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