// SPDX-License-Identifier: GPL-2.0 // TI LM3692x LED chip family driver // Copyright (C) 2017-18 Texas Instruments Incorporated - http://www.ti.com/ #include <linux/gpio/consumer.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/leds.h> #include <linux/log2.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/of.h> #include <linux/of_gpio.h> #include <linux/regmap.h> #include <linux/regulator/consumer.h> #include <linux/slab.h> #define LM36922_MODEL 0 #define LM36923_MODEL 1 #define LM3692X_REV 0x0 #define LM3692X_RESET 0x1 #define LM3692X_EN 0x10 #define LM3692X_BRT_CTRL 0x11 #define LM3692X_PWM_CTRL 0x12 #define LM3692X_BOOST_CTRL 0x13 #define LM3692X_AUTO_FREQ_HI 0x15 #define LM3692X_AUTO_FREQ_LO 0x16 #define LM3692X_BL_ADJ_THRESH 0x17 #define LM3692X_BRT_LSB 0x18 #define LM3692X_BRT_MSB 0x19 #define LM3692X_FAULT_CTRL 0x1e #define LM3692X_FAULT_FLAGS 0x1f #define LM3692X_SW_RESET BIT(0) #define LM3692X_DEVICE_EN BIT(0) #define LM3692X_LED1_EN BIT(1) #define LM3692X_LED2_EN BIT(2) #define LM36923_LED3_EN BIT(3) #define LM3692X_ENABLE_MASK (LM3692X_DEVICE_EN | LM3692X_LED1_EN | \ LM3692X_LED2_EN | LM36923_LED3_EN) /* Brightness Control Bits */ #define LM3692X_BL_ADJ_POL BIT(0) #define LM3692X_RAMP_RATE_125us 0x00 #define LM3692X_RAMP_RATE_250us BIT(1) #define LM3692X_RAMP_RATE_500us BIT(2) #define LM3692X_RAMP_RATE_1ms (BIT(1) | BIT(2)) #define LM3692X_RAMP_RATE_2ms BIT(3) #define LM3692X_RAMP_RATE_4ms (BIT(3) | BIT(1)) #define LM3692X_RAMP_RATE_8ms (BIT(2) | BIT(3)) #define LM3692X_RAMP_RATE_16ms (BIT(1) | BIT(2) | BIT(3)) #define LM3692X_RAMP_EN BIT(4) #define LM3692X_BRHT_MODE_REG 0x00 #define LM3692X_BRHT_MODE_PWM BIT(5) #define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6) #define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6)) #define LM3692X_MAP_MODE_EXP BIT(7) /* PWM Register Bits */ #define LM3692X_PWM_FILTER_100 BIT(0) #define LM3692X_PWM_FILTER_150 BIT(1) #define LM3692X_PWM_FILTER_200 (BIT(0) | BIT(1)) #define LM3692X_PWM_HYSTER_1LSB BIT(2) #define LM3692X_PWM_HYSTER_2LSB BIT(3) #define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2)) #define LM3692X_PWM_HYSTER_4LSB BIT(4) #define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2)) #define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3)) #define LM3692X_PWM_POLARITY BIT(5) #define LM3692X_PWM_SAMP_4MHZ BIT(6) #define LM3692X_PWM_SAMP_24MHZ BIT(7) /* Boost Control Bits */ #define LM3692X_OCP_PROT_1A BIT(0) #define LM3692X_OCP_PROT_1_25A BIT(1) #define LM3692X_OCP_PROT_1_5A (BIT(0) | BIT(1)) #define LM3692X_OVP_21V BIT(2) #define LM3692X_OVP_25V BIT(3) #define LM3692X_OVP_29V (BIT(2) | BIT(3)) #define LM3692X_MIN_IND_22UH BIT(4) #define LM3692X_BOOST_SW_1MHZ BIT(5) #define LM3692X_BOOST_SW_NO_SHIFT BIT(6) /* Fault Control Bits */ #define LM3692X_FAULT_CTRL_OVP BIT(0) #define LM3692X_FAULT_CTRL_OCP BIT(1) #define LM3692X_FAULT_CTRL_TSD BIT(2) #define LM3692X_FAULT_CTRL_OPEN BIT(3) /* Fault Flag Bits */ #define LM3692X_FAULT_FLAG_OVP BIT(0) #define LM3692X_FAULT_FLAG_OCP BIT(1) #define LM3692X_FAULT_FLAG_TSD BIT(2) #define LM3692X_FAULT_FLAG_SHRT BIT(3) #define LM3692X_FAULT_FLAG_OPEN BIT(4) /** * struct lm3692x_led - * @lock - Lock for reading/writing the device * @client - Pointer to the I2C client * @led_dev - LED class device pointer * @regmap - Devices register map * @enable_gpio - VDDIO/EN gpio to enable communication interface * @regulator - LED supply regulator pointer * @led_enable - LED sync to be enabled * @model_id - Current device model ID enumerated */ struct lm3692x_led { struct mutex lock; struct i2c_client *client; struct led_classdev led_dev; struct regmap *regmap; struct gpio_desc *enable_gpio; struct regulator *regulator; int led_enable; int model_id; u8 boost_ctrl, brightness_ctrl; bool enabled; }; static const struct reg_default lm3692x_reg_defs[] = { {LM3692X_EN, 0xf}, {LM3692X_BRT_CTRL, 0x61}, {LM3692X_PWM_CTRL, 0x73}, {LM3692X_BOOST_CTRL, 0x6f}, {LM3692X_AUTO_FREQ_HI, 0x0}, {LM3692X_AUTO_FREQ_LO, 0x0}, {LM3692X_BL_ADJ_THRESH, 0x0}, {LM3692X_BRT_LSB, 0x7}, {LM3692X_BRT_MSB, 0xff}, {LM3692X_FAULT_CTRL, 0x7}, }; static const struct regmap_config lm3692x_regmap_config = { .reg_bits = 8, .val_bits = 8, .max_register = LM3692X_FAULT_FLAGS, .reg_defaults = lm3692x_reg_defs, .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs), .cache_type = REGCACHE_RBTREE, }; static int lm3692x_fault_check(struct lm3692x_led *led) { int ret; unsigned int read_buf; ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); if (ret) return ret; if (read_buf) dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf); /* The first read may clear the fault. Check again to see if the fault * still exits and return that value. */ regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); if (read_buf) dev_err(&led->client->dev, "Second read of fault flags 0x%X\n", read_buf); return read_buf; } static int lm3692x_leds_enable(struct lm3692x_led *led) { int enable_state; int ret, reg_ret; if (led->enabled) return 0; if (led->regulator) { ret = regulator_enable(led->regulator); if (ret) { dev_err(&led->client->dev, "Failed to enable regulator: %d\n", ret); return ret; } } if (led->enable_gpio) gpiod_direction_output(led->enable_gpio, 1); ret = lm3692x_fault_check(led); if (ret) { dev_err(&led->client->dev, "Cannot read/clear faults: %d\n", ret); goto out; } ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00); if (ret) goto out; /* * For glitch free operation, the following data should * only be written while LEDx enable bits are 0 and the device enable * bit is set to 1. * per Section 7.5.14 of the data sheet */ ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN); if (ret) goto out; /* Set the brightness to 0 so when enabled the LEDs do not come * on with full brightness. */ ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0); if (ret) goto out; ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0); if (ret) goto out; ret = regmap_write(led->regmap, LM3692X_PWM_CTRL, LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ); if (ret) goto out; ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, led->boost_ctrl); if (ret) goto out; ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00); if (ret) goto out; ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00); if (ret) goto out; ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00); if (ret) goto out; ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN); if (ret) goto out; switch (led->led_enable) { case 0: default: if (led->model_id == LM36923_MODEL) enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN | LM36923_LED3_EN; else enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN; break; case 1: enable_state = LM3692X_LED1_EN; break; case 2: enable_state = LM3692X_LED2_EN; break; case 3: if (led->model_id == LM36923_MODEL) { enable_state = LM36923_LED3_EN; break; } ret = -EINVAL; dev_err(&led->client->dev, "LED3 sync not available on this device\n"); goto out; } ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK, enable_state | LM3692X_DEVICE_EN); led->enabled = true; return ret; out: dev_err(&led->client->dev, "Fail writing initialization values\n"); if (led->enable_gpio) gpiod_direction_output(led->enable_gpio, 0); if (led->regulator) { reg_ret = regulator_disable(led->regulator); if (reg_ret) dev_err(&led->client->dev, "Failed to disable regulator: %d\n", reg_ret); } return ret; } static int lm3692x_leds_disable(struct lm3692x_led *led) { int ret; if (!led->enabled) return 0; ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0); if (ret) { dev_err(&led->client->dev, "Failed to disable regulator: %d\n", ret); return ret; } if (led->enable_gpio) gpiod_direction_output(led->enable_gpio, 0); if (led->regulator) { ret = regulator_disable(led->regulator); if (ret) dev_err(&led->client->dev, "Failed to disable regulator: %d\n", ret); } led->enabled = false; return ret; } static int lm3692x_brightness_set(struct led_classdev *led_cdev, enum led_brightness brt_val) { struct lm3692x_led *led = container_of(led_cdev, struct lm3692x_led, led_dev); int ret; int led_brightness_lsb = (brt_val >> 5); mutex_lock(&led->lock); if (brt_val == 0) { ret = lm3692x_leds_disable(led); goto out; } else { lm3692x_leds_enable(led); } ret = lm3692x_fault_check(led); if (ret) { dev_err(&led->client->dev, "Cannot read/clear faults: %d\n", ret); goto out; } ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val); if (ret) { dev_err(&led->client->dev, "Cannot write MSB: %d\n", ret); goto out; } ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb); if (ret) { dev_err(&led->client->dev, "Cannot write LSB: %d\n", ret); goto out; } out: mutex_unlock(&led->lock); return ret; } static enum led_brightness lm3692x_max_brightness(struct lm3692x_led *led, u32 max_cur) { u32 max_code; /* see p.12 of LM36922 data sheet for brightness formula */ max_code = ((max_cur * 1000) - 37806) / 12195; if (max_code > 0x7FF) max_code = 0x7FF; return max_code >> 3; } static int lm3692x_probe_dt(struct lm3692x_led *led) { struct fwnode_handle *child = NULL; struct led_init_data init_data = {}; u32 ovp, max_cur; int ret; led->enable_gpio = devm_gpiod_get_optional(&led->client->dev, "enable", GPIOD_OUT_LOW); if (IS_ERR(led->enable_gpio)) { ret = PTR_ERR(led->enable_gpio); dev_err(&led->client->dev, "Failed to get enable gpio: %d\n", ret); return ret; } led->regulator = devm_regulator_get_optional(&led->client->dev, "vled"); if (IS_ERR(led->regulator)) { ret = PTR_ERR(led->regulator); if (ret != -ENODEV) { if (ret != -EPROBE_DEFER) dev_err(&led->client->dev, "Failed to get vled regulator: %d\n", ret); return ret; } led->regulator = NULL; } led->boost_ctrl = LM3692X_BOOST_SW_1MHZ | LM3692X_BOOST_SW_NO_SHIFT | LM3692X_OCP_PROT_1_5A; ret = device_property_read_u32(&led->client->dev, "ti,ovp-microvolt", &ovp); if (ret) { led->boost_ctrl |= LM3692X_OVP_29V; } else { switch (ovp) { case 17000000: break; case 21000000: led->boost_ctrl |= LM3692X_OVP_21V; break; case 25000000: led->boost_ctrl |= LM3692X_OVP_25V; break; case 29000000: led->boost_ctrl |= LM3692X_OVP_29V; break; default: dev_err(&led->client->dev, "Invalid OVP %d\n", ovp); return -EINVAL; } } child = device_get_next_child_node(&led->client->dev, child); if (!child) { dev_err(&led->client->dev, "No LED Child node\n"); return -ENODEV; } fwnode_property_read_string(child, "linux,default-trigger", &led->led_dev.default_trigger); ret = fwnode_property_read_u32(child, "reg", &led->led_enable); if (ret) { dev_err(&led->client->dev, "reg DT property missing\n"); return ret; } ret = fwnode_property_read_u32(child, "led-max-microamp", &max_cur); led->led_dev.max_brightness = ret ? LED_FULL : lm3692x_max_brightness(led, max_cur); init_data.fwnode = child; init_data.devicename = led->client->name; init_data.default_label = ":"; ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev, &init_data); if (ret) { dev_err(&led->client->dev, "led register err: %d\n", ret); return ret; } return 0; } static int lm3692x_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct lm3692x_led *led; int ret; led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL); if (!led) return -ENOMEM; mutex_init(&led->lock); led->client = client; led->led_dev.brightness_set_blocking = lm3692x_brightness_set; led->model_id = id->driver_data; i2c_set_clientdata(client, led); led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config); if (IS_ERR(led->regmap)) { ret = PTR_ERR(led->regmap); dev_err(&client->dev, "Failed to allocate register map: %d\n", ret); return ret; } ret = lm3692x_probe_dt(led); if (ret) return ret; ret = lm3692x_leds_enable(led); if (ret) return ret; return 0; } static int lm3692x_remove(struct i2c_client *client) { struct lm3692x_led *led = i2c_get_clientdata(client); int ret; ret = lm3692x_leds_disable(led); if (ret) return ret; mutex_destroy(&led->lock); return 0; } static const struct i2c_device_id lm3692x_id[] = { { "lm36922", LM36922_MODEL }, { "lm36923", LM36923_MODEL }, { } }; MODULE_DEVICE_TABLE(i2c, lm3692x_id); static const struct of_device_id of_lm3692x_leds_match[] = { { .compatible = "ti,lm36922", }, { .compatible = "ti,lm36923", }, {}, }; MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match); static struct i2c_driver lm3692x_driver = { .driver = { .name = "lm3692x", .of_match_table = of_lm3692x_leds_match, }, .probe = lm3692x_probe, .remove = lm3692x_remove, .id_table = lm3692x_id, }; module_i2c_driver(lm3692x_driver); MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver"); MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); MODULE_LICENSE("GPL v2");