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