[PATCH v7 2/5] leds: Add helper for getting default pattern from Device Tree

From: Krzysztof Kozlowski
Date: Wed Jan 09 2019 - 09:45:05 EST


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

Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
---
drivers/leds/led-core.c | 30 ++++++++++++++++++++++++++++++
include/linux/leds.h | 13 +++++++++++++
2 files changed, 43 insertions(+)

diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index ede4fa0ac2cc..e3da7c03da1b 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 +312,34 @@ int led_update_brightness(struct led_classdev *led_cdev)
}
EXPORT_SYMBOL_GPL(led_update_brightness);

+u32 *led_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)) {
+ kfree(pattern);
+ return NULL;
+ }
+
+ *size = count;
+
+ return pattern;
+}
+EXPORT_SYMBOL_GPL(led_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..78204650fe2a 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -219,6 +219,19 @@ extern int led_set_brightness_sync(struct led_classdev *led_cdev,
extern int led_update_brightness(struct led_classdev *led_cdev);

/**
+ * led_get_default_pattern - return default pattern
+ *
+ * @led_cdev: the LED to get default pattern for
+ * @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 device tree
+ * or NULL. Caller is responsible for kfree().
+ */
+extern u32 *led_get_default_pattern(struct led_classdev *led_cdev,
+ unsigned int *size);
+
+/**
* led_sysfs_disable - disable LED sysfs interface
* @led_cdev: the LED to set
*
--
2.7.4