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:
23 * Datasheet can be found here:
24 * http://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf mcp3001
25 * http://ww1.microchip.com/downloads/en/DeviceDoc/21294E.pdf mcp3002
26 * http://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf mcp3004/08
27 * http://ww1.microchip.com/downloads/en/DeviceDoc/21290D.pdf mcp3201
28 * http://ww1.microchip.com/downloads/en/DeviceDoc/21034D.pdf mcp3202
29 * http://ww1.microchip.com/downloads/en/DeviceDoc/21298c.pdf mcp3204/08
30 * http://ww1.microchip.com/downloads/en/DeviceDoc/21700E.pdf mcp3301
32 * This program is free software; you can redistribute it and/or modify
33 * it under the terms of the GNU General Public License version 2 as
34 * published by the Free Software Foundation.
37 #include <linux/err.h>
38 #include <linux/delay.h>
39 #include <linux/spi/spi.h>
40 #include <linux/module.h>
41 #include <linux/iio/iio.h>
42 #include <linux/regulator/consumer.h>
56 struct mcp320x_chip_info
{
57 const struct iio_chan_spec
*channels
;
58 unsigned int num_channels
;
59 unsigned int resolution
;
63 struct spi_device
*spi
;
64 struct spi_message msg
;
65 struct spi_transfer transfer
[2];
67 struct regulator
*reg
;
69 const struct mcp320x_chip_info
*chip_info
;
71 u8 tx_buf ____cacheline_aligned
;
75 static int mcp320x_channel_to_tx_data(int device_index
,
76 const unsigned int channel
, bool differential
)
80 switch (device_index
) {
87 return ((start_bit
<< 4) | (!differential
<< 3) |
93 return ((start_bit
<< 6) | (!differential
<< 5) |
100 static int mcp320x_adc_conversion(struct mcp320x
*adc
, u8 channel
,
101 bool differential
, int device_index
, int *val
)
107 adc
->tx_buf
= mcp320x_channel_to_tx_data(device_index
,
108 channel
, differential
);
110 if (device_index
!= mcp3001
&& device_index
!= mcp3201
&& device_index
!= mcp3301
) {
111 ret
= spi_sync(adc
->spi
, &adc
->msg
);
115 ret
= spi_read(adc
->spi
, &adc
->rx_buf
, sizeof(adc
->rx_buf
));
120 switch (device_index
) {
122 *val
= (adc
->rx_buf
[0] << 5 | adc
->rx_buf
[1] >> 3);
127 *val
= (adc
->rx_buf
[0] << 2 | adc
->rx_buf
[1] >> 6);
130 *val
= (adc
->rx_buf
[0] << 7 | adc
->rx_buf
[1] >> 1);
135 *val
= (adc
->rx_buf
[0] << 4 | adc
->rx_buf
[1] >> 4);
138 *val
= sign_extend32((adc
->rx_buf
[0] & 0x1f) << 8
139 | adc
->rx_buf
[1], 12);
146 static int mcp320x_read_raw(struct iio_dev
*indio_dev
,
147 struct iio_chan_spec
const *channel
, int *val
,
148 int *val2
, long mask
)
150 struct mcp320x
*adc
= iio_priv(indio_dev
);
152 int device_index
= 0;
154 mutex_lock(&adc
->lock
);
156 device_index
= spi_get_device_id(adc
->spi
)->driver_data
;
159 case IIO_CHAN_INFO_RAW
:
160 ret
= mcp320x_adc_conversion(adc
, channel
->address
,
161 channel
->differential
, device_index
, val
);
168 case IIO_CHAN_INFO_SCALE
:
169 ret
= regulator_get_voltage(adc
->reg
);
173 /* convert regulator output voltage to mV */
175 *val2
= adc
->chip_info
->resolution
;
176 ret
= IIO_VAL_FRACTIONAL_LOG2
;
181 mutex_unlock(&adc
->lock
);
186 #define MCP320X_VOLTAGE_CHANNEL(num) \
188 .type = IIO_VOLTAGE, \
192 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
193 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
196 #define MCP320X_VOLTAGE_CHANNEL_DIFF(num) \
198 .type = IIO_VOLTAGE, \
200 .channel = (num * 2), \
201 .channel2 = (num * 2 + 1), \
202 .address = (num * 2), \
204 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
205 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
208 static const struct iio_chan_spec mcp3201_channels
[] = {
209 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
212 static const struct iio_chan_spec mcp3202_channels
[] = {
213 MCP320X_VOLTAGE_CHANNEL(0),
214 MCP320X_VOLTAGE_CHANNEL(1),
215 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
218 static const struct iio_chan_spec mcp3204_channels
[] = {
219 MCP320X_VOLTAGE_CHANNEL(0),
220 MCP320X_VOLTAGE_CHANNEL(1),
221 MCP320X_VOLTAGE_CHANNEL(2),
222 MCP320X_VOLTAGE_CHANNEL(3),
223 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
224 MCP320X_VOLTAGE_CHANNEL_DIFF(1),
227 static const struct iio_chan_spec mcp3208_channels
[] = {
228 MCP320X_VOLTAGE_CHANNEL(0),
229 MCP320X_VOLTAGE_CHANNEL(1),
230 MCP320X_VOLTAGE_CHANNEL(2),
231 MCP320X_VOLTAGE_CHANNEL(3),
232 MCP320X_VOLTAGE_CHANNEL(4),
233 MCP320X_VOLTAGE_CHANNEL(5),
234 MCP320X_VOLTAGE_CHANNEL(6),
235 MCP320X_VOLTAGE_CHANNEL(7),
236 MCP320X_VOLTAGE_CHANNEL_DIFF(0),
237 MCP320X_VOLTAGE_CHANNEL_DIFF(1),
238 MCP320X_VOLTAGE_CHANNEL_DIFF(2),
239 MCP320X_VOLTAGE_CHANNEL_DIFF(3),
242 static const struct iio_info mcp320x_info
= {
243 .read_raw
= mcp320x_read_raw
,
244 .driver_module
= THIS_MODULE
,
247 static const struct mcp320x_chip_info mcp320x_chip_infos
[] = {
249 .channels
= mcp3201_channels
,
250 .num_channels
= ARRAY_SIZE(mcp3201_channels
),
254 .channels
= mcp3202_channels
,
255 .num_channels
= ARRAY_SIZE(mcp3202_channels
),
259 .channels
= mcp3204_channels
,
260 .num_channels
= ARRAY_SIZE(mcp3204_channels
),
264 .channels
= mcp3208_channels
,
265 .num_channels
= ARRAY_SIZE(mcp3208_channels
),
269 .channels
= mcp3201_channels
,
270 .num_channels
= ARRAY_SIZE(mcp3201_channels
),
274 .channels
= mcp3202_channels
,
275 .num_channels
= ARRAY_SIZE(mcp3202_channels
),
279 .channels
= mcp3204_channels
,
280 .num_channels
= ARRAY_SIZE(mcp3204_channels
),
284 .channels
= mcp3208_channels
,
285 .num_channels
= ARRAY_SIZE(mcp3208_channels
),
289 .channels
= mcp3201_channels
,
290 .num_channels
= ARRAY_SIZE(mcp3201_channels
),
295 static int mcp320x_probe(struct spi_device
*spi
)
297 struct iio_dev
*indio_dev
;
299 const struct mcp320x_chip_info
*chip_info
;
302 indio_dev
= devm_iio_device_alloc(&spi
->dev
, sizeof(*adc
));
306 adc
= iio_priv(indio_dev
);
309 indio_dev
->dev
.parent
= &spi
->dev
;
310 indio_dev
->name
= spi_get_device_id(spi
)->name
;
311 indio_dev
->modes
= INDIO_DIRECT_MODE
;
312 indio_dev
->info
= &mcp320x_info
;
313 spi_set_drvdata(spi
, indio_dev
);
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
[] = {
365 .compatible
= "mcp3001",
366 .data
= &mcp320x_chip_infos
[mcp3001
],
368 .compatible
= "mcp3002",
369 .data
= &mcp320x_chip_infos
[mcp3002
],
371 .compatible
= "mcp3004",
372 .data
= &mcp320x_chip_infos
[mcp3004
],
374 .compatible
= "mcp3008",
375 .data
= &mcp320x_chip_infos
[mcp3008
],
377 .compatible
= "mcp3201",
378 .data
= &mcp320x_chip_infos
[mcp3201
],
380 .compatible
= "mcp3202",
381 .data
= &mcp320x_chip_infos
[mcp3202
],
383 .compatible
= "mcp3204",
384 .data
= &mcp320x_chip_infos
[mcp3204
],
386 .compatible
= "mcp3208",
387 .data
= &mcp320x_chip_infos
[mcp3208
],
389 .compatible
= "mcp3301",
390 .data
= &mcp320x_chip_infos
[mcp3301
],
394 MODULE_DEVICE_TABLE(of
, mcp320x_dt_ids
);
397 static const struct spi_device_id mcp320x_id
[] = {
398 { "mcp3001", mcp3001
},
399 { "mcp3002", mcp3002
},
400 { "mcp3004", mcp3004
},
401 { "mcp3008", mcp3008
},
402 { "mcp3201", mcp3201
},
403 { "mcp3202", mcp3202
},
404 { "mcp3204", mcp3204
},
405 { "mcp3208", mcp3208
},
406 { "mcp3301", mcp3301
},
409 MODULE_DEVICE_TABLE(spi
, mcp320x_id
);
411 static struct spi_driver mcp320x_driver
= {
414 .of_match_table
= of_match_ptr(mcp320x_dt_ids
),
416 .probe
= mcp320x_probe
,
417 .remove
= mcp320x_remove
,
418 .id_table
= mcp320x_id
,
420 module_spi_driver(mcp320x_driver
);
422 MODULE_AUTHOR("Oskar Andero <oskar.andero@gmail.com>");
423 MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08");
424 MODULE_LICENSE("GPL v2");