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, reg)
  28 #define M48T59_WRITE(val, reg)  pdata->write_byte(dev, reg, val)
  29
  30 #define M48T59_SET_BITS(mask, reg)      \
  31         M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg))
  32 #define M48T59_CLEAR_BITS(mask, reg)    \
  33         M48T59_WRITE((M48T59_READ(reg) & ~(mask)), (reg))
  34
  35 struct m48t59_private {
  36         void __iomem *ioaddr;
  37         unsigned int size; /* iomem size */
  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 ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) {
  86                 dev_dbg(dev, "Century bit is enabled\n");
  87                 tm->tm_year += 100;     /* one century */
  88         }
  89
  90         tm->tm_wday     = BCD2BIN(val & 0x07);
  91         tm->tm_hour     = BCD2BIN(M48T59_READ(M48T59_HOUR) & 0x3F);
  92         tm->tm_min      = BCD2BIN(M48T59_READ(M48T59_MIN) & 0x7F);
  93         tm->tm_sec      = BCD2BIN(M48T59_READ(M48T59_SEC) & 0x7F);
  94
  95         /* Clear the READ bit */
  96         M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
  97         spin_unlock_irqrestore(&m48t59->lock, flags);
  98
  99         dev_dbg(dev, "RTC read time %04d-%02d-%02d %02d/%02d/%02d\n",
 100                 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
 101                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 102         return 0;
 103 }
 104
 105 static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm)
 106 {
 107         struct platform_device *pdev = to_platform_device(dev);
 108         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 109         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 110         unsigned long flags;
 111         u8 val = 0;
 112
 113         dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n",
 114                 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
 115                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 116
 117         spin_lock_irqsave(&m48t59->lock, flags);
 118         /* Issue the WRITE command */
 119         M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 120
 121         M48T59_WRITE((BIN2BCD(tm->tm_sec) & 0x7F), M48T59_SEC);
 122         M48T59_WRITE((BIN2BCD(tm->tm_min) & 0x7F), M48T59_MIN);
 123         M48T59_WRITE((BIN2BCD(tm->tm_hour) & 0x3F), M48T59_HOUR);
 124         M48T59_WRITE((BIN2BCD(tm->tm_mday) & 0x3F), M48T59_MDAY);
 125         /* tm_mon is 0-11 */
 126         M48T59_WRITE((BIN2BCD(tm->tm_mon + 1) & 0x1F), M48T59_MONTH);
 127         M48T59_WRITE(BIN2BCD(tm->tm_year % 100), M48T59_YEAR);
 128
 129         if (tm->tm_year/100)
 130                 val = (M48T59_WDAY_CEB | M48T59_WDAY_CB);
 131         val |= (BIN2BCD(tm->tm_wday) & 0x07);
 132         M48T59_WRITE(val, M48T59_WDAY);
 133
 134         /* Clear the WRITE bit */
 135         M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 136         spin_unlock_irqrestore(&m48t59->lock, flags);
 137         return 0;
 138 }
 139
 140 /*
 141  * Read alarm time and date in RTC
 142  */
 143 static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 144 {
 145         struct platform_device *pdev = to_platform_device(dev);
 146         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 147         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 148         struct rtc_time *tm = &alrm->time;
 149         unsigned long flags;
 150         u8 val;
 151
 152         /* If no irq, we don't support ALARM */
 153         if (m48t59->irq == NO_IRQ)
 154                 return -EIO;
 155
 156         spin_lock_irqsave(&m48t59->lock, flags);
 157         /* Issue the READ command */
 158         M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
 159
 160         tm->tm_year = BCD2BIN(M48T59_READ(M48T59_YEAR));
 161         /* tm_mon is 0-11 */
 162         tm->tm_mon = BCD2BIN(M48T59_READ(M48T59_MONTH)) - 1;
 163
 164         val = M48T59_READ(M48T59_WDAY);
 165         if ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB))
 166                 tm->tm_year += 100;     /* one century */
 167
 168         tm->tm_mday = BCD2BIN(M48T59_READ(M48T59_ALARM_DATE));
 169         tm->tm_hour = BCD2BIN(M48T59_READ(M48T59_ALARM_HOUR));
 170         tm->tm_min = BCD2BIN(M48T59_READ(M48T59_ALARM_MIN));
 171         tm->tm_sec = BCD2BIN(M48T59_READ(M48T59_ALARM_SEC));
 172
 173         /* Clear the READ bit */
 174         M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
 175         spin_unlock_irqrestore(&m48t59->lock, flags);
 176
 177         dev_dbg(dev, "RTC read alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
 178                 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
 179                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 180         return 0;
 181 }
 182
 183 /*
 184  * Set alarm time and date in RTC
 185  */
 186 static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 187 {
 188         struct platform_device *pdev = to_platform_device(dev);
 189         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 190         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 191         struct rtc_time *tm = &alrm->time;
 192         u8 mday, hour, min, sec;
 193         unsigned long flags;
 194
 195         /* If no irq, we don't support ALARM */
 196         if (m48t59->irq == NO_IRQ)
 197                 return -EIO;
 198
 199         /*
 200          * 0xff means "always match"
 201          */
 202         mday = tm->tm_mday;
 203         mday = (mday >= 1 && mday <= 31) ? BIN2BCD(mday) : 0xff;
 204         if (mday == 0xff)
 205                 mday = M48T59_READ(M48T59_MDAY);
 206
 207         hour = tm->tm_hour;
 208         hour = (hour < 24) ? BIN2BCD(hour) : 0x00;
 209
 210         min = tm->tm_min;
 211         min = (min < 60) ? BIN2BCD(min) : 0x00;
 212
 213         sec = tm->tm_sec;
 214         sec = (sec < 60) ? BIN2BCD(sec) : 0x00;
 215
 216         spin_lock_irqsave(&m48t59->lock, flags);
 217         /* Issue the WRITE command */
 218         M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 219
 220         M48T59_WRITE(mday, M48T59_ALARM_DATE);
 221         M48T59_WRITE(hour, M48T59_ALARM_HOUR);
 222         M48T59_WRITE(min, M48T59_ALARM_MIN);
 223         M48T59_WRITE(sec, M48T59_ALARM_SEC);
 224
 225         /* Clear the WRITE bit */
 226         M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 227         spin_unlock_irqrestore(&m48t59->lock, flags);
 228
 229         dev_dbg(dev, "RTC set alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
 230                 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
 231                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 232         return 0;
 233 }
 234
 235 /*
 236  * Handle commands from user-space
 237  */
 238 static int m48t59_rtc_ioctl(struct device *dev, unsigned int cmd,
 239                         unsigned long arg)
 240 {
 241         struct platform_device *pdev = to_platform_device(dev);
 242         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 243         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 244         unsigned long flags;
 245         int ret = 0;
 246
 247         spin_lock_irqsave(&m48t59->lock, flags);
 248         switch (cmd) {
 249         case RTC_AIE_OFF:       /* alarm interrupt off */
 250                 M48T59_WRITE(0x00, M48T59_INTR);
 251                 break;
 252         case RTC_AIE_ON:        /* alarm interrupt on */
 253                 M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR);
 254                 break;
 255         default:
 256                 ret = -ENOIOCTLCMD;
 257                 break;
 258         }
 259         spin_unlock_irqrestore(&m48t59->lock, flags);
 260
 261         return ret;
 262 }
 263
 264 static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq)
 265 {
 266         struct platform_device *pdev = to_platform_device(dev);
 267         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 268         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 269         unsigned long flags;
 270         u8 val;
 271
 272         spin_lock_irqsave(&m48t59->lock, flags);
 273         val = M48T59_READ(M48T59_FLAGS);
 274         spin_unlock_irqrestore(&m48t59->lock, flags);
 275
 276         seq_printf(seq, "battery\t\t: %s\n",
 277                  (val & M48T59_FLAGS_BF) ? "low" : "normal");
 278         return 0;
 279 }
 280
 281 /*
 282  * IRQ handler for the RTC
 283  */
 284 static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id)
 285 {
 286         struct device *dev = (struct device *)dev_id;
 287         struct platform_device *pdev = to_platform_device(dev);
 288         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 289         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 290         u8 event;
 291
 292         spin_lock(&m48t59->lock);
 293         event = M48T59_READ(M48T59_FLAGS);
 294         spin_unlock(&m48t59->lock);
 295
 296         if (event & M48T59_FLAGS_AF) {
 297                 rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF));
 298                 return IRQ_HANDLED;
 299         }
 300
 301         return IRQ_NONE;
 302 }
 303
 304 static const struct rtc_class_ops m48t59_rtc_ops = {
 305         .ioctl          = m48t59_rtc_ioctl,
 306         .read_time      = m48t59_rtc_read_time,
 307         .set_time       = m48t59_rtc_set_time,
 308         .read_alarm     = m48t59_rtc_readalarm,
 309         .set_alarm      = m48t59_rtc_setalarm,
 310         .proc           = m48t59_rtc_proc,
 311 };
 312
 313 static ssize_t m48t59_nvram_read(struct kobject *kobj,
 314                                 struct bin_attribute *bin_attr,
 315                                 char *buf, loff_t pos, size_t size)
 316 {
 317         struct device *dev = container_of(kobj, struct device, kobj);
 318         struct platform_device *pdev = to_platform_device(dev);
 319         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 320         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 321         ssize_t cnt = 0;
 322         unsigned long flags;
 323
 324         for (; size > 0 && pos < M48T59_NVRAM_SIZE; cnt++, size--) {
 325                 spin_lock_irqsave(&m48t59->lock, flags);
 326                 *buf++ = M48T59_READ(cnt);
 327                 spin_unlock_irqrestore(&m48t59->lock, flags);
 328         }
 329
 330         return cnt;
 331 }
 332
 333 static ssize_t m48t59_nvram_write(struct kobject *kobj,
 334                                 struct bin_attribute *bin_attr,
 335                                 char *buf, loff_t pos, size_t size)
 336 {
 337         struct device *dev = container_of(kobj, struct device, kobj);
 338         struct platform_device *pdev = to_platform_device(dev);
 339         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 340         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 341         ssize_t cnt = 0;
 342         unsigned long flags;
 343
 344         for (; size > 0 && pos < M48T59_NVRAM_SIZE; cnt++, size--) {
 345                 spin_lock_irqsave(&m48t59->lock, flags);
 346                 M48T59_WRITE(*buf++, cnt);
 347                 spin_unlock_irqrestore(&m48t59->lock, flags);
 348         }
 349
 350         return cnt;
 351 }
 352
 353 static struct bin_attribute m48t59_nvram_attr = {
 354         .attr = {
 355                 .name = "nvram",
 356                 .mode = S_IRUGO | S_IWUSR,
 357                 .owner = THIS_MODULE,
 358         },
 359         .read = m48t59_nvram_read,
 360         .write = m48t59_nvram_write,
 361         .size = M48T59_NVRAM_SIZE,
 362 };
 363
 364 static int __devinit m48t59_rtc_probe(struct platform_device *pdev)
 365 {
 366         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 367         struct m48t59_private *m48t59 = NULL;
 368         struct resource *res;
 369         int ret = -ENOMEM;
 370
 371         /* This chip could be memory-mapped or I/O-mapped */
 372         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 373         if (!res) {
 374                 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 375                 if (!res)
 376                         return -EINVAL;
 377         }
 378
 379         if (res->flags & IORESOURCE_IO) {
 380                 /* If we are I/O-mapped, the platform should provide
 381                  * the operations accessing chip registers.
 382                  */
 383                 if (!pdata || !pdata->write_byte || !pdata->read_byte)
 384                         return -EINVAL;
 385         } else if (res->flags & IORESOURCE_MEM) {
 386                 /* we are memory-mapped */
 387                 if (!pdata) {
 388                         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 389                         if (!pdata)
 390                                 return -ENOMEM;
 391                         /* Ensure we only kmalloc platform data once */
 392                         pdev->dev.platform_data = pdata;
 393                 }
 394
 395                 /* Try to use the generic memory read/write ops */
 396                 if (!pdata->write_byte)
 397                         pdata->write_byte = m48t59_mem_writeb;
 398                 if (!pdata->read_byte)
 399                         pdata->read_byte = m48t59_mem_readb;
 400         }
 401
 402         m48t59 = kzalloc(sizeof(*m48t59), GFP_KERNEL);
 403         if (!m48t59)
 404                 return -ENOMEM;
 405
 406         m48t59->size = res->end - res->start + 1;
 407         m48t59->ioaddr = ioremap(res->start, m48t59->size);
 408         if (!m48t59->ioaddr)
 409                 goto out;
 410
 411         /* Try to get irq number. We also can work in
 412          * the mode without IRQ.
 413          */
 414         m48t59->irq = platform_get_irq(pdev, 0);
 415         if (m48t59->irq < 0)
 416                 m48t59->irq = NO_IRQ;
 417
 418         if (m48t59->irq != NO_IRQ) {
 419                 ret = request_irq(m48t59->irq, m48t59_rtc_interrupt,
 420                         IRQF_SHARED, "rtc-m48t59", &pdev->dev);
 421                 if (ret)
 422                         goto out;
 423         }
 424
 425         m48t59->rtc = rtc_device_register("m48t59", &pdev->dev,
 426                                 &m48t59_rtc_ops, THIS_MODULE);
 427         if (IS_ERR(m48t59->rtc)) {
 428                 ret = PTR_ERR(m48t59->rtc);
 429                 goto out;
 430         }
 431
 432         ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
 433         if (ret)
 434                 goto out;
 435
 436         spin_lock_init(&m48t59->lock);
 437         platform_set_drvdata(pdev, m48t59);
 438         return 0;
 439
 440 out:
 441         if (!IS_ERR(m48t59->rtc))
 442                 rtc_device_unregister(m48t59->rtc);
 443         if (m48t59->irq != NO_IRQ)
 444                 free_irq(m48t59->irq, &pdev->dev);
 445         if (m48t59->ioaddr)
 446                 iounmap(m48t59->ioaddr);
 447         if (m48t59)
 448                 kfree(m48t59);
 449         return ret;
 450 }
 451
 452 static int __devexit m48t59_rtc_remove(struct platform_device *pdev)
 453 {
 454         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 455
 456         sysfs_remove_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
 457         if (!IS_ERR(m48t59->rtc))
 458                 rtc_device_unregister(m48t59->rtc);
 459         if (m48t59->ioaddr)
 460                 iounmap(m48t59->ioaddr);
 461         if (m48t59->irq != NO_IRQ)
 462                 free_irq(m48t59->irq, &pdev->dev);
 463         platform_set_drvdata(pdev, NULL);
 464         kfree(m48t59);
 465         return 0;
 466 }
 467
 468 /* work with hotplug and coldplug */
 469 MODULE_ALIAS("platform:rtc-m48t59");
 470
 471 static struct platform_driver m48t59_rtc_driver = {
 472         .driver         = {
 473                 .name   = "rtc-m48t59",
 474                 .owner  = THIS_MODULE,
 475         },
 476         .probe          = m48t59_rtc_probe,
 477         .remove         = __devexit_p(m48t59_rtc_remove),
 478 };
 479
 480 static int __init m48t59_rtc_init(void)
 481 {
 482         return platform_driver_register(&m48t59_rtc_driver);
 483 }
 484
 485 static void __exit m48t59_rtc_exit(void)
 486 {
 487         platform_driver_unregister(&m48t59_rtc_driver);
 488 }
 489
 490 module_init(m48t59_rtc_init);
 491 module_exit(m48t59_rtc_exit);
 492
 493 MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>");
 494 MODULE_DESCRIPTION("M48T59 RTC driver");
 495 MODULE_LICENSE("GPL");