1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Texas Instruments ADS131E0x 4-, 6- and 8-Channel ADCs
4 *
5 * Copyright (c) 2020 AVL DiTEST GmbH
6 * Tomislav Denis <tomislav.denis@avl.com>
7 *
8 * Datasheet: https://www.ti.com/lit/ds/symlink/ads131e08.pdf
9 */
10
11#include <linux/bitfield.h>
12#include <linux/clk.h>
13#include <linux/delay.h>
14#include <linux/module.h>
15
16#include <linux/iio/buffer.h>
17#include <linux/iio/iio.h>
18#include <linux/iio/sysfs.h>
19#include <linux/iio/trigger.h>
20#include <linux/iio/trigger_consumer.h>
21#include <linux/iio/triggered_buffer.h>
22
23#include <linux/regulator/consumer.h>
24#include <linux/spi/spi.h>
25
26#include <asm/unaligned.h>
27
28/* Commands */
29#define ADS131E08_CMD_RESET 0x06
30#define ADS131E08_CMD_START 0x08
31#define ADS131E08_CMD_STOP 0x0A
32#define ADS131E08_CMD_OFFSETCAL 0x1A
33#define ADS131E08_CMD_SDATAC 0x11
34#define ADS131E08_CMD_RDATA 0x12
35#define ADS131E08_CMD_RREG(r) (BIT(5) | (r & GENMASK(4, 0)))
36#define ADS131E08_CMD_WREG(r) (BIT(6) | (r & GENMASK(4, 0)))
37
38/* Registers */
39#define ADS131E08_ADR_CFG1R 0x01
40#define ADS131E08_ADR_CFG3R 0x03
41#define ADS131E08_ADR_CH0R 0x05
42
43/* Configuration register 1 */
44#define ADS131E08_CFG1R_DR_MASK GENMASK(2, 0)
45
46/* Configuration register 3 */
47#define ADS131E08_CFG3R_PDB_REFBUF_MASK BIT(7)
48#define ADS131E08_CFG3R_VREF_4V_MASK BIT(5)
49
50/* Channel settings register */
51#define ADS131E08_CHR_GAIN_MASK GENMASK(6, 4)
52#define ADS131E08_CHR_MUX_MASK GENMASK(2, 0)
53#define ADS131E08_CHR_PWD_MASK BIT(7)
54
55/* ADC misc */
56#define ADS131E08_DEFAULT_DATA_RATE 1
57#define ADS131E08_DEFAULT_PGA_GAIN 1
58#define ADS131E08_DEFAULT_MUX 0
59
60#define ADS131E08_VREF_2V4_mV 2400
61#define ADS131E08_VREF_4V_mV 4000
62
63#define ADS131E08_WAIT_RESET_CYCLES 18
64#define ADS131E08_WAIT_SDECODE_CYCLES 4
65#define ADS131E08_WAIT_OFFSETCAL_MS 153
66#define ADS131E08_MAX_SETTLING_TIME_MS 6
67
68#define ADS131E08_NUM_STATUS_BYTES 3
69#define ADS131E08_NUM_DATA_BYTES_MAX 24
70#define ADS131E08_NUM_DATA_BYTES(dr) (((dr) >= 32) ? 2 : 3)
71#define ADS131E08_NUM_DATA_BITS(dr) (ADS131E08_NUM_DATA_BYTES(dr) * 8)
72#define ADS131E08_NUM_STORAGE_BYTES 4
73
74enum ads131e08_ids {
75 ads131e04,
76 ads131e06,
77 ads131e08,
78};
79
80struct ads131e08_info {
81 unsigned int max_channels;
82 const char *name;
83};
84
85struct ads131e08_channel_config {
86 unsigned int pga_gain;
87 unsigned int mux;
88};
89
90struct ads131e08_state {
91 const struct ads131e08_info *info;
92 struct spi_device *spi;
93 struct iio_trigger *trig;
94 struct clk *adc_clk;
95 struct regulator *vref_reg;
96 struct ads131e08_channel_config *channel_config;
97 unsigned int data_rate;
98 unsigned int vref_mv;
99 unsigned int sdecode_delay_us;
100 unsigned int reset_delay_us;
101 unsigned int readback_len;
102 struct completion completion;
103 struct {
104 u8 data[ADS131E08_NUM_DATA_BYTES_MAX];
105 s64 ts __aligned(8);
106 } tmp_buf;
107
108 u8 tx_buf[3] __aligned(IIO_DMA_MINALIGN);
109 /*
110 * Add extra one padding byte to be able to access the last channel
111 * value using u32 pointer
112 */
113 u8 rx_buf[ADS131E08_NUM_STATUS_BYTES +
114 ADS131E08_NUM_DATA_BYTES_MAX + 1];
115};
116
117static const struct ads131e08_info ads131e08_info_tbl[] = {
118 [ads131e04] = {
119 .max_channels = 4,
120 .name = "ads131e04",
121 },
122 [ads131e06] = {
123 .max_channels = 6,
124 .name = "ads131e06",
125 },
126 [ads131e08] = {
127 .max_channels = 8,
128 .name = "ads131e08",
129 },
130};
131
132struct ads131e08_data_rate_desc {
133 unsigned int rate; /* data rate in kSPS */
134 u8 reg; /* reg value */
135};
136
137static const struct ads131e08_data_rate_desc ads131e08_data_rate_tbl[] = {
138 { .rate = 64, .reg = 0x00 },
139 { .rate = 32, .reg = 0x01 },
140 { .rate = 16, .reg = 0x02 },
141 { .rate = 8, .reg = 0x03 },
142 { .rate = 4, .reg = 0x04 },
143 { .rate = 2, .reg = 0x05 },
144 { .rate = 1, .reg = 0x06 },
145};
146
147struct ads131e08_pga_gain_desc {
148 unsigned int gain; /* PGA gain value */
149 u8 reg; /* field value */
150};
151
152static const struct ads131e08_pga_gain_desc ads131e08_pga_gain_tbl[] = {
153 { .gain = 1, .reg = 0x01 },
154 { .gain = 2, .reg = 0x02 },
155 { .gain = 4, .reg = 0x04 },
156 { .gain = 8, .reg = 0x05 },
157 { .gain = 12, .reg = 0x06 },
158};
159
160static const u8 ads131e08_valid_channel_mux_values[] = { 0, 1, 3, 4 };
161
162static int ads131e08_exec_cmd(struct ads131e08_state *st, u8 cmd)
163{
164 int ret;
165
166 ret = spi_write_then_read(spi: st->spi, txbuf: &cmd, n_tx: 1, NULL, n_rx: 0);
167 if (ret)
168 dev_err(&st->spi->dev, "Exec cmd(%02x) failed\n", cmd);
169
170 return ret;
171}
172
173static int ads131e08_read_reg(struct ads131e08_state *st, u8 reg)
174{
175 int ret;
176 struct spi_transfer transfer[] = {
177 {
178 .tx_buf = &st->tx_buf,
179 .len = 2,
180 .delay = {
181 .value = st->sdecode_delay_us,
182 .unit = SPI_DELAY_UNIT_USECS,
183 },
184 }, {
185 .rx_buf = &st->rx_buf,
186 .len = 1,
187 },
188 };
189
190 st->tx_buf[0] = ADS131E08_CMD_RREG(reg);
191 st->tx_buf[1] = 0;
192
193 ret = spi_sync_transfer(spi: st->spi, xfers: transfer, ARRAY_SIZE(transfer));
194 if (ret) {
195 dev_err(&st->spi->dev, "Read register failed\n");
196 return ret;
197 }
198
199 return st->rx_buf[0];
200}
201
202static int ads131e08_write_reg(struct ads131e08_state *st, u8 reg, u8 value)
203{
204 int ret;
205 struct spi_transfer transfer[] = {
206 {
207 .tx_buf = &st->tx_buf,
208 .len = 3,
209 .delay = {
210 .value = st->sdecode_delay_us,
211 .unit = SPI_DELAY_UNIT_USECS,
212 },
213 }
214 };
215
216 st->tx_buf[0] = ADS131E08_CMD_WREG(reg);
217 st->tx_buf[1] = 0;
218 st->tx_buf[2] = value;
219
220 ret = spi_sync_transfer(spi: st->spi, xfers: transfer, ARRAY_SIZE(transfer));
221 if (ret)
222 dev_err(&st->spi->dev, "Write register failed\n");
223
224 return ret;
225}
226
227static int ads131e08_read_data(struct ads131e08_state *st, int rx_len)
228{
229 int ret;
230 struct spi_transfer transfer[] = {
231 {
232 .tx_buf = &st->tx_buf,
233 .len = 1,
234 }, {
235 .rx_buf = &st->rx_buf,
236 .len = rx_len,
237 },
238 };
239
240 st->tx_buf[0] = ADS131E08_CMD_RDATA;
241
242 ret = spi_sync_transfer(spi: st->spi, xfers: transfer, ARRAY_SIZE(transfer));
243 if (ret)
244 dev_err(&st->spi->dev, "Read data failed\n");
245
246 return ret;
247}
248
249static int ads131e08_set_data_rate(struct ads131e08_state *st, int data_rate)
250{
251 int i, reg, ret;
252
253 for (i = 0; i < ARRAY_SIZE(ads131e08_data_rate_tbl); i++) {
254 if (ads131e08_data_rate_tbl[i].rate == data_rate)
255 break;
256 }
257
258 if (i == ARRAY_SIZE(ads131e08_data_rate_tbl)) {
259 dev_err(&st->spi->dev, "invalid data rate value\n");
260 return -EINVAL;
261 }
262
263 reg = ads131e08_read_reg(st, ADS131E08_ADR_CFG1R);
264 if (reg < 0)
265 return reg;
266
267 reg &= ~ADS131E08_CFG1R_DR_MASK;
268 reg |= FIELD_PREP(ADS131E08_CFG1R_DR_MASK,
269 ads131e08_data_rate_tbl[i].reg);
270
271 ret = ads131e08_write_reg(st, ADS131E08_ADR_CFG1R, value: reg);
272 if (ret)
273 return ret;
274
275 st->data_rate = data_rate;
276 st->readback_len = ADS131E08_NUM_STATUS_BYTES +
277 ADS131E08_NUM_DATA_BYTES(st->data_rate) *
278 st->info->max_channels;
279
280 return 0;
281}
282
283static int ads131e08_pga_gain_to_field_value(struct ads131e08_state *st,
284 unsigned int pga_gain)
285{
286 int i;
287
288 for (i = 0; i < ARRAY_SIZE(ads131e08_pga_gain_tbl); i++) {
289 if (ads131e08_pga_gain_tbl[i].gain == pga_gain)
290 break;
291 }
292
293 if (i == ARRAY_SIZE(ads131e08_pga_gain_tbl)) {
294 dev_err(&st->spi->dev, "invalid PGA gain value\n");
295 return -EINVAL;
296 }
297
298 return ads131e08_pga_gain_tbl[i].reg;
299}
300
301static int ads131e08_set_pga_gain(struct ads131e08_state *st,
302 unsigned int channel, unsigned int pga_gain)
303{
304 int field_value, reg;
305
306 field_value = ads131e08_pga_gain_to_field_value(st, pga_gain);
307 if (field_value < 0)
308 return field_value;
309
310 reg = ads131e08_read_reg(st, ADS131E08_ADR_CH0R + channel);
311 if (reg < 0)
312 return reg;
313
314 reg &= ~ADS131E08_CHR_GAIN_MASK;
315 reg |= FIELD_PREP(ADS131E08_CHR_GAIN_MASK, field_value);
316
317 return ads131e08_write_reg(st, ADS131E08_ADR_CH0R + channel, value: reg);
318}
319
320static int ads131e08_validate_channel_mux(struct ads131e08_state *st,
321 unsigned int mux)
322{
323 int i;
324
325 for (i = 0; i < ARRAY_SIZE(ads131e08_valid_channel_mux_values); i++) {
326 if (ads131e08_valid_channel_mux_values[i] == mux)
327 break;
328 }
329
330 if (i == ARRAY_SIZE(ads131e08_valid_channel_mux_values)) {
331 dev_err(&st->spi->dev, "invalid channel mux value\n");
332 return -EINVAL;
333 }
334
335 return 0;
336}
337
338static int ads131e08_set_channel_mux(struct ads131e08_state *st,
339 unsigned int channel, unsigned int mux)
340{
341 int reg;
342
343 reg = ads131e08_read_reg(st, ADS131E08_ADR_CH0R + channel);
344 if (reg < 0)
345 return reg;
346
347 reg &= ~ADS131E08_CHR_MUX_MASK;
348 reg |= FIELD_PREP(ADS131E08_CHR_MUX_MASK, mux);
349
350 return ads131e08_write_reg(st, ADS131E08_ADR_CH0R + channel, value: reg);
351}
352
353static int ads131e08_power_down_channel(struct ads131e08_state *st,
354 unsigned int channel, bool value)
355{
356 int reg;
357
358 reg = ads131e08_read_reg(st, ADS131E08_ADR_CH0R + channel);
359 if (reg < 0)
360 return reg;
361
362 reg &= ~ADS131E08_CHR_PWD_MASK;
363 reg |= FIELD_PREP(ADS131E08_CHR_PWD_MASK, value);
364
365 return ads131e08_write_reg(st, ADS131E08_ADR_CH0R + channel, value: reg);
366}
367
368static int ads131e08_config_reference_voltage(struct ads131e08_state *st)
369{
370 int reg;
371
372 reg = ads131e08_read_reg(st, ADS131E08_ADR_CFG3R);
373 if (reg < 0)
374 return reg;
375
376 reg &= ~ADS131E08_CFG3R_PDB_REFBUF_MASK;
377 if (!st->vref_reg) {
378 reg |= FIELD_PREP(ADS131E08_CFG3R_PDB_REFBUF_MASK, 1);
379 reg &= ~ADS131E08_CFG3R_VREF_4V_MASK;
380 reg |= FIELD_PREP(ADS131E08_CFG3R_VREF_4V_MASK,
381 st->vref_mv == ADS131E08_VREF_4V_mV);
382 }
383
384 return ads131e08_write_reg(st, ADS131E08_ADR_CFG3R, value: reg);
385}
386
387static int ads131e08_initial_config(struct iio_dev *indio_dev)
388{
389 const struct iio_chan_spec *channel = indio_dev->channels;
390 struct ads131e08_state *st = iio_priv(indio_dev);
391 unsigned long active_channels = 0;
392 int ret, i;
393
394 ret = ads131e08_exec_cmd(st, ADS131E08_CMD_RESET);
395 if (ret)
396 return ret;
397
398 udelay(st->reset_delay_us);
399
400 /* Disable read data in continuous mode (enabled by default) */
401 ret = ads131e08_exec_cmd(st, ADS131E08_CMD_SDATAC);
402 if (ret)
403 return ret;
404
405 ret = ads131e08_set_data_rate(st, ADS131E08_DEFAULT_DATA_RATE);
406 if (ret)
407 return ret;
408
409 ret = ads131e08_config_reference_voltage(st);
410 if (ret)
411 return ret;
412
413 for (i = 0; i < indio_dev->num_channels; i++) {
414 ret = ads131e08_set_pga_gain(st, channel: channel->channel,
415 pga_gain: st->channel_config[i].pga_gain);
416 if (ret)
417 return ret;
418
419 ret = ads131e08_set_channel_mux(st, channel: channel->channel,
420 mux: st->channel_config[i].mux);
421 if (ret)
422 return ret;
423
424 active_channels |= BIT(channel->channel);
425 channel++;
426 }
427
428 /* Power down unused channels */
429 for_each_clear_bit(i, &active_channels, st->info->max_channels) {
430 ret = ads131e08_power_down_channel(st, channel: i, value: true);
431 if (ret)
432 return ret;
433 }
434
435 /* Request channel offset calibration */
436 ret = ads131e08_exec_cmd(st, ADS131E08_CMD_OFFSETCAL);
437 if (ret)
438 return ret;
439
440 /*
441 * Channel offset calibration is triggered with the first START
442 * command. Since calibration takes more time than settling operation,
443 * this causes timeout error when command START is sent first
444 * time (e.g. first call of the ads131e08_read_direct method).
445 * To avoid this problem offset calibration is triggered here.
446 */
447 ret = ads131e08_exec_cmd(st, ADS131E08_CMD_START);
448 if (ret)
449 return ret;
450
451 msleep(ADS131E08_WAIT_OFFSETCAL_MS);
452
453 return ads131e08_exec_cmd(st, ADS131E08_CMD_STOP);
454}
455
456static int ads131e08_pool_data(struct ads131e08_state *st)
457{
458 unsigned long timeout;
459 int ret;
460
461 reinit_completion(x: &st->completion);
462
463 ret = ads131e08_exec_cmd(st, ADS131E08_CMD_START);
464 if (ret)
465 return ret;
466
467 timeout = msecs_to_jiffies(ADS131E08_MAX_SETTLING_TIME_MS);
468 ret = wait_for_completion_timeout(x: &st->completion, timeout);
469 if (!ret)
470 return -ETIMEDOUT;
471
472 ret = ads131e08_read_data(st, rx_len: st->readback_len);
473 if (ret)
474 return ret;
475
476 return ads131e08_exec_cmd(st, ADS131E08_CMD_STOP);
477}
478
479static int ads131e08_read_direct(struct iio_dev *indio_dev,
480 struct iio_chan_spec const *channel, int *value)
481{
482 struct ads131e08_state *st = iio_priv(indio_dev);
483 u8 num_bits, *src;
484 int ret;
485
486 ret = ads131e08_pool_data(st);
487 if (ret)
488 return ret;
489
490 src = st->rx_buf + ADS131E08_NUM_STATUS_BYTES +
491 channel->channel * ADS131E08_NUM_DATA_BYTES(st->data_rate);
492
493 num_bits = ADS131E08_NUM_DATA_BITS(st->data_rate);
494 *value = sign_extend32(value: get_unaligned_be32(p: src) >> (32 - num_bits), index: num_bits - 1);
495
496 return 0;
497}
498
499static int ads131e08_read_raw(struct iio_dev *indio_dev,
500 struct iio_chan_spec const *channel, int *value,
501 int *value2, long mask)
502{
503 struct ads131e08_state *st = iio_priv(indio_dev);
504 int ret;
505
506 switch (mask) {
507 case IIO_CHAN_INFO_RAW:
508 ret = iio_device_claim_direct_mode(indio_dev);
509 if (ret)
510 return ret;
511
512 ret = ads131e08_read_direct(indio_dev, channel, value);
513 iio_device_release_direct_mode(indio_dev);
514 if (ret)
515 return ret;
516
517 return IIO_VAL_INT;
518
519 case IIO_CHAN_INFO_SCALE:
520 if (st->vref_reg) {
521 ret = regulator_get_voltage(regulator: st->vref_reg);
522 if (ret < 0)
523 return ret;
524
525 *value = ret / 1000;
526 } else {
527 *value = st->vref_mv;
528 }
529
530 *value /= st->channel_config[channel->address].pga_gain;
531 *value2 = ADS131E08_NUM_DATA_BITS(st->data_rate) - 1;
532
533 return IIO_VAL_FRACTIONAL_LOG2;
534
535 case IIO_CHAN_INFO_SAMP_FREQ:
536 *value = st->data_rate;
537
538 return IIO_VAL_INT;
539
540 default:
541 return -EINVAL;
542 }
543}
544
545static int ads131e08_write_raw(struct iio_dev *indio_dev,
546 struct iio_chan_spec const *channel, int value,
547 int value2, long mask)
548{
549 struct ads131e08_state *st = iio_priv(indio_dev);
550 int ret;
551
552 switch (mask) {
553 case IIO_CHAN_INFO_SAMP_FREQ:
554 ret = iio_device_claim_direct_mode(indio_dev);
555 if (ret)
556 return ret;
557
558 ret = ads131e08_set_data_rate(st, data_rate: value);
559 iio_device_release_direct_mode(indio_dev);
560 return ret;
561
562 default:
563 return -EINVAL;
564 }
565}
566
567static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("1 2 4 8 16 32 64");
568
569static struct attribute *ads131e08_attributes[] = {
570 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
571 NULL
572};
573
574static const struct attribute_group ads131e08_attribute_group = {
575 .attrs = ads131e08_attributes,
576};
577
578static int ads131e08_debugfs_reg_access(struct iio_dev *indio_dev,
579 unsigned int reg, unsigned int writeval, unsigned int *readval)
580{
581 struct ads131e08_state *st = iio_priv(indio_dev);
582
583 if (readval) {
584 int ret = ads131e08_read_reg(st, reg);
585 *readval = ret;
586 return ret;
587 }
588
589 return ads131e08_write_reg(st, reg, value: writeval);
590}
591
592static const struct iio_info ads131e08_iio_info = {
593 .read_raw = ads131e08_read_raw,
594 .write_raw = ads131e08_write_raw,
595 .attrs = &ads131e08_attribute_group,
596 .debugfs_reg_access = &ads131e08_debugfs_reg_access,
597};
598
599static int ads131e08_set_trigger_state(struct iio_trigger *trig, bool state)
600{
601 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
602 struct ads131e08_state *st = iio_priv(indio_dev);
603 u8 cmd = state ? ADS131E08_CMD_START : ADS131E08_CMD_STOP;
604
605 return ads131e08_exec_cmd(st, cmd);
606}
607
608static const struct iio_trigger_ops ads131e08_trigger_ops = {
609 .set_trigger_state = &ads131e08_set_trigger_state,
610 .validate_device = &iio_trigger_validate_own_device,
611};
612
613static irqreturn_t ads131e08_trigger_handler(int irq, void *private)
614{
615 struct iio_poll_func *pf = private;
616 struct iio_dev *indio_dev = pf->indio_dev;
617 struct ads131e08_state *st = iio_priv(indio_dev);
618 unsigned int chn, i = 0;
619 u8 *src, *dest;
620 int ret;
621
622 /*
623 * The number of data bits per channel depends on the data rate.
624 * For 32 and 64 ksps data rates, number of data bits per channel
625 * is 16. This case is not compliant with used (fixed) scan element
626 * type (be:s24/32>>8). So we use a little tweak to pack properly
627 * 16 bits of data into the buffer.
628 */
629 unsigned int num_bytes = ADS131E08_NUM_DATA_BYTES(st->data_rate);
630 u8 tweek_offset = num_bytes == 2 ? 1 : 0;
631
632 if (iio_trigger_using_own(indio_dev))
633 ret = ads131e08_read_data(st, rx_len: st->readback_len);
634 else
635 ret = ads131e08_pool_data(st);
636
637 if (ret)
638 goto out;
639
640 for_each_set_bit(chn, indio_dev->active_scan_mask, indio_dev->masklength) {
641 src = st->rx_buf + ADS131E08_NUM_STATUS_BYTES + chn * num_bytes;
642 dest = st->tmp_buf.data + i * ADS131E08_NUM_STORAGE_BYTES;
643
644 /*
645 * Tweek offset is 0:
646 * +---+---+---+---+
647 * |D0 |D1 |D2 | X | (3 data bytes)
648 * +---+---+---+---+
649 * a+0 a+1 a+2 a+3
650 *
651 * Tweek offset is 1:
652 * +---+---+---+---+
653 * |P0 |D0 |D1 | X | (one padding byte and 2 data bytes)
654 * +---+---+---+---+
655 * a+0 a+1 a+2 a+3
656 */
657 memcpy(dest + tweek_offset, src, num_bytes);
658
659 /*
660 * Data conversion from 16 bits of data to 24 bits of data
661 * is done by sign extension (properly filling padding byte).
662 */
663 if (tweek_offset)
664 *dest = *src & BIT(7) ? 0xff : 0x00;
665
666 i++;
667 }
668
669 iio_push_to_buffers_with_timestamp(indio_dev, data: st->tmp_buf.data,
670 timestamp: iio_get_time_ns(indio_dev));
671
672out:
673 iio_trigger_notify_done(trig: indio_dev->trig);
674
675 return IRQ_HANDLED;
676}
677
678static irqreturn_t ads131e08_interrupt(int irq, void *private)
679{
680 struct iio_dev *indio_dev = private;
681 struct ads131e08_state *st = iio_priv(indio_dev);
682
683 if (iio_buffer_enabled(indio_dev) && iio_trigger_using_own(indio_dev))
684 iio_trigger_poll(trig: st->trig);
685 else
686 complete(&st->completion);
687
688 return IRQ_HANDLED;
689}
690
691static int ads131e08_alloc_channels(struct iio_dev *indio_dev)
692{
693 struct ads131e08_state *st = iio_priv(indio_dev);
694 struct ads131e08_channel_config *channel_config;
695 struct device *dev = &st->spi->dev;
696 struct iio_chan_spec *channels;
697 struct fwnode_handle *node;
698 unsigned int channel, tmp;
699 int num_channels, i, ret;
700
701 ret = device_property_read_u32(dev, propname: "ti,vref-internal", val: &tmp);
702 if (ret)
703 tmp = 0;
704
705 switch (tmp) {
706 case 0:
707 st->vref_mv = ADS131E08_VREF_2V4_mV;
708 break;
709 case 1:
710 st->vref_mv = ADS131E08_VREF_4V_mV;
711 break;
712 default:
713 dev_err(&st->spi->dev, "invalid internal voltage reference\n");
714 return -EINVAL;
715 }
716
717 num_channels = device_get_child_node_count(dev);
718 if (num_channels == 0) {
719 dev_err(&st->spi->dev, "no channel children\n");
720 return -ENODEV;
721 }
722
723 if (num_channels > st->info->max_channels) {
724 dev_err(&st->spi->dev, "num of channel children out of range\n");
725 return -EINVAL;
726 }
727
728 channels = devm_kcalloc(dev: &st->spi->dev, n: num_channels,
729 size: sizeof(*channels), GFP_KERNEL);
730 if (!channels)
731 return -ENOMEM;
732
733 channel_config = devm_kcalloc(dev: &st->spi->dev, n: num_channels,
734 size: sizeof(*channel_config), GFP_KERNEL);
735 if (!channel_config)
736 return -ENOMEM;
737
738 i = 0;
739 device_for_each_child_node(dev, node) {
740 ret = fwnode_property_read_u32(fwnode: node, propname: "reg", val: &channel);
741 if (ret)
742 goto err_child_out;
743
744 ret = fwnode_property_read_u32(fwnode: node, propname: "ti,gain", val: &tmp);
745 if (ret) {
746 channel_config[i].pga_gain = ADS131E08_DEFAULT_PGA_GAIN;
747 } else {
748 ret = ads131e08_pga_gain_to_field_value(st, pga_gain: tmp);
749 if (ret < 0)
750 goto err_child_out;
751
752 channel_config[i].pga_gain = tmp;
753 }
754
755 ret = fwnode_property_read_u32(fwnode: node, propname: "ti,mux", val: &tmp);
756 if (ret) {
757 channel_config[i].mux = ADS131E08_DEFAULT_MUX;
758 } else {
759 ret = ads131e08_validate_channel_mux(st, mux: tmp);
760 if (ret)
761 goto err_child_out;
762
763 channel_config[i].mux = tmp;
764 }
765
766 channels[i].type = IIO_VOLTAGE;
767 channels[i].indexed = 1;
768 channels[i].channel = channel;
769 channels[i].address = i;
770 channels[i].info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
771 BIT(IIO_CHAN_INFO_SCALE);
772 channels[i].info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ);
773 channels[i].scan_index = channel;
774 channels[i].scan_type.sign = 's';
775 channels[i].scan_type.realbits = 24;
776 channels[i].scan_type.storagebits = 32;
777 channels[i].scan_type.shift = 8;
778 channels[i].scan_type.endianness = IIO_BE;
779 i++;
780 }
781
782 indio_dev->channels = channels;
783 indio_dev->num_channels = num_channels;
784 st->channel_config = channel_config;
785
786 return 0;
787
788err_child_out:
789 fwnode_handle_put(fwnode: node);
790 return ret;
791}
792
793static void ads131e08_regulator_disable(void *data)
794{
795 struct ads131e08_state *st = data;
796
797 regulator_disable(regulator: st->vref_reg);
798}
799
800static int ads131e08_probe(struct spi_device *spi)
801{
802 const struct ads131e08_info *info;
803 struct ads131e08_state *st;
804 struct iio_dev *indio_dev;
805 unsigned long adc_clk_hz;
806 unsigned long adc_clk_ns;
807 int ret;
808
809 info = device_get_match_data(dev: &spi->dev);
810 if (!info)
811 info = (void *)spi_get_device_id(sdev: spi)->driver_data;
812 if (!info) {
813 dev_err(&spi->dev, "failed to get match data\n");
814 return -ENODEV;
815 }
816
817 indio_dev = devm_iio_device_alloc(parent: &spi->dev, sizeof_priv: sizeof(*st));
818 if (!indio_dev) {
819 dev_err(&spi->dev, "failed to allocate IIO device\n");
820 return -ENOMEM;
821 }
822
823 st = iio_priv(indio_dev);
824 st->info = info;
825 st->spi = spi;
826
827 ret = ads131e08_alloc_channels(indio_dev);
828 if (ret)
829 return ret;
830
831 indio_dev->name = st->info->name;
832 indio_dev->info = &ads131e08_iio_info;
833 indio_dev->modes = INDIO_DIRECT_MODE;
834
835 init_completion(x: &st->completion);
836
837 if (spi->irq) {
838 ret = devm_request_irq(dev: &spi->dev, irq: spi->irq,
839 handler: ads131e08_interrupt,
840 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
841 devname: spi->dev.driver->name, dev_id: indio_dev);
842 if (ret)
843 return dev_err_probe(dev: &spi->dev, err: ret,
844 fmt: "request irq failed\n");
845 } else {
846 dev_err(&spi->dev, "data ready IRQ missing\n");
847 return -ENODEV;
848 }
849
850 st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
851 indio_dev->name, iio_device_id(indio_dev));
852 if (!st->trig) {
853 dev_err(&spi->dev, "failed to allocate IIO trigger\n");
854 return -ENOMEM;
855 }
856
857 st->trig->ops = &ads131e08_trigger_ops;
858 st->trig->dev.parent = &spi->dev;
859 iio_trigger_set_drvdata(trig: st->trig, data: indio_dev);
860 ret = devm_iio_trigger_register(dev: &spi->dev, trig_info: st->trig);
861 if (ret) {
862 dev_err(&spi->dev, "failed to register IIO trigger\n");
863 return -ENOMEM;
864 }
865
866 indio_dev->trig = iio_trigger_get(trig: st->trig);
867
868 ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
869 NULL, &ads131e08_trigger_handler, NULL);
870 if (ret) {
871 dev_err(&spi->dev, "failed to setup IIO buffer\n");
872 return ret;
873 }
874
875 st->vref_reg = devm_regulator_get_optional(dev: &spi->dev, id: "vref");
876 if (!IS_ERR(ptr: st->vref_reg)) {
877 ret = regulator_enable(regulator: st->vref_reg);
878 if (ret) {
879 dev_err(&spi->dev,
880 "failed to enable external vref supply\n");
881 return ret;
882 }
883
884 ret = devm_add_action_or_reset(&spi->dev, ads131e08_regulator_disable, st);
885 if (ret)
886 return ret;
887 } else {
888 if (PTR_ERR(ptr: st->vref_reg) != -ENODEV)
889 return PTR_ERR(ptr: st->vref_reg);
890
891 st->vref_reg = NULL;
892 }
893
894 st->adc_clk = devm_clk_get_enabled(dev: &spi->dev, id: "adc-clk");
895 if (IS_ERR(ptr: st->adc_clk))
896 return dev_err_probe(dev: &spi->dev, err: PTR_ERR(ptr: st->adc_clk),
897 fmt: "failed to get the ADC clock\n");
898
899 adc_clk_hz = clk_get_rate(clk: st->adc_clk);
900 if (!adc_clk_hz) {
901 dev_err(&spi->dev, "failed to get the ADC clock rate\n");
902 return -EINVAL;
903 }
904
905 adc_clk_ns = NSEC_PER_SEC / adc_clk_hz;
906 st->sdecode_delay_us = DIV_ROUND_UP(
907 ADS131E08_WAIT_SDECODE_CYCLES * adc_clk_ns, NSEC_PER_USEC);
908 st->reset_delay_us = DIV_ROUND_UP(
909 ADS131E08_WAIT_RESET_CYCLES * adc_clk_ns, NSEC_PER_USEC);
910
911 ret = ads131e08_initial_config(indio_dev);
912 if (ret) {
913 dev_err(&spi->dev, "initial configuration failed\n");
914 return ret;
915 }
916
917 return devm_iio_device_register(&spi->dev, indio_dev);
918}
919
920static const struct of_device_id ads131e08_of_match[] = {
921 { .compatible = "ti,ads131e04",
922 .data = &ads131e08_info_tbl[ads131e04], },
923 { .compatible = "ti,ads131e06",
924 .data = &ads131e08_info_tbl[ads131e06], },
925 { .compatible = "ti,ads131e08",
926 .data = &ads131e08_info_tbl[ads131e08], },
927 {}
928};
929MODULE_DEVICE_TABLE(of, ads131e08_of_match);
930
931static const struct spi_device_id ads131e08_ids[] = {
932 { "ads131e04", (kernel_ulong_t)&ads131e08_info_tbl[ads131e04] },
933 { "ads131e06", (kernel_ulong_t)&ads131e08_info_tbl[ads131e06] },
934 { "ads131e08", (kernel_ulong_t)&ads131e08_info_tbl[ads131e08] },
935 {}
936};
937MODULE_DEVICE_TABLE(spi, ads131e08_ids);
938
939static struct spi_driver ads131e08_driver = {
940 .driver = {
941 .name = "ads131e08",
942 .of_match_table = ads131e08_of_match,
943 },
944 .probe = ads131e08_probe,
945 .id_table = ads131e08_ids,
946};
947module_spi_driver(ads131e08_driver);
948
949MODULE_AUTHOR("Tomislav Denis <tomislav.denis@avl.com>");
950MODULE_DESCRIPTION("Driver for ADS131E0x ADC family");
951MODULE_LICENSE("GPL v2");
952

source code of linux/drivers/iio/adc/ti-ads131e08.c