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