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linux-next/drivers/leds/leds-lm3692x.c
Dan Murphy 9699cb6bbe leds: lm3692x: Introduce LM3692x dual string driver 
Introducing the LM3692x Dual-String white LED driver.

Data sheet is located
http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
2018-01-08 21:28:11 +01:00

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/*
* 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");
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