Commit 8b385d9b authored by Sonic Zhang's avatar Sonic Zhang Committed by Liam Girdwood
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regulator: new drivers for AD5398 and AD5821 



The AD5398 and AD5821 are single 10-bit DAC with 120 mA output current
sink capability. They feature an internal reference and operates from
a single 2.7 V to 5.5 V supply.

This driver supports both the AD5398 and the AD5821.  It adapts into the
voltage and current framework.

Signed-off-by: default avatarSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
Acked-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: default avatarLiam Girdwood <lrg@slimlogic.co.uk>
parent 3d30701b

drivers/regulator/Kconfig

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Original line number Diff line number Diff line
@@ -201,5 +201,11 @@ config REGULATOR_88PM8607 
	help

	  This driver supports 88PM8607 voltage regulator chips.



config REGULATOR_AD5398

	tristate "Analog Devices AD5398/AD5821 regulators"

	depends on I2C

	help

	  This driver supports AD5398 and AD5821 current regulator chips.

	  If building into module, its name is ad5398.ko.

endif

drivers/regulator/Makefile

+1 −0
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@@ -8,6 +8,7 @@ obj-$(CONFIG_REGULATOR_FIXED_VOLTAGE) += fixed.o 
obj-$(CONFIG_REGULATOR_VIRTUAL_CONSUMER) += virtual.o

obj-$(CONFIG_REGULATOR_USERSPACE_CONSUMER) += userspace-consumer.o



obj-$(CONFIG_REGULATOR_AD5398) += ad5398.o

obj-$(CONFIG_REGULATOR_BQ24022) += bq24022.o

obj-$(CONFIG_REGULATOR_DUMMY) += dummy.o

obj-$(CONFIG_REGULATOR_LP3971) += lp3971.o

drivers/regulator/ad5398.c

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/*

 * 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_dev *rdev;

	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;



	rdev = regulator_register(&ad5398_reg, &client->dev, init_data, chip);

	if (IS_ERR(rdev)) {

		ret = PTR_ERR(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);

}

module_init(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");

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