/*
* Copyright (C) 2011 ST-Ericsson SA.
* Copyright (C) 2009 Motorola, Inc.
*
* License Terms: GNU General Public License v2
*
* Simple driver for National Semiconductor LM3530 Backlight driver chip
*
* Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
* based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
*/
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/led-lm3530.h>
#include <linux/types.h>
#include <linux/regulator/consumer.h>
#include <linux/module.h>
#define LM3530_LED_DEV "lcd-backlight"
#define LM3530_NAME "lm3530-led"
#define LM3530_GEN_CONFIG 0x10
#define LM3530_ALS_CONFIG 0x20
#define LM3530_BRT_RAMP_RATE 0x30
#define LM3530_ALS_IMP_SELECT 0x41
#define LM3530_BRT_CTRL_REG 0xA0
#define LM3530_ALS_ZB0_REG 0x60
#define LM3530_ALS_ZB1_REG 0x61
#define LM3530_ALS_ZB2_REG 0x62
#define LM3530_ALS_ZB3_REG 0x63
#define LM3530_ALS_Z0T_REG 0x70
#define LM3530_ALS_Z1T_REG 0x71
#define LM3530_ALS_Z2T_REG 0x72
#define LM3530_ALS_Z3T_REG 0x73
#define LM3530_ALS_Z4T_REG 0x74
#define LM3530_REG_MAX 14
/* General Control Register */
#define LM3530_EN_I2C_SHIFT (0)
#define LM3530_RAMP_LAW_SHIFT (1)
#define LM3530_MAX_CURR_SHIFT (2)
#define LM3530_EN_PWM_SHIFT (5)
#define LM3530_PWM_POL_SHIFT (6)
#define LM3530_EN_PWM_SIMPLE_SHIFT (7)
#define LM3530_ENABLE_I2C (1 << LM3530_EN_I2C_SHIFT)
#define LM3530_ENABLE_PWM (1 << LM3530_EN_PWM_SHIFT)
#define LM3530_POL_LOW (1 << LM3530_PWM_POL_SHIFT)
#define LM3530_ENABLE_PWM_SIMPLE (1 << LM3530_EN_PWM_SIMPLE_SHIFT)
/* ALS Config Register Options */
#define LM3530_ALS_AVG_TIME_SHIFT (0)
#define LM3530_EN_ALS_SHIFT (3)
#define LM3530_ALS_SEL_SHIFT (5)
#define LM3530_ENABLE_ALS (3 << LM3530_EN_ALS_SHIFT)
/* Brightness Ramp Rate Register */
#define LM3530_BRT_RAMP_FALL_SHIFT (0)
#define LM3530_BRT_RAMP_RISE_SHIFT (3)
/* ALS Resistor Select */
#define LM3530_ALS1_IMP_SHIFT (0)
#define LM3530_ALS2_IMP_SHIFT (4)
/* Zone Boundary Register defaults */
#define LM3530_ALS_ZB_MAX (4)
#define LM3530_ALS_WINDOW_mV (1000)
#define LM3530_ALS_OFFSET_mV (4)
/* Zone Target Register defaults */
#define LM3530_DEF_ZT_0 (0x7F)
#define LM3530_DEF_ZT_1 (0x66)
#define LM3530_DEF_ZT_2 (0x4C)
#define LM3530_DEF_ZT_3 (0x33)
#define LM3530_DEF_ZT_4 (0x19)
/* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
#define MAX_BRIGHTNESS (127)
struct lm3530_mode_map {
const char *mode;
enum lm3530_mode mode_val;
};
static struct lm3530_mode_map mode_map[] = {
{ "man", LM3530_BL_MODE_MANUAL },
{ "als", LM3530_BL_MODE_ALS },
{ "pwm", LM3530_BL_MODE_PWM },
};
/**
* struct lm3530_data
* @led_dev: led class device
* @client: i2c client
* @pdata: LM3530 platform data
* @mode: mode of operation - manual, ALS, PWM
* @regulator: regulator
* @brighness: previous brightness value
* @enable: regulator is enabled
*/
struct lm3530_data {
struct led_classdev led_dev;
struct i2c_client *client;
struct lm3530_platform_data *pdata;
enum lm3530_mode mode;
struct regulator *regulator;
enum led_brightness brightness;
bool enable;
};
/*
* struct lm3530_als_data
* @config : value of ALS configuration register
* @imp_sel : value of ALS resistor select register
* @zone : values of ALS ZB(Zone Boundary) registers
*/
struct lm3530_als_data {
u8 config;
u8 imp_sel;
u8 zones[LM3530_ALS_ZB_MAX];
};
static const u8 lm3530_reg[LM3530_REG_MAX] = {
LM3530_GEN_CONFIG,
LM3530_ALS_CONFIG,
LM3530_BRT_RAMP_RATE,
LM3530_ALS_IMP_SELECT,
LM3530_BRT_CTRL_REG,
LM3530_ALS_ZB0_REG,
LM3530_ALS_ZB1_REG,
LM3530_ALS_ZB2_REG,
LM3530_ALS_ZB3_REG,
LM3530_ALS_Z0T_REG,
LM3530_ALS_Z1T_REG,
LM3530_ALS_Z2T_REG,
LM3530_ALS_Z3T_REG,
LM3530_ALS_Z4T_REG,
};
static int lm3530_get_mode_from_str(const char *str)
{
int i;
for (i = 0; i < ARRAY_SIZE(mode_map); i++)
if (sysfs_streq(str, mode_map[i].mode))
return mode_map[i].mode_val;
return -1;
}
static void lm3530_als_configure(struct lm3530_platform_data *pdata,
struct lm3530_als_data *als)
{
int i;
u32 als_vmin, als_vmax, als_vstep;
if (pdata->als_vmax == 0) {
pdata->als_vmin = 0;
pdata->als_vmax = LM3530_ALS_WINDOW_mV;
}
als_vmin = pdata->als_vmin;
als_vmax = pdata->als_vmax;
if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
pdata->als_vmax = als_vmax = als_vmin + LM3530_ALS_WINDOW_mV;
/* n zone boundary makes n+1 zones */
als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
als->zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
als_vstep + (i * als_vstep)) * LED_FULL) / 1000;
als->config =
(pdata->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
(LM3530_ENABLE_ALS) |
(pdata->als_input_mode << LM3530_ALS_SEL_SHIFT);
als->imp_sel =
(pdata->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
(pdata->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
}
static int lm3530_init_registers(struct lm3530_data *drvdata)
{
int ret = 0;
int i;
u8 gen_config;
u8 brt_ramp;
u8 brightness;
u8 reg_val[LM3530_REG_MAX];
struct lm3530_platform_data *pdata = drvdata->pdata;
struct i2c_client *client = drvdata->client;
struct lm3530_pwm_data *pwm = &pdata->pwm_data;
struct lm3530_als_data als;
memset(&als, 0, sizeof(struct lm3530_als_data));
gen_config = (pdata->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
((pdata->max_current & 7) << LM3530_MAX_CURR_SHIFT);
switch (drvdata->mode) {
case LM3530_BL_MODE_MANUAL:
gen_config |= LM3530_ENABLE_I2C;
break;
case LM3530_BL_MODE_ALS:
gen_config |= LM3530_ENABLE_I2C;
lm3530_als_configure(pdata, &als);
break;
case LM3530_BL_MODE_PWM:
gen_config |= LM3530_ENABLE_PWM | LM3530_ENABLE_PWM_SIMPLE |
(pdata->pwm_pol_hi << LM3530_PWM_POL_SHIFT);
break;
}
brt_ramp = (pdata->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
(pdata->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
if (drvdata->brightness)
brightness = drvdata->brightness;
else
brightness = drvdata->brightness = pdata->brt_val;
if (brightness > drvdata->led_dev.max_brightness)
brightness = drvdata->led_dev.max_brightness;
reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */
reg_val[1] = als.config; /* LM3530_ALS_CONFIG */
reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */
reg_val[3] = als.imp_sel; /* LM3530_ALS_IMP_SELECT */
reg_val[4] = brightness; /* LM3530_BRT_CTRL_REG */
reg_val[5] = als.zones[0]; /* LM3530_ALS_ZB0_REG */
reg_val[6] = als.zones[1]; /* LM3530_ALS_ZB1_REG */
reg_val[7] = als.zones[2]; /* LM3530_ALS_ZB2_REG */
reg_val[8] = als.zones[3]; /* LM3530_ALS_ZB3_REG */
reg_val[9] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
reg_val[10] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
reg_val[11] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
reg_val[12] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
reg_val[13] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */
if (!drvdata->enable) {
ret = regulator_enable(drvdata->regulator);
if (ret) {
dev_err(&drvdata->client->dev,
"Enable regulator failed\n");
return ret;
}
drvdata->enable = true;
}
for (i = 0; i < LM3530_REG_MAX; i++) {
/* do not update brightness register when pwm mode */
if (lm3530_reg[i] == LM3530_BRT_CTRL_REG &&
drvdata->mode == LM3530_BL_MODE_PWM) {
if (pwm->pwm_set_intensity)
pwm->pwm_set_intensity(reg_val[i],
drvdata->led_dev.max_brightness);
continue;
}
ret = i2c_smbus_write_byte_data(client,
lm3530_reg[i], reg_val[i]);
if (ret)
break;
}
return ret;
}
static void lm3530_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brt_val)
{
int err;
struct lm3530_data *drvdata =
container_of(led_cdev, struct lm3530_data, led_dev);
struct lm3530_platform_data *pdata = drvdata->pdata;
struct lm3530_pwm_data *pwm = &pdata->pwm_data;
u8 max_brightness = led_cdev->max_brightness;
switch (drvdata->mode) {
case LM3530_BL_MODE_MANUAL:
if (!drvdata->enable) {
err = lm3530_init_registers(drvdata);
if (err) {
dev_err(&drvdata->client->dev,
"Register Init failed: %d\n", err);
break;
}
}
/* set the brightness in brightness control register*/
err = i2c_smbus_write_byte_data(drvdata->client,
LM3530_BRT_CTRL_REG, brt_val);
if (err)
dev_err(&drvdata->client->dev,
"Unable to set brightness: %d\n", err);
else
drvdata->brightness = brt_val;
if (brt_val == 0) {
err = regulator_disable(drvdata->regulator);
if (err)
dev_err(&drvdata->client->dev,
"Disable regulator failed\n");
drvdata->enable = false;
}
break;
case LM3530_BL_MODE_ALS:
break;
case LM3530_BL_MODE_PWM:
if (pwm->pwm_set_intensity)
pwm->pwm_set_intensity(brt_val, max_brightness);
break;
default:
break;
}
}
static ssize_t lm3530_mode_get(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct lm3530_data *drvdata;
int i, len = 0;
drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
for (i = 0; i < ARRAY_SIZE(mode_map); i++)
if (drvdata->mode == mode_map[i].mode_val)
len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
else
len += sprintf(buf + len, "%s ", mode_map[i].mode);
len += sprintf(buf + len, "\n");
return len;
}
static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
*attr, const char *buf, size_t size)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct lm3530_data *drvdata;
struct lm3530_pwm_data *pwm;
u8 max_brightness;
int mode, err;
drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
pwm = &drvdata->pdata->pwm_data;
max_brightness = led_cdev->max_brightness;
mode = lm3530_get_mode_from_str(buf);
if (mode < 0) {
dev_err(dev, "Invalid mode\n");
return -EINVAL;
}
drvdata->mode = mode;
/* set pwm to low if unnecessary */
if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity)
pwm->pwm_set_intensity(0, max_brightness);
err = lm3530_init_registers(drvdata);
if (err) {
dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
return err;
}
return sizeof(drvdata->mode);
}
static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set);
static int __devinit lm3530_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct lm3530_platform_data *pdata = client->dev.platform_data;
struct lm3530_data *drvdata;
int err = 0;
if (pdata == NULL) {
dev_err(&client->dev, "platform data required\n");
return -ENODEV;
}
/* BL mode */
if (pdata->mode > LM3530_BL_MODE_PWM) {
dev_err(&client->dev, "Illegal Mode request\n");
return -EINVAL;
}
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
return -EIO;
}
drvdata = devm_kzalloc(&client->dev, sizeof(struct lm3530_data),
GFP_KERNEL);
if (drvdata == NULL)
return -ENOMEM;
drvdata->mode = pdata->mode;
drvdata->client = client;
drvdata->pdata = pdata;
drvdata->brightness = LED_OFF;
drvdata->enable = false;
drvdata->led_dev.name = LM3530_LED_DEV;
drvdata->led_dev.brightness_set = lm3530_brightness_set;
drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
i2c_set_clientdata(client, drvdata);
drvdata->regulator = regulator_get(&client->dev, "vin");
if (IS_ERR(drvdata->regulator)) {
dev_err(&client->dev, "regulator get failed\n");
err = PTR_ERR(drvdata->regulator);
drvdata->regulator = NULL;
return err;
}
if (drvdata->pdata->brt_val) {
err = lm3530_init_registers(drvdata);
if (err < 0) {
dev_err(&client->dev,
"Register Init failed: %d\n", err);
err = -ENODEV;
goto err_reg_init;
}
}
err = led_classdev_register(&client->dev, &drvdata->led_dev);
if (err < 0) {
dev_err(&client->dev, "Register led class failed: %d\n", err);
err = -ENODEV;
goto err_class_register;
}
err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
if (err < 0) {
dev_err(&client->dev, "File device creation failed: %d\n", err);
err = -ENODEV;
goto err_create_file;
}
return 0;
err_create_file:
led_classdev_unregister(&drvdata->led_dev);
err_class_register:
err_reg_init:
regulator_put(drvdata->regulator);
return err;
}
static int __devexit lm3530_remove(struct i2c_client *client)
{
struct lm3530_data *drvdata = i2c_get_clientdata(client);
device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
if (drvdata->enable)
regulator_disable(drvdata->regulator);
regulator_put(drvdata->regulator);
led_classdev_unregister(&drvdata->led_dev);
return 0;
}
static const struct i2c_device_id lm3530_id[] = {
{LM3530_NAME, 0},
{}
};
MODULE_DEVICE_TABLE(i2c, lm3530_id);
static struct i2c_driver lm3530_i2c_driver = {
.probe = lm3530_probe,
.remove = __devexit_p(lm3530_remove),
.id_table = lm3530_id,
.driver = {
.name = LM3530_NAME,
.owner = THIS_MODULE,
},
};
module_i2c_driver(lm3530_i2c_driver);
MODULE_DESCRIPTION("Back Light driver for LM3530");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");
