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/backend.h> 13 #include <linux/iio/buffer.h> 14 #include <linux/iio/hw-consumer.h> 15 #include <linux/iio/sysfs.h> 16 #include <linux/iio/timer/stm32-lptim-trigger.h> 17 #include <linux/iio/timer/stm32-timer-trigger.h> 18 #include <linux/iio/trigger.h> 19 #include <linux/iio/trigger_consumer.h> 20 #include <linux/iio/triggered_buffer.h> 21 #include <linux/interrupt.h> 22 #include <linux/module.h> 23 #include <linux/of.h> 24 #include <linux/of_platform.h> 25 #include <linux/platform_device.h> 26 #include <linux/regmap.h> 27 #include <linux/slab.h> 28 29 #include "stm32-dfsdm.h" 30 31 #define DFSDM_DMA_BUFFER_SIZE (4 * PAGE_SIZE) 32 33 /* Conversion timeout */ 34 #define DFSDM_TIMEOUT_US 100000 35 #define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000)) 36 37 /* Oversampling attribute default */ 38 #define DFSDM_DEFAULT_OVERSAMPLING 100 39 40 /* Oversampling max values */ 41 #define DFSDM_MAX_INT_OVERSAMPLING 256 42 #define DFSDM_MAX_FL_OVERSAMPLING 1024 43 44 /* Limit filter output resolution to 31 bits. (i.e. sample range is +/-2^30) */ 45 #define DFSDM_DATA_MAX BIT(30) 46 /* 47 * Data are output as two's complement data in a 24 bit field. 48 * Data from filters are in the range +/-2^(n-1) 49 * 2^(n-1) maximum positive value cannot be coded in 2's complement n bits 50 * An extra bit is required to avoid wrap-around of the binary code for 2^(n-1) 51 * So, the resolution of samples from filter is actually limited to 23 bits 52 */ 53 #define DFSDM_DATA_RES 24 54 55 /* Filter configuration */ 56 #define DFSDM_CR1_CFG_MASK (DFSDM_CR1_RCH_MASK | DFSDM_CR1_RCONT_MASK | \ 57 DFSDM_CR1_RSYNC_MASK | DFSDM_CR1_JSYNC_MASK | \ 58 DFSDM_CR1_JSCAN_MASK) 59 60 enum sd_converter_type { 61 DFSDM_AUDIO, 62 DFSDM_IIO, 63 }; 64 65 struct stm32_dfsdm_dev_data { 66 int type; 67 int (*init)(struct device *dev, struct iio_dev *indio_dev); 68 unsigned int num_channels; 69 const struct regmap_config *regmap_cfg; 70 }; 71 72 struct stm32_dfsdm_adc { 73 struct stm32_dfsdm *dfsdm; 74 const struct stm32_dfsdm_dev_data *dev_data; 75 unsigned int fl_id; 76 unsigned int nconv; 77 unsigned long smask; 78 79 /* ADC specific */ 80 unsigned int oversamp; 81 struct iio_hw_consumer *hwc; 82 struct iio_backend **backend; 83 struct completion completion; 84 u32 *buffer; 85 86 /* Audio specific */ 87 unsigned int spi_freq; /* SPI bus clock frequency */ 88 unsigned int sample_freq; /* Sample frequency after filter decimation */ 89 int (*cb)(const void *data, size_t size, void *cb_priv); 90 void *cb_priv; 91 92 /* DMA */ 93 u8 *rx_buf; 94 unsigned int bufi; /* Buffer current position */ 95 unsigned int buf_sz; /* Buffer size */ 96 struct dma_chan *dma_chan; 97 dma_addr_t dma_buf; 98 }; 99 100 struct stm32_dfsdm_str2field { 101 const char *name; 102 unsigned int val; 103 }; 104 105 /* DFSDM channel serial interface type */ 106 static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_type[] = { 107 { "SPI_R", 0 }, /* SPI with data on rising edge */ 108 { "SPI_F", 1 }, /* SPI with data on falling edge */ 109 { "MANCH_R", 2 }, /* Manchester codec, rising edge = logic 0 */ 110 { "MANCH_F", 3 }, /* Manchester codec, falling edge = logic 1 */ 111 {}, 112 }; 113 114 /* DFSDM channel clock source */ 115 static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_src[] = { 116 /* External SPI clock (CLKIN x) */ 117 { "CLKIN", DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL }, 118 /* Internal SPI clock (CLKOUT) */ 119 { "CLKOUT", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL }, 120 /* Internal SPI clock divided by 2 (falling edge) */ 121 { "CLKOUT_F", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING }, 122 /* Internal SPI clock divided by 2 (falling edge) */ 123 { "CLKOUT_R", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING }, 124 {}, 125 }; 126 127 static int stm32_dfsdm_str2val(const char *str, 128 const struct stm32_dfsdm_str2field *list) 129 { 130 const struct stm32_dfsdm_str2field *p = list; 131 132 for (p = list; p && p->name; p++) 133 if (!strcmp(p->name, str)) 134 return p->val; 135 136 return -EINVAL; 137 } 138 139 /** 140 * struct stm32_dfsdm_trig_info - DFSDM trigger info 141 * @name: name of the trigger, corresponding to its source 142 * @jextsel: trigger signal selection 143 */ 144 struct stm32_dfsdm_trig_info { 145 const char *name; 146 unsigned int jextsel; 147 }; 148 149 /* hardware injected trigger enable, edge selection */ 150 enum stm32_dfsdm_jexten { 151 STM32_DFSDM_JEXTEN_DISABLED, 152 STM32_DFSDM_JEXTEN_RISING_EDGE, 153 STM32_DFSDM_JEXTEN_FALLING_EDGE, 154 STM32_DFSDM_EXTEN_BOTH_EDGES, 155 }; 156 157 static const struct stm32_dfsdm_trig_info stm32_dfsdm_trigs[] = { 158 { TIM1_TRGO, 0 }, 159 { TIM1_TRGO2, 1 }, 160 { TIM8_TRGO, 2 }, 161 { TIM8_TRGO2, 3 }, 162 { TIM3_TRGO, 4 }, 163 { TIM4_TRGO, 5 }, 164 { TIM16_OC1, 6 }, 165 { TIM6_TRGO, 7 }, 166 { TIM7_TRGO, 8 }, 167 { LPTIM1_OUT, 26 }, 168 { LPTIM2_OUT, 27 }, 169 { LPTIM3_OUT, 28 }, 170 {}, 171 }; 172 173 static int stm32_dfsdm_get_jextsel(struct iio_dev *indio_dev, 174 struct iio_trigger *trig) 175 { 176 int i; 177 178 /* lookup triggers registered by stm32 timer trigger driver */ 179 for (i = 0; stm32_dfsdm_trigs[i].name; i++) { 180 /** 181 * Checking both stm32 timer trigger type and trig name 182 * should be safe against arbitrary trigger names. 183 */ 184 if ((is_stm32_timer_trigger(trig) || 185 is_stm32_lptim_trigger(trig)) && 186 !strcmp(stm32_dfsdm_trigs[i].name, trig->name)) { 187 return stm32_dfsdm_trigs[i].jextsel; 188 } 189 } 190 191 return -EINVAL; 192 } 193 194 static int stm32_dfsdm_compute_osrs(struct stm32_dfsdm_filter *fl, 195 unsigned int fast, unsigned int oversamp) 196 { 197 unsigned int i, d, fosr, iosr; 198 u64 res, max; 199 int bits, shift; 200 unsigned int m = 1; /* multiplication factor */ 201 unsigned int p = fl->ford; /* filter order (ford) */ 202 struct stm32_dfsdm_filter_osr *flo = &fl->flo[fast]; 203 204 pr_debug("Requested oversampling: %d\n", oversamp); 205 /* 206 * This function tries to compute filter oversampling and integrator 207 * oversampling, base on oversampling ratio requested by user. 208 * 209 * Decimation d depends on the filter order and the oversampling ratios. 210 * ford: filter order 211 * fosr: filter over sampling ratio 212 * iosr: integrator over sampling ratio 213 */ 214 if (fl->ford == DFSDM_FASTSINC_ORDER) { 215 m = 2; 216 p = 2; 217 } 218 219 /* 220 * Look for filter and integrator oversampling ratios which allows 221 * to maximize data output resolution. 222 */ 223 for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) { 224 for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) { 225 if (fast) 226 d = fosr * iosr; 227 else if (fl->ford == DFSDM_FASTSINC_ORDER) 228 d = fosr * (iosr + 3) + 2; 229 else 230 d = fosr * (iosr - 1 + p) + p; 231 232 if (d > oversamp) 233 break; 234 else if (d != oversamp) 235 continue; 236 /* 237 * Check resolution (limited to signed 32 bits) 238 * res <= 2^31 239 * Sincx filters: 240 * res = m * fosr^p x iosr (with m=1, p=ford) 241 * FastSinc filter 242 * res = m * fosr^p x iosr (with m=2, p=2) 243 */ 244 res = fosr; 245 for (i = p - 1; i > 0; i--) { 246 res = res * (u64)fosr; 247 if (res > DFSDM_DATA_MAX) 248 break; 249 } 250 if (res > DFSDM_DATA_MAX) 251 continue; 252 253 res = res * (u64)m * (u64)iosr; 254 if (res > DFSDM_DATA_MAX) 255 continue; 256 257 if (res >= flo->res) { 258 flo->res = res; 259 flo->fosr = fosr; 260 flo->iosr = iosr; 261 262 bits = fls(flo->res); 263 /* 8 LBSs in data register contain chan info */ 264 max = flo->res << 8; 265 266 /* if resolution is not a power of two */ 267 if (flo->res > BIT(bits - 1)) 268 bits++; 269 else 270 max--; 271 272 shift = DFSDM_DATA_RES - bits; 273 /* 274 * Compute right/left shift 275 * Right shift is performed by hardware 276 * when transferring samples to data register. 277 * Left shift is done by software on buffer 278 */ 279 if (shift > 0) { 280 /* Resolution is lower than 24 bits */ 281 flo->rshift = 0; 282 flo->lshift = shift; 283 } else { 284 /* 285 * If resolution is 24 bits or more, 286 * max positive value may be ambiguous 287 * (equal to max negative value as sign 288 * bit is dropped). 289 * Reduce resolution to 23 bits (rshift) 290 * to keep the sign on bit 23 and treat 291 * saturation before rescaling on 24 292 * bits (lshift). 293 */ 294 flo->rshift = 1 - shift; 295 flo->lshift = 1; 296 max >>= flo->rshift; 297 } 298 flo->max = (s32)max; 299 flo->bits = bits; 300 301 pr_debug("fast %d, fosr %d, iosr %d, res 0x%llx/%d bits, rshift %d, lshift %d\n", 302 fast, flo->fosr, flo->iosr, 303 flo->res, bits, flo->rshift, 304 flo->lshift); 305 } 306 } 307 } 308 309 if (!flo->res) 310 return -EINVAL; 311 312 return 0; 313 } 314 315 static int stm32_dfsdm_compute_all_osrs(struct iio_dev *indio_dev, 316 unsigned int oversamp) 317 { 318 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 319 struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; 320 int ret0, ret1; 321 322 memset(&fl->flo[0], 0, sizeof(fl->flo[0])); 323 memset(&fl->flo[1], 0, sizeof(fl->flo[1])); 324 325 ret0 = stm32_dfsdm_compute_osrs(fl, 0, oversamp); 326 ret1 = stm32_dfsdm_compute_osrs(fl, 1, oversamp); 327 if (ret0 < 0 && ret1 < 0) { 328 dev_err(&indio_dev->dev, 329 "Filter parameters not found: errors %d/%d\n", 330 ret0, ret1); 331 return -EINVAL; 332 } 333 334 return 0; 335 } 336 337 static int stm32_dfsdm_start_channel(struct iio_dev *indio_dev) 338 { 339 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 340 struct regmap *regmap = adc->dfsdm->regmap; 341 const struct iio_chan_spec *chan; 342 unsigned int bit; 343 int ret; 344 345 for_each_set_bit(bit, &adc->smask, sizeof(adc->smask) * BITS_PER_BYTE) { 346 chan = indio_dev->channels + bit; 347 ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(chan->channel), 348 DFSDM_CHCFGR1_CHEN_MASK, 349 DFSDM_CHCFGR1_CHEN(1)); 350 if (ret < 0) 351 return ret; 352 } 353 354 return 0; 355 } 356 357 static void stm32_dfsdm_stop_channel(struct iio_dev *indio_dev) 358 { 359 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 360 struct regmap *regmap = adc->dfsdm->regmap; 361 const struct iio_chan_spec *chan; 362 unsigned int bit; 363 364 for_each_set_bit(bit, &adc->smask, sizeof(adc->smask) * BITS_PER_BYTE) { 365 chan = indio_dev->channels + bit; 366 regmap_update_bits(regmap, DFSDM_CHCFGR1(chan->channel), 367 DFSDM_CHCFGR1_CHEN_MASK, 368 DFSDM_CHCFGR1_CHEN(0)); 369 } 370 } 371 372 static int stm32_dfsdm_chan_configure(struct stm32_dfsdm *dfsdm, 373 struct stm32_dfsdm_channel *ch) 374 { 375 unsigned int id = ch->id; 376 struct regmap *regmap = dfsdm->regmap; 377 int ret; 378 379 ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id), 380 DFSDM_CHCFGR1_SITP_MASK, 381 DFSDM_CHCFGR1_SITP(ch->type)); 382 if (ret < 0) 383 return ret; 384 ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id), 385 DFSDM_CHCFGR1_SPICKSEL_MASK, 386 DFSDM_CHCFGR1_SPICKSEL(ch->src)); 387 if (ret < 0) 388 return ret; 389 return regmap_update_bits(regmap, DFSDM_CHCFGR1(id), 390 DFSDM_CHCFGR1_CHINSEL_MASK, 391 DFSDM_CHCFGR1_CHINSEL(ch->alt_si)); 392 } 393 394 static int stm32_dfsdm_start_filter(struct stm32_dfsdm_adc *adc, 395 unsigned int fl_id, 396 struct iio_trigger *trig) 397 { 398 struct stm32_dfsdm *dfsdm = adc->dfsdm; 399 int ret; 400 401 /* Enable filter */ 402 ret = regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id), 403 DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(1)); 404 if (ret < 0) 405 return ret; 406 407 /* Nothing more to do for injected (scan mode/triggered) conversions */ 408 if (adc->nconv > 1 || trig) 409 return 0; 410 411 /* Software start (single or continuous) regular conversion */ 412 return regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id), 413 DFSDM_CR1_RSWSTART_MASK, 414 DFSDM_CR1_RSWSTART(1)); 415 } 416 417 static void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm, 418 unsigned int fl_id) 419 { 420 /* Disable conversion */ 421 regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id), 422 DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(0)); 423 } 424 425 static int stm32_dfsdm_filter_set_trig(struct iio_dev *indio_dev, 426 unsigned int fl_id, 427 struct iio_trigger *trig) 428 { 429 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 430 struct regmap *regmap = adc->dfsdm->regmap; 431 u32 jextsel = 0, jexten = STM32_DFSDM_JEXTEN_DISABLED; 432 int ret; 433 434 if (trig) { 435 ret = stm32_dfsdm_get_jextsel(indio_dev, trig); 436 if (ret < 0) 437 return ret; 438 439 /* set trigger source and polarity (default to rising edge) */ 440 jextsel = ret; 441 jexten = STM32_DFSDM_JEXTEN_RISING_EDGE; 442 } 443 444 ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id), 445 DFSDM_CR1_JEXTSEL_MASK | DFSDM_CR1_JEXTEN_MASK, 446 DFSDM_CR1_JEXTSEL(jextsel) | 447 DFSDM_CR1_JEXTEN(jexten)); 448 if (ret < 0) 449 return ret; 450 451 return 0; 452 } 453 454 static int stm32_dfsdm_channels_configure(struct iio_dev *indio_dev, 455 unsigned int fl_id, 456 struct iio_trigger *trig) 457 { 458 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 459 struct regmap *regmap = adc->dfsdm->regmap; 460 struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id]; 461 struct stm32_dfsdm_filter_osr *flo = &fl->flo[0]; 462 const struct iio_chan_spec *chan; 463 unsigned int bit; 464 int ret; 465 466 fl->fast = 0; 467 468 /* 469 * In continuous mode, use fast mode configuration, 470 * if it provides a better resolution. 471 */ 472 if (adc->nconv == 1 && !trig && iio_buffer_enabled(indio_dev)) { 473 if (fl->flo[1].res >= fl->flo[0].res) { 474 fl->fast = 1; 475 flo = &fl->flo[1]; 476 } 477 } 478 479 if (!flo->res) 480 return -EINVAL; 481 482 dev_dbg(&indio_dev->dev, "Samples actual resolution: %d bits", 483 min(flo->bits, (u32)DFSDM_DATA_RES - 1)); 484 485 for_each_set_bit(bit, &adc->smask, 486 sizeof(adc->smask) * BITS_PER_BYTE) { 487 chan = indio_dev->channels + bit; 488 489 ret = regmap_update_bits(regmap, 490 DFSDM_CHCFGR2(chan->channel), 491 DFSDM_CHCFGR2_DTRBS_MASK, 492 DFSDM_CHCFGR2_DTRBS(flo->rshift)); 493 if (ret) 494 return ret; 495 } 496 497 return 0; 498 } 499 500 static int stm32_dfsdm_filter_configure(struct iio_dev *indio_dev, 501 unsigned int fl_id, 502 struct iio_trigger *trig) 503 { 504 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 505 struct regmap *regmap = adc->dfsdm->regmap; 506 struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id]; 507 struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast]; 508 u32 cr1; 509 const struct iio_chan_spec *chan; 510 unsigned int bit, jchg = 0; 511 int ret; 512 513 /* Average integrator oversampling */ 514 ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_IOSR_MASK, 515 DFSDM_FCR_IOSR(flo->iosr - 1)); 516 if (ret) 517 return ret; 518 519 /* Filter order and Oversampling */ 520 ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FOSR_MASK, 521 DFSDM_FCR_FOSR(flo->fosr - 1)); 522 if (ret) 523 return ret; 524 525 ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FORD_MASK, 526 DFSDM_FCR_FORD(fl->ford)); 527 if (ret) 528 return ret; 529 530 ret = stm32_dfsdm_filter_set_trig(indio_dev, fl_id, trig); 531 if (ret) 532 return ret; 533 534 ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id), 535 DFSDM_CR1_FAST_MASK, 536 DFSDM_CR1_FAST(fl->fast)); 537 if (ret) 538 return ret; 539 540 /* 541 * DFSDM modes configuration W.R.T audio/iio type modes 542 * ---------------------------------------------------------------- 543 * Modes | regular | regular | injected | injected | 544 * | | continuous | | + scan | 545 * --------------|---------|--------------|----------|------------| 546 * single conv | x | | | | 547 * (1 chan) | | | | | 548 * --------------|---------|--------------|----------|------------| 549 * 1 Audio chan | | sample freq | | | 550 * | | or sync_mode | | | 551 * --------------|---------|--------------|----------|------------| 552 * 1 IIO chan | | sample freq | trigger | | 553 * | | or sync_mode | | | 554 * --------------|---------|--------------|----------|------------| 555 * 2+ IIO chans | | | | trigger or | 556 * | | | | sync_mode | 557 * ---------------------------------------------------------------- 558 */ 559 if (adc->nconv == 1 && !trig) { 560 bit = __ffs(adc->smask); 561 chan = indio_dev->channels + bit; 562 563 /* Use regular conversion for single channel without trigger */ 564 cr1 = DFSDM_CR1_RCH(chan->channel); 565 566 /* Continuous conversions triggered by SPI clk in buffer mode */ 567 if (iio_buffer_enabled(indio_dev)) 568 cr1 |= DFSDM_CR1_RCONT(1); 569 570 cr1 |= DFSDM_CR1_RSYNC(fl->sync_mode); 571 } else { 572 /* Use injected conversion for multiple channels */ 573 for_each_set_bit(bit, &adc->smask, 574 sizeof(adc->smask) * BITS_PER_BYTE) { 575 chan = indio_dev->channels + bit; 576 jchg |= BIT(chan->channel); 577 } 578 ret = regmap_write(regmap, DFSDM_JCHGR(fl_id), jchg); 579 if (ret < 0) 580 return ret; 581 582 /* Use scan mode for multiple channels */ 583 cr1 = DFSDM_CR1_JSCAN((adc->nconv > 1) ? 1 : 0); 584 585 /* 586 * Continuous conversions not supported in injected mode, 587 * either use: 588 * - conversions in sync with filter 0 589 * - triggered conversions 590 */ 591 if (!fl->sync_mode && !trig) 592 return -EINVAL; 593 cr1 |= DFSDM_CR1_JSYNC(fl->sync_mode); 594 } 595 596 return regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_CFG_MASK, 597 cr1); 598 } 599 600 static int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm, 601 struct iio_dev *indio_dev, 602 struct iio_chan_spec *ch) 603 { 604 struct stm32_dfsdm_channel *df_ch; 605 const char *of_str; 606 int chan_idx = ch->scan_index; 607 int ret, val; 608 609 ret = of_property_read_u32_index(indio_dev->dev.of_node, 610 "st,adc-channels", chan_idx, 611 &ch->channel); 612 if (ret < 0) { 613 dev_err(&indio_dev->dev, 614 " Error parsing 'st,adc-channels' for idx %d\n", 615 chan_idx); 616 return ret; 617 } 618 if (ch->channel >= dfsdm->num_chs) { 619 dev_err(&indio_dev->dev, 620 " Error bad channel number %d (max = %d)\n", 621 ch->channel, dfsdm->num_chs); 622 return -EINVAL; 623 } 624 625 ret = of_property_read_string_index(indio_dev->dev.of_node, 626 "st,adc-channel-names", chan_idx, 627 &ch->datasheet_name); 628 if (ret < 0) { 629 dev_err(&indio_dev->dev, 630 " Error parsing 'st,adc-channel-names' for idx %d\n", 631 chan_idx); 632 return ret; 633 } 634 635 df_ch = &dfsdm->ch_list[ch->channel]; 636 df_ch->id = ch->channel; 637 638 ret = of_property_read_string_index(indio_dev->dev.of_node, 639 "st,adc-channel-types", chan_idx, 640 &of_str); 641 if (!ret) { 642 val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_type); 643 if (val < 0) 644 return val; 645 } else { 646 val = 0; 647 } 648 df_ch->type = val; 649 650 ret = of_property_read_string_index(indio_dev->dev.of_node, 651 "st,adc-channel-clk-src", chan_idx, 652 &of_str); 653 if (!ret) { 654 val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_src); 655 if (val < 0) 656 return val; 657 } else { 658 val = 0; 659 } 660 df_ch->src = val; 661 662 ret = of_property_read_u32_index(indio_dev->dev.of_node, 663 "st,adc-alt-channel", chan_idx, 664 &df_ch->alt_si); 665 if (ret < 0) 666 df_ch->alt_si = 0; 667 668 return 0; 669 } 670 671 static int stm32_dfsdm_generic_channel_parse_of(struct stm32_dfsdm *dfsdm, 672 struct iio_dev *indio_dev, 673 struct iio_chan_spec *ch, 674 struct fwnode_handle *node) 675 { 676 struct stm32_dfsdm_channel *df_ch; 677 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 678 struct iio_backend *backend; 679 const char *of_str; 680 int ret, val; 681 682 ret = fwnode_property_read_u32(node, "reg", &ch->channel); 683 if (ret < 0) { 684 dev_err(&indio_dev->dev, "Missing channel index %d\n", ret); 685 return ret; 686 } 687 688 if (ch->channel >= dfsdm->num_chs) { 689 dev_err(&indio_dev->dev, " Error bad channel number %d (max = %d)\n", 690 ch->channel, dfsdm->num_chs); 691 return -EINVAL; 692 } 693 694 if (fwnode_property_present(node, "label")) { 695 /* label is optional */ 696 ret = fwnode_property_read_string(node, "label", &ch->datasheet_name); 697 if (ret < 0) { 698 dev_err(&indio_dev->dev, 699 " Error parsing 'label' for idx %d\n", ch->channel); 700 return ret; 701 } 702 } 703 704 df_ch = &dfsdm->ch_list[ch->channel]; 705 df_ch->id = ch->channel; 706 707 ret = fwnode_property_read_string(node, "st,adc-channel-type", &of_str); 708 if (!ret) { 709 val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_type); 710 if (val < 0) 711 return val; 712 } else { 713 val = 0; 714 } 715 df_ch->type = val; 716 717 ret = fwnode_property_read_string(node, "st,adc-channel-clk-src", &of_str); 718 if (!ret) { 719 val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_src); 720 if (val < 0) 721 return val; 722 } else { 723 val = 0; 724 } 725 df_ch->src = val; 726 727 ret = fwnode_property_read_u32(node, "st,adc-alt-channel", &df_ch->alt_si); 728 if (ret != -EINVAL) 729 df_ch->alt_si = 0; 730 731 if (adc->dev_data->type == DFSDM_IIO) { 732 backend = devm_iio_backend_fwnode_get(&indio_dev->dev, NULL, node); 733 if (IS_ERR(backend)) 734 return dev_err_probe(&indio_dev->dev, PTR_ERR(backend), 735 "Failed to get backend\n"); 736 adc->backend[ch->scan_index] = backend; 737 } 738 739 return 0; 740 } 741 742 static ssize_t dfsdm_adc_audio_get_spiclk(struct iio_dev *indio_dev, 743 uintptr_t priv, 744 const struct iio_chan_spec *chan, 745 char *buf) 746 { 747 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 748 749 return snprintf(buf, PAGE_SIZE, "%d\n", adc->spi_freq); 750 } 751 752 static int dfsdm_adc_set_samp_freq(struct iio_dev *indio_dev, 753 unsigned int sample_freq, 754 unsigned int spi_freq) 755 { 756 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 757 unsigned int oversamp; 758 int ret; 759 760 oversamp = DIV_ROUND_CLOSEST(spi_freq, sample_freq); 761 if (spi_freq % sample_freq) 762 dev_dbg(&indio_dev->dev, 763 "Rate not accurate. requested (%u), actual (%u)\n", 764 sample_freq, spi_freq / oversamp); 765 766 ret = stm32_dfsdm_compute_all_osrs(indio_dev, oversamp); 767 if (ret < 0) 768 return ret; 769 770 adc->sample_freq = spi_freq / oversamp; 771 adc->oversamp = oversamp; 772 773 return 0; 774 } 775 776 static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev, 777 uintptr_t priv, 778 const struct iio_chan_spec *chan, 779 const char *buf, size_t len) 780 { 781 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 782 struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel]; 783 unsigned int sample_freq = adc->sample_freq; 784 unsigned int spi_freq; 785 int ret; 786 787 dev_err(&indio_dev->dev, "enter %s\n", __func__); 788 /* If DFSDM is master on SPI, SPI freq can not be updated */ 789 if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL) 790 return -EPERM; 791 792 ret = kstrtoint(buf, 0, &spi_freq); 793 if (ret) 794 return ret; 795 796 if (!spi_freq) 797 return -EINVAL; 798 799 if (sample_freq) { 800 ret = dfsdm_adc_set_samp_freq(indio_dev, sample_freq, spi_freq); 801 if (ret < 0) 802 return ret; 803 } 804 adc->spi_freq = spi_freq; 805 806 return len; 807 } 808 809 static int stm32_dfsdm_start_conv(struct iio_dev *indio_dev, 810 struct iio_trigger *trig) 811 { 812 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 813 struct regmap *regmap = adc->dfsdm->regmap; 814 int ret; 815 816 ret = stm32_dfsdm_channels_configure(indio_dev, adc->fl_id, trig); 817 if (ret < 0) 818 return ret; 819 820 ret = stm32_dfsdm_start_channel(indio_dev); 821 if (ret < 0) 822 return ret; 823 824 ret = stm32_dfsdm_filter_configure(indio_dev, adc->fl_id, trig); 825 if (ret < 0) 826 goto stop_channels; 827 828 ret = stm32_dfsdm_start_filter(adc, adc->fl_id, trig); 829 if (ret < 0) 830 goto filter_unconfigure; 831 832 return 0; 833 834 filter_unconfigure: 835 regmap_clear_bits(regmap, DFSDM_CR1(adc->fl_id), DFSDM_CR1_CFG_MASK); 836 stop_channels: 837 stm32_dfsdm_stop_channel(indio_dev); 838 839 return ret; 840 } 841 842 static void stm32_dfsdm_stop_conv(struct iio_dev *indio_dev) 843 { 844 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 845 struct regmap *regmap = adc->dfsdm->regmap; 846 847 stm32_dfsdm_stop_filter(adc->dfsdm, adc->fl_id); 848 849 regmap_clear_bits(regmap, DFSDM_CR1(adc->fl_id), DFSDM_CR1_CFG_MASK); 850 851 stm32_dfsdm_stop_channel(indio_dev); 852 } 853 854 static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev, 855 unsigned int val) 856 { 857 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 858 unsigned int watermark = DFSDM_DMA_BUFFER_SIZE / 2; 859 unsigned int rx_buf_sz = DFSDM_DMA_BUFFER_SIZE; 860 861 /* 862 * DMA cyclic transfers are used, buffer is split into two periods. 863 * There should be : 864 * - always one buffer (period) DMA is working on 865 * - one buffer (period) driver pushed to ASoC side. 866 */ 867 watermark = min(watermark, val * (unsigned int)(sizeof(u32))); 868 adc->buf_sz = min(rx_buf_sz, watermark * 2 * adc->nconv); 869 870 return 0; 871 } 872 873 static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_adc *adc) 874 { 875 struct dma_tx_state state; 876 enum dma_status status; 877 878 status = dmaengine_tx_status(adc->dma_chan, 879 adc->dma_chan->cookie, 880 &state); 881 if (status == DMA_IN_PROGRESS) { 882 /* Residue is size in bytes from end of buffer */ 883 unsigned int i = adc->buf_sz - state.residue; 884 unsigned int size; 885 886 /* Return available bytes */ 887 if (i >= adc->bufi) 888 size = i - adc->bufi; 889 else 890 size = adc->buf_sz + i - adc->bufi; 891 892 return size; 893 } 894 895 return 0; 896 } 897 898 static inline void stm32_dfsdm_process_data(struct stm32_dfsdm_adc *adc, 899 s32 *buffer) 900 { 901 struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; 902 struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast]; 903 unsigned int i = adc->nconv; 904 s32 *ptr = buffer; 905 906 while (i--) { 907 /* Mask 8 LSB that contains the channel ID */ 908 *ptr &= 0xFFFFFF00; 909 /* Convert 2^(n-1) sample to 2^(n-1)-1 to avoid wrap-around */ 910 if (*ptr > flo->max) 911 *ptr -= 1; 912 /* 913 * Samples from filter are retrieved with 23 bits resolution 914 * or less. Shift left to align MSB on 24 bits. 915 */ 916 *ptr <<= flo->lshift; 917 918 ptr++; 919 } 920 } 921 922 static void stm32_dfsdm_dma_buffer_done(void *data) 923 { 924 struct iio_dev *indio_dev = data; 925 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 926 int available = stm32_dfsdm_adc_dma_residue(adc); 927 size_t old_pos; 928 929 /* 930 * FIXME: In Kernel interface does not support cyclic DMA buffer,and 931 * offers only an interface to push data samples per samples. 932 * For this reason IIO buffer interface is not used and interface is 933 * bypassed using a private callback registered by ASoC. 934 * This should be a temporary solution waiting a cyclic DMA engine 935 * support in IIO. 936 */ 937 938 dev_dbg(&indio_dev->dev, "pos = %d, available = %d\n", 939 adc->bufi, available); 940 old_pos = adc->bufi; 941 942 while (available >= indio_dev->scan_bytes) { 943 s32 *buffer = (s32 *)&adc->rx_buf[adc->bufi]; 944 945 stm32_dfsdm_process_data(adc, buffer); 946 947 available -= indio_dev->scan_bytes; 948 adc->bufi += indio_dev->scan_bytes; 949 if (adc->bufi >= adc->buf_sz) { 950 if (adc->cb) 951 adc->cb(&adc->rx_buf[old_pos], 952 adc->buf_sz - old_pos, adc->cb_priv); 953 adc->bufi = 0; 954 old_pos = 0; 955 } 956 /* 957 * In DMA mode the trigger services of IIO are not used 958 * (e.g. no call to iio_trigger_poll). 959 * Calling irq handler associated to the hardware trigger is not 960 * relevant as the conversions have already been done. Data 961 * transfers are performed directly in DMA callback instead. 962 * This implementation avoids to call trigger irq handler that 963 * may sleep, in an atomic context (DMA irq handler context). 964 */ 965 if (adc->dev_data->type == DFSDM_IIO) 966 iio_push_to_buffers(indio_dev, buffer); 967 } 968 if (adc->cb) 969 adc->cb(&adc->rx_buf[old_pos], adc->bufi - old_pos, 970 adc->cb_priv); 971 } 972 973 static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev) 974 { 975 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 976 /* 977 * The DFSDM supports half-word transfers. However, for 16 bits record, 978 * 4 bytes buswidth is kept, to avoid losing samples LSBs when left 979 * shift is required. 980 */ 981 struct dma_slave_config config = { 982 .src_addr = (dma_addr_t)adc->dfsdm->phys_base, 983 .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES, 984 }; 985 struct dma_async_tx_descriptor *desc; 986 dma_cookie_t cookie; 987 int ret; 988 989 if (!adc->dma_chan) 990 return -EINVAL; 991 992 dev_dbg(&indio_dev->dev, "size=%d watermark=%d\n", 993 adc->buf_sz, adc->buf_sz / 2); 994 995 if (adc->nconv == 1 && !indio_dev->trig) 996 config.src_addr += DFSDM_RDATAR(adc->fl_id); 997 else 998 config.src_addr += DFSDM_JDATAR(adc->fl_id); 999 ret = dmaengine_slave_config(adc->dma_chan, &config); 1000 if (ret) 1001 return ret; 1002 1003 /* Prepare a DMA cyclic transaction */ 1004 desc = dmaengine_prep_dma_cyclic(adc->dma_chan, 1005 adc->dma_buf, 1006 adc->buf_sz, adc->buf_sz / 2, 1007 DMA_DEV_TO_MEM, 1008 DMA_PREP_INTERRUPT); 1009 if (!desc) 1010 return -EBUSY; 1011 1012 desc->callback = stm32_dfsdm_dma_buffer_done; 1013 desc->callback_param = indio_dev; 1014 1015 cookie = dmaengine_submit(desc); 1016 ret = dma_submit_error(cookie); 1017 if (ret) 1018 goto err_stop_dma; 1019 1020 /* Issue pending DMA requests */ 1021 dma_async_issue_pending(adc->dma_chan); 1022 1023 if (adc->nconv == 1 && !indio_dev->trig) { 1024 /* Enable regular DMA transfer*/ 1025 ret = regmap_set_bits(adc->dfsdm->regmap, 1026 DFSDM_CR1(adc->fl_id), 1027 DFSDM_CR1_RDMAEN_MASK); 1028 } else { 1029 /* Enable injected DMA transfer*/ 1030 ret = regmap_set_bits(adc->dfsdm->regmap, 1031 DFSDM_CR1(adc->fl_id), 1032 DFSDM_CR1_JDMAEN_MASK); 1033 } 1034 1035 if (ret < 0) 1036 goto err_stop_dma; 1037 1038 return 0; 1039 1040 err_stop_dma: 1041 dmaengine_terminate_all(adc->dma_chan); 1042 1043 return ret; 1044 } 1045 1046 static void stm32_dfsdm_adc_dma_stop(struct iio_dev *indio_dev) 1047 { 1048 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1049 1050 if (!adc->dma_chan) 1051 return; 1052 1053 regmap_clear_bits(adc->dfsdm->regmap, DFSDM_CR1(adc->fl_id), 1054 DFSDM_CR1_RDMAEN_MASK | DFSDM_CR1_JDMAEN_MASK); 1055 dmaengine_terminate_all(adc->dma_chan); 1056 } 1057 1058 static int stm32_dfsdm_update_scan_mode(struct iio_dev *indio_dev, 1059 const unsigned long *scan_mask) 1060 { 1061 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1062 1063 adc->nconv = bitmap_weight(scan_mask, iio_get_masklength(indio_dev)); 1064 adc->smask = *scan_mask; 1065 1066 dev_dbg(&indio_dev->dev, "nconv=%d mask=%lx\n", adc->nconv, *scan_mask); 1067 1068 return 0; 1069 } 1070 1071 static int stm32_dfsdm_postenable(struct iio_dev *indio_dev) 1072 { 1073 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1074 int i = 0; 1075 int ret; 1076 1077 /* Reset adc buffer index */ 1078 adc->bufi = 0; 1079 1080 if (adc->hwc) { 1081 ret = iio_hw_consumer_enable(adc->hwc); 1082 if (ret < 0) 1083 return ret; 1084 } 1085 1086 if (adc->backend) { 1087 while (adc->backend[i]) { 1088 ret = iio_backend_enable(adc->backend[i]); 1089 if (ret < 0) 1090 return ret; 1091 i++; 1092 } 1093 } 1094 1095 ret = stm32_dfsdm_start_dfsdm(adc->dfsdm); 1096 if (ret < 0) 1097 goto err_stop_hwc; 1098 1099 ret = stm32_dfsdm_adc_dma_start(indio_dev); 1100 if (ret) { 1101 dev_err(&indio_dev->dev, "Can't start DMA\n"); 1102 goto stop_dfsdm; 1103 } 1104 1105 ret = stm32_dfsdm_start_conv(indio_dev, indio_dev->trig); 1106 if (ret) { 1107 dev_err(&indio_dev->dev, "Can't start conversion\n"); 1108 goto err_stop_dma; 1109 } 1110 1111 return 0; 1112 1113 err_stop_dma: 1114 stm32_dfsdm_adc_dma_stop(indio_dev); 1115 stop_dfsdm: 1116 stm32_dfsdm_stop_dfsdm(adc->dfsdm); 1117 err_stop_hwc: 1118 if (adc->hwc) 1119 iio_hw_consumer_disable(adc->hwc); 1120 1121 return ret; 1122 } 1123 1124 static int stm32_dfsdm_predisable(struct iio_dev *indio_dev) 1125 { 1126 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1127 int i = 0; 1128 1129 stm32_dfsdm_stop_conv(indio_dev); 1130 1131 stm32_dfsdm_adc_dma_stop(indio_dev); 1132 1133 stm32_dfsdm_stop_dfsdm(adc->dfsdm); 1134 1135 if (adc->backend) { 1136 while (adc->backend[i]) { 1137 iio_backend_disable(adc->backend[i]); 1138 i++; 1139 } 1140 } 1141 1142 if (adc->hwc) 1143 iio_hw_consumer_disable(adc->hwc); 1144 1145 return 0; 1146 } 1147 1148 static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = { 1149 .postenable = &stm32_dfsdm_postenable, 1150 .predisable = &stm32_dfsdm_predisable, 1151 }; 1152 1153 /** 1154 * stm32_dfsdm_get_buff_cb() - register a callback that will be called when 1155 * DMA transfer period is achieved. 1156 * 1157 * @iio_dev: Handle to IIO device. 1158 * @cb: Pointer to callback function: 1159 * - data: pointer to data buffer 1160 * - size: size in byte of the data buffer 1161 * - private: pointer to consumer private structure. 1162 * @private: Pointer to consumer private structure. 1163 */ 1164 int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev, 1165 int (*cb)(const void *data, size_t size, 1166 void *private), 1167 void *private) 1168 { 1169 struct stm32_dfsdm_adc *adc; 1170 1171 if (!iio_dev) 1172 return -EINVAL; 1173 adc = iio_priv(iio_dev); 1174 1175 adc->cb = cb; 1176 adc->cb_priv = private; 1177 1178 return 0; 1179 } 1180 EXPORT_SYMBOL_GPL(stm32_dfsdm_get_buff_cb); 1181 1182 /** 1183 * stm32_dfsdm_release_buff_cb - unregister buffer callback 1184 * 1185 * @iio_dev: Handle to IIO device. 1186 */ 1187 int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev) 1188 { 1189 struct stm32_dfsdm_adc *adc; 1190 1191 if (!iio_dev) 1192 return -EINVAL; 1193 adc = iio_priv(iio_dev); 1194 1195 adc->cb = NULL; 1196 adc->cb_priv = NULL; 1197 1198 return 0; 1199 } 1200 EXPORT_SYMBOL_GPL(stm32_dfsdm_release_buff_cb); 1201 1202 static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev, 1203 const struct iio_chan_spec *chan, int *res) 1204 { 1205 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1206 long time_left; 1207 int ret; 1208 1209 reinit_completion(&adc->completion); 1210 1211 adc->buffer = res; 1212 1213 ret = stm32_dfsdm_start_dfsdm(adc->dfsdm); 1214 if (ret < 0) 1215 return ret; 1216 1217 ret = regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id), 1218 DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(1)); 1219 if (ret < 0) 1220 goto stop_dfsdm; 1221 1222 adc->nconv = 1; 1223 adc->smask = BIT(chan->scan_index); 1224 ret = stm32_dfsdm_start_conv(indio_dev, NULL); 1225 if (ret < 0) { 1226 regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id), 1227 DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0)); 1228 goto stop_dfsdm; 1229 } 1230 1231 time_left = wait_for_completion_interruptible_timeout(&adc->completion, 1232 DFSDM_TIMEOUT); 1233 1234 /* Mask IRQ for regular conversion achievement*/ 1235 regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id), 1236 DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0)); 1237 1238 if (time_left == 0) 1239 ret = -ETIMEDOUT; 1240 else if (time_left < 0) 1241 ret = time_left; 1242 else 1243 ret = IIO_VAL_INT; 1244 1245 stm32_dfsdm_stop_conv(indio_dev); 1246 1247 stm32_dfsdm_process_data(adc, res); 1248 1249 stop_dfsdm: 1250 stm32_dfsdm_stop_dfsdm(adc->dfsdm); 1251 1252 return ret; 1253 } 1254 1255 static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev, 1256 struct iio_chan_spec const *chan, 1257 int val, int val2, long mask) 1258 { 1259 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1260 struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel]; 1261 unsigned int spi_freq; 1262 int ret = -EINVAL; 1263 1264 switch (ch->src) { 1265 case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL: 1266 spi_freq = adc->dfsdm->spi_master_freq; 1267 break; 1268 case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING: 1269 case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING: 1270 spi_freq = adc->dfsdm->spi_master_freq / 2; 1271 break; 1272 default: 1273 spi_freq = adc->spi_freq; 1274 } 1275 1276 switch (mask) { 1277 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 1278 ret = iio_device_claim_direct_mode(indio_dev); 1279 if (ret) 1280 return ret; 1281 1282 ret = stm32_dfsdm_compute_all_osrs(indio_dev, val); 1283 if (!ret) { 1284 dev_dbg(&indio_dev->dev, 1285 "Sampling rate changed from (%u) to (%u)\n", 1286 adc->sample_freq, spi_freq / val); 1287 adc->oversamp = val; 1288 adc->sample_freq = spi_freq / val; 1289 } 1290 iio_device_release_direct_mode(indio_dev); 1291 return ret; 1292 1293 case IIO_CHAN_INFO_SAMP_FREQ: 1294 if (!val) 1295 return -EINVAL; 1296 1297 ret = iio_device_claim_direct_mode(indio_dev); 1298 if (ret) 1299 return ret; 1300 1301 ret = dfsdm_adc_set_samp_freq(indio_dev, val, spi_freq); 1302 iio_device_release_direct_mode(indio_dev); 1303 return ret; 1304 } 1305 1306 return -EINVAL; 1307 } 1308 1309 static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev, 1310 struct iio_chan_spec const *chan, int *val, 1311 int *val2, long mask) 1312 { 1313 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1314 1315 struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id]; 1316 struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast]; 1317 u32 max = flo->max << (flo->lshift - chan->scan_type.shift); 1318 int idx = chan->scan_index; 1319 int ret; 1320 1321 if (flo->lshift < chan->scan_type.shift) 1322 max = flo->max >> (chan->scan_type.shift - flo->lshift); 1323 1324 switch (mask) { 1325 case IIO_CHAN_INFO_RAW: 1326 ret = iio_device_claim_direct_mode(indio_dev); 1327 if (ret) 1328 return ret; 1329 if (adc->hwc) 1330 ret = iio_hw_consumer_enable(adc->hwc); 1331 if (adc->backend) 1332 ret = iio_backend_enable(adc->backend[idx]); 1333 if (ret < 0) { 1334 dev_err(&indio_dev->dev, 1335 "%s: IIO enable failed (channel %d)\n", 1336 __func__, chan->channel); 1337 iio_device_release_direct_mode(indio_dev); 1338 return ret; 1339 } 1340 ret = stm32_dfsdm_single_conv(indio_dev, chan, val); 1341 if (adc->hwc) 1342 iio_hw_consumer_disable(adc->hwc); 1343 if (adc->backend) 1344 iio_backend_disable(adc->backend[idx]); 1345 if (ret < 0) { 1346 dev_err(&indio_dev->dev, 1347 "%s: Conversion failed (channel %d)\n", 1348 __func__, chan->channel); 1349 iio_device_release_direct_mode(indio_dev); 1350 return ret; 1351 } 1352 iio_device_release_direct_mode(indio_dev); 1353 return IIO_VAL_INT; 1354 1355 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 1356 *val = adc->oversamp; 1357 1358 return IIO_VAL_INT; 1359 1360 case IIO_CHAN_INFO_SAMP_FREQ: 1361 *val = adc->sample_freq; 1362 1363 return IIO_VAL_INT; 1364 1365 case IIO_CHAN_INFO_SCALE: 1366 /* 1367 * Scale is expressed in mV. 1368 * When fast mode is disabled, actual resolution may be lower 1369 * than 2^n, where n = realbits - 1. 1370 * This leads to underestimating the input voltage. 1371 * To compensate this deviation, the voltage reference can be 1372 * corrected with a factor = realbits resolution / actual max 1373 */ 1374 if (adc->backend) { 1375 ret = iio_backend_read_scale(adc->backend[idx], chan, val, NULL); 1376 if (ret < 0) 1377 return ret; 1378 1379 *val = div_u64((u64)*val * (u64)BIT(DFSDM_DATA_RES - 1), max); 1380 *val2 = chan->scan_type.realbits; 1381 if (chan->differential) 1382 *val *= 2; 1383 } 1384 return IIO_VAL_FRACTIONAL_LOG2; 1385 1386 case IIO_CHAN_INFO_OFFSET: 1387 /* 1388 * DFSDM output data are in the range [-2^n, 2^n], 1389 * with n = realbits - 1. 1390 * - Differential modulator: 1391 * Offset correspond to SD modulator offset. 1392 * - Single ended modulator: 1393 * Input is in [0V, Vref] range, 1394 * where 0V corresponds to -2^n, and Vref to 2^n. 1395 * Add 2^n to offset. (i.e. middle of input range) 1396 * offset = offset(sd) * vref / res(sd) * max / vref. 1397 */ 1398 if (adc->backend) { 1399 ret = iio_backend_read_offset(adc->backend[idx], chan, val, NULL); 1400 if (ret < 0) 1401 return ret; 1402 1403 *val = div_u64((u64)max * *val, BIT(*val2 - 1)); 1404 if (!chan->differential) 1405 *val += max; 1406 } 1407 return IIO_VAL_INT; 1408 } 1409 1410 return -EINVAL; 1411 } 1412 1413 static int stm32_dfsdm_validate_trigger(struct iio_dev *indio_dev, 1414 struct iio_trigger *trig) 1415 { 1416 return stm32_dfsdm_get_jextsel(indio_dev, trig) < 0 ? -EINVAL : 0; 1417 } 1418 1419 static const struct iio_info stm32_dfsdm_info_audio = { 1420 .hwfifo_set_watermark = stm32_dfsdm_set_watermark, 1421 .read_raw = stm32_dfsdm_read_raw, 1422 .write_raw = stm32_dfsdm_write_raw, 1423 .update_scan_mode = stm32_dfsdm_update_scan_mode, 1424 }; 1425 1426 static const struct iio_info stm32_dfsdm_info_adc = { 1427 .hwfifo_set_watermark = stm32_dfsdm_set_watermark, 1428 .read_raw = stm32_dfsdm_read_raw, 1429 .write_raw = stm32_dfsdm_write_raw, 1430 .update_scan_mode = stm32_dfsdm_update_scan_mode, 1431 .validate_trigger = stm32_dfsdm_validate_trigger, 1432 }; 1433 1434 static irqreturn_t stm32_dfsdm_irq(int irq, void *arg) 1435 { 1436 struct iio_dev *indio_dev = arg; 1437 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1438 struct regmap *regmap = adc->dfsdm->regmap; 1439 unsigned int status, int_en; 1440 1441 regmap_read(regmap, DFSDM_ISR(adc->fl_id), &status); 1442 regmap_read(regmap, DFSDM_CR2(adc->fl_id), &int_en); 1443 1444 if (status & DFSDM_ISR_REOCF_MASK) { 1445 /* Read the data register clean the IRQ status */ 1446 regmap_read(regmap, DFSDM_RDATAR(adc->fl_id), adc->buffer); 1447 complete(&adc->completion); 1448 } 1449 1450 if (status & DFSDM_ISR_ROVRF_MASK) { 1451 if (int_en & DFSDM_CR2_ROVRIE_MASK) 1452 dev_warn(&indio_dev->dev, "Overrun detected\n"); 1453 regmap_set_bits(regmap, DFSDM_ICR(adc->fl_id), 1454 DFSDM_ICR_CLRROVRF_MASK); 1455 } 1456 1457 return IRQ_HANDLED; 1458 } 1459 1460 /* 1461 * Define external info for SPI Frequency and audio sampling rate that can be 1462 * configured by ASoC driver through consumer.h API 1463 */ 1464 static const struct iio_chan_spec_ext_info dfsdm_adc_audio_ext_info[] = { 1465 /* spi_clk_freq : clock freq on SPI/manchester bus used by channel */ 1466 { 1467 .name = "spi_clk_freq", 1468 .shared = IIO_SHARED_BY_TYPE, 1469 .read = dfsdm_adc_audio_get_spiclk, 1470 .write = dfsdm_adc_audio_set_spiclk, 1471 }, 1472 { } 1473 }; 1474 1475 static void stm32_dfsdm_dma_release(struct iio_dev *indio_dev) 1476 { 1477 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1478 1479 if (adc->dma_chan) { 1480 dma_free_coherent(adc->dma_chan->device->dev, 1481 DFSDM_DMA_BUFFER_SIZE, 1482 adc->rx_buf, adc->dma_buf); 1483 dma_release_channel(adc->dma_chan); 1484 } 1485 } 1486 1487 static int stm32_dfsdm_dma_request(struct device *dev, 1488 struct iio_dev *indio_dev) 1489 { 1490 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1491 1492 adc->dma_chan = dma_request_chan(dev, "rx"); 1493 if (IS_ERR(adc->dma_chan)) { 1494 int ret = PTR_ERR(adc->dma_chan); 1495 1496 adc->dma_chan = NULL; 1497 return ret; 1498 } 1499 1500 adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, 1501 DFSDM_DMA_BUFFER_SIZE, 1502 &adc->dma_buf, GFP_KERNEL); 1503 if (!adc->rx_buf) { 1504 dma_release_channel(adc->dma_chan); 1505 return -ENOMEM; 1506 } 1507 1508 indio_dev->modes |= INDIO_BUFFER_SOFTWARE; 1509 indio_dev->setup_ops = &stm32_dfsdm_buffer_setup_ops; 1510 1511 return 0; 1512 } 1513 1514 static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev, struct iio_chan_spec *ch, 1515 struct fwnode_handle *child) 1516 { 1517 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1518 int ret; 1519 1520 if (child) 1521 ret = stm32_dfsdm_generic_channel_parse_of(adc->dfsdm, indio_dev, ch, child); 1522 else /* Legacy binding */ 1523 ret = stm32_dfsdm_channel_parse_of(adc->dfsdm, indio_dev, ch); 1524 if (ret < 0) 1525 return dev_err_probe(&indio_dev->dev, ret, "Failed to parse channel\n"); 1526 1527 ch->type = IIO_VOLTAGE; 1528 ch->indexed = 1; 1529 1530 /* 1531 * IIO_CHAN_INFO_RAW: used to compute regular conversion 1532 * IIO_CHAN_INFO_OVERSAMPLING_RATIO: used to set oversampling 1533 */ 1534 if (child) { 1535 ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 1536 BIT(IIO_CHAN_INFO_SCALE) | 1537 BIT(IIO_CHAN_INFO_OFFSET); 1538 } else { 1539 /* Legacy. Scaling not supported */ 1540 ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); 1541 } 1542 1543 ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | 1544 BIT(IIO_CHAN_INFO_SAMP_FREQ); 1545 1546 if (adc->dev_data->type == DFSDM_AUDIO) { 1547 ch->ext_info = dfsdm_adc_audio_ext_info; 1548 ch->scan_index = 0; 1549 } else { 1550 ch->scan_type.shift = 8; 1551 } 1552 ch->scan_type.sign = 's'; 1553 ch->scan_type.realbits = 24; 1554 ch->scan_type.storagebits = 32; 1555 1556 return stm32_dfsdm_chan_configure(adc->dfsdm, 1557 &adc->dfsdm->ch_list[ch->channel]); 1558 } 1559 1560 static int stm32_dfsdm_chan_init(struct iio_dev *indio_dev, struct iio_chan_spec *channels) 1561 { 1562 int num_ch = indio_dev->num_channels; 1563 int chan_idx = 0; 1564 int ret; 1565 1566 for (chan_idx = 0; chan_idx < num_ch; chan_idx++) { 1567 channels[chan_idx].scan_index = chan_idx; 1568 ret = stm32_dfsdm_adc_chan_init_one(indio_dev, &channels[chan_idx], NULL); 1569 if (ret < 0) 1570 return dev_err_probe(&indio_dev->dev, ret, "Channels init failed\n"); 1571 } 1572 1573 return 0; 1574 } 1575 1576 static int stm32_dfsdm_generic_chan_init(struct iio_dev *indio_dev, struct iio_chan_spec *channels) 1577 { 1578 int chan_idx = 0, ret; 1579 1580 device_for_each_child_node_scoped(&indio_dev->dev, child) { 1581 /* Skip DAI node in DFSDM audio nodes */ 1582 if (fwnode_property_present(child, "compatible")) 1583 continue; 1584 1585 channels[chan_idx].scan_index = chan_idx; 1586 ret = stm32_dfsdm_adc_chan_init_one(indio_dev, &channels[chan_idx], child); 1587 if (ret < 0) 1588 return dev_err_probe(&indio_dev->dev, ret, "Channels init failed\n"); 1589 1590 chan_idx++; 1591 } 1592 1593 return chan_idx; 1594 } 1595 1596 static int stm32_dfsdm_audio_init(struct device *dev, struct iio_dev *indio_dev) 1597 { 1598 struct iio_chan_spec *ch; 1599 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1600 struct stm32_dfsdm_channel *d_ch; 1601 bool legacy = false; 1602 int num_ch, ret; 1603 1604 /* If st,adc-channels is defined legacy binding is used. Else assume generic binding. */ 1605 num_ch = of_property_count_u32_elems(indio_dev->dev.of_node, "st,adc-channels"); 1606 if (num_ch == 1) 1607 legacy = true; 1608 1609 ch = devm_kzalloc(&indio_dev->dev, sizeof(*ch), GFP_KERNEL); 1610 if (!ch) 1611 return -ENOMEM; 1612 1613 indio_dev->num_channels = 1; 1614 indio_dev->channels = ch; 1615 1616 if (legacy) 1617 ret = stm32_dfsdm_chan_init(indio_dev, ch); 1618 else 1619 ret = stm32_dfsdm_generic_chan_init(indio_dev, ch); 1620 1621 if (ret < 0) { 1622 dev_err(&indio_dev->dev, "Channels init failed\n"); 1623 return ret; 1624 } 1625 ch->info_mask_separate = BIT(IIO_CHAN_INFO_SAMP_FREQ); 1626 1627 d_ch = &adc->dfsdm->ch_list[ch->channel]; 1628 if (d_ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL) 1629 adc->spi_freq = adc->dfsdm->spi_master_freq; 1630 1631 return stm32_dfsdm_dma_request(dev, indio_dev); 1632 } 1633 1634 static int stm32_dfsdm_adc_init(struct device *dev, struct iio_dev *indio_dev) 1635 { 1636 struct iio_chan_spec *ch; 1637 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1638 int num_ch, ret; 1639 bool legacy = false; 1640 1641 adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING; 1642 ret = stm32_dfsdm_compute_all_osrs(indio_dev, adc->oversamp); 1643 if (ret < 0) 1644 return ret; 1645 1646 num_ch = device_get_child_node_count(&indio_dev->dev); 1647 if (!num_ch) { 1648 /* No channels nodes found. Assume legacy binding */ 1649 num_ch = of_property_count_u32_elems(indio_dev->dev.of_node, "st,adc-channels"); 1650 if (num_ch < 0) { 1651 dev_err(&indio_dev->dev, "Bad st,adc-channels\n"); 1652 return num_ch; 1653 } 1654 1655 legacy = true; 1656 } 1657 1658 if (num_ch > adc->dfsdm->num_chs) { 1659 dev_err(&indio_dev->dev, "Number of channel [%d] exceeds [%d]\n", 1660 num_ch, adc->dfsdm->num_chs); 1661 return -EINVAL; 1662 } 1663 indio_dev->num_channels = num_ch; 1664 1665 if (legacy) { 1666 /* Bind to SD modulator IIO device. */ 1667 adc->hwc = devm_iio_hw_consumer_alloc(&indio_dev->dev); 1668 if (IS_ERR(adc->hwc)) 1669 return dev_err_probe(&indio_dev->dev, -EPROBE_DEFER, 1670 "waiting for SD modulator\n"); 1671 } else { 1672 /* Generic binding. SD modulator IIO device not used. Use SD modulator backend. */ 1673 adc->hwc = NULL; 1674 1675 adc->backend = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*adc->backend), 1676 GFP_KERNEL); 1677 if (!adc->backend) 1678 return -ENOMEM; 1679 } 1680 1681 ch = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*ch), GFP_KERNEL); 1682 if (!ch) 1683 return -ENOMEM; 1684 indio_dev->channels = ch; 1685 1686 if (legacy) 1687 ret = stm32_dfsdm_chan_init(indio_dev, ch); 1688 else 1689 ret = stm32_dfsdm_generic_chan_init(indio_dev, ch); 1690 if (ret < 0) 1691 return ret; 1692 1693 init_completion(&adc->completion); 1694 1695 /* Optionally request DMA */ 1696 ret = stm32_dfsdm_dma_request(dev, indio_dev); 1697 if (ret) { 1698 if (ret != -ENODEV) 1699 return dev_err_probe(dev, ret, 1700 "DMA channel request failed with\n"); 1701 1702 dev_dbg(dev, "No DMA support\n"); 1703 return 0; 1704 } 1705 1706 ret = iio_triggered_buffer_setup(indio_dev, 1707 &iio_pollfunc_store_time, NULL, 1708 &stm32_dfsdm_buffer_setup_ops); 1709 if (ret) { 1710 stm32_dfsdm_dma_release(indio_dev); 1711 dev_err(&indio_dev->dev, "buffer setup failed\n"); 1712 return ret; 1713 } 1714 1715 /* lptimer/timer hardware triggers */ 1716 indio_dev->modes |= INDIO_HARDWARE_TRIGGERED; 1717 1718 return 0; 1719 } 1720 1721 static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_adc_data = { 1722 .type = DFSDM_IIO, 1723 .init = stm32_dfsdm_adc_init, 1724 }; 1725 1726 static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_audio_data = { 1727 .type = DFSDM_AUDIO, 1728 .init = stm32_dfsdm_audio_init, 1729 }; 1730 1731 static const struct of_device_id stm32_dfsdm_adc_match[] = { 1732 { 1733 .compatible = "st,stm32-dfsdm-adc", 1734 .data = &stm32h7_dfsdm_adc_data, 1735 }, 1736 { 1737 .compatible = "st,stm32-dfsdm-dmic", 1738 .data = &stm32h7_dfsdm_audio_data, 1739 }, 1740 {} 1741 }; 1742 MODULE_DEVICE_TABLE(of, stm32_dfsdm_adc_match); 1743 1744 static int stm32_dfsdm_adc_probe(struct platform_device *pdev) 1745 { 1746 struct device *dev = &pdev->dev; 1747 struct stm32_dfsdm_adc *adc; 1748 struct device_node *np = dev->of_node; 1749 const struct stm32_dfsdm_dev_data *dev_data; 1750 struct iio_dev *iio; 1751 char *name; 1752 int ret, irq, val; 1753 1754 dev_data = of_device_get_match_data(dev); 1755 iio = devm_iio_device_alloc(dev, sizeof(*adc)); 1756 if (!iio) { 1757 dev_err(dev, "%s: Failed to allocate IIO\n", __func__); 1758 return -ENOMEM; 1759 } 1760 1761 adc = iio_priv(iio); 1762 adc->dfsdm = dev_get_drvdata(dev->parent); 1763 1764 iio->dev.of_node = np; 1765 iio->modes = INDIO_DIRECT_MODE; 1766 1767 platform_set_drvdata(pdev, iio); 1768 1769 ret = of_property_read_u32(dev->of_node, "reg", &adc->fl_id); 1770 if (ret != 0 || adc->fl_id >= adc->dfsdm->num_fls) { 1771 dev_err(dev, "Missing or bad reg property\n"); 1772 return -EINVAL; 1773 } 1774 1775 name = devm_kzalloc(dev, sizeof("dfsdm-adc0"), GFP_KERNEL); 1776 if (!name) 1777 return -ENOMEM; 1778 if (dev_data->type == DFSDM_AUDIO) { 1779 iio->info = &stm32_dfsdm_info_audio; 1780 snprintf(name, sizeof("dfsdm-pdm0"), "dfsdm-pdm%d", adc->fl_id); 1781 } else { 1782 iio->info = &stm32_dfsdm_info_adc; 1783 snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id); 1784 } 1785 iio->name = name; 1786 1787 /* 1788 * In a first step IRQs generated for channels are not treated. 1789 * So IRQ associated to filter instance 0 is dedicated to the Filter 0. 1790 */ 1791 irq = platform_get_irq(pdev, 0); 1792 if (irq < 0) 1793 return irq; 1794 1795 ret = devm_request_irq(dev, irq, stm32_dfsdm_irq, 1796 0, pdev->name, iio); 1797 if (ret < 0) { 1798 dev_err(dev, "Failed to request IRQ\n"); 1799 return ret; 1800 } 1801 1802 ret = of_property_read_u32(dev->of_node, "st,filter-order", &val); 1803 if (ret < 0) { 1804 dev_err(dev, "Failed to set filter order\n"); 1805 return ret; 1806 } 1807 1808 adc->dfsdm->fl_list[adc->fl_id].ford = val; 1809 1810 ret = of_property_read_u32(dev->of_node, "st,filter0-sync", &val); 1811 if (!ret) 1812 adc->dfsdm->fl_list[adc->fl_id].sync_mode = val; 1813 1814 adc->dev_data = dev_data; 1815 ret = dev_data->init(dev, iio); 1816 if (ret < 0) 1817 return ret; 1818 1819 ret = iio_device_register(iio); 1820 if (ret < 0) 1821 goto err_cleanup; 1822 1823 if (dev_data->type == DFSDM_AUDIO) { 1824 ret = of_platform_populate(np, NULL, NULL, dev); 1825 if (ret < 0) { 1826 dev_err(dev, "Failed to find an audio DAI\n"); 1827 goto err_unregister; 1828 } 1829 } 1830 1831 return 0; 1832 1833 err_unregister: 1834 iio_device_unregister(iio); 1835 err_cleanup: 1836 stm32_dfsdm_dma_release(iio); 1837 1838 return ret; 1839 } 1840 1841 static void stm32_dfsdm_adc_remove(struct platform_device *pdev) 1842 { 1843 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 1844 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1845 1846 if (adc->dev_data->type == DFSDM_AUDIO) 1847 of_platform_depopulate(&pdev->dev); 1848 iio_device_unregister(indio_dev); 1849 stm32_dfsdm_dma_release(indio_dev); 1850 } 1851 1852 static int stm32_dfsdm_adc_suspend(struct device *dev) 1853 { 1854 struct iio_dev *indio_dev = dev_get_drvdata(dev); 1855 1856 if (iio_buffer_enabled(indio_dev)) 1857 stm32_dfsdm_predisable(indio_dev); 1858 1859 return 0; 1860 } 1861 1862 static int stm32_dfsdm_adc_resume(struct device *dev) 1863 { 1864 struct iio_dev *indio_dev = dev_get_drvdata(dev); 1865 struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); 1866 const struct iio_chan_spec *chan; 1867 struct stm32_dfsdm_channel *ch; 1868 int i, ret; 1869 1870 /* restore channels configuration */ 1871 for (i = 0; i < indio_dev->num_channels; i++) { 1872 chan = indio_dev->channels + i; 1873 ch = &adc->dfsdm->ch_list[chan->channel]; 1874 ret = stm32_dfsdm_chan_configure(adc->dfsdm, ch); 1875 if (ret) 1876 return ret; 1877 } 1878 1879 if (iio_buffer_enabled(indio_dev)) 1880 stm32_dfsdm_postenable(indio_dev); 1881 1882 return 0; 1883 } 1884 1885 static DEFINE_SIMPLE_DEV_PM_OPS(stm32_dfsdm_adc_pm_ops, 1886 stm32_dfsdm_adc_suspend, 1887 stm32_dfsdm_adc_resume); 1888 1889 static struct platform_driver stm32_dfsdm_adc_driver = { 1890 .driver = { 1891 .name = "stm32-dfsdm-adc", 1892 .of_match_table = stm32_dfsdm_adc_match, 1893 .pm = pm_sleep_ptr(&stm32_dfsdm_adc_pm_ops), 1894 }, 1895 .probe = stm32_dfsdm_adc_probe, 1896 .remove = stm32_dfsdm_adc_remove, 1897 }; 1898 module_platform_driver(stm32_dfsdm_adc_driver); 1899 1900 MODULE_DESCRIPTION("STM32 sigma delta ADC"); 1901 MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>"); 1902 MODULE_LICENSE("GPL v2"); 1903 MODULE_IMPORT_NS("IIO_BACKEND"); 1904