[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/of.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

/* LP8555/7 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 LP8555_EPROM_START		0x10
#define LP8555_EPROM_END		0x7A
#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 LP8555:
		start = LP8555_EPROM_START;
		end = LP8555_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:
	case LP8551:
	case LP8552:
	case LP8553:
	case LP8556:
		lp->cfg = &lp855x_dev_cfg;
		break;
	case LP8555:
	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->size_program > 0) {
		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_CORE_FBBLANK))
		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 = devm_backlight_device_register(lp->dev, name, lp->dev, lp,
				       &lp855x_bl_ops, &props);
	if (IS_ERR(bl))
		return PTR_ERR(bl);

	lp->bl = bl;

	return 0;
}

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,
};

#ifdef CONFIG_OF
static int lp855x_parse_dt(struct device *dev, struct device_node *node)
{
	struct lp855x_platform_data *pdata;
	int rom_length;

	if (!node) {
		dev_err(dev, "no platform data\n");
		return -EINVAL;
	}

	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;

	of_property_read_string(node, "bl-name", &pdata->name);
	of_property_read_u8(node, "dev-ctrl", &pdata->device_control);
	of_property_read_u8(node, "init-brt", &pdata->initial_brightness);
	of_property_read_u32(node, "pwm-period", &pdata->period_ns);

	/* Fill ROM platform data if defined */
	rom_length = of_get_child_count(node);
	if (rom_length > 0) {
		struct lp855x_rom_data *rom;
		struct device_node *child;
		int i = 0;

		rom = devm_kzalloc(dev, sizeof(*rom) * rom_length, GFP_KERNEL);
		if (!rom)
			return -ENOMEM;

		for_each_child_of_node(node, child) {
			of_property_read_u8(child, "rom-addr", &rom[i].addr);
			of_property_read_u8(child, "rom-val", &rom[i].val);
			i++;
		}

		pdata->size_program = rom_length;
		pdata->rom_data = &rom[0];
	}

	dev->platform_data = pdata;

	return 0;
}
#else
static int lp855x_parse_dt(struct device *dev, struct device_node *node)
{
	return -EINVAL;
}
#endif

static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
{
	struct lp855x *lp;
	struct lp855x_platform_data *pdata = dev_get_platdata(&cl->dev);
	struct device_node *node = cl->dev.of_node;
	int ret;

	if (!pdata) {
		ret = lp855x_parse_dt(&cl->dev, node);
		if (ret < 0)
			return ret;

		pdata = dev_get_platdata(&cl->dev);
	}

	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);
		return ret;
	}

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

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

	backlight_update_status(lp->bl);
	return 0;
}

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);

	return 0;
}

static const struct of_device_id lp855x_dt_ids[] = {
	{ .compatible = "ti,lp8550", },
	{ .compatible = "ti,lp8551", },
	{ .compatible = "ti,lp8552", },
	{ .compatible = "ti,lp8553", },
	{ .compatible = "ti,lp8555", },
	{ .compatible = "ti,lp8556", },
	{ .compatible = "ti,lp8557", },
	{ }
};
MODULE_DEVICE_TABLE(of, lp855x_dt_ids);

static const struct i2c_device_id lp855x_ids[] = {
	{"lp8550", LP8550},
	{"lp8551", LP8551},
	{"lp8552", LP8552},
	{"lp8553", LP8553},
	{"lp8555", LP8555},
	{"lp8556", LP8556},
	{"lp8557", LP8557},
	{ }
};
MODULE_DEVICE_TABLE(i2c, lp855x_ids);

static struct i2c_driver lp855x_driver = {
	.driver = {
		   .name = "lp855x",
		   .of_match_table = of_match_ptr(lp855x_dt_ids),
		   },
	.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>
4add0664	17	#include <linux/of.h>
f7f95056	18	#include <linux/platform_data/lp855x.h>
8cc9764c	19	#include <linux/pwm.h>
7be865ab	20
26e8ccc2 KM	21	/* LP8550/1/2/3/6 Registers */
	22	#define LP855X_BRIGHTNESS_CTRL 0x00
	23	#define LP855X_DEVICE_CTRL 0x01
	24	#define LP855X_EEPROM_START 0xA0
	25	#define LP855X_EEPROM_END 0xA7
	26	#define LP8556_EPROM_START 0xA0
	27	#define LP8556_EPROM_END 0xAF
	28
5812c13a	29	/* LP8555/7 Registers */
26e8ccc2 KM	30	#define LP8557_BL_CMD 0x00
	31	#define LP8557_BL_MASK 0x01
	32	#define LP8557_BL_ON 0x01
	33	#define LP8557_BL_OFF 0x00
	34	#define LP8557_BRIGHTNESS_CTRL 0x04
	35	#define LP8557_CONFIG 0x10
5812c13a MK	36	#define LP8555_EPROM_START 0x10
5812c13a MK	37	#define LP8555_EPROM_END 0x7A
26e8ccc2 KM	38	#define LP8557_EPROM_START 0x10
26e8ccc2 KM	39	#define LP8557_EPROM_END 0x1E
7be865ab	40
7be865ab KM	41	#define DEFAULT_BL_NAME "lcd-backlight"
	42	#define MAX_BRIGHTNESS 255
	43
0b818573 KM	44	enum lp855x_brightness_ctrl_mode {
	45	PWM_BASED = 1,
	46	REGISTER_BASED,
	47	};
	48
68853bc2 KM	49	struct lp855x;
	50
	51	/*
	52	* struct lp855x_device_config
	53	* @pre_init_device: init device function call before updating the brightness
	54	* @reg_brightness: register address for brigthenss control
	55	* @reg_devicectrl: register address for device control
	56	* @post_init_device: late init device function call
	57	*/
	58	struct lp855x_device_config {
	59	int (pre_init_device)(struct lp855x );
	60	u8 reg_brightness;
	61	u8 reg_devicectrl;
	62	int (post_init_device)(struct lp855x );
	63	};
	64
7be865ab KM	65	struct lp855x {
	66	const char *chipname;
	67	enum lp855x_chip_id chip_id;
0b818573	68	enum lp855x_brightness_ctrl_mode mode;
68853bc2	69	struct lp855x_device_config *cfg;
7be865ab KM	70	struct i2c_client *client;
	71	struct backlight_device *bl;
	72	struct device *dev;
7be865ab	73	struct lp855x_platform_data *pdata;
8cc9764c	74	struct pwm_device *pwm;
7be865ab KM	75	};
7be865ab KM	76
7be865ab KM	77	static int lp855x_write_byte(struct lp855x *lp, u8 reg, u8 data)
7be865ab KM	78	{
eaa4d02f	79	return i2c_smbus_write_byte_data(lp->client, reg, data);
7be865ab KM	80	}
7be865ab KM	81
26e8ccc2 KM	82	static int lp855x_update_bit(struct lp855x *lp, u8 reg, u8 mask, u8 data)
	83	{
	84	int ret;
	85	u8 tmp;
	86
	87	ret = i2c_smbus_read_byte_data(lp->client, reg);
	88	if (ret < 0) {
	89	dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
	90	return ret;
	91	}
	92
	93	tmp = (u8)ret;
	94	tmp &= ~mask;
	95	tmp \|= data & mask;
	96
	97	return lp855x_write_byte(lp, reg, tmp);
	98	}
	99
7be865ab KM	100	static bool lp855x_is_valid_rom_area(struct lp855x *lp, u8 addr)
	101	{
	102	u8 start, end;
	103
	104	switch (lp->chip_id) {
	105	case LP8550:
	106	case LP8551:
	107	case LP8552:
	108	case LP8553:
26e8ccc2 KM	109	start = LP855X_EEPROM_START;
26e8ccc2 KM	110	end = LP855X_EEPROM_END;
7be865ab KM	111	break;
7be865ab KM	112	case LP8556:
26e8ccc2 KM	113	start = LP8556_EPROM_START;
	114	end = LP8556_EPROM_END;
	115	break;
5812c13a MK	116	case LP8555:
	117	start = LP8555_EPROM_START;
	118	end = LP8555_EPROM_END;
	119	break;
26e8ccc2 KM	120	case LP8557:
	121	start = LP8557_EPROM_START;
	122	end = LP8557_EPROM_END;
7be865ab KM	123	break;
	124	default:
	125	return false;
	126	}
	127
	128	return (addr >= start && addr <= end);
	129	}
	130
26e8ccc2 KM	131	static int lp8557_bl_off(struct lp855x *lp)
	132	{
	133	/* BL_ON = 0 before updating EPROM settings */
	134	return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
	135	LP8557_BL_OFF);
	136	}
	137
	138	static int lp8557_bl_on(struct lp855x *lp)
	139	{
	140	/* BL_ON = 1 after updating EPROM settings */
	141	return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
	142	LP8557_BL_ON);
	143	}
	144
68853bc2	145	static struct lp855x_device_config lp855x_dev_cfg = {
26e8ccc2 KM	146	.reg_brightness = LP855X_BRIGHTNESS_CTRL,
	147	.reg_devicectrl = LP855X_DEVICE_CTRL,
	148	};
	149
	150	static struct lp855x_device_config lp8557_dev_cfg = {
	151	.reg_brightness = LP8557_BRIGHTNESS_CTRL,
	152	.reg_devicectrl = LP8557_CONFIG,
	153	.pre_init_device = lp8557_bl_off,
	154	.post_init_device = lp8557_bl_on,
68853bc2 KM	155	};
	156
	157	/*
	158	* Device specific configuration flow
	159	*
	160	* a) pre_init_device(optional)
	161	* b) update the brightness register
	162	* c) update device control register
	163	* d) update ROM area(optional)
	164	* e) post_init_device(optional)
	165	*
	166	*/
	167	static int lp855x_configure(struct lp855x *lp)
7be865ab KM	168	{
	169	u8 val, addr;
	170	int i, ret;
	171	struct lp855x_platform_data *pd = lp->pdata;
	172
68853bc2	173	switch (lp->chip_id) {
5812c13a MK	174	case LP8550:
	175	case LP8551:
	176	case LP8552:
	177	case LP8553:
	178	case LP8556:
68853bc2 KM	179	lp->cfg = &lp855x_dev_cfg;
68853bc2 KM	180	break;
5812c13a	181	case LP8555:
26e8ccc2 KM	182	case LP8557:
	183	lp->cfg = &lp8557_dev_cfg;
	184	break;
68853bc2 KM	185	default:
	186	return -EINVAL;
	187	}
	188
	189	if (lp->cfg->pre_init_device) {
	190	ret = lp->cfg->pre_init_device(lp);
	191	if (ret) {
	192	dev_err(lp->dev, "pre init device err: %d\n", ret);
	193	goto err;
	194	}
	195	}
	196
7be865ab	197	val = pd->initial_brightness;
68853bc2	198	ret = lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
7be865ab	199	if (ret)
68853bc2	200	goto err;
7be865ab KM	201
7be865ab KM	202	val = pd->device_control;
68853bc2	203	ret = lp855x_write_byte(lp, lp->cfg->reg_devicectrl, val);
7be865ab	204	if (ret)
68853bc2	205	goto err;
7be865ab	206
c365e59d	207	if (pd->size_program > 0) {
7be865ab KM	208	for (i = 0; i < pd->size_program; i++) {
	209	addr = pd->rom_data[i].addr;
	210	val = pd->rom_data[i].val;
	211	if (!lp855x_is_valid_rom_area(lp, addr))
	212	continue;
	213
	214	ret = lp855x_write_byte(lp, addr, val);
	215	if (ret)
68853bc2 KM	216	goto err;
	217	}
	218	}
	219
	220	if (lp->cfg->post_init_device) {
	221	ret = lp->cfg->post_init_device(lp);
	222	if (ret) {
	223	dev_err(lp->dev, "post init device err: %d\n", ret);
	224	goto err;
7be865ab KM	225	}
	226	}
	227
68853bc2 KM	228	return 0;
	229
	230	err:
7be865ab KM	231	return ret;
	232	}
	233
8cc9764c KM	234	static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
	235	{
	236	unsigned int period = lp->pdata->period_ns;
	237	unsigned int duty = br * period / max_br;
	238	struct pwm_device *pwm;
	239
	240	/* request pwm device with the consumer name */
	241	if (!lp->pwm) {
	242	pwm = devm_pwm_get(lp->dev, lp->chipname);
	243	if (IS_ERR(pwm))
	244	return;
	245
	246	lp->pwm = pwm;
	247	}
	248
	249	pwm_config(lp->pwm, duty, period);
	250	if (duty)
	251	pwm_enable(lp->pwm);
	252	else
	253	pwm_disable(lp->pwm);
	254	}
	255
7be865ab KM	256	static int lp855x_bl_update_status(struct backlight_device *bl)
	257	{
	258	struct lp855x *lp = bl_get_data(bl);
7be865ab	259
9f0a511f	260	if (bl->props.state & (BL_CORE_SUSPENDED \| BL_CORE_FBBLANK))
7be865ab KM	261	bl->props.brightness = 0;
7be865ab KM	262
0b818573	263	if (lp->mode == PWM_BASED) {
7be865ab KM	264	int br = bl->props.brightness;
	265	int max_br = bl->props.max_brightness;
	266
8cc9764c	267	lp855x_pwm_ctrl(lp, br, max_br);
7be865ab	268
0b818573	269	} else if (lp->mode == REGISTER_BASED) {
7be865ab	270	u8 val = bl->props.brightness;
26e8ccc2	271	lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
7be865ab KM	272	}
	273
	274	return 0;
	275	}
	276
	277	static int lp855x_bl_get_brightness(struct backlight_device *bl)
	278	{
7be865ab KM	279	return bl->props.brightness;
	280	}
	281
	282	static const struct backlight_ops lp855x_bl_ops = {
	283	.options = BL_CORE_SUSPENDRESUME,
	284	.update_status = lp855x_bl_update_status,
	285	.get_brightness = lp855x_bl_get_brightness,
	286	};
	287
	288	static int lp855x_backlight_register(struct lp855x *lp)
	289	{
	290	struct backlight_device *bl;
	291	struct backlight_properties props;
	292	struct lp855x_platform_data *pdata = lp->pdata;
600ffd33	293	const char *name = pdata->name ? : DEFAULT_BL_NAME;
7be865ab KM	294
	295	props.type = BACKLIGHT_PLATFORM;
	296	props.max_brightness = MAX_BRIGHTNESS;
	297
	298	if (pdata->initial_brightness > props.max_brightness)
	299	pdata->initial_brightness = props.max_brightness;
	300
	301	props.brightness = pdata->initial_brightness;
	302
6255e8e9	303	bl = devm_backlight_device_register(lp->dev, name, lp->dev, lp,
7be865ab KM	304	&lp855x_bl_ops, &props);
	305	if (IS_ERR(bl))
	306	return PTR_ERR(bl);
	307
	308	lp->bl = bl;
	309
	310	return 0;
	311	}
	312
7be865ab KM	313	static ssize_t lp855x_get_chip_id(struct device *dev,
	314	struct device_attribute attr, char buf)
	315	{
	316	struct lp855x *lp = dev_get_drvdata(dev);
6a7aeb1a	317	return scnprintf(buf, PAGE_SIZE, "%s\n", lp->chipname);
7be865ab KM	318	}
	319
	320	static ssize_t lp855x_get_bl_ctl_mode(struct device *dev,
	321	struct device_attribute attr, char buf)
	322	{
	323	struct lp855x *lp = dev_get_drvdata(dev);
7be865ab KM	324	char *strmode = NULL;
7be865ab KM	325
0b818573	326	if (lp->mode == PWM_BASED)
7be865ab	327	strmode = "pwm based";
0b818573	328	else if (lp->mode == REGISTER_BASED)
7be865ab KM	329	strmode = "register based";
7be865ab KM	330
6a7aeb1a	331	return scnprintf(buf, PAGE_SIZE, "%s\n", strmode);
7be865ab KM	332	}
	333
	334	static DEVICE_ATTR(chip_id, S_IRUGO, lp855x_get_chip_id, NULL);
	335	static DEVICE_ATTR(bl_ctl_mode, S_IRUGO, lp855x_get_bl_ctl_mode, NULL);
	336
	337	static struct attribute *lp855x_attributes[] = {
	338	&dev_attr_chip_id.attr,
	339	&dev_attr_bl_ctl_mode.attr,
	340	NULL,
	341	};
	342
	343	static const struct attribute_group lp855x_attr_group = {
	344	.attrs = lp855x_attributes,
	345	};
	346
4add0664 KM	347	#ifdef CONFIG_OF
	348	static int lp855x_parse_dt(struct device dev, struct device_node node)
	349	{
	350	struct lp855x_platform_data *pdata;
	351	int rom_length;
	352
	353	if (!node) {
	354	dev_err(dev, "no platform data\n");
	355	return -EINVAL;
	356	}
	357
	358	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
	359	if (!pdata)
	360	return -ENOMEM;
	361
	362	of_property_read_string(node, "bl-name", &pdata->name);
	363	of_property_read_u8(node, "dev-ctrl", &pdata->device_control);
	364	of_property_read_u8(node, "init-brt", &pdata->initial_brightness);
	365	of_property_read_u32(node, "pwm-period", &pdata->period_ns);
	366
	367	/* Fill ROM platform data if defined */
	368	rom_length = of_get_child_count(node);
	369	if (rom_length > 0) {
	370	struct lp855x_rom_data *rom;
	371	struct device_node *child;
	372	int i = 0;
	373
	374	rom = devm_kzalloc(dev, sizeof(rom) rom_length, GFP_KERNEL);
	375	if (!rom)
	376	return -ENOMEM;
	377
	378	for_each_child_of_node(node, child) {
	379	of_property_read_u8(child, "rom-addr", &rom[i].addr);
	380	of_property_read_u8(child, "rom-val", &rom[i].val);
	381	i++;
	382	}
	383
	384	pdata->size_program = rom_length;
	385	pdata->rom_data = &rom[0];
	386	}
	387
	388	dev->platform_data = pdata;
	389
	390	return 0;
	391	}
	392	#else
	393	static int lp855x_parse_dt(struct device dev, struct device_node node)
	394	{
	395	return -EINVAL;
	396	}
	397	#endif
	398
7be865ab KM	399	static int lp855x_probe(struct i2c_client cl, const struct i2c_device_id id)
	400	{
	401	struct lp855x *lp;
c512794c	402	struct lp855x_platform_data *pdata = dev_get_platdata(&cl->dev);
4add0664	403	struct device_node *node = cl->dev.of_node;
7be865ab KM	404	int ret;
	405
	406	if (!pdata) {
4add0664 KM	407	ret = lp855x_parse_dt(&cl->dev, node);
	408	if (ret < 0)
	409	return ret;
	410
c512794c	411	pdata = dev_get_platdata(&cl->dev);
7be865ab KM	412	}
	413
	414	if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
	415	return -EIO;
	416
	417	lp = devm_kzalloc(&cl->dev, sizeof(struct lp855x), GFP_KERNEL);
	418	if (!lp)
	419	return -ENOMEM;
	420
0b818573 KM	421	if (pdata->period_ns > 0)
	422	lp->mode = PWM_BASED;
	423	else
	424	lp->mode = REGISTER_BASED;
	425
7be865ab KM	426	lp->client = cl;
	427	lp->dev = &cl->dev;
	428	lp->pdata = pdata;
	429	lp->chipname = id->name;
	430	lp->chip_id = id->driver_data;
	431	i2c_set_clientdata(cl, lp);
	432
68853bc2	433	ret = lp855x_configure(lp);
7be865ab	434	if (ret) {
68853bc2	435	dev_err(lp->dev, "device config err: %d", ret);
6255e8e9	436	return ret;
7be865ab KM	437	}
	438
	439	ret = lp855x_backlight_register(lp);
	440	if (ret) {
	441	dev_err(lp->dev,
	442	"failed to register backlight. err: %d\n", ret);
6255e8e9	443	return ret;
7be865ab KM	444	}
	445
	446	ret = sysfs_create_group(&lp->dev->kobj, &lp855x_attr_group);
	447	if (ret) {
	448	dev_err(lp->dev, "failed to register sysfs. err: %d\n", ret);
6255e8e9	449	return ret;
7be865ab KM	450	}
	451
	452	backlight_update_status(lp->bl);
	453	return 0;
7be865ab KM	454	}
7be865ab KM	455
7e4b9d0b	456	static int lp855x_remove(struct i2c_client *cl)
7be865ab KM	457	{
	458	struct lp855x *lp = i2c_get_clientdata(cl);
	459
	460	lp->bl->props.brightness = 0;
	461	backlight_update_status(lp->bl);
	462	sysfs_remove_group(&lp->dev->kobj, &lp855x_attr_group);
7be865ab KM	463
	464	return 0;
	465	}
	466
4add0664 KM	467	static const struct of_device_id lp855x_dt_ids[] = {
	468	{ .compatible = "ti,lp8550", },
	469	{ .compatible = "ti,lp8551", },
	470	{ .compatible = "ti,lp8552", },
	471	{ .compatible = "ti,lp8553", },
5812c13a	472	{ .compatible = "ti,lp8555", },
4add0664 KM	473	{ .compatible = "ti,lp8556", },
	474	{ .compatible = "ti,lp8557", },
	475	{ }
	476	};
	477	MODULE_DEVICE_TABLE(of, lp855x_dt_ids);
	478
7be865ab KM	479	static const struct i2c_device_id lp855x_ids[] = {
	480	{"lp8550", LP8550},
	481	{"lp8551", LP8551},
	482	{"lp8552", LP8552},
	483	{"lp8553", LP8553},
5812c13a	484	{"lp8555", LP8555},
7be865ab	485	{"lp8556", LP8556},
26e8ccc2	486	{"lp8557", LP8557},
7be865ab KM	487	{ }
	488	};
	489	MODULE_DEVICE_TABLE(i2c, lp855x_ids);
	490
	491	static struct i2c_driver lp855x_driver = {
	492	.driver = {
	493	.name = "lp855x",
4add0664	494	.of_match_table = of_match_ptr(lp855x_dt_ids),
7be865ab KM	495	},
7be865ab KM	496	.probe = lp855x_probe,
d1723fa2	497	.remove = lp855x_remove,
7be865ab KM	498	.id_table = lp855x_ids,
	499	};
	500
	501	module_i2c_driver(lp855x_driver);
	502
	503	MODULE_DESCRIPTION("Texas Instruments LP855x Backlight driver");
	504	MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
	505	MODULE_LICENSE("GPL");