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)(T: &adc->lock);
49
50 adc->buffer[0] = channel << 3;
51 adc->buffer[1] = 0;
52
53 ret = spi_write(spi: adc->spi, buf: &adc->buffer, len: sizeof(adc->buffer));
54 if (ret < 0)
55 return ret;
56
57 ret = spi_read(spi: adc->spi, buf: &adc->buffer16, len: 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->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 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 char * const bd79104_regulators[] = { "iovdd" };
126
127static const struct adc128_configuration adc128_config[] = {
128 {
129 .channels = adc128s052_channels,
130 .num_channels = ARRAY_SIZE(adc128s052_channels),
131 .refname = "vref",
132 }, {
133 .channels = adc122s021_channels,
134 .num_channels = ARRAY_SIZE(adc122s021_channels),
135 .refname = "vref",
136 }, {
137 .channels = adc124s021_channels,
138 .num_channels = ARRAY_SIZE(adc124s021_channels),
139 .refname = "vref",
140 }, {
141 .channels = adc128s052_channels,
142 .num_channels = ARRAY_SIZE(adc128s052_channels),
143 .refname = "vdd",
144 .other_regulators = &bd79104_regulators,
145 .num_other_regulators = 1,
146 },
147};
148
149static const struct iio_info adc128_info = {
150 .read_raw = adc128_read_raw,
151};
152
153static int adc128_probe(struct spi_device *spi)
154{
155 const struct adc128_configuration *config;
156 struct iio_dev *indio_dev;
157 struct adc128 *adc;
158 int ret;
159
160 indio_dev = devm_iio_device_alloc(parent: &spi->dev, sizeof_priv: sizeof(*adc));
161 if (!indio_dev)
162 return -ENOMEM;
163
164 adc = iio_priv(indio_dev);
165 adc->spi = spi;
166
167 indio_dev->name = spi_get_device_id(sdev: spi)->name;
168 indio_dev->modes = INDIO_DIRECT_MODE;
169 indio_dev->info = &adc128_info;
170
171 config = spi_get_device_match_data(sdev: spi);
172
173 indio_dev->channels = config->channels;
174 indio_dev->num_channels = config->num_channels;
175
176 ret = devm_regulator_get_enable_read_voltage(dev: &spi->dev,
177 id: config->refname);
178 if (ret < 0)
179 return dev_err_probe(dev: &spi->dev, err: ret,
180 fmt: "failed to read '%s' voltage",
181 config->refname);
182
183 adc->vref_mv = ret / 1000;
184
185 if (config->num_other_regulators) {
186 ret = devm_regulator_bulk_get_enable(dev: &spi->dev,
187 num_consumers: config->num_other_regulators,
188 id: *config->other_regulators);
189 if (ret)
190 return dev_err_probe(dev: &spi->dev, err: ret,
191 fmt: "Failed to enable regulators\n");
192 }
193
194 ret = devm_mutex_init(&spi->dev, &adc->lock);
195 if (ret)
196 return ret;
197
198 return devm_iio_device_register(&spi->dev, indio_dev);
199}
200
201static const struct of_device_id adc128_of_match[] = {
202 { .compatible = "ti,adc128s052", .data = &adc128_config[0] },
203 { .compatible = "ti,adc122s021", .data = &adc128_config[1] },
204 { .compatible = "ti,adc122s051", .data = &adc128_config[1] },
205 { .compatible = "ti,adc122s101", .data = &adc128_config[1] },
206 { .compatible = "ti,adc124s021", .data = &adc128_config[2] },
207 { .compatible = "ti,adc124s051", .data = &adc128_config[2] },
208 { .compatible = "ti,adc124s101", .data = &adc128_config[2] },
209 { .compatible = "rohm,bd79104", .data = &adc128_config[3] },
210 { }
211};
212MODULE_DEVICE_TABLE(of, adc128_of_match);
213
214static const struct spi_device_id adc128_id[] = {
215 { "adc128s052", (kernel_ulong_t)&adc128_config[0] },
216 { "adc122s021", (kernel_ulong_t)&adc128_config[1] },
217 { "adc122s051", (kernel_ulong_t)&adc128_config[1] },
218 { "adc122s101", (kernel_ulong_t)&adc128_config[1] },
219 { "adc124s021", (kernel_ulong_t)&adc128_config[2] },
220 { "adc124s051", (kernel_ulong_t)&adc128_config[2] },
221 { "adc124s101", (kernel_ulong_t)&adc128_config[2] },
222 { "bd79104", (kernel_ulong_t)&adc128_config[3] },
223 { }
224};
225MODULE_DEVICE_TABLE(spi, adc128_id);
226
227static const struct acpi_device_id adc128_acpi_match[] = {
228 { "AANT1280", (kernel_ulong_t)&adc128_config[2] },
229 { }
230};
231MODULE_DEVICE_TABLE(acpi, adc128_acpi_match);
232
233static struct spi_driver adc128_driver = {
234 .driver = {
235 .name = "adc128s052",
236 .of_match_table = adc128_of_match,
237 .acpi_match_table = adc128_acpi_match,
238 },
239 .probe = adc128_probe,
240 .id_table = adc128_id,
241};
242module_spi_driver(adc128_driver);
243
244MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
245MODULE_DESCRIPTION("Texas Instruments ADC128S052");
246MODULE_LICENSE("GPL v2");
247

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source code of linux/drivers/iio/adc/ti-adc128s052.c