[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 < 0)
		dev_err(&client->dev, "I2C write error\n");

	return ret;
}

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

	selector = ((min_uA - chip->min_uA) * chip->current_level +
			range_uA - 1) / range_uA;
	if (ad5398_calc_current(chip, selector) > max_uA)
		return -EINVAL;

	dev_dbg(&client->dev, "changing current %dmA\n",
		ad5398_calc_current(chip, selector) / 1000);

	/* 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 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 __devinit ad5398_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	struct regulator_init_data *init_data = client->dev.platform_data;
	struct ad5398_chip_info *chip;
	const struct ad5398_current_data_format *df =
			(struct ad5398_current_data_format *)id->driver_data;
	int ret;

	if (!init_data)
		return -EINVAL;

	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
	if (!chip)
		return -ENOMEM;

	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 = regulator_register(&ad5398_reg, &client->dev,
					init_data, chip);
	if (IS_ERR(chip->rdev)) {
		ret = PTR_ERR(chip->rdev);
		dev_err(&client->dev, "failed to register %s %s\n",
			id->name, ad5398_reg.name);
		goto err;
	}

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

err:
	kfree(chip);
	return ret;
}

static int __devexit ad5398_remove(struct i2c_client *client)
{
	struct ad5398_chip_info *chip = i2c_get_clientdata(client);

	regulator_unregister(chip->rdev);
	kfree(chip);

	return 0;
}

static struct i2c_driver ad5398_driver = {
	.probe = ad5398_probe,
	.remove = __devexit_p(ad5398_remove),
	.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");
MODULE_ALIAS("i2c:ad5398-regulator");
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);
	61	if (ret < 0)
	62	dev_err(&client->dev, "I2C write error\n");
	63
	64	return ret;
	65	}
	66
	67	static int ad5398_get_current_limit(struct regulator_dev *rdev)
	68	{
	69	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	70	struct i2c_client *client = chip->client;
	71	unsigned short data;
	72	int ret;
	73
	74	ret = ad5398_read_reg(client, &data);
	75	if (ret < 0)
	76	return ret;
	77
	78	ret = (data & chip->current_mask) >> chip->current_offset;
	79
	80	return ad5398_calc_current(chip, ret);
	81	}
	82
	83	static int ad5398_set_current_limit(struct regulator_dev *rdev, int min_uA, int max_uA)
	84	{
	85	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
	86	struct i2c_client *client = chip->client;
	87	unsigned range_uA = chip->max_uA - chip->min_uA;
	88	unsigned selector;
	89	unsigned short data;
	90	int ret;
	91
	92	if (min_uA > chip->max_uA \|\| min_uA < chip->min_uA)
93	return -EINVAL;
94	if (max_uA > chip->max_uA \|\| max_uA < chip->min_uA)
95	return -EINVAL;
96
97	selector = ((min_uA - chip->min_uA) * chip->current_level +
98	range_uA - 1) / range_uA;
99	if (ad5398_calc_current(chip, selector) > max_uA)
100	return -EINVAL;
101
102	dev_dbg(&client->dev, "changing current %dmA\n",
103	ad5398_calc_current(chip, selector) / 1000);
104
105	/* read chip enable bit */
106	ret = ad5398_read_reg(client, &data);
107	if (ret < 0)
108	return ret;
109
110	/* prepare register data */
111	selector = (selector << chip->current_offset) & chip->current_mask;
112	data = (unsigned short)selector \| (data & AD5398_CURRENT_EN_MASK);
113
114	/* write the new current value back as well as enable bit */
115	ret = ad5398_write_reg(client, data);
116
117	return ret;
118	}
119
120	static int ad5398_is_enabled(struct regulator_dev *rdev)
121	{
122	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
123	struct i2c_client *client = chip->client;
124	unsigned short data;
125	int ret;
126
127	ret = ad5398_read_reg(client, &data);
128	if (ret < 0)
129	return ret;
130
131	if (data & AD5398_CURRENT_EN_MASK)
132	return 1;
133	else
134	return 0;
135	}
136
137	static int ad5398_enable(struct regulator_dev *rdev)
138	{
139	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
140	struct i2c_client *client = chip->client;
141	unsigned short data;
142	int ret;
143
144	ret = ad5398_read_reg(client, &data);
145	if (ret < 0)
146	return ret;
147
148	if (data & AD5398_CURRENT_EN_MASK)
149	return 0;
150
151	data \|= AD5398_CURRENT_EN_MASK;
152
153	ret = ad5398_write_reg(client, data);
154
155	return ret;
156	}
157
158	static int ad5398_disable(struct regulator_dev *rdev)
159	{
160	struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
161	struct i2c_client *client = chip->client;
162	unsigned short data;
163	int ret;
164
165	ret = ad5398_read_reg(client, &data);
166	if (ret < 0)
167	return ret;
168
169	if (!(data & AD5398_CURRENT_EN_MASK))
170	return 0;
171
172	data &= ~AD5398_CURRENT_EN_MASK;
173
174	ret = ad5398_write_reg(client, data);
175
176	return ret;
177	}
178
179	static struct regulator_ops ad5398_ops = {
180	.get_current_limit = ad5398_get_current_limit,
181	.set_current_limit = ad5398_set_current_limit,
182	.enable = ad5398_enable,
183	.disable = ad5398_disable,
184	.is_enabled = ad5398_is_enabled,
185	};
186
187	static struct regulator_desc ad5398_reg = {
188	.name = "isink",
189	.id = 0,
190	.ops = &ad5398_ops,
191	.type = REGULATOR_CURRENT,
192	.owner = THIS_MODULE,
193	};
194
195	struct ad5398_current_data_format {
196	int current_bits;
197	int current_offset;
198	int min_uA;
199	int max_uA;
200	};
201
202	static const struct ad5398_current_data_format df_10_4_120 = {10, 4, 0, 120000};
203
204	static const struct i2c_device_id ad5398_id[] = {
205	{ "ad5398", (kernel_ulong_t)&df_10_4_120 },
206	{ "ad5821", (kernel_ulong_t)&df_10_4_120 },
207	{ }
208	};
209	MODULE_DEVICE_TABLE(i2c, ad5398_id);
210
211	static int __devinit ad5398_probe(struct i2c_client *client,
212	const struct i2c_device_id *id)
213	{
8b385d9b SZ	214	struct regulator_init_data *init_data = client->dev.platform_data;
	215	struct ad5398_chip_info *chip;
	216	const struct ad5398_current_data_format *df =
	217	(struct ad5398_current_data_format *)id->driver_data;
	218	int ret;
	219
	220	if (!init_data)
	221	return -EINVAL;
	222
	223	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
	224	if (!chip)
	225	return -ENOMEM;
	226
	227	chip->client = client;
	228
	229	chip->min_uA = df->min_uA;
	230	chip->max_uA = df->max_uA;
	231	chip->current_level = 1 << df->current_bits;
	232	chip->current_offset = df->current_offset;
	233	chip->current_mask = (chip->current_level - 1) << chip->current_offset;
	234
58d463ee AL	235	chip->rdev = regulator_register(&ad5398_reg, &client->dev,
	236	init_data, chip);
	237	if (IS_ERR(chip->rdev)) {
	238	ret = PTR_ERR(chip->rdev);
8b385d9b SZ	239	dev_err(&client->dev, "failed to register %s %s\n",
	240	id->name, ad5398_reg.name);
	241	goto err;
	242	}
	243
	244	i2c_set_clientdata(client, chip);
	245	dev_dbg(&client->dev, "%s regulator driver is registered.\n", id->name);
	246	return 0;
	247
	248	err:
	249	kfree(chip);
	250	return ret;
	251	}
	252
	253	static int __devexit ad5398_remove(struct i2c_client *client)
	254	{
	255	struct ad5398_chip_info *chip = i2c_get_clientdata(client);
	256
58d463ee	257	regulator_unregister(chip->rdev);
8b385d9b	258	kfree(chip);
8b385d9b SZ	259
	260	return 0;
	261	}
	262
	263	static struct i2c_driver ad5398_driver = {
	264	.probe = ad5398_probe,
	265	.remove = __devexit_p(ad5398_remove),
	266	.driver = {
	267	.name = "ad5398",
	268	},
	269	.id_table = ad5398_id,
	270	};
	271
	272	static int __init ad5398_init(void)
	273	{
	274	return i2c_add_driver(&ad5398_driver);
	275	}
839b8362	276	subsys_initcall(ad5398_init);
8b385d9b SZ	277
	278	static void __exit ad5398_exit(void)
	279	{
	280	i2c_del_driver(&ad5398_driver);
	281	}
	282	module_exit(ad5398_exit);
	283
	284	MODULE_DESCRIPTION("AD5398 and AD5821 current regulator driver");
	285	MODULE_AUTHOR("Sonic Zhang");
	286	MODULE_LICENSE("GPL");
	287	MODULE_ALIAS("i2c:ad5398-regulator");