[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/delay.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/platform_data/lp855x.h>
#include <linux/pwm.h>
#include <linux/regulator/consumer.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;
	struct regulator *supply;	/* regulator for VDD input */
	struct regulator *enable;	/* regulator for EN/VDDIO input */
};

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;

		/*
		 * FIXME: pwm_apply_args() should be removed when switching to
		 * the atomic PWM API.
		 */
		pwm_apply_args(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);
	int brightness = bl->props.brightness;

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

	if (lp->mode == PWM_BASED)
		lp855x_pwm_ctrl(lp, brightness, bl->props.max_brightness);
	else if (lp->mode == REGISTER_BASED)
		lp855x_write_byte(lp, lp->cfg->reg_brightness, (u8)brightness);

	return 0;
}

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

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;

	memset(&props, 0, sizeof(props));
	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 lp855x *lp)
{
	struct device *dev = lp->dev;
	struct device_node *node = dev->of_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];
	}

	lp->pdata = pdata;

	return 0;
}
#else
static int lp855x_parse_dt(struct lp855x *lp)
{
	return -EINVAL;
}
#endif

static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
{
	struct lp855x *lp;
	int ret;

	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;

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

	if (!lp->pdata) {
		ret = lp855x_parse_dt(lp);
		if (ret < 0)
			return ret;
	}

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

	lp->supply = devm_regulator_get(lp->dev, "power");
	if (IS_ERR(lp->supply)) {
		if (PTR_ERR(lp->supply) == -EPROBE_DEFER)
			return -EPROBE_DEFER;
		lp->supply = NULL;
	}

	lp->enable = devm_regulator_get_optional(lp->dev, "enable");
	if (IS_ERR(lp->enable)) {
		ret = PTR_ERR(lp->enable);
		if (ret == -ENODEV) {
			lp->enable = NULL;
		} else {
			if (ret != -EPROBE_DEFER)
				dev_err(lp->dev, "error getting enable regulator: %d\n",
					ret);
			return ret;
		}
	}

	if (lp->supply) {
		ret = regulator_enable(lp->supply);
		if (ret < 0) {
			dev_err(&cl->dev, "failed to enable supply: %d\n", ret);
			return ret;
		}
	}

	if (lp->enable) {
		ret = regulator_enable(lp->enable);
		if (ret < 0) {
			dev_err(lp->dev, "failed to enable vddio: %d\n", ret);
			return ret;
		}

		/*
		 * LP8555 datasheet says t_RESPONSE (time between VDDIO and
		 * I2C) is 1ms.
		 */
		usleep_range(1000, 2000);
	}

	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);
	if (lp->supply)
		regulator_disable(lp->supply);
	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>
60255307	16	#include <linux/delay.h>
7be865ab	17	#include <linux/err.h>
4add0664	18	#include <linux/of.h>
f7f95056	19	#include <linux/platform_data/lp855x.h>
8cc9764c	20	#include <linux/pwm.h>
829b030e	21	#include <linux/regulator/consumer.h>
7be865ab	22
26e8ccc2 KM	23	/* LP8550/1/2/3/6 Registers */
	24	#define LP855X_BRIGHTNESS_CTRL 0x00
	25	#define LP855X_DEVICE_CTRL 0x01
	26	#define LP855X_EEPROM_START 0xA0
	27	#define LP855X_EEPROM_END 0xA7
	28	#define LP8556_EPROM_START 0xA0
	29	#define LP8556_EPROM_END 0xAF
	30
5812c13a	31	/* LP8555/7 Registers */
26e8ccc2 KM	32	#define LP8557_BL_CMD 0x00
	33	#define LP8557_BL_MASK 0x01
	34	#define LP8557_BL_ON 0x01
	35	#define LP8557_BL_OFF 0x00
	36	#define LP8557_BRIGHTNESS_CTRL 0x04
	37	#define LP8557_CONFIG 0x10
5812c13a MK	38	#define LP8555_EPROM_START 0x10
5812c13a MK	39	#define LP8555_EPROM_END 0x7A
26e8ccc2 KM	40	#define LP8557_EPROM_START 0x10
26e8ccc2 KM	41	#define LP8557_EPROM_END 0x1E
7be865ab	42
7be865ab KM	43	#define DEFAULT_BL_NAME "lcd-backlight"
	44	#define MAX_BRIGHTNESS 255
	45
0b818573 KM	46	enum lp855x_brightness_ctrl_mode {
	47	PWM_BASED = 1,
	48	REGISTER_BASED,
	49	};
	50
68853bc2 KM	51	struct lp855x;
	52
	53	/*
	54	* struct lp855x_device_config
	55	* @pre_init_device: init device function call before updating the brightness
	56	* @reg_brightness: register address for brigthenss control
	57	* @reg_devicectrl: register address for device control
	58	* @post_init_device: late init device function call
	59	*/
	60	struct lp855x_device_config {
	61	int (pre_init_device)(struct lp855x );
	62	u8 reg_brightness;
	63	u8 reg_devicectrl;
	64	int (post_init_device)(struct lp855x );
	65	};
	66
7be865ab KM	67	struct lp855x {
	68	const char *chipname;
	69	enum lp855x_chip_id chip_id;
0b818573	70	enum lp855x_brightness_ctrl_mode mode;
68853bc2	71	struct lp855x_device_config *cfg;
7be865ab KM	72	struct i2c_client *client;
	73	struct backlight_device *bl;
	74	struct device *dev;
7be865ab	75	struct lp855x_platform_data *pdata;
8cc9764c	76	struct pwm_device *pwm;
fe009175	77	struct regulator supply; / regulator for VDD input */
60255307	78	struct regulator enable; / regulator for EN/VDDIO input */
7be865ab KM	79	};
7be865ab KM	80
7be865ab KM	81	static int lp855x_write_byte(struct lp855x *lp, u8 reg, u8 data)
7be865ab KM	82	{
eaa4d02f	83	return i2c_smbus_write_byte_data(lp->client, reg, data);
7be865ab KM	84	}
7be865ab KM	85
26e8ccc2 KM	86	static int lp855x_update_bit(struct lp855x *lp, u8 reg, u8 mask, u8 data)
	87	{
	88	int ret;
	89	u8 tmp;
	90
	91	ret = i2c_smbus_read_byte_data(lp->client, reg);
	92	if (ret < 0) {
	93	dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
	94	return ret;
	95	}
	96
	97	tmp = (u8)ret;
	98	tmp &= ~mask;
	99	tmp \|= data & mask;
	100
	101	return lp855x_write_byte(lp, reg, tmp);
	102	}
	103
7be865ab KM	104	static bool lp855x_is_valid_rom_area(struct lp855x *lp, u8 addr)
	105	{
	106	u8 start, end;
	107
	108	switch (lp->chip_id) {
	109	case LP8550:
	110	case LP8551:
	111	case LP8552:
	112	case LP8553:
26e8ccc2 KM	113	start = LP855X_EEPROM_START;
26e8ccc2 KM	114	end = LP855X_EEPROM_END;
7be865ab KM	115	break;
7be865ab KM	116	case LP8556:
26e8ccc2 KM	117	start = LP8556_EPROM_START;
	118	end = LP8556_EPROM_END;
	119	break;
5812c13a MK	120	case LP8555:
	121	start = LP8555_EPROM_START;
	122	end = LP8555_EPROM_END;
	123	break;
26e8ccc2 KM	124	case LP8557:
	125	start = LP8557_EPROM_START;
	126	end = LP8557_EPROM_END;
7be865ab KM	127	break;
	128	default:
	129	return false;
	130	}
	131
2ce23860	132	return addr >= start && addr <= end;
7be865ab KM	133	}
7be865ab KM	134
26e8ccc2 KM	135	static int lp8557_bl_off(struct lp855x *lp)
	136	{
	137	/* BL_ON = 0 before updating EPROM settings */
	138	return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
	139	LP8557_BL_OFF);
	140	}
	141
	142	static int lp8557_bl_on(struct lp855x *lp)
	143	{
	144	/* BL_ON = 1 after updating EPROM settings */
	145	return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
	146	LP8557_BL_ON);
	147	}
	148
68853bc2	149	static struct lp855x_device_config lp855x_dev_cfg = {
26e8ccc2 KM	150	.reg_brightness = LP855X_BRIGHTNESS_CTRL,
	151	.reg_devicectrl = LP855X_DEVICE_CTRL,
	152	};
	153
	154	static struct lp855x_device_config lp8557_dev_cfg = {
	155	.reg_brightness = LP8557_BRIGHTNESS_CTRL,
	156	.reg_devicectrl = LP8557_CONFIG,
	157	.pre_init_device = lp8557_bl_off,
	158	.post_init_device = lp8557_bl_on,
68853bc2 KM	159	};
	160
	161	/*
	162	* Device specific configuration flow
	163	*
	164	* a) pre_init_device(optional)
	165	* b) update the brightness register
	166	* c) update device control register
	167	* d) update ROM area(optional)
	168	* e) post_init_device(optional)
	169	*
	170	*/
	171	static int lp855x_configure(struct lp855x *lp)
7be865ab KM	172	{
	173	u8 val, addr;
	174	int i, ret;
	175	struct lp855x_platform_data *pd = lp->pdata;
	176
68853bc2	177	switch (lp->chip_id) {
5812c13a MK	178	case LP8550:
	179	case LP8551:
	180	case LP8552:
	181	case LP8553:
	182	case LP8556:
68853bc2 KM	183	lp->cfg = &lp855x_dev_cfg;
68853bc2 KM	184	break;
5812c13a	185	case LP8555:
26e8ccc2 KM	186	case LP8557:
	187	lp->cfg = &lp8557_dev_cfg;
	188	break;
68853bc2 KM	189	default:
	190	return -EINVAL;
	191	}
	192
	193	if (lp->cfg->pre_init_device) {
	194	ret = lp->cfg->pre_init_device(lp);
	195	if (ret) {
	196	dev_err(lp->dev, "pre init device err: %d\n", ret);
	197	goto err;
	198	}
	199	}
	200
7be865ab	201	val = pd->initial_brightness;
68853bc2	202	ret = lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
7be865ab	203	if (ret)
68853bc2	204	goto err;
7be865ab KM	205
7be865ab KM	206	val = pd->device_control;
68853bc2	207	ret = lp855x_write_byte(lp, lp->cfg->reg_devicectrl, val);
7be865ab	208	if (ret)
68853bc2	209	goto err;
7be865ab	210
c365e59d	211	if (pd->size_program > 0) {
7be865ab KM	212	for (i = 0; i < pd->size_program; i++) {
	213	addr = pd->rom_data[i].addr;
	214	val = pd->rom_data[i].val;
	215	if (!lp855x_is_valid_rom_area(lp, addr))
	216	continue;
	217
	218	ret = lp855x_write_byte(lp, addr, val);
	219	if (ret)
68853bc2 KM	220	goto err;
	221	}
	222	}
	223
	224	if (lp->cfg->post_init_device) {
	225	ret = lp->cfg->post_init_device(lp);
	226	if (ret) {
	227	dev_err(lp->dev, "post init device err: %d\n", ret);
	228	goto err;
7be865ab KM	229	}
	230	}
	231
68853bc2 KM	232	return 0;
	233
	234	err:
7be865ab KM	235	return ret;
	236	}
	237
8cc9764c KM	238	static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
	239	{
	240	unsigned int period = lp->pdata->period_ns;
	241	unsigned int duty = br * period / max_br;
	242	struct pwm_device *pwm;
	243
	244	/* request pwm device with the consumer name */
	245	if (!lp->pwm) {
	246	pwm = devm_pwm_get(lp->dev, lp->chipname);
	247	if (IS_ERR(pwm))
	248	return;
	249
	250	lp->pwm = pwm;
6fbab835 BB	251
	252	/*
	253	* FIXME: pwm_apply_args() should be removed when switching to
	254	* the atomic PWM API.
	255	*/
	256	pwm_apply_args(pwm);
8cc9764c KM	257	}
	258
	259	pwm_config(lp->pwm, duty, period);
	260	if (duty)
	261	pwm_enable(lp->pwm);
	262	else
	263	pwm_disable(lp->pwm);
	264	}
	265
7be865ab KM	266	static int lp855x_bl_update_status(struct backlight_device *bl)
	267	{
	268	struct lp855x *lp = bl_get_data(bl);
61c1c614	269	int brightness = bl->props.brightness;
7be865ab	270
9f0a511f	271	if (bl->props.state & (BL_CORE_SUSPENDED \| BL_CORE_FBBLANK))
61c1c614	272	brightness = 0;
7be865ab	273
61c1c614 SP	274	if (lp->mode == PWM_BASED)
	275	lp855x_pwm_ctrl(lp, brightness, bl->props.max_brightness);
	276	else if (lp->mode == REGISTER_BASED)
	277	lp855x_write_byte(lp, lp->cfg->reg_brightness, (u8)brightness);
7be865ab KM	278
	279	return 0;
	280	}
	281
7be865ab KM	282	static const struct backlight_ops lp855x_bl_ops = {
	283	.options = BL_CORE_SUSPENDRESUME,
	284	.update_status = lp855x_bl_update_status,
7be865ab KM	285	};
	286
	287	static int lp855x_backlight_register(struct lp855x *lp)
	288	{
	289	struct backlight_device *bl;
	290	struct backlight_properties props;
	291	struct lp855x_platform_data *pdata = lp->pdata;
600ffd33	292	const char *name = pdata->name ? : DEFAULT_BL_NAME;
7be865ab	293
9f7898f3	294	memset(&props, 0, sizeof(props));
7be865ab KM	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);
a94cb126	317
6a7aeb1a	318	return scnprintf(buf, PAGE_SIZE, "%s\n", lp->chipname);
7be865ab KM	319	}
	320
	321	static ssize_t lp855x_get_bl_ctl_mode(struct device *dev,
	322	struct device_attribute attr, char buf)
	323	{
	324	struct lp855x *lp = dev_get_drvdata(dev);
7be865ab KM	325	char *strmode = NULL;
7be865ab KM	326
0b818573	327	if (lp->mode == PWM_BASED)
7be865ab	328	strmode = "pwm based";
0b818573	329	else if (lp->mode == REGISTER_BASED)
7be865ab KM	330	strmode = "register based";
7be865ab KM	331
6a7aeb1a	332	return scnprintf(buf, PAGE_SIZE, "%s\n", strmode);
7be865ab KM	333	}
	334
	335	static DEVICE_ATTR(chip_id, S_IRUGO, lp855x_get_chip_id, NULL);
	336	static DEVICE_ATTR(bl_ctl_mode, S_IRUGO, lp855x_get_bl_ctl_mode, NULL);
	337
	338	static struct attribute *lp855x_attributes[] = {
	339	&dev_attr_chip_id.attr,
	340	&dev_attr_bl_ctl_mode.attr,
	341	NULL,
	342	};
	343
	344	static const struct attribute_group lp855x_attr_group = {
	345	.attrs = lp855x_attributes,
	346	};
	347
4add0664	348	#ifdef CONFIG_OF
47726656	349	static int lp855x_parse_dt(struct lp855x *lp)
4add0664	350	{
47726656 SP	351	struct device *dev = lp->dev;
47726656 SP	352	struct device_node *node = dev->of_node;
4add0664 KM	353	struct lp855x_platform_data *pdata;
	354	int rom_length;
	355
	356	if (!node) {
	357	dev_err(dev, "no platform data\n");
	358	return -EINVAL;
	359	}
	360
	361	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
	362	if (!pdata)
	363	return -ENOMEM;
	364
	365	of_property_read_string(node, "bl-name", &pdata->name);
	366	of_property_read_u8(node, "dev-ctrl", &pdata->device_control);
	367	of_property_read_u8(node, "init-brt", &pdata->initial_brightness);
	368	of_property_read_u32(node, "pwm-period", &pdata->period_ns);
	369
	370	/* Fill ROM platform data if defined */
	371	rom_length = of_get_child_count(node);
	372	if (rom_length > 0) {
	373	struct lp855x_rom_data *rom;
	374	struct device_node *child;
	375	int i = 0;
	376
	377	rom = devm_kzalloc(dev, sizeof(rom) rom_length, GFP_KERNEL);
	378	if (!rom)
	379	return -ENOMEM;
	380
	381	for_each_child_of_node(node, child) {
	382	of_property_read_u8(child, "rom-addr", &rom[i].addr);
	383	of_property_read_u8(child, "rom-val", &rom[i].val);
	384	i++;
	385	}
	386
	387	pdata->size_program = rom_length;
	388	pdata->rom_data = &rom[0];
	389	}
	390
47726656	391	lp->pdata = pdata;
4add0664 KM	392
	393	return 0;
	394	}
	395	#else
47726656	396	static int lp855x_parse_dt(struct lp855x *lp)
4add0664 KM	397	{
	398	return -EINVAL;
	399	}
	400	#endif
	401
7be865ab KM	402	static int lp855x_probe(struct i2c_client cl, const struct i2c_device_id id)
	403	{
	404	struct lp855x *lp;
7be865ab KM	405	int ret;
7be865ab KM	406
7be865ab KM	407	if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
	408	return -EIO;
	409
	410	lp = devm_kzalloc(&cl->dev, sizeof(struct lp855x), GFP_KERNEL);
	411	if (!lp)
	412	return -ENOMEM;
	413
7be865ab KM	414	lp->client = cl;
7be865ab KM	415	lp->dev = &cl->dev;
7be865ab KM	416	lp->chipname = id->name;
7be865ab KM	417	lp->chip_id = id->driver_data;
47726656 SP	418	lp->pdata = dev_get_platdata(&cl->dev);
	419
	420	if (!lp->pdata) {
	421	ret = lp855x_parse_dt(lp);
	422	if (ret < 0)
	423	return ret;
	424	}
	425
	426	if (lp->pdata->period_ns > 0)
	427	lp->mode = PWM_BASED;
	428	else
	429	lp->mode = REGISTER_BASED;
	430
fe009175 MK	431	lp->supply = devm_regulator_get(lp->dev, "power");
	432	if (IS_ERR(lp->supply)) {
	433	if (PTR_ERR(lp->supply) == -EPROBE_DEFER)
	434	return -EPROBE_DEFER;
	435	lp->supply = NULL;
	436	}
	437
60255307 BN	438	lp->enable = devm_regulator_get_optional(lp->dev, "enable");
	439	if (IS_ERR(lp->enable)) {
	440	ret = PTR_ERR(lp->enable);
	441	if (ret == -ENODEV) {
	442	lp->enable = NULL;
	443	} else {
	444	if (ret != -EPROBE_DEFER)
	445	dev_err(lp->dev, "error getting enable regulator: %d\n",
	446	ret);
	447	return ret;
	448	}
	449	}
	450
fe009175 MK	451	if (lp->supply) {
fe009175 MK	452	ret = regulator_enable(lp->supply);
829b030e SP	453	if (ret < 0) {
	454	dev_err(&cl->dev, "failed to enable supply: %d\n", ret);
	455	return ret;
	456	}
	457	}
	458
60255307 BN	459	if (lp->enable) {
	460	ret = regulator_enable(lp->enable);
	461	if (ret < 0) {
	462	dev_err(lp->dev, "failed to enable vddio: %d\n", ret);
	463	return ret;
	464	}
	465
	466	/*
	467	* LP8555 datasheet says t_RESPONSE (time between VDDIO and
	468	* I2C) is 1ms.
	469	*/
	470	usleep_range(1000, 2000);
	471	}
	472
7be865ab KM	473	i2c_set_clientdata(cl, lp);
7be865ab KM	474
68853bc2	475	ret = lp855x_configure(lp);
7be865ab	476	if (ret) {
68853bc2	477	dev_err(lp->dev, "device config err: %d", ret);
6255e8e9	478	return ret;
7be865ab KM	479	}
	480
	481	ret = lp855x_backlight_register(lp);
	482	if (ret) {
	483	dev_err(lp->dev,
	484	"failed to register backlight. err: %d\n", ret);
6255e8e9	485	return ret;
7be865ab KM	486	}
	487
	488	ret = sysfs_create_group(&lp->dev->kobj, &lp855x_attr_group);
	489	if (ret) {
	490	dev_err(lp->dev, "failed to register sysfs. err: %d\n", ret);
6255e8e9	491	return ret;
7be865ab KM	492	}
	493
	494	backlight_update_status(lp->bl);
	495	return 0;
7be865ab KM	496	}
7be865ab KM	497
7e4b9d0b	498	static int lp855x_remove(struct i2c_client *cl)
7be865ab KM	499	{
	500	struct lp855x *lp = i2c_get_clientdata(cl);
	501
	502	lp->bl->props.brightness = 0;
	503	backlight_update_status(lp->bl);
fe009175 MK	504	if (lp->supply)
fe009175 MK	505	regulator_disable(lp->supply);
7be865ab	506	sysfs_remove_group(&lp->dev->kobj, &lp855x_attr_group);
7be865ab KM	507
	508	return 0;
	509	}
	510
4add0664 KM	511	static const struct of_device_id lp855x_dt_ids[] = {
	512	{ .compatible = "ti,lp8550", },
	513	{ .compatible = "ti,lp8551", },
	514	{ .compatible = "ti,lp8552", },
	515	{ .compatible = "ti,lp8553", },
5812c13a	516	{ .compatible = "ti,lp8555", },
4add0664 KM	517	{ .compatible = "ti,lp8556", },
	518	{ .compatible = "ti,lp8557", },
	519	{ }
	520	};
	521	MODULE_DEVICE_TABLE(of, lp855x_dt_ids);
	522
7be865ab KM	523	static const struct i2c_device_id lp855x_ids[] = {
	524	{"lp8550", LP8550},
	525	{"lp8551", LP8551},
	526	{"lp8552", LP8552},
	527	{"lp8553", LP8553},
5812c13a	528	{"lp8555", LP8555},
7be865ab	529	{"lp8556", LP8556},
26e8ccc2	530	{"lp8557", LP8557},
7be865ab KM	531	{ }
	532	};
	533	MODULE_DEVICE_TABLE(i2c, lp855x_ids);
	534
	535	static struct i2c_driver lp855x_driver = {
	536	.driver = {
	537	.name = "lp855x",
4add0664	538	.of_match_table = of_match_ptr(lp855x_dt_ids),
7be865ab KM	539	},
7be865ab KM	540	.probe = lp855x_probe,
d1723fa2	541	.remove = lp855x_remove,
7be865ab KM	542	.id_table = lp855x_ids,
	543	};
	544
	545	module_i2c_driver(lp855x_driver);
	546
	547	MODULE_DESCRIPTION("Texas Instruments LP855x Backlight driver");
	548	MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
	549	MODULE_LICENSE("GPL");