diff options
Diffstat (limited to 'drivers/leds/leds-lm3692x.c')
| -rw-r--r-- | drivers/leds/leds-lm3692x.c | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/drivers/leds/leds-lm3692x.c b/drivers/leds/leds-lm3692x.c new file mode 100644 index 000000000000..437173d1712c --- /dev/null +++ b/drivers/leds/leds-lm3692x.c @@ -0,0 +1,393 @@ +/* + * TI lm3692x LED Driver + * + * Copyright (C) 2017 Texas Instruments + * + * Author: Dan Murphy <dmurphy@ti.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * Data sheet is located + * http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf + */ + +#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/of_gpio.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/slab.h> +#include <uapi/linux/uleds.h> + +#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) + +/* 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 + * @label - LED label + */ +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; + char label[LED_MAX_NAME_SIZE]; +}; + +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_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); + + ret = lm3692x_fault_check(led); + if (ret) { + dev_err(&led->client->dev, "Cannot read/clear faults\n"); + goto out; + } + + ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val); + if (ret) { + dev_err(&led->client->dev, "Cannot write MSB\n"); + goto out; + } + + ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb); + if (ret) { + dev_err(&led->client->dev, "Cannot write LSB\n"); + goto out; + } +out: + mutex_unlock(&led->lock); + return ret; +} + +static int lm3692x_init(struct lm3692x_led *led) +{ + int ret; + + if (led->regulator) { + ret = regulator_enable(led->regulator); + if (ret) { + dev_err(&led->client->dev, + "Failed to enable regulator\n"); + 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\n"); + 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 device enable bit is 0 + * per Section 7.5.14 of the data sheet + */ + 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, + LM3692X_BRHT_MODE_RAMP_MULTI | + LM3692X_BL_ADJ_POL | + LM3692X_RAMP_RATE_250us); + 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_PWM_HYSTER_4LSB); + if (ret) + goto out; + + 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) { + ret = regulator_disable(led->regulator); + if (ret) + dev_err(&led->client->dev, + "Failed to disable regulator\n"); + } + + return ret; +} + +static int lm3692x_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int ret; + struct lm3692x_led *led; + struct device_node *np = client->dev.of_node; + struct device_node *child_node; + const char *name; + + led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL); + if (!led) + return -ENOMEM; + + for_each_available_child_of_node(np, child_node) { + led->led_dev.default_trigger = of_get_property(child_node, + "linux,default-trigger", + NULL); + + ret = of_property_read_string(child_node, "label", &name); + if (!ret) + snprintf(led->label, sizeof(led->label), + "%s:%s", id->name, name); + else + snprintf(led->label, sizeof(led->label), + "%s::backlight_cluster", id->name); + }; + + led->enable_gpio = devm_gpiod_get_optional(&client->dev, + "enable", GPIOD_OUT_LOW); + if (IS_ERR(led->enable_gpio)) { + ret = PTR_ERR(led->enable_gpio); + dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret); + return ret; + } + + led->regulator = devm_regulator_get(&client->dev, "vled"); + if (IS_ERR(led->regulator)) + led->regulator = NULL; + + led->client = client; + led->led_dev.name = led->label; + led->led_dev.brightness_set_blocking = lm3692x_brightness_set; + + mutex_init(&led->lock); + + 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_init(led); + if (ret) + return ret; + + ret = devm_led_classdev_register(&client->dev, &led->led_dev); + if (ret) { + dev_err(&client->dev, "led register err: %d\n", ret); + return ret; + } + + return 0; +} + +static int lm3692x_remove(struct i2c_client *client) +{ + struct lm3692x_led *led = i2c_get_clientdata(client); + int 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\n"); + } + + mutex_destroy(&led->lock); + + return 0; +} + +static const struct i2c_device_id lm3692x_id[] = { + { "lm36922", 0 }, + { "lm36923", 1 }, + { } +}; +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"); |