diff mbox series

[v2,2/2] leds: multicolor: Read default-intensities property

Message ID 980857efbf41b77667b0e0b5044f06409295d7d0.1651577132.git.sven.schwermer@disruptive-technologies.com
State Superseded
Headers show
Series [v2,1/2] dt-bindings: leds: Add multi-color default-intensities property | expand

Commit Message

Sven Schwermer May 3, 2022, 11:27 a.m. UTC 
From: Sven Schwermer <sven.schwermer@disruptive-technologies.com>

This allows to assign intensity values taken from the firmware interface
(if available) to the indivisual sub LEDs (colors) at driver probe time,
i.e. most commonly at kernel boot time. This is crucial for setting a
specific color and early in the boot process. While it would be possible
to set a static color in the bootloader, this mechanism allows setting a
pattern (e.g. blinking) at a specific color.

Signed-off-by: Sven Schwermer <sven.schwermer@disruptive-technologies.com>
---

Notes:
    V1->V2: Fix mixup

 drivers/leds/led-class-multicolor.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
diff mbox series

Patch

diff --git a/drivers/leds/led-class-multicolor.c b/drivers/leds/led-class-multicolor.c
index e317408583df..84f237784246 100644
--- a/drivers/leds/led-class-multicolor.c
+++ b/drivers/leds/led-class-multicolor.c
@@ -9,6 +9,7 @@ 
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/property.h>
 
 #include "leds.h"
 
@@ -116,6 +117,26 @@  static struct attribute *led_multicolor_attrs[] = {
 };
 ATTRIBUTE_GROUPS(led_multicolor);
 
+static void multi_load_default_intensities(struct device *parent,
+					   struct led_classdev_mc *mcled_cdev,
+					   struct fwnode_handle *fwnode)
+{
+	u32 intensities[LED_COLOR_ID_MAX];
+	unsigned int i;
+	int ret;
+
+	ret = fwnode_property_read_u32_array(fwnode, "default-intensities",
+					     intensities, mcled_cdev->num_colors);
+	if (ret < 0) {
+		if (ret != -ENODATA)
+			dev_warn(parent, "failed to read default-intensities property: %d", ret);
+		return;
+	}
+
+	for (i = 0; i < mcled_cdev->num_colors; i++)
+		mcled_cdev->subled_info[i].intensity = intensities[i];
+}
+
 int led_classdev_multicolor_register_ext(struct device *parent,
 				     struct led_classdev_mc *mcled_cdev,
 				     struct led_init_data *init_data)
@@ -134,6 +155,9 @@  int led_classdev_multicolor_register_ext(struct device *parent,
 	led_cdev = &mcled_cdev->led_cdev;
 	mcled_cdev->led_cdev.groups = led_multicolor_groups;
 
+	if (init_data && init_data->fwnode)
+		multi_load_default_intensities(parent, mcled_cdev, init_data->fwnode);
+
 	return led_classdev_register_ext(parent, led_cdev, init_data);
 }
 EXPORT_SYMBOL_GPL(led_classdev_multicolor_register_ext);