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    Subject[PATCH 1/2] regulator: new driver for the AD5398 and AD5821
    Date
    From: Sonic Zhang <sonic.zhang@analog.com>

    This driver supports both the AD5398 and the AD5821. It adapts into the
    voltage and current framework. The generic userspace-consumer and virtual
    consumer should be selected to access devices via this driver.

    Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
    Signed-off-by: Mike Frysinger <vapier@gentoo.org>
    ---
    drivers/regulator/Kconfig | 6 +
    drivers/regulator/Makefile | 1 +
    drivers/regulator/ad5398.c | 270 ++++++++++++++++++++++++++++++++++++++
    include/linux/regulator/ad5398.h | 30 ++++
    4 files changed, 307 insertions(+), 0 deletions(-)
    create mode 100644 drivers/regulator/ad5398.c
    create mode 100644 include/linux/regulator/ad5398.h

    diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
    index 04f2e08..2ade09c 100644
    --- a/drivers/regulator/Kconfig
    +++ b/drivers/regulator/Kconfig
    @@ -201,5 +201,11 @@ config REGULATOR_88PM8607
    help
    This driver supports 88PM8607 voltage regulator chips.

    +config REGULATOR_AD5398
    + tristate "Ananlog Devices AD5398/AD5821 regulators"
    + depends on I2C
    + help
    + This driver supports AD5398 and AD5821 current regulator chips.
    +
    endif

    diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
    index 4e7feec..c256668 100644
    --- a/drivers/regulator/Makefile
    +++ b/drivers/regulator/Makefile
    @@ -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
    diff --git a/drivers/regulator/ad5398.c b/drivers/regulator/ad5398.c
    new file mode 100644
    index 0000000..9dbfc05
    --- /dev/null
    +++ b/drivers/regulator/ad5398.c
    @@ -0,0 +1,270 @@
    +/*
    + * 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/ad5398.h>
    +
    +struct ad5398_chip_info {
    + struct i2c_client *client;
    + unsigned int min_uA;
    + unsigned 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_get(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 = i2c_master_recv(client, (char *)&data, 2);
    + if (ret < 0) {
    + dev_err(&client->dev, "I2C read error\n");
    + return ret;
    + }
    +
    + ret = (be16_to_cpu(data) & chip->current_mask) >> chip->current_offset;
    +
    + return ad5398_calc_current(chip, ret);
    +}
    +
    +static int ad5398_set(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 || max_uA < chip->min_uA)
    + return -EINVAL;
    + if (min_uA < chip->min_uA)
    + min_uA = chip->min_uA;
    +
    + 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 = i2c_master_recv(client, (char *)&data, 2);
    + if (ret < 0) {
    + dev_err(&client->dev, "I2C read error\n");
    + return ret;
    + }
    + data = be16_to_cpu(data);
    +
    + /* prepare register data */
    + selector = (selector << chip->current_offset) & chip->current_mask;
    + selector |= (data & CURRENT_EN_MASK);
    +
    + /* write the new current value back as well as enable bit */
    + data = cpu_to_be16((unsigned short)selector);
    + ret = i2c_master_send(client, (char *)&data, 2);
    + if (ret < 0)
    + dev_err(&client->dev, "I2C write error\n");
    +
    + 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 = i2c_master_recv(client, (char *)&data, 2);
    + if (ret < 0) {
    + dev_err(&client->dev, "I2C read error\n");
    + return ret;
    + }
    +
    + if (be16_to_cpu(data) & 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 = i2c_master_recv(client, (char *)&data, 2);
    + if (ret < 0) {
    + dev_err(&client->dev, "I2C read error\n");
    + return ret;
    + }
    + data = be16_to_cpu(data);
    + if (data & CURRENT_EN_MASK)
    + return 0;
    +
    + data = cpu_to_be16(data | CURRENT_EN_MASK);
    +
    + ret = i2c_master_send(client, (char *)&data, 2);
    + if (ret < 0)
    + dev_err(&client->dev, "I2C write error\n");
    +
    + 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 = i2c_master_recv(client, (char *)&data, 2);
    + if (ret < 0) {
    + dev_err(&client->dev, "I2C read error\n");
    + return ret;
    + }
    + if (!(data & CURRENT_EN_MASK))
    + return 0;
    +
    + data = cpu_to_be16(data & ~CURRENT_EN_MASK);
    +
    + ret = i2c_master_send(client, (char *)&data, 2);
    + if (ret < 0)
    + dev_err(&client->dev, "I2C write error\n");
    +
    + return ret;
    +}
    +
    +static struct regulator_ops ad5398_ops = {
    + .get_current_limit = ad5398_get,
    + .set_current_limit = ad5398_set,
    + .enable = ad5398_enable,
    + .disable = ad5398_disable,
    + .is_enabled = ad5398_is_enabled,
    + .set_suspend_enable = ad5398_enable,
    + .set_suspend_disable = ad5398_disable,
    +};
    +
    +static struct regulator_desc ad5398_reg = {
    + .name = "isink",
    + .id = 0,
    + .ops = &ad5398_ops,
    + .type = REGULATOR_CURRENT,
    + .owner = THIS_MODULE,
    +};
    +
    +static int ad5398_probe(struct i2c_client *client,
    + const struct i2c_device_id *id)
    +{
    + struct regulator_dev *rdev;
    + struct ad5398_platform_data *pdata = client->dev.platform_data;
    + struct ad5398_chip_info *chip;
    + int ret;
    +
    + if (!pdata || !(pdata->regulator_data))
    + return -EINVAL;
    +
    + if (pdata->current_bits >= CURRENT_BITS_MAX)
    + return -EINVAL;
    +
    + chip = kzalloc(sizeof(struct ad5398_chip_info), GFP_KERNEL);
    + if (!chip)
    + return -ENOMEM;
    +
    + chip->client = client;
    +
    + chip->min_uA = pdata->regulator_data->constraints.min_uA;
    + chip->max_uA = pdata->regulator_data->constraints.max_uA;
    + chip->current_level = 1 << pdata->current_bits;
    + chip->current_offset = pdata->current_offset;
    + chip->current_mask = (chip->current_level - 1) << chip->current_offset;
    +
    + rdev = regulator_register(&ad5398_reg, &client->dev,
    + pdata->regulator_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_info(&client->dev, "%s regulator driver loaded\n", id->name);
    + return 0;
    +
    +err:
    + kfree(chip);
    + return ret;
    +}
    +
    +static int ad5398_remove(struct i2c_client *client)
    +{
    + struct ad5398_chip_info *chip = i2c_get_clientdata(client);
    +
    + if (chip) {
    + regulator_unregister(&chip->rdev);
    + kfree(chip);
    + }
    + i2c_set_clientdata(client, NULL);
    +
    + return 0;
    +}
    +
    +static const struct i2c_device_id ad5398_id[] = {
    + { "ad5398", 0 },
    + { "ad5821", 1 },
    + { }
    +};
    +MODULE_DEVICE_TABLE(i2c, ad5398_id);
    +
    +static struct i2c_driver ad5398_driver = {
    + .probe = ad5398_probe,
    + .remove = 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");
    diff --git a/include/linux/regulator/ad5398.h b/include/linux/regulator/ad5398.h
    new file mode 100644
    index 0000000..92c9fcb
    --- /dev/null
    +++ b/include/linux/regulator/ad5398.h
    @@ -0,0 +1,30 @@
    +/*
    + * ad5398.h -- 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.
    + */
    +#ifndef REGULATOR_AD5398
    +#define REGULATOR_AD5398
    +
    +#include <linux/regulator/machine.h>
    +
    +#define CURRENT_EN_MASK 0x8000
    +#define CURRENT_BITS_MAX 16
    +
    +/**
    + * ad5398_platform_data - platform data for ad5398
    + * @current_bits: effective bits in register
    + * @current_offset: offset of effective bits in register
    + * @ad5398_init_data: regulator init data
    + */
    +struct ad5398_platform_data {
    + unsigned short current_bits;
    + unsigned short current_offset;
    + struct regulator_init_data *regulator_data;
    +};
    +
    +#endif
    --
    1.7.1


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