1 // SPDX-License-Identifier: GPL-2.0-only
3 * AD7266/65 SPI ADC driver
5 * Copyright 2012 Analog Devices Inc.
8 #include <linux/device.h>
9 #include <linux/kernel.h>
10 #include <linux/slab.h>
11 #include <linux/spi/spi.h>
12 #include <linux/regulator/consumer.h>
13 #include <linux/err.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/module.h>
17 #include <linux/interrupt.h>
19 #include <linux/iio/iio.h>
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/trigger_consumer.h>
22 #include <linux/iio/triggered_buffer.h>
24 #include <linux/platform_data/ad7266.h>
27 struct spi_device *spi;
28 struct regulator *reg;
29 unsigned long vref_mv;
31 struct spi_transfer single_xfer[3];
32 struct spi_message single_msg;
34 enum ad7266_range range;
35 enum ad7266_mode mode;
37 struct gpio_desc *gpios[3];
40 * DMA (thus cache coherency maintenance) requires the
41 * transfer buffers to live in their own cache lines.
42 * The buffer needs to be large enough to hold two samples (4 bytes) and
43 * the naturally aligned timestamp (8 bytes).
48 } data ____cacheline_aligned;
51 static int ad7266_wakeup(struct ad7266_state *st)
53 /* Any read with >= 2 bytes will wake the device */
54 return spi_read(st->spi, &st->data.sample[0], 2);
57 static int ad7266_powerdown(struct ad7266_state *st)
59 /* Any read with < 2 bytes will powerdown the device */
60 return spi_read(st->spi, &st->data.sample[0], 1);
63 static int ad7266_preenable(struct iio_dev *indio_dev)
65 struct ad7266_state *st = iio_priv(indio_dev);
66 return ad7266_wakeup(st);
69 static int ad7266_postdisable(struct iio_dev *indio_dev)
71 struct ad7266_state *st = iio_priv(indio_dev);
72 return ad7266_powerdown(st);
75 static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
76 .preenable = &ad7266_preenable,
77 .postenable = &iio_triggered_buffer_postenable,
78 .predisable = &iio_triggered_buffer_predisable,
79 .postdisable = &ad7266_postdisable,
82 static irqreturn_t ad7266_trigger_handler(int irq, void *p)
84 struct iio_poll_func *pf = p;
85 struct iio_dev *indio_dev = pf->indio_dev;
86 struct ad7266_state *st = iio_priv(indio_dev);
89 ret = spi_read(st->spi, st->data.sample, 4);
91 iio_push_to_buffers_with_timestamp(indio_dev, &st->data,
95 iio_trigger_notify_done(indio_dev->trig);
100 static void ad7266_select_input(struct ad7266_state *st, unsigned int nr)
108 case AD7266_MODE_SINGLE_ENDED:
111 case AD7266_MODE_PSEUDO_DIFF:
114 case AD7266_MODE_DIFF:
119 for (i = 0; i < 3; ++i)
120 gpiod_set_value(st->gpios[i], (bool)(nr & BIT(i)));
123 static int ad7266_update_scan_mode(struct iio_dev *indio_dev,
124 const unsigned long *scan_mask)
126 struct ad7266_state *st = iio_priv(indio_dev);
127 unsigned int nr = find_first_bit(scan_mask, indio_dev->masklength);
129 ad7266_select_input(st, nr);
134 static int ad7266_read_single(struct ad7266_state *st, int *val,
135 unsigned int address)
139 ad7266_select_input(st, address);
141 ret = spi_sync(st->spi, &st->single_msg);
142 *val = be16_to_cpu(st->data.sample[address % 2]);
147 static int ad7266_read_raw(struct iio_dev *indio_dev,
148 struct iio_chan_spec const *chan, int *val, int *val2, long m)
150 struct ad7266_state *st = iio_priv(indio_dev);
151 unsigned long scale_mv;
155 case IIO_CHAN_INFO_RAW:
156 ret = iio_device_claim_direct_mode(indio_dev);
159 ret = ad7266_read_single(st, val, chan->address);
160 iio_device_release_direct_mode(indio_dev);
162 *val = (*val >> 2) & 0xfff;
163 if (chan->scan_type.sign == 's')
164 *val = sign_extend32(*val, 11);
167 case IIO_CHAN_INFO_SCALE:
168 scale_mv = st->vref_mv;
169 if (st->mode == AD7266_MODE_DIFF)
171 if (st->range == AD7266_RANGE_2VREF)
175 *val2 = chan->scan_type.realbits;
176 return IIO_VAL_FRACTIONAL_LOG2;
177 case IIO_CHAN_INFO_OFFSET:
178 if (st->range == AD7266_RANGE_2VREF &&
179 st->mode != AD7266_MODE_DIFF)
188 #define AD7266_CHAN(_chan, _sign) { \
189 .type = IIO_VOLTAGE, \
191 .channel = (_chan), \
192 .address = (_chan), \
193 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
194 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
195 | BIT(IIO_CHAN_INFO_OFFSET), \
196 .scan_index = (_chan), \
202 .endianness = IIO_BE, \
206 #define AD7266_DECLARE_SINGLE_ENDED_CHANNELS(_name, _sign) \
207 const struct iio_chan_spec ad7266_channels_##_name[] = { \
208 AD7266_CHAN(0, (_sign)), \
209 AD7266_CHAN(1, (_sign)), \
210 AD7266_CHAN(2, (_sign)), \
211 AD7266_CHAN(3, (_sign)), \
212 AD7266_CHAN(4, (_sign)), \
213 AD7266_CHAN(5, (_sign)), \
214 AD7266_CHAN(6, (_sign)), \
215 AD7266_CHAN(7, (_sign)), \
216 AD7266_CHAN(8, (_sign)), \
217 AD7266_CHAN(9, (_sign)), \
218 AD7266_CHAN(10, (_sign)), \
219 AD7266_CHAN(11, (_sign)), \
220 IIO_CHAN_SOFT_TIMESTAMP(13), \
223 #define AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(_name, _sign) \
224 const struct iio_chan_spec ad7266_channels_##_name##_fixed[] = { \
225 AD7266_CHAN(0, (_sign)), \
226 AD7266_CHAN(1, (_sign)), \
227 IIO_CHAN_SOFT_TIMESTAMP(2), \
230 static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(u, 'u');
231 static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(s, 's');
232 static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(u, 'u');
233 static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(s, 's');
235 #define AD7266_CHAN_DIFF(_chan, _sign) { \
236 .type = IIO_VOLTAGE, \
238 .channel = (_chan) * 2, \
239 .channel2 = (_chan) * 2 + 1, \
240 .address = (_chan), \
241 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
242 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
243 | BIT(IIO_CHAN_INFO_OFFSET), \
244 .scan_index = (_chan), \
250 .endianness = IIO_BE, \
255 #define AD7266_DECLARE_DIFF_CHANNELS(_name, _sign) \
256 const struct iio_chan_spec ad7266_channels_diff_##_name[] = { \
257 AD7266_CHAN_DIFF(0, (_sign)), \
258 AD7266_CHAN_DIFF(1, (_sign)), \
259 AD7266_CHAN_DIFF(2, (_sign)), \
260 AD7266_CHAN_DIFF(3, (_sign)), \
261 AD7266_CHAN_DIFF(4, (_sign)), \
262 AD7266_CHAN_DIFF(5, (_sign)), \
263 IIO_CHAN_SOFT_TIMESTAMP(6), \
266 static AD7266_DECLARE_DIFF_CHANNELS(s, 's');
267 static AD7266_DECLARE_DIFF_CHANNELS(u, 'u');
269 #define AD7266_DECLARE_DIFF_CHANNELS_FIXED(_name, _sign) \
270 const struct iio_chan_spec ad7266_channels_diff_fixed_##_name[] = { \
271 AD7266_CHAN_DIFF(0, (_sign)), \
272 AD7266_CHAN_DIFF(1, (_sign)), \
273 IIO_CHAN_SOFT_TIMESTAMP(2), \
276 static AD7266_DECLARE_DIFF_CHANNELS_FIXED(s, 's');
277 static AD7266_DECLARE_DIFF_CHANNELS_FIXED(u, 'u');
279 static const struct iio_info ad7266_info = {
280 .read_raw = &ad7266_read_raw,
281 .update_scan_mode = &ad7266_update_scan_mode,
284 static const unsigned long ad7266_available_scan_masks[] = {
294 static const unsigned long ad7266_available_scan_masks_diff[] = {
301 static const unsigned long ad7266_available_scan_masks_fixed[] = {
306 struct ad7266_chan_info {
307 const struct iio_chan_spec *channels;
308 unsigned int num_channels;
309 const unsigned long *scan_masks;
312 #define AD7266_CHAN_INFO_INDEX(_differential, _signed, _fixed) \
313 (((_differential) << 2) | ((_signed) << 1) | ((_fixed) << 0))
315 static const struct ad7266_chan_info ad7266_chan_infos[] = {
316 [AD7266_CHAN_INFO_INDEX(0, 0, 0)] = {
317 .channels = ad7266_channels_u,
318 .num_channels = ARRAY_SIZE(ad7266_channels_u),
319 .scan_masks = ad7266_available_scan_masks,
321 [AD7266_CHAN_INFO_INDEX(0, 0, 1)] = {
322 .channels = ad7266_channels_u_fixed,
323 .num_channels = ARRAY_SIZE(ad7266_channels_u_fixed),
324 .scan_masks = ad7266_available_scan_masks_fixed,
326 [AD7266_CHAN_INFO_INDEX(0, 1, 0)] = {
327 .channels = ad7266_channels_s,
328 .num_channels = ARRAY_SIZE(ad7266_channels_s),
329 .scan_masks = ad7266_available_scan_masks,
331 [AD7266_CHAN_INFO_INDEX(0, 1, 1)] = {
332 .channels = ad7266_channels_s_fixed,
333 .num_channels = ARRAY_SIZE(ad7266_channels_s_fixed),
334 .scan_masks = ad7266_available_scan_masks_fixed,
336 [AD7266_CHAN_INFO_INDEX(1, 0, 0)] = {
337 .channels = ad7266_channels_diff_u,
338 .num_channels = ARRAY_SIZE(ad7266_channels_diff_u),
339 .scan_masks = ad7266_available_scan_masks_diff,
341 [AD7266_CHAN_INFO_INDEX(1, 0, 1)] = {
342 .channels = ad7266_channels_diff_fixed_u,
343 .num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_u),
344 .scan_masks = ad7266_available_scan_masks_fixed,
346 [AD7266_CHAN_INFO_INDEX(1, 1, 0)] = {
347 .channels = ad7266_channels_diff_s,
348 .num_channels = ARRAY_SIZE(ad7266_channels_diff_s),
349 .scan_masks = ad7266_available_scan_masks_diff,
351 [AD7266_CHAN_INFO_INDEX(1, 1, 1)] = {
352 .channels = ad7266_channels_diff_fixed_s,
353 .num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_s),
354 .scan_masks = ad7266_available_scan_masks_fixed,
358 static void ad7266_init_channels(struct iio_dev *indio_dev)
360 struct ad7266_state *st = iio_priv(indio_dev);
361 bool is_differential, is_signed;
362 const struct ad7266_chan_info *chan_info;
365 is_differential = st->mode != AD7266_MODE_SINGLE_ENDED;
366 is_signed = (st->range == AD7266_RANGE_2VREF) |
367 (st->mode == AD7266_MODE_DIFF);
369 i = AD7266_CHAN_INFO_INDEX(is_differential, is_signed, st->fixed_addr);
370 chan_info = &ad7266_chan_infos[i];
372 indio_dev->channels = chan_info->channels;
373 indio_dev->num_channels = chan_info->num_channels;
374 indio_dev->available_scan_masks = chan_info->scan_masks;
375 indio_dev->masklength = chan_info->num_channels - 1;
378 static const char * const ad7266_gpio_labels[] = {
382 static int ad7266_probe(struct spi_device *spi)
384 struct ad7266_platform_data *pdata = spi->dev.platform_data;
385 struct iio_dev *indio_dev;
386 struct ad7266_state *st;
390 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
391 if (indio_dev == NULL)
394 st = iio_priv(indio_dev);
396 st->reg = devm_regulator_get_optional(&spi->dev, "vref");
397 if (!IS_ERR(st->reg)) {
398 ret = regulator_enable(st->reg);
402 ret = regulator_get_voltage(st->reg);
404 goto error_disable_reg;
406 st->vref_mv = ret / 1000;
408 /* Any other error indicates that the regulator does exist */
409 if (PTR_ERR(st->reg) != -ENODEV)
410 return PTR_ERR(st->reg);
411 /* Use internal reference */
416 st->fixed_addr = pdata->fixed_addr;
417 st->mode = pdata->mode;
418 st->range = pdata->range;
420 if (!st->fixed_addr) {
421 for (i = 0; i < ARRAY_SIZE(st->gpios); ++i) {
422 st->gpios[i] = devm_gpiod_get(&spi->dev,
423 ad7266_gpio_labels[i],
425 if (IS_ERR(st->gpios[i])) {
426 ret = PTR_ERR(st->gpios[i]);
427 goto error_disable_reg;
432 st->fixed_addr = true;
433 st->range = AD7266_RANGE_VREF;
434 st->mode = AD7266_MODE_DIFF;
437 spi_set_drvdata(spi, indio_dev);
440 indio_dev->dev.parent = &spi->dev;
441 indio_dev->dev.of_node = spi->dev.of_node;
442 indio_dev->name = spi_get_device_id(spi)->name;
443 indio_dev->modes = INDIO_DIRECT_MODE;
444 indio_dev->info = &ad7266_info;
446 ad7266_init_channels(indio_dev);
449 st->single_xfer[0].rx_buf = &st->data.sample[0];
450 st->single_xfer[0].len = 2;
451 st->single_xfer[0].cs_change = 1;
453 st->single_xfer[1].rx_buf = st->data.sample;
454 st->single_xfer[1].len = 4;
455 st->single_xfer[1].cs_change = 1;
457 st->single_xfer[2].tx_buf = &st->data.sample[0];
458 st->single_xfer[2].len = 1;
460 spi_message_init(&st->single_msg);
461 spi_message_add_tail(&st->single_xfer[0], &st->single_msg);
462 spi_message_add_tail(&st->single_xfer[1], &st->single_msg);
463 spi_message_add_tail(&st->single_xfer[2], &st->single_msg);
465 ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
466 &ad7266_trigger_handler, &iio_triggered_buffer_setup_ops);
468 goto error_disable_reg;
470 ret = iio_device_register(indio_dev);
472 goto error_buffer_cleanup;
476 error_buffer_cleanup:
477 iio_triggered_buffer_cleanup(indio_dev);
479 if (!IS_ERR(st->reg))
480 regulator_disable(st->reg);
485 static int ad7266_remove(struct spi_device *spi)
487 struct iio_dev *indio_dev = spi_get_drvdata(spi);
488 struct ad7266_state *st = iio_priv(indio_dev);
490 iio_device_unregister(indio_dev);
491 iio_triggered_buffer_cleanup(indio_dev);
492 if (!IS_ERR(st->reg))
493 regulator_disable(st->reg);
498 static const struct spi_device_id ad7266_id[] = {
503 MODULE_DEVICE_TABLE(spi, ad7266_id);
505 static struct spi_driver ad7266_driver = {
509 .probe = ad7266_probe,
510 .remove = ad7266_remove,
511 .id_table = ad7266_id,
513 module_spi_driver(ad7266_driver);
515 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
516 MODULE_DESCRIPTION("Analog Devices AD7266/65 ADC");
517 MODULE_LICENSE("GPL v2");