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};
62
63static int mp2629_read_raw(struct iio_dev *indio_dev,
64			struct iio_chan_spec const *chan,
65			int *val, int *val2, long mask)
66{
67	struct mp2629_adc *info = iio_priv(indio_dev);
68	unsigned int rval;
69	int ret;
70
71	switch (mask) {
72	case IIO_CHAN_INFO_RAW:
73		ret = regmap_read(info->regmap, chan->address, &rval);
74		if (ret)
75			return ret;
76
77		if (chan->channel == MP2629_INPUT_VOLT)
78			rval &= GENMASK(6, 0);
79		*val = rval;
80		return IIO_VAL_INT;
81
82	case IIO_CHAN_INFO_SCALE:
83		switch (chan->channel) {
84		case MP2629_BATT_VOLT:
85		case MP2629_SYSTEM_VOLT:
86			*val = 20;
87			return IIO_VAL_INT;
88
89		case MP2629_INPUT_VOLT:
90			*val = 60;
91			return IIO_VAL_INT;
92
93		case MP2629_BATT_CURRENT:
94			*val = 175;
95			*val2 = 10;
96			return IIO_VAL_FRACTIONAL;
97
98		case MP2629_INPUT_CURRENT:
99			*val = 133;
100			*val2 = 10;
101			return IIO_VAL_FRACTIONAL;
102
103		default:
104			return -EINVAL;
105		}
106
107	default:
108		return -EINVAL;
109	}
110}
111
112static const struct iio_info mp2629_adc_info = {
113	.read_raw = &mp2629_read_raw,
114};
115
116static int mp2629_adc_probe(struct platform_device *pdev)
117{
118	struct device *dev = &pdev->dev;
119	struct mp2629_data *ddata = dev_get_drvdata(dev->parent);
120	struct mp2629_adc *info;
121	struct iio_dev *indio_dev;
122	int ret;
123
124	indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
125	if (!indio_dev)
126		return -ENOMEM;
127
128	info = iio_priv(indio_dev);
129	info->regmap = ddata->regmap;
130	info->dev = dev;
131	platform_set_drvdata(pdev, indio_dev);
132
133	ret = regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
134				MP2629_ADC_START | MP2629_ADC_CONTINUOUS,
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->dev.parent = dev;
149	indio_dev->channels = mp2629_channels;
150	indio_dev->num_channels = ARRAY_SIZE(mp2629_channels);
151	indio_dev->modes = INDIO_DIRECT_MODE;
152	indio_dev->info = &mp2629_adc_info;
153
154	ret = iio_device_register(indio_dev);
155	if (ret) {
156		dev_err(dev, "IIO device register fail: %d\n", ret);
157		goto fail_map_unregister;
158	}
159
160	return 0;
161
162fail_map_unregister:
163	iio_map_array_unregister(indio_dev);
164
165fail_disable:
166	regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
167					 MP2629_ADC_CONTINUOUS, 0);
168	regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
169					 MP2629_ADC_START, 0);
170
171	return ret;
172}
173
174static int mp2629_adc_remove(struct platform_device *pdev)
175{
176	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
177	struct mp2629_adc *info = iio_priv(indio_dev);
178
179	iio_device_unregister(indio_dev);
180
181	iio_map_array_unregister(indio_dev);
182
183	regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
184					 MP2629_ADC_CONTINUOUS, 0);
185	regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
186					 MP2629_ADC_START, 0);
187
188	return 0;
189}
190
191static const struct of_device_id mp2629_adc_of_match[] = {
192	{ .compatible = "mps,mp2629_adc"},
193	{}
194};
195MODULE_DEVICE_TABLE(of, mp2629_adc_of_match);
196
197static struct platform_driver mp2629_adc_driver = {
198	.driver = {
199		.name = "mp2629_adc",
200		.of_match_table = mp2629_adc_of_match,
201	},
202	.probe		= mp2629_adc_probe,
203	.remove		= mp2629_adc_remove,
204};
205module_platform_driver(mp2629_adc_driver);
206
207MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
208MODULE_DESCRIPTION("MP2629 ADC driver");
209MODULE_LICENSE("GPL");
210