drivers/rtc/rtc-twl.c

   1 /*
   2  * rtc-twl.c -- TWL Real Time Clock interface
   3  *
   4  * Copyright (C) 2007 MontaVista Software, Inc
   5  * Author: Alexandre Rusev <source@mvista.com>
   6  *
   7  * Based on original TI driver twl4030-rtc.c
   8  *   Copyright (C) 2006 Texas Instruments, Inc.
   9  *
  10  * Based on rtc-omap.c
  11  *   Copyright (C) 2003 MontaVista Software, Inc.
  12  *   Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
  13  *   Copyright (C) 2006 David Brownell
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License
  17  * as published by the Free Software Foundation; either version
  18  * 2 of the License, or (at your option) any later version.
  19  */
  20
  21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/kernel.h>
  24 #include <linux/errno.h>
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/rtc.h>
  29 #include <linux/bcd.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/of.h>
  33
  34 #include <linux/i2c/twl.h>
  35
  36 enum twl_class {
  37         TWL_4030 = 0,
  38         TWL_6030,
  39 };
  40
  41 /*
  42  * RTC block register offsets (use TWL_MODULE_RTC)
  43  */
  44 enum {
  45         REG_SECONDS_REG = 0,
  46         REG_MINUTES_REG,
  47         REG_HOURS_REG,
  48         REG_DAYS_REG,
  49         REG_MONTHS_REG,
  50         REG_YEARS_REG,
  51         REG_WEEKS_REG,
  52
  53         REG_ALARM_SECONDS_REG,
  54         REG_ALARM_MINUTES_REG,
  55         REG_ALARM_HOURS_REG,
  56         REG_ALARM_DAYS_REG,
  57         REG_ALARM_MONTHS_REG,
  58         REG_ALARM_YEARS_REG,
  59
  60         REG_RTC_CTRL_REG,
  61         REG_RTC_STATUS_REG,
  62         REG_RTC_INTERRUPTS_REG,
  63
  64         REG_RTC_COMP_LSB_REG,
  65         REG_RTC_COMP_MSB_REG,
  66 };
  67 static const u8 twl4030_rtc_reg_map[] = {
  68         [REG_SECONDS_REG] = 0x00,
  69         [REG_MINUTES_REG] = 0x01,
  70         [REG_HOURS_REG] = 0x02,
  71         [REG_DAYS_REG] = 0x03,
  72         [REG_MONTHS_REG] = 0x04,
  73         [REG_YEARS_REG] = 0x05,
  74         [REG_WEEKS_REG] = 0x06,
  75
  76         [REG_ALARM_SECONDS_REG] = 0x07,
  77         [REG_ALARM_MINUTES_REG] = 0x08,
  78         [REG_ALARM_HOURS_REG] = 0x09,
  79         [REG_ALARM_DAYS_REG] = 0x0A,
  80         [REG_ALARM_MONTHS_REG] = 0x0B,
  81         [REG_ALARM_YEARS_REG] = 0x0C,
  82
  83         [REG_RTC_CTRL_REG] = 0x0D,
  84         [REG_RTC_STATUS_REG] = 0x0E,
  85         [REG_RTC_INTERRUPTS_REG] = 0x0F,
  86
  87         [REG_RTC_COMP_LSB_REG] = 0x10,
  88         [REG_RTC_COMP_MSB_REG] = 0x11,
  89 };
  90 static const u8 twl6030_rtc_reg_map[] = {
  91         [REG_SECONDS_REG] = 0x00,
  92         [REG_MINUTES_REG] = 0x01,
  93         [REG_HOURS_REG] = 0x02,
  94         [REG_DAYS_REG] = 0x03,
  95         [REG_MONTHS_REG] = 0x04,
  96         [REG_YEARS_REG] = 0x05,
  97         [REG_WEEKS_REG] = 0x06,
  98
  99         [REG_ALARM_SECONDS_REG] = 0x08,
 100         [REG_ALARM_MINUTES_REG] = 0x09,
 101         [REG_ALARM_HOURS_REG] = 0x0A,
 102         [REG_ALARM_DAYS_REG] = 0x0B,
 103         [REG_ALARM_MONTHS_REG] = 0x0C,
 104         [REG_ALARM_YEARS_REG] = 0x0D,
 105
 106         [REG_RTC_CTRL_REG] = 0x10,
 107         [REG_RTC_STATUS_REG] = 0x11,
 108         [REG_RTC_INTERRUPTS_REG] = 0x12,
 109
 110         [REG_RTC_COMP_LSB_REG] = 0x13,
 111         [REG_RTC_COMP_MSB_REG] = 0x14,
 112 };
 113
 114 /* RTC_CTRL_REG bitfields */
 115 #define BIT_RTC_CTRL_REG_STOP_RTC_M              0x01
 116 #define BIT_RTC_CTRL_REG_ROUND_30S_M             0x02
 117 #define BIT_RTC_CTRL_REG_AUTO_COMP_M             0x04
 118 #define BIT_RTC_CTRL_REG_MODE_12_24_M            0x08
 119 #define BIT_RTC_CTRL_REG_TEST_MODE_M             0x10
 120 #define BIT_RTC_CTRL_REG_SET_32_COUNTER_M        0x20
 121 #define BIT_RTC_CTRL_REG_GET_TIME_M              0x40
 122 #define BIT_RTC_CTRL_REG_RTC_V_OPT               0x80
 123
 124 /* RTC_STATUS_REG bitfields */
 125 #define BIT_RTC_STATUS_REG_RUN_M                 0x02
 126 #define BIT_RTC_STATUS_REG_1S_EVENT_M            0x04
 127 #define BIT_RTC_STATUS_REG_1M_EVENT_M            0x08
 128 #define BIT_RTC_STATUS_REG_1H_EVENT_M            0x10
 129 #define BIT_RTC_STATUS_REG_1D_EVENT_M            0x20
 130 #define BIT_RTC_STATUS_REG_ALARM_M               0x40
 131 #define BIT_RTC_STATUS_REG_POWER_UP_M            0x80
 132
 133 /* RTC_INTERRUPTS_REG bitfields */
 134 #define BIT_RTC_INTERRUPTS_REG_EVERY_M           0x03
 135 #define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M        0x04
 136 #define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M        0x08
 137
 138
 139 /* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
 140 #define ALL_TIME_REGS           6
 141
 142 /*----------------------------------------------------------------------*/
 143 struct twl_rtc {
 144         struct device *dev;
 145         struct rtc_device *rtc;
 146         u8 *reg_map;
 147         /*
 148          * Cache the value for timer/alarm interrupts register; this is
 149          * only changed by callers holding rtc ops lock (or resume).
 150          */
 151         unsigned char rtc_irq_bits;
 152         bool wake_enabled;
 153 #ifdef CONFIG_PM_SLEEP
 154         unsigned char irqstat;
 155 #endif
 156         enum twl_class class;
 157 };
 158
 159 /*
 160  * Supports 1 byte read from TWL RTC register.
 161  */
 162 static int twl_rtc_read_u8(struct twl_rtc *twl_rtc, u8 *data, u8 reg)
 163 {
 164         int ret;
 165
 166         ret = twl_i2c_read_u8(TWL_MODULE_RTC, data, (twl_rtc->reg_map[reg]));
 167         if (ret < 0)
 168                 pr_err("Could not read TWL register %X - error %d\n", reg, ret);
 169         return ret;
 170 }
 171
 172 /*
 173  * Supports 1 byte write to TWL RTC registers.
 174  */
 175 static int twl_rtc_write_u8(struct twl_rtc *twl_rtc, u8 data, u8 reg)
 176 {
 177         int ret;
 178
 179         ret = twl_i2c_write_u8(TWL_MODULE_RTC, data, (twl_rtc->reg_map[reg]));
 180         if (ret < 0)
 181                 pr_err("Could not write TWL register %X - error %d\n",
 182                        reg, ret);
 183         return ret;
 184 }
 185
 186 /*
 187  * Enable 1/second update and/or alarm interrupts.
 188  */
 189 static int set_rtc_irq_bit(struct twl_rtc *twl_rtc, unsigned char bit)
 190 {
 191         unsigned char val;
 192         int ret;
 193
 194         /* if the bit is set, return from here */
 195         if (twl_rtc->rtc_irq_bits & bit)
 196                 return 0;
 197
 198         val = twl_rtc->rtc_irq_bits | bit;
 199         val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M;
 200         ret = twl_rtc_write_u8(twl_rtc, val, REG_RTC_INTERRUPTS_REG);
 201         if (ret == 0)
 202                 twl_rtc->rtc_irq_bits = val;
 203
 204         return ret;
 205 }
 206
 207 /*
 208  * Disable update and/or alarm interrupts.
 209  */
 210 static int mask_rtc_irq_bit(struct twl_rtc *twl_rtc, unsigned char bit)
 211 {
 212         unsigned char val;
 213         int ret;
 214
 215         /* if the bit is clear, return from here */
 216         if (!(twl_rtc->rtc_irq_bits & bit))
 217                 return 0;
 218
 219         val = twl_rtc->rtc_irq_bits & ~bit;
 220         ret = twl_rtc_write_u8(twl_rtc, val, REG_RTC_INTERRUPTS_REG);
 221         if (ret == 0)
 222                 twl_rtc->rtc_irq_bits = val;
 223
 224         return ret;
 225 }
 226
 227 static int twl_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
 228 {
 229         struct platform_device *pdev = to_platform_device(dev);
 230         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 231         int irq = platform_get_irq(pdev, 0);
 232         int ret;
 233
 234         if (enabled) {
 235                 ret = set_rtc_irq_bit(twl_rtc,
 236                                       BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
 237                 if (device_can_wakeup(dev) && !twl_rtc->wake_enabled) {
 238                         enable_irq_wake(irq);
 239                         twl_rtc->wake_enabled = true;
 240                 }
 241         } else {
 242                 ret = mask_rtc_irq_bit(twl_rtc,
 243                                        BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
 244                 if (twl_rtc->wake_enabled) {
 245                         disable_irq_wake(irq);
 246                         twl_rtc->wake_enabled = false;
 247                 }
 248         }
 249
 250         return ret;
 251 }
 252
 253 /*
 254  * Gets current TWL RTC time and date parameters.
 255  *
 256  * The RTC's time/alarm representation is not what gmtime(3) requires
 257  * Linux to use:
 258  *
 259  *  - Months are 1..12 vs Linux 0-11
 260  *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
 261  */
 262 static int twl_rtc_read_time(struct device *dev, struct rtc_time *tm)
 263 {
 264         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 265         unsigned char rtc_data[ALL_TIME_REGS];
 266         int ret;
 267         u8 save_control;
 268         u8 rtc_control;
 269
 270         ret = twl_rtc_read_u8(twl_rtc, &save_control, REG_RTC_CTRL_REG);
 271         if (ret < 0) {
 272                 dev_err(dev, "%s: reading CTRL_REG, error %d\n", __func__, ret);
 273                 return ret;
 274         }
 275         /* for twl6030/32 make sure BIT_RTC_CTRL_REG_GET_TIME_M is clear */
 276         if (twl_rtc->class == TWL_6030) {
 277                 if (save_control & BIT_RTC_CTRL_REG_GET_TIME_M) {
 278                         save_control &= ~BIT_RTC_CTRL_REG_GET_TIME_M;
 279                         ret = twl_rtc_write_u8(twl_rtc, save_control,
 280                                                REG_RTC_CTRL_REG);
 281                         if (ret < 0) {
 282                                 dev_err(dev, "%s clr GET_TIME, error %d\n",
 283                                         __func__, ret);
 284                                 return ret;
 285                         }
 286                 }
 287         }
 288
 289         /* Copy RTC counting registers to static registers or latches */
 290         rtc_control = save_control | BIT_RTC_CTRL_REG_GET_TIME_M;
 291
 292         /* for twl6030/32 enable read access to static shadowed registers */
 293         if (twl_rtc->class == TWL_6030)
 294                 rtc_control |= BIT_RTC_CTRL_REG_RTC_V_OPT;
 295
 296         ret = twl_rtc_write_u8(twl_rtc, rtc_control, REG_RTC_CTRL_REG);
 297         if (ret < 0) {
 298                 dev_err(dev, "%s: writing CTRL_REG, error %d\n", __func__, ret);
 299                 return ret;
 300         }
 301
 302         ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
 303                         (twl_rtc->reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
 304
 305         if (ret < 0) {
 306                 dev_err(dev, "%s: reading data, error %d\n", __func__, ret);
 307                 return ret;
 308         }
 309
 310         /* for twl6030 restore original state of rtc control register */
 311         if (twl_rtc->class == TWL_6030) {
 312                 ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
 313                 if (ret < 0) {
 314                         dev_err(dev, "%s: restore CTRL_REG, error %d\n",
 315                                 __func__, ret);
 316                         return ret;
 317                 }
 318         }
 319
 320         tm->tm_sec = bcd2bin(rtc_data[0]);
 321         tm->tm_min = bcd2bin(rtc_data[1]);
 322         tm->tm_hour = bcd2bin(rtc_data[2]);
 323         tm->tm_mday = bcd2bin(rtc_data[3]);
 324         tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
 325         tm->tm_year = bcd2bin(rtc_data[5]) + 100;
 326
 327         return ret;
 328 }
 329
 330 static int twl_rtc_set_time(struct device *dev, struct rtc_time *tm)
 331 {
 332         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 333         unsigned char save_control;
 334         unsigned char rtc_data[ALL_TIME_REGS];
 335         int ret;
 336
 337         rtc_data[0] = bin2bcd(tm->tm_sec);
 338         rtc_data[1] = bin2bcd(tm->tm_min);
 339         rtc_data[2] = bin2bcd(tm->tm_hour);
 340         rtc_data[3] = bin2bcd(tm->tm_mday);
 341         rtc_data[4] = bin2bcd(tm->tm_mon + 1);
 342         rtc_data[5] = bin2bcd(tm->tm_year - 100);
 343
 344         /* Stop RTC while updating the TC registers */
 345         ret = twl_rtc_read_u8(twl_rtc, &save_control, REG_RTC_CTRL_REG);
 346         if (ret < 0)
 347                 goto out;
 348
 349         save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
 350         ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
 351         if (ret < 0)
 352                 goto out;
 353
 354         /* update all the time registers in one shot */
 355         ret = twl_i2c_write(TWL_MODULE_RTC, rtc_data,
 356                 (twl_rtc->reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
 357         if (ret < 0) {
 358                 dev_err(dev, "rtc_set_time error %d\n", ret);
 359                 goto out;
 360         }
 361
 362         /* Start back RTC */
 363         save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M;
 364         ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
 365
 366 out:
 367         return ret;
 368 }
 369
 370 /*
 371  * Gets current TWL RTC alarm time.
 372  */
 373 static int twl_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 374 {
 375         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 376         unsigned char rtc_data[ALL_TIME_REGS];
 377         int ret;
 378
 379         ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
 380                         twl_rtc->reg_map[REG_ALARM_SECONDS_REG], ALL_TIME_REGS);
 381         if (ret < 0) {
 382                 dev_err(dev, "rtc_read_alarm error %d\n", ret);
 383                 return ret;
 384         }
 385
 386         /* some of these fields may be wildcard/"match all" */
 387         alm->time.tm_sec = bcd2bin(rtc_data[0]);
 388         alm->time.tm_min = bcd2bin(rtc_data[1]);
 389         alm->time.tm_hour = bcd2bin(rtc_data[2]);
 390         alm->time.tm_mday = bcd2bin(rtc_data[3]);
 391         alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1;
 392         alm->time.tm_year = bcd2bin(rtc_data[5]) + 100;
 393
 394         /* report cached alarm enable state */
 395         if (twl_rtc->rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M)
 396                 alm->enabled = 1;
 397
 398         return ret;
 399 }
 400
 401 static int twl_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 402 {
 403         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 404
 405         unsigned char alarm_data[ALL_TIME_REGS];
 406         int ret;
 407
 408         ret = twl_rtc_alarm_irq_enable(dev, 0);
 409         if (ret)
 410                 goto out;
 411
 412         alarm_data[0] = bin2bcd(alm->time.tm_sec);
 413         alarm_data[1] = bin2bcd(alm->time.tm_min);
 414         alarm_data[2] = bin2bcd(alm->time.tm_hour);
 415         alarm_data[3] = bin2bcd(alm->time.tm_mday);
 416         alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
 417         alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
 418
 419         /* update all the alarm registers in one shot */
 420         ret = twl_i2c_write(TWL_MODULE_RTC, alarm_data,
 421                         twl_rtc->reg_map[REG_ALARM_SECONDS_REG], ALL_TIME_REGS);
 422         if (ret) {
 423                 dev_err(dev, "rtc_set_alarm error %d\n", ret);
 424                 goto out;
 425         }
 426
 427         if (alm->enabled)
 428                 ret = twl_rtc_alarm_irq_enable(dev, 1);
 429 out:
 430         return ret;
 431 }
 432
 433 static irqreturn_t twl_rtc_interrupt(int irq, void *data)
 434 {
 435         struct twl_rtc *twl_rtc = data;
 436         unsigned long events;
 437         int ret = IRQ_NONE;
 438         int res;
 439         u8 rd_reg;
 440
 441         res = twl_rtc_read_u8(twl_rtc, &rd_reg, REG_RTC_STATUS_REG);
 442         if (res)
 443                 goto out;
 444         /*
 445          * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
 446          * only one (ALARM or RTC) interrupt source may be enabled
 447          * at time, we also could check our results
 448          * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
 449          */
 450         if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
 451                 events = RTC_IRQF | RTC_AF;
 452         else
 453                 events = RTC_IRQF | RTC_PF;
 454
 455         res = twl_rtc_write_u8(twl_rtc, BIT_RTC_STATUS_REG_ALARM_M,
 456                                REG_RTC_STATUS_REG);
 457         if (res)
 458                 goto out;
 459
 460         if (twl_rtc->class == TWL_4030) {
 461                 /* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1
 462                  * needs 2 reads to clear the interrupt. One read is done in
 463                  * do_twl_pwrirq(). Doing the second read, to clear
 464                  * the bit.
 465                  *
 466                  * FIXME the reason PWR_ISR1 needs an extra read is that
 467                  * RTC_IF retriggered until we cleared REG_ALARM_M above.
 468                  * But re-reading like this is a bad hack; by doing so we
 469                  * risk wrongly clearing status for some other IRQ (losing
 470                  * the interrupt).  Be smarter about handling RTC_UF ...
 471                  */
 472                 res = twl_i2c_read_u8(TWL4030_MODULE_INT,
 473                         &rd_reg, TWL4030_INT_PWR_ISR1);
 474                 if (res)
 475                         goto out;
 476         }
 477
 478         /* Notify RTC core on event */
 479         rtc_update_irq(twl_rtc->rtc, 1, events);
 480
 481         ret = IRQ_HANDLED;
 482 out:
 483         return ret;
 484 }
 485
 486 static const struct rtc_class_ops twl_rtc_ops = {
 487         .read_time      = twl_rtc_read_time,
 488         .set_time       = twl_rtc_set_time,
 489         .read_alarm     = twl_rtc_read_alarm,
 490         .set_alarm      = twl_rtc_set_alarm,
 491         .alarm_irq_enable = twl_rtc_alarm_irq_enable,
 492 };
 493
 494 /*----------------------------------------------------------------------*/
 495
 496 static int twl_rtc_probe(struct platform_device *pdev)
 497 {
 498         struct twl_rtc *twl_rtc;
 499         struct device_node *np = pdev->dev.of_node;
 500         int ret = -EINVAL;
 501         int irq = platform_get_irq(pdev, 0);
 502         u8 rd_reg;
 503
 504         if (!np) {
 505                 dev_err(&pdev->dev, "no DT info\n");
 506                 return -EINVAL;
 507         }
 508
 509         if (irq <= 0)
 510                 return ret;
 511
 512         twl_rtc = devm_kzalloc(&pdev->dev, sizeof(*twl_rtc), GFP_KERNEL);
 513         if (!twl_rtc)
 514                 return -ENOMEM;
 515
 516         if (twl_class_is_4030()) {
 517                 twl_rtc->class = TWL_4030;
 518                 twl_rtc->reg_map = (u8 *)twl4030_rtc_reg_map;
 519         } else if (twl_class_is_6030()) {
 520                 twl_rtc->class = TWL_6030;
 521                 twl_rtc->reg_map = (u8 *)twl6030_rtc_reg_map;
 522         } else {
 523                 dev_err(&pdev->dev, "TWL Class not supported.\n");
 524                 return -EINVAL;
 525         }
 526
 527         ret = twl_rtc_read_u8(twl_rtc, &rd_reg, REG_RTC_STATUS_REG);
 528         if (ret < 0)
 529                 return ret;
 530
 531         if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
 532                 dev_warn(&pdev->dev, "Power up reset detected.\n");
 533
 534         if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
 535                 dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");
 536
 537         /* Clear RTC Power up reset and pending alarm interrupts */
 538         ret = twl_rtc_write_u8(twl_rtc, rd_reg, REG_RTC_STATUS_REG);
 539         if (ret < 0)
 540                 return ret;
 541
 542         if (twl_rtc->class == TWL_6030) {
 543                 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
 544                         REG_INT_MSK_LINE_A);
 545                 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
 546                         REG_INT_MSK_STS_A);
 547         }
 548
 549         dev_info(&pdev->dev, "Enabling TWL-RTC\n");
 550         ret = twl_rtc_write_u8(twl_rtc, BIT_RTC_CTRL_REG_STOP_RTC_M,
 551                                REG_RTC_CTRL_REG);
 552         if (ret < 0)
 553                 return ret;
 554
 555         /* ensure interrupts are disabled, bootloaders can be strange */
 556         ret = twl_rtc_write_u8(twl_rtc, 0, REG_RTC_INTERRUPTS_REG);
 557         if (ret < 0)
 558                 dev_warn(&pdev->dev, "unable to disable interrupt\n");
 559
 560         /* init cached IRQ enable bits */
 561         ret = twl_rtc_read_u8(twl_rtc, &twl_rtc->rtc_irq_bits,
 562                               REG_RTC_INTERRUPTS_REG);
 563         if (ret < 0)
 564                 return ret;
 565
 566         platform_set_drvdata(pdev, twl_rtc);
 567         device_init_wakeup(&pdev->dev, 1);
 568
 569         twl_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 570                                         &twl_rtc_ops, THIS_MODULE);
 571         if (IS_ERR(twl_rtc->rtc)) {
 572                 dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
 573                         PTR_ERR(twl_rtc->rtc));
 574                 return PTR_ERR(twl_rtc->rtc);
 575         }
 576
 577         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 578                                         twl_rtc_interrupt,
 579                                         IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 580                                         dev_name(&twl_rtc->rtc->dev), twl_rtc);
 581         if (ret < 0) {
 582                 dev_err(&pdev->dev, "IRQ is not free.\n");
 583                 return ret;
 584         }
 585
 586         return 0;
 587 }
 588
 589 /*
 590  * Disable all TWL RTC module interrupts.
 591  * Sets status flag to free.
 592  */
 593 static int twl_rtc_remove(struct platform_device *pdev)
 594 {
 595         struct twl_rtc *twl_rtc = platform_get_drvdata(pdev);
 596
 597         /* leave rtc running, but disable irqs */
 598         mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
 599         mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
 600         if (twl_rtc->class == TWL_6030) {
 601                 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
 602                         REG_INT_MSK_LINE_A);
 603                 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
 604                         REG_INT_MSK_STS_A);
 605         }
 606
 607         return 0;
 608 }
 609
 610 static void twl_rtc_shutdown(struct platform_device *pdev)
 611 {
 612         struct twl_rtc *twl_rtc = platform_get_drvdata(pdev);
 613
 614         /* mask timer interrupts, but leave alarm interrupts on to enable
 615            power-on when alarm is triggered */
 616         mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
 617 }
 618
 619 #ifdef CONFIG_PM_SLEEP
 620 static int twl_rtc_suspend(struct device *dev)
 621 {
 622         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 623
 624         twl_rtc->irqstat = twl_rtc->rtc_irq_bits;
 625
 626         mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
 627         return 0;
 628 }
 629
 630 static int twl_rtc_resume(struct device *dev)
 631 {
 632         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 633
 634         set_rtc_irq_bit(twl_rtc, twl_rtc->irqstat);
 635         return 0;
 636 }
 637 #endif
 638
 639 static SIMPLE_DEV_PM_OPS(twl_rtc_pm_ops, twl_rtc_suspend, twl_rtc_resume);
 640
 641 static const struct of_device_id twl_rtc_of_match[] = {
 642         {.compatible = "ti,twl4030-rtc", },
 643         { },
 644 };
 645 MODULE_DEVICE_TABLE(of, twl_rtc_of_match);
 646
 647 static struct platform_driver twl4030rtc_driver = {
 648         .probe          = twl_rtc_probe,
 649         .remove         = twl_rtc_remove,
 650         .shutdown       = twl_rtc_shutdown,
 651         .driver         = {
 652                 .name           = "twl_rtc",
 653                 .pm             = &twl_rtc_pm_ops,
 654                 .of_match_table = twl_rtc_of_match,
 655         },
 656 };
 657
 658 module_platform_driver(twl4030rtc_driver);
 659
 660 MODULE_AUTHOR("Texas Instruments, MontaVista Software");
 661 MODULE_LICENSE("GPL");