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 DECLARE_AD7787_CHANNELS(name, bits, storagebits) \ 68 const struct iio_chan_spec name[] = { \ 69 AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \ 70 (bits), (storagebits), 0), \ 71 AD_SD_CHANNEL(1, 1, AD7791_CH_AIN2, (bits), (storagebits), 0), \ 72 AD_SD_SHORTED_CHANNEL(2, 0, AD7791_CH_AIN1N_AIN1N, \ 73 (bits), (storagebits), 0), \ 74 AD_SD_SUPPLY_CHANNEL(3, 2, AD7791_CH_AVDD_MONITOR, \ 75 (bits), (storagebits), 0), \ 76 IIO_CHAN_SOFT_TIMESTAMP(4), \ 77 } 78 79 #define DECLARE_AD7791_CHANNELS(name, bits, storagebits) \ 80 const struct iio_chan_spec name[] = { \ 81 AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \ 82 (bits), (storagebits), 0), \ 83 AD_SD_SHORTED_CHANNEL(1, 0, AD7791_CH_AIN1N_AIN1N, \ 84 (bits), (storagebits), 0), \ 85 AD_SD_SUPPLY_CHANNEL(2, 1, AD7791_CH_AVDD_MONITOR, \ 86 (bits), (storagebits), 0), \ 87 IIO_CHAN_SOFT_TIMESTAMP(3), \ 88 } 89 90 static DECLARE_AD7787_CHANNELS(ad7787_channels, 24, 32); 91 static DECLARE_AD7791_CHANNELS(ad7790_channels, 16, 16); 92 static DECLARE_AD7791_CHANNELS(ad7791_channels, 24, 32); 93 94 enum { 95 AD7787, 96 AD7788, 97 AD7789, 98 AD7790, 99 AD7791, 100 }; 101 102 enum ad7791_chip_info_flags { 103 AD7791_FLAG_HAS_FILTER = (1 << 0), 104 AD7791_FLAG_HAS_BUFFER = (1 << 1), 105 AD7791_FLAG_HAS_UNIPOLAR = (1 << 2), 106 AD7791_FLAG_HAS_BURNOUT = (1 << 3), 107 }; 108 109 struct ad7791_chip_info { 110 const struct iio_chan_spec *channels; 111 unsigned int num_channels; 112 enum ad7791_chip_info_flags flags; 113 }; 114 115 static const struct ad7791_chip_info ad7791_chip_infos[] = { 116 [AD7787] = { 117 .channels = ad7787_channels, 118 .num_channels = ARRAY_SIZE(ad7787_channels), 119 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | 120 AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT, 121 }, 122 [AD7788] = { 123 .channels = ad7790_channels, 124 .num_channels = ARRAY_SIZE(ad7790_channels), 125 .flags = AD7791_FLAG_HAS_UNIPOLAR, 126 }, 127 [AD7789] = { 128 .channels = ad7791_channels, 129 .num_channels = ARRAY_SIZE(ad7791_channels), 130 .flags = AD7791_FLAG_HAS_UNIPOLAR, 131 }, 132 [AD7790] = { 133 .channels = ad7790_channels, 134 .num_channels = ARRAY_SIZE(ad7790_channels), 135 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | 136 AD7791_FLAG_HAS_BURNOUT, 137 }, 138 [AD7791] = { 139 .channels = ad7791_channels, 140 .num_channels = ARRAY_SIZE(ad7791_channels), 141 .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | 142 AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT, 143 }, 144 }; 145 146 struct ad7791_state { 147 struct ad_sigma_delta sd; 148 uint8_t mode; 149 uint8_t filter; 150 151 struct regulator *reg; 152 const struct ad7791_chip_info *info; 153 }; 154 155 static const int ad7791_sample_freq_avail[8][2] = { 156 [AD7791_FILTER_RATE_120] = { 120, 0 }, 157 [AD7791_FILTER_RATE_100] = { 100, 0 }, 158 [AD7791_FILTER_RATE_33_3] = { 33, 300000 }, 159 [AD7791_FILTER_RATE_20] = { 20, 0 }, 160 [AD7791_FILTER_RATE_16_6] = { 16, 600000 }, 161 [AD7791_FILTER_RATE_16_7] = { 16, 700000 }, 162 [AD7791_FILTER_RATE_13_3] = { 13, 300000 }, 163 [AD7791_FILTER_RATE_9_5] = { 9, 500000 }, 164 }; 165 166 static struct ad7791_state *ad_sigma_delta_to_ad7791(struct ad_sigma_delta *sd) 167 { 168 return container_of(sd, struct ad7791_state, sd); 169 } 170 171 static int ad7791_set_channel(struct ad_sigma_delta *sd, unsigned int channel) 172 { 173 ad_sd_set_comm(sd, channel); 174 175 return 0; 176 } 177 178 static int ad7791_set_mode(struct ad_sigma_delta *sd, 179 enum ad_sigma_delta_mode mode) 180 { 181 struct ad7791_state *st = ad_sigma_delta_to_ad7791(sd); 182 183 switch (mode) { 184 case AD_SD_MODE_CONTINUOUS: 185 mode = AD7791_MODE_CONTINUOUS; 186 break; 187 case AD_SD_MODE_SINGLE: 188 mode = AD7791_MODE_SINGLE; 189 break; 190 case AD_SD_MODE_IDLE: 191 case AD_SD_MODE_POWERDOWN: 192 mode = AD7791_MODE_POWERDOWN; 193 break; 194 } 195 196 st->mode &= ~AD7791_MODE_SEL_MASK; 197 st->mode |= AD7791_MODE_SEL(mode); 198 199 return ad_sd_write_reg(sd, AD7791_REG_MODE, sizeof(st->mode), st->mode); 200 } 201 202 static const struct ad_sigma_delta_info ad7791_sigma_delta_info = { 203 .set_channel = ad7791_set_channel, 204 .set_mode = ad7791_set_mode, 205 .has_registers = true, 206 .addr_shift = 4, 207 .read_mask = BIT(3), 208 }; 209 210 static int ad7791_read_raw(struct iio_dev *indio_dev, 211 const struct iio_chan_spec *chan, int *val, int *val2, long info) 212 { 213 struct ad7791_state *st = iio_priv(indio_dev); 214 bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR); 215 unsigned int rate; 216 217 switch (info) { 218 case IIO_CHAN_INFO_RAW: 219 return ad_sigma_delta_single_conversion(indio_dev, chan, val); 220 case IIO_CHAN_INFO_OFFSET: 221 /** 222 * Unipolar: 0 to VREF 223 * Bipolar -VREF to VREF 224 **/ 225 if (unipolar) 226 *val = 0; 227 else 228 *val = -(1 << (chan->scan_type.realbits - 1)); 229 return IIO_VAL_INT; 230 case IIO_CHAN_INFO_SCALE: 231 /* The monitor channel uses an internal reference. */ 232 if (chan->address == AD7791_CH_AVDD_MONITOR) { 233 /* 234 * The signal is attenuated by a factor of 5 and 235 * compared against a 1.17V internal reference. 236 */ 237 *val = 1170 * 5; 238 } else { 239 int voltage_uv; 240 241 voltage_uv = regulator_get_voltage(st->reg); 242 if (voltage_uv < 0) 243 return voltage_uv; 244 245 *val = voltage_uv / 1000; 246 } 247 if (unipolar) 248 *val2 = chan->scan_type.realbits; 249 else 250 *val2 = chan->scan_type.realbits - 1; 251 252 return IIO_VAL_FRACTIONAL_LOG2; 253 case IIO_CHAN_INFO_SAMP_FREQ: 254 rate = st->filter & AD7791_FILTER_RATE_MASK; 255 *val = ad7791_sample_freq_avail[rate][0]; 256 *val2 = ad7791_sample_freq_avail[rate][1]; 257 return IIO_VAL_INT_PLUS_MICRO; 258 } 259 260 return -EINVAL; 261 } 262 263 static int ad7791_write_raw(struct iio_dev *indio_dev, 264 struct iio_chan_spec const *chan, int val, int val2, long mask) 265 { 266 struct ad7791_state *st = iio_priv(indio_dev); 267 int ret, i; 268 269 ret = iio_device_claim_direct_mode(indio_dev); 270 if (ret) 271 return ret; 272 273 switch (mask) { 274 case IIO_CHAN_INFO_SAMP_FREQ: 275 for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) { 276 if (ad7791_sample_freq_avail[i][0] == val && 277 ad7791_sample_freq_avail[i][1] == val2) 278 break; 279 } 280 281 if (i == ARRAY_SIZE(ad7791_sample_freq_avail)) { 282 ret = -EINVAL; 283 break; 284 } 285 286 st->filter &= ~AD7791_FILTER_RATE_MASK; 287 st->filter |= i; 288 ad_sd_write_reg(&st->sd, AD7791_REG_FILTER, 289 sizeof(st->filter), 290 st->filter); 291 break; 292 default: 293 ret = -EINVAL; 294 } 295 296 iio_device_release_direct_mode(indio_dev); 297 return ret; 298 } 299 300 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("120 100 33.3 20 16.7 16.6 13.3 9.5"); 301 302 static struct attribute *ad7791_attributes[] = { 303 &iio_const_attr_sampling_frequency_available.dev_attr.attr, 304 NULL 305 }; 306 307 static const struct attribute_group ad7791_attribute_group = { 308 .attrs = ad7791_attributes, 309 }; 310 311 static const struct iio_info ad7791_info = { 312 .read_raw = &ad7791_read_raw, 313 .write_raw = &ad7791_write_raw, 314 .attrs = &ad7791_attribute_group, 315 .validate_trigger = ad_sd_validate_trigger, 316 }; 317 318 static const struct iio_info ad7791_no_filter_info = { 319 .read_raw = &ad7791_read_raw, 320 .write_raw = &ad7791_write_raw, 321 .validate_trigger = ad_sd_validate_trigger, 322 }; 323 324 static int ad7791_setup(struct ad7791_state *st, 325 struct ad7791_platform_data *pdata) 326 { 327 /* Set to poweron-reset default values */ 328 st->mode = AD7791_MODE_BUFFER; 329 st->filter = AD7791_FILTER_RATE_16_6; 330 331 if (!pdata) 332 return 0; 333 334 if ((st->info->flags & AD7791_FLAG_HAS_BUFFER) && !pdata->buffered) 335 st->mode &= ~AD7791_MODE_BUFFER; 336 337 if ((st->info->flags & AD7791_FLAG_HAS_BURNOUT) && 338 pdata->burnout_current) 339 st->mode |= AD7791_MODE_BURNOUT; 340 341 if ((st->info->flags & AD7791_FLAG_HAS_UNIPOLAR) && pdata->unipolar) 342 st->mode |= AD7791_MODE_UNIPOLAR; 343 344 return ad_sd_write_reg(&st->sd, AD7791_REG_MODE, sizeof(st->mode), 345 st->mode); 346 } 347 348 static int ad7791_probe(struct spi_device *spi) 349 { 350 struct ad7791_platform_data *pdata = spi->dev.platform_data; 351 struct iio_dev *indio_dev; 352 struct ad7791_state *st; 353 int ret; 354 355 if (!spi->irq) { 356 dev_err(&spi->dev, "Missing IRQ.\n"); 357 return -ENXIO; 358 } 359 360 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 361 if (!indio_dev) 362 return -ENOMEM; 363 364 st = iio_priv(indio_dev); 365 366 st->reg = devm_regulator_get(&spi->dev, "refin"); 367 if (IS_ERR(st->reg)) 368 return PTR_ERR(st->reg); 369 370 ret = regulator_enable(st->reg); 371 if (ret) 372 return ret; 373 374 st->info = &ad7791_chip_infos[spi_get_device_id(spi)->driver_data]; 375 ad_sd_init(&st->sd, indio_dev, spi, &ad7791_sigma_delta_info); 376 377 spi_set_drvdata(spi, indio_dev); 378 379 indio_dev->dev.parent = &spi->dev; 380 indio_dev->dev.of_node = spi->dev.of_node; 381 indio_dev->name = spi_get_device_id(spi)->name; 382 indio_dev->modes = INDIO_DIRECT_MODE; 383 indio_dev->channels = st->info->channels; 384 indio_dev->num_channels = st->info->num_channels; 385 if (st->info->flags & AD7791_FLAG_HAS_FILTER) 386 indio_dev->info = &ad7791_info; 387 else 388 indio_dev->info = &ad7791_no_filter_info; 389 390 ret = ad_sd_setup_buffer_and_trigger(indio_dev); 391 if (ret) 392 goto error_disable_reg; 393 394 ret = ad7791_setup(st, pdata); 395 if (ret) 396 goto error_remove_trigger; 397 398 ret = iio_device_register(indio_dev); 399 if (ret) 400 goto error_remove_trigger; 401 402 return 0; 403 404 error_remove_trigger: 405 ad_sd_cleanup_buffer_and_trigger(indio_dev); 406 error_disable_reg: 407 regulator_disable(st->reg); 408 409 return ret; 410 } 411 412 static int ad7791_remove(struct spi_device *spi) 413 { 414 struct iio_dev *indio_dev = spi_get_drvdata(spi); 415 struct ad7791_state *st = iio_priv(indio_dev); 416 417 iio_device_unregister(indio_dev); 418 ad_sd_cleanup_buffer_and_trigger(indio_dev); 419 420 regulator_disable(st->reg); 421 422 return 0; 423 } 424 425 static const struct spi_device_id ad7791_spi_ids[] = { 426 { "ad7787", AD7787 }, 427 { "ad7788", AD7788 }, 428 { "ad7789", AD7789 }, 429 { "ad7790", AD7790 }, 430 { "ad7791", AD7791 }, 431 {} 432 }; 433 MODULE_DEVICE_TABLE(spi, ad7791_spi_ids); 434 435 static struct spi_driver ad7791_driver = { 436 .driver = { 437 .name = "ad7791", 438 }, 439 .probe = ad7791_probe, 440 .remove = ad7791_remove, 441 .id_table = ad7791_spi_ids, 442 }; 443 module_spi_driver(ad7791_driver); 444 445 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 446 MODULE_DESCRIPTION("Analog Device AD7787/AD7788/AD7789/AD7790/AD7791 ADC driver"); 447 MODULE_LICENSE("GPL v2"); 448