linux/drivers/regulator/ad5398.c
Mark Brown c172708d38 regulator: core: Use a struct to pass in regulator runtime configuration
Rather than adding new arguments to regulator_register() every time we
want to add a new bit of dynamic information at runtime change the function
to take these via a struct. By doing this we avoid needing to do further
changes like the recent addition of device tree support which required each
regulator driver to be updated to take an additional parameter.

The regulator_desc which should (mostly) be static data is still passed
separately as most drivers are able to configure this statically at build
time.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-04-09 12:37:09 +01:00

288 lines
6.4 KiB
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 = 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 __devinit ad5398_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct regulator_init_data *init_data = client->dev.platform_data;
struct regulator_config config = { };
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 = 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 = regulator_register(&ad5398_reg, &config);
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:
return ret;
}
static int __devexit ad5398_remove(struct i2c_client *client)
{
struct ad5398_chip_info *chip = i2c_get_clientdata(client);
regulator_unregister(chip->rdev);
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");