drivers/staging/iio/adc/ad7280a.c

   1 /*
   2  * AD7280A Lithium Ion Battery Monitoring System
   3  *
   4  * Copyright 2011 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2.
   7  */
   8
   9 #include <linux/device.h>
  10 #include <linux/kernel.h>
  11 #include <linux/slab.h>
  12 #include <linux/sysfs.h>
  13 #include <linux/spi/spi.h>
  14 #include <linux/err.h>
  15 #include <linux/delay.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/module.h>
  18
  19 #include <linux/iio/iio.h>
  20 #include <linux/iio/sysfs.h>
  21 #include <linux/iio/events.h>
  22
  23 #include "ad7280a.h"
  24
  25 /* Registers */
  26 #define AD7280A_CELL_VOLTAGE_1          0x0  /* D11 to D0, Read only */
  27 #define AD7280A_CELL_VOLTAGE_2          0x1  /* D11 to D0, Read only */
  28 #define AD7280A_CELL_VOLTAGE_3          0x2  /* D11 to D0, Read only */
  29 #define AD7280A_CELL_VOLTAGE_4          0x3  /* D11 to D0, Read only */
  30 #define AD7280A_CELL_VOLTAGE_5          0x4  /* D11 to D0, Read only */
  31 #define AD7280A_CELL_VOLTAGE_6          0x5  /* D11 to D0, Read only */
  32 #define AD7280A_AUX_ADC_1               0x6  /* D11 to D0, Read only */
  33 #define AD7280A_AUX_ADC_2               0x7  /* D11 to D0, Read only */
  34 #define AD7280A_AUX_ADC_3               0x8  /* D11 to D0, Read only */
  35 #define AD7280A_AUX_ADC_4               0x9  /* D11 to D0, Read only */
  36 #define AD7280A_AUX_ADC_5               0xA  /* D11 to D0, Read only */
  37 #define AD7280A_AUX_ADC_6               0xB  /* D11 to D0, Read only */
  38 #define AD7280A_SELF_TEST               0xC  /* D11 to D0, Read only */
  39 #define AD7280A_CONTROL_HB              0xD  /* D15 to D8, Read/write */
  40 #define AD7280A_CONTROL_LB              0xE  /* D7 to D0, Read/write */
  41 #define AD7280A_CELL_OVERVOLTAGE        0xF  /* D7 to D0, Read/write */
  42 #define AD7280A_CELL_UNDERVOLTAGE       0x10 /* D7 to D0, Read/write */
  43 #define AD7280A_AUX_ADC_OVERVOLTAGE     0x11 /* D7 to D0, Read/write */
  44 #define AD7280A_AUX_ADC_UNDERVOLTAGE    0x12 /* D7 to D0, Read/write */
  45 #define AD7280A_ALERT                   0x13 /* D7 to D0, Read/write */
  46 #define AD7280A_CELL_BALANCE            0x14 /* D7 to D0, Read/write */
  47 #define AD7280A_CB1_TIMER               0x15 /* D7 to D0, Read/write */
  48 #define AD7280A_CB2_TIMER               0x16 /* D7 to D0, Read/write */
  49 #define AD7280A_CB3_TIMER               0x17 /* D7 to D0, Read/write */
  50 #define AD7280A_CB4_TIMER               0x18 /* D7 to D0, Read/write */
  51 #define AD7280A_CB5_TIMER               0x19 /* D7 to D0, Read/write */
  52 #define AD7280A_CB6_TIMER               0x1A /* D7 to D0, Read/write */
  53 #define AD7280A_PD_TIMER                0x1B /* D7 to D0, Read/write */
  54 #define AD7280A_READ                    0x1C /* D7 to D0, Read/write */
  55 #define AD7280A_CNVST_CONTROL           0x1D /* D7 to D0, Read/write */
  56
  57 /* Bits and Masks */
  58 #define AD7280A_CTRL_HB_CONV_INPUT_ALL                  0
  59 #define AD7280A_CTRL_HB_CONV_INPUT_6CELL_AUX1_3_4       BIT(6)
  60 #define AD7280A_CTRL_HB_CONV_INPUT_6CELL                BIT(7)
  61 #define AD7280A_CTRL_HB_CONV_INPUT_SELF_TEST            (BIT(7) | BIT(6))
  62 #define AD7280A_CTRL_HB_CONV_RES_READ_ALL               0
  63 #define AD7280A_CTRL_HB_CONV_RES_READ_6CELL_AUX1_3_4    BIT(4)
  64 #define AD7280A_CTRL_HB_CONV_RES_READ_6CELL             BIT(5)
  65 #define AD7280A_CTRL_HB_CONV_RES_READ_NO                (BIT(5) | BIT(4))
  66 #define AD7280A_CTRL_HB_CONV_START_CNVST                0
  67 #define AD7280A_CTRL_HB_CONV_START_CS                   BIT(3)
  68 #define AD7280A_CTRL_HB_CONV_AVG_DIS                    0
  69 #define AD7280A_CTRL_HB_CONV_AVG_2                      BIT(1)
  70 #define AD7280A_CTRL_HB_CONV_AVG_4                      BIT(2)
  71 #define AD7280A_CTRL_HB_CONV_AVG_8                      (BIT(2) | BIT(1))
  72 #define AD7280A_CTRL_HB_CONV_AVG(x)                     ((x) << 1)
  73 #define AD7280A_CTRL_HB_PWRDN_SW                        BIT(0)
  74
  75 #define AD7280A_CTRL_LB_SWRST                           BIT(7)
  76 #define AD7280A_CTRL_LB_ACQ_TIME_400ns                  0
  77 #define AD7280A_CTRL_LB_ACQ_TIME_800ns                  BIT(5)
  78 #define AD7280A_CTRL_LB_ACQ_TIME_1200ns                 BIT(6)
  79 #define AD7280A_CTRL_LB_ACQ_TIME_1600ns                 (BIT(6) | BIT(5))
  80 #define AD7280A_CTRL_LB_ACQ_TIME(x)                     ((x) << 5)
  81 #define AD7280A_CTRL_LB_MUST_SET                        BIT(4)
  82 #define AD7280A_CTRL_LB_THERMISTOR_EN                   BIT(3)
  83 #define AD7280A_CTRL_LB_LOCK_DEV_ADDR                   BIT(2)
  84 #define AD7280A_CTRL_LB_INC_DEV_ADDR                    BIT(1)
  85 #define AD7280A_CTRL_LB_DAISY_CHAIN_RB_EN               BIT(0)
  86
  87 #define AD7280A_ALERT_GEN_STATIC_HIGH                   BIT(6)
  88 #define AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN              (BIT(7) | BIT(6))
  89
  90 #define AD7280A_ALL_CELLS                               (0xAD << 16)
  91
  92 #define AD7280A_MAX_SPI_CLK_HZ          700000 /* < 1MHz */
  93 #define AD7280A_MAX_CHAIN               8
  94 #define AD7280A_CELLS_PER_DEV           6
  95 #define AD7280A_BITS                    12
  96 #define AD7280A_NUM_CH                  (AD7280A_AUX_ADC_6 - \
  97                                         AD7280A_CELL_VOLTAGE_1 + 1)
  98
  99 #define AD7280A_DEVADDR_MASTER          0
 100 #define AD7280A_DEVADDR_ALL             0x1F
 101 /* 5-bit device address is sent LSB first */
 102 #define AD7280A_DEVADDR(addr)   (((addr & 0x1) << 4) | ((addr & 0x2) << 3) | \
 103                                 (addr & 0x4) | ((addr & 0x8) >> 3) | \
 104                                 ((addr & 0x10) >> 4))
 105
 106 /* During a read a valid write is mandatory.
 107  * So writing to the highest available address (Address 0x1F)
 108  * and setting the address all parts bit to 0 is recommended
 109  * So the TXVAL is AD7280A_DEVADDR_ALL + CRC
 110  */
 111 #define AD7280A_READ_TXVAL      0xF800030A
 112
 113 /*
 114  * AD7280 CRC
 115  *
 116  * P(x) = x^8 + x^5 + x^3 + x^2 + x^1 + x^0 = 0b100101111 => 0x2F
 117  */
 118 #define POLYNOM         0x2F
 119 #define POLYNOM_ORDER   8
 120 #define HIGHBIT         (1 << (POLYNOM_ORDER - 1))
 121
 122 struct ad7280_state {
 123         struct spi_device               *spi;
 124         struct iio_chan_spec            *channels;
 125         struct iio_dev_attr             *iio_attr;
 126         int                             slave_num;
 127         int                             scan_cnt;
 128         int                             readback_delay_us;
 129         unsigned char                   crc_tab[256];
 130         unsigned char                   ctrl_hb;
 131         unsigned char                   ctrl_lb;
 132         unsigned char                   cell_threshhigh;
 133         unsigned char                   cell_threshlow;
 134         unsigned char                   aux_threshhigh;
 135         unsigned char                   aux_threshlow;
 136         unsigned char                   cb_mask[AD7280A_MAX_CHAIN];
 137
 138         __be32                          buf[2] ____cacheline_aligned;
 139 };
 140
 141 static void ad7280_crc8_build_table(unsigned char *crc_tab)
 142 {
 143         unsigned char bit, crc;
 144         int cnt, i;
 145
 146         for (cnt = 0; cnt < 256; cnt++) {
 147                 crc = cnt;
 148                 for (i = 0; i < 8; i++) {
 149                         bit = crc & HIGHBIT;
 150                         crc <<= 1;
 151                         if (bit)
 152                                 crc ^= POLYNOM;
 153                 }
 154                 crc_tab[cnt] = crc;
 155         }
 156 }
 157
 158 static unsigned char ad7280_calc_crc8(unsigned char *crc_tab, unsigned val)
 159 {
 160         unsigned char crc;
 161
 162         crc = crc_tab[val >> 16 & 0xFF];
 163         crc = crc_tab[crc ^ (val >> 8 & 0xFF)];
 164
 165         return  crc ^ (val & 0xFF);
 166 }
 167
 168 static int ad7280_check_crc(struct ad7280_state *st, unsigned val)
 169 {
 170         unsigned char crc = ad7280_calc_crc8(st->crc_tab, val >> 10);
 171
 172         if (crc != ((val >> 2) & 0xFF))
 173                 return -EIO;
 174
 175         return 0;
 176 }
 177
 178 /* After initiating a conversion sequence we need to wait until the
 179  * conversion is done. The delay is typically in the range of 15..30 us
 180  * however depending an the number of devices in the daisy chain and the
 181  * number of averages taken, conversion delays and acquisition time options
 182  * it may take up to 250us, in this case we better sleep instead of busy
 183  * wait.
 184  */
 185
 186 static void ad7280_delay(struct ad7280_state *st)
 187 {
 188         if (st->readback_delay_us < 50)
 189                 udelay(st->readback_delay_us);
 190         else
 191                 usleep_range(250, 500);
 192 }
 193
 194 static int __ad7280_read32(struct ad7280_state *st, unsigned *val)
 195 {
 196         int ret;
 197         struct spi_transfer t = {
 198                 .tx_buf = &st->buf[0],
 199                 .rx_buf = &st->buf[1],
 200                 .len = 4,
 201         };
 202
 203         st->buf[0] = cpu_to_be32(AD7280A_READ_TXVAL);
 204
 205         ret = spi_sync_transfer(st->spi, &t, 1);
 206         if (ret)
 207                 return ret;
 208
 209         *val = be32_to_cpu(st->buf[1]);
 210
 211         return 0;
 212 }
 213
 214 static int ad7280_write(struct ad7280_state *st, unsigned devaddr,
 215                         unsigned addr, bool all, unsigned val)
 216 {
 217         unsigned reg = (devaddr << 27 | addr << 21 |
 218                         (val & 0xFF) << 13 | all << 12);
 219
 220         reg |= ad7280_calc_crc8(st->crc_tab, reg >> 11) << 3 | 0x2;
 221         st->buf[0] = cpu_to_be32(reg);
 222
 223         return spi_write(st->spi, &st->buf[0], 4);
 224 }
 225
 226 static int ad7280_read(struct ad7280_state *st, unsigned devaddr,
 227                        unsigned addr)
 228 {
 229         int ret;
 230         unsigned tmp;
 231
 232         /* turns off the read operation on all parts */
 233         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 234                            AD7280A_CTRL_HB_CONV_INPUT_ALL |
 235                            AD7280A_CTRL_HB_CONV_RES_READ_NO |
 236                            st->ctrl_hb);
 237         if (ret)
 238                 return ret;
 239
 240         /* turns on the read operation on the addressed part */
 241         ret = ad7280_write(st, devaddr, AD7280A_CONTROL_HB, 0,
 242                            AD7280A_CTRL_HB_CONV_INPUT_ALL |
 243                            AD7280A_CTRL_HB_CONV_RES_READ_ALL |
 244                            st->ctrl_hb);
 245         if (ret)
 246                 return ret;
 247
 248         /* Set register address on the part to be read from */
 249         ret = ad7280_write(st, devaddr, AD7280A_READ, 0, addr << 2);
 250         if (ret)
 251                 return ret;
 252
 253         __ad7280_read32(st, &tmp);
 254
 255         if (ad7280_check_crc(st, tmp))
 256                 return -EIO;
 257
 258         if (((tmp >> 27) != devaddr) || (((tmp >> 21) & 0x3F) != addr))
 259                 return -EFAULT;
 260
 261         return (tmp >> 13) & 0xFF;
 262 }
 263
 264 static int ad7280_read_channel(struct ad7280_state *st, unsigned devaddr,
 265                                unsigned addr)
 266 {
 267         int ret;
 268         unsigned tmp;
 269
 270         ret = ad7280_write(st, devaddr, AD7280A_READ, 0, addr << 2);
 271         if (ret)
 272                 return ret;
 273
 274         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 275                            AD7280A_CTRL_HB_CONV_INPUT_ALL |
 276                            AD7280A_CTRL_HB_CONV_RES_READ_NO |
 277                            st->ctrl_hb);
 278         if (ret)
 279                 return ret;
 280
 281         ret = ad7280_write(st, devaddr, AD7280A_CONTROL_HB, 0,
 282                            AD7280A_CTRL_HB_CONV_INPUT_ALL |
 283                            AD7280A_CTRL_HB_CONV_RES_READ_ALL |
 284                            AD7280A_CTRL_HB_CONV_START_CS |
 285                            st->ctrl_hb);
 286         if (ret)
 287                 return ret;
 288
 289         ad7280_delay(st);
 290
 291         __ad7280_read32(st, &tmp);
 292
 293         if (ad7280_check_crc(st, tmp))
 294                 return -EIO;
 295
 296         if (((tmp >> 27) != devaddr) || (((tmp >> 23) & 0xF) != addr))
 297                 return -EFAULT;
 298
 299         return (tmp >> 11) & 0xFFF;
 300 }
 301
 302 static int ad7280_read_all_channels(struct ad7280_state *st, unsigned cnt,
 303                                     unsigned *array)
 304 {
 305         int i, ret;
 306         unsigned tmp, sum = 0;
 307
 308         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ, 1,
 309                            AD7280A_CELL_VOLTAGE_1 << 2);
 310         if (ret)
 311                 return ret;
 312
 313         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 314                            AD7280A_CTRL_HB_CONV_INPUT_ALL |
 315                            AD7280A_CTRL_HB_CONV_RES_READ_ALL |
 316                            AD7280A_CTRL_HB_CONV_START_CS |
 317                            st->ctrl_hb);
 318         if (ret)
 319                 return ret;
 320
 321         ad7280_delay(st);
 322
 323         for (i = 0; i < cnt; i++) {
 324                 __ad7280_read32(st, &tmp);
 325
 326                 if (ad7280_check_crc(st, tmp))
 327                         return -EIO;
 328
 329                 if (array)
 330                         array[i] = tmp;
 331                 /* only sum cell voltages */
 332                 if (((tmp >> 23) & 0xF) <= AD7280A_CELL_VOLTAGE_6)
 333                         sum += ((tmp >> 11) & 0xFFF);
 334         }
 335
 336         return sum;
 337 }
 338
 339 static int ad7280_chain_setup(struct ad7280_state *st)
 340 {
 341         unsigned val, n;
 342         int ret;
 343
 344         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_LB, 1,
 345                            AD7280A_CTRL_LB_DAISY_CHAIN_RB_EN |
 346                            AD7280A_CTRL_LB_LOCK_DEV_ADDR |
 347                            AD7280A_CTRL_LB_MUST_SET |
 348                            AD7280A_CTRL_LB_SWRST |
 349                            st->ctrl_lb);
 350         if (ret)
 351                 return ret;
 352
 353         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_LB, 1,
 354                            AD7280A_CTRL_LB_DAISY_CHAIN_RB_EN |
 355                            AD7280A_CTRL_LB_LOCK_DEV_ADDR |
 356                            AD7280A_CTRL_LB_MUST_SET |
 357                            st->ctrl_lb);
 358         if (ret)
 359                 return ret;
 360
 361         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ, 1,
 362                            AD7280A_CONTROL_LB << 2);
 363         if (ret)
 364                 return ret;
 365
 366         for (n = 0; n <= AD7280A_MAX_CHAIN; n++) {
 367                 __ad7280_read32(st, &val);
 368                 if (val == 0)
 369                         return n - 1;
 370
 371                 if (ad7280_check_crc(st, val))
 372                         return -EIO;
 373
 374                 if (n != AD7280A_DEVADDR(val >> 27))
 375                         return -EIO;
 376         }
 377
 378         return -EFAULT;
 379 }
 380
 381 static ssize_t ad7280_show_balance_sw(struct device *dev,
 382                                       struct device_attribute *attr,
 383                                       char *buf)
 384 {
 385         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 386         struct ad7280_state *st = iio_priv(indio_dev);
 387         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 388
 389         return sprintf(buf, "%d\n",
 390                        !!(st->cb_mask[this_attr->address >> 8] &
 391                        (1 << ((this_attr->address & 0xFF) + 2))));
 392 }
 393
 394 static ssize_t ad7280_store_balance_sw(struct device *dev,
 395                                        struct device_attribute *attr,
 396                                        const char *buf,
 397                                        size_t len)
 398 {
 399         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 400         struct ad7280_state *st = iio_priv(indio_dev);
 401         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 402         bool readin;
 403         int ret;
 404         unsigned devaddr, ch;
 405
 406         ret = strtobool(buf, &readin);
 407         if (ret)
 408                 return ret;
 409
 410         devaddr = this_attr->address >> 8;
 411         ch = this_attr->address & 0xFF;
 412
 413         mutex_lock(&indio_dev->mlock);
 414         if (readin)
 415                 st->cb_mask[devaddr] |= 1 << (ch + 2);
 416         else
 417                 st->cb_mask[devaddr] &= ~(1 << (ch + 2));
 418
 419         ret = ad7280_write(st, devaddr, AD7280A_CELL_BALANCE,
 420                            0, st->cb_mask[devaddr]);
 421         mutex_unlock(&indio_dev->mlock);
 422
 423         return ret ? ret : len;
 424 }
 425
 426 static ssize_t ad7280_show_balance_timer(struct device *dev,
 427                                          struct device_attribute *attr,
 428                                          char *buf)
 429 {
 430         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 431         struct ad7280_state *st = iio_priv(indio_dev);
 432         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 433         int ret;
 434         unsigned msecs;
 435
 436         mutex_lock(&indio_dev->mlock);
 437         ret = ad7280_read(st, this_attr->address >> 8,
 438                           this_attr->address & 0xFF);
 439         mutex_unlock(&indio_dev->mlock);
 440
 441         if (ret < 0)
 442                 return ret;
 443
 444         msecs = (ret >> 3) * 71500;
 445
 446         return sprintf(buf, "%u\n", msecs);
 447 }
 448
 449 static ssize_t ad7280_store_balance_timer(struct device *dev,
 450                                           struct device_attribute *attr,
 451                                           const char *buf,
 452                                           size_t len)
 453 {
 454         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 455         struct ad7280_state *st = iio_priv(indio_dev);
 456         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 457         unsigned long val;
 458         int ret;
 459
 460         ret = kstrtoul(buf, 10, &val);
 461         if (ret)
 462                 return ret;
 463
 464         val /= 71500;
 465
 466         if (val > 31)
 467                 return -EINVAL;
 468
 469         mutex_lock(&indio_dev->mlock);
 470         ret = ad7280_write(st, this_attr->address >> 8,
 471                            this_attr->address & 0xFF,
 472                            0, (val & 0x1F) << 3);
 473         mutex_unlock(&indio_dev->mlock);
 474
 475         return ret ? ret : len;
 476 }
 477
 478 static struct attribute *ad7280_attributes[AD7280A_MAX_CHAIN *
 479                                            AD7280A_CELLS_PER_DEV * 2 + 1];
 480
 481 static struct attribute_group ad7280_attrs_group = {
 482         .attrs = ad7280_attributes,
 483 };
 484
 485 static int ad7280_channel_init(struct ad7280_state *st)
 486 {
 487         int dev, ch, cnt;
 488
 489         st->channels = kcalloc((st->slave_num + 1) * 12 + 2,
 490                                sizeof(*st->channels), GFP_KERNEL);
 491         if (!st->channels)
 492                 return -ENOMEM;
 493
 494         for (dev = 0, cnt = 0; dev <= st->slave_num; dev++)
 495                 for (ch = AD7280A_CELL_VOLTAGE_1; ch <= AD7280A_AUX_ADC_6;
 496                         ch++, cnt++) {
 497                         if (ch < AD7280A_AUX_ADC_1) {
 498                                 st->channels[cnt].type = IIO_VOLTAGE;
 499                                 st->channels[cnt].differential = 1;
 500                                 st->channels[cnt].channel = (dev * 6) + ch;
 501                                 st->channels[cnt].channel2 =
 502                                         st->channels[cnt].channel + 1;
 503                         } else {
 504                                 st->channels[cnt].type = IIO_TEMP;
 505                                 st->channels[cnt].channel = (dev * 6) + ch - 6;
 506                         }
 507                         st->channels[cnt].indexed = 1;
 508                         st->channels[cnt].info_mask_separate =
 509                                 BIT(IIO_CHAN_INFO_RAW);
 510                         st->channels[cnt].info_mask_shared_by_type =
 511                                 BIT(IIO_CHAN_INFO_SCALE);
 512                         st->channels[cnt].address =
 513                                 AD7280A_DEVADDR(dev) << 8 | ch;
 514                         st->channels[cnt].scan_index = cnt;
 515                         st->channels[cnt].scan_type.sign = 'u';
 516                         st->channels[cnt].scan_type.realbits = 12;
 517                         st->channels[cnt].scan_type.storagebits = 32;
 518                         st->channels[cnt].scan_type.shift = 0;
 519                 }
 520
 521         st->channels[cnt].type = IIO_VOLTAGE;
 522         st->channels[cnt].differential = 1;
 523         st->channels[cnt].channel = 0;
 524         st->channels[cnt].channel2 = dev * 6;
 525         st->channels[cnt].address = AD7280A_ALL_CELLS;
 526         st->channels[cnt].indexed = 1;
 527         st->channels[cnt].info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
 528         st->channels[cnt].info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
 529         st->channels[cnt].scan_index = cnt;
 530         st->channels[cnt].scan_type.sign = 'u';
 531         st->channels[cnt].scan_type.realbits = 32;
 532         st->channels[cnt].scan_type.storagebits = 32;
 533         st->channels[cnt].scan_type.shift = 0;
 534         cnt++;
 535         st->channels[cnt].type = IIO_TIMESTAMP;
 536         st->channels[cnt].channel = -1;
 537         st->channels[cnt].scan_index = cnt;
 538         st->channels[cnt].scan_type.sign = 's';
 539         st->channels[cnt].scan_type.realbits = 64;
 540         st->channels[cnt].scan_type.storagebits = 64;
 541         st->channels[cnt].scan_type.shift = 0;
 542
 543         return cnt + 1;
 544 }
 545
 546 static int ad7280_attr_init(struct ad7280_state *st)
 547 {
 548         int dev, ch, cnt;
 549
 550         st->iio_attr = kcalloc(2, sizeof(*st->iio_attr) *
 551                                (st->slave_num + 1) * AD7280A_CELLS_PER_DEV,
 552                                GFP_KERNEL);
 553         if (!st->iio_attr)
 554                 return -ENOMEM;
 555
 556         for (dev = 0, cnt = 0; dev <= st->slave_num; dev++)
 557                 for (ch = AD7280A_CELL_VOLTAGE_1; ch <= AD7280A_CELL_VOLTAGE_6;
 558                         ch++, cnt++) {
 559                         st->iio_attr[cnt].address =
 560                                 AD7280A_DEVADDR(dev) << 8 | ch;
 561                         st->iio_attr[cnt].dev_attr.attr.mode =
 562                                 S_IWUSR | S_IRUGO;
 563                         st->iio_attr[cnt].dev_attr.show =
 564                                 ad7280_show_balance_sw;
 565                         st->iio_attr[cnt].dev_attr.store =
 566                                 ad7280_store_balance_sw;
 567                         st->iio_attr[cnt].dev_attr.attr.name =
 568                                 kasprintf(GFP_KERNEL,
 569                                           "in%d-in%d_balance_switch_en",
 570                                           dev * AD7280A_CELLS_PER_DEV + ch,
 571                                           dev * AD7280A_CELLS_PER_DEV + ch + 1);
 572                         ad7280_attributes[cnt] =
 573                                 &st->iio_attr[cnt].dev_attr.attr;
 574                         cnt++;
 575                         st->iio_attr[cnt].address =
 576                                 AD7280A_DEVADDR(dev) << 8 |
 577                                 (AD7280A_CB1_TIMER + ch);
 578                         st->iio_attr[cnt].dev_attr.attr.mode =
 579                                 S_IWUSR | S_IRUGO;
 580                         st->iio_attr[cnt].dev_attr.show =
 581                                 ad7280_show_balance_timer;
 582                         st->iio_attr[cnt].dev_attr.store =
 583                                 ad7280_store_balance_timer;
 584                         st->iio_attr[cnt].dev_attr.attr.name =
 585                                 kasprintf(GFP_KERNEL,
 586                                           "in%d-in%d_balance_timer",
 587                                           dev * AD7280A_CELLS_PER_DEV + ch,
 588                                           dev * AD7280A_CELLS_PER_DEV + ch + 1);
 589                         ad7280_attributes[cnt] =
 590                                 &st->iio_attr[cnt].dev_attr.attr;
 591                 }
 592
 593         ad7280_attributes[cnt] = NULL;
 594
 595         return 0;
 596 }
 597
 598 static ssize_t ad7280_read_channel_config(struct device *dev,
 599                                           struct device_attribute *attr,
 600                                           char *buf)
 601 {
 602         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 603         struct ad7280_state *st = iio_priv(indio_dev);
 604         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 605         unsigned val;
 606
 607         switch ((u32)this_attr->address) {
 608         case AD7280A_CELL_OVERVOLTAGE:
 609                 val = 1000 + (st->cell_threshhigh * 1568) / 100;
 610                 break;
 611         case AD7280A_CELL_UNDERVOLTAGE:
 612                 val = 1000 + (st->cell_threshlow * 1568) / 100;
 613                 break;
 614         case AD7280A_AUX_ADC_OVERVOLTAGE:
 615                 val = (st->aux_threshhigh * 196) / 10;
 616                 break;
 617         case AD7280A_AUX_ADC_UNDERVOLTAGE:
 618                 val = (st->aux_threshlow * 196) / 10;
 619                 break;
 620         default:
 621                 return -EINVAL;
 622         }
 623
 624         return sprintf(buf, "%u\n", val);
 625 }
 626
 627 static ssize_t ad7280_write_channel_config(struct device *dev,
 628                                            struct device_attribute *attr,
 629                                            const char *buf,
 630                                            size_t len)
 631 {
 632         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 633         struct ad7280_state *st = iio_priv(indio_dev);
 634         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 635
 636         long val;
 637         int ret;
 638
 639         ret = kstrtol(buf, 10, &val);
 640         if (ret)
 641                 return ret;
 642
 643         switch ((u32)this_attr->address) {
 644         case AD7280A_CELL_OVERVOLTAGE:
 645         case AD7280A_CELL_UNDERVOLTAGE:
 646                 val = ((val - 1000) * 100) / 1568; /* LSB 15.68mV */
 647                 break;
 648         case AD7280A_AUX_ADC_OVERVOLTAGE:
 649         case AD7280A_AUX_ADC_UNDERVOLTAGE:
 650                 val = (val * 10) / 196; /* LSB 19.6mV */
 651                 break;
 652         default:
 653                 return -EFAULT;
 654         }
 655
 656         val = clamp(val, 0L, 0xFFL);
 657
 658         mutex_lock(&indio_dev->mlock);
 659         switch ((u32)this_attr->address) {
 660         case AD7280A_CELL_OVERVOLTAGE:
 661                 st->cell_threshhigh = val;
 662                 break;
 663         case AD7280A_CELL_UNDERVOLTAGE:
 664                 st->cell_threshlow = val;
 665                 break;
 666         case AD7280A_AUX_ADC_OVERVOLTAGE:
 667                 st->aux_threshhigh = val;
 668                 break;
 669         case AD7280A_AUX_ADC_UNDERVOLTAGE:
 670                 st->aux_threshlow = val;
 671                 break;
 672         }
 673
 674         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
 675                            this_attr->address, 1, val);
 676
 677         mutex_unlock(&indio_dev->mlock);
 678
 679         return ret ? ret : len;
 680 }
 681
 682 static irqreturn_t ad7280_event_handler(int irq, void *private)
 683 {
 684         struct iio_dev *indio_dev = private;
 685         struct ad7280_state *st = iio_priv(indio_dev);
 686         unsigned *channels;
 687         int i, ret;
 688
 689         channels = kcalloc(st->scan_cnt, sizeof(*channels), GFP_KERNEL);
 690         if (!channels)
 691                 return IRQ_HANDLED;
 692
 693         ret = ad7280_read_all_channels(st, st->scan_cnt, channels);
 694         if (ret < 0)
 695                 goto out;
 696
 697         for (i = 0; i < st->scan_cnt; i++) {
 698                 if (((channels[i] >> 23) & 0xF) <= AD7280A_CELL_VOLTAGE_6) {
 699                         if (((channels[i] >> 11) & 0xFFF) >=
 700                                 st->cell_threshhigh)
 701                                 iio_push_event(indio_dev,
 702                                                IIO_EVENT_CODE(IIO_VOLTAGE,
 703                                                         1,
 704                                                         0,
 705                                                         IIO_EV_DIR_RISING,
 706                                                         IIO_EV_TYPE_THRESH,
 707                                                         0, 0, 0),
 708                                                iio_get_time_ns());
 709                         else if (((channels[i] >> 11) & 0xFFF) <=
 710                                 st->cell_threshlow)
 711                                 iio_push_event(indio_dev,
 712                                                IIO_EVENT_CODE(IIO_VOLTAGE,
 713                                                         1,
 714                                                         0,
 715                                                         IIO_EV_DIR_FALLING,
 716                                                         IIO_EV_TYPE_THRESH,
 717                                                         0, 0, 0),
 718                                                iio_get_time_ns());
 719                 } else {
 720                         if (((channels[i] >> 11) & 0xFFF) >= st->aux_threshhigh)
 721                                 iio_push_event(indio_dev,
 722                                                IIO_UNMOD_EVENT_CODE(
 723                                                         IIO_TEMP,
 724                                                         0,
 725                                                         IIO_EV_TYPE_THRESH,
 726                                                         IIO_EV_DIR_RISING),
 727                                                iio_get_time_ns());
 728                         else if (((channels[i] >> 11) & 0xFFF) <=
 729                                 st->aux_threshlow)
 730                                 iio_push_event(indio_dev,
 731                                                IIO_UNMOD_EVENT_CODE(
 732                                                         IIO_TEMP,
 733                                                         0,
 734                                                         IIO_EV_TYPE_THRESH,
 735                                                         IIO_EV_DIR_FALLING),
 736                                                iio_get_time_ns());
 737                 }
 738         }
 739
 740 out:
 741         kfree(channels);
 742
 743         return IRQ_HANDLED;
 744 }
 745
 746 static IIO_DEVICE_ATTR_NAMED(in_thresh_low_value,
 747                 in_voltage-voltage_thresh_low_value,
 748                 S_IRUGO | S_IWUSR,
 749                 ad7280_read_channel_config,
 750                 ad7280_write_channel_config,
 751                 AD7280A_CELL_UNDERVOLTAGE);
 752
 753 static IIO_DEVICE_ATTR_NAMED(in_thresh_high_value,
 754                 in_voltage-voltage_thresh_high_value,
 755                 S_IRUGO | S_IWUSR,
 756                 ad7280_read_channel_config,
 757                 ad7280_write_channel_config,
 758                 AD7280A_CELL_OVERVOLTAGE);
 759
 760 static IIO_DEVICE_ATTR(in_temp_thresh_low_value,
 761                 S_IRUGO | S_IWUSR,
 762                 ad7280_read_channel_config,
 763                 ad7280_write_channel_config,
 764                 AD7280A_AUX_ADC_UNDERVOLTAGE);
 765
 766 static IIO_DEVICE_ATTR(in_temp_thresh_high_value,
 767                 S_IRUGO | S_IWUSR,
 768                 ad7280_read_channel_config,
 769                 ad7280_write_channel_config,
 770                 AD7280A_AUX_ADC_OVERVOLTAGE);
 771
 772 static struct attribute *ad7280_event_attributes[] = {
 773         &iio_dev_attr_in_thresh_low_value.dev_attr.attr,
 774         &iio_dev_attr_in_thresh_high_value.dev_attr.attr,
 775         &iio_dev_attr_in_temp_thresh_low_value.dev_attr.attr,
 776         &iio_dev_attr_in_temp_thresh_high_value.dev_attr.attr,
 777         NULL,
 778 };
 779
 780 static struct attribute_group ad7280_event_attrs_group = {
 781         .attrs = ad7280_event_attributes,
 782 };
 783
 784 static int ad7280_read_raw(struct iio_dev *indio_dev,
 785                            struct iio_chan_spec const *chan,
 786                            int *val,
 787                            int *val2,
 788                            long m)
 789 {
 790         struct ad7280_state *st = iio_priv(indio_dev);
 791         int ret;
 792
 793         switch (m) {
 794         case IIO_CHAN_INFO_RAW:
 795                 mutex_lock(&indio_dev->mlock);
 796                 if (chan->address == AD7280A_ALL_CELLS)
 797                         ret = ad7280_read_all_channels(st, st->scan_cnt, NULL);
 798                 else
 799                         ret = ad7280_read_channel(st, chan->address >> 8,
 800                                                   chan->address & 0xFF);
 801                 mutex_unlock(&indio_dev->mlock);
 802
 803                 if (ret < 0)
 804                         return ret;
 805
 806                 *val = ret;
 807
 808                 return IIO_VAL_INT;
 809         case IIO_CHAN_INFO_SCALE:
 810                 if ((chan->address & 0xFF) <= AD7280A_CELL_VOLTAGE_6)
 811                         *val = 4000;
 812                 else
 813                         *val = 5000;
 814
 815                 *val2 = AD7280A_BITS;
 816                 return IIO_VAL_FRACTIONAL_LOG2;
 817         }
 818         return -EINVAL;
 819 }
 820
 821 static const struct iio_info ad7280_info = {
 822         .read_raw = ad7280_read_raw,
 823         .event_attrs = &ad7280_event_attrs_group,
 824         .attrs = &ad7280_attrs_group,
 825         .driver_module = THIS_MODULE,
 826 };
 827
 828 static const struct ad7280_platform_data ad7793_default_pdata = {
 829         .acquisition_time = AD7280A_ACQ_TIME_400ns,
 830         .conversion_averaging = AD7280A_CONV_AVG_DIS,
 831         .thermistor_term_en = true,
 832 };
 833
 834 static int ad7280_probe(struct spi_device *spi)
 835 {
 836         const struct ad7280_platform_data *pdata = spi->dev.platform_data;
 837         struct ad7280_state *st;
 838         int ret;
 839         const unsigned short tACQ_ns[4] = {465, 1010, 1460, 1890};
 840         const unsigned short nAVG[4] = {1, 2, 4, 8};
 841         struct iio_dev *indio_dev;
 842
 843         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 844         if (!indio_dev)
 845                 return -ENOMEM;
 846
 847         st = iio_priv(indio_dev);
 848         spi_set_drvdata(spi, indio_dev);
 849         st->spi = spi;
 850
 851         if (!pdata)
 852                 pdata = &ad7793_default_pdata;
 853
 854         ad7280_crc8_build_table(st->crc_tab);
 855
 856         st->spi->max_speed_hz = AD7280A_MAX_SPI_CLK_HZ;
 857         st->spi->mode = SPI_MODE_1;
 858         spi_setup(st->spi);
 859
 860         st->ctrl_lb = AD7280A_CTRL_LB_ACQ_TIME(pdata->acquisition_time & 0x3);
 861         st->ctrl_hb = AD7280A_CTRL_HB_CONV_AVG(pdata->conversion_averaging
 862                         & 0x3) | (pdata->thermistor_term_en ?
 863                         AD7280A_CTRL_LB_THERMISTOR_EN : 0);
 864
 865         ret = ad7280_chain_setup(st);
 866         if (ret < 0)
 867                 return ret;
 868
 869         st->slave_num = ret;
 870         st->scan_cnt = (st->slave_num + 1) * AD7280A_NUM_CH;
 871         st->cell_threshhigh = 0xFF;
 872         st->aux_threshhigh = 0xFF;
 873
 874         /*
 875          * Total Conversion Time = ((tACQ + tCONV) *
 876          *                         (Number of Conversions per Part)) −
 877          *                         tACQ + ((N - 1) * tDELAY)
 878          *
 879          * Readback Delay = Total Conversion Time + tWAIT
 880          */
 881
 882         st->readback_delay_us =
 883                 ((tACQ_ns[pdata->acquisition_time & 0x3] + 695) *
 884                 (AD7280A_NUM_CH * nAVG[pdata->conversion_averaging & 0x3]))
 885                 - tACQ_ns[pdata->acquisition_time & 0x3] +
 886                 st->slave_num * 250;
 887
 888         /* Convert to usecs */
 889         st->readback_delay_us = DIV_ROUND_UP(st->readback_delay_us, 1000);
 890         st->readback_delay_us += 5; /* Add tWAIT */
 891
 892         indio_dev->name = spi_get_device_id(spi)->name;
 893         indio_dev->dev.parent = &spi->dev;
 894         indio_dev->modes = INDIO_DIRECT_MODE;
 895
 896         ret = ad7280_channel_init(st);
 897         if (ret < 0)
 898                 return ret;
 899
 900         indio_dev->num_channels = ret;
 901         indio_dev->channels = st->channels;
 902         indio_dev->info = &ad7280_info;
 903
 904         ret = ad7280_attr_init(st);
 905         if (ret < 0)
 906                 goto error_free_channels;
 907
 908         ret = iio_device_register(indio_dev);
 909         if (ret)
 910                 goto error_free_attr;
 911
 912         if (spi->irq > 0) {
 913                 ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
 914                                    AD7280A_ALERT, 1,
 915                                    AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN);
 916                 if (ret)
 917                         goto error_unregister;
 918
 919                 ret = ad7280_write(st, AD7280A_DEVADDR(st->slave_num),
 920                                    AD7280A_ALERT, 0,
 921                                    AD7280A_ALERT_GEN_STATIC_HIGH |
 922                                    (pdata->chain_last_alert_ignore & 0xF));
 923                 if (ret)
 924                         goto error_unregister;
 925
 926                 ret = request_threaded_irq(spi->irq,
 927                                            NULL,
 928                                            ad7280_event_handler,
 929                                            IRQF_TRIGGER_FALLING |
 930                                            IRQF_ONESHOT,
 931                                            indio_dev->name,
 932                                            indio_dev);
 933                 if (ret)
 934                         goto error_unregister;
 935         }
 936
 937         return 0;
 938 error_unregister:
 939         iio_device_unregister(indio_dev);
 940
 941 error_free_attr:
 942         kfree(st->iio_attr);
 943
 944 error_free_channels:
 945         kfree(st->channels);
 946
 947         return ret;
 948 }
 949
 950 static int ad7280_remove(struct spi_device *spi)
 951 {
 952         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 953         struct ad7280_state *st = iio_priv(indio_dev);
 954
 955         if (spi->irq > 0)
 956                 free_irq(spi->irq, indio_dev);
 957         iio_device_unregister(indio_dev);
 958
 959         ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 960                      AD7280A_CTRL_HB_PWRDN_SW | st->ctrl_hb);
 961
 962         kfree(st->channels);
 963         kfree(st->iio_attr);
 964
 965         return 0;
 966 }
 967
 968 static const struct spi_device_id ad7280_id[] = {
 969         {"ad7280a", 0},
 970         {}
 971 };
 972 MODULE_DEVICE_TABLE(spi, ad7280_id);
 973
 974 static struct spi_driver ad7280_driver = {
 975         .driver = {
 976                 .name   = "ad7280",
 977         },
 978         .probe          = ad7280_probe,
 979         .remove         = ad7280_remove,
 980         .id_table       = ad7280_id,
 981 };
 982 module_spi_driver(ad7280_driver);
 983
 984 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 985 MODULE_DESCRIPTION("Analog Devices AD7280A");
 986 MODULE_LICENSE("GPL v2");