drivers/rtc/rtc-ds1685.c

   1 /*
   2  * An rtc driver for the Dallas/Maxim DS1685/DS1687 and related real-time
   3  * chips.
   4  *
   5  * Copyright (C) 2011-2014 Joshua Kinard <kumba@gentoo.org>.
   6  * Copyright (C) 2009 Matthias Fuchs <matthias.fuchs@esd-electronics.com>.
   7  *
   8  * References:
   9  *    DS1685/DS1687 3V/5V Real-Time Clocks, 19-5215, Rev 4/10.
  10  *    DS17x85/DS17x87 3V/5V Real-Time Clocks, 19-5222, Rev 4/10.
  11  *    DS1689/DS1693 3V/5V Serialized Real-Time Clocks, Rev 112105.
  12  *    Application Note 90, Using the Multiplex Bus RTC Extended Features.
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License version 2 as
  16  * published by the Free Software Foundation.
  17  */
  18
  19 #include <linux/bcd.h>
  20 #include <linux/delay.h>
  21 #include <linux/io.h>
  22 #include <linux/module.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/rtc.h>
  25 #include <linux/workqueue.h>
  26
  27 #include <linux/rtc/ds1685.h>
  28
  29 #ifdef CONFIG_PROC_FS
  30 #include <linux/proc_fs.h>
  31 #endif
  32
  33 #define DRV_VERSION     "0.42.0"
  34
  35
  36 /* ----------------------------------------------------------------------- */
  37 /* Standard read/write functions if platform does not provide overrides */
  38
  39 /**
  40  * ds1685_read - read a value from an rtc register.
  41  * @rtc: pointer to the ds1685 rtc structure.
  42  * @reg: the register address to read.
  43  */
  44 static u8
  45 ds1685_read(struct ds1685_priv *rtc, int reg)
  46 {
  47         return readb((u8 __iomem *)rtc->regs +
  48                      (reg * rtc->regstep));
  49 }
  50
  51 /**
  52  * ds1685_write - write a value to an rtc register.
  53  * @rtc: pointer to the ds1685 rtc structure.
  54  * @reg: the register address to write.
  55  * @value: value to write to the register.
  56  */
  57 static void
  58 ds1685_write(struct ds1685_priv *rtc, int reg, u8 value)
  59 {
  60         writeb(value, ((u8 __iomem *)rtc->regs +
  61                        (reg * rtc->regstep)));
  62 }
  63 /* ----------------------------------------------------------------------- */
  64
  65
  66 /* ----------------------------------------------------------------------- */
  67 /* Inlined functions */
  68
  69 /**
  70  * ds1685_rtc_bcd2bin - bcd2bin wrapper in case platform doesn't support BCD.
  71  * @rtc: pointer to the ds1685 rtc structure.
  72  * @val: u8 time value to consider converting.
  73  * @bcd_mask: u8 mask value if BCD mode is used.
  74  * @bin_mask: u8 mask value if BIN mode is used.
  75  *
  76  * Returns the value, converted to BIN if originally in BCD and bcd_mode TRUE.
  77  */
  78 static inline u8
  79 ds1685_rtc_bcd2bin(struct ds1685_priv *rtc, u8 val, u8 bcd_mask, u8 bin_mask)
  80 {
  81         if (rtc->bcd_mode)
  82                 return (bcd2bin(val) & bcd_mask);
  83
  84         return (val & bin_mask);
  85 }
  86
  87 /**
  88  * ds1685_rtc_bin2bcd - bin2bcd wrapper in case platform doesn't support BCD.
  89  * @rtc: pointer to the ds1685 rtc structure.
  90  * @val: u8 time value to consider converting.
  91  * @bin_mask: u8 mask value if BIN mode is used.
  92  * @bcd_mask: u8 mask value if BCD mode is used.
  93  *
  94  * Returns the value, converted to BCD if originally in BIN and bcd_mode TRUE.
  95  */
  96 static inline u8
  97 ds1685_rtc_bin2bcd(struct ds1685_priv *rtc, u8 val, u8 bin_mask, u8 bcd_mask)
  98 {
  99         if (rtc->bcd_mode)
 100                 return (bin2bcd(val) & bcd_mask);
 101
 102         return (val & bin_mask);
 103 }
 104
 105 /**
 106  * ds1685_rtc_switch_to_bank0 - switch the rtc to bank 0.
 107  * @rtc: pointer to the ds1685 rtc structure.
 108  */
 109 static inline void
 110 ds1685_rtc_switch_to_bank0(struct ds1685_priv *rtc)
 111 {
 112         rtc->write(rtc, RTC_CTRL_A,
 113                    (rtc->read(rtc, RTC_CTRL_A) & ~(RTC_CTRL_A_DV0)));
 114 }
 115
 116 /**
 117  * ds1685_rtc_switch_to_bank1 - switch the rtc to bank 1.
 118  * @rtc: pointer to the ds1685 rtc structure.
 119  */
 120 static inline void
 121 ds1685_rtc_switch_to_bank1(struct ds1685_priv *rtc)
 122 {
 123         rtc->write(rtc, RTC_CTRL_A,
 124                    (rtc->read(rtc, RTC_CTRL_A) | RTC_CTRL_A_DV0));
 125 }
 126
 127 /**
 128  * ds1685_rtc_begin_data_access - prepare the rtc for data access.
 129  * @rtc: pointer to the ds1685 rtc structure.
 130  *
 131  * This takes several steps to prepare the rtc for access to get/set time
 132  * and alarm values from the rtc registers:
 133  *  - Sets the SET bit in Control Register B.
 134  *  - Reads Ext Control Register 4A and checks the INCR bit.
 135  *  - If INCR is active, a short delay is added before Ext Control Register 4A
 136  *    is read again in a loop until INCR is inactive.
 137  *  - Switches the rtc to bank 1.  This allows access to all relevant
 138  *    data for normal rtc operation, as bank 0 contains only the nvram.
 139  */
 140 static inline void
 141 ds1685_rtc_begin_data_access(struct ds1685_priv *rtc)
 142 {
 143         /* Set the SET bit in Ctrl B */
 144         rtc->write(rtc, RTC_CTRL_B,
 145                    (rtc->read(rtc, RTC_CTRL_B) | RTC_CTRL_B_SET));
 146
 147         /* Read Ext Ctrl 4A and check the INCR bit to avoid a lockout. */
 148         while (rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_INCR)
 149                 cpu_relax();
 150
 151         /* Switch to Bank 1 */
 152         ds1685_rtc_switch_to_bank1(rtc);
 153 }
 154
 155 /**
 156  * ds1685_rtc_end_data_access - end data access on the rtc.
 157  * @rtc: pointer to the ds1685 rtc structure.
 158  *
 159  * This ends what was started by ds1685_rtc_begin_data_access:
 160  *  - Switches the rtc back to bank 0.
 161  *  - Clears the SET bit in Control Register B.
 162  */
 163 static inline void
 164 ds1685_rtc_end_data_access(struct ds1685_priv *rtc)
 165 {
 166         /* Switch back to Bank 0 */
 167         ds1685_rtc_switch_to_bank1(rtc);
 168
 169         /* Clear the SET bit in Ctrl B */
 170         rtc->write(rtc, RTC_CTRL_B,
 171                    (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_SET)));
 172 }
 173
 174 /**
 175  * ds1685_rtc_begin_ctrl_access - prepare the rtc for ctrl access.
 176  * @rtc: pointer to the ds1685 rtc structure.
 177  * @flags: irq flags variable for spin_lock_irqsave.
 178  *
 179  * This takes several steps to prepare the rtc for access to read just the
 180  * control registers:
 181  *  - Sets a spinlock on the rtc IRQ.
 182  *  - Switches the rtc to bank 1.  This allows access to the two extended
 183  *    control registers.
 184  *
 185  * Only use this where you are certain another lock will not be held.
 186  */
 187 static inline void
 188 ds1685_rtc_begin_ctrl_access(struct ds1685_priv *rtc, unsigned long flags)
 189 {
 190         spin_lock_irqsave(&rtc->lock, flags);
 191         ds1685_rtc_switch_to_bank1(rtc);
 192 }
 193
 194 /**
 195  * ds1685_rtc_end_ctrl_access - end ctrl access on the rtc.
 196  * @rtc: pointer to the ds1685 rtc structure.
 197  * @flags: irq flags variable for spin_unlock_irqrestore.
 198  *
 199  * This ends what was started by ds1685_rtc_begin_ctrl_access:
 200  *  - Switches the rtc back to bank 0.
 201  *  - Unsets the spinlock on the rtc IRQ.
 202  */
 203 static inline void
 204 ds1685_rtc_end_ctrl_access(struct ds1685_priv *rtc, unsigned long flags)
 205 {
 206         ds1685_rtc_switch_to_bank0(rtc);
 207         spin_unlock_irqrestore(&rtc->lock, flags);
 208 }
 209
 210 /**
 211  * ds1685_rtc_get_ssn - retrieve the silicon serial number.
 212  * @rtc: pointer to the ds1685 rtc structure.
 213  * @ssn: u8 array to hold the bits of the silicon serial number.
 214  *
 215  * This number starts at 0x40, and is 8-bytes long, ending at 0x47. The
 216  * first byte is the model number, the next six bytes are the serial number
 217  * digits, and the final byte is a CRC check byte.  Together, they form the
 218  * silicon serial number.
 219  *
 220  * These values are stored in bank1, so ds1685_rtc_switch_to_bank1 must be
 221  * called first before calling this function, else data will be read out of
 222  * the bank0 NVRAM.  Be sure to call ds1685_rtc_switch_to_bank0 when done.
 223  */
 224 static inline void
 225 ds1685_rtc_get_ssn(struct ds1685_priv *rtc, u8 *ssn)
 226 {
 227         ssn[0] = rtc->read(rtc, RTC_BANK1_SSN_MODEL);
 228         ssn[1] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_1);
 229         ssn[2] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_2);
 230         ssn[3] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_3);
 231         ssn[4] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_4);
 232         ssn[5] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_5);
 233         ssn[6] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_6);
 234         ssn[7] = rtc->read(rtc, RTC_BANK1_SSN_CRC);
 235 }
 236 /* ----------------------------------------------------------------------- */
 237
 238
 239 /* ----------------------------------------------------------------------- */
 240 /* Read/Set Time & Alarm functions */
 241
 242 /**
 243  * ds1685_rtc_read_time - reads the time registers.
 244  * @dev: pointer to device structure.
 245  * @tm: pointer to rtc_time structure.
 246  */
 247 static int
 248 ds1685_rtc_read_time(struct device *dev, struct rtc_time *tm)
 249 {
 250         struct platform_device *pdev = to_platform_device(dev);
 251         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
 252         u8 ctrlb, century;
 253         u8 seconds, minutes, hours, wday, mday, month, years;
 254
 255         /* Fetch the time info from the RTC registers. */
 256         ds1685_rtc_begin_data_access(rtc);
 257         seconds = rtc->read(rtc, RTC_SECS);
 258         minutes = rtc->read(rtc, RTC_MINS);
 259         hours   = rtc->read(rtc, RTC_HRS);
 260         wday    = rtc->read(rtc, RTC_WDAY);
 261         mday    = rtc->read(rtc, RTC_MDAY);
 262         month   = rtc->read(rtc, RTC_MONTH);
 263         years   = rtc->read(rtc, RTC_YEAR);
 264         century = rtc->read(rtc, RTC_CENTURY);
 265         ctrlb   = rtc->read(rtc, RTC_CTRL_B);
 266         ds1685_rtc_end_data_access(rtc);
 267
 268         /* bcd2bin if needed, perform fixups, and store to rtc_time. */
 269         years        = ds1685_rtc_bcd2bin(rtc, years, RTC_YEAR_BCD_MASK,
 270                                           RTC_YEAR_BIN_MASK);
 271         century      = ds1685_rtc_bcd2bin(rtc, century, RTC_CENTURY_MASK,
 272                                           RTC_CENTURY_MASK);
 273         tm->tm_sec   = ds1685_rtc_bcd2bin(rtc, seconds, RTC_SECS_BCD_MASK,
 274                                           RTC_SECS_BIN_MASK);
 275         tm->tm_min   = ds1685_rtc_bcd2bin(rtc, minutes, RTC_MINS_BCD_MASK,
 276                                           RTC_MINS_BIN_MASK);
 277         tm->tm_hour  = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_24_BCD_MASK,
 278                                           RTC_HRS_24_BIN_MASK);
 279         tm->tm_wday  = (ds1685_rtc_bcd2bin(rtc, wday, RTC_WDAY_MASK,
 280                                            RTC_WDAY_MASK) - 1);
 281         tm->tm_mday  = ds1685_rtc_bcd2bin(rtc, mday, RTC_MDAY_BCD_MASK,
 282                                           RTC_MDAY_BIN_MASK);
 283         tm->tm_mon   = (ds1685_rtc_bcd2bin(rtc, month, RTC_MONTH_BCD_MASK,
 284                                            RTC_MONTH_BIN_MASK) - 1);
 285         tm->tm_year  = ((years + (century * 100)) - 1900);
 286         tm->tm_yday  = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 287         tm->tm_isdst = 0; /* RTC has hardcoded timezone, so don't use. */
 288
 289         return rtc_valid_tm(tm);
 290 }
 291
 292 /**
 293  * ds1685_rtc_set_time - sets the time registers.
 294  * @dev: pointer to device structure.
 295  * @tm: pointer to rtc_time structure.
 296  */
 297 static int
 298 ds1685_rtc_set_time(struct device *dev, struct rtc_time *tm)
 299 {
 300         struct platform_device *pdev = to_platform_device(dev);
 301         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
 302         u8 ctrlb, seconds, minutes, hours, wday, mday, month, years, century;
 303
 304         /* Fetch the time info from rtc_time. */
 305         seconds = ds1685_rtc_bin2bcd(rtc, tm->tm_sec, RTC_SECS_BIN_MASK,
 306                                      RTC_SECS_BCD_MASK);
 307         minutes = ds1685_rtc_bin2bcd(rtc, tm->tm_min, RTC_MINS_BIN_MASK,
 308                                      RTC_MINS_BCD_MASK);
 309         hours   = ds1685_rtc_bin2bcd(rtc, tm->tm_hour, RTC_HRS_24_BIN_MASK,
 310                                      RTC_HRS_24_BCD_MASK);
 311         wday    = ds1685_rtc_bin2bcd(rtc, (tm->tm_wday + 1), RTC_WDAY_MASK,
 312                                      RTC_WDAY_MASK);
 313         mday    = ds1685_rtc_bin2bcd(rtc, tm->tm_mday, RTC_MDAY_BIN_MASK,
 314                                      RTC_MDAY_BCD_MASK);
 315         month   = ds1685_rtc_bin2bcd(rtc, (tm->tm_mon + 1), RTC_MONTH_BIN_MASK,
 316                                      RTC_MONTH_BCD_MASK);
 317         years   = ds1685_rtc_bin2bcd(rtc, (tm->tm_year % 100),
 318                                      RTC_YEAR_BIN_MASK, RTC_YEAR_BCD_MASK);
 319         century = ds1685_rtc_bin2bcd(rtc, ((tm->tm_year + 1900) / 100),
 320                                      RTC_CENTURY_MASK, RTC_CENTURY_MASK);
 321
 322         /*
 323          * Perform Sanity Checks:
 324          *   - Months: !> 12, Month Day != 0.
 325          *   - Month Day !> Max days in current month.
 326          *   - Hours !>= 24, Mins !>= 60, Secs !>= 60, & Weekday !> 7.
 327          */
 328         if ((tm->tm_mon > 11) || (mday == 0))
 329                 return -EDOM;
 330
 331         if (tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year))
 332                 return -EDOM;
 333
 334         if ((tm->tm_hour >= 24) || (tm->tm_min >= 60) ||
 335             (tm->tm_sec >= 60)  || (wday > 7))
 336                 return -EDOM;
 337
 338         /*
 339          * Set the data mode to use and store the time values in the
 340          * RTC registers.
 341          */
 342         ds1685_rtc_begin_data_access(rtc);
 343         ctrlb = rtc->read(rtc, RTC_CTRL_B);
 344         if (rtc->bcd_mode)
 345                 ctrlb &= ~(RTC_CTRL_B_DM);
 346         else
 347                 ctrlb |= RTC_CTRL_B_DM;
 348         rtc->write(rtc, RTC_CTRL_B, ctrlb);
 349         rtc->write(rtc, RTC_SECS, seconds);
 350         rtc->write(rtc, RTC_MINS, minutes);
 351         rtc->write(rtc, RTC_HRS, hours);
 352         rtc->write(rtc, RTC_WDAY, wday);
 353         rtc->write(rtc, RTC_MDAY, mday);
 354         rtc->write(rtc, RTC_MONTH, month);
 355         rtc->write(rtc, RTC_YEAR, years);
 356         rtc->write(rtc, RTC_CENTURY, century);
 357         ds1685_rtc_end_data_access(rtc);
 358
 359         return 0;
 360 }
 361
 362 /**
 363  * ds1685_rtc_read_alarm - reads the alarm registers.
 364  * @dev: pointer to device structure.
 365  * @alrm: pointer to rtc_wkalrm structure.
 366  *
 367  * There are three primary alarm registers: seconds, minutes, and hours.
 368  * A fourth alarm register for the month date is also available in bank1 for
 369  * kickstart/wakeup features.  The DS1685/DS1687 manual states that a
 370  * "don't care" value ranging from 0xc0 to 0xff may be written into one or
 371  * more of the three alarm bytes to act as a wildcard value.  The fourth
 372  * byte doesn't support a "don't care" value.
 373  */
 374 static int
 375 ds1685_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 376 {
 377         struct platform_device *pdev = to_platform_device(dev);
 378         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
 379         u8 seconds, minutes, hours, mday, ctrlb, ctrlc;
 380
 381         /* Fetch the alarm info from the RTC alarm registers. */
 382         ds1685_rtc_begin_data_access(rtc);
 383         seconds = rtc->read(rtc, RTC_SECS_ALARM);
 384         minutes = rtc->read(rtc, RTC_MINS_ALARM);
 385         hours   = rtc->read(rtc, RTC_HRS_ALARM);
 386         mday    = rtc->read(rtc, RTC_MDAY_ALARM);
 387         ctrlb   = rtc->read(rtc, RTC_CTRL_B);
 388         ctrlc   = rtc->read(rtc, RTC_CTRL_C);
 389         ds1685_rtc_end_data_access(rtc);
 390
 391         /* Check month date. */
 392         if (!(mday >= 1) && (mday <= 31))
 393                 return -EDOM;
 394
 395         /*
 396          * Check the three alarm bytes.
 397          *
 398          * The Linux RTC system doesn't support the "don't care" capability
 399          * of this RTC chip.  We check for it anyways in case support is
 400          * added in the future.
 401          */
 402         if (unlikely(seconds >= 0xc0))
 403                 alrm->time.tm_sec = -1;
 404         else
 405                 alrm->time.tm_sec = ds1685_rtc_bcd2bin(rtc, seconds,
 406                                                        RTC_SECS_BCD_MASK,
 407                                                        RTC_SECS_BIN_MASK);
 408
 409         if (unlikely(minutes >= 0xc0))
 410                 alrm->time.tm_min = -1;
 411         else
 412                 alrm->time.tm_min = ds1685_rtc_bcd2bin(rtc, minutes,
 413                                                        RTC_MINS_BCD_MASK,
 414                                                        RTC_MINS_BIN_MASK);
 415
 416         if (unlikely(hours >= 0xc0))
 417                 alrm->time.tm_hour = -1;
 418         else
 419                 alrm->time.tm_hour = ds1685_rtc_bcd2bin(rtc, hours,
 420                                                         RTC_HRS_24_BCD_MASK,
 421                                                         RTC_HRS_24_BIN_MASK);
 422
 423         /* Write the data to rtc_wkalrm. */
 424         alrm->time.tm_mday = ds1685_rtc_bcd2bin(rtc, mday, RTC_MDAY_BCD_MASK,
 425                                                 RTC_MDAY_BIN_MASK);
 426         alrm->time.tm_mon = -1;
 427         alrm->time.tm_year = -1;
 428         alrm->time.tm_wday = -1;
 429         alrm->time.tm_yday = -1;
 430         alrm->time.tm_isdst = -1;
 431         alrm->enabled = !!(ctrlb & RTC_CTRL_B_AIE);
 432         alrm->pending = !!(ctrlc & RTC_CTRL_C_AF);
 433
 434         return 0;
 435 }
 436
 437 /**
 438  * ds1685_rtc_set_alarm - sets the alarm in registers.
 439  * @dev: pointer to device structure.
 440  * @alrm: pointer to rtc_wkalrm structure.
 441  */
 442 static int
 443 ds1685_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 444 {
 445         struct platform_device *pdev = to_platform_device(dev);
 446         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
 447         u8 ctrlb, seconds, minutes, hours, mday;
 448
 449         /* Fetch the alarm info and convert to BCD. */
 450         seconds = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_sec,
 451                                      RTC_SECS_BIN_MASK,
 452                                      RTC_SECS_BCD_MASK);
 453         minutes = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_min,
 454                                      RTC_MINS_BIN_MASK,
 455                                      RTC_MINS_BCD_MASK);
 456         hours   = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_hour,
 457                                      RTC_HRS_24_BIN_MASK,
 458                                      RTC_HRS_24_BCD_MASK);
 459         mday    = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_mday,
 460                                      RTC_MDAY_BIN_MASK,
 461                                      RTC_MDAY_BCD_MASK);
 462
 463         /* Check the month date for validity. */
 464         if (!(mday >= 1) && (mday <= 31))
 465                 return -EDOM;
 466
 467         /*
 468          * Check the three alarm bytes.
 469          *
 470          * The Linux RTC system doesn't support the "don't care" capability
 471          * of this RTC chip because rtc_valid_tm tries to validate every
 472          * field, and we only support four fields.  We put the support
 473          * here anyways for the future.
 474          */
 475         if (unlikely(seconds >= 0xc0))
 476                 seconds = 0xff;
 477
 478         if (unlikely(minutes >= 0xc0))
 479                 minutes = 0xff;
 480
 481         if (unlikely(hours >= 0xc0))
 482                 hours = 0xff;
 483
 484         alrm->time.tm_mon       = -1;
 485         alrm->time.tm_year      = -1;
 486         alrm->time.tm_wday      = -1;
 487         alrm->time.tm_yday      = -1;
 488         alrm->time.tm_isdst     = -1;
 489
 490         /* Disable the alarm interrupt first. */
 491         ds1685_rtc_begin_data_access(rtc);
 492         ctrlb = rtc->read(rtc, RTC_CTRL_B);
 493         rtc->write(rtc, RTC_CTRL_B, (ctrlb & ~(RTC_CTRL_B_AIE)));
 494
 495         /* Read ctrlc to clear RTC_CTRL_C_AF. */
 496         rtc->read(rtc, RTC_CTRL_C);
 497
 498         /*
 499          * Set the data mode to use and store the time values in the
 500          * RTC registers.
 501          */
 502         ctrlb = rtc->read(rtc, RTC_CTRL_B);
 503         if (rtc->bcd_mode)
 504                 ctrlb &= ~(RTC_CTRL_B_DM);
 505         else
 506                 ctrlb |= RTC_CTRL_B_DM;
 507         rtc->write(rtc, RTC_CTRL_B, ctrlb);
 508         rtc->write(rtc, RTC_SECS_ALARM, seconds);
 509         rtc->write(rtc, RTC_MINS_ALARM, minutes);
 510         rtc->write(rtc, RTC_HRS_ALARM, hours);
 511         rtc->write(rtc, RTC_MDAY_ALARM, mday);
 512
 513         /* Re-enable the alarm if needed. */
 514         if (alrm->enabled) {
 515                 ctrlb = rtc->read(rtc, RTC_CTRL_B);
 516                 ctrlb |= RTC_CTRL_B_AIE;
 517                 rtc->write(rtc, RTC_CTRL_B, ctrlb);
 518         }
 519
 520         /* Done! */
 521         ds1685_rtc_end_data_access(rtc);
 522
 523         return 0;
 524 }
 525 /* ----------------------------------------------------------------------- */
 526
 527
 528 /* ----------------------------------------------------------------------- */
 529 /* /dev/rtcX Interface functions */
 530
 531 /**
 532  * ds1685_rtc_alarm_irq_enable - replaces ioctl() RTC_AIE on/off.
 533  * @dev: pointer to device structure.
 534  * @enabled: flag indicating whether to enable or disable.
 535  */
 536 static int
 537 ds1685_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 538 {
 539         struct ds1685_priv *rtc = dev_get_drvdata(dev);
 540         unsigned long flags = 0;
 541
 542         /* Enable/disable the Alarm IRQ-Enable flag. */
 543         spin_lock_irqsave(&rtc->lock, flags);
 544
 545         /* Flip the requisite interrupt-enable bit. */
 546         if (enabled)
 547                 rtc->write(rtc, RTC_CTRL_B, (rtc->read(rtc, RTC_CTRL_B) |
 548                                              RTC_CTRL_B_AIE));
 549         else
 550                 rtc->write(rtc, RTC_CTRL_B, (rtc->read(rtc, RTC_CTRL_B) &
 551                                              ~(RTC_CTRL_B_AIE)));
 552
 553         /* Read Control C to clear all the flag bits. */
 554         rtc->read(rtc, RTC_CTRL_C);
 555         spin_unlock_irqrestore(&rtc->lock, flags);
 556
 557         return 0;
 558 }
 559 /* ----------------------------------------------------------------------- */
 560
 561
 562 /* ----------------------------------------------------------------------- */
 563 /* IRQ handler & workqueue. */
 564
 565 /**
 566  * ds1685_rtc_irq_handler - IRQ handler.
 567  * @irq: IRQ number.
 568  * @dev_id: platform device pointer.
 569  */
 570 static irqreturn_t
 571 ds1685_rtc_irq_handler(int irq, void *dev_id)
 572 {
 573         struct platform_device *pdev = dev_id;
 574         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
 575         u8 ctrlb, ctrlc;
 576         unsigned long events = 0;
 577         u8 num_irqs = 0;
 578
 579         /* Abort early if the device isn't ready yet (i.e., DEBUG_SHIRQ). */
 580         if (unlikely(!rtc))
 581                 return IRQ_HANDLED;
 582
 583         /* Ctrlb holds the interrupt-enable bits and ctrlc the flag bits. */
 584         spin_lock(&rtc->lock);
 585         ctrlb = rtc->read(rtc, RTC_CTRL_B);
 586         ctrlc = rtc->read(rtc, RTC_CTRL_C);
 587
 588         /* Is the IRQF bit set? */
 589         if (likely(ctrlc & RTC_CTRL_C_IRQF)) {
 590                 /*
 591                  * We need to determine if it was one of the standard
 592                  * events: PF, AF, or UF.  If so, we handle them and
 593                  * update the RTC core.
 594                  */
 595                 if (likely(ctrlc & RTC_CTRL_B_PAU_MASK)) {
 596                         events = RTC_IRQF;
 597
 598                         /* Check for a periodic interrupt. */
 599                         if ((ctrlb & RTC_CTRL_B_PIE) &&
 600                             (ctrlc & RTC_CTRL_C_PF)) {
 601                                 events |= RTC_PF;
 602                                 num_irqs++;
 603                         }
 604
 605                         /* Check for an alarm interrupt. */
 606                         if ((ctrlb & RTC_CTRL_B_AIE) &&
 607                             (ctrlc & RTC_CTRL_C_AF)) {
 608                                 events |= RTC_AF;
 609                                 num_irqs++;
 610                         }
 611
 612                         /* Check for an update interrupt. */
 613                         if ((ctrlb & RTC_CTRL_B_UIE) &&
 614                             (ctrlc & RTC_CTRL_C_UF)) {
 615                                 events |= RTC_UF;
 616                                 num_irqs++;
 617                         }
 618
 619                         rtc_update_irq(rtc->dev, num_irqs, events);
 620                 } else {
 621                         /*
 622                          * One of the "extended" interrupts was received that
 623                          * is not recognized by the RTC core.  These need to
 624                          * be handled in task context as they can call other
 625                          * functions and the time spent in irq context needs
 626                          * to be minimized.  Schedule them into a workqueue
 627                          * and inform the RTC core that the IRQs were handled.
 628                          */
 629                         spin_unlock(&rtc->lock);
 630                         schedule_work(&rtc->work);
 631                         rtc_update_irq(rtc->dev, 0, 0);
 632                         return IRQ_HANDLED;
 633                 }
 634         }
 635         spin_unlock(&rtc->lock);
 636
 637         return events ? IRQ_HANDLED : IRQ_NONE;
 638 }
 639
 640 /**
 641  * ds1685_rtc_work_queue - work queue handler.
 642  * @work: work_struct containing data to work on in task context.
 643  */
 644 static void
 645 ds1685_rtc_work_queue(struct work_struct *work)
 646 {
 647         struct ds1685_priv *rtc = container_of(work,
 648                                                struct ds1685_priv, work);
 649         struct platform_device *pdev = to_platform_device(&rtc->dev->dev);
 650         struct mutex *rtc_mutex = &rtc->dev->ops_lock;
 651         u8 ctrl4a, ctrl4b;
 652
 653         mutex_lock(rtc_mutex);
 654
 655         ds1685_rtc_switch_to_bank1(rtc);
 656         ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
 657         ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
 658
 659         /*
 660          * Check for a kickstart interrupt. With Vcc applied, this
 661          * typically means that the power button was pressed, so we
 662          * begin the shutdown sequence.
 663          */
 664         if ((ctrl4b & RTC_CTRL_4B_KSE) && (ctrl4a & RTC_CTRL_4A_KF)) {
 665                 /* Briefly disable kickstarts to debounce button presses. */
 666                 rtc->write(rtc, RTC_EXT_CTRL_4B,
 667                            (rtc->read(rtc, RTC_EXT_CTRL_4B) &
 668                             ~(RTC_CTRL_4B_KSE)));
 669
 670                 /* Clear the kickstart flag. */
 671                 rtc->write(rtc, RTC_EXT_CTRL_4A,
 672                            (ctrl4a & ~(RTC_CTRL_4A_KF)));
 673
 674
 675                 /*
 676                  * Sleep 500ms before re-enabling kickstarts.  This allows
 677                  * adequate time to avoid reading signal jitter as additional
 678                  * button presses.
 679                  */
 680                 msleep(500);
 681                 rtc->write(rtc, RTC_EXT_CTRL_4B,
 682                            (rtc->read(rtc, RTC_EXT_CTRL_4B) |
 683                             RTC_CTRL_4B_KSE));
 684
 685                 /* Call the platform pre-poweroff function. Else, shutdown. */
 686                 if (rtc->prepare_poweroff != NULL)
 687                         rtc->prepare_poweroff();
 688                 else
 689                         ds1685_rtc_poweroff(pdev);
 690         }
 691
 692         /*
 693          * Check for a wake-up interrupt.  With Vcc applied, this is
 694          * essentially a second alarm interrupt, except it takes into
 695          * account the 'date' register in bank1 in addition to the
 696          * standard three alarm registers.
 697          */
 698         if ((ctrl4b & RTC_CTRL_4B_WIE) && (ctrl4a & RTC_CTRL_4A_WF)) {
 699                 rtc->write(rtc, RTC_EXT_CTRL_4A,
 700                            (ctrl4a & ~(RTC_CTRL_4A_WF)));
 701
 702                 /* Call the platform wake_alarm function if defined. */
 703                 if (rtc->wake_alarm != NULL)
 704                         rtc->wake_alarm();
 705                 else
 706                         dev_warn(&pdev->dev,
 707                                  "Wake Alarm IRQ just occurred!\n");
 708         }
 709
 710         /*
 711          * Check for a ram-clear interrupt.  This happens if RIE=1 and RF=0
 712          * when RCE=1 in 4B.  This clears all NVRAM bytes in bank0 by setting
 713          * each byte to a logic 1.  This has no effect on any extended
 714          * NV-SRAM that might be present, nor on the time/calendar/alarm
 715          * registers.  After a ram-clear is completed, there is a minimum
 716          * recovery time of ~150ms in which all reads/writes are locked out.
 717          * NOTE: A ram-clear can still occur if RCE=1 and RIE=0.  We cannot
 718          * catch this scenario.
 719          */
 720         if ((ctrl4b & RTC_CTRL_4B_RIE) && (ctrl4a & RTC_CTRL_4A_RF)) {
 721                 rtc->write(rtc, RTC_EXT_CTRL_4A,
 722                            (ctrl4a & ~(RTC_CTRL_4A_RF)));
 723                 msleep(150);
 724
 725                 /* Call the platform post_ram_clear function if defined. */
 726                 if (rtc->post_ram_clear != NULL)
 727                         rtc->post_ram_clear();
 728                 else
 729                         dev_warn(&pdev->dev,
 730                                  "RAM-Clear IRQ just occurred!\n");
 731         }
 732         ds1685_rtc_switch_to_bank0(rtc);
 733
 734         mutex_unlock(rtc_mutex);
 735 }
 736 /* ----------------------------------------------------------------------- */
 737
 738
 739 /* ----------------------------------------------------------------------- */
 740 /* ProcFS interface */
 741
 742 #ifdef CONFIG_PROC_FS
 743 #define NUM_REGS        6       /* Num of control registers. */
 744 #define NUM_BITS        8       /* Num bits per register. */
 745 #define NUM_SPACES      4       /* Num spaces between each bit. */
 746
 747 /*
 748  * Periodic Interrupt Rates.
 749  */
 750 static const char *ds1685_rtc_pirq_rate[16] = {
 751         "none", "3.90625ms", "7.8125ms", "0.122070ms", "0.244141ms",
 752         "0.488281ms", "0.9765625ms", "1.953125ms", "3.90625ms", "7.8125ms",
 753         "15.625ms", "31.25ms", "62.5ms", "125ms", "250ms", "500ms"
 754 };
 755
 756 /*
 757  * Square-Wave Output Frequencies.
 758  */
 759 static const char *ds1685_rtc_sqw_freq[16] = {
 760         "none", "256Hz", "128Hz", "8192Hz", "4096Hz", "2048Hz", "1024Hz",
 761         "512Hz", "256Hz", "128Hz", "64Hz", "32Hz", "16Hz", "8Hz", "4Hz", "2Hz"
 762 };
 763
 764 #ifdef CONFIG_RTC_DS1685_PROC_REGS
 765 /**
 766  * ds1685_rtc_print_regs - helper function to print register values.
 767  * @hex: hex byte to convert into binary bits.
 768  * @dest: destination char array.
 769  *
 770  * This is basically a hex->binary function, just with extra spacing between
 771  * the digits.  It only works on 1-byte values (8 bits).
 772  */
 773 static char*
 774 ds1685_rtc_print_regs(u8 hex, char *dest)
 775 {
 776         u32 i, j;
 777         char *tmp = dest;
 778
 779         for (i = 0; i < NUM_BITS; i++) {
 780                 *tmp++ = ((hex & 0x80) != 0 ? '1' : '0');
 781                 for (j = 0; j < NUM_SPACES; j++)
 782                         *tmp++ = ' ';
 783                 hex <<= 1;
 784         }
 785         *tmp++ = '\0';
 786
 787         return dest;
 788 }
 789 #endif
 790
 791 /**
 792  * ds1685_rtc_proc - procfs access function.
 793  * @dev: pointer to device structure.
 794  * @seq: pointer to seq_file structure.
 795  */
 796 static int
 797 ds1685_rtc_proc(struct device *dev, struct seq_file *seq)
 798 {
 799         struct platform_device *pdev = to_platform_device(dev);
 800         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
 801         u8 ctrla, ctrlb, ctrlc, ctrld, ctrl4a, ctrl4b, ssn[8];
 802         char *model = '\0';
 803 #ifdef CONFIG_RTC_DS1685_PROC_REGS
 804         char bits[NUM_REGS][(NUM_BITS * NUM_SPACES) + NUM_BITS + 1];
 805 #endif
 806
 807         /* Read all the relevant data from the control registers. */
 808         ds1685_rtc_switch_to_bank1(rtc);
 809         ds1685_rtc_get_ssn(rtc, ssn);
 810         ctrla = rtc->read(rtc, RTC_CTRL_A);
 811         ctrlb = rtc->read(rtc, RTC_CTRL_B);
 812         ctrlc = rtc->read(rtc, RTC_CTRL_C);
 813         ctrld = rtc->read(rtc, RTC_CTRL_D);
 814         ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
 815         ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
 816         ds1685_rtc_switch_to_bank0(rtc);
 817
 818         /* Determine the RTC model. */
 819         switch (ssn[0]) {
 820         case RTC_MODEL_DS1685:
 821                 model = "DS1685/DS1687\0";
 822                 break;
 823         case RTC_MODEL_DS1689:
 824                 model = "DS1689/DS1693\0";
 825                 break;
 826         case RTC_MODEL_DS17285:
 827                 model = "DS17285/DS17287\0";
 828                 break;
 829         case RTC_MODEL_DS17485:
 830                 model = "DS17485/DS17487\0";
 831                 break;
 832         case RTC_MODEL_DS17885:
 833                 model = "DS17885/DS17887\0";
 834                 break;
 835         default:
 836                 model = "Unknown\0";
 837                 break;
 838         }
 839
 840         /* Print out the information. */
 841         seq_printf(seq,
 842            "Model\t\t: %s\n"
 843            "Oscillator\t: %s\n"
 844            "12/24hr\t\t: %s\n"
 845            "DST\t\t: %s\n"
 846            "Data mode\t: %s\n"
 847            "Battery\t\t: %s\n"
 848            "Aux batt\t: %s\n"
 849            "Update IRQ\t: %s\n"
 850            "Periodic IRQ\t: %s\n"
 851            "Periodic Rate\t: %s\n"
 852            "SQW Freq\t: %s\n"
 853 #ifdef CONFIG_RTC_DS1685_PROC_REGS
 854            "Serial #\t: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n"
 855            "Register Status\t:\n"
 856            "   Ctrl A\t: UIP  DV2  DV1  DV0  RS3  RS2  RS1  RS0\n"
 857            "\t\t:  %s\n"
 858            "   Ctrl B\t: SET  PIE  AIE  UIE  SQWE  DM  2412 DSE\n"
 859            "\t\t:  %s\n"
 860            "   Ctrl C\t: IRQF  PF   AF   UF  ---  ---  ---  ---\n"
 861            "\t\t:  %s\n"
 862            "   Ctrl D\t: VRT  ---  ---  ---  ---  ---  ---  ---\n"
 863            "\t\t:  %s\n"
 864 #if !defined(CONFIG_RTC_DRV_DS1685) && !defined(CONFIG_RTC_DRV_DS1689)
 865            "   Ctrl 4A\t: VRT2 INCR BME  ---  PAB   RF   WF   KF\n"
 866 #else
 867            "   Ctrl 4A\t: VRT2 INCR ---  ---  PAB   RF   WF   KF\n"
 868 #endif
 869            "\t\t:  %s\n"
 870            "   Ctrl 4B\t: ABE  E32k  CS  RCE  PRS  RIE  WIE  KSE\n"
 871            "\t\t:  %s\n",
 872 #else
 873            "Serial #\t: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
 874 #endif
 875            model,
 876            ((ctrla & RTC_CTRL_A_DV1) ? "enabled" : "disabled"),
 877            ((ctrlb & RTC_CTRL_B_2412) ? "24-hour" : "12-hour"),
 878            ((ctrlb & RTC_CTRL_B_DSE) ? "enabled" : "disabled"),
 879            ((ctrlb & RTC_CTRL_B_DM) ? "binary" : "BCD"),
 880            ((ctrld & RTC_CTRL_D_VRT) ? "ok" : "exhausted or n/a"),
 881            ((ctrl4a & RTC_CTRL_4A_VRT2) ? "ok" : "exhausted or n/a"),
 882            ((ctrlb & RTC_CTRL_B_UIE) ? "yes" : "no"),
 883            ((ctrlb & RTC_CTRL_B_PIE) ? "yes" : "no"),
 884            (!(ctrl4b & RTC_CTRL_4B_E32K) ?
 885             ds1685_rtc_pirq_rate[(ctrla & RTC_CTRL_A_RS_MASK)] : "none"),
 886            (!((ctrl4b & RTC_CTRL_4B_E32K)) ?
 887             ds1685_rtc_sqw_freq[(ctrla & RTC_CTRL_A_RS_MASK)] : "32768Hz"),
 888 #ifdef CONFIG_RTC_DS1685_PROC_REGS
 889            ssn[0], ssn[1], ssn[2], ssn[3], ssn[4], ssn[5], ssn[6], ssn[7],
 890            ds1685_rtc_print_regs(ctrla, bits[0]),
 891            ds1685_rtc_print_regs(ctrlb, bits[1]),
 892            ds1685_rtc_print_regs(ctrlc, bits[2]),
 893            ds1685_rtc_print_regs(ctrld, bits[3]),
 894            ds1685_rtc_print_regs(ctrl4a, bits[4]),
 895            ds1685_rtc_print_regs(ctrl4b, bits[5]));
 896 #else
 897            ssn[0], ssn[1], ssn[2], ssn[3], ssn[4], ssn[5], ssn[6], ssn[7]);
 898 #endif
 899         return 0;
 900 }
 901 #else
 902 #define ds1685_rtc_proc NULL
 903 #endif /* CONFIG_PROC_FS */
 904 /* ----------------------------------------------------------------------- */
 905
 906
 907 /* ----------------------------------------------------------------------- */
 908 /* RTC Class operations */
 909
 910 static const struct rtc_class_ops
 911 ds1685_rtc_ops = {
 912         .proc = ds1685_rtc_proc,
 913         .read_time = ds1685_rtc_read_time,
 914         .set_time = ds1685_rtc_set_time,
 915         .read_alarm = ds1685_rtc_read_alarm,
 916         .set_alarm = ds1685_rtc_set_alarm,
 917         .alarm_irq_enable = ds1685_rtc_alarm_irq_enable,
 918 };
 919 /* ----------------------------------------------------------------------- */
 920
 921
 922 /* ----------------------------------------------------------------------- */
 923 /* SysFS interface */
 924
 925 #ifdef CONFIG_SYSFS
 926 /**
 927  * ds1685_rtc_sysfs_nvram_read - reads rtc nvram via sysfs.
 928  * @file: pointer to file structure.
 929  * @kobj: pointer to kobject structure.
 930  * @bin_attr: pointer to bin_attribute structure.
 931  * @buf: pointer to char array to hold the output.
 932  * @pos: current file position pointer.
 933  * @size: size of the data to read.
 934  */
 935 static ssize_t
 936 ds1685_rtc_sysfs_nvram_read(struct file *filp, struct kobject *kobj,
 937                             struct bin_attribute *bin_attr, char *buf,
 938                             loff_t pos, size_t size)
 939 {
 940         struct platform_device *pdev =
 941                 to_platform_device(container_of(kobj, struct device, kobj));
 942         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
 943         ssize_t count;
 944         unsigned long flags = 0;
 945
 946         spin_lock_irqsave(&rtc->lock, flags);
 947         ds1685_rtc_switch_to_bank0(rtc);
 948
 949         /* Read NVRAM in time and bank0 registers. */
 950         for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ_BANK0;
 951              count++, size--) {
 952                 if (count < NVRAM_SZ_TIME)
 953                         *buf++ = rtc->read(rtc, (NVRAM_TIME_BASE + pos++));
 954                 else
 955                         *buf++ = rtc->read(rtc, (NVRAM_BANK0_BASE + pos++));
 956         }
 957
 958 #ifndef CONFIG_RTC_DRV_DS1689
 959         if (size > 0) {
 960                 ds1685_rtc_switch_to_bank1(rtc);
 961
 962 #ifndef CONFIG_RTC_DRV_DS1685
 963                 /* Enable burst-mode on DS17x85/DS17x87 */
 964                 rtc->write(rtc, RTC_EXT_CTRL_4A,
 965                            (rtc->read(rtc, RTC_EXT_CTRL_4A) |
 966                             RTC_CTRL_4A_BME));
 967
 968                 /* We need one write to RTC_BANK1_RAM_ADDR_LSB to start
 969                  * reading with burst-mode */
 970                 rtc->write(rtc, RTC_BANK1_RAM_ADDR_LSB,
 971                            (pos - NVRAM_TOTAL_SZ_BANK0));
 972 #endif
 973
 974                 /* Read NVRAM in bank1 registers. */
 975                 for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ;
 976                      count++, size--) {
 977 #ifdef CONFIG_RTC_DRV_DS1685
 978                         /* DS1685/DS1687 has to write to RTC_BANK1_RAM_ADDR
 979                          * before each read. */
 980                         rtc->write(rtc, RTC_BANK1_RAM_ADDR,
 981                                    (pos - NVRAM_TOTAL_SZ_BANK0));
 982 #endif
 983                         *buf++ = rtc->read(rtc, RTC_BANK1_RAM_DATA_PORT);
 984                         pos++;
 985                 }
 986
 987 #ifndef CONFIG_RTC_DRV_DS1685
 988                 /* Disable burst-mode on DS17x85/DS17x87 */
 989                 rtc->write(rtc, RTC_EXT_CTRL_4A,
 990                            (rtc->read(rtc, RTC_EXT_CTRL_4A) &
 991                             ~(RTC_CTRL_4A_BME)));
 992 #endif
 993                 ds1685_rtc_switch_to_bank0(rtc);
 994         }
 995 #endif /* !CONFIG_RTC_DRV_DS1689 */
 996         spin_unlock_irqrestore(&rtc->lock, flags);
 997
 998         /*
 999          * XXX: Bug? this appears to cause the function to get executed
1000          * several times in succession.  But it's the only way to actually get
1001          * data written out to a file.
1002          */
1003         return count;
1004 }
1005
1006 /**
1007  * ds1685_rtc_sysfs_nvram_write - writes rtc nvram via sysfs.
1008  * @file: pointer to file structure.
1009  * @kobj: pointer to kobject structure.
1010  * @bin_attr: pointer to bin_attribute structure.
1011  * @buf: pointer to char array to hold the input.
1012  * @pos: current file position pointer.
1013  * @size: size of the data to write.
1014  */
1015 static ssize_t
1016 ds1685_rtc_sysfs_nvram_write(struct file *filp, struct kobject *kobj,
1017                              struct bin_attribute *bin_attr, char *buf,
1018                              loff_t pos, size_t size)
1019 {
1020         struct platform_device *pdev =
1021                 to_platform_device(container_of(kobj, struct device, kobj));
1022         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
1023         ssize_t count;
1024         unsigned long flags = 0;
1025
1026         spin_lock_irqsave(&rtc->lock, flags);
1027         ds1685_rtc_switch_to_bank0(rtc);
1028
1029         /* Write NVRAM in time and bank0 registers. */
1030         for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ_BANK0;
1031              count++, size--)
1032                 if (count < NVRAM_SZ_TIME)
1033                         rtc->write(rtc, (NVRAM_TIME_BASE + pos++),
1034                                    *buf++);
1035                 else
1036                         rtc->write(rtc, (NVRAM_BANK0_BASE), *buf++);
1037
1038 #ifndef CONFIG_RTC_DRV_DS1689
1039         if (size > 0) {
1040                 ds1685_rtc_switch_to_bank1(rtc);
1041
1042 #ifndef CONFIG_RTC_DRV_DS1685
1043                 /* Enable burst-mode on DS17x85/DS17x87 */
1044                 rtc->write(rtc, RTC_EXT_CTRL_4A,
1045                            (rtc->read(rtc, RTC_EXT_CTRL_4A) |
1046                             RTC_CTRL_4A_BME));
1047
1048                 /* We need one write to RTC_BANK1_RAM_ADDR_LSB to start
1049                  * writing with burst-mode */
1050                 rtc->write(rtc, RTC_BANK1_RAM_ADDR_LSB,
1051                            (pos - NVRAM_TOTAL_SZ_BANK0));
1052 #endif
1053
1054                 /* Write NVRAM in bank1 registers. */
1055                 for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ;
1056                      count++, size--) {
1057 #ifdef CONFIG_RTC_DRV_DS1685
1058                         /* DS1685/DS1687 has to write to RTC_BANK1_RAM_ADDR
1059                          * before each read. */
1060                         rtc->write(rtc, RTC_BANK1_RAM_ADDR,
1061                                    (pos - NVRAM_TOTAL_SZ_BANK0));
1062 #endif
1063                         rtc->write(rtc, RTC_BANK1_RAM_DATA_PORT, *buf++);
1064                         pos++;
1065                 }
1066
1067 #ifndef CONFIG_RTC_DRV_DS1685
1068                 /* Disable burst-mode on DS17x85/DS17x87 */
1069                 rtc->write(rtc, RTC_EXT_CTRL_4A,
1070                            (rtc->read(rtc, RTC_EXT_CTRL_4A) &
1071                             ~(RTC_CTRL_4A_BME)));
1072 #endif
1073                 ds1685_rtc_switch_to_bank0(rtc);
1074         }
1075 #endif /* !CONFIG_RTC_DRV_DS1689 */
1076         spin_unlock_irqrestore(&rtc->lock, flags);
1077
1078         return count;
1079 }
1080
1081 /**
1082  * struct ds1685_rtc_sysfs_nvram_attr - sysfs attributes for rtc nvram.
1083  * @attr: nvram attributes.
1084  * @read: nvram read function.
1085  * @write: nvram write function.
1086  * @size: nvram total size (bank0 + extended).
1087  */
1088 static struct bin_attribute
1089 ds1685_rtc_sysfs_nvram_attr = {
1090         .attr = {
1091                 .name = "nvram",
1092                 .mode = S_IRUGO | S_IWUSR,
1093         },
1094         .read = ds1685_rtc_sysfs_nvram_read,
1095         .write = ds1685_rtc_sysfs_nvram_write,
1096         .size = NVRAM_TOTAL_SZ
1097 };
1098
1099 /**
1100  * ds1685_rtc_sysfs_battery_show - sysfs file for main battery status.
1101  * @dev: pointer to device structure.
1102  * @attr: pointer to device_attribute structure.
1103  * @buf: pointer to char array to hold the output.
1104  */
1105 static ssize_t
1106 ds1685_rtc_sysfs_battery_show(struct device *dev,
1107                               struct device_attribute *attr, char *buf)
1108 {
1109         struct platform_device *pdev = to_platform_device(dev);
1110         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
1111         u8 ctrld;
1112
1113         ctrld = rtc->read(rtc, RTC_CTRL_D);
1114
1115         return snprintf(buf, 13, "%s\n",
1116                         (ctrld & RTC_CTRL_D_VRT) ? "ok" : "not ok or N/A");
1117 }
1118 static DEVICE_ATTR(battery, S_IRUGO, ds1685_rtc_sysfs_battery_show, NULL);
1119
1120 /**
1121  * ds1685_rtc_sysfs_auxbatt_show - sysfs file for aux battery status.
1122  * @dev: pointer to device structure.
1123  * @attr: pointer to device_attribute structure.
1124  * @buf: pointer to char array to hold the output.
1125  */
1126 static ssize_t
1127 ds1685_rtc_sysfs_auxbatt_show(struct device *dev,
1128                               struct device_attribute *attr, char *buf)
1129 {
1130         struct platform_device *pdev = to_platform_device(dev);
1131         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
1132         u8 ctrl4a;
1133
1134         ds1685_rtc_switch_to_bank1(rtc);
1135         ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
1136         ds1685_rtc_switch_to_bank0(rtc);
1137
1138         return snprintf(buf, 13, "%s\n",
1139                         (ctrl4a & RTC_CTRL_4A_VRT2) ? "ok" : "not ok or N/A");
1140 }
1141 static DEVICE_ATTR(auxbatt, S_IRUGO, ds1685_rtc_sysfs_auxbatt_show, NULL);
1142
1143 /**
1144  * ds1685_rtc_sysfs_serial_show - sysfs file for silicon serial number.
1145  * @dev: pointer to device structure.
1146  * @attr: pointer to device_attribute structure.
1147  * @buf: pointer to char array to hold the output.
1148  */
1149 static ssize_t
1150 ds1685_rtc_sysfs_serial_show(struct device *dev,
1151                              struct device_attribute *attr, char *buf)
1152 {
1153         struct platform_device *pdev = to_platform_device(dev);
1154         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
1155         u8 ssn[8];
1156
1157         ds1685_rtc_switch_to_bank1(rtc);
1158         ds1685_rtc_get_ssn(rtc, ssn);
1159         ds1685_rtc_switch_to_bank0(rtc);
1160
1161         return snprintf(buf, 24, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
1162                         ssn[0], ssn[1], ssn[2], ssn[3], ssn[4], ssn[5],
1163                         ssn[6], ssn[7]);
1164
1165         return 0;
1166 }
1167 static DEVICE_ATTR(serial, S_IRUGO, ds1685_rtc_sysfs_serial_show, NULL);
1168
1169 /**
1170  * struct ds1685_rtc_sysfs_misc_attrs - list for misc RTC features.
1171  */
1172 static struct attribute*
1173 ds1685_rtc_sysfs_misc_attrs[] = {
1174         &dev_attr_battery.attr,
1175         &dev_attr_auxbatt.attr,
1176         &dev_attr_serial.attr,
1177         NULL,
1178 };
1179
1180 /**
1181  * struct ds1685_rtc_sysfs_misc_grp - attr group for misc RTC features.
1182  */
1183 static const struct attribute_group
1184 ds1685_rtc_sysfs_misc_grp = {
1185         .name = "misc",
1186         .attrs = ds1685_rtc_sysfs_misc_attrs,
1187 };
1188
1189 #ifdef CONFIG_RTC_DS1685_SYSFS_REGS
1190 /**
1191  * struct ds1685_rtc_ctrl_regs.
1192  * @name: char pointer for the bit name.
1193  * @reg: control register the bit is in.
1194  * @bit: the bit's offset in the register.
1195  */
1196 struct ds1685_rtc_ctrl_regs {
1197         const char *name;
1198         const u8 reg;
1199         const u8 bit;
1200 };
1201
1202 /*
1203  * Ctrl register bit lookup table.
1204  */
1205 static const struct ds1685_rtc_ctrl_regs
1206 ds1685_ctrl_regs_table[] = {
1207         { "uip",  RTC_CTRL_A,      RTC_CTRL_A_UIP   },
1208         { "dv2",  RTC_CTRL_A,      RTC_CTRL_A_DV2   },
1209         { "dv1",  RTC_CTRL_A,      RTC_CTRL_A_DV1   },
1210         { "dv0",  RTC_CTRL_A,      RTC_CTRL_A_DV0   },
1211         { "rs3",  RTC_CTRL_A,      RTC_CTRL_A_RS3   },
1212         { "rs2",  RTC_CTRL_A,      RTC_CTRL_A_RS2   },
1213         { "rs1",  RTC_CTRL_A,      RTC_CTRL_A_RS1   },
1214         { "rs0",  RTC_CTRL_A,      RTC_CTRL_A_RS0   },
1215         { "set",  RTC_CTRL_B,      RTC_CTRL_B_SET   },
1216         { "pie",  RTC_CTRL_B,      RTC_CTRL_B_PIE   },
1217         { "aie",  RTC_CTRL_B,      RTC_CTRL_B_AIE   },
1218         { "uie",  RTC_CTRL_B,      RTC_CTRL_B_UIE   },
1219         { "sqwe", RTC_CTRL_B,      RTC_CTRL_B_SQWE  },
1220         { "dm",   RTC_CTRL_B,      RTC_CTRL_B_DM    },
1221         { "2412", RTC_CTRL_B,      RTC_CTRL_B_2412  },
1222         { "dse",  RTC_CTRL_B,      RTC_CTRL_B_DSE   },
1223         { "irqf", RTC_CTRL_C,      RTC_CTRL_C_IRQF  },
1224         { "pf",   RTC_CTRL_C,      RTC_CTRL_C_PF    },
1225         { "af",   RTC_CTRL_C,      RTC_CTRL_C_AF    },
1226         { "uf",   RTC_CTRL_C,      RTC_CTRL_C_UF    },
1227         { "vrt",  RTC_CTRL_D,      RTC_CTRL_D_VRT   },
1228         { "vrt2", RTC_EXT_CTRL_4A, RTC_CTRL_4A_VRT2 },
1229         { "incr", RTC_EXT_CTRL_4A, RTC_CTRL_4A_INCR },
1230         { "pab",  RTC_EXT_CTRL_4A, RTC_CTRL_4A_PAB  },
1231         { "rf",   RTC_EXT_CTRL_4A, RTC_CTRL_4A_RF   },
1232         { "wf",   RTC_EXT_CTRL_4A, RTC_CTRL_4A_WF   },
1233         { "kf",   RTC_EXT_CTRL_4A, RTC_CTRL_4A_KF   },
1234 #if !defined(CONFIG_RTC_DRV_DS1685) && !defined(CONFIG_RTC_DRV_DS1689)
1235         { "bme",  RTC_EXT_CTRL_4A, RTC_CTRL_4A_BME  },
1236 #endif
1237         { "abe",  RTC_EXT_CTRL_4B, RTC_CTRL_4B_ABE  },
1238         { "e32k", RTC_EXT_CTRL_4B, RTC_CTRL_4B_E32K },
1239         { "cs",   RTC_EXT_CTRL_4B, RTC_CTRL_4B_CS   },
1240         { "rce",  RTC_EXT_CTRL_4B, RTC_CTRL_4B_RCE  },
1241         { "prs",  RTC_EXT_CTRL_4B, RTC_CTRL_4B_PRS  },
1242         { "rie",  RTC_EXT_CTRL_4B, RTC_CTRL_4B_RIE  },
1243         { "wie",  RTC_EXT_CTRL_4B, RTC_CTRL_4B_WIE  },
1244         { "kse",  RTC_EXT_CTRL_4B, RTC_CTRL_4B_KSE  },
1245         { NULL,   0,               0                },
1246 };
1247
1248 /**
1249  * ds1685_rtc_sysfs_ctrl_regs_lookup - ctrl register bit lookup function.
1250  * @name: ctrl register bit to look up in ds1685_ctrl_regs_table.
1251  */
1252 static const struct ds1685_rtc_ctrl_regs*
1253 ds1685_rtc_sysfs_ctrl_regs_lookup(const char *name)
1254 {
1255         const struct ds1685_rtc_ctrl_regs *p = ds1685_ctrl_regs_table;
1256
1257         for (; p->name != NULL; ++p)
1258                 if (strcmp(p->name, name) == 0)
1259                         return p;
1260
1261         return NULL;
1262 }
1263
1264 /**
1265  * ds1685_rtc_sysfs_ctrl_regs_show - reads a ctrl register bit via sysfs.
1266  * @dev: pointer to device structure.
1267  * @attr: pointer to device_attribute structure.
1268  * @buf: pointer to char array to hold the output.
1269  */
1270 static ssize_t
1271 ds1685_rtc_sysfs_ctrl_regs_show(struct device *dev,
1272                                 struct device_attribute *attr, char *buf)
1273 {
1274         u8 tmp;
1275         struct ds1685_priv *rtc = dev_get_drvdata(dev);
1276         const struct ds1685_rtc_ctrl_regs *reg_info =
1277                 ds1685_rtc_sysfs_ctrl_regs_lookup(attr->attr.name);
1278
1279         /* Make sure we actually matched something. */
1280         if (!reg_info)
1281                 return -EINVAL;
1282
1283         /* No spinlock during a read -- mutex is already held. */
1284         ds1685_rtc_switch_to_bank1(rtc);
1285         tmp = rtc->read(rtc, reg_info->reg) & reg_info->bit;
1286         ds1685_rtc_switch_to_bank0(rtc);
1287
1288         return snprintf(buf, 2, "%d\n", (tmp ? 1 : 0));
1289 }
1290
1291 /**
1292  * ds1685_rtc_sysfs_ctrl_regs_store - writes a ctrl register bit via sysfs.
1293  * @dev: pointer to device structure.
1294  * @attr: pointer to device_attribute structure.
1295  * @buf: pointer to char array to hold the output.
1296  * @count: number of bytes written.
1297  */
1298 static ssize_t
1299 ds1685_rtc_sysfs_ctrl_regs_store(struct device *dev,
1300                                  struct device_attribute *attr,
1301                                  const char *buf, size_t count)
1302 {
1303         struct ds1685_priv *rtc = dev_get_drvdata(dev);
1304         u8 reg = 0, bit = 0, tmp;
1305         unsigned long flags = 0;
1306         long int val = 0;
1307         const struct ds1685_rtc_ctrl_regs *reg_info =
1308                 ds1685_rtc_sysfs_ctrl_regs_lookup(attr->attr.name);
1309
1310         /* We only accept numbers. */
1311         if (kstrtol(buf, 10, &val) < 0)
1312                 return -EINVAL;
1313
1314         /* bits are binary, 0 or 1 only. */
1315         if ((val != 0) && (val != 1))
1316                 return -ERANGE;
1317
1318         /* Make sure we actually matched something. */
1319         if (!reg_info)
1320                 return -EINVAL;
1321
1322         reg = reg_info->reg;
1323         bit = reg_info->bit;
1324
1325         /* Safe to spinlock during a write. */
1326         ds1685_rtc_begin_ctrl_access(rtc, flags);
1327         tmp = rtc->read(rtc, reg);
1328         rtc->write(rtc, reg, (val ? (tmp | bit) : (tmp & ~(bit))));
1329         ds1685_rtc_end_ctrl_access(rtc, flags);
1330
1331         return count;
1332 }
1333
1334 /**
1335  * DS1685_RTC_SYSFS_CTRL_REG_RO - device_attribute for read-only register bit.
1336  * @bit: bit to read.
1337  */
1338 #define DS1685_RTC_SYSFS_CTRL_REG_RO(bit)                               \
1339         static DEVICE_ATTR(bit, S_IRUGO,                                \
1340         ds1685_rtc_sysfs_ctrl_regs_show, NULL)
1341
1342 /**
1343  * DS1685_RTC_SYSFS_CTRL_REG_RW - device_attribute for read-write register bit.
1344  * @bit: bit to read or write.
1345  */
1346 #define DS1685_RTC_SYSFS_CTRL_REG_RW(bit)                               \
1347         static DEVICE_ATTR(bit, S_IRUGO | S_IWUSR,                      \
1348         ds1685_rtc_sysfs_ctrl_regs_show,                                \
1349         ds1685_rtc_sysfs_ctrl_regs_store)
1350
1351 /*
1352  * Control Register A bits.
1353  */
1354 DS1685_RTC_SYSFS_CTRL_REG_RO(uip);
1355 DS1685_RTC_SYSFS_CTRL_REG_RW(dv2);
1356 DS1685_RTC_SYSFS_CTRL_REG_RW(dv1);
1357 DS1685_RTC_SYSFS_CTRL_REG_RO(dv0);
1358 DS1685_RTC_SYSFS_CTRL_REG_RW(rs3);
1359 DS1685_RTC_SYSFS_CTRL_REG_RW(rs2);
1360 DS1685_RTC_SYSFS_CTRL_REG_RW(rs1);
1361 DS1685_RTC_SYSFS_CTRL_REG_RW(rs0);
1362
1363 static struct attribute*
1364 ds1685_rtc_sysfs_ctrla_attrs[] = {
1365         &dev_attr_uip.attr,
1366         &dev_attr_dv2.attr,
1367         &dev_attr_dv1.attr,
1368         &dev_attr_dv0.attr,
1369         &dev_attr_rs3.attr,
1370         &dev_attr_rs2.attr,
1371         &dev_attr_rs1.attr,
1372         &dev_attr_rs0.attr,
1373         NULL,
1374 };
1375
1376 static const struct attribute_group
1377 ds1685_rtc_sysfs_ctrla_grp = {
1378         .name = "ctrla",
1379         .attrs = ds1685_rtc_sysfs_ctrla_attrs,
1380 };
1381
1382
1383 /*
1384  * Control Register B bits.
1385  */
1386 DS1685_RTC_SYSFS_CTRL_REG_RO(set);
1387 DS1685_RTC_SYSFS_CTRL_REG_RW(pie);
1388 DS1685_RTC_SYSFS_CTRL_REG_RW(aie);
1389 DS1685_RTC_SYSFS_CTRL_REG_RW(uie);
1390 DS1685_RTC_SYSFS_CTRL_REG_RW(sqwe);
1391 DS1685_RTC_SYSFS_CTRL_REG_RO(dm);
1392 DS1685_RTC_SYSFS_CTRL_REG_RO(2412);
1393 DS1685_RTC_SYSFS_CTRL_REG_RO(dse);
1394
1395 static struct attribute*
1396 ds1685_rtc_sysfs_ctrlb_attrs[] = {
1397         &dev_attr_set.attr,
1398         &dev_attr_pie.attr,
1399         &dev_attr_aie.attr,
1400         &dev_attr_uie.attr,
1401         &dev_attr_sqwe.attr,
1402         &dev_attr_dm.attr,
1403         &dev_attr_2412.attr,
1404         &dev_attr_dse.attr,
1405         NULL,
1406 };
1407
1408 static const struct attribute_group
1409 ds1685_rtc_sysfs_ctrlb_grp = {
1410         .name = "ctrlb",
1411         .attrs = ds1685_rtc_sysfs_ctrlb_attrs,
1412 };
1413
1414 /*
1415  * Control Register C bits.
1416  *
1417  * Reading Control C clears these bits!  Reading them individually can
1418  * possibly cause an interrupt to be missed.  Use the /proc interface
1419  * to see all the bits in this register simultaneously.
1420  */
1421 DS1685_RTC_SYSFS_CTRL_REG_RO(irqf);
1422 DS1685_RTC_SYSFS_CTRL_REG_RO(pf);
1423 DS1685_RTC_SYSFS_CTRL_REG_RO(af);
1424 DS1685_RTC_SYSFS_CTRL_REG_RO(uf);
1425
1426 static struct attribute*
1427 ds1685_rtc_sysfs_ctrlc_attrs[] = {
1428         &dev_attr_irqf.attr,
1429         &dev_attr_pf.attr,
1430         &dev_attr_af.attr,
1431         &dev_attr_uf.attr,
1432         NULL,
1433 };
1434
1435 static const struct attribute_group
1436 ds1685_rtc_sysfs_ctrlc_grp = {
1437         .name = "ctrlc",
1438         .attrs = ds1685_rtc_sysfs_ctrlc_attrs,
1439 };
1440
1441 /*
1442  * Control Register D bits.
1443  */
1444 DS1685_RTC_SYSFS_CTRL_REG_RO(vrt);
1445
1446 static struct attribute*
1447 ds1685_rtc_sysfs_ctrld_attrs[] = {
1448         &dev_attr_vrt.attr,
1449         NULL,
1450 };
1451
1452 static const struct attribute_group
1453 ds1685_rtc_sysfs_ctrld_grp = {
1454         .name = "ctrld",
1455         .attrs = ds1685_rtc_sysfs_ctrld_attrs,
1456 };
1457
1458 /*
1459  * Control Register 4A bits.
1460  */
1461 DS1685_RTC_SYSFS_CTRL_REG_RO(vrt2);
1462 DS1685_RTC_SYSFS_CTRL_REG_RO(incr);
1463 DS1685_RTC_SYSFS_CTRL_REG_RW(pab);
1464 DS1685_RTC_SYSFS_CTRL_REG_RW(rf);
1465 DS1685_RTC_SYSFS_CTRL_REG_RW(wf);
1466 DS1685_RTC_SYSFS_CTRL_REG_RW(kf);
1467 #if !defined(CONFIG_RTC_DRV_DS1685) && !defined(CONFIG_RTC_DRV_DS1689)
1468 DS1685_RTC_SYSFS_CTRL_REG_RO(bme);
1469 #endif
1470
1471 static struct attribute*
1472 ds1685_rtc_sysfs_ctrl4a_attrs[] = {
1473         &dev_attr_vrt2.attr,
1474         &dev_attr_incr.attr,
1475         &dev_attr_pab.attr,
1476         &dev_attr_rf.attr,
1477         &dev_attr_wf.attr,
1478         &dev_attr_kf.attr,
1479 #if !defined(CONFIG_RTC_DRV_DS1685) && !defined(CONFIG_RTC_DRV_DS1689)
1480         &dev_attr_bme.attr,
1481 #endif
1482         NULL,
1483 };
1484
1485 static const struct attribute_group
1486 ds1685_rtc_sysfs_ctrl4a_grp = {
1487         .name = "ctrl4a",
1488         .attrs = ds1685_rtc_sysfs_ctrl4a_attrs,
1489 };
1490
1491 /*
1492  * Control Register 4B bits.
1493  */
1494 DS1685_RTC_SYSFS_CTRL_REG_RW(abe);
1495 DS1685_RTC_SYSFS_CTRL_REG_RW(e32k);
1496 DS1685_RTC_SYSFS_CTRL_REG_RO(cs);
1497 DS1685_RTC_SYSFS_CTRL_REG_RW(rce);
1498 DS1685_RTC_SYSFS_CTRL_REG_RW(prs);
1499 DS1685_RTC_SYSFS_CTRL_REG_RW(rie);
1500 DS1685_RTC_SYSFS_CTRL_REG_RW(wie);
1501 DS1685_RTC_SYSFS_CTRL_REG_RW(kse);
1502
1503 static struct attribute*
1504 ds1685_rtc_sysfs_ctrl4b_attrs[] = {
1505         &dev_attr_abe.attr,
1506         &dev_attr_e32k.attr,
1507         &dev_attr_cs.attr,
1508         &dev_attr_rce.attr,
1509         &dev_attr_prs.attr,
1510         &dev_attr_rie.attr,
1511         &dev_attr_wie.attr,
1512         &dev_attr_kse.attr,
1513         NULL,
1514 };
1515
1516 static const struct attribute_group
1517 ds1685_rtc_sysfs_ctrl4b_grp = {
1518         .name = "ctrl4b",
1519         .attrs = ds1685_rtc_sysfs_ctrl4b_attrs,
1520 };
1521
1522
1523 /**
1524  * struct ds1685_rtc_ctrl_regs.
1525  * @name: char pointer for the bit name.
1526  * @reg: control register the bit is in.
1527  * @bit: the bit's offset in the register.
1528  */
1529 struct ds1685_rtc_time_regs {
1530         const char *name;
1531         const u8 reg;
1532         const u8 mask;
1533         const u8 min;
1534         const u8 max;
1535 };
1536
1537 /*
1538  * Time/Date register lookup tables.
1539  */
1540 static const struct ds1685_rtc_time_regs
1541 ds1685_time_regs_bcd_table[] = {
1542         { "seconds",       RTC_SECS,       RTC_SECS_BCD_MASK,   0, 59 },
1543         { "minutes",       RTC_MINS,       RTC_MINS_BCD_MASK,   0, 59 },
1544         { "hours",         RTC_HRS,        RTC_HRS_24_BCD_MASK, 0, 23 },
1545         { "wday",          RTC_WDAY,       RTC_WDAY_MASK,       1,  7 },
1546         { "mday",          RTC_MDAY,       RTC_MDAY_BCD_MASK,   1, 31 },
1547         { "month",         RTC_MONTH,      RTC_MONTH_BCD_MASK,  1, 12 },
1548         { "year",          RTC_YEAR,       RTC_YEAR_BCD_MASK,   0, 99 },
1549         { "century",       RTC_CENTURY,    RTC_CENTURY_MASK,    0, 99 },
1550         { "alarm_seconds", RTC_SECS_ALARM, RTC_SECS_BCD_MASK,   0, 59 },
1551         { "alarm_minutes", RTC_MINS_ALARM, RTC_MINS_BCD_MASK,   0, 59 },
1552         { "alarm_hours",   RTC_HRS_ALARM,  RTC_HRS_24_BCD_MASK, 0, 23 },
1553         { "alarm_mday",    RTC_MDAY_ALARM, RTC_MDAY_ALARM_MASK, 1, 31 },
1554         { NULL,            0,              0,                   0,  0 },
1555 };
1556
1557 static const struct ds1685_rtc_time_regs
1558 ds1685_time_regs_bin_table[] = {
1559         { "seconds",       RTC_SECS,       RTC_SECS_BIN_MASK,   0x00, 0x3b },
1560         { "minutes",       RTC_MINS,       RTC_MINS_BIN_MASK,   0x00, 0x3b },
1561         { "hours",         RTC_HRS,        RTC_HRS_24_BIN_MASK, 0x00, 0x17 },
1562         { "wday",          RTC_WDAY,       RTC_WDAY_MASK,       0x01, 0x07 },
1563         { "mday",          RTC_MDAY,       RTC_MDAY_BIN_MASK,   0x01, 0x1f },
1564         { "month",         RTC_MONTH,      RTC_MONTH_BIN_MASK,  0x01, 0x0c },
1565         { "year",          RTC_YEAR,       RTC_YEAR_BIN_MASK,   0x00, 0x63 },
1566         { "century",       RTC_CENTURY,    RTC_CENTURY_MASK,    0x00, 0x63 },
1567         { "alarm_seconds", RTC_SECS_ALARM, RTC_SECS_BIN_MASK,   0x00, 0x3b },
1568         { "alarm_minutes", RTC_MINS_ALARM, RTC_MINS_BIN_MASK,   0x00, 0x3b },
1569         { "alarm_hours",   RTC_HRS_ALARM,  RTC_HRS_24_BIN_MASK, 0x00, 0x17 },
1570         { "alarm_mday",    RTC_MDAY_ALARM, RTC_MDAY_ALARM_MASK, 0x01, 0x1f },
1571         { NULL,            0,              0,                   0x00, 0x00 },
1572 };
1573
1574 /**
1575  * ds1685_rtc_sysfs_time_regs_bcd_lookup - time/date reg bit lookup function.
1576  * @name: register bit to look up in ds1685_time_regs_bcd_table.
1577  */
1578 static const struct ds1685_rtc_time_regs*
1579 ds1685_rtc_sysfs_time_regs_lookup(const char *name, bool bcd_mode)
1580 {
1581         const struct ds1685_rtc_time_regs *p;
1582
1583         if (bcd_mode)
1584                 p = ds1685_time_regs_bcd_table;
1585         else
1586                 p = ds1685_time_regs_bin_table;
1587
1588         for (; p->name != NULL; ++p)
1589                 if (strcmp(p->name, name) == 0)
1590                         return p;
1591
1592         return NULL;
1593 }
1594
1595 /**
1596  * ds1685_rtc_sysfs_time_regs_show - reads a time/date register via sysfs.
1597  * @dev: pointer to device structure.
1598  * @attr: pointer to device_attribute structure.
1599  * @buf: pointer to char array to hold the output.
1600  */
1601 static ssize_t
1602 ds1685_rtc_sysfs_time_regs_show(struct device *dev,
1603                                 struct device_attribute *attr, char *buf)
1604 {
1605         u8 tmp;
1606         struct ds1685_priv *rtc = dev_get_drvdata(dev);
1607         const struct ds1685_rtc_time_regs *bcd_reg_info =
1608                 ds1685_rtc_sysfs_time_regs_lookup(attr->attr.name, true);
1609         const struct ds1685_rtc_time_regs *bin_reg_info =
1610                 ds1685_rtc_sysfs_time_regs_lookup(attr->attr.name, false);
1611
1612         /* Make sure we actually matched something. */
1613         if (!bcd_reg_info || !bin_reg_info)
1614                 return -EINVAL;
1615
1616         /* bcd_reg_info->reg == bin_reg_info->reg. */
1617         ds1685_rtc_begin_data_access(rtc);
1618         tmp = rtc->read(rtc, bcd_reg_info->reg);
1619         ds1685_rtc_end_data_access(rtc);
1620
1621         tmp = ds1685_rtc_bcd2bin(rtc, tmp, bcd_reg_info->mask,
1622                                  bin_reg_info->mask);
1623
1624         return snprintf(buf, 4, "%d\n", tmp);
1625 }
1626
1627 /**
1628  * ds1685_rtc_sysfs_time_regs_store - writes a time/date register via sysfs.
1629  * @dev: pointer to device structure.
1630  * @attr: pointer to device_attribute structure.
1631  * @buf: pointer to char array to hold the output.
1632  * @count: number of bytes written.
1633  */
1634 static ssize_t
1635 ds1685_rtc_sysfs_time_regs_store(struct device *dev,
1636                                  struct device_attribute *attr,
1637                                  const char *buf, size_t count)
1638 {
1639         long int val = 0;
1640         struct ds1685_priv *rtc = dev_get_drvdata(dev);
1641         const struct ds1685_rtc_time_regs *bcd_reg_info =
1642                 ds1685_rtc_sysfs_time_regs_lookup(attr->attr.name, true);
1643         const struct ds1685_rtc_time_regs *bin_reg_info =
1644                 ds1685_rtc_sysfs_time_regs_lookup(attr->attr.name, false);
1645
1646         /* We only accept numbers. */
1647         if (kstrtol(buf, 10, &val) < 0)
1648                 return -EINVAL;
1649
1650         /* Make sure we actually matched something. */
1651         if (!bcd_reg_info || !bin_reg_info)
1652                 return -EINVAL;
1653
1654         /* Check for a valid range. */
1655         if (rtc->bcd_mode) {
1656                 if ((val < bcd_reg_info->min) || (val > bcd_reg_info->max))
1657                         return -ERANGE;
1658         } else {
1659                 if ((val < bin_reg_info->min) || (val > bin_reg_info->max))
1660                         return -ERANGE;
1661         }
1662
1663         val = ds1685_rtc_bin2bcd(rtc, val, bin_reg_info->mask,
1664                                  bcd_reg_info->mask);
1665
1666         /* bcd_reg_info->reg == bin_reg_info->reg. */
1667         ds1685_rtc_begin_data_access(rtc);
1668         rtc->write(rtc, bcd_reg_info->reg, val);
1669         ds1685_rtc_end_data_access(rtc);
1670
1671         return count;
1672 }
1673
1674 /**
1675  * DS1685_RTC_SYSFS_REG_RW - device_attribute for a read-write time register.
1676  * @reg: time/date register to read or write.
1677  */
1678 #define DS1685_RTC_SYSFS_TIME_REG_RW(reg)                               \
1679         static DEVICE_ATTR(reg, S_IRUGO | S_IWUSR,                      \
1680         ds1685_rtc_sysfs_time_regs_show,                                \
1681         ds1685_rtc_sysfs_time_regs_store)
1682
1683 /*
1684  * Time/Date Register bits.
1685  */
1686 DS1685_RTC_SYSFS_TIME_REG_RW(seconds);
1687 DS1685_RTC_SYSFS_TIME_REG_RW(minutes);
1688 DS1685_RTC_SYSFS_TIME_REG_RW(hours);
1689 DS1685_RTC_SYSFS_TIME_REG_RW(wday);
1690 DS1685_RTC_SYSFS_TIME_REG_RW(mday);
1691 DS1685_RTC_SYSFS_TIME_REG_RW(month);
1692 DS1685_RTC_SYSFS_TIME_REG_RW(year);
1693 DS1685_RTC_SYSFS_TIME_REG_RW(century);
1694 DS1685_RTC_SYSFS_TIME_REG_RW(alarm_seconds);
1695 DS1685_RTC_SYSFS_TIME_REG_RW(alarm_minutes);
1696 DS1685_RTC_SYSFS_TIME_REG_RW(alarm_hours);
1697 DS1685_RTC_SYSFS_TIME_REG_RW(alarm_mday);
1698
1699 static struct attribute*
1700 ds1685_rtc_sysfs_time_attrs[] = {
1701         &dev_attr_seconds.attr,
1702         &dev_attr_minutes.attr,
1703         &dev_attr_hours.attr,
1704         &dev_attr_wday.attr,
1705         &dev_attr_mday.attr,
1706         &dev_attr_month.attr,
1707         &dev_attr_year.attr,
1708         &dev_attr_century.attr,
1709         NULL,
1710 };
1711
1712 static const struct attribute_group
1713 ds1685_rtc_sysfs_time_grp = {
1714         .name = "datetime",
1715         .attrs = ds1685_rtc_sysfs_time_attrs,
1716 };
1717
1718 static struct attribute*
1719 ds1685_rtc_sysfs_alarm_attrs[] = {
1720         &dev_attr_alarm_seconds.attr,
1721         &dev_attr_alarm_minutes.attr,
1722         &dev_attr_alarm_hours.attr,
1723         &dev_attr_alarm_mday.attr,
1724         NULL,
1725 };
1726
1727 static const struct attribute_group
1728 ds1685_rtc_sysfs_alarm_grp = {
1729         .name = "alarm",
1730         .attrs = ds1685_rtc_sysfs_alarm_attrs,
1731 };
1732 #endif /* CONFIG_RTC_DS1685_SYSFS_REGS */
1733
1734
1735 /**
1736  * ds1685_rtc_sysfs_register - register sysfs files.
1737  * @dev: pointer to device structure.
1738  */
1739 static int
1740 ds1685_rtc_sysfs_register(struct device *dev)
1741 {
1742         int ret = 0;
1743
1744         sysfs_bin_attr_init(&ds1685_rtc_sysfs_nvram_attr);
1745         ret = sysfs_create_bin_file(&dev->kobj, &ds1685_rtc_sysfs_nvram_attr);
1746         if (ret)
1747                 return ret;
1748
1749         ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_misc_grp);
1750         if (ret)
1751                 return ret;
1752
1753 #ifdef CONFIG_RTC_DS1685_SYSFS_REGS
1754         ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrla_grp);
1755         if (ret)
1756                 return ret;
1757
1758         ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrlb_grp);
1759         if (ret)
1760                 return ret;
1761
1762         ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrlc_grp);
1763         if (ret)
1764                 return ret;
1765
1766         ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrld_grp);
1767         if (ret)
1768                 return ret;
1769
1770         ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrl4a_grp);
1771         if (ret)
1772                 return ret;
1773
1774         ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_ctrl4b_grp);
1775         if (ret)
1776                 return ret;
1777
1778         ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_time_grp);
1779         if (ret)
1780                 return ret;
1781
1782         ret = sysfs_create_group(&dev->kobj, &ds1685_rtc_sysfs_alarm_grp);
1783         if (ret)
1784                 return ret;
1785 #endif
1786         return 0;
1787 }
1788
1789 /**
1790  * ds1685_rtc_sysfs_unregister - unregister sysfs files.
1791  * @dev: pointer to device structure.
1792  */
1793 static int
1794 ds1685_rtc_sysfs_unregister(struct device *dev)
1795 {
1796         sysfs_remove_bin_file(&dev->kobj, &ds1685_rtc_sysfs_nvram_attr);
1797         sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_misc_grp);
1798
1799 #ifdef CONFIG_RTC_DS1685_SYSFS_REGS
1800         sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrla_grp);
1801         sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrlb_grp);
1802         sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrlc_grp);
1803         sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrld_grp);
1804         sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrl4a_grp);
1805         sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_ctrl4b_grp);
1806         sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_time_grp);
1807         sysfs_remove_group(&dev->kobj, &ds1685_rtc_sysfs_alarm_grp);
1808 #endif
1809
1810         return 0;
1811 }
1812 #endif /* CONFIG_SYSFS */
1813
1814
1815
1816 /* ----------------------------------------------------------------------- */
1817 /* Driver Probe/Removal */
1818
1819 /**
1820  * ds1685_rtc_probe - initializes rtc driver.
1821  * @pdev: pointer to platform_device structure.
1822  */
1823 static int
1824 ds1685_rtc_probe(struct platform_device *pdev)
1825 {
1826         struct rtc_device *rtc_dev;
1827         struct resource *res;
1828         struct ds1685_priv *rtc;
1829         struct ds1685_rtc_platform_data *pdata;
1830         u8 ctrla, ctrlb, hours;
1831         unsigned char am_pm;
1832         int ret = 0;
1833
1834         /* Get the platform data. */
1835         pdata = (struct ds1685_rtc_platform_data *) pdev->dev.platform_data;
1836         if (!pdata)
1837                 return -ENODEV;
1838
1839         /* Allocate memory for the rtc device. */
1840         rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
1841         if (!rtc)
1842                 return -ENOMEM;
1843
1844         /*
1845          * Allocate/setup any IORESOURCE_MEM resources, if required.  Not all
1846          * platforms put the RTC in an easy-access place.  Like the SGI Octane,
1847          * which attaches the RTC to a "ByteBus", hooked to a SuperIO chip
1848          * that sits behind the IOC3 PCI metadevice.
1849          */
1850         if (pdata->alloc_io_resources) {
1851                 /* Get the platform resources. */
1852                 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1853                 if (!res)
1854                         return -ENXIO;
1855                 rtc->size = resource_size(res);
1856
1857                 /* Request a memory region. */
1858                 /* XXX: mmio-only for now. */
1859                 if (!devm_request_mem_region(&pdev->dev, res->start, rtc->size,
1860                                              pdev->name))
1861                         return -EBUSY;
1862
1863                 /*
1864                  * Set the base address for the rtc, and ioremap its
1865                  * registers.
1866                  */
1867                 rtc->baseaddr = res->start;
1868                 rtc->regs = devm_ioremap(&pdev->dev, res->start, rtc->size);
1869                 if (!rtc->regs)
1870                         return -ENOMEM;
1871         }
1872         rtc->alloc_io_resources = pdata->alloc_io_resources;
1873
1874         /* Get the register step size. */
1875         if (pdata->regstep > 0)
1876                 rtc->regstep = pdata->regstep;
1877         else
1878                 rtc->regstep = 1;
1879
1880         /* Platform read function, else default if mmio setup */
1881         if (pdata->plat_read)
1882                 rtc->read = pdata->plat_read;
1883         else
1884                 if (pdata->alloc_io_resources)
1885                         rtc->read = ds1685_read;
1886                 else
1887                         return -ENXIO;
1888
1889         /* Platform write function, else default if mmio setup */
1890         if (pdata->plat_write)
1891                 rtc->write = pdata->plat_write;
1892         else
1893                 if (pdata->alloc_io_resources)
1894                         rtc->write = ds1685_write;
1895                 else
1896                         return -ENXIO;
1897
1898         /* Platform pre-shutdown function, if defined. */
1899         if (pdata->plat_prepare_poweroff)
1900                 rtc->prepare_poweroff = pdata->plat_prepare_poweroff;
1901
1902         /* Platform wake_alarm function, if defined. */
1903         if (pdata->plat_wake_alarm)
1904                 rtc->wake_alarm = pdata->plat_wake_alarm;
1905
1906         /* Platform post_ram_clear function, if defined. */
1907         if (pdata->plat_post_ram_clear)
1908                 rtc->post_ram_clear = pdata->plat_post_ram_clear;
1909
1910         /* Init the spinlock, workqueue, & set the driver data. */
1911         spin_lock_init(&rtc->lock);
1912         INIT_WORK(&rtc->work, ds1685_rtc_work_queue);
1913         platform_set_drvdata(pdev, rtc);
1914
1915         /* Turn the oscillator on if is not already on (DV1 = 1). */
1916         ctrla = rtc->read(rtc, RTC_CTRL_A);
1917         if (!(ctrla & RTC_CTRL_A_DV1))
1918                 ctrla |= RTC_CTRL_A_DV1;
1919
1920         /* Enable the countdown chain (DV2 = 0) */
1921         ctrla &= ~(RTC_CTRL_A_DV2);
1922
1923         /* Clear RS3-RS0 in Control A. */
1924         ctrla &= ~(RTC_CTRL_A_RS_MASK);
1925
1926         /*
1927          * All done with Control A.  Switch to Bank 1 for the remainder of
1928          * the RTC setup so we have access to the extended functions.
1929          */
1930         ctrla |= RTC_CTRL_A_DV0;
1931         rtc->write(rtc, RTC_CTRL_A, ctrla);
1932
1933         /* Default to 32768kHz output. */
1934         rtc->write(rtc, RTC_EXT_CTRL_4B,
1935                    (rtc->read(rtc, RTC_EXT_CTRL_4B) | RTC_CTRL_4B_E32K));
1936
1937         /* Set the SET bit in Control B so we can do some housekeeping. */
1938         rtc->write(rtc, RTC_CTRL_B,
1939                    (rtc->read(rtc, RTC_CTRL_B) | RTC_CTRL_B_SET));
1940
1941         /* Read Ext Ctrl 4A and check the INCR bit to avoid a lockout. */
1942         while (rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_INCR)
1943                 cpu_relax();
1944
1945         /*
1946          * If the platform supports BCD mode, then set DM=0 in Control B.
1947          * Otherwise, set DM=1 for BIN mode.
1948          */
1949         ctrlb = rtc->read(rtc, RTC_CTRL_B);
1950         if (pdata->bcd_mode)
1951                 ctrlb &= ~(RTC_CTRL_B_DM);
1952         else
1953                 ctrlb |= RTC_CTRL_B_DM;
1954         rtc->bcd_mode = pdata->bcd_mode;
1955
1956         /*
1957          * Disable Daylight Savings Time (DSE = 0).
1958          * The RTC has hardcoded timezone information that is rendered
1959          * obselete.  We'll let the OS deal with DST settings instead.
1960          */
1961         if (ctrlb & RTC_CTRL_B_DSE)
1962                 ctrlb &= ~(RTC_CTRL_B_DSE);
1963
1964         /* Force 24-hour mode (2412 = 1). */
1965         if (!(ctrlb & RTC_CTRL_B_2412)) {
1966                 /* Reinitialize the time hours. */
1967                 hours = rtc->read(rtc, RTC_HRS);
1968                 am_pm = hours & RTC_HRS_AMPM_MASK;
1969                 hours = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_12_BCD_MASK,
1970                                            RTC_HRS_12_BIN_MASK);
1971                 hours = ((hours == 12) ? 0 : ((am_pm) ? hours + 12 : hours));
1972
1973                 /* Enable 24-hour mode. */
1974                 ctrlb |= RTC_CTRL_B_2412;
1975
1976                 /* Write back to Control B, including DM & DSE bits. */
1977                 rtc->write(rtc, RTC_CTRL_B, ctrlb);
1978
1979                 /* Write the time hours back. */
1980                 rtc->write(rtc, RTC_HRS,
1981                            ds1685_rtc_bin2bcd(rtc, hours,
1982                                               RTC_HRS_24_BIN_MASK,
1983                                               RTC_HRS_24_BCD_MASK));
1984
1985                 /* Reinitialize the alarm hours. */
1986                 hours = rtc->read(rtc, RTC_HRS_ALARM);
1987                 am_pm = hours & RTC_HRS_AMPM_MASK;
1988                 hours = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_12_BCD_MASK,
1989                                            RTC_HRS_12_BIN_MASK);
1990                 hours = ((hours == 12) ? 0 : ((am_pm) ? hours + 12 : hours));
1991
1992                 /* Write the alarm hours back. */
1993                 rtc->write(rtc, RTC_HRS_ALARM,
1994                            ds1685_rtc_bin2bcd(rtc, hours,
1995                                               RTC_HRS_24_BIN_MASK,
1996                                               RTC_HRS_24_BCD_MASK));
1997         } else {
1998                 /* 24-hour mode is already set, so write Control B back. */
1999                 rtc->write(rtc, RTC_CTRL_B, ctrlb);
2000         }
2001
2002         /* Unset the SET bit in Control B so the RTC can update. */
2003         rtc->write(rtc, RTC_CTRL_B,
2004                    (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_SET)));
2005
2006         /* Check the main battery. */
2007         if (!(rtc->read(rtc, RTC_CTRL_D) & RTC_CTRL_D_VRT))
2008                 dev_warn(&pdev->dev,
2009                          "Main battery is exhausted! RTC may be invalid!\n");
2010
2011         /* Check the auxillary battery.  It is optional. */
2012         if (!(rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_VRT2))
2013                 dev_warn(&pdev->dev,
2014                          "Aux battery is exhausted or not available.\n");
2015
2016         /* Read Ctrl B and clear PIE/AIE/UIE. */
2017         rtc->write(rtc, RTC_CTRL_B,
2018                    (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_PAU_MASK)));
2019
2020         /* Reading Ctrl C auto-clears PF/AF/UF. */
2021         rtc->read(rtc, RTC_CTRL_C);
2022
2023         /* Read Ctrl 4B and clear RIE/WIE/KSE. */
2024         rtc->write(rtc, RTC_EXT_CTRL_4B,
2025                    (rtc->read(rtc, RTC_EXT_CTRL_4B) & ~(RTC_CTRL_4B_RWK_MASK)));
2026
2027         /* Clear RF/WF/KF in Ctrl 4A. */
2028         rtc->write(rtc, RTC_EXT_CTRL_4A,
2029                    (rtc->read(rtc, RTC_EXT_CTRL_4A) & ~(RTC_CTRL_4A_RWK_MASK)));
2030
2031         /*
2032          * Re-enable KSE to handle power button events.  We do not enable
2033          * WIE or RIE by default.
2034          */
2035         rtc->write(rtc, RTC_EXT_CTRL_4B,
2036                    (rtc->read(rtc, RTC_EXT_CTRL_4B) | RTC_CTRL_4B_KSE));
2037
2038         /*
2039          * Fetch the IRQ and setup the interrupt handler.
2040          *
2041          * Not all platforms have the IRQF pin tied to something.  If not, the
2042          * RTC will still set the *IE / *F flags and raise IRQF in ctrlc, but
2043          * there won't be an automatic way of notifying the kernel about it,
2044          * unless ctrlc is explicitly polled.
2045          */
2046         if (!pdata->no_irq) {
2047                 ret = platform_get_irq(pdev, 0);
2048                 if (ret > 0) {
2049                         rtc->irq_num = ret;
2050
2051                         /* Request an IRQ. */
2052                         ret = devm_request_irq(&pdev->dev, rtc->irq_num,
2053                                                ds1685_rtc_irq_handler,
2054                                                IRQF_SHARED, pdev->name, pdev);
2055
2056                         /* Check to see if something came back. */
2057                         if (unlikely(ret)) {
2058                                 dev_warn(&pdev->dev,
2059                                          "RTC interrupt not available\n");
2060                                 rtc->irq_num = 0;
2061                         }
2062                 } else
2063                         return ret;
2064         }
2065         rtc->no_irq = pdata->no_irq;
2066
2067         /* Setup complete. */
2068         ds1685_rtc_switch_to_bank0(rtc);
2069
2070         /* Register the device as an RTC. */
2071         rtc_dev = rtc_device_register(pdev->name, &pdev->dev,
2072                                       &ds1685_rtc_ops, THIS_MODULE);
2073
2074         /* Success? */
2075         if (IS_ERR(rtc_dev))
2076                 return PTR_ERR(rtc_dev);
2077
2078         /* Maximum periodic rate is 8192Hz (0.122070ms). */
2079         rtc_dev->max_user_freq = RTC_MAX_USER_FREQ;
2080
2081         /* See if the platform doesn't support UIE. */
2082         if (pdata->uie_unsupported)
2083                 rtc_dev->uie_unsupported = 1;
2084         rtc->uie_unsupported = pdata->uie_unsupported;
2085
2086         rtc->dev = rtc_dev;
2087
2088 #ifdef CONFIG_SYSFS
2089         ret = ds1685_rtc_sysfs_register(&pdev->dev);
2090         if (ret)
2091                 rtc_device_unregister(rtc->dev);
2092 #endif
2093
2094         /* Done! */
2095         return ret;
2096 }
2097
2098 /**
2099  * ds1685_rtc_remove - removes rtc driver.
2100  * @pdev: pointer to platform_device structure.
2101  */
2102 static int
2103 ds1685_rtc_remove(struct platform_device *pdev)
2104 {
2105         struct ds1685_priv *rtc = platform_get_drvdata(pdev);
2106
2107 #ifdef CONFIG_SYSFS
2108         ds1685_rtc_sysfs_unregister(&pdev->dev);
2109 #endif
2110
2111         rtc_device_unregister(rtc->dev);
2112
2113         /* Read Ctrl B and clear PIE/AIE/UIE. */
2114         rtc->write(rtc, RTC_CTRL_B,
2115                    (rtc->read(rtc, RTC_CTRL_B) &
2116                     ~(RTC_CTRL_B_PAU_MASK)));
2117
2118         /* Reading Ctrl C auto-clears PF/AF/UF. */
2119         rtc->read(rtc, RTC_CTRL_C);
2120
2121         /* Read Ctrl 4B and clear RIE/WIE/KSE. */
2122         rtc->write(rtc, RTC_EXT_CTRL_4B,
2123                    (rtc->read(rtc, RTC_EXT_CTRL_4B) &
2124                     ~(RTC_CTRL_4B_RWK_MASK)));
2125
2126         /* Manually clear RF/WF/KF in Ctrl 4A. */
2127         rtc->write(rtc, RTC_EXT_CTRL_4A,
2128                    (rtc->read(rtc, RTC_EXT_CTRL_4A) &
2129                     ~(RTC_CTRL_4A_RWK_MASK)));
2130
2131         cancel_work_sync(&rtc->work);
2132
2133         return 0;
2134 }
2135
2136 /**
2137  * ds1685_rtc_driver - rtc driver properties.
2138  */
2139 static struct platform_driver ds1685_rtc_driver = {
2140         .driver         = {
2141                 .name   = "rtc-ds1685",
2142                 .owner  = THIS_MODULE,
2143         },
2144         .probe          = ds1685_rtc_probe,
2145         .remove         = ds1685_rtc_remove,
2146 };
2147
2148 /**
2149  * ds1685_rtc_init - rtc module init.
2150  */
2151 static int __init
2152 ds1685_rtc_init(void)
2153 {
2154         return platform_driver_register(&ds1685_rtc_driver);
2155 }
2156
2157 /**
2158  * ds1685_rtc_exit - rtc module exit.
2159  */
2160 static void __exit
2161 ds1685_rtc_exit(void)
2162 {
2163         platform_driver_unregister(&ds1685_rtc_driver);
2164 }
2165
2166 module_init(ds1685_rtc_init);
2167 module_exit(ds1685_rtc_exit);
2168 /* ----------------------------------------------------------------------- */
2169
2170
2171 /* ----------------------------------------------------------------------- */
2172 /* Poweroff function */
2173
2174 /**
2175  * ds1685_rtc_poweroff - uses the RTC chip to power the system off.
2176  * @pdev: pointer to platform_device structure.
2177  */
2178 extern void __noreturn
2179 ds1685_rtc_poweroff(struct platform_device *pdev)
2180 {
2181         u8 ctrla, ctrl4a, ctrl4b;
2182         struct ds1685_priv *rtc;
2183
2184         /* Check for valid RTC data, else, spin forever. */
2185         if (unlikely(!pdev)) {
2186                 pr_emerg("rtc-ds1685: platform device data not available, spinning forever ...\n");
2187                 unreachable();
2188         } else {
2189                 /* Get the rtc data. */
2190                 rtc = platform_get_drvdata(pdev);
2191
2192                 /*
2193                  * Disable our IRQ.  We're powering down, so we're not
2194                  * going to worry about cleaning up.  Most of that should
2195                  * have been taken care of by the shutdown scripts and this
2196                  * is the final function call.
2197                  */
2198                 if (!rtc->no_irq)
2199                         disable_irq_nosync(rtc->irq_num);
2200
2201                 /* Oscillator must be on and the countdown chain enabled. */
2202                 ctrla = rtc->read(rtc, RTC_CTRL_A);
2203                 ctrla |= RTC_CTRL_A_DV1;
2204                 ctrla &= ~(RTC_CTRL_A_DV2);
2205                 rtc->write(rtc, RTC_CTRL_A, ctrla);
2206
2207                 /*
2208                  * Read Control 4A and check the status of the auxillary
2209                  * battery.  This must be present and working (VRT2 = 1)
2210                  * for wakeup and kickstart functionality to be useful.
2211                  */
2212                 ds1685_rtc_switch_to_bank1(rtc);
2213                 ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
2214                 if (ctrl4a & RTC_CTRL_4A_VRT2) {
2215                         /* Clear all of the interrupt flags on Control 4A. */
2216                         ctrl4a &= ~(RTC_CTRL_4A_RWK_MASK);
2217                         rtc->write(rtc, RTC_EXT_CTRL_4A, ctrl4a);
2218
2219                         /*
2220                          * The auxillary battery is present and working.
2221                          * Enable extended functions (ABE=1), enable
2222                          * wake-up (WIE=1), and enable kickstart (KSE=1)
2223                          * in Control 4B.
2224                          */
2225                         ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
2226                         ctrl4b |= (RTC_CTRL_4B_ABE | RTC_CTRL_4B_WIE |
2227                                    RTC_CTRL_4B_KSE);
2228                         rtc->write(rtc, RTC_EXT_CTRL_4B, ctrl4b);
2229                 }
2230
2231                 /* Set PAB to 1 in Control 4A to power the system down. */
2232                 dev_warn(&pdev->dev, "Powerdown.\n");
2233                 msleep(20);
2234                 rtc->write(rtc, RTC_EXT_CTRL_4A,
2235                            (ctrl4a | RTC_CTRL_4A_PAB));
2236
2237                 /* Spin ... we do not switch back to bank0. */
2238                 unreachable();
2239         }
2240 }
2241 EXPORT_SYMBOL(ds1685_rtc_poweroff);
2242 /* ----------------------------------------------------------------------- */
2243
2244
2245 MODULE_AUTHOR("Joshua Kinard <kumba@gentoo.org>");
2246 MODULE_AUTHOR("Matthias Fuchs <matthias.fuchs@esd-electronics.com>");
2247 MODULE_DESCRIPTION("Dallas/Maxim DS1685/DS1687-series RTC driver");
2248 MODULE_LICENSE("GPL");
2249 MODULE_VERSION(DRV_VERSION);
2250 MODULE_ALIAS("platform:rtc-ds1685");