[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 DEFAULT_BL_NAME		"lcd-backlight"
#define MAX_BRIGHTNESS		255

enum lp855x_brightness_ctrl_mode {
	PWM_BASED = 1,
	REGISTER_BASED,
};

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;
	enum lp855x_brightness_ctrl_mode mode;
	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);

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

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

		lp855x_pwm_ctrl(lp, br, max_br);

	} else if (lp->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;
	const 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, PAGE_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);
	char *strmode = NULL;

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

	return scnprintf(buf, PAGE_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;
	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;

	if (pdata->period_ns > 0)
		lp->mode = PWM_BASED;
	else
		lp->mode = REGISTER_BASED;

	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	37
7be865ab KM	38	#define DEFAULT_BL_NAME "lcd-backlight"
	39	#define MAX_BRIGHTNESS 255
	40
0b818573 KM	41	enum lp855x_brightness_ctrl_mode {
	42	PWM_BASED = 1,
	43	REGISTER_BASED,
	44	};
	45
68853bc2 KM	46	struct lp855x;
	47
	48	/*
	49	* struct lp855x_device_config
	50	* @pre_init_device: init device function call before updating the brightness
	51	* @reg_brightness: register address for brigthenss control
	52	* @reg_devicectrl: register address for device control
	53	* @post_init_device: late init device function call
	54	*/
	55	struct lp855x_device_config {
	56	int (pre_init_device)(struct lp855x );
	57	u8 reg_brightness;
	58	u8 reg_devicectrl;
	59	int (post_init_device)(struct lp855x );
	60	};
	61
7be865ab KM	62	struct lp855x {
	63	const char *chipname;
	64	enum lp855x_chip_id chip_id;
0b818573	65	enum lp855x_brightness_ctrl_mode mode;
68853bc2	66	struct lp855x_device_config *cfg;
7be865ab KM	67	struct i2c_client *client;
	68	struct backlight_device *bl;
	69	struct device *dev;
7be865ab	70	struct lp855x_platform_data *pdata;
8cc9764c	71	struct pwm_device *pwm;
7be865ab KM	72	};
7be865ab KM	73
7be865ab KM	74	static int lp855x_write_byte(struct lp855x *lp, u8 reg, u8 data)
7be865ab KM	75	{
eaa4d02f	76	return i2c_smbus_write_byte_data(lp->client, reg, data);
7be865ab KM	77	}
7be865ab KM	78
26e8ccc2 KM	79	static int lp855x_update_bit(struct lp855x *lp, u8 reg, u8 mask, u8 data)
	80	{
	81	int ret;
	82	u8 tmp;
	83
	84	ret = i2c_smbus_read_byte_data(lp->client, reg);
	85	if (ret < 0) {
	86	dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
	87	return ret;
	88	}
	89
	90	tmp = (u8)ret;
	91	tmp &= ~mask;
	92	tmp \|= data & mask;
	93
	94	return lp855x_write_byte(lp, reg, tmp);
	95	}
	96
7be865ab KM	97	static bool lp855x_is_valid_rom_area(struct lp855x *lp, u8 addr)
	98	{
	99	u8 start, end;
	100
	101	switch (lp->chip_id) {
	102	case LP8550:
	103	case LP8551:
	104	case LP8552:
	105	case LP8553:
26e8ccc2 KM	106	start = LP855X_EEPROM_START;
26e8ccc2 KM	107	end = LP855X_EEPROM_END;
7be865ab KM	108	break;
7be865ab KM	109	case LP8556:
26e8ccc2 KM	110	start = LP8556_EPROM_START;
	111	end = LP8556_EPROM_END;
	112	break;
	113	case LP8557:
	114	start = LP8557_EPROM_START;
	115	end = LP8557_EPROM_END;
7be865ab KM	116	break;
	117	default:
	118	return false;
	119	}
	120
	121	return (addr >= start && addr <= end);
	122	}
	123
26e8ccc2 KM	124	static int lp8557_bl_off(struct lp855x *lp)
	125	{
	126	/* BL_ON = 0 before updating EPROM settings */
	127	return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
	128	LP8557_BL_OFF);
	129	}
	130
	131	static int lp8557_bl_on(struct lp855x *lp)
	132	{
	133	/* BL_ON = 1 after updating EPROM settings */
	134	return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
	135	LP8557_BL_ON);
	136	}
	137
68853bc2	138	static struct lp855x_device_config lp855x_dev_cfg = {
26e8ccc2 KM	139	.reg_brightness = LP855X_BRIGHTNESS_CTRL,
	140	.reg_devicectrl = LP855X_DEVICE_CTRL,
	141	};
	142
	143	static struct lp855x_device_config lp8557_dev_cfg = {
	144	.reg_brightness = LP8557_BRIGHTNESS_CTRL,
	145	.reg_devicectrl = LP8557_CONFIG,
	146	.pre_init_device = lp8557_bl_off,
	147	.post_init_device = lp8557_bl_on,
68853bc2 KM	148	};
	149
	150	/*
	151	* Device specific configuration flow
	152	*
	153	* a) pre_init_device(optional)
	154	* b) update the brightness register
	155	* c) update device control register
	156	* d) update ROM area(optional)
	157	* e) post_init_device(optional)
	158	*
	159	*/
	160	static int lp855x_configure(struct lp855x *lp)
7be865ab KM	161	{
	162	u8 val, addr;
	163	int i, ret;
	164	struct lp855x_platform_data *pd = lp->pdata;
	165
68853bc2 KM	166	switch (lp->chip_id) {
	167	case LP8550 ... LP8556:
	168	lp->cfg = &lp855x_dev_cfg;
	169	break;
26e8ccc2 KM	170	case LP8557:
	171	lp->cfg = &lp8557_dev_cfg;
	172	break;
68853bc2 KM	173	default:
	174	return -EINVAL;
	175	}
	176
	177	if (lp->cfg->pre_init_device) {
	178	ret = lp->cfg->pre_init_device(lp);
	179	if (ret) {
	180	dev_err(lp->dev, "pre init device err: %d\n", ret);
	181	goto err;
	182	}
	183	}
	184
7be865ab	185	val = pd->initial_brightness;
68853bc2	186	ret = lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
7be865ab	187	if (ret)
68853bc2	188	goto err;
7be865ab KM	189
7be865ab KM	190	val = pd->device_control;
68853bc2	191	ret = lp855x_write_byte(lp, lp->cfg->reg_devicectrl, val);
7be865ab	192	if (ret)
68853bc2	193	goto err;
7be865ab KM	194
	195	if (pd->load_new_rom_data && pd->size_program) {
	196	for (i = 0; i < pd->size_program; i++) {
	197	addr = pd->rom_data[i].addr;
	198	val = pd->rom_data[i].val;
	199	if (!lp855x_is_valid_rom_area(lp, addr))
	200	continue;
	201
	202	ret = lp855x_write_byte(lp, addr, val);
	203	if (ret)
68853bc2 KM	204	goto err;
	205	}
	206	}
	207
	208	if (lp->cfg->post_init_device) {
	209	ret = lp->cfg->post_init_device(lp);
	210	if (ret) {
	211	dev_err(lp->dev, "post init device err: %d\n", ret);
	212	goto err;
7be865ab KM	213	}
	214	}
	215
68853bc2 KM	216	return 0;
	217
	218	err:
7be865ab KM	219	return ret;
	220	}
	221
8cc9764c KM	222	static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
	223	{
	224	unsigned int period = lp->pdata->period_ns;
	225	unsigned int duty = br * period / max_br;
	226	struct pwm_device *pwm;
	227
	228	/* request pwm device with the consumer name */
	229	if (!lp->pwm) {
	230	pwm = devm_pwm_get(lp->dev, lp->chipname);
	231	if (IS_ERR(pwm))
	232	return;
	233
	234	lp->pwm = pwm;
	235	}
	236
	237	pwm_config(lp->pwm, duty, period);
	238	if (duty)
	239	pwm_enable(lp->pwm);
	240	else
	241	pwm_disable(lp->pwm);
	242	}
	243
7be865ab KM	244	static int lp855x_bl_update_status(struct backlight_device *bl)
	245	{
	246	struct lp855x *lp = bl_get_data(bl);
7be865ab KM	247
	248	if (bl->props.state & BL_CORE_SUSPENDED)
	249	bl->props.brightness = 0;
	250
0b818573	251	if (lp->mode == PWM_BASED) {
7be865ab KM	252	int br = bl->props.brightness;
	253	int max_br = bl->props.max_brightness;
	254
8cc9764c	255	lp855x_pwm_ctrl(lp, br, max_br);
7be865ab	256
0b818573	257	} else if (lp->mode == REGISTER_BASED) {
7be865ab	258	u8 val = bl->props.brightness;
26e8ccc2	259	lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
7be865ab KM	260	}
	261
	262	return 0;
	263	}
	264
	265	static int lp855x_bl_get_brightness(struct backlight_device *bl)
	266	{
7be865ab KM	267	return bl->props.brightness;
	268	}
	269
	270	static const struct backlight_ops lp855x_bl_ops = {
	271	.options = BL_CORE_SUSPENDRESUME,
	272	.update_status = lp855x_bl_update_status,
	273	.get_brightness = lp855x_bl_get_brightness,
	274	};
	275
	276	static int lp855x_backlight_register(struct lp855x *lp)
	277	{
	278	struct backlight_device *bl;
	279	struct backlight_properties props;
	280	struct lp855x_platform_data *pdata = lp->pdata;
600ffd33	281	const char *name = pdata->name ? : DEFAULT_BL_NAME;
7be865ab KM	282
	283	props.type = BACKLIGHT_PLATFORM;
	284	props.max_brightness = MAX_BRIGHTNESS;
	285
	286	if (pdata->initial_brightness > props.max_brightness)
	287	pdata->initial_brightness = props.max_brightness;
	288
	289	props.brightness = pdata->initial_brightness;
	290
	291	bl = backlight_device_register(name, lp->dev, lp,
	292	&lp855x_bl_ops, &props);
	293	if (IS_ERR(bl))
	294	return PTR_ERR(bl);
	295
	296	lp->bl = bl;
	297
	298	return 0;
	299	}
	300
	301	static void lp855x_backlight_unregister(struct lp855x *lp)
	302	{
	303	if (lp->bl)
	304	backlight_device_unregister(lp->bl);
	305	}
	306
	307	static ssize_t lp855x_get_chip_id(struct device *dev,
	308	struct device_attribute attr, char buf)
	309	{
	310	struct lp855x *lp = dev_get_drvdata(dev);
6a7aeb1a	311	return scnprintf(buf, PAGE_SIZE, "%s\n", lp->chipname);
7be865ab KM	312	}
	313
	314	static ssize_t lp855x_get_bl_ctl_mode(struct device *dev,
	315	struct device_attribute attr, char buf)
	316	{
	317	struct lp855x *lp = dev_get_drvdata(dev);
7be865ab KM	318	char *strmode = NULL;
7be865ab KM	319
0b818573	320	if (lp->mode == PWM_BASED)
7be865ab	321	strmode = "pwm based";
0b818573	322	else if (lp->mode == REGISTER_BASED)
7be865ab KM	323	strmode = "register based";
7be865ab KM	324
6a7aeb1a	325	return scnprintf(buf, PAGE_SIZE, "%s\n", strmode);
7be865ab KM	326	}
	327
	328	static DEVICE_ATTR(chip_id, S_IRUGO, lp855x_get_chip_id, NULL);
	329	static DEVICE_ATTR(bl_ctl_mode, S_IRUGO, lp855x_get_bl_ctl_mode, NULL);
	330
	331	static struct attribute *lp855x_attributes[] = {
	332	&dev_attr_chip_id.attr,
	333	&dev_attr_bl_ctl_mode.attr,
	334	NULL,
	335	};
	336
	337	static const struct attribute_group lp855x_attr_group = {
	338	.attrs = lp855x_attributes,
	339	};
	340
	341	static int lp855x_probe(struct i2c_client cl, const struct i2c_device_id id)
	342	{
	343	struct lp855x *lp;
	344	struct lp855x_platform_data *pdata = cl->dev.platform_data;
7be865ab KM	345	int ret;
	346
	347	if (!pdata) {
	348	dev_err(&cl->dev, "no platform data supplied\n");
	349	return -EINVAL;
	350	}
	351
	352	if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
	353	return -EIO;
	354
	355	lp = devm_kzalloc(&cl->dev, sizeof(struct lp855x), GFP_KERNEL);
	356	if (!lp)
	357	return -ENOMEM;
	358
0b818573 KM	359	if (pdata->period_ns > 0)
	360	lp->mode = PWM_BASED;
	361	else
	362	lp->mode = REGISTER_BASED;
	363
7be865ab KM	364	lp->client = cl;
	365	lp->dev = &cl->dev;
	366	lp->pdata = pdata;
	367	lp->chipname = id->name;
	368	lp->chip_id = id->driver_data;
	369	i2c_set_clientdata(cl, lp);
	370
68853bc2	371	ret = lp855x_configure(lp);
7be865ab	372	if (ret) {
68853bc2 KM	373	dev_err(lp->dev, "device config err: %d", ret);
68853bc2 KM	374	goto err_dev;
7be865ab KM	375	}
	376
	377	ret = lp855x_backlight_register(lp);
	378	if (ret) {
	379	dev_err(lp->dev,
	380	"failed to register backlight. err: %d\n", ret);
	381	goto err_dev;
	382	}
	383
	384	ret = sysfs_create_group(&lp->dev->kobj, &lp855x_attr_group);
	385	if (ret) {
	386	dev_err(lp->dev, "failed to register sysfs. err: %d\n", ret);
	387	goto err_sysfs;
	388	}
	389
	390	backlight_update_status(lp->bl);
	391	return 0;
	392
	393	err_sysfs:
	394	lp855x_backlight_unregister(lp);
	395	err_dev:
	396	return ret;
	397	}
	398
7e4b9d0b	399	static int lp855x_remove(struct i2c_client *cl)
7be865ab KM	400	{
	401	struct lp855x *lp = i2c_get_clientdata(cl);
	402
	403	lp->bl->props.brightness = 0;
	404	backlight_update_status(lp->bl);
	405	sysfs_remove_group(&lp->dev->kobj, &lp855x_attr_group);
	406	lp855x_backlight_unregister(lp);
	407
	408	return 0;
	409	}
	410
	411	static const struct i2c_device_id lp855x_ids[] = {
	412	{"lp8550", LP8550},
	413	{"lp8551", LP8551},
	414	{"lp8552", LP8552},
	415	{"lp8553", LP8553},
	416	{"lp8556", LP8556},
26e8ccc2	417	{"lp8557", LP8557},
7be865ab KM	418	{ }
	419	};
	420	MODULE_DEVICE_TABLE(i2c, lp855x_ids);
	421
	422	static struct i2c_driver lp855x_driver = {
	423	.driver = {
	424	.name = "lp855x",
	425	},
	426	.probe = lp855x_probe,
d1723fa2	427	.remove = lp855x_remove,
7be865ab KM	428	.id_table = lp855x_ids,
	429	};
	430
	431	module_i2c_driver(lp855x_driver);
	432
	433	MODULE_DESCRIPTION("Texas Instruments LP855x Backlight driver");
	434	MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
	435	MODULE_LICENSE("GPL");