linux/drivers/rtc/rtc-isl1208.c
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   1/*
   2 * Intersil ISL1208 rtc class driver
   3 *
   4 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
   5 *
   6 *  This program is free software; you can redistribute  it and/or modify it
   7 *  under  the terms of  the GNU General  Public License as published by the
   8 *  Free Software Foundation;  either version 2 of the  License, or (at your
   9 *  option) any later version.
  10 *
  11 */
  12
  13#include <linux/module.h>
  14#include <linux/i2c.h>
  15#include <linux/bcd.h>
  16#include <linux/rtc.h>
  17
  18#define DRV_VERSION "0.3"
  19
  20/* Register map */
  21/* rtc section */
  22#define ISL1208_REG_SC  0x00
  23#define ISL1208_REG_MN  0x01
  24#define ISL1208_REG_HR  0x02
  25#define ISL1208_REG_HR_MIL     (1<<7)   /* 24h/12h mode */
  26#define ISL1208_REG_HR_PM      (1<<5)   /* PM/AM bit in 12h mode */
  27#define ISL1208_REG_DT  0x03
  28#define ISL1208_REG_MO  0x04
  29#define ISL1208_REG_YR  0x05
  30#define ISL1208_REG_DW  0x06
  31#define ISL1208_RTC_SECTION_LEN 7
  32
  33/* control/status section */
  34#define ISL1208_REG_SR  0x07
  35#define ISL1208_REG_SR_ARST    (1<<7)   /* auto reset */
  36#define ISL1208_REG_SR_XTOSCB  (1<<6)   /* crystal oscillator */
  37#define ISL1208_REG_SR_WRTC    (1<<4)   /* write rtc */
  38#define ISL1208_REG_SR_ALM     (1<<2)   /* alarm */
  39#define ISL1208_REG_SR_BAT     (1<<1)   /* battery */
  40#define ISL1208_REG_SR_RTCF    (1<<0)   /* rtc fail */
  41#define ISL1208_REG_INT 0x08
  42#define ISL1208_REG_INT_ALME   (1<<6)   /* alarm enable */
  43#define ISL1208_REG_INT_IM     (1<<7)   /* interrupt/alarm mode */
  44#define ISL1208_REG_09  0x09    /* reserved */
  45#define ISL1208_REG_ATR 0x0a
  46#define ISL1208_REG_DTR 0x0b
  47
  48/* alarm section */
  49#define ISL1208_REG_SCA 0x0c
  50#define ISL1208_REG_MNA 0x0d
  51#define ISL1208_REG_HRA 0x0e
  52#define ISL1208_REG_DTA 0x0f
  53#define ISL1208_REG_MOA 0x10
  54#define ISL1208_REG_DWA 0x11
  55#define ISL1208_ALARM_SECTION_LEN 6
  56
  57/* user section */
  58#define ISL1208_REG_USR1 0x12
  59#define ISL1208_REG_USR2 0x13
  60#define ISL1208_USR_SECTION_LEN 2
  61
  62static struct i2c_driver isl1208_driver;
  63
  64/* block read */
  65static int
  66isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
  67                      unsigned len)
  68{
  69        u8 reg_addr[1] = { reg };
  70        struct i2c_msg msgs[2] = {
  71                {client->addr, 0, sizeof(reg_addr), reg_addr}
  72                ,
  73                {client->addr, I2C_M_RD, len, buf}
  74        };
  75        int ret;
  76
  77        BUG_ON(reg > ISL1208_REG_USR2);
  78        BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
  79
  80        ret = i2c_transfer(client->adapter, msgs, 2);
  81        if (ret > 0)
  82                ret = 0;
  83        return ret;
  84}
  85
  86/* block write */
  87static int
  88isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
  89                     unsigned len)
  90{
  91        u8 i2c_buf[ISL1208_REG_USR2 + 2];
  92        struct i2c_msg msgs[1] = {
  93                {client->addr, 0, len + 1, i2c_buf}
  94        };
  95        int ret;
  96
  97        BUG_ON(reg > ISL1208_REG_USR2);
  98        BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
  99
 100        i2c_buf[0] = reg;
 101        memcpy(&i2c_buf[1], &buf[0], len);
 102
 103        ret = i2c_transfer(client->adapter, msgs, 1);
 104        if (ret > 0)
 105                ret = 0;
 106        return ret;
 107}
 108
 109/* simple check to see wether we have a isl1208 */
 110static int
 111isl1208_i2c_validate_client(struct i2c_client *client)
 112{
 113        u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
 114        u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
 115                0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
 116        };
 117        int i;
 118        int ret;
 119
 120        ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
 121        if (ret < 0)
 122                return ret;
 123
 124        for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
 125                if (regs[i] & zero_mask[i])     /* check if bits are cleared */
 126                        return -ENODEV;
 127        }
 128
 129        return 0;
 130}
 131
 132static int
 133isl1208_i2c_get_sr(struct i2c_client *client)
 134{
 135        int sr = i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
 136        if (sr < 0)
 137                return -EIO;
 138
 139        return sr;
 140}
 141
 142static int
 143isl1208_i2c_get_atr(struct i2c_client *client)
 144{
 145        int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
 146        if (atr < 0)
 147                return atr;
 148
 149        /* The 6bit value in the ATR register controls the load
 150         * capacitance C_load * in steps of 0.25pF
 151         *
 152         * bit (1<<5) of the ATR register is inverted
 153         *
 154         * C_load(ATR=0x20) =  4.50pF
 155         * C_load(ATR=0x00) = 12.50pF
 156         * C_load(ATR=0x1f) = 20.25pF
 157         *
 158         */
 159
 160        atr &= 0x3f;            /* mask out lsb */
 161        atr ^= 1 << 5;          /* invert 6th bit */
 162        atr += 2 * 9;           /* add offset of 4.5pF; unit[atr] = 0.25pF */
 163
 164        return atr;
 165}
 166
 167static int
 168isl1208_i2c_get_dtr(struct i2c_client *client)
 169{
 170        int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
 171        if (dtr < 0)
 172                return -EIO;
 173
 174        /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
 175        dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
 176
 177        return dtr;
 178}
 179
 180static int
 181isl1208_i2c_get_usr(struct i2c_client *client)
 182{
 183        u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
 184        int ret;
 185
 186        ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
 187                                    ISL1208_USR_SECTION_LEN);
 188        if (ret < 0)
 189                return ret;
 190
 191        return (buf[1] << 8) | buf[0];
 192}
 193
 194static int
 195isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
 196{
 197        u8 buf[ISL1208_USR_SECTION_LEN];
 198
 199        buf[0] = usr & 0xff;
 200        buf[1] = (usr >> 8) & 0xff;
 201
 202        return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
 203                                    ISL1208_USR_SECTION_LEN);
 204}
 205
 206static int
 207isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
 208{
 209        int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
 210
 211        if (icr < 0) {
 212                dev_err(&client->dev, "%s: reading INT failed\n", __func__);
 213                return icr;
 214        }
 215
 216        if (enable)
 217                icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
 218        else
 219                icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
 220
 221        icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
 222        if (icr < 0) {
 223                dev_err(&client->dev, "%s: writing INT failed\n", __func__);
 224                return icr;
 225        }
 226
 227        return 0;
 228}
 229
 230static int
 231isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
 232{
 233        struct i2c_client *const client = to_i2c_client(dev);
 234        int sr, dtr, atr, usr;
 235
 236        sr = isl1208_i2c_get_sr(client);
 237        if (sr < 0) {
 238                dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 239                return sr;
 240        }
 241
 242        seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
 243                   (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
 244                   (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
 245                   (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
 246                   (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
 247                   (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
 248                   (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
 249
 250        seq_printf(seq, "batt_status\t: %s\n",
 251                   (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
 252
 253        dtr = isl1208_i2c_get_dtr(client);
 254        if (dtr >= 0 - 1)
 255                seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);
 256
 257        atr = isl1208_i2c_get_atr(client);
 258        if (atr >= 0)
 259                seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
 260                           atr >> 2, (atr & 0x3) * 25);
 261
 262        usr = isl1208_i2c_get_usr(client);
 263        if (usr >= 0)
 264                seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
 265
 266        return 0;
 267}
 268
 269static int
 270isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
 271{
 272        int sr;
 273        u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
 274
 275        sr = isl1208_i2c_get_sr(client);
 276        if (sr < 0) {
 277                dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 278                return -EIO;
 279        }
 280
 281        sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
 282        if (sr < 0) {
 283                dev_err(&client->dev, "%s: reading RTC section failed\n",
 284                        __func__);
 285                return sr;
 286        }
 287
 288        tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]);
 289        tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]);
 290
 291        /* HR field has a more complex interpretation */
 292        {
 293                const u8 _hr = regs[ISL1208_REG_HR];
 294                if (_hr & ISL1208_REG_HR_MIL)   /* 24h format */
 295                        tm->tm_hour = bcd2bin(_hr & 0x3f);
 296                else {
 297                        /* 12h format */
 298                        tm->tm_hour = bcd2bin(_hr & 0x1f);
 299                        if (_hr & ISL1208_REG_HR_PM)    /* PM flag set */
 300                                tm->tm_hour += 12;
 301                }
 302        }
 303
 304        tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]);
 305        tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
 306        tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100;
 307        tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]);
 308
 309        return 0;
 310}
 311
 312static int
 313isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
 314{
 315        struct rtc_time *const tm = &alarm->time;
 316        u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
 317        int icr, yr, sr = isl1208_i2c_get_sr(client);
 318
 319        if (sr < 0) {
 320                dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 321                return sr;
 322        }
 323
 324        sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
 325                                   ISL1208_ALARM_SECTION_LEN);
 326        if (sr < 0) {
 327                dev_err(&client->dev, "%s: reading alarm section failed\n",
 328                        __func__);
 329                return sr;
 330        }
 331
 332        /* MSB of each alarm register is an enable bit */
 333        tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
 334        tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
 335        tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
 336        tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
 337        tm->tm_mon =
 338                bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
 339        tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
 340
 341        /* The alarm doesn't store the year so get it from the rtc section */
 342        yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
 343        if (yr < 0) {
 344                dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
 345                return yr;
 346        }
 347        tm->tm_year = bcd2bin(yr) + 100;
 348
 349        icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
 350        if (icr < 0) {
 351                dev_err(&client->dev, "%s: reading INT failed\n", __func__);
 352                return icr;
 353        }
 354        alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
 355
 356        return 0;
 357}
 358
 359static int
 360isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
 361{
 362        struct rtc_time *alarm_tm = &alarm->time;
 363        u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
 364        const int offs = ISL1208_REG_SCA;
 365        unsigned long rtc_secs, alarm_secs;
 366        struct rtc_time rtc_tm;
 367        int err, enable;
 368
 369        err = isl1208_i2c_read_time(client, &rtc_tm);
 370        if (err)
 371                return err;
 372        err = rtc_tm_to_time(&rtc_tm, &rtc_secs);
 373        if (err)
 374                return err;
 375        err = rtc_tm_to_time(alarm_tm, &alarm_secs);
 376        if (err)
 377                return err;
 378
 379        /* If the alarm time is before the current time disable the alarm */
 380        if (!alarm->enabled || alarm_secs <= rtc_secs)
 381                enable = 0x00;
 382        else
 383                enable = 0x80;
 384
 385        /* Program the alarm and enable it for each setting */
 386        regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
 387        regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
 388        regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
 389                ISL1208_REG_HR_MIL | enable;
 390
 391        regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
 392        regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
 393        regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
 394
 395        /* write ALARM registers */
 396        err = isl1208_i2c_set_regs(client, offs, regs,
 397                                  ISL1208_ALARM_SECTION_LEN);
 398        if (err < 0) {
 399                dev_err(&client->dev, "%s: writing ALARM section failed\n",
 400                        __func__);
 401                return err;
 402        }
 403
 404        err = isl1208_rtc_toggle_alarm(client, enable);
 405        if (err)
 406                return err;
 407
 408        return 0;
 409}
 410
 411static int
 412isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
 413{
 414        return isl1208_i2c_read_time(to_i2c_client(dev), tm);
 415}
 416
 417static int
 418isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
 419{
 420        int sr;
 421        u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
 422
 423        /* The clock has an 8 bit wide bcd-coded register (they never learn)
 424         * for the year. tm_year is an offset from 1900 and we are interested
 425         * in the 2000-2099 range, so any value less than 100 is invalid.
 426         */
 427        if (tm->tm_year < 100)
 428                return -EINVAL;
 429
 430        regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec);
 431        regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min);
 432        regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL;
 433
 434        regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday);
 435        regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1);
 436        regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100);
 437
 438        regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7);
 439
 440        sr = isl1208_i2c_get_sr(client);
 441        if (sr < 0) {
 442                dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 443                return sr;
 444        }
 445
 446        /* set WRTC */
 447        sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
 448                                       sr | ISL1208_REG_SR_WRTC);
 449        if (sr < 0) {
 450                dev_err(&client->dev, "%s: writing SR failed\n", __func__);
 451                return sr;
 452        }
 453
 454        /* write RTC registers */
 455        sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
 456        if (sr < 0) {
 457                dev_err(&client->dev, "%s: writing RTC section failed\n",
 458                        __func__);
 459                return sr;
 460        }
 461
 462        /* clear WRTC again */
 463        sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
 464                                       sr & ~ISL1208_REG_SR_WRTC);
 465        if (sr < 0) {
 466                dev_err(&client->dev, "%s: writing SR failed\n", __func__);
 467                return sr;
 468        }
 469
 470        return 0;
 471}
 472
 473
 474static int
 475isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
 476{
 477        return isl1208_i2c_set_time(to_i2c_client(dev), tm);
 478}
 479
 480static int
 481isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 482{
 483        return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
 484}
 485
 486static int
 487isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 488{
 489        return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
 490}
 491
 492static irqreturn_t
 493isl1208_rtc_interrupt(int irq, void *data)
 494{
 495        unsigned long timeout = jiffies + msecs_to_jiffies(1000);
 496        struct i2c_client *client = data;
 497        int handled = 0, sr, err;
 498
 499        /*
 500         * I2C reads get NAK'ed if we read straight away after an interrupt?
 501         * Using a mdelay/msleep didn't seem to help either, so we work around
 502         * this by continually trying to read the register for a short time.
 503         */
 504        while (1) {
 505                sr = isl1208_i2c_get_sr(client);
 506                if (sr >= 0)
 507                        break;
 508
 509                if (time_after(jiffies, timeout)) {
 510                        dev_err(&client->dev, "%s: reading SR failed\n",
 511                                __func__);
 512                        return sr;
 513                }
 514        }
 515
 516        if (sr & ISL1208_REG_SR_ALM) {
 517                dev_dbg(&client->dev, "alarm!\n");
 518
 519                /* Clear the alarm */
 520                sr &= ~ISL1208_REG_SR_ALM;
 521                sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
 522                if (sr < 0)
 523                        dev_err(&client->dev, "%s: writing SR failed\n",
 524                                __func__);
 525                else
 526                        handled = 1;
 527
 528                /* Disable the alarm */
 529                err = isl1208_rtc_toggle_alarm(client, 0);
 530                if (err)
 531                        return err;
 532        }
 533
 534        return handled ? IRQ_HANDLED : IRQ_NONE;
 535}
 536
 537static const struct rtc_class_ops isl1208_rtc_ops = {
 538        .proc = isl1208_rtc_proc,
 539        .read_time = isl1208_rtc_read_time,
 540        .set_time = isl1208_rtc_set_time,
 541        .read_alarm = isl1208_rtc_read_alarm,
 542        .set_alarm = isl1208_rtc_set_alarm,
 543};
 544
 545/* sysfs interface */
 546
 547static ssize_t
 548isl1208_sysfs_show_atrim(struct device *dev,
 549                         struct device_attribute *attr, char *buf)
 550{
 551        int atr = isl1208_i2c_get_atr(to_i2c_client(dev));
 552        if (atr < 0)
 553                return atr;
 554
 555        return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
 556}
 557
 558static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
 559
 560static ssize_t
 561isl1208_sysfs_show_dtrim(struct device *dev,
 562                         struct device_attribute *attr, char *buf)
 563{
 564        int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));
 565        if (dtr < 0)
 566                return dtr;
 567
 568        return sprintf(buf, "%d ppm\n", dtr);
 569}
 570
 571static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
 572
 573static ssize_t
 574isl1208_sysfs_show_usr(struct device *dev,
 575                       struct device_attribute *attr, char *buf)
 576{
 577        int usr = isl1208_i2c_get_usr(to_i2c_client(dev));
 578        if (usr < 0)
 579                return usr;
 580
 581        return sprintf(buf, "0x%.4x\n", usr);
 582}
 583
 584static ssize_t
 585isl1208_sysfs_store_usr(struct device *dev,
 586                        struct device_attribute *attr,
 587                        const char *buf, size_t count)
 588{
 589        int usr = -1;
 590
 591        if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
 592                if (sscanf(buf, "%x", &usr) != 1)
 593                        return -EINVAL;
 594        } else {
 595                if (sscanf(buf, "%d", &usr) != 1)
 596                        return -EINVAL;
 597        }
 598
 599        if (usr < 0 || usr > 0xffff)
 600                return -EINVAL;
 601
 602        return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;
 603}
 604
 605static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
 606                   isl1208_sysfs_store_usr);
 607
 608static struct attribute *isl1208_rtc_attrs[] = {
 609        &dev_attr_atrim.attr,
 610        &dev_attr_dtrim.attr,
 611        &dev_attr_usr.attr,
 612        NULL
 613};
 614
 615static const struct attribute_group isl1208_rtc_sysfs_files = {
 616        .attrs  = isl1208_rtc_attrs,
 617};
 618
 619static int
 620isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
 621{
 622        int rc = 0;
 623        struct rtc_device *rtc;
 624
 625        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 626                return -ENODEV;
 627
 628        if (isl1208_i2c_validate_client(client) < 0)
 629                return -ENODEV;
 630
 631        dev_info(&client->dev,
 632                 "chip found, driver version " DRV_VERSION "\n");
 633
 634        if (client->irq > 0) {
 635                rc = request_threaded_irq(client->irq, NULL,
 636                                          isl1208_rtc_interrupt,
 637                                          IRQF_SHARED,
 638                                          isl1208_driver.driver.name, client);
 639                if (!rc) {
 640                        device_init_wakeup(&client->dev, 1);
 641                        enable_irq_wake(client->irq);
 642                } else {
 643                        dev_err(&client->dev,
 644                                "Unable to request irq %d, no alarm support\n",
 645                                client->irq);
 646                        client->irq = 0;
 647                }
 648        }
 649
 650        rtc = rtc_device_register(isl1208_driver.driver.name,
 651                                  &client->dev, &isl1208_rtc_ops,
 652                                  THIS_MODULE);
 653        if (IS_ERR(rtc)) {
 654                rc = PTR_ERR(rtc);
 655                goto exit_free_irq;
 656        }
 657
 658        i2c_set_clientdata(client, rtc);
 659
 660        rc = isl1208_i2c_get_sr(client);
 661        if (rc < 0) {
 662                dev_err(&client->dev, "reading status failed\n");
 663                goto exit_unregister;
 664        }
 665
 666        if (rc & ISL1208_REG_SR_RTCF)
 667                dev_warn(&client->dev, "rtc power failure detected, "
 668                         "please set clock.\n");
 669
 670        rc = sysfs_create_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
 671        if (rc)
 672                goto exit_unregister;
 673
 674        return 0;
 675
 676exit_unregister:
 677        rtc_device_unregister(rtc);
 678exit_free_irq:
 679        if (client->irq)
 680                free_irq(client->irq, client);
 681
 682        return rc;
 683}
 684
 685static int
 686isl1208_remove(struct i2c_client *client)
 687{
 688        struct rtc_device *rtc = i2c_get_clientdata(client);
 689
 690        sysfs_remove_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
 691        rtc_device_unregister(rtc);
 692        if (client->irq)
 693                free_irq(client->irq, client);
 694
 695        return 0;
 696}
 697
 698static const struct i2c_device_id isl1208_id[] = {
 699        { "isl1208", 0 },
 700        { }
 701};
 702MODULE_DEVICE_TABLE(i2c, isl1208_id);
 703
 704static struct i2c_driver isl1208_driver = {
 705        .driver = {
 706                   .name = "rtc-isl1208",
 707                   },
 708        .probe = isl1208_probe,
 709        .remove = isl1208_remove,
 710        .id_table = isl1208_id,
 711};
 712
 713module_i2c_driver(isl1208_driver);
 714
 715MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
 716MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
 717MODULE_LICENSE("GPL");
 718MODULE_VERSION(DRV_VERSION);
 719
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