[PATCH v1 1/2] dt-bindings: leds: Add multi-color default-intensities property

[PATCH v1 1/2] dt-bindings: leds: Add multi-color default-intensities property

[Sven Schwermer]

From: Sven Schwermer <sven.schwermer@disruptive-technologies.com>

This allows to assign intensity values 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 early in the boot process.

Signed-off-by: Sven Schwermer <sven.schwermer@disruptive-technologies.com>
---
 .../devicetree/bindings/leds/leds-class-multicolor.yaml    | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml b/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
index 37445c68cdef..c483967a847c 100644
--- a/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
+++ b/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
@@ -31,6 +31,13 @@ patternProperties:
           include/linux/leds/common.h.
         enum: [ 8, 9 ]
 
+      default-intensities:
+        description: |
+          This parameter, if present, sets the initial intensities of the
+          individual colors. This array must have the same length as the
+          multi-color LED has sub LEDs (colors).
+        $ref: /schemas/types.yaml#/definitions/uint32-array
+
     $ref: "common.yaml#"
 
     required:
-- 
2.36.0

[PATCH v1 2/2] leds: multicolor: Read default-intensities property

[Sven Schwermer]

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>
---
 drivers/leds/led-class-multicolor.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/leds/led-class-multicolor.c b/drivers/leds/led-class-multicolor.c
index e317408583df..eb7f11345ec1 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 +117,23 @@ 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];
+	int ret;
+	int i;
+
+	ret = fwnode_property_read_u32_array(fwnode, "default-intensities",
+					     intensities, mcled_cdev->num_colors);
+	if (ret < 0 && ret != -ENODATA)
+		dev_warn(parent, "failed to read default-intensities property: %d", ret);
+
+	for (i = 0; i < ret; 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 +152,9 @@ 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);
-- 
2.36.0

[PATCH v2 1/2] dt-bindings: leds: Add multi-color default-intensities property

[Sven Schwermer]

From: Sven Schwermer <sven.schwermer@disruptive-technologies.com>

This allows to assign intensity values 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 early in the boot process.

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

Notes:
    V1->V2: no changes

 .../devicetree/bindings/leds/leds-class-multicolor.yaml    | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml b/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
index 37445c68cdef..c483967a847c 100644
--- a/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
+++ b/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
@@ -31,6 +31,13 @@ patternProperties:
           include/linux/leds/common.h.
         enum: [ 8, 9 ]
 
+      default-intensities:
+        description: |
+          This parameter, if present, sets the initial intensities of the
+          individual colors. This array must have the same length as the
+          multi-color LED has sub LEDs (colors).
+        $ref: /schemas/types.yaml#/definitions/uint32-array
+
     $ref: "common.yaml#"
 
     required:
-- 
2.36.0

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

[Sven Schwermer]

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 --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);
-- 
2.36.0

AW: [PATCH v2 1/2] dt-bindings: leds: Add multi-color default-intensities property

[Sven Schuchmann]

Hello Sven,

tried this some time ago for the LP50XX
https://lore.kernel.org/all/20210204143726.27977-1-schuchmann@schleissheimer.de/

Your solution looks much better.
Could you give an example of how to use it?

My Configuration at this time looks like this:

multi-led@0 {
		#address-cells = <1>;
		#size-cells = <0>;
		reg = <0x0>;
		color = <LED_COLOR_ID_RGB>;
		function = "eee-led-status";

		led-0 {
			color = <LED_COLOR_ID_RED>;
		};

		led-1 {
			color = <LED_COLOR_ID_GREEN>;
		};

		led-2 {
			color = <LED_COLOR_ID_BLUE>;
		};
	};


Where do I put the "default-intensities"?

Regards,

   Sven

> -----Ursprüngliche Nachricht-----
> Von: Sven Schwermer <sven@svenschwermer.de>
> Gesendet: Dienstag, 3. Mai 2022 13:27
> An: linux-leds@vger.kernel.org; linux-kernel@vger.kernel.org; pavel@ucw.cz;
> robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; dmurphy@ti.com;
> devicetree@vger.kernel.org
> Cc: Sven Schwermer <sven.schwermer@disruptive-technologies.com>
> Betreff: [PATCH v2 1/2] dt-bindings: leds: Add multi-color default-intensities property
> 
> From: Sven Schwermer <sven.schwermer@disruptive-technologies.com>
> 
> This allows to assign intensity values 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 early in the boot process.
> 
> Signed-off-by: Sven Schwermer <sven.schwermer@disruptive-technologies.com>
> ---
> 
> Notes:
>     V1->V2: no changes
> 
>  .../devicetree/bindings/leds/leds-class-multicolor.yaml    | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
> b/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
> index 37445c68cdef..c483967a847c 100644
> --- a/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
> +++ b/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
> @@ -31,6 +31,13 @@ patternProperties:
>            include/linux/leds/common.h.
>          enum: [ 8, 9 ]
> 
> +      default-intensities:
> +        description: |
> +          This parameter, if present, sets the initial intensities of the
> +          individual colors. This array must have the same length as the
> +          multi-color LED has sub LEDs (colors).
> +        $ref: /schemas/types.yaml#/definitions/uint32-array
> +
>      $ref: "common.yaml#"
> 
>      required:
> --
> 2.36.0

[PATCH v3 1/2] dt-bindings: leds: Add multi-color default-intensities property

[Sven Schwermer]

From: Sven Schwermer <sven.schwermer@disruptive-technologies.com>

This allows to assign intensity values to the individual sub LEDs
(colors) at driver probe time, i.e. most commonly at kernel boot time.
This is crucial for setting a specific color early in the boot process.

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

Notes:
    V1->V2: no changes
    V2->V3:
    - Use color-intensity mapping instead of simple intensity array
    - Add example DTS snippet

 .../bindings/leds/leds-class-multicolor.yaml  | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml b/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
index f41d021ed677..41050de496f6 100644
--- a/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
+++ b/Documentation/devicetree/bindings/leds/leds-class-multicolor.yaml
@@ -31,6 +31,19 @@ patternProperties:
           include/linux/leds/common.h.
         enum: [ 8, 9 ]
 
+      default-intensities:
+        description: |
+          This parameter, if present, sets the initial intensities of the
+          individual colors. The format is a list of pairs, mapping an intensity
+          value to a sub LED identified by its color.
+        $ref: /schemas/types.yaml#/definitions/uint32-matrix
+        items:
+          minItems: 2
+          maxItems: 2
+          items:
+            - description: color identifier (LED_COLOR_ID_*)
+            - description: intensity value
+
     $ref: "common.yaml#"
 
     required:
@@ -38,4 +51,28 @@ patternProperties:
 
 additionalProperties: true
 
+examples:
+  - |
+    #include <dt-bindings/leds/common.h>
+
+    multi-led {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      color = <LED_COLOR_ID_RGB>;
+      default-intensities = <LED_COLOR_ID_RED 64>,
+                            <LED_COLOR_ID_BLUE 0>;
+      led@0 {
+        reg = <0>;
+        color = <LED_COLOR_ID_RED>;
+      };
+      led@1 {
+        reg = <1>;
+        color = <LED_COLOR_ID_GREEN>;
+      };
+      led@2 {
+        reg = <2>;
+        color = <LED_COLOR_ID_BLUE>;
+      };
+    };
 ...
-- 
2.36.0

[PATCH v3 2/2] leds: multicolor: Read default-intensities property

[Sven Schwermer]

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
    V2->V3: Use color-intensity mapping instead of simple intensity array

 drivers/leds/led-class-multicolor.c | 48 +++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/drivers/leds/led-class-multicolor.c b/drivers/leds/led-class-multicolor.c
index e317408583df..2900dd02fe41 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 +117,50 @@ 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[2 * LED_COLOR_ID_MAX];
+	unsigned int j;
+	int len;
+	int ret;
+	int i;
+
+	len = fwnode_property_read_u32_array(fwnode, "default-intensities",
+					     NULL, 0);
+	if (len < 0) {
+		if (len != -ENODATA)
+			dev_warn(parent,
+				 "failed to read default-intensities property length: %d", ret);
+		return;
+	}
+	if (len % 2 != 0) {
+		dev_warn(parent, "default-intensities property has uneven number of values");
+		return;
+	}
+	if (len > ARRAY_SIZE(intensities)) {
+		dev_warn(parent, "default-intensities property has too many values");
+		return;
+	}
+
+	ret = fwnode_property_read_u32_array(fwnode, "default-intensities",
+					     intensities, len);
+	if (ret < 0) {
+		dev_warn(parent, "failed to read default-intensities property values: %d", ret);
+		return;
+	}
+
+	for (i = 0; i < len; i += 2) {
+		for (j = 0; j < mcled_cdev->num_colors; j++) {
+			if (intensities[i] == mcled_cdev->subled_info[j].color_index) {
+				mcled_cdev->subled_info[j].intensity = intensities[i + 1];
+				break;
+			}
+		}
+	}
+}
+
 int led_classdev_multicolor_register_ext(struct device *parent,
 				     struct led_classdev_mc *mcled_cdev,
 				     struct led_init_data *init_data)
@@ -134,6 +179,9 @@ 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);
-- 
2.36.0

Re: [PATCH v3 1/2] dt-bindings: leds: Add multi-color default-intensities property

[Rob Herring]

On Thu, 05 May 2022 11:50:08 +0200, Sven Schwermer wrote:
> From: Sven Schwermer <sven.schwermer@disruptive-technologies.com>
> 
> This allows to assign intensity values to the individual sub LEDs
> (colors) at driver probe time, i.e. most commonly at kernel boot time.
> This is crucial for setting a specific color early in the boot process.
> 
> Signed-off-by: Sven Schwermer <sven.schwermer@disruptive-technologies.com>
> ---
> 
> Notes:
>     V1->V2: no changes
>     V2->V3:
>     - Use color-intensity mapping instead of simple intensity array
>     - Add example DTS snippet
> 
>  .../bindings/leds/leds-class-multicolor.yaml  | 37 +++++++++++++++++++
>  1 file changed, 37 insertions(+)
> 

Acked-by: Rob Herring <robh@kernel.org>