linux/drivers/staging/iio/adc/ad7280a.c
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   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
 122struct 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
 141static 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
 158static 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
 168static 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
 186static 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
 194static 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
 214static 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
 226static 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
 264static 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
 302static 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
 339static 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
 381static 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
 394static 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
 426static 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
 449static 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
 478static struct attribute *ad7280_attributes[AD7280A_MAX_CHAIN *
 479                                           AD7280A_CELLS_PER_DEV * 2 + 1];
 480
 481static struct attribute_group ad7280_attrs_group = {
 482        .attrs = ad7280_attributes,
 483};
 484
 485static 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 == NULL)
 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; ch++,
 496                        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
 546static 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 == NULL)
 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, "in%d-in%d_balance_timer",
 586                                        (dev * AD7280A_CELLS_PER_DEV) + ch,
 587                                        (dev * AD7280A_CELLS_PER_DEV) + ch + 1);
 588                        ad7280_attributes[cnt] =
 589                                &st->iio_attr[cnt].dev_attr.attr;
 590                }
 591
 592        ad7280_attributes[cnt] = NULL;
 593
 594        return 0;
 595}
 596
 597static ssize_t ad7280_read_channel_config(struct device *dev,
 598                                        struct device_attribute *attr,
 599                                        char *buf)
 600{
 601        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 602        struct ad7280_state *st = iio_priv(indio_dev);
 603        struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 604        unsigned val;
 605
 606        switch ((u32) this_attr->address) {
 607        case AD7280A_CELL_OVERVOLTAGE:
 608                val = 1000 + (st->cell_threshhigh * 1568) / 100;
 609                break;
 610        case AD7280A_CELL_UNDERVOLTAGE:
 611                val = 1000 + (st->cell_threshlow * 1568) / 100;
 612                break;
 613        case AD7280A_AUX_ADC_OVERVOLTAGE:
 614                val = (st->aux_threshhigh * 196) / 10;
 615                break;
 616        case AD7280A_AUX_ADC_UNDERVOLTAGE:
 617                val = (st->aux_threshlow * 196) / 10;
 618                break;
 619        default:
 620                return -EINVAL;
 621        }
 622
 623        return sprintf(buf, "%u\n", val);
 624}
 625
 626static ssize_t ad7280_write_channel_config(struct device *dev,
 627                                         struct device_attribute *attr,
 628                                         const char *buf,
 629                                         size_t len)
 630{
 631        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 632        struct ad7280_state *st = iio_priv(indio_dev);
 633        struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 634
 635        long val;
 636        int ret;
 637
 638        ret = kstrtol(buf, 10, &val);
 639        if (ret)
 640                return ret;
 641
 642        switch ((u32) this_attr->address) {
 643        case AD7280A_CELL_OVERVOLTAGE:
 644        case AD7280A_CELL_UNDERVOLTAGE:
 645                val = ((val - 1000) * 100) / 1568; /* LSB 15.68mV */
 646                break;
 647        case AD7280A_AUX_ADC_OVERVOLTAGE:
 648        case AD7280A_AUX_ADC_UNDERVOLTAGE:
 649                val = (val * 10) / 196; /* LSB 19.6mV */
 650                break;
 651        default:
 652                return -EFAULT;
 653        }
 654
 655        val = clamp(val, 0L, 0xFFL);
 656
 657        mutex_lock(&indio_dev->mlock);
 658        switch ((u32) this_attr->address) {
 659        case AD7280A_CELL_OVERVOLTAGE:
 660                st->cell_threshhigh = val;
 661                break;
 662        case AD7280A_CELL_UNDERVOLTAGE:
 663                st->cell_threshlow = val;
 664                break;
 665        case AD7280A_AUX_ADC_OVERVOLTAGE:
 666                st->aux_threshhigh = val;
 667                break;
 668        case AD7280A_AUX_ADC_UNDERVOLTAGE:
 669                st->aux_threshlow = val;
 670                break;
 671        }
 672
 673        ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
 674                           this_attr->address, 1, val);
 675
 676        mutex_unlock(&indio_dev->mlock);
 677
 678        return ret ? ret : len;
 679}
 680
 681static irqreturn_t ad7280_event_handler(int irq, void *private)
 682{
 683        struct iio_dev *indio_dev = private;
 684        struct ad7280_state *st = iio_priv(indio_dev);
 685        unsigned *channels;
 686        int i, ret;
 687
 688        channels = kcalloc(st->scan_cnt, sizeof(*channels), GFP_KERNEL);
 689        if (channels == NULL)
 690                return IRQ_HANDLED;
 691
 692        ret = ad7280_read_all_channels(st, st->scan_cnt, channels);
 693        if (ret < 0)
 694                goto out;
 695
 696        for (i = 0; i < st->scan_cnt; i++) {
 697                if (((channels[i] >> 23) & 0xF) <= AD7280A_CELL_VOLTAGE_6) {
 698                        if (((channels[i] >> 11) & 0xFFF) >=
 699                                st->cell_threshhigh)
 700                                iio_push_event(indio_dev,
 701                                        IIO_EVENT_CODE(IIO_VOLTAGE,
 702                                                       1,
 703                                                       0,
 704                                                       IIO_EV_DIR_RISING,
 705                                                       IIO_EV_TYPE_THRESH,
 706                                                       0, 0, 0),
 707                                        iio_get_time_ns());
 708                        else if (((channels[i] >> 11) & 0xFFF) <=
 709                                st->cell_threshlow)
 710                                iio_push_event(indio_dev,
 711                                        IIO_EVENT_CODE(IIO_VOLTAGE,
 712                                                       1,
 713                                                       0,
 714                                                       IIO_EV_DIR_FALLING,
 715                                                       IIO_EV_TYPE_THRESH,
 716                                                       0, 0, 0),
 717                                        iio_get_time_ns());
 718                } else {
 719                        if (((channels[i] >> 11) & 0xFFF) >= st->aux_threshhigh)
 720                                iio_push_event(indio_dev,
 721                                        IIO_UNMOD_EVENT_CODE(IIO_TEMP,
 722                                        0,
 723                                        IIO_EV_TYPE_THRESH,
 724                                        IIO_EV_DIR_RISING),
 725                                        iio_get_time_ns());
 726                        else if (((channels[i] >> 11) & 0xFFF) <=
 727                                st->aux_threshlow)
 728                                iio_push_event(indio_dev,
 729                                        IIO_UNMOD_EVENT_CODE(IIO_TEMP,
 730                                        0,
 731                                        IIO_EV_TYPE_THRESH,
 732                                        IIO_EV_DIR_FALLING),
 733                                        iio_get_time_ns());
 734                }
 735        }
 736
 737out:
 738        kfree(channels);
 739
 740        return IRQ_HANDLED;
 741}
 742
 743static IIO_DEVICE_ATTR_NAMED(in_thresh_low_value,
 744                in_voltage-voltage_thresh_low_value,
 745                S_IRUGO | S_IWUSR,
 746                ad7280_read_channel_config,
 747                ad7280_write_channel_config,
 748                AD7280A_CELL_UNDERVOLTAGE);
 749
 750static IIO_DEVICE_ATTR_NAMED(in_thresh_high_value,
 751                in_voltage-voltage_thresh_high_value,
 752                S_IRUGO | S_IWUSR,
 753                ad7280_read_channel_config,
 754                ad7280_write_channel_config,
 755                AD7280A_CELL_OVERVOLTAGE);
 756
 757static IIO_DEVICE_ATTR(in_temp_thresh_low_value,
 758                S_IRUGO | S_IWUSR,
 759                ad7280_read_channel_config,
 760                ad7280_write_channel_config,
 761                AD7280A_AUX_ADC_UNDERVOLTAGE);
 762
 763static IIO_DEVICE_ATTR(in_temp_thresh_high_value,
 764                S_IRUGO | S_IWUSR,
 765                ad7280_read_channel_config,
 766                ad7280_write_channel_config,
 767                AD7280A_AUX_ADC_OVERVOLTAGE);
 768
 769
 770static struct attribute *ad7280_event_attributes[] = {
 771        &iio_dev_attr_in_thresh_low_value.dev_attr.attr,
 772        &iio_dev_attr_in_thresh_high_value.dev_attr.attr,
 773        &iio_dev_attr_in_temp_thresh_low_value.dev_attr.attr,
 774        &iio_dev_attr_in_temp_thresh_high_value.dev_attr.attr,
 775        NULL,
 776};
 777
 778static struct attribute_group ad7280_event_attrs_group = {
 779        .attrs = ad7280_event_attributes,
 780};
 781
 782static int ad7280_read_raw(struct iio_dev *indio_dev,
 783                           struct iio_chan_spec const *chan,
 784                           int *val,
 785                           int *val2,
 786                           long m)
 787{
 788        struct ad7280_state *st = iio_priv(indio_dev);
 789        int ret;
 790
 791        switch (m) {
 792        case IIO_CHAN_INFO_RAW:
 793                mutex_lock(&indio_dev->mlock);
 794                if (chan->address == AD7280A_ALL_CELLS)
 795                        ret = ad7280_read_all_channels(st, st->scan_cnt, NULL);
 796                else
 797                        ret = ad7280_read_channel(st, chan->address >> 8,
 798                                                  chan->address & 0xFF);
 799                mutex_unlock(&indio_dev->mlock);
 800
 801                if (ret < 0)
 802                        return ret;
 803
 804                *val = ret;
 805
 806                return IIO_VAL_INT;
 807        case IIO_CHAN_INFO_SCALE:
 808                if ((chan->address & 0xFF) <= AD7280A_CELL_VOLTAGE_6)
 809                        *val = 4000;
 810                else
 811                        *val = 5000;
 812
 813                *val2 = AD7280A_BITS;
 814                return IIO_VAL_FRACTIONAL_LOG2;
 815        }
 816        return -EINVAL;
 817}
 818
 819static const struct iio_info ad7280_info = {
 820        .read_raw = &ad7280_read_raw,
 821        .event_attrs = &ad7280_event_attrs_group,
 822        .attrs = &ad7280_attrs_group,
 823        .driver_module = THIS_MODULE,
 824};
 825
 826static const struct ad7280_platform_data ad7793_default_pdata = {
 827        .acquisition_time = AD7280A_ACQ_TIME_400ns,
 828        .conversion_averaging = AD7280A_CONV_AVG_DIS,
 829        .thermistor_term_en = true,
 830};
 831
 832static int ad7280_probe(struct spi_device *spi)
 833{
 834        const struct ad7280_platform_data *pdata = spi->dev.platform_data;
 835        struct ad7280_state *st;
 836        int ret;
 837        const unsigned short tACQ_ns[4] = {465, 1010, 1460, 1890};
 838        const unsigned short nAVG[4] = {1, 2, 4, 8};
 839        struct iio_dev *indio_dev;
 840
 841        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 842        if (indio_dev == NULL)
 843                return -ENOMEM;
 844
 845        st = iio_priv(indio_dev);
 846        spi_set_drvdata(spi, indio_dev);
 847        st->spi = spi;
 848
 849        if (!pdata)
 850                pdata = &ad7793_default_pdata;
 851
 852        ad7280_crc8_build_table(st->crc_tab);
 853
 854        st->spi->max_speed_hz = AD7280A_MAX_SPI_CLK_Hz;
 855        st->spi->mode = SPI_MODE_1;
 856        spi_setup(st->spi);
 857
 858        st->ctrl_lb = AD7280A_CTRL_LB_ACQ_TIME(pdata->acquisition_time & 0x3);
 859        st->ctrl_hb = AD7280A_CTRL_HB_CONV_AVG(pdata->conversion_averaging
 860                        & 0x3) | (pdata->thermistor_term_en ?
 861                        AD7280A_CTRL_LB_THERMISTOR_EN : 0);
 862
 863        ret = ad7280_chain_setup(st);
 864        if (ret < 0)
 865                return ret;
 866
 867        st->slave_num = ret;
 868        st->scan_cnt = (st->slave_num + 1) * AD7280A_NUM_CH;
 869        st->cell_threshhigh = 0xFF;
 870        st->aux_threshhigh = 0xFF;
 871
 872        /*
 873         * Total Conversion Time = ((tACQ + tCONV) *
 874         *                         (Number of Conversions per Part)) −
 875         *                         tACQ + ((N - 1) * tDELAY)
 876         *
 877         * Readback Delay = Total Conversion Time + tWAIT
 878         */
 879
 880        st->readback_delay_us =
 881                ((tACQ_ns[pdata->acquisition_time & 0x3] + 695) *
 882                (AD7280A_NUM_CH * nAVG[pdata->conversion_averaging & 0x3]))
 883                - tACQ_ns[pdata->acquisition_time & 0x3] +
 884                st->slave_num * 250;
 885
 886        /* Convert to usecs */
 887        st->readback_delay_us = DIV_ROUND_UP(st->readback_delay_us, 1000);
 888        st->readback_delay_us += 5; /* Add tWAIT */
 889
 890        indio_dev->name = spi_get_device_id(spi)->name;
 891        indio_dev->dev.parent = &spi->dev;
 892        indio_dev->modes = INDIO_DIRECT_MODE;
 893
 894        ret = ad7280_channel_init(st);
 895        if (ret < 0)
 896                return ret;
 897
 898        indio_dev->num_channels = ret;
 899        indio_dev->channels = st->channels;
 900        indio_dev->info = &ad7280_info;
 901
 902        ret = ad7280_attr_init(st);
 903        if (ret < 0)
 904                goto error_free_channels;
 905
 906        ret = iio_device_register(indio_dev);
 907        if (ret)
 908                goto error_free_attr;
 909
 910        if (spi->irq > 0) {
 911                ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
 912                                   AD7280A_ALERT, 1,
 913                                   AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN);
 914                if (ret)
 915                        goto error_unregister;
 916
 917                ret = ad7280_write(st, AD7280A_DEVADDR(st->slave_num),
 918                                   AD7280A_ALERT, 0,
 919                                   AD7280A_ALERT_GEN_STATIC_HIGH |
 920                                   (pdata->chain_last_alert_ignore & 0xF));
 921                if (ret)
 922                        goto error_unregister;
 923
 924                ret = request_threaded_irq(spi->irq,
 925                                           NULL,
 926                                           ad7280_event_handler,
 927                                           IRQF_TRIGGER_FALLING |
 928                                           IRQF_ONESHOT,
 929                                           indio_dev->name,
 930                                           indio_dev);
 931                if (ret)
 932                        goto error_unregister;
 933        }
 934
 935        return 0;
 936error_unregister:
 937        iio_device_unregister(indio_dev);
 938
 939error_free_attr:
 940        kfree(st->iio_attr);
 941
 942error_free_channels:
 943        kfree(st->channels);
 944
 945        return ret;
 946}
 947
 948static int ad7280_remove(struct spi_device *spi)
 949{
 950        struct iio_dev *indio_dev = spi_get_drvdata(spi);
 951        struct ad7280_state *st = iio_priv(indio_dev);
 952
 953        if (spi->irq > 0)
 954                free_irq(spi->irq, indio_dev);
 955        iio_device_unregister(indio_dev);
 956
 957        ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 958                        AD7280A_CTRL_HB_PWRDN_SW | st->ctrl_hb);
 959
 960        kfree(st->channels);
 961        kfree(st->iio_attr);
 962
 963        return 0;
 964}
 965
 966static const struct spi_device_id ad7280_id[] = {
 967        {"ad7280a", 0},
 968        {}
 969};
 970MODULE_DEVICE_TABLE(spi, ad7280_id);
 971
 972static struct spi_driver ad7280_driver = {
 973        .driver = {
 974                .name   = "ad7280",
 975                .owner  = THIS_MODULE,
 976        },
 977        .probe          = ad7280_probe,
 978        .remove         = ad7280_remove,
 979        .id_table       = ad7280_id,
 980};
 981module_spi_driver(ad7280_driver);
 982
 983MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 984MODULE_DESCRIPTION("Analog Devices AD7280A");
 985MODULE_LICENSE("GPL v2");
 986