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alistair23-linux/drivers/leds/leds-lm3530.c
Shreshtha Kumar Sahu 9b2da53f76 drivers/leds/leds-lm3530.c: add regulator 
Add add regulator support to lm3530 driver.  The lm3530 driver needs to
get proper regulator during device probe and enable it before accessing
the device.  Also it disables the regulator in case of brightness ==
LED_OFF, and puts it back during driver removal.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:51 -07:00

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/*
* 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>
#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_ZONE_REG 0x40
#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 15
/* 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_DEF_ZB_0 (0x33)
#define LM3530_DEF_ZB_1 (0x66)
#define LM3530_DEF_ZB_2 (0x99)
#define LM3530_DEF_ZB_3 (0xCC)
/* Zone Target Register defaults */
#define LM3530_DEF_ZT_0 (0x19)
#define LM3530_DEF_ZT_1 (0x33)
#define LM3530_DEF_ZT_2 (0x4C)
#define LM3530_DEF_ZT_3 (0x66)
#define LM3530_DEF_ZT_4 (0x7F)
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;
};
static const u8 lm3530_reg[LM3530_REG_MAX] = {
LM3530_GEN_CONFIG,
LM3530_ALS_CONFIG,
LM3530_BRT_RAMP_RATE,
LM3530_ALS_ZONE_REG,
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 int lm3530_init_registers(struct lm3530_data *drvdata)
{
int ret = 0;
int i;
u8 gen_config;
u8 als_config = 0;
u8 brt_ramp;
u8 als_imp_sel = 0;
u8 brightness;
u8 reg_val[LM3530_REG_MAX];
struct lm3530_platform_data *pltfm = drvdata->pdata;
struct i2c_client *client = drvdata->client;
gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
drvdata->mode == LM3530_BL_MODE_ALS)
gen_config |= (LM3530_ENABLE_I2C);
if (drvdata->mode == LM3530_BL_MODE_ALS) {
als_config =
(pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
(LM3530_ENABLE_ALS) |
(pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
als_imp_sel =
(pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
(pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
}
if (drvdata->mode == LM3530_BL_MODE_PWM)
gen_config |= (LM3530_ENABLE_PWM) |
(pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
(LM3530_ENABLE_PWM_SIMPLE);
brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
(pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
if (drvdata->brightness)
brightness = drvdata->brightness;
else
brightness = drvdata->brightness = pltfm->brt_val;
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] = 0x00; /* LM3530_ALS_ZONE_REG */
reg_val[4] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */
reg_val[5] = brightness; /* LM3530_BRT_CTRL_REG */
reg_val[6] = LM3530_DEF_ZB_0; /* LM3530_ALS_ZB0_REG */
reg_val[7] = LM3530_DEF_ZB_1; /* LM3530_ALS_ZB1_REG */
reg_val[8] = LM3530_DEF_ZB_2; /* LM3530_ALS_ZB2_REG */
reg_val[9] = LM3530_DEF_ZB_3; /* LM3530_ALS_ZB3_REG */
reg_val[10] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
reg_val[11] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
reg_val[12] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
reg_val[13] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
reg_val[14] = 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++) {
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);
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 / 2);
if (err)
dev_err(&drvdata->client->dev,
"Unable to set brightness: %d\n", err);
else
drvdata->brightness = brt_val / 2;
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:
break;
default:
break;
}
}
static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
*attr, const char *buf, size_t size)
{
int err;
struct i2c_client *client = container_of(
dev->parent, struct i2c_client, dev);
struct lm3530_data *drvdata = i2c_get_clientdata(client);
int mode;
mode = lm3530_get_mode_from_str(buf);
if (mode < 0) {
dev_err(dev, "Invalid mode\n");
return -EINVAL;
}
if (mode == LM3530_BL_MODE_MANUAL)
drvdata->mode = LM3530_BL_MODE_MANUAL;
else if (mode == LM3530_BL_MODE_ALS)
drvdata->mode = LM3530_BL_MODE_ALS;
else if (mode == LM3530_BL_MODE_PWM) {
dev_err(dev, "PWM mode not supported\n");
return -EINVAL;
}
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, NULL, 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");
err = -ENODEV;
goto err_out;
}
/* BL mode */
if (pdata->mode > LM3530_BL_MODE_PWM) {
dev_err(&client->dev, "Illegal Mode request\n");
err = -EINVAL;
goto err_out;
}
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
err = -EIO;
goto err_out;
}
drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
if (drvdata == NULL) {
err = -ENOMEM;
goto err_out;
}
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;
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;
goto err_regulator_get;
}
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);
err_regulator_get:
i2c_set_clientdata(client, NULL);
kfree(drvdata);
err_out:
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);
kfree(drvdata);
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 = lm3530_remove,
.id_table = lm3530_id,
.driver = {
.name = LM3530_NAME,
.owner = THIS_MODULE,
},
};
static int __init lm3530_init(void)
{
return i2c_add_driver(&lm3530_i2c_driver);
}
static void __exit lm3530_exit(void)
{
i2c_del_driver(&lm3530_i2c_driver);
}
module_init(lm3530_init);
module_exit(lm3530_exit);
MODULE_DESCRIPTION("Back Light driver for LM3530");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");
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