summaryrefslogtreecommitdiffstats
path: root/drivers/iio/adc/lp8788_adc.c
blob: 152cfc8e1c7b690c81c7717fd6cfc1422b974f83 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
/*
 * TI LP8788 MFD - ADC driver
 *
 * Copyright 2012 Texas Instruments
 *
 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/driver.h>
#include <linux/iio/machine.h>
#include <linux/mfd/lp8788.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

/* register address */
#define LP8788_ADC_CONF			0x60
#define LP8788_ADC_RAW			0x61
#define LP8788_ADC_DONE			0x63

#define ADC_CONV_START			1

struct lp8788_adc {
	struct lp8788 *lp;
	struct iio_map *map;
	struct mutex lock;
};

static const int lp8788_scale[LPADC_MAX] = {
	[LPADC_VBATT_5P5] = 1343101,
	[LPADC_VIN_CHG]   = 3052503,
	[LPADC_IBATT]     = 610500,
	[LPADC_IC_TEMP]   = 61050,
	[LPADC_VBATT_6P0] = 1465201,
	[LPADC_VBATT_5P0] = 1221001,
	[LPADC_ADC1]      = 610500,
	[LPADC_ADC2]      = 610500,
	[LPADC_VDD]       = 1025641,
	[LPADC_VCOIN]     = 757020,
	[LPADC_ADC3]      = 610500,
	[LPADC_ADC4]      = 610500,
};

static int lp8788_get_adc_result(struct lp8788_adc *adc, enum lp8788_adc_id id,
				int *val)
{
	unsigned int msb;
	unsigned int lsb;
	unsigned int result;
	u8 data;
	u8 rawdata[2];
	int size = ARRAY_SIZE(rawdata);
	int retry = 5;
	int ret;

	data = (id << 1) | ADC_CONV_START;
	ret = lp8788_write_byte(adc->lp, LP8788_ADC_CONF, data);
	if (ret)
		goto err_io;

	/* retry until adc conversion is done */
	data = 0;
	while (retry--) {
		usleep_range(100, 200);

		ret = lp8788_read_byte(adc->lp, LP8788_ADC_DONE, &data);
		if (ret)
			goto err_io;

		/* conversion done */
		if (data)
			break;
	}

	ret = lp8788_read_multi_bytes(adc->lp, LP8788_ADC_RAW, rawdata, size);
	if (ret)
		goto err_io;

	msb = (rawdata[0] << 4) & 0x00000ff0;
	lsb = (rawdata[1] >> 4) & 0x0000000f;
	result = msb | lsb;
	*val = result;

	return 0;

err_io:
	return ret;
}

static int lp8788_adc_read_raw(struct iio_dev *indio_dev,
			struct iio_chan_spec const *chan,
			int *val, int *val2, long mask)
{
	struct lp8788_adc *adc = iio_priv(indio_dev);
	enum lp8788_adc_id id = chan->channel;
	int ret;

	mutex_lock(&adc->lock);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = lp8788_get_adc_result(adc, id, val) ? -EIO : IIO_VAL_INT;
		break;
	case IIO_CHAN_INFO_SCALE:
		*val = lp8788_scale[id] / 1000000;
		*val2 = lp8788_scale[id] % 1000000;
		ret = IIO_VAL_INT_PLUS_MICRO;
		break;
	default:
		ret = -EINVAL;
		break;
	}

	mutex_unlock(&adc->lock);

	return ret;
}

static const struct iio_info lp8788_adc_info = {
	.read_raw = &lp8788_adc_read_raw,
	.driver_module = THIS_MODULE,
};

#define LP8788_CHAN(_id, _type) {				\
		.type = _type,					\
		.indexed = 1,					\
		.channel = LPADC_##_id,				\
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
			BIT(IIO_CHAN_INFO_SCALE),		\
		.datasheet_name = #_id,				\
}

static const struct iio_chan_spec lp8788_adc_channels[] = {
	[LPADC_VBATT_5P5] = LP8788_CHAN(VBATT_5P5, IIO_VOLTAGE),
	[LPADC_VIN_CHG]   = LP8788_CHAN(VIN_CHG, IIO_VOLTAGE),
	[LPADC_IBATT]     = LP8788_CHAN(IBATT, IIO_CURRENT),
	[LPADC_IC_TEMP]   = LP8788_CHAN(IC_TEMP, IIO_TEMP),
	[LPADC_VBATT_6P0] = LP8788_CHAN(VBATT_6P0, IIO_VOLTAGE),
	[LPADC_VBATT_5P0] = LP8788_CHAN(VBATT_5P0, IIO_VOLTAGE),
	[LPADC_ADC1]      = LP8788_CHAN(ADC1, IIO_VOLTAGE),
	[LPADC_ADC2]      = LP8788_CHAN(ADC2, IIO_VOLTAGE),
	[LPADC_VDD]       = LP8788_CHAN(VDD, IIO_VOLTAGE),
	[LPADC_VCOIN]     = LP8788_CHAN(VCOIN, IIO_VOLTAGE),
	[LPADC_ADC3]      = LP8788_CHAN(ADC3, IIO_VOLTAGE),
	[LPADC_ADC4]      = LP8788_CHAN(ADC4, IIO_VOLTAGE),
};

/* default maps used by iio consumer (lp8788-charger driver) */
static struct iio_map lp8788_default_iio_maps[] = {
	{
		.consumer_dev_name = "lp8788-charger",
		.consumer_channel = "lp8788_vbatt_5p0",
		.adc_channel_label = "VBATT_5P0",
	},
	{
		.consumer_dev_name = "lp8788-charger",
		.consumer_channel = "lp8788_adc1",
		.adc_channel_label = "ADC1",
	},
	{ }
};

static int lp8788_iio_map_register(struct iio_dev *indio_dev,
				struct lp8788_platform_data *pdata,
				struct lp8788_adc *adc)
{
	struct iio_map *map;
	int ret;

	map = (!pdata || !pdata->adc_pdata) ?
		lp8788_default_iio_maps : pdata->adc_pdata;

	ret = iio_map_array_register(indio_dev, map);
	if (ret) {
		dev_err(&indio_dev->dev, "iio map err: %d\n", ret);
		return ret;
	}

	adc->map = map;
	return 0;
}

static int lp8788_adc_probe(struct platform_device *pdev)
{
	struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
	struct iio_dev *indio_dev;
	struct lp8788_adc *adc;
	int ret;

	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
	if (!indio_dev)
		return -ENOMEM;

	adc = iio_priv(indio_dev);
	adc->lp = lp;
	platform_set_drvdata(pdev, indio_dev);

	indio_dev->dev.of_node = pdev->dev.of_node;
	ret = lp8788_iio_map_register(indio_dev, lp->pdata, adc);
	if (ret)
		return ret;

	mutex_init(&adc->lock);

	indio_dev->dev.parent = &pdev->dev;
	indio_dev->name = pdev->name;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->info = &lp8788_adc_info;
	indio_dev->channels = lp8788_adc_channels;
	indio_dev->num_channels = ARRAY_SIZE(lp8788_adc_channels);

	ret = iio_device_register(indio_dev);
	if (ret) {
		dev_err(&pdev->dev, "iio dev register err: %d\n", ret);
		goto err_iio_device;
	}

	return 0;

err_iio_device:
	iio_map_array_unregister(indio_dev);
	return ret;
}

static int lp8788_adc_remove(struct platform_device *pdev)
{
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);

	iio_device_unregister(indio_dev);
	iio_map_array_unregister(indio_dev);

	return 0;
}

static struct platform_driver lp8788_adc_driver = {
	.probe = lp8788_adc_probe,
	.remove = lp8788_adc_remove,
	.driver = {
		.name = LP8788_DEV_ADC,
	},
};
module_platform_driver(lp8788_adc_driver);

MODULE_DESCRIPTION("Texas Instruments LP8788 ADC Driver");
MODULE_AUTHOR("Milo Kim");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:lp8788-adc");