drivers/rtc/rtc-davinci.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * DaVinci Power Management and Real Time Clock Driver for TI platforms
   4  *
   5  * Copyright (C) 2009 Texas Instruments, Inc
   6  *
   7  * Author: Miguel Aguilar <miguel.aguilar@ridgerun.com>
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/ioport.h>
  13 #include <linux/delay.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/rtc.h>
  16 #include <linux/bcd.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/io.h>
  19 #include <linux/slab.h>
  20
  21 /*
  22  * The DaVinci RTC is a simple RTC with the following
  23  * Sec: 0 - 59 : BCD count
  24  * Min: 0 - 59 : BCD count
  25  * Hour: 0 - 23 : BCD count
  26  * Day: 0 - 0x7FFF(32767) : Binary count ( Over 89 years )
  27  */
  28
  29 /* PRTC interface registers */
  30 #define DAVINCI_PRTCIF_PID              0x00
  31 #define PRTCIF_CTLR                     0x04
  32 #define PRTCIF_LDATA                    0x08
  33 #define PRTCIF_UDATA                    0x0C
  34 #define PRTCIF_INTEN                    0x10
  35 #define PRTCIF_INTFLG                   0x14
  36
  37 /* PRTCIF_CTLR bit fields */
  38 #define PRTCIF_CTLR_BUSY                BIT(31)
  39 #define PRTCIF_CTLR_SIZE                BIT(25)
  40 #define PRTCIF_CTLR_DIR                 BIT(24)
  41 #define PRTCIF_CTLR_BENU_MSB            BIT(23)
  42 #define PRTCIF_CTLR_BENU_3RD_BYTE       BIT(22)
  43 #define PRTCIF_CTLR_BENU_2ND_BYTE       BIT(21)
  44 #define PRTCIF_CTLR_BENU_LSB            BIT(20)
  45 #define PRTCIF_CTLR_BENU_MASK           (0x00F00000)
  46 #define PRTCIF_CTLR_BENL_MSB            BIT(19)
  47 #define PRTCIF_CTLR_BENL_3RD_BYTE       BIT(18)
  48 #define PRTCIF_CTLR_BENL_2ND_BYTE       BIT(17)
  49 #define PRTCIF_CTLR_BENL_LSB            BIT(16)
  50 #define PRTCIF_CTLR_BENL_MASK           (0x000F0000)
  51
  52 /* PRTCIF_INTEN bit fields */
  53 #define PRTCIF_INTEN_RTCSS              BIT(1)
  54 #define PRTCIF_INTEN_RTCIF              BIT(0)
  55 #define PRTCIF_INTEN_MASK               (PRTCIF_INTEN_RTCSS \
  56                                         | PRTCIF_INTEN_RTCIF)
  57
  58 /* PRTCIF_INTFLG bit fields */
  59 #define PRTCIF_INTFLG_RTCSS             BIT(1)
  60 #define PRTCIF_INTFLG_RTCIF             BIT(0)
  61 #define PRTCIF_INTFLG_MASK              (PRTCIF_INTFLG_RTCSS \
  62                                         | PRTCIF_INTFLG_RTCIF)
  63
  64 /* PRTC subsystem registers */
  65 #define PRTCSS_RTC_INTC_EXTENA1         (0x0C)
  66 #define PRTCSS_RTC_CTRL                 (0x10)
  67 #define PRTCSS_RTC_WDT                  (0x11)
  68 #define PRTCSS_RTC_TMR0                 (0x12)
  69 #define PRTCSS_RTC_TMR1                 (0x13)
  70 #define PRTCSS_RTC_CCTRL                (0x14)
  71 #define PRTCSS_RTC_SEC                  (0x15)
  72 #define PRTCSS_RTC_MIN                  (0x16)
  73 #define PRTCSS_RTC_HOUR                 (0x17)
  74 #define PRTCSS_RTC_DAY0                 (0x18)
  75 #define PRTCSS_RTC_DAY1                 (0x19)
  76 #define PRTCSS_RTC_AMIN                 (0x1A)
  77 #define PRTCSS_RTC_AHOUR                (0x1B)
  78 #define PRTCSS_RTC_ADAY0                (0x1C)
  79 #define PRTCSS_RTC_ADAY1                (0x1D)
  80 #define PRTCSS_RTC_CLKC_CNT             (0x20)
  81
  82 /* PRTCSS_RTC_INTC_EXTENA1 */
  83 #define PRTCSS_RTC_INTC_EXTENA1_MASK    (0x07)
  84
  85 /* PRTCSS_RTC_CTRL bit fields */
  86 #define PRTCSS_RTC_CTRL_WDTBUS          BIT(7)
  87 #define PRTCSS_RTC_CTRL_WEN             BIT(6)
  88 #define PRTCSS_RTC_CTRL_WDRT            BIT(5)
  89 #define PRTCSS_RTC_CTRL_WDTFLG          BIT(4)
  90 #define PRTCSS_RTC_CTRL_TE              BIT(3)
  91 #define PRTCSS_RTC_CTRL_TIEN            BIT(2)
  92 #define PRTCSS_RTC_CTRL_TMRFLG          BIT(1)
  93 #define PRTCSS_RTC_CTRL_TMMD            BIT(0)
  94
  95 /* PRTCSS_RTC_CCTRL bit fields */
  96 #define PRTCSS_RTC_CCTRL_CALBUSY        BIT(7)
  97 #define PRTCSS_RTC_CCTRL_DAEN           BIT(5)
  98 #define PRTCSS_RTC_CCTRL_HAEN           BIT(4)
  99 #define PRTCSS_RTC_CCTRL_MAEN           BIT(3)
 100 #define PRTCSS_RTC_CCTRL_ALMFLG         BIT(2)
 101 #define PRTCSS_RTC_CCTRL_AIEN           BIT(1)
 102 #define PRTCSS_RTC_CCTRL_CAEN           BIT(0)
 103
 104 static DEFINE_SPINLOCK(davinci_rtc_lock);
 105
 106 struct davinci_rtc {
 107         struct rtc_device               *rtc;
 108         void __iomem                    *base;
 109         int                             irq;
 110 };
 111
 112 static inline void rtcif_write(struct davinci_rtc *davinci_rtc,
 113                                u32 val, u32 addr)
 114 {
 115         writel(val, davinci_rtc->base + addr);
 116 }
 117
 118 static inline u32 rtcif_read(struct davinci_rtc *davinci_rtc, u32 addr)
 119 {
 120         return readl(davinci_rtc->base + addr);
 121 }
 122
 123 static inline void rtcif_wait(struct davinci_rtc *davinci_rtc)
 124 {
 125         while (rtcif_read(davinci_rtc, PRTCIF_CTLR) & PRTCIF_CTLR_BUSY)
 126                 cpu_relax();
 127 }
 128
 129 static inline void rtcss_write(struct davinci_rtc *davinci_rtc,
 130                                unsigned long val, u8 addr)
 131 {
 132         rtcif_wait(davinci_rtc);
 133
 134         rtcif_write(davinci_rtc, PRTCIF_CTLR_BENL_LSB | addr, PRTCIF_CTLR);
 135         rtcif_write(davinci_rtc, val, PRTCIF_LDATA);
 136
 137         rtcif_wait(davinci_rtc);
 138 }
 139
 140 static inline u8 rtcss_read(struct davinci_rtc *davinci_rtc, u8 addr)
 141 {
 142         rtcif_wait(davinci_rtc);
 143
 144         rtcif_write(davinci_rtc, PRTCIF_CTLR_DIR | PRTCIF_CTLR_BENL_LSB | addr,
 145                     PRTCIF_CTLR);
 146
 147         rtcif_wait(davinci_rtc);
 148
 149         return rtcif_read(davinci_rtc, PRTCIF_LDATA);
 150 }
 151
 152 static inline void davinci_rtcss_calendar_wait(struct davinci_rtc *davinci_rtc)
 153 {
 154         while (rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL) &
 155                PRTCSS_RTC_CCTRL_CALBUSY)
 156                 cpu_relax();
 157 }
 158
 159 static irqreturn_t davinci_rtc_interrupt(int irq, void *class_dev)
 160 {
 161         struct davinci_rtc *davinci_rtc = class_dev;
 162         unsigned long events = 0;
 163         u32 irq_flg;
 164         u8 alm_irq, tmr_irq;
 165         u8 rtc_ctrl, rtc_cctrl;
 166         int ret = IRQ_NONE;
 167
 168         irq_flg = rtcif_read(davinci_rtc, PRTCIF_INTFLG) &
 169                   PRTCIF_INTFLG_RTCSS;
 170
 171         alm_irq = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL) &
 172                   PRTCSS_RTC_CCTRL_ALMFLG;
 173
 174         tmr_irq = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL) &
 175                   PRTCSS_RTC_CTRL_TMRFLG;
 176
 177         if (irq_flg) {
 178                 if (alm_irq) {
 179                         events |= RTC_IRQF | RTC_AF;
 180                         rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL);
 181                         rtc_cctrl |=  PRTCSS_RTC_CCTRL_ALMFLG;
 182                         rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL);
 183                 } else if (tmr_irq) {
 184                         events |= RTC_IRQF | RTC_PF;
 185                         rtc_ctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL);
 186                         rtc_ctrl |=  PRTCSS_RTC_CTRL_TMRFLG;
 187                         rtcss_write(davinci_rtc, rtc_ctrl, PRTCSS_RTC_CTRL);
 188                 }
 189
 190                 rtcif_write(davinci_rtc, PRTCIF_INTFLG_RTCSS,
 191                                     PRTCIF_INTFLG);
 192                 rtc_update_irq(davinci_rtc->rtc, 1, events);
 193
 194                 ret = IRQ_HANDLED;
 195         }
 196
 197         return ret;
 198 }
 199
 200 static int
 201 davinci_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 202 {
 203         struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
 204         u8 rtc_ctrl;
 205         unsigned long flags;
 206         int ret = 0;
 207
 208         spin_lock_irqsave(&davinci_rtc_lock, flags);
 209
 210         rtc_ctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL);
 211
 212         switch (cmd) {
 213         case RTC_WIE_ON:
 214                 rtc_ctrl |= PRTCSS_RTC_CTRL_WEN | PRTCSS_RTC_CTRL_WDTFLG;
 215                 break;
 216         case RTC_WIE_OFF:
 217                 rtc_ctrl &= ~PRTCSS_RTC_CTRL_WEN;
 218                 break;
 219         default:
 220                 ret = -ENOIOCTLCMD;
 221         }
 222
 223         rtcss_write(davinci_rtc, rtc_ctrl, PRTCSS_RTC_CTRL);
 224
 225         spin_unlock_irqrestore(&davinci_rtc_lock, flags);
 226
 227         return ret;
 228 }
 229
 230 static void convertfromdays(u16 days, struct rtc_time *tm)
 231 {
 232         int tmp_days, year, mon;
 233
 234         for (year = 2000;; year++) {
 235                 tmp_days = rtc_year_days(1, 12, year);
 236                 if (days >= tmp_days)
 237                         days -= tmp_days;
 238                 else {
 239                         for (mon = 0;; mon++) {
 240                                 tmp_days = rtc_month_days(mon, year);
 241                                 if (days >= tmp_days) {
 242                                         days -= tmp_days;
 243                                 } else {
 244                                         tm->tm_year = year - 1900;
 245                                         tm->tm_mon = mon;
 246                                         tm->tm_mday = days + 1;
 247                                         break;
 248                                 }
 249                         }
 250                         break;
 251                 }
 252         }
 253 }
 254
 255 static void convert2days(u16 *days, struct rtc_time *tm)
 256 {
 257         int i;
 258         *days = 0;
 259
 260         for (i = 2000; i < 1900 + tm->tm_year; i++)
 261                 *days += rtc_year_days(1, 12, i);
 262
 263         *days += rtc_year_days(tm->tm_mday, tm->tm_mon, 1900 + tm->tm_year);
 264 }
 265
 266 static int davinci_rtc_read_time(struct device *dev, struct rtc_time *tm)
 267 {
 268         struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
 269         u16 days = 0;
 270         u8 day0, day1;
 271         unsigned long flags;
 272
 273         spin_lock_irqsave(&davinci_rtc_lock, flags);
 274
 275         davinci_rtcss_calendar_wait(davinci_rtc);
 276         tm->tm_sec = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_SEC));
 277
 278         davinci_rtcss_calendar_wait(davinci_rtc);
 279         tm->tm_min = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_MIN));
 280
 281         davinci_rtcss_calendar_wait(davinci_rtc);
 282         tm->tm_hour = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_HOUR));
 283
 284         davinci_rtcss_calendar_wait(davinci_rtc);
 285         day0 = rtcss_read(davinci_rtc, PRTCSS_RTC_DAY0);
 286
 287         davinci_rtcss_calendar_wait(davinci_rtc);
 288         day1 = rtcss_read(davinci_rtc, PRTCSS_RTC_DAY1);
 289
 290         spin_unlock_irqrestore(&davinci_rtc_lock, flags);
 291
 292         days |= day1;
 293         days <<= 8;
 294         days |= day0;
 295
 296         convertfromdays(days, tm);
 297
 298         return 0;
 299 }
 300
 301 static int davinci_rtc_set_time(struct device *dev, struct rtc_time *tm)
 302 {
 303         struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
 304         u16 days;
 305         u8 rtc_cctrl;
 306         unsigned long flags;
 307
 308         convert2days(&days, tm);
 309
 310         spin_lock_irqsave(&davinci_rtc_lock, flags);
 311
 312         davinci_rtcss_calendar_wait(davinci_rtc);
 313         rtcss_write(davinci_rtc, bin2bcd(tm->tm_sec), PRTCSS_RTC_SEC);
 314
 315         davinci_rtcss_calendar_wait(davinci_rtc);
 316         rtcss_write(davinci_rtc, bin2bcd(tm->tm_min), PRTCSS_RTC_MIN);
 317
 318         davinci_rtcss_calendar_wait(davinci_rtc);
 319         rtcss_write(davinci_rtc, bin2bcd(tm->tm_hour), PRTCSS_RTC_HOUR);
 320
 321         davinci_rtcss_calendar_wait(davinci_rtc);
 322         rtcss_write(davinci_rtc, days & 0xFF, PRTCSS_RTC_DAY0);
 323
 324         davinci_rtcss_calendar_wait(davinci_rtc);
 325         rtcss_write(davinci_rtc, (days & 0xFF00) >> 8, PRTCSS_RTC_DAY1);
 326
 327         rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL);
 328         rtc_cctrl |= PRTCSS_RTC_CCTRL_CAEN;
 329         rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL);
 330
 331         spin_unlock_irqrestore(&davinci_rtc_lock, flags);
 332
 333         return 0;
 334 }
 335
 336 static int davinci_rtc_alarm_irq_enable(struct device *dev,
 337                                         unsigned int enabled)
 338 {
 339         struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
 340         unsigned long flags;
 341         u8 rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL);
 342
 343         spin_lock_irqsave(&davinci_rtc_lock, flags);
 344
 345         if (enabled)
 346                 rtc_cctrl |= PRTCSS_RTC_CCTRL_DAEN |
 347                              PRTCSS_RTC_CCTRL_HAEN |
 348                              PRTCSS_RTC_CCTRL_MAEN |
 349                              PRTCSS_RTC_CCTRL_ALMFLG |
 350                              PRTCSS_RTC_CCTRL_AIEN;
 351         else
 352                 rtc_cctrl &= ~PRTCSS_RTC_CCTRL_AIEN;
 353
 354         davinci_rtcss_calendar_wait(davinci_rtc);
 355         rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL);
 356
 357         spin_unlock_irqrestore(&davinci_rtc_lock, flags);
 358
 359         return 0;
 360 }
 361
 362 static int davinci_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 363 {
 364         struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
 365         u16 days = 0;
 366         u8 day0, day1;
 367         unsigned long flags;
 368
 369         alm->time.tm_sec = 0;
 370
 371         spin_lock_irqsave(&davinci_rtc_lock, flags);
 372
 373         davinci_rtcss_calendar_wait(davinci_rtc);
 374         alm->time.tm_min = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_AMIN));
 375
 376         davinci_rtcss_calendar_wait(davinci_rtc);
 377         alm->time.tm_hour = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_AHOUR));
 378
 379         davinci_rtcss_calendar_wait(davinci_rtc);
 380         day0 = rtcss_read(davinci_rtc, PRTCSS_RTC_ADAY0);
 381
 382         davinci_rtcss_calendar_wait(davinci_rtc);
 383         day1 = rtcss_read(davinci_rtc, PRTCSS_RTC_ADAY1);
 384
 385         spin_unlock_irqrestore(&davinci_rtc_lock, flags);
 386         days |= day1;
 387         days <<= 8;
 388         days |= day0;
 389
 390         convertfromdays(days, &alm->time);
 391
 392         alm->pending = !!(rtcss_read(davinci_rtc,
 393                           PRTCSS_RTC_CCTRL) &
 394                         PRTCSS_RTC_CCTRL_AIEN);
 395         alm->enabled = alm->pending && device_may_wakeup(dev);
 396
 397         return 0;
 398 }
 399
 400 static int davinci_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 401 {
 402         struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
 403         unsigned long flags;
 404         u16 days;
 405
 406         convert2days(&days, &alm->time);
 407
 408         spin_lock_irqsave(&davinci_rtc_lock, flags);
 409
 410         davinci_rtcss_calendar_wait(davinci_rtc);
 411         rtcss_write(davinci_rtc, bin2bcd(alm->time.tm_min), PRTCSS_RTC_AMIN);
 412
 413         davinci_rtcss_calendar_wait(davinci_rtc);
 414         rtcss_write(davinci_rtc, bin2bcd(alm->time.tm_hour), PRTCSS_RTC_AHOUR);
 415
 416         davinci_rtcss_calendar_wait(davinci_rtc);
 417         rtcss_write(davinci_rtc, days & 0xFF, PRTCSS_RTC_ADAY0);
 418
 419         davinci_rtcss_calendar_wait(davinci_rtc);
 420         rtcss_write(davinci_rtc, (days & 0xFF00) >> 8, PRTCSS_RTC_ADAY1);
 421
 422         spin_unlock_irqrestore(&davinci_rtc_lock, flags);
 423
 424         return 0;
 425 }
 426
 427 static const struct rtc_class_ops davinci_rtc_ops = {
 428         .ioctl                  = davinci_rtc_ioctl,
 429         .read_time              = davinci_rtc_read_time,
 430         .set_time               = davinci_rtc_set_time,
 431         .alarm_irq_enable       = davinci_rtc_alarm_irq_enable,
 432         .read_alarm             = davinci_rtc_read_alarm,
 433         .set_alarm              = davinci_rtc_set_alarm,
 434 };
 435
 436 static int __init davinci_rtc_probe(struct platform_device *pdev)
 437 {
 438         struct device *dev = &pdev->dev;
 439         struct davinci_rtc *davinci_rtc;
 440         int ret = 0;
 441
 442         davinci_rtc = devm_kzalloc(&pdev->dev, sizeof(struct davinci_rtc), GFP_KERNEL);
 443         if (!davinci_rtc)
 444                 return -ENOMEM;
 445
 446         davinci_rtc->irq = platform_get_irq(pdev, 0);
 447         if (davinci_rtc->irq < 0)
 448                 return davinci_rtc->irq;
 449
 450         davinci_rtc->base = devm_platform_ioremap_resource(pdev, 0);
 451         if (IS_ERR(davinci_rtc->base))
 452                 return PTR_ERR(davinci_rtc->base);
 453
 454         platform_set_drvdata(pdev, davinci_rtc);
 455
 456         davinci_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
 457         if (IS_ERR(davinci_rtc->rtc))
 458                 return PTR_ERR(davinci_rtc->rtc);
 459
 460         davinci_rtc->rtc->ops = &davinci_rtc_ops;
 461         davinci_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 462         davinci_rtc->rtc->range_max = RTC_TIMESTAMP_BEGIN_2000 + (1 << 16) * 86400ULL - 1;
 463
 464         rtcif_write(davinci_rtc, PRTCIF_INTFLG_RTCSS, PRTCIF_INTFLG);
 465         rtcif_write(davinci_rtc, 0, PRTCIF_INTEN);
 466         rtcss_write(davinci_rtc, 0, PRTCSS_RTC_INTC_EXTENA1);
 467
 468         rtcss_write(davinci_rtc, 0, PRTCSS_RTC_CTRL);
 469         rtcss_write(davinci_rtc, 0, PRTCSS_RTC_CCTRL);
 470
 471         ret = devm_request_irq(dev, davinci_rtc->irq, davinci_rtc_interrupt,
 472                           0, "davinci_rtc", davinci_rtc);
 473         if (ret < 0) {
 474                 dev_err(dev, "unable to register davinci RTC interrupt\n");
 475                 return ret;
 476         }
 477
 478         /* Enable interrupts */
 479         rtcif_write(davinci_rtc, PRTCIF_INTEN_RTCSS, PRTCIF_INTEN);
 480         rtcss_write(davinci_rtc, PRTCSS_RTC_INTC_EXTENA1_MASK,
 481                             PRTCSS_RTC_INTC_EXTENA1);
 482
 483         rtcss_write(davinci_rtc, PRTCSS_RTC_CCTRL_CAEN, PRTCSS_RTC_CCTRL);
 484
 485         device_init_wakeup(&pdev->dev, 0);
 486
 487         return rtc_register_device(davinci_rtc->rtc);
 488 }
 489
 490 static int __exit davinci_rtc_remove(struct platform_device *pdev)
 491 {
 492         struct davinci_rtc *davinci_rtc = platform_get_drvdata(pdev);
 493
 494         device_init_wakeup(&pdev->dev, 0);
 495
 496         rtcif_write(davinci_rtc, 0, PRTCIF_INTEN);
 497
 498         return 0;
 499 }
 500
 501 static struct platform_driver davinci_rtc_driver = {
 502         .remove         = __exit_p(davinci_rtc_remove),
 503         .driver         = {
 504                 .name = "rtc_davinci",
 505         },
 506 };
 507
 508 module_platform_driver_probe(davinci_rtc_driver, davinci_rtc_probe);
 509
 510 MODULE_AUTHOR("Miguel Aguilar <miguel.aguilar@ridgerun.com>");
 511 MODULE_DESCRIPTION("Texas Instruments DaVinci PRTC Driver");
 512 MODULE_LICENSE("GPL");