linux/drivers/iio/adc/mp2629_adc.c
Saravanan Sekar 7abd9fb646 iio: adc: mp2629: Add support for mp2629 ADC driver
Add support for 8-bit resolution ADC readings for input power
supply and battery charging measurement. Provides voltage, current
readings to mp2629 power supply driver.

Signed-off-by: Saravanan Sekar <sravanhome@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2020-05-26 10:41:47 +01:00

209 lines
4.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* MP2629 Driver for ADC
*
* Copyright 2020 Monolithic Power Systems, Inc
*
* Author: Saravanan Sekar <sravanhome@gmail.com>
*/
#include <linux/iio/driver.h>
#include <linux/iio/iio.h>
#include <linux/iio/machine.h>
#include <linux/mfd/mp2629.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#define MP2629_REG_ADC_CTRL 0x03
#define MP2629_REG_BATT_VOLT 0x0e
#define MP2629_REG_SYSTEM_VOLT 0x0f
#define MP2629_REG_INPUT_VOLT 0x11
#define MP2629_REG_BATT_CURRENT 0x12
#define MP2629_REG_INPUT_CURRENT 0x13
#define MP2629_ADC_START BIT(7)
#define MP2629_ADC_CONTINUOUS BIT(6)
#define MP2629_MAP(_mp, _mpc) IIO_MAP(#_mp, "mp2629_charger", "mp2629-"_mpc)
#define MP2629_ADC_CHAN(_ch, _type) { \
.type = _type, \
.indexed = 1, \
.datasheet_name = #_ch, \
.channel = MP2629_ ## _ch, \
.address = MP2629_REG_ ## _ch, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
}
struct mp2629_adc {
struct regmap *regmap;
struct device *dev;
};
static struct iio_chan_spec mp2629_channels[] = {
MP2629_ADC_CHAN(BATT_VOLT, IIO_VOLTAGE),
MP2629_ADC_CHAN(SYSTEM_VOLT, IIO_VOLTAGE),
MP2629_ADC_CHAN(INPUT_VOLT, IIO_VOLTAGE),
MP2629_ADC_CHAN(BATT_CURRENT, IIO_CURRENT),
MP2629_ADC_CHAN(INPUT_CURRENT, IIO_CURRENT)
};
static struct iio_map mp2629_adc_maps[] = {
MP2629_MAP(BATT_VOLT, "batt-volt"),
MP2629_MAP(SYSTEM_VOLT, "system-volt"),
MP2629_MAP(INPUT_VOLT, "input-volt"),
MP2629_MAP(BATT_CURRENT, "batt-current"),
MP2629_MAP(INPUT_CURRENT, "input-current")
};
static int mp2629_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct mp2629_adc *info = iio_priv(indio_dev);
unsigned int rval;
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = regmap_read(info->regmap, chan->address, &rval);
if (ret)
return ret;
if (chan->address == MP2629_INPUT_VOLT)
rval &= GENMASK(6, 0);
*val = rval;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
switch (chan->channel) {
case MP2629_BATT_VOLT:
case MP2629_SYSTEM_VOLT:
*val = 20;
return IIO_VAL_INT;
case MP2629_INPUT_VOLT:
*val = 60;
return IIO_VAL_INT;
case MP2629_BATT_CURRENT:
*val = 175;
*val2 = 10;
return IIO_VAL_FRACTIONAL;
case MP2629_INPUT_CURRENT:
*val = 133;
*val2 = 10;
return IIO_VAL_FRACTIONAL;
default:
return -EINVAL;
}
default:
return -EINVAL;
}
}
static const struct iio_info mp2629_adc_info = {
.read_raw = &mp2629_read_raw,
};
static int mp2629_adc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct mp2629_data *ddata = dev_get_drvdata(dev->parent);
struct mp2629_adc *info;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
if (!indio_dev)
return -ENOMEM;
info = iio_priv(indio_dev);
info->regmap = ddata->regmap;
info->dev = dev;
platform_set_drvdata(pdev, indio_dev);
ret = regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
MP2629_ADC_START | MP2629_ADC_CONTINUOUS,
MP2629_ADC_START | MP2629_ADC_CONTINUOUS);
if (ret) {
dev_err(dev, "adc enable fail: %d\n", ret);
return ret;
}
ret = iio_map_array_register(indio_dev, mp2629_adc_maps);
if (ret) {
dev_err(dev, "IIO maps register fail: %d\n", ret);
goto fail_disable;
}
indio_dev->name = "mp2629-adc";
indio_dev->dev.parent = dev;
indio_dev->channels = mp2629_channels;
indio_dev->num_channels = ARRAY_SIZE(mp2629_channels);
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &mp2629_adc_info;
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(dev, "IIO device register fail: %d\n", ret);
goto fail_map_unregister;
}
return 0;
fail_map_unregister:
iio_map_array_unregister(indio_dev);
fail_disable:
regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
MP2629_ADC_CONTINUOUS, 0);
regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
MP2629_ADC_START, 0);
return ret;
}
static int mp2629_adc_remove(struct platform_device *pdev)
{
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
struct mp2629_adc *info = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
iio_map_array_unregister(indio_dev);
regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
MP2629_ADC_CONTINUOUS, 0);
regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
MP2629_ADC_START, 0);
return 0;
}
static const struct of_device_id mp2629_adc_of_match[] = {
{ .compatible = "mps,mp2629_adc"},
{}
};
MODULE_DEVICE_TABLE(of, mp2629_adc_of_match);
static struct platform_driver mp2629_adc_driver = {
.driver = {
.name = "mp2629_adc",
.of_match_table = mp2629_adc_of_match,
},
.probe = mp2629_adc_probe,
.remove = mp2629_adc_remove,
};
module_platform_driver(mp2629_adc_driver);
MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
MODULE_DESCRIPTION("MP2629 ADC driver");
MODULE_LICENSE("GPL");