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Subject[PATCH v5 2/5] leds: Add helper for getting default pattern from Device Tree
Date
Multiple LED triggers might need to access default pattern so add a
helper for that.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
drivers/leds/led-core.c | 43 +++++++++++++++++++++++++++++++++++++++++
include/linux/leds.h | 3 +++
2 files changed, 46 insertions(+)

diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index ede4fa0ac2cc..e4b6da73bc12 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -16,7 +16,9 @@
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/of.h>
#include <linux/rwsem.h>
+#include <linux/slab.h>
#include "leds.h"

DECLARE_RWSEM(leds_list_lock);
@@ -310,6 +312,47 @@ int led_update_brightness(struct led_classdev *led_cdev)
}
EXPORT_SYMBOL_GPL(led_update_brightness);

+/**
+ * led_classdev_get_default_pattern - return default pattern
+ *
+ * @led_cdev: the led_classdev structure for this device
+ * @size: pointer for storing the number of elements in returned array,
+ * modified only if return != NULL
+ *
+ * Return: Allocated array of integers with default pattern from DeviceTree
+ * or NULL. Caller is responsible for kfree().
+ */
+u32 *led_classdev_get_default_pattern(struct led_classdev *led_cdev,
+ unsigned int *size)
+{
+ struct device_node *np = dev_of_node(led_cdev->dev);
+ u32 *pattern;
+ int count;
+
+ if (!np)
+ return NULL;
+
+ count = of_property_count_u32_elems(np, "led-pattern");
+ if (count < 0)
+ return NULL;
+
+ pattern = kcalloc(count, sizeof(*pattern), GFP_KERNEL);
+ if (!pattern)
+ return NULL;
+
+ if (of_property_read_u32_array(np, "led-pattern", pattern, count))
+ goto err;
+
+ *size = count;
+
+ return pattern;
+
+err:
+ kfree(pattern);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(led_classdev_get_default_pattern);
+
/* Caller must ensure led_cdev->led_access held */
void led_sysfs_disable(struct led_classdev *led_cdev)
{
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 5263f87e1d2c..70edf574ba81 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -129,6 +129,9 @@ struct led_classdev {
struct mutex led_access;
};

+extern u32 *led_classdev_get_default_pattern(struct led_classdev *led_cdev,
+ unsigned int *size);
+
extern int of_led_classdev_register(struct device *parent,
struct device_node *np,
struct led_classdev *led_cdev);
--
2.17.1
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