drivers/iio/adc/stm32-dfsdm-adc.c

   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/iio/adc/stm32-dfsdm-adc.h>
  12 #include <linux/iio/buffer.h>
  13 #include <linux/iio/hw-consumer.h>
  14 #include <linux/iio/sysfs.h>
  15 #include <linux/iio/timer/stm32-lptim-trigger.h>
  16 #include <linux/iio/timer/stm32-timer-trigger.h>
  17 #include <linux/iio/trigger.h>
  18 #include <linux/iio/trigger_consumer.h>
  19 #include <linux/iio/triggered_buffer.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/module.h>
  22 #include <linux/of.h>
  23 #include <linux/of_platform.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/regmap.h>
  26 #include <linux/slab.h>
  27
  28 #include "stm32-dfsdm.h"
  29
  30 #define DFSDM_DMA_BUFFER_SIZE (4 * PAGE_SIZE)
  31
  32 /* Conversion timeout */
  33 #define DFSDM_TIMEOUT_US 100000
  34 #define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000))
  35
  36 /* Oversampling attribute default */
  37 #define DFSDM_DEFAULT_OVERSAMPLING  100
  38
  39 /* Oversampling max values */
  40 #define DFSDM_MAX_INT_OVERSAMPLING 256
  41 #define DFSDM_MAX_FL_OVERSAMPLING 1024
  42
  43 /* Limit filter output resolution to 31 bits. (i.e. sample range is +/-2^30) */
  44 #define DFSDM_DATA_MAX BIT(30)
  45 /*
  46  * Data are output as two's complement data in a 24 bit field.
  47  * Data from filters are in the range +/-2^(n-1)
  48  * 2^(n-1) maximum positive value cannot be coded in 2's complement n bits
  49  * An extra bit is required to avoid wrap-around of the binary code for 2^(n-1)
  50  * So, the resolution of samples from filter is actually limited to 23 bits
  51  */
  52 #define DFSDM_DATA_RES 24
  53
  54 /* Filter configuration */
  55 #define DFSDM_CR1_CFG_MASK (DFSDM_CR1_RCH_MASK | DFSDM_CR1_RCONT_MASK | \
  56                             DFSDM_CR1_RSYNC_MASK | DFSDM_CR1_JSYNC_MASK | \
  57                             DFSDM_CR1_JSCAN_MASK)
  58
  59 enum sd_converter_type {
  60         DFSDM_AUDIO,
  61         DFSDM_IIO,
  62 };
  63
  64 struct stm32_dfsdm_dev_data {
  65         int type;
  66         int (*init)(struct device *dev, struct iio_dev *indio_dev);
  67         unsigned int num_channels;
  68         const struct regmap_config *regmap_cfg;
  69 };
  70
  71 struct stm32_dfsdm_adc {
  72         struct stm32_dfsdm *dfsdm;
  73         const struct stm32_dfsdm_dev_data *dev_data;
  74         unsigned int fl_id;
  75         unsigned int nconv;
  76         unsigned long smask;
  77
  78         /* ADC specific */
  79         unsigned int oversamp;
  80         struct iio_hw_consumer *hwc;
  81         struct completion completion;
  82         u32 *buffer;
  83
  84         /* Audio specific */
  85         unsigned int spi_freq;  /* SPI bus clock frequency */
  86         unsigned int sample_freq; /* Sample frequency after filter decimation */
  87         int (*cb)(const void *data, size_t size, void *cb_priv);
  88         void *cb_priv;
  89
  90         /* DMA */
  91         u8 *rx_buf;
  92         unsigned int bufi; /* Buffer current position */
  93         unsigned int buf_sz; /* Buffer size */
  94         struct dma_chan *dma_chan;
  95         dma_addr_t dma_buf;
  96 };
  97
  98 struct stm32_dfsdm_str2field {
  99         const char      *name;
 100         unsigned int    val;
 101 };
 102
 103 /* DFSDM channel serial interface type */
 104 static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_type[] = {
 105         { "SPI_R", 0 }, /* SPI with data on rising edge */
 106         { "SPI_F", 1 }, /* SPI with data on falling edge */
 107         { "MANCH_R", 2 }, /* Manchester codec, rising edge = logic 0 */
 108         { "MANCH_F", 3 }, /* Manchester codec, falling edge = logic 1 */
 109         {},
 110 };
 111
 112 /* DFSDM channel clock source */
 113 static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_src[] = {
 114         /* External SPI clock (CLKIN x) */
 115         { "CLKIN", DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL },
 116         /* Internal SPI clock (CLKOUT) */
 117         { "CLKOUT", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL },
 118         /* Internal SPI clock divided by 2 (falling edge) */
 119         { "CLKOUT_F", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING },
 120         /* Internal SPI clock divided by 2 (falling edge) */
 121         { "CLKOUT_R", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING },
 122         {},
 123 };
 124
 125 static int stm32_dfsdm_str2val(const char *str,
 126                                const struct stm32_dfsdm_str2field *list)
 127 {
 128         const struct stm32_dfsdm_str2field *p = list;
 129
 130         for (p = list; p && p->name; p++)
 131                 if (!strcmp(p->name, str))
 132                         return p->val;
 133
 134         return -EINVAL;
 135 }
 136
 137 /**
 138  * struct stm32_dfsdm_trig_info - DFSDM trigger info
 139  * @name:               name of the trigger, corresponding to its source
 140  * @jextsel:            trigger signal selection
 141  */
 142 struct stm32_dfsdm_trig_info {
 143         const char *name;
 144         unsigned int jextsel;
 145 };
 146
 147 /* hardware injected trigger enable, edge selection */
 148 enum stm32_dfsdm_jexten {
 149         STM32_DFSDM_JEXTEN_DISABLED,
 150         STM32_DFSDM_JEXTEN_RISING_EDGE,
 151         STM32_DFSDM_JEXTEN_FALLING_EDGE,
 152         STM32_DFSDM_EXTEN_BOTH_EDGES,
 153 };
 154
 155 static const struct stm32_dfsdm_trig_info stm32_dfsdm_trigs[] = {
 156         { TIM1_TRGO, 0 },
 157         { TIM1_TRGO2, 1 },
 158         { TIM8_TRGO, 2 },
 159         { TIM8_TRGO2, 3 },
 160         { TIM3_TRGO, 4 },
 161         { TIM4_TRGO, 5 },
 162         { TIM16_OC1, 6 },
 163         { TIM6_TRGO, 7 },
 164         { TIM7_TRGO, 8 },
 165         { LPTIM1_OUT, 26 },
 166         { LPTIM2_OUT, 27 },
 167         { LPTIM3_OUT, 28 },
 168         {},
 169 };
 170
 171 static int stm32_dfsdm_get_jextsel(struct iio_dev *indio_dev,
 172                                    struct iio_trigger *trig)
 173 {
 174         int i;
 175
 176         /* lookup triggers registered by stm32 timer trigger driver */
 177         for (i = 0; stm32_dfsdm_trigs[i].name; i++) {
 178                 /**
 179                  * Checking both stm32 timer trigger type and trig name
 180                  * should be safe against arbitrary trigger names.
 181                  */
 182                 if ((is_stm32_timer_trigger(trig) ||
 183                      is_stm32_lptim_trigger(trig)) &&
 184                     !strcmp(stm32_dfsdm_trigs[i].name, trig->name)) {
 185                         return stm32_dfsdm_trigs[i].jextsel;
 186                 }
 187         }
 188
 189         return -EINVAL;
 190 }
 191
 192 static int stm32_dfsdm_compute_osrs(struct stm32_dfsdm_filter *fl,
 193                                     unsigned int fast, unsigned int oversamp)
 194 {
 195         unsigned int i, d, fosr, iosr;
 196         u64 res, max;
 197         int bits, shift;
 198         unsigned int m = 1;     /* multiplication factor */
 199         unsigned int p = fl->ford;      /* filter order (ford) */
 200         struct stm32_dfsdm_filter_osr *flo = &fl->flo[fast];
 201
 202         pr_debug("Requested oversampling: %d\n", oversamp);
 203         /*
 204          * This function tries to compute filter oversampling and integrator
 205          * oversampling, base on oversampling ratio requested by user.
 206          *
 207          * Decimation d depends on the filter order and the oversampling ratios.
 208          * ford: filter order
 209          * fosr: filter over sampling ratio
 210          * iosr: integrator over sampling ratio
 211          */
 212         if (fl->ford == DFSDM_FASTSINC_ORDER) {
 213                 m = 2;
 214                 p = 2;
 215         }
 216
 217         /*
 218          * Look for filter and integrator oversampling ratios which allows
 219          * to maximize data output resolution.
 220          */
 221         for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) {
 222                 for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) {
 223                         if (fast)
 224                                 d = fosr * iosr;
 225                         else if (fl->ford == DFSDM_FASTSINC_ORDER)
 226                                 d = fosr * (iosr + 3) + 2;
 227                         else
 228                                 d = fosr * (iosr - 1 + p) + p;
 229
 230                         if (d > oversamp)
 231                                 break;
 232                         else if (d != oversamp)
 233                                 continue;
 234                         /*
 235                          * Check resolution (limited to signed 32 bits)
 236                          *   res <= 2^31
 237                          * Sincx filters:
 238                          *   res = m * fosr^p x iosr (with m=1, p=ford)
 239                          * FastSinc filter
 240                          *   res = m * fosr^p x iosr (with m=2, p=2)
 241                          */
 242                         res = fosr;
 243                         for (i = p - 1; i > 0; i--) {
 244                                 res = res * (u64)fosr;
 245                                 if (res > DFSDM_DATA_MAX)
 246                                         break;
 247                         }
 248                         if (res > DFSDM_DATA_MAX)
 249                                 continue;
 250
 251                         res = res * (u64)m * (u64)iosr;
 252                         if (res > DFSDM_DATA_MAX)
 253                                 continue;
 254
 255                         if (res >= flo->res) {
 256                                 flo->res = res;
 257                                 flo->fosr = fosr;
 258                                 flo->iosr = iosr;
 259
 260                                 bits = fls(flo->res);
 261                                 /* 8 LBSs in data register contain chan info */
 262                                 max = flo->res << 8;
 263
 264                                 /* if resolution is not a power of two */
 265                                 if (flo->res > BIT(bits - 1))
 266                                         bits++;
 267                                 else
 268                                         max--;
 269
 270                                 shift = DFSDM_DATA_RES - bits;
 271                                 /*
 272                                  * Compute right/left shift
 273                                  * Right shift is performed by hardware
 274                                  * when transferring samples to data register.
 275                                  * Left shift is done by software on buffer
 276                                  */
 277                                 if (shift > 0) {
 278                                         /* Resolution is lower than 24 bits */
 279                                         flo->rshift = 0;
 280                                         flo->lshift = shift;
 281                                 } else {
 282                                         /*
 283                                          * If resolution is 24 bits or more,
 284                                          * max positive value may be ambiguous
 285                                          * (equal to max negative value as sign
 286                                          * bit is dropped).
 287                                          * Reduce resolution to 23 bits (rshift)
 288                                          * to keep the sign on bit 23 and treat
 289                                          * saturation before rescaling on 24
 290                                          * bits (lshift).
 291                                          */
 292                                         flo->rshift = 1 - shift;
 293                                         flo->lshift = 1;
 294                                         max >>= flo->rshift;
 295                                 }
 296                                 flo->max = (s32)max;
 297                                 flo->bits = bits;
 298
 299                                 pr_debug("fast %d, fosr %d, iosr %d, res 0x%llx/%d bits, rshift %d, lshift %d\n",
 300                                          fast, flo->fosr, flo->iosr,
 301                                          flo->res, bits, flo->rshift,
 302                                          flo->lshift);
 303                         }
 304                 }
 305         }
 306
 307         if (!flo->res)
 308                 return -EINVAL;
 309
 310         return 0;
 311 }
 312
 313 static int stm32_dfsdm_compute_all_osrs(struct iio_dev *indio_dev,
 314                                         unsigned int oversamp)
 315 {
 316         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 317         struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
 318         int ret0, ret1;
 319
 320         memset(&fl->flo[0], 0, sizeof(fl->flo[0]));
 321         memset(&fl->flo[1], 0, sizeof(fl->flo[1]));
 322
 323         ret0 = stm32_dfsdm_compute_osrs(fl, 0, oversamp);
 324         ret1 = stm32_dfsdm_compute_osrs(fl, 1, oversamp);
 325         if (ret0 < 0 && ret1 < 0) {
 326                 dev_err(&indio_dev->dev,
 327                         "Filter parameters not found: errors %d/%d\n",
 328                         ret0, ret1);
 329                 return -EINVAL;
 330         }
 331
 332         return 0;
 333 }
 334
 335 static int stm32_dfsdm_start_channel(struct iio_dev *indio_dev)
 336 {
 337         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 338         struct regmap *regmap = adc->dfsdm->regmap;
 339         const struct iio_chan_spec *chan;
 340         unsigned int bit;
 341         int ret;
 342
 343         for_each_set_bit(bit, &adc->smask, sizeof(adc->smask) * BITS_PER_BYTE) {
 344                 chan = indio_dev->channels + bit;
 345                 ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(chan->channel),
 346                                          DFSDM_CHCFGR1_CHEN_MASK,
 347                                          DFSDM_CHCFGR1_CHEN(1));
 348                 if (ret < 0)
 349                         return ret;
 350         }
 351
 352         return 0;
 353 }
 354
 355 static void stm32_dfsdm_stop_channel(struct iio_dev *indio_dev)
 356 {
 357         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 358         struct regmap *regmap = adc->dfsdm->regmap;
 359         const struct iio_chan_spec *chan;
 360         unsigned int bit;
 361
 362         for_each_set_bit(bit, &adc->smask, sizeof(adc->smask) * BITS_PER_BYTE) {
 363                 chan = indio_dev->channels + bit;
 364                 regmap_update_bits(regmap, DFSDM_CHCFGR1(chan->channel),
 365                                    DFSDM_CHCFGR1_CHEN_MASK,
 366                                    DFSDM_CHCFGR1_CHEN(0));
 367         }
 368 }
 369
 370 static int stm32_dfsdm_chan_configure(struct stm32_dfsdm *dfsdm,
 371                                       struct stm32_dfsdm_channel *ch)
 372 {
 373         unsigned int id = ch->id;
 374         struct regmap *regmap = dfsdm->regmap;
 375         int ret;
 376
 377         ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
 378                                  DFSDM_CHCFGR1_SITP_MASK,
 379                                  DFSDM_CHCFGR1_SITP(ch->type));
 380         if (ret < 0)
 381                 return ret;
 382         ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
 383                                  DFSDM_CHCFGR1_SPICKSEL_MASK,
 384                                  DFSDM_CHCFGR1_SPICKSEL(ch->src));
 385         if (ret < 0)
 386                 return ret;
 387         return regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
 388                                   DFSDM_CHCFGR1_CHINSEL_MASK,
 389                                   DFSDM_CHCFGR1_CHINSEL(ch->alt_si));
 390 }
 391
 392 static int stm32_dfsdm_start_filter(struct stm32_dfsdm_adc *adc,
 393                                     unsigned int fl_id,
 394                                     struct iio_trigger *trig)
 395 {
 396         struct stm32_dfsdm *dfsdm = adc->dfsdm;
 397         int ret;
 398
 399         /* Enable filter */
 400         ret = regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
 401                                  DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(1));
 402         if (ret < 0)
 403                 return ret;
 404
 405         /* Nothing more to do for injected (scan mode/triggered) conversions */
 406         if (adc->nconv > 1 || trig)
 407                 return 0;
 408
 409         /* Software start (single or continuous) regular conversion */
 410         return regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
 411                                   DFSDM_CR1_RSWSTART_MASK,
 412                                   DFSDM_CR1_RSWSTART(1));
 413 }
 414
 415 static void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm,
 416                                     unsigned int fl_id)
 417 {
 418         /* Disable conversion */
 419         regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
 420                            DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(0));
 421 }
 422
 423 static int stm32_dfsdm_filter_set_trig(struct iio_dev *indio_dev,
 424                                        unsigned int fl_id,
 425                                        struct iio_trigger *trig)
 426 {
 427         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 428         struct regmap *regmap = adc->dfsdm->regmap;
 429         u32 jextsel = 0, jexten = STM32_DFSDM_JEXTEN_DISABLED;
 430         int ret;
 431
 432         if (trig) {
 433                 ret = stm32_dfsdm_get_jextsel(indio_dev, trig);
 434                 if (ret < 0)
 435                         return ret;
 436
 437                 /* set trigger source and polarity (default to rising edge) */
 438                 jextsel = ret;
 439                 jexten = STM32_DFSDM_JEXTEN_RISING_EDGE;
 440         }
 441
 442         ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id),
 443                                  DFSDM_CR1_JEXTSEL_MASK | DFSDM_CR1_JEXTEN_MASK,
 444                                  DFSDM_CR1_JEXTSEL(jextsel) |
 445                                  DFSDM_CR1_JEXTEN(jexten));
 446         if (ret < 0)
 447                 return ret;
 448
 449         return 0;
 450 }
 451
 452 static int stm32_dfsdm_channels_configure(struct iio_dev *indio_dev,
 453                                           unsigned int fl_id,
 454                                           struct iio_trigger *trig)
 455 {
 456         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 457         struct regmap *regmap = adc->dfsdm->regmap;
 458         struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id];
 459         struct stm32_dfsdm_filter_osr *flo = &fl->flo[0];
 460         const struct iio_chan_spec *chan;
 461         unsigned int bit;
 462         int ret;
 463
 464         fl->fast = 0;
 465
 466         /*
 467          * In continuous mode, use fast mode configuration,
 468          * if it provides a better resolution.
 469          */
 470         if (adc->nconv == 1 && !trig && iio_buffer_enabled(indio_dev)) {
 471                 if (fl->flo[1].res >= fl->flo[0].res) {
 472                         fl->fast = 1;
 473                         flo = &fl->flo[1];
 474                 }
 475         }
 476
 477         if (!flo->res)
 478                 return -EINVAL;
 479
 480         dev_dbg(&indio_dev->dev, "Samples actual resolution: %d bits",
 481                 min(flo->bits, (u32)DFSDM_DATA_RES - 1));
 482
 483         for_each_set_bit(bit, &adc->smask,
 484                          sizeof(adc->smask) * BITS_PER_BYTE) {
 485                 chan = indio_dev->channels + bit;
 486
 487                 ret = regmap_update_bits(regmap,
 488                                          DFSDM_CHCFGR2(chan->channel),
 489                                          DFSDM_CHCFGR2_DTRBS_MASK,
 490                                          DFSDM_CHCFGR2_DTRBS(flo->rshift));
 491                 if (ret)
 492                         return ret;
 493         }
 494
 495         return 0;
 496 }
 497
 498 static int stm32_dfsdm_filter_configure(struct iio_dev *indio_dev,
 499                                         unsigned int fl_id,
 500                                         struct iio_trigger *trig)
 501 {
 502         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 503         struct regmap *regmap = adc->dfsdm->regmap;
 504         struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id];
 505         struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast];
 506         u32 cr1;
 507         const struct iio_chan_spec *chan;
 508         unsigned int bit, jchg = 0;
 509         int ret;
 510
 511         /* Average integrator oversampling */
 512         ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_IOSR_MASK,
 513                                  DFSDM_FCR_IOSR(flo->iosr - 1));
 514         if (ret)
 515                 return ret;
 516
 517         /* Filter order and Oversampling */
 518         ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FOSR_MASK,
 519                                  DFSDM_FCR_FOSR(flo->fosr - 1));
 520         if (ret)
 521                 return ret;
 522
 523         ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FORD_MASK,
 524                                  DFSDM_FCR_FORD(fl->ford));
 525         if (ret)
 526                 return ret;
 527
 528         ret = stm32_dfsdm_filter_set_trig(indio_dev, fl_id, trig);
 529         if (ret)
 530                 return ret;
 531
 532         ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id),
 533                                  DFSDM_CR1_FAST_MASK,
 534                                  DFSDM_CR1_FAST(fl->fast));
 535         if (ret)
 536                 return ret;
 537
 538         /*
 539          * DFSDM modes configuration W.R.T audio/iio type modes
 540          * ----------------------------------------------------------------
 541          * Modes         | regular |  regular     | injected | injected   |
 542          *               |         |  continuous  |          | + scan     |
 543          * --------------|---------|--------------|----------|------------|
 544          * single conv   |    x    |              |          |            |
 545          * (1 chan)      |         |              |          |            |
 546          * --------------|---------|--------------|----------|------------|
 547          * 1 Audio chan  |         | sample freq  |          |            |
 548          *               |         | or sync_mode |          |            |
 549          * --------------|---------|--------------|----------|------------|
 550          * 1 IIO chan    |         | sample freq  | trigger  |            |
 551          *               |         | or sync_mode |          |            |
 552          * --------------|---------|--------------|----------|------------|
 553          * 2+ IIO chans  |         |              |          | trigger or |
 554          *               |         |              |          | sync_mode  |
 555          * ----------------------------------------------------------------
 556          */
 557         if (adc->nconv == 1 && !trig) {
 558                 bit = __ffs(adc->smask);
 559                 chan = indio_dev->channels + bit;
 560
 561                 /* Use regular conversion for single channel without trigger */
 562                 cr1 = DFSDM_CR1_RCH(chan->channel);
 563
 564                 /* Continuous conversions triggered by SPI clk in buffer mode */
 565                 if (iio_buffer_enabled(indio_dev))
 566                         cr1 |= DFSDM_CR1_RCONT(1);
 567
 568                 cr1 |= DFSDM_CR1_RSYNC(fl->sync_mode);
 569         } else {
 570                 /* Use injected conversion for multiple channels */
 571                 for_each_set_bit(bit, &adc->smask,
 572                                  sizeof(adc->smask) * BITS_PER_BYTE) {
 573                         chan = indio_dev->channels + bit;
 574                         jchg |= BIT(chan->channel);
 575                 }
 576                 ret = regmap_write(regmap, DFSDM_JCHGR(fl_id), jchg);
 577                 if (ret < 0)
 578                         return ret;
 579
 580                 /* Use scan mode for multiple channels */
 581                 cr1 = DFSDM_CR1_JSCAN((adc->nconv > 1) ? 1 : 0);
 582
 583                 /*
 584                  * Continuous conversions not supported in injected mode,
 585                  * either use:
 586                  * - conversions in sync with filter 0
 587                  * - triggered conversions
 588                  */
 589                 if (!fl->sync_mode && !trig)
 590                         return -EINVAL;
 591                 cr1 |= DFSDM_CR1_JSYNC(fl->sync_mode);
 592         }
 593
 594         return regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_CFG_MASK,
 595                                   cr1);
 596 }
 597
 598 static int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
 599                                         struct iio_dev *indio_dev,
 600                                         struct iio_chan_spec *ch)
 601 {
 602         struct stm32_dfsdm_channel *df_ch;
 603         const char *of_str;
 604         int chan_idx = ch->scan_index;
 605         int ret, val;
 606
 607         ret = of_property_read_u32_index(indio_dev->dev.of_node,
 608                                          "st,adc-channels", chan_idx,
 609                                          &ch->channel);
 610         if (ret < 0) {
 611                 dev_err(&indio_dev->dev,
 612                         " Error parsing 'st,adc-channels' for idx %d\n",
 613                         chan_idx);
 614                 return ret;
 615         }
 616         if (ch->channel >= dfsdm->num_chs) {
 617                 dev_err(&indio_dev->dev,
 618                         " Error bad channel number %d (max = %d)\n",
 619                         ch->channel, dfsdm->num_chs);
 620                 return -EINVAL;
 621         }
 622
 623         ret = of_property_read_string_index(indio_dev->dev.of_node,
 624                                             "st,adc-channel-names", chan_idx,
 625                                             &ch->datasheet_name);
 626         if (ret < 0) {
 627                 dev_err(&indio_dev->dev,
 628                         " Error parsing 'st,adc-channel-names' for idx %d\n",
 629                         chan_idx);
 630                 return ret;
 631         }
 632
 633         df_ch =  &dfsdm->ch_list[ch->channel];
 634         df_ch->id = ch->channel;
 635
 636         ret = of_property_read_string_index(indio_dev->dev.of_node,
 637                                             "st,adc-channel-types", chan_idx,
 638                                             &of_str);
 639         if (!ret) {
 640                 val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_type);
 641                 if (val < 0)
 642                         return val;
 643         } else {
 644                 val = 0;
 645         }
 646         df_ch->type = val;
 647
 648         ret = of_property_read_string_index(indio_dev->dev.of_node,
 649                                             "st,adc-channel-clk-src", chan_idx,
 650                                             &of_str);
 651         if (!ret) {
 652                 val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_src);
 653                 if (val < 0)
 654                         return val;
 655         } else {
 656                 val = 0;
 657         }
 658         df_ch->src = val;
 659
 660         ret = of_property_read_u32_index(indio_dev->dev.of_node,
 661                                          "st,adc-alt-channel", chan_idx,
 662                                          &df_ch->alt_si);
 663         if (ret < 0)
 664                 df_ch->alt_si = 0;
 665
 666         return 0;
 667 }
 668
 669 static ssize_t dfsdm_adc_audio_get_spiclk(struct iio_dev *indio_dev,
 670                                           uintptr_t priv,
 671                                           const struct iio_chan_spec *chan,
 672                                           char *buf)
 673 {
 674         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 675
 676         return snprintf(buf, PAGE_SIZE, "%d\n", adc->spi_freq);
 677 }
 678
 679 static int dfsdm_adc_set_samp_freq(struct iio_dev *indio_dev,
 680                                    unsigned int sample_freq,
 681                                    unsigned int spi_freq)
 682 {
 683         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 684         unsigned int oversamp;
 685         int ret;
 686
 687         oversamp = DIV_ROUND_CLOSEST(spi_freq, sample_freq);
 688         if (spi_freq % sample_freq)
 689                 dev_dbg(&indio_dev->dev,
 690                         "Rate not accurate. requested (%u), actual (%u)\n",
 691                         sample_freq, spi_freq / oversamp);
 692
 693         ret = stm32_dfsdm_compute_all_osrs(indio_dev, oversamp);
 694         if (ret < 0)
 695                 return ret;
 696
 697         adc->sample_freq = spi_freq / oversamp;
 698         adc->oversamp = oversamp;
 699
 700         return 0;
 701 }
 702
 703 static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev,
 704                                           uintptr_t priv,
 705                                           const struct iio_chan_spec *chan,
 706                                           const char *buf, size_t len)
 707 {
 708         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 709         struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel];
 710         unsigned int sample_freq = adc->sample_freq;
 711         unsigned int spi_freq;
 712         int ret;
 713
 714         dev_err(&indio_dev->dev, "enter %s\n", __func__);
 715         /* If DFSDM is master on SPI, SPI freq can not be updated */
 716         if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
 717                 return -EPERM;
 718
 719         ret = kstrtoint(buf, 0, &spi_freq);
 720         if (ret)
 721                 return ret;
 722
 723         if (!spi_freq)
 724                 return -EINVAL;
 725
 726         if (sample_freq) {
 727                 ret = dfsdm_adc_set_samp_freq(indio_dev, sample_freq, spi_freq);
 728                 if (ret < 0)
 729                         return ret;
 730         }
 731         adc->spi_freq = spi_freq;
 732
 733         return len;
 734 }
 735
 736 static int stm32_dfsdm_start_conv(struct iio_dev *indio_dev,
 737                                   struct iio_trigger *trig)
 738 {
 739         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 740         struct regmap *regmap = adc->dfsdm->regmap;
 741         int ret;
 742
 743         ret = stm32_dfsdm_channels_configure(indio_dev, adc->fl_id, trig);
 744         if (ret < 0)
 745                 return ret;
 746
 747         ret = stm32_dfsdm_start_channel(indio_dev);
 748         if (ret < 0)
 749                 return ret;
 750
 751         ret = stm32_dfsdm_filter_configure(indio_dev, adc->fl_id, trig);
 752         if (ret < 0)
 753                 goto stop_channels;
 754
 755         ret = stm32_dfsdm_start_filter(adc, adc->fl_id, trig);
 756         if (ret < 0)
 757                 goto filter_unconfigure;
 758
 759         return 0;
 760
 761 filter_unconfigure:
 762         regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
 763                            DFSDM_CR1_CFG_MASK, 0);
 764 stop_channels:
 765         stm32_dfsdm_stop_channel(indio_dev);
 766
 767         return ret;
 768 }
 769
 770 static void stm32_dfsdm_stop_conv(struct iio_dev *indio_dev)
 771 {
 772         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 773         struct regmap *regmap = adc->dfsdm->regmap;
 774
 775         stm32_dfsdm_stop_filter(adc->dfsdm, adc->fl_id);
 776
 777         regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
 778                            DFSDM_CR1_CFG_MASK, 0);
 779
 780         stm32_dfsdm_stop_channel(indio_dev);
 781 }
 782
 783 static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev,
 784                                      unsigned int val)
 785 {
 786         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 787         unsigned int watermark = DFSDM_DMA_BUFFER_SIZE / 2;
 788         unsigned int rx_buf_sz = DFSDM_DMA_BUFFER_SIZE;
 789
 790         /*
 791          * DMA cyclic transfers are used, buffer is split into two periods.
 792          * There should be :
 793          * - always one buffer (period) DMA is working on
 794          * - one buffer (period) driver pushed to ASoC side.
 795          */
 796         watermark = min(watermark, val * (unsigned int)(sizeof(u32)));
 797         adc->buf_sz = min(rx_buf_sz, watermark * 2 * adc->nconv);
 798
 799         return 0;
 800 }
 801
 802 static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_adc *adc)
 803 {
 804         struct dma_tx_state state;
 805         enum dma_status status;
 806
 807         status = dmaengine_tx_status(adc->dma_chan,
 808                                      adc->dma_chan->cookie,
 809                                      &state);
 810         if (status == DMA_IN_PROGRESS) {
 811                 /* Residue is size in bytes from end of buffer */
 812                 unsigned int i = adc->buf_sz - state.residue;
 813                 unsigned int size;
 814
 815                 /* Return available bytes */
 816                 if (i >= adc->bufi)
 817                         size = i - adc->bufi;
 818                 else
 819                         size = adc->buf_sz + i - adc->bufi;
 820
 821                 return size;
 822         }
 823
 824         return 0;
 825 }
 826
 827 static inline void stm32_dfsdm_process_data(struct stm32_dfsdm_adc *adc,
 828                                             s32 *buffer)
 829 {
 830         struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
 831         struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast];
 832         unsigned int i = adc->nconv;
 833         s32 *ptr = buffer;
 834
 835         while (i--) {
 836                 /* Mask 8 LSB that contains the channel ID */
 837                 *ptr &= 0xFFFFFF00;
 838                 /* Convert 2^(n-1) sample to 2^(n-1)-1 to avoid wrap-around */
 839                 if (*ptr > flo->max)
 840                         *ptr -= 1;
 841                 /*
 842                  * Samples from filter are retrieved with 23 bits resolution
 843                  * or less. Shift left to align MSB on 24 bits.
 844                  */
 845                 *ptr <<= flo->lshift;
 846
 847                 ptr++;
 848         }
 849 }
 850
 851 static void stm32_dfsdm_dma_buffer_done(void *data)
 852 {
 853         struct iio_dev *indio_dev = data;
 854         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 855         int available = stm32_dfsdm_adc_dma_residue(adc);
 856         size_t old_pos;
 857
 858         /*
 859          * FIXME: In Kernel interface does not support cyclic DMA buffer,and
 860          * offers only an interface to push data samples per samples.
 861          * For this reason IIO buffer interface is not used and interface is
 862          * bypassed using a private callback registered by ASoC.
 863          * This should be a temporary solution waiting a cyclic DMA engine
 864          * support in IIO.
 865          */
 866
 867         dev_dbg(&indio_dev->dev, "pos = %d, available = %d\n",
 868                 adc->bufi, available);
 869         old_pos = adc->bufi;
 870
 871         while (available >= indio_dev->scan_bytes) {
 872                 s32 *buffer = (s32 *)&adc->rx_buf[adc->bufi];
 873
 874                 stm32_dfsdm_process_data(adc, buffer);
 875
 876                 available -= indio_dev->scan_bytes;
 877                 adc->bufi += indio_dev->scan_bytes;
 878                 if (adc->bufi >= adc->buf_sz) {
 879                         if (adc->cb)
 880                                 adc->cb(&adc->rx_buf[old_pos],
 881                                          adc->buf_sz - old_pos, adc->cb_priv);
 882                         adc->bufi = 0;
 883                         old_pos = 0;
 884                 }
 885                 /*
 886                  * In DMA mode the trigger services of IIO are not used
 887                  * (e.g. no call to iio_trigger_poll).
 888                  * Calling irq handler associated to the hardware trigger is not
 889                  * relevant as the conversions have already been done. Data
 890                  * transfers are performed directly in DMA callback instead.
 891                  * This implementation avoids to call trigger irq handler that
 892                  * may sleep, in an atomic context (DMA irq handler context).
 893                  */
 894                 if (adc->dev_data->type == DFSDM_IIO)
 895                         iio_push_to_buffers(indio_dev, buffer);
 896         }
 897         if (adc->cb)
 898                 adc->cb(&adc->rx_buf[old_pos], adc->bufi - old_pos,
 899                         adc->cb_priv);
 900 }
 901
 902 static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
 903 {
 904         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 905         /*
 906          * The DFSDM supports half-word transfers. However, for 16 bits record,
 907          * 4 bytes buswidth is kept, to avoid losing samples LSBs when left
 908          * shift is required.
 909          */
 910         struct dma_slave_config config = {
 911                 .src_addr = (dma_addr_t)adc->dfsdm->phys_base,
 912                 .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
 913         };
 914         struct dma_async_tx_descriptor *desc;
 915         dma_cookie_t cookie;
 916         int ret;
 917
 918         if (!adc->dma_chan)
 919                 return -EINVAL;
 920
 921         dev_dbg(&indio_dev->dev, "size=%d watermark=%d\n",
 922                 adc->buf_sz, adc->buf_sz / 2);
 923
 924         if (adc->nconv == 1 && !indio_dev->trig)
 925                 config.src_addr += DFSDM_RDATAR(adc->fl_id);
 926         else
 927                 config.src_addr += DFSDM_JDATAR(adc->fl_id);
 928         ret = dmaengine_slave_config(adc->dma_chan, &config);
 929         if (ret)
 930                 return ret;
 931
 932         /* Prepare a DMA cyclic transaction */
 933         desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
 934                                          adc->dma_buf,
 935                                          adc->buf_sz, adc->buf_sz / 2,
 936                                          DMA_DEV_TO_MEM,
 937                                          DMA_PREP_INTERRUPT);
 938         if (!desc)
 939                 return -EBUSY;
 940
 941         desc->callback = stm32_dfsdm_dma_buffer_done;
 942         desc->callback_param = indio_dev;
 943
 944         cookie = dmaengine_submit(desc);
 945         ret = dma_submit_error(cookie);
 946         if (ret)
 947                 goto err_stop_dma;
 948
 949         /* Issue pending DMA requests */
 950         dma_async_issue_pending(adc->dma_chan);
 951
 952         if (adc->nconv == 1 && !indio_dev->trig) {
 953                 /* Enable regular DMA transfer*/
 954                 ret = regmap_update_bits(adc->dfsdm->regmap,
 955                                          DFSDM_CR1(adc->fl_id),
 956                                          DFSDM_CR1_RDMAEN_MASK,
 957                                          DFSDM_CR1_RDMAEN_MASK);
 958         } else {
 959                 /* Enable injected DMA transfer*/
 960                 ret = regmap_update_bits(adc->dfsdm->regmap,
 961                                          DFSDM_CR1(adc->fl_id),
 962                                          DFSDM_CR1_JDMAEN_MASK,
 963                                          DFSDM_CR1_JDMAEN_MASK);
 964         }
 965
 966         if (ret < 0)
 967                 goto err_stop_dma;
 968
 969         return 0;
 970
 971 err_stop_dma:
 972         dmaengine_terminate_all(adc->dma_chan);
 973
 974         return ret;
 975 }
 976
 977 static void stm32_dfsdm_adc_dma_stop(struct iio_dev *indio_dev)
 978 {
 979         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 980
 981         if (!adc->dma_chan)
 982                 return;
 983
 984         regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR1(adc->fl_id),
 985                            DFSDM_CR1_RDMAEN_MASK | DFSDM_CR1_JDMAEN_MASK, 0);
 986         dmaengine_terminate_all(adc->dma_chan);
 987 }
 988
 989 static int stm32_dfsdm_update_scan_mode(struct iio_dev *indio_dev,
 990                                         const unsigned long *scan_mask)
 991 {
 992         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
 993
 994         adc->nconv = bitmap_weight(scan_mask, indio_dev->masklength);
 995         adc->smask = *scan_mask;
 996
 997         dev_dbg(&indio_dev->dev, "nconv=%d mask=%lx\n", adc->nconv, *scan_mask);
 998
 999         return 0;
1000 }
1001
1002 static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
1003 {
1004         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1005         int ret;
1006
1007         /* Reset adc buffer index */
1008         adc->bufi = 0;
1009
1010         if (adc->hwc) {
1011                 ret = iio_hw_consumer_enable(adc->hwc);
1012                 if (ret < 0)
1013                         return ret;
1014         }
1015
1016         ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
1017         if (ret < 0)
1018                 goto err_stop_hwc;
1019
1020         ret = stm32_dfsdm_adc_dma_start(indio_dev);
1021         if (ret) {
1022                 dev_err(&indio_dev->dev, "Can't start DMA\n");
1023                 goto stop_dfsdm;
1024         }
1025
1026         ret = stm32_dfsdm_start_conv(indio_dev, indio_dev->trig);
1027         if (ret) {
1028                 dev_err(&indio_dev->dev, "Can't start conversion\n");
1029                 goto err_stop_dma;
1030         }
1031
1032         return 0;
1033
1034 err_stop_dma:
1035         stm32_dfsdm_adc_dma_stop(indio_dev);
1036 stop_dfsdm:
1037         stm32_dfsdm_stop_dfsdm(adc->dfsdm);
1038 err_stop_hwc:
1039         if (adc->hwc)
1040                 iio_hw_consumer_disable(adc->hwc);
1041
1042         return ret;
1043 }
1044
1045 static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)
1046 {
1047         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1048
1049         stm32_dfsdm_stop_conv(indio_dev);
1050
1051         stm32_dfsdm_adc_dma_stop(indio_dev);
1052
1053         stm32_dfsdm_stop_dfsdm(adc->dfsdm);
1054
1055         if (adc->hwc)
1056                 iio_hw_consumer_disable(adc->hwc);
1057
1058         return 0;
1059 }
1060
1061 static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = {
1062         .postenable = &stm32_dfsdm_postenable,
1063         .predisable = &stm32_dfsdm_predisable,
1064 };
1065
1066 /**
1067  * stm32_dfsdm_get_buff_cb() - register a callback that will be called when
1068  *                             DMA transfer period is achieved.
1069  *
1070  * @iio_dev: Handle to IIO device.
1071  * @cb: Pointer to callback function:
1072  *      - data: pointer to data buffer
1073  *      - size: size in byte of the data buffer
1074  *      - private: pointer to consumer private structure.
1075  * @private: Pointer to consumer private structure.
1076  */
1077 int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev,
1078                             int (*cb)(const void *data, size_t size,
1079                                       void *private),
1080                             void *private)
1081 {
1082         struct stm32_dfsdm_adc *adc;
1083
1084         if (!iio_dev)
1085                 return -EINVAL;
1086         adc = iio_priv(iio_dev);
1087
1088         adc->cb = cb;
1089         adc->cb_priv = private;
1090
1091         return 0;
1092 }
1093 EXPORT_SYMBOL_GPL(stm32_dfsdm_get_buff_cb);
1094
1095 /**
1096  * stm32_dfsdm_release_buff_cb - unregister buffer callback
1097  *
1098  * @iio_dev: Handle to IIO device.
1099  */
1100 int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev)
1101 {
1102         struct stm32_dfsdm_adc *adc;
1103
1104         if (!iio_dev)
1105                 return -EINVAL;
1106         adc = iio_priv(iio_dev);
1107
1108         adc->cb = NULL;
1109         adc->cb_priv = NULL;
1110
1111         return 0;
1112 }
1113 EXPORT_SYMBOL_GPL(stm32_dfsdm_release_buff_cb);
1114
1115 static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
1116                                    const struct iio_chan_spec *chan, int *res)
1117 {
1118         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1119         long timeout;
1120         int ret;
1121
1122         reinit_completion(&adc->completion);
1123
1124         adc->buffer = res;
1125
1126         ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
1127         if (ret < 0)
1128                 return ret;
1129
1130         ret = regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
1131                                  DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(1));
1132         if (ret < 0)
1133                 goto stop_dfsdm;
1134
1135         adc->nconv = 1;
1136         adc->smask = BIT(chan->scan_index);
1137         ret = stm32_dfsdm_start_conv(indio_dev, NULL);
1138         if (ret < 0) {
1139                 regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
1140                                    DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
1141                 goto stop_dfsdm;
1142         }
1143
1144         timeout = wait_for_completion_interruptible_timeout(&adc->completion,
1145                                                             DFSDM_TIMEOUT);
1146
1147         /* Mask IRQ for regular conversion achievement*/
1148         regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
1149                            DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
1150
1151         if (timeout == 0)
1152                 ret = -ETIMEDOUT;
1153         else if (timeout < 0)
1154                 ret = timeout;
1155         else
1156                 ret = IIO_VAL_INT;
1157
1158         stm32_dfsdm_stop_conv(indio_dev);
1159
1160         stm32_dfsdm_process_data(adc, res);
1161
1162 stop_dfsdm:
1163         stm32_dfsdm_stop_dfsdm(adc->dfsdm);
1164
1165         return ret;
1166 }
1167
1168 static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev,
1169                                  struct iio_chan_spec const *chan,
1170                                  int val, int val2, long mask)
1171 {
1172         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1173         struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel];
1174         unsigned int spi_freq;
1175         int ret = -EINVAL;
1176
1177         switch (ch->src) {
1178         case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL:
1179                 spi_freq = adc->dfsdm->spi_master_freq;
1180                 break;
1181         case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING:
1182         case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING:
1183                 spi_freq = adc->dfsdm->spi_master_freq / 2;
1184                 break;
1185         default:
1186                 spi_freq = adc->spi_freq;
1187         }
1188
1189         switch (mask) {
1190         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
1191                 ret = iio_device_claim_direct_mode(indio_dev);
1192                 if (ret)
1193                         return ret;
1194
1195                 ret = stm32_dfsdm_compute_all_osrs(indio_dev, val);
1196                 if (!ret) {
1197                         dev_dbg(&indio_dev->dev,
1198                                 "Sampling rate changed from (%u) to (%u)\n",
1199                                 adc->sample_freq, spi_freq / val);
1200                         adc->oversamp = val;
1201                         adc->sample_freq = spi_freq / val;
1202                 }
1203                 iio_device_release_direct_mode(indio_dev);
1204                 return ret;
1205
1206         case IIO_CHAN_INFO_SAMP_FREQ:
1207                 if (!val)
1208                         return -EINVAL;
1209
1210                 ret = iio_device_claim_direct_mode(indio_dev);
1211                 if (ret)
1212                         return ret;
1213
1214                 ret = dfsdm_adc_set_samp_freq(indio_dev, val, spi_freq);
1215                 iio_device_release_direct_mode(indio_dev);
1216                 return ret;
1217         }
1218
1219         return -EINVAL;
1220 }
1221
1222 static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
1223                                 struct iio_chan_spec const *chan, int *val,
1224                                 int *val2, long mask)
1225 {
1226         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1227         int ret;
1228
1229         switch (mask) {
1230         case IIO_CHAN_INFO_RAW:
1231                 ret = iio_device_claim_direct_mode(indio_dev);
1232                 if (ret)
1233                         return ret;
1234                 ret = iio_hw_consumer_enable(adc->hwc);
1235                 if (ret < 0) {
1236                         dev_err(&indio_dev->dev,
1237                                 "%s: IIO enable failed (channel %d)\n",
1238                                 __func__, chan->channel);
1239                         iio_device_release_direct_mode(indio_dev);
1240                         return ret;
1241                 }
1242                 ret = stm32_dfsdm_single_conv(indio_dev, chan, val);
1243                 iio_hw_consumer_disable(adc->hwc);
1244                 if (ret < 0) {
1245                         dev_err(&indio_dev->dev,
1246                                 "%s: Conversion failed (channel %d)\n",
1247                                 __func__, chan->channel);
1248                         iio_device_release_direct_mode(indio_dev);
1249                         return ret;
1250                 }
1251                 iio_device_release_direct_mode(indio_dev);
1252                 return IIO_VAL_INT;
1253
1254         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
1255                 *val = adc->oversamp;
1256
1257                 return IIO_VAL_INT;
1258
1259         case IIO_CHAN_INFO_SAMP_FREQ:
1260                 *val = adc->sample_freq;
1261
1262                 return IIO_VAL_INT;
1263         }
1264
1265         return -EINVAL;
1266 }
1267
1268 static int stm32_dfsdm_validate_trigger(struct iio_dev *indio_dev,
1269                                         struct iio_trigger *trig)
1270 {
1271         return stm32_dfsdm_get_jextsel(indio_dev, trig) < 0 ? -EINVAL : 0;
1272 }
1273
1274 static const struct iio_info stm32_dfsdm_info_audio = {
1275         .hwfifo_set_watermark = stm32_dfsdm_set_watermark,
1276         .read_raw = stm32_dfsdm_read_raw,
1277         .write_raw = stm32_dfsdm_write_raw,
1278         .update_scan_mode = stm32_dfsdm_update_scan_mode,
1279 };
1280
1281 static const struct iio_info stm32_dfsdm_info_adc = {
1282         .hwfifo_set_watermark = stm32_dfsdm_set_watermark,
1283         .read_raw = stm32_dfsdm_read_raw,
1284         .write_raw = stm32_dfsdm_write_raw,
1285         .update_scan_mode = stm32_dfsdm_update_scan_mode,
1286         .validate_trigger = stm32_dfsdm_validate_trigger,
1287 };
1288
1289 static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
1290 {
1291         struct iio_dev *indio_dev = arg;
1292         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1293         struct regmap *regmap = adc->dfsdm->regmap;
1294         unsigned int status, int_en;
1295
1296         regmap_read(regmap, DFSDM_ISR(adc->fl_id), &status);
1297         regmap_read(regmap, DFSDM_CR2(adc->fl_id), &int_en);
1298
1299         if (status & DFSDM_ISR_REOCF_MASK) {
1300                 /* Read the data register clean the IRQ status */
1301                 regmap_read(regmap, DFSDM_RDATAR(adc->fl_id), adc->buffer);
1302                 complete(&adc->completion);
1303         }
1304
1305         if (status & DFSDM_ISR_ROVRF_MASK) {
1306                 if (int_en & DFSDM_CR2_ROVRIE_MASK)
1307                         dev_warn(&indio_dev->dev, "Overrun detected\n");
1308                 regmap_update_bits(regmap, DFSDM_ICR(adc->fl_id),
1309                                    DFSDM_ICR_CLRROVRF_MASK,
1310                                    DFSDM_ICR_CLRROVRF_MASK);
1311         }
1312
1313         return IRQ_HANDLED;
1314 }
1315
1316 /*
1317  * Define external info for SPI Frequency and audio sampling rate that can be
1318  * configured by ASoC driver through consumer.h API
1319  */
1320 static const struct iio_chan_spec_ext_info dfsdm_adc_audio_ext_info[] = {
1321         /* spi_clk_freq : clock freq on SPI/manchester bus used by channel */
1322         {
1323                 .name = "spi_clk_freq",
1324                 .shared = IIO_SHARED_BY_TYPE,
1325                 .read = dfsdm_adc_audio_get_spiclk,
1326                 .write = dfsdm_adc_audio_set_spiclk,
1327         },
1328         {},
1329 };
1330
1331 static void stm32_dfsdm_dma_release(struct iio_dev *indio_dev)
1332 {
1333         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1334
1335         if (adc->dma_chan) {
1336                 dma_free_coherent(adc->dma_chan->device->dev,
1337                                   DFSDM_DMA_BUFFER_SIZE,
1338                                   adc->rx_buf, adc->dma_buf);
1339                 dma_release_channel(adc->dma_chan);
1340         }
1341 }
1342
1343 static int stm32_dfsdm_dma_request(struct device *dev,
1344                                    struct iio_dev *indio_dev)
1345 {
1346         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1347
1348         adc->dma_chan = dma_request_chan(dev, "rx");
1349         if (IS_ERR(adc->dma_chan)) {
1350                 int ret = PTR_ERR(adc->dma_chan);
1351
1352                 adc->dma_chan = NULL;
1353                 return ret;
1354         }
1355
1356         adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
1357                                          DFSDM_DMA_BUFFER_SIZE,
1358                                          &adc->dma_buf, GFP_KERNEL);
1359         if (!adc->rx_buf) {
1360                 dma_release_channel(adc->dma_chan);
1361                 return -ENOMEM;
1362         }
1363
1364         indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
1365         indio_dev->setup_ops = &stm32_dfsdm_buffer_setup_ops;
1366
1367         return 0;
1368 }
1369
1370 static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
1371                                          struct iio_chan_spec *ch)
1372 {
1373         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1374         int ret;
1375
1376         ret = stm32_dfsdm_channel_parse_of(adc->dfsdm, indio_dev, ch);
1377         if (ret < 0)
1378                 return ret;
1379
1380         ch->type = IIO_VOLTAGE;
1381         ch->indexed = 1;
1382
1383         /*
1384          * IIO_CHAN_INFO_RAW: used to compute regular conversion
1385          * IIO_CHAN_INFO_OVERSAMPLING_RATIO: used to set oversampling
1386          */
1387         ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
1388         ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) |
1389                                         BIT(IIO_CHAN_INFO_SAMP_FREQ);
1390
1391         if (adc->dev_data->type == DFSDM_AUDIO) {
1392                 ch->ext_info = dfsdm_adc_audio_ext_info;
1393         } else {
1394                 ch->scan_type.shift = 8;
1395         }
1396         ch->scan_type.sign = 's';
1397         ch->scan_type.realbits = 24;
1398         ch->scan_type.storagebits = 32;
1399
1400         return stm32_dfsdm_chan_configure(adc->dfsdm,
1401                                           &adc->dfsdm->ch_list[ch->channel]);
1402 }
1403
1404 static int stm32_dfsdm_audio_init(struct device *dev, struct iio_dev *indio_dev)
1405 {
1406         struct iio_chan_spec *ch;
1407         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1408         struct stm32_dfsdm_channel *d_ch;
1409         int ret;
1410
1411         ch = devm_kzalloc(&indio_dev->dev, sizeof(*ch), GFP_KERNEL);
1412         if (!ch)
1413                 return -ENOMEM;
1414
1415         ch->scan_index = 0;
1416
1417         ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
1418         if (ret < 0) {
1419                 dev_err(&indio_dev->dev, "Channels init failed\n");
1420                 return ret;
1421         }
1422         ch->info_mask_separate = BIT(IIO_CHAN_INFO_SAMP_FREQ);
1423
1424         d_ch = &adc->dfsdm->ch_list[ch->channel];
1425         if (d_ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
1426                 adc->spi_freq = adc->dfsdm->spi_master_freq;
1427
1428         indio_dev->num_channels = 1;
1429         indio_dev->channels = ch;
1430
1431         return stm32_dfsdm_dma_request(dev, indio_dev);
1432 }
1433
1434 static int stm32_dfsdm_adc_init(struct device *dev, struct iio_dev *indio_dev)
1435 {
1436         struct iio_chan_spec *ch;
1437         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1438         int num_ch;
1439         int ret, chan_idx;
1440
1441         adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING;
1442         ret = stm32_dfsdm_compute_all_osrs(indio_dev, adc->oversamp);
1443         if (ret < 0)
1444                 return ret;
1445
1446         num_ch = of_property_count_u32_elems(indio_dev->dev.of_node,
1447                                              "st,adc-channels");
1448         if (num_ch < 0 || num_ch > adc->dfsdm->num_chs) {
1449                 dev_err(&indio_dev->dev, "Bad st,adc-channels\n");
1450                 return num_ch < 0 ? num_ch : -EINVAL;
1451         }
1452
1453         /* Bind to SD modulator IIO device */
1454         adc->hwc = devm_iio_hw_consumer_alloc(&indio_dev->dev);
1455         if (IS_ERR(adc->hwc))
1456                 return -EPROBE_DEFER;
1457
1458         ch = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*ch),
1459                           GFP_KERNEL);
1460         if (!ch)
1461                 return -ENOMEM;
1462
1463         for (chan_idx = 0; chan_idx < num_ch; chan_idx++) {
1464                 ch[chan_idx].scan_index = chan_idx;
1465                 ret = stm32_dfsdm_adc_chan_init_one(indio_dev, &ch[chan_idx]);
1466                 if (ret < 0) {
1467                         dev_err(&indio_dev->dev, "Channels init failed\n");
1468                         return ret;
1469                 }
1470         }
1471
1472         indio_dev->num_channels = num_ch;
1473         indio_dev->channels = ch;
1474
1475         init_completion(&adc->completion);
1476
1477         /* Optionally request DMA */
1478         ret = stm32_dfsdm_dma_request(dev, indio_dev);
1479         if (ret) {
1480                 if (ret != -ENODEV)
1481                         return dev_err_probe(dev, ret,
1482                                              "DMA channel request failed with\n");
1483
1484                 dev_dbg(dev, "No DMA support\n");
1485                 return 0;
1486         }
1487
1488         ret = iio_triggered_buffer_setup(indio_dev,
1489                                          &iio_pollfunc_store_time, NULL,
1490                                          &stm32_dfsdm_buffer_setup_ops);
1491         if (ret) {
1492                 stm32_dfsdm_dma_release(indio_dev);
1493                 dev_err(&indio_dev->dev, "buffer setup failed\n");
1494                 return ret;
1495         }
1496
1497         /* lptimer/timer hardware triggers */
1498         indio_dev->modes |= INDIO_HARDWARE_TRIGGERED;
1499
1500         return 0;
1501 }
1502
1503 static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_adc_data = {
1504         .type = DFSDM_IIO,
1505         .init = stm32_dfsdm_adc_init,
1506 };
1507
1508 static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_audio_data = {
1509         .type = DFSDM_AUDIO,
1510         .init = stm32_dfsdm_audio_init,
1511 };
1512
1513 static const struct of_device_id stm32_dfsdm_adc_match[] = {
1514         {
1515                 .compatible = "st,stm32-dfsdm-adc",
1516                 .data = &stm32h7_dfsdm_adc_data,
1517         },
1518         {
1519                 .compatible = "st,stm32-dfsdm-dmic",
1520                 .data = &stm32h7_dfsdm_audio_data,
1521         },
1522         {}
1523 };
1524 MODULE_DEVICE_TABLE(of, stm32_dfsdm_adc_match);
1525
1526 static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
1527 {
1528         struct device *dev = &pdev->dev;
1529         struct stm32_dfsdm_adc *adc;
1530         struct device_node *np = dev->of_node;
1531         const struct stm32_dfsdm_dev_data *dev_data;
1532         struct iio_dev *iio;
1533         char *name;
1534         int ret, irq, val;
1535
1536         dev_data = of_device_get_match_data(dev);
1537         iio = devm_iio_device_alloc(dev, sizeof(*adc));
1538         if (!iio) {
1539                 dev_err(dev, "%s: Failed to allocate IIO\n", __func__);
1540                 return -ENOMEM;
1541         }
1542
1543         adc = iio_priv(iio);
1544         adc->dfsdm = dev_get_drvdata(dev->parent);
1545
1546         iio->dev.of_node = np;
1547         iio->modes = INDIO_DIRECT_MODE;
1548
1549         platform_set_drvdata(pdev, iio);
1550
1551         ret = of_property_read_u32(dev->of_node, "reg", &adc->fl_id);
1552         if (ret != 0 || adc->fl_id >= adc->dfsdm->num_fls) {
1553                 dev_err(dev, "Missing or bad reg property\n");
1554                 return -EINVAL;
1555         }
1556
1557         name = devm_kzalloc(dev, sizeof("dfsdm-adc0"), GFP_KERNEL);
1558         if (!name)
1559                 return -ENOMEM;
1560         if (dev_data->type == DFSDM_AUDIO) {
1561                 iio->info = &stm32_dfsdm_info_audio;
1562                 snprintf(name, sizeof("dfsdm-pdm0"), "dfsdm-pdm%d", adc->fl_id);
1563         } else {
1564                 iio->info = &stm32_dfsdm_info_adc;
1565                 snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id);
1566         }
1567         iio->name = name;
1568
1569         /*
1570          * In a first step IRQs generated for channels are not treated.
1571          * So IRQ associated to filter instance 0 is dedicated to the Filter 0.
1572          */
1573         irq = platform_get_irq(pdev, 0);
1574         if (irq < 0)
1575                 return irq;
1576
1577         ret = devm_request_irq(dev, irq, stm32_dfsdm_irq,
1578                                0, pdev->name, iio);
1579         if (ret < 0) {
1580                 dev_err(dev, "Failed to request IRQ\n");
1581                 return ret;
1582         }
1583
1584         ret = of_property_read_u32(dev->of_node, "st,filter-order", &val);
1585         if (ret < 0) {
1586                 dev_err(dev, "Failed to set filter order\n");
1587                 return ret;
1588         }
1589
1590         adc->dfsdm->fl_list[adc->fl_id].ford = val;
1591
1592         ret = of_property_read_u32(dev->of_node, "st,filter0-sync", &val);
1593         if (!ret)
1594                 adc->dfsdm->fl_list[adc->fl_id].sync_mode = val;
1595
1596         adc->dev_data = dev_data;
1597         ret = dev_data->init(dev, iio);
1598         if (ret < 0)
1599                 return ret;
1600
1601         ret = iio_device_register(iio);
1602         if (ret < 0)
1603                 goto err_cleanup;
1604
1605         if (dev_data->type == DFSDM_AUDIO) {
1606                 ret = of_platform_populate(np, NULL, NULL, dev);
1607                 if (ret < 0) {
1608                         dev_err(dev, "Failed to find an audio DAI\n");
1609                         goto err_unregister;
1610                 }
1611         }
1612
1613         return 0;
1614
1615 err_unregister:
1616         iio_device_unregister(iio);
1617 err_cleanup:
1618         stm32_dfsdm_dma_release(iio);
1619
1620         return ret;
1621 }
1622
1623 static void stm32_dfsdm_adc_remove(struct platform_device *pdev)
1624 {
1625         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1626         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1627
1628         if (adc->dev_data->type == DFSDM_AUDIO)
1629                 of_platform_depopulate(&pdev->dev);
1630         iio_device_unregister(indio_dev);
1631         stm32_dfsdm_dma_release(indio_dev);
1632 }
1633
1634 static int stm32_dfsdm_adc_suspend(struct device *dev)
1635 {
1636         struct iio_dev *indio_dev = dev_get_drvdata(dev);
1637
1638         if (iio_buffer_enabled(indio_dev))
1639                 stm32_dfsdm_predisable(indio_dev);
1640
1641         return 0;
1642 }
1643
1644 static int stm32_dfsdm_adc_resume(struct device *dev)
1645 {
1646         struct iio_dev *indio_dev = dev_get_drvdata(dev);
1647         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
1648         const struct iio_chan_spec *chan;
1649         struct stm32_dfsdm_channel *ch;
1650         int i, ret;
1651
1652         /* restore channels configuration */
1653         for (i = 0; i < indio_dev->num_channels; i++) {
1654                 chan = indio_dev->channels + i;
1655                 ch = &adc->dfsdm->ch_list[chan->channel];
1656                 ret = stm32_dfsdm_chan_configure(adc->dfsdm, ch);
1657                 if (ret)
1658                         return ret;
1659         }
1660
1661         if (iio_buffer_enabled(indio_dev))
1662                 stm32_dfsdm_postenable(indio_dev);
1663
1664         return 0;
1665 }
1666
1667 static DEFINE_SIMPLE_DEV_PM_OPS(stm32_dfsdm_adc_pm_ops,
1668                                 stm32_dfsdm_adc_suspend,
1669                                 stm32_dfsdm_adc_resume);
1670
1671 static struct platform_driver stm32_dfsdm_adc_driver = {
1672         .driver = {
1673                 .name = "stm32-dfsdm-adc",
1674                 .of_match_table = stm32_dfsdm_adc_match,
1675                 .pm = pm_sleep_ptr(&stm32_dfsdm_adc_pm_ops),
1676         },
1677         .probe = stm32_dfsdm_adc_probe,
1678         .remove_new = stm32_dfsdm_adc_remove,
1679 };
1680 module_platform_driver(stm32_dfsdm_adc_driver);
1681
1682 MODULE_DESCRIPTION("STM32 sigma delta ADC");
1683 MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
1684 MODULE_LICENSE("GPL v2");