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
29 * This program is free software; you can redistribute it and/or modify
30 * it under the terms of the GNU General Public License version 2 as
31 * published by the Free Software Foundation.
34 #include <linux/err.h>
35 #include <linux/delay.h>
36 #include <linux/spi/spi.h>
37 #include <linux/module.h>
38 #include <linux/iio/iio.h>
39 #include <linux/regulator/consumer.h>
52 struct mcp320x_chip_info {
53 const struct iio_chan_spec *channels;
54 unsigned int num_channels;
55 unsigned int resolution;
59 struct spi_device *spi;
60 struct spi_message msg;
61 struct spi_transfer transfer[2];
63 struct regulator *reg;
65 const struct mcp320x_chip_info *chip_info;
67 u8 tx_buf ____cacheline_aligned;
71 static int mcp320x_channel_to_tx_data(int device_index,
72 const unsigned int channel, bool differential)
76 switch (device_index) {
82 return ((start_bit << 4) | (!differential << 3) |
88 return ((start_bit << 6) | (!differential << 5) |
95 static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel,
96 bool differential, int device_index)
102 adc->tx_buf = mcp320x_channel_to_tx_data(device_index,
103 channel, differential);
105 if (device_index != mcp3001 && device_index != mcp3201) {
106 ret = spi_sync(adc->spi, &adc->msg);
110 ret = spi_read(adc->spi, &adc->rx_buf, sizeof(adc->rx_buf));
115 switch (device_index) {
117 return (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);
121 return (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);
123 return (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);
127 return (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);
133 static int mcp320x_read_raw(struct iio_dev *indio_dev,
134 struct iio_chan_spec const *channel, int *val,
135 int *val2, long mask)
137 struct mcp320x *adc = iio_priv(indio_dev);
139 int device_index = 0;
141 mutex_lock(&adc->lock);
143 device_index = spi_get_device_id(adc->spi)->driver_data;
146 case IIO_CHAN_INFO_RAW:
147 ret = mcp320x_adc_conversion(adc, channel->address,
148 channel->differential, device_index);
157 case IIO_CHAN_INFO_SCALE:
158 ret = regulator_get_voltage(adc->reg);
162 /* convert regulator output voltage to mV */
164 *val2 = adc->chip_info->resolution;
165 ret = IIO_VAL_FRACTIONAL_LOG2;
170 mutex_unlock(&adc->lock);
175 #define MCP320X_VOLTAGE_CHANNEL(num) \
177 .type = IIO_VOLTAGE, \
181 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
182 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
185 #define MCP320X_VOLTAGE_CHANNEL_DIFF(num) \
187 .type = IIO_VOLTAGE, \
189 .channel = (num * 2), \
190 .channel2 = (num * 2 + 1), \
191 .address = (num * 2), \
193 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
194 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
197 static const struct iio_chan_spec mcp3201_channels[] = {
198 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
201 static const struct iio_chan_spec mcp3202_channels[] = {
202 MCP320X_VOLTAGE_CHANNEL(0),
203 MCP320X_VOLTAGE_CHANNEL(1),
204 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
207 static const struct iio_chan_spec mcp3204_channels[] = {
208 MCP320X_VOLTAGE_CHANNEL(0),
209 MCP320X_VOLTAGE_CHANNEL(1),
210 MCP320X_VOLTAGE_CHANNEL(2),
211 MCP320X_VOLTAGE_CHANNEL(3),
212 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
213 MCP320X_VOLTAGE_CHANNEL_DIFF(1),
216 static const struct iio_chan_spec mcp3208_channels[] = {
217 MCP320X_VOLTAGE_CHANNEL(0),
218 MCP320X_VOLTAGE_CHANNEL(1),
219 MCP320X_VOLTAGE_CHANNEL(2),
220 MCP320X_VOLTAGE_CHANNEL(3),
221 MCP320X_VOLTAGE_CHANNEL(4),
222 MCP320X_VOLTAGE_CHANNEL(5),
223 MCP320X_VOLTAGE_CHANNEL(6),
224 MCP320X_VOLTAGE_CHANNEL(7),
225 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
226 MCP320X_VOLTAGE_CHANNEL_DIFF(1),
227 MCP320X_VOLTAGE_CHANNEL_DIFF(2),
228 MCP320X_VOLTAGE_CHANNEL_DIFF(3),
231 static const struct iio_info mcp320x_info = {
232 .read_raw = mcp320x_read_raw,
233 .driver_module = THIS_MODULE,
236 static const struct mcp320x_chip_info mcp320x_chip_infos[] = {
238 .channels = mcp3201_channels,
239 .num_channels = ARRAY_SIZE(mcp3201_channels),
243 .channels = mcp3202_channels,
244 .num_channels = ARRAY_SIZE(mcp3202_channels),
248 .channels = mcp3204_channels,
249 .num_channels = ARRAY_SIZE(mcp3204_channels),
253 .channels = mcp3208_channels,
254 .num_channels = ARRAY_SIZE(mcp3208_channels),
258 .channels = mcp3201_channels,
259 .num_channels = ARRAY_SIZE(mcp3201_channels),
263 .channels = mcp3202_channels,
264 .num_channels = ARRAY_SIZE(mcp3202_channels),
268 .channels = mcp3204_channels,
269 .num_channels = ARRAY_SIZE(mcp3204_channels),
273 .channels = mcp3208_channels,
274 .num_channels = ARRAY_SIZE(mcp3208_channels),
279 static int mcp320x_probe(struct spi_device *spi)
281 struct iio_dev *indio_dev;
283 const struct mcp320x_chip_info *chip_info;
286 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
290 adc = iio_priv(indio_dev);
293 indio_dev->dev.parent = &spi->dev;
294 indio_dev->name = spi_get_device_id(spi)->name;
295 indio_dev->modes = INDIO_DIRECT_MODE;
296 indio_dev->info = &mcp320x_info;
298 chip_info = &mcp320x_chip_infos[spi_get_device_id(spi)->driver_data];
299 indio_dev->channels = chip_info->channels;
300 indio_dev->num_channels = chip_info->num_channels;
302 adc->chip_info = chip_info;
304 adc->transfer[0].tx_buf = &adc->tx_buf;
305 adc->transfer[0].len = sizeof(adc->tx_buf);
306 adc->transfer[1].rx_buf = adc->rx_buf;
307 adc->transfer[1].len = sizeof(adc->rx_buf);
309 spi_message_init_with_transfers(&adc->msg, adc->transfer,
310 ARRAY_SIZE(adc->transfer));
312 adc->reg = devm_regulator_get(&spi->dev, "vref");
313 if (IS_ERR(adc->reg))
314 return PTR_ERR(adc->reg);
316 ret = regulator_enable(adc->reg);
320 mutex_init(&adc->lock);
322 ret = iio_device_register(indio_dev);
329 regulator_disable(adc->reg);
334 static int mcp320x_remove(struct spi_device *spi)
336 struct iio_dev *indio_dev = spi_get_drvdata(spi);
337 struct mcp320x *adc = iio_priv(indio_dev);
339 iio_device_unregister(indio_dev);
340 regulator_disable(adc->reg);
345 #if defined(CONFIG_OF)
346 static const struct of_device_id mcp320x_dt_ids[] = {
348 .compatible = "mcp3001",
349 .data = &mcp320x_chip_infos[mcp3001],
351 .compatible = "mcp3002",
352 .data = &mcp320x_chip_infos[mcp3002],
354 .compatible = "mcp3004",
355 .data = &mcp320x_chip_infos[mcp3004],
357 .compatible = "mcp3008",
358 .data = &mcp320x_chip_infos[mcp3008],
360 .compatible = "mcp3201",
361 .data = &mcp320x_chip_infos[mcp3201],
363 .compatible = "mcp3202",
364 .data = &mcp320x_chip_infos[mcp3202],
366 .compatible = "mcp3204",
367 .data = &mcp320x_chip_infos[mcp3204],
369 .compatible = "mcp3208",
370 .data = &mcp320x_chip_infos[mcp3208],
374 MODULE_DEVICE_TABLE(of, mcp320x_dt_ids);
377 static const struct spi_device_id mcp320x_id[] = {
378 { "mcp3001", mcp3001 },
379 { "mcp3002", mcp3002 },
380 { "mcp3004", mcp3004 },
381 { "mcp3008", mcp3008 },
382 { "mcp3201", mcp3201 },
383 { "mcp3202", mcp3202 },
384 { "mcp3204", mcp3204 },
385 { "mcp3208", mcp3208 },
388 MODULE_DEVICE_TABLE(spi, mcp320x_id);
390 static struct spi_driver mcp320x_driver = {
393 .owner = THIS_MODULE,
395 .probe = mcp320x_probe,
396 .remove = mcp320x_remove,
397 .id_table = mcp320x_id,
399 module_spi_driver(mcp320x_driver);
401 MODULE_AUTHOR("Oskar Andero <oskar.andero@gmail.com>");
402 MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08");
403 MODULE_LICENSE("GPL v2");