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[mirror_ubuntu-zesty-kernel.git] / drivers / iio / adc / mcp320x.c
1 /*
2 * Copyright (C) 2013 Oskar Andero <oskar.andero@gmail.com>
3 * Copyright (C) 2014 Rose Technology
4 * Allan Bendorff Jensen <abj@rosetechnology.dk>
5 * Soren Andersen <san@rosetechnology.dk>
6 *
7 * Driver for following ADC chips from Microchip Technology's:
8 * 10 Bit converter
9 * MCP3001
10 * MCP3002
11 * MCP3004
12 * MCP3008
13 * ------------
14 * 12 bit converter
15 * MCP3201
16 * MCP3202
17 * MCP3204
18 * MCP3208
19 * ------------
20 *
21 * Datasheet can be found here:
22 * http://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf mcp3001
23 * http://ww1.microchip.com/downloads/en/DeviceDoc/21294E.pdf mcp3002
24 * http://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf mcp3004/08
25 * http://ww1.microchip.com/downloads/en/DeviceDoc/21290D.pdf mcp3201
26 * http://ww1.microchip.com/downloads/en/DeviceDoc/21034D.pdf mcp3202
27 * http://ww1.microchip.com/downloads/en/DeviceDoc/21298c.pdf mcp3204/08
28 * http://ww1.microchip.com/downloads/en/DeviceDoc/21700E.pdf mcp3301
29 *
30 * This program is free software; you can redistribute it and/or modify
31 * it under the terms of the GNU General Public License version 2 as
32 * published by the Free Software Foundation.
33 */
34
35 #include <linux/err.h>
36 #include <linux/delay.h>
37 #include <linux/spi/spi.h>
38 #include <linux/module.h>
39 #include <linux/iio/iio.h>
40 #include <linux/regulator/consumer.h>
41
42 enum {
43 mcp3001,
44 mcp3002,
45 mcp3004,
46 mcp3008,
47 mcp3201,
48 mcp3202,
49 mcp3204,
50 mcp3208,
51 mcp3301,
52 };
53
54 struct mcp320x_chip_info {
55 const struct iio_chan_spec *channels;
56 unsigned int num_channels;
57 unsigned int resolution;
58 };
59
60 struct mcp320x {
61 struct spi_device *spi;
62 struct spi_message msg;
63 struct spi_transfer transfer[2];
64
65 struct regulator *reg;
66 struct mutex lock;
67 const struct mcp320x_chip_info *chip_info;
68
69 u8 tx_buf ____cacheline_aligned;
70 u8 rx_buf[2];
71 };
72
73 static int mcp320x_channel_to_tx_data(int device_index,
74 const unsigned int channel, bool differential)
75 {
76 int start_bit = 1;
77
78 switch (device_index) {
79 case mcp3001:
80 case mcp3201:
81 case mcp3301:
82 return 0;
83 case mcp3002:
84 case mcp3202:
85 return ((start_bit << 4) | (!differential << 3) |
86 (channel << 2));
87 case mcp3004:
88 case mcp3204:
89 case mcp3008:
90 case mcp3208:
91 return ((start_bit << 6) | (!differential << 5) |
92 (channel << 2));
93 default:
94 return -EINVAL;
95 }
96 }
97
98 static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel,
99 bool differential, int device_index)
100 {
101 int ret;
102
103 adc->rx_buf[0] = 0;
104 adc->rx_buf[1] = 0;
105 adc->tx_buf = mcp320x_channel_to_tx_data(device_index,
106 channel, differential);
107
108 if (device_index != mcp3001 && device_index != mcp3201 && device_index != mcp3301) {
109 ret = spi_sync(adc->spi, &adc->msg);
110 if (ret < 0)
111 return ret;
112 } else {
113 ret = spi_read(adc->spi, &adc->rx_buf, sizeof(adc->rx_buf));
114 if (ret < 0)
115 return ret;
116 }
117
118 switch (device_index) {
119 case mcp3001:
120 return (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);
121 case mcp3002:
122 case mcp3004:
123 case mcp3008:
124 return (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);
125 case mcp3201:
126 return (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);
127 case mcp3202:
128 case mcp3204:
129 case mcp3208:
130 return (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);
131 case mcp3301:
132 return sign_extend32((adc->rx_buf[0] & 0x1f) << 8 | adc->rx_buf[1], 12);
133 default:
134 return -EINVAL;
135 }
136 }
137
138 static int mcp320x_read_raw(struct iio_dev *indio_dev,
139 struct iio_chan_spec const *channel, int *val,
140 int *val2, long mask)
141 {
142 struct mcp320x *adc = iio_priv(indio_dev);
143 int ret = -EINVAL;
144 int device_index = 0;
145
146 mutex_lock(&adc->lock);
147
148 device_index = spi_get_device_id(adc->spi)->driver_data;
149
150 switch (mask) {
151 case IIO_CHAN_INFO_RAW:
152 ret = mcp320x_adc_conversion(adc, channel->address,
153 channel->differential, device_index);
154
155 if (ret < 0)
156 goto out;
157
158 *val = ret;
159 ret = IIO_VAL_INT;
160 break;
161
162 case IIO_CHAN_INFO_SCALE:
163 ret = regulator_get_voltage(adc->reg);
164 if (ret < 0)
165 goto out;
166
167 /* convert regulator output voltage to mV */
168 *val = ret / 1000;
169 *val2 = adc->chip_info->resolution;
170 ret = IIO_VAL_FRACTIONAL_LOG2;
171 break;
172 }
173
174 out:
175 mutex_unlock(&adc->lock);
176
177 return ret;
178 }
179
180 #define MCP320X_VOLTAGE_CHANNEL(num) \
181 { \
182 .type = IIO_VOLTAGE, \
183 .indexed = 1, \
184 .channel = (num), \
185 .address = (num), \
186 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
187 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
188 }
189
190 #define MCP320X_VOLTAGE_CHANNEL_DIFF(num) \
191 { \
192 .type = IIO_VOLTAGE, \
193 .indexed = 1, \
194 .channel = (num * 2), \
195 .channel2 = (num * 2 + 1), \
196 .address = (num * 2), \
197 .differential = 1, \
198 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
199 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
200 }
201
202 static const struct iio_chan_spec mcp3201_channels[] = {
203 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
204 };
205
206 static const struct iio_chan_spec mcp3202_channels[] = {
207 MCP320X_VOLTAGE_CHANNEL(0),
208 MCP320X_VOLTAGE_CHANNEL(1),
209 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
210 };
211
212 static const struct iio_chan_spec mcp3204_channels[] = {
213 MCP320X_VOLTAGE_CHANNEL(0),
214 MCP320X_VOLTAGE_CHANNEL(1),
215 MCP320X_VOLTAGE_CHANNEL(2),
216 MCP320X_VOLTAGE_CHANNEL(3),
217 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
218 MCP320X_VOLTAGE_CHANNEL_DIFF(1),
219 };
220
221 static const struct iio_chan_spec mcp3208_channels[] = {
222 MCP320X_VOLTAGE_CHANNEL(0),
223 MCP320X_VOLTAGE_CHANNEL(1),
224 MCP320X_VOLTAGE_CHANNEL(2),
225 MCP320X_VOLTAGE_CHANNEL(3),
226 MCP320X_VOLTAGE_CHANNEL(4),
227 MCP320X_VOLTAGE_CHANNEL(5),
228 MCP320X_VOLTAGE_CHANNEL(6),
229 MCP320X_VOLTAGE_CHANNEL(7),
230 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
231 MCP320X_VOLTAGE_CHANNEL_DIFF(1),
232 MCP320X_VOLTAGE_CHANNEL_DIFF(2),
233 MCP320X_VOLTAGE_CHANNEL_DIFF(3),
234 };
235
236 static const struct iio_info mcp320x_info = {
237 .read_raw = mcp320x_read_raw,
238 .driver_module = THIS_MODULE,
239 };
240
241 static const struct mcp320x_chip_info mcp320x_chip_infos[] = {
242 [mcp3001] = {
243 .channels = mcp3201_channels,
244 .num_channels = ARRAY_SIZE(mcp3201_channels),
245 .resolution = 10
246 },
247 [mcp3002] = {
248 .channels = mcp3202_channels,
249 .num_channels = ARRAY_SIZE(mcp3202_channels),
250 .resolution = 10
251 },
252 [mcp3004] = {
253 .channels = mcp3204_channels,
254 .num_channels = ARRAY_SIZE(mcp3204_channels),
255 .resolution = 10
256 },
257 [mcp3008] = {
258 .channels = mcp3208_channels,
259 .num_channels = ARRAY_SIZE(mcp3208_channels),
260 .resolution = 10
261 },
262 [mcp3201] = {
263 .channels = mcp3201_channels,
264 .num_channels = ARRAY_SIZE(mcp3201_channels),
265 .resolution = 12
266 },
267 [mcp3202] = {
268 .channels = mcp3202_channels,
269 .num_channels = ARRAY_SIZE(mcp3202_channels),
270 .resolution = 12
271 },
272 [mcp3204] = {
273 .channels = mcp3204_channels,
274 .num_channels = ARRAY_SIZE(mcp3204_channels),
275 .resolution = 12
276 },
277 [mcp3208] = {
278 .channels = mcp3208_channels,
279 .num_channels = ARRAY_SIZE(mcp3208_channels),
280 .resolution = 12
281 },
282 [mcp3301] = {
283 .channels = mcp3201_channels,
284 .num_channels = ARRAY_SIZE(mcp3201_channels),
285 .resolution = 13
286 },
287 };
288
289 static int mcp320x_probe(struct spi_device *spi)
290 {
291 struct iio_dev *indio_dev;
292 struct mcp320x *adc;
293 const struct mcp320x_chip_info *chip_info;
294 int ret;
295
296 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
297 if (!indio_dev)
298 return -ENOMEM;
299
300 adc = iio_priv(indio_dev);
301 adc->spi = spi;
302
303 indio_dev->dev.parent = &spi->dev;
304 indio_dev->name = spi_get_device_id(spi)->name;
305 indio_dev->modes = INDIO_DIRECT_MODE;
306 indio_dev->info = &mcp320x_info;
307
308 chip_info = &mcp320x_chip_infos[spi_get_device_id(spi)->driver_data];
309 indio_dev->channels = chip_info->channels;
310 indio_dev->num_channels = chip_info->num_channels;
311
312 adc->chip_info = chip_info;
313
314 adc->transfer[0].tx_buf = &adc->tx_buf;
315 adc->transfer[0].len = sizeof(adc->tx_buf);
316 adc->transfer[1].rx_buf = adc->rx_buf;
317 adc->transfer[1].len = sizeof(adc->rx_buf);
318
319 spi_message_init_with_transfers(&adc->msg, adc->transfer,
320 ARRAY_SIZE(adc->transfer));
321
322 adc->reg = devm_regulator_get(&spi->dev, "vref");
323 if (IS_ERR(adc->reg))
324 return PTR_ERR(adc->reg);
325
326 ret = regulator_enable(adc->reg);
327 if (ret < 0)
328 return ret;
329
330 mutex_init(&adc->lock);
331
332 ret = iio_device_register(indio_dev);
333 if (ret < 0)
334 goto reg_disable;
335
336 return 0;
337
338 reg_disable:
339 regulator_disable(adc->reg);
340
341 return ret;
342 }
343
344 static int mcp320x_remove(struct spi_device *spi)
345 {
346 struct iio_dev *indio_dev = spi_get_drvdata(spi);
347 struct mcp320x *adc = iio_priv(indio_dev);
348
349 iio_device_unregister(indio_dev);
350 regulator_disable(adc->reg);
351
352 return 0;
353 }
354
355 #if defined(CONFIG_OF)
356 static const struct of_device_id mcp320x_dt_ids[] = {
357 /* NOTE: The use of compatibles with no vendor prefix is deprecated. */
358 {
359 .compatible = "mcp3001",
360 .data = &mcp320x_chip_infos[mcp3001],
361 }, {
362 .compatible = "mcp3002",
363 .data = &mcp320x_chip_infos[mcp3002],
364 }, {
365 .compatible = "mcp3004",
366 .data = &mcp320x_chip_infos[mcp3004],
367 }, {
368 .compatible = "mcp3008",
369 .data = &mcp320x_chip_infos[mcp3008],
370 }, {
371 .compatible = "mcp3201",
372 .data = &mcp320x_chip_infos[mcp3201],
373 }, {
374 .compatible = "mcp3202",
375 .data = &mcp320x_chip_infos[mcp3202],
376 }, {
377 .compatible = "mcp3204",
378 .data = &mcp320x_chip_infos[mcp3204],
379 }, {
380 .compatible = "mcp3208",
381 .data = &mcp320x_chip_infos[mcp3208],
382 }, {
383 .compatible = "mcp3301",
384 .data = &mcp320x_chip_infos[mcp3301],
385 }, {
386 .compatible = "microchip,mcp3001",
387 .data = &mcp320x_chip_infos[mcp3001],
388 }, {
389 .compatible = "microchip,mcp3002",
390 .data = &mcp320x_chip_infos[mcp3002],
391 }, {
392 .compatible = "microchip,mcp3004",
393 .data = &mcp320x_chip_infos[mcp3004],
394 }, {
395 .compatible = "microchip,mcp3008",
396 .data = &mcp320x_chip_infos[mcp3008],
397 }, {
398 .compatible = "microchip,mcp3201",
399 .data = &mcp320x_chip_infos[mcp3201],
400 }, {
401 .compatible = "microchip,mcp3202",
402 .data = &mcp320x_chip_infos[mcp3202],
403 }, {
404 .compatible = "microchip,mcp3204",
405 .data = &mcp320x_chip_infos[mcp3204],
406 }, {
407 .compatible = "microchip,mcp3208",
408 .data = &mcp320x_chip_infos[mcp3208],
409 }, {
410 .compatible = "microchip,mcp3301",
411 .data = &mcp320x_chip_infos[mcp3301],
412 }, {
413 }
414 };
415 MODULE_DEVICE_TABLE(of, mcp320x_dt_ids);
416 #endif
417
418 static const struct spi_device_id mcp320x_id[] = {
419 { "mcp3001", mcp3001 },
420 { "mcp3002", mcp3002 },
421 { "mcp3004", mcp3004 },
422 { "mcp3008", mcp3008 },
423 { "mcp3201", mcp3201 },
424 { "mcp3202", mcp3202 },
425 { "mcp3204", mcp3204 },
426 { "mcp3208", mcp3208 },
427 { "mcp3301", mcp3301 },
428 { }
429 };
430 MODULE_DEVICE_TABLE(spi, mcp320x_id);
431
432 static struct spi_driver mcp320x_driver = {
433 .driver = {
434 .name = "mcp320x",
435 .of_match_table = of_match_ptr(mcp320x_dt_ids),
436 },
437 .probe = mcp320x_probe,
438 .remove = mcp320x_remove,
439 .id_table = mcp320x_id,
440 };
441 module_spi_driver(mcp320x_driver);
442
443 MODULE_AUTHOR("Oskar Andero <oskar.andero@gmail.com>");
444 MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08");
445 MODULE_LICENSE("GPL v2");