drivers/iio/imu/adis.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Common library for ADIS16XXX devices
   4  *
   5  * Copyright 2012 Analog Devices Inc.
   6  *   Author: Lars-Peter Clausen <lars@metafoo.de>
   7  */
   8
   9 #include <linux/delay.h>
  10 #include <linux/gpio/consumer.h>
  11 #include <linux/mutex.h>
  12 #include <linux/device.h>
  13 #include <linux/kernel.h>
  14 #include <linux/spi/spi.h>
  15 #include <linux/slab.h>
  16 #include <linux/sysfs.h>
  17 #include <linux/module.h>
  18 #include <asm/unaligned.h>
  19
  20 #include <linux/iio/iio.h>
  21 #include <linux/iio/sysfs.h>
  22 #include <linux/iio/buffer.h>
  23 #include <linux/iio/imu/adis.h>
  24
  25 #define ADIS_MSC_CTRL_DATA_RDY_EN       BIT(2)
  26 #define ADIS_MSC_CTRL_DATA_RDY_POL_HIGH BIT(1)
  27 #define ADIS_MSC_CTRL_DATA_RDY_DIO2     BIT(0)
  28 #define ADIS_GLOB_CMD_SW_RESET          BIT(7)
  29
  30 /**
  31  * __adis_write_reg() - write N bytes to register (unlocked version)
  32  * @adis: The adis device
  33  * @reg: The address of the lower of the two registers
  34  * @value: The value to write to device (up to 4 bytes)
  35  * @size: The size of the @value (in bytes)
  36  */
  37 int __adis_write_reg(struct adis *adis, unsigned int reg,
  38         unsigned int value, unsigned int size)
  39 {
  40         unsigned int page = reg / ADIS_PAGE_SIZE;
  41         int ret, i;
  42         struct spi_message msg;
  43         struct spi_transfer xfers[] = {
  44                 {
  45                         .tx_buf = adis->tx,
  46                         .bits_per_word = 8,
  47                         .len = 2,
  48                         .cs_change = 1,
  49                         .delay.value = adis->data->write_delay,
  50                         .delay.unit = SPI_DELAY_UNIT_USECS,
  51                         .cs_change_delay.value = adis->data->cs_change_delay,
  52                         .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
  53                 }, {
  54                         .tx_buf = adis->tx + 2,
  55                         .bits_per_word = 8,
  56                         .len = 2,
  57                         .cs_change = 1,
  58                         .delay.value = adis->data->write_delay,
  59                         .delay.unit = SPI_DELAY_UNIT_USECS,
  60                         .cs_change_delay.value = adis->data->cs_change_delay,
  61                         .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
  62                 }, {
  63                         .tx_buf = adis->tx + 4,
  64                         .bits_per_word = 8,
  65                         .len = 2,
  66                         .cs_change = 1,
  67                         .delay.value = adis->data->write_delay,
  68                         .delay.unit = SPI_DELAY_UNIT_USECS,
  69                         .cs_change_delay.value = adis->data->cs_change_delay,
  70                         .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
  71                 }, {
  72                         .tx_buf = adis->tx + 6,
  73                         .bits_per_word = 8,
  74                         .len = 2,
  75                         .delay.value = adis->data->write_delay,
  76                         .delay.unit = SPI_DELAY_UNIT_USECS,
  77                 }, {
  78                         .tx_buf = adis->tx + 8,
  79                         .bits_per_word = 8,
  80                         .len = 2,
  81                         .delay.value = adis->data->write_delay,
  82                         .delay.unit = SPI_DELAY_UNIT_USECS,
  83                 },
  84         };
  85
  86         spi_message_init(&msg);
  87
  88         if (adis->current_page != page) {
  89                 adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
  90                 adis->tx[1] = page;
  91                 spi_message_add_tail(&xfers[0], &msg);
  92         }
  93
  94         switch (size) {
  95         case 4:
  96                 adis->tx[8] = ADIS_WRITE_REG(reg + 3);
  97                 adis->tx[9] = (value >> 24) & 0xff;
  98                 adis->tx[6] = ADIS_WRITE_REG(reg + 2);
  99                 adis->tx[7] = (value >> 16) & 0xff;
 100                 /* fall through */
 101         case 2:
 102                 adis->tx[4] = ADIS_WRITE_REG(reg + 1);
 103                 adis->tx[5] = (value >> 8) & 0xff;
 104                 /* fall through */
 105         case 1:
 106                 adis->tx[2] = ADIS_WRITE_REG(reg);
 107                 adis->tx[3] = value & 0xff;
 108                 break;
 109         default:
 110                 return -EINVAL;
 111         }
 112
 113         xfers[size].cs_change = 0;
 114
 115         for (i = 1; i <= size; i++)
 116                 spi_message_add_tail(&xfers[i], &msg);
 117
 118         ret = spi_sync(adis->spi, &msg);
 119         if (ret) {
 120                 dev_err(&adis->spi->dev, "Failed to write register 0x%02X: %d\n",
 121                                 reg, ret);
 122         } else {
 123                 adis->current_page = page;
 124         }
 125
 126         return ret;
 127 }
 128 EXPORT_SYMBOL_GPL(__adis_write_reg);
 129
 130 /**
 131  * __adis_read_reg() - read N bytes from register (unlocked version)
 132  * @adis: The adis device
 133  * @reg: The address of the lower of the two registers
 134  * @val: The value read back from the device
 135  * @size: The size of the @val buffer
 136  */
 137 int __adis_read_reg(struct adis *adis, unsigned int reg,
 138         unsigned int *val, unsigned int size)
 139 {
 140         unsigned int page = reg / ADIS_PAGE_SIZE;
 141         struct spi_message msg;
 142         int ret;
 143         struct spi_transfer xfers[] = {
 144                 {
 145                         .tx_buf = adis->tx,
 146                         .bits_per_word = 8,
 147                         .len = 2,
 148                         .cs_change = 1,
 149                         .delay.value = adis->data->write_delay,
 150                         .delay.unit = SPI_DELAY_UNIT_USECS,
 151                         .cs_change_delay.value = adis->data->cs_change_delay,
 152                         .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
 153                 }, {
 154                         .tx_buf = adis->tx + 2,
 155                         .bits_per_word = 8,
 156                         .len = 2,
 157                         .cs_change = 1,
 158                         .delay.value = adis->data->read_delay,
 159                         .delay.unit = SPI_DELAY_UNIT_USECS,
 160                         .cs_change_delay.value = adis->data->cs_change_delay,
 161                         .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
 162                 }, {
 163                         .tx_buf = adis->tx + 4,
 164                         .rx_buf = adis->rx,
 165                         .bits_per_word = 8,
 166                         .len = 2,
 167                         .cs_change = 1,
 168                         .delay.value = adis->data->read_delay,
 169                         .delay.unit = SPI_DELAY_UNIT_USECS,
 170                         .cs_change_delay.value = adis->data->cs_change_delay,
 171                         .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
 172                 }, {
 173                         .rx_buf = adis->rx + 2,
 174                         .bits_per_word = 8,
 175                         .len = 2,
 176                         .delay.value = adis->data->read_delay,
 177                         .delay.unit = SPI_DELAY_UNIT_USECS,
 178                 },
 179         };
 180
 181         spi_message_init(&msg);
 182
 183         if (adis->current_page != page) {
 184                 adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
 185                 adis->tx[1] = page;
 186                 spi_message_add_tail(&xfers[0], &msg);
 187         }
 188
 189         switch (size) {
 190         case 4:
 191                 adis->tx[2] = ADIS_READ_REG(reg + 2);
 192                 adis->tx[3] = 0;
 193                 spi_message_add_tail(&xfers[1], &msg);
 194                 /* fall through */
 195         case 2:
 196                 adis->tx[4] = ADIS_READ_REG(reg);
 197                 adis->tx[5] = 0;
 198                 spi_message_add_tail(&xfers[2], &msg);
 199                 spi_message_add_tail(&xfers[3], &msg);
 200                 break;
 201         default:
 202                 return -EINVAL;
 203         }
 204
 205         ret = spi_sync(adis->spi, &msg);
 206         if (ret) {
 207                 dev_err(&adis->spi->dev, "Failed to read register 0x%02X: %d\n",
 208                                 reg, ret);
 209                 return ret;
 210         } else {
 211                 adis->current_page = page;
 212         }
 213
 214         switch (size) {
 215         case 4:
 216                 *val = get_unaligned_be32(adis->rx);
 217                 break;
 218         case 2:
 219                 *val = get_unaligned_be16(adis->rx + 2);
 220                 break;
 221         }
 222
 223         return ret;
 224 }
 225 EXPORT_SYMBOL_GPL(__adis_read_reg);
 226
 227 #ifdef CONFIG_DEBUG_FS
 228
 229 int adis_debugfs_reg_access(struct iio_dev *indio_dev,
 230         unsigned int reg, unsigned int writeval, unsigned int *readval)
 231 {
 232         struct adis *adis = iio_device_get_drvdata(indio_dev);
 233
 234         if (readval) {
 235                 uint16_t val16;
 236                 int ret;
 237
 238                 ret = adis_read_reg_16(adis, reg, &val16);
 239                 if (ret == 0)
 240                         *readval = val16;
 241
 242                 return ret;
 243         } else {
 244                 return adis_write_reg_16(adis, reg, writeval);
 245         }
 246 }
 247 EXPORT_SYMBOL(adis_debugfs_reg_access);
 248
 249 #endif
 250
 251 /**
 252  * adis_enable_irq() - Enable or disable data ready IRQ
 253  * @adis: The adis device
 254  * @enable: Whether to enable the IRQ
 255  *
 256  * Returns 0 on success, negative error code otherwise
 257  */
 258 int adis_enable_irq(struct adis *adis, bool enable)
 259 {
 260         int ret = 0;
 261         uint16_t msc;
 262
 263         mutex_lock(&adis->state_lock);
 264
 265         if (adis->data->enable_irq) {
 266                 ret = adis->data->enable_irq(adis, enable);
 267                 goto out_unlock;
 268         }
 269
 270         ret = __adis_read_reg_16(adis, adis->data->msc_ctrl_reg, &msc);
 271         if (ret)
 272                 goto out_unlock;
 273
 274         msc |= ADIS_MSC_CTRL_DATA_RDY_POL_HIGH;
 275         msc &= ~ADIS_MSC_CTRL_DATA_RDY_DIO2;
 276         if (enable)
 277                 msc |= ADIS_MSC_CTRL_DATA_RDY_EN;
 278         else
 279                 msc &= ~ADIS_MSC_CTRL_DATA_RDY_EN;
 280
 281         ret = __adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc);
 282
 283 out_unlock:
 284         mutex_unlock(&adis->state_lock);
 285         return ret;
 286 }
 287 EXPORT_SYMBOL(adis_enable_irq);
 288
 289 /**
 290  * __adis_check_status() - Check the device for error conditions (unlocked)
 291  * @adis: The adis device
 292  *
 293  * Returns 0 on success, a negative error code otherwise
 294  */
 295 int __adis_check_status(struct adis *adis)
 296 {
 297         uint16_t status;
 298         int ret;
 299         int i;
 300
 301         ret = __adis_read_reg_16(adis, adis->data->diag_stat_reg, &status);
 302         if (ret)
 303                 return ret;
 304
 305         status &= adis->data->status_error_mask;
 306
 307         if (status == 0)
 308                 return 0;
 309
 310         for (i = 0; i < 16; ++i) {
 311                 if (status & BIT(i)) {
 312                         dev_err(&adis->spi->dev, "%s.\n",
 313                                 adis->data->status_error_msgs[i]);
 314                 }
 315         }
 316
 317         return -EIO;
 318 }
 319 EXPORT_SYMBOL_GPL(__adis_check_status);
 320
 321 /**
 322  * __adis_reset() - Reset the device (unlocked version)
 323  * @adis: The adis device
 324  *
 325  * Returns 0 on success, a negative error code otherwise
 326  */
 327 int __adis_reset(struct adis *adis)
 328 {
 329         int ret;
 330         const struct adis_timeout *timeouts = adis->data->timeouts;
 331
 332         ret = __adis_write_reg_8(adis, adis->data->glob_cmd_reg,
 333                         ADIS_GLOB_CMD_SW_RESET);
 334         if (ret) {
 335                 dev_err(&adis->spi->dev, "Failed to reset device: %d\n", ret);
 336                 return ret;
 337         }
 338
 339         msleep(timeouts->sw_reset_ms);
 340
 341         return 0;
 342 }
 343 EXPORT_SYMBOL_GPL(__adis_reset);
 344
 345 static int adis_self_test(struct adis *adis)
 346 {
 347         int ret;
 348         const struct adis_timeout *timeouts = adis->data->timeouts;
 349
 350         ret = __adis_write_reg_16(adis, adis->data->self_test_reg,
 351                                   adis->data->self_test_mask);
 352         if (ret) {
 353                 dev_err(&adis->spi->dev, "Failed to initiate self test: %d\n",
 354                         ret);
 355                 return ret;
 356         }
 357
 358         msleep(timeouts->self_test_ms);
 359
 360         ret = __adis_check_status(adis);
 361
 362         if (adis->data->self_test_no_autoclear)
 363                 __adis_write_reg_16(adis, adis->data->self_test_reg, 0x00);
 364
 365         return ret;
 366 }
 367
 368 /**
 369  * __adis_initial_startup() - Device initial setup
 370  * @adis: The adis device
 371  *
 372  * The function performs a HW reset via a reset pin that should be specified
 373  * via GPIOLIB. If no pin is configured a SW reset will be performed.
 374  * The RST pin for the ADIS devices should be configured as ACTIVE_LOW.
 375  *
 376  * After the self-test operation is performed, the function will also check
 377  * that the product ID is as expected. This assumes that drivers providing
 378  * 'prod_id_reg' will also provide the 'prod_id'.
 379  *
 380  * Returns 0 if the device is operational, a negative error code otherwise.
 381  *
 382  * This function should be called early on in the device initialization sequence
 383  * to ensure that the device is in a sane and known state and that it is usable.
 384  */
 385 int __adis_initial_startup(struct adis *adis)
 386 {
 387         const struct adis_timeout *timeouts = adis->data->timeouts;
 388         struct gpio_desc *gpio;
 389         uint16_t prod_id;
 390         int ret;
 391
 392         /* check if the device has rst pin low */
 393         gpio = devm_gpiod_get_optional(&adis->spi->dev, "reset", GPIOD_ASIS);
 394         if (IS_ERR(gpio))
 395                 return PTR_ERR(gpio);
 396
 397         if (gpio) {
 398                 gpiod_set_value_cansleep(gpio, 1);
 399                 msleep(10);
 400                 /* bring device out of reset */
 401                 gpiod_set_value_cansleep(gpio, 0);
 402                 msleep(timeouts->reset_ms);
 403         } else {
 404                 ret = __adis_reset(adis);
 405                 if (ret)
 406                         return ret;
 407         }
 408
 409         ret = adis_self_test(adis);
 410         if (ret)
 411                 return ret;
 412
 413         if (!adis->data->prod_id_reg)
 414                 return 0;
 415
 416         ret = adis_read_reg_16(adis, adis->data->prod_id_reg, &prod_id);
 417         if (ret)
 418                 return ret;
 419
 420         if (prod_id != adis->data->prod_id)
 421                 dev_warn(&adis->spi->dev,
 422                          "Device ID(%u) and product ID(%u) do not match.",
 423                          adis->data->prod_id, prod_id);
 424
 425         return 0;
 426 }
 427 EXPORT_SYMBOL_GPL(__adis_initial_startup);
 428
 429 /**
 430  * adis_single_conversion() - Performs a single sample conversion
 431  * @indio_dev: The IIO device
 432  * @chan: The IIO channel
 433  * @error_mask: Mask for the error bit
 434  * @val: Result of the conversion
 435  *
 436  * Returns IIO_VAL_INT on success, a negative error code otherwise.
 437  *
 438  * The function performs a single conversion on a given channel and post
 439  * processes the value accordingly to the channel spec. If a error_mask is given
 440  * the function will check if the mask is set in the returned raw value. If it
 441  * is set the function will perform a self-check. If the device does not report
 442  * a error bit in the channels raw value set error_mask to 0.
 443  */
 444 int adis_single_conversion(struct iio_dev *indio_dev,
 445         const struct iio_chan_spec *chan, unsigned int error_mask, int *val)
 446 {
 447         struct adis *adis = iio_device_get_drvdata(indio_dev);
 448         unsigned int uval;
 449         int ret;
 450
 451         mutex_lock(&adis->state_lock);
 452
 453         ret = __adis_read_reg(adis, chan->address, &uval,
 454                         chan->scan_type.storagebits / 8);
 455         if (ret)
 456                 goto err_unlock;
 457
 458         if (uval & error_mask) {
 459                 ret = __adis_check_status(adis);
 460                 if (ret)
 461                         goto err_unlock;
 462         }
 463
 464         if (chan->scan_type.sign == 's')
 465                 *val = sign_extend32(uval, chan->scan_type.realbits - 1);
 466         else
 467                 *val = uval & ((1 << chan->scan_type.realbits) - 1);
 468
 469         ret = IIO_VAL_INT;
 470 err_unlock:
 471         mutex_unlock(&adis->state_lock);
 472         return ret;
 473 }
 474 EXPORT_SYMBOL_GPL(adis_single_conversion);
 475
 476 /**
 477  * adis_init() - Initialize adis device structure
 478  * @adis:       The adis device
 479  * @indio_dev:  The iio device
 480  * @spi:        The spi device
 481  * @data:       Chip specific data
 482  *
 483  * Returns 0 on success, a negative error code otherwise.
 484  *
 485  * This function must be called, before any other adis helper function may be
 486  * called.
 487  */
 488 int adis_init(struct adis *adis, struct iio_dev *indio_dev,
 489         struct spi_device *spi, const struct adis_data *data)
 490 {
 491         if (!data || !data->timeouts) {
 492                 dev_err(&spi->dev, "No config data or timeouts not defined!\n");
 493                 return -EINVAL;
 494         }
 495
 496         mutex_init(&adis->state_lock);
 497         adis->spi = spi;
 498         adis->data = data;
 499         iio_device_set_drvdata(indio_dev, adis);
 500
 501         if (data->has_paging) {
 502                 /* Need to set the page before first read/write */
 503                 adis->current_page = -1;
 504         } else {
 505                 /* Page will always be 0 */
 506                 adis->current_page = 0;
 507         }
 508
 509         return adis_enable_irq(adis, false);
 510 }
 511 EXPORT_SYMBOL_GPL(adis_init);
 512
 513 MODULE_LICENSE("GPL");
 514 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 515 MODULE_DESCRIPTION("Common library code for ADIS16XXX devices");