[deliverable/linux.git] / drivers / video / backlight / lp855x_bl.c

/*
 * TI LP855x Backlight Driver
 *
 *			Copyright (C) 2011 Texas Instruments
 *
 * 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.
 *
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/platform_data/lp855x.h>
#include <linux/pwm.h>

/* LP8550/1/2/3/6 Registers */
#define LP855X_BRIGHTNESS_CTRL		0x00
#define LP855X_DEVICE_CTRL		0x01
#define LP855X_EEPROM_START		0xA0
#define LP855X_EEPROM_END		0xA7
#define LP8556_EPROM_START		0xA0
#define LP8556_EPROM_END		0xAF

/* LP8557 Registers */
#define LP8557_BL_CMD			0x00
#define LP8557_BL_MASK			0x01
#define LP8557_BL_ON			0x01
#define LP8557_BL_OFF			0x00
#define LP8557_BRIGHTNESS_CTRL		0x04
#define LP8557_CONFIG			0x10
#define LP8557_EPROM_START		0x10
#define LP8557_EPROM_END		0x1E

#define BUF_SIZE		20
#define DEFAULT_BL_NAME		"lcd-backlight"
#define MAX_BRIGHTNESS		255

struct lp855x;

/*
 * struct lp855x_device_config
 * @pre_init_device: init device function call before updating the brightness
 * @reg_brightness: register address for brigthenss control
 * @reg_devicectrl: register address for device control
 * @post_init_device: late init device function call
 */
struct lp855x_device_config {
	int (*pre_init_device)(struct lp855x *);
	u8 reg_brightness;
	u8 reg_devicectrl;
	int (*post_init_device)(struct lp855x *);
};

struct lp855x {
	const char *chipname;
	enum lp855x_chip_id chip_id;
	struct lp855x_device_config *cfg;
	struct i2c_client *client;
	struct backlight_device *bl;
	struct device *dev;
	struct lp855x_platform_data *pdata;
	struct pwm_device *pwm;
};

static int lp855x_write_byte(struct lp855x *lp, u8 reg, u8 data)
{
	return i2c_smbus_write_byte_data(lp->client, reg, data);
}

static int lp855x_update_bit(struct lp855x *lp, u8 reg, u8 mask, u8 data)
{
	int ret;
	u8 tmp;

	ret = i2c_smbus_read_byte_data(lp->client, reg);
	if (ret < 0) {
		dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
		return ret;
	}

	tmp = (u8)ret;
	tmp &= ~mask;
	tmp |= data & mask;

	return lp855x_write_byte(lp, reg, tmp);
}

static bool lp855x_is_valid_rom_area(struct lp855x *lp, u8 addr)
{
	u8 start, end;

	switch (lp->chip_id) {
	case LP8550:
	case LP8551:
	case LP8552:
	case LP8553:
		start = LP855X_EEPROM_START;
		end = LP855X_EEPROM_END;
		break;
	case LP8556:
		start = LP8556_EPROM_START;
		end = LP8556_EPROM_END;
		break;
	case LP8557:
		start = LP8557_EPROM_START;
		end = LP8557_EPROM_END;
		break;
	default:
		return false;
	}

	return (addr >= start && addr <= end);
}

static int lp8557_bl_off(struct lp855x *lp)
{
	/* BL_ON = 0 before updating EPROM settings */
	return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
				LP8557_BL_OFF);
}

static int lp8557_bl_on(struct lp855x *lp)
{
	/* BL_ON = 1 after updating EPROM settings */
	return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
				LP8557_BL_ON);
}

static struct lp855x_device_config lp855x_dev_cfg = {
	.reg_brightness = LP855X_BRIGHTNESS_CTRL,
	.reg_devicectrl = LP855X_DEVICE_CTRL,
};

static struct lp855x_device_config lp8557_dev_cfg = {
	.reg_brightness = LP8557_BRIGHTNESS_CTRL,
	.reg_devicectrl = LP8557_CONFIG,
	.pre_init_device = lp8557_bl_off,
	.post_init_device = lp8557_bl_on,
};

/*
 * Device specific configuration flow
 *
 *    a) pre_init_device(optional)
 *    b) update the brightness register
 *    c) update device control register
 *    d) update ROM area(optional)
 *    e) post_init_device(optional)
 *
 */
static int lp855x_configure(struct lp855x *lp)
{
	u8 val, addr;
	int i, ret;
	struct lp855x_platform_data *pd = lp->pdata;

	switch (lp->chip_id) {
	case LP8550 ... LP8556:
		lp->cfg = &lp855x_dev_cfg;
		break;
	case LP8557:
		lp->cfg = &lp8557_dev_cfg;
		break;
	default:
		return -EINVAL;
	}

	if (lp->cfg->pre_init_device) {
		ret = lp->cfg->pre_init_device(lp);
		if (ret) {
			dev_err(lp->dev, "pre init device err: %d\n", ret);
			goto err;
		}
	}

	val = pd->initial_brightness;
	ret = lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
	if (ret)
		goto err;

	val = pd->device_control;
	ret = lp855x_write_byte(lp, lp->cfg->reg_devicectrl, val);
	if (ret)
		goto err;

	if (pd->load_new_rom_data && pd->size_program) {
		for (i = 0; i < pd->size_program; i++) {
			addr = pd->rom_data[i].addr;
			val = pd->rom_data[i].val;
			if (!lp855x_is_valid_rom_area(lp, addr))
				continue;

			ret = lp855x_write_byte(lp, addr, val);
			if (ret)
				goto err;
		}
	}

	if (lp->cfg->post_init_device) {
		ret = lp->cfg->post_init_device(lp);
		if (ret) {
			dev_err(lp->dev, "post init device err: %d\n", ret);
			goto err;
		}
	}

	return 0;

err:
	return ret;
}

static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
{
	unsigned int period = lp->pdata->period_ns;
	unsigned int duty = br * period / max_br;
	struct pwm_device *pwm;

	/* request pwm device with the consumer name */
	if (!lp->pwm) {
		pwm = devm_pwm_get(lp->dev, lp->chipname);
		if (IS_ERR(pwm))
			return;

		lp->pwm = pwm;
	}

	pwm_config(lp->pwm, duty, period);
	if (duty)
		pwm_enable(lp->pwm);
	else
		pwm_disable(lp->pwm);
}

static int lp855x_bl_update_status(struct backlight_device *bl)
{
	struct lp855x *lp = bl_get_data(bl);
	enum lp855x_brightness_ctrl_mode mode = lp->pdata->mode;

	if (bl->props.state & BL_CORE_SUSPENDED)
		bl->props.brightness = 0;

	if (mode == PWM_BASED) {
		int br = bl->props.brightness;
		int max_br = bl->props.max_brightness;

		lp855x_pwm_ctrl(lp, br, max_br);

	} else if (mode == REGISTER_BASED) {
		u8 val = bl->props.brightness;
		lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
	}

	return 0;
}

static int lp855x_bl_get_brightness(struct backlight_device *bl)
{
	return bl->props.brightness;
}

static const struct backlight_ops lp855x_bl_ops = {
	.options = BL_CORE_SUSPENDRESUME,
	.update_status = lp855x_bl_update_status,
	.get_brightness = lp855x_bl_get_brightness,
};

static int lp855x_backlight_register(struct lp855x *lp)
{
	struct backlight_device *bl;
	struct backlight_properties props;
	struct lp855x_platform_data *pdata = lp->pdata;
	char *name = pdata->name ? : DEFAULT_BL_NAME;

	props.type = BACKLIGHT_PLATFORM;
	props.max_brightness = MAX_BRIGHTNESS;

	if (pdata->initial_brightness > props.max_brightness)
		pdata->initial_brightness = props.max_brightness;

	props.brightness = pdata->initial_brightness;

	bl = backlight_device_register(name, lp->dev, lp,
				       &lp855x_bl_ops, &props);
	if (IS_ERR(bl))
		return PTR_ERR(bl);

	lp->bl = bl;

	return 0;
}

static void lp855x_backlight_unregister(struct lp855x *lp)
{
	if (lp->bl)
		backlight_device_unregister(lp->bl);
}

static ssize_t lp855x_get_chip_id(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct lp855x *lp = dev_get_drvdata(dev);
	return scnprintf(buf, BUF_SIZE, "%s\n", lp->chipname);
}

static ssize_t lp855x_get_bl_ctl_mode(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	struct lp855x *lp = dev_get_drvdata(dev);
	enum lp855x_brightness_ctrl_mode mode = lp->pdata->mode;
	char *strmode = NULL;

	if (mode == PWM_BASED)
		strmode = "pwm based";
	else if (mode == REGISTER_BASED)
		strmode = "register based";

	return scnprintf(buf, BUF_SIZE, "%s\n", strmode);
}

static DEVICE_ATTR(chip_id, S_IRUGO, lp855x_get_chip_id, NULL);
static DEVICE_ATTR(bl_ctl_mode, S_IRUGO, lp855x_get_bl_ctl_mode, NULL);

static struct attribute *lp855x_attributes[] = {
	&dev_attr_chip_id.attr,
	&dev_attr_bl_ctl_mode.attr,
	NULL,
};

static const struct attribute_group lp855x_attr_group = {
	.attrs = lp855x_attributes,
};

static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
{
	struct lp855x *lp;
	struct lp855x_platform_data *pdata = cl->dev.platform_data;
	enum lp855x_brightness_ctrl_mode mode;
	int ret;

	if (!pdata) {
		dev_err(&cl->dev, "no platform data supplied\n");
		return -EINVAL;
	}

	if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
		return -EIO;

	lp = devm_kzalloc(&cl->dev, sizeof(struct lp855x), GFP_KERNEL);
	if (!lp)
		return -ENOMEM;

	mode = pdata->mode;
	lp->client = cl;
	lp->dev = &cl->dev;
	lp->pdata = pdata;
	lp->chipname = id->name;
	lp->chip_id = id->driver_data;
	i2c_set_clientdata(cl, lp);

	ret = lp855x_configure(lp);
	if (ret) {
		dev_err(lp->dev, "device config err: %d", ret);
		goto err_dev;
	}

	ret = lp855x_backlight_register(lp);
	if (ret) {
		dev_err(lp->dev,
			"failed to register backlight. err: %d\n", ret);
		goto err_dev;
	}

	ret = sysfs_create_group(&lp->dev->kobj, &lp855x_attr_group);
	if (ret) {
		dev_err(lp->dev, "failed to register sysfs. err: %d\n", ret);
		goto err_sysfs;
	}

	backlight_update_status(lp->bl);
	return 0;

err_sysfs:
	lp855x_backlight_unregister(lp);
err_dev:
	return ret;
}

static int lp855x_remove(struct i2c_client *cl)
{
	struct lp855x *lp = i2c_get_clientdata(cl);

	lp->bl->props.brightness = 0;
	backlight_update_status(lp->bl);
	sysfs_remove_group(&lp->dev->kobj, &lp855x_attr_group);
	lp855x_backlight_unregister(lp);

	return 0;
}

static const struct i2c_device_id lp855x_ids[] = {
	{"lp8550", LP8550},
	{"lp8551", LP8551},
	{"lp8552", LP8552},
	{"lp8553", LP8553},
	{"lp8556", LP8556},
	{"lp8557", LP8557},
	{ }
};
MODULE_DEVICE_TABLE(i2c, lp855x_ids);

static struct i2c_driver lp855x_driver = {
	.driver = {
		   .name = "lp855x",
		   },
	.probe = lp855x_probe,
	.remove = lp855x_remove,
	.id_table = lp855x_ids,
};

module_i2c_driver(lp855x_driver);

MODULE_DESCRIPTION("Texas Instruments LP855x Backlight driver");
MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
MODULE_LICENSE("GPL");
Commit	Line	Data
7be865ab KM	1	/*
	2	* TI LP855x Backlight Driver
	3	*
	4	* Copyright (C) 2011 Texas Instruments
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/slab.h>
	14	#include <linux/i2c.h>
	15	#include <linux/backlight.h>
	16	#include <linux/err.h>
f7f95056	17	#include <linux/platform_data/lp855x.h>
8cc9764c	18	#include <linux/pwm.h>
7be865ab	19
26e8ccc2 KM	20	/* LP8550/1/2/3/6 Registers */
	21	#define LP855X_BRIGHTNESS_CTRL 0x00
	22	#define LP855X_DEVICE_CTRL 0x01
	23	#define LP855X_EEPROM_START 0xA0
	24	#define LP855X_EEPROM_END 0xA7
	25	#define LP8556_EPROM_START 0xA0
	26	#define LP8556_EPROM_END 0xAF
	27
	28	/* LP8557 Registers */
	29	#define LP8557_BL_CMD 0x00
	30	#define LP8557_BL_MASK 0x01
	31	#define LP8557_BL_ON 0x01
	32	#define LP8557_BL_OFF 0x00
	33	#define LP8557_BRIGHTNESS_CTRL 0x04
	34	#define LP8557_CONFIG 0x10
	35	#define LP8557_EPROM_START 0x10
	36	#define LP8557_EPROM_END 0x1E
7be865ab KM	37
	38	#define BUF_SIZE 20
	39	#define DEFAULT_BL_NAME "lcd-backlight"
	40	#define MAX_BRIGHTNESS 255
	41
68853bc2 KM	42	struct lp855x;
	43
	44	/*
	45	* struct lp855x_device_config
	46	* @pre_init_device: init device function call before updating the brightness
	47	* @reg_brightness: register address for brigthenss control
	48	* @reg_devicectrl: register address for device control
	49	* @post_init_device: late init device function call
	50	*/
	51	struct lp855x_device_config {
	52	int (pre_init_device)(struct lp855x );
	53	u8 reg_brightness;
	54	u8 reg_devicectrl;
	55	int (post_init_device)(struct lp855x );
	56	};
	57
7be865ab KM	58	struct lp855x {
	59	const char *chipname;
	60	enum lp855x_chip_id chip_id;
68853bc2	61	struct lp855x_device_config *cfg;
7be865ab KM	62	struct i2c_client *client;
	63	struct backlight_device *bl;
	64	struct device *dev;
7be865ab	65	struct lp855x_platform_data *pdata;
8cc9764c	66	struct pwm_device *pwm;
7be865ab KM	67	};
7be865ab KM	68
7be865ab KM	69	static int lp855x_write_byte(struct lp855x *lp, u8 reg, u8 data)
7be865ab KM	70	{
eaa4d02f	71	return i2c_smbus_write_byte_data(lp->client, reg, data);
7be865ab KM	72	}
7be865ab KM	73
26e8ccc2 KM	74	static int lp855x_update_bit(struct lp855x *lp, u8 reg, u8 mask, u8 data)
	75	{
	76	int ret;
	77	u8 tmp;
	78
	79	ret = i2c_smbus_read_byte_data(lp->client, reg);
	80	if (ret < 0) {
	81	dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
	82	return ret;
	83	}
	84
	85	tmp = (u8)ret;
	86	tmp &= ~mask;
	87	tmp \|= data & mask;
	88
	89	return lp855x_write_byte(lp, reg, tmp);
	90	}
	91
7be865ab KM	92	static bool lp855x_is_valid_rom_area(struct lp855x *lp, u8 addr)
	93	{
	94	u8 start, end;
	95
	96	switch (lp->chip_id) {
	97	case LP8550:
	98	case LP8551:
	99	case LP8552:
	100	case LP8553:
26e8ccc2 KM	101	start = LP855X_EEPROM_START;
26e8ccc2 KM	102	end = LP855X_EEPROM_END;
7be865ab KM	103	break;
7be865ab KM	104	case LP8556:
26e8ccc2 KM	105	start = LP8556_EPROM_START;
	106	end = LP8556_EPROM_END;
	107	break;
	108	case LP8557:
	109	start = LP8557_EPROM_START;
	110	end = LP8557_EPROM_END;
7be865ab KM	111	break;
	112	default:
	113	return false;
	114	}
	115
	116	return (addr >= start && addr <= end);
	117	}
	118
26e8ccc2 KM	119	static int lp8557_bl_off(struct lp855x *lp)
	120	{
	121	/* BL_ON = 0 before updating EPROM settings */
	122	return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
	123	LP8557_BL_OFF);
	124	}
	125
	126	static int lp8557_bl_on(struct lp855x *lp)
	127	{
	128	/* BL_ON = 1 after updating EPROM settings */
	129	return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
	130	LP8557_BL_ON);
	131	}
	132
68853bc2	133	static struct lp855x_device_config lp855x_dev_cfg = {
26e8ccc2 KM	134	.reg_brightness = LP855X_BRIGHTNESS_CTRL,
	135	.reg_devicectrl = LP855X_DEVICE_CTRL,
	136	};
	137
	138	static struct lp855x_device_config lp8557_dev_cfg = {
	139	.reg_brightness = LP8557_BRIGHTNESS_CTRL,
	140	.reg_devicectrl = LP8557_CONFIG,
	141	.pre_init_device = lp8557_bl_off,
	142	.post_init_device = lp8557_bl_on,
68853bc2 KM	143	};
	144
	145	/*
	146	* Device specific configuration flow
	147	*
	148	* a) pre_init_device(optional)
	149	* b) update the brightness register
	150	* c) update device control register
	151	* d) update ROM area(optional)
	152	* e) post_init_device(optional)
	153	*
	154	*/
	155	static int lp855x_configure(struct lp855x *lp)
7be865ab KM	156	{
	157	u8 val, addr;
	158	int i, ret;
	159	struct lp855x_platform_data *pd = lp->pdata;
	160
68853bc2 KM	161	switch (lp->chip_id) {
	162	case LP8550 ... LP8556:
	163	lp->cfg = &lp855x_dev_cfg;
	164	break;
26e8ccc2 KM	165	case LP8557:
	166	lp->cfg = &lp8557_dev_cfg;
	167	break;
68853bc2 KM	168	default:
	169	return -EINVAL;
	170	}
	171
	172	if (lp->cfg->pre_init_device) {
	173	ret = lp->cfg->pre_init_device(lp);
	174	if (ret) {
	175	dev_err(lp->dev, "pre init device err: %d\n", ret);
	176	goto err;
	177	}
	178	}
	179
7be865ab	180	val = pd->initial_brightness;
68853bc2	181	ret = lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
7be865ab	182	if (ret)
68853bc2	183	goto err;
7be865ab KM	184
7be865ab KM	185	val = pd->device_control;
68853bc2	186	ret = lp855x_write_byte(lp, lp->cfg->reg_devicectrl, val);
7be865ab	187	if (ret)
68853bc2	188	goto err;
7be865ab KM	189
	190	if (pd->load_new_rom_data && pd->size_program) {
	191	for (i = 0; i < pd->size_program; i++) {
	192	addr = pd->rom_data[i].addr;
	193	val = pd->rom_data[i].val;
	194	if (!lp855x_is_valid_rom_area(lp, addr))
	195	continue;
	196
	197	ret = lp855x_write_byte(lp, addr, val);
	198	if (ret)
68853bc2 KM	199	goto err;
	200	}
	201	}
	202
	203	if (lp->cfg->post_init_device) {
	204	ret = lp->cfg->post_init_device(lp);
	205	if (ret) {
	206	dev_err(lp->dev, "post init device err: %d\n", ret);
	207	goto err;
7be865ab KM	208	}
	209	}
	210
68853bc2 KM	211	return 0;
	212
	213	err:
7be865ab KM	214	return ret;
	215	}
	216
8cc9764c KM	217	static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
	218	{
	219	unsigned int period = lp->pdata->period_ns;
	220	unsigned int duty = br * period / max_br;
	221	struct pwm_device *pwm;
	222
	223	/* request pwm device with the consumer name */
	224	if (!lp->pwm) {
	225	pwm = devm_pwm_get(lp->dev, lp->chipname);
	226	if (IS_ERR(pwm))
	227	return;
	228
	229	lp->pwm = pwm;
	230	}
	231
	232	pwm_config(lp->pwm, duty, period);
	233	if (duty)
	234	pwm_enable(lp->pwm);
	235	else
	236	pwm_disable(lp->pwm);
	237	}
	238
7be865ab KM	239	static int lp855x_bl_update_status(struct backlight_device *bl)
	240	{
	241	struct lp855x *lp = bl_get_data(bl);
	242	enum lp855x_brightness_ctrl_mode mode = lp->pdata->mode;
	243
	244	if (bl->props.state & BL_CORE_SUSPENDED)
	245	bl->props.brightness = 0;
	246
	247	if (mode == PWM_BASED) {
7be865ab KM	248	int br = bl->props.brightness;
	249	int max_br = bl->props.max_brightness;
	250
8cc9764c	251	lp855x_pwm_ctrl(lp, br, max_br);
7be865ab KM	252
	253	} else if (mode == REGISTER_BASED) {
	254	u8 val = bl->props.brightness;
26e8ccc2	255	lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
7be865ab KM	256	}
	257
	258	return 0;
	259	}
	260
	261	static int lp855x_bl_get_brightness(struct backlight_device *bl)
	262	{
7be865ab KM	263	return bl->props.brightness;
	264	}
	265
	266	static const struct backlight_ops lp855x_bl_ops = {
	267	.options = BL_CORE_SUSPENDRESUME,
	268	.update_status = lp855x_bl_update_status,
	269	.get_brightness = lp855x_bl_get_brightness,
	270	};
	271
	272	static int lp855x_backlight_register(struct lp855x *lp)
	273	{
	274	struct backlight_device *bl;
	275	struct backlight_properties props;
	276	struct lp855x_platform_data *pdata = lp->pdata;
	277	char *name = pdata->name ? : DEFAULT_BL_NAME;
	278
	279	props.type = BACKLIGHT_PLATFORM;
	280	props.max_brightness = MAX_BRIGHTNESS;
	281
	282	if (pdata->initial_brightness > props.max_brightness)
	283	pdata->initial_brightness = props.max_brightness;
	284
	285	props.brightness = pdata->initial_brightness;
	286
	287	bl = backlight_device_register(name, lp->dev, lp,
	288	&lp855x_bl_ops, &props);
	289	if (IS_ERR(bl))
	290	return PTR_ERR(bl);
	291
	292	lp->bl = bl;
	293
	294	return 0;
	295	}
	296
	297	static void lp855x_backlight_unregister(struct lp855x *lp)
	298	{
	299	if (lp->bl)
	300	backlight_device_unregister(lp->bl);
	301	}
	302
	303	static ssize_t lp855x_get_chip_id(struct device *dev,
	304	struct device_attribute attr, char buf)
	305	{
	306	struct lp855x *lp = dev_get_drvdata(dev);
	307	return scnprintf(buf, BUF_SIZE, "%s\n", lp->chipname);
	308	}
	309
	310	static ssize_t lp855x_get_bl_ctl_mode(struct device *dev,
	311	struct device_attribute attr, char buf)
	312	{
	313	struct lp855x *lp = dev_get_drvdata(dev);
	314	enum lp855x_brightness_ctrl_mode mode = lp->pdata->mode;
	315	char *strmode = NULL;
	316
	317	if (mode == PWM_BASED)
	318	strmode = "pwm based";
	319	else if (mode == REGISTER_BASED)
	320	strmode = "register based";
	321
	322	return scnprintf(buf, BUF_SIZE, "%s\n", strmode);
	323	}
	324
	325	static DEVICE_ATTR(chip_id, S_IRUGO, lp855x_get_chip_id, NULL);
	326	static DEVICE_ATTR(bl_ctl_mode, S_IRUGO, lp855x_get_bl_ctl_mode, NULL);
327
328	static struct attribute *lp855x_attributes[] = {
329	&dev_attr_chip_id.attr,
330	&dev_attr_bl_ctl_mode.attr,
331	NULL,
332	};
333
334	static const struct attribute_group lp855x_attr_group = {
335	.attrs = lp855x_attributes,
336	};
337
338	static int lp855x_probe(struct i2c_client cl, const struct i2c_device_id id)
339	{
340	struct lp855x *lp;
341	struct lp855x_platform_data *pdata = cl->dev.platform_data;
342	enum lp855x_brightness_ctrl_mode mode;
343	int ret;
344
345	if (!pdata) {
346	dev_err(&cl->dev, "no platform data supplied\n");
347	return -EINVAL;
348	}
349
350	if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
351	return -EIO;
352
353	lp = devm_kzalloc(&cl->dev, sizeof(struct lp855x), GFP_KERNEL);
354	if (!lp)
355	return -ENOMEM;
356
357	mode = pdata->mode;
358	lp->client = cl;
359	lp->dev = &cl->dev;
360	lp->pdata = pdata;
361	lp->chipname = id->name;
362	lp->chip_id = id->driver_data;
363	i2c_set_clientdata(cl, lp);
364
68853bc2	365	ret = lp855x_configure(lp);
7be865ab	366	if (ret) {
68853bc2 KM	367	dev_err(lp->dev, "device config err: %d", ret);
68853bc2 KM	368	goto err_dev;
7be865ab KM	369	}
	370
	371	ret = lp855x_backlight_register(lp);
	372	if (ret) {
	373	dev_err(lp->dev,
	374	"failed to register backlight. err: %d\n", ret);
	375	goto err_dev;
	376	}
	377
	378	ret = sysfs_create_group(&lp->dev->kobj, &lp855x_attr_group);
	379	if (ret) {
	380	dev_err(lp->dev, "failed to register sysfs. err: %d\n", ret);
	381	goto err_sysfs;
	382	}
	383
	384	backlight_update_status(lp->bl);
	385	return 0;
	386
	387	err_sysfs:
	388	lp855x_backlight_unregister(lp);
	389	err_dev:
	390	return ret;
	391	}
	392
7e4b9d0b	393	static int lp855x_remove(struct i2c_client *cl)
7be865ab KM	394	{
	395	struct lp855x *lp = i2c_get_clientdata(cl);
	396
	397	lp->bl->props.brightness = 0;
	398	backlight_update_status(lp->bl);
	399	sysfs_remove_group(&lp->dev->kobj, &lp855x_attr_group);
	400	lp855x_backlight_unregister(lp);
	401
	402	return 0;
	403	}
	404
	405	static const struct i2c_device_id lp855x_ids[] = {
	406	{"lp8550", LP8550},
	407	{"lp8551", LP8551},
	408	{"lp8552", LP8552},
	409	{"lp8553", LP8553},
	410	{"lp8556", LP8556},
26e8ccc2	411	{"lp8557", LP8557},
7be865ab KM	412	{ }
	413	};
	414	MODULE_DEVICE_TABLE(i2c, lp855x_ids);
	415
	416	static struct i2c_driver lp855x_driver = {
	417	.driver = {
	418	.name = "lp855x",
	419	},
	420	.probe = lp855x_probe,
d1723fa2	421	.remove = lp855x_remove,
7be865ab KM	422	.id_table = lp855x_ids,
	423	};
	424
	425	module_i2c_driver(lp855x_driver);
	426
	427	MODULE_DESCRIPTION("Texas Instruments LP855x Backlight driver");
	428	MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
	429	MODULE_LICENSE("GPL");