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/fs.h>
  21 #include <linux/init.h>
  22 #include <linux/ioport.h>
  23 #include <linux/irq.h>
  24 #include <linux/module.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/rtc.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/types.h>
  29
  30 #include <asm/div64.h>
  31 #include <asm/io.h>
  32 #include <asm/uaccess.h>
  33 #include <asm/vr41xx/irq.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 #define RTC1_TYPE1_START        0x0b0000c0UL
  40 #define RTC1_TYPE1_END          0x0b0000dfUL
  41 #define RTC2_TYPE1_START        0x0b0001c0UL
  42 #define RTC2_TYPE1_END          0x0b0001dfUL
  43
  44 #define RTC1_TYPE2_START        0x0f000100UL
  45 #define RTC1_TYPE2_END          0x0f00011fUL
  46 #define RTC2_TYPE2_START        0x0f000120UL
  47 #define RTC2_TYPE2_END          0x0f00013fUL
  48
  49 #define RTC1_SIZE               0x20
  50 #define RTC2_SIZE               0x20
  51
  52 /* RTC 1 registers */
  53 #define ETIMELREG               0x00
  54 #define ETIMEMREG               0x02
  55 #define ETIMEHREG               0x04
  56 /* RFU */
  57 #define ECMPLREG                0x08
  58 #define ECMPMREG                0x0a
  59 #define ECMPHREG                0x0c
  60 /* RFU */
  61 #define RTCL1LREG               0x10
  62 #define RTCL1HREG               0x12
  63 #define RTCL1CNTLREG            0x14
  64 #define RTCL1CNTHREG            0x16
  65 #define RTCL2LREG               0x18
  66 #define RTCL2HREG               0x1a
  67 #define RTCL2CNTLREG            0x1c
  68 #define RTCL2CNTHREG            0x1e
  69
  70 /* RTC 2 registers */
  71 #define TCLKLREG                0x00
  72 #define TCLKHREG                0x02
  73 #define TCLKCNTLREG             0x04
  74 #define TCLKCNTHREG             0x06
  75 /* RFU */
  76 #define RTCINTREG               0x1e
  77  #define TCLOCK_INT             0x08
  78  #define RTCLONG2_INT           0x04
  79  #define RTCLONG1_INT           0x02
  80  #define ELAPSEDTIME_INT        0x01
  81
  82 #define RTC_FREQUENCY           32768
  83 #define MAX_PERIODIC_RATE       6553
  84
  85 static void __iomem *rtc1_base;
  86 static void __iomem *rtc2_base;
  87
  88 #define rtc1_read(offset)               readw(rtc1_base + (offset))
  89 #define rtc1_write(offset, value)       writew((value), rtc1_base + (offset))
  90
  91 #define rtc2_read(offset)               readw(rtc2_base + (offset))
  92 #define rtc2_write(offset, value)       writew((value), rtc2_base + (offset))
  93
  94 static unsigned long epoch = 1970;      /* Jan 1 1970 00:00:00 */
  95
  96 static DEFINE_SPINLOCK(rtc_lock);
  97 static char rtc_name[] = "RTC";
  98 static unsigned long periodic_frequency;
  99 static unsigned long periodic_count;
 100
 101 struct resource rtc_resource[2] = {
 102         {       .name   = rtc_name,
 103                 .flags  = IORESOURCE_MEM,       },
 104         {       .name   = rtc_name,
 105                 .flags  = IORESOURCE_MEM,       },
 106 };
 107
 108 static inline unsigned long read_elapsed_second(void)
 109 {
 110
 111         unsigned long first_low, first_mid, first_high;
 112
 113         unsigned long second_low, second_mid, second_high;
 114
 115         do {
 116                 first_low = rtc1_read(ETIMELREG);
 117                 first_mid = rtc1_read(ETIMEMREG);
 118                 first_high = rtc1_read(ETIMEHREG);
 119                 second_low = rtc1_read(ETIMELREG);
 120                 second_mid = rtc1_read(ETIMEMREG);
 121                 second_high = rtc1_read(ETIMEHREG);
 122         } while (first_low != second_low || first_mid != second_mid ||
 123                  first_high != second_high);
 124
 125         return (first_high << 17) | (first_mid << 1) | (first_low >> 15);
 126 }
 127
 128 static inline void write_elapsed_second(unsigned long sec)
 129 {
 130         spin_lock_irq(&rtc_lock);
 131
 132         rtc1_write(ETIMELREG, (uint16_t)(sec << 15));
 133         rtc1_write(ETIMEMREG, (uint16_t)(sec >> 1));
 134         rtc1_write(ETIMEHREG, (uint16_t)(sec >> 17));
 135
 136         spin_unlock_irq(&rtc_lock);
 137 }
 138
 139 static void vr41xx_rtc_release(struct device *dev)
 140 {
 141
 142         spin_lock_irq(&rtc_lock);
 143
 144         rtc1_write(ECMPLREG, 0);
 145         rtc1_write(ECMPMREG, 0);
 146         rtc1_write(ECMPHREG, 0);
 147         rtc1_write(RTCL1LREG, 0);
 148         rtc1_write(RTCL1HREG, 0);
 149
 150         spin_unlock_irq(&rtc_lock);
 151
 152         disable_irq(ELAPSEDTIME_IRQ);
 153         disable_irq(RTCLONG1_IRQ);
 154 }
 155
 156 static int vr41xx_rtc_read_time(struct device *dev, struct rtc_time *time)
 157 {
 158         unsigned long epoch_sec, elapsed_sec;
 159
 160         epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
 161         elapsed_sec = read_elapsed_second();
 162
 163         rtc_time_to_tm(epoch_sec + elapsed_sec, time);
 164
 165         return 0;
 166 }
 167
 168 static int vr41xx_rtc_set_time(struct device *dev, struct rtc_time *time)
 169 {
 170         unsigned long epoch_sec, current_sec;
 171
 172         epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
 173         current_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
 174                              time->tm_hour, time->tm_min, time->tm_sec);
 175
 176         write_elapsed_second(current_sec - epoch_sec);
 177
 178         return 0;
 179 }
 180
 181 static int vr41xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 182 {
 183         unsigned long low, mid, high;
 184         struct rtc_time *time = &wkalrm->time;
 185
 186         spin_lock_irq(&rtc_lock);
 187
 188         low = rtc1_read(ECMPLREG);
 189         mid = rtc1_read(ECMPMREG);
 190         high = rtc1_read(ECMPHREG);
 191
 192         spin_unlock_irq(&rtc_lock);
 193
 194         rtc_time_to_tm((high << 17) | (mid << 1) | (low >> 15), time);
 195
 196         return 0;
 197 }
 198
 199 static int vr41xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 200 {
 201         unsigned long alarm_sec;
 202         struct rtc_time *time = &wkalrm->time;
 203
 204         alarm_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
 205                            time->tm_hour, time->tm_min, time->tm_sec);
 206
 207         spin_lock_irq(&rtc_lock);
 208
 209         rtc1_write(ECMPLREG, (uint16_t)(alarm_sec << 15));
 210         rtc1_write(ECMPMREG, (uint16_t)(alarm_sec >> 1));
 211         rtc1_write(ECMPHREG, (uint16_t)(alarm_sec >> 17));
 212
 213         spin_unlock_irq(&rtc_lock);
 214
 215         return 0;
 216 }
 217
 218 static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 219 {
 220         unsigned long count;
 221
 222         switch (cmd) {
 223         case RTC_AIE_ON:
 224                 enable_irq(ELAPSEDTIME_IRQ);
 225                 break;
 226         case RTC_AIE_OFF:
 227                 disable_irq(ELAPSEDTIME_IRQ);
 228                 break;
 229         case RTC_PIE_ON:
 230                 enable_irq(RTCLONG1_IRQ);
 231                 break;
 232         case RTC_PIE_OFF:
 233                 disable_irq(RTCLONG1_IRQ);
 234                 break;
 235         case RTC_IRQP_READ:
 236                 return put_user(periodic_frequency, (unsigned long __user *)arg);
 237                 break;
 238         case RTC_IRQP_SET:
 239                 if (arg > MAX_PERIODIC_RATE)
 240                         return -EINVAL;
 241
 242                 periodic_frequency = arg;
 243
 244                 count = RTC_FREQUENCY;
 245                 do_div(count, arg);
 246
 247                 periodic_count = count;
 248
 249                 spin_lock_irq(&rtc_lock);
 250
 251                 rtc1_write(RTCL1LREG, count);
 252                 rtc1_write(RTCL1HREG, count >> 16);
 253
 254                 spin_unlock_irq(&rtc_lock);
 255                 break;
 256         case RTC_EPOCH_READ:
 257                 return put_user(epoch, (unsigned long __user *)arg);
 258         case RTC_EPOCH_SET:
 259                 /* Doesn't support before 1900 */
 260                 if (arg < 1900)
 261                         return -EINVAL;
 262                 epoch = arg;
 263                 break;
 264         default:
 265                 return -ENOIOCTLCMD;
 266         }
 267
 268         return 0;
 269 }
 270
 271 static irqreturn_t elapsedtime_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 272 {
 273         struct platform_device *pdev = (struct platform_device *)dev_id;
 274         struct rtc_device *rtc = platform_get_drvdata(pdev);
 275
 276         rtc2_write(RTCINTREG, ELAPSEDTIME_INT);
 277
 278         rtc_update_irq(&rtc->class_dev, 1, RTC_AF);
 279
 280         return IRQ_HANDLED;
 281 }
 282
 283 static irqreturn_t rtclong1_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 284 {
 285         struct platform_device *pdev = (struct platform_device *)dev_id;
 286         struct rtc_device *rtc = platform_get_drvdata(pdev);
 287         unsigned long count = periodic_count;
 288
 289         rtc2_write(RTCINTREG, RTCLONG1_INT);
 290
 291         rtc1_write(RTCL1LREG, count);
 292         rtc1_write(RTCL1HREG, count >> 16);
 293
 294         rtc_update_irq(&rtc->class_dev, 1, RTC_PF);
 295
 296         return IRQ_HANDLED;
 297 }
 298
 299 static const struct rtc_class_ops vr41xx_rtc_ops = {
 300         .release        = vr41xx_rtc_release,
 301         .ioctl          = vr41xx_rtc_ioctl,
 302         .read_time      = vr41xx_rtc_read_time,
 303         .set_time       = vr41xx_rtc_set_time,
 304         .read_alarm     = vr41xx_rtc_read_alarm,
 305         .set_alarm      = vr41xx_rtc_set_alarm,
 306 };
 307
 308 static int __devinit rtc_probe(struct platform_device *pdev)
 309 {
 310         struct rtc_device *rtc;
 311         unsigned int irq;
 312         int retval;
 313
 314         if (pdev->num_resources != 2)
 315                 return -EBUSY;
 316
 317         rtc1_base = ioremap(pdev->resource[0].start, RTC1_SIZE);
 318         if (rtc1_base == NULL)
 319                 return -EBUSY;
 320
 321         rtc2_base = ioremap(pdev->resource[1].start, RTC2_SIZE);
 322         if (rtc2_base == NULL) {
 323                 iounmap(rtc1_base);
 324                 rtc1_base = NULL;
 325                 return -EBUSY;
 326         }
 327
 328         rtc = rtc_device_register(rtc_name, &pdev->dev, &vr41xx_rtc_ops, THIS_MODULE);
 329         if (IS_ERR(rtc)) {
 330                 iounmap(rtc1_base);
 331                 iounmap(rtc2_base);
 332                 rtc1_base = NULL;
 333                 rtc2_base = NULL;
 334                 return PTR_ERR(rtc);
 335         }
 336
 337         spin_lock_irq(&rtc_lock);
 338
 339         rtc1_write(ECMPLREG, 0);
 340         rtc1_write(ECMPMREG, 0);
 341         rtc1_write(ECMPHREG, 0);
 342         rtc1_write(RTCL1LREG, 0);
 343         rtc1_write(RTCL1HREG, 0);
 344
 345         spin_unlock_irq(&rtc_lock);
 346
 347         irq = ELAPSEDTIME_IRQ;
 348         retval = request_irq(irq, elapsedtime_interrupt, IRQF_DISABLED,
 349                              "elapsed_time", pdev);
 350         if (retval == 0) {
 351                 irq = RTCLONG1_IRQ;
 352                 retval = request_irq(irq, rtclong1_interrupt, IRQF_DISABLED,
 353                                      "rtclong1", pdev);
 354         }
 355
 356         if (retval < 0) {
 357                 printk(KERN_ERR "rtc: IRQ%d is busy\n", irq);
 358                 rtc_device_unregister(rtc);
 359                 if (irq == RTCLONG1_IRQ)
 360                         free_irq(ELAPSEDTIME_IRQ, NULL);
 361                 iounmap(rtc1_base);
 362                 iounmap(rtc2_base);
 363                 rtc1_base = NULL;
 364                 rtc2_base = NULL;
 365                 return retval;
 366         }
 367
 368         platform_set_drvdata(pdev, rtc);
 369
 370         disable_irq(ELAPSEDTIME_IRQ);
 371         disable_irq(RTCLONG1_IRQ);
 372
 373         printk(KERN_INFO "rtc: Real Time Clock of NEC VR4100 series\n");
 374
 375         return 0;
 376 }
 377
 378 static int __devexit rtc_remove(struct platform_device *pdev)
 379 {
 380         struct rtc_device *rtc;
 381
 382         rtc = platform_get_drvdata(pdev);
 383         if (rtc != NULL)
 384                 rtc_device_unregister(rtc);
 385
 386         platform_set_drvdata(pdev, NULL);
 387
 388         free_irq(ELAPSEDTIME_IRQ, NULL);
 389         free_irq(RTCLONG1_IRQ, NULL);
 390         if (rtc1_base != NULL)
 391                 iounmap(rtc1_base);
 392         if (rtc2_base != NULL)
 393                 iounmap(rtc2_base);
 394
 395         return 0;
 396 }
 397
 398 static struct platform_device *rtc_platform_device;
 399
 400 static struct platform_driver rtc_platform_driver = {
 401         .probe          = rtc_probe,
 402         .remove         = __devexit_p(rtc_remove),
 403         .driver         = {
 404                 .name   = rtc_name,
 405                 .owner  = THIS_MODULE,
 406         },
 407 };
 408
 409 static int __init vr41xx_rtc_init(void)
 410 {
 411         int retval;
 412
 413         switch (current_cpu_data.cputype) {
 414         case CPU_VR4111:
 415         case CPU_VR4121:
 416                 rtc_resource[0].start = RTC1_TYPE1_START;
 417                 rtc_resource[0].end = RTC1_TYPE1_END;
 418                 rtc_resource[1].start = RTC2_TYPE1_START;
 419                 rtc_resource[1].end = RTC2_TYPE1_END;
 420                 break;
 421         case CPU_VR4122:
 422         case CPU_VR4131:
 423         case CPU_VR4133:
 424                 rtc_resource[0].start = RTC1_TYPE2_START;
 425                 rtc_resource[0].end = RTC1_TYPE2_END;
 426                 rtc_resource[1].start = RTC2_TYPE2_START;
 427                 rtc_resource[1].end = RTC2_TYPE2_END;
 428                 break;
 429         default:
 430                 return -ENODEV;
 431                 break;
 432         }
 433
 434         rtc_platform_device = platform_device_alloc("RTC", -1);
 435         if (rtc_platform_device == NULL)
 436                 return -ENOMEM;
 437
 438         retval = platform_device_add_resources(rtc_platform_device,
 439                                 rtc_resource, ARRAY_SIZE(rtc_resource));
 440
 441         if (retval == 0)
 442                 retval = platform_device_add(rtc_platform_device);
 443
 444         if (retval < 0) {
 445                 platform_device_put(rtc_platform_device);
 446                 return retval;
 447         }
 448
 449         retval = platform_driver_register(&rtc_platform_driver);
 450         if (retval < 0)
 451                 platform_device_unregister(rtc_platform_device);
 452
 453         return retval;
 454 }
 455
 456 static void __exit vr41xx_rtc_exit(void)
 457 {
 458         platform_driver_unregister(&rtc_platform_driver);
 459         platform_device_unregister(rtc_platform_device);
 460 }
 461
 462 module_init(vr41xx_rtc_init);
 463 module_exit(vr41xx_rtc_exit);