[PATCH v2 0/5] platform/chrome: cros_kbd_led_backlight: add EC PWM backend

[PATCH v2 0/5] platform/chrome: cros_kbd_led_backlight: add EC PWM backend

[Tzung-Bi Shih]

The series adds EC PWM as an backend option for ChromeOS keyboard LED
backlight.

The 1st patch reorder the headers alphabetically.

The 2nd patch separates the ACPI backend as an independent option.

The 3rd patch is the DT binding document for the proposed compatible string.

The 4th patch supports OF match.

The 5th patch adds EC PWM as another backend option.

Changes from v1:
(https://patchwork.kernel.org/project/chrome-platform/cover/20220214053646.3088298-1-tzungbi@google.com/)
- Update email address accordingly.

Tzung-Bi Shih (5):
  platform/chrome: cros_kbd_led_backlight: sort headers alphabetically
  platform/chrome: cros_kbd_led_backlight: separate ACPI backend
  dt-bindings: add google,cros-kbd-led-backlight
  platform/chrome: cros_kbd_led_backlight: support OF match
  platform/chrome: cros_kbd_led_backlight: support EC PWM backend

 .../chrome/google,cros-kbd-led-backlight.yaml |  35 +++
 .../bindings/mfd/google,cros-ec.yaml          |   3 +
 drivers/platform/chrome/Kconfig               |  14 +-
 .../platform/chrome/cros_kbd_led_backlight.c  | 220 ++++++++++++++++--
 4 files changed, 249 insertions(+), 23 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/chrome/google,cros-kbd-led-backlight.yaml

-- 
2.35.1.723.g4982287a31-goog

[PATCH v2 1/5] platform/chrome: cros_kbd_led_backlight: sort headers alphabetically

[Tzung-Bi Shih]

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
Changes from v1:
- Update email address accordingly.

 drivers/platform/chrome/cros_kbd_led_backlight.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c
index aa409f0201fb..f9587a562bb7 100644
--- a/drivers/platform/chrome/cros_kbd_led_backlight.c
+++ b/drivers/platform/chrome/cros_kbd_led_backlight.c
@@ -4,12 +4,12 @@
 // Copyright (C) 2012 Google, Inc.
 
 #include <linux/acpi.h>
-#include <linux/leds.h>
 #include <linux/delay.h>
 #include <linux/err.h>
-#include <linux/module.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
-- 
2.35.1.723.g4982287a31-goog

Re: [PATCH v2 1/5] platform/chrome: cros_kbd_led_backlight: sort headers alphabetically

[Guenter Roeck]

On Mon, Mar 14, 2022 at 05:08:31PM +0800, Tzung-Bi Shih wrote:

Nit: There should be some text here describing the rationale.

With that added,

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
> ---
> Changes from v1:
> - Update email address accordingly.
> 
>  drivers/platform/chrome/cros_kbd_led_backlight.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c
> index aa409f0201fb..f9587a562bb7 100644
> --- a/drivers/platform/chrome/cros_kbd_led_backlight.c
> +++ b/drivers/platform/chrome/cros_kbd_led_backlight.c
> @@ -4,12 +4,12 @@
>  // Copyright (C) 2012 Google, Inc.
>  
>  #include <linux/acpi.h>
> -#include <linux/leds.h>
>  #include <linux/delay.h>
>  #include <linux/err.h>
> -#include <linux/module.h>
>  #include <linux/init.h>
>  #include <linux/kernel.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
>  #include <linux/platform_device.h>
>  #include <linux/slab.h>
>  

[PATCH v2 2/5] platform/chrome: cros_kbd_led_backlight: separate ACPI backend

[Tzung-Bi Shih]

cros_kbd_led_backlight uses ACPI_KEYBOARD_BACKLIGHT_WRITE and
ACPI_KEYBOARD_BACKLIGHT_READ for setting and getting the brightness
respectively.

Separate ACPI operations as an independent option for preparing the
driver to support other backends.

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
Changes from v1:
- Update email address accordingly.
- Use CONFIG_ACPI guard per "kernel test robot <lkp@intel.com>" reported an
  unused variable issue.

 drivers/platform/chrome/Kconfig               |  8 +-
 .../platform/chrome/cros_kbd_led_backlight.c  | 93 ++++++++++++++++---
 2 files changed, 87 insertions(+), 14 deletions(-)

diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
index ccc23d8686e8..3f74679a556c 100644
--- a/drivers/platform/chrome/Kconfig
+++ b/drivers/platform/chrome/Kconfig
@@ -128,7 +128,7 @@ config CROS_EC_PROTO
 
 config CROS_KBD_LED_BACKLIGHT
 	tristate "Backlight LED support for Chrome OS keyboards"
-	depends on LEDS_CLASS && ACPI
+	depends on LEDS_CLASS
 	help
 	  This option enables support for the keyboard backlight LEDs on
 	  select Chrome OS systems.
@@ -136,6 +136,12 @@ config CROS_KBD_LED_BACKLIGHT
 	  To compile this driver as a module, choose M here: the
 	  module will be called cros_kbd_led_backlight.
 
+config CROS_KBD_LED_BACKLIGHT_ACPI
+	bool "ChromeOS keyboard backlight ACPI backend"
+	depends on ACPI && CROS_KBD_LED_BACKLIGHT
+	help
+	  ChromeOS keyboard backlight ACPI backend.
+
 config CROS_EC_CHARDEV
 	tristate "ChromeOS EC miscdevice"
 	depends on MFD_CROS_EC_DEV
diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c
index f9587a562bb7..e26d1d4cd801 100644
--- a/drivers/platform/chrome/cros_kbd_led_backlight.c
+++ b/drivers/platform/chrome/cros_kbd_led_backlight.c
@@ -13,6 +13,33 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
+/**
+ * struct keyboard_led_drvdata - keyboard LED driver data.
+ * @init:			Init function.
+ * @brightness_get:		Get LED brightness level.
+ * @brightness_set:		Set LED brightness level.  Must not sleep.
+ * @brightness_set_blocking:	Set LED brightness level.  It can block the
+ *				caller for the time required for accessing a
+ *				LED device register
+ * @max_brightness:		Maximum brightness.
+ *
+ * See struct led_classdev in include/linux/leds.h for more details.
+ */
+struct keyboard_led_drvdata {
+	int (*init)(struct platform_device *pdev);
+
+	enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
+
+	void (*brightness_set)(struct led_classdev *led_cdev,
+			       enum led_brightness brightness);
+	int (*brightness_set_blocking)(struct led_classdev *led_cdev,
+				       enum led_brightness brightness);
+
+	enum led_brightness max_brightness;
+};
+
+#if IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_ACPI)
+
 /* Keyboard LED ACPI Device must be defined in firmware */
 #define ACPI_KEYBOARD_BACKLIGHT_DEVICE	"\\_SB.KBLT"
 #define ACPI_KEYBOARD_BACKLIGHT_READ	ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBQC"
@@ -20,8 +47,8 @@
 
 #define ACPI_KEYBOARD_BACKLIGHT_MAX		100
 
-static void keyboard_led_set_brightness(struct led_classdev *cdev,
-					enum led_brightness brightness)
+static void keyboard_led_set_brightness_acpi(struct led_classdev *cdev,
+					     enum led_brightness brightness)
 {
 	union acpi_object param;
 	struct acpi_object_list input;
@@ -40,7 +67,7 @@ static void keyboard_led_set_brightness(struct led_classdev *cdev,
 }
 
 static enum led_brightness
-keyboard_led_get_brightness(struct led_classdev *cdev)
+keyboard_led_get_brightness_acpi(struct led_classdev *cdev)
 {
 	unsigned long long brightness;
 	acpi_status status;
@@ -56,12 +83,10 @@ keyboard_led_get_brightness(struct led_classdev *cdev)
 	return brightness;
 }
 
-static int keyboard_led_probe(struct platform_device *pdev)
+static int keyboard_led_init_acpi(struct platform_device *pdev)
 {
-	struct led_classdev *cdev;
 	acpi_handle handle;
 	acpi_status status;
-	int error;
 
 	/* Look for the keyboard LED ACPI Device */
 	status = acpi_get_handle(ACPI_ROOT_OBJECT,
@@ -73,15 +98,55 @@ static int keyboard_led_probe(struct platform_device *pdev)
 		return -ENXIO;
 	}
 
+	return 0;
+}
+
+static const struct keyboard_led_drvdata keyboard_led_drvdata_acpi = {
+	.init = keyboard_led_init_acpi,
+	.brightness_set = keyboard_led_set_brightness_acpi,
+	.brightness_get = keyboard_led_get_brightness_acpi,
+	.max_brightness = ACPI_KEYBOARD_BACKLIGHT_MAX,
+};
+
+#else /* IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_ACPI) */
+
+static int keyboard_led_init_acpi_null(struct platform_device *pdev)
+{
+	return -EOPNOTSUPP;
+}
+
+static const struct keyboard_led_drvdata keyboard_led_drvdata_acpi = {
+	.init = keyboard_led_init_acpi_null,
+};
+
+#endif /* IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_ACPI) */
+
+static int keyboard_led_probe(struct platform_device *pdev)
+{
+	struct led_classdev *cdev;
+	const struct keyboard_led_drvdata *drvdata;
+	int error;
+
+	drvdata = acpi_device_get_match_data(&pdev->dev);
+	if (!drvdata)
+		return -EINVAL;
+
+	if (drvdata->init) {
+		error = drvdata->init(pdev);
+		if (error)
+			return error;
+	}
+
 	cdev = devm_kzalloc(&pdev->dev, sizeof(*cdev), GFP_KERNEL);
 	if (!cdev)
 		return -ENOMEM;
 
 	cdev->name = "chromeos::kbd_backlight";
-	cdev->max_brightness = ACPI_KEYBOARD_BACKLIGHT_MAX;
 	cdev->flags |= LED_CORE_SUSPENDRESUME;
-	cdev->brightness_set = keyboard_led_set_brightness;
-	cdev->brightness_get = keyboard_led_get_brightness;
+	cdev->max_brightness = drvdata->max_brightness;
+	cdev->brightness_set = drvdata->brightness_set;
+	cdev->brightness_set_blocking = drvdata->brightness_set_blocking;
+	cdev->brightness_get = drvdata->brightness_get;
 
 	error = devm_led_classdev_register(&pdev->dev, cdev);
 	if (error)
@@ -90,16 +155,18 @@ static int keyboard_led_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct acpi_device_id keyboard_led_id[] = {
-	{ "GOOG0002", 0 },
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id keyboard_led_acpi_match[] = {
+	{ "GOOG0002", (kernel_ulong_t)&keyboard_led_drvdata_acpi },
 	{ }
 };
-MODULE_DEVICE_TABLE(acpi, keyboard_led_id);
+MODULE_DEVICE_TABLE(acpi, keyboard_led_acpi_match);
+#endif
 
 static struct platform_driver keyboard_led_driver = {
 	.driver		= {
 		.name	= "chromeos-keyboard-leds",
-		.acpi_match_table = ACPI_PTR(keyboard_led_id),
+		.acpi_match_table = ACPI_PTR(keyboard_led_acpi_match),
 	},
 	.probe		= keyboard_led_probe,
 };
-- 
2.35.1.723.g4982287a31-goog

[PATCH v2 3/5] dt-bindings: add google,cros-kbd-led-backlight

[Tzung-Bi Shih]

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
Changes from v1:
(https://patchwork.kernel.org/project/chrome-platform/patch/20220214053646.3088298-4-tzungbi@google.com/)
- Update email address accordingly.
- Add A-b tag.

 .../chrome/google,cros-kbd-led-backlight.yaml | 35 +++++++++++++++++++
 .../bindings/mfd/google,cros-ec.yaml          |  3 ++
 2 files changed, 38 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/chrome/google,cros-kbd-led-backlight.yaml

diff --git a/Documentation/devicetree/bindings/chrome/google,cros-kbd-led-backlight.yaml b/Documentation/devicetree/bindings/chrome/google,cros-kbd-led-backlight.yaml
new file mode 100644
index 000000000000..5b875af6a95a
--- /dev/null
+++ b/Documentation/devicetree/bindings/chrome/google,cros-kbd-led-backlight.yaml
@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/chrome/google,cros-kbd-led-backlight.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ChromeOS keyboard backlight LED driver.
+
+maintainers:
+  - Tzung-Bi Shih <tzungbi@kernel.org>
+
+properties:
+  compatible:
+    const: google,cros-kbd-led-backlight
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    spi0 {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      cros_ec: ec@0 {
+        compatible = "google,cros-ec-spi";
+        reg = <0>;
+
+        kbd-led-backlight {
+          compatible = "google,cros-kbd-led-backlight";
+        };
+      };
+    };
diff --git a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
index d1f53bd449f7..1815ca0e8ebc 100644
--- a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
+++ b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
@@ -90,6 +90,9 @@ properties:
   ec-pwm:
     $ref: "/schemas/pwm/google,cros-ec-pwm.yaml#"
 
+  kbd-led-backlight:
+    $ref: "/schemas/chrome/google,cros-kbd-led-backlight.yaml#"
+
   keyboard-controller:
     $ref: "/schemas/input/google,cros-ec-keyb.yaml#"
 
-- 
2.35.1.723.g4982287a31-goog

[PATCH v2 4/5] platform/chrome: cros_kbd_led_backlight: support OF match

[Tzung-Bi Shih]

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
Changes from v1:
(https://patchwork.kernel.org/project/chrome-platform/patch/20220214053646.3088298-5-tzungbi@google.com/)
- Update email address accordingly.
- Use device_get_match_data() per review comment in v1.

 drivers/platform/chrome/cros_kbd_led_backlight.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c
index e26d1d4cd801..1f2750c830d4 100644
--- a/drivers/platform/chrome/cros_kbd_led_backlight.c
+++ b/drivers/platform/chrome/cros_kbd_led_backlight.c
@@ -10,7 +10,9 @@
 #include <linux/kernel.h>
 #include <linux/leds.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 #include <linux/slab.h>
 
 /**
@@ -127,7 +129,7 @@ static int keyboard_led_probe(struct platform_device *pdev)
 	const struct keyboard_led_drvdata *drvdata;
 	int error;
 
-	drvdata = acpi_device_get_match_data(&pdev->dev);
+	drvdata = device_get_match_data(&pdev->dev);
 	if (!drvdata)
 		return -EINVAL;
 
@@ -163,10 +165,21 @@ static const struct acpi_device_id keyboard_led_acpi_match[] = {
 MODULE_DEVICE_TABLE(acpi, keyboard_led_acpi_match);
 #endif
 
+#ifdef CONFIG_OF
+static const struct of_device_id keyboard_led_of_match[] = {
+	{
+		.compatible = "google,cros-kbd-led-backlight",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, keyboard_led_of_match);
+#endif
+
 static struct platform_driver keyboard_led_driver = {
 	.driver		= {
 		.name	= "chromeos-keyboard-leds",
 		.acpi_match_table = ACPI_PTR(keyboard_led_acpi_match),
+		.of_match_table = of_match_ptr(keyboard_led_of_match),
 	},
 	.probe		= keyboard_led_probe,
 };
-- 
2.35.1.723.g4982287a31-goog

Re: [PATCH v2 4/5] platform/chrome: cros_kbd_led_backlight: support OF match

[Guenter Roeck]

On Mon, Mar 14, 2022 at 05:08:34PM +0800, Tzung-Bi Shih wrote:

Nit: There should be some text here.

Otherwise

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

Guenter

> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
> ---
> Changes from v1:
> (https://patchwork.kernel.org/project/chrome-platform/patch/20220214053646.3088298-5-tzungbi@google.com/)
> - Update email address accordingly.
> - Use device_get_match_data() per review comment in v1.
> 
>  drivers/platform/chrome/cros_kbd_led_backlight.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c
> index e26d1d4cd801..1f2750c830d4 100644
> --- a/drivers/platform/chrome/cros_kbd_led_backlight.c
> +++ b/drivers/platform/chrome/cros_kbd_led_backlight.c
> @@ -10,7 +10,9 @@
>  #include <linux/kernel.h>
>  #include <linux/leds.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
>  #include <linux/platform_device.h>
> +#include <linux/property.h>
>  #include <linux/slab.h>
>  
>  /**
> @@ -127,7 +129,7 @@ static int keyboard_led_probe(struct platform_device *pdev)
>  	const struct keyboard_led_drvdata *drvdata;
>  	int error;
>  
> -	drvdata = acpi_device_get_match_data(&pdev->dev);
> +	drvdata = device_get_match_data(&pdev->dev);
>  	if (!drvdata)
>  		return -EINVAL;
>  
> @@ -163,10 +165,21 @@ static const struct acpi_device_id keyboard_led_acpi_match[] = {
>  MODULE_DEVICE_TABLE(acpi, keyboard_led_acpi_match);
>  #endif
>  
> +#ifdef CONFIG_OF
> +static const struct of_device_id keyboard_led_of_match[] = {
> +	{
> +		.compatible = "google,cros-kbd-led-backlight",
> +	},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, keyboard_led_of_match);
> +#endif
> +
>  static struct platform_driver keyboard_led_driver = {
>  	.driver		= {
>  		.name	= "chromeos-keyboard-leds",
>  		.acpi_match_table = ACPI_PTR(keyboard_led_acpi_match),
> +		.of_match_table = of_match_ptr(keyboard_led_of_match),
>  	},
>  	.probe		= keyboard_led_probe,
>  };

[PATCH v2 5/5] platform/chrome: cros_kbd_led_backlight: support EC PWM backend

[Tzung-Bi Shih]

EC PWM backend uses EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT and
EC_CMD_PWM_GET_KEYBOARD_BACKLIGHT for setting and getting the brightness
respectively.

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
Changes from v1:
- Update email address accordingly.

 drivers/platform/chrome/Kconfig               |   6 +
 .../platform/chrome/cros_kbd_led_backlight.c  | 126 +++++++++++++++---
 2 files changed, 117 insertions(+), 15 deletions(-)

diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
index 3f74679a556c..298a49550857 100644
--- a/drivers/platform/chrome/Kconfig
+++ b/drivers/platform/chrome/Kconfig
@@ -142,6 +142,12 @@ config CROS_KBD_LED_BACKLIGHT_ACPI
 	help
 	  ChromeOS keyboard backlight ACPI backend.
 
+config CROS_KBD_LED_BACKLIGHT_EC_PWM
+	tristate "ChromeOS keyboard backlight EC PWM backend"
+	depends on CROS_EC && CROS_KBD_LED_BACKLIGHT
+	help
+	  ChromeOS keyboard backlight EC PWM backend.
+
 config CROS_EC_CHARDEV
 	tristate "ChromeOS EC miscdevice"
 	depends on MFD_CROS_EC_DEV
diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c
index 1f2750c830d4..05a93b71d222 100644
--- a/drivers/platform/chrome/cros_kbd_led_backlight.c
+++ b/drivers/platform/chrome/cros_kbd_led_backlight.c
@@ -11,10 +11,17 @@
 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/slab.h>
 
+struct keyboard_led_private {
+	struct led_classdev cdev;
+	struct cros_ec_device *ec;
+};
+
 /**
  * struct keyboard_led_drvdata - keyboard LED driver data.
  * @init:			Init function.
@@ -40,6 +47,8 @@ struct keyboard_led_drvdata {
 	enum led_brightness max_brightness;
 };
 
+#define KEYBOARD_BACKLIGHT_MAX 100
+
 #if IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_ACPI)
 
 /* Keyboard LED ACPI Device must be defined in firmware */
@@ -47,8 +56,6 @@ struct keyboard_led_drvdata {
 #define ACPI_KEYBOARD_BACKLIGHT_READ	ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBQC"
 #define ACPI_KEYBOARD_BACKLIGHT_WRITE	ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBCM"
 
-#define ACPI_KEYBOARD_BACKLIGHT_MAX		100
-
 static void keyboard_led_set_brightness_acpi(struct led_classdev *cdev,
 					     enum led_brightness brightness)
 {
@@ -107,7 +114,7 @@ static const struct keyboard_led_drvdata keyboard_led_drvdata_acpi = {
 	.init = keyboard_led_init_acpi,
 	.brightness_set = keyboard_led_set_brightness_acpi,
 	.brightness_get = keyboard_led_get_brightness_acpi,
-	.max_brightness = ACPI_KEYBOARD_BACKLIGHT_MAX,
+	.max_brightness = KEYBOARD_BACKLIGHT_MAX,
 };
 
 #else /* IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_ACPI) */
@@ -123,34 +130,122 @@ static const struct keyboard_led_drvdata keyboard_led_drvdata_acpi = {
 
 #endif /* IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_ACPI) */
 
+#if IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_EC_PWM)
+
+static int
+keyboard_led_set_brightness_blocking_ec_pwm(struct led_classdev *cdev,
+					    enum led_brightness brightness)
+{
+	struct {
+		struct cros_ec_command msg;
+		struct ec_params_pwm_set_keyboard_backlight params;
+	} __packed buf;
+	struct ec_params_pwm_set_keyboard_backlight *params = &buf.params;
+	struct cros_ec_command *msg = &buf.msg;
+	struct keyboard_led_private *private =
+		container_of(cdev, struct keyboard_led_private, cdev);
+
+	memset(&buf, 0, sizeof(buf));
+
+	msg->version = 0;
+	msg->command = EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT;
+	msg->insize = 0;
+	msg->outsize = sizeof(*params);
+
+	params->percent = brightness;
+
+	return cros_ec_cmd_xfer_status(private->ec, msg);
+}
+
+static enum led_brightness
+keyboard_led_get_brightness_ec_pwm(struct led_classdev *cdev)
+{
+	struct {
+		struct cros_ec_command msg;
+		struct ec_response_pwm_get_keyboard_backlight resp;
+	} __packed buf;
+	struct ec_response_pwm_get_keyboard_backlight *resp = &buf.resp;
+	struct cros_ec_command *msg = &buf.msg;
+	struct keyboard_led_private *private =
+		container_of(cdev, struct keyboard_led_private, cdev);
+	int ret;
+
+	memset(&buf, 0, sizeof(buf));
+
+	msg->version = 0;
+	msg->command = EC_CMD_PWM_GET_KEYBOARD_BACKLIGHT;
+	msg->insize = sizeof(*resp);
+	msg->outsize = 0;
+
+	ret = cros_ec_cmd_xfer_status(private->ec, msg);
+	if (ret < 0)
+		return ret;
+
+	return resp->percent;
+}
+
+static int keyboard_led_init_ec_pwm(struct platform_device *pdev)
+{
+	struct keyboard_led_private *private = platform_get_drvdata(pdev);
+
+	private->ec = dev_get_drvdata(pdev->dev.parent);
+	if (!private->ec) {
+		dev_err(&pdev->dev, "no parent EC device\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = {
+	.init = keyboard_led_init_ec_pwm,
+	.brightness_set_blocking = keyboard_led_set_brightness_blocking_ec_pwm,
+	.brightness_get = keyboard_led_get_brightness_ec_pwm,
+	.max_brightness = KEYBOARD_BACKLIGHT_MAX,
+};
+
+#else /* IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_EC_PWM) */
+
+static int keyboard_led_init_ec_pwm_null(struct platform_device *pdev)
+{
+	return -EOPNOTSUPP;
+}
+
+static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = {
+	.init = keyboard_led_init_ec_pwm_null,
+};
+
+#endif /* IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_EC_PWM) */
+
 static int keyboard_led_probe(struct platform_device *pdev)
 {
-	struct led_classdev *cdev;
 	const struct keyboard_led_drvdata *drvdata;
+	struct keyboard_led_private *private;
 	int error;
 
 	drvdata = device_get_match_data(&pdev->dev);
 	if (!drvdata)
 		return -EINVAL;
 
+	private = devm_kzalloc(&pdev->dev, sizeof(*private), GFP_KERNEL);
+	if (!private)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, private);
+
 	if (drvdata->init) {
 		error = drvdata->init(pdev);
 		if (error)
 			return error;
 	}
 
-	cdev = devm_kzalloc(&pdev->dev, sizeof(*cdev), GFP_KERNEL);
-	if (!cdev)
-		return -ENOMEM;
-
-	cdev->name = "chromeos::kbd_backlight";
-	cdev->flags |= LED_CORE_SUSPENDRESUME;
-	cdev->max_brightness = drvdata->max_brightness;
-	cdev->brightness_set = drvdata->brightness_set;
-	cdev->brightness_set_blocking = drvdata->brightness_set_blocking;
-	cdev->brightness_get = drvdata->brightness_get;
+	private->cdev.name = "chromeos::kbd_backlight";
+	private->cdev.flags |= LED_CORE_SUSPENDRESUME;
+	private->cdev.max_brightness = drvdata->max_brightness;
+	private->cdev.brightness_set = drvdata->brightness_set;
+	private->cdev.brightness_set_blocking = drvdata->brightness_set_blocking;
+	private->cdev.brightness_get = drvdata->brightness_get;
 
-	error = devm_led_classdev_register(&pdev->dev, cdev);
+	error = devm_led_classdev_register(&pdev->dev, &private->cdev);
 	if (error)
 		return error;
 
@@ -169,6 +264,7 @@ MODULE_DEVICE_TABLE(acpi, keyboard_led_acpi_match);
 static const struct of_device_id keyboard_led_of_match[] = {
 	{
 		.compatible = "google,cros-kbd-led-backlight",
+		.data = &keyboard_led_drvdata_ec_pwm,
 	},
 	{}
 };
-- 
2.35.1.723.g4982287a31-goog

Re: [PATCH v2 5/5] platform/chrome: cros_kbd_led_backlight: support EC PWM backend

[Guenter Roeck]

On Mon, Mar 14, 2022 at 05:08:35PM +0800, Tzung-Bi Shih wrote:
> EC PWM backend uses EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT and
> EC_CMD_PWM_GET_KEYBOARD_BACKLIGHT for setting and getting the brightness
> respectively.
> 
> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
> ---
> Changes from v1:
> - Update email address accordingly.
> 
>  drivers/platform/chrome/Kconfig               |   6 +
>  .../platform/chrome/cros_kbd_led_backlight.c  | 126 +++++++++++++++---
>  2 files changed, 117 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
> index 3f74679a556c..298a49550857 100644
> --- a/drivers/platform/chrome/Kconfig
> +++ b/drivers/platform/chrome/Kconfig
> @@ -142,6 +142,12 @@ config CROS_KBD_LED_BACKLIGHT_ACPI
>  	help
>  	  ChromeOS keyboard backlight ACPI backend.
>  
> +config CROS_KBD_LED_BACKLIGHT_EC_PWM
> +	tristate "ChromeOS keyboard backlight EC PWM backend"

This is not a standa-alone module and should therefore be bool,
not tristate.

Thanks,
Guenter

> +	depends on CROS_EC && CROS_KBD_LED_BACKLIGHT
> +	help
> +	  ChromeOS keyboard backlight EC PWM backend.
> +
>  config CROS_EC_CHARDEV
>  	tristate "ChromeOS EC miscdevice"
>  	depends on MFD_CROS_EC_DEV
> diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c
> index 1f2750c830d4..05a93b71d222 100644
> --- a/drivers/platform/chrome/cros_kbd_led_backlight.c
> +++ b/drivers/platform/chrome/cros_kbd_led_backlight.c
> @@ -11,10 +11,17 @@
>  #include <linux/leds.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/platform_data/cros_ec_commands.h>
> +#include <linux/platform_data/cros_ec_proto.h>
>  #include <linux/platform_device.h>
>  #include <linux/property.h>
>  #include <linux/slab.h>
>  
> +struct keyboard_led_private {
> +	struct led_classdev cdev;
> +	struct cros_ec_device *ec;
> +};
> +
>  /**
>   * struct keyboard_led_drvdata - keyboard LED driver data.
>   * @init:			Init function.
> @@ -40,6 +47,8 @@ struct keyboard_led_drvdata {
>  	enum led_brightness max_brightness;
>  };
>  
> +#define KEYBOARD_BACKLIGHT_MAX 100
> +
>  #if IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_ACPI)
>  
>  /* Keyboard LED ACPI Device must be defined in firmware */
> @@ -47,8 +56,6 @@ struct keyboard_led_drvdata {
>  #define ACPI_KEYBOARD_BACKLIGHT_READ	ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBQC"
>  #define ACPI_KEYBOARD_BACKLIGHT_WRITE	ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBCM"
>  
> -#define ACPI_KEYBOARD_BACKLIGHT_MAX		100
> -
>  static void keyboard_led_set_brightness_acpi(struct led_classdev *cdev,
>  					     enum led_brightness brightness)
>  {
> @@ -107,7 +114,7 @@ static const struct keyboard_led_drvdata keyboard_led_drvdata_acpi = {
>  	.init = keyboard_led_init_acpi,
>  	.brightness_set = keyboard_led_set_brightness_acpi,
>  	.brightness_get = keyboard_led_get_brightness_acpi,
> -	.max_brightness = ACPI_KEYBOARD_BACKLIGHT_MAX,
> +	.max_brightness = KEYBOARD_BACKLIGHT_MAX,
>  };
>  
>  #else /* IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_ACPI) */
> @@ -123,34 +130,122 @@ static const struct keyboard_led_drvdata keyboard_led_drvdata_acpi = {
>  
>  #endif /* IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_ACPI) */
>  
> +#if IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_EC_PWM)

#ifdef (with bool) should do.

> +
> +static int
> +keyboard_led_set_brightness_blocking_ec_pwm(struct led_classdev *cdev,
> +					    enum led_brightness brightness)
> +{
> +	struct {
> +		struct cros_ec_command msg;
> +		struct ec_params_pwm_set_keyboard_backlight params;
> +	} __packed buf;
> +	struct ec_params_pwm_set_keyboard_backlight *params = &buf.params;
> +	struct cros_ec_command *msg = &buf.msg;
> +	struct keyboard_led_private *private =
> +		container_of(cdev, struct keyboard_led_private, cdev);
> +
> +	memset(&buf, 0, sizeof(buf));
> +
> +	msg->version = 0;
> +	msg->command = EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT;
> +	msg->insize = 0;
> +	msg->outsize = sizeof(*params);
> +
> +	params->percent = brightness;
> +
> +	return cros_ec_cmd_xfer_status(private->ec, msg);
> +}
> +
> +static enum led_brightness
> +keyboard_led_get_brightness_ec_pwm(struct led_classdev *cdev)
> +{
> +	struct {
> +		struct cros_ec_command msg;
> +		struct ec_response_pwm_get_keyboard_backlight resp;
> +	} __packed buf;
> +	struct ec_response_pwm_get_keyboard_backlight *resp = &buf.resp;
> +	struct cros_ec_command *msg = &buf.msg;
> +	struct keyboard_led_private *private =
> +		container_of(cdev, struct keyboard_led_private, cdev);
> +	int ret;
> +
> +	memset(&buf, 0, sizeof(buf));
> +
> +	msg->version = 0;
> +	msg->command = EC_CMD_PWM_GET_KEYBOARD_BACKLIGHT;
> +	msg->insize = sizeof(*resp);
> +	msg->outsize = 0;
> +
> +	ret = cros_ec_cmd_xfer_status(private->ec, msg);
> +	if (ret < 0)
> +		return ret;
> +
> +	return resp->percent;
> +}
> +
> +static int keyboard_led_init_ec_pwm(struct platform_device *pdev)
> +{
> +	struct keyboard_led_private *private = platform_get_drvdata(pdev);
> +
> +	private->ec = dev_get_drvdata(pdev->dev.parent);
> +	if (!private->ec) {
> +		dev_err(&pdev->dev, "no parent EC device\n");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = {
> +	.init = keyboard_led_init_ec_pwm,
> +	.brightness_set_blocking = keyboard_led_set_brightness_blocking_ec_pwm,
> +	.brightness_get = keyboard_led_get_brightness_ec_pwm,
> +	.max_brightness = KEYBOARD_BACKLIGHT_MAX,
> +};
> +
> +#else /* IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_EC_PWM) */
> +
> +static int keyboard_led_init_ec_pwm_null(struct platform_device *pdev)
> +{
> +	return -EOPNOTSUPP;
> +}
> +
> +static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = {
> +	.init = keyboard_led_init_ec_pwm_null,
> +};
> +
> +#endif /* IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_EC_PWM) */
> +
>  static int keyboard_led_probe(struct platform_device *pdev)
>  {
> -	struct led_classdev *cdev;
>  	const struct keyboard_led_drvdata *drvdata;
> +	struct keyboard_led_private *private;
>  	int error;
>  
>  	drvdata = device_get_match_data(&pdev->dev);
>  	if (!drvdata)
>  		return -EINVAL;
>  
> +	private = devm_kzalloc(&pdev->dev, sizeof(*private), GFP_KERNEL);
> +	if (!private)
> +		return -ENOMEM;
> +	platform_set_drvdata(pdev, private);
> +
>  	if (drvdata->init) {
>  		error = drvdata->init(pdev);
>  		if (error)
>  			return error;
>  	}
>  
> -	cdev = devm_kzalloc(&pdev->dev, sizeof(*cdev), GFP_KERNEL);
> -	if (!cdev)
> -		return -ENOMEM;
> -
> -	cdev->name = "chromeos::kbd_backlight";
> -	cdev->flags |= LED_CORE_SUSPENDRESUME;
> -	cdev->max_brightness = drvdata->max_brightness;
> -	cdev->brightness_set = drvdata->brightness_set;
> -	cdev->brightness_set_blocking = drvdata->brightness_set_blocking;
> -	cdev->brightness_get = drvdata->brightness_get;
> +	private->cdev.name = "chromeos::kbd_backlight";
> +	private->cdev.flags |= LED_CORE_SUSPENDRESUME;
> +	private->cdev.max_brightness = drvdata->max_brightness;
> +	private->cdev.brightness_set = drvdata->brightness_set;
> +	private->cdev.brightness_set_blocking = drvdata->brightness_set_blocking;
> +	private->cdev.brightness_get = drvdata->brightness_get;
>  
> -	error = devm_led_classdev_register(&pdev->dev, cdev);
> +	error = devm_led_classdev_register(&pdev->dev, &private->cdev);
>  	if (error)
>  		return error;
>  
> @@ -169,6 +264,7 @@ MODULE_DEVICE_TABLE(acpi, keyboard_led_acpi_match);
>  static const struct of_device_id keyboard_led_of_match[] = {
>  	{
>  		.compatible = "google,cros-kbd-led-backlight",
> +		.data = &keyboard_led_drvdata_ec_pwm,
>  	},
>  	{}
>  };

Re: [PATCH v2 5/5] platform/chrome: cros_kbd_led_backlight: support EC PWM backend

[Tzung-Bi Shih]

On Fri, Mar 18, 2022 at 10:07:51AM -0700, Guenter Roeck wrote:
> On Mon, Mar 14, 2022 at 05:08:35PM +0800, Tzung-Bi Shih wrote:
> > @@ -142,6 +142,12 @@ config CROS_KBD_LED_BACKLIGHT_ACPI
> >  	help
> >  	  ChromeOS keyboard backlight ACPI backend.
> >  
> > +config CROS_KBD_LED_BACKLIGHT_EC_PWM
> > +	tristate "ChromeOS keyboard backlight EC PWM backend"
> 
> This is not a standa-alone module and should therefore be bool,
> not tristate.

Ack.

> > @@ -123,34 +130,122 @@ static const struct keyboard_led_drvdata keyboard_led_drvdata_acpi = {
> >  
> >  #endif /* IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_ACPI) */
> >  
> > +#if IS_ENABLED(CONFIG_CROS_KBD_LED_BACKLIGHT_EC_PWM)
> 
> #ifdef (with bool) should do.

Ack.  Will apply the fix for CONFIG_CROS_KBD_LED_BACKLIGHT_ACPI too.