drivers/rtc/rtc-m48t59.c

   1 /*
   2  * ST M48T59 RTC driver
   3  *
   4  * Copyright (c) 2007 Wind River Systems, Inc.
   5  *
   6  * Author: Mark Zhan <rongkai.zhan@windriver.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/io.h>
  17 #include <linux/device.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/rtc.h>
  20 #include <linux/rtc/m48t59.h>
  21 #include <linux/bcd.h>
  22
  23 #ifndef NO_IRQ
  24 #define NO_IRQ  (-1)
  25 #endif
  26
  27 #define M48T59_READ(reg) (pdata->read_byte(dev, pdata->offset + reg))
  28 #define M48T59_WRITE(val, reg) \
  29         (pdata->write_byte(dev, pdata->offset + reg, val))
  30
  31 #define M48T59_SET_BITS(mask, reg)      \
  32         M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg))
  33 #define M48T59_CLEAR_BITS(mask, reg)    \
  34         M48T59_WRITE((M48T59_READ(reg) & ~(mask)), (reg))
  35
  36 struct m48t59_private {
  37         void __iomem *ioaddr;
  38         int irq;
  39         struct rtc_device *rtc;
  40         spinlock_t lock; /* serialize the NVRAM and RTC access */
  41 };
  42
  43 /*
  44  * This is the generic access method when the chip is memory-mapped
  45  */
  46 static void
  47 m48t59_mem_writeb(struct device *dev, u32 ofs, u8 val)
  48 {
  49         struct platform_device *pdev = to_platform_device(dev);
  50         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
  51
  52         writeb(val, m48t59->ioaddr+ofs);
  53 }
  54
  55 static u8
  56 m48t59_mem_readb(struct device *dev, u32 ofs)
  57 {
  58         struct platform_device *pdev = to_platform_device(dev);
  59         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
  60
  61         return readb(m48t59->ioaddr+ofs);
  62 }
  63
  64 /*
  65  * NOTE: M48T59 only uses BCD mode
  66  */
  67 static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm)
  68 {
  69         struct platform_device *pdev = to_platform_device(dev);
  70         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
  71         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
  72         unsigned long flags;
  73         u8 val;
  74
  75         spin_lock_irqsave(&m48t59->lock, flags);
  76         /* Issue the READ command */
  77         M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
  78
  79         tm->tm_year     = bcd2bin(M48T59_READ(M48T59_YEAR));
  80         /* tm_mon is 0-11 */
  81         tm->tm_mon      = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
  82         tm->tm_mday     = bcd2bin(M48T59_READ(M48T59_MDAY));
  83
  84         val = M48T59_READ(M48T59_WDAY);
  85         if ((pdata->type == M48T59RTC_TYPE_M48T59) &&
  86             (val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) {
  87                 dev_dbg(dev, "Century bit is enabled\n");
  88                 tm->tm_year += 100;     /* one century */
  89         }
  90
  91         tm->tm_wday     = bcd2bin(val & 0x07);
  92         tm->tm_hour     = bcd2bin(M48T59_READ(M48T59_HOUR) & 0x3F);
  93         tm->tm_min      = bcd2bin(M48T59_READ(M48T59_MIN) & 0x7F);
  94         tm->tm_sec      = bcd2bin(M48T59_READ(M48T59_SEC) & 0x7F);
  95
  96         /* Clear the READ bit */
  97         M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
  98         spin_unlock_irqrestore(&m48t59->lock, flags);
  99
 100         dev_dbg(dev, "RTC read time %04d-%02d-%02d %02d/%02d/%02d\n",
 101                 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
 102                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 103         return 0;
 104 }
 105
 106 static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm)
 107 {
 108         struct platform_device *pdev = to_platform_device(dev);
 109         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 110         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 111         unsigned long flags;
 112         u8 val = 0;
 113
 114         dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n",
 115                 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
 116                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 117
 118         spin_lock_irqsave(&m48t59->lock, flags);
 119         /* Issue the WRITE command */
 120         M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 121
 122         M48T59_WRITE((bin2bcd(tm->tm_sec) & 0x7F), M48T59_SEC);
 123         M48T59_WRITE((bin2bcd(tm->tm_min) & 0x7F), M48T59_MIN);
 124         M48T59_WRITE((bin2bcd(tm->tm_hour) & 0x3F), M48T59_HOUR);
 125         M48T59_WRITE((bin2bcd(tm->tm_mday) & 0x3F), M48T59_MDAY);
 126         /* tm_mon is 0-11 */
 127         M48T59_WRITE((bin2bcd(tm->tm_mon + 1) & 0x1F), M48T59_MONTH);
 128         M48T59_WRITE(bin2bcd(tm->tm_year % 100), M48T59_YEAR);
 129
 130         if (pdata->type == M48T59RTC_TYPE_M48T59 && (tm->tm_year / 100))
 131                 val = (M48T59_WDAY_CEB | M48T59_WDAY_CB);
 132         val |= (bin2bcd(tm->tm_wday) & 0x07);
 133         M48T59_WRITE(val, M48T59_WDAY);
 134
 135         /* Clear the WRITE bit */
 136         M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 137         spin_unlock_irqrestore(&m48t59->lock, flags);
 138         return 0;
 139 }
 140
 141 /*
 142  * Read alarm time and date in RTC
 143  */
 144 static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 145 {
 146         struct platform_device *pdev = to_platform_device(dev);
 147         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 148         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 149         struct rtc_time *tm = &alrm->time;
 150         unsigned long flags;
 151         u8 val;
 152
 153         /* If no irq, we don't support ALARM */
 154         if (m48t59->irq == NO_IRQ)
 155                 return -EIO;
 156
 157         spin_lock_irqsave(&m48t59->lock, flags);
 158         /* Issue the READ command */
 159         M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
 160
 161         tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR));
 162         /* tm_mon is 0-11 */
 163         tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
 164
 165         val = M48T59_READ(M48T59_WDAY);
 166         if ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB))
 167                 tm->tm_year += 100;     /* one century */
 168
 169         tm->tm_mday = bcd2bin(M48T59_READ(M48T59_ALARM_DATE));
 170         tm->tm_hour = bcd2bin(M48T59_READ(M48T59_ALARM_HOUR));
 171         tm->tm_min = bcd2bin(M48T59_READ(M48T59_ALARM_MIN));
 172         tm->tm_sec = bcd2bin(M48T59_READ(M48T59_ALARM_SEC));
 173
 174         /* Clear the READ bit */
 175         M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
 176         spin_unlock_irqrestore(&m48t59->lock, flags);
 177
 178         dev_dbg(dev, "RTC read alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
 179                 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
 180                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 181         return 0;
 182 }
 183
 184 /*
 185  * Set alarm time and date in RTC
 186  */
 187 static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 188 {
 189         struct platform_device *pdev = to_platform_device(dev);
 190         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 191         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 192         struct rtc_time *tm = &alrm->time;
 193         u8 mday, hour, min, sec;
 194         unsigned long flags;
 195
 196         /* If no irq, we don't support ALARM */
 197         if (m48t59->irq == NO_IRQ)
 198                 return -EIO;
 199
 200         /*
 201          * 0xff means "always match"
 202          */
 203         mday = tm->tm_mday;
 204         mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
 205         if (mday == 0xff)
 206                 mday = M48T59_READ(M48T59_MDAY);
 207
 208         hour = tm->tm_hour;
 209         hour = (hour < 24) ? bin2bcd(hour) : 0x00;
 210
 211         min = tm->tm_min;
 212         min = (min < 60) ? bin2bcd(min) : 0x00;
 213
 214         sec = tm->tm_sec;
 215         sec = (sec < 60) ? bin2bcd(sec) : 0x00;
 216
 217         spin_lock_irqsave(&m48t59->lock, flags);
 218         /* Issue the WRITE command */
 219         M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 220
 221         M48T59_WRITE(mday, M48T59_ALARM_DATE);
 222         M48T59_WRITE(hour, M48T59_ALARM_HOUR);
 223         M48T59_WRITE(min, M48T59_ALARM_MIN);
 224         M48T59_WRITE(sec, M48T59_ALARM_SEC);
 225
 226         /* Clear the WRITE bit */
 227         M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 228         spin_unlock_irqrestore(&m48t59->lock, flags);
 229
 230         dev_dbg(dev, "RTC set alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
 231                 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
 232                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 233         return 0;
 234 }
 235
 236 /*
 237  * Handle commands from user-space
 238  */
 239 static int m48t59_rtc_ioctl(struct device *dev, unsigned int cmd,
 240                         unsigned long arg)
 241 {
 242         struct platform_device *pdev = to_platform_device(dev);
 243         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 244         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 245         unsigned long flags;
 246         int ret = 0;
 247
 248         spin_lock_irqsave(&m48t59->lock, flags);
 249         switch (cmd) {
 250         case RTC_AIE_OFF:       /* alarm interrupt off */
 251                 M48T59_WRITE(0x00, M48T59_INTR);
 252                 break;
 253         case RTC_AIE_ON:        /* alarm interrupt on */
 254                 M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR);
 255                 break;
 256         default:
 257                 ret = -ENOIOCTLCMD;
 258                 break;
 259         }
 260         spin_unlock_irqrestore(&m48t59->lock, flags);
 261
 262         return ret;
 263 }
 264
 265 static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq)
 266 {
 267         struct platform_device *pdev = to_platform_device(dev);
 268         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 269         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 270         unsigned long flags;
 271         u8 val;
 272
 273         spin_lock_irqsave(&m48t59->lock, flags);
 274         val = M48T59_READ(M48T59_FLAGS);
 275         spin_unlock_irqrestore(&m48t59->lock, flags);
 276
 277         seq_printf(seq, "battery\t\t: %s\n",
 278                  (val & M48T59_FLAGS_BF) ? "low" : "normal");
 279         return 0;
 280 }
 281
 282 /*
 283  * IRQ handler for the RTC
 284  */
 285 static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id)
 286 {
 287         struct device *dev = (struct device *)dev_id;
 288         struct platform_device *pdev = to_platform_device(dev);
 289         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 290         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 291         u8 event;
 292
 293         spin_lock(&m48t59->lock);
 294         event = M48T59_READ(M48T59_FLAGS);
 295         spin_unlock(&m48t59->lock);
 296
 297         if (event & M48T59_FLAGS_AF) {
 298                 rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF));
 299                 return IRQ_HANDLED;
 300         }
 301
 302         return IRQ_NONE;
 303 }
 304
 305 static const struct rtc_class_ops m48t59_rtc_ops = {
 306         .ioctl          = m48t59_rtc_ioctl,
 307         .read_time      = m48t59_rtc_read_time,
 308         .set_time       = m48t59_rtc_set_time,
 309         .read_alarm     = m48t59_rtc_readalarm,
 310         .set_alarm      = m48t59_rtc_setalarm,
 311         .proc           = m48t59_rtc_proc,
 312 };
 313
 314 static const struct rtc_class_ops m48t02_rtc_ops = {
 315         .read_time      = m48t59_rtc_read_time,
 316         .set_time       = m48t59_rtc_set_time,
 317 };
 318
 319 static ssize_t m48t59_nvram_read(struct kobject *kobj,
 320                                 struct bin_attribute *bin_attr,
 321                                 char *buf, loff_t pos, size_t size)
 322 {
 323         struct device *dev = container_of(kobj, struct device, kobj);
 324         struct platform_device *pdev = to_platform_device(dev);
 325         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 326         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 327         ssize_t cnt = 0;
 328         unsigned long flags;
 329
 330         for (; size > 0 && pos < pdata->offset; cnt++, size--) {
 331                 spin_lock_irqsave(&m48t59->lock, flags);
 332                 *buf++ = M48T59_READ(cnt);
 333                 spin_unlock_irqrestore(&m48t59->lock, flags);
 334         }
 335
 336         return cnt;
 337 }
 338
 339 static ssize_t m48t59_nvram_write(struct kobject *kobj,
 340                                 struct bin_attribute *bin_attr,
 341                                 char *buf, loff_t pos, size_t size)
 342 {
 343         struct device *dev = container_of(kobj, struct device, kobj);
 344         struct platform_device *pdev = to_platform_device(dev);
 345         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 346         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 347         ssize_t cnt = 0;
 348         unsigned long flags;
 349
 350         for (; size > 0 && pos < pdata->offset; cnt++, size--) {
 351                 spin_lock_irqsave(&m48t59->lock, flags);
 352                 M48T59_WRITE(*buf++, cnt);
 353                 spin_unlock_irqrestore(&m48t59->lock, flags);
 354         }
 355
 356         return cnt;
 357 }
 358
 359 static struct bin_attribute m48t59_nvram_attr = {
 360         .attr = {
 361                 .name = "nvram",
 362                 .mode = S_IRUGO | S_IWUSR,
 363         },
 364         .read = m48t59_nvram_read,
 365         .write = m48t59_nvram_write,
 366 };
 367
 368 static int __devinit m48t59_rtc_probe(struct platform_device *pdev)
 369 {
 370         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 371         struct m48t59_private *m48t59 = NULL;
 372         struct resource *res;
 373         int ret = -ENOMEM;
 374         char *name;
 375         const struct rtc_class_ops *ops;
 376
 377         /* This chip could be memory-mapped or I/O-mapped */
 378         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 379         if (!res) {
 380                 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 381                 if (!res)
 382                         return -EINVAL;
 383         }
 384
 385         if (res->flags & IORESOURCE_IO) {
 386                 /* If we are I/O-mapped, the platform should provide
 387                  * the operations accessing chip registers.
 388                  */
 389                 if (!pdata || !pdata->write_byte || !pdata->read_byte)
 390                         return -EINVAL;
 391         } else if (res->flags & IORESOURCE_MEM) {
 392                 /* we are memory-mapped */
 393                 if (!pdata) {
 394                         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 395                         if (!pdata)
 396                                 return -ENOMEM;
 397                         /* Ensure we only kmalloc platform data once */
 398                         pdev->dev.platform_data = pdata;
 399                 }
 400                 if (!pdata->type)
 401                         pdata->type = M48T59RTC_TYPE_M48T59;
 402
 403                 /* Try to use the generic memory read/write ops */
 404                 if (!pdata->write_byte)
 405                         pdata->write_byte = m48t59_mem_writeb;
 406                 if (!pdata->read_byte)
 407                         pdata->read_byte = m48t59_mem_readb;
 408         }
 409
 410         m48t59 = kzalloc(sizeof(*m48t59), GFP_KERNEL);
 411         if (!m48t59)
 412                 return -ENOMEM;
 413
 414         m48t59->ioaddr = pdata->ioaddr;
 415
 416         if (!m48t59->ioaddr) {
 417                 /* ioaddr not mapped externally */
 418                 m48t59->ioaddr = ioremap(res->start, res->end - res->start + 1);
 419                 if (!m48t59->ioaddr)
 420                         goto out;
 421         }
 422
 423         /* Try to get irq number. We also can work in
 424          * the mode without IRQ.
 425          */
 426         m48t59->irq = platform_get_irq(pdev, 0);
 427         if (m48t59->irq < 0)
 428                 m48t59->irq = NO_IRQ;
 429
 430         if (m48t59->irq != NO_IRQ) {
 431                 ret = request_irq(m48t59->irq, m48t59_rtc_interrupt,
 432                         IRQF_SHARED, "rtc-m48t59", &pdev->dev);
 433                 if (ret)
 434                         goto out;
 435         }
 436         switch (pdata->type) {
 437         case M48T59RTC_TYPE_M48T59:
 438                 name = "m48t59";
 439                 ops = &m48t59_rtc_ops;
 440                 pdata->offset = 0x1ff0;
 441                 break;
 442         case M48T59RTC_TYPE_M48T02:
 443                 name = "m48t02";
 444                 ops = &m48t02_rtc_ops;
 445                 pdata->offset = 0x7f0;
 446                 break;
 447         case M48T59RTC_TYPE_M48T08:
 448                 name = "m48t08";
 449                 ops = &m48t02_rtc_ops;
 450                 pdata->offset = 0x1ff0;
 451                 break;
 452         default:
 453                 dev_err(&pdev->dev, "Unknown RTC type\n");
 454                 ret = -ENODEV;
 455                 goto out;
 456         }
 457
 458         m48t59->rtc = rtc_device_register(name, &pdev->dev, ops, THIS_MODULE);
 459         if (IS_ERR(m48t59->rtc)) {
 460                 ret = PTR_ERR(m48t59->rtc);
 461                 goto out;
 462         }
 463
 464         m48t59_nvram_attr.size = pdata->offset;
 465
 466         ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
 467         if (ret)
 468                 goto out;
 469
 470         spin_lock_init(&m48t59->lock);
 471         platform_set_drvdata(pdev, m48t59);
 472         return 0;
 473
 474 out:
 475         if (!IS_ERR(m48t59->rtc))
 476                 rtc_device_unregister(m48t59->rtc);
 477         if (m48t59->irq != NO_IRQ)
 478                 free_irq(m48t59->irq, &pdev->dev);
 479         if (m48t59->ioaddr)
 480                 iounmap(m48t59->ioaddr);
 481         if (m48t59)
 482                 kfree(m48t59);
 483         return ret;
 484 }
 485
 486 static int __devexit m48t59_rtc_remove(struct platform_device *pdev)
 487 {
 488         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 489         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 490
 491         sysfs_remove_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
 492         if (!IS_ERR(m48t59->rtc))
 493                 rtc_device_unregister(m48t59->rtc);
 494         if (m48t59->ioaddr && !pdata->ioaddr)
 495                 iounmap(m48t59->ioaddr);
 496         if (m48t59->irq != NO_IRQ)
 497                 free_irq(m48t59->irq, &pdev->dev);
 498         platform_set_drvdata(pdev, NULL);
 499         kfree(m48t59);
 500         return 0;
 501 }
 502
 503 /* work with hotplug and coldplug */
 504 MODULE_ALIAS("platform:rtc-m48t59");
 505
 506 static struct platform_driver m48t59_rtc_driver = {
 507         .driver         = {
 508                 .name   = "rtc-m48t59",
 509                 .owner  = THIS_MODULE,
 510         },
 511         .probe          = m48t59_rtc_probe,
 512         .remove         = __devexit_p(m48t59_rtc_remove),
 513 };
 514
 515 static int __init m48t59_rtc_init(void)
 516 {
 517         return platform_driver_register(&m48t59_rtc_driver);
 518 }
 519
 520 static void __exit m48t59_rtc_exit(void)
 521 {
 522         platform_driver_unregister(&m48t59_rtc_driver);
 523 }
 524
 525 module_init(m48t59_rtc_init);
 526 module_exit(m48t59_rtc_exit);
 527
 528 MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>");
 529 MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver");
 530 MODULE_LICENSE("GPL");