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 "../iio.h"
  20#include "../sysfs.h"
  21#include "../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 << 6)
  59#define AD7280A_CTRL_HB_CONV_INPUT_6CELL_AUX1_3_4       (1 << 6)
  60#define AD7280A_CTRL_HB_CONV_INPUT_6CELL                (2 << 6)
  61#define AD7280A_CTRL_HB_CONV_INPUT_SELF_TEST            (3 << 6)
  62#define AD7280A_CTRL_HB_CONV_RES_READ_ALL               (0 << 4)
  63#define AD7280A_CTRL_HB_CONV_RES_READ_6CELL_AUX1_3_4    (1 << 4)
  64#define AD7280A_CTRL_HB_CONV_RES_READ_6CELL             (2 << 4)
  65#define AD7280A_CTRL_HB_CONV_RES_READ_NO                (3 << 4)
  66#define AD7280A_CTRL_HB_CONV_START_CNVST                (0 << 3)
  67#define AD7280A_CTRL_HB_CONV_START_CS                   (1 << 3)
  68#define AD7280A_CTRL_HB_CONV_AVG_DIS                    (0 << 1)
  69#define AD7280A_CTRL_HB_CONV_AVG_2                      (1 << 1)
  70#define AD7280A_CTRL_HB_CONV_AVG_4                      (2 << 1)
  71#define AD7280A_CTRL_HB_CONV_AVG_8                      (3 << 1)
  72#define AD7280A_CTRL_HB_CONV_AVG(x)                     ((x) << 1)
  73#define AD7280A_CTRL_HB_PWRDN_SW                        (1 << 0)
  74
  75#define AD7280A_CTRL_LB_SWRST                           (1 << 7)
  76#define AD7280A_CTRL_LB_ACQ_TIME_400ns                  (0 << 5)
  77#define AD7280A_CTRL_LB_ACQ_TIME_800ns                  (1 << 5)
  78#define AD7280A_CTRL_LB_ACQ_TIME_1200ns                 (2 << 5)
  79#define AD7280A_CTRL_LB_ACQ_TIME_1600ns                 (3 << 5)
  80#define AD7280A_CTRL_LB_ACQ_TIME(x)                     ((x) << 5)
  81#define AD7280A_CTRL_LB_MUST_SET                        (1 << 4)
  82#define AD7280A_CTRL_LB_THERMISTOR_EN                   (1 << 3)
  83#define AD7280A_CTRL_LB_LOCK_DEV_ADDR                   (1 << 2)
  84#define AD7280A_CTRL_LB_INC_DEV_ADDR                    (1 << 1)
  85#define AD7280A_CTRL_LB_DAISY_CHAIN_RB_EN               (1 << 0)
  86
  87#define AD7280A_ALERT_GEN_STATIC_HIGH                   (1 << 6)
  88#define AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN              (3 << 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
 139static void ad7280_crc8_build_table(unsigned char *crc_tab)
 140{
 141        unsigned char bit, crc;
 142        int cnt, i;
 143
 144        for (cnt = 0; cnt < 256; cnt++) {
 145                crc = cnt;
 146                for (i = 0; i < 8; i++) {
 147                        bit = crc & HIGHBIT;
 148                        crc <<= 1;
 149                        if (bit)
 150                                crc ^= POLYNOM;
 151                }
 152                crc_tab[cnt] = crc;
 153        }
 154}
 155
 156static unsigned char ad7280_calc_crc8(unsigned char *crc_tab, unsigned val)
 157{
 158        unsigned char crc;
 159
 160        crc = crc_tab[val >> 16 & 0xFF];
 161        crc = crc_tab[crc ^ (val >> 8 & 0xFF)];
 162
 163        return  crc ^ (val & 0xFF);
 164}
 165
 166static int ad7280_check_crc(struct ad7280_state *st, unsigned val)
 167{
 168        unsigned char crc = ad7280_calc_crc8(st->crc_tab, val >> 10);
 169
 170        if (crc != ((val >> 2) & 0xFF))
 171                return -EIO;
 172
 173        return 0;
 174}
 175
 176/* After initiating a conversion sequence we need to wait until the
 177 * conversion is done. The delay is typically in the range of 15..30 us
 178 * however depending an the number of devices in the daisy chain and the
 179 * number of averages taken, conversion delays and acquisition time options
 180 * it may take up to 250us, in this case we better sleep instead of busy
 181 * wait.
 182 */
 183
 184static void ad7280_delay(struct ad7280_state *st)
 185{
 186        if (st->readback_delay_us < 50)
 187                udelay(st->readback_delay_us);
 188        else
 189                msleep(1);
 190}
 191
 192static int __ad7280_read32(struct spi_device *spi, unsigned *val)
 193{
 194        unsigned rx_buf, tx_buf = cpu_to_be32(AD7280A_READ_TXVAL);
 195        int ret;
 196
 197        struct spi_transfer t = {
 198                .tx_buf = &tx_buf,
 199                .rx_buf = &rx_buf,
 200                .len = 4,
 201        };
 202        struct spi_message m;
 203
 204        spi_message_init(&m);
 205        spi_message_add_tail(&t, &m);
 206
 207        ret = spi_sync(spi, &m);
 208        if (ret)
 209                return ret;
 210
 211        *val = be32_to_cpu(rx_buf);
 212
 213        return 0;
 214}
 215
 216static int ad7280_write(struct ad7280_state *st, unsigned devaddr,
 217                        unsigned addr, bool all, unsigned val)
 218{
 219        unsigned reg = (devaddr << 27 | addr << 21 |
 220                        (val & 0xFF) << 13 | all << 12);
 221
 222        reg |= ad7280_calc_crc8(st->crc_tab, reg >> 11) << 3 | 0x2;
 223        reg = cpu_to_be32(reg);
 224
 225        return spi_write(st->spi, &reg, 4);
 226}
 227
 228static int ad7280_read(struct ad7280_state *st, unsigned devaddr,
 229                        unsigned addr)
 230{
 231        int ret;
 232        unsigned tmp;
 233
 234        /* turns off the read operation on all parts */
 235        ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 236                        AD7280A_CTRL_HB_CONV_INPUT_ALL |
 237                        AD7280A_CTRL_HB_CONV_RES_READ_NO |
 238                        st->ctrl_hb);
 239        if (ret)
 240                return ret;
 241
 242        /* turns on the read operation on the addressed part */
 243        ret = ad7280_write(st, devaddr, AD7280A_CONTROL_HB, 0,
 244                        AD7280A_CTRL_HB_CONV_INPUT_ALL |
 245                        AD7280A_CTRL_HB_CONV_RES_READ_ALL |
 246                        st->ctrl_hb);
 247        if (ret)
 248                return ret;
 249
 250        /* Set register address on the part to be read from */
 251        ret = ad7280_write(st, devaddr, AD7280A_READ, 0, addr << 2);
 252        if (ret)
 253                return ret;
 254
 255        __ad7280_read32(st->spi, &tmp);
 256
 257        if (ad7280_check_crc(st, tmp))
 258                return -EIO;
 259
 260        if (((tmp >> 27) != devaddr) || (((tmp >> 21) & 0x3F) != addr))
 261                return -EFAULT;
 262
 263        return (tmp >> 13) & 0xFF;
 264}
 265
 266static int ad7280_read_channel(struct ad7280_state *st, unsigned devaddr,
 267                               unsigned addr)
 268{
 269        int ret;
 270        unsigned tmp;
 271
 272        ret = ad7280_write(st, devaddr, AD7280A_READ, 0, addr << 2);
 273        if (ret)
 274                return ret;
 275
 276        ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 277                        AD7280A_CTRL_HB_CONV_INPUT_ALL |
 278                        AD7280A_CTRL_HB_CONV_RES_READ_NO |
 279                        st->ctrl_hb);
 280        if (ret)
 281                return ret;
 282
 283        ret = ad7280_write(st, devaddr, AD7280A_CONTROL_HB, 0,
 284                        AD7280A_CTRL_HB_CONV_INPUT_ALL |
 285                        AD7280A_CTRL_HB_CONV_RES_READ_ALL |
 286                        AD7280A_CTRL_HB_CONV_START_CS |
 287                        st->ctrl_hb);
 288        if (ret)
 289                return ret;
 290
 291        ad7280_delay(st);
 292
 293        __ad7280_read32(st->spi, &tmp);
 294
 295        if (ad7280_check_crc(st, tmp))
 296                return -EIO;
 297
 298        if (((tmp >> 27) != devaddr) || (((tmp >> 23) & 0xF) != addr))
 299                return -EFAULT;
 300
 301        return (tmp >> 11) & 0xFFF;
 302}
 303
 304static int ad7280_read_all_channels(struct ad7280_state *st, unsigned cnt,
 305                             unsigned *array)
 306{
 307        int i, ret;
 308        unsigned tmp, sum = 0;
 309
 310        ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ, 1,
 311                           AD7280A_CELL_VOLTAGE_1 << 2);
 312        if (ret)
 313                return ret;
 314
 315        ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
 316                        AD7280A_CTRL_HB_CONV_INPUT_ALL |
 317                        AD7280A_CTRL_HB_CONV_RES_READ_ALL |
 318                        AD7280A_CTRL_HB_CONV_START_CS |
 319                        st->ctrl_hb);
 320        if (ret)
 321                return ret;
 322
 323        ad7280_delay(st);
 324
 325        for (i = 0; i < cnt; i++) {
 326                __ad7280_read32(st->spi, &tmp);
 327
 328                if (ad7280_check_crc(st, tmp))
 329                        return -EIO;
 330
 331                if (array)
 332                        array[i] = tmp;
 333                /* only sum cell voltages */
 334                if (((tmp >> 23) & 0xF) <= AD7280A_CELL_VOLTAGE_6)
 335                        sum += ((tmp >> 11) & 0xFFF);
 336        }
 337
 338        return sum;
 339}
 340
 341static int ad7280_chain_setup(struct ad7280_state *st)
 342{
 343        unsigned val, n;
 344        int ret;
 345
 346        ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_LB, 1,
 347                        AD7280A_CTRL_LB_DAISY_CHAIN_RB_EN |
 348                        AD7280A_CTRL_LB_LOCK_DEV_ADDR |
 349                        AD7280A_CTRL_LB_MUST_SET |
 350                        AD7280A_CTRL_LB_SWRST |
 351                        st->ctrl_lb);
 352        if (ret)
 353                return ret;
 354
 355        ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_LB, 1,
 356                        AD7280A_CTRL_LB_DAISY_CHAIN_RB_EN |
 357                        AD7280A_CTRL_LB_LOCK_DEV_ADDR |
 358                        AD7280A_CTRL_LB_MUST_SET |
 359                        st->ctrl_lb);
 360        if (ret)
 361                return ret;
 362
 363        ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ, 1,
 364                        AD7280A_CONTROL_LB << 2);
 365        if (ret)
 366                return ret;
 367
 368        for (n = 0; n <= AD7280A_MAX_CHAIN; n++) {
 369                __ad7280_read32(st->spi, &val);
 370                if (val == 0)
 371                        return n - 1;
 372
 373                if (ad7280_check_crc(st, val))
 374                        return -EIO;
 375
 376                if (n != AD7280A_DEVADDR(val >> 27))
 377                        return -EIO;
 378        }
 379
 380        return -EFAULT;
 381}
 382
 383static ssize_t ad7280_show_balance_sw(struct device *dev,
 384                                        struct device_attribute *attr,
 385                                        char *buf)
 386{
 387        struct iio_dev *indio_dev = dev_get_drvdata(dev);
 388        struct ad7280_state *st = iio_priv(indio_dev);
 389        struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 390
 391        return sprintf(buf, "%d\n",
 392                       !!(st->cb_mask[this_attr->address >> 8] &
 393                       (1 << ((this_attr->address & 0xFF) + 2))));
 394}
 395
 396static ssize_t ad7280_store_balance_sw(struct device *dev,
 397                                         struct device_attribute *attr,
 398                                         const char *buf,
 399                                         size_t len)
 400{
 401        struct iio_dev *indio_dev = dev_get_drvdata(dev);
 402        struct ad7280_state *st = iio_priv(indio_dev);
 403        struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 404        bool readin;
 405        int ret;
 406        unsigned devaddr, ch;
 407
 408        ret = strtobool(buf, &readin);
 409        if (ret)
 410                return ret;
 411
 412        devaddr = this_attr->address >> 8;
 413        ch = this_attr->address & 0xFF;
 414
 415        mutex_lock(&indio_dev->mlock);
 416        if (readin)
 417                st->cb_mask[devaddr] |= 1 << (ch + 2);
 418        else
 419                st->cb_mask[devaddr] &= ~(1 << (ch + 2));
 420
 421        ret = ad7280_write(st, devaddr, AD7280A_CELL_BALANCE,
 422                           0, st->cb_mask[devaddr]);
 423        mutex_unlock(&indio_dev->mlock);
 424
 425        return ret ? ret : len;
 426}
 427
 428static ssize_t ad7280_show_balance_timer(struct device *dev,
 429                                        struct device_attribute *attr,
 430                                        char *buf)
 431{
 432        struct iio_dev *indio_dev = dev_get_drvdata(dev);
 433        struct ad7280_state *st = iio_priv(indio_dev);
 434        struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 435        int ret;
 436        unsigned msecs;
 437
 438        mutex_lock(&indio_dev->mlock);
 439        ret = ad7280_read(st, this_attr->address >> 8,
 440                        this_attr->address & 0xFF);
 441        mutex_unlock(&indio_dev->mlock);
 442
 443        if (ret < 0)
 444                return ret;
 445
 446        msecs = (ret >> 3) * 71500;
 447
 448        return sprintf(buf, "%d\n", msecs);
 449}
 450
 451static ssize_t ad7280_store_balance_timer(struct device *dev,
 452                                         struct device_attribute *attr,
 453                                         const char *buf,
 454                                         size_t len)
 455{
 456        struct iio_dev *indio_dev = dev_get_drvdata(dev);
 457        struct ad7280_state *st = iio_priv(indio_dev);
 458        struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 459        unsigned long val;
 460        int ret;
 461
 462        ret = kstrtoul(buf, 10, &val);
 463        if (ret)
 464                return ret;
 465
 466        val /= 71500;
 467
 468        if (val > 31)
 469                return -EINVAL;
 470
 471        mutex_lock(&indio_dev->mlock);
 472        ret = ad7280_write(st, this_attr->address >> 8,
 473                           this_attr->address & 0xFF,
 474                           0, (val & 0x1F) << 3);
 475        mutex_unlock(&indio_dev->mlock);
 476
 477        return ret ? ret : len;
 478}
 479
 480static struct attribute *ad7280_attributes[AD7280A_MAX_CHAIN *
 481                                           AD7280A_CELLS_PER_DEV * 2 + 1];
 482
 483static struct attribute_group ad7280_attrs_group = {
 484        .attrs = ad7280_attributes,
 485};
 486
 487static int ad7280_channel_init(struct ad7280_state *st)
 488{
 489        int dev, ch, cnt;
 490
 491        st->channels = kcalloc((st->slave_num + 1) * 12 + 2,
 492                               sizeof(*st->channels), GFP_KERNEL);
 493        if (st->channels == NULL)
 494                return -ENOMEM;
 495
 496        for (dev = 0, cnt = 0; dev <= st->slave_num; dev++)
 497                for (ch = AD7280A_CELL_VOLTAGE_1; ch <= AD7280A_AUX_ADC_6; ch++,
 498                        cnt++) {
 499                        if (ch < AD7280A_AUX_ADC_1) {
 500                                st->channels[cnt].type = IIO_VOLTAGE;
 501                                st->channels[cnt].differential = 1;
 502                                st->channels[cnt].channel = (dev * 6) + ch;
 503                                st->channels[cnt].channel2 =
 504                                        st->channels[cnt].channel + 1;
 505                        } else {
 506                                st->channels[cnt].type = IIO_TEMP;
 507                                st->channels[cnt].channel = (dev * 6) + ch - 6;
 508                        }
 509                        st->channels[cnt].indexed = 1;
 510                        st->channels[cnt].info_mask =
 511                                IIO_CHAN_INFO_SCALE_SHARED_BIT;
 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 = IIO_CHAN_INFO_SCALE_SHARED_BIT;
 528        st->channels[cnt].scan_index = cnt;
 529        st->channels[cnt].scan_type.sign = 'u';
 530        st->channels[cnt].scan_type.realbits = 32;
 531        st->channels[cnt].scan_type.storagebits = 32;
 532        st->channels[cnt].scan_type.shift = 0;
 533        cnt++;
 534        st->channels[cnt].type = IIO_TIMESTAMP;
 535        st->channels[cnt].channel = -1;
 536        st->channels[cnt].scan_index = cnt;
 537        st->channels[cnt].scan_type.sign = 's';
 538        st->channels[cnt].scan_type.realbits = 64;
 539        st->channels[cnt].scan_type.storagebits = 64;
 540        st->channels[cnt].scan_type.shift = 0;
 541
 542        return cnt + 1;
 543}
 544
 545static int ad7280_attr_init(struct ad7280_state *st)
 546{
 547        int dev, ch, cnt;
 548
 549        st->iio_attr = kzalloc(sizeof(*st->iio_attr) * (st->slave_num + 1) *
 550                                AD7280A_CELLS_PER_DEV * 2, GFP_KERNEL);
 551        if (st->iio_attr == NULL)
 552                return -ENOMEM;
 553
 554        for (dev = 0, cnt = 0; dev <= st->slave_num; dev++)
 555                for (ch = AD7280A_CELL_VOLTAGE_1; ch <= AD7280A_CELL_VOLTAGE_6;
 556                        ch++, cnt++) {
 557                        st->iio_attr[cnt].address =
 558                                AD7280A_DEVADDR(dev) << 8 | ch;
 559                        st->iio_attr[cnt].dev_attr.attr.mode =
 560                                S_IWUSR | S_IRUGO;
 561                        st->iio_attr[cnt].dev_attr.show =
 562                                ad7280_show_balance_sw;
 563                        st->iio_attr[cnt].dev_attr.store =
 564                                ad7280_store_balance_sw;
 565                        st->iio_attr[cnt].dev_attr.attr.name =
 566                                kasprintf(GFP_KERNEL,
 567                                        "in%d-in%d_balance_switch_en",
 568                                        (dev * AD7280A_CELLS_PER_DEV) + ch,
 569                                        (dev * AD7280A_CELLS_PER_DEV) + ch + 1);
 570                        ad7280_attributes[cnt] =
 571                                &st->iio_attr[cnt].dev_attr.attr;
 572                        cnt++;
 573                        st->iio_attr[cnt].address =
 574                                AD7280A_DEVADDR(dev) << 8 |
 575                                (AD7280A_CB1_TIMER + ch);
 576                        st->iio_attr[cnt].dev_attr.attr.mode =
 577                                S_IWUSR | S_IRUGO;
 578                        st->iio_attr[cnt].dev_attr.show =
 579                                ad7280_show_balance_timer;
 580                        st->iio_attr[cnt].dev_attr.store =
 581                                ad7280_store_balance_timer;
 582                        st->iio_attr[cnt].dev_attr.attr.name =
 583                                kasprintf(GFP_KERNEL, "in%d-in%d_balance_timer",
 584                                        (dev * AD7280A_CELLS_PER_DEV) + ch,
 585                                        (dev * AD7280A_CELLS_PER_DEV) + ch + 1);
 586                        ad7280_attributes[cnt] =
 587                                &st->iio_attr[cnt].dev_attr.attr;
 588                }
 589
 590        ad7280_attributes[cnt] = NULL;
 591
 592        return 0;
 593}
 594
 595static ssize_t ad7280_read_channel_config(struct device *dev,
 596                                        struct device_attribute *attr,
 597                                        char *buf)
 598{
 599        struct iio_dev *indio_dev = dev_get_drvdata(dev);
 600        struct ad7280_state *st = iio_priv(indio_dev);
 601        struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 602        unsigned val;
 603
 604        switch ((u32) this_attr->address) {
 605        case AD7280A_CELL_OVERVOLTAGE:
 606                val = 1000 + (st->cell_threshhigh * 1568) / 100;
 607                break;
 608        case AD7280A_CELL_UNDERVOLTAGE:
 609                val = 1000 + (st->cell_threshlow * 1568) / 100;
 610                break;
 611        case AD7280A_AUX_ADC_OVERVOLTAGE:
 612                val = (st->aux_threshhigh * 196) / 10;
 613                break;
 614        case AD7280A_AUX_ADC_UNDERVOLTAGE:
 615                val = (st->aux_threshlow * 196) / 10;
 616                break;
 617        default:
 618                return -EINVAL;
 619        }
 620
 621        return sprintf(buf, "%d\n", val);
 622}
 623
 624static ssize_t ad7280_write_channel_config(struct device *dev,
 625                                         struct device_attribute *attr,
 626                                         const char *buf,
 627                                         size_t len)
 628{
 629        struct iio_dev *indio_dev = dev_get_drvdata(dev);
 630        struct ad7280_state *st = iio_priv(indio_dev);
 631        struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 632
 633        long val;
 634        int ret;
 635
 636        ret = strict_strtol(buf, 10, &val);
 637        if (ret)
 638                return ret;
 639
 640        switch ((u32) this_attr->address) {
 641        case AD7280A_CELL_OVERVOLTAGE:
 642        case AD7280A_CELL_UNDERVOLTAGE:
 643                val = ((val - 1000) * 100) / 1568; /* LSB 15.68mV */
 644                break;
 645        case AD7280A_AUX_ADC_OVERVOLTAGE:
 646        case AD7280A_AUX_ADC_UNDERVOLTAGE:
 647                val = (val * 10) / 196; /* LSB 19.6mV */
 648                break;
 649        default:
 650                return -EFAULT;
 651        }
 652
 653        val = clamp(val, 0L, 0xFFL);
 654
 655        mutex_lock(&indio_dev->mlock);
 656        switch ((u32) this_attr->address) {
 657        case AD7280A_CELL_OVERVOLTAGE:
 658                st->cell_threshhigh = val;
 659                break;
 660        case AD7280A_CELL_UNDERVOLTAGE:
 661                st->cell_threshlow = val;
 662                break;
 663        case AD7280A_AUX_ADC_OVERVOLTAGE:
 664                st->aux_threshhigh = val;
 665                break;
 666        case AD7280A_AUX_ADC_UNDERVOLTAGE:
 667                st->aux_threshlow = val;
 668                break;
 669        }
 670
 671        ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
 672                           this_attr->address, 1, val);
 673
 674        mutex_unlock(&indio_dev->mlock);
 675
 676        return ret ? ret : len;
 677}
 678
 679static irqreturn_t ad7280_event_handler(int irq, void *private)
 680{
 681        struct iio_dev *indio_dev = private;
 682        struct ad7280_state *st = iio_priv(indio_dev);
 683        unsigned *channels;
 684        int i, ret;
 685
 686        channels = kcalloc(st->scan_cnt, sizeof(*channels), GFP_KERNEL);
 687        if (channels == NULL)
 688                return IRQ_HANDLED;
 689
 690        ret = ad7280_read_all_channels(st, st->scan_cnt, channels);
 691        if (ret < 0)
 692                goto out;
 693
 694        for (i = 0; i < st->scan_cnt; i++) {
 695                if (((channels[i] >> 23) & 0xF) <= AD7280A_CELL_VOLTAGE_6) {
 696                        if (((channels[i] >> 11) & 0xFFF) >=
 697                                st->cell_threshhigh)
 698                                iio_push_event(indio_dev,
 699                                        IIO_EVENT_CODE(IIO_VOLTAGE,
 700                                                       1,
 701                                                       0,
 702                                                       IIO_EV_DIR_RISING,
 703                                                       IIO_EV_TYPE_THRESH,
 704                                                       0, 0, 0),
 705                                        iio_get_time_ns());
 706                        else if (((channels[i] >> 11) & 0xFFF) <=
 707                                st->cell_threshlow)
 708                                iio_push_event(indio_dev,
 709                                        IIO_EVENT_CODE(IIO_VOLTAGE,
 710                                                       1,
 711                                                       0,
 712                                                       IIO_EV_DIR_FALLING,
 713                                                       IIO_EV_TYPE_THRESH,
 714                                                       0, 0, 0),
 715                                        iio_get_time_ns());
 716                } else {
 717                        if (((channels[i] >> 11) & 0xFFF) >= st->aux_threshhigh)
 718                                iio_push_event(indio_dev,
 719                                        IIO_UNMOD_EVENT_CODE(IIO_TEMP,
 720                                        0,
 721                                        IIO_EV_TYPE_THRESH,
 722                                        IIO_EV_DIR_RISING),
 723                                        iio_get_time_ns());
 724                        else if (((channels[i] >> 11) & 0xFFF) <=
 725                                st->aux_threshlow)
 726                                iio_push_event(indio_dev,
 727                                        IIO_UNMOD_EVENT_CODE(IIO_TEMP,
 728                                        0,
 729                                        IIO_EV_TYPE_THRESH,
 730                                        IIO_EV_DIR_FALLING),
 731                                        iio_get_time_ns());
 732                }
 733        }
 734
 735out:
 736        kfree(channels);
 737
 738        return IRQ_HANDLED;
 739}
 740
 741static IIO_DEVICE_ATTR_NAMED(in_thresh_low_value,
 742                in_voltage-voltage_thresh_low_value,
 743                S_IRUGO | S_IWUSR,
 744                ad7280_read_channel_config,
 745                ad7280_write_channel_config,
 746                AD7280A_CELL_UNDERVOLTAGE);
 747
 748static IIO_DEVICE_ATTR_NAMED(in_thresh_high_value,
 749                in_voltage-voltage_thresh_high_value,
 750                S_IRUGO | S_IWUSR,
 751                ad7280_read_channel_config,
 752                ad7280_write_channel_config,
 753                AD7280A_CELL_OVERVOLTAGE);
 754
 755static IIO_DEVICE_ATTR(in_temp_thresh_low_value,
 756                S_IRUGO | S_IWUSR,
 757                ad7280_read_channel_config,
 758                ad7280_write_channel_config,
 759                AD7280A_AUX_ADC_UNDERVOLTAGE);
 760
 761static IIO_DEVICE_ATTR(in_temp_thresh_high_value,
 762                S_IRUGO | S_IWUSR,
 763                ad7280_read_channel_config,
 764                ad7280_write_channel_config,
 765                AD7280A_AUX_ADC_OVERVOLTAGE);
 766
 767
 768static struct attribute *ad7280_event_attributes[] = {
 769        &iio_dev_attr_in_thresh_low_value.dev_attr.attr,
 770        &iio_dev_attr_in_thresh_high_value.dev_attr.attr,
 771        &iio_dev_attr_in_temp_thresh_low_value.dev_attr.attr,
 772        &iio_dev_attr_in_temp_thresh_high_value.dev_attr.attr,
 773        NULL,
 774};
 775
 776static struct attribute_group ad7280_event_attrs_group = {
 777        .attrs = ad7280_event_attributes,
 778};
 779
 780static int ad7280_read_raw(struct iio_dev *indio_dev,
 781                           struct iio_chan_spec const *chan,
 782                           int *val,
 783                           int *val2,
 784                           long m)
 785{
 786        struct ad7280_state *st = iio_priv(indio_dev);
 787        unsigned int scale_uv;
 788        int ret;
 789
 790        switch (m) {
 791        case 0:
 792                mutex_lock(&indio_dev->mlock);
 793                if (chan->address == AD7280A_ALL_CELLS)
 794                        ret = ad7280_read_all_channels(st, st->scan_cnt, NULL);
 795                else
 796                        ret = ad7280_read_channel(st, chan->address >> 8,
 797                                                  chan->address & 0xFF);
 798                mutex_unlock(&indio_dev->mlock);
 799
 800                if (ret < 0)
 801                        return ret;
 802
 803                *val = ret;
 804
 805                return IIO_VAL_INT;
 806        case IIO_CHAN_INFO_SCALE:
 807                if ((chan->address & 0xFF) <= AD7280A_CELL_VOLTAGE_6)
 808                        scale_uv = (4000 * 1000) >> AD7280A_BITS;
 809                else
 810                        scale_uv = (5000 * 1000) >> AD7280A_BITS;
 811
 812                *val =  scale_uv / 1000;
 813                *val2 = (scale_uv % 1000) * 1000;
 814                return IIO_VAL_INT_PLUS_MICRO;
 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 __devinit 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 = iio_allocate_device(sizeof(*st));
 840
 841        if (indio_dev == NULL)
 842                return -ENOMEM;
 843
 844        st = iio_priv(indio_dev);
 845        spi_set_drvdata(spi, indio_dev);
 846        st->spi = spi;
 847
 848        if (!pdata)
 849                pdata = &ad7793_default_pdata;
 850
 851        ad7280_crc8_build_table(st->crc_tab);
 852
 853        st->spi->max_speed_hz = AD7280A_MAX_SPI_CLK_Hz;
 854        st->spi->mode = SPI_MODE_1;
 855        spi_setup(st->spi);
 856
 857        st->ctrl_lb = AD7280A_CTRL_LB_ACQ_TIME(pdata->acquisition_time & 0x3);
 858        st->ctrl_hb = AD7280A_CTRL_HB_CONV_AVG(pdata->conversion_averaging
 859                        & 0x3) | (pdata->thermistor_term_en ?
 860                        AD7280A_CTRL_LB_THERMISTOR_EN : 0);
 861
 862        ret = ad7280_chain_setup(st);
 863        if (ret < 0)
 864                goto error_free_device;
 865
 866        st->slave_num = ret;
 867        st->scan_cnt = (st->slave_num + 1) * AD7280A_NUM_CH;
 868        st->cell_threshhigh = 0xFF;
 869        st->aux_threshhigh = 0xFF;
 870
 871        /*
 872         * Total Conversion Time = ((tACQ + tCONV) *
 873         *                         (Number of Conversions per Part)) −
 874         *                         tACQ + ((N - 1) * tDELAY)
 875         *
 876         * Readback Delay = Total Conversion Time + tWAIT
 877         */
 878
 879        st->readback_delay_us =
 880                ((tACQ_ns[pdata->acquisition_time & 0x3] + 695) *
 881                (AD7280A_NUM_CH * nAVG[pdata->conversion_averaging & 0x3]))
 882                - tACQ_ns[pdata->acquisition_time & 0x3] +
 883                st->slave_num * 250;
 884
 885        /* Convert to usecs */
 886        st->readback_delay_us = DIV_ROUND_UP(st->readback_delay_us, 1000);
 887        st->readback_delay_us += 5; /* Add tWAIT */
 888
 889        indio_dev->name = spi_get_device_id(spi)->name;
 890        indio_dev->dev.parent = &spi->dev;
 891        indio_dev->modes = INDIO_DIRECT_MODE;
 892
 893        ret = ad7280_channel_init(st);
 894        if (ret < 0)
 895                goto error_free_device;
 896
 897        indio_dev->num_channels = ret;
 898        indio_dev->channels = st->channels;
 899        indio_dev->info = &ad7280_info;
 900
 901        ret = ad7280_attr_init(st);
 902        if (ret < 0)
 903                goto error_free_channels;
 904
 905        ret = iio_device_register(indio_dev);
 906        if (ret)
 907                goto error_free_attr;
 908
 909        if (spi->irq > 0) {
 910                ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
 911                                   AD7280A_ALERT, 1,
 912                                   AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN);
 913                if (ret)
 914                        goto error_unregister;
 915
 916                ret = ad7280_write(st, AD7280A_DEVADDR(st->slave_num),
 917                                   AD7280A_ALERT, 0,
 918                                   AD7280A_ALERT_GEN_STATIC_HIGH |
 919                                   (pdata->chain_last_alert_ignore & 0xF));
 920                if (ret)
 921                        goto error_unregister;
 922
 923                ret = request_threaded_irq(spi->irq,
 924                                           NULL,
 925                                           ad7280_event_handler,
 926                                           IRQF_TRIGGER_FALLING |
 927                                           IRQF_ONESHOT,
 928                                           indio_dev->name,
 929                                           indio_dev);
 930                if (ret)
 931                        goto error_unregister;
 932        }
 933
 934        return 0;
 935error_unregister:
 936        iio_device_unregister(indio_dev);
 937
 938error_free_attr:
 939        kfree(st->iio_attr);
 940
 941error_free_channels:
 942        kfree(st->channels);
 943
 944error_free_device:
 945        iio_free_device(indio_dev);
 946
 947        return ret;
 948}
 949
 950static int __devexit 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        iio_free_device(indio_dev);
 965
 966        return 0;
 967}
 968
 969static const struct spi_device_id ad7280_id[] = {
 970        {"ad7280a", 0},
 971        {}
 972};
 973MODULE_DEVICE_TABLE(spi, ad7280_id);
 974
 975static struct spi_driver ad7280_driver = {
 976        .driver = {
 977                .name   = "ad7280",
 978                .owner  = THIS_MODULE,
 979        },
 980        .probe          = ad7280_probe,
 981        .remove         = __devexit_p(ad7280_remove),
 982        .id_table       = ad7280_id,
 983};
 984module_spi_driver(ad7280_driver);
 985
 986MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 987MODULE_DESCRIPTION("Analog Devices AD7280A");
 988MODULE_LICENSE("GPL v2");
 989
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