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/err.h>
13#include <linux/iio/iio.h>
14#include <linux/mod_devicetable.h>
15#include <linux/module.h>
16#include <linux/property.h>
17#include <linux/regulator/consumer.h>
18#include <linux/spi/spi.h>
19
20struct adc128_configuration {
21	const struct iio_chan_spec	*channels;
22	u8				num_channels;
23};
24
25struct adc128 {
26	struct spi_device *spi;
27
28	struct regulator *reg;
29	struct mutex lock;
30
31	u8 buffer[2] __aligned(IIO_DMA_MINALIGN);
32};
33
34static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
35{
36	int ret;
37
38	mutex_lock(&adc->lock);
39
40	adc->buffer[0] = channel << 3;
41	adc->buffer[1] = 0;
42
43	ret = spi_write(adc->spi, &adc->buffer, 2);
44	if (ret < 0) {
45		mutex_unlock(&adc->lock);
46		return ret;
47	}
48
49	ret = spi_read(adc->spi, &adc->buffer, 2);
50
51	mutex_unlock(&adc->lock);
52
53	if (ret < 0)
54		return ret;
55
56	return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF);
57}
58
59static int adc128_read_raw(struct iio_dev *indio_dev,
60			   struct iio_chan_spec const *channel, int *val,
61			   int *val2, long mask)
62{
63	struct adc128 *adc = iio_priv(indio_dev);
64	int ret;
65
66	switch (mask) {
67	case IIO_CHAN_INFO_RAW:
68
69		ret = adc128_adc_conversion(adc, channel->channel);
70		if (ret < 0)
71			return ret;
72
73		*val = ret;
74		return IIO_VAL_INT;
75
76	case IIO_CHAN_INFO_SCALE:
77
78		ret = regulator_get_voltage(adc->reg);
79		if (ret < 0)
80			return ret;
81
82		*val = ret / 1000;
83		*val2 = 12;
84		return IIO_VAL_FRACTIONAL_LOG2;
85
86	default:
87		return -EINVAL;
88	}
89
90}
91
92#define ADC128_VOLTAGE_CHANNEL(num)	\
93	{ \
94		.type = IIO_VOLTAGE, \
95		.indexed = 1, \
96		.channel = (num), \
97		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
98		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
99	}
100
101static const struct iio_chan_spec adc128s052_channels[] = {
102	ADC128_VOLTAGE_CHANNEL(0),
103	ADC128_VOLTAGE_CHANNEL(1),
104	ADC128_VOLTAGE_CHANNEL(2),
105	ADC128_VOLTAGE_CHANNEL(3),
106	ADC128_VOLTAGE_CHANNEL(4),
107	ADC128_VOLTAGE_CHANNEL(5),
108	ADC128_VOLTAGE_CHANNEL(6),
109	ADC128_VOLTAGE_CHANNEL(7),
110};
111
112static const struct iio_chan_spec adc122s021_channels[] = {
113	ADC128_VOLTAGE_CHANNEL(0),
114	ADC128_VOLTAGE_CHANNEL(1),
115};
116
117static const struct iio_chan_spec adc124s021_channels[] = {
118	ADC128_VOLTAGE_CHANNEL(0),
119	ADC128_VOLTAGE_CHANNEL(1),
120	ADC128_VOLTAGE_CHANNEL(2),
121	ADC128_VOLTAGE_CHANNEL(3),
122};
123
124static const struct adc128_configuration adc128_config[] = {
125	{ adc128s052_channels, ARRAY_SIZE(adc128s052_channels) },
126	{ adc122s021_channels, ARRAY_SIZE(adc122s021_channels) },
127	{ adc124s021_channels, ARRAY_SIZE(adc124s021_channels) },
128};
129
130static const struct iio_info adc128_info = {
131	.read_raw = adc128_read_raw,
132};
133
134static void adc128_disable_regulator(void *reg)
135{
136	regulator_disable(reg);
137}
138
139static int adc128_probe(struct spi_device *spi)
140{
141	const struct adc128_configuration *config;
142	struct iio_dev *indio_dev;
143	struct adc128 *adc;
144	int ret;
145
146	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
147	if (!indio_dev)
148		return -ENOMEM;
149
150	adc = iio_priv(indio_dev);
151	adc->spi = spi;
152
153	indio_dev->name = spi_get_device_id(spi)->name;
154	indio_dev->modes = INDIO_DIRECT_MODE;
155	indio_dev->info = &adc128_info;
156
157	config = spi_get_device_match_data(spi);
158
159	indio_dev->channels = config->channels;
160	indio_dev->num_channels = config->num_channels;
161
162	adc->reg = devm_regulator_get(&spi->dev, "vref");
163	if (IS_ERR(adc->reg))
164		return PTR_ERR(adc->reg);
165
166	ret = regulator_enable(adc->reg);
167	if (ret < 0)
168		return ret;
169	ret = devm_add_action_or_reset(&spi->dev, adc128_disable_regulator,
170				       adc->reg);
171	if (ret)
172		return ret;
173
174	mutex_init(&adc->lock);
175
176	return devm_iio_device_register(&spi->dev, indio_dev);
177}
178
179static const struct of_device_id adc128_of_match[] = {
180	{ .compatible = "ti,adc128s052", .data = &adc128_config[0] },
181	{ .compatible = "ti,adc122s021", .data = &adc128_config[1] },
182	{ .compatible = "ti,adc122s051", .data = &adc128_config[1] },
183	{ .compatible = "ti,adc122s101", .data = &adc128_config[1] },
184	{ .compatible = "ti,adc124s021", .data = &adc128_config[2] },
185	{ .compatible = "ti,adc124s051", .data = &adc128_config[2] },
186	{ .compatible = "ti,adc124s101", .data = &adc128_config[2] },
187	{ /* sentinel */ },
188};
189MODULE_DEVICE_TABLE(of, adc128_of_match);
190
191static const struct spi_device_id adc128_id[] = {
192	{ "adc128s052", (kernel_ulong_t)&adc128_config[0] },
193	{ "adc122s021",	(kernel_ulong_t)&adc128_config[1] },
194	{ "adc122s051",	(kernel_ulong_t)&adc128_config[1] },
195	{ "adc122s101",	(kernel_ulong_t)&adc128_config[1] },
196	{ "adc124s021", (kernel_ulong_t)&adc128_config[2] },
197	{ "adc124s051", (kernel_ulong_t)&adc128_config[2] },
198	{ "adc124s101", (kernel_ulong_t)&adc128_config[2] },
199	{ }
200};
201MODULE_DEVICE_TABLE(spi, adc128_id);
202
203static const struct acpi_device_id adc128_acpi_match[] = {
204	{ "AANT1280", (kernel_ulong_t)&adc128_config[2] },
205	{ }
206};
207MODULE_DEVICE_TABLE(acpi, adc128_acpi_match);
208
209static struct spi_driver adc128_driver = {
210	.driver = {
211		.name = "adc128s052",
212		.of_match_table = adc128_of_match,
213		.acpi_match_table = adc128_acpi_match,
214	},
215	.probe = adc128_probe,
216	.id_table = adc128_id,
217};
218module_spi_driver(adc128_driver);
219
220MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
221MODULE_DESCRIPTION("Texas Instruments ADC128S052");
222MODULE_LICENSE("GPL v2");
223