summaryrefslogtreecommitdiff
path: root/drivers/iio/adc/ti-adc081c.c
blob: bd48b073e7200c279a0d2cf406e4f2c00b2570a0 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver
 *
 * Copyright (C) 2012 Avionic Design GmbH
 * Copyright (C) 2016 Intel
 *
 * Datasheets:
 *	https://www.ti.com/lit/ds/symlink/adc081c021.pdf
 *	https://www.ti.com/lit/ds/symlink/adc101c021.pdf
 *	https://www.ti.com/lit/ds/symlink/adc121c021.pdf
 *
 * The devices have a very similar interface and differ mostly in the number of
 * bits handled. For the 8-bit and 10-bit models the least-significant 4 or 2
 * bits of value registers are reserved.
 */

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/property.h>

#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/regulator/consumer.h>

struct adc081c {
	struct i2c_client *i2c;
	struct regulator *ref;

	/* 8, 10 or 12 */
	int bits;

	/* Ensure natural alignment of buffer elements */
	struct {
		u16 channel;
		s64 ts __aligned(8);
	} scan;
};

#define REG_CONV_RES 0x00

static int adc081c_read_raw(struct iio_dev *iio,
			    struct iio_chan_spec const *channel, int *value,
			    int *shift, long mask)
{
	struct adc081c *adc = iio_priv(iio);
	int err;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
		if (err < 0)
			return err;

		*value = (err & 0xFFF) >> (12 - adc->bits);
		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:
		err = regulator_get_voltage(adc->ref);
		if (err < 0)
			return err;

		*value = err / 1000;
		*shift = adc->bits;

		return IIO_VAL_FRACTIONAL_LOG2;

	default:
		break;
	}

	return -EINVAL;
}

#define ADCxx1C_CHAN(_bits) {					\
	.type = IIO_VOLTAGE,					\
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
	.scan_type = {						\
		.sign = 'u',					\
		.realbits = (_bits),				\
		.storagebits = 16,				\
		.shift = 12 - (_bits),				\
		.endianness = IIO_CPU,				\
	},							\
}

#define DEFINE_ADCxx1C_CHANNELS(_name, _bits)				\
	static const struct iio_chan_spec _name ## _channels[] = {	\
		ADCxx1C_CHAN((_bits)),					\
		IIO_CHAN_SOFT_TIMESTAMP(1),				\
	};								\

#define ADC081C_NUM_CHANNELS 2

struct adcxx1c_model {
	const struct iio_chan_spec* channels;
	int bits;
};

#define ADCxx1C_MODEL(_name, _bits)					\
	{								\
		.channels = _name ## _channels,				\
		.bits = (_bits),					\
	}

DEFINE_ADCxx1C_CHANNELS(adc081c,  8);
DEFINE_ADCxx1C_CHANNELS(adc101c, 10);
DEFINE_ADCxx1C_CHANNELS(adc121c, 12);

/* Model ids are indexes in _models array */
enum adcxx1c_model_id {
	ADC081C = 0,
	ADC101C = 1,
	ADC121C = 2,
};

static struct adcxx1c_model adcxx1c_models[] = {
	ADCxx1C_MODEL(adc081c,  8),
	ADCxx1C_MODEL(adc101c, 10),
	ADCxx1C_MODEL(adc121c, 12),
};

static const struct iio_info adc081c_info = {
	.read_raw = adc081c_read_raw,
};

static irqreturn_t adc081c_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct adc081c *data = iio_priv(indio_dev);
	int ret;

	ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);
	if (ret < 0)
		goto out;
	data->scan.channel = ret;
	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
					   iio_get_time_ns(indio_dev));
out:
	iio_trigger_notify_done(indio_dev->trig);
	return IRQ_HANDLED;
}

static void adc081c_reg_disable(void *reg)
{
	regulator_disable(reg);
}

static int adc081c_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct iio_dev *iio;
	struct adc081c *adc;
	const struct adcxx1c_model *model;
	int err;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
		return -EOPNOTSUPP;

	if (dev_fwnode(&client->dev))
		model = device_get_match_data(&client->dev);
	else
		model = &adcxx1c_models[id->driver_data];

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

	adc = iio_priv(iio);
	adc->i2c = client;
	adc->bits = model->bits;

	adc->ref = devm_regulator_get(&client->dev, "vref");
	if (IS_ERR(adc->ref))
		return PTR_ERR(adc->ref);

	err = regulator_enable(adc->ref);
	if (err < 0)
		return err;

	err = devm_add_action_or_reset(&client->dev, adc081c_reg_disable,
				       adc->ref);
	if (err)
		return err;

	iio->name = dev_name(&client->dev);
	iio->modes = INDIO_DIRECT_MODE;
	iio->info = &adc081c_info;

	iio->channels = model->channels;
	iio->num_channels = ADC081C_NUM_CHANNELS;

	err = devm_iio_triggered_buffer_setup(&client->dev, iio, NULL,
					      adc081c_trigger_handler, NULL);
	if (err < 0) {
		dev_err(&client->dev, "iio triggered buffer setup failed\n");
		return err;
	}

	return devm_iio_device_register(&client->dev, iio);
}

static const struct i2c_device_id adc081c_id[] = {
	{ "adc081c", ADC081C },
	{ "adc101c", ADC101C },
	{ "adc121c", ADC121C },
	{ }
};
MODULE_DEVICE_TABLE(i2c, adc081c_id);

static const struct acpi_device_id adc081c_acpi_match[] = {
	/* Used on some AAEON boards */
	{ "ADC081C", (kernel_ulong_t)&adcxx1c_models[ADC081C] },
	{ }
};
MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match);

static const struct of_device_id adc081c_of_match[] = {
	{ .compatible = "ti,adc081c", .data = &adcxx1c_models[ADC081C] },
	{ .compatible = "ti,adc101c", .data = &adcxx1c_models[ADC101C] },
	{ .compatible = "ti,adc121c", .data = &adcxx1c_models[ADC121C] },
	{ }
};
MODULE_DEVICE_TABLE(of, adc081c_of_match);

static struct i2c_driver adc081c_driver = {
	.driver = {
		.name = "adc081c",
		.of_match_table = adc081c_of_match,
		.acpi_match_table = adc081c_acpi_match,
	},
	.probe = adc081c_probe,
	.id_table = adc081c_id,
};
module_i2c_driver(adc081c_driver);

MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver");
MODULE_LICENSE("GPL v2");