root/drivers/rtc/rtc-twl.c

DEFINITIONS

1. twl_rtc_read_u8
2. twl_rtc_write_u8
3. set_rtc_irq_bit
4. mask_rtc_irq_bit
5. twl_rtc_alarm_irq_enable
6. twl_rtc_read_time
7. twl_rtc_set_time
8. twl_rtc_read_alarm
9. twl_rtc_set_alarm
10. twl_rtc_interrupt
11. twl_rtc_probe
12. twl_rtc_remove
13. twl_rtc_shutdown
14. twl_rtc_suspend
15. twl_rtc_resume

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * rtc-twl.c -- TWL Real Time Clock interface
   4  *
   5  * Copyright (C) 2007 MontaVista Software, Inc
   6  * Author: Alexandre Rusev <source@mvista.com>
   7  *
   8  * Based on original TI driver twl4030-rtc.c
   9  *   Copyright (C) 2006 Texas Instruments, Inc.
  10  *
  11  * Based on rtc-omap.c
  12  *   Copyright (C) 2003 MontaVista Software, Inc.
  13  *   Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
  14  *   Copyright (C) 2006 David Brownell
  15  */
  16 
  17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18 
  19 #include <linux/kernel.h>
  20 #include <linux/errno.h>
  21 #include <linux/init.h>
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/rtc.h>
  25 #include <linux/bcd.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/of.h>
  29 
  30 #include <linux/mfd/twl.h>
  31 
  32 enum twl_class {
  33         TWL_4030 = 0,
  34         TWL_6030,
  35 };
  36 
  37 /*
  38  * RTC block register offsets (use TWL_MODULE_RTC)
  39  */
  40 enum {
  41         REG_SECONDS_REG = 0,
  42         REG_MINUTES_REG,
  43         REG_HOURS_REG,
  44         REG_DAYS_REG,
  45         REG_MONTHS_REG,
  46         REG_YEARS_REG,
  47         REG_WEEKS_REG,
  48 
  49         REG_ALARM_SECONDS_REG,
  50         REG_ALARM_MINUTES_REG,
  51         REG_ALARM_HOURS_REG,
  52         REG_ALARM_DAYS_REG,
  53         REG_ALARM_MONTHS_REG,
  54         REG_ALARM_YEARS_REG,
  55 
  56         REG_RTC_CTRL_REG,
  57         REG_RTC_STATUS_REG,
  58         REG_RTC_INTERRUPTS_REG,
  59 
  60         REG_RTC_COMP_LSB_REG,
  61         REG_RTC_COMP_MSB_REG,
  62 };
  63 static const u8 twl4030_rtc_reg_map[] = {
  64         [REG_SECONDS_REG] = 0x00,
  65         [REG_MINUTES_REG] = 0x01,
  66         [REG_HOURS_REG] = 0x02,
  67         [REG_DAYS_REG] = 0x03,
  68         [REG_MONTHS_REG] = 0x04,
  69         [REG_YEARS_REG] = 0x05,
  70         [REG_WEEKS_REG] = 0x06,
  71 
  72         [REG_ALARM_SECONDS_REG] = 0x07,
  73         [REG_ALARM_MINUTES_REG] = 0x08,
  74         [REG_ALARM_HOURS_REG] = 0x09,
  75         [REG_ALARM_DAYS_REG] = 0x0A,
  76         [REG_ALARM_MONTHS_REG] = 0x0B,
  77         [REG_ALARM_YEARS_REG] = 0x0C,
  78 
  79         [REG_RTC_CTRL_REG] = 0x0D,
  80         [REG_RTC_STATUS_REG] = 0x0E,
  81         [REG_RTC_INTERRUPTS_REG] = 0x0F,
  82 
  83         [REG_RTC_COMP_LSB_REG] = 0x10,
  84         [REG_RTC_COMP_MSB_REG] = 0x11,
  85 };
  86 static const u8 twl6030_rtc_reg_map[] = {
  87         [REG_SECONDS_REG] = 0x00,
  88         [REG_MINUTES_REG] = 0x01,
  89         [REG_HOURS_REG] = 0x02,
  90         [REG_DAYS_REG] = 0x03,
  91         [REG_MONTHS_REG] = 0x04,
  92         [REG_YEARS_REG] = 0x05,
  93         [REG_WEEKS_REG] = 0x06,
  94 
  95         [REG_ALARM_SECONDS_REG] = 0x08,
  96         [REG_ALARM_MINUTES_REG] = 0x09,
  97         [REG_ALARM_HOURS_REG] = 0x0A,
  98         [REG_ALARM_DAYS_REG] = 0x0B,
  99         [REG_ALARM_MONTHS_REG] = 0x0C,
 100         [REG_ALARM_YEARS_REG] = 0x0D,
 101 
 102         [REG_RTC_CTRL_REG] = 0x10,
 103         [REG_RTC_STATUS_REG] = 0x11,
 104         [REG_RTC_INTERRUPTS_REG] = 0x12,
 105 
 106         [REG_RTC_COMP_LSB_REG] = 0x13,
 107         [REG_RTC_COMP_MSB_REG] = 0x14,
 108 };
 109 
 110 /* RTC_CTRL_REG bitfields */
 111 #define BIT_RTC_CTRL_REG_STOP_RTC_M              0x01
 112 #define BIT_RTC_CTRL_REG_ROUND_30S_M             0x02
 113 #define BIT_RTC_CTRL_REG_AUTO_COMP_M             0x04
 114 #define BIT_RTC_CTRL_REG_MODE_12_24_M            0x08
 115 #define BIT_RTC_CTRL_REG_TEST_MODE_M             0x10
 116 #define BIT_RTC_CTRL_REG_SET_32_COUNTER_M        0x20
 117 #define BIT_RTC_CTRL_REG_GET_TIME_M              0x40
 118 #define BIT_RTC_CTRL_REG_RTC_V_OPT               0x80
 119 
 120 /* RTC_STATUS_REG bitfields */
 121 #define BIT_RTC_STATUS_REG_RUN_M                 0x02
 122 #define BIT_RTC_STATUS_REG_1S_EVENT_M            0x04
 123 #define BIT_RTC_STATUS_REG_1M_EVENT_M            0x08
 124 #define BIT_RTC_STATUS_REG_1H_EVENT_M            0x10
 125 #define BIT_RTC_STATUS_REG_1D_EVENT_M            0x20
 126 #define BIT_RTC_STATUS_REG_ALARM_M               0x40
 127 #define BIT_RTC_STATUS_REG_POWER_UP_M            0x80
 128 
 129 /* RTC_INTERRUPTS_REG bitfields */
 130 #define BIT_RTC_INTERRUPTS_REG_EVERY_M           0x03
 131 #define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M        0x04
 132 #define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M        0x08
 133 
 134 
 135 /* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
 136 #define ALL_TIME_REGS           6
 137 
 138 /*----------------------------------------------------------------------*/
 139 struct twl_rtc {
 140         struct device *dev;
 141         struct rtc_device *rtc;
 142         u8 *reg_map;
 143         /*
 144          * Cache the value for timer/alarm interrupts register; this is
 145          * only changed by callers holding rtc ops lock (or resume).
 146          */
 147         unsigned char rtc_irq_bits;
 148         bool wake_enabled;
 149 #ifdef CONFIG_PM_SLEEP
 150         unsigned char irqstat;
 151 #endif
 152         enum twl_class class;
 153 };
 154 
 155 /*
 156  * Supports 1 byte read from TWL RTC register.
 157  */
 158 static int twl_rtc_read_u8(struct twl_rtc *twl_rtc, u8 *data, u8 reg)
 159 {
 160         int ret;
 161 
 162         ret = twl_i2c_read_u8(TWL_MODULE_RTC, data, (twl_rtc->reg_map[reg]));
 163         if (ret < 0)
 164                 pr_err("Could not read TWL register %X - error %d\n", reg, ret);
 165         return ret;
 166 }
 167 
 168 /*
 169  * Supports 1 byte write to TWL RTC registers.
 170  */
 171 static int twl_rtc_write_u8(struct twl_rtc *twl_rtc, u8 data, u8 reg)
 172 {
 173         int ret;
 174 
 175         ret = twl_i2c_write_u8(TWL_MODULE_RTC, data, (twl_rtc->reg_map[reg]));
 176         if (ret < 0)
 177                 pr_err("Could not write TWL register %X - error %d\n",
 178                        reg, ret);
 179         return ret;
 180 }
 181 
 182 /*
 183  * Enable 1/second update and/or alarm interrupts.
 184  */
 185 static int set_rtc_irq_bit(struct twl_rtc *twl_rtc, unsigned char bit)
 186 {
 187         unsigned char val;
 188         int ret;
 189 
 190         /* if the bit is set, return from here */
 191         if (twl_rtc->rtc_irq_bits & bit)
 192                 return 0;
 193 
 194         val = twl_rtc->rtc_irq_bits | bit;
 195         val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M;
 196         ret = twl_rtc_write_u8(twl_rtc, val, REG_RTC_INTERRUPTS_REG);
 197         if (ret == 0)
 198                 twl_rtc->rtc_irq_bits = val;
 199 
 200         return ret;
 201 }
 202 
 203 /*
 204  * Disable update and/or alarm interrupts.
 205  */
 206 static int mask_rtc_irq_bit(struct twl_rtc *twl_rtc, unsigned char bit)
 207 {
 208         unsigned char val;
 209         int ret;
 210 
 211         /* if the bit is clear, return from here */
 212         if (!(twl_rtc->rtc_irq_bits & bit))
 213                 return 0;
 214 
 215         val = twl_rtc->rtc_irq_bits & ~bit;
 216         ret = twl_rtc_write_u8(twl_rtc, val, REG_RTC_INTERRUPTS_REG);
 217         if (ret == 0)
 218                 twl_rtc->rtc_irq_bits = val;
 219 
 220         return ret;
 221 }
 222 
 223 static int twl_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
 224 {
 225         struct platform_device *pdev = to_platform_device(dev);
 226         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 227         int irq = platform_get_irq(pdev, 0);
 228         int ret;
 229 
 230         if (enabled) {
 231                 ret = set_rtc_irq_bit(twl_rtc,
 232                                       BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
 233                 if (device_can_wakeup(dev) && !twl_rtc->wake_enabled) {
 234                         enable_irq_wake(irq);
 235                         twl_rtc->wake_enabled = true;
 236                 }
 237         } else {
 238                 ret = mask_rtc_irq_bit(twl_rtc,
 239                                        BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
 240                 if (twl_rtc->wake_enabled) {
 241                         disable_irq_wake(irq);
 242                         twl_rtc->wake_enabled = false;
 243                 }
 244         }
 245 
 246         return ret;
 247 }
 248 
 249 /*
 250  * Gets current TWL RTC time and date parameters.
 251  *
 252  * The RTC's time/alarm representation is not what gmtime(3) requires
 253  * Linux to use:
 254  *
 255  *  - Months are 1..12 vs Linux 0-11
 256  *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
 257  */
 258 static int twl_rtc_read_time(struct device *dev, struct rtc_time *tm)
 259 {
 260         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 261         unsigned char rtc_data[ALL_TIME_REGS];
 262         int ret;
 263         u8 save_control;
 264         u8 rtc_control;
 265 
 266         ret = twl_rtc_read_u8(twl_rtc, &save_control, REG_RTC_CTRL_REG);
 267         if (ret < 0) {
 268                 dev_err(dev, "%s: reading CTRL_REG, error %d\n", __func__, ret);
 269                 return ret;
 270         }
 271         /* for twl6030/32 make sure BIT_RTC_CTRL_REG_GET_TIME_M is clear */
 272         if (twl_rtc->class == TWL_6030) {
 273                 if (save_control & BIT_RTC_CTRL_REG_GET_TIME_M) {
 274                         save_control &= ~BIT_RTC_CTRL_REG_GET_TIME_M;
 275                         ret = twl_rtc_write_u8(twl_rtc, save_control,
 276                                                REG_RTC_CTRL_REG);
 277                         if (ret < 0) {
 278                                 dev_err(dev, "%s clr GET_TIME, error %d\n",
 279                                         __func__, ret);
 280                                 return ret;
 281                         }
 282                 }
 283         }
 284 
 285         /* Copy RTC counting registers to static registers or latches */
 286         rtc_control = save_control | BIT_RTC_CTRL_REG_GET_TIME_M;
 287 
 288         /* for twl6030/32 enable read access to static shadowed registers */
 289         if (twl_rtc->class == TWL_6030)
 290                 rtc_control |= BIT_RTC_CTRL_REG_RTC_V_OPT;
 291 
 292         ret = twl_rtc_write_u8(twl_rtc, rtc_control, REG_RTC_CTRL_REG);
 293         if (ret < 0) {
 294                 dev_err(dev, "%s: writing CTRL_REG, error %d\n", __func__, ret);
 295                 return ret;
 296         }
 297 
 298         ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
 299                         (twl_rtc->reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
 300 
 301         if (ret < 0) {
 302                 dev_err(dev, "%s: reading data, error %d\n", __func__, ret);
 303                 return ret;
 304         }
 305 
 306         /* for twl6030 restore original state of rtc control register */
 307         if (twl_rtc->class == TWL_6030) {
 308                 ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
 309                 if (ret < 0) {
 310                         dev_err(dev, "%s: restore CTRL_REG, error %d\n",
 311                                 __func__, ret);
 312                         return ret;
 313                 }
 314         }
 315 
 316         tm->tm_sec = bcd2bin(rtc_data[0]);
 317         tm->tm_min = bcd2bin(rtc_data[1]);
 318         tm->tm_hour = bcd2bin(rtc_data[2]);
 319         tm->tm_mday = bcd2bin(rtc_data[3]);
 320         tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
 321         tm->tm_year = bcd2bin(rtc_data[5]) + 100;
 322 
 323         return ret;
 324 }
 325 
 326 static int twl_rtc_set_time(struct device *dev, struct rtc_time *tm)
 327 {
 328         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 329         unsigned char save_control;
 330         unsigned char rtc_data[ALL_TIME_REGS];
 331         int ret;
 332 
 333         rtc_data[0] = bin2bcd(tm->tm_sec);
 334         rtc_data[1] = bin2bcd(tm->tm_min);
 335         rtc_data[2] = bin2bcd(tm->tm_hour);
 336         rtc_data[3] = bin2bcd(tm->tm_mday);
 337         rtc_data[4] = bin2bcd(tm->tm_mon + 1);
 338         rtc_data[5] = bin2bcd(tm->tm_year - 100);
 339 
 340         /* Stop RTC while updating the TC registers */
 341         ret = twl_rtc_read_u8(twl_rtc, &save_control, REG_RTC_CTRL_REG);
 342         if (ret < 0)
 343                 goto out;
 344 
 345         save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
 346         ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
 347         if (ret < 0)
 348                 goto out;
 349 
 350         /* update all the time registers in one shot */
 351         ret = twl_i2c_write(TWL_MODULE_RTC, rtc_data,
 352                 (twl_rtc->reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
 353         if (ret < 0) {
 354                 dev_err(dev, "rtc_set_time error %d\n", ret);
 355                 goto out;
 356         }
 357 
 358         /* Start back RTC */
 359         save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M;
 360         ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG);
 361 
 362 out:
 363         return ret;
 364 }
 365 
 366 /*
 367  * Gets current TWL RTC alarm time.
 368  */
 369 static int twl_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 370 {
 371         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 372         unsigned char rtc_data[ALL_TIME_REGS];
 373         int ret;
 374 
 375         ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
 376                         twl_rtc->reg_map[REG_ALARM_SECONDS_REG], ALL_TIME_REGS);
 377         if (ret < 0) {
 378                 dev_err(dev, "rtc_read_alarm error %d\n", ret);
 379                 return ret;
 380         }
 381 
 382         /* some of these fields may be wildcard/"match all" */
 383         alm->time.tm_sec = bcd2bin(rtc_data[0]);
 384         alm->time.tm_min = bcd2bin(rtc_data[1]);
 385         alm->time.tm_hour = bcd2bin(rtc_data[2]);
 386         alm->time.tm_mday = bcd2bin(rtc_data[3]);
 387         alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1;
 388         alm->time.tm_year = bcd2bin(rtc_data[5]) + 100;
 389 
 390         /* report cached alarm enable state */
 391         if (twl_rtc->rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M)
 392                 alm->enabled = 1;
 393 
 394         return ret;
 395 }
 396 
 397 static int twl_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 398 {
 399         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 400 
 401         unsigned char alarm_data[ALL_TIME_REGS];
 402         int ret;
 403 
 404         ret = twl_rtc_alarm_irq_enable(dev, 0);
 405         if (ret)
 406                 goto out;
 407 
 408         alarm_data[0] = bin2bcd(alm->time.tm_sec);
 409         alarm_data[1] = bin2bcd(alm->time.tm_min);
 410         alarm_data[2] = bin2bcd(alm->time.tm_hour);
 411         alarm_data[3] = bin2bcd(alm->time.tm_mday);
 412         alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
 413         alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
 414 
 415         /* update all the alarm registers in one shot */
 416         ret = twl_i2c_write(TWL_MODULE_RTC, alarm_data,
 417                         twl_rtc->reg_map[REG_ALARM_SECONDS_REG], ALL_TIME_REGS);
 418         if (ret) {
 419                 dev_err(dev, "rtc_set_alarm error %d\n", ret);
 420                 goto out;
 421         }
 422 
 423         if (alm->enabled)
 424                 ret = twl_rtc_alarm_irq_enable(dev, 1);
 425 out:
 426         return ret;
 427 }
 428 
 429 static irqreturn_t twl_rtc_interrupt(int irq, void *data)
 430 {
 431         struct twl_rtc *twl_rtc = data;
 432         unsigned long events;
 433         int ret = IRQ_NONE;
 434         int res;
 435         u8 rd_reg;
 436 
 437         res = twl_rtc_read_u8(twl_rtc, &rd_reg, REG_RTC_STATUS_REG);
 438         if (res)
 439                 goto out;
 440         /*
 441          * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
 442          * only one (ALARM or RTC) interrupt source may be enabled
 443          * at time, we also could check our results
 444          * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
 445          */
 446         if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
 447                 events = RTC_IRQF | RTC_AF;
 448         else
 449                 events = RTC_IRQF | RTC_PF;
 450 
 451         res = twl_rtc_write_u8(twl_rtc, BIT_RTC_STATUS_REG_ALARM_M,
 452                                REG_RTC_STATUS_REG);
 453         if (res)
 454                 goto out;
 455 
 456         if (twl_rtc->class == TWL_4030) {
 457                 /* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1
 458                  * needs 2 reads to clear the interrupt. One read is done in
 459                  * do_twl_pwrirq(). Doing the second read, to clear
 460                  * the bit.
 461                  *
 462                  * FIXME the reason PWR_ISR1 needs an extra read is that
 463                  * RTC_IF retriggered until we cleared REG_ALARM_M above.
 464                  * But re-reading like this is a bad hack; by doing so we
 465                  * risk wrongly clearing status for some other IRQ (losing
 466                  * the interrupt).  Be smarter about handling RTC_UF ...
 467                  */
 468                 res = twl_i2c_read_u8(TWL4030_MODULE_INT,
 469                         &rd_reg, TWL4030_INT_PWR_ISR1);
 470                 if (res)
 471                         goto out;
 472         }
 473 
 474         /* Notify RTC core on event */
 475         rtc_update_irq(twl_rtc->rtc, 1, events);
 476 
 477         ret = IRQ_HANDLED;
 478 out:
 479         return ret;
 480 }
 481 
 482 static const struct rtc_class_ops twl_rtc_ops = {
 483         .read_time      = twl_rtc_read_time,
 484         .set_time       = twl_rtc_set_time,
 485         .read_alarm     = twl_rtc_read_alarm,
 486         .set_alarm      = twl_rtc_set_alarm,
 487         .alarm_irq_enable = twl_rtc_alarm_irq_enable,
 488 };
 489 
 490 /*----------------------------------------------------------------------*/
 491 
 492 static int twl_rtc_probe(struct platform_device *pdev)
 493 {
 494         struct twl_rtc *twl_rtc;
 495         struct device_node *np = pdev->dev.of_node;
 496         int ret = -EINVAL;
 497         int irq = platform_get_irq(pdev, 0);
 498         u8 rd_reg;
 499 
 500         if (!np) {
 501                 dev_err(&pdev->dev, "no DT info\n");
 502                 return -EINVAL;
 503         }
 504 
 505         if (irq <= 0)
 506                 return ret;
 507 
 508         twl_rtc = devm_kzalloc(&pdev->dev, sizeof(*twl_rtc), GFP_KERNEL);
 509         if (!twl_rtc)
 510                 return -ENOMEM;
 511 
 512         if (twl_class_is_4030()) {
 513                 twl_rtc->class = TWL_4030;
 514                 twl_rtc->reg_map = (u8 *)twl4030_rtc_reg_map;
 515         } else if (twl_class_is_6030()) {
 516                 twl_rtc->class = TWL_6030;
 517                 twl_rtc->reg_map = (u8 *)twl6030_rtc_reg_map;
 518         } else {
 519                 dev_err(&pdev->dev, "TWL Class not supported.\n");
 520                 return -EINVAL;
 521         }
 522 
 523         ret = twl_rtc_read_u8(twl_rtc, &rd_reg, REG_RTC_STATUS_REG);
 524         if (ret < 0)
 525                 return ret;
 526 
 527         if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
 528                 dev_warn(&pdev->dev, "Power up reset detected.\n");
 529 
 530         if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
 531                 dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");
 532 
 533         /* Clear RTC Power up reset and pending alarm interrupts */
 534         ret = twl_rtc_write_u8(twl_rtc, rd_reg, REG_RTC_STATUS_REG);
 535         if (ret < 0)
 536                 return ret;
 537 
 538         if (twl_rtc->class == TWL_6030) {
 539                 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
 540                         REG_INT_MSK_LINE_A);
 541                 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
 542                         REG_INT_MSK_STS_A);
 543         }
 544 
 545         dev_info(&pdev->dev, "Enabling TWL-RTC\n");
 546         ret = twl_rtc_write_u8(twl_rtc, BIT_RTC_CTRL_REG_STOP_RTC_M,
 547                                REG_RTC_CTRL_REG);
 548         if (ret < 0)
 549                 return ret;
 550 
 551         /* ensure interrupts are disabled, bootloaders can be strange */
 552         ret = twl_rtc_write_u8(twl_rtc, 0, REG_RTC_INTERRUPTS_REG);
 553         if (ret < 0)
 554                 dev_warn(&pdev->dev, "unable to disable interrupt\n");
 555 
 556         /* init cached IRQ enable bits */
 557         ret = twl_rtc_read_u8(twl_rtc, &twl_rtc->rtc_irq_bits,
 558                               REG_RTC_INTERRUPTS_REG);
 559         if (ret < 0)
 560                 return ret;
 561 
 562         platform_set_drvdata(pdev, twl_rtc);
 563         device_init_wakeup(&pdev->dev, 1);
 564 
 565         twl_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 566                                         &twl_rtc_ops, THIS_MODULE);
 567         if (IS_ERR(twl_rtc->rtc)) {
 568                 dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
 569                         PTR_ERR(twl_rtc->rtc));
 570                 return PTR_ERR(twl_rtc->rtc);
 571         }
 572 
 573         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 574                                         twl_rtc_interrupt,
 575                                         IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 576                                         dev_name(&twl_rtc->rtc->dev), twl_rtc);
 577         if (ret < 0) {
 578                 dev_err(&pdev->dev, "IRQ is not free.\n");
 579                 return ret;
 580         }
 581 
 582         return 0;
 583 }
 584 
 585 /*
 586  * Disable all TWL RTC module interrupts.
 587  * Sets status flag to free.
 588  */
 589 static int twl_rtc_remove(struct platform_device *pdev)
 590 {
 591         struct twl_rtc *twl_rtc = platform_get_drvdata(pdev);
 592 
 593         /* leave rtc running, but disable irqs */
 594         mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
 595         mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
 596         if (twl_rtc->class == TWL_6030) {
 597                 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
 598                         REG_INT_MSK_LINE_A);
 599                 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
 600                         REG_INT_MSK_STS_A);
 601         }
 602 
 603         return 0;
 604 }
 605 
 606 static void twl_rtc_shutdown(struct platform_device *pdev)
 607 {
 608         struct twl_rtc *twl_rtc = platform_get_drvdata(pdev);
 609 
 610         /* mask timer interrupts, but leave alarm interrupts on to enable
 611            power-on when alarm is triggered */
 612         mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
 613 }
 614 
 615 #ifdef CONFIG_PM_SLEEP
 616 static int twl_rtc_suspend(struct device *dev)
 617 {
 618         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 619 
 620         twl_rtc->irqstat = twl_rtc->rtc_irq_bits;
 621 
 622         mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
 623         return 0;
 624 }
 625 
 626 static int twl_rtc_resume(struct device *dev)
 627 {
 628         struct twl_rtc *twl_rtc = dev_get_drvdata(dev);
 629 
 630         set_rtc_irq_bit(twl_rtc, twl_rtc->irqstat);
 631         return 0;
 632 }
 633 #endif
 634 
 635 static SIMPLE_DEV_PM_OPS(twl_rtc_pm_ops, twl_rtc_suspend, twl_rtc_resume);
 636 
 637 static const struct of_device_id twl_rtc_of_match[] = {
 638         {.compatible = "ti,twl4030-rtc", },
 639         { },
 640 };
 641 MODULE_DEVICE_TABLE(of, twl_rtc_of_match);
 642 
 643 static struct platform_driver twl4030rtc_driver = {
 644         .probe          = twl_rtc_probe,
 645         .remove         = twl_rtc_remove,
 646         .shutdown       = twl_rtc_shutdown,
 647         .driver         = {
 648                 .name           = "twl_rtc",
 649                 .pm             = &twl_rtc_pm_ops,
 650                 .of_match_table = twl_rtc_of_match,
 651         },
 652 };
 653 
 654 module_platform_driver(twl4030rtc_driver);
 655 
 656 MODULE_AUTHOR("Texas Instruments, MontaVista Software");
 657 MODULE_LICENSE("GPL");