux-leds@...r.kernel.org, devicetree@...r.kernel.org,
	linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:	kyungmin.park@...sung.com, b.zolnierkie@...sung.com,
	Jacek Anaszewski <j.anaszewski@...sung.com>,
	Bryan Wu <cooloney@...il.com>,
	Richard Purdie <rpurdie@...ys.net>
Subject: [PATCH/RFC v5 1/4] leds: Improve and export led_update_brightness

led_update_brightness helper function used to be exploited only locally
in the led-class.c module, where its result was being passed to the
brightness_show sysfs callback. With the introduction of v4l2-flash
subdevice the same functionality becomes required for reading current
brightness from a LED device. This patch adds checking of return value
of the brightness_get callback and moves the led_update_brightness()
function to the LED subsystem public API.

Signed-off-by: Jacek Anaszewski <j.anaszewski@...sung.com>
Acked-by: Kyungmin Park <kyungmin.park@...sung.com>
Cc: Bryan Wu <cooloney@...il.com>
Cc: Richard Purdie <rpurdie@...ys.net>
---
 drivers/leds/led-class.c |    6 ------
 drivers/leds/led-core.c  |   16 ++++++++++++++++
 include/linux/leds.h     |   10 ++++++++++
 3 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index f4e5bb4..6f82a76 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -23,12 +23,6 @@
 
 static struct class *leds_class;
 
-static void led_update_brightness(struct led_classdev *led_cdev)
-{
-	if (led_cdev->brightness_get)
-		led_cdev->brightness = led_cdev->brightness_get(led_cdev);
-}
-
 static ssize_t brightness_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index 8380eb7..466ce5a 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -127,3 +127,19 @@ void led_set_brightness(struct led_classdev *led_cdev,
 	__led_set_brightness(led_cdev, brightness);
 }
 EXPORT_SYMBOL(led_set_brightness);
+
+int led_update_brightness(struct led_classdev *led_cdev)
+{
+	int ret = 0;
+
+	if (led_cdev->brightness_get) {
+		ret = led_cdev->brightness_get(led_cdev);
+		if (ret >= 0) {
+			led_cdev->brightness = ret;
+			return 0;
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(led_update_brightness);
diff --git a/include/linux/leds.h b/include/linux/leds.h
index bc221d11..cc85b16 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -139,6 +139,16 @@ extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
  */
 extern void led_set_brightness(struct led_classdev *led_cdev,
 			       enum led_brightness brightness);
+/**
+ * led_update_brightness - update LED brightness
+ * @led_cdev: the LED to query
+ *
+ * Get an LED's current brightness and update led_cdev->brightness
+ * member with the obtained value.
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+extern int led_update_brightness(struct led_classdev *led_cdev);
 
 /*
  * LED Triggers
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/