1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AD7787/AD7788/AD7789/AD7790/AD7791 SPI ADC driver 4 * 5 * Copyright 2012 Analog Devices Inc. 6 * Author: Lars-Peter Clausen <lars@metafoo.de> 7 */ 8 9 #include <linux/interrupt.h> 10 #include <linux/device.h> 11 #include <linux/kernel.h> 12 #include <linux/slab.h> 13 #include <linux/sysfs.h> 14 #include <linux/spi/spi.h> 15 #include <linux/regulator/consumer.h> 16 #include <linux/err.h> 17 #include <linux/sched.h> 18 #include <linux/delay.h> 19 #include <linux/module.h> 20 21 #include <linux/iio/iio.h> 22 #include <linux/iio/sysfs.h> 23 #include <linux/iio/buffer.h> 24 #include <linux/iio/trigger.h> 25 #include <linux/iio/trigger_consumer.h> 26 #include <linux/iio/triggered_buffer.h> 27 #include <linux/iio/adc/ad_sigma_delta.h> 28 29 #include <linux/platform_data/ad7791.h> 30 31 #define AD7791_REG_COMM 0x0 /* For writes */ 32 #define AD7791_REG_STATUS 0x0 /* For reads */ 33 #define AD7791_REG_MODE 0x1 34 #define AD7791_REG_FILTER 0x2 35 #define AD7791_REG_DATA 0x3 36 37 #define AD7791_MODE_CONTINUOUS 0x00 38 #define AD7791_MODE_SINGLE 0x02 39 #define AD7791_MODE_POWERDOWN 0x03 40 41 #define AD7791_CH_AIN1P_AIN1N 0x00 42 #define AD7791_CH_AIN2 0x01 43 #define AD7791_CH_AIN1N_AIN1N 0x02 44 #define AD7791_CH_AVDD_MONITOR 0x03 45 46 #define AD7791_FILTER_CLK_DIV_1 (0x0 << 4) 47 #define AD7791_FILTER_CLK_DIV_2 (0x1 << 4) 48 #define AD7791_FILTER_CLK_DIV_4 (0x2 << 4) 49 #define AD7791_FILTER_CLK_DIV_8 (0x3 << 4) 50 #define AD7791_FILTER_CLK_MASK (0x3 << 4) 51 #define AD7791_FILTER_RATE_120 0x0 52 #define AD7791_FILTER_RATE_100 0x1 53 #define AD7791_FILTER_RATE_33_3 0x2 54 #define AD7791_FILTER_RATE_20 0x3 55 #define AD7791_FILTER_RATE_16_6 0x4 56 #define AD7791_FILTER_RATE_16_7 0x5 57 #define AD7791_FILTER_RATE_13_3 0x6 58 #define AD7791_FILTER_RATE_9_5 0x7 59 #define AD7791_FILTER_RATE_MASK 0x7 60 61 #define AD7791_MODE_BUFFER BIT(1) 62 #define AD7791_MODE_UNIPOLAR BIT(2) 63 #define AD7791_MODE_BURNOUT BIT(3) 64 #define AD7791_MODE_SEL_MASK (0x3 << 6) 65 #define AD7791_MODE_SEL(x) ((x) << 6) 66 67 #define __AD7991_CHANNEL(_si, _channel1, _channel2, _address, _bits, \ 68 _storagebits, _shift, _extend_name, _type, _mask_all) \ 69 { \ 70 .type = (_type), \ 71 .differential = (_channel2 == -1 ? 0 : 1), \ 72 .indexed = 1, \ 73 .channel = (_channel1), \ 74 .channel2 = (_channel2), \ 75 .address = (_address), \ 76 .extend_name = (_extend_name), \ 77 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 78 BIT(IIO_CHAN_INFO_OFFSET), \ 79 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 80 .info_mask_shared_by_all = _mask_all, \ 81 .scan_index = (_si), \ 82 .scan_type = { \ 83 .sign = 'u', \ 84 .realbits = (_bits), \ 85 .storagebits = (_storagebits), \ 86 .shift = (_shift), \ 87 .endianness = IIO_BE, \ 88 }, \ 89 } 90 91 #define AD7991_SHORTED_CHANNEL(_si, _channel, _address, _bits, \ 92 _storagebits, _shift) \ 93 __AD7991_CHANNEL(_si, _channel, _channel, _address, _bits, \ 94 _storagebits, _shift, "shorted", IIO_VOLTAGE, \ 95 BIT(IIO_CHAN_INFO_SAMP_FREQ)) 96 97 #define AD7991_CHANNEL(_si, _channel, _address, _bits, \ 98 _storagebits, _shift) \ 99 __AD7991_CHANNEL(_si, _channel, -1, _address, _bits, \ 100 _storagebits, _shift, NULL, IIO_VOLTAGE, \ 101 BIT(IIO_CHAN_INFO_SAMP_FREQ)) 102 103 #define AD7991_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \ 104 _storagebits, _shift) \ 105 __AD7991_CHANNEL(_si, _channel1, _channel2, _address, _bits, \ 106 _storagebits, _shift, NULL, IIO_VOLTAGE, \ 107 BIT(IIO_CHAN_INFO_SAMP_FREQ)) 108 109 #define AD7991_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \ 110 _shift) \ 111 __AD7991_CHANNEL(_si, _channel, -1, _address, _bits, \ 112 _storagebits, _shift, "supply", IIO_VOLTAGE, \ 113 BIT(IIO_CHAN_INFO_SAMP_FREQ)) 114 115 #define DECLARE_AD7787_CHANNELS(name, bits, storagebits) \ 116 const struct iio_chan_spec name[] = { \ 117 AD7991_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \ 118 (bits), (storagebits), 0), \ 119 AD7991_CHANNEL(1, 1, AD7791_CH_AIN2, (bits), (storagebits), 0), \ 120 AD7991_SHORTED_CHANNEL(2, 0, AD7791_CH_AIN1N_AIN1N, \ 121 (bits), (storagebits), 0), \ 122 AD7991_SUPPLY_CHANNEL(3, 2, AD7791_CH_AVDD_MONITOR, \ 123 (bits), (storagebits), 0), \ 124 IIO_CHAN_SOFT_TIMESTAMP(4), \ 125 } 126 127 #define DECLARE_AD7791_CHANNELS(name, bits, storagebits) \ 128 const struct iio_chan_spec name[] = { \ 129 AD7991_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \ 130 (bits), (storagebits), 0), \ 131 AD7991_SHORTED_CHANNEL(1, 0, AD7791_CH_AIN1N_AIN1N, \ 132 (bits), (storagebits), 0), \ 133 AD7991_SUPPLY_CHANNEL(2, 1, AD7791_CH_AVDD_MONITOR, \ 134 (bits), (storagebits), 0), \ 135 IIO_CHAN_SOFT_TIMESTAMP(3), \ 136 } 137 138 static DECLARE_AD7787_CHANNELS(ad7787_channels, 24, 32); 139 static DECLARE_AD7791_CHANNELS(ad7790_channels, 16, 16); 140 static DECLARE_AD7791_CHANNELS(ad7791_channels, 24, 32); 141 142 enum { 143 AD7787, 144 AD7788, 145 AD7789, 146 AD7790, 147 AD7791, 148 }; 149 150 enum ad7791_chip_info_flags { 151 AD7791_FLAG_HAS_FILTER = (1 << 0), 152 AD7791_FLAG_HAS_BUFFER = (1 << 1), 153 AD7791_FLAG_HAS_UNIPOLAR = (1 << 2), 154 AD7791_FLAG_HAS_BURNOUT = (1 << 3), 155 }; 156 157 struct ad7791_chip_info { 158 const struct iio_chan_spec *channels; 159 unsigned int num_channels; 160 enum ad7791_chip_info_flags flags; 161 }; 162 163 static const struct ad7791_chip_info ad7791_chip_infos[] = { 164 [AD7787] = { 165 .channels = ad7787_channels, 166 .num_channels = ARRAY_SIZE(ad7787_channels), 167 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | 168 AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT, 169 }, 170 [AD7788] = { 171 .channels = ad7790_channels, 172 .num_channels = ARRAY_SIZE(ad7790_channels), 173 .flags = AD7791_FLAG_HAS_UNIPOLAR, 174 }, 175 [AD7789] = { 176 .channels = ad7791_channels, 177 .num_channels = ARRAY_SIZE(ad7791_channels), 178 .flags = AD7791_FLAG_HAS_UNIPOLAR, 179 }, 180 [AD7790] = { 181 .channels = ad7790_channels, 182 .num_channels = ARRAY_SIZE(ad7790_channels), 183 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | 184 AD7791_FLAG_HAS_BURNOUT, 185 }, 186 [AD7791] = { 187 .channels = ad7791_channels, 188 .num_channels = ARRAY_SIZE(ad7791_channels), 189 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | 190 AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT, 191 }, 192 }; 193 194 struct ad7791_state { 195 struct ad_sigma_delta sd; 196 uint8_t mode; 197 uint8_t filter; 198 199 struct regulator *reg; 200 const struct ad7791_chip_info *info; 201 }; 202 203 static const int ad7791_sample_freq_avail[8][2] = { 204 [AD7791_FILTER_RATE_120] = { 120, 0 }, 205 [AD7791_FILTER_RATE_100] = { 100, 0 }, 206 [AD7791_FILTER_RATE_33_3] = { 33, 300000 }, 207 [AD7791_FILTER_RATE_20] = { 20, 0 }, 208 [AD7791_FILTER_RATE_16_6] = { 16, 600000 }, 209 [AD7791_FILTER_RATE_16_7] = { 16, 700000 }, 210 [AD7791_FILTER_RATE_13_3] = { 13, 300000 }, 211 [AD7791_FILTER_RATE_9_5] = { 9, 500000 }, 212 }; 213 214 static struct ad7791_state *ad_sigma_delta_to_ad7791(struct ad_sigma_delta *sd) 215 { 216 return container_of(sd, struct ad7791_state, sd); 217 } 218 219 static int ad7791_set_channel(struct ad_sigma_delta *sd, unsigned int channel) 220 { 221 ad_sd_set_comm(sd, channel); 222 223 return 0; 224 } 225 226 static int ad7791_set_mode(struct ad_sigma_delta *sd, 227 enum ad_sigma_delta_mode mode) 228 { 229 struct ad7791_state *st = ad_sigma_delta_to_ad7791(sd); 230 231 switch (mode) { 232 case AD_SD_MODE_CONTINUOUS: 233 mode = AD7791_MODE_CONTINUOUS; 234 break; 235 case AD_SD_MODE_SINGLE: 236 mode = AD7791_MODE_SINGLE; 237 break; 238 case AD_SD_MODE_IDLE: 239 case AD_SD_MODE_POWERDOWN: 240 mode = AD7791_MODE_POWERDOWN; 241 break; 242 } 243 244 st->mode &= ~AD7791_MODE_SEL_MASK; 245 st->mode |= AD7791_MODE_SEL(mode); 246 247 return ad_sd_write_reg(sd, AD7791_REG_MODE, sizeof(st->mode), st->mode); 248 } 249 250 static const struct ad_sigma_delta_info ad7791_sigma_delta_info = { 251 .set_channel = ad7791_set_channel, 252 .set_mode = ad7791_set_mode, 253 .has_registers = true, 254 .addr_shift = 4, 255 .read_mask = BIT(3), 256 .irq_flags = IRQF_TRIGGER_LOW, 257 }; 258 259 static int ad7791_read_raw(struct iio_dev *indio_dev, 260 const struct iio_chan_spec *chan, int *val, int *val2, long info) 261 { 262 struct ad7791_state *st = iio_priv(indio_dev); 263 bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR); 264 unsigned int rate; 265 266 switch (info) { 267 case IIO_CHAN_INFO_RAW: 268 return ad_sigma_delta_single_conversion(indio_dev, chan, val); 269 case IIO_CHAN_INFO_OFFSET: 270 /** 271 * Unipolar: 0 to VREF 272 * Bipolar -VREF to VREF 273 **/ 274 if (unipolar) 275 *val = 0; 276 else 277 *val = -(1 << (chan->scan_type.realbits - 1)); 278 return IIO_VAL_INT; 279 case IIO_CHAN_INFO_SCALE: 280 /* The monitor channel uses an internal reference. */ 281 if (chan->address == AD7791_CH_AVDD_MONITOR) { 282 /* 283 * The signal is attenuated by a factor of 5 and 284 * compared against a 1.17V internal reference. 285 */ 286 *val = 1170 * 5; 287 } else { 288 int voltage_uv; 289 290 voltage_uv = regulator_get_voltage(st->reg); 291 if (voltage_uv < 0) 292 return voltage_uv; 293 294 *val = voltage_uv / 1000; 295 } 296 if (unipolar) 297 *val2 = chan->scan_type.realbits; 298 else 299 *val2 = chan->scan_type.realbits - 1; 300 301 return IIO_VAL_FRACTIONAL_LOG2; 302 case IIO_CHAN_INFO_SAMP_FREQ: 303 rate = st->filter & AD7791_FILTER_RATE_MASK; 304 *val = ad7791_sample_freq_avail[rate][0]; 305 *val2 = ad7791_sample_freq_avail[rate][1]; 306 return IIO_VAL_INT_PLUS_MICRO; 307 } 308 309 return -EINVAL; 310 } 311 312 static int ad7791_write_raw(struct iio_dev *indio_dev, 313 struct iio_chan_spec const *chan, int val, int val2, long mask) 314 { 315 struct ad7791_state *st = iio_priv(indio_dev); 316 int ret, i; 317 318 ret = iio_device_claim_direct_mode(indio_dev); 319 if (ret) 320 return ret; 321 322 switch (mask) { 323 case IIO_CHAN_INFO_SAMP_FREQ: 324 for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) { 325 if (ad7791_sample_freq_avail[i][0] == val && 326 ad7791_sample_freq_avail[i][1] == val2) 327 break; 328 } 329 330 if (i == ARRAY_SIZE(ad7791_sample_freq_avail)) { 331 ret = -EINVAL; 332 break; 333 } 334 335 st->filter &= ~AD7791_FILTER_RATE_MASK; 336 st->filter |= i; 337 ad_sd_write_reg(&st->sd, AD7791_REG_FILTER, 338 sizeof(st->filter), 339 st->filter); 340 break; 341 default: 342 ret = -EINVAL; 343 } 344 345 iio_device_release_direct_mode(indio_dev); 346 return ret; 347 } 348 349 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("120 100 33.3 20 16.7 16.6 13.3 9.5"); 350 351 static struct attribute *ad7791_attributes[] = { 352 &iio_const_attr_sampling_frequency_available.dev_attr.attr, 353 NULL 354 }; 355 356 static const struct attribute_group ad7791_attribute_group = { 357 .attrs = ad7791_attributes, 358 }; 359 360 static const struct iio_info ad7791_info = { 361 .read_raw = &ad7791_read_raw, 362 .write_raw = &ad7791_write_raw, 363 .attrs = &ad7791_attribute_group, 364 .validate_trigger = ad_sd_validate_trigger, 365 }; 366 367 static const struct iio_info ad7791_no_filter_info = { 368 .read_raw = &ad7791_read_raw, 369 .write_raw = &ad7791_write_raw, 370 .validate_trigger = ad_sd_validate_trigger, 371 }; 372 373 static int ad7791_setup(struct ad7791_state *st, 374 struct ad7791_platform_data *pdata) 375 { 376 /* Set to poweron-reset default values */ 377 st->mode = AD7791_MODE_BUFFER; 378 st->filter = AD7791_FILTER_RATE_16_6; 379 380 if (!pdata) 381 return 0; 382 383 if ((st->info->flags & AD7791_FLAG_HAS_BUFFER) && !pdata->buffered) 384 st->mode &= ~AD7791_MODE_BUFFER; 385 386 if ((st->info->flags & AD7791_FLAG_HAS_BURNOUT) && 387 pdata->burnout_current) 388 st->mode |= AD7791_MODE_BURNOUT; 389 390 if ((st->info->flags & AD7791_FLAG_HAS_UNIPOLAR) && pdata->unipolar) 391 st->mode |= AD7791_MODE_UNIPOLAR; 392 393 return ad_sd_write_reg(&st->sd, AD7791_REG_MODE, sizeof(st->mode), 394 st->mode); 395 } 396 397 static void ad7791_reg_disable(void *reg) 398 { 399 regulator_disable(reg); 400 } 401 402 static int ad7791_probe(struct spi_device *spi) 403 { 404 struct ad7791_platform_data *pdata = spi->dev.platform_data; 405 struct iio_dev *indio_dev; 406 struct ad7791_state *st; 407 int ret; 408 409 if (!spi->irq) { 410 dev_err(&spi->dev, "Missing IRQ.\n"); 411 return -ENXIO; 412 } 413 414 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 415 if (!indio_dev) 416 return -ENOMEM; 417 418 st = iio_priv(indio_dev); 419 420 st->reg = devm_regulator_get(&spi->dev, "refin"); 421 if (IS_ERR(st->reg)) 422 return PTR_ERR(st->reg); 423 424 ret = regulator_enable(st->reg); 425 if (ret) 426 return ret; 427 428 ret = devm_add_action_or_reset(&spi->dev, ad7791_reg_disable, st->reg); 429 if (ret) 430 return ret; 431 432 st->info = &ad7791_chip_infos[spi_get_device_id(spi)->driver_data]; 433 ad_sd_init(&st->sd, indio_dev, spi, &ad7791_sigma_delta_info); 434 435 indio_dev->name = spi_get_device_id(spi)->name; 436 indio_dev->modes = INDIO_DIRECT_MODE; 437 indio_dev->channels = st->info->channels; 438 indio_dev->num_channels = st->info->num_channels; 439 if (st->info->flags & AD7791_FLAG_HAS_FILTER) 440 indio_dev->info = &ad7791_info; 441 else 442 indio_dev->info = &ad7791_no_filter_info; 443 444 ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev); 445 if (ret) 446 return ret; 447 448 ret = ad7791_setup(st, pdata); 449 if (ret) 450 return ret; 451 452 return devm_iio_device_register(&spi->dev, indio_dev); 453 } 454 455 static const struct spi_device_id ad7791_spi_ids[] = { 456 { "ad7787", AD7787 }, 457 { "ad7788", AD7788 }, 458 { "ad7789", AD7789 }, 459 { "ad7790", AD7790 }, 460 { "ad7791", AD7791 }, 461 {} 462 }; 463 MODULE_DEVICE_TABLE(spi, ad7791_spi_ids); 464 465 static struct spi_driver ad7791_driver = { 466 .driver = { 467 .name = "ad7791", 468 }, 469 .probe = ad7791_probe, 470 .id_table = ad7791_spi_ids, 471 }; 472 module_spi_driver(ad7791_driver); 473 474 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 475 MODULE_DESCRIPTION("Analog Devices AD7787/AD7788/AD7789/AD7790/AD7791 ADC driver"); 476 MODULE_LICENSE("GPL v2"); 477