drivers/staging/iio/adc/ad7280a.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * AD7280A Lithium Ion Battery Monitoring System
   4  *
   5  * Copyright 2011 Analog Devices Inc.
   6  */
   7
   8 #include <linux/crc8.h>
   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_CALC_VOLTAGE_CHAN_NUM(d, c) (((d) * AD7280A_CELLS_PER_DEV) + \
 100                                              (c))
 101 #define AD7280A_CALC_TEMP_CHAN_NUM(d, c)    (((d) * AD7280A_CELLS_PER_DEV) + \
 102                                              (c) - AD7280A_CELLS_PER_DEV)
 103
 104 #define AD7280A_DEVADDR_MASTER          0
 105 #define AD7280A_DEVADDR_ALL             0x1F
 106 /* 5-bit device address is sent LSB first */
 107 static unsigned int ad7280a_devaddr(unsigned int addr)
 108 {
 109         return ((addr & 0x1) << 4) |
 110                ((addr & 0x2) << 3) |
 111                (addr & 0x4) |
 112                ((addr & 0x8) >> 3) |
 113                ((addr & 0x10) >> 4);
 114 }
 115
 116 /* During a read a valid write is mandatory.
 117  * So writing to the highest available address (Address 0x1F)
 118  * and setting the address all parts bit to 0 is recommended
 119  * So the TXVAL is AD7280A_DEVADDR_ALL + CRC
 120  */
 121 #define AD7280A_READ_TXVAL      0xF800030A
 122
 123 /*
 124  * AD7280 CRC
 125  *
 126  * P(x) = x^8 + x^5 + x^3 + x^2 + x^1 + x^0 = 0b100101111 => 0x2F
 127  */
 128 #define POLYNOM         0x2F
 129
 130 struct ad7280_state {
 131         struct spi_device               *spi;
 132         struct iio_chan_spec            *channels;
 133         struct iio_dev_attr             *iio_attr;
 134         int                             slave_num;
 135         int                             scan_cnt;
 136         int                             readback_delay_us;
 137         unsigned char                   crc_tab[CRC8_TABLE_SIZE];
 138         unsigned char                   ctrl_hb;
 139         unsigned char                   ctrl_lb;
 140         unsigned char                   cell_threshhigh;
 141         unsigned char                   cell_threshlow;
 142         unsigned char                   aux_threshhigh;
 143         unsigned char                   aux_threshlow;
 144         unsigned char                   cb_mask[AD7280A_MAX_CHAIN];
 145         struct mutex                    lock; /* protect sensor state */
 146
 147         __be32                          buf[2] ____cacheline_aligned;
 148 };
 149
 150 static unsigned char ad7280_calc_crc8(unsigned char *crc_tab, unsigned int val)
 151 {
 152         unsigned char crc;
 153
 154         crc = crc_tab[val >> 16 & 0xFF];
 155         crc = crc_tab[crc ^ (val >> 8 & 0xFF)];
 156
 157         return  crc ^ (val & 0xFF);
 158 }
 159
 160 static int ad7280_check_crc(struct ad7280_state *st, unsigned int val)
 161 {
 162         unsigned char crc = ad7280_calc_crc8(st->crc_tab, val >> 10);
 163
 164         if (crc != ((val >> 2) & 0xFF))
 165                 return -EIO;
 166
 167         return 0;
 168 }
 169
 170 /* After initiating a conversion sequence we need to wait until the
 171  * conversion is done. The delay is typically in the range of 15..30 us
 172  * however depending an the number of devices in the daisy chain and the
 173  * number of averages taken, conversion delays and acquisition time options
 174  * it may take up to 250us, in this case we better sleep instead of busy
 175  * wait.
 176  */
 177
 178 static void ad7280_delay(struct ad7280_state *st)
 179 {
 180         if (st->readback_delay_us < 50)
 181                 udelay(st->readback_delay_us);
 182         else
 183                 usleep_range(250, 500);
 184 }
 185
 186 static int __ad7280_read32(struct ad7280_state *st, unsigned int *val)
 187 {
 188         int ret;
 189         struct spi_transfer t = {
 190                 .tx_buf = &st->buf[0],
 191                 .rx_buf = &st->buf[1],
 192                 .len = 4,
 193         };
 194
 195         st->buf[0] = cpu_to_be32(AD7280A_READ_TXVAL);
 196
 197         ret = spi_sync_transfer(st->spi, &t, 1);
 198         if (ret)
 199                 return ret;
 200
 201         *val = be32_to_cpu(st->buf[1]);
 202
 203         return 0;
 204 }
 205
 206 static int ad7280_write(struct ad7280_state *st, unsigned int devaddr,
 207                         unsigned int addr, bool all, unsigned int val)
 208 {
 209         unsigned int reg = devaddr << 27 | addr << 21 |
 210                         (val & 0xFF) << 13 | all << 12;
 211
 212         reg |= ad7280_calc_crc8(st->crc_tab, reg >> 11) << 3 | 0x2;
 213         st->buf[0] = cpu_to_be32(reg);
 214
 215         return spi_write(st->spi, &st->buf[0], 4);
 216 }
 217
 218 static int ad7280_read(struct ad7280_state *st, unsigned int devaddr,
 219                        unsigned int addr)
 220 {
 221         int ret;
 222         unsigned int tmp;
 223
 224         /* turns off the read operation on all parts */
 225         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 226                            AD7280A_CTRL_HB_CONV_INPUT_ALL |
 227                            AD7280A_CTRL_HB_CONV_RES_READ_NO |
 228                            st->ctrl_hb);
 229         if (ret)
 230                 return ret;
 231
 232         /* turns on the read operation on the addressed part */
 233         ret = ad7280_write(st, devaddr, AD7280A_CONTROL_HB, 0,
 234                            AD7280A_CTRL_HB_CONV_INPUT_ALL |
 235                            AD7280A_CTRL_HB_CONV_RES_READ_ALL |
 236                            st->ctrl_hb);
 237         if (ret)
 238                 return ret;
 239
 240         /* Set register address on the part to be read from */
 241         ret = ad7280_write(st, devaddr, AD7280A_READ, 0, addr << 2);
 242         if (ret)
 243                 return ret;
 244
 245         ret = __ad7280_read32(st, &tmp);
 246         if (ret)
 247                 return ret;
 248
 249         if (ad7280_check_crc(st, tmp))
 250                 return -EIO;
 251
 252         if (((tmp >> 27) != devaddr) || (((tmp >> 21) & 0x3F) != addr))
 253                 return -EFAULT;
 254
 255         return (tmp >> 13) & 0xFF;
 256 }
 257
 258 static int ad7280_read_channel(struct ad7280_state *st, unsigned int devaddr,
 259                                unsigned int addr)
 260 {
 261         int ret;
 262         unsigned int tmp;
 263
 264         ret = ad7280_write(st, devaddr, AD7280A_READ, 0, addr << 2);
 265         if (ret)
 266                 return ret;
 267
 268         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 269                            AD7280A_CTRL_HB_CONV_INPUT_ALL |
 270                            AD7280A_CTRL_HB_CONV_RES_READ_NO |
 271                            st->ctrl_hb);
 272         if (ret)
 273                 return ret;
 274
 275         ret = ad7280_write(st, devaddr, AD7280A_CONTROL_HB, 0,
 276                            AD7280A_CTRL_HB_CONV_INPUT_ALL |
 277                            AD7280A_CTRL_HB_CONV_RES_READ_ALL |
 278                            AD7280A_CTRL_HB_CONV_START_CS |
 279                            st->ctrl_hb);
 280         if (ret)
 281                 return ret;
 282
 283         ad7280_delay(st);
 284
 285         ret = __ad7280_read32(st, &tmp);
 286         if (ret)
 287                 return ret;
 288
 289         if (ad7280_check_crc(st, tmp))
 290                 return -EIO;
 291
 292         if (((tmp >> 27) != devaddr) || (((tmp >> 23) & 0xF) != addr))
 293                 return -EFAULT;
 294
 295         return (tmp >> 11) & 0xFFF;
 296 }
 297
 298 static int ad7280_read_all_channels(struct ad7280_state *st, unsigned int cnt,
 299                                     unsigned int *array)
 300 {
 301         int i, ret;
 302         unsigned int tmp, sum = 0;
 303
 304         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ, 1,
 305                            AD7280A_CELL_VOLTAGE_1 << 2);
 306         if (ret)
 307                 return ret;
 308
 309         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 310                            AD7280A_CTRL_HB_CONV_INPUT_ALL |
 311                            AD7280A_CTRL_HB_CONV_RES_READ_ALL |
 312                            AD7280A_CTRL_HB_CONV_START_CS |
 313                            st->ctrl_hb);
 314         if (ret)
 315                 return ret;
 316
 317         ad7280_delay(st);
 318
 319         for (i = 0; i < cnt; i++) {
 320                 ret = __ad7280_read32(st, &tmp);
 321                 if (ret)
 322                         return ret;
 323
 324                 if (ad7280_check_crc(st, tmp))
 325                         return -EIO;
 326
 327                 if (array)
 328                         array[i] = tmp;
 329                 /* only sum cell voltages */
 330                 if (((tmp >> 23) & 0xF) <= AD7280A_CELL_VOLTAGE_6)
 331                         sum += ((tmp >> 11) & 0xFFF);
 332         }
 333
 334         return sum;
 335 }
 336
 337 static void ad7280_sw_power_down(void *data)
 338 {
 339         struct ad7280_state *st = data;
 340
 341         ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 342                      AD7280A_CTRL_HB_PWRDN_SW | st->ctrl_hb);
 343 }
 344
 345 static int ad7280_chain_setup(struct ad7280_state *st)
 346 {
 347         unsigned int val, n;
 348         int ret;
 349
 350         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_LB, 1,
 351                            AD7280A_CTRL_LB_DAISY_CHAIN_RB_EN |
 352                            AD7280A_CTRL_LB_LOCK_DEV_ADDR |
 353                            AD7280A_CTRL_LB_MUST_SET |
 354                            AD7280A_CTRL_LB_SWRST |
 355                            st->ctrl_lb);
 356         if (ret)
 357                 return ret;
 358
 359         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_LB, 1,
 360                            AD7280A_CTRL_LB_DAISY_CHAIN_RB_EN |
 361                            AD7280A_CTRL_LB_LOCK_DEV_ADDR |
 362                            AD7280A_CTRL_LB_MUST_SET |
 363                            st->ctrl_lb);
 364         if (ret)
 365                 goto error_power_down;
 366
 367         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ, 1,
 368                            AD7280A_CONTROL_LB << 2);
 369         if (ret)
 370                 goto error_power_down;
 371
 372         for (n = 0; n <= AD7280A_MAX_CHAIN; n++) {
 373                 ret = __ad7280_read32(st, &val);
 374                 if (ret)
 375                         goto error_power_down;
 376
 377                 if (val == 0)
 378                         return n - 1;
 379
 380                 if (ad7280_check_crc(st, val)) {
 381                         ret = -EIO;
 382                         goto error_power_down;
 383                 }
 384
 385                 if (n != ad7280a_devaddr(val >> 27)) {
 386                         ret = -EIO;
 387                         goto error_power_down;
 388                 }
 389         }
 390         ret = -EFAULT;
 391
 392 error_power_down:
 393         ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 394                      AD7280A_CTRL_HB_PWRDN_SW | st->ctrl_hb);
 395
 396         return ret;
 397 }
 398
 399 static ssize_t ad7280_show_balance_sw(struct device *dev,
 400                                       struct device_attribute *attr,
 401                                       char *buf)
 402 {
 403         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 404         struct ad7280_state *st = iio_priv(indio_dev);
 405         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 406
 407         return sprintf(buf, "%d\n",
 408                        !!(st->cb_mask[this_attr->address >> 8] &
 409                        (1 << ((this_attr->address & 0xFF) + 2))));
 410 }
 411
 412 static ssize_t ad7280_store_balance_sw(struct device *dev,
 413                                        struct device_attribute *attr,
 414                                        const char *buf,
 415                                        size_t len)
 416 {
 417         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 418         struct ad7280_state *st = iio_priv(indio_dev);
 419         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 420         bool readin;
 421         int ret;
 422         unsigned int devaddr, ch;
 423
 424         ret = strtobool(buf, &readin);
 425         if (ret)
 426                 return ret;
 427
 428         devaddr = this_attr->address >> 8;
 429         ch = this_attr->address & 0xFF;
 430
 431         mutex_lock(&st->lock);
 432         if (readin)
 433                 st->cb_mask[devaddr] |= 1 << (ch + 2);
 434         else
 435                 st->cb_mask[devaddr] &= ~(1 << (ch + 2));
 436
 437         ret = ad7280_write(st, devaddr, AD7280A_CELL_BALANCE,
 438                            0, st->cb_mask[devaddr]);
 439         mutex_unlock(&st->lock);
 440
 441         return ret ? ret : len;
 442 }
 443
 444 static ssize_t ad7280_show_balance_timer(struct device *dev,
 445                                          struct device_attribute *attr,
 446                                          char *buf)
 447 {
 448         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 449         struct ad7280_state *st = iio_priv(indio_dev);
 450         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 451         int ret;
 452         unsigned int msecs;
 453
 454         mutex_lock(&st->lock);
 455         ret = ad7280_read(st, this_attr->address >> 8,
 456                           this_attr->address & 0xFF);
 457         mutex_unlock(&st->lock);
 458
 459         if (ret < 0)
 460                 return ret;
 461
 462         msecs = (ret >> 3) * 71500;
 463
 464         return sprintf(buf, "%u\n", msecs);
 465 }
 466
 467 static ssize_t ad7280_store_balance_timer(struct device *dev,
 468                                           struct device_attribute *attr,
 469                                           const char *buf,
 470                                           size_t len)
 471 {
 472         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 473         struct ad7280_state *st = iio_priv(indio_dev);
 474         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 475         unsigned long val;
 476         int ret;
 477
 478         ret = kstrtoul(buf, 10, &val);
 479         if (ret)
 480                 return ret;
 481
 482         val /= 71500;
 483
 484         if (val > 31)
 485                 return -EINVAL;
 486
 487         mutex_lock(&st->lock);
 488         ret = ad7280_write(st, this_attr->address >> 8,
 489                            this_attr->address & 0xFF,
 490                            0, (val & 0x1F) << 3);
 491         mutex_unlock(&st->lock);
 492
 493         return ret ? ret : len;
 494 }
 495
 496 static struct attribute *ad7280_attributes[AD7280A_MAX_CHAIN *
 497                                            AD7280A_CELLS_PER_DEV * 2 + 1];
 498
 499 static const struct attribute_group ad7280_attrs_group = {
 500         .attrs = ad7280_attributes,
 501 };
 502
 503 static void ad7280_voltage_channel_init(struct iio_chan_spec *chan, int i)
 504 {
 505         chan->type = IIO_VOLTAGE;
 506         chan->differential = 1;
 507         chan->channel = i;
 508         chan->channel2 = chan->channel + 1;
 509 }
 510
 511 static void ad7280_temp_channel_init(struct iio_chan_spec *chan, int i)
 512 {
 513         chan->type = IIO_TEMP;
 514         chan->channel = i;
 515 }
 516
 517 static void ad7280_common_fields_init(struct iio_chan_spec *chan, int addr,
 518                                       int cnt)
 519 {
 520         chan->indexed = 1;
 521         chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
 522         chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
 523         chan->address = addr;
 524         chan->scan_index = cnt;
 525         chan->scan_type.sign = 'u';
 526         chan->scan_type.realbits = 12;
 527         chan->scan_type.storagebits = 32;
 528 }
 529
 530 static void ad7280_total_voltage_channel_init(struct iio_chan_spec *chan,
 531                                               int cnt, int dev)
 532 {
 533         chan->type = IIO_VOLTAGE;
 534         chan->differential = 1;
 535         chan->channel = 0;
 536         chan->channel2 = dev * AD7280A_CELLS_PER_DEV;
 537         chan->address = AD7280A_ALL_CELLS;
 538         chan->indexed = 1;
 539         chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
 540         chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
 541         chan->scan_index = cnt;
 542         chan->scan_type.sign = 'u';
 543         chan->scan_type.realbits = 32;
 544         chan->scan_type.storagebits = 32;
 545 }
 546
 547 static void ad7280_timestamp_channel_init(struct iio_chan_spec *chan, int cnt)
 548 {
 549         chan->type = IIO_TIMESTAMP;
 550         chan->channel = -1;
 551         chan->scan_index = cnt;
 552         chan->scan_type.sign = 's';
 553         chan->scan_type.realbits = 64;
 554         chan->scan_type.storagebits = 64;
 555 }
 556
 557 static void ad7280_init_dev_channels(struct ad7280_state *st, int dev, int *cnt)
 558 {
 559         int addr, ch, i;
 560         struct iio_chan_spec *chan;
 561
 562         for (ch = AD7280A_CELL_VOLTAGE_1; ch <= AD7280A_AUX_ADC_6; ch++) {
 563                 chan = &st->channels[*cnt];
 564
 565                 if (ch < AD7280A_AUX_ADC_1) {
 566                         i = AD7280A_CALC_VOLTAGE_CHAN_NUM(dev, ch);
 567                         ad7280_voltage_channel_init(chan, i);
 568                 } else {
 569                         i = AD7280A_CALC_TEMP_CHAN_NUM(dev, ch);
 570                         ad7280_temp_channel_init(chan, i);
 571                 }
 572
 573                 addr = ad7280a_devaddr(dev) << 8 | ch;
 574                 ad7280_common_fields_init(chan, addr, *cnt);
 575
 576                 (*cnt)++;
 577         }
 578 }
 579
 580 static int ad7280_channel_init(struct ad7280_state *st)
 581 {
 582         int dev, cnt = 0;
 583
 584         st->channels = devm_kcalloc(&st->spi->dev, (st->slave_num + 1) * 12 + 2,
 585                                     sizeof(*st->channels), GFP_KERNEL);
 586         if (!st->channels)
 587                 return -ENOMEM;
 588
 589         for (dev = 0; dev <= st->slave_num; dev++)
 590                 ad7280_init_dev_channels(st, dev, &cnt);
 591
 592         ad7280_total_voltage_channel_init(&st->channels[cnt], cnt, dev);
 593         cnt++;
 594         ad7280_timestamp_channel_init(&st->channels[cnt], cnt);
 595
 596         return cnt + 1;
 597 }
 598
 599 static int ad7280_balance_switch_attr_init(struct iio_dev_attr *attr,
 600                                            struct device *dev, int addr, int i)
 601 {
 602         attr->address = addr;
 603         attr->dev_attr.attr.mode = 0644;
 604         attr->dev_attr.show = ad7280_show_balance_sw;
 605         attr->dev_attr.store = ad7280_store_balance_sw;
 606         attr->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
 607                                                   "in%d-in%d_balance_switch_en",
 608                                                   i, i + 1);
 609         if (!attr->dev_attr.attr.name)
 610                 return -ENOMEM;
 611
 612         return 0;
 613 }
 614
 615 static int ad7280_balance_timer_attr_init(struct iio_dev_attr *attr,
 616                                           struct device *dev, int addr, int i)
 617 {
 618         attr->address = addr;
 619         attr->dev_attr.attr.mode = 0644;
 620         attr->dev_attr.show = ad7280_show_balance_timer;
 621         attr->dev_attr.store = ad7280_store_balance_timer;
 622         attr->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
 623                                                   "in%d-in%d_balance_timer",
 624                                                   i, i + 1);
 625         if (!attr->dev_attr.attr.name)
 626                 return -ENOMEM;
 627
 628         return 0;
 629 }
 630
 631 static int ad7280_init_dev_attrs(struct ad7280_state *st, int dev, int *cnt)
 632 {
 633         int addr, ch, i, ret;
 634         struct iio_dev_attr *iio_attr;
 635         struct device *sdev = &st->spi->dev;
 636
 637         for (ch = AD7280A_CELL_VOLTAGE_1; ch <= AD7280A_CELL_VOLTAGE_6; ch++) {
 638                 iio_attr = &st->iio_attr[*cnt];
 639                 addr = ad7280a_devaddr(dev) << 8 | ch;
 640                 i = dev * AD7280A_CELLS_PER_DEV + ch;
 641
 642                 ret = ad7280_balance_switch_attr_init(iio_attr, sdev, addr, i);
 643                 if (ret < 0)
 644                         return ret;
 645
 646                 ad7280_attributes[*cnt] = &iio_attr->dev_attr.attr;
 647
 648                 (*cnt)++;
 649                 iio_attr = &st->iio_attr[*cnt];
 650                 addr = ad7280a_devaddr(dev) << 8 | (AD7280A_CB1_TIMER + ch);
 651
 652                 ret = ad7280_balance_timer_attr_init(iio_attr, sdev, addr, i);
 653                 if (ret < 0)
 654                         return ret;
 655
 656                 ad7280_attributes[*cnt] = &iio_attr->dev_attr.attr;
 657                 (*cnt)++;
 658         }
 659
 660         ad7280_attributes[*cnt] = NULL;
 661
 662         return 0;
 663 }
 664
 665 static int ad7280_attr_init(struct ad7280_state *st)
 666 {
 667         int dev, cnt = 0, ret;
 668
 669         st->iio_attr = devm_kcalloc(&st->spi->dev, 2, sizeof(*st->iio_attr) *
 670                                     (st->slave_num + 1) * AD7280A_CELLS_PER_DEV,
 671                                     GFP_KERNEL);
 672         if (!st->iio_attr)
 673                 return -ENOMEM;
 674
 675         for (dev = 0; dev <= st->slave_num; dev++) {
 676                 ret = ad7280_init_dev_attrs(st, dev, &cnt);
 677                 if (ret < 0)
 678                         return ret;
 679         }
 680
 681         return 0;
 682 }
 683
 684 static ssize_t ad7280_read_channel_config(struct device *dev,
 685                                           struct device_attribute *attr,
 686                                           char *buf)
 687 {
 688         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 689         struct ad7280_state *st = iio_priv(indio_dev);
 690         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 691         unsigned int val;
 692
 693         switch (this_attr->address) {
 694         case AD7280A_CELL_OVERVOLTAGE:
 695                 val = 1000 + (st->cell_threshhigh * 1568) / 100;
 696                 break;
 697         case AD7280A_CELL_UNDERVOLTAGE:
 698                 val = 1000 + (st->cell_threshlow * 1568) / 100;
 699                 break;
 700         case AD7280A_AUX_ADC_OVERVOLTAGE:
 701                 val = (st->aux_threshhigh * 196) / 10;
 702                 break;
 703         case AD7280A_AUX_ADC_UNDERVOLTAGE:
 704                 val = (st->aux_threshlow * 196) / 10;
 705                 break;
 706         default:
 707                 return -EINVAL;
 708         }
 709
 710         return sprintf(buf, "%u\n", val);
 711 }
 712
 713 static ssize_t ad7280_write_channel_config(struct device *dev,
 714                                            struct device_attribute *attr,
 715                                            const char *buf,
 716                                            size_t len)
 717 {
 718         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 719         struct ad7280_state *st = iio_priv(indio_dev);
 720         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 721
 722         long val;
 723         int ret;
 724
 725         ret = kstrtol(buf, 10, &val);
 726         if (ret)
 727                 return ret;
 728
 729         switch (this_attr->address) {
 730         case AD7280A_CELL_OVERVOLTAGE:
 731         case AD7280A_CELL_UNDERVOLTAGE:
 732                 val = ((val - 1000) * 100) / 1568; /* LSB 15.68mV */
 733                 break;
 734         case AD7280A_AUX_ADC_OVERVOLTAGE:
 735         case AD7280A_AUX_ADC_UNDERVOLTAGE:
 736                 val = (val * 10) / 196; /* LSB 19.6mV */
 737                 break;
 738         default:
 739                 return -EFAULT;
 740         }
 741
 742         val = clamp(val, 0L, 0xFFL);
 743
 744         mutex_lock(&st->lock);
 745         switch (this_attr->address) {
 746         case AD7280A_CELL_OVERVOLTAGE:
 747                 st->cell_threshhigh = val;
 748                 break;
 749         case AD7280A_CELL_UNDERVOLTAGE:
 750                 st->cell_threshlow = val;
 751                 break;
 752         case AD7280A_AUX_ADC_OVERVOLTAGE:
 753                 st->aux_threshhigh = val;
 754                 break;
 755         case AD7280A_AUX_ADC_UNDERVOLTAGE:
 756                 st->aux_threshlow = val;
 757                 break;
 758         }
 759
 760         ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
 761                            this_attr->address, 1, val);
 762
 763         mutex_unlock(&st->lock);
 764
 765         return ret ? ret : len;
 766 }
 767
 768 static irqreturn_t ad7280_event_handler(int irq, void *private)
 769 {
 770         struct iio_dev *indio_dev = private;
 771         struct ad7280_state *st = iio_priv(indio_dev);
 772         unsigned int *channels;
 773         int i, ret;
 774
 775         channels = kcalloc(st->scan_cnt, sizeof(*channels), GFP_KERNEL);
 776         if (!channels)
 777                 return IRQ_HANDLED;
 778
 779         ret = ad7280_read_all_channels(st, st->scan_cnt, channels);
 780         if (ret < 0)
 781                 goto out;
 782
 783         for (i = 0; i < st->scan_cnt; i++) {
 784                 if (((channels[i] >> 23) & 0xF) <= AD7280A_CELL_VOLTAGE_6) {
 785                         if (((channels[i] >> 11) & 0xFFF) >=
 786                             st->cell_threshhigh) {
 787                                 u64 tmp = IIO_EVENT_CODE(IIO_VOLTAGE, 1, 0,
 788                                                          IIO_EV_DIR_RISING,
 789                                                          IIO_EV_TYPE_THRESH,
 790                                                          0, 0, 0);
 791                                 iio_push_event(indio_dev, tmp,
 792                                                iio_get_time_ns(indio_dev));
 793                         } else if (((channels[i] >> 11) & 0xFFF) <=
 794                                    st->cell_threshlow) {
 795                                 u64 tmp = IIO_EVENT_CODE(IIO_VOLTAGE, 1, 0,
 796                                                          IIO_EV_DIR_FALLING,
 797                                                          IIO_EV_TYPE_THRESH,
 798                                                          0, 0, 0);
 799                                 iio_push_event(indio_dev, tmp,
 800                                                iio_get_time_ns(indio_dev));
 801                         }
 802                 } else {
 803                         if (((channels[i] >> 11) & 0xFFF) >=
 804                             st->aux_threshhigh) {
 805                                 u64 tmp = IIO_UNMOD_EVENT_CODE(IIO_TEMP, 0,
 806                                                         IIO_EV_TYPE_THRESH,
 807                                                         IIO_EV_DIR_RISING);
 808                                 iio_push_event(indio_dev, tmp,
 809                                                iio_get_time_ns(indio_dev));
 810                         } else if (((channels[i] >> 11) & 0xFFF) <=
 811                                 st->aux_threshlow) {
 812                                 u64 tmp = IIO_UNMOD_EVENT_CODE(IIO_TEMP, 0,
 813                                                         IIO_EV_TYPE_THRESH,
 814                                                         IIO_EV_DIR_FALLING);
 815                                 iio_push_event(indio_dev, tmp,
 816                                                iio_get_time_ns(indio_dev));
 817                         }
 818                 }
 819         }
 820
 821 out:
 822         kfree(channels);
 823
 824         return IRQ_HANDLED;
 825 }
 826
 827 /* Note: No need to fix checkpatch warning that reads:
 828  *      CHECK: spaces preferred around that '-' (ctx:VxV)
 829  * The function argument is stringified and doesn't need a fix
 830  */
 831 static IIO_DEVICE_ATTR_NAMED(in_thresh_low_value,
 832                              in_voltage-voltage_thresh_low_value,
 833                              0644,
 834                              ad7280_read_channel_config,
 835                              ad7280_write_channel_config,
 836                              AD7280A_CELL_UNDERVOLTAGE);
 837
 838 static IIO_DEVICE_ATTR_NAMED(in_thresh_high_value,
 839                              in_voltage-voltage_thresh_high_value,
 840                              0644,
 841                              ad7280_read_channel_config,
 842                              ad7280_write_channel_config,
 843                              AD7280A_CELL_OVERVOLTAGE);
 844
 845 static IIO_DEVICE_ATTR(in_temp_thresh_low_value,
 846                        0644,
 847                        ad7280_read_channel_config,
 848                        ad7280_write_channel_config,
 849                        AD7280A_AUX_ADC_UNDERVOLTAGE);
 850
 851 static IIO_DEVICE_ATTR(in_temp_thresh_high_value,
 852                        0644,
 853                        ad7280_read_channel_config,
 854                        ad7280_write_channel_config,
 855                        AD7280A_AUX_ADC_OVERVOLTAGE);
 856
 857 static struct attribute *ad7280_event_attributes[] = {
 858         &iio_dev_attr_in_thresh_low_value.dev_attr.attr,
 859         &iio_dev_attr_in_thresh_high_value.dev_attr.attr,
 860         &iio_dev_attr_in_temp_thresh_low_value.dev_attr.attr,
 861         &iio_dev_attr_in_temp_thresh_high_value.dev_attr.attr,
 862         NULL,
 863 };
 864
 865 static const struct attribute_group ad7280_event_attrs_group = {
 866         .attrs = ad7280_event_attributes,
 867 };
 868
 869 static int ad7280_read_raw(struct iio_dev *indio_dev,
 870                            struct iio_chan_spec const *chan,
 871                            int *val,
 872                            int *val2,
 873                            long m)
 874 {
 875         struct ad7280_state *st = iio_priv(indio_dev);
 876         int ret;
 877
 878         switch (m) {
 879         case IIO_CHAN_INFO_RAW:
 880                 mutex_lock(&st->lock);
 881                 if (chan->address == AD7280A_ALL_CELLS)
 882                         ret = ad7280_read_all_channels(st, st->scan_cnt, NULL);
 883                 else
 884                         ret = ad7280_read_channel(st, chan->address >> 8,
 885                                                   chan->address & 0xFF);
 886                 mutex_unlock(&st->lock);
 887
 888                 if (ret < 0)
 889                         return ret;
 890
 891                 *val = ret;
 892
 893                 return IIO_VAL_INT;
 894         case IIO_CHAN_INFO_SCALE:
 895                 if ((chan->address & 0xFF) <= AD7280A_CELL_VOLTAGE_6)
 896                         *val = 4000;
 897                 else
 898                         *val = 5000;
 899
 900                 *val2 = AD7280A_BITS;
 901                 return IIO_VAL_FRACTIONAL_LOG2;
 902         }
 903         return -EINVAL;
 904 }
 905
 906 static const struct iio_info ad7280_info = {
 907         .read_raw = ad7280_read_raw,
 908         .event_attrs = &ad7280_event_attrs_group,
 909         .attrs = &ad7280_attrs_group,
 910 };
 911
 912 static const struct ad7280_platform_data ad7793_default_pdata = {
 913         .acquisition_time = AD7280A_ACQ_TIME_400ns,
 914         .conversion_averaging = AD7280A_CONV_AVG_DIS,
 915         .thermistor_term_en = true,
 916 };
 917
 918 static int ad7280_probe(struct spi_device *spi)
 919 {
 920         const struct ad7280_platform_data *pdata = dev_get_platdata(&spi->dev);
 921         struct ad7280_state *st;
 922         int ret;
 923         const unsigned short t_acq_ns[4] = {465, 1010, 1460, 1890};
 924         const unsigned short n_avg[4] = {1, 2, 4, 8};
 925         struct iio_dev *indio_dev;
 926
 927         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 928         if (!indio_dev)
 929                 return -ENOMEM;
 930
 931         st = iio_priv(indio_dev);
 932         spi_set_drvdata(spi, indio_dev);
 933         st->spi = spi;
 934         mutex_init(&st->lock);
 935
 936         if (!pdata)
 937                 pdata = &ad7793_default_pdata;
 938
 939         crc8_populate_msb(st->crc_tab, POLYNOM);
 940
 941         st->spi->max_speed_hz = AD7280A_MAX_SPI_CLK_HZ;
 942         st->spi->mode = SPI_MODE_1;
 943         spi_setup(st->spi);
 944
 945         st->ctrl_lb = AD7280A_CTRL_LB_ACQ_TIME(pdata->acquisition_time & 0x3);
 946         st->ctrl_hb = AD7280A_CTRL_HB_CONV_AVG(pdata->conversion_averaging
 947                         & 0x3) | (pdata->thermistor_term_en ?
 948                         AD7280A_CTRL_LB_THERMISTOR_EN : 0);
 949
 950         ret = ad7280_chain_setup(st);
 951         if (ret < 0)
 952                 return ret;
 953
 954         st->slave_num = ret;
 955         st->scan_cnt = (st->slave_num + 1) * AD7280A_NUM_CH;
 956         st->cell_threshhigh = 0xFF;
 957         st->aux_threshhigh = 0xFF;
 958
 959         ret = devm_add_action_or_reset(&spi->dev, ad7280_sw_power_down, st);
 960         if (ret)
 961                 return ret;
 962
 963         /*
 964          * Total Conversion Time = ((tACQ + tCONV) *
 965          *                         (Number of Conversions per Part)) −
 966          *                         tACQ + ((N - 1) * tDELAY)
 967          *
 968          * Readback Delay = Total Conversion Time + tWAIT
 969          */
 970
 971         st->readback_delay_us =
 972                 ((t_acq_ns[pdata->acquisition_time & 0x3] + 695) *
 973                  (AD7280A_NUM_CH * n_avg[pdata->conversion_averaging & 0x3])) -
 974                 t_acq_ns[pdata->acquisition_time & 0x3] + st->slave_num * 250;
 975
 976         /* Convert to usecs */
 977         st->readback_delay_us = DIV_ROUND_UP(st->readback_delay_us, 1000);
 978         st->readback_delay_us += 5; /* Add tWAIT */
 979
 980         indio_dev->name = spi_get_device_id(spi)->name;
 981         indio_dev->modes = INDIO_DIRECT_MODE;
 982
 983         ret = ad7280_channel_init(st);
 984         if (ret < 0)
 985                 return ret;
 986
 987         indio_dev->num_channels = ret;
 988         indio_dev->channels = st->channels;
 989         indio_dev->info = &ad7280_info;
 990
 991         ret = ad7280_attr_init(st);
 992         if (ret < 0)
 993                 return ret;
 994
 995         ret = devm_iio_device_register(&spi->dev, indio_dev);
 996         if (ret)
 997                 return ret;
 998
 999         if (spi->irq > 0) {
1000                 ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
1001                                    AD7280A_ALERT, 1,
1002                                    AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN);
1003                 if (ret)
1004                         return ret;
1005
1006                 ret = ad7280_write(st, ad7280a_devaddr(st->slave_num),
1007                                    AD7280A_ALERT, 0,
1008                                    AD7280A_ALERT_GEN_STATIC_HIGH |
1009                                    (pdata->chain_last_alert_ignore & 0xF));
1010                 if (ret)
1011                         return ret;
1012
1013                 ret = devm_request_threaded_irq(&spi->dev, spi->irq,
1014                                                 NULL,
1015                                                 ad7280_event_handler,
1016                                                 IRQF_TRIGGER_FALLING |
1017                                                 IRQF_ONESHOT,
1018                                                 indio_dev->name,
1019                                                 indio_dev);
1020                 if (ret)
1021                         return ret;
1022         }
1023
1024         return 0;
1025 }
1026
1027 static const struct spi_device_id ad7280_id[] = {
1028         {"ad7280a", 0},
1029         {}
1030 };
1031 MODULE_DEVICE_TABLE(spi, ad7280_id);
1032
1033 static struct spi_driver ad7280_driver = {
1034         .driver = {
1035                 .name   = "ad7280",
1036         },
1037         .probe          = ad7280_probe,
1038         .id_table       = ad7280_id,
1039 };
1040 module_spi_driver(ad7280_driver);
1041
1042 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
1043 MODULE_DESCRIPTION("Analog Devices AD7280A");
1044 MODULE_LICENSE("GPL v2");