sca3000_core.c revision c8a9f8056f40f6201b84fdddb49a1c62630902c5
1/* 2 * sca3000_core.c -- support VTI sca3000 series accelerometers via SPI 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 as published by 6 * the Free Software Foundation. 7 * 8 * Copyright (c) 2009 Jonathan Cameron <jic23@cam.ac.uk> 9 * 10 * See industrialio/accels/sca3000.h for comments. 11 */ 12 13#include <linux/interrupt.h> 14#include <linux/fs.h> 15#include <linux/device.h> 16#include <linux/slab.h> 17#include <linux/kernel.h> 18#include <linux/spi/spi.h> 19#include <linux/sysfs.h> 20#include <linux/module.h> 21#include "../iio.h" 22#include "../sysfs.h" 23#include "../events.h" 24#include "../buffer.h" 25 26#include "sca3000.h" 27 28enum sca3000_variant { 29 d01, 30 e02, 31 e04, 32 e05, 33}; 34 35/* Note where option modes are not defined, the chip simply does not 36 * support any. 37 * Other chips in the sca3000 series use i2c and are not included here. 38 * 39 * Some of these devices are only listed in the family data sheet and 40 * do not actually appear to be available. 41 */ 42static const struct sca3000_chip_info sca3000_spi_chip_info_tbl[] = { 43 [d01] = { 44 .scale = 7357, 45 .temp_output = true, 46 .measurement_mode_freq = 250, 47 .option_mode_1 = SCA3000_OP_MODE_BYPASS, 48 .option_mode_1_freq = 250, 49 .mot_det_mult_xz = {50, 100, 200, 350, 650, 1300}, 50 .mot_det_mult_y = {50, 100, 150, 250, 450, 850, 1750}, 51 }, 52 [e02] = { 53 .scale = 9810, 54 .measurement_mode_freq = 125, 55 .option_mode_1 = SCA3000_OP_MODE_NARROW, 56 .option_mode_1_freq = 63, 57 .mot_det_mult_xz = {100, 150, 300, 550, 1050, 2050}, 58 .mot_det_mult_y = {50, 100, 200, 350, 700, 1350, 2700}, 59 }, 60 [e04] = { 61 .scale = 19620, 62 .measurement_mode_freq = 100, 63 .option_mode_1 = SCA3000_OP_MODE_NARROW, 64 .option_mode_1_freq = 50, 65 .option_mode_2 = SCA3000_OP_MODE_WIDE, 66 .option_mode_2_freq = 400, 67 .mot_det_mult_xz = {200, 300, 600, 1100, 2100, 4100}, 68 .mot_det_mult_y = {100, 200, 400, 7000, 1400, 2700, 54000}, 69 }, 70 [e05] = { 71 .scale = 61313, 72 .measurement_mode_freq = 200, 73 .option_mode_1 = SCA3000_OP_MODE_NARROW, 74 .option_mode_1_freq = 50, 75 .option_mode_2 = SCA3000_OP_MODE_WIDE, 76 .option_mode_2_freq = 400, 77 .mot_det_mult_xz = {600, 900, 1700, 3200, 6100, 11900}, 78 .mot_det_mult_y = {300, 600, 1200, 2000, 4100, 7800, 15600}, 79 }, 80}; 81 82int sca3000_write_reg(struct sca3000_state *st, u8 address, u8 val) 83{ 84 st->tx[0] = SCA3000_WRITE_REG(address); 85 st->tx[1] = val; 86 return spi_write(st->us, st->tx, 2); 87} 88 89int sca3000_read_data_short(struct sca3000_state *st, 90 uint8_t reg_address_high, 91 int len) 92{ 93 struct spi_message msg; 94 struct spi_transfer xfer[2] = { 95 { 96 .len = 1, 97 .tx_buf = st->tx, 98 }, { 99 .len = len, 100 .rx_buf = st->rx, 101 } 102 }; 103 st->tx[0] = SCA3000_READ_REG(reg_address_high); 104 spi_message_init(&msg); 105 spi_message_add_tail(&xfer[0], &msg); 106 spi_message_add_tail(&xfer[1], &msg); 107 108 return spi_sync(st->us, &msg); 109} 110 111/** 112 * sca3000_reg_lock_on() test if the ctrl register lock is on 113 * 114 * Lock must be held. 115 **/ 116static int sca3000_reg_lock_on(struct sca3000_state *st) 117{ 118 int ret; 119 120 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_STATUS, 1); 121 if (ret < 0) 122 return ret; 123 124 return !(st->rx[0] & SCA3000_LOCKED); 125} 126 127/** 128 * __sca3000_unlock_reg_lock() unlock the control registers 129 * 130 * Note the device does not appear to support doing this in a single transfer. 131 * This should only ever be used as part of ctrl reg read. 132 * Lock must be held before calling this 133 **/ 134static int __sca3000_unlock_reg_lock(struct sca3000_state *st) 135{ 136 struct spi_message msg; 137 struct spi_transfer xfer[3] = { 138 { 139 .len = 2, 140 .cs_change = 1, 141 .tx_buf = st->tx, 142 }, { 143 .len = 2, 144 .cs_change = 1, 145 .tx_buf = st->tx + 2, 146 }, { 147 .len = 2, 148 .tx_buf = st->tx + 4, 149 }, 150 }; 151 st->tx[0] = SCA3000_WRITE_REG(SCA3000_REG_ADDR_UNLOCK); 152 st->tx[1] = 0x00; 153 st->tx[2] = SCA3000_WRITE_REG(SCA3000_REG_ADDR_UNLOCK); 154 st->tx[3] = 0x50; 155 st->tx[4] = SCA3000_WRITE_REG(SCA3000_REG_ADDR_UNLOCK); 156 st->tx[5] = 0xA0; 157 spi_message_init(&msg); 158 spi_message_add_tail(&xfer[0], &msg); 159 spi_message_add_tail(&xfer[1], &msg); 160 spi_message_add_tail(&xfer[2], &msg); 161 162 return spi_sync(st->us, &msg); 163} 164 165/** 166 * sca3000_write_ctrl_reg() write to a lock protect ctrl register 167 * @sel: selects which registers we wish to write to 168 * @val: the value to be written 169 * 170 * Certain control registers are protected against overwriting by the lock 171 * register and use a shared write address. This function allows writing of 172 * these registers. 173 * Lock must be held. 174 **/ 175static int sca3000_write_ctrl_reg(struct sca3000_state *st, 176 uint8_t sel, 177 uint8_t val) 178{ 179 180 int ret; 181 182 ret = sca3000_reg_lock_on(st); 183 if (ret < 0) 184 goto error_ret; 185 if (ret) { 186 ret = __sca3000_unlock_reg_lock(st); 187 if (ret) 188 goto error_ret; 189 } 190 191 /* Set the control select register */ 192 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_SEL, sel); 193 if (ret) 194 goto error_ret; 195 196 /* Write the actual value into the register */ 197 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_DATA, val); 198 199error_ret: 200 return ret; 201} 202 203/* Crucial that lock is called before calling this */ 204/** 205 * sca3000_read_ctrl_reg() read from lock protected control register. 206 * 207 * Lock must be held. 208 **/ 209static int sca3000_read_ctrl_reg(struct sca3000_state *st, 210 u8 ctrl_reg) 211{ 212 int ret; 213 214 ret = sca3000_reg_lock_on(st); 215 if (ret < 0) 216 goto error_ret; 217 if (ret) { 218 ret = __sca3000_unlock_reg_lock(st); 219 if (ret) 220 goto error_ret; 221 } 222 /* Set the control select register */ 223 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_CTRL_SEL, ctrl_reg); 224 if (ret) 225 goto error_ret; 226 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_CTRL_DATA, 1); 227 if (ret) 228 goto error_ret; 229 else 230 return st->rx[0]; 231error_ret: 232 return ret; 233} 234 235#ifdef SCA3000_DEBUG 236/** 237 * sca3000_check_status() check the status register 238 * 239 * Only used for debugging purposes 240 **/ 241static int sca3000_check_status(struct device *dev) 242{ 243 int ret; 244 struct iio_dev *indio_dev = dev_get_drvdata(dev); 245 struct sca3000_state *st = iio_priv(indio_dev); 246 247 mutex_lock(&st->lock); 248 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_STATUS, 1); 249 if (ret < 0) 250 goto error_ret; 251 if (st->rx[0] & SCA3000_EEPROM_CS_ERROR) 252 dev_err(dev, "eeprom error\n"); 253 if (st->rx[0] & SCA3000_SPI_FRAME_ERROR) 254 dev_err(dev, "Previous SPI Frame was corrupt\n"); 255 256error_ret: 257 mutex_unlock(&st->lock); 258 return ret; 259} 260#endif /* SCA3000_DEBUG */ 261 262 263/** 264 * sca3000_show_reg() - sysfs interface to read the chip revision number 265 **/ 266static ssize_t sca3000_show_rev(struct device *dev, 267 struct device_attribute *attr, 268 char *buf) 269{ 270 int len = 0, ret; 271 struct iio_dev *indio_dev = dev_get_drvdata(dev); 272 struct sca3000_state *st = iio_priv(indio_dev); 273 274 mutex_lock(&st->lock); 275 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_REVID, 1); 276 if (ret < 0) 277 goto error_ret; 278 len += sprintf(buf + len, 279 "major=%d, minor=%d\n", 280 st->rx[0] & SCA3000_REVID_MAJOR_MASK, 281 st->rx[0] & SCA3000_REVID_MINOR_MASK); 282error_ret: 283 mutex_unlock(&st->lock); 284 285 return ret ? ret : len; 286} 287 288/** 289 * sca3000_show_available_measurement_modes() display available modes 290 * 291 * This is all read from chip specific data in the driver. Not all 292 * of the sca3000 series support modes other than normal. 293 **/ 294static ssize_t 295sca3000_show_available_measurement_modes(struct device *dev, 296 struct device_attribute *attr, 297 char *buf) 298{ 299 struct iio_dev *indio_dev = dev_get_drvdata(dev); 300 struct sca3000_state *st = iio_priv(indio_dev); 301 int len = 0; 302 303 len += sprintf(buf + len, "0 - normal mode"); 304 switch (st->info->option_mode_1) { 305 case SCA3000_OP_MODE_NARROW: 306 len += sprintf(buf + len, ", 1 - narrow mode"); 307 break; 308 case SCA3000_OP_MODE_BYPASS: 309 len += sprintf(buf + len, ", 1 - bypass mode"); 310 break; 311 } 312 switch (st->info->option_mode_2) { 313 case SCA3000_OP_MODE_WIDE: 314 len += sprintf(buf + len, ", 2 - wide mode"); 315 break; 316 } 317 /* always supported */ 318 len += sprintf(buf + len, " 3 - motion detection\n"); 319 320 return len; 321} 322 323/** 324 * sca3000_show_measurmenet_mode() sysfs read of current mode 325 **/ 326static ssize_t 327sca3000_show_measurement_mode(struct device *dev, 328 struct device_attribute *attr, 329 char *buf) 330{ 331 struct iio_dev *indio_dev = dev_get_drvdata(dev); 332 struct sca3000_state *st = iio_priv(indio_dev); 333 int len = 0, ret; 334 335 mutex_lock(&st->lock); 336 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1); 337 if (ret) 338 goto error_ret; 339 /* mask bottom 2 bits - only ones that are relevant */ 340 st->rx[0] &= 0x03; 341 switch (st->rx[0]) { 342 case SCA3000_MEAS_MODE_NORMAL: 343 len += sprintf(buf + len, "0 - normal mode\n"); 344 break; 345 case SCA3000_MEAS_MODE_MOT_DET: 346 len += sprintf(buf + len, "3 - motion detection\n"); 347 break; 348 case SCA3000_MEAS_MODE_OP_1: 349 switch (st->info->option_mode_1) { 350 case SCA3000_OP_MODE_NARROW: 351 len += sprintf(buf + len, "1 - narrow mode\n"); 352 break; 353 case SCA3000_OP_MODE_BYPASS: 354 len += sprintf(buf + len, "1 - bypass mode\n"); 355 break; 356 } 357 break; 358 case SCA3000_MEAS_MODE_OP_2: 359 switch (st->info->option_mode_2) { 360 case SCA3000_OP_MODE_WIDE: 361 len += sprintf(buf + len, "2 - wide mode\n"); 362 break; 363 } 364 break; 365 } 366 367error_ret: 368 mutex_unlock(&st->lock); 369 370 return ret ? ret : len; 371} 372 373/** 374 * sca3000_store_measurement_mode() set the current mode 375 **/ 376static ssize_t 377sca3000_store_measurement_mode(struct device *dev, 378 struct device_attribute *attr, 379 const char *buf, 380 size_t len) 381{ 382 struct iio_dev *indio_dev = dev_get_drvdata(dev); 383 struct sca3000_state *st = iio_priv(indio_dev); 384 int ret; 385 int mask = 0x03; 386 long val; 387 388 mutex_lock(&st->lock); 389 ret = strict_strtol(buf, 10, &val); 390 if (ret) 391 goto error_ret; 392 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1); 393 if (ret) 394 goto error_ret; 395 st->rx[0] &= ~mask; 396 st->rx[0] |= (val & mask); 397 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE, st->rx[0]); 398 if (ret) 399 goto error_ret; 400 mutex_unlock(&st->lock); 401 402 return len; 403 404error_ret: 405 mutex_unlock(&st->lock); 406 407 return ret; 408} 409 410 411/* Not even vaguely standard attributes so defined here rather than 412 * in the relevant IIO core headers 413 */ 414static IIO_DEVICE_ATTR(measurement_mode_available, S_IRUGO, 415 sca3000_show_available_measurement_modes, 416 NULL, 0); 417 418static IIO_DEVICE_ATTR(measurement_mode, S_IRUGO | S_IWUSR, 419 sca3000_show_measurement_mode, 420 sca3000_store_measurement_mode, 421 0); 422 423/* More standard attributes */ 424 425static IIO_DEVICE_ATTR(revision, S_IRUGO, sca3000_show_rev, NULL, 0); 426 427#define SCA3000_INFO_MASK \ 428 IIO_CHAN_INFO_SCALE_SHARED_BIT 429#define SCA3000_EVENT_MASK \ 430 (IIO_EV_BIT(IIO_EV_TYPE_MAG, IIO_EV_DIR_RISING)) 431 432static struct iio_chan_spec sca3000_channels[] = { 433 IIO_CHAN(IIO_ACCEL, 1, 0, 0, NULL, 0, IIO_MOD_X, SCA3000_INFO_MASK, 434 0, 0, IIO_ST('s', 11, 16, 5), SCA3000_EVENT_MASK), 435 IIO_CHAN(IIO_ACCEL, 1, 0, 0, NULL, 0, IIO_MOD_Y, SCA3000_INFO_MASK, 436 1, 1, IIO_ST('s', 11, 16, 5), SCA3000_EVENT_MASK), 437 IIO_CHAN(IIO_ACCEL, 1, 0, 0, NULL, 0, IIO_MOD_Z, SCA3000_INFO_MASK, 438 2, 2, IIO_ST('s', 11, 16, 5), SCA3000_EVENT_MASK), 439}; 440 441static u8 sca3000_addresses[3][3] = { 442 [0] = {SCA3000_REG_ADDR_X_MSB, SCA3000_REG_CTRL_SEL_MD_X_TH, 443 SCA3000_MD_CTRL_OR_X}, 444 [1] = {SCA3000_REG_ADDR_Y_MSB, SCA3000_REG_CTRL_SEL_MD_Y_TH, 445 SCA3000_MD_CTRL_OR_Y}, 446 [2] = {SCA3000_REG_ADDR_Z_MSB, SCA3000_REG_CTRL_SEL_MD_Z_TH, 447 SCA3000_MD_CTRL_OR_Z}, 448}; 449 450static int sca3000_read_raw(struct iio_dev *indio_dev, 451 struct iio_chan_spec const *chan, 452 int *val, 453 int *val2, 454 long mask) 455{ 456 struct sca3000_state *st = iio_priv(indio_dev); 457 int ret; 458 u8 address; 459 460 switch (mask) { 461 case 0: 462 mutex_lock(&st->lock); 463 if (st->mo_det_use_count) { 464 mutex_unlock(&st->lock); 465 return -EBUSY; 466 } 467 address = sca3000_addresses[chan->address][0]; 468 ret = sca3000_read_data_short(st, address, 2); 469 if (ret < 0) { 470 mutex_unlock(&st->lock); 471 return ret; 472 } 473 *val = (be16_to_cpup((__be16 *)st->rx) >> 3) & 0x1FFF; 474 *val = ((*val) << (sizeof(*val)*8 - 13)) >> 475 (sizeof(*val)*8 - 13); 476 mutex_unlock(&st->lock); 477 return IIO_VAL_INT; 478 case IIO_CHAN_INFO_SCALE: 479 *val = 0; 480 if (chan->type == IIO_ACCEL) 481 *val2 = st->info->scale; 482 else /* temperature */ 483 *val2 = 555556; 484 return IIO_VAL_INT_PLUS_MICRO; 485 default: 486 return -EINVAL; 487 } 488} 489 490/** 491 * sca3000_read_av_freq() sysfs function to get available frequencies 492 * 493 * The later modes are only relevant to the ring buffer - and depend on current 494 * mode. Note that data sheet gives rather wide tolerances for these so integer 495 * division will give good enough answer and not all chips have them specified 496 * at all. 497 **/ 498static ssize_t sca3000_read_av_freq(struct device *dev, 499 struct device_attribute *attr, 500 char *buf) 501{ 502 struct iio_dev *indio_dev = dev_get_drvdata(dev); 503 struct sca3000_state *st = iio_priv(indio_dev); 504 int len = 0, ret, val; 505 506 mutex_lock(&st->lock); 507 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1); 508 val = st->rx[0]; 509 mutex_unlock(&st->lock); 510 if (ret) 511 goto error_ret; 512 513 switch (val & 0x03) { 514 case SCA3000_MEAS_MODE_NORMAL: 515 len += sprintf(buf + len, "%d %d %d\n", 516 st->info->measurement_mode_freq, 517 st->info->measurement_mode_freq/2, 518 st->info->measurement_mode_freq/4); 519 break; 520 case SCA3000_MEAS_MODE_OP_1: 521 len += sprintf(buf + len, "%d %d %d\n", 522 st->info->option_mode_1_freq, 523 st->info->option_mode_1_freq/2, 524 st->info->option_mode_1_freq/4); 525 break; 526 case SCA3000_MEAS_MODE_OP_2: 527 len += sprintf(buf + len, "%d %d %d\n", 528 st->info->option_mode_2_freq, 529 st->info->option_mode_2_freq/2, 530 st->info->option_mode_2_freq/4); 531 break; 532 } 533 return len; 534error_ret: 535 return ret; 536} 537/** 538 * __sca3000_get_base_frequency() obtain mode specific base frequency 539 * 540 * lock must be held 541 **/ 542static inline int __sca3000_get_base_freq(struct sca3000_state *st, 543 const struct sca3000_chip_info *info, 544 int *base_freq) 545{ 546 int ret; 547 548 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1); 549 if (ret) 550 goto error_ret; 551 switch (0x03 & st->rx[0]) { 552 case SCA3000_MEAS_MODE_NORMAL: 553 *base_freq = info->measurement_mode_freq; 554 break; 555 case SCA3000_MEAS_MODE_OP_1: 556 *base_freq = info->option_mode_1_freq; 557 break; 558 case SCA3000_MEAS_MODE_OP_2: 559 *base_freq = info->option_mode_2_freq; 560 break; 561 } 562error_ret: 563 return ret; 564} 565 566/** 567 * sca3000_read_frequency() sysfs interface to get the current frequency 568 **/ 569static ssize_t sca3000_read_frequency(struct device *dev, 570 struct device_attribute *attr, 571 char *buf) 572{ 573 struct iio_dev *indio_dev = dev_get_drvdata(dev); 574 struct sca3000_state *st = iio_priv(indio_dev); 575 int ret, len = 0, base_freq = 0, val; 576 577 mutex_lock(&st->lock); 578 ret = __sca3000_get_base_freq(st, st->info, &base_freq); 579 if (ret) 580 goto error_ret_mut; 581 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL); 582 mutex_unlock(&st->lock); 583 if (ret) 584 goto error_ret; 585 val = ret; 586 if (base_freq > 0) 587 switch (val & 0x03) { 588 case 0x00: 589 case 0x03: 590 len = sprintf(buf, "%d\n", base_freq); 591 break; 592 case 0x01: 593 len = sprintf(buf, "%d\n", base_freq/2); 594 break; 595 case 0x02: 596 len = sprintf(buf, "%d\n", base_freq/4); 597 break; 598 } 599 600 return len; 601error_ret_mut: 602 mutex_unlock(&st->lock); 603error_ret: 604 return ret; 605} 606 607/** 608 * sca3000_set_frequency() sysfs interface to set the current frequency 609 **/ 610static ssize_t sca3000_set_frequency(struct device *dev, 611 struct device_attribute *attr, 612 const char *buf, 613 size_t len) 614{ 615 struct iio_dev *indio_dev = dev_get_drvdata(dev); 616 struct sca3000_state *st = iio_priv(indio_dev); 617 int ret, base_freq = 0; 618 int ctrlval; 619 long val; 620 621 ret = strict_strtol(buf, 10, &val); 622 if (ret) 623 return ret; 624 625 mutex_lock(&st->lock); 626 /* What mode are we in? */ 627 ret = __sca3000_get_base_freq(st, st->info, &base_freq); 628 if (ret) 629 goto error_free_lock; 630 631 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL); 632 if (ret < 0) 633 goto error_free_lock; 634 ctrlval = ret; 635 /* clear the bits */ 636 ctrlval &= ~0x03; 637 638 if (val == base_freq/2) { 639 ctrlval |= SCA3000_OUT_CTRL_BUF_DIV_2; 640 } else if (val == base_freq/4) { 641 ctrlval |= SCA3000_OUT_CTRL_BUF_DIV_4; 642 } else if (val != base_freq) { 643 ret = -EINVAL; 644 goto error_free_lock; 645 } 646 ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL, 647 ctrlval); 648error_free_lock: 649 mutex_unlock(&st->lock); 650 651 return ret ? ret : len; 652} 653 654/* Should only really be registered if ring buffer support is compiled in. 655 * Does no harm however and doing it right would add a fair bit of complexity 656 */ 657static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(sca3000_read_av_freq); 658 659static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, 660 sca3000_read_frequency, 661 sca3000_set_frequency); 662 663 664/** 665 * sca3000_read_temp() sysfs interface to get the temperature when available 666 * 667* The alignment of data in here is downright odd. See data sheet. 668* Converting this into a meaningful value is left to inline functions in 669* userspace part of header. 670**/ 671static ssize_t sca3000_read_temp(struct device *dev, 672 struct device_attribute *attr, 673 char *buf) 674{ 675 struct iio_dev *indio_dev = dev_get_drvdata(dev); 676 struct sca3000_state *st = iio_priv(indio_dev); 677 int ret; 678 int val; 679 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_TEMP_MSB, 2); 680 if (ret < 0) 681 goto error_ret; 682 val = ((st->rx[0] & 0x3F) << 3) | ((st->rx[1] & 0xE0) >> 5); 683 684 return sprintf(buf, "%d\n", val); 685 686error_ret: 687 return ret; 688} 689static IIO_DEV_ATTR_TEMP_RAW(sca3000_read_temp); 690 691static IIO_CONST_ATTR_TEMP_SCALE("0.555556"); 692static IIO_CONST_ATTR_TEMP_OFFSET("-214.6"); 693 694/** 695 * sca3000_read_thresh() - query of a threshold 696 **/ 697static int sca3000_read_thresh(struct iio_dev *indio_dev, 698 u64 e, 699 int *val) 700{ 701 int ret, i; 702 struct sca3000_state *st = iio_priv(indio_dev); 703 int num = IIO_EVENT_CODE_EXTRACT_MODIFIER(e); 704 mutex_lock(&st->lock); 705 ret = sca3000_read_ctrl_reg(st, sca3000_addresses[num][1]); 706 mutex_unlock(&st->lock); 707 if (ret < 0) 708 return ret; 709 *val = 0; 710 if (num == 1) 711 for_each_set_bit(i, (unsigned long *)&ret, 712 ARRAY_SIZE(st->info->mot_det_mult_y)) 713 *val += st->info->mot_det_mult_y[i]; 714 else 715 for_each_set_bit(i, (unsigned long *)&ret, 716 ARRAY_SIZE(st->info->mot_det_mult_xz)) 717 *val += st->info->mot_det_mult_xz[i]; 718 719 return 0; 720} 721 722/** 723 * sca3000_write_thresh() control of threshold 724 **/ 725static int sca3000_write_thresh(struct iio_dev *indio_dev, 726 u64 e, 727 int val) 728{ 729 struct sca3000_state *st = iio_priv(indio_dev); 730 int num = IIO_EVENT_CODE_EXTRACT_MODIFIER(e); 731 int ret; 732 int i; 733 u8 nonlinear = 0; 734 735 if (num == 1) { 736 i = ARRAY_SIZE(st->info->mot_det_mult_y); 737 while (i > 0) 738 if (val >= st->info->mot_det_mult_y[--i]) { 739 nonlinear |= (1 << i); 740 val -= st->info->mot_det_mult_y[i]; 741 } 742 } else { 743 i = ARRAY_SIZE(st->info->mot_det_mult_xz); 744 while (i > 0) 745 if (val >= st->info->mot_det_mult_xz[--i]) { 746 nonlinear |= (1 << i); 747 val -= st->info->mot_det_mult_xz[i]; 748 } 749 } 750 751 mutex_lock(&st->lock); 752 ret = sca3000_write_ctrl_reg(st, sca3000_addresses[num][1], nonlinear); 753 mutex_unlock(&st->lock); 754 755 return ret; 756} 757 758static struct attribute *sca3000_attributes[] = { 759 &iio_dev_attr_revision.dev_attr.attr, 760 &iio_dev_attr_measurement_mode_available.dev_attr.attr, 761 &iio_dev_attr_measurement_mode.dev_attr.attr, 762 &iio_dev_attr_sampling_frequency_available.dev_attr.attr, 763 &iio_dev_attr_sampling_frequency.dev_attr.attr, 764 NULL, 765}; 766 767static struct attribute *sca3000_attributes_with_temp[] = { 768 &iio_dev_attr_revision.dev_attr.attr, 769 &iio_dev_attr_measurement_mode_available.dev_attr.attr, 770 &iio_dev_attr_measurement_mode.dev_attr.attr, 771 &iio_dev_attr_sampling_frequency_available.dev_attr.attr, 772 &iio_dev_attr_sampling_frequency.dev_attr.attr, 773 /* Only present if temp sensor is */ 774 &iio_dev_attr_in_temp_raw.dev_attr.attr, 775 &iio_const_attr_in_temp_offset.dev_attr.attr, 776 &iio_const_attr_in_temp_scale.dev_attr.attr, 777 NULL, 778}; 779 780static const struct attribute_group sca3000_attribute_group = { 781 .attrs = sca3000_attributes, 782}; 783 784static const struct attribute_group sca3000_attribute_group_with_temp = { 785 .attrs = sca3000_attributes_with_temp, 786}; 787 788/* RING RELATED interrupt handler */ 789/* depending on event, push to the ring buffer event chrdev or the event one */ 790 791/** 792 * sca3000_event_handler() - handling ring and non ring events 793 * 794 * This function is complicated by the fact that the devices can signify ring 795 * and non ring events via the same interrupt line and they can only 796 * be distinguished via a read of the relevant status register. 797 **/ 798static irqreturn_t sca3000_event_handler(int irq, void *private) 799{ 800 struct iio_dev *indio_dev = private; 801 struct sca3000_state *st = iio_priv(indio_dev); 802 int ret, val; 803 s64 last_timestamp = iio_get_time_ns(); 804 805 /* Could lead if badly timed to an extra read of status reg, 806 * but ensures no interrupt is missed. 807 */ 808 mutex_lock(&st->lock); 809 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_STATUS, 1); 810 val = st->rx[0]; 811 mutex_unlock(&st->lock); 812 if (ret) 813 goto done; 814 815 sca3000_ring_int_process(val, indio_dev->buffer); 816 817 if (val & SCA3000_INT_STATUS_FREE_FALL) 818 iio_push_event(indio_dev, 819 IIO_MOD_EVENT_CODE(IIO_ACCEL, 820 0, 821 IIO_MOD_X_AND_Y_AND_Z, 822 IIO_EV_TYPE_MAG, 823 IIO_EV_DIR_FALLING), 824 last_timestamp); 825 826 if (val & SCA3000_INT_STATUS_Y_TRIGGER) 827 iio_push_event(indio_dev, 828 IIO_MOD_EVENT_CODE(IIO_ACCEL, 829 0, 830 IIO_MOD_Y, 831 IIO_EV_TYPE_MAG, 832 IIO_EV_DIR_RISING), 833 last_timestamp); 834 835 if (val & SCA3000_INT_STATUS_X_TRIGGER) 836 iio_push_event(indio_dev, 837 IIO_MOD_EVENT_CODE(IIO_ACCEL, 838 0, 839 IIO_MOD_X, 840 IIO_EV_TYPE_MAG, 841 IIO_EV_DIR_RISING), 842 last_timestamp); 843 844 if (val & SCA3000_INT_STATUS_Z_TRIGGER) 845 iio_push_event(indio_dev, 846 IIO_MOD_EVENT_CODE(IIO_ACCEL, 847 0, 848 IIO_MOD_Z, 849 IIO_EV_TYPE_MAG, 850 IIO_EV_DIR_RISING), 851 last_timestamp); 852 853done: 854 return IRQ_HANDLED; 855} 856 857/** 858 * sca3000_read_event_config() what events are enabled 859 **/ 860static int sca3000_read_event_config(struct iio_dev *indio_dev, 861 u64 e) 862{ 863 struct sca3000_state *st = iio_priv(indio_dev); 864 int ret; 865 u8 protect_mask = 0x03; 866 int num = IIO_EVENT_CODE_EXTRACT_MODIFIER(e); 867 868 /* read current value of mode register */ 869 mutex_lock(&st->lock); 870 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1); 871 if (ret) 872 goto error_ret; 873 874 if ((st->rx[0] & protect_mask) != SCA3000_MEAS_MODE_MOT_DET) 875 ret = 0; 876 else { 877 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL); 878 if (ret < 0) 879 goto error_ret; 880 /* only supporting logical or's for now */ 881 ret = !!(ret & sca3000_addresses[num][2]); 882 } 883error_ret: 884 mutex_unlock(&st->lock); 885 886 return ret; 887} 888/** 889 * sca3000_query_free_fall_mode() is free fall mode enabled 890 **/ 891static ssize_t sca3000_query_free_fall_mode(struct device *dev, 892 struct device_attribute *attr, 893 char *buf) 894{ 895 int ret, len; 896 struct iio_dev *indio_dev = dev_get_drvdata(dev); 897 struct sca3000_state *st = iio_priv(indio_dev); 898 int val; 899 900 mutex_lock(&st->lock); 901 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1); 902 val = st->rx[0]; 903 mutex_unlock(&st->lock); 904 if (ret < 0) 905 return ret; 906 len = sprintf(buf, "%d\n", 907 !!(val & SCA3000_FREE_FALL_DETECT)); 908 return len; 909} 910 911/** 912 * sca3000_set_free_fall_mode() simple on off control for free fall int 913 * 914 * In these chips the free fall detector should send an interrupt if 915 * the device falls more than 25cm. This has not been tested due 916 * to fragile wiring. 917 **/ 918 919static ssize_t sca3000_set_free_fall_mode(struct device *dev, 920 struct device_attribute *attr, 921 const char *buf, 922 size_t len) 923{ 924 struct iio_dev *indio_dev = dev_get_drvdata(dev); 925 struct sca3000_state *st = iio_priv(indio_dev); 926 long val; 927 int ret; 928 u8 protect_mask = SCA3000_FREE_FALL_DETECT; 929 930 mutex_lock(&st->lock); 931 ret = strict_strtol(buf, 10, &val); 932 if (ret) 933 goto error_ret; 934 935 /* read current value of mode register */ 936 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1); 937 if (ret) 938 goto error_ret; 939 940 /*if off and should be on*/ 941 if (val && !(st->rx[0] & protect_mask)) 942 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE, 943 (st->rx[0] | SCA3000_FREE_FALL_DETECT)); 944 /* if on and should be off */ 945 else if (!val && (st->rx[0] & protect_mask)) 946 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE, 947 (st->rx[0] & ~protect_mask)); 948error_ret: 949 mutex_unlock(&st->lock); 950 951 return ret ? ret : len; 952} 953 954/** 955 * sca3000_set_mo_det() simple on off control for motion detector 956 * 957 * This is a per axis control, but enabling any will result in the 958 * motion detector unit being enabled. 959 * N.B. enabling motion detector stops normal data acquisition. 960 * There is a complexity in knowing which mode to return to when 961 * this mode is disabled. Currently normal mode is assumed. 962 **/ 963static int sca3000_write_event_config(struct iio_dev *indio_dev, 964 u64 e, 965 int state) 966{ 967 struct sca3000_state *st = iio_priv(indio_dev); 968 int ret, ctrlval; 969 u8 protect_mask = 0x03; 970 int num = IIO_EVENT_CODE_EXTRACT_MODIFIER(e); 971 972 mutex_lock(&st->lock); 973 /* First read the motion detector config to find out if 974 * this axis is on*/ 975 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL); 976 if (ret < 0) 977 goto exit_point; 978 ctrlval = ret; 979 /* Off and should be on */ 980 if (state && !(ctrlval & sca3000_addresses[num][2])) { 981 ret = sca3000_write_ctrl_reg(st, 982 SCA3000_REG_CTRL_SEL_MD_CTRL, 983 ctrlval | 984 sca3000_addresses[num][2]); 985 if (ret) 986 goto exit_point; 987 st->mo_det_use_count++; 988 } else if (!state && (ctrlval & sca3000_addresses[num][2])) { 989 ret = sca3000_write_ctrl_reg(st, 990 SCA3000_REG_CTRL_SEL_MD_CTRL, 991 ctrlval & 992 ~(sca3000_addresses[num][2])); 993 if (ret) 994 goto exit_point; 995 st->mo_det_use_count--; 996 } 997 998 /* read current value of mode register */ 999 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1); 1000 if (ret) 1001 goto exit_point; 1002 /*if off and should be on*/ 1003 if ((st->mo_det_use_count) 1004 && ((st->rx[0] & protect_mask) != SCA3000_MEAS_MODE_MOT_DET)) 1005 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE, 1006 (st->rx[0] & ~protect_mask) 1007 | SCA3000_MEAS_MODE_MOT_DET); 1008 /* if on and should be off */ 1009 else if (!(st->mo_det_use_count) 1010 && ((st->rx[0] & protect_mask) == SCA3000_MEAS_MODE_MOT_DET)) 1011 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE, 1012 (st->rx[0] & ~protect_mask)); 1013exit_point: 1014 mutex_unlock(&st->lock); 1015 1016 return ret; 1017} 1018 1019/* Free fall detector related event attribute */ 1020static IIO_DEVICE_ATTR_NAMED(accel_xayaz_mag_falling_en, 1021 in_accel_x&y&z_mag_falling_en, 1022 S_IRUGO | S_IWUSR, 1023 sca3000_query_free_fall_mode, 1024 sca3000_set_free_fall_mode, 1025 0); 1026 1027static IIO_CONST_ATTR_NAMED(accel_xayaz_mag_falling_period, 1028 in_accel_x&y&z_mag_falling_period, 1029 "0.226"); 1030 1031static struct attribute *sca3000_event_attributes[] = { 1032 &iio_dev_attr_accel_xayaz_mag_falling_en.dev_attr.attr, 1033 &iio_const_attr_accel_xayaz_mag_falling_period.dev_attr.attr, 1034 NULL, 1035}; 1036 1037static struct attribute_group sca3000_event_attribute_group = { 1038 .attrs = sca3000_event_attributes, 1039 .name = "events", 1040}; 1041 1042/** 1043 * sca3000_clean_setup() get the device into a predictable state 1044 * 1045 * Devices use flash memory to store many of the register values 1046 * and hence can come up in somewhat unpredictable states. 1047 * Hence reset everything on driver load. 1048 **/ 1049static int sca3000_clean_setup(struct sca3000_state *st) 1050{ 1051 int ret; 1052 1053 mutex_lock(&st->lock); 1054 /* Ensure all interrupts have been acknowledged */ 1055 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_STATUS, 1); 1056 if (ret) 1057 goto error_ret; 1058 1059 /* Turn off all motion detection channels */ 1060 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL); 1061 if (ret < 0) 1062 goto error_ret; 1063 ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL, 1064 ret & SCA3000_MD_CTRL_PROT_MASK); 1065 if (ret) 1066 goto error_ret; 1067 1068 /* Disable ring buffer */ 1069 ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL); 1070 ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL, 1071 (ret & SCA3000_OUT_CTRL_PROT_MASK) 1072 | SCA3000_OUT_CTRL_BUF_X_EN 1073 | SCA3000_OUT_CTRL_BUF_Y_EN 1074 | SCA3000_OUT_CTRL_BUF_Z_EN 1075 | SCA3000_OUT_CTRL_BUF_DIV_4); 1076 if (ret) 1077 goto error_ret; 1078 /* Enable interrupts, relevant to mode and set up as active low */ 1079 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_MASK, 1); 1080 if (ret) 1081 goto error_ret; 1082 ret = sca3000_write_reg(st, 1083 SCA3000_REG_ADDR_INT_MASK, 1084 (ret & SCA3000_INT_MASK_PROT_MASK) 1085 | SCA3000_INT_MASK_ACTIVE_LOW); 1086 if (ret) 1087 goto error_ret; 1088 /* Select normal measurement mode, free fall off, ring off */ 1089 /* Ring in 12 bit mode - it is fine to overwrite reserved bits 3,5 1090 * as that occurs in one of the example on the datasheet */ 1091 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_MODE, 1); 1092 if (ret) 1093 goto error_ret; 1094 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_MODE, 1095 (st->rx[0] & SCA3000_MODE_PROT_MASK)); 1096 st->bpse = 11; 1097 1098error_ret: 1099 mutex_unlock(&st->lock); 1100 return ret; 1101} 1102 1103static const struct iio_info sca3000_info = { 1104 .attrs = &sca3000_attribute_group, 1105 .read_raw = &sca3000_read_raw, 1106 .event_attrs = &sca3000_event_attribute_group, 1107 .read_event_value = &sca3000_read_thresh, 1108 .write_event_value = &sca3000_write_thresh, 1109 .read_event_config = &sca3000_read_event_config, 1110 .write_event_config = &sca3000_write_event_config, 1111 .driver_module = THIS_MODULE, 1112}; 1113 1114static const struct iio_info sca3000_info_with_temp = { 1115 .attrs = &sca3000_attribute_group_with_temp, 1116 .read_raw = &sca3000_read_raw, 1117 .read_event_value = &sca3000_read_thresh, 1118 .write_event_value = &sca3000_write_thresh, 1119 .read_event_config = &sca3000_read_event_config, 1120 .write_event_config = &sca3000_write_event_config, 1121 .driver_module = THIS_MODULE, 1122}; 1123 1124static int __devinit sca3000_probe(struct spi_device *spi) 1125{ 1126 int ret; 1127 struct sca3000_state *st; 1128 struct iio_dev *indio_dev; 1129 1130 indio_dev = iio_allocate_device(sizeof(*st)); 1131 if (indio_dev == NULL) { 1132 ret = -ENOMEM; 1133 goto error_ret; 1134 } 1135 1136 st = iio_priv(indio_dev); 1137 spi_set_drvdata(spi, indio_dev); 1138 st->us = spi; 1139 mutex_init(&st->lock); 1140 st->info = &sca3000_spi_chip_info_tbl[spi_get_device_id(spi) 1141 ->driver_data]; 1142 1143 indio_dev->dev.parent = &spi->dev; 1144 indio_dev->name = spi_get_device_id(spi)->name; 1145 if (st->info->temp_output) 1146 indio_dev->info = &sca3000_info_with_temp; 1147 else { 1148 indio_dev->info = &sca3000_info; 1149 indio_dev->channels = sca3000_channels; 1150 indio_dev->num_channels = ARRAY_SIZE(sca3000_channels); 1151 } 1152 indio_dev->modes = INDIO_DIRECT_MODE; 1153 1154 sca3000_configure_ring(indio_dev); 1155 ret = iio_device_register(indio_dev); 1156 if (ret < 0) 1157 goto error_free_dev; 1158 1159 ret = iio_buffer_register(indio_dev, 1160 sca3000_channels, 1161 ARRAY_SIZE(sca3000_channels)); 1162 if (ret < 0) 1163 goto error_unregister_dev; 1164 if (indio_dev->buffer) { 1165 iio_scan_mask_set(indio_dev->buffer, 0); 1166 iio_scan_mask_set(indio_dev->buffer, 1); 1167 iio_scan_mask_set(indio_dev->buffer, 2); 1168 } 1169 1170 if (spi->irq) { 1171 ret = request_threaded_irq(spi->irq, 1172 NULL, 1173 &sca3000_event_handler, 1174 IRQF_TRIGGER_FALLING, 1175 "sca3000", 1176 indio_dev); 1177 if (ret) 1178 goto error_unregister_ring; 1179 } 1180 sca3000_register_ring_funcs(indio_dev); 1181 ret = sca3000_clean_setup(st); 1182 if (ret) 1183 goto error_free_irq; 1184 return 0; 1185 1186error_free_irq: 1187 if (spi->irq) 1188 free_irq(spi->irq, indio_dev); 1189error_unregister_ring: 1190 iio_buffer_unregister(indio_dev); 1191error_unregister_dev: 1192 iio_device_unregister(indio_dev); 1193error_free_dev: 1194 iio_free_device(indio_dev); 1195 1196error_ret: 1197 return ret; 1198} 1199 1200static int sca3000_stop_all_interrupts(struct sca3000_state *st) 1201{ 1202 int ret; 1203 1204 mutex_lock(&st->lock); 1205 ret = sca3000_read_data_short(st, SCA3000_REG_ADDR_INT_MASK, 1); 1206 if (ret) 1207 goto error_ret; 1208 ret = sca3000_write_reg(st, SCA3000_REG_ADDR_INT_MASK, 1209 (st->rx[0] & 1210 ~(SCA3000_INT_MASK_RING_THREE_QUARTER | 1211 SCA3000_INT_MASK_RING_HALF | 1212 SCA3000_INT_MASK_ALL_INTS))); 1213error_ret: 1214 mutex_unlock(&st->lock); 1215 return ret; 1216} 1217 1218static int sca3000_remove(struct spi_device *spi) 1219{ 1220 struct iio_dev *indio_dev = spi_get_drvdata(spi); 1221 struct sca3000_state *st = iio_priv(indio_dev); 1222 int ret; 1223 /* Must ensure no interrupts can be generated after this!*/ 1224 ret = sca3000_stop_all_interrupts(st); 1225 if (ret) 1226 return ret; 1227 if (spi->irq) 1228 free_irq(spi->irq, indio_dev); 1229 iio_device_unregister(indio_dev); 1230 iio_buffer_unregister(indio_dev); 1231 sca3000_unconfigure_ring(indio_dev); 1232 iio_free_device(indio_dev); 1233 1234 return 0; 1235} 1236 1237static const struct spi_device_id sca3000_id[] = { 1238 {"sca3000_d01", d01}, 1239 {"sca3000_e02", e02}, 1240 {"sca3000_e04", e04}, 1241 {"sca3000_e05", e05}, 1242 {} 1243}; 1244 1245static struct spi_driver sca3000_driver = { 1246 .driver = { 1247 .name = "sca3000", 1248 .owner = THIS_MODULE, 1249 }, 1250 .probe = sca3000_probe, 1251 .remove = __devexit_p(sca3000_remove), 1252 .id_table = sca3000_id, 1253}; 1254 1255static __init int sca3000_init(void) 1256{ 1257 return spi_register_driver(&sca3000_driver); 1258} 1259module_init(sca3000_init); 1260 1261static __exit void sca3000_exit(void) 1262{ 1263 spi_unregister_driver(&sca3000_driver); 1264} 1265module_exit(sca3000_exit); 1266 1267MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>"); 1268MODULE_DESCRIPTION("VTI SCA3000 Series Accelerometers SPI driver"); 1269MODULE_LICENSE("GPL v2"); 1270