drivers/regulator/ad5398.c - linux - Git at Google

 /*
  * 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);
 	i2c_set_clientdata(client, NULL);

 	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");
	/*
	* 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);
	i2c_set_clientdata(client, NULL);

	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");