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 #ifdef CONFIG_SPARC
  91         /* Sun SPARC machines count years since 1968 */
  92         tm->tm_year += 68;
  93 #endif
  94
  95         tm->tm_wday     = bcd2bin(val & 0x07);
  96         tm->tm_hour     = bcd2bin(M48T59_READ(M48T59_HOUR) & 0x3F);
  97         tm->tm_min      = bcd2bin(M48T59_READ(M48T59_MIN) & 0x7F);
  98         tm->tm_sec      = bcd2bin(M48T59_READ(M48T59_SEC) & 0x7F);
  99
 100         /* Clear the READ bit */
 101         M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
 102         spin_unlock_irqrestore(&m48t59->lock, flags);
 103
 104         dev_dbg(dev, "RTC read time %04d-%02d-%02d %02d/%02d/%02d\n",
 105                 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
 106                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 107         return 0;
 108 }
 109
 110 static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm)
 111 {
 112         struct platform_device *pdev = to_platform_device(dev);
 113         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 114         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 115         unsigned long flags;
 116         u8 val = 0;
 117         int year = tm->tm_year;
 118
 119 #ifdef CONFIG_SPARC
 120         /* Sun SPARC machines count years since 1968 */
 121         year -= 68;
 122 #endif
 123
 124         dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n",
 125                 year + 1900, tm->tm_mon, tm->tm_mday,
 126                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 127
 128         if (year < 0)
 129                 return -EINVAL;
 130
 131         spin_lock_irqsave(&m48t59->lock, flags);
 132         /* Issue the WRITE command */
 133         M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 134
 135         M48T59_WRITE((bin2bcd(tm->tm_sec) & 0x7F), M48T59_SEC);
 136         M48T59_WRITE((bin2bcd(tm->tm_min) & 0x7F), M48T59_MIN);
 137         M48T59_WRITE((bin2bcd(tm->tm_hour) & 0x3F), M48T59_HOUR);
 138         M48T59_WRITE((bin2bcd(tm->tm_mday) & 0x3F), M48T59_MDAY);
 139         /* tm_mon is 0-11 */
 140         M48T59_WRITE((bin2bcd(tm->tm_mon + 1) & 0x1F), M48T59_MONTH);
 141         M48T59_WRITE(bin2bcd(year % 100), M48T59_YEAR);
 142
 143         if (pdata->type == M48T59RTC_TYPE_M48T59 && (year / 100))
 144                 val = (M48T59_WDAY_CEB | M48T59_WDAY_CB);
 145         val |= (bin2bcd(tm->tm_wday) & 0x07);
 146         M48T59_WRITE(val, M48T59_WDAY);
 147
 148         /* Clear the WRITE bit */
 149         M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 150         spin_unlock_irqrestore(&m48t59->lock, flags);
 151         return 0;
 152 }
 153
 154 /*
 155  * Read alarm time and date in RTC
 156  */
 157 static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 158 {
 159         struct platform_device *pdev = to_platform_device(dev);
 160         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 161         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 162         struct rtc_time *tm = &alrm->time;
 163         unsigned long flags;
 164         u8 val;
 165
 166         /* If no irq, we don't support ALARM */
 167         if (m48t59->irq == NO_IRQ)
 168                 return -EIO;
 169
 170         spin_lock_irqsave(&m48t59->lock, flags);
 171         /* Issue the READ command */
 172         M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
 173
 174         tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR));
 175 #ifdef CONFIG_SPARC
 176         /* Sun SPARC machines count years since 1968 */
 177         tm->tm_year += 68;
 178 #endif
 179         /* tm_mon is 0-11 */
 180         tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
 181
 182         val = M48T59_READ(M48T59_WDAY);
 183         if ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB))
 184                 tm->tm_year += 100;     /* one century */
 185
 186         tm->tm_mday = bcd2bin(M48T59_READ(M48T59_ALARM_DATE));
 187         tm->tm_hour = bcd2bin(M48T59_READ(M48T59_ALARM_HOUR));
 188         tm->tm_min = bcd2bin(M48T59_READ(M48T59_ALARM_MIN));
 189         tm->tm_sec = bcd2bin(M48T59_READ(M48T59_ALARM_SEC));
 190
 191         /* Clear the READ bit */
 192         M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
 193         spin_unlock_irqrestore(&m48t59->lock, flags);
 194
 195         dev_dbg(dev, "RTC read alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
 196                 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
 197                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 198         return 0;
 199 }
 200
 201 /*
 202  * Set alarm time and date in RTC
 203  */
 204 static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 205 {
 206         struct platform_device *pdev = to_platform_device(dev);
 207         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 208         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 209         struct rtc_time *tm = &alrm->time;
 210         u8 mday, hour, min, sec;
 211         unsigned long flags;
 212         int year = tm->tm_year;
 213
 214 #ifdef CONFIG_SPARC
 215         /* Sun SPARC machines count years since 1968 */
 216         year -= 68;
 217 #endif
 218
 219         /* If no irq, we don't support ALARM */
 220         if (m48t59->irq == NO_IRQ)
 221                 return -EIO;
 222
 223         if (year < 0)
 224                 return -EINVAL;
 225
 226         /*
 227          * 0xff means "always match"
 228          */
 229         mday = tm->tm_mday;
 230         mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
 231         if (mday == 0xff)
 232                 mday = M48T59_READ(M48T59_MDAY);
 233
 234         hour = tm->tm_hour;
 235         hour = (hour < 24) ? bin2bcd(hour) : 0x00;
 236
 237         min = tm->tm_min;
 238         min = (min < 60) ? bin2bcd(min) : 0x00;
 239
 240         sec = tm->tm_sec;
 241         sec = (sec < 60) ? bin2bcd(sec) : 0x00;
 242
 243         spin_lock_irqsave(&m48t59->lock, flags);
 244         /* Issue the WRITE command */
 245         M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 246
 247         M48T59_WRITE(mday, M48T59_ALARM_DATE);
 248         M48T59_WRITE(hour, M48T59_ALARM_HOUR);
 249         M48T59_WRITE(min, M48T59_ALARM_MIN);
 250         M48T59_WRITE(sec, M48T59_ALARM_SEC);
 251
 252         /* Clear the WRITE bit */
 253         M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
 254         spin_unlock_irqrestore(&m48t59->lock, flags);
 255
 256         dev_dbg(dev, "RTC set alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
 257                 year + 1900, tm->tm_mon, tm->tm_mday,
 258                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 259         return 0;
 260 }
 261
 262 /*
 263  * Handle commands from user-space
 264  */
 265 static int m48t59_rtc_ioctl(struct device *dev, unsigned int cmd,
 266                         unsigned long arg)
 267 {
 268         struct platform_device *pdev = to_platform_device(dev);
 269         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 270         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 271         unsigned long flags;
 272         int ret = 0;
 273
 274         spin_lock_irqsave(&m48t59->lock, flags);
 275         switch (cmd) {
 276         case RTC_AIE_OFF:       /* alarm interrupt off */
 277                 M48T59_WRITE(0x00, M48T59_INTR);
 278                 break;
 279         case RTC_AIE_ON:        /* alarm interrupt on */
 280                 M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR);
 281                 break;
 282         default:
 283                 ret = -ENOIOCTLCMD;
 284                 break;
 285         }
 286         spin_unlock_irqrestore(&m48t59->lock, flags);
 287
 288         return ret;
 289 }
 290
 291 static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq)
 292 {
 293         struct platform_device *pdev = to_platform_device(dev);
 294         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 295         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 296         unsigned long flags;
 297         u8 val;
 298
 299         spin_lock_irqsave(&m48t59->lock, flags);
 300         val = M48T59_READ(M48T59_FLAGS);
 301         spin_unlock_irqrestore(&m48t59->lock, flags);
 302
 303         seq_printf(seq, "battery\t\t: %s\n",
 304                  (val & M48T59_FLAGS_BF) ? "low" : "normal");
 305         return 0;
 306 }
 307
 308 /*
 309  * IRQ handler for the RTC
 310  */
 311 static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id)
 312 {
 313         struct device *dev = (struct device *)dev_id;
 314         struct platform_device *pdev = to_platform_device(dev);
 315         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 316         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 317         u8 event;
 318
 319         spin_lock(&m48t59->lock);
 320         event = M48T59_READ(M48T59_FLAGS);
 321         spin_unlock(&m48t59->lock);
 322
 323         if (event & M48T59_FLAGS_AF) {
 324                 rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF));
 325                 return IRQ_HANDLED;
 326         }
 327
 328         return IRQ_NONE;
 329 }
 330
 331 static const struct rtc_class_ops m48t59_rtc_ops = {
 332         .ioctl          = m48t59_rtc_ioctl,
 333         .read_time      = m48t59_rtc_read_time,
 334         .set_time       = m48t59_rtc_set_time,
 335         .read_alarm     = m48t59_rtc_readalarm,
 336         .set_alarm      = m48t59_rtc_setalarm,
 337         .proc           = m48t59_rtc_proc,
 338 };
 339
 340 static const struct rtc_class_ops m48t02_rtc_ops = {
 341         .read_time      = m48t59_rtc_read_time,
 342         .set_time       = m48t59_rtc_set_time,
 343 };
 344
 345 static ssize_t m48t59_nvram_read(struct kobject *kobj,
 346                                 struct bin_attribute *bin_attr,
 347                                 char *buf, loff_t pos, size_t size)
 348 {
 349         struct device *dev = container_of(kobj, struct device, kobj);
 350         struct platform_device *pdev = to_platform_device(dev);
 351         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 352         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 353         ssize_t cnt = 0;
 354         unsigned long flags;
 355
 356         for (; size > 0 && pos < pdata->offset; cnt++, size--) {
 357                 spin_lock_irqsave(&m48t59->lock, flags);
 358                 *buf++ = M48T59_READ(cnt);
 359                 spin_unlock_irqrestore(&m48t59->lock, flags);
 360         }
 361
 362         return cnt;
 363 }
 364
 365 static ssize_t m48t59_nvram_write(struct kobject *kobj,
 366                                 struct bin_attribute *bin_attr,
 367                                 char *buf, loff_t pos, size_t size)
 368 {
 369         struct device *dev = container_of(kobj, struct device, kobj);
 370         struct platform_device *pdev = to_platform_device(dev);
 371         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 372         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 373         ssize_t cnt = 0;
 374         unsigned long flags;
 375
 376         for (; size > 0 && pos < pdata->offset; cnt++, size--) {
 377                 spin_lock_irqsave(&m48t59->lock, flags);
 378                 M48T59_WRITE(*buf++, cnt);
 379                 spin_unlock_irqrestore(&m48t59->lock, flags);
 380         }
 381
 382         return cnt;
 383 }
 384
 385 static struct bin_attribute m48t59_nvram_attr = {
 386         .attr = {
 387                 .name = "nvram",
 388                 .mode = S_IRUGO | S_IWUSR,
 389         },
 390         .read = m48t59_nvram_read,
 391         .write = m48t59_nvram_write,
 392 };
 393
 394 static int __devinit m48t59_rtc_probe(struct platform_device *pdev)
 395 {
 396         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 397         struct m48t59_private *m48t59 = NULL;
 398         struct resource *res;
 399         int ret = -ENOMEM;
 400         char *name;
 401         const struct rtc_class_ops *ops;
 402
 403         /* This chip could be memory-mapped or I/O-mapped */
 404         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 405         if (!res) {
 406                 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 407                 if (!res)
 408                         return -EINVAL;
 409         }
 410
 411         if (res->flags & IORESOURCE_IO) {
 412                 /* If we are I/O-mapped, the platform should provide
 413                  * the operations accessing chip registers.
 414                  */
 415                 if (!pdata || !pdata->write_byte || !pdata->read_byte)
 416                         return -EINVAL;
 417         } else if (res->flags & IORESOURCE_MEM) {
 418                 /* we are memory-mapped */
 419                 if (!pdata) {
 420                         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 421                         if (!pdata)
 422                                 return -ENOMEM;
 423                         /* Ensure we only kmalloc platform data once */
 424                         pdev->dev.platform_data = pdata;
 425                 }
 426                 if (!pdata->type)
 427                         pdata->type = M48T59RTC_TYPE_M48T59;
 428
 429                 /* Try to use the generic memory read/write ops */
 430                 if (!pdata->write_byte)
 431                         pdata->write_byte = m48t59_mem_writeb;
 432                 if (!pdata->read_byte)
 433                         pdata->read_byte = m48t59_mem_readb;
 434         }
 435
 436         m48t59 = kzalloc(sizeof(*m48t59), GFP_KERNEL);
 437         if (!m48t59)
 438                 return -ENOMEM;
 439
 440         m48t59->ioaddr = pdata->ioaddr;
 441
 442         if (!m48t59->ioaddr) {
 443                 /* ioaddr not mapped externally */
 444                 m48t59->ioaddr = ioremap(res->start, res->end - res->start + 1);
 445                 if (!m48t59->ioaddr)
 446                         goto out;
 447         }
 448
 449         /* Try to get irq number. We also can work in
 450          * the mode without IRQ.
 451          */
 452         m48t59->irq = platform_get_irq(pdev, 0);
 453         if (m48t59->irq <= 0)
 454                 m48t59->irq = NO_IRQ;
 455
 456         if (m48t59->irq != NO_IRQ) {
 457                 ret = request_irq(m48t59->irq, m48t59_rtc_interrupt,
 458                         IRQF_SHARED, "rtc-m48t59", &pdev->dev);
 459                 if (ret)
 460                         goto out;
 461         }
 462         switch (pdata->type) {
 463         case M48T59RTC_TYPE_M48T59:
 464                 name = "m48t59";
 465                 ops = &m48t59_rtc_ops;
 466                 pdata->offset = 0x1ff0;
 467                 break;
 468         case M48T59RTC_TYPE_M48T02:
 469                 name = "m48t02";
 470                 ops = &m48t02_rtc_ops;
 471                 pdata->offset = 0x7f0;
 472                 break;
 473         case M48T59RTC_TYPE_M48T08:
 474                 name = "m48t08";
 475                 ops = &m48t02_rtc_ops;
 476                 pdata->offset = 0x1ff0;
 477                 break;
 478         default:
 479                 dev_err(&pdev->dev, "Unknown RTC type\n");
 480                 ret = -ENODEV;
 481                 goto out;
 482         }
 483
 484         spin_lock_init(&m48t59->lock);
 485         platform_set_drvdata(pdev, m48t59);
 486
 487         m48t59->rtc = rtc_device_register(name, &pdev->dev, ops, THIS_MODULE);
 488         if (IS_ERR(m48t59->rtc)) {
 489                 ret = PTR_ERR(m48t59->rtc);
 490                 goto out;
 491         }
 492
 493         m48t59_nvram_attr.size = pdata->offset;
 494
 495         ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
 496         if (ret) {
 497                 rtc_device_unregister(m48t59->rtc);
 498                 goto out;
 499         }
 500
 501         return 0;
 502
 503 out:
 504         if (m48t59->irq != NO_IRQ)
 505                 free_irq(m48t59->irq, &pdev->dev);
 506         if (m48t59->ioaddr)
 507                 iounmap(m48t59->ioaddr);
 508         if (m48t59)
 509                 kfree(m48t59);
 510         return ret;
 511 }
 512
 513 static int __devexit m48t59_rtc_remove(struct platform_device *pdev)
 514 {
 515         struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 516         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 517
 518         sysfs_remove_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
 519         if (!IS_ERR(m48t59->rtc))
 520                 rtc_device_unregister(m48t59->rtc);
 521         if (m48t59->ioaddr && !pdata->ioaddr)
 522                 iounmap(m48t59->ioaddr);
 523         if (m48t59->irq != NO_IRQ)
 524                 free_irq(m48t59->irq, &pdev->dev);
 525         platform_set_drvdata(pdev, NULL);
 526         kfree(m48t59);
 527         return 0;
 528 }
 529
 530 /* work with hotplug and coldplug */
 531 MODULE_ALIAS("platform:rtc-m48t59");
 532
 533 static struct platform_driver m48t59_rtc_driver = {
 534         .driver         = {
 535                 .name   = "rtc-m48t59",
 536                 .owner  = THIS_MODULE,
 537         },
 538         .probe          = m48t59_rtc_probe,
 539         .remove         = __devexit_p(m48t59_rtc_remove),
 540 };
 541
 542 static int __init m48t59_rtc_init(void)
 543 {
 544         return platform_driver_register(&m48t59_rtc_driver);
 545 }
 546
 547 static void __exit m48t59_rtc_exit(void)
 548 {
 549         platform_driver_unregister(&m48t59_rtc_driver);
 550 }
 551
 552 module_init(m48t59_rtc_init);
 553 module_exit(m48t59_rtc_exit);
 554
 555 MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>");
 556 MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver");
 557 MODULE_LICENSE("GPL");