drivers/leds/leds-turris-omnia.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * CZ.NIC's Turris Omnia LEDs driver
  *
  * 2020 by Marek Behún <kabel@kernel.org>
  */

 #include <linux/i2c.h>
 #include <linux/led-class-multicolor.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include "leds.h"

 #define OMNIA_BOARD_LEDS	12
 #define OMNIA_LED_NUM_CHANNELS	3

 #define CMD_LED_MODE		3
 #define CMD_LED_MODE_LED(l)	((l) & 0x0f)
 #define CMD_LED_MODE_USER	0x10

 #define CMD_LED_STATE		4
 #define CMD_LED_STATE_LED(l)	((l) & 0x0f)
 #define CMD_LED_STATE_ON	0x10

 #define CMD_LED_COLOR		5
 #define CMD_LED_SET_BRIGHTNESS	7
 #define CMD_LED_GET_BRIGHTNESS	8

 struct omnia_led {
 	struct led_classdev_mc mc_cdev;
 	struct mc_subled subled_info[OMNIA_LED_NUM_CHANNELS];
 	int reg;
 };

 #define to_omnia_led(l)		container_of(l, struct omnia_led, mc_cdev)

 struct omnia_leds {
 	struct i2c_client *client;
 	struct mutex lock;
 	struct omnia_led leds[];
 };

 static int omnia_led_brightness_set_blocking(struct led_classdev *cdev,
 					     enum led_brightness brightness)
 {
 	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
 	struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
 	struct omnia_led *led = to_omnia_led(mc_cdev);
 	u8 buf[5], state;
 	int ret;

 	mutex_lock(&leds->lock);

 	led_mc_calc_color_components(&led->mc_cdev, brightness);

 	buf[0] = CMD_LED_COLOR;
 	buf[1] = led->reg;
 	buf[2] = mc_cdev->subled_info[0].brightness;
 	buf[3] = mc_cdev->subled_info[1].brightness;
 	buf[4] = mc_cdev->subled_info[2].brightness;

 	state = CMD_LED_STATE_LED(led->reg);
 	if (buf[2] || buf[3] || buf[4])
 		state |= CMD_LED_STATE_ON;

 	ret = i2c_smbus_write_byte_data(leds->client, CMD_LED_STATE, state);
 	if (ret >= 0 && (state & CMD_LED_STATE_ON))
 		ret = i2c_master_send(leds->client, buf, 5);

 	mutex_unlock(&leds->lock);

 	return ret;
 }

 static int omnia_led_register(struct i2c_client *client, struct omnia_led *led,
 			      struct device_node *np)
 {
 	struct led_init_data init_data = {};
 	struct device *dev = &client->dev;
 	struct led_classdev *cdev;
 	int ret, color;

 	ret = of_property_read_u32(np, "reg", &led->reg);
 	if (ret || led->reg >= OMNIA_BOARD_LEDS) {
 		dev_warn(dev,
 			 "Node %pOF: must contain 'reg' property with values between 0 and %i\n",
 			 np, OMNIA_BOARD_LEDS - 1);
 		return 0;
 	}

 	ret = of_property_read_u32(np, "color", &color);
 	if (ret || color != LED_COLOR_ID_RGB) {
 		dev_warn(dev,
 			 "Node %pOF: must contain 'color' property with value LED_COLOR_ID_RGB\n",
 			 np);
 		return 0;
 	}

 	led->subled_info[0].color_index = LED_COLOR_ID_RED;
 	led->subled_info[0].channel = 0;
 	led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
 	led->subled_info[1].channel = 1;
 	led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
 	led->subled_info[2].channel = 2;

 	led->mc_cdev.subled_info = led->subled_info;
 	led->mc_cdev.num_colors = OMNIA_LED_NUM_CHANNELS;

 	init_data.fwnode = &np->fwnode;

 	cdev = &led->mc_cdev.led_cdev;
 	cdev->max_brightness = 255;
 	cdev->brightness_set_blocking = omnia_led_brightness_set_blocking;

 	/* put the LED into software mode */
 	ret = i2c_smbus_write_byte_data(client, CMD_LED_MODE,
 					CMD_LED_MODE_LED(led->reg) |
 					CMD_LED_MODE_USER);
 	if (ret < 0) {
 		dev_err(dev, "Cannot set LED %pOF to software mode: %i\n", np,
 			ret);
 		return ret;
 	}

 	/* disable the LED */
 	ret = i2c_smbus_write_byte_data(client, CMD_LED_STATE,
 					CMD_LED_STATE_LED(led->reg));
 	if (ret < 0) {
 		dev_err(dev, "Cannot set LED %pOF brightness: %i\n", np, ret);
 		return ret;
 	}

 	ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev,
 							&init_data);
 	if (ret < 0) {
 		dev_err(dev, "Cannot register LED %pOF: %i\n", np, ret);
 		return ret;
 	}

 	return 1;
 }

 /*
  * On the front panel of the Turris Omnia router there is also a button which
  * can be used to control the intensity of all the LEDs at once, so that if they
  * are too bright, user can dim them.
  * The microcontroller cycles between 8 levels of this global brightness (from
  * 100% to 0%), but this setting can have any integer value between 0 and 100.
  * It is therefore convenient to be able to change this setting from software.
  * We expose this setting via a sysfs attribute file called "brightness". This
  * file lives in the device directory of the LED controller, not an individual
  * LED, so it should not confuse users.
  */
 static ssize_t brightness_show(struct device *dev, struct device_attribute *a,
 			       char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	int ret;

 	ret = i2c_smbus_read_byte_data(client, CMD_LED_GET_BRIGHTNESS);

 	if (ret < 0)
 		return ret;

 	return sysfs_emit(buf, "%d\n", ret);
 }

 static ssize_t brightness_store(struct device *dev, struct device_attribute *a,
 				const char *buf, size_t count)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	unsigned long brightness;
 	int ret;

 	if (kstrtoul(buf, 10, &brightness))
 		return -EINVAL;

 	if (brightness > 100)
 		return -EINVAL;

 	ret = i2c_smbus_write_byte_data(client, CMD_LED_SET_BRIGHTNESS,
 					(u8)brightness);

 	return ret < 0 ? ret : count;
 }
 static DEVICE_ATTR_RW(brightness);

 static struct attribute *omnia_led_controller_attrs[] = {
 	&dev_attr_brightness.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(omnia_led_controller);

 static int omnia_leds_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct device_node *np = dev_of_node(dev), *child;
 	struct omnia_leds *leds;
 	struct omnia_led *led;
 	int ret, count;

 	count = of_get_available_child_count(np);
 	if (!count) {
 		dev_err(dev, "LEDs are not defined in device tree!\n");
 		return -ENODEV;
 	} else if (count > OMNIA_BOARD_LEDS) {
 		dev_err(dev, "Too many LEDs defined in device tree!\n");
 		return -EINVAL;
 	}

 	leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL);
 	if (!leds)
 		return -ENOMEM;

 	leds->client = client;
 	i2c_set_clientdata(client, leds);

 	mutex_init(&leds->lock);

 	led = &leds->leds[0];
 	for_each_available_child_of_node(np, child) {
 		ret = omnia_led_register(client, led, child);
 		if (ret < 0) {
 			of_node_put(child);
 			return ret;
 		}

 		led += ret;
 	}

 	return 0;
 }

 static void omnia_leds_remove(struct i2c_client *client)
 {
 	u8 buf[5];

 	/* put all LEDs into default (HW triggered) mode */
 	i2c_smbus_write_byte_data(client, CMD_LED_MODE,
 				  CMD_LED_MODE_LED(OMNIA_BOARD_LEDS));

 	/* set all LEDs color to [255, 255, 255] */
 	buf[0] = CMD_LED_COLOR;
 	buf[1] = OMNIA_BOARD_LEDS;
 	buf[2] = 255;
 	buf[3] = 255;
 	buf[4] = 255;

 	i2c_master_send(client, buf, 5);
 }

 static const struct of_device_id of_omnia_leds_match[] = {
 	{ .compatible = "cznic,turris-omnia-leds", },
 	{},
 };

 static const struct i2c_device_id omnia_id[] = {
 	{ "omnia", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, omnia_id);

 static struct i2c_driver omnia_leds_driver = {
 	.probe		= omnia_leds_probe,
 	.remove		= omnia_leds_remove,
 	.id_table	= omnia_id,
 	.driver		= {
 		.name	= "leds-turris-omnia",
 		.of_match_table = of_omnia_leds_match,
 		.dev_groups = omnia_led_controller_groups,
 	},
 };

 module_i2c_driver(omnia_leds_driver);

 MODULE_AUTHOR("Marek Behun <kabel@kernel.org>");
 MODULE_DESCRIPTION("CZ.NIC's Turris Omnia LEDs");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* CZ.NIC's Turris Omnia LEDs driver
	*
	* 2020 by Marek Behún <kabel@kernel.org>
	*/

	#include <linux/i2c.h>
	#include <linux/led-class-multicolor.h>
	#include <linux/module.h>
	#include <linux/mutex.h>
	#include <linux/of.h>
	#include "leds.h"

	#define OMNIA_BOARD_LEDS 12
	#define OMNIA_LED_NUM_CHANNELS 3

	#define CMD_LED_MODE 3
	#define CMD_LED_MODE_LED(l) ((l) & 0x0f)
	#define CMD_LED_MODE_USER 0x10

	#define CMD_LED_STATE 4
	#define CMD_LED_STATE_LED(l) ((l) & 0x0f)
	#define CMD_LED_STATE_ON 0x10

	#define CMD_LED_COLOR 5
	#define CMD_LED_SET_BRIGHTNESS 7
	#define CMD_LED_GET_BRIGHTNESS 8

	struct omnia_led {
	struct led_classdev_mc mc_cdev;
	struct mc_subled subled_info[OMNIA_LED_NUM_CHANNELS];
	int reg;
	};

	#define to_omnia_led(l) container_of(l, struct omnia_led, mc_cdev)

	struct omnia_leds {
	struct i2c_client *client;
	struct mutex lock;
	struct omnia_led leds[];
	};

	static int omnia_led_brightness_set_blocking(struct led_classdev *cdev,
	enum led_brightness brightness)
	{
	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
	struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
	struct omnia_led *led = to_omnia_led(mc_cdev);
	u8 buf[5], state;
	int ret;

	mutex_lock(&leds->lock);

	led_mc_calc_color_components(&led->mc_cdev, brightness);

	buf[0] = CMD_LED_COLOR;
	buf[1] = led->reg;
	buf[2] = mc_cdev->subled_info[0].brightness;
	buf[3] = mc_cdev->subled_info[1].brightness;
	buf[4] = mc_cdev->subled_info[2].brightness;

	state = CMD_LED_STATE_LED(led->reg);
	if (buf[2] \|\| buf[3] \|\| buf[4])
	state \|= CMD_LED_STATE_ON;

	ret = i2c_smbus_write_byte_data(leds->client, CMD_LED_STATE, state);
	if (ret >= 0 && (state & CMD_LED_STATE_ON))
	ret = i2c_master_send(leds->client, buf, 5);

	mutex_unlock(&leds->lock);

	return ret;
	}

	static int omnia_led_register(struct i2c_client client, struct omnia_led led,
	struct device_node *np)
	{
	struct led_init_data init_data = {};
	struct device *dev = &client->dev;
	struct led_classdev *cdev;
	int ret, color;

	ret = of_property_read_u32(np, "reg", &led->reg);
	if (ret \|\| led->reg >= OMNIA_BOARD_LEDS) {
	dev_warn(dev,
	"Node %pOF: must contain 'reg' property with values between 0 and %i\n",
	np, OMNIA_BOARD_LEDS - 1);
	return 0;
	}

	ret = of_property_read_u32(np, "color", &color);
	if (ret \|\| color != LED_COLOR_ID_RGB) {
	dev_warn(dev,
	"Node %pOF: must contain 'color' property with value LED_COLOR_ID_RGB\n",
	np);
	return 0;
	}

	led->subled_info[0].color_index = LED_COLOR_ID_RED;
	led->subled_info[0].channel = 0;
	led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
	led->subled_info[1].channel = 1;
	led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
	led->subled_info[2].channel = 2;

	led->mc_cdev.subled_info = led->subled_info;
	led->mc_cdev.num_colors = OMNIA_LED_NUM_CHANNELS;

	init_data.fwnode = &np->fwnode;

	cdev = &led->mc_cdev.led_cdev;
	cdev->max_brightness = 255;
	cdev->brightness_set_blocking = omnia_led_brightness_set_blocking;

	/* put the LED into software mode */
	ret = i2c_smbus_write_byte_data(client, CMD_LED_MODE,
	CMD_LED_MODE_LED(led->reg) \|
	CMD_LED_MODE_USER);
	if (ret < 0) {
	dev_err(dev, "Cannot set LED %pOF to software mode: %i\n", np,
	ret);
	return ret;
	}

	/* disable the LED */
	ret = i2c_smbus_write_byte_data(client, CMD_LED_STATE,
	CMD_LED_STATE_LED(led->reg));
	if (ret < 0) {
	dev_err(dev, "Cannot set LED %pOF brightness: %i\n", np, ret);
	return ret;
	}

	ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev,
	&init_data);
	if (ret < 0) {
	dev_err(dev, "Cannot register LED %pOF: %i\n", np, ret);
	return ret;
	}

	return 1;
	}

	/*
	* On the front panel of the Turris Omnia router there is also a button which
	* can be used to control the intensity of all the LEDs at once, so that if they
	* are too bright, user can dim them.
	* The microcontroller cycles between 8 levels of this global brightness (from
	* 100% to 0%), but this setting can have any integer value between 0 and 100.
	* It is therefore convenient to be able to change this setting from software.
	* We expose this setting via a sysfs attribute file called "brightness". This
	* file lives in the device directory of the LED controller, not an individual
	* LED, so it should not confuse users.
	*/
	static ssize_t brightness_show(struct device dev, struct device_attribute a,
	char *buf)
	{
	struct i2c_client *client = to_i2c_client(dev);
	int ret;

	ret = i2c_smbus_read_byte_data(client, CMD_LED_GET_BRIGHTNESS);

	if (ret < 0)
	return ret;

	return sysfs_emit(buf, "%d\n", ret);
	}

	static ssize_t brightness_store(struct device dev, struct device_attribute a,
	const char *buf, size_t count)
	{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned long brightness;
	int ret;

	if (kstrtoul(buf, 10, &brightness))
	return -EINVAL;

	if (brightness > 100)
	return -EINVAL;

	ret = i2c_smbus_write_byte_data(client, CMD_LED_SET_BRIGHTNESS,
	(u8)brightness);

	return ret < 0 ? ret : count;
	}
	static DEVICE_ATTR_RW(brightness);

	static struct attribute *omnia_led_controller_attrs[] = {
	&dev_attr_brightness.attr,
	NULL,
	};
	ATTRIBUTE_GROUPS(omnia_led_controller);

	static int omnia_leds_probe(struct i2c_client *client)
	{
	struct device *dev = &client->dev;
	struct device_node np = dev_of_node(dev), child;
	struct omnia_leds *leds;
	struct omnia_led *led;
	int ret, count;

	count = of_get_available_child_count(np);
	if (!count) {
	dev_err(dev, "LEDs are not defined in device tree!\n");
	return -ENODEV;
	} else if (count > OMNIA_BOARD_LEDS) {
	dev_err(dev, "Too many LEDs defined in device tree!\n");
	return -EINVAL;
	}

	leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL);
	if (!leds)
	return -ENOMEM;

	leds->client = client;
	i2c_set_clientdata(client, leds);

	mutex_init(&leds->lock);

	led = &leds->leds[0];
	for_each_available_child_of_node(np, child) {
	ret = omnia_led_register(client, led, child);
	if (ret < 0) {
	of_node_put(child);
	return ret;
	}

	led += ret;
	}

	return 0;
	}

	static void omnia_leds_remove(struct i2c_client *client)
	{
	u8 buf[5];

	/* put all LEDs into default (HW triggered) mode */
	i2c_smbus_write_byte_data(client, CMD_LED_MODE,
	CMD_LED_MODE_LED(OMNIA_BOARD_LEDS));

	/* set all LEDs color to [255, 255, 255] */
	buf[0] = CMD_LED_COLOR;
	buf[1] = OMNIA_BOARD_LEDS;
	buf[2] = 255;
	buf[3] = 255;
	buf[4] = 255;

	i2c_master_send(client, buf, 5);
	}

	static const struct of_device_id of_omnia_leds_match[] = {
	{ .compatible = "cznic,turris-omnia-leds", },
	{},
	};

	static const struct i2c_device_id omnia_id[] = {
	{ "omnia", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, omnia_id);

	static struct i2c_driver omnia_leds_driver = {
	.probe = omnia_leds_probe,
	.remove = omnia_leds_remove,
	.id_table = omnia_id,
	.driver = {
	.name = "leds-turris-omnia",
	.of_match_table = of_omnia_leds_match,
	.dev_groups = omnia_led_controller_groups,
	},
	};

	module_i2c_driver(omnia_leds_driver);

	MODULE_AUTHOR("Marek Behun <kabel@kernel.org>");
	MODULE_DESCRIPTION("CZ.NIC's Turris Omnia LEDs");
	MODULE_LICENSE("GPL v2");