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_1341,
  43         ds_1388,
  44         ds_3231,
  45         m41t0,
  46         m41t00,
  47         mcp794xx,
  48         rx_8025,
  49         rx_8130,
  50         last_ds_type /* always last */
  51         /* rs5c372 too?  different address... */
  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 struct ds1307 {
 117         enum ds_type            type;
 118         unsigned long           flags;
 119 #define HAS_NVRAM       0               /* bit 0 == sysfs file active */
 120 #define HAS_ALARM       1               /* bit 1 == irq claimed */
 121         struct device           *dev;
 122         struct regmap           *regmap;
 123         const char              *name;
 124         struct rtc_device       *rtc;
 125 #ifdef CONFIG_COMMON_CLK
 126         struct clk_hw           clks[2];
 127 #endif
 128 };
 129
 130 struct chip_desc {
 131         unsigned                alarm:1;
 132         u16                     nvram_offset;
 133         u16                     nvram_size;
 134         u8                      offset; /* register's offset */
 135         u8                      century_reg;
 136         u8                      century_enable_bit;
 137         u8                      century_bit;
 138         u8                      bbsqi_bit;
 139         irq_handler_t           irq_handler;
 140         const struct rtc_class_ops *rtc_ops;
 141         u16                     trickle_charger_reg;
 142         u8                      (*do_trickle_setup)(struct ds1307 *, u32,
 143                                                     bool);
 144 };
 145
 146 static int ds1307_get_time(struct device *dev, struct rtc_time *t);
 147 static int ds1307_set_time(struct device *dev, struct rtc_time *t);
 148 static u8 do_trickle_setup_ds1339(struct ds1307 *, u32 ohms, bool diode);
 149 static irqreturn_t rx8130_irq(int irq, void *dev_id);
 150 static int rx8130_read_alarm(struct device *dev, struct rtc_wkalrm *t);
 151 static int rx8130_set_alarm(struct device *dev, struct rtc_wkalrm *t);
 152 static int rx8130_alarm_irq_enable(struct device *dev, unsigned int enabled);
 153 static irqreturn_t mcp794xx_irq(int irq, void *dev_id);
 154 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t);
 155 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t);
 156 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled);
 157
 158 static const struct rtc_class_ops rx8130_rtc_ops = {
 159         .read_time      = ds1307_get_time,
 160         .set_time       = ds1307_set_time,
 161         .read_alarm     = rx8130_read_alarm,
 162         .set_alarm      = rx8130_set_alarm,
 163         .alarm_irq_enable = rx8130_alarm_irq_enable,
 164 };
 165
 166 static const struct rtc_class_ops mcp794xx_rtc_ops = {
 167         .read_time      = ds1307_get_time,
 168         .set_time       = ds1307_set_time,
 169         .read_alarm     = mcp794xx_read_alarm,
 170         .set_alarm      = mcp794xx_set_alarm,
 171         .alarm_irq_enable = mcp794xx_alarm_irq_enable,
 172 };
 173
 174 static const struct chip_desc chips[last_ds_type] = {
 175         [ds_1307] = {
 176                 .nvram_offset   = 8,
 177                 .nvram_size     = 56,
 178         },
 179         [ds_1308] = {
 180                 .nvram_offset   = 8,
 181                 .nvram_size     = 56,
 182         },
 183         [ds_1337] = {
 184                 .alarm          = 1,
 185                 .century_reg    = DS1307_REG_MONTH,
 186                 .century_bit    = DS1337_BIT_CENTURY,
 187         },
 188         [ds_1338] = {
 189                 .nvram_offset   = 8,
 190                 .nvram_size     = 56,
 191         },
 192         [ds_1339] = {
 193                 .alarm          = 1,
 194                 .century_reg    = DS1307_REG_MONTH,
 195                 .century_bit    = DS1337_BIT_CENTURY,
 196                 .bbsqi_bit      = DS1339_BIT_BBSQI,
 197                 .trickle_charger_reg = 0x10,
 198                 .do_trickle_setup = &do_trickle_setup_ds1339,
 199         },
 200         [ds_1340] = {
 201                 .century_reg    = DS1307_REG_HOUR,
 202                 .century_enable_bit = DS1340_BIT_CENTURY_EN,
 203                 .century_bit    = DS1340_BIT_CENTURY,
 204                 .do_trickle_setup = &do_trickle_setup_ds1339,
 205                 .trickle_charger_reg = 0x08,
 206         },
 207         [ds_1341] = {
 208                 .century_reg    = DS1307_REG_MONTH,
 209                 .century_bit    = DS1337_BIT_CENTURY,
 210         },
 211         [ds_1388] = {
 212                 .offset         = 1,
 213                 .trickle_charger_reg = 0x0a,
 214         },
 215         [ds_3231] = {
 216                 .alarm          = 1,
 217                 .century_reg    = DS1307_REG_MONTH,
 218                 .century_bit    = DS1337_BIT_CENTURY,
 219                 .bbsqi_bit      = DS3231_BIT_BBSQW,
 220         },
 221         [rx_8130] = {
 222                 .alarm          = 1,
 223                 /* this is battery backed SRAM */
 224                 .nvram_offset   = 0x20,
 225                 .nvram_size     = 4,    /* 32bit (4 word x 8 bit) */
 226                 .offset         = 0x10,
 227                 .irq_handler = rx8130_irq,
 228                 .rtc_ops = &rx8130_rtc_ops,
 229         },
 230         [mcp794xx] = {
 231                 .alarm          = 1,
 232                 /* this is battery backed SRAM */
 233                 .nvram_offset   = 0x20,
 234                 .nvram_size     = 0x40,
 235                 .irq_handler = mcp794xx_irq,
 236                 .rtc_ops = &mcp794xx_rtc_ops,
 237         },
 238 };
 239
 240 static const struct i2c_device_id ds1307_id[] = {
 241         { "ds1307", ds_1307 },
 242         { "ds1308", ds_1308 },
 243         { "ds1337", ds_1337 },
 244         { "ds1338", ds_1338 },
 245         { "ds1339", ds_1339 },
 246         { "ds1388", ds_1388 },
 247         { "ds1340", ds_1340 },
 248         { "ds1341", ds_1341 },
 249         { "ds3231", ds_3231 },
 250         { "m41t0", m41t0 },
 251         { "m41t00", m41t00 },
 252         { "mcp7940x", mcp794xx },
 253         { "mcp7941x", mcp794xx },
 254         { "pt7c4338", ds_1307 },
 255         { "rx8025", rx_8025 },
 256         { "isl12057", ds_1337 },
 257         { "rx8130", rx_8130 },
 258         { }
 259 };
 260 MODULE_DEVICE_TABLE(i2c, ds1307_id);
 261
 262 #ifdef CONFIG_OF
 263 static const struct of_device_id ds1307_of_match[] = {
 264         {
 265                 .compatible = "dallas,ds1307",
 266                 .data = (void *)ds_1307
 267         },
 268         {
 269                 .compatible = "dallas,ds1308",
 270                 .data = (void *)ds_1308
 271         },
 272         {
 273                 .compatible = "dallas,ds1337",
 274                 .data = (void *)ds_1337
 275         },
 276         {
 277                 .compatible = "dallas,ds1338",
 278                 .data = (void *)ds_1338
 279         },
 280         {
 281                 .compatible = "dallas,ds1339",
 282                 .data = (void *)ds_1339
 283         },
 284         {
 285                 .compatible = "dallas,ds1388",
 286                 .data = (void *)ds_1388
 287         },
 288         {
 289                 .compatible = "dallas,ds1340",
 290                 .data = (void *)ds_1340
 291         },
 292         {
 293                 .compatible = "dallas,ds1341",
 294                 .data = (void *)ds_1341
 295         },
 296         {
 297                 .compatible = "maxim,ds3231",
 298                 .data = (void *)ds_3231
 299         },
 300         {
 301                 .compatible = "st,m41t0",
 302                 .data = (void *)m41t00
 303         },
 304         {
 305                 .compatible = "st,m41t00",
 306                 .data = (void *)m41t00
 307         },
 308         {
 309                 .compatible = "microchip,mcp7940x",
 310                 .data = (void *)mcp794xx
 311         },
 312         {
 313                 .compatible = "microchip,mcp7941x",
 314                 .data = (void *)mcp794xx
 315         },
 316         {
 317                 .compatible = "pericom,pt7c4338",
 318                 .data = (void *)ds_1307
 319         },
 320         {
 321                 .compatible = "epson,rx8025",
 322                 .data = (void *)rx_8025
 323         },
 324         {
 325                 .compatible = "isil,isl12057",
 326                 .data = (void *)ds_1337
 327         },
 328         {
 329                 .compatible = "epson,rx8130",
 330                 .data = (void *)rx_8130
 331         },
 332         { }
 333 };
 334 MODULE_DEVICE_TABLE(of, ds1307_of_match);
 335 #endif
 336
 337 #ifdef CONFIG_ACPI
 338 static const struct acpi_device_id ds1307_acpi_ids[] = {
 339         { .id = "DS1307", .driver_data = ds_1307 },
 340         { .id = "DS1308", .driver_data = ds_1308 },
 341         { .id = "DS1337", .driver_data = ds_1337 },
 342         { .id = "DS1338", .driver_data = ds_1338 },
 343         { .id = "DS1339", .driver_data = ds_1339 },
 344         { .id = "DS1388", .driver_data = ds_1388 },
 345         { .id = "DS1340", .driver_data = ds_1340 },
 346         { .id = "DS1341", .driver_data = ds_1341 },
 347         { .id = "DS3231", .driver_data = ds_3231 },
 348         { .id = "M41T0", .driver_data = m41t0 },
 349         { .id = "M41T00", .driver_data = m41t00 },
 350         { .id = "MCP7940X", .driver_data = mcp794xx },
 351         { .id = "MCP7941X", .driver_data = mcp794xx },
 352         { .id = "PT7C4338", .driver_data = ds_1307 },
 353         { .id = "RX8025", .driver_data = rx_8025 },
 354         { .id = "ISL12057", .driver_data = ds_1337 },
 355         { .id = "RX8130", .driver_data = rx_8130 },
 356         { }
 357 };
 358 MODULE_DEVICE_TABLE(acpi, ds1307_acpi_ids);
 359 #endif
 360
 361 /*
 362  * The ds1337 and ds1339 both have two alarms, but we only use the first
 363  * one (with a "seconds" field).  For ds1337 we expect nINTA is our alarm
 364  * signal; ds1339 chips have only one alarm signal.
 365  */
 366 static irqreturn_t ds1307_irq(int irq, void *dev_id)
 367 {
 368         struct ds1307           *ds1307 = dev_id;
 369         struct mutex            *lock = &ds1307->rtc->ops_lock;
 370         int                     stat, ret;
 371
 372         mutex_lock(lock);
 373         ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &stat);
 374         if (ret)
 375                 goto out;
 376
 377         if (stat & DS1337_BIT_A1I) {
 378                 stat &= ~DS1337_BIT_A1I;
 379                 regmap_write(ds1307->regmap, DS1337_REG_STATUS, stat);
 380
 381                 ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
 382                                          DS1337_BIT_A1IE, 0);
 383                 if (ret)
 384                         goto out;
 385
 386                 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
 387         }
 388
 389 out:
 390         mutex_unlock(lock);
 391
 392         return IRQ_HANDLED;
 393 }
 394
 395 /*----------------------------------------------------------------------*/
 396
 397 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
 398 {
 399         struct ds1307   *ds1307 = dev_get_drvdata(dev);
 400         int             tmp, ret;
 401         const struct chip_desc *chip = &chips[ds1307->type];
 402         u8 regs[7];
 403
 404         /* read the RTC date and time registers all at once */
 405         ret = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
 406                                sizeof(regs));
 407         if (ret) {
 408                 dev_err(dev, "%s error %d\n", "read", ret);
 409                 return ret;
 410         }
 411
 412         dev_dbg(dev, "%s: %7ph\n", "read", regs);
 413
 414         /* if oscillator fail bit is set, no data can be trusted */
 415         if (ds1307->type == m41t0 &&
 416             regs[DS1307_REG_MIN] & M41T0_BIT_OF) {
 417                 dev_warn_once(dev, "oscillator failed, set time!\n");
 418                 return -EINVAL;
 419         }
 420
 421         t->tm_sec = bcd2bin(regs[DS1307_REG_SECS] & 0x7f);
 422         t->tm_min = bcd2bin(regs[DS1307_REG_MIN] & 0x7f);
 423         tmp = regs[DS1307_REG_HOUR] & 0x3f;
 424         t->tm_hour = bcd2bin(tmp);
 425         t->tm_wday = bcd2bin(regs[DS1307_REG_WDAY] & 0x07) - 1;
 426         t->tm_mday = bcd2bin(regs[DS1307_REG_MDAY] & 0x3f);
 427         tmp = regs[DS1307_REG_MONTH] & 0x1f;
 428         t->tm_mon = bcd2bin(tmp) - 1;
 429         t->tm_year = bcd2bin(regs[DS1307_REG_YEAR]) + 100;
 430
 431         if (regs[chip->century_reg] & chip->century_bit &&
 432             IS_ENABLED(CONFIG_RTC_DRV_DS1307_CENTURY))
 433                 t->tm_year += 100;
 434
 435         dev_dbg(dev, "%s secs=%d, mins=%d, "
 436                 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
 437                 "read", t->tm_sec, t->tm_min,
 438                 t->tm_hour, t->tm_mday,
 439                 t->tm_mon, t->tm_year, t->tm_wday);
 440
 441         return 0;
 442 }
 443
 444 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
 445 {
 446         struct ds1307   *ds1307 = dev_get_drvdata(dev);
 447         const struct chip_desc *chip = &chips[ds1307->type];
 448         int             result;
 449         int             tmp;
 450         u8              regs[7];
 451
 452         dev_dbg(dev, "%s secs=%d, mins=%d, "
 453                 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
 454                 "write", t->tm_sec, t->tm_min,
 455                 t->tm_hour, t->tm_mday,
 456                 t->tm_mon, t->tm_year, t->tm_wday);
 457
 458         if (t->tm_year < 100)
 459                 return -EINVAL;
 460
 461 #ifdef CONFIG_RTC_DRV_DS1307_CENTURY
 462         if (t->tm_year > (chip->century_bit ? 299 : 199))
 463                 return -EINVAL;
 464 #else
 465         if (t->tm_year > 199)
 466                 return -EINVAL;
 467 #endif
 468
 469         regs[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
 470         regs[DS1307_REG_MIN] = bin2bcd(t->tm_min);
 471         regs[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
 472         regs[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
 473         regs[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
 474         regs[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
 475
 476         /* assume 20YY not 19YY */
 477         tmp = t->tm_year - 100;
 478         regs[DS1307_REG_YEAR] = bin2bcd(tmp);
 479
 480         if (chip->century_enable_bit)
 481                 regs[chip->century_reg] |= chip->century_enable_bit;
 482         if (t->tm_year > 199 && chip->century_bit)
 483                 regs[chip->century_reg] |= chip->century_bit;
 484
 485         if (ds1307->type == mcp794xx) {
 486                 /*
 487                  * these bits were cleared when preparing the date/time
 488                  * values and need to be set again before writing the
 489                  * regsfer out to the device.
 490                  */
 491                 regs[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
 492                 regs[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
 493         }
 494
 495         dev_dbg(dev, "%s: %7ph\n", "write", regs);
 496
 497         result = regmap_bulk_write(ds1307->regmap, chip->offset, regs,
 498                                    sizeof(regs));
 499         if (result) {
 500                 dev_err(dev, "%s error %d\n", "write", result);
 501                 return result;
 502         }
 503         return 0;
 504 }
 505
 506 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 507 {
 508         struct ds1307           *ds1307 = dev_get_drvdata(dev);
 509         int                     ret;
 510         u8                      regs[9];
 511
 512         if (!test_bit(HAS_ALARM, &ds1307->flags))
 513                 return -EINVAL;
 514
 515         /* read all ALARM1, ALARM2, and status registers at once */
 516         ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS,
 517                                regs, sizeof(regs));
 518         if (ret) {
 519                 dev_err(dev, "%s error %d\n", "alarm read", ret);
 520                 return ret;
 521         }
 522
 523         dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read",
 524                 &regs[0], &regs[4], &regs[7]);
 525
 526         /*
 527          * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
 528          * and that all four fields are checked matches
 529          */
 530         t->time.tm_sec = bcd2bin(regs[0] & 0x7f);
 531         t->time.tm_min = bcd2bin(regs[1] & 0x7f);
 532         t->time.tm_hour = bcd2bin(regs[2] & 0x3f);
 533         t->time.tm_mday = bcd2bin(regs[3] & 0x3f);
 534
 535         /* ... and status */
 536         t->enabled = !!(regs[7] & DS1337_BIT_A1IE);
 537         t->pending = !!(regs[8] & DS1337_BIT_A1I);
 538
 539         dev_dbg(dev, "%s secs=%d, mins=%d, "
 540                 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
 541                 "alarm read", t->time.tm_sec, t->time.tm_min,
 542                 t->time.tm_hour, t->time.tm_mday,
 543                 t->enabled, t->pending);
 544
 545         return 0;
 546 }
 547
 548 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 549 {
 550         struct ds1307           *ds1307 = dev_get_drvdata(dev);
 551         unsigned char           regs[9];
 552         u8                      control, status;
 553         int                     ret;
 554
 555         if (!test_bit(HAS_ALARM, &ds1307->flags))
 556                 return -EINVAL;
 557
 558         dev_dbg(dev, "%s secs=%d, mins=%d, "
 559                 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
 560                 "alarm set", t->time.tm_sec, t->time.tm_min,
 561                 t->time.tm_hour, t->time.tm_mday,
 562                 t->enabled, t->pending);
 563
 564         /* read current status of both alarms and the chip */
 565         ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs,
 566                                sizeof(regs));
 567         if (ret) {
 568                 dev_err(dev, "%s error %d\n", "alarm write", ret);
 569                 return ret;
 570         }
 571         control = regs[7];
 572         status = regs[8];
 573
 574         dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)",
 575                 &regs[0], &regs[4], control, status);
 576
 577         /* set ALARM1, using 24 hour and day-of-month modes */
 578         regs[0] = bin2bcd(t->time.tm_sec);
 579         regs[1] = bin2bcd(t->time.tm_min);
 580         regs[2] = bin2bcd(t->time.tm_hour);
 581         regs[3] = bin2bcd(t->time.tm_mday);
 582
 583         /* set ALARM2 to non-garbage */
 584         regs[4] = 0;
 585         regs[5] = 0;
 586         regs[6] = 0;
 587
 588         /* disable alarms */
 589         regs[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
 590         regs[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
 591
 592         ret = regmap_bulk_write(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs,
 593                                 sizeof(regs));
 594         if (ret) {
 595                 dev_err(dev, "can't set alarm time\n");
 596                 return ret;
 597         }
 598
 599         /* optionally enable ALARM1 */
 600         if (t->enabled) {
 601                 dev_dbg(dev, "alarm IRQ armed\n");
 602                 regs[7] |= DS1337_BIT_A1IE;     /* only ALARM1 is used */
 603                 regmap_write(ds1307->regmap, DS1337_REG_CONTROL, regs[7]);
 604         }
 605
 606         return 0;
 607 }
 608
 609 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
 610 {
 611         struct ds1307           *ds1307 = dev_get_drvdata(dev);
 612
 613         if (!test_bit(HAS_ALARM, &ds1307->flags))
 614                 return -ENOTTY;
 615
 616         return regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
 617                                   DS1337_BIT_A1IE,
 618                                   enabled ? DS1337_BIT_A1IE : 0);
 619 }
 620
 621 static const struct rtc_class_ops ds13xx_rtc_ops = {
 622         .read_time      = ds1307_get_time,
 623         .set_time       = ds1307_set_time,
 624         .read_alarm     = ds1337_read_alarm,
 625         .set_alarm      = ds1337_set_alarm,
 626         .alarm_irq_enable = ds1307_alarm_irq_enable,
 627 };
 628
 629 /*----------------------------------------------------------------------*/
 630
 631 /*
 632  * Alarm support for rx8130 devices.
 633  */
 634
 635 #define RX8130_REG_ALARM_MIN            0x07
 636 #define RX8130_REG_ALARM_HOUR           0x08
 637 #define RX8130_REG_ALARM_WEEK_OR_DAY    0x09
 638 #define RX8130_REG_EXTENSION            0x0c
 639 #define RX8130_REG_EXTENSION_WADA       BIT(3)
 640 #define RX8130_REG_FLAG                 0x0d
 641 #define RX8130_REG_FLAG_AF              BIT(3)
 642 #define RX8130_REG_CONTROL0             0x0e
 643 #define RX8130_REG_CONTROL0_AIE         BIT(3)
 644
 645 static irqreturn_t rx8130_irq(int irq, void *dev_id)
 646 {
 647         struct ds1307           *ds1307 = dev_id;
 648         struct mutex            *lock = &ds1307->rtc->ops_lock;
 649         u8 ctl[3];
 650         int ret;
 651
 652         mutex_lock(lock);
 653
 654         /* Read control registers. */
 655         ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
 656                                sizeof(ctl));
 657         if (ret < 0)
 658                 goto out;
 659         if (!(ctl[1] & RX8130_REG_FLAG_AF))
 660                 goto out;
 661         ctl[1] &= ~RX8130_REG_FLAG_AF;
 662         ctl[2] &= ~RX8130_REG_CONTROL0_AIE;
 663
 664         ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
 665                                 sizeof(ctl));
 666         if (ret < 0)
 667                 goto out;
 668
 669         rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
 670
 671 out:
 672         mutex_unlock(lock);
 673
 674         return IRQ_HANDLED;
 675 }
 676
 677 static int rx8130_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 678 {
 679         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 680         u8 ald[3], ctl[3];
 681         int ret;
 682
 683         if (!test_bit(HAS_ALARM, &ds1307->flags))
 684                 return -EINVAL;
 685
 686         /* Read alarm registers. */
 687         ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_ALARM_MIN, ald,
 688                                sizeof(ald));
 689         if (ret < 0)
 690                 return ret;
 691
 692         /* Read control registers. */
 693         ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
 694                                sizeof(ctl));
 695         if (ret < 0)
 696                 return ret;
 697
 698         t->enabled = !!(ctl[2] & RX8130_REG_CONTROL0_AIE);
 699         t->pending = !!(ctl[1] & RX8130_REG_FLAG_AF);
 700
 701         /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
 702         t->time.tm_sec = -1;
 703         t->time.tm_min = bcd2bin(ald[0] & 0x7f);
 704         t->time.tm_hour = bcd2bin(ald[1] & 0x7f);
 705         t->time.tm_wday = -1;
 706         t->time.tm_mday = bcd2bin(ald[2] & 0x7f);
 707         t->time.tm_mon = -1;
 708         t->time.tm_year = -1;
 709         t->time.tm_yday = -1;
 710         t->time.tm_isdst = -1;
 711
 712         dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d enabled=%d\n",
 713                 __func__, t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 714                 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled);
 715
 716         return 0;
 717 }
 718
 719 static int rx8130_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 720 {
 721         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 722         u8 ald[3], ctl[3];
 723         int ret;
 724
 725         if (!test_bit(HAS_ALARM, &ds1307->flags))
 726                 return -EINVAL;
 727
 728         dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
 729                 "enabled=%d pending=%d\n", __func__,
 730                 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 731                 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
 732                 t->enabled, t->pending);
 733
 734         /* Read control registers. */
 735         ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
 736                                sizeof(ctl));
 737         if (ret < 0)
 738                 return ret;
 739
 740         ctl[0] &= ~RX8130_REG_EXTENSION_WADA;
 741         ctl[1] |= RX8130_REG_FLAG_AF;
 742         ctl[2] &= ~RX8130_REG_CONTROL0_AIE;
 743
 744         ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
 745                                 sizeof(ctl));
 746         if (ret < 0)
 747                 return ret;
 748
 749         /* Hardware alarm precision is 1 minute! */
 750         ald[0] = bin2bcd(t->time.tm_min);
 751         ald[1] = bin2bcd(t->time.tm_hour);
 752         ald[2] = bin2bcd(t->time.tm_mday);
 753
 754         ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_ALARM_MIN, ald,
 755                                 sizeof(ald));
 756         if (ret < 0)
 757                 return ret;
 758
 759         if (!t->enabled)
 760                 return 0;
 761
 762         ctl[2] |= RX8130_REG_CONTROL0_AIE;
 763
 764         return regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
 765                                  sizeof(ctl));
 766 }
 767
 768 static int rx8130_alarm_irq_enable(struct device *dev, unsigned int enabled)
 769 {
 770         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 771         int ret, reg;
 772
 773         if (!test_bit(HAS_ALARM, &ds1307->flags))
 774                 return -EINVAL;
 775
 776         ret = regmap_read(ds1307->regmap, RX8130_REG_CONTROL0, &reg);
 777         if (ret < 0)
 778                 return ret;
 779
 780         if (enabled)
 781                 reg |= RX8130_REG_CONTROL0_AIE;
 782         else
 783                 reg &= ~RX8130_REG_CONTROL0_AIE;
 784
 785         return regmap_write(ds1307->regmap, RX8130_REG_CONTROL0, reg);
 786 }
 787
 788 /*----------------------------------------------------------------------*/
 789
 790 /*
 791  * Alarm support for mcp794xx devices.
 792  */
 793
 794 #define MCP794XX_REG_CONTROL            0x07
 795 #       define MCP794XX_BIT_ALM0_EN     0x10
 796 #       define MCP794XX_BIT_ALM1_EN     0x20
 797 #define MCP794XX_REG_ALARM0_BASE        0x0a
 798 #define MCP794XX_REG_ALARM0_CTRL        0x0d
 799 #define MCP794XX_REG_ALARM1_BASE        0x11
 800 #define MCP794XX_REG_ALARM1_CTRL        0x14
 801 #       define MCP794XX_BIT_ALMX_IF     BIT(3)
 802 #       define MCP794XX_BIT_ALMX_C0     BIT(4)
 803 #       define MCP794XX_BIT_ALMX_C1     BIT(5)
 804 #       define MCP794XX_BIT_ALMX_C2     BIT(6)
 805 #       define MCP794XX_BIT_ALMX_POL    BIT(7)
 806 #       define MCP794XX_MSK_ALMX_MATCH  (MCP794XX_BIT_ALMX_C0 | \
 807                                          MCP794XX_BIT_ALMX_C1 | \
 808                                          MCP794XX_BIT_ALMX_C2)
 809
 810 static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
 811 {
 812         struct ds1307           *ds1307 = dev_id;
 813         struct mutex            *lock = &ds1307->rtc->ops_lock;
 814         int reg, ret;
 815
 816         mutex_lock(lock);
 817
 818         /* Check and clear alarm 0 interrupt flag. */
 819         ret = regmap_read(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, &reg);
 820         if (ret)
 821                 goto out;
 822         if (!(reg & MCP794XX_BIT_ALMX_IF))
 823                 goto out;
 824         reg &= ~MCP794XX_BIT_ALMX_IF;
 825         ret = regmap_write(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, reg);
 826         if (ret)
 827                 goto out;
 828
 829         /* Disable alarm 0. */
 830         ret = regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL,
 831                                  MCP794XX_BIT_ALM0_EN, 0);
 832         if (ret)
 833                 goto out;
 834
 835         rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
 836
 837 out:
 838         mutex_unlock(lock);
 839
 840         return IRQ_HANDLED;
 841 }
 842
 843 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 844 {
 845         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 846         u8 regs[10];
 847         int ret;
 848
 849         if (!test_bit(HAS_ALARM, &ds1307->flags))
 850                 return -EINVAL;
 851
 852         /* Read control and alarm 0 registers. */
 853         ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
 854                                sizeof(regs));
 855         if (ret)
 856                 return ret;
 857
 858         t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
 859
 860         /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
 861         t->time.tm_sec = bcd2bin(regs[3] & 0x7f);
 862         t->time.tm_min = bcd2bin(regs[4] & 0x7f);
 863         t->time.tm_hour = bcd2bin(regs[5] & 0x3f);
 864         t->time.tm_wday = bcd2bin(regs[6] & 0x7) - 1;
 865         t->time.tm_mday = bcd2bin(regs[7] & 0x3f);
 866         t->time.tm_mon = bcd2bin(regs[8] & 0x1f) - 1;
 867         t->time.tm_year = -1;
 868         t->time.tm_yday = -1;
 869         t->time.tm_isdst = -1;
 870
 871         dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
 872                 "enabled=%d polarity=%d irq=%d match=%lu\n", __func__,
 873                 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 874                 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
 875                 !!(regs[6] & MCP794XX_BIT_ALMX_POL),
 876                 !!(regs[6] & MCP794XX_BIT_ALMX_IF),
 877                 (regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
 878
 879         return 0;
 880 }
 881
 882 /*
 883  * We may have a random RTC weekday, therefore calculate alarm weekday based
 884  * on current weekday we read from the RTC timekeeping regs
 885  */
 886 static int mcp794xx_alm_weekday(struct device *dev, struct rtc_time *tm_alarm)
 887 {
 888         struct rtc_time tm_now;
 889         int days_now, days_alarm, ret;
 890
 891         ret = ds1307_get_time(dev, &tm_now);
 892         if (ret)
 893                 return ret;
 894
 895         days_now = div_s64(rtc_tm_to_time64(&tm_now), 24 * 60 * 60);
 896         days_alarm = div_s64(rtc_tm_to_time64(tm_alarm), 24 * 60 * 60);
 897
 898         return (tm_now.tm_wday + days_alarm - days_now) % 7 + 1;
 899 }
 900
 901 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 902 {
 903         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 904         unsigned char regs[10];
 905         int wday, ret;
 906
 907         if (!test_bit(HAS_ALARM, &ds1307->flags))
 908                 return -EINVAL;
 909
 910         wday = mcp794xx_alm_weekday(dev, &t->time);
 911         if (wday < 0)
 912                 return wday;
 913
 914         dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
 915                 "enabled=%d pending=%d\n", __func__,
 916                 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 917                 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
 918                 t->enabled, t->pending);
 919
 920         /* Read control and alarm 0 registers. */
 921         ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
 922                                sizeof(regs));
 923         if (ret)
 924                 return ret;
 925
 926         /* Set alarm 0, using 24-hour and day-of-month modes. */
 927         regs[3] = bin2bcd(t->time.tm_sec);
 928         regs[4] = bin2bcd(t->time.tm_min);
 929         regs[5] = bin2bcd(t->time.tm_hour);
 930         regs[6] = wday;
 931         regs[7] = bin2bcd(t->time.tm_mday);
 932         regs[8] = bin2bcd(t->time.tm_mon + 1);
 933
 934         /* Clear the alarm 0 interrupt flag. */
 935         regs[6] &= ~MCP794XX_BIT_ALMX_IF;
 936         /* Set alarm match: second, minute, hour, day, date, month. */
 937         regs[6] |= MCP794XX_MSK_ALMX_MATCH;
 938         /* Disable interrupt. We will not enable until completely programmed */
 939         regs[0] &= ~MCP794XX_BIT_ALM0_EN;
 940
 941         ret = regmap_bulk_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
 942                                 sizeof(regs));
 943         if (ret)
 944                 return ret;
 945
 946         if (!t->enabled)
 947                 return 0;
 948         regs[0] |= MCP794XX_BIT_ALM0_EN;
 949         return regmap_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs[0]);
 950 }
 951
 952 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
 953 {
 954         struct ds1307 *ds1307 = dev_get_drvdata(dev);
 955
 956         if (!test_bit(HAS_ALARM, &ds1307->flags))
 957                 return -EINVAL;
 958
 959         return regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL,
 960                                   MCP794XX_BIT_ALM0_EN,
 961                                   enabled ? MCP794XX_BIT_ALM0_EN : 0);
 962 }
 963
 964 /*----------------------------------------------------------------------*/
 965
 966 static int ds1307_nvram_read(void *priv, unsigned int offset, void *val,
 967                              size_t bytes)
 968 {
 969         struct ds1307 *ds1307 = priv;
 970         const struct chip_desc *chip = &chips[ds1307->type];
 971
 972         return regmap_bulk_read(ds1307->regmap, chip->nvram_offset + offset,
 973                                 val, bytes);
 974 }
 975
 976 static int ds1307_nvram_write(void *priv, unsigned int offset, void *val,
 977                               size_t bytes)
 978 {
 979         struct ds1307 *ds1307 = priv;
 980         const struct chip_desc *chip = &chips[ds1307->type];
 981
 982         return regmap_bulk_write(ds1307->regmap, chip->nvram_offset + offset,
 983                                  val, bytes);
 984 }
 985
 986 /*----------------------------------------------------------------------*/
 987
 988 static u8 do_trickle_setup_ds1339(struct ds1307 *ds1307,
 989                                   u32 ohms, bool diode)
 990 {
 991         u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
 992                 DS1307_TRICKLE_CHARGER_NO_DIODE;
 993
 994         switch (ohms) {
 995         case 250:
 996                 setup |= DS1307_TRICKLE_CHARGER_250_OHM;
 997                 break;
 998         case 2000:
 999                 setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
1000                 break;
1001         case 4000:
1002                 setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
1003                 break;
1004         default:
1005                 dev_warn(ds1307->dev,
1006                          "Unsupported ohm value %u in dt\n", ohms);
1007                 return 0;
1008         }
1009         return setup;
1010 }
1011
1012 static u8 ds1307_trickle_init(struct ds1307 *ds1307,
1013                               const struct chip_desc *chip)
1014 {
1015         u32 ohms;
1016         bool diode = true;
1017
1018         if (!chip->do_trickle_setup)
1019                 return 0;
1020
1021         if (device_property_read_u32(ds1307->dev, "trickle-resistor-ohms",
1022                                      &ohms))
1023                 return 0;
1024
1025         if (device_property_read_bool(ds1307->dev, "trickle-diode-disable"))
1026                 diode = false;
1027
1028         return chip->do_trickle_setup(ds1307, ohms, diode);
1029 }
1030
1031 /*----------------------------------------------------------------------*/
1032
1033 #ifdef CONFIG_RTC_DRV_DS1307_HWMON
1034
1035 /*
1036  * Temperature sensor support for ds3231 devices.
1037  */
1038
1039 #define DS3231_REG_TEMPERATURE  0x11
1040
1041 /*
1042  * A user-initiated temperature conversion is not started by this function,
1043  * so the temperature is updated once every 64 seconds.
1044  */
1045 static int ds3231_hwmon_read_temp(struct device *dev, s32 *mC)
1046 {
1047         struct ds1307 *ds1307 = dev_get_drvdata(dev);
1048         u8 temp_buf[2];
1049         s16 temp;
1050         int ret;
1051
1052         ret = regmap_bulk_read(ds1307->regmap, DS3231_REG_TEMPERATURE,
1053                                temp_buf, sizeof(temp_buf));
1054         if (ret)
1055                 return ret;
1056         /*
1057          * Temperature is represented as a 10-bit code with a resolution of
1058          * 0.25 degree celsius and encoded in two's complement format.
1059          */
1060         temp = (temp_buf[0] << 8) | temp_buf[1];
1061         temp >>= 6;
1062         *mC = temp * 250;
1063
1064         return 0;
1065 }
1066
1067 static ssize_t ds3231_hwmon_show_temp(struct device *dev,
1068                                       struct device_attribute *attr, char *buf)
1069 {
1070         int ret;
1071         s32 temp;
1072
1073         ret = ds3231_hwmon_read_temp(dev, &temp);
1074         if (ret)
1075                 return ret;
1076
1077         return sprintf(buf, "%d\n", temp);
1078 }
1079 static SENSOR_DEVICE_ATTR(temp1_input, 0444, ds3231_hwmon_show_temp,
1080                           NULL, 0);
1081
1082 static struct attribute *ds3231_hwmon_attrs[] = {
1083         &sensor_dev_attr_temp1_input.dev_attr.attr,
1084         NULL,
1085 };
1086 ATTRIBUTE_GROUPS(ds3231_hwmon);
1087
1088 static void ds1307_hwmon_register(struct ds1307 *ds1307)
1089 {
1090         struct device *dev;
1091
1092         if (ds1307->type != ds_3231)
1093                 return;
1094
1095         dev = devm_hwmon_device_register_with_groups(ds1307->dev, ds1307->name,
1096                                                      ds1307,
1097                                                      ds3231_hwmon_groups);
1098         if (IS_ERR(dev)) {
1099                 dev_warn(ds1307->dev, "unable to register hwmon device %ld\n",
1100                          PTR_ERR(dev));
1101         }
1102 }
1103
1104 #else
1105
1106 static void ds1307_hwmon_register(struct ds1307 *ds1307)
1107 {
1108 }
1109
1110 #endif /* CONFIG_RTC_DRV_DS1307_HWMON */
1111
1112 /*----------------------------------------------------------------------*/
1113
1114 /*
1115  * Square-wave output support for DS3231
1116  * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf
1117  */
1118 #ifdef CONFIG_COMMON_CLK
1119
1120 enum {
1121         DS3231_CLK_SQW = 0,
1122         DS3231_CLK_32KHZ,
1123 };
1124
1125 #define clk_sqw_to_ds1307(clk)  \
1126         container_of(clk, struct ds1307, clks[DS3231_CLK_SQW])
1127 #define clk_32khz_to_ds1307(clk)        \
1128         container_of(clk, struct ds1307, clks[DS3231_CLK_32KHZ])
1129
1130 static int ds3231_clk_sqw_rates[] = {
1131         1,
1132         1024,
1133         4096,
1134         8192,
1135 };
1136
1137 static int ds1337_write_control(struct ds1307 *ds1307, u8 mask, u8 value)
1138 {
1139         struct mutex *lock = &ds1307->rtc->ops_lock;
1140         int ret;
1141
1142         mutex_lock(lock);
1143         ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
1144                                  mask, value);
1145         mutex_unlock(lock);
1146
1147         return ret;
1148 }
1149
1150 static unsigned long ds3231_clk_sqw_recalc_rate(struct clk_hw *hw,
1151                                                 unsigned long parent_rate)
1152 {
1153         struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1154         int control, ret;
1155         int rate_sel = 0;
1156
1157         ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control);
1158         if (ret)
1159                 return ret;
1160         if (control & DS1337_BIT_RS1)
1161                 rate_sel += 1;
1162         if (control & DS1337_BIT_RS2)
1163                 rate_sel += 2;
1164
1165         return ds3231_clk_sqw_rates[rate_sel];
1166 }
1167
1168 static long ds3231_clk_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
1169                                       unsigned long *prate)
1170 {
1171         int i;
1172
1173         for (i = ARRAY_SIZE(ds3231_clk_sqw_rates) - 1; i >= 0; i--) {
1174                 if (ds3231_clk_sqw_rates[i] <= rate)
1175                         return ds3231_clk_sqw_rates[i];
1176         }
1177
1178         return 0;
1179 }
1180
1181 static int ds3231_clk_sqw_set_rate(struct clk_hw *hw, unsigned long rate,
1182                                    unsigned long parent_rate)
1183 {
1184         struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1185         int control = 0;
1186         int rate_sel;
1187
1188         for (rate_sel = 0; rate_sel < ARRAY_SIZE(ds3231_clk_sqw_rates);
1189                         rate_sel++) {
1190                 if (ds3231_clk_sqw_rates[rate_sel] == rate)
1191                         break;
1192         }
1193
1194         if (rate_sel == ARRAY_SIZE(ds3231_clk_sqw_rates))
1195                 return -EINVAL;
1196
1197         if (rate_sel & 1)
1198                 control |= DS1337_BIT_RS1;
1199         if (rate_sel & 2)
1200                 control |= DS1337_BIT_RS2;
1201
1202         return ds1337_write_control(ds1307, DS1337_BIT_RS1 | DS1337_BIT_RS2,
1203                                 control);
1204 }
1205
1206 static int ds3231_clk_sqw_prepare(struct clk_hw *hw)
1207 {
1208         struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1209
1210         return ds1337_write_control(ds1307, DS1337_BIT_INTCN, 0);
1211 }
1212
1213 static void ds3231_clk_sqw_unprepare(struct clk_hw *hw)
1214 {
1215         struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1216
1217         ds1337_write_control(ds1307, DS1337_BIT_INTCN, DS1337_BIT_INTCN);
1218 }
1219
1220 static int ds3231_clk_sqw_is_prepared(struct clk_hw *hw)
1221 {
1222         struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1223         int control, ret;
1224
1225         ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control);
1226         if (ret)
1227                 return ret;
1228
1229         return !(control & DS1337_BIT_INTCN);
1230 }
1231
1232 static const struct clk_ops ds3231_clk_sqw_ops = {
1233         .prepare = ds3231_clk_sqw_prepare,
1234         .unprepare = ds3231_clk_sqw_unprepare,
1235         .is_prepared = ds3231_clk_sqw_is_prepared,
1236         .recalc_rate = ds3231_clk_sqw_recalc_rate,
1237         .round_rate = ds3231_clk_sqw_round_rate,
1238         .set_rate = ds3231_clk_sqw_set_rate,
1239 };
1240
1241 static unsigned long ds3231_clk_32khz_recalc_rate(struct clk_hw *hw,
1242                                                   unsigned long parent_rate)
1243 {
1244         return 32768;
1245 }
1246
1247 static int ds3231_clk_32khz_control(struct ds1307 *ds1307, bool enable)
1248 {
1249         struct mutex *lock = &ds1307->rtc->ops_lock;
1250         int ret;
1251
1252         mutex_lock(lock);
1253         ret = regmap_update_bits(ds1307->regmap, DS1337_REG_STATUS,
1254                                  DS3231_BIT_EN32KHZ,
1255                                  enable ? DS3231_BIT_EN32KHZ : 0);
1256         mutex_unlock(lock);
1257
1258         return ret;
1259 }
1260
1261 static int ds3231_clk_32khz_prepare(struct clk_hw *hw)
1262 {
1263         struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1264
1265         return ds3231_clk_32khz_control(ds1307, true);
1266 }
1267
1268 static void ds3231_clk_32khz_unprepare(struct clk_hw *hw)
1269 {
1270         struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1271
1272         ds3231_clk_32khz_control(ds1307, false);
1273 }
1274
1275 static int ds3231_clk_32khz_is_prepared(struct clk_hw *hw)
1276 {
1277         struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1278         int status, ret;
1279
1280         ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &status);
1281         if (ret)
1282                 return ret;
1283
1284         return !!(status & DS3231_BIT_EN32KHZ);
1285 }
1286
1287 static const struct clk_ops ds3231_clk_32khz_ops = {
1288         .prepare = ds3231_clk_32khz_prepare,
1289         .unprepare = ds3231_clk_32khz_unprepare,
1290         .is_prepared = ds3231_clk_32khz_is_prepared,
1291         .recalc_rate = ds3231_clk_32khz_recalc_rate,
1292 };
1293
1294 static struct clk_init_data ds3231_clks_init[] = {
1295         [DS3231_CLK_SQW] = {
1296                 .name = "ds3231_clk_sqw",
1297                 .ops = &ds3231_clk_sqw_ops,
1298         },
1299         [DS3231_CLK_32KHZ] = {
1300                 .name = "ds3231_clk_32khz",
1301                 .ops = &ds3231_clk_32khz_ops,
1302         },
1303 };
1304
1305 static int ds3231_clks_register(struct ds1307 *ds1307)
1306 {
1307         struct device_node *node = ds1307->dev->of_node;
1308         struct clk_onecell_data *onecell;
1309         int i;
1310
1311         onecell = devm_kzalloc(ds1307->dev, sizeof(*onecell), GFP_KERNEL);
1312         if (!onecell)
1313                 return -ENOMEM;
1314
1315         onecell->clk_num = ARRAY_SIZE(ds3231_clks_init);
1316         onecell->clks = devm_kcalloc(ds1307->dev, onecell->clk_num,
1317                                      sizeof(onecell->clks[0]), GFP_KERNEL);
1318         if (!onecell->clks)
1319                 return -ENOMEM;
1320
1321         for (i = 0; i < ARRAY_SIZE(ds3231_clks_init); i++) {
1322                 struct clk_init_data init = ds3231_clks_init[i];
1323
1324                 /*
1325                  * Interrupt signal due to alarm conditions and square-wave
1326                  * output share same pin, so don't initialize both.
1327                  */
1328                 if (i == DS3231_CLK_SQW && test_bit(HAS_ALARM, &ds1307->flags))
1329                         continue;
1330
1331                 /* optional override of the clockname */
1332                 of_property_read_string_index(node, "clock-output-names", i,
1333                                               &init.name);
1334                 ds1307->clks[i].init = &init;
1335
1336                 onecell->clks[i] = devm_clk_register(ds1307->dev,
1337                                                      &ds1307->clks[i]);
1338                 if (IS_ERR(onecell->clks[i]))
1339                         return PTR_ERR(onecell->clks[i]);
1340         }
1341
1342         if (!node)
1343                 return 0;
1344
1345         of_clk_add_provider(node, of_clk_src_onecell_get, onecell);
1346
1347         return 0;
1348 }
1349
1350 static void ds1307_clks_register(struct ds1307 *ds1307)
1351 {
1352         int ret;
1353
1354         if (ds1307->type != ds_3231)
1355                 return;
1356
1357         ret = ds3231_clks_register(ds1307);
1358         if (ret) {
1359                 dev_warn(ds1307->dev, "unable to register clock device %d\n",
1360                          ret);
1361         }
1362 }
1363
1364 #else
1365
1366 static void ds1307_clks_register(struct ds1307 *ds1307)
1367 {
1368 }
1369
1370 #endif /* CONFIG_COMMON_CLK */
1371
1372 static const struct regmap_config regmap_config = {
1373         .reg_bits = 8,
1374         .val_bits = 8,
1375         .max_register = 0x9,
1376 };
1377
1378 static int ds1307_probe(struct i2c_client *client,
1379                         const struct i2c_device_id *id)
1380 {
1381         struct ds1307           *ds1307;
1382         int                     err = -ENODEV;
1383         int                     tmp;
1384         const struct chip_desc  *chip;
1385         bool                    want_irq;
1386         bool                    ds1307_can_wakeup_device = false;
1387         unsigned char           regs[8];
1388         struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
1389         u8                      trickle_charger_setup = 0;
1390
1391         ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
1392         if (!ds1307)
1393                 return -ENOMEM;
1394
1395         dev_set_drvdata(&client->dev, ds1307);
1396         ds1307->dev = &client->dev;
1397         ds1307->name = client->name;
1398
1399         ds1307->regmap = devm_regmap_init_i2c(client, &regmap_config);
1400         if (IS_ERR(ds1307->regmap)) {
1401                 dev_err(ds1307->dev, "regmap allocation failed\n");
1402                 return PTR_ERR(ds1307->regmap);
1403         }
1404
1405         i2c_set_clientdata(client, ds1307);
1406
1407         if (client->dev.of_node) {
1408                 ds1307->type = (enum ds_type)
1409                         of_device_get_match_data(&client->dev);
1410                 chip = &chips[ds1307->type];
1411         } else if (id) {
1412                 chip = &chips[id->driver_data];
1413                 ds1307->type = id->driver_data;
1414         } else {
1415                 const struct acpi_device_id *acpi_id;
1416
1417                 acpi_id = acpi_match_device(ACPI_PTR(ds1307_acpi_ids),
1418                                             ds1307->dev);
1419                 if (!acpi_id)
1420                         return -ENODEV;
1421                 chip = &chips[acpi_id->driver_data];
1422                 ds1307->type = acpi_id->driver_data;
1423         }
1424
1425         want_irq = client->irq > 0 && chip->alarm;
1426
1427         if (!pdata)
1428                 trickle_charger_setup = ds1307_trickle_init(ds1307, chip);
1429         else if (pdata->trickle_charger_setup)
1430                 trickle_charger_setup = pdata->trickle_charger_setup;
1431
1432         if (trickle_charger_setup && chip->trickle_charger_reg) {
1433                 trickle_charger_setup |= DS13XX_TRICKLE_CHARGER_MAGIC;
1434                 dev_dbg(ds1307->dev,
1435                         "writing trickle charger info 0x%x to 0x%x\n",
1436                         trickle_charger_setup, chip->trickle_charger_reg);
1437                 regmap_write(ds1307->regmap, chip->trickle_charger_reg,
1438                              trickle_charger_setup);
1439         }
1440
1441 #ifdef CONFIG_OF
1442 /*
1443  * For devices with no IRQ directly connected to the SoC, the RTC chip
1444  * can be forced as a wakeup source by stating that explicitly in
1445  * the device's .dts file using the "wakeup-source" boolean property.
1446  * If the "wakeup-source" property is set, don't request an IRQ.
1447  * This will guarantee the 'wakealarm' sysfs entry is available on the device,
1448  * if supported by the RTC.
1449  */
1450         if (chip->alarm && of_property_read_bool(client->dev.of_node,
1451                                                  "wakeup-source"))
1452                 ds1307_can_wakeup_device = true;
1453 #endif
1454
1455         switch (ds1307->type) {
1456         case ds_1337:
1457         case ds_1339:
1458         case ds_1341:
1459         case ds_3231:
1460                 /* get registers that the "rtc" read below won't read... */
1461                 err = regmap_bulk_read(ds1307->regmap, DS1337_REG_CONTROL,
1462                                        regs, 2);
1463                 if (err) {
1464                         dev_dbg(ds1307->dev, "read error %d\n", err);
1465                         goto exit;
1466                 }
1467
1468                 /* oscillator off?  turn it on, so clock can tick. */
1469                 if (regs[0] & DS1337_BIT_nEOSC)
1470                         regs[0] &= ~DS1337_BIT_nEOSC;
1471
1472                 /*
1473                  * Using IRQ or defined as wakeup-source?
1474                  * Disable the square wave and both alarms.
1475                  * For some variants, be sure alarms can trigger when we're
1476                  * running on Vbackup (BBSQI/BBSQW)
1477                  */
1478                 if (want_irq || ds1307_can_wakeup_device) {
1479                         regs[0] |= DS1337_BIT_INTCN | chip->bbsqi_bit;
1480                         regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
1481                 }
1482
1483                 regmap_write(ds1307->regmap, DS1337_REG_CONTROL,
1484                              regs[0]);
1485
1486                 /* oscillator fault?  clear flag, and warn */
1487                 if (regs[1] & DS1337_BIT_OSF) {
1488                         regmap_write(ds1307->regmap, DS1337_REG_STATUS,
1489                                      regs[1] & ~DS1337_BIT_OSF);
1490                         dev_warn(ds1307->dev, "SET TIME!\n");
1491                 }
1492                 break;
1493
1494         case rx_8025:
1495                 err = regmap_bulk_read(ds1307->regmap,
1496                                        RX8025_REG_CTRL1 << 4 | 0x08, regs, 2);
1497                 if (err) {
1498                         dev_dbg(ds1307->dev, "read error %d\n", err);
1499                         goto exit;
1500                 }
1501
1502                 /* oscillator off?  turn it on, so clock can tick. */
1503                 if (!(regs[1] & RX8025_BIT_XST)) {
1504                         regs[1] |= RX8025_BIT_XST;
1505                         regmap_write(ds1307->regmap,
1506                                      RX8025_REG_CTRL2 << 4 | 0x08,
1507                                      regs[1]);
1508                         dev_warn(ds1307->dev,
1509                                  "oscillator stop detected - SET TIME!\n");
1510                 }
1511
1512                 if (regs[1] & RX8025_BIT_PON) {
1513                         regs[1] &= ~RX8025_BIT_PON;
1514                         regmap_write(ds1307->regmap,
1515                                      RX8025_REG_CTRL2 << 4 | 0x08,
1516                                      regs[1]);
1517                         dev_warn(ds1307->dev, "power-on detected\n");
1518                 }
1519
1520                 if (regs[1] & RX8025_BIT_VDET) {
1521                         regs[1] &= ~RX8025_BIT_VDET;
1522                         regmap_write(ds1307->regmap,
1523                                      RX8025_REG_CTRL2 << 4 | 0x08,
1524                                      regs[1]);
1525                         dev_warn(ds1307->dev, "voltage drop detected\n");
1526                 }
1527
1528                 /* make sure we are running in 24hour mode */
1529                 if (!(regs[0] & RX8025_BIT_2412)) {
1530                         u8 hour;
1531
1532                         /* switch to 24 hour mode */
1533                         regmap_write(ds1307->regmap,
1534                                      RX8025_REG_CTRL1 << 4 | 0x08,
1535                                      regs[0] | RX8025_BIT_2412);
1536
1537                         err = regmap_bulk_read(ds1307->regmap,
1538                                                RX8025_REG_CTRL1 << 4 | 0x08,
1539                                                regs, 2);
1540                         if (err) {
1541                                 dev_dbg(ds1307->dev, "read error %d\n", err);
1542                                 goto exit;
1543                         }
1544
1545                         /* correct hour */
1546                         hour = bcd2bin(regs[DS1307_REG_HOUR]);
1547                         if (hour == 12)
1548                                 hour = 0;
1549                         if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1550                                 hour += 12;
1551
1552                         regmap_write(ds1307->regmap,
1553                                      DS1307_REG_HOUR << 4 | 0x08, hour);
1554                 }
1555                 break;
1556         default:
1557                 break;
1558         }
1559
1560 read_rtc:
1561         /* read RTC registers */
1562         err = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
1563                                sizeof(regs));
1564         if (err) {
1565                 dev_dbg(ds1307->dev, "read error %d\n", err);
1566                 goto exit;
1567         }
1568
1569         /*
1570          * minimal sanity checking; some chips (like DS1340) don't
1571          * specify the extra bits as must-be-zero, but there are
1572          * still a few values that are clearly out-of-range.
1573          */
1574         tmp = regs[DS1307_REG_SECS];
1575         switch (ds1307->type) {
1576         case ds_1307:
1577         case m41t0:
1578         case m41t00:
1579                 /* clock halted?  turn it on, so clock can tick. */
1580                 if (tmp & DS1307_BIT_CH) {
1581                         regmap_write(ds1307->regmap, DS1307_REG_SECS, 0);
1582                         dev_warn(ds1307->dev, "SET TIME!\n");
1583                         goto read_rtc;
1584                 }
1585                 break;
1586         case ds_1308:
1587         case ds_1338:
1588                 /* clock halted?  turn it on, so clock can tick. */
1589                 if (tmp & DS1307_BIT_CH)
1590                         regmap_write(ds1307->regmap, DS1307_REG_SECS, 0);
1591
1592                 /* oscillator fault?  clear flag, and warn */
1593                 if (regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
1594                         regmap_write(ds1307->regmap, DS1307_REG_CONTROL,
1595                                      regs[DS1307_REG_CONTROL] &
1596                                      ~DS1338_BIT_OSF);
1597                         dev_warn(ds1307->dev, "SET TIME!\n");
1598                         goto read_rtc;
1599                 }
1600                 break;
1601         case ds_1340:
1602                 /* clock halted?  turn it on, so clock can tick. */
1603                 if (tmp & DS1340_BIT_nEOSC)
1604                         regmap_write(ds1307->regmap, DS1307_REG_SECS, 0);
1605
1606                 err = regmap_read(ds1307->regmap, DS1340_REG_FLAG, &tmp);
1607                 if (err) {
1608                         dev_dbg(ds1307->dev, "read error %d\n", err);
1609                         goto exit;
1610                 }
1611
1612                 /* oscillator fault?  clear flag, and warn */
1613                 if (tmp & DS1340_BIT_OSF) {
1614                         regmap_write(ds1307->regmap, DS1340_REG_FLAG, 0);
1615                         dev_warn(ds1307->dev, "SET TIME!\n");
1616                 }
1617                 break;
1618         case mcp794xx:
1619                 /* make sure that the backup battery is enabled */
1620                 if (!(regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
1621                         regmap_write(ds1307->regmap, DS1307_REG_WDAY,
1622                                      regs[DS1307_REG_WDAY] |
1623                                      MCP794XX_BIT_VBATEN);
1624                 }
1625
1626                 /* clock halted?  turn it on, so clock can tick. */
1627                 if (!(tmp & MCP794XX_BIT_ST)) {
1628                         regmap_write(ds1307->regmap, DS1307_REG_SECS,
1629                                      MCP794XX_BIT_ST);
1630                         dev_warn(ds1307->dev, "SET TIME!\n");
1631                         goto read_rtc;
1632                 }
1633
1634                 break;
1635         default:
1636                 break;
1637         }
1638
1639         tmp = regs[DS1307_REG_HOUR];
1640         switch (ds1307->type) {
1641         case ds_1340:
1642         case m41t0:
1643         case m41t00:
1644                 /*
1645                  * NOTE: ignores century bits; fix before deploying
1646                  * systems that will run through year 2100.
1647                  */
1648                 break;
1649         case rx_8025:
1650                 break;
1651         default:
1652                 if (!(tmp & DS1307_BIT_12HR))
1653                         break;
1654
1655                 /*
1656                  * Be sure we're in 24 hour mode.  Multi-master systems
1657                  * take note...
1658                  */
1659                 tmp = bcd2bin(tmp & 0x1f);
1660                 if (tmp == 12)
1661                         tmp = 0;
1662                 if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1663                         tmp += 12;
1664                 regmap_write(ds1307->regmap, chip->offset + DS1307_REG_HOUR,
1665                              bin2bcd(tmp));
1666         }
1667
1668         if (want_irq || ds1307_can_wakeup_device) {
1669                 device_set_wakeup_capable(ds1307->dev, true);
1670                 set_bit(HAS_ALARM, &ds1307->flags);
1671         }
1672
1673         ds1307->rtc = devm_rtc_allocate_device(ds1307->dev);
1674         if (IS_ERR(ds1307->rtc))
1675                 return PTR_ERR(ds1307->rtc);
1676
1677         if (ds1307_can_wakeup_device && !want_irq) {
1678                 dev_info(ds1307->dev,
1679                          "'wakeup-source' is set, request for an IRQ is disabled!\n");
1680                 /* We cannot support UIE mode if we do not have an IRQ line */
1681                 ds1307->rtc->uie_unsupported = 1;
1682         }
1683
1684         if (want_irq) {
1685                 err = devm_request_threaded_irq(ds1307->dev, client->irq, NULL,
1686                                                 chip->irq_handler ?: ds1307_irq,
1687                                                 IRQF_SHARED | IRQF_ONESHOT,
1688                                                 ds1307->name, ds1307);
1689                 if (err) {
1690                         client->irq = 0;
1691                         device_set_wakeup_capable(ds1307->dev, false);
1692                         clear_bit(HAS_ALARM, &ds1307->flags);
1693                         dev_err(ds1307->dev, "unable to request IRQ!\n");
1694                 } else {
1695                         dev_dbg(ds1307->dev, "got IRQ %d\n", client->irq);
1696                 }
1697         }
1698
1699         ds1307->rtc->ops = chip->rtc_ops ?: &ds13xx_rtc_ops;
1700         err = rtc_register_device(ds1307->rtc);
1701         if (err)
1702                 return err;
1703
1704         if (chip->nvram_size) {
1705                 struct nvmem_config nvmem_cfg = {
1706                         .name = "ds1307_nvram",
1707                         .word_size = 1,
1708                         .stride = 1,
1709                         .size = chip->nvram_size,
1710                         .reg_read = ds1307_nvram_read,
1711                         .reg_write = ds1307_nvram_write,
1712                         .priv = ds1307,
1713                 };
1714
1715                 ds1307->rtc->nvram_old_abi = true;
1716                 rtc_nvmem_register(ds1307->rtc, &nvmem_cfg);
1717         }
1718
1719         ds1307_hwmon_register(ds1307);
1720         ds1307_clks_register(ds1307);
1721
1722         return 0;
1723
1724 exit:
1725         return err;
1726 }
1727
1728 static struct i2c_driver ds1307_driver = {
1729         .driver = {
1730                 .name   = "rtc-ds1307",
1731                 .of_match_table = of_match_ptr(ds1307_of_match),
1732                 .acpi_match_table = ACPI_PTR(ds1307_acpi_ids),
1733         },
1734         .probe          = ds1307_probe,
1735         .id_table       = ds1307_id,
1736 };
1737
1738 module_i2c_driver(ds1307_driver);
1739
1740 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
1741 MODULE_LICENSE("GPL");