1 /* 2 * Common library for ADIS16XXX devices 3 * 4 * Copyright 2012 Analog Devices Inc. 5 * Author: Lars-Peter Clausen <lars@metafoo.de> 6 * 7 * Licensed under the GPL-2 or later. 8 */ 9 10 #include <linux/delay.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 int adis_write_reg(struct adis *adis, unsigned int reg, 31 unsigned int value, unsigned int size) 32 { 33 unsigned int page = reg / ADIS_PAGE_SIZE; 34 int ret, i; 35 struct spi_message msg; 36 struct spi_transfer xfers[] = { 37 { 38 .tx_buf = adis->tx, 39 .bits_per_word = 8, 40 .len = 2, 41 .cs_change = 1, 42 .delay_usecs = adis->data->write_delay, 43 }, { 44 .tx_buf = adis->tx + 2, 45 .bits_per_word = 8, 46 .len = 2, 47 .cs_change = 1, 48 .delay_usecs = adis->data->write_delay, 49 }, { 50 .tx_buf = adis->tx + 4, 51 .bits_per_word = 8, 52 .len = 2, 53 .cs_change = 1, 54 .delay_usecs = adis->data->write_delay, 55 }, { 56 .tx_buf = adis->tx + 6, 57 .bits_per_word = 8, 58 .len = 2, 59 .delay_usecs = adis->data->write_delay, 60 }, { 61 .tx_buf = adis->tx + 8, 62 .bits_per_word = 8, 63 .len = 2, 64 .delay_usecs = adis->data->write_delay, 65 }, 66 }; 67 68 mutex_lock(&adis->txrx_lock); 69 70 spi_message_init(&msg); 71 72 if (adis->current_page != page) { 73 adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID); 74 adis->tx[1] = page; 75 spi_message_add_tail(&xfers[0], &msg); 76 } 77 78 switch (size) { 79 case 4: 80 adis->tx[8] = ADIS_WRITE_REG(reg + 3); 81 adis->tx[9] = (value >> 24) & 0xff; 82 adis->tx[6] = ADIS_WRITE_REG(reg + 2); 83 adis->tx[7] = (value >> 16) & 0xff; 84 case 2: 85 adis->tx[4] = ADIS_WRITE_REG(reg + 1); 86 adis->tx[5] = (value >> 8) & 0xff; 87 case 1: 88 adis->tx[2] = ADIS_WRITE_REG(reg); 89 adis->tx[3] = value & 0xff; 90 break; 91 default: 92 ret = -EINVAL; 93 goto out_unlock; 94 } 95 96 xfers[size].cs_change = 0; 97 98 for (i = 1; i <= size; i++) 99 spi_message_add_tail(&xfers[i], &msg); 100 101 ret = spi_sync(adis->spi, &msg); 102 if (ret) { 103 dev_err(&adis->spi->dev, "Failed to write register 0x%02X: %d\n", 104 reg, ret); 105 } else { 106 adis->current_page = page; 107 } 108 109 out_unlock: 110 mutex_unlock(&adis->txrx_lock); 111 112 return ret; 113 } 114 EXPORT_SYMBOL_GPL(adis_write_reg); 115 116 /** 117 * adis_read_reg() - read 2 bytes from a 16-bit register 118 * @adis: The adis device 119 * @reg: The address of the lower of the two registers 120 * @val: The value read back from the device 121 */ 122 int adis_read_reg(struct adis *adis, unsigned int reg, 123 unsigned int *val, unsigned int size) 124 { 125 unsigned int page = reg / ADIS_PAGE_SIZE; 126 struct spi_message msg; 127 int ret; 128 struct spi_transfer xfers[] = { 129 { 130 .tx_buf = adis->tx, 131 .bits_per_word = 8, 132 .len = 2, 133 .cs_change = 1, 134 .delay_usecs = adis->data->write_delay, 135 }, { 136 .tx_buf = adis->tx + 2, 137 .bits_per_word = 8, 138 .len = 2, 139 .cs_change = 1, 140 .delay_usecs = adis->data->read_delay, 141 }, { 142 .tx_buf = adis->tx + 4, 143 .rx_buf = adis->rx, 144 .bits_per_word = 8, 145 .len = 2, 146 .cs_change = 1, 147 .delay_usecs = adis->data->read_delay, 148 }, { 149 .rx_buf = adis->rx + 2, 150 .bits_per_word = 8, 151 .len = 2, 152 .delay_usecs = adis->data->read_delay, 153 }, 154 }; 155 156 mutex_lock(&adis->txrx_lock); 157 spi_message_init(&msg); 158 159 if (adis->current_page != page) { 160 adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID); 161 adis->tx[1] = page; 162 spi_message_add_tail(&xfers[0], &msg); 163 } 164 165 switch (size) { 166 case 4: 167 adis->tx[2] = ADIS_READ_REG(reg + 2); 168 adis->tx[3] = 0; 169 spi_message_add_tail(&xfers[1], &msg); 170 case 2: 171 adis->tx[4] = ADIS_READ_REG(reg); 172 adis->tx[5] = 0; 173 spi_message_add_tail(&xfers[2], &msg); 174 spi_message_add_tail(&xfers[3], &msg); 175 break; 176 default: 177 ret = -EINVAL; 178 goto out_unlock; 179 } 180 181 ret = spi_sync(adis->spi, &msg); 182 if (ret) { 183 dev_err(&adis->spi->dev, "Failed to read register 0x%02X: %d\n", 184 reg, ret); 185 goto out_unlock; 186 } else { 187 adis->current_page = page; 188 } 189 190 switch (size) { 191 case 4: 192 *val = get_unaligned_be32(adis->rx); 193 break; 194 case 2: 195 *val = get_unaligned_be16(adis->rx + 2); 196 break; 197 } 198 199 out_unlock: 200 mutex_unlock(&adis->txrx_lock); 201 202 return ret; 203 } 204 EXPORT_SYMBOL_GPL(adis_read_reg); 205 206 #ifdef CONFIG_DEBUG_FS 207 208 int adis_debugfs_reg_access(struct iio_dev *indio_dev, 209 unsigned int reg, unsigned int writeval, unsigned int *readval) 210 { 211 struct adis *adis = iio_device_get_drvdata(indio_dev); 212 213 if (readval) { 214 uint16_t val16; 215 int ret; 216 217 ret = adis_read_reg_16(adis, reg, &val16); 218 *readval = val16; 219 220 return ret; 221 } else { 222 return adis_write_reg_16(adis, reg, writeval); 223 } 224 } 225 EXPORT_SYMBOL(adis_debugfs_reg_access); 226 227 #endif 228 229 /** 230 * adis_enable_irq() - Enable or disable data ready IRQ 231 * @adis: The adis device 232 * @enable: Whether to enable the IRQ 233 * 234 * Returns 0 on success, negative error code otherwise 235 */ 236 int adis_enable_irq(struct adis *adis, bool enable) 237 { 238 int ret = 0; 239 uint16_t msc; 240 241 if (adis->data->enable_irq) 242 return adis->data->enable_irq(adis, enable); 243 244 ret = adis_read_reg_16(adis, adis->data->msc_ctrl_reg, &msc); 245 if (ret) 246 goto error_ret; 247 248 msc |= ADIS_MSC_CTRL_DATA_RDY_POL_HIGH; 249 msc &= ~ADIS_MSC_CTRL_DATA_RDY_DIO2; 250 if (enable) 251 msc |= ADIS_MSC_CTRL_DATA_RDY_EN; 252 else 253 msc &= ~ADIS_MSC_CTRL_DATA_RDY_EN; 254 255 ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc); 256 257 error_ret: 258 return ret; 259 } 260 EXPORT_SYMBOL(adis_enable_irq); 261 262 /** 263 * adis_check_status() - Check the device for error conditions 264 * @adis: The adis device 265 * 266 * Returns 0 on success, a negative error code otherwise 267 */ 268 int adis_check_status(struct adis *adis) 269 { 270 uint16_t status; 271 int ret; 272 int i; 273 274 ret = adis_read_reg_16(adis, adis->data->diag_stat_reg, &status); 275 if (ret < 0) 276 return ret; 277 278 status &= adis->data->status_error_mask; 279 280 if (status == 0) 281 return 0; 282 283 for (i = 0; i < 16; ++i) { 284 if (status & BIT(i)) { 285 dev_err(&adis->spi->dev, "%s.\n", 286 adis->data->status_error_msgs[i]); 287 } 288 } 289 290 return -EIO; 291 } 292 EXPORT_SYMBOL_GPL(adis_check_status); 293 294 /** 295 * adis_reset() - Reset the device 296 * @adis: The adis device 297 * 298 * Returns 0 on success, a negative error code otherwise 299 */ 300 int adis_reset(struct adis *adis) 301 { 302 int ret; 303 304 ret = adis_write_reg_8(adis, adis->data->glob_cmd_reg, 305 ADIS_GLOB_CMD_SW_RESET); 306 if (ret) 307 dev_err(&adis->spi->dev, "Failed to reset device: %d\n", ret); 308 309 return ret; 310 } 311 EXPORT_SYMBOL_GPL(adis_reset); 312 313 static int adis_self_test(struct adis *adis) 314 { 315 int ret; 316 317 ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg, 318 adis->data->self_test_mask); 319 if (ret) { 320 dev_err(&adis->spi->dev, "Failed to initiate self test: %d\n", 321 ret); 322 return ret; 323 } 324 325 msleep(adis->data->startup_delay); 326 327 return adis_check_status(adis); 328 } 329 330 /** 331 * adis_inital_startup() - Performs device self-test 332 * @adis: The adis device 333 * 334 * Returns 0 if the device is operational, a negative error code otherwise. 335 * 336 * This function should be called early on in the device initialization sequence 337 * to ensure that the device is in a sane and known state and that it is usable. 338 */ 339 int adis_initial_startup(struct adis *adis) 340 { 341 int ret; 342 343 ret = adis_self_test(adis); 344 if (ret) { 345 dev_err(&adis->spi->dev, "Self-test failed, trying reset.\n"); 346 adis_reset(adis); 347 msleep(adis->data->startup_delay); 348 ret = adis_self_test(adis); 349 if (ret) { 350 dev_err(&adis->spi->dev, "Second self-test failed, giving up.\n"); 351 return ret; 352 } 353 } 354 355 return 0; 356 } 357 EXPORT_SYMBOL_GPL(adis_initial_startup); 358 359 /** 360 * adis_single_conversion() - Performs a single sample conversion 361 * @indio_dev: The IIO device 362 * @chan: The IIO channel 363 * @error_mask: Mask for the error bit 364 * @val: Result of the conversion 365 * 366 * Returns IIO_VAL_INT on success, a negative error code otherwise. 367 * 368 * The function performs a single conversion on a given channel and post 369 * processes the value accordingly to the channel spec. If a error_mask is given 370 * the function will check if the mask is set in the returned raw value. If it 371 * is set the function will perform a self-check. If the device does not report 372 * a error bit in the channels raw value set error_mask to 0. 373 */ 374 int adis_single_conversion(struct iio_dev *indio_dev, 375 const struct iio_chan_spec *chan, unsigned int error_mask, int *val) 376 { 377 struct adis *adis = iio_device_get_drvdata(indio_dev); 378 unsigned int uval; 379 int ret; 380 381 mutex_lock(&indio_dev->mlock); 382 383 ret = adis_read_reg(adis, chan->address, &uval, 384 chan->scan_type.storagebits / 8); 385 if (ret) 386 goto err_unlock; 387 388 if (uval & error_mask) { 389 ret = adis_check_status(adis); 390 if (ret) 391 goto err_unlock; 392 } 393 394 if (chan->scan_type.sign == 's') 395 *val = sign_extend32(uval, chan->scan_type.realbits - 1); 396 else 397 *val = uval & ((1 << chan->scan_type.realbits) - 1); 398 399 ret = IIO_VAL_INT; 400 err_unlock: 401 mutex_unlock(&indio_dev->mlock); 402 return ret; 403 } 404 EXPORT_SYMBOL_GPL(adis_single_conversion); 405 406 /** 407 * adis_init() - Initialize adis device structure 408 * @adis: The adis device 409 * @indio_dev: The iio device 410 * @spi: The spi device 411 * @data: Chip specific data 412 * 413 * Returns 0 on success, a negative error code otherwise. 414 * 415 * This function must be called, before any other adis helper function may be 416 * called. 417 */ 418 int adis_init(struct adis *adis, struct iio_dev *indio_dev, 419 struct spi_device *spi, const struct adis_data *data) 420 { 421 mutex_init(&adis->txrx_lock); 422 adis->spi = spi; 423 adis->data = data; 424 iio_device_set_drvdata(indio_dev, adis); 425 426 if (data->has_paging) { 427 /* Need to set the page before first read/write */ 428 adis->current_page = -1; 429 } else { 430 /* Page will always be 0 */ 431 adis->current_page = 0; 432 } 433 434 return adis_enable_irq(adis, false); 435 } 436 EXPORT_SYMBOL_GPL(adis_init); 437 438 MODULE_LICENSE("GPL"); 439 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 440 MODULE_DESCRIPTION("Common library code for ADIS16XXX devices"); 441