drivers/staging/iio/resolver/ad2s1210.c

   1 /*
   2  * ad2s1210.c support for the ADI Resolver to Digital Converters: AD2S1210
   3  *
   4  * Copyright (c) 2010-2010 Analog Devices Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11 #include <linux/types.h>
  12 #include <linux/mutex.h>
  13 #include <linux/device.h>
  14 #include <linux/spi/spi.h>
  15 #include <linux/slab.h>
  16 #include <linux/sysfs.h>
  17 #include <linux/delay.h>
  18 #include <linux/gpio.h>
  19 #include <linux/module.h>
  20
  21 #include "../iio.h"
  22 #include "../sysfs.h"
  23 #include "ad2s1210.h"
  24
  25 #define DRV_NAME "ad2s1210"
  26
  27 #define AD2S1210_DEF_CONTROL            0x7E
  28
  29 #define AD2S1210_MSB_IS_HIGH            0x80
  30 #define AD2S1210_MSB_IS_LOW             0x7F
  31 #define AD2S1210_PHASE_LOCK_RANGE_44    0x20
  32 #define AD2S1210_ENABLE_HYSTERESIS      0x10
  33 #define AD2S1210_SET_ENRES1             0x08
  34 #define AD2S1210_SET_ENRES0             0x04
  35 #define AD2S1210_SET_RES1               0x02
  36 #define AD2S1210_SET_RES0               0x01
  37
  38 #define AD2S1210_SET_ENRESOLUTION       (AD2S1210_SET_ENRES1 |  \
  39                                          AD2S1210_SET_ENRES0)
  40 #define AD2S1210_SET_RESOLUTION         (AD2S1210_SET_RES1 | AD2S1210_SET_RES0)
  41
  42 #define AD2S1210_REG_POSITION           0x80
  43 #define AD2S1210_REG_VELOCITY           0x82
  44 #define AD2S1210_REG_LOS_THRD           0x88
  45 #define AD2S1210_REG_DOS_OVR_THRD       0x89
  46 #define AD2S1210_REG_DOS_MIS_THRD       0x8A
  47 #define AD2S1210_REG_DOS_RST_MAX_THRD   0x8B
  48 #define AD2S1210_REG_DOS_RST_MIN_THRD   0x8C
  49 #define AD2S1210_REG_LOT_HIGH_THRD      0x8D
  50 #define AD2S1210_REG_LOT_LOW_THRD       0x8E
  51 #define AD2S1210_REG_EXCIT_FREQ         0x91
  52 #define AD2S1210_REG_CONTROL            0x92
  53 #define AD2S1210_REG_SOFT_RESET         0xF0
  54 #define AD2S1210_REG_FAULT              0xFF
  55
  56 /* pin SAMPLE, A0, A1, RES0, RES1, is controlled by driver */
  57 #define AD2S1210_SAA            3
  58 #define AD2S1210_PN             (AD2S1210_SAA + AD2S1210_RES)
  59
  60 #define AD2S1210_MIN_CLKIN      6144000
  61 #define AD2S1210_MAX_CLKIN      10240000
  62 #define AD2S1210_MIN_EXCIT      2000
  63 #define AD2S1210_MAX_EXCIT      20000
  64 #define AD2S1210_MIN_FCW        0x4
  65 #define AD2S1210_MAX_FCW        0x50
  66
  67 /* default input clock on serial interface */
  68 #define AD2S1210_DEF_CLKIN      8192000
  69 /* clock period in nano second */
  70 #define AD2S1210_DEF_TCK        (1000000000/AD2S1210_DEF_CLKIN)
  71 #define AD2S1210_DEF_EXCIT      10000
  72
  73 enum ad2s1210_mode {
  74         MOD_POS = 0,
  75         MOD_VEL,
  76         MOD_CONFIG,
  77         MOD_RESERVED,
  78 };
  79
  80 static const unsigned int ad2s1210_resolution_value[] = { 10, 12, 14, 16 };
  81
  82 struct ad2s1210_state {
  83         const struct ad2s1210_platform_data *pdata;
  84         struct mutex lock;
  85         struct spi_device *sdev;
  86         unsigned int fclkin;
  87         unsigned int fexcit;
  88         bool hysteresis;
  89         bool old_data;
  90         u8 resolution;
  91         enum ad2s1210_mode mode;
  92         u8 rx[2] ____cacheline_aligned;
  93         u8 tx[2] ____cacheline_aligned;
  94 };
  95
  96 static const int ad2s1210_mode_vals[4][2] = {
  97         [MOD_POS] = { 0, 0 },
  98         [MOD_VEL] = { 0, 1 },
  99         [MOD_CONFIG] = { 1, 0 },
 100 };
 101 static inline void ad2s1210_set_mode(enum ad2s1210_mode mode,
 102                                      struct ad2s1210_state *st)
 103 {
 104         gpio_set_value(st->pdata->a[0], ad2s1210_mode_vals[mode][0]);
 105         gpio_set_value(st->pdata->a[1], ad2s1210_mode_vals[mode][1]);
 106         st->mode = mode;
 107 }
 108
 109 /* write 1 bytes (address or data) to the chip */
 110 static int ad2s1210_config_write(struct ad2s1210_state *st, u8 data)
 111 {
 112         int ret;
 113
 114         ad2s1210_set_mode(MOD_CONFIG, st);
 115         st->tx[0] = data;
 116         ret = spi_write(st->sdev, st->tx, 1);
 117         if (ret < 0)
 118                 return ret;
 119         st->old_data = true;
 120
 121         return 0;
 122 }
 123
 124 /* read value from one of the registers */
 125 static int ad2s1210_config_read(struct ad2s1210_state *st,
 126                        unsigned char address)
 127 {
 128         struct spi_transfer xfer = {
 129                 .len = 2,
 130                 .rx_buf = st->rx,
 131                 .tx_buf = st->tx,
 132         };
 133         struct spi_message msg;
 134         int ret = 0;
 135
 136         ad2s1210_set_mode(MOD_CONFIG, st);
 137         spi_message_init(&msg);
 138         spi_message_add_tail(&xfer, &msg);
 139         st->tx[0] = address | AD2S1210_MSB_IS_HIGH;
 140         st->tx[1] = AD2S1210_REG_FAULT;
 141         ret = spi_sync(st->sdev, &msg);
 142         if (ret < 0)
 143                 return ret;
 144         st->old_data = true;
 145
 146         return st->rx[1];
 147 }
 148
 149 static inline
 150 int ad2s1210_update_frequency_control_word(struct ad2s1210_state *st)
 151 {
 152         int ret;
 153         unsigned char fcw;
 154
 155         fcw = (unsigned char)(st->fexcit * (1 << 15) / st->fclkin);
 156         if (fcw < AD2S1210_MIN_FCW || fcw > AD2S1210_MAX_FCW) {
 157                 pr_err("ad2s1210: FCW out of range\n");
 158                 return -ERANGE;
 159         }
 160
 161         ret = ad2s1210_config_write(st, AD2S1210_REG_EXCIT_FREQ);
 162         if (ret < 0)
 163                 return ret;
 164
 165         return ad2s1210_config_write(st, fcw);
 166 }
 167
 168 static unsigned char ad2s1210_read_resolution_pin(struct ad2s1210_state *st)
 169 {
 170         return ad2s1210_resolution_value[
 171                 (gpio_get_value(st->pdata->res[0]) << 1) |
 172                 gpio_get_value(st->pdata->res[1])];
 173 }
 174
 175 static const int ad2s1210_res_pins[4][2] = {
 176         { 0, 0 }, {0, 1}, {1, 0}, {1, 1}
 177 };
 178
 179 static inline void ad2s1210_set_resolution_pin(struct ad2s1210_state *st)
 180 {
 181         gpio_set_value(st->pdata->res[0],
 182                        ad2s1210_res_pins[(st->resolution - 10)/2][0]);
 183         gpio_set_value(st->pdata->res[1],
 184                        ad2s1210_res_pins[(st->resolution - 10)/2][1]);
 185 }
 186
 187 static inline int ad2s1210_soft_reset(struct ad2s1210_state *st)
 188 {
 189         int ret;
 190
 191         ret = ad2s1210_config_write(st, AD2S1210_REG_SOFT_RESET);
 192         if (ret < 0)
 193                 return ret;
 194
 195         return ad2s1210_config_write(st, 0x0);
 196 }
 197
 198
 199 /* return the OLD DATA since last spi bus write */
 200 static ssize_t ad2s1210_show_raw(struct device *dev,
 201                                  struct device_attribute *attr,
 202                                  char *buf)
 203 {
 204         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 205         int ret = 0;
 206
 207         mutex_lock(&st->lock);
 208         if (st->old_data) {
 209                 ret = sprintf(buf, "0x%x\n", st->rx[0]);
 210                 st->old_data = false;
 211         }
 212         mutex_unlock(&st->lock);
 213
 214         return ret;
 215 }
 216
 217 static ssize_t ad2s1210_store_raw(struct device *dev,
 218                                   struct device_attribute *attr,
 219                                   const char *buf,
 220                                   size_t len)
 221 {
 222         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 223         unsigned long udata;
 224         unsigned char data;
 225         int ret;
 226
 227         ret = strict_strtoul(buf, 16, &udata);
 228         if (ret)
 229                 return -EINVAL;
 230
 231         data = udata & 0xff;
 232         mutex_lock(&st->lock);
 233         ret = ad2s1210_config_write(st, data);
 234         mutex_unlock(&st->lock);
 235
 236         return ret < 0 ? ret : len;
 237 }
 238
 239 static ssize_t ad2s1210_store_softreset(struct device *dev,
 240                                         struct device_attribute *attr,
 241                                         const char *buf,
 242                                         size_t len)
 243 {
 244         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 245         int ret;
 246
 247         mutex_lock(&st->lock);
 248         ret = ad2s1210_soft_reset(st);
 249         mutex_unlock(&st->lock);
 250
 251         return ret < 0 ? ret : len;
 252 }
 253
 254 static ssize_t ad2s1210_show_fclkin(struct device *dev,
 255                                     struct device_attribute *attr,
 256                                     char *buf)
 257 {
 258         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 259         return sprintf(buf, "%d\n", st->fclkin);
 260 }
 261
 262 static ssize_t ad2s1210_store_fclkin(struct device *dev,
 263                                      struct device_attribute *attr,
 264                                      const char *buf,
 265                                      size_t len)
 266 {
 267         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 268         unsigned long fclkin;
 269         int ret;
 270
 271         ret = strict_strtoul(buf, 10, &fclkin);
 272         if (ret)
 273                 return ret;
 274         if (fclkin < AD2S1210_MIN_CLKIN || fclkin > AD2S1210_MAX_CLKIN) {
 275                 pr_err("ad2s1210: fclkin out of range\n");
 276                 return -EINVAL;
 277         }
 278
 279         mutex_lock(&st->lock);
 280         st->fclkin = fclkin;
 281
 282         ret = ad2s1210_update_frequency_control_word(st);
 283         if (ret < 0)
 284                 goto error_ret;
 285         ret = ad2s1210_soft_reset(st);
 286 error_ret:
 287         mutex_unlock(&st->lock);
 288
 289         return ret < 0 ? ret : len;
 290 }
 291
 292 static ssize_t ad2s1210_show_fexcit(struct device *dev,
 293                                     struct device_attribute *attr,
 294                                     char *buf)
 295 {
 296         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 297         return sprintf(buf, "%d\n", st->fexcit);
 298 }
 299
 300 static ssize_t ad2s1210_store_fexcit(struct device *dev,
 301                                      struct device_attribute *attr,
 302                                      const char *buf, size_t len)
 303 {
 304         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 305         unsigned long fexcit;
 306         int ret;
 307
 308         ret = strict_strtoul(buf, 10, &fexcit);
 309         if (ret < 0)
 310                 return ret;
 311         if (fexcit < AD2S1210_MIN_EXCIT || fexcit > AD2S1210_MAX_EXCIT) {
 312                 pr_err("ad2s1210: excitation frequency out of range\n");
 313                 return -EINVAL;
 314         }
 315         mutex_lock(&st->lock);
 316         st->fexcit = fexcit;
 317         ret = ad2s1210_update_frequency_control_word(st);
 318         if (ret < 0)
 319                 goto error_ret;
 320         ret = ad2s1210_soft_reset(st);
 321 error_ret:
 322         mutex_unlock(&st->lock);
 323
 324         return ret < 0 ? ret : len;
 325 }
 326
 327 static ssize_t ad2s1210_show_control(struct device *dev,
 328                                      struct device_attribute *attr,
 329                                      char *buf)
 330 {
 331         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 332         int ret;
 333         mutex_lock(&st->lock);
 334         ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
 335         mutex_unlock(&st->lock);
 336         return ret < 0 ? ret : sprintf(buf, "0x%x\n", ret);
 337 }
 338
 339 static ssize_t ad2s1210_store_control(struct device *dev,
 340                         struct device_attribute *attr,
 341                         const char *buf, size_t len)
 342 {
 343         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 344         unsigned long udata;
 345         unsigned char data;
 346         int ret;
 347
 348         ret = strict_strtoul(buf, 16, &udata);
 349         if (ret)
 350                 return -EINVAL;
 351
 352         mutex_lock(&st->lock);
 353         ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
 354         if (ret < 0)
 355                 goto error_ret;
 356         data = udata & AD2S1210_MSB_IS_LOW;
 357         ret = ad2s1210_config_write(st, data);
 358         if (ret < 0)
 359                 goto error_ret;
 360
 361         ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
 362         if (ret < 0)
 363                 goto error_ret;
 364         if (ret & AD2S1210_MSB_IS_HIGH) {
 365                 ret = -EIO;
 366                 pr_err("ad2s1210: write control register fail\n");
 367                 goto error_ret;
 368         }
 369         st->resolution
 370                 = ad2s1210_resolution_value[data & AD2S1210_SET_RESOLUTION];
 371         if (st->pdata->gpioin) {
 372                 data = ad2s1210_read_resolution_pin(st);
 373                 if (data != st->resolution)
 374                         pr_warning("ad2s1210: resolution settings not match\n");
 375         } else
 376                 ad2s1210_set_resolution_pin(st);
 377
 378         ret = len;
 379         st->hysteresis = !!(data & AD2S1210_ENABLE_HYSTERESIS);
 380
 381 error_ret:
 382         mutex_unlock(&st->lock);
 383         return ret;
 384 }
 385
 386 static ssize_t ad2s1210_show_resolution(struct device *dev,
 387                         struct device_attribute *attr, char *buf)
 388 {
 389         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 390         return sprintf(buf, "%d\n", st->resolution);
 391 }
 392
 393 static ssize_t ad2s1210_store_resolution(struct device *dev,
 394                         struct device_attribute *attr,
 395                         const char *buf, size_t len)
 396 {
 397         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 398         unsigned char data;
 399         unsigned long udata;
 400         int ret;
 401
 402         ret = strict_strtoul(buf, 10, &udata);
 403         if (ret || udata < 10 || udata > 16) {
 404                 pr_err("ad2s1210: resolution out of range\n");
 405                 return -EINVAL;
 406         }
 407         mutex_lock(&st->lock);
 408         ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
 409         if (ret < 0)
 410                 goto error_ret;
 411         data = ret;
 412         data &= ~AD2S1210_SET_RESOLUTION;
 413         data |= (udata - 10) >> 1;
 414         ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
 415         if (ret < 0)
 416                 goto error_ret;
 417         ret = ad2s1210_config_write(st, data & AD2S1210_MSB_IS_LOW);
 418         if (ret < 0)
 419                 goto error_ret;
 420         ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
 421         if (ret < 0)
 422                 goto error_ret;
 423         data = ret;
 424         if (data & AD2S1210_MSB_IS_HIGH) {
 425                 ret = -EIO;
 426                 pr_err("ad2s1210: setting resolution fail\n");
 427                 goto error_ret;
 428         }
 429         st->resolution
 430                 = ad2s1210_resolution_value[data & AD2S1210_SET_RESOLUTION];
 431         if (st->pdata->gpioin) {
 432                 data = ad2s1210_read_resolution_pin(st);
 433                 if (data != st->resolution)
 434                         pr_warning("ad2s1210: resolution settings not match\n");
 435         } else
 436                 ad2s1210_set_resolution_pin(st);
 437         ret = len;
 438 error_ret:
 439         mutex_unlock(&st->lock);
 440         return ret;
 441 }
 442
 443 /* read the fault register since last sample */
 444 static ssize_t ad2s1210_show_fault(struct device *dev,
 445                         struct device_attribute *attr, char *buf)
 446 {
 447         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 448         int ret;
 449
 450         mutex_lock(&st->lock);
 451         ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
 452         mutex_unlock(&st->lock);
 453
 454         return ret ? ret : sprintf(buf, "0x%x\n", ret);
 455 }
 456
 457 static ssize_t ad2s1210_clear_fault(struct device *dev,
 458                                     struct device_attribute *attr,
 459                                     const char *buf,
 460                                     size_t len)
 461 {
 462         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 463         int ret;
 464
 465         mutex_lock(&st->lock);
 466         gpio_set_value(st->pdata->sample, 0);
 467         /* delay (2 * tck + 20) nano seconds */
 468         udelay(1);
 469         gpio_set_value(st->pdata->sample, 1);
 470         ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
 471         if (ret < 0)
 472                 goto error_ret;
 473         gpio_set_value(st->pdata->sample, 0);
 474         gpio_set_value(st->pdata->sample, 1);
 475 error_ret:
 476         mutex_unlock(&st->lock);
 477
 478         return ret < 0 ? ret : len;
 479 }
 480
 481 static ssize_t ad2s1210_show_reg(struct device *dev,
 482                                  struct device_attribute *attr,
 483                                  char *buf)
 484 {
 485         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 486         struct iio_dev_attr *iattr = to_iio_dev_attr(attr);
 487         int ret;
 488
 489         mutex_lock(&st->lock);
 490         ret = ad2s1210_config_read(st, iattr->address);
 491         mutex_unlock(&st->lock);
 492
 493         return ret < 0 ? ret : sprintf(buf, "%d\n", ret);
 494 }
 495
 496 static ssize_t ad2s1210_store_reg(struct device *dev,
 497                 struct device_attribute *attr, const char *buf, size_t len)
 498 {
 499         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 500         unsigned long data;
 501         int ret;
 502         struct iio_dev_attr *iattr = to_iio_dev_attr(attr);
 503
 504         ret = strict_strtoul(buf, 10, &data);
 505         if (ret)
 506                 return -EINVAL;
 507         mutex_lock(&st->lock);
 508         ret = ad2s1210_config_write(st, iattr->address);
 509         if (ret < 0)
 510                 goto error_ret;
 511         ret = ad2s1210_config_write(st, data & AD2S1210_MSB_IS_LOW);
 512 error_ret:
 513         mutex_unlock(&st->lock);
 514         return ret < 0 ? ret : len;
 515 }
 516
 517 static ssize_t ad2s1210_show_pos(struct device *dev,
 518                                  struct device_attribute *attr,
 519                                  char *buf)
 520 {
 521         int ret = 0;
 522         ssize_t len = 0;
 523         u16 pos;
 524         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 525
 526         mutex_lock(&st->lock);
 527         gpio_set_value(st->pdata->sample, 0);
 528         /* delay (6 * tck + 20) nano seconds */
 529         udelay(1);
 530
 531         ad2s1210_set_mode(MOD_POS, st);
 532         ret = spi_read(st->sdev, st->rx, 2);
 533         if (ret)
 534                 goto error_ret;
 535         pos = be16_to_cpup((u16 *)st->rx);
 536         if (st->hysteresis)
 537                 pos >>= 16 - st->resolution;
 538         len = sprintf(buf, "%d\n", pos);
 539 error_ret:
 540         gpio_set_value(st->pdata->sample, 1);
 541         /* delay (2 * tck + 20) nano seconds */
 542         udelay(1);
 543         mutex_unlock(&st->lock);
 544
 545         return ret < 0 ? ret : len;
 546 }
 547
 548 static ssize_t ad2s1210_show_vel(struct device *dev,
 549                                  struct device_attribute *attr,
 550                                  char *buf)
 551 {
 552         unsigned short negative;
 553         int ret = 0;
 554         ssize_t len = 0;
 555         s16 vel;
 556         struct ad2s1210_state *st = iio_priv(dev_get_drvdata(dev));
 557
 558         mutex_lock(&st->lock);
 559         gpio_set_value(st->pdata->sample, 0);
 560         /* delay (6 * tck + 20) nano seconds */
 561         udelay(1);
 562
 563         ad2s1210_set_mode(MOD_VEL, st);
 564         ret = spi_read(st->sdev, st->rx, 2);
 565         if (ret)
 566                 goto error_ret;
 567         negative = st->rx[0] & 0x80;
 568         vel = be16_to_cpup((s16 *)st->rx);
 569         vel >>= 16 - st->resolution;
 570         if (vel & 0x8000) {
 571                 negative = (0xffff >> st->resolution) << st->resolution;
 572                 vel |= negative;
 573         }
 574         len = sprintf(buf, "%d\n", vel);
 575 error_ret:
 576         gpio_set_value(st->pdata->sample, 1);
 577         /* delay (2 * tck + 20) nano seconds */
 578         udelay(1);
 579         mutex_unlock(&st->lock);
 580
 581         return ret < 0 ? ret : len;
 582 }
 583
 584 static IIO_DEVICE_ATTR(raw_io, S_IRUGO | S_IWUSR,
 585                        ad2s1210_show_raw, ad2s1210_store_raw, 0);
 586 static IIO_DEVICE_ATTR(reset, S_IWUSR,
 587                        NULL, ad2s1210_store_softreset, 0);
 588 static IIO_DEVICE_ATTR(fclkin, S_IRUGO | S_IWUSR,
 589                        ad2s1210_show_fclkin, ad2s1210_store_fclkin, 0);
 590 static IIO_DEVICE_ATTR(fexcit, S_IRUGO | S_IWUSR,
 591                        ad2s1210_show_fexcit,    ad2s1210_store_fexcit, 0);
 592 static IIO_DEVICE_ATTR(control, S_IRUGO | S_IWUSR,
 593                        ad2s1210_show_control, ad2s1210_store_control, 0);
 594 static IIO_DEVICE_ATTR(bits, S_IRUGO | S_IWUSR,
 595                        ad2s1210_show_resolution, ad2s1210_store_resolution, 0);
 596 static IIO_DEVICE_ATTR(fault, S_IRUGO | S_IWUSR,
 597                        ad2s1210_show_fault, ad2s1210_clear_fault, 0);
 598 static IIO_DEVICE_ATTR(pos, S_IRUGO, ad2s1210_show_pos, NULL, 0);
 599 static IIO_DEVICE_ATTR(vel, S_IRUGO,  ad2s1210_show_vel, NULL, 0);
 600 static IIO_DEVICE_ATTR(los_thrd, S_IRUGO | S_IWUSR,
 601                        ad2s1210_show_reg, ad2s1210_store_reg,
 602                        AD2S1210_REG_LOS_THRD);
 603 static IIO_DEVICE_ATTR(dos_ovr_thrd, S_IRUGO | S_IWUSR,
 604                        ad2s1210_show_reg, ad2s1210_store_reg,
 605                        AD2S1210_REG_DOS_OVR_THRD);
 606 static IIO_DEVICE_ATTR(dos_mis_thrd, S_IRUGO | S_IWUSR,
 607                        ad2s1210_show_reg, ad2s1210_store_reg,
 608                        AD2S1210_REG_DOS_MIS_THRD);
 609 static IIO_DEVICE_ATTR(dos_rst_max_thrd, S_IRUGO | S_IWUSR,
 610                        ad2s1210_show_reg, ad2s1210_store_reg,
 611                        AD2S1210_REG_DOS_RST_MAX_THRD);
 612 static IIO_DEVICE_ATTR(dos_rst_min_thrd, S_IRUGO | S_IWUSR,
 613                        ad2s1210_show_reg, ad2s1210_store_reg,
 614                        AD2S1210_REG_DOS_RST_MIN_THRD);
 615 static IIO_DEVICE_ATTR(lot_high_thrd, S_IRUGO | S_IWUSR,
 616                        ad2s1210_show_reg, ad2s1210_store_reg,
 617                        AD2S1210_REG_LOT_HIGH_THRD);
 618 static IIO_DEVICE_ATTR(lot_low_thrd, S_IRUGO | S_IWUSR,
 619                        ad2s1210_show_reg, ad2s1210_store_reg,
 620                        AD2S1210_REG_LOT_LOW_THRD);
 621
 622 static struct attribute *ad2s1210_attributes[] = {
 623         &iio_dev_attr_raw_io.dev_attr.attr,
 624         &iio_dev_attr_reset.dev_attr.attr,
 625         &iio_dev_attr_fclkin.dev_attr.attr,
 626         &iio_dev_attr_fexcit.dev_attr.attr,
 627         &iio_dev_attr_control.dev_attr.attr,
 628         &iio_dev_attr_bits.dev_attr.attr,
 629         &iio_dev_attr_fault.dev_attr.attr,
 630         &iio_dev_attr_pos.dev_attr.attr,
 631         &iio_dev_attr_vel.dev_attr.attr,
 632         &iio_dev_attr_los_thrd.dev_attr.attr,
 633         &iio_dev_attr_dos_ovr_thrd.dev_attr.attr,
 634         &iio_dev_attr_dos_mis_thrd.dev_attr.attr,
 635         &iio_dev_attr_dos_rst_max_thrd.dev_attr.attr,
 636         &iio_dev_attr_dos_rst_min_thrd.dev_attr.attr,
 637         &iio_dev_attr_lot_high_thrd.dev_attr.attr,
 638         &iio_dev_attr_lot_low_thrd.dev_attr.attr,
 639         NULL,
 640 };
 641
 642 static const struct attribute_group ad2s1210_attribute_group = {
 643         .attrs = ad2s1210_attributes,
 644 };
 645
 646 static int __devinit ad2s1210_initial(struct ad2s1210_state *st)
 647 {
 648         unsigned char data;
 649         int ret;
 650
 651         mutex_lock(&st->lock);
 652         if (st->pdata->gpioin)
 653                 st->resolution = ad2s1210_read_resolution_pin(st);
 654         else
 655                 ad2s1210_set_resolution_pin(st);
 656
 657         ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
 658         if (ret < 0)
 659                 goto error_ret;
 660         data = AD2S1210_DEF_CONTROL & ~(AD2S1210_SET_RESOLUTION);
 661         data |= (st->resolution - 10) >> 1;
 662         ret = ad2s1210_config_write(st, data);
 663         if (ret < 0)
 664                 goto error_ret;
 665         ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
 666         if (ret < 0)
 667                 goto error_ret;
 668
 669         if (ret & AD2S1210_MSB_IS_HIGH) {
 670                 ret = -EIO;
 671                 goto error_ret;
 672         }
 673
 674         ret = ad2s1210_update_frequency_control_word(st);
 675         if (ret < 0)
 676                 goto error_ret;
 677         ret = ad2s1210_soft_reset(st);
 678 error_ret:
 679         mutex_unlock(&st->lock);
 680         return ret;
 681 }
 682
 683 static const struct iio_info ad2s1210_info = {
 684         .attrs = &ad2s1210_attribute_group,
 685         .driver_module = THIS_MODULE,
 686 };
 687
 688 static int ad2s1210_setup_gpios(struct ad2s1210_state *st)
 689 {
 690         int ret;
 691         unsigned long flags = st->pdata->gpioin ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
 692
 693         ret = gpio_request_one(st->pdata->sample, GPIOF_DIR_IN, "sample");
 694         if (ret < 0)
 695                 goto error_ret;
 696         ret = gpio_request_one(st->pdata->a[0], flags, "a0");
 697         if (ret < 0)
 698                 goto error_free_sample;
 699         ret = gpio_request_one(st->pdata->a[1], flags, "a1");
 700         if (ret < 0)
 701                 goto error_free_a0;
 702         ret = gpio_request_one(st->pdata->res[1], flags, "res0");
 703         if (ret < 0)
 704                 goto error_free_a1;
 705         ret = gpio_request_one(st->pdata->res[1], flags, "res1");
 706         if (ret < 0)
 707                 goto error_free_res0;
 708
 709         return 0;
 710 error_free_res0:
 711         gpio_free(st->pdata->res[0]);
 712 error_free_a1:
 713         gpio_free(st->pdata->a[1]);
 714 error_free_a0:
 715         gpio_free(st->pdata->a[0]);
 716 error_free_sample:
 717         gpio_free(st->pdata->sample);
 718 error_ret:
 719         return ret;
 720 }
 721
 722 static void ad2s1210_free_gpios(struct ad2s1210_state *st)
 723 {
 724         gpio_free(st->pdata->res[1]);
 725         gpio_free(st->pdata->res[0]);
 726         gpio_free(st->pdata->a[1]);
 727         gpio_free(st->pdata->a[0]);
 728         gpio_free(st->pdata->sample);
 729 }
 730
 731 static int __devinit ad2s1210_probe(struct spi_device *spi)
 732 {
 733         struct iio_dev *indio_dev;
 734         struct ad2s1210_state *st;
 735         int ret;
 736
 737         if (spi->dev.platform_data == NULL)
 738                 return -EINVAL;
 739
 740         indio_dev = iio_allocate_device(sizeof(*st));
 741         if (indio_dev == NULL) {
 742                 ret = -ENOMEM;
 743                 goto error_ret;
 744         }
 745         st = iio_priv(indio_dev);
 746         st->pdata = spi->dev.platform_data;
 747         ret = ad2s1210_setup_gpios(st);
 748         if (ret < 0)
 749                 goto error_free_dev;
 750
 751         spi_set_drvdata(spi, indio_dev);
 752
 753         mutex_init(&st->lock);
 754         st->sdev = spi;
 755         st->hysteresis = true;
 756         st->mode = MOD_CONFIG;
 757         st->resolution = 12;
 758         st->fexcit = AD2S1210_DEF_EXCIT;
 759
 760         indio_dev->dev.parent = &spi->dev;
 761         indio_dev->info = &ad2s1210_info;
 762         indio_dev->modes = INDIO_DIRECT_MODE;
 763
 764         ret = iio_device_register(indio_dev);
 765         if (ret)
 766                 goto error_free_gpios;
 767
 768         st->fclkin = spi->max_speed_hz;
 769         spi->mode = SPI_MODE_3;
 770         spi_setup(spi);
 771         ad2s1210_initial(st);
 772
 773         return 0;
 774
 775 error_free_gpios:
 776         ad2s1210_free_gpios(st);
 777 error_free_dev:
 778         iio_free_device(indio_dev);
 779 error_ret:
 780         return ret;
 781 }
 782
 783 static int __devexit ad2s1210_remove(struct spi_device *spi)
 784 {
 785         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 786         struct ad2s1210_state *st = iio_priv(indio_dev);
 787
 788         ad2s1210_free_gpios(st);
 789         iio_device_unregister(indio_dev);
 790
 791         return 0;
 792 }
 793
 794 static struct spi_driver ad2s1210_driver = {
 795         .driver = {
 796                 .name = DRV_NAME,
 797                 .owner = THIS_MODULE,
 798         },
 799         .probe = ad2s1210_probe,
 800         .remove = __devexit_p(ad2s1210_remove),
 801 };
 802
 803 static __init int ad2s1210_spi_init(void)
 804 {
 805         return spi_register_driver(&ad2s1210_driver);
 806 }
 807 module_init(ad2s1210_spi_init);
 808
 809 static __exit void ad2s1210_spi_exit(void)
 810 {
 811         spi_unregister_driver(&ad2s1210_driver);
 812 }
 813 module_exit(ad2s1210_spi_exit);
 814
 815 MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
 816 MODULE_DESCRIPTION("Analog Devices AD2S1210 Resolver to Digital SPI driver");
 817 MODULE_LICENSE("GPL v2");