drivers/rtc/rtc-vr41xx.c

   1 /*
   2  *  Driver for NEC VR4100 series Real Time Clock unit.
   3  *
   4  *  Copyright (C) 2003-2006  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20 #include <linux/err.h>
  21 #include <linux/fs.h>
  22 #include <linux/init.h>
  23 #include <linux/ioport.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/module.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/rtc.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/types.h>
  30
  31 #include <asm/div64.h>
  32 #include <asm/io.h>
  33 #include <asm/uaccess.h>
  34
  35 MODULE_AUTHOR("Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>");
  36 MODULE_DESCRIPTION("NEC VR4100 series RTC driver");
  37 MODULE_LICENSE("GPL");
  38
  39 /* RTC 1 registers */
  40 #define ETIMELREG               0x00
  41 #define ETIMEMREG               0x02
  42 #define ETIMEHREG               0x04
  43 /* RFU */
  44 #define ECMPLREG                0x08
  45 #define ECMPMREG                0x0a
  46 #define ECMPHREG                0x0c
  47 /* RFU */
  48 #define RTCL1LREG               0x10
  49 #define RTCL1HREG               0x12
  50 #define RTCL1CNTLREG            0x14
  51 #define RTCL1CNTHREG            0x16
  52 #define RTCL2LREG               0x18
  53 #define RTCL2HREG               0x1a
  54 #define RTCL2CNTLREG            0x1c
  55 #define RTCL2CNTHREG            0x1e
  56
  57 /* RTC 2 registers */
  58 #define TCLKLREG                0x00
  59 #define TCLKHREG                0x02
  60 #define TCLKCNTLREG             0x04
  61 #define TCLKCNTHREG             0x06
  62 /* RFU */
  63 #define RTCINTREG               0x1e
  64  #define TCLOCK_INT             0x08
  65  #define RTCLONG2_INT           0x04
  66  #define RTCLONG1_INT           0x02
  67  #define ELAPSEDTIME_INT        0x01
  68
  69 #define RTC_FREQUENCY           32768
  70 #define MAX_PERIODIC_RATE       6553
  71
  72 static void __iomem *rtc1_base;
  73 static void __iomem *rtc2_base;
  74
  75 #define rtc1_read(offset)               readw(rtc1_base + (offset))
  76 #define rtc1_write(offset, value)       writew((value), rtc1_base + (offset))
  77
  78 #define rtc2_read(offset)               readw(rtc2_base + (offset))
  79 #define rtc2_write(offset, value)       writew((value), rtc2_base + (offset))
  80
  81 static unsigned long epoch = 1970;      /* Jan 1 1970 00:00:00 */
  82
  83 static DEFINE_SPINLOCK(rtc_lock);
  84 static char rtc_name[] = "RTC";
  85 static unsigned long periodic_frequency;
  86 static unsigned long periodic_count;
  87 static unsigned int alarm_enabled;
  88 static int aie_irq = -1;
  89 static int pie_irq = -1;
  90
  91 static inline unsigned long read_elapsed_second(void)
  92 {
  93
  94         unsigned long first_low, first_mid, first_high;
  95
  96         unsigned long second_low, second_mid, second_high;
  97
  98         do {
  99                 first_low = rtc1_read(ETIMELREG);
 100                 first_mid = rtc1_read(ETIMEMREG);
 101                 first_high = rtc1_read(ETIMEHREG);
 102                 second_low = rtc1_read(ETIMELREG);
 103                 second_mid = rtc1_read(ETIMEMREG);
 104                 second_high = rtc1_read(ETIMEHREG);
 105         } while (first_low != second_low || first_mid != second_mid ||
 106                  first_high != second_high);
 107
 108         return (first_high << 17) | (first_mid << 1) | (first_low >> 15);
 109 }
 110
 111 static inline void write_elapsed_second(unsigned long sec)
 112 {
 113         spin_lock_irq(&rtc_lock);
 114
 115         rtc1_write(ETIMELREG, (uint16_t)(sec << 15));
 116         rtc1_write(ETIMEMREG, (uint16_t)(sec >> 1));
 117         rtc1_write(ETIMEHREG, (uint16_t)(sec >> 17));
 118
 119         spin_unlock_irq(&rtc_lock);
 120 }
 121
 122 static void vr41xx_rtc_release(struct device *dev)
 123 {
 124
 125         spin_lock_irq(&rtc_lock);
 126
 127         rtc1_write(ECMPLREG, 0);
 128         rtc1_write(ECMPMREG, 0);
 129         rtc1_write(ECMPHREG, 0);
 130         rtc1_write(RTCL1LREG, 0);
 131         rtc1_write(RTCL1HREG, 0);
 132
 133         spin_unlock_irq(&rtc_lock);
 134
 135         disable_irq(aie_irq);
 136         disable_irq(pie_irq);
 137 }
 138
 139 static int vr41xx_rtc_read_time(struct device *dev, struct rtc_time *time)
 140 {
 141         unsigned long epoch_sec, elapsed_sec;
 142
 143         epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
 144         elapsed_sec = read_elapsed_second();
 145
 146         rtc_time_to_tm(epoch_sec + elapsed_sec, time);
 147
 148         return 0;
 149 }
 150
 151 static int vr41xx_rtc_set_time(struct device *dev, struct rtc_time *time)
 152 {
 153         unsigned long epoch_sec, current_sec;
 154
 155         epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
 156         current_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
 157                              time->tm_hour, time->tm_min, time->tm_sec);
 158
 159         write_elapsed_second(current_sec - epoch_sec);
 160
 161         return 0;
 162 }
 163
 164 static int vr41xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 165 {
 166         unsigned long low, mid, high;
 167         struct rtc_time *time = &wkalrm->time;
 168
 169         spin_lock_irq(&rtc_lock);
 170
 171         low = rtc1_read(ECMPLREG);
 172         mid = rtc1_read(ECMPMREG);
 173         high = rtc1_read(ECMPHREG);
 174         wkalrm->enabled = alarm_enabled;
 175
 176         spin_unlock_irq(&rtc_lock);
 177
 178         rtc_time_to_tm((high << 17) | (mid << 1) | (low >> 15), time);
 179
 180         return 0;
 181 }
 182
 183 static int vr41xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 184 {
 185         unsigned long alarm_sec;
 186         struct rtc_time *time = &wkalrm->time;
 187
 188         alarm_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
 189                            time->tm_hour, time->tm_min, time->tm_sec);
 190
 191         spin_lock_irq(&rtc_lock);
 192
 193         if (alarm_enabled)
 194                 disable_irq(aie_irq);
 195
 196         rtc1_write(ECMPLREG, (uint16_t)(alarm_sec << 15));
 197         rtc1_write(ECMPMREG, (uint16_t)(alarm_sec >> 1));
 198         rtc1_write(ECMPHREG, (uint16_t)(alarm_sec >> 17));
 199
 200         if (wkalrm->enabled)
 201                 enable_irq(aie_irq);
 202
 203         alarm_enabled = wkalrm->enabled;
 204
 205         spin_unlock_irq(&rtc_lock);
 206
 207         return 0;
 208 }
 209
 210 static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 211 {
 212         unsigned long count;
 213
 214         switch (cmd) {
 215         case RTC_AIE_ON:
 216                 spin_lock_irq(&rtc_lock);
 217
 218                 if (!alarm_enabled) {
 219                         enable_irq(aie_irq);
 220                         alarm_enabled = 1;
 221                 }
 222
 223                 spin_unlock_irq(&rtc_lock);
 224                 break;
 225         case RTC_AIE_OFF:
 226                 spin_lock_irq(&rtc_lock);
 227
 228                 if (alarm_enabled) {
 229                         disable_irq(aie_irq);
 230                         alarm_enabled = 0;
 231                 }
 232
 233                 spin_unlock_irq(&rtc_lock);
 234                 break;
 235         case RTC_PIE_ON:
 236                 enable_irq(pie_irq);
 237                 break;
 238         case RTC_PIE_OFF:
 239                 disable_irq(pie_irq);
 240                 break;
 241         case RTC_IRQP_READ:
 242                 return put_user(periodic_frequency, (unsigned long __user *)arg);
 243                 break;
 244         case RTC_IRQP_SET:
 245                 if (arg > MAX_PERIODIC_RATE)
 246                         return -EINVAL;
 247
 248                 periodic_frequency = arg;
 249
 250                 count = RTC_FREQUENCY;
 251                 do_div(count, arg);
 252
 253                 periodic_count = count;
 254
 255                 spin_lock_irq(&rtc_lock);
 256
 257                 rtc1_write(RTCL1LREG, count);
 258                 rtc1_write(RTCL1HREG, count >> 16);
 259
 260                 spin_unlock_irq(&rtc_lock);
 261                 break;
 262         case RTC_EPOCH_READ:
 263                 return put_user(epoch, (unsigned long __user *)arg);
 264         case RTC_EPOCH_SET:
 265                 /* Doesn't support before 1900 */
 266                 if (arg < 1900)
 267                         return -EINVAL;
 268                 epoch = arg;
 269                 break;
 270         default:
 271                 return -ENOIOCTLCMD;
 272         }
 273
 274         return 0;
 275 }
 276
 277 static irqreturn_t elapsedtime_interrupt(int irq, void *dev_id)
 278 {
 279         struct platform_device *pdev = (struct platform_device *)dev_id;
 280         struct rtc_device *rtc = platform_get_drvdata(pdev);
 281
 282         rtc2_write(RTCINTREG, ELAPSEDTIME_INT);
 283
 284         rtc_update_irq(rtc, 1, RTC_AF);
 285
 286         return IRQ_HANDLED;
 287 }
 288
 289 static irqreturn_t rtclong1_interrupt(int irq, void *dev_id)
 290 {
 291         struct platform_device *pdev = (struct platform_device *)dev_id;
 292         struct rtc_device *rtc = platform_get_drvdata(pdev);
 293         unsigned long count = periodic_count;
 294
 295         rtc2_write(RTCINTREG, RTCLONG1_INT);
 296
 297         rtc1_write(RTCL1LREG, count);
 298         rtc1_write(RTCL1HREG, count >> 16);
 299
 300         rtc_update_irq(rtc, 1, RTC_PF);
 301
 302         return IRQ_HANDLED;
 303 }
 304
 305 static const struct rtc_class_ops vr41xx_rtc_ops = {
 306         .release        = vr41xx_rtc_release,
 307         .ioctl          = vr41xx_rtc_ioctl,
 308         .read_time      = vr41xx_rtc_read_time,
 309         .set_time       = vr41xx_rtc_set_time,
 310         .read_alarm     = vr41xx_rtc_read_alarm,
 311         .set_alarm      = vr41xx_rtc_set_alarm,
 312 };
 313
 314 static int __devinit rtc_probe(struct platform_device *pdev)
 315 {
 316         struct resource *res;
 317         struct rtc_device *rtc;
 318         int retval;
 319
 320         if (pdev->num_resources != 4)
 321                 return -EBUSY;
 322
 323         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 324         if (!res)
 325                 return -EBUSY;
 326
 327         rtc1_base = ioremap(res->start, res->end - res->start + 1);
 328         if (!rtc1_base)
 329                 return -EBUSY;
 330
 331         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 332         if (!res) {
 333                 retval = -EBUSY;
 334                 goto err_rtc1_iounmap;
 335         }
 336
 337         rtc2_base = ioremap(res->start, res->end - res->start + 1);
 338         if (!rtc2_base) {
 339                 retval = -EBUSY;
 340                 goto err_rtc1_iounmap;
 341         }
 342
 343         rtc = rtc_device_register(rtc_name, &pdev->dev, &vr41xx_rtc_ops, THIS_MODULE);
 344         if (IS_ERR(rtc)) {
 345                 retval = PTR_ERR(rtc);
 346                 goto err_iounmap_all;
 347         }
 348
 349         spin_lock_irq(&rtc_lock);
 350
 351         rtc1_write(ECMPLREG, 0);
 352         rtc1_write(ECMPMREG, 0);
 353         rtc1_write(ECMPHREG, 0);
 354         rtc1_write(RTCL1LREG, 0);
 355         rtc1_write(RTCL1HREG, 0);
 356
 357         spin_unlock_irq(&rtc_lock);
 358
 359         aie_irq = platform_get_irq(pdev, 0);
 360         if (aie_irq < 0 || aie_irq >= NR_IRQS) {
 361                 retval = -EBUSY;
 362                 goto err_device_unregister;
 363         }
 364
 365         retval = request_irq(aie_irq, elapsedtime_interrupt, IRQF_DISABLED,
 366                              "elapsed_time", pdev);
 367         if (retval < 0)
 368                 goto err_device_unregister;
 369
 370         pie_irq = platform_get_irq(pdev, 1);
 371         if (pie_irq < 0 || pie_irq >= NR_IRQS)
 372                 goto err_free_irq;
 373
 374         retval = request_irq(pie_irq, rtclong1_interrupt, IRQF_DISABLED,
 375                              "rtclong1", pdev);
 376         if (retval < 0)
 377                 goto err_free_irq;
 378
 379         platform_set_drvdata(pdev, rtc);
 380
 381         disable_irq(aie_irq);
 382         disable_irq(pie_irq);
 383
 384         printk(KERN_INFO "rtc: Real Time Clock of NEC VR4100 series\n");
 385
 386         return 0;
 387
 388 err_free_irq:
 389         free_irq(aie_irq, pdev);
 390
 391 err_device_unregister:
 392         rtc_device_unregister(rtc);
 393
 394 err_iounmap_all:
 395         iounmap(rtc2_base);
 396         rtc2_base = NULL;
 397
 398 err_rtc1_iounmap:
 399         iounmap(rtc1_base);
 400         rtc1_base = NULL;
 401
 402         return retval;
 403 }
 404
 405 static int __devexit rtc_remove(struct platform_device *pdev)
 406 {
 407         struct rtc_device *rtc;
 408
 409         rtc = platform_get_drvdata(pdev);
 410         if (rtc)
 411                 rtc_device_unregister(rtc);
 412
 413         platform_set_drvdata(pdev, NULL);
 414
 415         free_irq(aie_irq, pdev);
 416         free_irq(pie_irq, pdev);
 417         if (rtc1_base)
 418                 iounmap(rtc1_base);
 419         if (rtc2_base)
 420                 iounmap(rtc2_base);
 421
 422         return 0;
 423 }
 424
 425 /* work with hotplug and coldplug */
 426 MODULE_ALIAS("platform:RTC");
 427
 428 static struct platform_driver rtc_platform_driver = {
 429         .probe          = rtc_probe,
 430         .remove         = __devexit_p(rtc_remove),
 431         .driver         = {
 432                 .name   = rtc_name,
 433                 .owner  = THIS_MODULE,
 434         },
 435 };
 436
 437 static int __init vr41xx_rtc_init(void)
 438 {
 439         return platform_driver_register(&rtc_platform_driver);
 440 }
 441
 442 static void __exit vr41xx_rtc_exit(void)
 443 {
 444         platform_driver_unregister(&rtc_platform_driver);
 445 }
 446
 447 module_init(vr41xx_rtc_init);
 448 module_exit(vr41xx_rtc_exit);