leds: lp8864: Add support for Texas Instruments LP8864, LP8864S, LP8866 LED-backlights (e14d8792) · Commits · git / linux-nf

MAINTAINERS

+7 −0

Original line number	Diff line number	Diff line
		@@ -23240,6 +23240,13 @@ S: Supported
		F: Documentation/devicetree/bindings/iio/dac/ti,dac7612.yaml
		F: drivers/iio/dac/ti-dac7612.c

		TEXAS INSTRUMENTS' LB8864 LED BACKLIGHT DRIVER
		M: Alexander Sverdlin <alexander.sverdlin@siemens.com>
		L: linux-leds@vger.kernel.org
		S: Maintained
		F: Documentation/devicetree/bindings/leds/backlight/ti,lp8864.yaml
		F: drivers/leds/leds-lp8864.c

		TEXAS INSTRUMENTS' SYSTEM CONTROL INTERFACE (TISCI) PROTOCOL DRIVER
		M: Nishanth Menon <nm@ti.com>
		M: Tero Kristo <kristo@kernel.org>

drivers/leds/Kconfig

+12 −0

Original line number	Diff line number	Diff line
		@@ -513,6 +513,18 @@ config LEDS_LP8860
		on the LP8860 4 channel LED driver using the I2C communication
		bus.

		config LEDS_LP8864
		tristate "LED support for the TI LP8864/LP8866 4/6 channel LED drivers"
		depends on LEDS_CLASS && I2C && OF
		select REGMAP_I2C
		help
		If you say yes here you get support for the TI LP8864-Q1,
		LP8864S-Q1, LP8866-Q1, LP8866S-Q1 4/6 channel LED backlight
		drivers with I2C interface.

		To compile this driver as a module, choose M here: the
		module will be called leds-lp8864.

		config LEDS_CLEVO_MAIL
		tristate "Mail LED on Clevo notebook"
		depends on LEDS_CLASS && BROKEN

drivers/leds/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -57,6 +57,7 @@ obj-$(CONFIG_LEDS_LP55XX_COMMON) += leds-lp55xx-common.o
		obj-$(CONFIG_LEDS_LP8501) += leds-lp8501.o
		obj-$(CONFIG_LEDS_LP8788) += leds-lp8788.o
		obj-$(CONFIG_LEDS_LP8860) += leds-lp8860.o
		obj-$(CONFIG_LEDS_LP8864) += leds-lp8864.o
		obj-$(CONFIG_LEDS_LT3593) += leds-lt3593.o
		obj-$(CONFIG_LEDS_MAX5970) += leds-max5970.o
		obj-$(CONFIG_LEDS_MAX77650) += leds-max77650.o

drivers/leds/leds-lp8864.c

0 → 100644

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Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* TI LP8864/LP8866 4/6 Channel LED Driver
		*
		* Copyright (C) 2024 Siemens AG
		*
		* Based on LP8860 driver by Dan Murphy <dmurphy@ti.com>
		*/

		#include <linux/gpio/consumer.h>
		#include <linux/i2c.h>
		#include <linux/init.h>
		#include <linux/leds.h>
		#include <linux/module.h>
		#include <linux/mutex.h>
		#include <linux/of.h>
		#include <linux/regmap.h>
		#include <linux/regulator/consumer.h>
		#include <linux/slab.h>

		#define LP8864_BRT_CONTROL 0x00
		#define LP8864_USER_CONFIG1 0x04
		#define LP8864_BRT_MODE_MASK GENMASK(9, 8)
		#define LP8864_BRT_MODE_REG BIT(9) /* Brightness control by DISPLAY_BRT reg */
		#define LP8864_SUPPLY_STATUS 0x0e
		#define LP8864_BOOST_STATUS 0x10
		#define LP8864_LED_STATUS 0x12
		#define LP8864_LED_STATUS_WR_MASK GENMASK(14, 9) /* Writeable bits in the LED_STATUS reg */

		/* Textual meaning for status bits, starting from bit 1 */
		static const char *const lp8864_supply_status_msg[] = {
		"Vin under-voltage fault",
		"Vin over-voltage fault",
		"Vdd under-voltage fault",
		"Vin over-current fault",
		"Missing charge pump fault",
		"Charge pump fault",
		"Missing boost sync fault",
		"CRC error fault ",
		};

		/* Textual meaning for status bits, starting from bit 1 */
		static const char *const lp8864_boost_status_msg[] = {
		"Boost OVP low fault",
		"Boost OVP high fault",
		"Boost over-current fault",
		"Missing boost FSET resistor fault",
		"Missing MODE SEL resistor fault",
		"Missing LED resistor fault",
		"ISET resistor short to ground fault",
		"Thermal shutdown fault",
		};

		/* Textual meaning for every register bit */
		static const char *const lp8864_led_status_msg[] = {
		"LED 1 fault",
		"LED 2 fault",
		"LED 3 fault",
		"LED 4 fault",
		"LED 5 fault",
		"LED 6 fault",
		"LED open fault",
		"LED internal short fault",
		"LED short to GND fault",
		NULL, NULL, NULL,
		"Invalid string configuration fault",
		NULL,
		"I2C time out fault",
		};

		/**
		* struct lp8864_led
		* @client: Pointer to the I2C client
		* @led_dev: led class device pointer
		* @regmap: Devices register map
		* @led_status_mask: Helps to report LED fault only once
		*/
		struct lp8864_led {
		struct i2c_client *client;
		struct led_classdev led_dev;
		struct regmap *regmap;
		u16 led_status_mask;
		};

		static int lp8864_fault_check(struct lp8864_led *led)
		{
		int ret, i;
		unsigned int val;

		ret = regmap_read(led->regmap, LP8864_SUPPLY_STATUS, &val);
		if (ret)
		goto err;

		/* Odd bits are status bits, even bits are clear bits */
		for (i = 0; i < ARRAY_SIZE(lp8864_supply_status_msg); i++)
		if (val & BIT(i * 2 + 1))
		dev_warn(&led->client->dev, "%s\n", lp8864_supply_status_msg[i]);

		/*
		* Clear bits have an index preceding the corresponding Status bits;
		* both have to be written "1" simultaneously to clear the corresponding
		* Status bit.
		*/
		if (val)
		ret = regmap_write(led->regmap, LP8864_SUPPLY_STATUS, val >> 1 \| val);
		if (ret)
		goto err;

		ret = regmap_read(led->regmap, LP8864_BOOST_STATUS, &val);
		if (ret)
		goto err;

		/* Odd bits are status bits, even bits are clear bits */
		for (i = 0; i < ARRAY_SIZE(lp8864_boost_status_msg); i++)
		if (val & BIT(i * 2 + 1))
		dev_warn(&led->client->dev, "%s\n", lp8864_boost_status_msg[i]);

		if (val)
		ret = regmap_write(led->regmap, LP8864_BOOST_STATUS, val >> 1 \| val);
		if (ret)
		goto err;

		ret = regmap_read(led->regmap, LP8864_LED_STATUS, &val);
		if (ret)
		goto err;

		/*
		* Clear already reported faults that maintain their value until device
		* power-down
		*/
		val &= ~led->led_status_mask;

		for (i = 0; i < ARRAY_SIZE(lp8864_led_status_msg); i++)
		if (lp8864_led_status_msg[i] && val & BIT(i))
		dev_warn(&led->client->dev, "%s\n", lp8864_led_status_msg[i]);

		/*
		* Mark those which maintain their value until device power-down as
		* "already reported"
		*/
		led->led_status_mask \|= val & ~LP8864_LED_STATUS_WR_MASK;

		/*
		* Only bits 14, 12, 10 have to be cleared here, but others are RO,
		* we don't care what we write to them.
		*/
		if (val & LP8864_LED_STATUS_WR_MASK)
		ret = regmap_write(led->regmap, LP8864_LED_STATUS, val >> 1 \| val);
		if (ret)
		goto err;

		return 0;

		err:
		dev_err(&led->client->dev, "Failed to read/clear faults (%pe)\n", ERR_PTR(ret));

		return ret;
		}

		static int lp8864_brightness_set(struct led_classdev *led_cdev,
		enum led_brightness brt_val)
		{
		struct lp8864_led *led = container_of(led_cdev, struct lp8864_led, led_dev);
		/* Scale 0..LED_FULL into 16-bit HW brightness */
		unsigned int val = brt_val * 0xffff / LED_FULL;
		int ret;

		ret = lp8864_fault_check(led);
		if (ret)
		return ret;

		ret = regmap_write(led->regmap, LP8864_BRT_CONTROL, val);
		if (ret)
		dev_err(&led->client->dev, "Failed to write brightness value\n");

		return ret;
		}

		static enum led_brightness lp8864_brightness_get(struct led_classdev *led_cdev)
		{
		struct lp8864_led *led = container_of(led_cdev, struct lp8864_led, led_dev);
		unsigned int val;
		int ret;

		ret = regmap_read(led->regmap, LP8864_BRT_CONTROL, &val);
		if (ret) {
		dev_err(&led->client->dev, "Failed to read brightness value\n");
		return ret;
		}

		/* Scale 16-bit HW brightness into 0..LED_FULL */
		return val * LED_FULL / 0xffff;
		}

		static const struct regmap_config lp8864_regmap_config = {
		.reg_bits = 8,
		.val_bits = 16,
		.val_format_endian = REGMAP_ENDIAN_LITTLE,
		};

		static void lp8864_disable_gpio(void *data)
		{
		struct gpio_desc *gpio = data;

		gpiod_set_value(gpio, 0);
		}

		static int lp8864_probe(struct i2c_client *client)
		{
		int ret;
		struct lp8864_led *led;
		struct device_node *np = dev_of_node(&client->dev);
		struct device_node *child_node;
		struct led_init_data init_data = {};
		struct gpio_desc *enable_gpio;

		led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
		if (!led)
		return -ENOMEM;

		child_node = of_get_next_available_child(np, NULL);
		if (!child_node) {
		dev_err(&client->dev, "No LED function defined\n");
		return -EINVAL;
		}

		ret = devm_regulator_get_enable_optional(&client->dev, "vled");
		if (ret && ret != -ENODEV)
		return dev_err_probe(&client->dev, ret, "Failed to enable vled regulator\n");

		enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", GPIOD_OUT_HIGH);
		if (IS_ERR(enable_gpio))
		return dev_err_probe(&client->dev, PTR_ERR(enable_gpio),
		"Failed to get enable GPIO\n");

		ret = devm_add_action_or_reset(&client->dev, lp8864_disable_gpio, enable_gpio);
		if (ret)
		return ret;

		led->client = client;
		led->led_dev.brightness_set_blocking = lp8864_brightness_set;
		led->led_dev.brightness_get = lp8864_brightness_get;

		led->regmap = devm_regmap_init_i2c(client, &lp8864_regmap_config);
		if (IS_ERR(led->regmap))
		return dev_err_probe(&client->dev, PTR_ERR(led->regmap),
		"Failed to allocate regmap\n");

		/* Control brightness by DISPLAY_BRT register */
		ret = regmap_update_bits(led->regmap, LP8864_USER_CONFIG1, LP8864_BRT_MODE_MASK,
		LP8864_BRT_MODE_REG);
		if (ret) {
		dev_err(&led->client->dev, "Failed to set brightness control mode\n");
		return ret;
		}

		ret = lp8864_fault_check(led);
		if (ret)
		return ret;

		init_data.fwnode = of_fwnode_handle(child_node);
		init_data.devicename = "lp8864";
		init_data.default_label = ":display_cluster";

		ret = devm_led_classdev_register_ext(&client->dev, &led->led_dev, &init_data);
		if (ret)
		dev_err(&client->dev, "Failed to register LED device (%pe)\n", ERR_PTR(ret));

		return ret;
		}

		static const struct i2c_device_id lp8864_id[] = {
		{ "lp8864" },
		{}
		};
		MODULE_DEVICE_TABLE(i2c, lp8864_id);

		static const struct of_device_id of_lp8864_leds_match[] = {
		{ .compatible = "ti,lp8864" },
		{}
		};
		MODULE_DEVICE_TABLE(of, of_lp8864_leds_match);

		static struct i2c_driver lp8864_driver = {
		.driver = {
		.name = "lp8864",
		.of_match_table = of_lp8864_leds_match,
		},
		.probe = lp8864_probe,
		.id_table = lp8864_id,
		};
		module_i2c_driver(lp8864_driver);

		MODULE_DESCRIPTION("Texas Instruments LP8864/LP8866 LED driver");
		MODULE_AUTHOR("Alexander Sverdlin <alexander.sverdlin@siemens.com>");
		MODULE_LICENSE("GPL");