1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * MP2629 Driver for ADC
  4 *
  5 * Copyright 2020 Monolithic Power Systems, Inc
  6 *
  7 * Author: Saravanan Sekar <sravanhome@gmail.com>
  8 */
  9
 10#include <linux/iio/driver.h>
 11#include <linux/iio/iio.h>
 12#include <linux/iio/machine.h>
 13#include <linux/mfd/mp2629.h>
 14#include <linux/module.h>
 15#include <linux/mutex.h>
 16#include <linux/platform_device.h>
 17#include <linux/regmap.h>
 18
 19#define	MP2629_REG_ADC_CTRL		0x03
 20#define	MP2629_REG_BATT_VOLT		0x0e
 21#define	MP2629_REG_SYSTEM_VOLT		0x0f
 22#define	MP2629_REG_INPUT_VOLT		0x11
 23#define	MP2629_REG_BATT_CURRENT		0x12
 24#define	MP2629_REG_INPUT_CURRENT	0x13
 25
 26#define	MP2629_ADC_START		BIT(7)
 27#define	MP2629_ADC_CONTINUOUS		BIT(6)
 28
 29#define MP2629_MAP(_mp, _mpc) IIO_MAP(#_mp, "mp2629_charger", "mp2629-"_mpc)
 30
 31#define MP2629_ADC_CHAN(_ch, _type) {				\
 32	.type = _type,						\
 33	.indexed = 1,						\
 34	.datasheet_name = #_ch,					\
 35	.channel = MP2629_ ## _ch,				\
 36	.address = MP2629_REG_ ## _ch,				\
 37	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 38	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
 39}
 40
 41struct mp2629_adc {
 42	struct regmap *regmap;
 43	struct device *dev;
 44};
 45
 46static struct iio_chan_spec mp2629_channels[] = {
 47	MP2629_ADC_CHAN(BATT_VOLT, IIO_VOLTAGE),
 48	MP2629_ADC_CHAN(SYSTEM_VOLT, IIO_VOLTAGE),
 49	MP2629_ADC_CHAN(INPUT_VOLT, IIO_VOLTAGE),
 50	MP2629_ADC_CHAN(BATT_CURRENT, IIO_CURRENT),
 51	MP2629_ADC_CHAN(INPUT_CURRENT, IIO_CURRENT)
 52};
 53
 54static struct iio_map mp2629_adc_maps[] = {
 55	MP2629_MAP(BATT_VOLT, "batt-volt"),
 56	MP2629_MAP(SYSTEM_VOLT, "system-volt"),
 57	MP2629_MAP(INPUT_VOLT, "input-volt"),
 58	MP2629_MAP(BATT_CURRENT, "batt-current"),
 59	MP2629_MAP(INPUT_CURRENT, "input-current")
 60};
 61
 62static int mp2629_read_raw(struct iio_dev *indio_dev,
 63			struct iio_chan_spec const *chan,
 64			int *val, int *val2, long mask)
 65{
 66	struct mp2629_adc *info = iio_priv(indio_dev);
 67	unsigned int rval;
 68	int ret;
 69
 70	switch (mask) {
 71	case IIO_CHAN_INFO_RAW:
 72		ret = regmap_read(info->regmap, chan->address, &rval);
 73		if (ret)
 74			return ret;
 75
 76		if (chan->address == MP2629_INPUT_VOLT)
 77			rval &= GENMASK(6, 0);
 78		*val = rval;
 79		return IIO_VAL_INT;
 80
 81	case IIO_CHAN_INFO_SCALE:
 82		switch (chan->channel) {
 83		case MP2629_BATT_VOLT:
 84		case MP2629_SYSTEM_VOLT:
 85			*val = 20;
 86			return IIO_VAL_INT;
 87
 88		case MP2629_INPUT_VOLT:
 89			*val = 60;
 90			return IIO_VAL_INT;
 91
 92		case MP2629_BATT_CURRENT:
 93			*val = 175;
 94			*val2 = 10;
 95			return IIO_VAL_FRACTIONAL;
 96
 97		case MP2629_INPUT_CURRENT:
 98			*val = 133;
 99			*val2 = 10;
100			return IIO_VAL_FRACTIONAL;
101
102		default:
103			return -EINVAL;
104		}
105
106	default:
107		return -EINVAL;
108	}
109}
110
111static const struct iio_info mp2629_adc_info = {
112	.read_raw = &mp2629_read_raw,
113};
114
115static int mp2629_adc_probe(struct platform_device *pdev)
116{
117	struct device *dev = &pdev->dev;
118	struct mp2629_data *ddata = dev_get_drvdata(dev->parent);
119	struct mp2629_adc *info;
120	struct iio_dev *indio_dev;
121	int ret;
122
123	indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
124	if (!indio_dev)
125		return -ENOMEM;
126
127	info = iio_priv(indio_dev);
128	info->regmap = ddata->regmap;
129	info->dev = dev;
130	platform_set_drvdata(pdev, indio_dev);
131
132	ret = regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
133				MP2629_ADC_START | MP2629_ADC_CONTINUOUS,
134				MP2629_ADC_START | MP2629_ADC_CONTINUOUS);
135	if (ret) {
136		dev_err(dev, "adc enable fail: %d\n", ret);
137		return ret;
138	}
139
140	ret = iio_map_array_register(indio_dev, mp2629_adc_maps);
141	if (ret) {
142		dev_err(dev, "IIO maps register fail: %d\n", ret);
143		goto fail_disable;
144	}
145
146	indio_dev->name = "mp2629-adc";
147	indio_dev->dev.parent = dev;
148	indio_dev->channels = mp2629_channels;
149	indio_dev->num_channels = ARRAY_SIZE(mp2629_channels);
150	indio_dev->modes = INDIO_DIRECT_MODE;
151	indio_dev->info = &mp2629_adc_info;
152
153	ret = iio_device_register(indio_dev);
154	if (ret) {
155		dev_err(dev, "IIO device register fail: %d\n", ret);
156		goto fail_map_unregister;
157	}
158
159	return 0;
160
161fail_map_unregister:
162	iio_map_array_unregister(indio_dev);
163
164fail_disable:
165	regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
166					 MP2629_ADC_CONTINUOUS, 0);
167	regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
168					 MP2629_ADC_START, 0);
169
170	return ret;
171}
172
173static int mp2629_adc_remove(struct platform_device *pdev)
174{
175	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
176	struct mp2629_adc *info = iio_priv(indio_dev);
177
178	iio_device_unregister(indio_dev);
179
180	iio_map_array_unregister(indio_dev);
181
182	regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
183					 MP2629_ADC_CONTINUOUS, 0);
184	regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
185					 MP2629_ADC_START, 0);
186
187	return 0;
188}
189
190static const struct of_device_id mp2629_adc_of_match[] = {
191	{ .compatible = "mps,mp2629_adc"},
192	{}
193};
194MODULE_DEVICE_TABLE(of, mp2629_adc_of_match);
195
196static struct platform_driver mp2629_adc_driver = {
197	.driver = {
198		.name = "mp2629_adc",
199		.of_match_table = mp2629_adc_of_match,
200	},
201	.probe		= mp2629_adc_probe,
202	.remove		= mp2629_adc_remove,
203};
204module_platform_driver(mp2629_adc_driver);
205
206MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
207MODULE_DESCRIPTION("MP2629 ADC driver");
208MODULE_LICENSE("GPL");