drivers/platform/chrome/cros_kbd_led_backlight.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 // Keyboard backlight LED driver for ChromeOS
 //
 // Copyright (C) 2012 Google, Inc.

 #include <linux/acpi.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/leds.h>
 #include <linux/mfd/core.h>
 #include <linux/mod_devicetable.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 {
 	struct led_classdev cdev;
 	struct cros_ec_device *ec;
 };

 /**
  * 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;
 };

 #define KEYBOARD_BACKLIGHT_MAX 100

 #ifdef CONFIG_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"
 #define ACPI_KEYBOARD_BACKLIGHT_WRITE	ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBCM"

 static void keyboard_led_set_brightness_acpi(struct led_classdev *cdev,
 					     enum led_brightness brightness)
 {
 	union acpi_object param;
 	struct acpi_object_list input;
 	acpi_status status;

 	param.type = ACPI_TYPE_INTEGER;
 	param.integer.value = brightness;
 	input.count = 1;
 	input.pointer = &param;

 	status = acpi_evaluate_object(NULL, ACPI_KEYBOARD_BACKLIGHT_WRITE,
 				      &input, NULL);
 	if (ACPI_FAILURE(status))
 		dev_err(cdev->dev, "Error setting keyboard LED value: %d\n",
 			status);
 }

 static enum led_brightness
 keyboard_led_get_brightness_acpi(struct led_classdev *cdev)
 {
 	unsigned long long brightness;
 	acpi_status status;

 	status = acpi_evaluate_integer(NULL, ACPI_KEYBOARD_BACKLIGHT_READ,
 				       NULL, &brightness);
 	if (ACPI_FAILURE(status)) {
 		dev_err(cdev->dev, "Error getting keyboard LED value: %d\n",
 			status);
 		return -EIO;
 	}

 	return brightness;
 }

 static int keyboard_led_init_acpi(struct platform_device *pdev)
 {
 	acpi_handle handle;
 	acpi_status status;

 	/* Look for the keyboard LED ACPI Device */
 	status = acpi_get_handle(ACPI_ROOT_OBJECT,
 				 ACPI_KEYBOARD_BACKLIGHT_DEVICE,
 				 &handle);
 	if (ACPI_FAILURE(status)) {
 		dev_err(&pdev->dev, "Unable to find ACPI device %s: %d\n",
 			ACPI_KEYBOARD_BACKLIGHT_DEVICE, status);
 		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 = KEYBOARD_BACKLIGHT_MAX,
 };

 #endif /* CONFIG_ACPI */

 #if IS_ENABLED(CONFIG_CROS_EC)

 static int
 keyboard_led_set_brightness_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 *keyboard_led = container_of(cdev, struct keyboard_led, cdev);

 	memset(&buf, 0, sizeof(buf));

 	msg->command = EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT;
 	msg->outsize = sizeof(*params);

 	params->percent = brightness;

 	return cros_ec_cmd_xfer_status(keyboard_led->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 *keyboard_led = container_of(cdev, struct keyboard_led, cdev);
 	int ret;

 	memset(&buf, 0, sizeof(buf));

 	msg->command = EC_CMD_PWM_GET_KEYBOARD_BACKLIGHT;
 	msg->insize = sizeof(*resp);

 	ret = cros_ec_cmd_xfer_status(keyboard_led->ec, msg);
 	if (ret < 0)
 		return ret;

 	return resp->percent;
 }

 static int keyboard_led_init_ec_pwm(struct platform_device *pdev)
 {
 	struct keyboard_led *keyboard_led = platform_get_drvdata(pdev);

 	keyboard_led->ec = dev_get_drvdata(pdev->dev.parent);
 	if (!keyboard_led->ec) {
 		dev_err(&pdev->dev, "no parent EC device\n");
 		return -EINVAL;
 	}

 	return 0;
 }

 static const __maybe_unused struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = {
 	.init = keyboard_led_init_ec_pwm,
 	.brightness_set_blocking = keyboard_led_set_brightness_ec_pwm,
 	.brightness_get = keyboard_led_get_brightness_ec_pwm,
 	.max_brightness = KEYBOARD_BACKLIGHT_MAX,
 };

 #else /* IS_ENABLED(CONFIG_CROS_EC) */

 static const __maybe_unused struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = {};

 #endif /* IS_ENABLED(CONFIG_CROS_EC) */

 #if IS_ENABLED(CONFIG_MFD_CROS_EC_DEV)
 static int keyboard_led_init_ec_pwm_mfd(struct platform_device *pdev)
 {
 	struct cros_ec_dev *ec_dev = dev_get_drvdata(pdev->dev.parent);
 	struct cros_ec_device *cros_ec = ec_dev->ec_dev;
 	struct keyboard_led *keyboard_led = platform_get_drvdata(pdev);

 	keyboard_led->ec = cros_ec;

 	return 0;
 }

 static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm_mfd = {
 	.init = keyboard_led_init_ec_pwm_mfd,
 	.brightness_set_blocking = keyboard_led_set_brightness_ec_pwm,
 	.brightness_get = keyboard_led_get_brightness_ec_pwm,
 	.max_brightness = KEYBOARD_BACKLIGHT_MAX,
 };

 #else /* IS_ENABLED(CONFIG_MFD_CROS_EC_DEV) */

 static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm_mfd = {};

 #endif /* IS_ENABLED(CONFIG_MFD_CROS_EC_DEV) */

 static int keyboard_led_is_mfd_device(struct platform_device *pdev)
 {
 	return IS_ENABLED(CONFIG_MFD_CROS_EC_DEV) && mfd_get_cell(pdev);
 }

 static int keyboard_led_probe(struct platform_device *pdev)
 {
 	const struct keyboard_led_drvdata *drvdata;
 	struct keyboard_led *keyboard_led;
 	int error;

 	if (keyboard_led_is_mfd_device(pdev))
 		drvdata = &keyboard_led_drvdata_ec_pwm_mfd;
 	else
 		drvdata = device_get_match_data(&pdev->dev);
 	if (!drvdata)
 		return -EINVAL;

 	keyboard_led = devm_kzalloc(&pdev->dev, sizeof(*keyboard_led), GFP_KERNEL);
 	if (!keyboard_led)
 		return -ENOMEM;
 	platform_set_drvdata(pdev, keyboard_led);

 	if (drvdata->init) {
 		error = drvdata->init(pdev);
 		if (error)
 			return error;
 	}

 	keyboard_led->cdev.name = "chromeos::kbd_backlight";
 	keyboard_led->cdev.flags |= LED_CORE_SUSPENDRESUME | LED_REJECT_NAME_CONFLICT;
 	keyboard_led->cdev.max_brightness = drvdata->max_brightness;
 	keyboard_led->cdev.brightness_set = drvdata->brightness_set;
 	keyboard_led->cdev.brightness_set_blocking = drvdata->brightness_set_blocking;
 	keyboard_led->cdev.brightness_get = drvdata->brightness_get;

 	error = devm_led_classdev_register(&pdev->dev, &keyboard_led->cdev);
 	if (error == -EEXIST) /* Already bound via other mechanism */
 		return -ENODEV;
 	if (error)
 		return error;

 	return 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_acpi_match);
 #endif

 #ifdef CONFIG_OF
 static const struct of_device_id keyboard_led_of_match[] = {
 	{
 		.compatible = "google,cros-kbd-led-backlight",
 		.data = &keyboard_led_drvdata_ec_pwm,
 	},
 	{}
 };
 MODULE_DEVICE_TABLE(of, keyboard_led_of_match);
 #endif

 static const struct platform_device_id keyboard_led_id[] = {
 	{ "cros-keyboard-leds", 0 },
 	{}
 };
 MODULE_DEVICE_TABLE(platform, keyboard_led_id);

 static struct platform_driver keyboard_led_driver = {
 	.driver		= {
 		.name	= "cros-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,
 	.id_table	= keyboard_led_id,
 };
 module_platform_driver(keyboard_led_driver);

 MODULE_AUTHOR("Simon Que <sque@chromium.org>");
 MODULE_DESCRIPTION("ChromeOS Keyboard backlight LED Driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0+
	// Keyboard backlight LED driver for ChromeOS
	//
	// Copyright (C) 2012 Google, Inc.

	#include <linux/acpi.h>
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/leds.h>
	#include <linux/mfd/core.h>
	#include <linux/mod_devicetable.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 {
	struct led_classdev cdev;
	struct cros_ec_device *ec;
	};

	/**
	* 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;
	};

	#define KEYBOARD_BACKLIGHT_MAX 100

	#ifdef CONFIG_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"
	#define ACPI_KEYBOARD_BACKLIGHT_WRITE ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBCM"

	static void keyboard_led_set_brightness_acpi(struct led_classdev *cdev,
	enum led_brightness brightness)
	{
	union acpi_object param;
	struct acpi_object_list input;
	acpi_status status;

	param.type = ACPI_TYPE_INTEGER;
	param.integer.value = brightness;
	input.count = 1;
	input.pointer = &param;

	status = acpi_evaluate_object(NULL, ACPI_KEYBOARD_BACKLIGHT_WRITE,
	&input, NULL);
	if (ACPI_FAILURE(status))
	dev_err(cdev->dev, "Error setting keyboard LED value: %d\n",
	status);
	}

	static enum led_brightness
	keyboard_led_get_brightness_acpi(struct led_classdev *cdev)
	{
	unsigned long long brightness;
	acpi_status status;

	status = acpi_evaluate_integer(NULL, ACPI_KEYBOARD_BACKLIGHT_READ,
	NULL, &brightness);
	if (ACPI_FAILURE(status)) {
	dev_err(cdev->dev, "Error getting keyboard LED value: %d\n",
	status);
	return -EIO;
	}

	return brightness;
	}

	static int keyboard_led_init_acpi(struct platform_device *pdev)
	{
	acpi_handle handle;
	acpi_status status;

	/* Look for the keyboard LED ACPI Device */
	status = acpi_get_handle(ACPI_ROOT_OBJECT,
	ACPI_KEYBOARD_BACKLIGHT_DEVICE,
	&handle);
	if (ACPI_FAILURE(status)) {
	dev_err(&pdev->dev, "Unable to find ACPI device %s: %d\n",
	ACPI_KEYBOARD_BACKLIGHT_DEVICE, status);
	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 = KEYBOARD_BACKLIGHT_MAX,
	};

	#endif /* CONFIG_ACPI */

	#if IS_ENABLED(CONFIG_CROS_EC)

	static int
	keyboard_led_set_brightness_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 *keyboard_led = container_of(cdev, struct keyboard_led, cdev);

	memset(&buf, 0, sizeof(buf));

	msg->command = EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT;
	msg->outsize = sizeof(*params);

	params->percent = brightness;

	return cros_ec_cmd_xfer_status(keyboard_led->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 *keyboard_led = container_of(cdev, struct keyboard_led, cdev);
	int ret;

	memset(&buf, 0, sizeof(buf));

	msg->command = EC_CMD_PWM_GET_KEYBOARD_BACKLIGHT;
	msg->insize = sizeof(*resp);

	ret = cros_ec_cmd_xfer_status(keyboard_led->ec, msg);
	if (ret < 0)
	return ret;

	return resp->percent;
	}

	static int keyboard_led_init_ec_pwm(struct platform_device *pdev)
	{
	struct keyboard_led *keyboard_led = platform_get_drvdata(pdev);

	keyboard_led->ec = dev_get_drvdata(pdev->dev.parent);
	if (!keyboard_led->ec) {
	dev_err(&pdev->dev, "no parent EC device\n");
	return -EINVAL;
	}

	return 0;
	}

	static const __maybe_unused struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = {
	.init = keyboard_led_init_ec_pwm,
	.brightness_set_blocking = keyboard_led_set_brightness_ec_pwm,
	.brightness_get = keyboard_led_get_brightness_ec_pwm,
	.max_brightness = KEYBOARD_BACKLIGHT_MAX,
	};

	#else /* IS_ENABLED(CONFIG_CROS_EC) */

	static const __maybe_unused struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = {};

	#endif /* IS_ENABLED(CONFIG_CROS_EC) */

	#if IS_ENABLED(CONFIG_MFD_CROS_EC_DEV)
	static int keyboard_led_init_ec_pwm_mfd(struct platform_device *pdev)
	{
	struct cros_ec_dev *ec_dev = dev_get_drvdata(pdev->dev.parent);
	struct cros_ec_device *cros_ec = ec_dev->ec_dev;
	struct keyboard_led *keyboard_led = platform_get_drvdata(pdev);

	keyboard_led->ec = cros_ec;

	return 0;
	}

	static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm_mfd = {
	.init = keyboard_led_init_ec_pwm_mfd,
	.brightness_set_blocking = keyboard_led_set_brightness_ec_pwm,
	.brightness_get = keyboard_led_get_brightness_ec_pwm,
	.max_brightness = KEYBOARD_BACKLIGHT_MAX,
	};

	#else /* IS_ENABLED(CONFIG_MFD_CROS_EC_DEV) */

	static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm_mfd = {};

	#endif /* IS_ENABLED(CONFIG_MFD_CROS_EC_DEV) */

	static int keyboard_led_is_mfd_device(struct platform_device *pdev)
	{
	return IS_ENABLED(CONFIG_MFD_CROS_EC_DEV) && mfd_get_cell(pdev);
	}

	static int keyboard_led_probe(struct platform_device *pdev)
	{
	const struct keyboard_led_drvdata *drvdata;
	struct keyboard_led *keyboard_led;
	int error;

	if (keyboard_led_is_mfd_device(pdev))
	drvdata = &keyboard_led_drvdata_ec_pwm_mfd;
	else
	drvdata = device_get_match_data(&pdev->dev);
	if (!drvdata)
	return -EINVAL;

	keyboard_led = devm_kzalloc(&pdev->dev, sizeof(*keyboard_led), GFP_KERNEL);
	if (!keyboard_led)
	return -ENOMEM;
	platform_set_drvdata(pdev, keyboard_led);

	if (drvdata->init) {
	error = drvdata->init(pdev);
	if (error)
	return error;
	}

	keyboard_led->cdev.name = "chromeos::kbd_backlight";
	keyboard_led->cdev.flags \|= LED_CORE_SUSPENDRESUME \| LED_REJECT_NAME_CONFLICT;
	keyboard_led->cdev.max_brightness = drvdata->max_brightness;
	keyboard_led->cdev.brightness_set = drvdata->brightness_set;
	keyboard_led->cdev.brightness_set_blocking = drvdata->brightness_set_blocking;
	keyboard_led->cdev.brightness_get = drvdata->brightness_get;

	error = devm_led_classdev_register(&pdev->dev, &keyboard_led->cdev);
	if (error == -EEXIST) /* Already bound via other mechanism */
	return -ENODEV;
	if (error)
	return error;

	return 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_acpi_match);
	#endif

	#ifdef CONFIG_OF
	static const struct of_device_id keyboard_led_of_match[] = {
	{
	.compatible = "google,cros-kbd-led-backlight",
	.data = &keyboard_led_drvdata_ec_pwm,
	},
	{}
	};
	MODULE_DEVICE_TABLE(of, keyboard_led_of_match);
	#endif

	static const struct platform_device_id keyboard_led_id[] = {
	{ "cros-keyboard-leds", 0 },
	{}
	};
	MODULE_DEVICE_TABLE(platform, keyboard_led_id);

	static struct platform_driver keyboard_led_driver = {
	.driver = {
	.name = "cros-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,
	.id_table = keyboard_led_id,
	};
	module_platform_driver(keyboard_led_driver);

	MODULE_AUTHOR("Simon Que <sque@chromium.org>");
	MODULE_DESCRIPTION("ChromeOS Keyboard backlight LED Driver");
	MODULE_LICENSE("GPL");