rtc-ds1742: fix races around device registration
[safe/jmp/linux-2.6] / drivers / rtc / rtc-sh.c
index c594b34..e95cc6f 100644 (file)
@@ -1,7 +1,7 @@
 /*
  * SuperH On-Chip RTC Support
  *
- * Copyright (C) 2006, 2007, 2008  Paul Mundt
+ * Copyright (C) 2006 - 2009  Paul Mundt
  * Copyright (C) 2006  Jamie Lenehan
  * Copyright (C) 2008  Angelo Castello
  *
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
 #include <linux/io.h>
+#include <linux/log2.h>
+#include <linux/clk.h>
 #include <asm/rtc.h>
 
 #define DRV_NAME       "sh-rtc"
-#define DRV_VERSION    "0.2.0"
+#define DRV_VERSION    "0.2.3"
 
 #define RTC_REG(r)     ((r) * rtc_reg_size)
 
 #define RCR2_START     0x01    /* Start bit               */
 
 struct sh_rtc {
-       void __iomem *regbase;
-       unsigned long regsize;
-       struct resource *res;
-       unsigned int alarm_irq, periodic_irq, carry_irq;
-       struct rtc_device *rtc_dev;
-       spinlock_t lock;
-       unsigned long capabilities;     /* See asm-sh/rtc.h for cap bits */
-       unsigned short periodic_freq;
+       void __iomem            *regbase;
+       unsigned long           regsize;
+       struct resource         *res;
+       int                     alarm_irq;
+       int                     periodic_irq;
+       int                     carry_irq;
+       struct clk              *clk;
+       struct rtc_device       *rtc_dev;
+       spinlock_t              lock;
+       unsigned long           capabilities;   /* See asm/rtc.h for cap bits */
+       unsigned short          periodic_freq;
 };
 
-static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
+static int __sh_rtc_interrupt(struct sh_rtc *rtc)
 {
-       struct sh_rtc *rtc = dev_id;
-       unsigned int tmp;
-
-       spin_lock(&rtc->lock);
+       unsigned int tmp, pending;
 
        tmp = readb(rtc->regbase + RCR1);
+       pending = tmp & RCR1_CF;
        tmp &= ~RCR1_CF;
        writeb(tmp, rtc->regbase + RCR1);
 
        /* Users have requested One x Second IRQ */
-       if (rtc->periodic_freq & PF_OXS)
+       if (pending && rtc->periodic_freq & PF_OXS)
                rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
 
-       spin_unlock(&rtc->lock);
-
-       return IRQ_HANDLED;
+       return pending;
 }
 
-static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
+static int __sh_rtc_alarm(struct sh_rtc *rtc)
 {
-       struct sh_rtc *rtc = dev_id;
-       unsigned int tmp;
-
-       spin_lock(&rtc->lock);
+       unsigned int tmp, pending;
 
        tmp = readb(rtc->regbase + RCR1);
+       pending = tmp & RCR1_AF;
        tmp &= ~(RCR1_AF | RCR1_AIE);
-               writeb(tmp, rtc->regbase + RCR1);
-
-       rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
+       writeb(tmp, rtc->regbase + RCR1);
 
-       spin_unlock(&rtc->lock);
+       if (pending)
+               rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
 
-       return IRQ_HANDLED;
+       return pending;
 }
 
-static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
+static int __sh_rtc_periodic(struct sh_rtc *rtc)
 {
-       struct sh_rtc *rtc = dev_id;
        struct rtc_device *rtc_dev = rtc->rtc_dev;
-       unsigned int tmp;
-
-       spin_lock(&rtc->lock);
+       struct rtc_task *irq_task;
+       unsigned int tmp, pending;
 
        tmp = readb(rtc->regbase + RCR2);
+       pending = tmp & RCR2_PEF;
        tmp &= ~RCR2_PEF;
        writeb(tmp, rtc->regbase + RCR2);
 
+       if (!pending)
+               return 0;
+
        /* Half period enabled than one skipped and the next notified */
        if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT))
                rtc->periodic_freq &= ~PF_COUNT;
@@ -154,19 +154,68 @@ static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
                        rtc->periodic_freq |= PF_COUNT;
                if (rtc->periodic_freq & PF_KOU) {
                        spin_lock(&rtc_dev->irq_task_lock);
-                       if (rtc_dev->irq_task)
-                               rtc_dev->irq_task->func(rtc_dev->irq_task->private_data);
+                       irq_task = rtc_dev->irq_task;
+                       if (irq_task)
+                               irq_task->func(irq_task->private_data);
                        spin_unlock(&rtc_dev->irq_task_lock);
                } else
                        rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
        }
 
+       return pending;
+}
+
+static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
+{
+       struct sh_rtc *rtc = dev_id;
+       int ret;
+
+       spin_lock(&rtc->lock);
+       ret = __sh_rtc_interrupt(rtc);
+       spin_unlock(&rtc->lock);
+
+       return IRQ_RETVAL(ret);
+}
+
+static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
+{
+       struct sh_rtc *rtc = dev_id;
+       int ret;
+
+       spin_lock(&rtc->lock);
+       ret = __sh_rtc_alarm(rtc);
        spin_unlock(&rtc->lock);
 
-       return IRQ_HANDLED;
+       return IRQ_RETVAL(ret);
 }
 
-static inline void sh_rtc_setpie(struct device *dev, unsigned int enable)
+static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
+{
+       struct sh_rtc *rtc = dev_id;
+       int ret;
+
+       spin_lock(&rtc->lock);
+       ret = __sh_rtc_periodic(rtc);
+       spin_unlock(&rtc->lock);
+
+       return IRQ_RETVAL(ret);
+}
+
+static irqreturn_t sh_rtc_shared(int irq, void *dev_id)
+{
+       struct sh_rtc *rtc = dev_id;
+       int ret;
+
+       spin_lock(&rtc->lock);
+       ret = __sh_rtc_interrupt(rtc);
+       ret |= __sh_rtc_alarm(rtc);
+       ret |= __sh_rtc_periodic(rtc);
+       spin_unlock(&rtc->lock);
+
+       return IRQ_RETVAL(ret);
+}
+
+static int sh_rtc_irq_set_state(struct device *dev, int enable)
 {
        struct sh_rtc *rtc = dev_get_drvdata(dev);
        unsigned int tmp;
@@ -176,17 +225,22 @@ static inline void sh_rtc_setpie(struct device *dev, unsigned int enable)
        tmp = readb(rtc->regbase + RCR2);
 
        if (enable) {
+               rtc->periodic_freq |= PF_KOU;
                tmp &= ~RCR2_PEF;       /* Clear PES bit */
                tmp |= (rtc->periodic_freq & ~PF_HP);   /* Set PES2-0 */
-       } else
+       } else {
+               rtc->periodic_freq &= ~PF_KOU;
                tmp &= ~(RCR2_PESMASK | RCR2_PEF);
+       }
 
        writeb(tmp, rtc->regbase + RCR2);
 
        spin_unlock_irq(&rtc->lock);
+
+       return 0;
 }
 
-static inline int sh_rtc_setfreq(struct device *dev, unsigned int freq)
+static int sh_rtc_irq_set_freq(struct device *dev, int freq)
 {
        struct sh_rtc *rtc = dev_get_drvdata(dev);
        int tmp, ret = 0;
@@ -229,10 +283,8 @@ static inline int sh_rtc_setfreq(struct device *dev, unsigned int freq)
                ret = -ENOTSUPP;
        }
 
-       if (ret == 0) {
+       if (ret == 0)
                rtc->periodic_freq |= tmp;
-               rtc->rtc_dev->irq_freq = freq;
-       }
 
        spin_unlock_irq(&rtc->lock);
        return ret;
@@ -247,22 +299,16 @@ static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
 
        tmp = readb(rtc->regbase + RCR1);
 
-       if (!enable)
-               tmp &= ~RCR1_AIE;
-       else
+       if (enable)
                tmp |= RCR1_AIE;
+       else
+               tmp &= ~RCR1_AIE;
 
        writeb(tmp, rtc->regbase + RCR1);
 
        spin_unlock_irq(&rtc->lock);
 }
 
-static void sh_rtc_release(struct device *dev)
-{
-       sh_rtc_setpie(dev, 0);
-       sh_rtc_setaie(dev, 0);
-}
-
 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
 {
        struct sh_rtc *rtc = dev_get_drvdata(dev);
@@ -278,32 +324,42 @@ static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
        return 0;
 }
 
+static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
+{
+       struct sh_rtc *rtc = dev_get_drvdata(dev);
+       unsigned int tmp;
+
+       spin_lock_irq(&rtc->lock);
+
+       tmp = readb(rtc->regbase + RCR1);
+
+       if (!enable)
+               tmp &= ~RCR1_CIE;
+       else
+               tmp |= RCR1_CIE;
+
+       writeb(tmp, rtc->regbase + RCR1);
+
+       spin_unlock_irq(&rtc->lock);
+}
+
 static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 {
        struct sh_rtc *rtc = dev_get_drvdata(dev);
        unsigned int ret = 0;
 
        switch (cmd) {
-       case RTC_PIE_OFF:
-       case RTC_PIE_ON:
-               sh_rtc_setpie(dev, cmd == RTC_PIE_ON);
-               break;
        case RTC_AIE_OFF:
        case RTC_AIE_ON:
                sh_rtc_setaie(dev, cmd == RTC_AIE_ON);
                break;
        case RTC_UIE_OFF:
                rtc->periodic_freq &= ~PF_OXS;
+               sh_rtc_setcie(dev, 0);
                break;
        case RTC_UIE_ON:
                rtc->periodic_freq |= PF_OXS;
-               break;
-       case RTC_IRQP_READ:
-               ret = put_user(rtc->rtc_dev->irq_freq,
-                              (unsigned long __user *)arg);
-               break;
-       case RTC_IRQP_SET:
-               ret = sh_rtc_setfreq(dev, arg);
+               sh_rtc_setcie(dev, 1);
                break;
        default:
                ret = -ENOIOCTLCMD;
@@ -330,23 +386,23 @@ static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
 
                sec128 = readb(rtc->regbase + R64CNT);
 
-               tm->tm_sec      = BCD2BIN(readb(rtc->regbase + RSECCNT));
-               tm->tm_min      = BCD2BIN(readb(rtc->regbase + RMINCNT));
-               tm->tm_hour     = BCD2BIN(readb(rtc->regbase + RHRCNT));
-               tm->tm_wday     = BCD2BIN(readb(rtc->regbase + RWKCNT));
-               tm->tm_mday     = BCD2BIN(readb(rtc->regbase + RDAYCNT));
-               tm->tm_mon      = BCD2BIN(readb(rtc->regbase + RMONCNT)) - 1;
+               tm->tm_sec      = bcd2bin(readb(rtc->regbase + RSECCNT));
+               tm->tm_min      = bcd2bin(readb(rtc->regbase + RMINCNT));
+               tm->tm_hour     = bcd2bin(readb(rtc->regbase + RHRCNT));
+               tm->tm_wday     = bcd2bin(readb(rtc->regbase + RWKCNT));
+               tm->tm_mday     = bcd2bin(readb(rtc->regbase + RDAYCNT));
+               tm->tm_mon      = bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
 
                if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
                        yr  = readw(rtc->regbase + RYRCNT);
-                       yr100 = BCD2BIN(yr >> 8);
+                       yr100 = bcd2bin(yr >> 8);
                        yr &= 0xff;
                } else {
                        yr  = readb(rtc->regbase + RYRCNT);
-                       yr100 = BCD2BIN((yr == 0x99) ? 0x19 : 0x20);
+                       yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
                }
 
-               tm->tm_year = (yr100 * 100 + BCD2BIN(yr)) - 1900;
+               tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
 
                sec2 = readb(rtc->regbase + R64CNT);
                cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
@@ -359,18 +415,17 @@ static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
                tm->tm_sec--;
 #endif
 
+       /* only keep the carry interrupt enabled if UIE is on */
+       if (!(rtc->periodic_freq & PF_OXS))
+               sh_rtc_setcie(dev, 0);
+
        dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
                "mday=%d, mon=%d, year=%d, wday=%d\n",
-               __FUNCTION__,
+               __func__,
                tm->tm_sec, tm->tm_min, tm->tm_hour,
                tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
 
-       if (rtc_valid_tm(tm) < 0) {
-               dev_err(dev, "invalid date\n");
-               rtc_time_to_tm(0, tm);
-       }
-
-       return 0;
+       return rtc_valid_tm(tm);
 }
 
 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
@@ -388,20 +443,20 @@ static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
        tmp &= ~RCR2_START;
        writeb(tmp, rtc->regbase + RCR2);
 
-       writeb(BIN2BCD(tm->tm_sec),  rtc->regbase + RSECCNT);
-       writeb(BIN2BCD(tm->tm_min),  rtc->regbase + RMINCNT);
-       writeb(BIN2BCD(tm->tm_hour), rtc->regbase + RHRCNT);
-       writeb(BIN2BCD(tm->tm_wday), rtc->regbase + RWKCNT);
-       writeb(BIN2BCD(tm->tm_mday), rtc->regbase + RDAYCNT);
-       writeb(BIN2BCD(tm->tm_mon + 1), rtc->regbase + RMONCNT);
+       writeb(bin2bcd(tm->tm_sec),  rtc->regbase + RSECCNT);
+       writeb(bin2bcd(tm->tm_min),  rtc->regbase + RMINCNT);
+       writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
+       writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
+       writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
+       writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
 
        if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
-               year = (BIN2BCD((tm->tm_year + 1900) / 100) << 8) |
-                       BIN2BCD(tm->tm_year % 100);
+               year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
+                       bin2bcd(tm->tm_year % 100);
                writew(year, rtc->regbase + RYRCNT);
        } else {
                year = tm->tm_year % 100;
-               writeb(BIN2BCD(year), rtc->regbase + RYRCNT);
+               writeb(bin2bcd(year), rtc->regbase + RYRCNT);
        }
 
        /* Start RTC */
@@ -423,7 +478,7 @@ static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
        byte = readb(rtc->regbase + reg_off);
        if (byte & AR_ENB) {
                byte &= ~AR_ENB;        /* strip the enable bit */
-               value = BCD2BIN(byte);
+               value = bcd2bin(byte);
        }
 
        return value;
@@ -461,7 +516,7 @@ static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
        if (value < 0)
                writeb(0, rtc->regbase + reg_off);
        else
-               writeb(BIN2BCD(value) | AR_ENB,  rtc->regbase + reg_off);
+               writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
 }
 
 static int sh_rtc_check_alarm(struct rtc_time *tm)
@@ -539,27 +594,7 @@ static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
        return 0;
 }
 
-static int sh_rtc_irq_set_state(struct device *dev, int enabled)
-{
-       struct platform_device *pdev = to_platform_device(dev);
-       struct sh_rtc *rtc = platform_get_drvdata(pdev);
-
-       if (enabled) {
-               rtc->periodic_freq |= PF_KOU;
-               return sh_rtc_ioctl(dev, RTC_PIE_ON, 0);
-       } else {
-               rtc->periodic_freq &= ~PF_KOU;
-               return sh_rtc_ioctl(dev, RTC_PIE_OFF, 0);
-       }
-}
-
-static int sh_rtc_irq_set_freq(struct device *dev, int freq)
-{
-       return sh_rtc_ioctl(dev, RTC_IRQP_SET, freq);
-}
-
 static struct rtc_class_ops sh_rtc_ops = {
-       .release        = sh_rtc_release,
        .ioctl          = sh_rtc_ioctl,
        .read_time      = sh_rtc_read_time,
        .set_time       = sh_rtc_set_time,
@@ -570,12 +605,13 @@ static struct rtc_class_ops sh_rtc_ops = {
        .proc           = sh_rtc_proc,
 };
 
-static int __devinit sh_rtc_probe(struct platform_device *pdev)
+static int __init sh_rtc_probe(struct platform_device *pdev)
 {
        struct sh_rtc *rtc;
        struct resource *res;
-       unsigned int tmp;
-       int ret = -ENOENT;
+       struct rtc_time r;
+       char clk_name[6];
+       int clk_id, ret;
 
        rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
        if (unlikely(!rtc))
@@ -584,31 +620,25 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
        spin_lock_init(&rtc->lock);
 
        /* get periodic/carry/alarm irqs */
-       rtc->periodic_irq = platform_get_irq(pdev, 0);
-       if (unlikely(rtc->periodic_irq < 0)) {
-               dev_err(&pdev->dev, "No IRQ for period\n");
+       ret = platform_get_irq(pdev, 0);
+       if (unlikely(ret <= 0)) {
+               ret = -ENOENT;
+               dev_err(&pdev->dev, "No IRQ resource\n");
                goto err_badres;
        }
 
+       rtc->periodic_irq = ret;
        rtc->carry_irq = platform_get_irq(pdev, 1);
-       if (unlikely(rtc->carry_irq < 0)) {
-               dev_err(&pdev->dev, "No IRQ for carry\n");
-               goto err_badres;
-       }
-
        rtc->alarm_irq = platform_get_irq(pdev, 2);
-       if (unlikely(rtc->alarm_irq < 0)) {
-               dev_err(&pdev->dev, "No IRQ for alarm\n");
-               goto err_badres;
-       }
 
        res = platform_get_resource(pdev, IORESOURCE_IO, 0);
        if (unlikely(res == NULL)) {
+               ret = -ENOENT;
                dev_err(&pdev->dev, "No IO resource\n");
                goto err_badres;
        }
 
-       rtc->regsize = res->end - res->start + 1;
+       rtc->regsize = resource_size(res);
 
        rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
        if (unlikely(!rtc->res)) {
@@ -616,19 +646,32 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
                goto err_badres;
        }
 
-       rtc->regbase = (void __iomem *)rtc->res->start;
+       rtc->regbase = ioremap_nocache(rtc->res->start, rtc->regsize);
        if (unlikely(!rtc->regbase)) {
                ret = -EINVAL;
                goto err_badmap;
        }
 
-       rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
-                                          &sh_rtc_ops, THIS_MODULE);
-       if (IS_ERR(rtc->rtc_dev)) {
-               ret = PTR_ERR(rtc->rtc_dev);
-               goto err_badmap;
+       clk_id = pdev->id;
+       /* With a single device, the clock id is still "rtc0" */
+       if (clk_id < 0)
+               clk_id = 0;
+
+       snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
+
+       rtc->clk = clk_get(&pdev->dev, clk_name);
+       if (IS_ERR(rtc->clk)) {
+               /*
+                * No error handling for rtc->clk intentionally, not all
+                * platforms will have a unique clock for the RTC, and
+                * the clk API can handle the struct clk pointer being
+                * NULL.
+                */
+               rtc->clk = NULL;
        }
 
+       clk_enable(rtc->clk);
+
        rtc->capabilities = RTC_DEF_CAPABILITIES;
        if (pdev->dev.platform_data) {
                struct sh_rtc_platform_info *pinfo = pdev->dev.platform_data;
@@ -640,50 +683,82 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
                rtc->capabilities |= pinfo->capabilities;
        }
 
-       rtc->rtc_dev->max_user_freq = 256;
-       rtc->rtc_dev->irq_freq = 1;
-       rtc->periodic_freq = 0x60;
+       if (rtc->carry_irq <= 0) {
+               /* register shared periodic/carry/alarm irq */
+               ret = request_irq(rtc->periodic_irq, sh_rtc_shared,
+                                 IRQF_DISABLED, "sh-rtc", rtc);
+               if (unlikely(ret)) {
+                       dev_err(&pdev->dev,
+                               "request IRQ failed with %d, IRQ %d\n", ret,
+                               rtc->periodic_irq);
+                       goto err_unmap;
+               }
+       } else {
+               /* register periodic/carry/alarm irqs */
+               ret = request_irq(rtc->periodic_irq, sh_rtc_periodic,
+                                 IRQF_DISABLED, "sh-rtc period", rtc);
+               if (unlikely(ret)) {
+                       dev_err(&pdev->dev,
+                               "request period IRQ failed with %d, IRQ %d\n",
+                               ret, rtc->periodic_irq);
+                       goto err_unmap;
+               }
 
-       platform_set_drvdata(pdev, rtc);
+               ret = request_irq(rtc->carry_irq, sh_rtc_interrupt,
+                                 IRQF_DISABLED, "sh-rtc carry", rtc);
+               if (unlikely(ret)) {
+                       dev_err(&pdev->dev,
+                               "request carry IRQ failed with %d, IRQ %d\n",
+                               ret, rtc->carry_irq);
+                       free_irq(rtc->periodic_irq, rtc);
+                       goto err_unmap;
+               }
 
-       /* register periodic/carry/alarm irqs */
-       ret = request_irq(rtc->periodic_irq, sh_rtc_periodic, IRQF_DISABLED,
-                         "sh-rtc period", rtc);
-       if (unlikely(ret)) {
-               dev_err(&pdev->dev,
-                       "request period IRQ failed with %d, IRQ %d\n", ret,
-                       rtc->periodic_irq);
-               goto err_badmap;
+               ret = request_irq(rtc->alarm_irq, sh_rtc_alarm,
+                                 IRQF_DISABLED, "sh-rtc alarm", rtc);
+               if (unlikely(ret)) {
+                       dev_err(&pdev->dev,
+                               "request alarm IRQ failed with %d, IRQ %d\n",
+                               ret, rtc->alarm_irq);
+                       free_irq(rtc->carry_irq, rtc);
+                       free_irq(rtc->periodic_irq, rtc);
+                       goto err_unmap;
+               }
        }
 
-       ret = request_irq(rtc->carry_irq, sh_rtc_interrupt, IRQF_DISABLED,
-                         "sh-rtc carry", rtc);
-       if (unlikely(ret)) {
-               dev_err(&pdev->dev,
-                       "request carry IRQ failed with %d, IRQ %d\n", ret,
-                       rtc->carry_irq);
-               free_irq(rtc->periodic_irq, rtc);
-               goto err_badmap;
-       }
+       platform_set_drvdata(pdev, rtc);
 
-       ret = request_irq(rtc->alarm_irq, sh_rtc_alarm, IRQF_DISABLED,
-                         "sh-rtc alarm", rtc);
-       if (unlikely(ret)) {
-               dev_err(&pdev->dev,
-                       "request alarm IRQ failed with %d, IRQ %d\n", ret,
-                       rtc->alarm_irq);
-               free_irq(rtc->carry_irq, rtc);
+       /* everything disabled by default */
+       sh_rtc_irq_set_freq(&pdev->dev, 0);
+       sh_rtc_irq_set_state(&pdev->dev, 0);
+       sh_rtc_setaie(&pdev->dev, 0);
+       sh_rtc_setcie(&pdev->dev, 0);
+
+       rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
+                                          &sh_rtc_ops, THIS_MODULE);
+       if (IS_ERR(rtc->rtc_dev)) {
+               ret = PTR_ERR(rtc->rtc_dev);
                free_irq(rtc->periodic_irq, rtc);
-               goto err_badmap;
+               free_irq(rtc->carry_irq, rtc);
+               free_irq(rtc->alarm_irq, rtc);
+               goto err_unmap;
        }
 
-       tmp = readb(rtc->regbase + RCR1);
-       tmp &= ~RCR1_CF;
-       tmp |= RCR1_CIE;
-       writeb(tmp, rtc->regbase + RCR1);
+       rtc->rtc_dev->max_user_freq = 256;
 
+       /* reset rtc to epoch 0 if time is invalid */
+       if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
+               rtc_time_to_tm(0, &r);
+               rtc_set_time(rtc->rtc_dev, &r);
+       }
+
+       device_init_wakeup(&pdev->dev, 1);
        return 0;
 
+err_unmap:
+       clk_disable(rtc->clk);
+       clk_put(rtc->clk);
+       iounmap(rtc->regbase);
 err_badmap:
        release_resource(rtc->res);
 err_badres:
@@ -692,40 +767,82 @@ err_badres:
        return ret;
 }
 
-static int __devexit sh_rtc_remove(struct platform_device *pdev)
+static int __exit sh_rtc_remove(struct platform_device *pdev)
 {
        struct sh_rtc *rtc = platform_get_drvdata(pdev);
 
-       if (likely(rtc->rtc_dev))
-               rtc_device_unregister(rtc->rtc_dev);
+       rtc_device_unregister(rtc->rtc_dev);
+       sh_rtc_irq_set_state(&pdev->dev, 0);
 
-       sh_rtc_setpie(&pdev->dev, 0);
        sh_rtc_setaie(&pdev->dev, 0);
+       sh_rtc_setcie(&pdev->dev, 0);
 
-       free_irq(rtc->carry_irq, rtc);
        free_irq(rtc->periodic_irq, rtc);
-       free_irq(rtc->alarm_irq, rtc);
 
+       if (rtc->carry_irq > 0) {
+               free_irq(rtc->carry_irq, rtc);
+               free_irq(rtc->alarm_irq, rtc);
+       }
+
+       iounmap(rtc->regbase);
        release_resource(rtc->res);
 
+       clk_disable(rtc->clk);
+       clk_put(rtc->clk);
+
        platform_set_drvdata(pdev, NULL);
 
        kfree(rtc);
 
        return 0;
 }
+
+static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct sh_rtc *rtc = platform_get_drvdata(pdev);
+
+       set_irq_wake(rtc->periodic_irq, enabled);
+
+       if (rtc->carry_irq > 0) {
+               set_irq_wake(rtc->carry_irq, enabled);
+               set_irq_wake(rtc->alarm_irq, enabled);
+       }
+}
+
+static int sh_rtc_suspend(struct device *dev)
+{
+       if (device_may_wakeup(dev))
+               sh_rtc_set_irq_wake(dev, 1);
+
+       return 0;
+}
+
+static int sh_rtc_resume(struct device *dev)
+{
+       if (device_may_wakeup(dev))
+               sh_rtc_set_irq_wake(dev, 0);
+
+       return 0;
+}
+
+static const struct dev_pm_ops sh_rtc_dev_pm_ops = {
+       .suspend = sh_rtc_suspend,
+       .resume = sh_rtc_resume,
+};
+
 static struct platform_driver sh_rtc_platform_driver = {
        .driver         = {
                .name   = DRV_NAME,
                .owner  = THIS_MODULE,
+               .pm     = &sh_rtc_dev_pm_ops,
        },
-       .probe          = sh_rtc_probe,
-       .remove         = __devexit_p(sh_rtc_remove),
+       .remove         = __exit_p(sh_rtc_remove),
 };
 
 static int __init sh_rtc_init(void)
 {
-       return platform_driver_register(&sh_rtc_platform_driver);
+       return platform_driver_probe(&sh_rtc_platform_driver, sh_rtc_probe);
 }
 
 static void __exit sh_rtc_exit(void)