mp2629_adc.c

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