[PATCH V2 1/2] dt-bindings: leds: pwm: Add enable-gpios property

[PATCH V2 1/2] dt-bindings: leds: pwm: Add enable-gpios property

[LI Qingwu]

Some PWM LED chips have a dedicated enable GPIO.
This commit adds the support to specify such GPIO.

Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
---
 Documentation/devicetree/bindings/leds/leds-pwm.yaml | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/leds/leds-pwm.yaml b/Documentation/devicetree/bindings/leds/leds-pwm.yaml
index 61b97e8bc36d0..2d38504f74c23 100644
--- a/Documentation/devicetree/bindings/leds/leds-pwm.yaml
+++ b/Documentation/devicetree/bindings/leds/leds-pwm.yaml
@@ -40,6 +40,14 @@ patternProperties:
           initialization. If the option is not set then max brightness is used.
         $ref: /schemas/types.yaml#/definitions/uint32
 
+      enable-gpios:
+        description:
+        enable-gpios:
+          GPIO for LED hardware enable control. Set active when brightness is
+          non-zero and inactive when brightness is zero.
+          The GPIO default state follows the "default-state" property.
+        maxItems: 1
+
     required:
       - pwms
       - max-brightness
-- 
2.43.0

[PATCH V2 2/2] leds: pwm: Add optional GPIO enable pin support

[LI Qingwu]

add support for optional GPIO-based enable pin control to PWM LED driver.
some PWM LED chips have a dedicated enable GPIO. This commit adds the
support to specify such GPIO, activating the pin when LED brightness
is non-zero and deactivating it when off.

Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
---
 drivers/leds/leds-pwm.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
index c73134e7b9514..1397149464b35 100644
--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -17,6 +17,7 @@
 #include <linux/err.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>
+#include <linux/gpio/consumer.h>
 
 struct led_pwm {
 	const char	*name;
@@ -29,6 +30,7 @@ struct led_pwm_data {
 	struct led_classdev	cdev;
 	struct pwm_device	*pwm;
 	struct pwm_state	pwmstate;
+	struct gpio_desc	*enable_gpio;
 	unsigned int		active_low;
 };
 
@@ -51,6 +53,9 @@ static int led_pwm_set(struct led_classdev *led_cdev,
 	if (led_dat->active_low)
 		duty = led_dat->pwmstate.period - duty;
 
+	gpiod_set_value_cansleep(led_dat->enable_gpio,
+				 brightness == LED_OFF ? 0 : 1);
+
 	led_dat->pwmstate.duty_cycle = duty;
 	/*
 	 * Disabling a PWM doesn't guarantee that it emits the inactive level.
@@ -132,6 +137,23 @@ static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
 		break;
 	}
 
+	/* Claim the GPIO as ASIS and set the value
+	 * later on to honor the different default states
+	 */
+	led_data->enable_gpio =
+		devm_fwnode_gpiod_get(dev, fwnode, "enable", GPIOD_ASIS, NULL);
+
+	/* enable_gpio is optional */
+	if (IS_ERR(led_data->enable_gpio)) {
+		if (PTR_ERR(led_data->enable_gpio) == -ENOENT)
+			led_data->enable_gpio = NULL;
+		else
+			return PTR_ERR(led_data->enable_gpio);
+	}
+
+	gpiod_direction_output(led_data->enable_gpio,
+			       !!led_data->cdev.brightness);
+
 	ret = devm_led_classdev_register_ext(dev, &led_data->cdev, &init_data);
 	if (ret) {
 		dev_err(dev, "failed to register PWM led for %s: %d\n",
-- 
2.43.0

Re: [PATCH V2 1/2] dt-bindings: leds: pwm: Add enable-gpios property

[Rob Herring (Arm)]

On Wed, 02 Jul 2025 19:47:58 +0800, LI Qingwu wrote:
> Some PWM LED chips have a dedicated enable GPIO.
> This commit adds the support to specify such GPIO.
> 
> Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
> ---
>  Documentation/devicetree/bindings/leds/leds-pwm.yaml | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:
./Documentation/devicetree/bindings/leds/leds-pwm.yaml:44:21: [error] empty value in block mapping (empty-values)

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/leds/leds-pwm.yaml: ignoring, error in schema: patternProperties: ^led(-[0-9a-f]+)?$: properties: enable-gpios: description
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/leds/leds-pwm.yaml: patternProperties:^led(-[0-9a-f]+)?$:properties:enable-gpios:description: None is not of type 'string'
	from schema $id: http://json-schema.org/draft-07/schema#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/leds/leds-pwm.yaml: patternProperties:^led(-[0-9a-f]+)?$:properties:enable-gpios: 'anyOf' conditional failed, one must be fixed:
	'enable-gpios' is not one of ['$ref', 'additionalItems', 'additionalProperties', 'allOf', 'anyOf', 'const', 'contains', 'default', 'dependencies', 'dependentRequired', 'dependentSchemas', 'deprecated', 'description', 'else', 'enum', 'exclusiveMaximum', 'exclusiveMinimum', 'items', 'if', 'minItems', 'minimum', 'maxItems', 'maximum', 'multipleOf', 'not', 'oneOf', 'pattern', 'patternProperties', 'properties', 'required', 'then', 'typeSize', 'unevaluatedProperties', 'uniqueItems']
	'type' was expected
	from schema $id: http://devicetree.org/meta-schemas/keywords.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/leds/leds-pwm.yaml: patternProperties:^led(-[0-9a-f]+)?$:properties:enable-gpios: 'anyOf' conditional failed, one must be fixed:
	'enable-gpios' is not one of ['maxItems', 'description', 'deprecated']
		hint: Only "maxItems" is required for a single entry if there are no constraints defined for the values.
	Additional properties are not allowed ('enable-gpios' was unexpected)
		hint: Arrays must be described with a combination of minItems/maxItems/items
	'enable-gpios' is not one of ['description', 'deprecated', 'const', 'enum', 'minimum', 'maximum', 'multipleOf', 'default', '$ref', 'oneOf']
	'maxItems' is not one of ['description', 'deprecated', 'const', 'enum', 'minimum', 'maximum', 'multipleOf', 'default', '$ref', 'oneOf']
	1 is less than the minimum of 2
		hint: Arrays must be described with a combination of minItems/maxItems/items
	hint: cell array properties must define how many entries and what the entries are when there is more than one entry.
	from schema $id: http://devicetree.org/meta-schemas/gpios.yaml#
Documentation/devicetree/bindings/leds/leds-pwm.example.dtb: /example-0/led-controller: failed to match any schema with compatible: ['pwm-leds']

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250702114759.223925-1-Qing-wu.Li@leica-geosystems.com.cn

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

RE: [PATCH V2 1/2] dt-bindings: leds: pwm: Add enable-gpios property

[LI Qingwu]

> -----Original Message-----
> From: Rob Herring (Arm) <robh@kernel.org>
> Sent: Wednesday, July 2, 2025 9:29 PM
> To: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
> Cc: krzk+dt@kernel.org; conor+dt@kernel.org; linux-kernel@vger.kernel.org;
> GEO-CHHER-bsp-development <bsp-development.geo@leica-geosystems.com>;
> lee@kernel.org; devicetree@vger.kernel.org; pavel@kernel.org;
> linux-leds@vger.kernel.org
> Subject: Re: [PATCH V2 1/2] dt-bindings: leds: pwm: Add enable-gpios property
> 
> [You don't often get email from robh@kernel.org. Learn why this is important at
> https://aka.ms/LearnAboutSenderIdentification ]
> 
> This email is not from Hexagon's Office 365 instance. Please be careful while
> clicking links, opening attachments, or replying to this email.
> 
> 
> On Wed, 02 Jul 2025 19:47:58 +0800, LI Qingwu wrote:
> > Some PWM LED chips have a dedicated enable GPIO.
> > This commit adds the support to specify such GPIO.
> >
> > Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
> > ---
> >  Documentation/devicetree/bindings/leds/leds-pwm.yaml | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> 
> My bot found errors running 'make dt_binding_check' on your patch:
> 
> yamllint warnings/errors:
> ./Documentation/devicetree/bindings/leds/leds-pwm.yaml:44:21: [error] empty
> value in block mapping (empty-values)

Fixed in V3

> 
> dtschema/dtc warnings/errors:
> /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/leds/l
> eds-pwm.yaml: ignoring, error in schema: patternProperties: ^led(-[0-9a-f]+)?$:
> properties: enable-gpios: description
> /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/leds/l
> eds-pwm.yaml:
> patternProperties:^led(-[0-9a-f]+)?$:properties:enable-gpios:description: None
> is not of type 'string'
>         from schema $id:
> https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fjson-sche
> ma.org%2Fdraft-07%2Fschema%23&data=05%7C02%7CQing-wu.Li%40leica-ge
> osystems.com.cn%7Caaeff71db4f841ea959f08ddb96c586e%7C1b16ab3eb8f64f
> e39f3e2db7fe549f6a%7C0%7C0%7C638870597187709015%7CUnknown%7CT
> WFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4
> zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=SMmSnn%
> 2BwemnBgU6prZWfMiZ3nMXk20PKDFB96E5vMoI%3D&reserved=0
> /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/leds/l
> eds-pwm.yaml: patternProperties:^led(-[0-9a-f]+)?$:properties:enable-gpios:
> 'anyOf' conditional failed, one must be fixed:
>         'enable-gpios' is not one of ['$ref', 'additionalItems',
> 'additionalProperties', 'allOf', 'anyOf', 'const', 'contains', 'default', 'dependencies',
> 'dependentRequired', 'dependentSchemas', 'deprecated', 'description', 'else',
> 'enum', 'exclusiveMaximum', 'exclusiveMinimum', 'items', 'if', 'minItems',
> 'minimum', 'maxItems', 'maximum', 'multipleOf', 'not', 'oneOf', 'pattern',
> 'patternProperties', 'properties', 'required', 'then', 'typeSize',
> 'unevaluatedProperties', 'uniqueItems']
>         'type' was expected
>         from schema $id:
> https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevicetre
> e.org%2Fmeta-schemas%2Fkeywords.yaml%23&data=05%7C02%7CQing-wu.Li
> %40leica-geosystems.com.cn%7Caaeff71db4f841ea959f08ddb96c586e%7C1b1
> 6ab3eb8f64fe39f3e2db7fe549f6a%7C0%7C0%7C638870597187750588%7CUnk
> nown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsI
> lAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=
> B4E7joIeKPsOCw1Vb0dr4O4WAZJi5OuPjFMdGyIH%2BqY%3D&reserved=0
> /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/leds/l
> eds-pwm.yaml: patternProperties:^led(-[0-9a-f]+)?$:properties:enable-gpios:
> 'anyOf' conditional failed, one must be fixed:
>         'enable-gpios' is not one of ['maxItems', 'description', 'deprecated']
>                 hint: Only "maxItems" is required for a single entry if there
> are no constraints defined for the values.
>         Additional properties are not allowed ('enable-gpios' was unexpected)
>                 hint: Arrays must be described with a combination of
> minItems/maxItems/items
>         'enable-gpios' is not one of ['description', 'deprecated', 'const', 'enum',
> 'minimum', 'maximum', 'multipleOf', 'default', '$ref', 'oneOf']
>         'maxItems' is not one of ['description', 'deprecated', 'const', 'enum',
> 'minimum', 'maximum', 'multipleOf', 'default', '$ref', 'oneOf']
>         1 is less than the minimum of 2
>                 hint: Arrays must be described with a combination of
> minItems/maxItems/items
>         hint: cell array properties must define how many entries and what the
> entries are when there is more than one entry.
>         from schema $id:
> https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevicetre
> e.org%2Fmeta-schemas%2Fgpios.yaml%23&data=05%7C02%7CQing-wu.Li%40l
> eica-geosystems.com.cn%7Caaeff71db4f841ea959f08ddb96c586e%7C1b16ab3
> eb8f64fe39f3e2db7fe549f6a%7C0%7C0%7C638870597187780819%7CUnknown
> %7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJ
> XaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=R9Ixi
> 0hiwK1YgNx1uHbGLDza2Id%2Fmfuw62TiQ6A2QVY%3D&reserved=0
> Documentation/devicetree/bindings/leds/leds-pwm.example.dtb:
> /example-0/led-controller: failed to match any schema with compatible:
> ['pwm-leds']
> 
> doc reference errors (make refcheckdocs):
> 
> See
> https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwor
> k.ozlabs.org%2Fproject%2Fdevicetree-bindings%2Fpatch%2F20250702114759.
> 223925-1-Qing-wu.Li%40leica-geosystems.com.cn&data=05%7C02%7CQing-wu
> .Li%40leica-geosystems.com.cn%7Caaeff71db4f841ea959f08ddb96c586e%7C1b
> 16ab3eb8f64fe39f3e2db7fe549f6a%7C0%7C0%7C638870597187806331%7CUn
> known%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCI
> sIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdat
> a=n%2BgfWLuIv%2FVPSodnF7rj7LqwTaMtOIbiAztOasgfDlQ%3D&reserved=0
> 
> The base for the series is generally the latest rc1. A different dependency should
> be noted in *this* patch.
> 
> If you already ran 'make dt_binding_check' and didn't see the above error(s),
> then make sure 'yamllint' is installed and dt-schema is up to
> date:
> 
> pip3 install dtschema --upgrade
> 
> Please check and re-submit after running the above command yourself. Note
> that DT_SCHEMA_FILES can be set to your schema file to speed up checking
> your schema. However, it must be unset to test all examples with your schema.

Re: [PATCH V2 1/2] dt-bindings: leds: pwm: Add enable-gpios property

[Krzysztof Kozlowski]

On 03/07/2025 05:54, LI Qingwu wrote:
>>
>> On Wed, 02 Jul 2025 19:47:58 +0800, LI Qingwu wrote:
>>> Some PWM LED chips have a dedicated enable GPIO.
>>> This commit adds the support to specify such GPIO.
>>>
>>> Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
>>> ---
>>>  Documentation/devicetree/bindings/leds/leds-pwm.yaml | 8 ++++++++
>>>  1 file changed, 8 insertions(+)
>>>
>>
>> My bot found errors running 'make dt_binding_check' on your patch:
>>
>> yamllint warnings/errors:
>> ./Documentation/devicetree/bindings/leds/leds-pwm.yaml:44:21: [error] empty
>> value in block mapping (empty-values)
> 
> Fixed in V3

So your answer to my "never tested" was to send again the same as v2 and
still not tested?

Best regards,
Krzysztof

RE: [PATCH V2 1/2] dt-bindings: leds: pwm: Add enable-gpios property

[LI Qingwu]

> -----Original Message-----
> From: Krzysztof Kozlowski <krzk@kernel.org>
> Sent: Thursday, July 3, 2025 3:12 PM
> To: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>; Rob Herring (Arm)
> <robh@kernel.org>
> Cc: krzk+dt@kernel.org; conor+dt@kernel.org; linux-kernel@vger.kernel.org;
> GEO-CHHER-bsp-development <bsp-development.geo@leica-geosystems.com>;
> lee@kernel.org; devicetree@vger.kernel.org; pavel@kernel.org;
> linux-leds@vger.kernel.org
> Subject: Re: [PATCH V2 1/2] dt-bindings: leds: pwm: Add enable-gpios property
> 
> This email is not from Hexagon’s Office 365 instance. Please be careful while
> clicking links, opening attachments, or replying to this email.
> 
> 
> On 03/07/2025 05:54, LI Qingwu wrote:
> >>
> >> On Wed, 02 Jul 2025 19:47:58 +0800, LI Qingwu wrote:
> >>> Some PWM LED chips have a dedicated enable GPIO.
> >>> This commit adds the support to specify such GPIO.
> >>>
> >>> Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
> >>> ---
> >>>  Documentation/devicetree/bindings/leds/leds-pwm.yaml | 8 ++++++++
> >>>  1 file changed, 8 insertions(+)
> >>>
> >>
> >> My bot found errors running 'make dt_binding_check' on your patch:
> >>
> >> yamllint warnings/errors:
> >> ./Documentation/devicetree/bindings/leds/leds-pwm.yaml:44:21: [error]
> >> empty value in block mapping (empty-values)
> >
> > Fixed in V3
> 
> So your answer to my "never tested" was to send again the same as v2 and still
> not tested?

Nop,  "Fixed in V3" answer "bot found errors running 'make dt_binding_check'"
Testing info comes later in v4

> 
> Best regards,
> Krzysztof

Re: [PATCH V2 1/2] dt-bindings: leds: pwm: Add enable-gpios property

[Krzysztof Kozlowski]

On 03/07/2025 10:52, LI Qingwu wrote:
> 
> 
>> -----Original Message-----
>> From: Krzysztof Kozlowski <krzk@kernel.org>
>> Sent: Thursday, July 3, 2025 3:12 PM
>> To: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>; Rob Herring (Arm)
>> <robh@kernel.org>
>> Cc: krzk+dt@kernel.org; conor+dt@kernel.org; linux-kernel@vger.kernel.org;
>> GEO-CHHER-bsp-development <bsp-development.geo@leica-geosystems.com>;
>> lee@kernel.org; devicetree@vger.kernel.org; pavel@kernel.org;
>> linux-leds@vger.kernel.org
>> Subject: Re: [PATCH V2 1/2] dt-bindings: leds: pwm: Add enable-gpios property
>>
>> This email is not from Hexagon’s Office 365 instance. Please be careful while
>> clicking links, opening attachments, or replying to this email.
>>
>>
>> On 03/07/2025 05:54, LI Qingwu wrote:
>>>>
>>>> On Wed, 02 Jul 2025 19:47:58 +0800, LI Qingwu wrote:
>>>>> Some PWM LED chips have a dedicated enable GPIO.
>>>>> This commit adds the support to specify such GPIO.
>>>>>
>>>>> Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
>>>>> ---
>>>>>  Documentation/devicetree/bindings/leds/leds-pwm.yaml | 8 ++++++++
>>>>>  1 file changed, 8 insertions(+)
>>>>>
>>>>
>>>> My bot found errors running 'make dt_binding_check' on your patch:
>>>>
>>>> yamllint warnings/errors:
>>>> ./Documentation/devicetree/bindings/leds/leds-pwm.yaml:44:21: [error]
>>>> empty value in block mapping (empty-values)
>>>
>>> Fixed in V3
>>
>> So your answer to my "never tested" was to send again the same as v2 and still
>> not tested?
> 
> Nop,  "Fixed in V3" answer "bot found errors running 'make dt_binding_check'"
> Testing info comes later in v4
I responded to you on v1 in the morning my time. 4 hours later you sent
v2, so what is the "Nop"?

Best regards,
Krzysztof