leds: lm3601x: Introduce the lm3601x LED driver

Introduce the family of LED devices that can
drive a torch, strobe or IR LED.

The LED driver can be configured with a strobe
timer to execute a strobe flash.  The IR LED
brightness is controlled via the torch brightness
register.

The data sheet for each the LM36010 and LM36011
LED drivers can be found here:
http://www.ti.com/product/LM36010
http://www.ti.com/product/LM36011

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

drivers/leds/Kconfig

@@ -158,6 +158,15 @@ config LEDS_LM3692X
 	  This option enables support for the TI LM3692x family
 	  of white LED string drivers used for backlighting.
 
+config LEDS_LM3601X
+	tristate "LED support for LM3601x Chips"
+	depends on LEDS_CLASS && I2C
+	depends on LEDS_CLASS_FLASH
+	select REGMAP_I2C
+	help
+	  This option enables support for the TI LM3601x family
+	  of flash, torch and indicator classes.
+
 config LEDS_LOCOMO
 	tristate "LED Support for Locomo device"
 	depends on LEDS_CLASS

drivers/leds/Makefile

@@ -77,6 +77,7 @@ obj-$(CONFIG_LEDS_NIC78BX)		+= leds-nic78bx.o
 obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o
 obj-$(CONFIG_LEDS_LM3692X)		+= leds-lm3692x.o
 obj-$(CONFIG_LEDS_SC27XX_BLTC)		+= leds-sc27xx-bltc.o
+obj-$(CONFIG_LEDS_LM3601X)		+= leds-lm3601x.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_CR0014114)		+= leds-cr0014114.o

drivers/leds/leds-lm3601x.c

@@ -0,0 +1,487 @@
+// SPDX-License-Identifier: GPL-2.0
+// Flash and torch driver for Texas Instruments LM3601X LED
+// Flash driver chip family
+// Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <uapi/linux/uleds.h>
+
+#define LM3601X_LED_IR		0x0
+#define LM3601X_LED_TORCH	0x1
+
+/* Registers */
+#define LM3601X_ENABLE_REG	0x01
+#define LM3601X_CFG_REG		0x02
+#define LM3601X_LED_FLASH_REG	0x03
+#define LM3601X_LED_TORCH_REG	0x04
+#define LM3601X_FLAGS_REG	0x05
+#define LM3601X_DEV_ID_REG	0x06
+
+#define LM3601X_SW_RESET	BIT(7)
+
+/* Enable Mode bits */
+#define LM3601X_MODE_STANDBY	0x00
+#define LM3601X_MODE_IR_DRV	BIT(0)
+#define LM3601X_MODE_TORCH	BIT(1)
+#define LM3601X_MODE_STROBE	(BIT(0) | BIT(1))
+#define LM3601X_STRB_EN		BIT(2)
+#define LM3601X_STRB_EDGE_TRIG	BIT(3)
+#define LM3601X_IVFM_EN		BIT(4)
+
+#define LM36010_BOOST_LIMIT_28	BIT(5)
+#define LM36010_BOOST_FREQ_4MHZ	BIT(6)
+#define LM36010_BOOST_MODE_PASS	BIT(7)
+
+/* Flag Mask */
+#define LM3601X_FLASH_TIME_OUT	BIT(0)
+#define LM3601X_UVLO_FAULT	BIT(1)
+#define LM3601X_THERM_SHUTDOWN	BIT(2)
+#define LM3601X_THERM_CURR	BIT(3)
+#define LM36010_CURR_LIMIT	BIT(4)
+#define LM3601X_SHORT_FAULT	BIT(5)
+#define LM3601X_IVFM_TRIP	BIT(6)
+#define LM36010_OVP_FAULT	BIT(7)
+
+#define LM3601X_MAX_TORCH_I_UA	376000
+#define LM3601X_MIN_TORCH_I_UA	2400
+#define LM3601X_TORCH_REG_DIV	2965
+
+#define LM3601X_MAX_STROBE_I_UA	1500000
+#define LM3601X_MIN_STROBE_I_UA	11000
+#define LM3601X_STROBE_REG_DIV	11800
+
+#define LM3601X_TIMEOUT_MASK	0x1e
+#define LM3601X_ENABLE_MASK	(LM3601X_MODE_IR_DRV | LM3601X_MODE_TORCH)
+
+#define LM3601X_LOWER_STEP_US	40000
+#define LM3601X_UPPER_STEP_US	200000
+#define LM3601X_MIN_TIMEOUT_US	40000
+#define LM3601X_MAX_TIMEOUT_US	1600000
+#define LM3601X_TIMEOUT_XOVER_US 400000
+
+enum lm3601x_type {
+	CHIP_LM36010 = 0,
+	CHIP_LM36011,
+};
+
+/**
+ * struct lm3601x_led -
+ * @fled_cdev: flash LED class device pointer
+ * @client: Pointer to the I2C client
+ * @regmap: Devices register map
+ * @lock: Lock for reading/writing the device
+ * @led_name: LED label for the Torch or IR LED
+ * @flash_timeout: the timeout for the flash
+ * @last_flag: last known flags register value
+ * @torch_current_max: maximum current for the torch
+ * @flash_current_max: maximum current for the flash
+ * @max_flash_timeout: maximum timeout for the flash
+ * @led_mode: The mode to enable either IR or Torch
+ */
+struct lm3601x_led {
+	struct led_classdev_flash fled_cdev;
+	struct i2c_client *client;
+	struct regmap *regmap;
+	struct mutex lock;
+
+	char led_name[LED_MAX_NAME_SIZE];
+
+	unsigned int flash_timeout;
+	unsigned int last_flag;
+
+	u32 torch_current_max;
+	u32 flash_current_max;
+	u32 max_flash_timeout;
+
+	u32 led_mode;
+};
+
+static const struct reg_default lm3601x_regmap_defs[] = {
+	{ LM3601X_ENABLE_REG, 0x20 },
+	{ LM3601X_CFG_REG, 0x15 },
+	{ LM3601X_LED_FLASH_REG, 0x00 },
+	{ LM3601X_LED_TORCH_REG, 0x00 },
+};
+
+static bool lm3601x_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case LM3601X_FLAGS_REG:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config lm3601x_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = LM3601X_DEV_ID_REG,
+	.reg_defaults = lm3601x_regmap_defs,
+	.num_reg_defaults = ARRAY_SIZE(lm3601x_regmap_defs),
+	.cache_type = REGCACHE_RBTREE,
+	.volatile_reg = lm3601x_volatile_reg,
+};
+
+static struct lm3601x_led *fled_cdev_to_led(struct led_classdev_flash *fled_cdev)
+{
+	return container_of(fled_cdev, struct lm3601x_led, fled_cdev);
+}
+
+static int lm3601x_read_faults(struct lm3601x_led *led)
+{
+	int flags_val;
+	int ret;
+
+	ret = regmap_read(led->regmap, LM3601X_FLAGS_REG, &flags_val);
+	if (ret < 0)
+		return -EIO;
+
+	led->last_flag = 0;
+
+	if (flags_val & LM36010_OVP_FAULT)
+		led->last_flag |= LED_FAULT_OVER_VOLTAGE;
+
+	if (flags_val & (LM3601X_THERM_SHUTDOWN | LM3601X_THERM_CURR))
+		led->last_flag |= LED_FAULT_OVER_TEMPERATURE;
+
+	if (flags_val & LM3601X_SHORT_FAULT)
+		led->last_flag |= LED_FAULT_SHORT_CIRCUIT;
+
+	if (flags_val & LM36010_CURR_LIMIT)
+		led->last_flag |= LED_FAULT_OVER_CURRENT;
+
+	if (flags_val & LM3601X_UVLO_FAULT)
+		led->last_flag |= LED_FAULT_UNDER_VOLTAGE;
+
+	if (flags_val & LM3601X_IVFM_TRIP)
+		led->last_flag |= LED_FAULT_INPUT_VOLTAGE;
+
+	if (flags_val & LM3601X_THERM_SHUTDOWN)
+		led->last_flag |= LED_FAULT_LED_OVER_TEMPERATURE;
+
+	return led->last_flag;
+}
+
+static int lm3601x_brightness_set(struct led_classdev *cdev,
+					enum led_brightness brightness)
+{
+	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(cdev);
+	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+	int ret, led_mode_val;
+
+	mutex_lock(&led->lock);
+
+	ret = lm3601x_read_faults(led);
+	if (ret < 0)
+		goto out;
+
+	if (led->led_mode == LM3601X_LED_TORCH)
+		led_mode_val = LM3601X_MODE_TORCH;
+	else
+		led_mode_val = LM3601X_MODE_IR_DRV;
+
+	if (brightness == LED_OFF) {
+		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+					led_mode_val, LED_OFF);
+		goto out;
+	}
+
+	ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+				LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
+				led_mode_val);
+out:
+	mutex_unlock(&led->lock);
+	return ret;
+}
+
+static int lm3601x_strobe_set(struct led_classdev_flash *fled_cdev,
+				bool state)
+{
+	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+	int timeout_reg_val;
+	int current_timeout;
+	int ret;
+
+	mutex_lock(&led->lock);
+
+	ret = regmap_read(led->regmap, LM3601X_CFG_REG, &current_timeout);
+	if (ret < 0)
+		goto out;
+
+	if (led->flash_timeout >= LM3601X_TIMEOUT_XOVER_US)
+		timeout_reg_val = led->flash_timeout / LM3601X_UPPER_STEP_US + 0x07;
+	else
+		timeout_reg_val = led->flash_timeout / LM3601X_LOWER_STEP_US - 0x01;
+
+	if (led->flash_timeout != current_timeout)
+		ret = regmap_update_bits(led->regmap, LM3601X_CFG_REG,
+					LM3601X_TIMEOUT_MASK, timeout_reg_val);
+
+	if (state)
+		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+					LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
+					LM3601X_MODE_STROBE);
+	else
+		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+					LM3601X_MODE_STROBE, LED_OFF);
+
+	ret = lm3601x_read_faults(led);
+out:
+	mutex_unlock(&led->lock);
+	return ret;
+}
+
+static int lm3601x_flash_brightness_set(struct led_classdev_flash *fled_cdev,
+					u32 brightness)
+{
+	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+	u8 brightness_val;
+	int ret;
+
+	mutex_lock(&led->lock);
+	ret = lm3601x_read_faults(led);
+	if (ret < 0)
+		goto out;
+
+	if (brightness == LED_OFF) {
+		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+					LM3601X_MODE_STROBE, LED_OFF);
+		goto out;
+	}
+
+	brightness_val = brightness / LM3601X_STROBE_REG_DIV;
+
+	ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
+out:
+	mutex_unlock(&led->lock);
+	return ret;
+}
+
+static int lm3601x_flash_timeout_set(struct led_classdev_flash *fled_cdev,
+				u32 timeout)
+{
+	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+
+	mutex_lock(&led->lock);
+
+	led->flash_timeout = timeout;
+
+	mutex_unlock(&led->lock);
+
+	return 0;
+}
+
+static int lm3601x_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
+{
+	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+	int strobe_state;
+	int ret;
+
+	mutex_lock(&led->lock);
+
+	ret = regmap_read(led->regmap, LM3601X_ENABLE_REG, &strobe_state);
+	if (ret < 0)
+		goto out;
+
+	*state = strobe_state & LM3601X_MODE_STROBE;
+
+out:
+	mutex_unlock(&led->lock);
+	return ret;
+}
+
+static int lm3601x_flash_fault_get(struct led_classdev_flash *fled_cdev,
+				u32 *fault)
+{
+	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
+
+	lm3601x_read_faults(led);
+
+	*fault = led->last_flag;
+
+	return 0;
+}
+
+static const struct led_flash_ops flash_ops = {
+	.flash_brightness_set	= lm3601x_flash_brightness_set,
+	.strobe_set		= lm3601x_strobe_set,
+	.strobe_get		= lm3601x_strobe_get,
+	.timeout_set		= lm3601x_flash_timeout_set,
+	.fault_get		= lm3601x_flash_fault_get,
+};
+
+static int lm3601x_register_leds(struct lm3601x_led *led)
+{
+	struct led_classdev *led_cdev;
+	struct led_flash_setting *setting;
+
+	led->fled_cdev.ops = &flash_ops;
+
+	setting = &led->fled_cdev.timeout;
+	setting->min = LM3601X_MIN_TIMEOUT_US;
+	setting->max = led->max_flash_timeout;
+	setting->step = LM3601X_LOWER_STEP_US;
+	setting->val = led->max_flash_timeout;
+
+	setting = &led->fled_cdev.brightness;
+	setting->min = LM3601X_MIN_STROBE_I_UA;
+	setting->max = led->flash_current_max;
+	setting->step = LM3601X_TORCH_REG_DIV;
+	setting->val = led->flash_current_max;
+
+	led_cdev = &led->fled_cdev.led_cdev;
+	led_cdev->name = led->led_name;
+	led_cdev->brightness_set_blocking = lm3601x_brightness_set;
+	led_cdev->max_brightness = DIV_ROUND_UP(led->torch_current_max,
+						LM3601X_TORCH_REG_DIV);
+	led_cdev->flags |= LED_DEV_CAP_FLASH;
+
+	return led_classdev_flash_register(&led->client->dev, &led->fled_cdev);
+}
+
+static int lm3601x_parse_node(struct lm3601x_led *led)
+{
+	struct fwnode_handle *child = NULL;
+	int ret = -ENODEV;
+	const char *name;
+
+	child = device_get_next_child_node(&led->client->dev, child);
+	if (!child) {
+		dev_err(&led->client->dev, "No LED Child node\n");
+		return ret;
+	}
+
+	ret = fwnode_property_read_u32(child, "reg", &led->led_mode);
+	if (ret) {
+		dev_err(&led->client->dev, "reg DT property missing\n");
+		goto out_err;
+	}
+
+	if (led->led_mode > LM3601X_LED_TORCH ||
+	    led->led_mode < LM3601X_LED_IR) {
+		dev_warn(&led->client->dev, "Invalid led mode requested\n");
+		ret = -EINVAL;
+		goto out_err;
+	}
+
+	ret = fwnode_property_read_string(child, "label", &name);
+	if (ret) {
+		if (led->led_mode == LM3601X_LED_TORCH)
+			name = "torch";
+		else
+			name = "infrared";
+	}
+
+	snprintf(led->led_name, sizeof(led->led_name),
+		"%s:%s", led->client->name, name);
+
+	ret = fwnode_property_read_u32(child, "led-max-microamp",
+					&led->torch_current_max);
+	if (ret) {
+		dev_warn(&led->client->dev,
+			"led-max-microamp DT property missing\n");
+		goto out_err;
+	}
+
+	ret = fwnode_property_read_u32(child, "flash-max-microamp",
+				&led->flash_current_max);
+	if (ret) {
+		dev_warn(&led->client->dev,
+			 "flash-max-microamp DT property missing\n");
+		goto out_err;
+	}
+
+	ret = fwnode_property_read_u32(child, "flash-max-timeout-us",
+				&led->max_flash_timeout);
+	if (ret) {
+		dev_warn(&led->client->dev,
+			 "flash-max-timeout-us DT property missing\n");
+		goto out_err;
+	}
+
+out_err:
+	fwnode_handle_put(child);
+	return ret;
+}
+
+static int lm3601x_probe(struct i2c_client *client)
+{
+	struct lm3601x_led *led;
+	int ret;
+
+	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	led->client = client;
+	i2c_set_clientdata(client, led);
+
+	ret = lm3601x_parse_node(led);
+	if (ret)
+		return -ENODEV;
+
+	led->regmap = devm_regmap_init_i2c(client, &lm3601x_regmap);
+	if (IS_ERR(led->regmap)) {
+		ret = PTR_ERR(led->regmap);
+		dev_err(&client->dev,
+			"Failed to allocate register map: %d\n", ret);
+		return ret;
+	}
+
+	mutex_init(&led->lock);
+
+	return lm3601x_register_leds(led);
+}
+
+static int lm3601x_remove(struct i2c_client *client)
+{
+	struct lm3601x_led *led = i2c_get_clientdata(client);
+
+	led_classdev_flash_unregister(&led->fled_cdev);
+	mutex_destroy(&led->lock);
+
+	return regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
+			   LM3601X_ENABLE_MASK,
+			   LM3601X_MODE_STANDBY);
+}
+
+static const struct i2c_device_id lm3601x_id[] = {
+	{ "LM36010", CHIP_LM36010 },
+	{ "LM36011", CHIP_LM36011 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lm3601x_id);
+
+static const struct of_device_id of_lm3601x_leds_match[] = {
+	{ .compatible = "ti,lm36010", },
+	{ .compatible = "ti,lm36011", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, of_lm3601x_leds_match);
+
+static struct i2c_driver lm3601x_i2c_driver = {
+	.driver = {
+		.name = "lm3601x",
+		.of_match_table = of_lm3601x_leds_match,
+	},
+	.probe_new = lm3601x_probe,
+	.remove = lm3601x_remove,
+	.id_table = lm3601x_id,
+};
+module_i2c_driver(lm3601x_i2c_driver);
+
+MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3601X");
+MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
+MODULE_LICENSE("GPL v2");