drivers/rtc/rtc-ds1307.c

   1 /*
   2  * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
   3  *
   4  *  Copyright (C) 2005 James Chapman (ds1337 core)
   5  *  Copyright (C) 2006 David Brownell
   6  *  Copyright (C) 2009 Matthias Fuchs (rx8025 support)
   7  *  Copyright (C) 2012 Bertrand Achard (nvram access fixes)
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/acpi.h>
  15 #include <linux/bcd.h>
  16 #include <linux/i2c.h>
  17 #include <linux/init.h>
  18 #include <linux/module.h>
  19 #include <linux/of_device.h>
  20 #include <linux/rtc/ds1307.h>
  21 #include <linux/rtc.h>
  22 #include <linux/slab.h>
  23 #include <linux/string.h>
  24 #include <linux/hwmon.h>
  25 #include <linux/hwmon-sysfs.h>
  26 #include <linux/clk-provider.h>
  27 #include <linux/regmap.h>
  28
  29 /*
  30  * We can't determine type by probing, but if we expect pre-Linux code
  31  * to have set the chip up as a clock (turning on the oscillator and
  32  * setting the date and time), Linux can ignore the non-clock features.
  33  * That's a natural job for a factory or repair bench.
  34  */
  35 enum ds_type {
  36         ds_1307,
  37         ds_1308,
  38         ds_1337,
  39         ds_1338,
  40         ds_1339,
  41         ds_1340,
  42         ds_1388,
  43         ds_3231,
  44         m41t0,
  45         m41t00,
  46         mcp794xx,
  47         rx_8025,
  48         rx_8130,
  49         last_ds_type /* always last */
  50         /* rs5c372 too?  different address... */
  51 };
  52
  53
  54 /* RTC registers don't differ much, except for the century flag */
  55 #define DS1307_REG_SECS         0x00    /* 00-59 */
  56 #       define DS1307_BIT_CH            0x80
  57 #       define DS1340_BIT_nEOSC         0x80
  58 #       define MCP794XX_BIT_ST          0x80
  59 #define DS1307_REG_MIN          0x01    /* 00-59 */
  60 #       define M41T0_BIT_OF             0x80
  61 #define DS1307_REG_HOUR         0x02    /* 00-23, or 1-12{am,pm} */
  62 #       define DS1307_BIT_12HR          0x40    /* in REG_HOUR */
  63 #       define DS1307_BIT_PM            0x20    /* in REG_HOUR */
  64 #       define DS1340_BIT_CENTURY_EN    0x80    /* in REG_HOUR */
  65 #       define DS1340_BIT_CENTURY       0x40    /* in REG_HOUR */
  66 #define DS1307_REG_WDAY         0x03    /* 01-07 */
  67 #       define MCP794XX_BIT_VBATEN      0x08
  68 #define DS1307_REG_MDAY         0x04    /* 01-31 */
  69 #define DS1307_REG_MONTH        0x05    /* 01-12 */
  70 #       define DS1337_BIT_CENTURY       0x80    /* in REG_MONTH */
  71 #define DS1307_REG_YEAR         0x06    /* 00-99 */
  72
  73 /*
  74  * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
  75  * start at 7, and they differ a LOT. Only control and status matter for
  76  * basic RTC date and time functionality; be careful using them.
  77  */
  78 #define DS1307_REG_CONTROL      0x07            /* or ds1338 */
  79 #       define DS1307_BIT_OUT           0x80
  80 #       define DS1338_BIT_OSF           0x20
  81 #       define DS1307_BIT_SQWE          0x10
  82 #       define DS1307_BIT_RS1           0x02
  83 #       define DS1307_BIT_RS0           0x01
  84 #define DS1337_REG_CONTROL      0x0e
  85 #       define DS1337_BIT_nEOSC         0x80
  86 #       define DS1339_BIT_BBSQI         0x20
  87 #       define DS3231_BIT_BBSQW         0x40 /* same as BBSQI */
  88 #       define DS1337_BIT_RS2           0x10
  89 #       define DS1337_BIT_RS1           0x08
  90 #       define DS1337_BIT_INTCN         0x04
  91 #       define DS1337_BIT_A2IE          0x02
  92 #       define DS1337_BIT_A1IE          0x01
  93 #define DS1340_REG_CONTROL      0x07
  94 #       define DS1340_BIT_OUT           0x80
  95 #       define DS1340_BIT_FT            0x40
  96 #       define DS1340_BIT_CALIB_SIGN    0x20
  97 #       define DS1340_M_CALIBRATION     0x1f
  98 #define DS1340_REG_FLAG         0x09
  99 #       define DS1340_BIT_OSF           0x80
 100 #define DS1337_REG_STATUS       0x0f
 101 #       define DS1337_BIT_OSF           0x80
 102 #       define DS3231_BIT_EN32KHZ       0x08
 103 #       define DS1337_BIT_A2I           0x02
 104 #       define DS1337_BIT_A1I           0x01
 105 #define DS1339_REG_ALARM1_SECS  0x07
 106
 107 #define DS13XX_TRICKLE_CHARGER_MAGIC    0xa0
 108
 109 #define RX8025_REG_CTRL1        0x0e
 110 #       define RX8025_BIT_2412          0x20
 111 #define RX8025_REG_CTRL2        0x0f
 112 #       define RX8025_BIT_PON           0x10
 113 #       define RX8025_BIT_VDET          0x40
 114 #       define RX8025_BIT_XST           0x20
 115
 116
 117 struct ds1307 {
 118         u8                      offset; /* register's offset */
 119         u8                      regs[11];
 120         u16                     nvram_offset;
 121         struct nvmem_config     nvmem_cfg;
 122         enum ds_type            type;
 123         unsigned long           flags;
 124 #define HAS_NVRAM       0               /* bit 0 == sysfs file active */
 125 #define HAS_ALARM       1               /* bit 1 == irq claimed */
 126         struct device           *dev;
 127         struct regmap           *regmap;
 128         const char              *name;
 129         int                     irq;
 130         struct rtc_device       *rtc;
 131 #ifdef CONFIG_COMMON_CLK
 132         struct clk_hw           clks[2];
 133 #endif
 134 };
 135
 136 struct chip_desc {
 137         unsigned                alarm:1;
 138         u16                     nvram_offset;
 139         u16                     nvram_size;
 140         u8                      century_reg;
 141         u8                      century_enable_bit;
 142         u8                      century_bit;
 143         u16                     trickle_charger_reg;
 144         u8                      trickle_charger_setup;
 145         u8                      (*do_trickle_setup)(struct ds1307 *, uint32_t,
 146                                                     bool);
 147 };
 148
 149 static u8 do_trickle_setup_ds1339(struct ds1307 *, uint32_t ohms, bool diode);
 150
 151 static struct chip_desc chips[last_ds_type] = {
 152         [ds_1307] = {
 153                 .nvram_offset   = 8,
 154                 .nvram_size     = 56,
 155         },
 156         [ds_1308] = {
 157                 .nvram_offset   = 8,
 158                 .nvram_size     = 56,
 159         },
 160         [ds_1337] = {
 161                 .alarm          = 1,
 162                 .century_reg    = DS1307_REG_MONTH,
 163                 .century_bit    = DS1337_BIT_CENTURY,
 164         },
 165         [ds_1338] = {
 166                 .nvram_offset   = 8,
 167                 .nvram_size     = 56,
 168         },
 169         [ds_1339] = {
 170                 .alarm          = 1,
 171                 .century_reg    = DS1307_REG_MONTH,
 172                 .century_bit    = DS1337_BIT_CENTURY,
 173                 .trickle_charger_reg = 0x10,
 174                 .do_trickle_setup = &do_trickle_setup_ds1339,
 175         },
 176         [ds_1340] = {
 177                 .century_reg    = DS1307_REG_HOUR,
 178                 .century_enable_bit = DS1340_BIT_CENTURY_EN,
 179                 .century_bit    = DS1340_BIT_CENTURY,
 180                 .trickle_charger_reg = 0x08,
 181         },
 182         [ds_1388] = {
 183                 .trickle_charger_reg = 0x0a,
 184         },
 185         [ds_3231] = {
 186                 .alarm          = 1,
 187                 .century_reg    = DS1307_REG_MONTH,
 188                 .century_bit    = DS1337_BIT_CENTURY,
 189         },
 190         [rx_8130] = {
 191                 .alarm          = 1,
 192                 /* this is battery backed SRAM */
 193                 .nvram_offset   = 0x20,
 194                 .nvram_size     = 4,    /* 32bit (4 word x 8 bit) */
 195         },
 196         [mcp794xx] = {
 197                 .alarm          = 1,
 198                 /* this is battery backed SRAM */
 199                 .nvram_offset   = 0x20,
 200                 .nvram_size     = 0x40,
 201         },
 202 };
 203
 204 static const struct i2c_device_id ds1307_id[] = {
 205         { "ds1307", ds_1307 },
 206         { "ds1308", ds_1308 },
 207         { "ds1337", ds_1337 },
 208         { "ds1338", ds_1338 },
 209         { "ds1339", ds_1339 },
 210         { "ds1388", ds_1388 },
 211         { "ds1340", ds_1340 },
 212         { "ds3231", ds_3231 },
 213         { "m41t0", m41t0 },
 214         { "m41t00", m41t00 },
 215         { "mcp7940x", mcp794xx },
 216         { "mcp7941x", mcp794xx },
 217         { "pt7c4338", ds_1307 },
 218         { "rx8025", rx_8025 },
 219         { "isl12057", ds_1337 },
 220         { "rx8130", rx_8130 },
 221         { }
 222 };
 223 MODULE_DEVICE_TABLE(i2c, ds1307_id);
 224
 225 #ifdef CONFIG_OF
 226 static const struct of_device_id ds1307_of_match[] = {
 227         {
 228                 .compatible = "dallas,ds1307",
 229                 .data = (void *)ds_1307
 230         },
 231         {
 232                 .compatible = "dallas,ds1308",
 233                 .data = (void *)ds_1308
 234         },
 235         {
 236                 .compatible = "dallas,ds1337",
 237                 .data = (void *)ds_1337
 238         },
 239         {
 240                 .compatible = "dallas,ds1338",
 241                 .data = (void *)ds_1338
 242         },
 243         {
 244                 .compatible = "dallas,ds1339",
 245                 .data = (void *)ds_1339
 246         },
 247         {
 248                 .compatible = "dallas,ds1388",
 249                 .data = (void *)ds_1388
 250         },
 251         {
 252                 .compatible = "dallas,ds1340",
 253                 .data = (void *)ds_1340
 254         },
 255         {
 256                 .compatible = "maxim,ds3231",
 257                 .data = (void *)ds_3231
 258         },
 259         {
 260                 .compatible = "st,m41t0",
 261                 .data = (void *)m41t00
 262         },
 263         {
 264                 .compatible = "st,m41t00",
 265                 .data = (void *)m41t00
 266         },
 267         {
 268                 .compatible = "microchip,mcp7940x",
 269                 .data = (void *)mcp794xx
 270         },
 271         {
 272                 .compatible = "microchip,mcp7941x",
 273                 .data = (void *)mcp794xx
 274         },
 275         {
 276                 .compatible = "pericom,pt7c4338",
 277                 .data = (void *)ds_1307
 278         },
 279         {
 280                 .compatible = "epson,rx8025",
 281                 .data = (void *)rx_8025
 282         },
 283         {
 284                 .compatible = "isil,isl12057",
 285                 .data = (void *)ds_1337
 286         },
 287         { }
 288 };
 289 MODULE_DEVICE_TABLE(of, ds1307_of_match);
 290 #endif
 291
 292 #ifdef CONFIG_ACPI
 293 static const struct acpi_device_id ds1307_acpi_ids[] = {
 294         { .id = "DS1307", .driver_data = ds_1307 },
 295         { .id = "DS1308", .driver_data = ds_1308 },
 296         { .id = "DS1337", .driver_data = ds_1337 },
 297         { .id = "DS1338", .driver_data = ds_1338 },
 298         { .id = "DS1339", .driver_data = ds_1339 },
 299         { .id = "DS1388", .driver_data = ds_1388 },
 300         { .id = "DS1340", .driver_data = ds_1340 },
 301         { .id = "DS3231", .driver_data = ds_3231 },
 302         { .id = "M41T0", .driver_data = m41t0 },
 303         { .id = "M41T00", .driver_data = m41t00 },
 304         { .id = "MCP7940X", .driver_data = mcp794xx },
 305         { .id = "MCP7941X", .driver_data = mcp794xx },
 306         { .id = "PT7C4338", .driver_data = ds_1307 },
 307         { .id = "RX8025", .driver_data = rx_8025 },
 308         { .id = "ISL12057", .driver_data = ds_1337 },
 309         { }
 310 };
 311 MODULE_DEVICE_TABLE(acpi, ds1307_acpi_ids);
 312 #endif
 313
 314 /*
 315  * The ds1337 and ds1339 both have two alarms, but we only use the first
 316  * one (with a "seconds" field).  For ds1337 we expect nINTA is our alarm
 317  * signal; ds1339 chips have only one alarm signal.
 318  */
 319 static irqreturn_t ds1307_irq(int irq, void *dev_id)
 320 {
 321         struct ds1307           *ds1307 = dev_id;
 322         struct mutex            *lock = &ds1307->rtc->ops_lock;
 323         int                     stat, ret;
 324
 325         mutex_lock(lock);
 326         ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &stat);
 327         if (ret)
 328                 goto out;
 329
 330         if (stat & DS1337_BIT_A1I) {
 331                 stat &= ~DS1337_BIT_A1I;
 332                 regmap_write(ds1307->regmap, DS1337_REG_STATUS, stat);
 333
 334                 ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
 335                                          DS1337_BIT_A1IE, 0);
 336                 if (ret)
 337                         goto out;
 338
 339                 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
 340         }
 341
 342 out:
 343         mutex_unlock(lock);
 344
 345         return IRQ_HANDLED;
 346 }
 347
 348 /*----------------------------------------------------------------------*/
 349
 350 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
 351 {
 352         struct ds1307   *ds1307 = dev_get_drvdata(dev);
 353         int             tmp, ret;
 354         const struct chip_desc *chip = &chips[ds1307->type];
 355
 356         /* read the RTC date and time registers all at once */
 357         ret = regmap_bulk_read(ds1307->regmap, ds1307->offset, ds1307->regs, 7);
 358         if (ret) {
 359                 dev_err(dev, "%s error %d\n", "read", ret);
 360                 return ret;
 361         }
 362
 363         dev_dbg(dev, "%s: %7ph\n", "read", ds1307->regs);
 364
 365         /* if oscillator fail bit is set, no data can be trusted */
 366         if (ds1307->type == m41t0 &&
 367             ds1307->regs[DS1307_REG_MIN] & M41T0_BIT_OF) {
 368                 dev_warn_once(dev, "oscillator failed, set time!\n");
 369                 return -EINVAL;
 370         }
 371
 372         t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
 373         t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
 374         tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
 375         t->tm_hour = bcd2bin(tmp);
 376         t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
 377         t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
 378         tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
 379         t->tm_mon = bcd2bin(tmp) - 1;
 380         t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
 381
 382         if (ds1307->regs[chip->century_reg] & chip->century_bit &&
 383             IS_ENABLED(CONFIG_RTC_DRV_DS1307_CENTURY))
 384                 t->tm_year += 100;
 385
 386         dev_dbg(dev, "%s secs=%d, mins=%d, "
 387                 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
 388                 "read", t->tm_sec, t->tm_min,
 389                 t->tm_hour, t->tm_mday,
 390                 t->tm_mon, t->tm_year, t->tm_wday);
 391
 392         /* initial clock setting can be undefined */
 393         return rtc_valid_tm(t);
 394 }
 395
 396 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
 397 {
 398         struct ds1307   *ds1307 = dev_get_drvdata(dev);
 399         const struct chip_desc *chip = &chips[ds1307->type];
 400         int             result;
 401         int             tmp;
 402         u8              *buf = ds1307->regs;
 403
 404         dev_dbg(dev, "%s secs=%d, mins=%d, "
 405                 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
 406                 "write", t->tm_sec, t->tm_min,
 407                 t->tm_hour, t->tm_mday,
 408                 t->tm_mon, t->tm_year, t->tm_wday);
 409
 410         if (t->tm_year < 100)
 411                 return -EINVAL;
 412
 413 #ifdef CONFIG_RTC_DRV_DS1307_CENTURY
 414         if (t->tm_year > (chip->century_bit ? 299 : 199))
 415                 return -EINVAL;
 416 #else
 417         if (t->tm_year > 199)
 418                 return -EINVAL;
 419 #endif
 420
 421         buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
 422         buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
 423         buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
 424         buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
 425         buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
 426         buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
 427
 428         /* assume 20YY not 19YY */
 429         tmp = t->tm_year - 100;
 430         buf[DS1307_REG_YEAR] = bin2bcd(tmp);
 431
 432         if (chip->century_enable_bit)
 433                 buf[chip->century_reg] |= chip->century_enable_bit;
 434         if (t->tm_year > 199 && chip->century_bit)
 435                 buf[chip->century_reg] |= chip->century_bit;
 436
 437         if (ds1307->type == mcp794xx) {
 438                 /*
 439                  * these bits were cleared when preparing the date/time
 440                  * values and need to be set again before writing the
 441                  * buffer out to the device.
 442                  */
 443                 buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
 444                 buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
 445         }
 446
 447         dev_dbg(dev, "%s: %7ph\n", "write", buf);
 448
 449         result = regmap_bulk_write(ds1307->regmap, ds1307->offset, buf, 7);
 450         if (result) {
 451                 dev_err(dev, "%s error %d\n", "write", result);
 452                 return result;
 453         }
 454         return 0;
 455 }
 456
 457 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 458 {
 459         struct ds1307           *ds1307 = dev_get_drvdata(dev);
 460         int                     ret;
 461
 462         if (!test_bit(HAS_ALARM, &ds1307->flags))
 463                 return -EINVAL;
 464
 465         /* read all ALARM1, ALARM2, and status registers at once */
 466         ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS,
 467                                ds1307->regs, 9);
 468         if (ret) {
 469                 dev_err(dev, "%s error %d\n", "alarm read", ret);
 470                 return ret;
 471         }
 472
 473         dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read",
 474                 &ds1307->regs[0], &ds1307->regs[4], &ds1307->regs[7]);
 475
 476         /*
 477          * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
 478          * and that all four fields are checked matches
 479          */
 480         t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
 481         t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
 482         t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
 483         t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
 484
 485         /* ... and status */
 486         t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
 487         t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
 488
 489         dev_dbg(dev, "%s secs=%d, mins=%d, "
 490                 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
 491                 "alarm read", t->time.tm_sec, t->time.tm_min,
 492                 t->time.tm_hour, t->time.tm_mday,
 493                 t->enabled, t->pending);
 494
 495         return 0;
 496 }
 497
 498 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 499 {
 500         struct ds1307           *ds1307 = dev_get_drvdata(dev);
 501         unsigned char           *buf = ds1307->regs;
 502         u8                      control, status;
 503         int                     ret;
 504
 505         if (!test_bit(HAS_ALARM, &ds1307->flags))
 506                 return -EINVAL;
 507
 508         dev_dbg(dev, "%s secs=%d, mins=%d, "
 509                 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
 510                 "alarm set", t->time.tm_sec, t->time.tm_min,
 511                 t->time.tm_hour, t->time.tm_mday,
 512                 t->enabled, t->pending);
 513
 514         /* read current status of both alarms and the chip */
 515         ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS, buf, 9);
 516         if (ret) {
 517                 dev_err(dev, "%s error %d\n", "alarm write", ret);
 518                 return ret;
 519         }
 520         control = ds1307->regs[7];
 521         status = ds1307->regs[8];
 522
 523         dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)",
 524                 &ds1307->regs[0], &ds1307->regs[4], control, status);
 525
 526         /* set ALARM1, using 24 hour and day-of-month modes */
 527         buf[0] = bin2bcd(t->time.tm_sec);
 528         buf[1] = bin2bcd(t->time.tm_min);
 529         buf[2] = bin2bcd(t->time.tm_hour);
 530         buf[3] = bin2bcd(t->time.tm_mday);
 531
 532         /* set ALARM2 to non-garbage */
 533         buf[4] = 0;
 534         buf[5] = 0;
 535         buf[6] = 0;
 536
 537         /* disable alarms */
 538         buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
 539         buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
 540
 541         ret = regmap_bulk_write(ds1307->regmap, DS1339_REG_ALARM1_SECS, buf, 9);
 542         if (ret) {
 543                 dev_err(dev, "can't set alarm time\n");
 544                 return ret;
 545         }
 546
 547         /* optionally enable ALARM1 */
 548         if (t->enabled) {
 549                 dev_dbg(dev, "alarm IRQ armed\n");
 550                 buf[7] |= DS1337_BIT_A1IE;      /* only ALARM1 is used */
 551                 regmap_write(ds1307->regmap, DS1337_REG_CONTROL, buf[7]);
 552         }
 553
 554         return 0;
 555 }
 556
 557 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
 558 {
 559         struct ds1307           *ds1307 = dev_get_drvdata(dev);
 560
 561         if (!test_bit(HAS_ALARM, &ds1307->flags))
 562                 return -ENOTTY;
 563
 564         return regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
 565                                   DS1337_BIT_A1IE,
 566                                   enabled ? DS1337_BIT_A1IE : 0);
 567 }
 568
 569 static const struct rtc_class_ops ds13xx_rtc_ops = {
 570         .read_time      = ds1307_get_time,
 571         .set_time       = ds1307_set_time,
 572         .read_alarm     = ds1337_read_alarm,
 573         .set_alarm      = ds1337_set_alarm,
 574         .alarm_irq_enable = ds1307_alarm_irq_enable,
 575 };
 576
 577 /*----------------------------------------------------------------------*/
 578
 579 /*
 580  * Alarm support for rx8130 devices.
 581  */
 582
 583 #define RX8130_REG_ALARM_MIN            0x07
 584 #define RX8130_REG_ALARM_HOUR           0x08
 585 #define RX8130_REG_ALARM_WEEK_OR_DAY    0x09
 586 #define RX8130_REG_EXTENSION            0x0c
 587 #define RX8130_REG_EXTENSION_WADA       (1 << 3)
 588 #define RX8130_REG_FLAG                 0x0d
 589 #define RX8130_REG_FLAG_AF              (1 << 3)
 590 #define RX8130_REG_CONTROL0             0x0e
 591 #define RX8130_REG_CONTROL0_AIE         (1 << 3)
 592
 593 static irqreturn_t rx8130_irq(int irq, void *dev_id)
 594 {
 595         struct ds1307           *ds1307 = dev_id;
 596         struct mutex            *lock = &ds1307->rtc->ops_lock;
 597         u8 ctl[3];
 598         int ret;
 599
 600         mutex_lock(lock);
 601
 602         /* Read control registers. */
 603         ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl, 3);
 604         if (ret < 0)
 605                 goto out;
 606         if (!(ctl[1] & RX8130_REG_FLAG_AF))
 607                 goto out;
 608         ctl[1] &= ~RX8130_REG_FLAG_AF;
 609         ctl[2] &= ~RX8130_REG_CONTROL0_AIE;
 610
 611         ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl, 3);
 612         if (ret < 0)
 613                 goto out;
 614
 615         rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
 616
 617 out:
 618         mutex_unlock(lock);
 619
 620         return IRQ_HANDLED;
 621 }
 622
 623 static int rx8130_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 624 {
 625         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 626         u8 ald[3], ctl[3];
 627         int ret;
 628
 629         if (!test_bit(HAS_ALARM, &ds1307->flags))
 630                 return -EINVAL;
 631
 632         /* Read alarm registers. */
 633         ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_ALARM_MIN, ald, 3);
 634         if (ret < 0)
 635                 return ret;
 636
 637         /* Read control registers. */
 638         ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl, 3);
 639         if (ret < 0)
 640                 return ret;
 641
 642         t->enabled = !!(ctl[2] & RX8130_REG_CONTROL0_AIE);
 643         t->pending = !!(ctl[1] & RX8130_REG_FLAG_AF);
 644
 645         /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
 646         t->time.tm_sec = -1;
 647         t->time.tm_min = bcd2bin(ald[0] & 0x7f);
 648         t->time.tm_hour = bcd2bin(ald[1] & 0x7f);
 649         t->time.tm_wday = -1;
 650         t->time.tm_mday = bcd2bin(ald[2] & 0x7f);
 651         t->time.tm_mon = -1;
 652         t->time.tm_year = -1;
 653         t->time.tm_yday = -1;
 654         t->time.tm_isdst = -1;
 655
 656         dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d enabled=%d\n",
 657                 __func__, t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 658                 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled);
 659
 660         return 0;
 661 }
 662
 663 static int rx8130_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 664 {
 665         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 666         u8 ald[3], ctl[3];
 667         int ret;
 668
 669         if (!test_bit(HAS_ALARM, &ds1307->flags))
 670                 return -EINVAL;
 671
 672         dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
 673                 "enabled=%d pending=%d\n", __func__,
 674                 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 675                 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
 676                 t->enabled, t->pending);
 677
 678         /* Read control registers. */
 679         ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl, 3);
 680         if (ret < 0)
 681                 return ret;
 682
 683         ctl[0] &= ~RX8130_REG_EXTENSION_WADA;
 684         ctl[1] |= RX8130_REG_FLAG_AF;
 685         ctl[2] &= ~RX8130_REG_CONTROL0_AIE;
 686
 687         ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl, 3);
 688         if (ret < 0)
 689                 return ret;
 690
 691         /* Hardware alarm precision is 1 minute! */
 692         ald[0] = bin2bcd(t->time.tm_min);
 693         ald[1] = bin2bcd(t->time.tm_hour);
 694         ald[2] = bin2bcd(t->time.tm_mday);
 695
 696         ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_ALARM_MIN, ald, 3);
 697         if (ret < 0)
 698                 return ret;
 699
 700         if (!t->enabled)
 701                 return 0;
 702
 703         ctl[2] |= RX8130_REG_CONTROL0_AIE;
 704
 705         return regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl, 3);
 706 }
 707
 708 static int rx8130_alarm_irq_enable(struct device *dev, unsigned int enabled)
 709 {
 710         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 711         int ret, reg;
 712
 713         if (!test_bit(HAS_ALARM, &ds1307->flags))
 714                 return -EINVAL;
 715
 716         ret = regmap_read(ds1307->regmap, RX8130_REG_CONTROL0, &reg);
 717         if (ret < 0)
 718                 return ret;
 719
 720         if (enabled)
 721                 reg |= RX8130_REG_CONTROL0_AIE;
 722         else
 723                 reg &= ~RX8130_REG_CONTROL0_AIE;
 724
 725         return regmap_write(ds1307->regmap, RX8130_REG_CONTROL0, reg);
 726 }
 727
 728 static const struct rtc_class_ops rx8130_rtc_ops = {
 729         .read_time      = ds1307_get_time,
 730         .set_time       = ds1307_set_time,
 731         .read_alarm     = rx8130_read_alarm,
 732         .set_alarm      = rx8130_set_alarm,
 733         .alarm_irq_enable = rx8130_alarm_irq_enable,
 734 };
 735
 736 /*----------------------------------------------------------------------*/
 737
 738 /*
 739  * Alarm support for mcp794xx devices.
 740  */
 741
 742 #define MCP794XX_REG_WEEKDAY            0x3
 743 #define MCP794XX_REG_WEEKDAY_WDAY_MASK  0x7
 744 #define MCP794XX_REG_CONTROL            0x07
 745 #       define MCP794XX_BIT_ALM0_EN     0x10
 746 #       define MCP794XX_BIT_ALM1_EN     0x20
 747 #define MCP794XX_REG_ALARM0_BASE        0x0a
 748 #define MCP794XX_REG_ALARM0_CTRL        0x0d
 749 #define MCP794XX_REG_ALARM1_BASE        0x11
 750 #define MCP794XX_REG_ALARM1_CTRL        0x14
 751 #       define MCP794XX_BIT_ALMX_IF     (1 << 3)
 752 #       define MCP794XX_BIT_ALMX_C0     (1 << 4)
 753 #       define MCP794XX_BIT_ALMX_C1     (1 << 5)
 754 #       define MCP794XX_BIT_ALMX_C2     (1 << 6)
 755 #       define MCP794XX_BIT_ALMX_POL    (1 << 7)
 756 #       define MCP794XX_MSK_ALMX_MATCH  (MCP794XX_BIT_ALMX_C0 | \
 757                                          MCP794XX_BIT_ALMX_C1 | \
 758                                          MCP794XX_BIT_ALMX_C2)
 759
 760 static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
 761 {
 762         struct ds1307           *ds1307 = dev_id;
 763         struct mutex            *lock = &ds1307->rtc->ops_lock;
 764         int reg, ret;
 765
 766         mutex_lock(lock);
 767
 768         /* Check and clear alarm 0 interrupt flag. */
 769         ret = regmap_read(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, &reg);
 770         if (ret)
 771                 goto out;
 772         if (!(reg & MCP794XX_BIT_ALMX_IF))
 773                 goto out;
 774         reg &= ~MCP794XX_BIT_ALMX_IF;
 775         ret = regmap_write(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, reg);
 776         if (ret)
 777                 goto out;
 778
 779         /* Disable alarm 0. */
 780         ret = regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL,
 781                                  MCP794XX_BIT_ALM0_EN, 0);
 782         if (ret)
 783                 goto out;
 784
 785         rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
 786
 787 out:
 788         mutex_unlock(lock);
 789
 790         return IRQ_HANDLED;
 791 }
 792
 793 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 794 {
 795         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 796         u8 *regs = ds1307->regs;
 797         int ret;
 798
 799         if (!test_bit(HAS_ALARM, &ds1307->flags))
 800                 return -EINVAL;
 801
 802         /* Read control and alarm 0 registers. */
 803         ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs, 10);
 804         if (ret)
 805                 return ret;
 806
 807         t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
 808
 809         /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
 810         t->time.tm_sec = bcd2bin(ds1307->regs[3] & 0x7f);
 811         t->time.tm_min = bcd2bin(ds1307->regs[4] & 0x7f);
 812         t->time.tm_hour = bcd2bin(ds1307->regs[5] & 0x3f);
 813         t->time.tm_wday = bcd2bin(ds1307->regs[6] & 0x7) - 1;
 814         t->time.tm_mday = bcd2bin(ds1307->regs[7] & 0x3f);
 815         t->time.tm_mon = bcd2bin(ds1307->regs[8] & 0x1f) - 1;
 816         t->time.tm_year = -1;
 817         t->time.tm_yday = -1;
 818         t->time.tm_isdst = -1;
 819
 820         dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
 821                 "enabled=%d polarity=%d irq=%d match=%d\n", __func__,
 822                 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 823                 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
 824                 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_POL),
 825                 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_IF),
 826                 (ds1307->regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
 827
 828         return 0;
 829 }
 830
 831 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 832 {
 833         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 834         unsigned char *regs = ds1307->regs;
 835         int ret;
 836
 837         if (!test_bit(HAS_ALARM, &ds1307->flags))
 838                 return -EINVAL;
 839
 840         dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
 841                 "enabled=%d pending=%d\n", __func__,
 842                 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 843                 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
 844                 t->enabled, t->pending);
 845
 846         /* Read control and alarm 0 registers. */
 847         ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs, 10);
 848         if (ret)
 849                 return ret;
 850
 851         /* Set alarm 0, using 24-hour and day-of-month modes. */
 852         regs[3] = bin2bcd(t->time.tm_sec);
 853         regs[4] = bin2bcd(t->time.tm_min);
 854         regs[5] = bin2bcd(t->time.tm_hour);
 855         regs[6] = bin2bcd(t->time.tm_wday + 1);
 856         regs[7] = bin2bcd(t->time.tm_mday);
 857         regs[8] = bin2bcd(t->time.tm_mon + 1);
 858
 859         /* Clear the alarm 0 interrupt flag. */
 860         regs[6] &= ~MCP794XX_BIT_ALMX_IF;
 861         /* Set alarm match: second, minute, hour, day, date, month. */
 862         regs[6] |= MCP794XX_MSK_ALMX_MATCH;
 863         /* Disable interrupt. We will not enable until completely programmed */
 864         regs[0] &= ~MCP794XX_BIT_ALM0_EN;
 865
 866         ret = regmap_bulk_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs, 10);
 867         if (ret)
 868                 return ret;
 869
 870         if (!t->enabled)
 871                 return 0;
 872         regs[0] |= MCP794XX_BIT_ALM0_EN;
 873         return regmap_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs[0]);
 874 }
 875
 876 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
 877 {
 878         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 879
 880         if (!test_bit(HAS_ALARM, &ds1307->flags))
 881                 return -EINVAL;
 882
 883         return regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL,
 884                                   MCP794XX_BIT_ALM0_EN,
 885                                   enabled ? MCP794XX_BIT_ALM0_EN : 0);
 886 }
 887
 888 static const struct rtc_class_ops mcp794xx_rtc_ops = {
 889         .read_time      = ds1307_get_time,
 890         .set_time       = ds1307_set_time,
 891         .read_alarm     = mcp794xx_read_alarm,
 892         .set_alarm      = mcp794xx_set_alarm,
 893         .alarm_irq_enable = mcp794xx_alarm_irq_enable,
 894 };
 895
 896 /*----------------------------------------------------------------------*/
 897
 898 static int ds1307_nvram_read(void *priv, unsigned int offset, void *val,
 899                              size_t bytes)
 900 {
 901         struct ds1307 *ds1307 = priv;
 902
 903         return regmap_bulk_read(ds1307->regmap, ds1307->nvram_offset + offset,
 904                                 val, bytes);
 905 }
 906
 907 static int ds1307_nvram_write(void *priv, unsigned int offset, void *val,
 908                               size_t bytes)
 909 {
 910         struct ds1307 *ds1307 = priv;
 911
 912         return regmap_bulk_write(ds1307->regmap, ds1307->nvram_offset + offset,
 913                                  val, bytes);
 914 }
 915
 916 /*----------------------------------------------------------------------*/
 917
 918 static u8 do_trickle_setup_ds1339(struct ds1307 *ds1307,
 919                                   uint32_t ohms, bool diode)
 920 {
 921         u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
 922                 DS1307_TRICKLE_CHARGER_NO_DIODE;
 923
 924         switch (ohms) {
 925         case 250:
 926                 setup |= DS1307_TRICKLE_CHARGER_250_OHM;
 927                 break;
 928         case 2000:
 929                 setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
 930                 break;
 931         case 4000:
 932                 setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
 933                 break;
 934         default:
 935                 dev_warn(ds1307->dev,
 936                          "Unsupported ohm value %u in dt\n", ohms);
 937                 return 0;
 938         }
 939         return setup;
 940 }
 941
 942 static void ds1307_trickle_init(struct ds1307 *ds1307,
 943                                 struct chip_desc *chip)
 944 {
 945         uint32_t ohms = 0;
 946         bool diode = true;
 947
 948         if (!chip->do_trickle_setup)
 949                 goto out;
 950         if (device_property_read_u32(ds1307->dev, "trickle-resistor-ohms",
 951                                      &ohms))
 952                 goto out;
 953         if (device_property_read_bool(ds1307->dev, "trickle-diode-disable"))
 954                 diode = false;
 955         chip->trickle_charger_setup = chip->do_trickle_setup(ds1307,
 956                                                              ohms, diode);
 957 out:
 958         return;
 959 }
 960
 961 /*----------------------------------------------------------------------*/
 962
 963 #ifdef CONFIG_RTC_DRV_DS1307_HWMON
 964
 965 /*
 966  * Temperature sensor support for ds3231 devices.
 967  */
 968
 969 #define DS3231_REG_TEMPERATURE  0x11
 970
 971 /*
 972  * A user-initiated temperature conversion is not started by this function,
 973  * so the temperature is updated once every 64 seconds.
 974  */
 975 static int ds3231_hwmon_read_temp(struct device *dev, s32 *mC)
 976 {
 977         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 978         u8 temp_buf[2];
 979         s16 temp;
 980         int ret;
 981
 982         ret = regmap_bulk_read(ds1307->regmap, DS3231_REG_TEMPERATURE,
 983                                temp_buf, sizeof(temp_buf));
 984         if (ret)
 985                 return ret;
 986         /*
 987          * Temperature is represented as a 10-bit code with a resolution of
 988          * 0.25 degree celsius and encoded in two's complement format.
 989          */
 990         temp = (temp_buf[0] << 8) | temp_buf[1];
 991         temp >>= 6;
 992         *mC = temp * 250;
 993
 994         return 0;
 995 }
 996
 997 static ssize_t ds3231_hwmon_show_temp(struct device *dev,
 998                                 struct device_attribute *attr, char *buf)
 999 {
1000         int ret;
1001         s32 temp;
1002
1003         ret = ds3231_hwmon_read_temp(dev, &temp);
1004         if (ret)
1005                 return ret;
1006
1007         return sprintf(buf, "%d\n", temp);
1008 }
1009 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ds3231_hwmon_show_temp,
1010                         NULL, 0);
1011
1012 static struct attribute *ds3231_hwmon_attrs[] = {
1013         &sensor_dev_attr_temp1_input.dev_attr.attr,
1014         NULL,
1015 };
1016 ATTRIBUTE_GROUPS(ds3231_hwmon);
1017
1018 static void ds1307_hwmon_register(struct ds1307 *ds1307)
1019 {
1020         struct device *dev;
1021
1022         if (ds1307->type != ds_3231)
1023                 return;
1024
1025         dev = devm_hwmon_device_register_with_groups(ds1307->dev, ds1307->name,
1026                                                 ds1307, ds3231_hwmon_groups);
1027         if (IS_ERR(dev)) {
1028                 dev_warn(ds1307->dev, "unable to register hwmon device %ld\n",
1029                          PTR_ERR(dev));
1030         }
1031 }
1032
1033 #else
1034
1035 static void ds1307_hwmon_register(struct ds1307 *ds1307)
1036 {
1037 }
1038
1039 #endif /* CONFIG_RTC_DRV_DS1307_HWMON */
1040
1041 /*----------------------------------------------------------------------*/
1042
1043 /*
1044  * Square-wave output support for DS3231
1045  * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf
1046  */
1047 #ifdef CONFIG_COMMON_CLK
1048
1049 enum {
1050         DS3231_CLK_SQW = 0,
1051         DS3231_CLK_32KHZ,
1052 };
1053
1054 #define clk_sqw_to_ds1307(clk)  \
1055         container_of(clk, struct ds1307, clks[DS3231_CLK_SQW])
1056 #define clk_32khz_to_ds1307(clk)        \
1057         container_of(clk, struct ds1307, clks[DS3231_CLK_32KHZ])
1058
1059 static int ds3231_clk_sqw_rates[] = {
1060         1,
1061         1024,
1062         4096,
1063         8192,
1064 };
1065
1066 static int ds1337_write_control(struct ds1307 *ds1307, u8 mask, u8 value)
1067 {
1068         struct mutex *lock = &ds1307->rtc->ops_lock;
1069         int ret;
1070
1071         mutex_lock(lock);
1072         ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
1073                                  mask, value);
1074         mutex_unlock(lock);
1075
1076         return ret;
1077 }
1078
1079 static unsigned long ds3231_clk_sqw_recalc_rate(struct clk_hw *hw,
1080                                                 unsigned long parent_rate)
1081 {
1082         struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1083         int control, ret;
1084         int rate_sel = 0;
1085
1086         ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control);
1087         if (ret)
1088                 return ret;
1089         if (control & DS1337_BIT_RS1)
1090                 rate_sel += 1;
1091         if (control & DS1337_BIT_RS2)
1092                 rate_sel += 2;
1093
1094         return ds3231_clk_sqw_rates[rate_sel];
1095 }
1096
1097 static long ds3231_clk_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
1098                                         unsigned long *prate)
1099 {
1100         int i;
1101
1102         for (i = ARRAY_SIZE(ds3231_clk_sqw_rates) - 1; i >= 0; i--) {
1103                 if (ds3231_clk_sqw_rates[i] <= rate)
1104                         return ds3231_clk_sqw_rates[i];
1105         }
1106
1107         return 0;
1108 }
1109
1110 static int ds3231_clk_sqw_set_rate(struct clk_hw *hw, unsigned long rate,
1111                                         unsigned long parent_rate)
1112 {
1113         struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1114         int control = 0;
1115         int rate_sel;
1116
1117         for (rate_sel = 0; rate_sel < ARRAY_SIZE(ds3231_clk_sqw_rates);
1118                         rate_sel++) {
1119                 if (ds3231_clk_sqw_rates[rate_sel] == rate)
1120                         break;
1121         }
1122
1123         if (rate_sel == ARRAY_SIZE(ds3231_clk_sqw_rates))
1124                 return -EINVAL;
1125
1126         if (rate_sel & 1)
1127                 control |= DS1337_BIT_RS1;
1128         if (rate_sel & 2)
1129                 control |= DS1337_BIT_RS2;
1130
1131         return ds1337_write_control(ds1307, DS1337_BIT_RS1 | DS1337_BIT_RS2,
1132                                 control);
1133 }
1134
1135 static int ds3231_clk_sqw_prepare(struct clk_hw *hw)
1136 {
1137         struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1138
1139         return ds1337_write_control(ds1307, DS1337_BIT_INTCN, 0);
1140 }
1141
1142 static void ds3231_clk_sqw_unprepare(struct clk_hw *hw)
1143 {
1144         struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1145
1146         ds1337_write_control(ds1307, DS1337_BIT_INTCN, DS1337_BIT_INTCN);
1147 }
1148
1149 static int ds3231_clk_sqw_is_prepared(struct clk_hw *hw)
1150 {
1151         struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1152         int control, ret;
1153
1154         ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control);
1155         if (ret)
1156                 return ret;
1157
1158         return !(control & DS1337_BIT_INTCN);
1159 }
1160
1161 static const struct clk_ops ds3231_clk_sqw_ops = {
1162         .prepare = ds3231_clk_sqw_prepare,
1163         .unprepare = ds3231_clk_sqw_unprepare,
1164         .is_prepared = ds3231_clk_sqw_is_prepared,
1165         .recalc_rate = ds3231_clk_sqw_recalc_rate,
1166         .round_rate = ds3231_clk_sqw_round_rate,
1167         .set_rate = ds3231_clk_sqw_set_rate,
1168 };
1169
1170 static unsigned long ds3231_clk_32khz_recalc_rate(struct clk_hw *hw,
1171                                                 unsigned long parent_rate)
1172 {
1173         return 32768;
1174 }
1175
1176 static int ds3231_clk_32khz_control(struct ds1307 *ds1307, bool enable)
1177 {
1178         struct mutex *lock = &ds1307->rtc->ops_lock;
1179         int ret;
1180
1181         mutex_lock(lock);
1182         ret = regmap_update_bits(ds1307->regmap, DS1337_REG_STATUS,
1183                                  DS3231_BIT_EN32KHZ,
1184                                  enable ? DS3231_BIT_EN32KHZ : 0);
1185         mutex_unlock(lock);
1186
1187         return ret;
1188 }
1189
1190 static int ds3231_clk_32khz_prepare(struct clk_hw *hw)
1191 {
1192         struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1193
1194         return ds3231_clk_32khz_control(ds1307, true);
1195 }
1196
1197 static void ds3231_clk_32khz_unprepare(struct clk_hw *hw)
1198 {
1199         struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1200
1201         ds3231_clk_32khz_control(ds1307, false);
1202 }
1203
1204 static int ds3231_clk_32khz_is_prepared(struct clk_hw *hw)
1205 {
1206         struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1207         int status, ret;
1208
1209         ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &status);
1210         if (ret)
1211                 return ret;
1212
1213         return !!(status & DS3231_BIT_EN32KHZ);
1214 }
1215
1216 static const struct clk_ops ds3231_clk_32khz_ops = {
1217         .prepare = ds3231_clk_32khz_prepare,
1218         .unprepare = ds3231_clk_32khz_unprepare,
1219         .is_prepared = ds3231_clk_32khz_is_prepared,
1220         .recalc_rate = ds3231_clk_32khz_recalc_rate,
1221 };
1222
1223 static struct clk_init_data ds3231_clks_init[] = {
1224         [DS3231_CLK_SQW] = {
1225                 .name = "ds3231_clk_sqw",
1226                 .ops = &ds3231_clk_sqw_ops,
1227         },
1228         [DS3231_CLK_32KHZ] = {
1229                 .name = "ds3231_clk_32khz",
1230                 .ops = &ds3231_clk_32khz_ops,
1231         },
1232 };
1233
1234 static int ds3231_clks_register(struct ds1307 *ds1307)
1235 {
1236         struct device_node *node = ds1307->dev->of_node;
1237         struct clk_onecell_data *onecell;
1238         int i;
1239
1240         onecell = devm_kzalloc(ds1307->dev, sizeof(*onecell), GFP_KERNEL);
1241         if (!onecell)
1242                 return -ENOMEM;
1243
1244         onecell->clk_num = ARRAY_SIZE(ds3231_clks_init);
1245         onecell->clks = devm_kcalloc(ds1307->dev, onecell->clk_num,
1246                                      sizeof(onecell->clks[0]), GFP_KERNEL);
1247         if (!onecell->clks)
1248                 return -ENOMEM;
1249
1250         for (i = 0; i < ARRAY_SIZE(ds3231_clks_init); i++) {
1251                 struct clk_init_data init = ds3231_clks_init[i];
1252
1253                 /*
1254                  * Interrupt signal due to alarm conditions and square-wave
1255                  * output share same pin, so don't initialize both.
1256                  */
1257                 if (i == DS3231_CLK_SQW && test_bit(HAS_ALARM, &ds1307->flags))
1258                         continue;
1259
1260                 /* optional override of the clockname */
1261                 of_property_read_string_index(node, "clock-output-names", i,
1262                                                 &init.name);
1263                 ds1307->clks[i].init = &init;
1264
1265                 onecell->clks[i] = devm_clk_register(ds1307->dev,
1266                                                      &ds1307->clks[i]);
1267                 if (IS_ERR(onecell->clks[i]))
1268                         return PTR_ERR(onecell->clks[i]);
1269         }
1270
1271         if (!node)
1272                 return 0;
1273
1274         of_clk_add_provider(node, of_clk_src_onecell_get, onecell);
1275
1276         return 0;
1277 }
1278
1279 static void ds1307_clks_register(struct ds1307 *ds1307)
1280 {
1281         int ret;
1282
1283         if (ds1307->type != ds_3231)
1284                 return;
1285
1286         ret = ds3231_clks_register(ds1307);
1287         if (ret) {
1288                 dev_warn(ds1307->dev, "unable to register clock device %d\n",
1289                          ret);
1290         }
1291 }
1292
1293 #else
1294
1295 static void ds1307_clks_register(struct ds1307 *ds1307)
1296 {
1297 }
1298
1299 #endif /* CONFIG_COMMON_CLK */
1300
1301 static const struct regmap_config regmap_config = {
1302         .reg_bits = 8,
1303         .val_bits = 8,
1304 };
1305
1306 static int ds1307_probe(struct i2c_client *client,
1307                         const struct i2c_device_id *id)
1308 {
1309         struct ds1307           *ds1307;
1310         int                     err = -ENODEV;
1311         int                     tmp, wday;
1312         struct chip_desc        *chip;
1313         bool                    want_irq = false;
1314         bool                    ds1307_can_wakeup_device = false;
1315         unsigned char           *buf;
1316         struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
1317         struct rtc_time         tm;
1318         unsigned long           timestamp;
1319
1320         irq_handler_t   irq_handler = ds1307_irq;
1321
1322         static const int        bbsqi_bitpos[] = {
1323                 [ds_1337] = 0,
1324                 [ds_1339] = DS1339_BIT_BBSQI,
1325                 [ds_3231] = DS3231_BIT_BBSQW,
1326         };
1327         const struct rtc_class_ops *rtc_ops = &ds13xx_rtc_ops;
1328
1329         ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
1330         if (!ds1307)
1331                 return -ENOMEM;
1332
1333         dev_set_drvdata(&client->dev, ds1307);
1334         ds1307->dev = &client->dev;
1335         ds1307->name = client->name;
1336         ds1307->irq = client->irq;
1337
1338         ds1307->regmap = devm_regmap_init_i2c(client, &regmap_config);
1339         if (IS_ERR(ds1307->regmap)) {
1340                 dev_err(ds1307->dev, "regmap allocation failed\n");
1341                 return PTR_ERR(ds1307->regmap);
1342         }
1343
1344         i2c_set_clientdata(client, ds1307);
1345
1346         if (client->dev.of_node) {
1347                 ds1307->type = (enum ds_type)
1348                         of_device_get_match_data(&client->dev);
1349                 chip = &chips[ds1307->type];
1350         } else if (id) {
1351                 chip = &chips[id->driver_data];
1352                 ds1307->type = id->driver_data;
1353         } else {
1354                 const struct acpi_device_id *acpi_id;
1355
1356                 acpi_id = acpi_match_device(ACPI_PTR(ds1307_acpi_ids),
1357                                             ds1307->dev);
1358                 if (!acpi_id)
1359                         return -ENODEV;
1360                 chip = &chips[acpi_id->driver_data];
1361                 ds1307->type = acpi_id->driver_data;
1362         }
1363
1364         if (!pdata)
1365                 ds1307_trickle_init(ds1307, chip);
1366         else if (pdata->trickle_charger_setup)
1367                 chip->trickle_charger_setup = pdata->trickle_charger_setup;
1368
1369         if (chip->trickle_charger_setup && chip->trickle_charger_reg) {
1370                 dev_dbg(ds1307->dev,
1371                         "writing trickle charger info 0x%x to 0x%x\n",
1372                     DS13XX_TRICKLE_CHARGER_MAGIC | chip->trickle_charger_setup,
1373                     chip->trickle_charger_reg);
1374                 regmap_write(ds1307->regmap, chip->trickle_charger_reg,
1375                     DS13XX_TRICKLE_CHARGER_MAGIC |
1376                     chip->trickle_charger_setup);
1377         }
1378
1379         buf = ds1307->regs;
1380
1381 #ifdef CONFIG_OF
1382 /*
1383  * For devices with no IRQ directly connected to the SoC, the RTC chip
1384  * can be forced as a wakeup source by stating that explicitly in
1385  * the device's .dts file using the "wakeup-source" boolean property.
1386  * If the "wakeup-source" property is set, don't request an IRQ.
1387  * This will guarantee the 'wakealarm' sysfs entry is available on the device,
1388  * if supported by the RTC.
1389  */
1390         if (of_property_read_bool(client->dev.of_node, "wakeup-source")) {
1391                 ds1307_can_wakeup_device = true;
1392         }
1393         /* Intersil ISL12057 DT backward compatibility */
1394         if (of_property_read_bool(client->dev.of_node,
1395                                   "isil,irq2-can-wakeup-machine")) {
1396                 ds1307_can_wakeup_device = true;
1397         }
1398 #endif
1399
1400         switch (ds1307->type) {
1401         case ds_1337:
1402         case ds_1339:
1403         case ds_3231:
1404                 /* get registers that the "rtc" read below won't read... */
1405                 err = regmap_bulk_read(ds1307->regmap, DS1337_REG_CONTROL,
1406                                        buf, 2);
1407                 if (err) {
1408                         dev_dbg(ds1307->dev, "read error %d\n", err);
1409                         goto exit;
1410                 }
1411
1412                 /* oscillator off?  turn it on, so clock can tick. */
1413                 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
1414                         ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
1415
1416                 /*
1417                  * Using IRQ or defined as wakeup-source?
1418                  * Disable the square wave and both alarms.
1419                  * For some variants, be sure alarms can trigger when we're
1420                  * running on Vbackup (BBSQI/BBSQW)
1421                  */
1422                 if (chip->alarm && (ds1307->irq > 0 ||
1423                                     ds1307_can_wakeup_device)) {
1424                         ds1307->regs[0] |= DS1337_BIT_INTCN
1425                                         | bbsqi_bitpos[ds1307->type];
1426                         ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
1427
1428                         want_irq = true;
1429                 }
1430
1431                 regmap_write(ds1307->regmap, DS1337_REG_CONTROL,
1432                              ds1307->regs[0]);
1433
1434                 /* oscillator fault?  clear flag, and warn */
1435                 if (ds1307->regs[1] & DS1337_BIT_OSF) {
1436                         regmap_write(ds1307->regmap, DS1337_REG_STATUS,
1437                                      ds1307->regs[1] & ~DS1337_BIT_OSF);
1438                         dev_warn(ds1307->dev, "SET TIME!\n");
1439                 }
1440                 break;
1441
1442         case rx_8025:
1443                 err = regmap_bulk_read(ds1307->regmap,
1444                                        RX8025_REG_CTRL1 << 4 | 0x08, buf, 2);
1445                 if (err) {
1446                         dev_dbg(ds1307->dev, "read error %d\n", err);
1447                         goto exit;
1448                 }
1449
1450                 /* oscillator off?  turn it on, so clock can tick. */
1451                 if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
1452                         ds1307->regs[1] |= RX8025_BIT_XST;
1453                         regmap_write(ds1307->regmap,
1454                                      RX8025_REG_CTRL2 << 4 | 0x08,
1455                                      ds1307->regs[1]);
1456                         dev_warn(ds1307->dev,
1457                                  "oscillator stop detected - SET TIME!\n");
1458                 }
1459
1460                 if (ds1307->regs[1] & RX8025_BIT_PON) {
1461                         ds1307->regs[1] &= ~RX8025_BIT_PON;
1462                         regmap_write(ds1307->regmap,
1463                                      RX8025_REG_CTRL2 << 4 | 0x08,
1464                                      ds1307->regs[1]);
1465                         dev_warn(ds1307->dev, "power-on detected\n");
1466                 }
1467
1468                 if (ds1307->regs[1] & RX8025_BIT_VDET) {
1469                         ds1307->regs[1] &= ~RX8025_BIT_VDET;
1470                         regmap_write(ds1307->regmap,
1471                                      RX8025_REG_CTRL2 << 4 | 0x08,
1472                                      ds1307->regs[1]);
1473                         dev_warn(ds1307->dev, "voltage drop detected\n");
1474                 }
1475
1476                 /* make sure we are running in 24hour mode */
1477                 if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
1478                         u8 hour;
1479
1480                         /* switch to 24 hour mode */
1481                         regmap_write(ds1307->regmap,
1482                                      RX8025_REG_CTRL1 << 4 | 0x08,
1483                                      ds1307->regs[0] | RX8025_BIT_2412);
1484
1485                         err = regmap_bulk_read(ds1307->regmap,
1486                                                RX8025_REG_CTRL1 << 4 | 0x08,
1487                                                buf, 2);
1488                         if (err) {
1489                                 dev_dbg(ds1307->dev, "read error %d\n", err);
1490                                 goto exit;
1491                         }
1492
1493                         /* correct hour */
1494                         hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
1495                         if (hour == 12)
1496                                 hour = 0;
1497                         if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1498                                 hour += 12;
1499
1500                         regmap_write(ds1307->regmap,
1501                                      DS1307_REG_HOUR << 4 | 0x08, hour);
1502                 }
1503                 break;
1504         case rx_8130:
1505                 ds1307->offset = 0x10; /* Seconds starts at 0x10 */
1506                 rtc_ops = &rx8130_rtc_ops;
1507                 if (chip->alarm && ds1307->irq > 0) {
1508                         irq_handler = rx8130_irq;
1509                         want_irq = true;
1510                 }
1511                 break;
1512         case ds_1388:
1513                 ds1307->offset = 1; /* Seconds starts at 1 */
1514                 break;
1515         case mcp794xx:
1516                 rtc_ops = &mcp794xx_rtc_ops;
1517                 if (chip->alarm && (ds1307->irq > 0 ||
1518                                     ds1307_can_wakeup_device)) {
1519                         irq_handler = mcp794xx_irq;
1520                         want_irq = true;
1521                 }
1522                 break;
1523         default:
1524                 break;
1525         }
1526
1527 read_rtc:
1528         /* read RTC registers */
1529         err = regmap_bulk_read(ds1307->regmap, ds1307->offset, buf, 8);
1530         if (err) {
1531                 dev_dbg(ds1307->dev, "read error %d\n", err);
1532                 goto exit;
1533         }
1534
1535         /*
1536          * minimal sanity checking; some chips (like DS1340) don't
1537          * specify the extra bits as must-be-zero, but there are
1538          * still a few values that are clearly out-of-range.
1539          */
1540         tmp = ds1307->regs[DS1307_REG_SECS];
1541         switch (ds1307->type) {
1542         case ds_1307:
1543         case m41t0:
1544         case m41t00:
1545                 /* clock halted?  turn it on, so clock can tick. */
1546                 if (tmp & DS1307_BIT_CH) {
1547                         regmap_write(ds1307->regmap, DS1307_REG_SECS, 0);
1548                         dev_warn(ds1307->dev, "SET TIME!\n");
1549                         goto read_rtc;
1550                 }
1551                 break;
1552         case ds_1308:
1553         case ds_1338:
1554                 /* clock halted?  turn it on, so clock can tick. */
1555                 if (tmp & DS1307_BIT_CH)
1556                         regmap_write(ds1307->regmap, DS1307_REG_SECS, 0);
1557
1558                 /* oscillator fault?  clear flag, and warn */
1559                 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
1560                         regmap_write(ds1307->regmap, DS1307_REG_CONTROL,
1561                                         ds1307->regs[DS1307_REG_CONTROL] &
1562                                         ~DS1338_BIT_OSF);
1563                         dev_warn(ds1307->dev, "SET TIME!\n");
1564                         goto read_rtc;
1565                 }
1566                 break;
1567         case ds_1340:
1568                 /* clock halted?  turn it on, so clock can tick. */
1569                 if (tmp & DS1340_BIT_nEOSC)
1570                         regmap_write(ds1307->regmap, DS1307_REG_SECS, 0);
1571
1572                 err = regmap_read(ds1307->regmap, DS1340_REG_FLAG, &tmp);
1573                 if (err) {
1574                         dev_dbg(ds1307->dev, "read error %d\n", err);
1575                         goto exit;
1576                 }
1577
1578                 /* oscillator fault?  clear flag, and warn */
1579                 if (tmp & DS1340_BIT_OSF) {
1580                         regmap_write(ds1307->regmap, DS1340_REG_FLAG, 0);
1581                         dev_warn(ds1307->dev, "SET TIME!\n");
1582                 }
1583                 break;
1584         case mcp794xx:
1585                 /* make sure that the backup battery is enabled */
1586                 if (!(ds1307->regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
1587                         regmap_write(ds1307->regmap, DS1307_REG_WDAY,
1588                                      ds1307->regs[DS1307_REG_WDAY] |
1589                                      MCP794XX_BIT_VBATEN);
1590                 }
1591
1592                 /* clock halted?  turn it on, so clock can tick. */
1593                 if (!(tmp & MCP794XX_BIT_ST)) {
1594                         regmap_write(ds1307->regmap, DS1307_REG_SECS,
1595                                      MCP794XX_BIT_ST);
1596                         dev_warn(ds1307->dev, "SET TIME!\n");
1597                         goto read_rtc;
1598                 }
1599
1600                 break;
1601         default:
1602                 break;
1603         }
1604
1605         tmp = ds1307->regs[DS1307_REG_HOUR];
1606         switch (ds1307->type) {
1607         case ds_1340:
1608         case m41t0:
1609         case m41t00:
1610                 /*
1611                  * NOTE: ignores century bits; fix before deploying
1612                  * systems that will run through year 2100.
1613                  */
1614                 break;
1615         case rx_8025:
1616                 break;
1617         default:
1618                 if (!(tmp & DS1307_BIT_12HR))
1619                         break;
1620
1621                 /*
1622                  * Be sure we're in 24 hour mode.  Multi-master systems
1623                  * take note...
1624                  */
1625                 tmp = bcd2bin(tmp & 0x1f);
1626                 if (tmp == 12)
1627                         tmp = 0;
1628                 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1629                         tmp += 12;
1630                 regmap_write(ds1307->regmap, ds1307->offset + DS1307_REG_HOUR,
1631                              bin2bcd(tmp));
1632         }
1633
1634         /*
1635          * Some IPs have weekday reset value = 0x1 which might not correct
1636          * hence compute the wday using the current date/month/year values
1637          */
1638         ds1307_get_time(ds1307->dev, &tm);
1639         wday = tm.tm_wday;
1640         timestamp = rtc_tm_to_time64(&tm);
1641         rtc_time64_to_tm(timestamp, &tm);
1642
1643         /*
1644          * Check if reset wday is different from the computed wday
1645          * If different then set the wday which we computed using
1646          * timestamp
1647          */
1648         if (wday != tm.tm_wday)
1649                 regmap_update_bits(ds1307->regmap, MCP794XX_REG_WEEKDAY,
1650                                    MCP794XX_REG_WEEKDAY_WDAY_MASK,
1651                                    tm.tm_wday + 1);
1652
1653         if (want_irq) {
1654                 device_set_wakeup_capable(ds1307->dev, true);
1655                 set_bit(HAS_ALARM, &ds1307->flags);
1656         }
1657
1658         ds1307->rtc = devm_rtc_allocate_device(ds1307->dev);
1659         if (IS_ERR(ds1307->rtc)) {
1660                 return PTR_ERR(ds1307->rtc);
1661         }
1662
1663         if (ds1307_can_wakeup_device && ds1307->irq <= 0) {
1664                 /* Disable request for an IRQ */
1665                 want_irq = false;
1666                 dev_info(ds1307->dev,
1667                          "'wakeup-source' is set, request for an IRQ is disabled!\n");
1668                 /* We cannot support UIE mode if we do not have an IRQ line */
1669                 ds1307->rtc->uie_unsupported = 1;
1670         }
1671
1672         if (want_irq) {
1673                 err = devm_request_threaded_irq(ds1307->dev,
1674                                                 ds1307->irq, NULL, irq_handler,
1675                                                 IRQF_SHARED | IRQF_ONESHOT,
1676                                                 ds1307->name, ds1307);
1677                 if (err) {
1678                         client->irq = 0;
1679                         device_set_wakeup_capable(ds1307->dev, false);
1680                         clear_bit(HAS_ALARM, &ds1307->flags);
1681                         dev_err(ds1307->dev, "unable to request IRQ!\n");
1682                 } else
1683                         dev_dbg(ds1307->dev, "got IRQ %d\n", client->irq);
1684         }
1685
1686         if (chip->nvram_size) {
1687                 ds1307->nvmem_cfg.name = "ds1307_nvram";
1688                 ds1307->nvmem_cfg.word_size = 1;
1689                 ds1307->nvmem_cfg.stride = 1;
1690                 ds1307->nvmem_cfg.size = chip->nvram_size;
1691                 ds1307->nvmem_cfg.reg_read = ds1307_nvram_read;
1692                 ds1307->nvmem_cfg.reg_write = ds1307_nvram_write;
1693                 ds1307->nvmem_cfg.priv = ds1307;
1694                 ds1307->nvram_offset = chip->nvram_offset;
1695
1696                 ds1307->rtc->nvmem_config = &ds1307->nvmem_cfg;
1697                 ds1307->rtc->nvram_old_abi = true;
1698         }
1699
1700         ds1307->rtc->ops = rtc_ops;
1701         err = rtc_register_device(ds1307->rtc);
1702         if (err)
1703                 return err;
1704
1705         ds1307_hwmon_register(ds1307);
1706         ds1307_clks_register(ds1307);
1707
1708         return 0;
1709
1710 exit:
1711         return err;
1712 }
1713
1714 static struct i2c_driver ds1307_driver = {
1715         .driver = {
1716                 .name   = "rtc-ds1307",
1717                 .of_match_table = of_match_ptr(ds1307_of_match),
1718                 .acpi_match_table = ACPI_PTR(ds1307_acpi_ids),
1719         },
1720         .probe          = ds1307_probe,
1721         .id_table       = ds1307_id,
1722 };
1723
1724 module_i2c_driver(ds1307_driver);
1725
1726 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
1727 MODULE_LICENSE("GPL");