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linux/drivers/iio/adc/max77541-adc.c
Okan Sahin 04c9a8eb72 iio: adc: max77541: Add ADI MAX77541 ADC Support
The MAX77541 has an 8-bit Successive Approximation Register (SAR) ADC
with four multiplexers for supporting the telemetry feature.

Signed-off-by: Okan Sahin <okan.sahin@analog.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230412111256.40013-4-okan.sahin@analog.com
Signed-off-by: Lee Jones <lee@kernel.org>
2023-06-28 15:18:11 +01:00

195 lines
4.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2022 Analog Devices, Inc.
* ADI MAX77541 ADC Driver with IIO interface
*/
#include <linux/bitfield.h>
#include <linux/iio/iio.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/units.h>
#include <linux/mfd/max77541.h>
enum max77541_adc_range {
LOW_RANGE,
MID_RANGE,
HIGH_RANGE,
};
enum max77541_adc_channel {
MAX77541_ADC_VSYS_V,
MAX77541_ADC_VOUT1_V,
MAX77541_ADC_VOUT2_V,
MAX77541_ADC_TEMP,
};
static int max77541_adc_offset(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2)
{
switch (chan->channel) {
case MAX77541_ADC_TEMP:
*val = DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, 1725);
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int max77541_adc_scale(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2)
{
struct regmap **regmap = iio_priv(indio_dev);
unsigned int reg_val;
int ret;
switch (chan->channel) {
case MAX77541_ADC_VSYS_V:
*val = 25;
return IIO_VAL_INT;
case MAX77541_ADC_VOUT1_V:
case MAX77541_ADC_VOUT2_V:
ret = regmap_read(*regmap, MAX77541_REG_M2_CFG1, &reg_val);
if (ret)
return ret;
reg_val = FIELD_GET(MAX77541_BITS_MX_CFG1_RNG, reg_val);
switch (reg_val) {
case LOW_RANGE:
*val = 6;
*val2 = 250000;
break;
case MID_RANGE:
*val = 12;
*val2 = 500000;
break;
case HIGH_RANGE:
*val = 25;
return IIO_VAL_INT;
default:
return -EINVAL;
}
return IIO_VAL_INT_PLUS_MICRO;
case MAX77541_ADC_TEMP:
*val = 1725;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int max77541_adc_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val)
{
struct regmap **regmap = iio_priv(indio_dev);
int ret;
ret = regmap_read(*regmap, chan->address, val);
if (ret)
return ret;
return IIO_VAL_INT;
}
#define MAX77541_ADC_CHANNEL_V(_channel, _name, _type, _reg) \
{ \
.type = _type, \
.indexed = 1, \
.channel = _channel, \
.address = _reg, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.datasheet_name = _name, \
}
#define MAX77541_ADC_CHANNEL_TEMP(_channel, _name, _type, _reg) \
{ \
.type = _type, \
.indexed = 1, \
.channel = _channel, \
.address = _reg, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE) |\
BIT(IIO_CHAN_INFO_OFFSET),\
.datasheet_name = _name, \
}
static const struct iio_chan_spec max77541_adc_channels[] = {
MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VSYS_V, "vsys_v", IIO_VOLTAGE,
MAX77541_REG_ADC_DATA_CH1),
MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VOUT1_V, "vout1_v", IIO_VOLTAGE,
MAX77541_REG_ADC_DATA_CH2),
MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VOUT2_V, "vout2_v", IIO_VOLTAGE,
MAX77541_REG_ADC_DATA_CH3),
MAX77541_ADC_CHANNEL_TEMP(MAX77541_ADC_TEMP, "temp", IIO_TEMP,
MAX77541_REG_ADC_DATA_CH6),
};
static int max77541_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
switch (mask) {
case IIO_CHAN_INFO_OFFSET:
return max77541_adc_offset(indio_dev, chan, val, val2);
case IIO_CHAN_INFO_SCALE:
return max77541_adc_scale(indio_dev, chan, val, val2);
case IIO_CHAN_INFO_RAW:
return max77541_adc_raw(indio_dev, chan, val);
default:
return -EINVAL;
}
}
static const struct iio_info max77541_adc_info = {
.read_raw = max77541_adc_read_raw,
};
static int max77541_adc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct iio_dev *indio_dev;
struct regmap **regmap;
indio_dev = devm_iio_device_alloc(dev, sizeof(*regmap));
if (!indio_dev)
return -ENOMEM;
regmap = iio_priv(indio_dev);
*regmap = dev_get_regmap(dev->parent, NULL);
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->name = "max77541";
indio_dev->info = &max77541_adc_info;
indio_dev->channels = max77541_adc_channels;
indio_dev->num_channels = ARRAY_SIZE(max77541_adc_channels);
return devm_iio_device_register(dev, indio_dev);
}
static const struct platform_device_id max77541_adc_platform_id[] = {
{ "max77541-adc" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, max77541_adc_platform_id);
static struct platform_driver max77541_adc_driver = {
.driver = {
.name = "max77541-adc",
},
.probe = max77541_adc_probe,
.id_table = max77541_adc_platform_id,
};
module_platform_driver(max77541_adc_driver);
MODULE_AUTHOR("Okan Sahin <Okan.Sahin@analog.com>");
MODULE_DESCRIPTION("MAX77541 ADC driver");
MODULE_LICENSE("GPL");