1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * AD7124 SPI ADC driver 4 * 5 * Copyright 2018 Analog Devices Inc. 6 */ 7 #include <linux/bitfield.h> 8 #include <linux/bitops.h> 9 #include <linux/clk.h> 10 #include <linux/delay.h> 11 #include <linux/device.h> 12 #include <linux/err.h> 13 #include <linux/interrupt.h> 14 #include <linux/kernel.h> 15 #include <linux/kfifo.h> 16 #include <linux/module.h> 17 #include <linux/of_device.h> 18 #include <linux/regulator/consumer.h> 19 #include <linux/spi/spi.h> 20 21 #include <linux/iio/iio.h> 22 #include <linux/iio/adc/ad_sigma_delta.h> 23 #include <linux/iio/sysfs.h> 24 25 /* AD7124 registers */ 26 #define AD7124_COMMS 0x00 27 #define AD7124_STATUS 0x00 28 #define AD7124_ADC_CONTROL 0x01 29 #define AD7124_DATA 0x02 30 #define AD7124_IO_CONTROL_1 0x03 31 #define AD7124_IO_CONTROL_2 0x04 32 #define AD7124_ID 0x05 33 #define AD7124_ERROR 0x06 34 #define AD7124_ERROR_EN 0x07 35 #define AD7124_MCLK_COUNT 0x08 36 #define AD7124_CHANNEL(x) (0x09 + (x)) 37 #define AD7124_CONFIG(x) (0x19 + (x)) 38 #define AD7124_FILTER(x) (0x21 + (x)) 39 #define AD7124_OFFSET(x) (0x29 + (x)) 40 #define AD7124_GAIN(x) (0x31 + (x)) 41 42 /* AD7124_STATUS */ 43 #define AD7124_STATUS_POR_FLAG_MSK BIT(4) 44 45 /* AD7124_ADC_CONTROL */ 46 #define AD7124_ADC_STATUS_EN_MSK BIT(10) 47 #define AD7124_ADC_STATUS_EN(x) FIELD_PREP(AD7124_ADC_STATUS_EN_MSK, x) 48 #define AD7124_ADC_CTRL_REF_EN_MSK BIT(8) 49 #define AD7124_ADC_CTRL_REF_EN(x) FIELD_PREP(AD7124_ADC_CTRL_REF_EN_MSK, x) 50 #define AD7124_ADC_CTRL_PWR_MSK GENMASK(7, 6) 51 #define AD7124_ADC_CTRL_PWR(x) FIELD_PREP(AD7124_ADC_CTRL_PWR_MSK, x) 52 #define AD7124_ADC_CTRL_MODE_MSK GENMASK(5, 2) 53 #define AD7124_ADC_CTRL_MODE(x) FIELD_PREP(AD7124_ADC_CTRL_MODE_MSK, x) 54 55 /* AD7124 ID */ 56 #define AD7124_DEVICE_ID_MSK GENMASK(7, 4) 57 #define AD7124_DEVICE_ID_GET(x) FIELD_GET(AD7124_DEVICE_ID_MSK, x) 58 #define AD7124_SILICON_REV_MSK GENMASK(3, 0) 59 #define AD7124_SILICON_REV_GET(x) FIELD_GET(AD7124_SILICON_REV_MSK, x) 60 61 #define CHIPID_AD7124_4 0x0 62 #define CHIPID_AD7124_8 0x1 63 64 /* AD7124_CHANNEL_X */ 65 #define AD7124_CHANNEL_EN_MSK BIT(15) 66 #define AD7124_CHANNEL_EN(x) FIELD_PREP(AD7124_CHANNEL_EN_MSK, x) 67 #define AD7124_CHANNEL_SETUP_MSK GENMASK(14, 12) 68 #define AD7124_CHANNEL_SETUP(x) FIELD_PREP(AD7124_CHANNEL_SETUP_MSK, x) 69 #define AD7124_CHANNEL_AINP_MSK GENMASK(9, 5) 70 #define AD7124_CHANNEL_AINP(x) FIELD_PREP(AD7124_CHANNEL_AINP_MSK, x) 71 #define AD7124_CHANNEL_AINM_MSK GENMASK(4, 0) 72 #define AD7124_CHANNEL_AINM(x) FIELD_PREP(AD7124_CHANNEL_AINM_MSK, x) 73 74 /* AD7124_CONFIG_X */ 75 #define AD7124_CONFIG_BIPOLAR_MSK BIT(11) 76 #define AD7124_CONFIG_BIPOLAR(x) FIELD_PREP(AD7124_CONFIG_BIPOLAR_MSK, x) 77 #define AD7124_CONFIG_REF_SEL_MSK GENMASK(4, 3) 78 #define AD7124_CONFIG_REF_SEL(x) FIELD_PREP(AD7124_CONFIG_REF_SEL_MSK, x) 79 #define AD7124_CONFIG_PGA_MSK GENMASK(2, 0) 80 #define AD7124_CONFIG_PGA(x) FIELD_PREP(AD7124_CONFIG_PGA_MSK, x) 81 #define AD7124_CONFIG_IN_BUFF_MSK GENMASK(6, 5) 82 #define AD7124_CONFIG_IN_BUFF(x) FIELD_PREP(AD7124_CONFIG_IN_BUFF_MSK, x) 83 84 /* AD7124_FILTER_X */ 85 #define AD7124_FILTER_FS_MSK GENMASK(10, 0) 86 #define AD7124_FILTER_FS(x) FIELD_PREP(AD7124_FILTER_FS_MSK, x) 87 #define AD7124_FILTER_TYPE_MSK GENMASK(23, 21) 88 #define AD7124_FILTER_TYPE_SEL(x) FIELD_PREP(AD7124_FILTER_TYPE_MSK, x) 89 90 #define AD7124_SINC3_FILTER 2 91 #define AD7124_SINC4_FILTER 0 92 93 #define AD7124_CONF_ADDR_OFFSET 20 94 #define AD7124_MAX_CONFIGS 8 95 #define AD7124_MAX_CHANNELS 16 96 97 enum ad7124_ids { 98 ID_AD7124_4, 99 ID_AD7124_8, 100 }; 101 102 enum ad7124_ref_sel { 103 AD7124_REFIN1, 104 AD7124_REFIN2, 105 AD7124_INT_REF, 106 AD7124_AVDD_REF, 107 }; 108 109 enum ad7124_power_mode { 110 AD7124_LOW_POWER, 111 AD7124_MID_POWER, 112 AD7124_FULL_POWER, 113 }; 114 115 static const unsigned int ad7124_gain[8] = { 116 1, 2, 4, 8, 16, 32, 64, 128 117 }; 118 119 static const unsigned int ad7124_reg_size[] = { 120 1, 2, 3, 3, 2, 1, 3, 3, 1, 2, 2, 2, 2, 121 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 122 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 123 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 124 3, 3, 3, 3, 3 125 }; 126 127 static const int ad7124_master_clk_freq_hz[3] = { 128 [AD7124_LOW_POWER] = 76800, 129 [AD7124_MID_POWER] = 153600, 130 [AD7124_FULL_POWER] = 614400, 131 }; 132 133 static const char * const ad7124_ref_names[] = { 134 [AD7124_REFIN1] = "refin1", 135 [AD7124_REFIN2] = "refin2", 136 [AD7124_INT_REF] = "int", 137 [AD7124_AVDD_REF] = "avdd", 138 }; 139 140 struct ad7124_chip_info { 141 const char *name; 142 unsigned int chip_id; 143 unsigned int num_inputs; 144 }; 145 146 struct ad7124_channel_config { 147 bool live; 148 unsigned int cfg_slot; 149 enum ad7124_ref_sel refsel; 150 bool bipolar; 151 bool buf_positive; 152 bool buf_negative; 153 unsigned int vref_mv; 154 unsigned int pga_bits; 155 unsigned int odr; 156 unsigned int odr_sel_bits; 157 unsigned int filter_type; 158 }; 159 160 struct ad7124_channel { 161 unsigned int nr; 162 struct ad7124_channel_config cfg; 163 unsigned int ain; 164 unsigned int slot; 165 }; 166 167 struct ad7124_state { 168 const struct ad7124_chip_info *chip_info; 169 struct ad_sigma_delta sd; 170 struct ad7124_channel *channels; 171 struct regulator *vref[4]; 172 struct clk *mclk; 173 unsigned int adc_control; 174 unsigned int num_channels; 175 struct mutex cfgs_lock; /* lock for configs access */ 176 unsigned long cfg_slots_status; /* bitmap with slot status (1 means it is used) */ 177 DECLARE_KFIFO(live_cfgs_fifo, struct ad7124_channel_config *, AD7124_MAX_CONFIGS); 178 }; 179 180 static const struct iio_chan_spec ad7124_channel_template = { 181 .type = IIO_VOLTAGE, 182 .indexed = 1, 183 .differential = 1, 184 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 185 BIT(IIO_CHAN_INFO_SCALE) | 186 BIT(IIO_CHAN_INFO_OFFSET) | 187 BIT(IIO_CHAN_INFO_SAMP_FREQ) | 188 BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), 189 .scan_type = { 190 .sign = 'u', 191 .realbits = 24, 192 .storagebits = 32, 193 .endianness = IIO_BE, 194 }, 195 }; 196 197 static struct ad7124_chip_info ad7124_chip_info_tbl[] = { 198 [ID_AD7124_4] = { 199 .name = "ad7124-4", 200 .chip_id = CHIPID_AD7124_4, 201 .num_inputs = 8, 202 }, 203 [ID_AD7124_8] = { 204 .name = "ad7124-8", 205 .chip_id = CHIPID_AD7124_8, 206 .num_inputs = 16, 207 }, 208 }; 209 210 static int ad7124_find_closest_match(const int *array, 211 unsigned int size, int val) 212 { 213 int i, idx; 214 unsigned int diff_new, diff_old; 215 216 diff_old = U32_MAX; 217 idx = 0; 218 219 for (i = 0; i < size; i++) { 220 diff_new = abs(val - array[i]); 221 if (diff_new < diff_old) { 222 diff_old = diff_new; 223 idx = i; 224 } 225 } 226 227 return idx; 228 } 229 230 static int ad7124_spi_write_mask(struct ad7124_state *st, 231 unsigned int addr, 232 unsigned long mask, 233 unsigned int val, 234 unsigned int bytes) 235 { 236 unsigned int readval; 237 int ret; 238 239 ret = ad_sd_read_reg(&st->sd, addr, bytes, &readval); 240 if (ret < 0) 241 return ret; 242 243 readval &= ~mask; 244 readval |= val; 245 246 return ad_sd_write_reg(&st->sd, addr, bytes, readval); 247 } 248 249 static int ad7124_set_mode(struct ad_sigma_delta *sd, 250 enum ad_sigma_delta_mode mode) 251 { 252 struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); 253 254 st->adc_control &= ~AD7124_ADC_CTRL_MODE_MSK; 255 st->adc_control |= AD7124_ADC_CTRL_MODE(mode); 256 257 return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control); 258 } 259 260 static void ad7124_set_channel_odr(struct ad7124_state *st, unsigned int channel, unsigned int odr) 261 { 262 unsigned int fclk, odr_sel_bits; 263 264 fclk = clk_get_rate(st->mclk); 265 /* 266 * FS[10:0] = fCLK / (fADC x 32) where: 267 * fADC is the output data rate 268 * fCLK is the master clock frequency 269 * FS[10:0] are the bits in the filter register 270 * FS[10:0] can have a value from 1 to 2047 271 */ 272 odr_sel_bits = DIV_ROUND_CLOSEST(fclk, odr * 32); 273 if (odr_sel_bits < 1) 274 odr_sel_bits = 1; 275 else if (odr_sel_bits > 2047) 276 odr_sel_bits = 2047; 277 278 if (odr_sel_bits != st->channels[channel].cfg.odr_sel_bits) 279 st->channels[channel].cfg.live = false; 280 281 /* fADC = fCLK / (FS[10:0] x 32) */ 282 st->channels[channel].cfg.odr = DIV_ROUND_CLOSEST(fclk, odr_sel_bits * 32); 283 st->channels[channel].cfg.odr_sel_bits = odr_sel_bits; 284 } 285 286 static int ad7124_get_3db_filter_freq(struct ad7124_state *st, 287 unsigned int channel) 288 { 289 unsigned int fadc; 290 291 fadc = st->channels[channel].cfg.odr; 292 293 switch (st->channels[channel].cfg.filter_type) { 294 case AD7124_SINC3_FILTER: 295 return DIV_ROUND_CLOSEST(fadc * 230, 1000); 296 case AD7124_SINC4_FILTER: 297 return DIV_ROUND_CLOSEST(fadc * 262, 1000); 298 default: 299 return -EINVAL; 300 } 301 } 302 303 static void ad7124_set_3db_filter_freq(struct ad7124_state *st, unsigned int channel, 304 unsigned int freq) 305 { 306 unsigned int sinc4_3db_odr; 307 unsigned int sinc3_3db_odr; 308 unsigned int new_filter; 309 unsigned int new_odr; 310 311 sinc4_3db_odr = DIV_ROUND_CLOSEST(freq * 1000, 230); 312 sinc3_3db_odr = DIV_ROUND_CLOSEST(freq * 1000, 262); 313 314 if (sinc4_3db_odr > sinc3_3db_odr) { 315 new_filter = AD7124_SINC3_FILTER; 316 new_odr = sinc4_3db_odr; 317 } else { 318 new_filter = AD7124_SINC4_FILTER; 319 new_odr = sinc3_3db_odr; 320 } 321 322 if (new_odr != st->channels[channel].cfg.odr) 323 st->channels[channel].cfg.live = false; 324 325 st->channels[channel].cfg.filter_type = new_filter; 326 st->channels[channel].cfg.odr = new_odr; 327 } 328 329 static struct ad7124_channel_config *ad7124_find_similar_live_cfg(struct ad7124_state *st, 330 struct ad7124_channel_config *cfg) 331 { 332 struct ad7124_channel_config *cfg_aux; 333 ptrdiff_t cmp_size; 334 int i; 335 336 cmp_size = (u8 *)&cfg->live - (u8 *)cfg; 337 for (i = 0; i < st->num_channels; i++) { 338 cfg_aux = &st->channels[i].cfg; 339 340 if (cfg_aux->live && !memcmp(cfg, cfg_aux, cmp_size)) 341 return cfg_aux; 342 } 343 344 return NULL; 345 } 346 347 static int ad7124_find_free_config_slot(struct ad7124_state *st) 348 { 349 unsigned int free_cfg_slot; 350 351 free_cfg_slot = find_first_zero_bit(&st->cfg_slots_status, AD7124_MAX_CONFIGS); 352 if (free_cfg_slot == AD7124_MAX_CONFIGS) 353 return -1; 354 355 return free_cfg_slot; 356 } 357 358 static int ad7124_init_config_vref(struct ad7124_state *st, struct ad7124_channel_config *cfg) 359 { 360 unsigned int refsel = cfg->refsel; 361 362 switch (refsel) { 363 case AD7124_REFIN1: 364 case AD7124_REFIN2: 365 case AD7124_AVDD_REF: 366 if (IS_ERR(st->vref[refsel])) { 367 dev_err(&st->sd.spi->dev, 368 "Error, trying to use external voltage reference without a %s regulator.\n", 369 ad7124_ref_names[refsel]); 370 return PTR_ERR(st->vref[refsel]); 371 } 372 cfg->vref_mv = regulator_get_voltage(st->vref[refsel]); 373 /* Conversion from uV to mV */ 374 cfg->vref_mv /= 1000; 375 return 0; 376 case AD7124_INT_REF: 377 cfg->vref_mv = 2500; 378 st->adc_control &= ~AD7124_ADC_CTRL_REF_EN_MSK; 379 st->adc_control |= AD7124_ADC_CTRL_REF_EN(1); 380 return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 381 2, st->adc_control); 382 default: 383 dev_err(&st->sd.spi->dev, "Invalid reference %d\n", refsel); 384 return -EINVAL; 385 } 386 } 387 388 static int ad7124_write_config(struct ad7124_state *st, struct ad7124_channel_config *cfg, 389 unsigned int cfg_slot) 390 { 391 unsigned int tmp; 392 unsigned int val; 393 int ret; 394 395 cfg->cfg_slot = cfg_slot; 396 397 tmp = (cfg->buf_positive << 1) + cfg->buf_negative; 398 val = AD7124_CONFIG_BIPOLAR(cfg->bipolar) | AD7124_CONFIG_REF_SEL(cfg->refsel) | 399 AD7124_CONFIG_IN_BUFF(tmp); 400 ret = ad_sd_write_reg(&st->sd, AD7124_CONFIG(cfg->cfg_slot), 2, val); 401 if (ret < 0) 402 return ret; 403 404 tmp = AD7124_FILTER_TYPE_SEL(cfg->filter_type); 405 ret = ad7124_spi_write_mask(st, AD7124_FILTER(cfg->cfg_slot), AD7124_FILTER_TYPE_MSK, 406 tmp, 3); 407 if (ret < 0) 408 return ret; 409 410 ret = ad7124_spi_write_mask(st, AD7124_FILTER(cfg->cfg_slot), AD7124_FILTER_FS_MSK, 411 AD7124_FILTER_FS(cfg->odr_sel_bits), 3); 412 if (ret < 0) 413 return ret; 414 415 return ad7124_spi_write_mask(st, AD7124_CONFIG(cfg->cfg_slot), AD7124_CONFIG_PGA_MSK, 416 AD7124_CONFIG_PGA(cfg->pga_bits), 2); 417 } 418 419 static struct ad7124_channel_config *ad7124_pop_config(struct ad7124_state *st) 420 { 421 struct ad7124_channel_config *lru_cfg; 422 struct ad7124_channel_config *cfg; 423 int ret; 424 int i; 425 426 /* 427 * Pop least recently used config from the fifo 428 * in order to make room for the new one 429 */ 430 ret = kfifo_get(&st->live_cfgs_fifo, &lru_cfg); 431 if (ret <= 0) 432 return NULL; 433 434 lru_cfg->live = false; 435 436 /* mark slot as free */ 437 assign_bit(lru_cfg->cfg_slot, &st->cfg_slots_status, 0); 438 439 /* invalidate all other configs that pointed to this one */ 440 for (i = 0; i < st->num_channels; i++) { 441 cfg = &st->channels[i].cfg; 442 443 if (cfg->cfg_slot == lru_cfg->cfg_slot) 444 cfg->live = false; 445 } 446 447 return lru_cfg; 448 } 449 450 static int ad7124_push_config(struct ad7124_state *st, struct ad7124_channel_config *cfg) 451 { 452 struct ad7124_channel_config *lru_cfg; 453 int free_cfg_slot; 454 455 free_cfg_slot = ad7124_find_free_config_slot(st); 456 if (free_cfg_slot >= 0) { 457 /* push the new config in configs queue */ 458 kfifo_put(&st->live_cfgs_fifo, cfg); 459 } else { 460 /* pop one config to make room for the new one */ 461 lru_cfg = ad7124_pop_config(st); 462 if (!lru_cfg) 463 return -EINVAL; 464 465 /* push the new config in configs queue */ 466 free_cfg_slot = lru_cfg->cfg_slot; 467 kfifo_put(&st->live_cfgs_fifo, cfg); 468 } 469 470 /* mark slot as used */ 471 assign_bit(free_cfg_slot, &st->cfg_slots_status, 1); 472 473 return ad7124_write_config(st, cfg, free_cfg_slot); 474 } 475 476 static int ad7124_enable_channel(struct ad7124_state *st, struct ad7124_channel *ch) 477 { 478 ch->cfg.live = true; 479 return ad_sd_write_reg(&st->sd, AD7124_CHANNEL(ch->nr), 2, ch->ain | 480 AD7124_CHANNEL_SETUP(ch->cfg.cfg_slot) | AD7124_CHANNEL_EN(1)); 481 } 482 483 static int ad7124_prepare_read(struct ad7124_state *st, int address) 484 { 485 struct ad7124_channel_config *cfg = &st->channels[address].cfg; 486 struct ad7124_channel_config *live_cfg; 487 488 /* 489 * Before doing any reads assign the channel a configuration. 490 * Check if channel's config is on the device 491 */ 492 if (!cfg->live) { 493 /* check if config matches another one */ 494 live_cfg = ad7124_find_similar_live_cfg(st, cfg); 495 if (!live_cfg) 496 ad7124_push_config(st, cfg); 497 else 498 cfg->cfg_slot = live_cfg->cfg_slot; 499 } 500 501 /* point channel to the config slot and enable */ 502 return ad7124_enable_channel(st, &st->channels[address]); 503 } 504 505 static int __ad7124_set_channel(struct ad_sigma_delta *sd, unsigned int channel) 506 { 507 struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); 508 509 return ad7124_prepare_read(st, channel); 510 } 511 512 static int ad7124_set_channel(struct ad_sigma_delta *sd, unsigned int channel) 513 { 514 struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); 515 int ret; 516 517 mutex_lock(&st->cfgs_lock); 518 ret = __ad7124_set_channel(sd, channel); 519 mutex_unlock(&st->cfgs_lock); 520 521 return ret; 522 } 523 524 static int ad7124_append_status(struct ad_sigma_delta *sd, bool append) 525 { 526 struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); 527 unsigned int adc_control = st->adc_control; 528 int ret; 529 530 adc_control &= ~AD7124_ADC_STATUS_EN_MSK; 531 adc_control |= AD7124_ADC_STATUS_EN(append); 532 533 ret = ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, adc_control); 534 if (ret < 0) 535 return ret; 536 537 st->adc_control = adc_control; 538 539 return 0; 540 } 541 542 static int ad7124_disable_all(struct ad_sigma_delta *sd) 543 { 544 struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); 545 int ret; 546 int i; 547 548 for (i = 0; i < st->num_channels; i++) { 549 ret = ad7124_spi_write_mask(st, AD7124_CHANNEL(i), AD7124_CHANNEL_EN_MSK, 0, 2); 550 if (ret < 0) 551 return ret; 552 } 553 554 return 0; 555 } 556 557 static const struct ad_sigma_delta_info ad7124_sigma_delta_info = { 558 .set_channel = ad7124_set_channel, 559 .append_status = ad7124_append_status, 560 .disable_all = ad7124_disable_all, 561 .set_mode = ad7124_set_mode, 562 .has_registers = true, 563 .addr_shift = 0, 564 .read_mask = BIT(6), 565 .status_ch_mask = GENMASK(3, 0), 566 .data_reg = AD7124_DATA, 567 .num_slots = 8, 568 .irq_flags = IRQF_TRIGGER_FALLING, 569 }; 570 571 static int ad7124_read_raw(struct iio_dev *indio_dev, 572 struct iio_chan_spec const *chan, 573 int *val, int *val2, long info) 574 { 575 struct ad7124_state *st = iio_priv(indio_dev); 576 int idx, ret; 577 578 switch (info) { 579 case IIO_CHAN_INFO_RAW: 580 ret = ad_sigma_delta_single_conversion(indio_dev, chan, val); 581 if (ret < 0) 582 return ret; 583 584 /* After the conversion is performed, disable the channel */ 585 ret = ad_sd_write_reg(&st->sd, AD7124_CHANNEL(chan->address), 2, 586 st->channels[chan->address].ain | AD7124_CHANNEL_EN(0)); 587 if (ret < 0) 588 return ret; 589 590 return IIO_VAL_INT; 591 case IIO_CHAN_INFO_SCALE: 592 mutex_lock(&st->cfgs_lock); 593 594 idx = st->channels[chan->address].cfg.pga_bits; 595 *val = st->channels[chan->address].cfg.vref_mv; 596 if (st->channels[chan->address].cfg.bipolar) 597 *val2 = chan->scan_type.realbits - 1 + idx; 598 else 599 *val2 = chan->scan_type.realbits + idx; 600 601 mutex_unlock(&st->cfgs_lock); 602 return IIO_VAL_FRACTIONAL_LOG2; 603 case IIO_CHAN_INFO_OFFSET: 604 mutex_lock(&st->cfgs_lock); 605 if (st->channels[chan->address].cfg.bipolar) 606 *val = -(1 << (chan->scan_type.realbits - 1)); 607 else 608 *val = 0; 609 610 mutex_unlock(&st->cfgs_lock); 611 return IIO_VAL_INT; 612 case IIO_CHAN_INFO_SAMP_FREQ: 613 mutex_lock(&st->cfgs_lock); 614 *val = st->channels[chan->address].cfg.odr; 615 mutex_unlock(&st->cfgs_lock); 616 617 return IIO_VAL_INT; 618 case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: 619 mutex_lock(&st->cfgs_lock); 620 *val = ad7124_get_3db_filter_freq(st, chan->scan_index); 621 mutex_unlock(&st->cfgs_lock); 622 623 return IIO_VAL_INT; 624 default: 625 return -EINVAL; 626 } 627 } 628 629 static int ad7124_write_raw(struct iio_dev *indio_dev, 630 struct iio_chan_spec const *chan, 631 int val, int val2, long info) 632 { 633 struct ad7124_state *st = iio_priv(indio_dev); 634 unsigned int res, gain, full_scale, vref; 635 int ret = 0; 636 637 mutex_lock(&st->cfgs_lock); 638 639 switch (info) { 640 case IIO_CHAN_INFO_SAMP_FREQ: 641 if (val2 != 0) { 642 ret = -EINVAL; 643 break; 644 } 645 646 ad7124_set_channel_odr(st, chan->address, val); 647 break; 648 case IIO_CHAN_INFO_SCALE: 649 if (val != 0) { 650 ret = -EINVAL; 651 break; 652 } 653 654 if (st->channels[chan->address].cfg.bipolar) 655 full_scale = 1 << (chan->scan_type.realbits - 1); 656 else 657 full_scale = 1 << chan->scan_type.realbits; 658 659 vref = st->channels[chan->address].cfg.vref_mv * 1000000LL; 660 res = DIV_ROUND_CLOSEST(vref, full_scale); 661 gain = DIV_ROUND_CLOSEST(res, val2); 662 res = ad7124_find_closest_match(ad7124_gain, ARRAY_SIZE(ad7124_gain), gain); 663 664 if (st->channels[chan->address].cfg.pga_bits != res) 665 st->channels[chan->address].cfg.live = false; 666 667 st->channels[chan->address].cfg.pga_bits = res; 668 break; 669 case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: 670 if (val2 != 0) { 671 ret = -EINVAL; 672 break; 673 } 674 675 ad7124_set_3db_filter_freq(st, chan->address, val); 676 break; 677 default: 678 ret = -EINVAL; 679 } 680 681 mutex_unlock(&st->cfgs_lock); 682 return ret; 683 } 684 685 static int ad7124_reg_access(struct iio_dev *indio_dev, 686 unsigned int reg, 687 unsigned int writeval, 688 unsigned int *readval) 689 { 690 struct ad7124_state *st = iio_priv(indio_dev); 691 int ret; 692 693 if (reg >= ARRAY_SIZE(ad7124_reg_size)) 694 return -EINVAL; 695 696 if (readval) 697 ret = ad_sd_read_reg(&st->sd, reg, ad7124_reg_size[reg], 698 readval); 699 else 700 ret = ad_sd_write_reg(&st->sd, reg, ad7124_reg_size[reg], 701 writeval); 702 703 return ret; 704 } 705 706 static IIO_CONST_ATTR(in_voltage_scale_available, 707 "0.000001164 0.000002328 0.000004656 0.000009313 0.000018626 0.000037252 0.000074505 0.000149011 0.000298023"); 708 709 static struct attribute *ad7124_attributes[] = { 710 &iio_const_attr_in_voltage_scale_available.dev_attr.attr, 711 NULL, 712 }; 713 714 static const struct attribute_group ad7124_attrs_group = { 715 .attrs = ad7124_attributes, 716 }; 717 718 static int ad7124_update_scan_mode(struct iio_dev *indio_dev, 719 const unsigned long *scan_mask) 720 { 721 struct ad7124_state *st = iio_priv(indio_dev); 722 bool bit_set; 723 int ret; 724 int i; 725 726 mutex_lock(&st->cfgs_lock); 727 for (i = 0; i < st->num_channels; i++) { 728 bit_set = test_bit(i, scan_mask); 729 if (bit_set) 730 ret = __ad7124_set_channel(&st->sd, i); 731 else 732 ret = ad7124_spi_write_mask(st, AD7124_CHANNEL(i), AD7124_CHANNEL_EN_MSK, 733 0, 2); 734 if (ret < 0) { 735 mutex_unlock(&st->cfgs_lock); 736 737 return ret; 738 } 739 } 740 741 mutex_unlock(&st->cfgs_lock); 742 743 return 0; 744 } 745 746 static const struct iio_info ad7124_info = { 747 .read_raw = ad7124_read_raw, 748 .write_raw = ad7124_write_raw, 749 .debugfs_reg_access = &ad7124_reg_access, 750 .validate_trigger = ad_sd_validate_trigger, 751 .update_scan_mode = ad7124_update_scan_mode, 752 .attrs = &ad7124_attrs_group, 753 }; 754 755 static int ad7124_soft_reset(struct ad7124_state *st) 756 { 757 unsigned int readval, timeout; 758 int ret; 759 760 ret = ad_sd_reset(&st->sd, 64); 761 if (ret < 0) 762 return ret; 763 764 timeout = 100; 765 do { 766 ret = ad_sd_read_reg(&st->sd, AD7124_STATUS, 1, &readval); 767 if (ret < 0) 768 return ret; 769 770 if (!(readval & AD7124_STATUS_POR_FLAG_MSK)) 771 return 0; 772 773 /* The AD7124 requires typically 2ms to power up and settle */ 774 usleep_range(100, 2000); 775 } while (--timeout); 776 777 dev_err(&st->sd.spi->dev, "Soft reset failed\n"); 778 779 return -EIO; 780 } 781 782 static int ad7124_check_chip_id(struct ad7124_state *st) 783 { 784 unsigned int readval, chip_id, silicon_rev; 785 int ret; 786 787 ret = ad_sd_read_reg(&st->sd, AD7124_ID, 1, &readval); 788 if (ret < 0) 789 return ret; 790 791 chip_id = AD7124_DEVICE_ID_GET(readval); 792 silicon_rev = AD7124_SILICON_REV_GET(readval); 793 794 if (chip_id != st->chip_info->chip_id) { 795 dev_err(&st->sd.spi->dev, 796 "Chip ID mismatch: expected %u, got %u\n", 797 st->chip_info->chip_id, chip_id); 798 return -ENODEV; 799 } 800 801 if (silicon_rev == 0) { 802 dev_err(&st->sd.spi->dev, 803 "Silicon revision empty. Chip may not be present\n"); 804 return -ENODEV; 805 } 806 807 return 0; 808 } 809 810 static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev, 811 struct device_node *np) 812 { 813 struct ad7124_state *st = iio_priv(indio_dev); 814 struct ad7124_channel_config *cfg; 815 struct ad7124_channel *channels; 816 struct device_node *child; 817 struct iio_chan_spec *chan; 818 unsigned int ain[2], channel = 0, tmp; 819 int ret; 820 821 st->num_channels = of_get_available_child_count(np); 822 if (!st->num_channels) { 823 dev_err(indio_dev->dev.parent, "no channel children\n"); 824 return -ENODEV; 825 } 826 827 chan = devm_kcalloc(indio_dev->dev.parent, st->num_channels, 828 sizeof(*chan), GFP_KERNEL); 829 if (!chan) 830 return -ENOMEM; 831 832 channels = devm_kcalloc(indio_dev->dev.parent, st->num_channels, sizeof(*channels), 833 GFP_KERNEL); 834 if (!channels) 835 return -ENOMEM; 836 837 indio_dev->channels = chan; 838 indio_dev->num_channels = st->num_channels; 839 st->channels = channels; 840 841 for_each_available_child_of_node(np, child) { 842 cfg = &st->channels[channel].cfg; 843 844 ret = of_property_read_u32(child, "reg", &channel); 845 if (ret) 846 goto err; 847 848 if (channel >= indio_dev->num_channels) { 849 dev_err(indio_dev->dev.parent, 850 "Channel index >= number of channels\n"); 851 ret = -EINVAL; 852 goto err; 853 } 854 855 ret = of_property_read_u32_array(child, "diff-channels", 856 ain, 2); 857 if (ret) 858 goto err; 859 860 st->channels[channel].nr = channel; 861 st->channels[channel].ain = AD7124_CHANNEL_AINP(ain[0]) | 862 AD7124_CHANNEL_AINM(ain[1]); 863 864 cfg->bipolar = of_property_read_bool(child, "bipolar"); 865 866 ret = of_property_read_u32(child, "adi,reference-select", &tmp); 867 if (ret) 868 cfg->refsel = AD7124_INT_REF; 869 else 870 cfg->refsel = tmp; 871 872 cfg->buf_positive = of_property_read_bool(child, "adi,buffered-positive"); 873 cfg->buf_negative = of_property_read_bool(child, "adi,buffered-negative"); 874 875 chan[channel] = ad7124_channel_template; 876 chan[channel].address = channel; 877 chan[channel].scan_index = channel; 878 chan[channel].channel = ain[0]; 879 chan[channel].channel2 = ain[1]; 880 } 881 882 return 0; 883 err: 884 of_node_put(child); 885 886 return ret; 887 } 888 889 static int ad7124_setup(struct ad7124_state *st) 890 { 891 unsigned int fclk, power_mode; 892 int i, ret; 893 894 fclk = clk_get_rate(st->mclk); 895 if (!fclk) 896 return -EINVAL; 897 898 /* The power mode changes the master clock frequency */ 899 power_mode = ad7124_find_closest_match(ad7124_master_clk_freq_hz, 900 ARRAY_SIZE(ad7124_master_clk_freq_hz), 901 fclk); 902 if (fclk != ad7124_master_clk_freq_hz[power_mode]) { 903 ret = clk_set_rate(st->mclk, fclk); 904 if (ret) 905 return ret; 906 } 907 908 /* Set the power mode */ 909 st->adc_control &= ~AD7124_ADC_CTRL_PWR_MSK; 910 st->adc_control |= AD7124_ADC_CTRL_PWR(power_mode); 911 ret = ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control); 912 if (ret < 0) 913 return ret; 914 915 mutex_init(&st->cfgs_lock); 916 INIT_KFIFO(st->live_cfgs_fifo); 917 for (i = 0; i < st->num_channels; i++) { 918 919 ret = ad7124_init_config_vref(st, &st->channels[i].cfg); 920 if (ret < 0) 921 return ret; 922 923 /* 924 * 9.38 SPS is the minimum output data rate supported 925 * regardless of the selected power mode. Round it up to 10 and 926 * set all channels to this default value. 927 */ 928 ad7124_set_channel_odr(st, i, 10); 929 } 930 931 return ret; 932 } 933 934 static void ad7124_reg_disable(void *r) 935 { 936 regulator_disable(r); 937 } 938 939 static int ad7124_probe(struct spi_device *spi) 940 { 941 const struct ad7124_chip_info *info; 942 struct ad7124_state *st; 943 struct iio_dev *indio_dev; 944 int i, ret; 945 946 info = of_device_get_match_data(&spi->dev); 947 if (!info) 948 info = (void *)spi_get_device_id(spi)->driver_data; 949 if (!info) 950 return -ENODEV; 951 952 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 953 if (!indio_dev) 954 return -ENOMEM; 955 956 st = iio_priv(indio_dev); 957 958 st->chip_info = info; 959 960 indio_dev->name = st->chip_info->name; 961 indio_dev->modes = INDIO_DIRECT_MODE; 962 indio_dev->info = &ad7124_info; 963 964 ret = ad_sd_init(&st->sd, indio_dev, spi, &ad7124_sigma_delta_info); 965 if (ret < 0) 966 return ret; 967 968 ret = ad7124_of_parse_channel_config(indio_dev, spi->dev.of_node); 969 if (ret < 0) 970 return ret; 971 972 for (i = 0; i < ARRAY_SIZE(st->vref); i++) { 973 if (i == AD7124_INT_REF) 974 continue; 975 976 st->vref[i] = devm_regulator_get_optional(&spi->dev, 977 ad7124_ref_names[i]); 978 if (PTR_ERR(st->vref[i]) == -ENODEV) 979 continue; 980 else if (IS_ERR(st->vref[i])) 981 return PTR_ERR(st->vref[i]); 982 983 ret = regulator_enable(st->vref[i]); 984 if (ret) 985 return ret; 986 987 ret = devm_add_action_or_reset(&spi->dev, ad7124_reg_disable, 988 st->vref[i]); 989 if (ret) 990 return ret; 991 } 992 993 st->mclk = devm_clk_get_enabled(&spi->dev, "mclk"); 994 if (IS_ERR(st->mclk)) 995 return PTR_ERR(st->mclk); 996 997 ret = ad7124_soft_reset(st); 998 if (ret < 0) 999 return ret; 1000 1001 ret = ad7124_check_chip_id(st); 1002 if (ret) 1003 return ret; 1004 1005 ret = ad7124_setup(st); 1006 if (ret < 0) 1007 return ret; 1008 1009 ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev); 1010 if (ret < 0) 1011 return ret; 1012 1013 return devm_iio_device_register(&spi->dev, indio_dev); 1014 1015 } 1016 1017 static const struct of_device_id ad7124_of_match[] = { 1018 { .compatible = "adi,ad7124-4", 1019 .data = &ad7124_chip_info_tbl[ID_AD7124_4], }, 1020 { .compatible = "adi,ad7124-8", 1021 .data = &ad7124_chip_info_tbl[ID_AD7124_8], }, 1022 { }, 1023 }; 1024 MODULE_DEVICE_TABLE(of, ad7124_of_match); 1025 1026 static const struct spi_device_id ad71124_ids[] = { 1027 { "ad7124-4", (kernel_ulong_t)&ad7124_chip_info_tbl[ID_AD7124_4] }, 1028 { "ad7124-8", (kernel_ulong_t)&ad7124_chip_info_tbl[ID_AD7124_8] }, 1029 {} 1030 }; 1031 MODULE_DEVICE_TABLE(spi, ad71124_ids); 1032 1033 static struct spi_driver ad71124_driver = { 1034 .driver = { 1035 .name = "ad7124", 1036 .of_match_table = ad7124_of_match, 1037 }, 1038 .probe = ad7124_probe, 1039 .id_table = ad71124_ids, 1040 }; 1041 module_spi_driver(ad71124_driver); 1042 1043 MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>"); 1044 MODULE_DESCRIPTION("Analog Devices AD7124 SPI driver"); 1045 MODULE_LICENSE("GPL"); 1046 MODULE_IMPORT_NS(IIO_AD_SIGMA_DELTA); 1047