[PATCH v3 2/5] leds: Add helper for getting default pattern from Device Tree

From: Krzysztof Kozlowski
Date: Wed Dec 12 2018 - 06:17:23 EST


Multiple LED triggers might need to access default pattern so add a
helper for that.

Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
---

New patch in the series

---
drivers/leds/led-class.c | 25 +++++++++++++++++++++++++
include/linux/leds.h | 3 +++
2 files changed, 28 insertions(+)

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 3c7e3487b373..44b95e6480f6 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -17,6 +17,7 @@
#include <linux/leds.h>
#include <linux/list.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
@@ -244,6 +245,30 @@ static int led_classdev_next_name(const char *init_name, char *name,
}

/**
+ * led_classdev_get_default_pattern - return default pattern
+ *
+ * @led_cdev: the led_classdev structure for this device
+ *
+ * Return: Null terminated string with default pattern from DeviceTree or NULL
+ */
+const char *led_classdev_get_default_pattern(struct led_classdev *led_cdev)
+{
+ struct device_node *np = dev_of_node(led_cdev->dev);
+ const char *pattern;
+
+ if (!np)
+ return NULL;
+
+ if (of_property_read_string(np, "led-pattern", &pattern))
+ return NULL;
+
+ if (!strlen(pattern))
+ return NULL;
+
+ return pattern;
+}
+
+/**
* of_led_classdev_register - register a new object of led_classdev class.
*
* @parent: parent of LED device
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 5263f87e1d2c..9da2bfa183ea 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -129,6 +129,9 @@ struct led_classdev {
struct mutex led_access;
};

+extern const char *
+led_classdev_get_default_pattern(struct led_classdev *led_cdev);
+
extern int of_led_classdev_register(struct device *parent,
struct device_node *np,
struct led_classdev *led_cdev);
--
2.7.4