LXR linux/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
  35struct 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 */
  46static void
  47m48t59_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
  55static u8
  56m48t59_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 */
  67static 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
 105static 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 */
 143static 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 */
 186static 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 */
 238static 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
 264static 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 */
 284static 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
 304static 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
 313static 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
 333static 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
 353static 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
 364static 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
 440out:
 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
 452static 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
 468static struct platform_driver m48t59_rtc_driver = {
 469        .driver         = {
 470                .name   = "rtc-m48t59",
 471                .owner  = THIS_MODULE,
 472        },
 473        .probe          = m48t59_rtc_probe,
 474        .remove         = __devexit_p(m48t59_rtc_remove),
 475};
 476
 477static int __init m48t59_rtc_init(void)
 478{
 479        return platform_driver_register(&m48t59_rtc_driver);
 480}
 481
 482static void __exit m48t59_rtc_exit(void)
 483{
 484        platform_driver_unregister(&m48t59_rtc_driver);
 485}
 486
 487module_init(m48t59_rtc_init);
 488module_exit(m48t59_rtc_exit);
 489
 490MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>");
 491MODULE_DESCRIPTION("M48T59 RTC driver");
 492MODULE_LICENSE("GPL");
 493