[deliverable/linux.git] / drivers / regulator / ad5398.c

/*
 * Voltage and current regulation for AD5398 and AD5821
 *
 * Copyright 2010 Analog Devices Inc.
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/module.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>

#define AD5398_CURRENT_EN_MASK	0x8000

struct ad5398_chip_info {
	struct i2c_client *client;
	int min_uA;
	int max_uA;
	unsigned int current_level;
	unsigned int current_mask;
	unsigned int current_offset;
	struct regulator_dev *rdev;
};

static int ad5398_calc_current(struct ad5398_chip_info *chip,
	unsigned selector)
{
	unsigned range_uA = chip->max_uA - chip->min_uA;

	return chip->min_uA + (selector * range_uA / chip->current_level);
}

static int ad5398_read_reg(struct i2c_client *client, unsigned short *data)
{
	unsigned short val;
	int ret;

	ret = i2c_master_recv(client, (char *)&val, 2);
	if (ret < 0) {
		dev_err(&client->dev, "I2C read error\n");
		return ret;
	}
	*data = be16_to_cpu(val);

	return ret;
}

static int ad5398_write_reg(struct i2c_client *client, const unsigned short data)
{
	unsigned short val;
	int ret;

	val = cpu_to_be16(data);
	ret = i2c_master_send(client, (char *)&val, 2);
	if (ret != 2) {
		dev_err(&client->dev, "I2C write error\n");
		return ret < 0 ? ret : -EIO;
	}

	return 0;
}

static int ad5398_get_current_limit(struct regulator_dev *rdev)
{
	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	struct i2c_client *client = chip->client;
	unsigned short data;
	int ret;

	ret = ad5398_read_reg(client, &data);
	if (ret < 0)
		return ret;

	ret = (data & chip->current_mask) >> chip->current_offset;

	return ad5398_calc_current(chip, ret);
}

static int ad5398_set_current_limit(struct regulator_dev *rdev, int min_uA, int max_uA)
{
	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	struct i2c_client *client = chip->client;
	unsigned range_uA = chip->max_uA - chip->min_uA;
	unsigned selector;
	unsigned short data;
	int ret;

	if (min_uA < chip->min_uA)
		min_uA = chip->min_uA;
	if (max_uA > chip->max_uA)
		max_uA = chip->max_uA;

	if (min_uA > chip->max_uA || max_uA < chip->min_uA)
		return -EINVAL;

	selector = DIV_ROUND_UP((min_uA - chip->min_uA) * chip->current_level,
				range_uA);
	if (ad5398_calc_current(chip, selector) > max_uA)
		return -EINVAL;

	dev_dbg(&client->dev, "changing current %duA\n",
		ad5398_calc_current(chip, selector));

	/* read chip enable bit */
	ret = ad5398_read_reg(client, &data);
	if (ret < 0)
		return ret;

	/* prepare register data */
	selector = (selector << chip->current_offset) & chip->current_mask;
	data = (unsigned short)selector | (data & AD5398_CURRENT_EN_MASK);

	/* write the new current value back as well as enable bit */
	ret = ad5398_write_reg(client, data);

	return ret;
}

static int ad5398_is_enabled(struct regulator_dev *rdev)
{
	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	struct i2c_client *client = chip->client;
	unsigned short data;
	int ret;

	ret = ad5398_read_reg(client, &data);
	if (ret < 0)
		return ret;

	if (data & AD5398_CURRENT_EN_MASK)
		return 1;
	else
		return 0;
}

static int ad5398_enable(struct regulator_dev *rdev)
{
	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	struct i2c_client *client = chip->client;
	unsigned short data;
	int ret;

	ret = ad5398_read_reg(client, &data);
	if (ret < 0)
		return ret;

	if (data & AD5398_CURRENT_EN_MASK)
		return 0;

	data |= AD5398_CURRENT_EN_MASK;

	ret = ad5398_write_reg(client, data);

	return ret;
}

static int ad5398_disable(struct regulator_dev *rdev)
{
	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	struct i2c_client *client = chip->client;
	unsigned short data;
	int ret;

	ret = ad5398_read_reg(client, &data);
	if (ret < 0)
		return ret;

	if (!(data & AD5398_CURRENT_EN_MASK))
		return 0;

	data &= ~AD5398_CURRENT_EN_MASK;

	ret = ad5398_write_reg(client, data);

	return ret;
}

static struct regulator_ops ad5398_ops = {
	.get_current_limit = ad5398_get_current_limit,
	.set_current_limit = ad5398_set_current_limit,
	.enable = ad5398_enable,
	.disable = ad5398_disable,
	.is_enabled = ad5398_is_enabled,
};

static const struct regulator_desc ad5398_reg = {
	.name = "isink",
	.id = 0,
	.ops = &ad5398_ops,
	.type = REGULATOR_CURRENT,
	.owner = THIS_MODULE,
};

struct ad5398_current_data_format {
	int current_bits;
	int current_offset;
	int min_uA;
	int max_uA;
};

static const struct ad5398_current_data_format df_10_4_120 = {10, 4, 0, 120000};

static const struct i2c_device_id ad5398_id[] = {
	{ "ad5398", (kernel_ulong_t)&df_10_4_120 },
	{ "ad5821", (kernel_ulong_t)&df_10_4_120 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ad5398_id);

static int ad5398_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	struct regulator_init_data *init_data = dev_get_platdata(&client->dev);
	struct regulator_config config = { };
	struct ad5398_chip_info *chip;
	const struct ad5398_current_data_format *df =
			(struct ad5398_current_data_format *)id->driver_data;

	if (!init_data)
		return -EINVAL;

	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
	if (!chip)
		return -ENOMEM;

	config.dev = &client->dev;
	config.init_data = init_data;
	config.driver_data = chip;

	chip->client = client;

	chip->min_uA = df->min_uA;
	chip->max_uA = df->max_uA;
	chip->current_level = 1 << df->current_bits;
	chip->current_offset = df->current_offset;
	chip->current_mask = (chip->current_level - 1) << chip->current_offset;

	chip->rdev = devm_regulator_register(&client->dev, &ad5398_reg,
					     &config);
	if (IS_ERR(chip->rdev)) {
		dev_err(&client->dev, "failed to register %s %s\n",
			id->name, ad5398_reg.name);
		return PTR_ERR(chip->rdev);
	}

	i2c_set_clientdata(client, chip);
	dev_dbg(&client->dev, "%s regulator driver is registered.\n", id->name);
	return 0;
}

static struct i2c_driver ad5398_driver = {
	.probe = ad5398_probe,
	.driver		= {
		.name	= "ad5398",
	},
	.id_table	= ad5398_id,
};

static int __init ad5398_init(void)
{
	return i2c_add_driver(&ad5398_driver);
}
subsys_initcall(ad5398_init);

static void __exit ad5398_exit(void)
{
	i2c_del_driver(&ad5398_driver);
}
module_exit(ad5398_exit);

MODULE_DESCRIPTION("AD5398 and AD5821 current regulator driver");
MODULE_AUTHOR("Sonic Zhang");
MODULE_LICENSE("GPL");
Commit	Line	Data
8b385d9b SZ	1	/*
	2	* Voltage and current regulation for AD5398 and AD5821
	3	*
	4	* Copyright 2010 Analog Devices Inc.
	5	*
	6	* Enter bugs at http://blackfin.uclinux.org/
	7	*
	8	* Licensed under the GPL-2 or later.
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/err.h>
	13	#include <linux/i2c.h>
	14	#include <linux/slab.h>
	15	#include <linux/platform_device.h>
	16	#include <linux/regulator/driver.h>
	17	#include <linux/regulator/machine.h>
	18
	19	#define AD5398_CURRENT_EN_MASK 0x8000
	20
	21	struct ad5398_chip_info {
	22	struct i2c_client *client;
	23	int min_uA;
	24	int max_uA;
	25	unsigned int current_level;
	26	unsigned int current_mask;
	27	unsigned int current_offset;
58d463ee	28	struct regulator_dev *rdev;
8b385d9b SZ	29	};
	30
	31	static int ad5398_calc_current(struct ad5398_chip_info *chip,
	32	unsigned selector)
	33	{
	34	unsigned range_uA = chip->max_uA - chip->min_uA;
	35
	36	return chip->min_uA + (selector * range_uA / chip->current_level);
	37	}
	38
	39	static int ad5398_read_reg(struct i2c_client client, unsigned short data)
	40	{
	41	unsigned short val;
	42	int ret;
	43
	44	ret = i2c_master_recv(client, (char *)&val, 2);
	45	if (ret < 0) {
	46	dev_err(&client->dev, "I2C read error\n");
	47	return ret;
	48	}
	49	*data = be16_to_cpu(val);
	50
	51	return ret;
	52	}
	53
	54	static int ad5398_write_reg(struct i2c_client *client, const unsigned short data)
	55	{
	56	unsigned short val;
	57	int ret;
	58
	59	val = cpu_to_be16(data);
	60	ret = i2c_master_send(client, (char *)&val, 2);
4434cee9	61	if (ret != 2) {
8b385d9b	62	dev_err(&client->dev, "I2C write error\n");
4434cee9 AL	63	return ret < 0 ? ret : -EIO;
4434cee9 AL	64	}
8b385d9b	65
4434cee9	66	return 0;
8b385d9b SZ	67	}
	68
	69	static int ad5398_get_current_limit(struct regulator_dev *rdev)
	70	{
	71	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	72	struct i2c_client *client = chip->client;
	73	unsigned short data;
	74	int ret;
	75
	76	ret = ad5398_read_reg(client, &data);
	77	if (ret < 0)
	78	return ret;
	79
	80	ret = (data & chip->current_mask) >> chip->current_offset;
	81
	82	return ad5398_calc_current(chip, ret);
	83	}
	84
	85	static int ad5398_set_current_limit(struct regulator_dev *rdev, int min_uA, int max_uA)
	86	{
	87	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	88	struct i2c_client *client = chip->client;
	89	unsigned range_uA = chip->max_uA - chip->min_uA;
	90	unsigned selector;
	91	unsigned short data;
	92	int ret;
	93
9c6a74c5 AL	94	if (min_uA < chip->min_uA)
	95	min_uA = chip->min_uA;
	96	if (max_uA > chip->max_uA)
	97	max_uA = chip->max_uA;
	98
	99	if (min_uA > chip->max_uA \|\| max_uA < chip->min_uA)
8b385d9b SZ	100	return -EINVAL;
8b385d9b SZ	101
8148ed6e AL	102	selector = DIV_ROUND_UP((min_uA - chip->min_uA) * chip->current_level,
8148ed6e AL	103	range_uA);
8b385d9b SZ	104	if (ad5398_calc_current(chip, selector) > max_uA)
	105	return -EINVAL;
	106
935c14a2 AL	107	dev_dbg(&client->dev, "changing current %duA\n",
935c14a2 AL	108	ad5398_calc_current(chip, selector));
8b385d9b SZ	109
	110	/* read chip enable bit */
	111	ret = ad5398_read_reg(client, &data);
	112	if (ret < 0)
	113	return ret;
	114
	115	/* prepare register data */
	116	selector = (selector << chip->current_offset) & chip->current_mask;
	117	data = (unsigned short)selector \| (data & AD5398_CURRENT_EN_MASK);
	118
	119	/* write the new current value back as well as enable bit */
	120	ret = ad5398_write_reg(client, data);
	121
	122	return ret;
	123	}
	124
	125	static int ad5398_is_enabled(struct regulator_dev *rdev)
	126	{
	127	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	128	struct i2c_client *client = chip->client;
	129	unsigned short data;
	130	int ret;
	131
	132	ret = ad5398_read_reg(client, &data);
	133	if (ret < 0)
	134	return ret;
	135
	136	if (data & AD5398_CURRENT_EN_MASK)
	137	return 1;
	138	else
	139	return 0;
	140	}
	141
	142	static int ad5398_enable(struct regulator_dev *rdev)
	143	{
	144	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	145	struct i2c_client *client = chip->client;
	146	unsigned short data;
	147	int ret;
	148
	149	ret = ad5398_read_reg(client, &data);
	150	if (ret < 0)
	151	return ret;
	152
	153	if (data & AD5398_CURRENT_EN_MASK)
	154	return 0;
	155
	156	data \|= AD5398_CURRENT_EN_MASK;
	157
	158	ret = ad5398_write_reg(client, data);
	159
	160	return ret;
	161	}
	162
	163	static int ad5398_disable(struct regulator_dev *rdev)
	164	{
	165	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	166	struct i2c_client *client = chip->client;
	167	unsigned short data;
	168	int ret;
	169
	170	ret = ad5398_read_reg(client, &data);
	171	if (ret < 0)
	172	return ret;
173
174	if (!(data & AD5398_CURRENT_EN_MASK))
175	return 0;
176
177	data &= ~AD5398_CURRENT_EN_MASK;
178
179	ret = ad5398_write_reg(client, data);
180
181	return ret;
182	}
183
184	static struct regulator_ops ad5398_ops = {
185	.get_current_limit = ad5398_get_current_limit,
186	.set_current_limit = ad5398_set_current_limit,
187	.enable = ad5398_enable,
188	.disable = ad5398_disable,
189	.is_enabled = ad5398_is_enabled,
190	};
191
487f71e6	192	static const struct regulator_desc ad5398_reg = {
8b385d9b SZ	193	.name = "isink",
	194	.id = 0,
	195	.ops = &ad5398_ops,
	196	.type = REGULATOR_CURRENT,
	197	.owner = THIS_MODULE,
	198	};
	199
	200	struct ad5398_current_data_format {
	201	int current_bits;
	202	int current_offset;
	203	int min_uA;
	204	int max_uA;
	205	};
	206
	207	static const struct ad5398_current_data_format df_10_4_120 = {10, 4, 0, 120000};
	208
	209	static const struct i2c_device_id ad5398_id[] = {
	210	{ "ad5398", (kernel_ulong_t)&df_10_4_120 },
	211	{ "ad5821", (kernel_ulong_t)&df_10_4_120 },
	212	{ }
	213	};
	214	MODULE_DEVICE_TABLE(i2c, ad5398_id);
	215
a5023574	216	static int ad5398_probe(struct i2c_client *client,
8b385d9b SZ	217	const struct i2c_device_id *id)
8b385d9b SZ	218	{
dff91d0b	219	struct regulator_init_data *init_data = dev_get_platdata(&client->dev);
c172708d	220	struct regulator_config config = { };
8b385d9b SZ	221	struct ad5398_chip_info *chip;
	222	const struct ad5398_current_data_format *df =
	223	(struct ad5398_current_data_format *)id->driver_data;
8b385d9b SZ	224
	225	if (!init_data)
	226	return -EINVAL;
	227
0df8c96f	228	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
8b385d9b SZ	229	if (!chip)
	230	return -ENOMEM;
	231
c172708d MB	232	config.dev = &client->dev;
	233	config.init_data = init_data;
	234	config.driver_data = chip;
	235
8b385d9b SZ	236	chip->client = client;
	237
	238	chip->min_uA = df->min_uA;
	239	chip->max_uA = df->max_uA;
	240	chip->current_level = 1 << df->current_bits;
	241	chip->current_offset = df->current_offset;
	242	chip->current_mask = (chip->current_level - 1) << chip->current_offset;
	243
9b2cdac7 AL	244	chip->rdev = devm_regulator_register(&client->dev, &ad5398_reg,
9b2cdac7 AL	245	&config);
58d463ee	246	if (IS_ERR(chip->rdev)) {
8b385d9b SZ	247	dev_err(&client->dev, "failed to register %s %s\n",
8b385d9b SZ	248	id->name, ad5398_reg.name);
9b2cdac7	249	return PTR_ERR(chip->rdev);
8b385d9b SZ	250	}
	251
	252	i2c_set_clientdata(client, chip);
	253	dev_dbg(&client->dev, "%s regulator driver is registered.\n", id->name);
	254	return 0;
8b385d9b SZ	255	}
	256
	257	static struct i2c_driver ad5398_driver = {
	258	.probe = ad5398_probe,
8b385d9b SZ	259	.driver = {
	260	.name = "ad5398",
	261	},
	262	.id_table = ad5398_id,
	263	};
	264
	265	static int __init ad5398_init(void)
	266	{
	267	return i2c_add_driver(&ad5398_driver);
	268	}
839b8362	269	subsys_initcall(ad5398_init);
8b385d9b SZ	270
	271	static void __exit ad5398_exit(void)
	272	{
	273	i2c_del_driver(&ad5398_driver);
	274	}
	275	module_exit(ad5398_exit);
	276
	277	MODULE_DESCRIPTION("AD5398 and AD5821 current regulator driver");
	278	MODULE_AUTHOR("Sonic Zhang");
	279	MODULE_LICENSE("GPL");