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>
7 * Driver for following ADC chips from Microchip Technology's:
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
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.
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>
54 struct mcp320x_chip_info {
55 const struct iio_chan_spec *channels;
56 unsigned int num_channels;
57 unsigned int resolution;
61 struct spi_device *spi;
62 struct spi_message msg;
63 struct spi_transfer transfer[2];
65 struct regulator *reg;
67 const struct mcp320x_chip_info *chip_info;
69 u8 tx_buf ____cacheline_aligned;
73 static int mcp320x_channel_to_tx_data(int device_index,
74 const unsigned int channel, bool differential)
78 switch (device_index) {
85 return ((start_bit << 4) | (!differential << 3) |
91 return ((start_bit << 6) | (!differential << 5) |
98 static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel,
99 bool differential, int device_index)
105 adc->tx_buf = mcp320x_channel_to_tx_data(device_index,
106 channel, differential);
108 if (device_index != mcp3001 && device_index != mcp3201 && device_index != mcp3301) {
109 ret = spi_sync(adc->spi, &adc->msg);
113 ret = spi_read(adc->spi, &adc->rx_buf, sizeof(adc->rx_buf));
118 switch (device_index) {
120 return (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);
124 return (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);
126 return (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);
130 return (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);
132 return sign_extend32((adc->rx_buf[0] & 0x1f) << 8 | adc->rx_buf[1], 12);
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)
142 struct mcp320x *adc = iio_priv(indio_dev);
144 int device_index = 0;
146 mutex_lock(&adc->lock);
148 device_index = spi_get_device_id(adc->spi)->driver_data;
151 case IIO_CHAN_INFO_RAW:
152 ret = mcp320x_adc_conversion(adc, channel->address,
153 channel->differential, device_index);
162 case IIO_CHAN_INFO_SCALE:
163 ret = regulator_get_voltage(adc->reg);
167 /* convert regulator output voltage to mV */
169 *val2 = adc->chip_info->resolution;
170 ret = IIO_VAL_FRACTIONAL_LOG2;
175 mutex_unlock(&adc->lock);
180 #define MCP320X_VOLTAGE_CHANNEL(num) \
182 .type = IIO_VOLTAGE, \
186 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
187 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
190 #define MCP320X_VOLTAGE_CHANNEL_DIFF(chan1, chan2) \
192 .type = IIO_VOLTAGE, \
194 .channel = (chan1), \
195 .channel2 = (chan2), \
196 .address = (chan1), \
198 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
199 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
202 static const struct iio_chan_spec mcp3201_channels[] = {
203 MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1),
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, 1),
210 MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0),
213 static const struct iio_chan_spec mcp3204_channels[] = {
214 MCP320X_VOLTAGE_CHANNEL(0),
215 MCP320X_VOLTAGE_CHANNEL(1),
216 MCP320X_VOLTAGE_CHANNEL(2),
217 MCP320X_VOLTAGE_CHANNEL(3),
218 MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1),
219 MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0),
220 MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3),
221 MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2),
224 static const struct iio_chan_spec mcp3208_channels[] = {
225 MCP320X_VOLTAGE_CHANNEL(0),
226 MCP320X_VOLTAGE_CHANNEL(1),
227 MCP320X_VOLTAGE_CHANNEL(2),
228 MCP320X_VOLTAGE_CHANNEL(3),
229 MCP320X_VOLTAGE_CHANNEL(4),
230 MCP320X_VOLTAGE_CHANNEL(5),
231 MCP320X_VOLTAGE_CHANNEL(6),
232 MCP320X_VOLTAGE_CHANNEL(7),
233 MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1),
234 MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0),
235 MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3),
236 MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2),
237 MCP320X_VOLTAGE_CHANNEL_DIFF(4, 5),
238 MCP320X_VOLTAGE_CHANNEL_DIFF(5, 4),
239 MCP320X_VOLTAGE_CHANNEL_DIFF(6, 7),
240 MCP320X_VOLTAGE_CHANNEL_DIFF(7, 6),
243 static const struct iio_info mcp320x_info = {
244 .read_raw = mcp320x_read_raw,
245 .driver_module = THIS_MODULE,
248 static const struct mcp320x_chip_info mcp320x_chip_infos[] = {
250 .channels = mcp3201_channels,
251 .num_channels = ARRAY_SIZE(mcp3201_channels),
255 .channels = mcp3202_channels,
256 .num_channels = ARRAY_SIZE(mcp3202_channels),
260 .channels = mcp3204_channels,
261 .num_channels = ARRAY_SIZE(mcp3204_channels),
265 .channels = mcp3208_channels,
266 .num_channels = ARRAY_SIZE(mcp3208_channels),
270 .channels = mcp3201_channels,
271 .num_channels = ARRAY_SIZE(mcp3201_channels),
275 .channels = mcp3202_channels,
276 .num_channels = ARRAY_SIZE(mcp3202_channels),
280 .channels = mcp3204_channels,
281 .num_channels = ARRAY_SIZE(mcp3204_channels),
285 .channels = mcp3208_channels,
286 .num_channels = ARRAY_SIZE(mcp3208_channels),
290 .channels = mcp3201_channels,
291 .num_channels = ARRAY_SIZE(mcp3201_channels),
296 static int mcp320x_probe(struct spi_device *spi)
298 struct iio_dev *indio_dev;
300 const struct mcp320x_chip_info *chip_info;
303 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
307 adc = iio_priv(indio_dev);
310 indio_dev->dev.parent = &spi->dev;
311 indio_dev->name = spi_get_device_id(spi)->name;
312 indio_dev->modes = INDIO_DIRECT_MODE;
313 indio_dev->info = &mcp320x_info;
315 chip_info = &mcp320x_chip_infos[spi_get_device_id(spi)->driver_data];
316 indio_dev->channels = chip_info->channels;
317 indio_dev->num_channels = chip_info->num_channels;
319 adc->chip_info = chip_info;
321 adc->transfer[0].tx_buf = &adc->tx_buf;
322 adc->transfer[0].len = sizeof(adc->tx_buf);
323 adc->transfer[1].rx_buf = adc->rx_buf;
324 adc->transfer[1].len = sizeof(adc->rx_buf);
326 spi_message_init_with_transfers(&adc->msg, adc->transfer,
327 ARRAY_SIZE(adc->transfer));
329 adc->reg = devm_regulator_get(&spi->dev, "vref");
330 if (IS_ERR(adc->reg))
331 return PTR_ERR(adc->reg);
333 ret = regulator_enable(adc->reg);
337 mutex_init(&adc->lock);
339 ret = iio_device_register(indio_dev);
346 regulator_disable(adc->reg);
351 static int mcp320x_remove(struct spi_device *spi)
353 struct iio_dev *indio_dev = spi_get_drvdata(spi);
354 struct mcp320x *adc = iio_priv(indio_dev);
356 iio_device_unregister(indio_dev);
357 regulator_disable(adc->reg);
362 #if defined(CONFIG_OF)
363 static const struct of_device_id mcp320x_dt_ids[] = {
364 /* NOTE: The use of compatibles with no vendor prefix is deprecated. */
366 .compatible = "mcp3001",
367 .data = &mcp320x_chip_infos[mcp3001],
369 .compatible = "mcp3002",
370 .data = &mcp320x_chip_infos[mcp3002],
372 .compatible = "mcp3004",
373 .data = &mcp320x_chip_infos[mcp3004],
375 .compatible = "mcp3008",
376 .data = &mcp320x_chip_infos[mcp3008],
378 .compatible = "mcp3201",
379 .data = &mcp320x_chip_infos[mcp3201],
381 .compatible = "mcp3202",
382 .data = &mcp320x_chip_infos[mcp3202],
384 .compatible = "mcp3204",
385 .data = &mcp320x_chip_infos[mcp3204],
387 .compatible = "mcp3208",
388 .data = &mcp320x_chip_infos[mcp3208],
390 .compatible = "mcp3301",
391 .data = &mcp320x_chip_infos[mcp3301],
393 .compatible = "microchip,mcp3001",
394 .data = &mcp320x_chip_infos[mcp3001],
396 .compatible = "microchip,mcp3002",
397 .data = &mcp320x_chip_infos[mcp3002],
399 .compatible = "microchip,mcp3004",
400 .data = &mcp320x_chip_infos[mcp3004],
402 .compatible = "microchip,mcp3008",
403 .data = &mcp320x_chip_infos[mcp3008],
405 .compatible = "microchip,mcp3201",
406 .data = &mcp320x_chip_infos[mcp3201],
408 .compatible = "microchip,mcp3202",
409 .data = &mcp320x_chip_infos[mcp3202],
411 .compatible = "microchip,mcp3204",
412 .data = &mcp320x_chip_infos[mcp3204],
414 .compatible = "microchip,mcp3208",
415 .data = &mcp320x_chip_infos[mcp3208],
417 .compatible = "microchip,mcp3301",
418 .data = &mcp320x_chip_infos[mcp3301],
422 MODULE_DEVICE_TABLE(of, mcp320x_dt_ids);
425 static const struct spi_device_id mcp320x_id[] = {
426 { "mcp3001", mcp3001 },
427 { "mcp3002", mcp3002 },
428 { "mcp3004", mcp3004 },
429 { "mcp3008", mcp3008 },
430 { "mcp3201", mcp3201 },
431 { "mcp3202", mcp3202 },
432 { "mcp3204", mcp3204 },
433 { "mcp3208", mcp3208 },
434 { "mcp3301", mcp3301 },
437 MODULE_DEVICE_TABLE(spi, mcp320x_id);
439 static struct spi_driver mcp320x_driver = {
442 .of_match_table = of_match_ptr(mcp320x_dt_ids),
444 .probe = mcp320x_probe,
445 .remove = mcp320x_remove,
446 .id_table = mcp320x_id,
448 module_spi_driver(mcp320x_driver);
450 MODULE_AUTHOR("Oskar Andero <oskar.andero@gmail.com>");
451 MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08");
452 MODULE_LICENSE("GPL v2");