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Linux kernel mirror (for testing)
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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/cleanup.h>
13#include <linux/err.h>
14#include <linux/iio/iio.h>
15#include <linux/mod_devicetable.h>
16#include <linux/module.h>
17#include <linux/property.h>
18#include <linux/regulator/consumer.h>
19#include <linux/spi/spi.h>
20
21struct adc128_configuration {
22 const struct iio_chan_spec *channels;
23 u8 num_channels;
24 const char *refname;
25 int num_other_regulators;
26 const char * const (*other_regulators)[];
27};
28
29struct adc128 {
30 struct spi_device *spi;
31
32 /*
33 * Serialize the SPI 'write-channel + read data' accesses and protect
34 * the shared buffer.
35 */
36 struct mutex lock;
37 int vref_mv;
38 union {
39 __be16 buffer16;
40 u8 buffer[2];
41 } __aligned(IIO_DMA_MINALIGN);
42};
43
44static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
45{
46 int ret;
47
48 guard(mutex)(&adc->lock);
49
50 adc->buffer[0] = channel << 3;
51 adc->buffer[1] = 0;
52
53 ret = spi_write(adc->spi, &adc->buffer, sizeof(adc->buffer));
54 if (ret < 0)
55 return ret;
56
57 ret = spi_read(adc->spi, &adc->buffer16, sizeof(adc->buffer16));
58 if (ret < 0)
59 return ret;
60
61 return be16_to_cpu(adc->buffer16) & 0xFFF;
62}
63
64static int adc128_read_raw(struct iio_dev *indio_dev,
65 struct iio_chan_spec const *channel, int *val,
66 int *val2, long mask)
67{
68 struct adc128 *adc = iio_priv(indio_dev);
69 int ret;
70
71 switch (mask) {
72 case IIO_CHAN_INFO_RAW:
73
74 ret = adc128_adc_conversion(adc, channel->channel);
75 if (ret < 0)
76 return ret;
77
78 *val = ret;
79 return IIO_VAL_INT;
80
81 case IIO_CHAN_INFO_SCALE:
82
83 *val = adc->vref_mv;
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 simple_1chan_adc_channels[] = {
103 ADC128_VOLTAGE_CHANNEL(0),
104};
105
106static const struct iio_chan_spec simple_2chan_adc_channels[] = {
107 ADC128_VOLTAGE_CHANNEL(0),
108 ADC128_VOLTAGE_CHANNEL(1),
109};
110
111static const struct iio_chan_spec simple_4chan_adc_channels[] = {
112 ADC128_VOLTAGE_CHANNEL(0),
113 ADC128_VOLTAGE_CHANNEL(1),
114 ADC128_VOLTAGE_CHANNEL(2),
115 ADC128_VOLTAGE_CHANNEL(3),
116};
117
118static const struct iio_chan_spec simple_8chan_adc_channels[] = {
119 ADC128_VOLTAGE_CHANNEL(0),
120 ADC128_VOLTAGE_CHANNEL(1),
121 ADC128_VOLTAGE_CHANNEL(2),
122 ADC128_VOLTAGE_CHANNEL(3),
123 ADC128_VOLTAGE_CHANNEL(4),
124 ADC128_VOLTAGE_CHANNEL(5),
125 ADC128_VOLTAGE_CHANNEL(6),
126 ADC128_VOLTAGE_CHANNEL(7),
127};
128
129static const char * const bd79104_regulators[] = { "iovdd" };
130
131static const struct adc128_configuration adc122s_config = {
132 .channels = simple_2chan_adc_channels,
133 .num_channels = ARRAY_SIZE(simple_2chan_adc_channels),
134 .refname = "vref",
135};
136
137static const struct adc128_configuration adc124s_config = {
138 .channels = simple_4chan_adc_channels,
139 .num_channels = ARRAY_SIZE(simple_4chan_adc_channels),
140 .refname = "vref",
141};
142
143static const struct adc128_configuration adc128s_config = {
144 .channels = simple_8chan_adc_channels,
145 .num_channels = ARRAY_SIZE(simple_8chan_adc_channels),
146 .refname = "vref",
147};
148
149static const struct adc128_configuration bd79100_config = {
150 .channels = simple_1chan_adc_channels,
151 .num_channels = ARRAY_SIZE(simple_1chan_adc_channels),
152 .refname = "vdd",
153 .other_regulators = &bd79104_regulators,
154 .num_other_regulators = 1,
155};
156
157static const struct adc128_configuration bd79101_config = {
158 .channels = simple_2chan_adc_channels,
159 .num_channels = ARRAY_SIZE(simple_2chan_adc_channels),
160 .refname = "vdd",
161 .other_regulators = &bd79104_regulators,
162 .num_other_regulators = 1,
163};
164
165static const struct adc128_configuration bd79102_config = {
166 .channels = simple_4chan_adc_channels,
167 .num_channels = ARRAY_SIZE(simple_4chan_adc_channels),
168 .refname = "vdd",
169 .other_regulators = &bd79104_regulators,
170 .num_other_regulators = 1,
171};
172
173static const struct adc128_configuration bd79104_config = {
174 .channels = simple_8chan_adc_channels,
175 .num_channels = ARRAY_SIZE(simple_8chan_adc_channels),
176 .refname = "vdd",
177 .other_regulators = &bd79104_regulators,
178 .num_other_regulators = 1,
179};
180
181static const struct iio_info adc128_info = {
182 .read_raw = adc128_read_raw,
183};
184
185static int adc128_probe(struct spi_device *spi)
186{
187 const struct adc128_configuration *config;
188 struct iio_dev *indio_dev;
189 struct adc128 *adc;
190 int ret;
191
192 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
193 if (!indio_dev)
194 return -ENOMEM;
195
196 adc = iio_priv(indio_dev);
197 adc->spi = spi;
198
199 indio_dev->name = spi_get_device_id(spi)->name;
200 indio_dev->modes = INDIO_DIRECT_MODE;
201 indio_dev->info = &adc128_info;
202
203 config = spi_get_device_match_data(spi);
204
205 indio_dev->channels = config->channels;
206 indio_dev->num_channels = config->num_channels;
207
208 ret = devm_regulator_get_enable_read_voltage(&spi->dev,
209 config->refname);
210 if (ret < 0)
211 return dev_err_probe(&spi->dev, ret,
212 "failed to read '%s' voltage",
213 config->refname);
214
215 adc->vref_mv = ret / 1000;
216
217 if (config->num_other_regulators) {
218 ret = devm_regulator_bulk_get_enable(&spi->dev,
219 config->num_other_regulators,
220 *config->other_regulators);
221 if (ret)
222 return dev_err_probe(&spi->dev, ret,
223 "Failed to enable regulators\n");
224 }
225
226 ret = devm_mutex_init(&spi->dev, &adc->lock);
227 if (ret)
228 return ret;
229
230 return devm_iio_device_register(&spi->dev, indio_dev);
231}
232
233static const struct of_device_id adc128_of_match[] = {
234 { .compatible = "ti,adc128s052", .data = &adc128s_config },
235 { .compatible = "ti,adc122s021", .data = &adc122s_config },
236 { .compatible = "ti,adc122s051", .data = &adc122s_config },
237 { .compatible = "ti,adc122s101", .data = &adc122s_config },
238 { .compatible = "ti,adc124s021", .data = &adc124s_config },
239 { .compatible = "ti,adc124s051", .data = &adc124s_config },
240 { .compatible = "ti,adc124s101", .data = &adc124s_config },
241 { .compatible = "rohm,bd79100", .data = &bd79100_config },
242 { .compatible = "rohm,bd79101", .data = &bd79101_config },
243 { .compatible = "rohm,bd79102", .data = &bd79102_config },
244 { .compatible = "rohm,bd79103", .data = &bd79104_config },
245 { .compatible = "rohm,bd79104", .data = &bd79104_config },
246 { }
247};
248MODULE_DEVICE_TABLE(of, adc128_of_match);
249
250static const struct spi_device_id adc128_id[] = {
251 { "adc128s052", (kernel_ulong_t)&adc128s_config },
252 { "adc122s021", (kernel_ulong_t)&adc122s_config },
253 { "adc122s051", (kernel_ulong_t)&adc122s_config },
254 { "adc122s101", (kernel_ulong_t)&adc122s_config },
255 { "adc124s021", (kernel_ulong_t)&adc124s_config },
256 { "adc124s051", (kernel_ulong_t)&adc124s_config },
257 { "adc124s101", (kernel_ulong_t)&adc124s_config },
258 { "bd79100", (kernel_ulong_t)&bd79100_config },
259 { "bd79101", (kernel_ulong_t)&bd79101_config },
260 { "bd79102", (kernel_ulong_t)&bd79102_config },
261 { "bd79103", (kernel_ulong_t)&bd79104_config },
262 { "bd79104", (kernel_ulong_t)&bd79104_config },
263 { }
264};
265MODULE_DEVICE_TABLE(spi, adc128_id);
266
267static const struct acpi_device_id adc128_acpi_match[] = {
268 { "AANT1280", (kernel_ulong_t)&adc124s_config },
269 { }
270};
271MODULE_DEVICE_TABLE(acpi, adc128_acpi_match);
272
273static struct spi_driver adc128_driver = {
274 .driver = {
275 .name = "adc128s052",
276 .of_match_table = adc128_of_match,
277 .acpi_match_table = adc128_acpi_match,
278 },
279 .probe = adc128_probe,
280 .id_table = adc128_id,
281};
282module_spi_driver(adc128_driver);
283
284MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
285MODULE_DESCRIPTION("Texas Instruments ADC128S052");
286MODULE_LICENSE("GPL v2");