max77541-adc.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (c) 2022 Analog Devices, Inc.
  4 * ADI MAX77541 ADC Driver with IIO interface
  5 */
  6
  7#include <linux/bitfield.h>
  8#include <linux/iio/iio.h>
  9#include <linux/mod_devicetable.h>
 10#include <linux/platform_device.h>
 11#include <linux/regmap.h>
 12#include <linux/units.h>
 13
 14#include <linux/mfd/max77541.h>
 15
 16enum max77541_adc_range {
 17	LOW_RANGE,
 18	MID_RANGE,
 19	HIGH_RANGE,
 20};
 21
 22enum max77541_adc_channel {
 23	MAX77541_ADC_VSYS_V,
 24	MAX77541_ADC_VOUT1_V,
 25	MAX77541_ADC_VOUT2_V,
 26	MAX77541_ADC_TEMP,
 27};
 28
 29static int max77541_adc_offset(struct iio_dev *indio_dev,
 30			       struct iio_chan_spec const *chan,
 31			       int *val, int *val2)
 32{
 33	switch (chan->channel) {
 34	case MAX77541_ADC_TEMP:
 35		*val = DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, 1725);
 36		return IIO_VAL_INT;
 37	default:
 38		return -EINVAL;
 39	}
 40}
 41
 42static int max77541_adc_scale(struct iio_dev *indio_dev,
 43			      struct iio_chan_spec const *chan,
 44			      int *val, int *val2)
 45{
 46	struct regmap **regmap = iio_priv(indio_dev);
 47	unsigned int reg_val;
 48	int ret;
 49
 50	switch (chan->channel) {
 51	case MAX77541_ADC_VSYS_V:
 52		*val = 25;
 53		return IIO_VAL_INT;
 54	case MAX77541_ADC_VOUT1_V:
 55	case MAX77541_ADC_VOUT2_V:
 56		ret = regmap_read(*regmap, MAX77541_REG_M2_CFG1, &reg_val);
 57		if (ret)
 58			return ret;
 59
 60		reg_val = FIELD_GET(MAX77541_BITS_MX_CFG1_RNG, reg_val);
 61		switch (reg_val) {
 62		case LOW_RANGE:
 63			*val = 6;
 64			*val2 = 250000;
 65			break;
 66		case MID_RANGE:
 67			*val = 12;
 68			*val2 = 500000;
 69			break;
 70		case HIGH_RANGE:
 71			*val = 25;
 72			return IIO_VAL_INT;
 73		default:
 74			return -EINVAL;
 75		}
 76
 77		return IIO_VAL_INT_PLUS_MICRO;
 78	case MAX77541_ADC_TEMP:
 79		*val = 1725;
 80		return IIO_VAL_INT;
 81	default:
 82		return -EINVAL;
 83	}
 84}
 85
 86static int max77541_adc_raw(struct iio_dev *indio_dev,
 87			    struct iio_chan_spec const *chan,
 88			    int *val)
 89{
 90	struct regmap **regmap = iio_priv(indio_dev);
 91	int ret;
 92
 93	ret = regmap_read(*regmap, chan->address, val);
 94	if (ret)
 95		return ret;
 96
 97	return IIO_VAL_INT;
 98}
 99
100#define MAX77541_ADC_CHANNEL_V(_channel, _name, _type, _reg) \
101	{							\
102		.type = _type,					\
103		.indexed = 1,					\
104		.channel = _channel,				\
105		.address = _reg,				\
106		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
107				      BIT(IIO_CHAN_INFO_SCALE), \
108		.datasheet_name = _name,			\
109	}
110
111#define MAX77541_ADC_CHANNEL_TEMP(_channel, _name, _type, _reg) \
112	{							\
113		.type = _type,					\
114		.indexed = 1,					\
115		.channel = _channel,				\
116		.address = _reg,				\
117		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
118				      BIT(IIO_CHAN_INFO_SCALE) |\
119				      BIT(IIO_CHAN_INFO_OFFSET),\
120		.datasheet_name = _name,			\
121	}
122
123static const struct iio_chan_spec max77541_adc_channels[] = {
124	MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VSYS_V, "vsys_v", IIO_VOLTAGE,
125			       MAX77541_REG_ADC_DATA_CH1),
126	MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VOUT1_V, "vout1_v", IIO_VOLTAGE,
127			       MAX77541_REG_ADC_DATA_CH2),
128	MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VOUT2_V, "vout2_v", IIO_VOLTAGE,
129			       MAX77541_REG_ADC_DATA_CH3),
130	MAX77541_ADC_CHANNEL_TEMP(MAX77541_ADC_TEMP, "temp", IIO_TEMP,
131				  MAX77541_REG_ADC_DATA_CH6),
132};
133
134static int max77541_adc_read_raw(struct iio_dev *indio_dev,
135				 struct iio_chan_spec const *chan,
136				 int *val, int *val2, long mask)
137{
138	switch (mask) {
139	case IIO_CHAN_INFO_OFFSET:
140		return max77541_adc_offset(indio_dev, chan, val, val2);
141	case IIO_CHAN_INFO_SCALE:
142		return max77541_adc_scale(indio_dev, chan, val, val2);
143	case IIO_CHAN_INFO_RAW:
144		return max77541_adc_raw(indio_dev, chan, val);
145	default:
146		return -EINVAL;
147	}
148}
149
150static const struct iio_info max77541_adc_info = {
151	.read_raw = max77541_adc_read_raw,
152};
153
154static int max77541_adc_probe(struct platform_device *pdev)
155{
156	struct device *dev = &pdev->dev;
157	struct iio_dev *indio_dev;
158	struct regmap **regmap;
159
160	indio_dev = devm_iio_device_alloc(dev, sizeof(*regmap));
161	if (!indio_dev)
162		return -ENOMEM;
163
164	regmap = iio_priv(indio_dev);
165
166	*regmap = dev_get_regmap(dev->parent, NULL);
167	indio_dev->modes = INDIO_DIRECT_MODE;
168
169	indio_dev->name = "max77541";
170	indio_dev->info = &max77541_adc_info;
171	indio_dev->channels = max77541_adc_channels;
172	indio_dev->num_channels = ARRAY_SIZE(max77541_adc_channels);
173
174	return devm_iio_device_register(dev, indio_dev);
175}
176
177static const struct platform_device_id max77541_adc_platform_id[] = {
178	{ "max77541-adc" },
179	{ }
180};
181MODULE_DEVICE_TABLE(platform, max77541_adc_platform_id);
182
183static struct platform_driver max77541_adc_driver = {
184	.driver = {
185		.name = "max77541-adc",
186	},
187	.probe = max77541_adc_probe,
188	.id_table = max77541_adc_platform_id,
189};
190module_platform_driver(max77541_adc_driver);
191
192MODULE_AUTHOR("Okan Sahin <Okan.Sahin@analog.com>");
193MODULE_DESCRIPTION("MAX77541 ADC driver");
194MODULE_LICENSE("GPL");