1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver
4 *
5 * Copyright (C) 2012 Avionic Design GmbH
6 * Copyright (C) 2016 Intel
7 *
8 * Datasheets:
9 *	https://www.ti.com/lit/ds/symlink/adc081c021.pdf
10 *	https://www.ti.com/lit/ds/symlink/adc101c021.pdf
11 *	https://www.ti.com/lit/ds/symlink/adc121c021.pdf
12 *
13 * The devices have a very similar interface and differ mostly in the number of
14 * bits handled. For the 8-bit and 10-bit models the least-significant 4 or 2
15 * bits of value registers are reserved.
16 */
17
18#include <linux/err.h>
19#include <linux/i2c.h>
20#include <linux/module.h>
21#include <linux/mod_devicetable.h>
22#include <linux/property.h>
23
24#include <linux/iio/iio.h>
25#include <linux/iio/buffer.h>
26#include <linux/iio/trigger_consumer.h>
27#include <linux/iio/triggered_buffer.h>
28#include <linux/regulator/consumer.h>
29
30struct adc081c {
31	struct i2c_client *i2c;
32	struct regulator *ref;
33
34	/* 8, 10 or 12 */
35	int bits;
36
37	/* Ensure natural alignment of buffer elements */
38	struct {
39		u16 channel;
40		s64 ts __aligned(8);
41	} scan;
42};
43
44#define REG_CONV_RES 0x00
45
46static int adc081c_read_raw(struct iio_dev *iio,
47			    struct iio_chan_spec const *channel, int *value,
48			    int *shift, long mask)
49{
50	struct adc081c *adc = iio_priv(iio);
51	int err;
52
53	switch (mask) {
54	case IIO_CHAN_INFO_RAW:
55		err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
56		if (err < 0)
57			return err;
58
59		*value = (err & 0xFFF) >> (12 - adc->bits);
60		return IIO_VAL_INT;
61
62	case IIO_CHAN_INFO_SCALE:
63		err = regulator_get_voltage(adc->ref);
64		if (err < 0)
65			return err;
66
67		*value = err / 1000;
68		*shift = adc->bits;
69
70		return IIO_VAL_FRACTIONAL_LOG2;
71
72	default:
73		break;
74	}
75
76	return -EINVAL;
77}
78
79#define ADCxx1C_CHAN(_bits) {					\
80	.type = IIO_VOLTAGE,					\
81	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
82	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
83	.scan_type = {						\
84		.sign = 'u',					\
85		.realbits = (_bits),				\
86		.storagebits = 16,				\
87		.shift = 12 - (_bits),				\
88		.endianness = IIO_CPU,				\
89	},							\
90}
91
92#define DEFINE_ADCxx1C_CHANNELS(_name, _bits)				\
93	static const struct iio_chan_spec _name ## _channels[] = {	\
94		ADCxx1C_CHAN((_bits)),					\
95		IIO_CHAN_SOFT_TIMESTAMP(1),				\
96	};								\
97
98#define ADC081C_NUM_CHANNELS 2
99
100struct adcxx1c_model {
101	const struct iio_chan_spec* channels;
102	int bits;
103};
104
105#define ADCxx1C_MODEL(_name, _bits)					\
106	{								\
107		.channels = _name ## _channels,				\
108		.bits = (_bits),					\
109	}
110
111DEFINE_ADCxx1C_CHANNELS(adc081c,  8);
112DEFINE_ADCxx1C_CHANNELS(adc101c, 10);
113DEFINE_ADCxx1C_CHANNELS(adc121c, 12);
114
115/* Model ids are indexes in _models array */
116enum adcxx1c_model_id {
117	ADC081C = 0,
118	ADC101C = 1,
119	ADC121C = 2,
120};
121
122static struct adcxx1c_model adcxx1c_models[] = {
123	ADCxx1C_MODEL(adc081c,  8),
124	ADCxx1C_MODEL(adc101c, 10),
125	ADCxx1C_MODEL(adc121c, 12),
126};
127
128static const struct iio_info adc081c_info = {
129	.read_raw = adc081c_read_raw,
130};
131
132static irqreturn_t adc081c_trigger_handler(int irq, void *p)
133{
134	struct iio_poll_func *pf = p;
135	struct iio_dev *indio_dev = pf->indio_dev;
136	struct adc081c *data = iio_priv(indio_dev);
137	int ret;
138
139	ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);
140	if (ret < 0)
141		goto out;
142	data->scan.channel = ret;
143	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
144					   iio_get_time_ns(indio_dev));
145out:
146	iio_trigger_notify_done(indio_dev->trig);
147	return IRQ_HANDLED;
148}
149
150static void adc081c_reg_disable(void *reg)
151{
152	regulator_disable(reg);
153}
154
155static int adc081c_probe(struct i2c_client *client)
156{
157	const struct i2c_device_id *id = i2c_client_get_device_id(client);
158	struct iio_dev *iio;
159	struct adc081c *adc;
160	const struct adcxx1c_model *model;
161	int err;
162
163	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
164		return -EOPNOTSUPP;
165
166	if (dev_fwnode(&client->dev))
167		model = device_get_match_data(&client->dev);
168	else
169		model = &adcxx1c_models[id->driver_data];
170
171	iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
172	if (!iio)
173		return -ENOMEM;
174
175	adc = iio_priv(iio);
176	adc->i2c = client;
177	adc->bits = model->bits;
178
179	adc->ref = devm_regulator_get(&client->dev, "vref");
180	if (IS_ERR(adc->ref))
181		return PTR_ERR(adc->ref);
182
183	err = regulator_enable(adc->ref);
184	if (err < 0)
185		return err;
186
187	err = devm_add_action_or_reset(&client->dev, adc081c_reg_disable,
188				       adc->ref);
189	if (err)
190		return err;
191
192	iio->name = dev_name(&client->dev);
193	iio->modes = INDIO_DIRECT_MODE;
194	iio->info = &adc081c_info;
195
196	iio->channels = model->channels;
197	iio->num_channels = ADC081C_NUM_CHANNELS;
198
199	err = devm_iio_triggered_buffer_setup(&client->dev, iio, NULL,
200					      adc081c_trigger_handler, NULL);
201	if (err < 0) {
202		dev_err(&client->dev, "iio triggered buffer setup failed\n");
203		return err;
204	}
205
206	return devm_iio_device_register(&client->dev, iio);
207}
208
209static const struct i2c_device_id adc081c_id[] = {
210	{ "adc081c", ADC081C },
211	{ "adc101c", ADC101C },
212	{ "adc121c", ADC121C },
213	{ }
214};
215MODULE_DEVICE_TABLE(i2c, adc081c_id);
216
217static const struct acpi_device_id adc081c_acpi_match[] = {
218	/* Used on some AAEON boards */
219	{ "ADC081C", (kernel_ulong_t)&adcxx1c_models[ADC081C] },
220	{ }
221};
222MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match);
223
224static const struct of_device_id adc081c_of_match[] = {
225	{ .compatible = "ti,adc081c", .data = &adcxx1c_models[ADC081C] },
226	{ .compatible = "ti,adc101c", .data = &adcxx1c_models[ADC101C] },
227	{ .compatible = "ti,adc121c", .data = &adcxx1c_models[ADC121C] },
228	{ }
229};
230MODULE_DEVICE_TABLE(of, adc081c_of_match);
231
232static struct i2c_driver adc081c_driver = {
233	.driver = {
234		.name = "adc081c",
235		.of_match_table = adc081c_of_match,
236		.acpi_match_table = adc081c_acpi_match,
237	},
238	.probe = adc081c_probe,
239	.id_table = adc081c_id,
240};
241module_i2c_driver(adc081c_driver);
242
243MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
244MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver");
245MODULE_LICENSE("GPL v2");
246