1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AD7266/65 SPI ADC driver 4 * 5 * Copyright 2012 Analog Devices Inc. 6 */ 7 8 #include <linux/device.h> 9 #include <linux/kernel.h> 10 #include <linux/slab.h> 11 #include <linux/spi/spi.h> 12 #include <linux/regulator/consumer.h> 13 #include <linux/err.h> 14 #include <linux/gpio/consumer.h> 15 #include <linux/module.h> 16 17 #include <linux/interrupt.h> 18 19 #include <linux/iio/iio.h> 20 #include <linux/iio/buffer.h> 21 #include <linux/iio/trigger_consumer.h> 22 #include <linux/iio/triggered_buffer.h> 23 24 #include <linux/platform_data/ad7266.h> 25 26 #define AD7266_INTERNAL_REF_MV 2500 27 28 struct ad7266_state { 29 struct spi_device *spi; 30 unsigned long vref_mv; 31 32 struct spi_transfer single_xfer[3]; 33 struct spi_message single_msg; 34 35 enum ad7266_range range; 36 enum ad7266_mode mode; 37 bool fixed_addr; 38 struct gpio_desc *gpios[3]; 39 40 /* 41 * DMA (thus cache coherency maintenance) may require the 42 * transfer buffers to live in their own cache lines. 43 * The buffer needs to be large enough to hold two samples (4 bytes) and 44 * the naturally aligned timestamp (8 bytes). 45 */ 46 struct { 47 __be16 sample[2]; 48 s64 timestamp; 49 } data __aligned(IIO_DMA_MINALIGN); 50 }; 51 52 static int ad7266_wakeup(struct ad7266_state *st) 53 { 54 /* Any read with >= 2 bytes will wake the device */ 55 return spi_read(st->spi, &st->data.sample[0], 2); 56 } 57 58 static int ad7266_powerdown(struct ad7266_state *st) 59 { 60 /* Any read with < 2 bytes will powerdown the device */ 61 return spi_read(st->spi, &st->data.sample[0], 1); 62 } 63 64 static int ad7266_preenable(struct iio_dev *indio_dev) 65 { 66 struct ad7266_state *st = iio_priv(indio_dev); 67 return ad7266_wakeup(st); 68 } 69 70 static int ad7266_postdisable(struct iio_dev *indio_dev) 71 { 72 struct ad7266_state *st = iio_priv(indio_dev); 73 return ad7266_powerdown(st); 74 } 75 76 static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = { 77 .preenable = &ad7266_preenable, 78 .postdisable = &ad7266_postdisable, 79 }; 80 81 static irqreturn_t ad7266_trigger_handler(int irq, void *p) 82 { 83 struct iio_poll_func *pf = p; 84 struct iio_dev *indio_dev = pf->indio_dev; 85 struct ad7266_state *st = iio_priv(indio_dev); 86 int ret; 87 88 ret = spi_read(st->spi, st->data.sample, 4); 89 if (ret == 0) { 90 iio_push_to_buffers_with_timestamp(indio_dev, &st->data, 91 pf->timestamp); 92 } 93 94 iio_trigger_notify_done(indio_dev->trig); 95 96 return IRQ_HANDLED; 97 } 98 99 static void ad7266_select_input(struct ad7266_state *st, unsigned int nr) 100 { 101 unsigned int i; 102 103 if (st->fixed_addr) 104 return; 105 106 switch (st->mode) { 107 case AD7266_MODE_SINGLE_ENDED: 108 nr >>= 1; 109 break; 110 case AD7266_MODE_PSEUDO_DIFF: 111 nr |= 1; 112 break; 113 case AD7266_MODE_DIFF: 114 nr &= ~1; 115 break; 116 } 117 118 for (i = 0; i < 3; ++i) 119 gpiod_set_value(st->gpios[i], (bool)(nr & BIT(i))); 120 } 121 122 static int ad7266_update_scan_mode(struct iio_dev *indio_dev, 123 const unsigned long *scan_mask) 124 { 125 struct ad7266_state *st = iio_priv(indio_dev); 126 unsigned int nr = find_first_bit(scan_mask, 127 iio_get_masklength(indio_dev)); 128 129 ad7266_select_input(st, nr); 130 131 return 0; 132 } 133 134 static int ad7266_read_single(struct ad7266_state *st, int *val, 135 unsigned int address) 136 { 137 int ret; 138 139 ad7266_select_input(st, address); 140 141 ret = spi_sync(st->spi, &st->single_msg); 142 *val = be16_to_cpu(st->data.sample[address % 2]); 143 144 return ret; 145 } 146 147 static int ad7266_read_raw(struct iio_dev *indio_dev, 148 struct iio_chan_spec const *chan, int *val, int *val2, long m) 149 { 150 struct ad7266_state *st = iio_priv(indio_dev); 151 unsigned long scale_mv; 152 int ret; 153 154 switch (m) { 155 case IIO_CHAN_INFO_RAW: 156 ret = iio_device_claim_direct_mode(indio_dev); 157 if (ret) 158 return ret; 159 ret = ad7266_read_single(st, val, chan->address); 160 iio_device_release_direct_mode(indio_dev); 161 162 if (ret < 0) 163 return ret; 164 *val = (*val >> 2) & 0xfff; 165 if (chan->scan_type.sign == 's') 166 *val = sign_extend32(*val, 167 chan->scan_type.realbits - 1); 168 169 return IIO_VAL_INT; 170 case IIO_CHAN_INFO_SCALE: 171 scale_mv = st->vref_mv; 172 if (st->mode == AD7266_MODE_DIFF) 173 scale_mv *= 2; 174 if (st->range == AD7266_RANGE_2VREF) 175 scale_mv *= 2; 176 177 *val = scale_mv; 178 *val2 = chan->scan_type.realbits; 179 return IIO_VAL_FRACTIONAL_LOG2; 180 case IIO_CHAN_INFO_OFFSET: 181 if (st->range == AD7266_RANGE_2VREF && 182 st->mode != AD7266_MODE_DIFF) 183 *val = 2048; 184 else 185 *val = 0; 186 return IIO_VAL_INT; 187 } 188 return -EINVAL; 189 } 190 191 #define AD7266_CHAN(_chan, _sign) { \ 192 .type = IIO_VOLTAGE, \ 193 .indexed = 1, \ 194 .channel = (_chan), \ 195 .address = (_chan), \ 196 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 197 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ 198 | BIT(IIO_CHAN_INFO_OFFSET), \ 199 .scan_index = (_chan), \ 200 .scan_type = { \ 201 .sign = (_sign), \ 202 .realbits = 12, \ 203 .storagebits = 16, \ 204 .shift = 2, \ 205 .endianness = IIO_BE, \ 206 }, \ 207 } 208 209 #define AD7266_DECLARE_SINGLE_ENDED_CHANNELS(_name, _sign) \ 210 const struct iio_chan_spec ad7266_channels_##_name[] = { \ 211 AD7266_CHAN(0, (_sign)), \ 212 AD7266_CHAN(1, (_sign)), \ 213 AD7266_CHAN(2, (_sign)), \ 214 AD7266_CHAN(3, (_sign)), \ 215 AD7266_CHAN(4, (_sign)), \ 216 AD7266_CHAN(5, (_sign)), \ 217 AD7266_CHAN(6, (_sign)), \ 218 AD7266_CHAN(7, (_sign)), \ 219 AD7266_CHAN(8, (_sign)), \ 220 AD7266_CHAN(9, (_sign)), \ 221 AD7266_CHAN(10, (_sign)), \ 222 AD7266_CHAN(11, (_sign)), \ 223 IIO_CHAN_SOFT_TIMESTAMP(13), \ 224 } 225 226 #define AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(_name, _sign) \ 227 const struct iio_chan_spec ad7266_channels_##_name##_fixed[] = { \ 228 AD7266_CHAN(0, (_sign)), \ 229 AD7266_CHAN(1, (_sign)), \ 230 IIO_CHAN_SOFT_TIMESTAMP(2), \ 231 } 232 233 static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(u, 'u'); 234 static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(s, 's'); 235 static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(u, 'u'); 236 static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(s, 's'); 237 238 #define AD7266_CHAN_DIFF(_chan, _sign) { \ 239 .type = IIO_VOLTAGE, \ 240 .indexed = 1, \ 241 .channel = (_chan) * 2, \ 242 .channel2 = (_chan) * 2 + 1, \ 243 .address = (_chan), \ 244 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 245 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ 246 | BIT(IIO_CHAN_INFO_OFFSET), \ 247 .scan_index = (_chan), \ 248 .scan_type = { \ 249 .sign = _sign, \ 250 .realbits = 12, \ 251 .storagebits = 16, \ 252 .shift = 2, \ 253 .endianness = IIO_BE, \ 254 }, \ 255 .differential = 1, \ 256 } 257 258 #define AD7266_DECLARE_DIFF_CHANNELS(_name, _sign) \ 259 const struct iio_chan_spec ad7266_channels_diff_##_name[] = { \ 260 AD7266_CHAN_DIFF(0, (_sign)), \ 261 AD7266_CHAN_DIFF(1, (_sign)), \ 262 AD7266_CHAN_DIFF(2, (_sign)), \ 263 AD7266_CHAN_DIFF(3, (_sign)), \ 264 AD7266_CHAN_DIFF(4, (_sign)), \ 265 AD7266_CHAN_DIFF(5, (_sign)), \ 266 IIO_CHAN_SOFT_TIMESTAMP(6), \ 267 } 268 269 static AD7266_DECLARE_DIFF_CHANNELS(s, 's'); 270 static AD7266_DECLARE_DIFF_CHANNELS(u, 'u'); 271 272 #define AD7266_DECLARE_DIFF_CHANNELS_FIXED(_name, _sign) \ 273 const struct iio_chan_spec ad7266_channels_diff_fixed_##_name[] = { \ 274 AD7266_CHAN_DIFF(0, (_sign)), \ 275 AD7266_CHAN_DIFF(1, (_sign)), \ 276 IIO_CHAN_SOFT_TIMESTAMP(2), \ 277 } 278 279 static AD7266_DECLARE_DIFF_CHANNELS_FIXED(s, 's'); 280 static AD7266_DECLARE_DIFF_CHANNELS_FIXED(u, 'u'); 281 282 static const struct iio_info ad7266_info = { 283 .read_raw = &ad7266_read_raw, 284 .update_scan_mode = &ad7266_update_scan_mode, 285 }; 286 287 static const unsigned long ad7266_available_scan_masks[] = { 288 0x003, 289 0x00c, 290 0x030, 291 0x0c0, 292 0x300, 293 0xc00, 294 0x000, 295 }; 296 297 static const unsigned long ad7266_available_scan_masks_diff[] = { 298 0x003, 299 0x00c, 300 0x030, 301 0x000, 302 }; 303 304 static const unsigned long ad7266_available_scan_masks_fixed[] = { 305 0x003, 306 0x000, 307 }; 308 309 struct ad7266_chan_info { 310 const struct iio_chan_spec *channels; 311 unsigned int num_channels; 312 const unsigned long *scan_masks; 313 }; 314 315 #define AD7266_CHAN_INFO_INDEX(_differential, _signed, _fixed) \ 316 (((_differential) << 2) | ((_signed) << 1) | ((_fixed) << 0)) 317 318 static const struct ad7266_chan_info ad7266_chan_infos[] = { 319 [AD7266_CHAN_INFO_INDEX(0, 0, 0)] = { 320 .channels = ad7266_channels_u, 321 .num_channels = ARRAY_SIZE(ad7266_channels_u), 322 .scan_masks = ad7266_available_scan_masks, 323 }, 324 [AD7266_CHAN_INFO_INDEX(0, 0, 1)] = { 325 .channels = ad7266_channels_u_fixed, 326 .num_channels = ARRAY_SIZE(ad7266_channels_u_fixed), 327 .scan_masks = ad7266_available_scan_masks_fixed, 328 }, 329 [AD7266_CHAN_INFO_INDEX(0, 1, 0)] = { 330 .channels = ad7266_channels_s, 331 .num_channels = ARRAY_SIZE(ad7266_channels_s), 332 .scan_masks = ad7266_available_scan_masks, 333 }, 334 [AD7266_CHAN_INFO_INDEX(0, 1, 1)] = { 335 .channels = ad7266_channels_s_fixed, 336 .num_channels = ARRAY_SIZE(ad7266_channels_s_fixed), 337 .scan_masks = ad7266_available_scan_masks_fixed, 338 }, 339 [AD7266_CHAN_INFO_INDEX(1, 0, 0)] = { 340 .channels = ad7266_channels_diff_u, 341 .num_channels = ARRAY_SIZE(ad7266_channels_diff_u), 342 .scan_masks = ad7266_available_scan_masks_diff, 343 }, 344 [AD7266_CHAN_INFO_INDEX(1, 0, 1)] = { 345 .channels = ad7266_channels_diff_fixed_u, 346 .num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_u), 347 .scan_masks = ad7266_available_scan_masks_fixed, 348 }, 349 [AD7266_CHAN_INFO_INDEX(1, 1, 0)] = { 350 .channels = ad7266_channels_diff_s, 351 .num_channels = ARRAY_SIZE(ad7266_channels_diff_s), 352 .scan_masks = ad7266_available_scan_masks_diff, 353 }, 354 [AD7266_CHAN_INFO_INDEX(1, 1, 1)] = { 355 .channels = ad7266_channels_diff_fixed_s, 356 .num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_s), 357 .scan_masks = ad7266_available_scan_masks_fixed, 358 }, 359 }; 360 361 static void ad7266_init_channels(struct iio_dev *indio_dev) 362 { 363 struct ad7266_state *st = iio_priv(indio_dev); 364 bool is_differential, is_signed; 365 const struct ad7266_chan_info *chan_info; 366 int i; 367 368 is_differential = st->mode != AD7266_MODE_SINGLE_ENDED; 369 is_signed = (st->range == AD7266_RANGE_2VREF) | 370 (st->mode == AD7266_MODE_DIFF); 371 372 i = AD7266_CHAN_INFO_INDEX(is_differential, is_signed, st->fixed_addr); 373 chan_info = &ad7266_chan_infos[i]; 374 375 indio_dev->channels = chan_info->channels; 376 indio_dev->num_channels = chan_info->num_channels; 377 indio_dev->available_scan_masks = chan_info->scan_masks; 378 } 379 380 static const char * const ad7266_gpio_labels[] = { 381 "ad0", "ad1", "ad2", 382 }; 383 384 static int ad7266_probe(struct spi_device *spi) 385 { 386 struct ad7266_platform_data *pdata = spi->dev.platform_data; 387 struct iio_dev *indio_dev; 388 struct ad7266_state *st; 389 unsigned int i; 390 int ret; 391 392 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 393 if (indio_dev == NULL) 394 return -ENOMEM; 395 396 st = iio_priv(indio_dev); 397 398 ret = devm_regulator_get_enable_read_voltage(&spi->dev, "vref"); 399 if (ret < 0 && ret != -ENODEV) 400 return ret; 401 402 st->vref_mv = ret == -ENODEV ? AD7266_INTERNAL_REF_MV : ret / 1000; 403 404 if (pdata) { 405 st->fixed_addr = pdata->fixed_addr; 406 st->mode = pdata->mode; 407 st->range = pdata->range; 408 409 if (!st->fixed_addr) { 410 for (i = 0; i < ARRAY_SIZE(st->gpios); ++i) { 411 st->gpios[i] = devm_gpiod_get(&spi->dev, 412 ad7266_gpio_labels[i], 413 GPIOD_OUT_LOW); 414 if (IS_ERR(st->gpios[i])) { 415 ret = PTR_ERR(st->gpios[i]); 416 return ret; 417 } 418 } 419 } 420 } else { 421 st->fixed_addr = true; 422 st->range = AD7266_RANGE_VREF; 423 st->mode = AD7266_MODE_DIFF; 424 } 425 426 st->spi = spi; 427 428 indio_dev->name = spi_get_device_id(spi)->name; 429 indio_dev->modes = INDIO_DIRECT_MODE; 430 indio_dev->info = &ad7266_info; 431 432 ad7266_init_channels(indio_dev); 433 434 /* wakeup */ 435 st->single_xfer[0].rx_buf = &st->data.sample[0]; 436 st->single_xfer[0].len = 2; 437 st->single_xfer[0].cs_change = 1; 438 /* conversion */ 439 st->single_xfer[1].rx_buf = st->data.sample; 440 st->single_xfer[1].len = 4; 441 st->single_xfer[1].cs_change = 1; 442 /* powerdown */ 443 st->single_xfer[2].tx_buf = &st->data.sample[0]; 444 st->single_xfer[2].len = 1; 445 446 spi_message_init(&st->single_msg); 447 spi_message_add_tail(&st->single_xfer[0], &st->single_msg); 448 spi_message_add_tail(&st->single_xfer[1], &st->single_msg); 449 spi_message_add_tail(&st->single_xfer[2], &st->single_msg); 450 451 ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, &iio_pollfunc_store_time, 452 &ad7266_trigger_handler, &iio_triggered_buffer_setup_ops); 453 if (ret) 454 return ret; 455 456 return devm_iio_device_register(&spi->dev, indio_dev); 457 } 458 459 static const struct spi_device_id ad7266_id[] = { 460 { "ad7265", 0 }, 461 { "ad7266", 0 }, 462 { } 463 }; 464 MODULE_DEVICE_TABLE(spi, ad7266_id); 465 466 static struct spi_driver ad7266_driver = { 467 .driver = { 468 .name = "ad7266", 469 }, 470 .probe = ad7266_probe, 471 .id_table = ad7266_id, 472 }; 473 module_spi_driver(ad7266_driver); 474 475 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 476 MODULE_DESCRIPTION("Analog Devices AD7266/65 ADC"); 477 MODULE_LICENSE("GPL v2"); 478