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6
7#include <linux/bitfield.h>
8#include <linux/clk.h>
9#include <linux/delay.h>
10#include <linux/device.h>
11#include <linux/err.h>
12#include <linux/gpio/consumer.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/regulator/consumer.h>
16#include <linux/sysfs.h>
17#include <linux/spi/spi.h>
18
19#include <linux/iio/buffer.h>
20#include <linux/iio/iio.h>
21#include <linux/iio/sysfs.h>
22#include <linux/iio/trigger.h>
23#include <linux/iio/triggered_buffer.h>
24#include <linux/iio/trigger_consumer.h>
25
26
27#define AD7768_REG_CHIP_TYPE 0x3
28#define AD7768_REG_PROD_ID_L 0x4
29#define AD7768_REG_PROD_ID_H 0x5
30#define AD7768_REG_CHIP_GRADE 0x6
31#define AD7768_REG_SCRATCH_PAD 0x0A
32#define AD7768_REG_VENDOR_L 0x0C
33#define AD7768_REG_VENDOR_H 0x0D
34#define AD7768_REG_INTERFACE_FORMAT 0x14
35#define AD7768_REG_POWER_CLOCK 0x15
36#define AD7768_REG_ANALOG 0x16
37#define AD7768_REG_ANALOG2 0x17
38#define AD7768_REG_CONVERSION 0x18
39#define AD7768_REG_DIGITAL_FILTER 0x19
40#define AD7768_REG_SINC3_DEC_RATE_MSB 0x1A
41#define AD7768_REG_SINC3_DEC_RATE_LSB 0x1B
42#define AD7768_REG_DUTY_CYCLE_RATIO 0x1C
43#define AD7768_REG_SYNC_RESET 0x1D
44#define AD7768_REG_GPIO_CONTROL 0x1E
45#define AD7768_REG_GPIO_WRITE 0x1F
46#define AD7768_REG_GPIO_READ 0x20
47#define AD7768_REG_OFFSET_HI 0x21
48#define AD7768_REG_OFFSET_MID 0x22
49#define AD7768_REG_OFFSET_LO 0x23
50#define AD7768_REG_GAIN_HI 0x24
51#define AD7768_REG_GAIN_MID 0x25
52#define AD7768_REG_GAIN_LO 0x26
53#define AD7768_REG_SPI_DIAG_ENABLE 0x28
54#define AD7768_REG_ADC_DIAG_ENABLE 0x29
55#define AD7768_REG_DIG_DIAG_ENABLE 0x2A
56#define AD7768_REG_ADC_DATA 0x2C
57#define AD7768_REG_MASTER_STATUS 0x2D
58#define AD7768_REG_SPI_DIAG_STATUS 0x2E
59#define AD7768_REG_ADC_DIAG_STATUS 0x2F
60#define AD7768_REG_DIG_DIAG_STATUS 0x30
61#define AD7768_REG_MCLK_COUNTER 0x31
62
63
64#define AD7768_PWR_MCLK_DIV_MSK GENMASK(5, 4)
65#define AD7768_PWR_MCLK_DIV(x) FIELD_PREP(AD7768_PWR_MCLK_DIV_MSK, x)
66#define AD7768_PWR_PWRMODE_MSK GENMASK(1, 0)
67#define AD7768_PWR_PWRMODE(x) FIELD_PREP(AD7768_PWR_PWRMODE_MSK, x)
68
69
70#define AD7768_DIG_FIL_FIL_MSK GENMASK(6, 4)
71#define AD7768_DIG_FIL_FIL(x) FIELD_PREP(AD7768_DIG_FIL_FIL_MSK, x)
72#define AD7768_DIG_FIL_DEC_MSK GENMASK(2, 0)
73#define AD7768_DIG_FIL_DEC_RATE(x) FIELD_PREP(AD7768_DIG_FIL_DEC_MSK, x)
74
75
76#define AD7768_CONV_MODE_MSK GENMASK(2, 0)
77#define AD7768_CONV_MODE(x) FIELD_PREP(AD7768_CONV_MODE_MSK, x)
78
79#define AD7768_RD_FLAG_MSK(x) (BIT(6) | ((x) & 0x3F))
80#define AD7768_WR_FLAG_MSK(x) ((x) & 0x3F)
81
82enum ad7768_conv_mode {
83 AD7768_CONTINUOUS,
84 AD7768_ONE_SHOT,
85 AD7768_SINGLE,
86 AD7768_PERIODIC,
87 AD7768_STANDBY
88};
89
90enum ad7768_pwrmode {
91 AD7768_ECO_MODE = 0,
92 AD7768_MED_MODE = 2,
93 AD7768_FAST_MODE = 3
94};
95
96enum ad7768_mclk_div {
97 AD7768_MCLK_DIV_16,
98 AD7768_MCLK_DIV_8,
99 AD7768_MCLK_DIV_4,
100 AD7768_MCLK_DIV_2
101};
102
103enum ad7768_dec_rate {
104 AD7768_DEC_RATE_32 = 0,
105 AD7768_DEC_RATE_64 = 1,
106 AD7768_DEC_RATE_128 = 2,
107 AD7768_DEC_RATE_256 = 3,
108 AD7768_DEC_RATE_512 = 4,
109 AD7768_DEC_RATE_1024 = 5,
110 AD7768_DEC_RATE_8 = 9,
111 AD7768_DEC_RATE_16 = 10
112};
113
114struct ad7768_clk_configuration {
115 enum ad7768_mclk_div mclk_div;
116 enum ad7768_dec_rate dec_rate;
117 unsigned int clk_div;
118 enum ad7768_pwrmode pwrmode;
119};
120
121static const struct ad7768_clk_configuration ad7768_clk_config[] = {
122 { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_8, 16, AD7768_FAST_MODE },
123 { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_16, 32, AD7768_FAST_MODE },
124 { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_32, 64, AD7768_FAST_MODE },
125 { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_64, 128, AD7768_FAST_MODE },
126 { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_128, 256, AD7768_FAST_MODE },
127 { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_128, 512, AD7768_MED_MODE },
128 { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_256, 1024, AD7768_MED_MODE },
129 { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_512, 2048, AD7768_MED_MODE },
130 { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_1024, 4096, AD7768_MED_MODE },
131 { AD7768_MCLK_DIV_8, AD7768_DEC_RATE_1024, 8192, AD7768_MED_MODE },
132 { AD7768_MCLK_DIV_16, AD7768_DEC_RATE_1024, 16384, AD7768_ECO_MODE },
133};
134
135static const struct iio_chan_spec ad7768_channels[] = {
136 {
137 .type = IIO_VOLTAGE,
138 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
139 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
140 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
141 .indexed = 1,
142 .channel = 0,
143 .scan_index = 0,
144 .scan_type = {
145 .sign = 'u',
146 .realbits = 24,
147 .storagebits = 32,
148 .shift = 8,
149 .endianness = IIO_BE,
150 },
151 },
152};
153
154struct ad7768_state {
155 struct spi_device *spi;
156 struct regulator *vref;
157 struct mutex lock;
158 struct clk *mclk;
159 unsigned int mclk_freq;
160 unsigned int samp_freq;
161 struct completion completion;
162 struct iio_trigger *trig;
163 struct gpio_desc *gpio_sync_in;
164
165
166
167
168 union {
169 __be32 d32;
170 u8 d8[2];
171 } data ____cacheline_aligned;
172};
173
174static int ad7768_spi_reg_read(struct ad7768_state *st, unsigned int addr,
175 unsigned int len)
176{
177 unsigned int shift;
178 int ret;
179
180 shift = 32 - (8 * len);
181 st->data.d8[0] = AD7768_RD_FLAG_MSK(addr);
182
183 ret = spi_write_then_read(st->spi, st->data.d8, 1,
184 &st->data.d32, len);
185 if (ret < 0)
186 return ret;
187
188 return (be32_to_cpu(st->data.d32) >> shift);
189}
190
191static int ad7768_spi_reg_write(struct ad7768_state *st,
192 unsigned int addr,
193 unsigned int val)
194{
195 st->data.d8[0] = AD7768_WR_FLAG_MSK(addr);
196 st->data.d8[1] = val & 0xFF;
197
198 return spi_write(st->spi, st->data.d8, 2);
199}
200
201static int ad7768_set_mode(struct ad7768_state *st,
202 enum ad7768_conv_mode mode)
203{
204 int regval;
205
206 regval = ad7768_spi_reg_read(st, AD7768_REG_CONVERSION, 1);
207 if (regval < 0)
208 return regval;
209
210 regval &= ~AD7768_CONV_MODE_MSK;
211 regval |= AD7768_CONV_MODE(mode);
212
213 return ad7768_spi_reg_write(st, AD7768_REG_CONVERSION, regval);
214}
215
216static int ad7768_scan_direct(struct iio_dev *indio_dev)
217{
218 struct ad7768_state *st = iio_priv(indio_dev);
219 int readval, ret;
220
221 reinit_completion(&st->completion);
222
223 ret = ad7768_set_mode(st, AD7768_ONE_SHOT);
224 if (ret < 0)
225 return ret;
226
227 ret = wait_for_completion_timeout(&st->completion,
228 msecs_to_jiffies(1000));
229 if (!ret)
230 return -ETIMEDOUT;
231
232 readval = ad7768_spi_reg_read(st, AD7768_REG_ADC_DATA, 3);
233 if (readval < 0)
234 return readval;
235
236
237
238
239 ret = ad7768_set_mode(st, AD7768_CONTINUOUS);
240 if (ret < 0)
241 return ret;
242
243 return readval;
244}
245
246static int ad7768_reg_access(struct iio_dev *indio_dev,
247 unsigned int reg,
248 unsigned int writeval,
249 unsigned int *readval)
250{
251 struct ad7768_state *st = iio_priv(indio_dev);
252 int ret;
253
254 mutex_lock(&st->lock);
255 if (readval) {
256 ret = ad7768_spi_reg_read(st, reg, 1);
257 if (ret < 0)
258 goto err_unlock;
259 *readval = ret;
260 ret = 0;
261 } else {
262 ret = ad7768_spi_reg_write(st, reg, writeval);
263 }
264err_unlock:
265 mutex_unlock(&st->lock);
266
267 return ret;
268}
269
270static int ad7768_set_dig_fil(struct ad7768_state *st,
271 enum ad7768_dec_rate dec_rate)
272{
273 unsigned int mode;
274 int ret;
275
276 if (dec_rate == AD7768_DEC_RATE_8 || dec_rate == AD7768_DEC_RATE_16)
277 mode = AD7768_DIG_FIL_FIL(dec_rate);
278 else
279 mode = AD7768_DIG_FIL_DEC_RATE(dec_rate);
280
281 ret = ad7768_spi_reg_write(st, AD7768_REG_DIGITAL_FILTER, mode);
282 if (ret < 0)
283 return ret;
284
285
286 gpiod_set_value(st->gpio_sync_in, 1);
287 gpiod_set_value(st->gpio_sync_in, 0);
288
289 return 0;
290}
291
292static int ad7768_set_freq(struct ad7768_state *st,
293 unsigned int freq)
294{
295 unsigned int diff_new, diff_old, pwr_mode, i, idx;
296 int res, ret;
297
298 diff_old = U32_MAX;
299 idx = 0;
300
301 res = DIV_ROUND_CLOSEST(st->mclk_freq, freq);
302
303
304 for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++) {
305 diff_new = abs(res - ad7768_clk_config[i].clk_div);
306 if (diff_new < diff_old) {
307 diff_old = diff_new;
308 idx = i;
309 }
310 }
311
312
313
314
315
316 pwr_mode = AD7768_PWR_MCLK_DIV(ad7768_clk_config[idx].mclk_div) |
317 AD7768_PWR_PWRMODE(ad7768_clk_config[idx].pwrmode);
318 ret = ad7768_spi_reg_write(st, AD7768_REG_POWER_CLOCK, pwr_mode);
319 if (ret < 0)
320 return ret;
321
322 ret = ad7768_set_dig_fil(st, ad7768_clk_config[idx].dec_rate);
323 if (ret < 0)
324 return ret;
325
326 st->samp_freq = DIV_ROUND_CLOSEST(st->mclk_freq,
327 ad7768_clk_config[idx].clk_div);
328
329 return 0;
330}
331
332static ssize_t ad7768_sampling_freq_avail(struct device *dev,
333 struct device_attribute *attr,
334 char *buf)
335{
336 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
337 struct ad7768_state *st = iio_priv(indio_dev);
338 unsigned int freq;
339 int i, len = 0;
340
341 for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++) {
342 freq = DIV_ROUND_CLOSEST(st->mclk_freq,
343 ad7768_clk_config[i].clk_div);
344 len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", freq);
345 }
346
347 buf[len - 1] = '\n';
348
349 return len;
350}
351
352static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(ad7768_sampling_freq_avail);
353
354static int ad7768_read_raw(struct iio_dev *indio_dev,
355 struct iio_chan_spec const *chan,
356 int *val, int *val2, long info)
357{
358 struct ad7768_state *st = iio_priv(indio_dev);
359 int scale_uv, ret;
360
361 switch (info) {
362 case IIO_CHAN_INFO_RAW:
363 ret = iio_device_claim_direct_mode(indio_dev);
364 if (ret)
365 return ret;
366
367 ret = ad7768_scan_direct(indio_dev);
368 if (ret >= 0)
369 *val = ret;
370
371 iio_device_release_direct_mode(indio_dev);
372 if (ret < 0)
373 return ret;
374
375 return IIO_VAL_INT;
376
377 case IIO_CHAN_INFO_SCALE:
378 scale_uv = regulator_get_voltage(st->vref);
379 if (scale_uv < 0)
380 return scale_uv;
381
382 *val = (scale_uv * 2) / 1000;
383 *val2 = chan->scan_type.realbits;
384
385 return IIO_VAL_FRACTIONAL_LOG2;
386
387 case IIO_CHAN_INFO_SAMP_FREQ:
388 *val = st->samp_freq;
389
390 return IIO_VAL_INT;
391 }
392
393 return -EINVAL;
394}
395
396static int ad7768_write_raw(struct iio_dev *indio_dev,
397 struct iio_chan_spec const *chan,
398 int val, int val2, long info)
399{
400 struct ad7768_state *st = iio_priv(indio_dev);
401
402 switch (info) {
403 case IIO_CHAN_INFO_SAMP_FREQ:
404 return ad7768_set_freq(st, val);
405 default:
406 return -EINVAL;
407 }
408}
409
410static struct attribute *ad7768_attributes[] = {
411 &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
412 NULL
413};
414
415static const struct attribute_group ad7768_group = {
416 .attrs = ad7768_attributes,
417};
418
419static const struct iio_info ad7768_info = {
420 .attrs = &ad7768_group,
421 .read_raw = &ad7768_read_raw,
422 .write_raw = &ad7768_write_raw,
423 .debugfs_reg_access = &ad7768_reg_access,
424};
425
426static int ad7768_setup(struct ad7768_state *st)
427{
428 int ret;
429
430
431
432
433
434
435
436 ret = ad7768_spi_reg_write(st, AD7768_REG_SYNC_RESET, 0x3);
437 if (ret)
438 return ret;
439
440 ret = ad7768_spi_reg_write(st, AD7768_REG_SYNC_RESET, 0x2);
441 if (ret)
442 return ret;
443
444 st->gpio_sync_in = devm_gpiod_get(&st->spi->dev, "adi,sync-in",
445 GPIOD_OUT_LOW);
446 if (IS_ERR(st->gpio_sync_in))
447 return PTR_ERR(st->gpio_sync_in);
448
449
450 return ad7768_set_freq(st, 32000);
451}
452
453static irqreturn_t ad7768_trigger_handler(int irq, void *p)
454{
455 struct iio_poll_func *pf = p;
456 struct iio_dev *indio_dev = pf->indio_dev;
457 struct ad7768_state *st = iio_priv(indio_dev);
458 int ret;
459
460 mutex_lock(&st->lock);
461
462 ret = spi_read(st->spi, &st->data.d32, 3);
463 if (ret < 0)
464 goto err_unlock;
465
466 iio_push_to_buffers_with_timestamp(indio_dev, &st->data.d32,
467 iio_get_time_ns(indio_dev));
468
469 iio_trigger_notify_done(indio_dev->trig);
470err_unlock:
471 mutex_unlock(&st->lock);
472
473 return IRQ_HANDLED;
474}
475
476static irqreturn_t ad7768_interrupt(int irq, void *dev_id)
477{
478 struct iio_dev *indio_dev = dev_id;
479 struct ad7768_state *st = iio_priv(indio_dev);
480
481 if (iio_buffer_enabled(indio_dev))
482 iio_trigger_poll(st->trig);
483 else
484 complete(&st->completion);
485
486 return IRQ_HANDLED;
487};
488
489static int ad7768_buffer_postenable(struct iio_dev *indio_dev)
490{
491 struct ad7768_state *st = iio_priv(indio_dev);
492
493 iio_triggered_buffer_postenable(indio_dev);
494
495
496
497
498
499 return ad7768_spi_reg_write(st, AD7768_REG_INTERFACE_FORMAT, 0x01);
500}
501
502static int ad7768_buffer_predisable(struct iio_dev *indio_dev)
503{
504 struct ad7768_state *st = iio_priv(indio_dev);
505 int ret;
506
507
508
509
510
511 ret = ad7768_spi_reg_read(st, AD7768_REG_ADC_DATA, 3);
512 if (ret < 0)
513 return ret;
514
515 return iio_triggered_buffer_predisable(indio_dev);
516}
517
518static const struct iio_buffer_setup_ops ad7768_buffer_ops = {
519 .postenable = &ad7768_buffer_postenable,
520 .predisable = &ad7768_buffer_predisable,
521};
522
523static const struct iio_trigger_ops ad7768_trigger_ops = {
524 .validate_device = iio_trigger_validate_own_device,
525};
526
527static void ad7768_regulator_disable(void *data)
528{
529 struct ad7768_state *st = data;
530
531 regulator_disable(st->vref);
532}
533
534static void ad7768_clk_disable(void *data)
535{
536 struct ad7768_state *st = data;
537
538 clk_disable_unprepare(st->mclk);
539}
540
541static int ad7768_probe(struct spi_device *spi)
542{
543 struct ad7768_state *st;
544 struct iio_dev *indio_dev;
545 int ret;
546
547 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
548 if (!indio_dev)
549 return -ENOMEM;
550
551 st = iio_priv(indio_dev);
552 st->spi = spi;
553
554 st->vref = devm_regulator_get(&spi->dev, "vref");
555 if (IS_ERR(st->vref))
556 return PTR_ERR(st->vref);
557
558 ret = regulator_enable(st->vref);
559 if (ret) {
560 dev_err(&spi->dev, "Failed to enable specified vref supply\n");
561 return ret;
562 }
563
564 ret = devm_add_action_or_reset(&spi->dev, ad7768_regulator_disable, st);
565 if (ret)
566 return ret;
567
568 st->mclk = devm_clk_get(&spi->dev, "mclk");
569 if (IS_ERR(st->mclk))
570 return PTR_ERR(st->mclk);
571
572 ret = clk_prepare_enable(st->mclk);
573 if (ret < 0)
574 return ret;
575
576 ret = devm_add_action_or_reset(&spi->dev, ad7768_clk_disable, st);
577 if (ret)
578 return ret;
579
580 st->mclk_freq = clk_get_rate(st->mclk);
581
582 spi_set_drvdata(spi, indio_dev);
583 mutex_init(&st->lock);
584
585 indio_dev->channels = ad7768_channels;
586 indio_dev->num_channels = ARRAY_SIZE(ad7768_channels);
587 indio_dev->dev.parent = &spi->dev;
588 indio_dev->name = spi_get_device_id(spi)->name;
589 indio_dev->info = &ad7768_info;
590 indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_TRIGGERED;
591
592 ret = ad7768_setup(st);
593 if (ret < 0) {
594 dev_err(&spi->dev, "AD7768 setup failed\n");
595 return ret;
596 }
597
598 st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
599 indio_dev->name, indio_dev->id);
600 if (!st->trig)
601 return -ENOMEM;
602
603 st->trig->ops = &ad7768_trigger_ops;
604 st->trig->dev.parent = &spi->dev;
605 iio_trigger_set_drvdata(st->trig, indio_dev);
606 ret = devm_iio_trigger_register(&spi->dev, st->trig);
607 if (ret)
608 return ret;
609
610 indio_dev->trig = iio_trigger_get(st->trig);
611
612 init_completion(&st->completion);
613
614 ret = devm_request_irq(&spi->dev, spi->irq,
615 &ad7768_interrupt,
616 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
617 indio_dev->name, indio_dev);
618 if (ret)
619 return ret;
620
621 ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
622 &iio_pollfunc_store_time,
623 &ad7768_trigger_handler,
624 &ad7768_buffer_ops);
625 if (ret)
626 return ret;
627
628 return devm_iio_device_register(&spi->dev, indio_dev);
629}
630
631static const struct spi_device_id ad7768_id_table[] = {
632 { "ad7768-1", 0 },
633 {}
634};
635MODULE_DEVICE_TABLE(spi, ad7768_id_table);
636
637static const struct of_device_id ad7768_of_match[] = {
638 { .compatible = "adi,ad7768-1" },
639 { },
640};
641MODULE_DEVICE_TABLE(of, ad7768_of_match);
642
643static struct spi_driver ad7768_driver = {
644 .driver = {
645 .name = "ad7768-1",
646 .of_match_table = ad7768_of_match,
647 },
648 .probe = ad7768_probe,
649 .id_table = ad7768_id_table,
650};
651module_spi_driver(ad7768_driver);
652
653MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
654MODULE_DESCRIPTION("Analog Devices AD7768-1 ADC driver");
655MODULE_LICENSE("GPL v2");
656
