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Diffstat (limited to 'drivers/iio/adc/stm32-dfsdm-adc.c')
-rw-r--r--drivers/iio/adc/stm32-dfsdm-adc.c1205
1 files changed, 1205 insertions, 0 deletions
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
new file mode 100644
index 000000000000..daa026d6a94f
--- /dev/null
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -0,0 +1,1205 @@
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * This file is the ADC part of the STM32 DFSDM driver
4 *
5 * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
6 * Author: Arnaud Pouliquen <arnaud.pouliquen@st.com>.
7 */
8
9#include <linux/dmaengine.h>
10#include <linux/dma-mapping.h>
11#include <linux/interrupt.h>
12#include <linux/iio/buffer.h>
13#include <linux/iio/hw-consumer.h>
14#include <linux/iio/iio.h>
15#include <linux/iio/sysfs.h>
16#include <linux/module.h>
17#include <linux/of_device.h>
18#include <linux/platform_device.h>
19#include <linux/regmap.h>
20#include <linux/slab.h>
21
22#include "stm32-dfsdm.h"
23
24#define DFSDM_DMA_BUFFER_SIZE (4 * PAGE_SIZE)
25
26/* Conversion timeout */
27#define DFSDM_TIMEOUT_US 100000
28#define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000))
29
30/* Oversampling attribute default */
31#define DFSDM_DEFAULT_OVERSAMPLING 100
32
33/* Oversampling max values */
34#define DFSDM_MAX_INT_OVERSAMPLING 256
35#define DFSDM_MAX_FL_OVERSAMPLING 1024
36
37/* Max sample resolutions */
38#define DFSDM_MAX_RES BIT(31)
39#define DFSDM_DATA_RES BIT(23)
40
41enum sd_converter_type {
42 DFSDM_AUDIO,
43 DFSDM_IIO,
44};
45
46struct stm32_dfsdm_dev_data {
47 int type;
48 int (*init)(struct iio_dev *indio_dev);
49 unsigned int num_channels;
50 const struct regmap_config *regmap_cfg;
51};
52
53struct stm32_dfsdm_adc {
54 struct stm32_dfsdm *dfsdm;
55 const struct stm32_dfsdm_dev_data *dev_data;
56 unsigned int fl_id;
57 unsigned int ch_id;
58
59 /* ADC specific */
60 unsigned int oversamp;
61 struct iio_hw_consumer *hwc;
62 struct completion completion;
63 u32 *buffer;
64
65 /* Audio specific */
66 unsigned int spi_freq; /* SPI bus clock frequency */
67 unsigned int sample_freq; /* Sample frequency after filter decimation */
68 int (*cb)(const void *data, size_t size, void *cb_priv);
69 void *cb_priv;
70
71 /* DMA */
72 u8 *rx_buf;
73 unsigned int bufi; /* Buffer current position */
74 unsigned int buf_sz; /* Buffer size */
75 struct dma_chan *dma_chan;
76 dma_addr_t dma_buf;
77};
78
79struct stm32_dfsdm_str2field {
80 const char *name;
81 unsigned int val;
82};
83
84/* DFSDM channel serial interface type */
85static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_type[] = {
86 { "SPI_R", 0 }, /* SPI with data on rising edge */
87 { "SPI_F", 1 }, /* SPI with data on falling edge */
88 { "MANCH_R", 2 }, /* Manchester codec, rising edge = logic 0 */
89 { "MANCH_F", 3 }, /* Manchester codec, falling edge = logic 1 */
90 {},
91};
92
93/* DFSDM channel clock source */
94static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_src[] = {
95 /* External SPI clock (CLKIN x) */
96 { "CLKIN", DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL },
97 /* Internal SPI clock (CLKOUT) */
98 { "CLKOUT", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL },
99 /* Internal SPI clock divided by 2 (falling edge) */
100 { "CLKOUT_F", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING },
101 /* Internal SPI clock divided by 2 (falling edge) */
102 { "CLKOUT_R", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING },
103 {},
104};
105
106static int stm32_dfsdm_str2val(const char *str,
107 const struct stm32_dfsdm_str2field *list)
108{
109 const struct stm32_dfsdm_str2field *p = list;
110
111 for (p = list; p && p->name; p++)
112 if (!strcmp(p->name, str))
113 return p->val;
114
115 return -EINVAL;
116}
117
118static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl,
119 unsigned int fast, unsigned int oversamp)
120{
121 unsigned int i, d, fosr, iosr;
122 u64 res;
123 s64 delta;
124 unsigned int m = 1; /* multiplication factor */
125 unsigned int p = fl->ford; /* filter order (ford) */
126
127 pr_debug("%s: Requested oversampling: %d\n", __func__, oversamp);
128 /*
129 * This function tries to compute filter oversampling and integrator
130 * oversampling, base on oversampling ratio requested by user.
131 *
132 * Decimation d depends on the filter order and the oversampling ratios.
133 * ford: filter order
134 * fosr: filter over sampling ratio
135 * iosr: integrator over sampling ratio
136 */
137 if (fl->ford == DFSDM_FASTSINC_ORDER) {
138 m = 2;
139 p = 2;
140 }
141
142 /*
143 * Look for filter and integrator oversampling ratios which allows
144 * to reach 24 bits data output resolution.
145 * Leave as soon as if exact resolution if reached.
146 * Otherwise the higher resolution below 32 bits is kept.
147 */
148 for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) {
149 for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) {
150 if (fast)
151 d = fosr * iosr;
152 else if (fl->ford == DFSDM_FASTSINC_ORDER)
153 d = fosr * (iosr + 3) + 2;
154 else
155 d = fosr * (iosr - 1 + p) + p;
156
157 if (d > oversamp)
158 break;
159 else if (d != oversamp)
160 continue;
161 /*
162 * Check resolution (limited to signed 32 bits)
163 * res <= 2^31
164 * Sincx filters:
165 * res = m * fosr^p x iosr (with m=1, p=ford)
166 * FastSinc filter
167 * res = m * fosr^p x iosr (with m=2, p=2)
168 */
169 res = fosr;
170 for (i = p - 1; i > 0; i--) {
171 res = res * (u64)fosr;
172 if (res > DFSDM_MAX_RES)
173 break;
174 }
175 if (res > DFSDM_MAX_RES)
176 continue;
177 res = res * (u64)m * (u64)iosr;
178 if (res > DFSDM_MAX_RES)
179 continue;
180
181 delta = res - DFSDM_DATA_RES;
182
183 if (res >= fl->res) {
184 fl->res = res;
185 fl->fosr = fosr;
186 fl->iosr = iosr;
187 fl->fast = fast;
188 pr_debug("%s: fosr = %d, iosr = %d\n",
189 __func__, fl->fosr, fl->iosr);
190 }
191
192 if (!delta)
193 return 0;
194 }
195 }
196
197 if (!fl->fosr)
198 return -EINVAL;
199
200 return 0;
201}
202
203static int stm32_dfsdm_start_channel(struct stm32_dfsdm *dfsdm,
204 unsigned int ch_id)
205{
206 return regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id),
207 DFSDM_CHCFGR1_CHEN_MASK,
208 DFSDM_CHCFGR1_CHEN(1));
209}
210
211static void stm32_dfsdm_stop_channel(struct stm32_dfsdm *dfsdm,
212 unsigned int ch_id)
213{
214 regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id),
215 DFSDM_CHCFGR1_CHEN_MASK, DFSDM_CHCFGR1_CHEN(0));
216}
217
218static int stm32_dfsdm_chan_configure(struct stm32_dfsdm *dfsdm,
219 struct stm32_dfsdm_channel *ch)
220{
221 unsigned int id = ch->id;
222 struct regmap *regmap = dfsdm->regmap;
223 int ret;
224
225 ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
226 DFSDM_CHCFGR1_SITP_MASK,
227 DFSDM_CHCFGR1_SITP(ch->type));
228 if (ret < 0)
229 return ret;
230 ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
231 DFSDM_CHCFGR1_SPICKSEL_MASK,
232 DFSDM_CHCFGR1_SPICKSEL(ch->src));
233 if (ret < 0)
234 return ret;
235 return regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
236 DFSDM_CHCFGR1_CHINSEL_MASK,
237 DFSDM_CHCFGR1_CHINSEL(ch->alt_si));
238}
239
240static int stm32_dfsdm_start_filter(struct stm32_dfsdm *dfsdm,
241 unsigned int fl_id)
242{
243 int ret;
244
245 /* Enable filter */
246 ret = regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
247 DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(1));
248 if (ret < 0)
249 return ret;
250
251 /* Start conversion */
252 return regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
253 DFSDM_CR1_RSWSTART_MASK,
254 DFSDM_CR1_RSWSTART(1));
255}
256
257static void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm, unsigned int fl_id)
258{
259 /* Disable conversion */
260 regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
261 DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(0));
262}
263
264static int stm32_dfsdm_filter_configure(struct stm32_dfsdm *dfsdm,
265 unsigned int fl_id, unsigned int ch_id)
266{
267 struct regmap *regmap = dfsdm->regmap;
268 struct stm32_dfsdm_filter *fl = &dfsdm->fl_list[fl_id];
269 int ret;
270
271 /* Average integrator oversampling */
272 ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_IOSR_MASK,
273 DFSDM_FCR_IOSR(fl->iosr - 1));
274 if (ret)
275 return ret;
276
277 /* Filter order and Oversampling */
278 ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FOSR_MASK,
279 DFSDM_FCR_FOSR(fl->fosr - 1));
280 if (ret)
281 return ret;
282
283 ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FORD_MASK,
284 DFSDM_FCR_FORD(fl->ford));
285 if (ret)
286 return ret;
287
288 /* No scan mode supported for the moment */
289 ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_RCH_MASK,
290 DFSDM_CR1_RCH(ch_id));
291 if (ret)
292 return ret;
293
294 return regmap_update_bits(regmap, DFSDM_CR1(fl_id),
295 DFSDM_CR1_RSYNC_MASK,
296 DFSDM_CR1_RSYNC(fl->sync_mode));
297}
298
299static int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
300 struct iio_dev *indio_dev,
301 struct iio_chan_spec *ch)
302{
303 struct stm32_dfsdm_channel *df_ch;
304 const char *of_str;
305 int chan_idx = ch->scan_index;
306 int ret, val;
307
308 ret = of_property_read_u32_index(indio_dev->dev.of_node,
309 "st,adc-channels", chan_idx,
310 &ch->channel);
311 if (ret < 0) {
312 dev_err(&indio_dev->dev,
313 " Error parsing 'st,adc-channels' for idx %d\n",
314 chan_idx);
315 return ret;
316 }
317 if (ch->channel >= dfsdm->num_chs) {
318 dev_err(&indio_dev->dev,
319 " Error bad channel number %d (max = %d)\n",
320 ch->channel, dfsdm->num_chs);
321 return -EINVAL;
322 }
323
324 ret = of_property_read_string_index(indio_dev->dev.of_node,
325 "st,adc-channel-names", chan_idx,
326 &ch->datasheet_name);
327 if (ret < 0) {
328 dev_err(&indio_dev->dev,
329 " Error parsing 'st,adc-channel-names' for idx %d\n",
330 chan_idx);
331 return ret;
332 }
333
334 df_ch = &dfsdm->ch_list[ch->channel];
335 df_ch->id = ch->channel;
336
337 ret = of_property_read_string_index(indio_dev->dev.of_node,
338 "st,adc-channel-types", chan_idx,
339 &of_str);
340 if (!ret) {
341 val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_type);
342 if (val < 0)
343 return val;
344 } else {
345 val = 0;
346 }
347 df_ch->type = val;
348
349 ret = of_property_read_string_index(indio_dev->dev.of_node,
350 "st,adc-channel-clk-src", chan_idx,
351 &of_str);
352 if (!ret) {
353 val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_src);
354 if (val < 0)
355 return val;
356 } else {
357 val = 0;
358 }
359 df_ch->src = val;
360
361 ret = of_property_read_u32_index(indio_dev->dev.of_node,
362 "st,adc-alt-channel", chan_idx,
363 &df_ch->alt_si);
364 if (ret < 0)
365 df_ch->alt_si = 0;
366
367 return 0;
368}
369
370static ssize_t dfsdm_adc_audio_get_spiclk(struct iio_dev *indio_dev,
371 uintptr_t priv,
372 const struct iio_chan_spec *chan,
373 char *buf)
374{
375 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
376
377 return snprintf(buf, PAGE_SIZE, "%d\n", adc->spi_freq);
378}
379
380static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev,
381 uintptr_t priv,
382 const struct iio_chan_spec *chan,
383 const char *buf, size_t len)
384{
385 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
386 struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
387 struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
388 unsigned int sample_freq = adc->sample_freq;
389 unsigned int spi_freq;
390 int ret;
391
392 dev_err(&indio_dev->dev, "enter %s\n", __func__);
393 /* If DFSDM is master on SPI, SPI freq can not be updated */
394 if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
395 return -EPERM;
396
397 ret = kstrtoint(buf, 0, &spi_freq);
398 if (ret)
399 return ret;
400
401 if (!spi_freq)
402 return -EINVAL;
403
404 if (sample_freq) {
405 if (spi_freq % sample_freq)
406 dev_warn(&indio_dev->dev,
407 "Sampling rate not accurate (%d)\n",
408 spi_freq / (spi_freq / sample_freq));
409
410 ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / sample_freq));
411 if (ret < 0) {
412 dev_err(&indio_dev->dev,
413 "No filter parameters that match!\n");
414 return ret;
415 }
416 }
417 adc->spi_freq = spi_freq;
418
419 return len;
420}
421
422static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma)
423{
424 struct regmap *regmap = adc->dfsdm->regmap;
425 int ret;
426 unsigned int dma_en = 0, cont_en = 0;
427
428 ret = stm32_dfsdm_start_channel(adc->dfsdm, adc->ch_id);
429 if (ret < 0)
430 return ret;
431
432 ret = stm32_dfsdm_filter_configure(adc->dfsdm, adc->fl_id,
433 adc->ch_id);
434 if (ret < 0)
435 goto stop_channels;
436
437 if (dma) {
438 /* Enable DMA transfer*/
439 dma_en = DFSDM_CR1_RDMAEN(1);
440 /* Enable conversion triggered by SPI clock*/
441 cont_en = DFSDM_CR1_RCONT(1);
442 }
443 /* Enable DMA transfer*/
444 ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
445 DFSDM_CR1_RDMAEN_MASK, dma_en);
446 if (ret < 0)
447 goto stop_channels;
448
449 /* Enable conversion triggered by SPI clock*/
450 ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
451 DFSDM_CR1_RCONT_MASK, cont_en);
452 if (ret < 0)
453 goto stop_channels;
454
455 ret = stm32_dfsdm_start_filter(adc->dfsdm, adc->fl_id);
456 if (ret < 0)
457 goto stop_channels;
458
459 return 0;
460
461stop_channels:
462 regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
463 DFSDM_CR1_RDMAEN_MASK, 0);
464
465 regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
466 DFSDM_CR1_RCONT_MASK, 0);
467 stm32_dfsdm_stop_channel(adc->dfsdm, adc->fl_id);
468
469 return ret;
470}
471
472static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
473{
474 struct regmap *regmap = adc->dfsdm->regmap;
475
476 stm32_dfsdm_stop_filter(adc->dfsdm, adc->fl_id);
477
478 /* Clean conversion options */
479 regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
480 DFSDM_CR1_RDMAEN_MASK, 0);
481
482 regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
483 DFSDM_CR1_RCONT_MASK, 0);
484
485 stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id);
486}
487
488static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev,
489 unsigned int val)
490{
491 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
492 unsigned int watermark = DFSDM_DMA_BUFFER_SIZE / 2;
493
494 /*
495 * DMA cyclic transfers are used, buffer is split into two periods.
496 * There should be :
497 * - always one buffer (period) DMA is working on
498 * - one buffer (period) driver pushed to ASoC side.
499 */
500 watermark = min(watermark, val * (unsigned int)(sizeof(u32)));
501 adc->buf_sz = watermark * 2;
502
503 return 0;
504}
505
506static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_adc *adc)
507{
508 struct dma_tx_state state;
509 enum dma_status status;
510
511 status = dmaengine_tx_status(adc->dma_chan,
512 adc->dma_chan->cookie,
513 &state);
514 if (status == DMA_IN_PROGRESS) {
515 /* Residue is size in bytes from end of buffer */
516 unsigned int i = adc->buf_sz - state.residue;
517 unsigned int size;
518
519 /* Return available bytes */
520 if (i >= adc->bufi)
521 size = i - adc->bufi;
522 else
523 size = adc->buf_sz + i - adc->bufi;
524
525 return size;
526 }
527
528 return 0;
529}
530
531static void stm32_dfsdm_audio_dma_buffer_done(void *data)
532{
533 struct iio_dev *indio_dev = data;
534 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
535 int available = stm32_dfsdm_adc_dma_residue(adc);
536 size_t old_pos;
537
538 /*
539 * FIXME: In Kernel interface does not support cyclic DMA buffer,and
540 * offers only an interface to push data samples per samples.
541 * For this reason IIO buffer interface is not used and interface is
542 * bypassed using a private callback registered by ASoC.
543 * This should be a temporary solution waiting a cyclic DMA engine
544 * support in IIO.
545 */
546
547 dev_dbg(&indio_dev->dev, "%s: pos = %d, available = %d\n", __func__,
548 adc->bufi, available);
549 old_pos = adc->bufi;
550
551 while (available >= indio_dev->scan_bytes) {
552 u32 *buffer = (u32 *)&adc->rx_buf[adc->bufi];
553
554 /* Mask 8 LSB that contains the channel ID */
555 *buffer = (*buffer & 0xFFFFFF00) << 8;
556 available -= indio_dev->scan_bytes;
557 adc->bufi += indio_dev->scan_bytes;
558 if (adc->bufi >= adc->buf_sz) {
559 if (adc->cb)
560 adc->cb(&adc->rx_buf[old_pos],
561 adc->buf_sz - old_pos, adc->cb_priv);
562 adc->bufi = 0;
563 old_pos = 0;
564 }
565 }
566 if (adc->cb)
567 adc->cb(&adc->rx_buf[old_pos], adc->bufi - old_pos,
568 adc->cb_priv);
569}
570
571static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
572{
573 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
574 struct dma_async_tx_descriptor *desc;
575 dma_cookie_t cookie;
576 int ret;
577
578 if (!adc->dma_chan)
579 return -EINVAL;
580
581 dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
582 adc->buf_sz, adc->buf_sz / 2);
583
584 /* Prepare a DMA cyclic transaction */
585 desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
586 adc->dma_buf,
587 adc->buf_sz, adc->buf_sz / 2,
588 DMA_DEV_TO_MEM,
589 DMA_PREP_INTERRUPT);
590 if (!desc)
591 return -EBUSY;
592
593 desc->callback = stm32_dfsdm_audio_dma_buffer_done;
594 desc->callback_param = indio_dev;
595
596 cookie = dmaengine_submit(desc);
597 ret = dma_submit_error(cookie);
598 if (ret) {
599 dmaengine_terminate_all(adc->dma_chan);
600 return ret;
601 }
602
603 /* Issue pending DMA requests */
604 dma_async_issue_pending(adc->dma_chan);
605
606 return 0;
607}
608
609static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
610{
611 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
612 int ret;
613
614 /* Reset adc buffer index */
615 adc->bufi = 0;
616
617 ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
618 if (ret < 0)
619 return ret;
620
621 ret = stm32_dfsdm_start_conv(adc, true);
622 if (ret) {
623 dev_err(&indio_dev->dev, "Can't start conversion\n");
624 goto stop_dfsdm;
625 }
626
627 if (adc->dma_chan) {
628 ret = stm32_dfsdm_adc_dma_start(indio_dev);
629 if (ret) {
630 dev_err(&indio_dev->dev, "Can't start DMA\n");
631 goto err_stop_conv;
632 }
633 }
634
635 return 0;
636
637err_stop_conv:
638 stm32_dfsdm_stop_conv(adc);
639stop_dfsdm:
640 stm32_dfsdm_stop_dfsdm(adc->dfsdm);
641
642 return ret;
643}
644
645static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)
646{
647 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
648
649 if (adc->dma_chan)
650 dmaengine_terminate_all(adc->dma_chan);
651
652 stm32_dfsdm_stop_conv(adc);
653
654 stm32_dfsdm_stop_dfsdm(adc->dfsdm);
655
656 return 0;
657}
658
659static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = {
660 .postenable = &stm32_dfsdm_postenable,
661 .predisable = &stm32_dfsdm_predisable,
662};
663
664/**
665 * stm32_dfsdm_get_buff_cb() - register a callback that will be called when
666 * DMA transfer period is achieved.
667 *
668 * @iio_dev: Handle to IIO device.
669 * @cb: Pointer to callback function:
670 * - data: pointer to data buffer
671 * - size: size in byte of the data buffer
672 * - private: pointer to consumer private structure.
673 * @private: Pointer to consumer private structure.
674 */
675int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev,
676 int (*cb)(const void *data, size_t size,
677 void *private),
678 void *private)
679{
680 struct stm32_dfsdm_adc *adc;
681
682 if (!iio_dev)
683 return -EINVAL;
684 adc = iio_priv(iio_dev);
685
686 adc->cb = cb;
687 adc->cb_priv = private;
688
689 return 0;
690}
691EXPORT_SYMBOL_GPL(stm32_dfsdm_get_buff_cb);
692
693/**
694 * stm32_dfsdm_release_buff_cb - unregister buffer callback
695 *
696 * @iio_dev: Handle to IIO device.
697 */
698int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev)
699{
700 struct stm32_dfsdm_adc *adc;
701
702 if (!iio_dev)
703 return -EINVAL;
704 adc = iio_priv(iio_dev);
705
706 adc->cb = NULL;
707 adc->cb_priv = NULL;
708
709 return 0;
710}
711EXPORT_SYMBOL_GPL(stm32_dfsdm_release_buff_cb);
712
713static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
714 const struct iio_chan_spec *chan, int *res)
715{
716 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
717 long timeout;
718 int ret;
719
720 reinit_completion(&adc->completion);
721
722 adc->buffer = res;
723
724 ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
725 if (ret < 0)
726 return ret;
727
728 ret = regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
729 DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(1));
730 if (ret < 0)
731 goto stop_dfsdm;
732
733 ret = stm32_dfsdm_start_conv(adc, false);
734 if (ret < 0) {
735 regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
736 DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
737 goto stop_dfsdm;
738 }
739
740 timeout = wait_for_completion_interruptible_timeout(&adc->completion,
741 DFSDM_TIMEOUT);
742
743 /* Mask IRQ for regular conversion achievement*/
744 regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
745 DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
746
747 if (timeout == 0)
748 ret = -ETIMEDOUT;
749 else if (timeout < 0)
750 ret = timeout;
751 else
752 ret = IIO_VAL_INT;
753
754 stm32_dfsdm_stop_conv(adc);
755
756stop_dfsdm:
757 stm32_dfsdm_stop_dfsdm(adc->dfsdm);
758
759 return ret;
760}
761
762static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev,
763 struct iio_chan_spec const *chan,
764 int val, int val2, long mask)
765{
766 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
767 struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
768 struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[adc->ch_id];
769 unsigned int spi_freq = adc->spi_freq;
770 int ret = -EINVAL;
771
772 switch (mask) {
773 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
774 ret = stm32_dfsdm_set_osrs(fl, 0, val);
775 if (!ret)
776 adc->oversamp = val;
777
778 return ret;
779
780 case IIO_CHAN_INFO_SAMP_FREQ:
781 if (!val)
782 return -EINVAL;
783 if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
784 spi_freq = adc->dfsdm->spi_master_freq;
785
786 if (spi_freq % val)
787 dev_warn(&indio_dev->dev,
788 "Sampling rate not accurate (%d)\n",
789 spi_freq / (spi_freq / val));
790
791 ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / val));
792 if (ret < 0) {
793 dev_err(&indio_dev->dev,
794 "Not able to find parameter that match!\n");
795 return ret;
796 }
797 adc->sample_freq = val;
798
799 return 0;
800 }
801
802 return -EINVAL;
803}
804
805static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
806 struct iio_chan_spec const *chan, int *val,
807 int *val2, long mask)
808{
809 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
810 int ret;
811
812 switch (mask) {
813 case IIO_CHAN_INFO_RAW:
814 ret = iio_hw_consumer_enable(adc->hwc);
815 if (ret < 0) {
816 dev_err(&indio_dev->dev,
817 "%s: IIO enable failed (channel %d)\n",
818 __func__, chan->channel);
819 return ret;
820 }
821 ret = stm32_dfsdm_single_conv(indio_dev, chan, val);
822 iio_hw_consumer_disable(adc->hwc);
823 if (ret < 0) {
824 dev_err(&indio_dev->dev,
825 "%s: Conversion failed (channel %d)\n",
826 __func__, chan->channel);
827 return ret;
828 }
829 return IIO_VAL_INT;
830
831 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
832 *val = adc->oversamp;
833
834 return IIO_VAL_INT;
835
836 case IIO_CHAN_INFO_SAMP_FREQ:
837 *val = adc->sample_freq;
838
839 return IIO_VAL_INT;
840 }
841
842 return -EINVAL;
843}
844
845static const struct iio_info stm32_dfsdm_info_audio = {
846 .hwfifo_set_watermark = stm32_dfsdm_set_watermark,
847 .read_raw = stm32_dfsdm_read_raw,
848 .write_raw = stm32_dfsdm_write_raw,
849};
850
851static const struct iio_info stm32_dfsdm_info_adc = {
852 .read_raw = stm32_dfsdm_read_raw,
853 .write_raw = stm32_dfsdm_write_raw,
854};
855
856static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
857{
858 struct stm32_dfsdm_adc *adc = arg;
859 struct iio_dev *indio_dev = iio_priv_to_dev(adc);
860 struct regmap *regmap = adc->dfsdm->regmap;
861 unsigned int status, int_en;
862
863 regmap_read(regmap, DFSDM_ISR(adc->fl_id), &status);
864 regmap_read(regmap, DFSDM_CR2(adc->fl_id), &int_en);
865
866 if (status & DFSDM_ISR_REOCF_MASK) {
867 /* Read the data register clean the IRQ status */
868 regmap_read(regmap, DFSDM_RDATAR(adc->fl_id), adc->buffer);
869 complete(&adc->completion);
870 }
871
872 if (status & DFSDM_ISR_ROVRF_MASK) {
873 if (int_en & DFSDM_CR2_ROVRIE_MASK)
874 dev_warn(&indio_dev->dev, "Overrun detected\n");
875 regmap_update_bits(regmap, DFSDM_ICR(adc->fl_id),
876 DFSDM_ICR_CLRROVRF_MASK,
877 DFSDM_ICR_CLRROVRF_MASK);
878 }
879
880 return IRQ_HANDLED;
881}
882
883/*
884 * Define external info for SPI Frequency and audio sampling rate that can be
885 * configured by ASoC driver through consumer.h API
886 */
887static const struct iio_chan_spec_ext_info dfsdm_adc_audio_ext_info[] = {
888 /* spi_clk_freq : clock freq on SPI/manchester bus used by channel */
889 {
890 .name = "spi_clk_freq",
891 .shared = IIO_SHARED_BY_TYPE,
892 .read = dfsdm_adc_audio_get_spiclk,
893 .write = dfsdm_adc_audio_set_spiclk,
894 },
895 {},
896};
897
898static void stm32_dfsdm_dma_release(struct iio_dev *indio_dev)
899{
900 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
901
902 if (adc->dma_chan) {
903 dma_free_coherent(adc->dma_chan->device->dev,
904 DFSDM_DMA_BUFFER_SIZE,
905 adc->rx_buf, adc->dma_buf);
906 dma_release_channel(adc->dma_chan);
907 }
908}
909
910static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev)
911{
912 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
913 struct dma_slave_config config = {
914 .src_addr = (dma_addr_t)adc->dfsdm->phys_base +
915 DFSDM_RDATAR(adc->fl_id),
916 .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
917 };
918 int ret;
919
920 adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx");
921 if (!adc->dma_chan)
922 return -EINVAL;
923
924 adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
925 DFSDM_DMA_BUFFER_SIZE,
926 &adc->dma_buf, GFP_KERNEL);
927 if (!adc->rx_buf) {
928 ret = -ENOMEM;
929 goto err_release;
930 }
931
932 ret = dmaengine_slave_config(adc->dma_chan, &config);
933 if (ret)
934 goto err_free;
935
936 return 0;
937
938err_free:
939 dma_free_coherent(adc->dma_chan->device->dev, DFSDM_DMA_BUFFER_SIZE,
940 adc->rx_buf, adc->dma_buf);
941err_release:
942 dma_release_channel(adc->dma_chan);
943
944 return ret;
945}
946
947static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
948 struct iio_chan_spec *ch)
949{
950 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
951 int ret;
952
953 ret = stm32_dfsdm_channel_parse_of(adc->dfsdm, indio_dev, ch);
954 if (ret < 0)
955 return ret;
956
957 ch->type = IIO_VOLTAGE;
958 ch->indexed = 1;
959
960 /*
961 * IIO_CHAN_INFO_RAW: used to compute regular conversion
962 * IIO_CHAN_INFO_OVERSAMPLING_RATIO: used to set oversampling
963 */
964 ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
965 ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO);
966
967 if (adc->dev_data->type == DFSDM_AUDIO) {
968 ch->scan_type.sign = 's';
969 ch->ext_info = dfsdm_adc_audio_ext_info;
970 } else {
971 ch->scan_type.sign = 'u';
972 }
973 ch->scan_type.realbits = 24;
974 ch->scan_type.storagebits = 32;
975 adc->ch_id = ch->channel;
976
977 return stm32_dfsdm_chan_configure(adc->dfsdm,
978 &adc->dfsdm->ch_list[ch->channel]);
979}
980
981static int stm32_dfsdm_audio_init(struct iio_dev *indio_dev)
982{
983 struct iio_chan_spec *ch;
984 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
985 struct stm32_dfsdm_channel *d_ch;
986 int ret;
987
988 indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
989 indio_dev->setup_ops = &stm32_dfsdm_buffer_setup_ops;
990
991 ch = devm_kzalloc(&indio_dev->dev, sizeof(*ch), GFP_KERNEL);
992 if (!ch)
993 return -ENOMEM;
994
995 ch->scan_index = 0;
996
997 ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
998 if (ret < 0) {
999 dev_err(&indio_dev->dev, "Channels init failed\n");
1000 return ret;
1001 }
1002 ch->info_mask_separate = BIT(IIO_CHAN_INFO_SAMP_FREQ);
1003
1004 d_ch = &adc->dfsdm->ch_list[adc->ch_id];
1005 if (d_ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
1006 adc->spi_freq = adc->dfsdm->spi_master_freq;
1007
1008 indio_dev->num_channels = 1;
1009 indio_dev->channels = ch;
1010
1011 return stm32_dfsdm_dma_request(indio_dev);
1012}
1013
1014static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
1015{
1016 struct iio_chan_spec *ch;
1017 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1018 int num_ch;
1019 int ret, chan_idx;
1020
1021 adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING;
1022 ret = stm32_dfsdm_set_osrs(&adc->dfsdm->fl_list[adc->fl_id], 0,
1023 adc->oversamp);
1024 if (ret < 0)
1025 return ret;
1026
1027 num_ch = of_property_count_u32_elems(indio_dev->dev.of_node,
1028 "st,adc-channels");
1029 if (num_ch < 0 || num_ch > adc->dfsdm->num_chs) {
1030 dev_err(&indio_dev->dev, "Bad st,adc-channels\n");
1031 return num_ch < 0 ? num_ch : -EINVAL;
1032 }
1033
1034 /* Bind to SD modulator IIO device */
1035 adc->hwc = devm_iio_hw_consumer_alloc(&indio_dev->dev);
1036 if (IS_ERR(adc->hwc))
1037 return -EPROBE_DEFER;
1038
1039 ch = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*ch),
1040 GFP_KERNEL);
1041 if (!ch)
1042 return -ENOMEM;
1043
1044 for (chan_idx = 0; chan_idx < num_ch; chan_idx++) {
1045 ch->scan_index = chan_idx;
1046 ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
1047 if (ret < 0) {
1048 dev_err(&indio_dev->dev, "Channels init failed\n");
1049 return ret;
1050 }
1051 }
1052
1053 indio_dev->num_channels = num_ch;
1054 indio_dev->channels = ch;
1055
1056 init_completion(&adc->completion);
1057
1058 return 0;
1059}
1060
1061static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_adc_data = {
1062 .type = DFSDM_IIO,
1063 .init = stm32_dfsdm_adc_init,
1064};
1065
1066static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_audio_data = {
1067 .type = DFSDM_AUDIO,
1068 .init = stm32_dfsdm_audio_init,
1069};
1070
1071static const struct of_device_id stm32_dfsdm_adc_match[] = {
1072 {
1073 .compatible = "st,stm32-dfsdm-adc",
1074 .data = &stm32h7_dfsdm_adc_data,
1075 },
1076 {
1077 .compatible = "st,stm32-dfsdm-dmic",
1078 .data = &stm32h7_dfsdm_audio_data,
1079 },
1080 {}
1081};
1082
1083static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
1084{
1085 struct device *dev = &pdev->dev;
1086 struct stm32_dfsdm_adc *adc;
1087 struct device_node *np = dev->of_node;
1088 const struct stm32_dfsdm_dev_data *dev_data;
1089 struct iio_dev *iio;
1090 char *name;
1091 int ret, irq, val;
1092
1093
1094 dev_data = of_device_get_match_data(dev);
1095 iio = devm_iio_device_alloc(dev, sizeof(*adc));
1096 if (!iio) {
1097 dev_err(dev, "%s: Failed to allocate IIO\n", __func__);
1098 return -ENOMEM;
1099 }
1100
1101 adc = iio_priv(iio);
1102 adc->dfsdm = dev_get_drvdata(dev->parent);
1103
1104 iio->dev.parent = dev;
1105 iio->dev.of_node = np;
1106 iio->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
1107
1108 platform_set_drvdata(pdev, adc);
1109
1110 ret = of_property_read_u32(dev->of_node, "reg", &adc->fl_id);
1111 if (ret != 0) {
1112 dev_err(dev, "Missing reg property\n");
1113 return -EINVAL;
1114 }
1115
1116 name = devm_kzalloc(dev, sizeof("dfsdm-adc0"), GFP_KERNEL);
1117 if (!name)
1118 return -ENOMEM;
1119 if (dev_data->type == DFSDM_AUDIO) {
1120 iio->info = &stm32_dfsdm_info_audio;
1121 snprintf(name, sizeof("dfsdm-pdm0"), "dfsdm-pdm%d", adc->fl_id);
1122 } else {
1123 iio->info = &stm32_dfsdm_info_adc;
1124 snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id);
1125 }
1126 iio->name = name;
1127
1128 /*
1129 * In a first step IRQs generated for channels are not treated.
1130 * So IRQ associated to filter instance 0 is dedicated to the Filter 0.
1131 */
1132 irq = platform_get_irq(pdev, 0);
1133 ret = devm_request_irq(dev, irq, stm32_dfsdm_irq,
1134 0, pdev->name, adc);
1135 if (ret < 0) {
1136 dev_err(dev, "Failed to request IRQ\n");
1137 return ret;
1138 }
1139
1140 ret = of_property_read_u32(dev->of_node, "st,filter-order", &val);
1141 if (ret < 0) {
1142 dev_err(dev, "Failed to set filter order\n");
1143 return ret;
1144 }
1145
1146 adc->dfsdm->fl_list[adc->fl_id].ford = val;
1147
1148 ret = of_property_read_u32(dev->of_node, "st,filter0-sync", &val);
1149 if (!ret)
1150 adc->dfsdm->fl_list[adc->fl_id].sync_mode = val;
1151
1152 adc->dev_data = dev_data;
1153 ret = dev_data->init(iio);
1154 if (ret < 0)
1155 return ret;
1156
1157 ret = iio_device_register(iio);
1158 if (ret < 0)
1159 goto err_cleanup;
1160
1161 dev_err(dev, "of_platform_populate\n");
1162 if (dev_data->type == DFSDM_AUDIO) {
1163 ret = of_platform_populate(np, NULL, NULL, dev);
1164 if (ret < 0) {
1165 dev_err(dev, "Failed to find an audio DAI\n");
1166 goto err_unregister;
1167 }
1168 }
1169
1170 return 0;
1171
1172err_unregister:
1173 iio_device_unregister(iio);
1174err_cleanup:
1175 stm32_dfsdm_dma_release(iio);
1176
1177 return ret;
1178}
1179
1180static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
1181{
1182 struct stm32_dfsdm_adc *adc = platform_get_drvdata(pdev);
1183 struct iio_dev *indio_dev = iio_priv_to_dev(adc);
1184
1185 if (adc->dev_data->type == DFSDM_AUDIO)
1186 of_platform_depopulate(&pdev->dev);
1187 iio_device_unregister(indio_dev);
1188 stm32_dfsdm_dma_release(indio_dev);
1189
1190 return 0;
1191}
1192
1193static struct platform_driver stm32_dfsdm_adc_driver = {
1194 .driver = {
1195 .name = "stm32-dfsdm-adc",
1196 .of_match_table = stm32_dfsdm_adc_match,
1197 },
1198 .probe = stm32_dfsdm_adc_probe,
1199 .remove = stm32_dfsdm_adc_remove,
1200};
1201module_platform_driver(stm32_dfsdm_adc_driver);
1202
1203MODULE_DESCRIPTION("STM32 sigma delta ADC");
1204MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
1205MODULE_LICENSE("GPL v2");
generated by cgit v1.2.2 (git 2.25.0) at 2025-09-02 16:33:03 -0400