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 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 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_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
135				MP2629_ADC_START | MP2629_ADC_CONTINUOUS,
136				MP2629_ADC_START | MP2629_ADC_CONTINUOUS);
137	if (ret) {
138		dev_err(dev, "adc enable fail: %d\n", ret);
139		return ret;
140	}
141
142	ret = iio_map_array_register(indio_dev, mp2629_adc_maps);
143	if (ret) {
144		dev_err(dev, "IIO maps register fail: %d\n", ret);
145		goto fail_disable;
146	}
147
148	indio_dev->name = "mp2629-adc";
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 void 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
189static const struct of_device_id mp2629_adc_of_match[] = {
190	{ .compatible = "mps,mp2629_adc"},
191	{}
192};
193MODULE_DEVICE_TABLE(of, mp2629_adc_of_match);
194
195static struct platform_driver mp2629_adc_driver = {
196	.driver = {
197		.name = "mp2629_adc",
198		.of_match_table = mp2629_adc_of_match,
199	},
200	.probe		= mp2629_adc_probe,
201	.remove_new	= mp2629_adc_remove,
202};
203module_platform_driver(mp2629_adc_driver);
204
205MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
206MODULE_DESCRIPTION("MP2629 ADC driver");
207MODULE_LICENSE("GPL");
208