1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * TI LP8788 MFD - ADC driver
4 *
5 * Copyright 2012 Texas Instruments
6 *
7 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
8 */
9
10#include <linux/delay.h>
11#include <linux/iio/iio.h>
12#include <linux/iio/driver.h>
13#include <linux/iio/machine.h>
14#include <linux/mfd/lp8788.h>
15#include <linux/module.h>
16#include <linux/mutex.h>
17#include <linux/platform_device.h>
18#include <linux/slab.h>
19
20/* register address */
21#define LP8788_ADC_CONF			0x60
22#define LP8788_ADC_RAW			0x61
23#define LP8788_ADC_DONE			0x63
24
25#define ADC_CONV_START			1
26
27struct lp8788_adc {
28	struct lp8788 *lp;
29	struct iio_map *map;
30	struct mutex lock;
31};
32
33static const int lp8788_scale[LPADC_MAX] = {
34	[LPADC_VBATT_5P5] = 1343101,
35	[LPADC_VIN_CHG]   = 3052503,
36	[LPADC_IBATT]     = 610500,
37	[LPADC_IC_TEMP]   = 61050,
38	[LPADC_VBATT_6P0] = 1465201,
39	[LPADC_VBATT_5P0] = 1221001,
40	[LPADC_ADC1]      = 610500,
41	[LPADC_ADC2]      = 610500,
42	[LPADC_VDD]       = 1025641,
43	[LPADC_VCOIN]     = 757020,
44	[LPADC_ADC3]      = 610500,
45	[LPADC_ADC4]      = 610500,
46};
47
48static int lp8788_get_adc_result(struct lp8788_adc *adc, enum lp8788_adc_id id,
49				int *val)
50{
51	unsigned int msb;
52	unsigned int lsb;
53	unsigned int result;
54	u8 data;
55	u8 rawdata[2];
56	int size = ARRAY_SIZE(rawdata);
57	int retry = 5;
58	int ret;
59
60	data = (id << 1) | ADC_CONV_START;
61	ret = lp8788_write_byte(adc->lp, LP8788_ADC_CONF, data);
62	if (ret)
63		goto err_io;
64
65	/* retry until adc conversion is done */
66	data = 0;
67	while (retry--) {
68		usleep_range(100, 200);
69
70		ret = lp8788_read_byte(adc->lp, LP8788_ADC_DONE, &data);
71		if (ret)
72			goto err_io;
73
74		/* conversion done */
75		if (data)
76			break;
77	}
78
79	ret = lp8788_read_multi_bytes(adc->lp, LP8788_ADC_RAW, rawdata, size);
80	if (ret)
81		goto err_io;
82
83	msb = (rawdata[0] << 4) & 0x00000ff0;
84	lsb = (rawdata[1] >> 4) & 0x0000000f;
85	result = msb | lsb;
86	*val = result;
87
88	return 0;
89
90err_io:
91	return ret;
92}
93
94static int lp8788_adc_read_raw(struct iio_dev *indio_dev,
95			struct iio_chan_spec const *chan,
96			int *val, int *val2, long mask)
97{
98	struct lp8788_adc *adc = iio_priv(indio_dev);
99	enum lp8788_adc_id id = chan->channel;
100	int ret;
101
102	mutex_lock(&adc->lock);
103
104	switch (mask) {
105	case IIO_CHAN_INFO_RAW:
106		ret = lp8788_get_adc_result(adc, id, val) ? -EIO : IIO_VAL_INT;
107		break;
108	case IIO_CHAN_INFO_SCALE:
109		*val = lp8788_scale[id] / 1000000;
110		*val2 = lp8788_scale[id] % 1000000;
111		ret = IIO_VAL_INT_PLUS_MICRO;
112		break;
113	default:
114		ret = -EINVAL;
115		break;
116	}
117
118	mutex_unlock(&adc->lock);
119
120	return ret;
121}
122
123static const struct iio_info lp8788_adc_info = {
124	.read_raw = &lp8788_adc_read_raw,
125};
126
127#define LP8788_CHAN(_id, _type) {				\
128		.type = _type,					\
129		.indexed = 1,					\
130		.channel = LPADC_##_id,				\
131		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
132			BIT(IIO_CHAN_INFO_SCALE),		\
133		.datasheet_name = #_id,				\
134}
135
136static const struct iio_chan_spec lp8788_adc_channels[] = {
137	[LPADC_VBATT_5P5] = LP8788_CHAN(VBATT_5P5, IIO_VOLTAGE),
138	[LPADC_VIN_CHG]   = LP8788_CHAN(VIN_CHG, IIO_VOLTAGE),
139	[LPADC_IBATT]     = LP8788_CHAN(IBATT, IIO_CURRENT),
140	[LPADC_IC_TEMP]   = LP8788_CHAN(IC_TEMP, IIO_TEMP),
141	[LPADC_VBATT_6P0] = LP8788_CHAN(VBATT_6P0, IIO_VOLTAGE),
142	[LPADC_VBATT_5P0] = LP8788_CHAN(VBATT_5P0, IIO_VOLTAGE),
143	[LPADC_ADC1]      = LP8788_CHAN(ADC1, IIO_VOLTAGE),
144	[LPADC_ADC2]      = LP8788_CHAN(ADC2, IIO_VOLTAGE),
145	[LPADC_VDD]       = LP8788_CHAN(VDD, IIO_VOLTAGE),
146	[LPADC_VCOIN]     = LP8788_CHAN(VCOIN, IIO_VOLTAGE),
147	[LPADC_ADC3]      = LP8788_CHAN(ADC3, IIO_VOLTAGE),
148	[LPADC_ADC4]      = LP8788_CHAN(ADC4, IIO_VOLTAGE),
149};
150
151/* default maps used by iio consumer (lp8788-charger driver) */
152static struct iio_map lp8788_default_iio_maps[] = {
153	{
154		.consumer_dev_name = "lp8788-charger",
155		.consumer_channel = "lp8788_vbatt_5p0",
156		.adc_channel_label = "VBATT_5P0",
157	},
158	{
159		.consumer_dev_name = "lp8788-charger",
160		.consumer_channel = "lp8788_adc1",
161		.adc_channel_label = "ADC1",
162	},
163	{ }
164};
165
166static int lp8788_iio_map_register(struct device *dev,
167				struct iio_dev *indio_dev,
168				struct lp8788_platform_data *pdata,
169				struct lp8788_adc *adc)
170{
171	struct iio_map *map;
172	int ret;
173
174	map = (!pdata || !pdata->adc_pdata) ?
175		lp8788_default_iio_maps : pdata->adc_pdata;
176
177	ret = devm_iio_map_array_register(dev, indio_dev, map);
178	if (ret) {
179		dev_err(&indio_dev->dev, "iio map err: %d\n", ret);
180		return ret;
181	}
182
183	adc->map = map;
184	return 0;
185}
186
187static int lp8788_adc_probe(struct platform_device *pdev)
188{
189	struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
190	struct iio_dev *indio_dev;
191	struct lp8788_adc *adc;
192	int ret;
193
194	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
195	if (!indio_dev)
196		return -ENOMEM;
197
198	adc = iio_priv(indio_dev);
199	adc->lp = lp;
200
201	ret = lp8788_iio_map_register(&pdev->dev, indio_dev, lp->pdata, adc);
202	if (ret)
203		return ret;
204
205	mutex_init(&adc->lock);
206
207	indio_dev->name = pdev->name;
208	indio_dev->modes = INDIO_DIRECT_MODE;
209	indio_dev->info = &lp8788_adc_info;
210	indio_dev->channels = lp8788_adc_channels;
211	indio_dev->num_channels = ARRAY_SIZE(lp8788_adc_channels);
212
213	return devm_iio_device_register(&pdev->dev, indio_dev);
214}
215
216static struct platform_driver lp8788_adc_driver = {
217	.probe = lp8788_adc_probe,
218	.driver = {
219		.name = LP8788_DEV_ADC,
220	},
221};
222module_platform_driver(lp8788_adc_driver);
223
224MODULE_DESCRIPTION("Texas Instruments LP8788 ADC Driver");
225MODULE_AUTHOR("Milo Kim");
226MODULE_LICENSE("GPL");
227MODULE_ALIAS("platform:lp8788-adc");
228