[PATCH 0/2] Make AUX gpio pin optional for ktd2692

[PATCH 0/2] Make AUX gpio pin optional for ktd2692

[Markuss Broks]

Some appliances of ktd2692 don't have the AUX pin connected to
a GPIO. Specifically, Samsung Galaxy J5 (2015), which uses ktd2692
for driving the front flash LED, has the pin not connected anywhere on
schematics. Make specifying the AUX pin optional, since it is additional
functionality and only affects amount of current going through the LED.

Also convert the txt device-tree bindings to yaml and pick up maintainership
over the yaml binding and the driver itself.

Markuss Broks (2):
  dt-bindings: leds: convert ktd2692 bindings to yaml
  leds: ktd2692: Make aux-gpios optional

 .../bindings/leds/kinetic,ktd2692.yaml        | 87 +++++++++++++++++++
 .../devicetree/bindings/leds/leds-ktd2692.txt | 50 -----------
 MAINTAINERS                                   |  6 ++
 drivers/leds/flash/leds-ktd2692.c             | 18 ++--
 4 files changed, 103 insertions(+), 58 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/leds/kinetic,ktd2692.yaml
 delete mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt

-- 
2.35.1

[PATCH 1/2] dt-bindings: leds: convert ktd2692 bindings to yaml

[Markuss Broks]

This patch converts the leds-ktd2692.txt bindings to modern yaml
style device-tree bindings.

Signed-off-by: Markuss Broks <markuss.broks@gmail.com>
---
 .../bindings/leds/kinetic,ktd2692.yaml        | 87 +++++++++++++++++++
 .../devicetree/bindings/leds/leds-ktd2692.txt | 50 -----------
 2 files changed, 87 insertions(+), 50 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/leds/kinetic,ktd2692.yaml
 delete mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt

diff --git a/Documentation/devicetree/bindings/leds/kinetic,ktd2692.yaml b/Documentation/devicetree/bindings/leds/kinetic,ktd2692.yaml
new file mode 100644
index 000000000000..e9058316a5ba
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/kinetic,ktd2692.yaml
@@ -0,0 +1,87 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/kinetic,ktd2692.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: KTD2692 Flash LED Driver from Kinetic Technologies
+
+maintainers:
+  - Markuss Broks <markuss.broks@gmail.com>
+
+description: |
+  KTD2692 is the ideal power solution for high-power flash LEDs.
+  It uses ExpressWire single-wire programming for maximum flexibility.
+
+  The ExpressWire interface through CTRL pin can control LED on/off and
+  enable/disable the IC, Movie(max 1/3 of Flash current) / Flash mode current,
+  Flash timeout, LVP(low voltage protection).
+
+  Also, When the AUX pin is pulled high while CTRL pin is high,
+  LED current will be ramped up to the flash-mode current level.
+
+properties:
+  compatible:
+    const: kinetic,ktd2692
+
+  ctrl-gpios:
+    maxItems: 1
+    description: Specifier of the GPIO connected to CTRL pin.
+
+  aux-gpios:
+    maxItems: 1
+    description: Specifier of the GPIO connected to CTRL pin.
+
+  vin-supply:
+    maxItems: 1
+    description: "vin" LED supply (2.7V to 5.5V).
+
+  led:
+    type: object
+    $ref: common.yaml#
+    description: Properties for the LED.
+      properties:
+        function: true
+        color: true
+        flash-max-timeout-us:
+          description: Flash LED maximum timeout.
+
+        led-max-microamp:
+          maximum: 300000
+          description: Minimum Threshold for Timer protection
+            is defined internally (Maximum 300mA).
+
+        flash-max-microamp:
+          description: Flash LED maximum current
+            Formula - I(mA) = 15000 / Rset.
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - ctrl-gpios
+  - led
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/leds/common.h>
+
+    ktd2692 {
+      compatible = "kinetic,ktd2692";
+      ctrl-gpios = <&gpc0 1 0>;
+      aux-gpios = <&gpc0 2 0>;
+      vin-supply = <&vbat>;
+
+      led {
+        function = LED_FUNCTION_FLASH;
+        color = <LED_COLOR_ID_WHITE>;
+        flash-max-timeout-us = <250000>;
+        flash-max-microamp = <150000>;
+        led-max-microamp = <25000>;
+      };
+    };
+
+...
diff --git a/Documentation/devicetree/bindings/leds/leds-ktd2692.txt b/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
deleted file mode 100644
index 853737452580..000000000000
--- a/Documentation/devicetree/bindings/leds/leds-ktd2692.txt
+++ /dev/null
@@ -1,50 +0,0 @@
-* Kinetic Technologies - KTD2692 Flash LED Driver
-
-KTD2692 is the ideal power solution for high-power flash LEDs.
-It uses ExpressWire single-wire programming for maximum flexibility.
-
-The ExpressWire interface through CTRL pin can control LED on/off and
-enable/disable the IC, Movie(max 1/3 of Flash current) / Flash mode current,
-Flash timeout, LVP(low voltage protection).
-
-Also, When the AUX pin is pulled high while CTRL pin is high,
-LED current will be ramped up to the flash-mode current level.
-
-Required properties:
-- compatible : Should be "kinetic,ktd2692".
-- ctrl-gpios : Specifier of the GPIO connected to CTRL pin.
-- aux-gpios : Specifier of the GPIO connected to AUX pin.
-
-Optional properties:
-- vin-supply : "vin" LED supply (2.7V to 5.5V).
-  See Documentation/devicetree/bindings/regulator/regulator.txt
-
-A discrete LED element connected to the device must be represented by a child
-node - See Documentation/devicetree/bindings/leds/common.txt
-
-Required properties for flash LED child nodes:
-  See Documentation/devicetree/bindings/leds/common.txt
-- led-max-microamp : Minimum Threshold for Timer protection
-  is defined internally (Maximum 300mA).
-- flash-max-microamp : Flash LED maximum current
-  Formula : I(mA) = 15000 / Rset.
-- flash-max-timeout-us : Flash LED maximum timeout.
-
-Optional properties for flash LED child nodes:
-- label : See Documentation/devicetree/bindings/leds/common.txt
-
-Example:
-
-ktd2692 {
-	compatible = "kinetic,ktd2692";
-	ctrl-gpios = <&gpc0 1 0>;
-	aux-gpios = <&gpc0 2 0>;
-	vin-supply = <&vbat>;
-
-	flash-led {
-		label = "ktd2692-flash";
-		led-max-microamp = <300000>;
-		flash-max-microamp = <1500000>;
-		flash-max-timeout-us = <1835000>;
-	};
-};
-- 
2.35.1

[PATCH 2/2] leds: ktd2692: Make aux-gpios optional

[Markuss Broks]

Make the AUX pin optional, since it isn't a core part of functionality,
and the device is designed to be operational with only one CTRL pin.

Also pick up maintainership for the LED driver and the yaml bindings.

Signed-off-by: Markuss Broks <markuss.broks@gmail.com>
---
 MAINTAINERS                       |  6 ++++++
 drivers/leds/flash/leds-ktd2692.c | 18 ++++++++++--------
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 2db49ea7ae55..8ef5667a1d98 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10479,6 +10479,12 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
 F:	drivers/video/backlight/ktd253-backlight.c
 
+KTD2692 FLASH LED DRIVER
+M:	Markuss Broks <markuss.broks@gmail.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/leds/backlight/kinetic,ktd2692.yaml
+F:	drivers/leds/flash/leds-ktd2692.yaml
+
 KTEST
 M:	Steven Rostedt <rostedt@goodmis.org>
 M:	John Hawley <warthog9@eaglescrag.net>
diff --git a/drivers/leds/flash/leds-ktd2692.c b/drivers/leds/flash/leds-ktd2692.c
index f341da1503a4..f30c4b11c84b 100644
--- a/drivers/leds/flash/leds-ktd2692.c
+++ b/drivers/leds/flash/leds-ktd2692.c
@@ -163,7 +163,8 @@ static int ktd2692_led_brightness_set(struct led_classdev *led_cdev,
 
 	if (brightness == LED_OFF) {
 		led->mode = KTD2692_MODE_DISABLE;
-		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
+		if (led->aux_gpio)
+			gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
 	} else {
 		ktd2692_expresswire_write(led, brightness |
 					KTD2692_REG_MOVIE_CURRENT_BASE);
@@ -191,10 +192,12 @@ static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
 				| KTD2692_REG_FLASH_TIMEOUT_BASE);
 
 		led->mode = KTD2692_MODE_FLASH;
-		gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
+		if (led->aux_gpio)
+			gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
 	} else {
 		led->mode = KTD2692_MODE_DISABLE;
-		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
+		if (led->aux_gpio)
+			gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
 	}
 
 	ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
@@ -248,7 +251,8 @@ static void ktd2692_setup(struct ktd2692_context *led)
 {
 	led->mode = KTD2692_MODE_DISABLE;
 	ktd2692_expresswire_reset(led);
-	gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
+	if (led->aux_gpio)
+		gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
 
 	ktd2692_expresswire_write(led, (KTD2692_MM_MIN_CURR_THRESHOLD_SCALE - 1)
 				 | KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
@@ -286,10 +290,8 @@ static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
 
 	led->aux_gpio = devm_gpiod_get(dev, "aux", GPIOD_ASIS);
 	ret = PTR_ERR_OR_ZERO(led->aux_gpio);
-	if (ret) {
-		dev_err(dev, "cannot get aux-gpios %d\n", ret);
-		return ret;
-	}
+	if (ret)
+		dev_info(dev, "aux-gpios not available, flash mode current might be reduced\n");
 
 	led->regulator = devm_regulator_get(dev, "vin");
 	if (IS_ERR(led->regulator))
-- 
2.35.1

Re: [PATCH 1/2] dt-bindings: leds: convert ktd2692 bindings to yaml

[Rob Herring]

On Thu, 07 Apr 2022 13:10:05 +0300, Markuss Broks wrote:
> This patch converts the leds-ktd2692.txt bindings to modern yaml
> style device-tree bindings.
> 
> Signed-off-by: Markuss Broks <markuss.broks@gmail.com>
> ---
>  .../bindings/leds/kinetic,ktd2692.yaml        | 87 +++++++++++++++++++
>  .../devicetree/bindings/leds/leds-ktd2692.txt | 50 -----------
>  2 files changed, 87 insertions(+), 50 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/leds/kinetic,ktd2692.yaml
>  delete mode 100644 Documentation/devicetree/bindings/leds/leds-ktd2692.txt
> 

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:
./Documentation/devicetree/bindings/leds/kinetic,ktd2692.yaml:37:24: [error] syntax error: expected <block end>, but found '<scalar>' (syntax)

dtschema/dtc warnings/errors:
make[1]: *** Deleting file 'Documentation/devicetree/bindings/leds/kinetic,ktd2692.example.dts'
Traceback (most recent call last):
  File "/usr/local/bin/dt-extract-example", line 52, in <module>
    binding = yaml.load(open(args.yamlfile, encoding='utf-8').read())
  File "/usr/local/lib/python3.8/dist-packages/ruamel/yaml/main.py", line 434, in load
    return constructor.get_single_data()
  File "/usr/local/lib/python3.8/dist-packages/ruamel/yaml/constructor.py", line 119, in get_single_data
    node = self.composer.get_single_node()
  File "_ruamel_yaml.pyx", line 706, in _ruamel_yaml.CParser.get_single_node
  File "_ruamel_yaml.pyx", line 724, in _ruamel_yaml.CParser._compose_document
  File "_ruamel_yaml.pyx", line 775, in _ruamel_yaml.CParser._compose_node
  File "_ruamel_yaml.pyx", line 889, in _ruamel_yaml.CParser._compose_mapping_node
  File "_ruamel_yaml.pyx", line 775, in _ruamel_yaml.CParser._compose_node
  File "_ruamel_yaml.pyx", line 889, in _ruamel_yaml.CParser._compose_mapping_node
  File "_ruamel_yaml.pyx", line 775, in _ruamel_yaml.CParser._compose_node
  File "_ruamel_yaml.pyx", line 891, in _ruamel_yaml.CParser._compose_mapping_node
  File "_ruamel_yaml.pyx", line 904, in _ruamel_yaml.CParser._parse_next_event
ruamel.yaml.parser.ParserError: while parsing a block mapping
  in "<unicode string>", line 36, column 5
did not find expected key
  in "<unicode string>", line 37, column 24
make[1]: *** [Documentation/devicetree/bindings/Makefile:26: Documentation/devicetree/bindings/leds/kinetic,ktd2692.example.dts] Error 1
make[1]: *** Waiting for unfinished jobs....
./Documentation/devicetree/bindings/leds/kinetic,ktd2692.yaml:  while parsing a block mapping
  in "<unicode string>", line 36, column 5
did not find expected key
  in "<unicode string>", line 37, column 24
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/leds/kinetic,ktd2692.yaml: ignoring, error parsing file
make: *** [Makefile:1401: dt_binding_check] Error 2

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/patch/

This check can fail if there are any dependencies. The base for a patch
series is generally the most recent rc1.

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.

Re: [PATCH 2/2] leds: ktd2692: Make aux-gpios optional

[Andy Shevchenko]

On Thu, Apr 7, 2022 at 1:33 PM Markuss Broks <markuss.broks@gmail.com> wrote:
>
> Make the AUX pin optional, since it isn't a core part of functionality,
> and the device is designed to be operational with only one CTRL pin.
>
> Also pick up maintainership for the LED driver and the yaml bindings.

maintenance?

...

> -               gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
> +               if (led->aux_gpio)
> +                       gpiod_direction_output(led->aux_gpio, KTD2692_LOW);

Redundant change.

...

> -               gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
> +               if (led->aux_gpio)
> +                       gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);

Ditto.

...

> -               gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
> +               if (led->aux_gpio)
> +                       gpiod_direction_output(led->aux_gpio, KTD2692_LOW);

Ditto.

...

> -       gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
> +       if (led->aux_gpio)
> +               gpiod_direction_output(led->aux_gpio, KTD2692_LOW);

Ditto.

...

>         ret = PTR_ERR_OR_ZERO(led->aux_gpio);
> -       if (ret) {
> -               dev_err(dev, "cannot get aux-gpios %d\n", ret);
> -               return ret;
> -       }
> +       if (ret)
> +               dev_info(dev, "aux-gpios not available, flash mode current might be reduced\n");

dev_warn()?

After this change the use of PTR_ERR_OR_ZERO() becomes unjustified, what about
        if (IS_ERR(led->aux_gpio))
?

But the problem here is the ignorance of important error codes, such a
deferred probe.

What you need is to switch to devm_gpiod_get_optional().

-- 
With Best Regards,
Andy Shevchenko