kernel/drivers/rtc/rtc-pcf8563.c

   1 /*
   2  * An I2C driver for the Philips PCF8563 RTC
   3  * Copyright 2005-06 Tower Technologies
   4  *
   5  * Author: Alessandro Zummo <a.zummo@towertech.it>
   6  * Maintainers: http://www.nslu2-linux.org/
   7  *
   8  * based on the other drivers in this same directory.
   9  *
  10  * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  */
  16
  17 #include <linux/clk-provider.h>
  18 #include <linux/i2c.h>
  19 #include <linux/bcd.h>
  20 #include <linux/rtc.h>
  21 #include <linux/slab.h>
  22 #include <linux/module.h>
  23 #include <linux/of.h>
  24 #include <linux/err.h>
  25
  26 #define DRV_VERSION "0.4.4"
  27
  28 #define PCF8563_REG_ST1         0x00 /* status */
  29 #define PCF8563_REG_ST2         0x01
  30 #define PCF8563_BIT_AIE         (1 << 1)
  31 #define PCF8563_BIT_AF          (1 << 3)
  32 #define PCF8563_BITS_ST2_N      (7 << 5)
  33
  34 #define PCF8563_REG_SC          0x02 /* datetime */
  35 #define PCF8563_REG_MN          0x03
  36 #define PCF8563_REG_HR          0x04
  37 #define PCF8563_REG_DM          0x05
  38 #define PCF8563_REG_DW          0x06
  39 #define PCF8563_REG_MO          0x07
  40 #define PCF8563_REG_YR          0x08
  41
  42 #define PCF8563_REG_AMN         0x09 /* alarm */
  43
  44 #define PCF8563_REG_CLKO                0x0D /* clock out */
  45 #define PCF8563_REG_CLKO_FE             0x80 /* clock out enabled */
  46 #define PCF8563_REG_CLKO_F_MASK         0x03 /* frequenc mask */
  47 #define PCF8563_REG_CLKO_F_32768HZ      0x00
  48 #define PCF8563_REG_CLKO_F_1024HZ       0x01
  49 #define PCF8563_REG_CLKO_F_32HZ         0x02
  50 #define PCF8563_REG_CLKO_F_1HZ          0x03
  51
  52 #define PCF8563_REG_TMRC        0x0E /* timer control */
  53 #define PCF8563_TMRC_ENABLE     BIT(7)
  54 #define PCF8563_TMRC_4096       0
  55 #define PCF8563_TMRC_64         1
  56 #define PCF8563_TMRC_1          2
  57 #define PCF8563_TMRC_1_60       3
  58 #define PCF8563_TMRC_MASK       3
  59
  60 #define PCF8563_REG_TMR         0x0F /* timer */
  61
  62 #define PCF8563_SC_LV           0x80 /* low voltage */
  63 #define PCF8563_MO_C            0x80 /* century */
  64
  65 static struct i2c_driver pcf8563_driver;
  66
  67 struct pcf8563 {
  68         struct rtc_device *rtc;
  69         /*
  70          * The meaning of MO_C bit varies by the chip type.
  71          * From PCF8563 datasheet: this bit is toggled when the years
  72          * register overflows from 99 to 00
  73          *   0 indicates the century is 20xx
  74          *   1 indicates the century is 19xx
  75          * From RTC8564 datasheet: this bit indicates change of
  76          * century. When the year digit data overflows from 99 to 00,
  77          * this bit is set. By presetting it to 0 while still in the
  78          * 20th century, it will be set in year 2000, ...
  79          * There seems no reliable way to know how the system use this
  80          * bit.  So let's do it heuristically, assuming we are live in
  81          * 1970...2069.
  82          */
  83         int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
  84         int voltage_low; /* incicates if a low_voltage was detected */
  85
  86         struct i2c_client *client;
  87 #ifdef CONFIG_COMMON_CLK
  88         struct clk_hw           clkout_hw;
  89 #endif
  90 };
  91
  92 static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
  93                                    unsigned char length, unsigned char *buf)
  94 {
  95         struct i2c_msg msgs[] = {
  96                 {/* setup read ptr */
  97                         .addr = client->addr,
  98                         .len = 1,
  99                         .buf = &reg,
 100                 },
 101                 {
 102                         .addr = client->addr,
 103                         .flags = I2C_M_RD,
 104                         .len = length,
 105                         .buf = buf
 106                 },
 107         };
 108
 109         if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
 110                 dev_err(&client->dev, "%s: read error\n", __func__);
 111                 return -EIO;
 112         }
 113
 114         return 0;
 115 }
 116
 117 static int pcf8563_write_block_data(struct i2c_client *client,
 118                                    unsigned char reg, unsigned char length,
 119                                    unsigned char *buf)
 120 {
 121         int i, err;
 122
 123         for (i = 0; i < length; i++) {
 124                 unsigned char data[2] = { reg + i, buf[i] };
 125
 126                 err = i2c_master_send(client, data, sizeof(data));
 127                 if (err != sizeof(data)) {
 128                         dev_err(&client->dev,
 129                                 "%s: err=%d addr=%02x, data=%02x\n",
 130                                 __func__, err, data[0], data[1]);
 131                         return -EIO;
 132                 }
 133         }
 134
 135         return 0;
 136 }
 137
 138 static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
 139 {
 140         unsigned char buf;
 141         int err;
 142
 143         err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
 144         if (err < 0)
 145                 return err;
 146
 147         if (on)
 148                 buf |= PCF8563_BIT_AIE;
 149         else
 150                 buf &= ~PCF8563_BIT_AIE;
 151
 152         buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
 153
 154         err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
 155         if (err < 0) {
 156                 dev_err(&client->dev, "%s: write error\n", __func__);
 157                 return -EIO;
 158         }
 159
 160         return 0;
 161 }
 162
 163 static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
 164                                   unsigned char *pen)
 165 {
 166         unsigned char buf;
 167         int err;
 168
 169         err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
 170         if (err)
 171                 return err;
 172
 173         if (en)
 174                 *en = !!(buf & PCF8563_BIT_AIE);
 175         if (pen)
 176                 *pen = !!(buf & PCF8563_BIT_AF);
 177
 178         return 0;
 179 }
 180
 181 static irqreturn_t pcf8563_irq(int irq, void *dev_id)
 182 {
 183         struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
 184         int err;
 185         char pending;
 186
 187         err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
 188         if (err)
 189                 return IRQ_NONE;
 190
 191         if (pending) {
 192                 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
 193                 pcf8563_set_alarm_mode(pcf8563->client, 1);
 194                 return IRQ_HANDLED;
 195         }
 196
 197         return IRQ_NONE;
 198 }
 199
 200 /*
 201  * In the routines that deal directly with the pcf8563 hardware, we use
 202  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
 203  */
 204 static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 205 {
 206         struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
 207         unsigned char buf[9];
 208         int err;
 209
 210         err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
 211         if (err)
 212                 return err;
 213
 214         if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
 215                 pcf8563->voltage_low = 1;
 216                 dev_err(&client->dev,
 217                         "low voltage detected, date/time is not reliable.\n");
 218                 return -EINVAL;
 219         }
 220
 221         dev_dbg(&client->dev,
 222                 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
 223                 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
 224                 __func__,
 225                 buf[0], buf[1], buf[2], buf[3],
 226                 buf[4], buf[5], buf[6], buf[7],
 227                 buf[8]);
 228
 229
 230         tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
 231         tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
 232         tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
 233         tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
 234         tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
 235         tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
 236         tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
 237         if (tm->tm_year < 70)
 238                 tm->tm_year += 100;     /* assume we are in 1970...2069 */
 239         /* detect the polarity heuristically. see note above. */
 240         pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
 241                 (tm->tm_year >= 100) : (tm->tm_year < 100);
 242
 243         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 244                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 245                 __func__,
 246                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 247                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 248
 249         return 0;
 250 }
 251
 252 static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 253 {
 254         struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
 255         unsigned char buf[9];
 256
 257         dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
 258                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 259                 __func__,
 260                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 261                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 262
 263         /* hours, minutes and seconds */
 264         buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
 265         buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
 266         buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
 267
 268         buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
 269
 270         /* month, 1 - 12 */
 271         buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
 272
 273         /* year and century */
 274         buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
 275         if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
 276                 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
 277
 278         buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
 279
 280         return pcf8563_write_block_data(client, PCF8563_REG_SC,
 281                                 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
 282 }
 283
 284 #ifdef CONFIG_RTC_INTF_DEV
 285 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 286 {
 287         struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
 288         struct rtc_time tm;
 289
 290         switch (cmd) {
 291         case RTC_VL_READ:
 292                 if (pcf8563->voltage_low)
 293                         dev_info(dev, "low voltage detected, date/time is not reliable.\n");
 294
 295                 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
 296                                         sizeof(int)))
 297                         return -EFAULT;
 298                 return 0;
 299         case RTC_VL_CLR:
 300                 /*
 301                  * Clear the VL bit in the seconds register in case
 302                  * the time has not been set already (which would
 303                  * have cleared it). This does not really matter
 304                  * because of the cached voltage_low value but do it
 305                  * anyway for consistency.
 306                  */
 307                 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
 308                         pcf8563_set_datetime(to_i2c_client(dev), &tm);
 309
 310                 /* Clear the cached value. */
 311                 pcf8563->voltage_low = 0;
 312
 313                 return 0;
 314         default:
 315                 return -ENOIOCTLCMD;
 316         }
 317 }
 318 #else
 319 #define pcf8563_rtc_ioctl NULL
 320 #endif
 321
 322 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
 323 {
 324         return pcf8563_get_datetime(to_i2c_client(dev), tm);
 325 }
 326
 327 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
 328 {
 329         return pcf8563_set_datetime(to_i2c_client(dev), tm);
 330 }
 331
 332 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
 333 {
 334         struct i2c_client *client = to_i2c_client(dev);
 335         unsigned char buf[4];
 336         int err;
 337
 338         err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
 339         if (err)
 340                 return err;
 341
 342         dev_dbg(&client->dev,
 343                 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
 344                 __func__, buf[0], buf[1], buf[2], buf[3]);
 345
 346         tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
 347         tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
 348         tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
 349         tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
 350         tm->time.tm_mon = -1;
 351         tm->time.tm_year = -1;
 352         tm->time.tm_yday = -1;
 353         tm->time.tm_isdst = -1;
 354
 355         err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
 356         if (err < 0)
 357                 return err;
 358
 359         dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
 360                 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
 361                 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
 362                 tm->enabled, tm->pending);
 363
 364         return 0;
 365 }
 366
 367 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
 368 {
 369         struct i2c_client *client = to_i2c_client(dev);
 370         unsigned char buf[4];
 371         int err;
 372
 373         /* The alarm has no seconds, round up to nearest minute */
 374         if (tm->time.tm_sec) {
 375                 time64_t alarm_time = rtc_tm_to_time64(&tm->time);
 376
 377                 alarm_time += 60 - tm->time.tm_sec;
 378                 rtc_time64_to_tm(alarm_time, &tm->time);
 379         }
 380
 381         dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
 382                 "enabled=%d pending=%d\n", __func__,
 383                 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
 384                 tm->time.tm_mday, tm->enabled, tm->pending);
 385
 386         buf[0] = bin2bcd(tm->time.tm_min);
 387         buf[1] = bin2bcd(tm->time.tm_hour);
 388         buf[2] = bin2bcd(tm->time.tm_mday);
 389         buf[3] = tm->time.tm_wday & 0x07;
 390
 391         err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
 392         if (err)
 393                 return err;
 394
 395         return pcf8563_set_alarm_mode(client, 1);
 396 }
 397
 398 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
 399 {
 400         dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
 401         return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
 402 }
 403
 404 #ifdef CONFIG_COMMON_CLK
 405 /*
 406  * Handling of the clkout
 407  */
 408
 409 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
 410
 411 static int clkout_rates[] = {
 412         32768,
 413         1024,
 414         32,
 415         1,
 416 };
 417
 418 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
 419                                                 unsigned long parent_rate)
 420 {
 421         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
 422         struct i2c_client *client = pcf8563->client;
 423         unsigned char buf;
 424         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 425
 426         if (ret < 0)
 427                 return 0;
 428
 429         buf &= PCF8563_REG_CLKO_F_MASK;
 430         return clkout_rates[ret];
 431 }
 432
 433 static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
 434                                       unsigned long *prate)
 435 {
 436         int i;
 437
 438         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 439                 if (clkout_rates[i] <= rate)
 440                         return clkout_rates[i];
 441
 442         return 0;
 443 }
 444
 445 static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
 446                                    unsigned long parent_rate)
 447 {
 448         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
 449         struct i2c_client *client = pcf8563->client;
 450         unsigned char buf;
 451         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 452         int i;
 453
 454         if (ret < 0)
 455                 return ret;
 456
 457         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 458                 if (clkout_rates[i] == rate) {
 459                         buf &= ~PCF8563_REG_CLKO_F_MASK;
 460                         buf |= i;
 461                         ret = pcf8563_write_block_data(client,
 462                                                        PCF8563_REG_CLKO, 1,
 463                                                        &buf);
 464                         return ret;
 465                 }
 466
 467         return -EINVAL;
 468 }
 469
 470 static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
 471 {
 472         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
 473         struct i2c_client *client = pcf8563->client;
 474         unsigned char buf;
 475         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 476
 477         if (ret < 0)
 478                 return ret;
 479
 480         if (enable)
 481                 buf |= PCF8563_REG_CLKO_FE;
 482         else
 483                 buf &= ~PCF8563_REG_CLKO_FE;
 484
 485         ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 486         return ret;
 487 }
 488
 489 static int pcf8563_clkout_prepare(struct clk_hw *hw)
 490 {
 491         return pcf8563_clkout_control(hw, 1);
 492 }
 493
 494 static void pcf8563_clkout_unprepare(struct clk_hw *hw)
 495 {
 496         pcf8563_clkout_control(hw, 0);
 497 }
 498
 499 static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
 500 {
 501         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
 502         struct i2c_client *client = pcf8563->client;
 503         unsigned char buf;
 504         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 505
 506         if (ret < 0)
 507                 return ret;
 508
 509         return !!(buf & PCF8563_REG_CLKO_FE);
 510 }
 511
 512 static const struct clk_ops pcf8563_clkout_ops = {
 513         .prepare = pcf8563_clkout_prepare,
 514         .unprepare = pcf8563_clkout_unprepare,
 515         .is_prepared = pcf8563_clkout_is_prepared,
 516         .recalc_rate = pcf8563_clkout_recalc_rate,
 517         .round_rate = pcf8563_clkout_round_rate,
 518         .set_rate = pcf8563_clkout_set_rate,
 519 };
 520
 521 static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
 522 {
 523         struct i2c_client *client = pcf8563->client;
 524         struct device_node *node = client->dev.of_node;
 525         struct clk *clk;
 526         struct clk_init_data init;
 527         int ret;
 528         unsigned char buf;
 529
 530         /* disable the clkout output */
 531         buf = 0;
 532         ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 533         if (ret < 0)
 534                 return ERR_PTR(ret);
 535
 536         init.name = "pcf8563-clkout";
 537         init.ops = &pcf8563_clkout_ops;
 538         init.flags = CLK_IS_ROOT;
 539         init.parent_names = NULL;
 540         init.num_parents = 0;
 541         pcf8563->clkout_hw.init = &init;
 542
 543         /* optional override of the clockname */
 544         of_property_read_string(node, "clock-output-names", &init.name);
 545
 546         /* register the clock */
 547         clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
 548
 549         if (!IS_ERR(clk))
 550                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 551
 552         return clk;
 553 }
 554 #endif
 555
 556 static const struct rtc_class_ops pcf8563_rtc_ops = {
 557         .ioctl          = pcf8563_rtc_ioctl,
 558         .read_time      = pcf8563_rtc_read_time,
 559         .set_time       = pcf8563_rtc_set_time,
 560         .read_alarm     = pcf8563_rtc_read_alarm,
 561         .set_alarm      = pcf8563_rtc_set_alarm,
 562         .alarm_irq_enable = pcf8563_irq_enable,
 563 };
 564
 565 static int pcf8563_probe(struct i2c_client *client,
 566                                 const struct i2c_device_id *id)
 567 {
 568         struct pcf8563 *pcf8563;
 569         int err;
 570         unsigned char buf;
 571         unsigned char alm_pending;
 572
 573         dev_dbg(&client->dev, "%s\n", __func__);
 574
 575         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 576                 return -ENODEV;
 577
 578         pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
 579                                 GFP_KERNEL);
 580         if (!pcf8563)
 581                 return -ENOMEM;
 582
 583         dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
 584
 585         i2c_set_clientdata(client, pcf8563);
 586         pcf8563->client = client;
 587         device_set_wakeup_capable(&client->dev, 1);
 588
 589         /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
 590         buf = PCF8563_TMRC_1_60;
 591         err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
 592         if (err < 0) {
 593                 dev_err(&client->dev, "%s: write error\n", __func__);
 594                 return err;
 595         }
 596
 597         err = pcf8563_get_alarm_mode(client, NULL, &alm_pending);
 598         if (err) {
 599                 dev_err(&client->dev, "%s: read error\n", __func__);
 600                 return err;
 601         }
 602         if (alm_pending)
 603                 pcf8563_set_alarm_mode(client, 0);
 604
 605         pcf8563->rtc = devm_rtc_device_register(&client->dev,
 606                                 pcf8563_driver.driver.name,
 607                                 &pcf8563_rtc_ops, THIS_MODULE);
 608
 609         if (IS_ERR(pcf8563->rtc))
 610                 return PTR_ERR(pcf8563->rtc);
 611
 612         if (client->irq > 0) {
 613                 err = devm_request_threaded_irq(&client->dev, client->irq,
 614                                 NULL, pcf8563_irq,
 615                                 IRQF_SHARED|IRQF_ONESHOT|IRQF_TRIGGER_FALLING,
 616                                 pcf8563->rtc->name, client);
 617                 if (err) {
 618                         dev_err(&client->dev, "unable to request IRQ %d\n",
 619                                                                 client->irq);
 620                         return err;
 621                 }
 622
 623         }
 624
 625 #ifdef CONFIG_COMMON_CLK
 626         /* register clk in common clk framework */
 627         pcf8563_clkout_register_clk(pcf8563);
 628 #endif
 629
 630         /* the pcf8563 alarm only supports a minute accuracy */
 631         pcf8563->rtc->uie_unsupported = 1;
 632
 633         return 0;
 634 }
 635
 636 static const struct i2c_device_id pcf8563_id[] = {
 637         { "pcf8563", 0 },
 638         { "rtc8564", 0 },
 639         { }
 640 };
 641 MODULE_DEVICE_TABLE(i2c, pcf8563_id);
 642
 643 #ifdef CONFIG_OF
 644 static const struct of_device_id pcf8563_of_match[] = {
 645         { .compatible = "nxp,pcf8563" },
 646         {}
 647 };
 648 MODULE_DEVICE_TABLE(of, pcf8563_of_match);
 649 #endif
 650
 651 static struct i2c_driver pcf8563_driver = {
 652         .driver         = {
 653                 .name   = "rtc-pcf8563",
 654                 .of_match_table = of_match_ptr(pcf8563_of_match),
 655         },
 656         .probe          = pcf8563_probe,
 657         .id_table       = pcf8563_id,
 658 };
 659
 660 module_i2c_driver(pcf8563_driver);
 661
 662 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 663 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
 664 MODULE_LICENSE("GPL");
 665 MODULE_VERSION(DRV_VERSION);