1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2014 Angelo Compagnucci <angelo.compagnucci@gmail.com>
4 *
5 * Driver for Texas Instruments' ADC128S052, ADC122S021 and ADC124S021 ADC chip.
6 * Datasheets can be found here:
7 * https://www.ti.com/lit/ds/symlink/adc128s052.pdf
8 * https://www.ti.com/lit/ds/symlink/adc122s021.pdf
9 * https://www.ti.com/lit/ds/symlink/adc124s021.pdf
10 */
11
12#include <linux/acpi.h>
13#include <linux/err.h>
14#include <linux/spi/spi.h>
15#include <linux/module.h>
16#include <linux/mod_devicetable.h>
17#include <linux/iio/iio.h>
18#include <linux/property.h>
19#include <linux/regulator/consumer.h>
20
21struct adc128_configuration {
22	const struct iio_chan_spec	*channels;
23	u8				num_channels;
24};
25
26struct adc128 {
27	struct spi_device *spi;
28
29	struct regulator *reg;
30	struct mutex lock;
31
32	u8 buffer[2] ____cacheline_aligned;
33};
34
35static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
36{
37	int ret;
38
39	mutex_lock(&adc->lock);
40
41	adc->buffer[0] = channel << 3;
42	adc->buffer[1] = 0;
43
44	ret = spi_write(adc->spi, &adc->buffer, 2);
45	if (ret < 0) {
46		mutex_unlock(&adc->lock);
47		return ret;
48	}
49
50	ret = spi_read(adc->spi, &adc->buffer, 2);
51
52	mutex_unlock(&adc->lock);
53
54	if (ret < 0)
55		return ret;
56
57	return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF);
58}
59
60static int adc128_read_raw(struct iio_dev *indio_dev,
61			   struct iio_chan_spec const *channel, int *val,
62			   int *val2, long mask)
63{
64	struct adc128 *adc = iio_priv(indio_dev);
65	int ret;
66
67	switch (mask) {
68	case IIO_CHAN_INFO_RAW:
69
70		ret = adc128_adc_conversion(adc, channel->channel);
71		if (ret < 0)
72			return ret;
73
74		*val = ret;
75		return IIO_VAL_INT;
76
77	case IIO_CHAN_INFO_SCALE:
78
79		ret = regulator_get_voltage(adc->reg);
80		if (ret < 0)
81			return ret;
82
83		*val = ret / 1000;
84		*val2 = 12;
85		return IIO_VAL_FRACTIONAL_LOG2;
86
87	default:
88		return -EINVAL;
89	}
90
91}
92
93#define ADC128_VOLTAGE_CHANNEL(num)	\
94	{ \
95		.type = IIO_VOLTAGE, \
96		.indexed = 1, \
97		.channel = (num), \
98		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
99		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
100	}
101
102static const struct iio_chan_spec adc128s052_channels[] = {
103	ADC128_VOLTAGE_CHANNEL(0),
104	ADC128_VOLTAGE_CHANNEL(1),
105	ADC128_VOLTAGE_CHANNEL(2),
106	ADC128_VOLTAGE_CHANNEL(3),
107	ADC128_VOLTAGE_CHANNEL(4),
108	ADC128_VOLTAGE_CHANNEL(5),
109	ADC128_VOLTAGE_CHANNEL(6),
110	ADC128_VOLTAGE_CHANNEL(7),
111};
112
113static const struct iio_chan_spec adc122s021_channels[] = {
114	ADC128_VOLTAGE_CHANNEL(0),
115	ADC128_VOLTAGE_CHANNEL(1),
116};
117
118static const struct iio_chan_spec adc124s021_channels[] = {
119	ADC128_VOLTAGE_CHANNEL(0),
120	ADC128_VOLTAGE_CHANNEL(1),
121	ADC128_VOLTAGE_CHANNEL(2),
122	ADC128_VOLTAGE_CHANNEL(3),
123};
124
125static const struct adc128_configuration adc128_config[] = {
126	{ adc128s052_channels, ARRAY_SIZE(adc128s052_channels) },
127	{ adc122s021_channels, ARRAY_SIZE(adc122s021_channels) },
128	{ adc124s021_channels, ARRAY_SIZE(adc124s021_channels) },
129};
130
131static const struct iio_info adc128_info = {
132	.read_raw = adc128_read_raw,
133};
134
135static int adc128_probe(struct spi_device *spi)
136{
137	struct iio_dev *indio_dev;
138	unsigned int config;
139	struct adc128 *adc;
140	int ret;
141
142	if (dev_fwnode(&spi->dev))
143		config = (unsigned long) device_get_match_data(&spi->dev);
144	else
145		config = spi_get_device_id(spi)->driver_data;
146
147	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
148	if (!indio_dev)
149		return -ENOMEM;
150
151	adc = iio_priv(indio_dev);
152	adc->spi = spi;
153
154	spi_set_drvdata(spi, indio_dev);
155
156	indio_dev->name = spi_get_device_id(spi)->name;
157	indio_dev->modes = INDIO_DIRECT_MODE;
158	indio_dev->info = &adc128_info;
159
160	indio_dev->channels = adc128_config[config].channels;
161	indio_dev->num_channels = adc128_config[config].num_channels;
162
163	adc->reg = devm_regulator_get(&spi->dev, "vref");
164	if (IS_ERR(adc->reg))
165		return PTR_ERR(adc->reg);
166
167	ret = regulator_enable(adc->reg);
168	if (ret < 0)
169		return ret;
170
171	mutex_init(&adc->lock);
172
173	ret = iio_device_register(indio_dev);
174	if (ret)
175		goto err_disable_regulator;
176
177	return 0;
178
179err_disable_regulator:
180	regulator_disable(adc->reg);
181	return ret;
182}
183
184static int adc128_remove(struct spi_device *spi)
185{
186	struct iio_dev *indio_dev = spi_get_drvdata(spi);
187	struct adc128 *adc = iio_priv(indio_dev);
188
189	iio_device_unregister(indio_dev);
190	regulator_disable(adc->reg);
191
192	return 0;
193}
194
195static const struct of_device_id adc128_of_match[] = {
196	{ .compatible = "ti,adc128s052", .data = (void*)0L, },
197	{ .compatible = "ti,adc122s021", .data = (void*)1L, },
198	{ .compatible = "ti,adc122s051", .data = (void*)1L, },
199	{ .compatible = "ti,adc122s101", .data = (void*)1L, },
200	{ .compatible = "ti,adc124s021", .data = (void*)2L, },
201	{ .compatible = "ti,adc124s051", .data = (void*)2L, },
202	{ .compatible = "ti,adc124s101", .data = (void*)2L, },
203	{ /* sentinel */ },
204};
205MODULE_DEVICE_TABLE(of, adc128_of_match);
206
207static const struct spi_device_id adc128_id[] = {
208	{ "adc128s052", 0 },	/* index into adc128_config */
209	{ "adc122s021",	1 },
210	{ "adc122s051",	1 },
211	{ "adc122s101",	1 },
212	{ "adc124s021", 2 },
213	{ "adc124s051", 2 },
214	{ "adc124s101", 2 },
215	{ }
216};
217MODULE_DEVICE_TABLE(spi, adc128_id);
218
219#ifdef CONFIG_ACPI
220static const struct acpi_device_id adc128_acpi_match[] = {
221	{ "AANT1280", 2 }, /* ADC124S021 compatible ACPI ID */
222	{ }
223};
224MODULE_DEVICE_TABLE(acpi, adc128_acpi_match);
225#endif
226
227static struct spi_driver adc128_driver = {
228	.driver = {
229		.name = "adc128s052",
230		.of_match_table = adc128_of_match,
231		.acpi_match_table = ACPI_PTR(adc128_acpi_match),
232	},
233	.probe = adc128_probe,
234	.remove = adc128_remove,
235	.id_table = adc128_id,
236};
237module_spi_driver(adc128_driver);
238
239MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
240MODULE_DESCRIPTION("Texas Instruments ADC128S052");
241MODULE_LICENSE("GPL v2");
242