forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
278 lines
6.3 KiB
278 lines
6.3 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* Voltage and current regulation for AD5398 and AD5821 |
|
* |
|
* Copyright 2010 Analog Devices Inc. |
|
* |
|
* Enter bugs at http://blackfin.uclinux.org/ |
|
*/ |
|
|
|
#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 const 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");
|
|
|