drivers/rtc/rtc-pcf8563.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * An I2C driver for the Philips PCF8563 RTC
   4  * Copyright 2005-06 Tower Technologies
   5  *
   6  * Author: Alessandro Zummo <a.zummo@towertech.it>
   7  * Maintainers: http://www.nslu2-linux.org/
   8  *
   9  * based on the other drivers in this same directory.
  10  *
  11  * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
  12  */
  13
  14 #include <linux/clk-provider.h>
  15 #include <linux/i2c.h>
  16 #include <linux/bcd.h>
  17 #include <linux/rtc.h>
  18 #include <linux/slab.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/err.h>
  22
  23 #define PCF8563_REG_ST1         0x00 /* status */
  24 #define PCF8563_REG_ST2         0x01
  25 #define PCF8563_BIT_AIE         (1 << 1)
  26 #define PCF8563_BIT_AF          (1 << 3)
  27 #define PCF8563_BITS_ST2_N      (7 << 5)
  28
  29 #define PCF8563_REG_SC          0x02 /* datetime */
  30 #define PCF8563_REG_MN          0x03
  31 #define PCF8563_REG_HR          0x04
  32 #define PCF8563_REG_DM          0x05
  33 #define PCF8563_REG_DW          0x06
  34 #define PCF8563_REG_MO          0x07
  35 #define PCF8563_REG_YR          0x08
  36
  37 #define PCF8563_REG_AMN         0x09 /* alarm */
  38
  39 #define PCF8563_REG_CLKO                0x0D /* clock out */
  40 #define PCF8563_REG_CLKO_FE             0x80 /* clock out enabled */
  41 #define PCF8563_REG_CLKO_F_MASK         0x03 /* frequenc mask */
  42 #define PCF8563_REG_CLKO_F_32768HZ      0x00
  43 #define PCF8563_REG_CLKO_F_1024HZ       0x01
  44 #define PCF8563_REG_CLKO_F_32HZ         0x02
  45 #define PCF8563_REG_CLKO_F_1HZ          0x03
  46
  47 #define PCF8563_REG_TMRC        0x0E /* timer control */
  48 #define PCF8563_TMRC_ENABLE     BIT(7)
  49 #define PCF8563_TMRC_4096       0
  50 #define PCF8563_TMRC_64         1
  51 #define PCF8563_TMRC_1          2
  52 #define PCF8563_TMRC_1_60       3
  53 #define PCF8563_TMRC_MASK       3
  54
  55 #define PCF8563_REG_TMR         0x0F /* timer */
  56
  57 #define PCF8563_SC_LV           0x80 /* low voltage */
  58 #define PCF8563_MO_C            0x80 /* century */
  59
  60 static struct i2c_driver pcf8563_driver;
  61
  62 struct pcf8563 {
  63         struct rtc_device *rtc;
  64         /*
  65          * The meaning of MO_C bit varies by the chip type.
  66          * From PCF8563 datasheet: this bit is toggled when the years
  67          * register overflows from 99 to 00
  68          *   0 indicates the century is 20xx
  69          *   1 indicates the century is 19xx
  70          * From RTC8564 datasheet: this bit indicates change of
  71          * century. When the year digit data overflows from 99 to 00,
  72          * this bit is set. By presetting it to 0 while still in the
  73          * 20th century, it will be set in year 2000, ...
  74          * There seems no reliable way to know how the system use this
  75          * bit.  So let's do it heuristically, assuming we are live in
  76          * 1970...2069.
  77          */
  78         int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
  79         int voltage_low; /* incicates if a low_voltage was detected */
  80
  81         struct i2c_client *client;
  82 #ifdef CONFIG_COMMON_CLK
  83         struct clk_hw           clkout_hw;
  84 #endif
  85 };
  86
  87 static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
  88                                    unsigned char length, unsigned char *buf)
  89 {
  90         struct i2c_msg msgs[] = {
  91                 {/* setup read ptr */
  92                         .addr = client->addr,
  93                         .len = 1,
  94                         .buf = &reg,
  95                 },
  96                 {
  97                         .addr = client->addr,
  98                         .flags = I2C_M_RD,
  99                         .len = length,
 100                         .buf = buf
 101                 },
 102         };
 103
 104         if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
 105                 dev_err(&client->dev, "%s: read error\n", __func__);
 106                 return -EIO;
 107         }
 108
 109         return 0;
 110 }
 111
 112 static int pcf8563_write_block_data(struct i2c_client *client,
 113                                    unsigned char reg, unsigned char length,
 114                                    unsigned char *buf)
 115 {
 116         int i, err;
 117
 118         for (i = 0; i < length; i++) {
 119                 unsigned char data[2] = { reg + i, buf[i] };
 120
 121                 err = i2c_master_send(client, data, sizeof(data));
 122                 if (err != sizeof(data)) {
 123                         dev_err(&client->dev,
 124                                 "%s: err=%d addr=%02x, data=%02x\n",
 125                                 __func__, err, data[0], data[1]);
 126                         return -EIO;
 127                 }
 128         }
 129
 130         return 0;
 131 }
 132
 133 static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
 134 {
 135         unsigned char buf;
 136         int err;
 137
 138         err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
 139         if (err < 0)
 140                 return err;
 141
 142         if (on)
 143                 buf |= PCF8563_BIT_AIE;
 144         else
 145                 buf &= ~PCF8563_BIT_AIE;
 146
 147         buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
 148
 149         err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
 150         if (err < 0) {
 151                 dev_err(&client->dev, "%s: write error\n", __func__);
 152                 return -EIO;
 153         }
 154
 155         return 0;
 156 }
 157
 158 static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
 159                                   unsigned char *pen)
 160 {
 161         unsigned char buf;
 162         int err;
 163
 164         err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
 165         if (err)
 166                 return err;
 167
 168         if (en)
 169                 *en = !!(buf & PCF8563_BIT_AIE);
 170         if (pen)
 171                 *pen = !!(buf & PCF8563_BIT_AF);
 172
 173         return 0;
 174 }
 175
 176 static irqreturn_t pcf8563_irq(int irq, void *dev_id)
 177 {
 178         struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
 179         int err;
 180         char pending;
 181
 182         err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
 183         if (err)
 184                 return IRQ_NONE;
 185
 186         if (pending) {
 187                 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
 188                 pcf8563_set_alarm_mode(pcf8563->client, 1);
 189                 return IRQ_HANDLED;
 190         }
 191
 192         return IRQ_NONE;
 193 }
 194
 195 /*
 196  * In the routines that deal directly with the pcf8563 hardware, we use
 197  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
 198  */
 199 static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 200 {
 201         struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
 202         unsigned char buf[9];
 203         int err;
 204
 205         err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
 206         if (err)
 207                 return err;
 208
 209         if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
 210                 pcf8563->voltage_low = 1;
 211                 dev_err(&client->dev,
 212                         "low voltage detected, date/time is not reliable.\n");
 213                 return -EINVAL;
 214         }
 215
 216         dev_dbg(&client->dev,
 217                 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
 218                 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
 219                 __func__,
 220                 buf[0], buf[1], buf[2], buf[3],
 221                 buf[4], buf[5], buf[6], buf[7],
 222                 buf[8]);
 223
 224
 225         tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
 226         tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
 227         tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
 228         tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
 229         tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
 230         tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
 231         tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
 232         if (tm->tm_year < 70)
 233                 tm->tm_year += 100;     /* assume we are in 1970...2069 */
 234         /* detect the polarity heuristically. see note above. */
 235         pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
 236                 (tm->tm_year >= 100) : (tm->tm_year < 100);
 237
 238         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 239                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 240                 __func__,
 241                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 242                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 243
 244         return 0;
 245 }
 246
 247 static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 248 {
 249         struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
 250         unsigned char buf[9];
 251
 252         dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
 253                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 254                 __func__,
 255                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 256                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 257
 258         /* hours, minutes and seconds */
 259         buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
 260         buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
 261         buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
 262
 263         buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
 264
 265         /* month, 1 - 12 */
 266         buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
 267
 268         /* year and century */
 269         buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
 270         if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
 271                 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
 272
 273         buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
 274
 275         return pcf8563_write_block_data(client, PCF8563_REG_SC,
 276                                 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
 277 }
 278
 279 #ifdef CONFIG_RTC_INTF_DEV
 280 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 281 {
 282         struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
 283         struct rtc_time tm;
 284
 285         switch (cmd) {
 286         case RTC_VL_READ:
 287                 if (pcf8563->voltage_low)
 288                         dev_info(dev, "low voltage detected, date/time is not reliable.\n");
 289
 290                 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
 291                                         sizeof(int)))
 292                         return -EFAULT;
 293                 return 0;
 294         case RTC_VL_CLR:
 295                 /*
 296                  * Clear the VL bit in the seconds register in case
 297                  * the time has not been set already (which would
 298                  * have cleared it). This does not really matter
 299                  * because of the cached voltage_low value but do it
 300                  * anyway for consistency.
 301                  */
 302                 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
 303                         pcf8563_set_datetime(to_i2c_client(dev), &tm);
 304
 305                 /* Clear the cached value. */
 306                 pcf8563->voltage_low = 0;
 307
 308                 return 0;
 309         default:
 310                 return -ENOIOCTLCMD;
 311         }
 312 }
 313 #else
 314 #define pcf8563_rtc_ioctl NULL
 315 #endif
 316
 317 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
 318 {
 319         return pcf8563_get_datetime(to_i2c_client(dev), tm);
 320 }
 321
 322 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
 323 {
 324         return pcf8563_set_datetime(to_i2c_client(dev), tm);
 325 }
 326
 327 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
 328 {
 329         struct i2c_client *client = to_i2c_client(dev);
 330         unsigned char buf[4];
 331         int err;
 332
 333         err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
 334         if (err)
 335                 return err;
 336
 337         dev_dbg(&client->dev,
 338                 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
 339                 __func__, buf[0], buf[1], buf[2], buf[3]);
 340
 341         tm->time.tm_sec = 0;
 342         tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
 343         tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
 344         tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
 345         tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
 346
 347         err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
 348         if (err < 0)
 349                 return err;
 350
 351         dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
 352                 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
 353                 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
 354                 tm->enabled, tm->pending);
 355
 356         return 0;
 357 }
 358
 359 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
 360 {
 361         struct i2c_client *client = to_i2c_client(dev);
 362         unsigned char buf[4];
 363         int err;
 364
 365         /* The alarm has no seconds, round up to nearest minute */
 366         if (tm->time.tm_sec) {
 367                 time64_t alarm_time = rtc_tm_to_time64(&tm->time);
 368
 369                 alarm_time += 60 - tm->time.tm_sec;
 370                 rtc_time64_to_tm(alarm_time, &tm->time);
 371         }
 372
 373         dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
 374                 "enabled=%d pending=%d\n", __func__,
 375                 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
 376                 tm->time.tm_mday, tm->enabled, tm->pending);
 377
 378         buf[0] = bin2bcd(tm->time.tm_min);
 379         buf[1] = bin2bcd(tm->time.tm_hour);
 380         buf[2] = bin2bcd(tm->time.tm_mday);
 381         buf[3] = tm->time.tm_wday & 0x07;
 382
 383         err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
 384         if (err)
 385                 return err;
 386
 387         return pcf8563_set_alarm_mode(client, !!tm->enabled);
 388 }
 389
 390 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
 391 {
 392         dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
 393         return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
 394 }
 395
 396 #ifdef CONFIG_COMMON_CLK
 397 /*
 398  * Handling of the clkout
 399  */
 400
 401 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
 402
 403 static int clkout_rates[] = {
 404         32768,
 405         1024,
 406         32,
 407         1,
 408 };
 409
 410 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
 411                                                 unsigned long parent_rate)
 412 {
 413         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
 414         struct i2c_client *client = pcf8563->client;
 415         unsigned char buf;
 416         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 417
 418         if (ret < 0)
 419                 return 0;
 420
 421         buf &= PCF8563_REG_CLKO_F_MASK;
 422         return clkout_rates[buf];
 423 }
 424
 425 static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
 426                                       unsigned long *prate)
 427 {
 428         int i;
 429
 430         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 431                 if (clkout_rates[i] <= rate)
 432                         return clkout_rates[i];
 433
 434         return 0;
 435 }
 436
 437 static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
 438                                    unsigned long parent_rate)
 439 {
 440         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
 441         struct i2c_client *client = pcf8563->client;
 442         unsigned char buf;
 443         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 444         int i;
 445
 446         if (ret < 0)
 447                 return ret;
 448
 449         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 450                 if (clkout_rates[i] == rate) {
 451                         buf &= ~PCF8563_REG_CLKO_F_MASK;
 452                         buf |= i;
 453                         ret = pcf8563_write_block_data(client,
 454                                                        PCF8563_REG_CLKO, 1,
 455                                                        &buf);
 456                         return ret;
 457                 }
 458
 459         return -EINVAL;
 460 }
 461
 462 static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
 463 {
 464         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
 465         struct i2c_client *client = pcf8563->client;
 466         unsigned char buf;
 467         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 468
 469         if (ret < 0)
 470                 return ret;
 471
 472         if (enable)
 473                 buf |= PCF8563_REG_CLKO_FE;
 474         else
 475                 buf &= ~PCF8563_REG_CLKO_FE;
 476
 477         ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 478         return ret;
 479 }
 480
 481 static int pcf8563_clkout_prepare(struct clk_hw *hw)
 482 {
 483         return pcf8563_clkout_control(hw, 1);
 484 }
 485
 486 static void pcf8563_clkout_unprepare(struct clk_hw *hw)
 487 {
 488         pcf8563_clkout_control(hw, 0);
 489 }
 490
 491 static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
 492 {
 493         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
 494         struct i2c_client *client = pcf8563->client;
 495         unsigned char buf;
 496         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 497
 498         if (ret < 0)
 499                 return ret;
 500
 501         return !!(buf & PCF8563_REG_CLKO_FE);
 502 }
 503
 504 static const struct clk_ops pcf8563_clkout_ops = {
 505         .prepare = pcf8563_clkout_prepare,
 506         .unprepare = pcf8563_clkout_unprepare,
 507         .is_prepared = pcf8563_clkout_is_prepared,
 508         .recalc_rate = pcf8563_clkout_recalc_rate,
 509         .round_rate = pcf8563_clkout_round_rate,
 510         .set_rate = pcf8563_clkout_set_rate,
 511 };
 512
 513 static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
 514 {
 515         struct i2c_client *client = pcf8563->client;
 516         struct device_node *node = client->dev.of_node;
 517         struct clk *clk;
 518         struct clk_init_data init;
 519         int ret;
 520         unsigned char buf;
 521
 522         /* disable the clkout output */
 523         buf = 0;
 524         ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
 525         if (ret < 0)
 526                 return ERR_PTR(ret);
 527
 528         init.name = "pcf8563-clkout";
 529         init.ops = &pcf8563_clkout_ops;
 530         init.flags = 0;
 531         init.parent_names = NULL;
 532         init.num_parents = 0;
 533         pcf8563->clkout_hw.init = &init;
 534
 535         /* optional override of the clockname */
 536         of_property_read_string(node, "clock-output-names", &init.name);
 537
 538         /* register the clock */
 539         clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
 540
 541         if (!IS_ERR(clk))
 542                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 543
 544         return clk;
 545 }
 546 #endif
 547
 548 static const struct rtc_class_ops pcf8563_rtc_ops = {
 549         .ioctl          = pcf8563_rtc_ioctl,
 550         .read_time      = pcf8563_rtc_read_time,
 551         .set_time       = pcf8563_rtc_set_time,
 552         .read_alarm     = pcf8563_rtc_read_alarm,
 553         .set_alarm      = pcf8563_rtc_set_alarm,
 554         .alarm_irq_enable = pcf8563_irq_enable,
 555 };
 556
 557 static int pcf8563_probe(struct i2c_client *client,
 558                                 const struct i2c_device_id *id)
 559 {
 560         struct pcf8563 *pcf8563;
 561         int err;
 562         unsigned char buf;
 563         unsigned char alm_pending;
 564
 565         dev_dbg(&client->dev, "%s\n", __func__);
 566
 567         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 568                 return -ENODEV;
 569
 570         pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
 571                                 GFP_KERNEL);
 572         if (!pcf8563)
 573                 return -ENOMEM;
 574
 575         i2c_set_clientdata(client, pcf8563);
 576         pcf8563->client = client;
 577         device_set_wakeup_capable(&client->dev, 1);
 578
 579         /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
 580         buf = PCF8563_TMRC_1_60;
 581         err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
 582         if (err < 0) {
 583                 dev_err(&client->dev, "%s: write error\n", __func__);
 584                 return err;
 585         }
 586
 587         err = pcf8563_get_alarm_mode(client, NULL, &alm_pending);
 588         if (err) {
 589                 dev_err(&client->dev, "%s: read error\n", __func__);
 590                 return err;
 591         }
 592         if (alm_pending)
 593                 pcf8563_set_alarm_mode(client, 0);
 594
 595         pcf8563->rtc = devm_rtc_device_register(&client->dev,
 596                                 pcf8563_driver.driver.name,
 597                                 &pcf8563_rtc_ops, THIS_MODULE);
 598
 599         if (IS_ERR(pcf8563->rtc))
 600                 return PTR_ERR(pcf8563->rtc);
 601
 602         if (client->irq > 0) {
 603                 err = devm_request_threaded_irq(&client->dev, client->irq,
 604                                 NULL, pcf8563_irq,
 605                                 IRQF_SHARED|IRQF_ONESHOT|IRQF_TRIGGER_FALLING,
 606                                 pcf8563_driver.driver.name, client);
 607                 if (err) {
 608                         dev_err(&client->dev, "unable to request IRQ %d\n",
 609                                                                 client->irq);
 610                         return err;
 611                 }
 612
 613         }
 614
 615 #ifdef CONFIG_COMMON_CLK
 616         /* register clk in common clk framework */
 617         pcf8563_clkout_register_clk(pcf8563);
 618 #endif
 619
 620         /* the pcf8563 alarm only supports a minute accuracy */
 621         pcf8563->rtc->uie_unsupported = 1;
 622
 623         return 0;
 624 }
 625
 626 static const struct i2c_device_id pcf8563_id[] = {
 627         { "pcf8563", 0 },
 628         { "rtc8564", 0 },
 629         { }
 630 };
 631 MODULE_DEVICE_TABLE(i2c, pcf8563_id);
 632
 633 #ifdef CONFIG_OF
 634 static const struct of_device_id pcf8563_of_match[] = {
 635         { .compatible = "nxp,pcf8563" },
 636         {}
 637 };
 638 MODULE_DEVICE_TABLE(of, pcf8563_of_match);
 639 #endif
 640
 641 static struct i2c_driver pcf8563_driver = {
 642         .driver         = {
 643                 .name   = "rtc-pcf8563",
 644                 .of_match_table = of_match_ptr(pcf8563_of_match),
 645         },
 646         .probe          = pcf8563_probe,
 647         .id_table       = pcf8563_id,
 648 };
 649
 650 module_i2c_driver(pcf8563_driver);
 651
 652 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 653 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
 654 MODULE_LICENSE("GPL");