rtc-sh.c

Go to the documentation of this file.

/*
 * SuperH On-Chip RTC Support
 *
 * Copyright (C) 2006 - 2009  Paul Mundt
 * Copyright (C) 2006  Jamie Lenehan
 * Copyright (C) 2008  Angelo Castello
 *
 * Based on the old arch/sh/kernel/cpu/rtc.c by:
 *
 *  Copyright (C) 2000  Philipp Rumpf <[email protected]>
 *  Copyright (C) 1999  Tetsuya Okada & Niibe Yutaka
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/log2.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <asm/rtc.h>

#define DRV_NAME    "sh-rtc"
#define DRV_VERSION "0.2.3"

#define RTC_REG(r)  ((r) * rtc_reg_size)

#define R64CNT      RTC_REG(0)

#define RSECCNT     RTC_REG(1)  /* RTC sec */
#define RMINCNT     RTC_REG(2)  /* RTC min */
#define RHRCNT      RTC_REG(3)  /* RTC hour */
#define RWKCNT      RTC_REG(4)  /* RTC week */
#define RDAYCNT     RTC_REG(5)  /* RTC day */
#define RMONCNT     RTC_REG(6)  /* RTC month */
#define RYRCNT      RTC_REG(7)  /* RTC year */
#define RSECAR      RTC_REG(8)  /* ALARM sec */
#define RMINAR      RTC_REG(9)  /* ALARM min */
#define RHRAR       RTC_REG(10) /* ALARM hour */
#define RWKAR       RTC_REG(11) /* ALARM week */
#define RDAYAR      RTC_REG(12) /* ALARM day */
#define RMONAR      RTC_REG(13) /* ALARM month */
#define RCR1        RTC_REG(14) /* Control */
#define RCR2        RTC_REG(15) /* Control */

/*
 * Note on RYRAR and RCR3: Up until this point most of the register
 * definitions are consistent across all of the available parts. However,
 * the placement of the optional RYRAR and RCR3 (the RYRAR control
 * register used to control RYRCNT/RYRAR compare) varies considerably
 * across various parts, occasionally being mapped in to a completely
 * unrelated address space. For proper RYRAR support a separate resource
 * would have to be handed off, but as this is purely optional in
 * practice, we simply opt not to support it, thereby keeping the code
 * quite a bit more simplified.
 */

/* ALARM Bits - or with BCD encoded value */
#define AR_ENB      0x80    /* Enable for alarm cmp   */

/* Period Bits */
#define PF_HP       0x100   /* Enable Half Period to support 8,32,128Hz */
#define PF_COUNT    0x200   /* Half periodic counter */
#define PF_OXS      0x400   /* Periodic One x Second */
#define PF_KOU      0x800   /* Kernel or User periodic request 1=kernel */
#define PF_MASK     0xf00

/* RCR1 Bits */
#define RCR1_CF     0x80    /* Carry Flag             */
#define RCR1_CIE    0x10    /* Carry Interrupt Enable */
#define RCR1_AIE    0x08    /* Alarm Interrupt Enable */
#define RCR1_AF     0x01    /* Alarm Flag             */

/* RCR2 Bits */
#define RCR2_PEF    0x80    /* PEriodic interrupt Flag */
#define RCR2_PESMASK    0x70    /* Periodic interrupt Set  */
#define RCR2_RTCEN  0x08    /* ENable RTC              */
#define RCR2_ADJ    0x04    /* ADJustment (30-second)  */
#define RCR2_RESET  0x02    /* Reset bit               */
#define RCR2_START  0x01    /* Start bit               */

struct sh_rtc {
    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 int __sh_rtc_interrupt(struct sh_rtc *rtc)
{
    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 (pending && rtc->periodic_freq & PF_OXS)
        rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);

    return pending;
}

static int __sh_rtc_alarm(struct sh_rtc *rtc)
{
    unsigned int tmp, pending;

    tmp = readb(rtc->regbase + RCR1);
    pending = tmp & RCR1_AF;
    tmp &= ~(RCR1_AF | RCR1_AIE);
    writeb(tmp, rtc->regbase + RCR1);

    if (pending)
        rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);

    return pending;
}

static int __sh_rtc_periodic(struct sh_rtc *rtc)
{
    struct rtc_device *rtc_dev = rtc->rtc_dev;
    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;
    else {
        if (rtc->periodic_freq & PF_HP)
            rtc->periodic_freq |= PF_COUNT;
        if (rtc->periodic_freq & PF_KOU) {
            spin_lock(&rtc_dev->irq_task_lock);
            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_RETVAL(ret);
}

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;

    spin_lock_irq(&rtc->lock);

    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 {
        rtc->periodic_freq &= ~PF_KOU;
        tmp &= ~(RCR2_PESMASK | RCR2_PEF);
    }

    writeb(tmp, rtc->regbase + RCR2);

    spin_unlock_irq(&rtc->lock);

    return 0;
}

static int sh_rtc_irq_set_freq(struct device *dev, int freq)
{
    struct sh_rtc *rtc = dev_get_drvdata(dev);
    int tmp, ret = 0;

    spin_lock_irq(&rtc->lock);
    tmp = rtc->periodic_freq & PF_MASK;

    switch (freq) {
    case 0:
        rtc->periodic_freq = 0x00;
        break;
    case 1:
        rtc->periodic_freq = 0x60;
        break;
    case 2:
        rtc->periodic_freq = 0x50;
        break;
    case 4:
        rtc->periodic_freq = 0x40;
        break;
    case 8:
        rtc->periodic_freq = 0x30 | PF_HP;
        break;
    case 16:
        rtc->periodic_freq = 0x30;
        break;
    case 32:
        rtc->periodic_freq = 0x20 | PF_HP;
        break;
    case 64:
        rtc->periodic_freq = 0x20;
        break;
    case 128:
        rtc->periodic_freq = 0x10 | PF_HP;
        break;
    case 256:
        rtc->periodic_freq = 0x10;
        break;
    default:
        ret = -ENOTSUPP;
    }

    if (ret == 0)
        rtc->periodic_freq |= tmp;

    spin_unlock_irq(&rtc->lock);
    return ret;
}

static inline void sh_rtc_setaie(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_AIE;
    else
        tmp &= ~RCR1_AIE;

    writeb(tmp, rtc->regbase + RCR1);

    spin_unlock_irq(&rtc->lock);
}

static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
{
    struct sh_rtc *rtc = dev_get_drvdata(dev);
    unsigned int tmp;

    tmp = readb(rtc->regbase + RCR1);
    seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");

    tmp = readb(rtc->regbase + RCR2);
    seq_printf(seq, "periodic_IRQ\t: %s\n",
           (tmp & RCR2_PESMASK) ? "yes" : "no");

    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_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
    sh_rtc_setaie(dev, enabled);
    return 0;
}

static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct sh_rtc *rtc = platform_get_drvdata(pdev);
    unsigned int sec128, sec2, yr, yr100, cf_bit;

    do {
        unsigned int tmp;

        spin_lock_irq(&rtc->lock);

        tmp = readb(rtc->regbase + RCR1);
        tmp &= ~RCR1_CF; /* Clear CF-bit */
        tmp |= RCR1_CIE;
        writeb(tmp, rtc->regbase + RCR1);

        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;

        if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
            yr  = readw(rtc->regbase + RYRCNT);
            yr100 = bcd2bin(yr >> 8);
            yr &= 0xff;
        } else {
            yr  = readb(rtc->regbase + RYRCNT);
            yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
        }

        tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;

        sec2 = readb(rtc->regbase + R64CNT);
        cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;

        spin_unlock_irq(&rtc->lock);
    } while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);

#if RTC_BIT_INVERTED != 0
    if ((sec128 & RTC_BIT_INVERTED))
        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",
        __func__,
        tm->tm_sec, tm->tm_min, tm->tm_hour,
        tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);

    return rtc_valid_tm(tm);
}

static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct sh_rtc *rtc = platform_get_drvdata(pdev);
    unsigned int tmp;
    int year;

    spin_lock_irq(&rtc->lock);

    /* Reset pre-scaler & stop RTC */
    tmp = readb(rtc->regbase + RCR2);
    tmp |= RCR2_RESET;
    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);

    if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
        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);
    }

    /* Start RTC */
    tmp = readb(rtc->regbase + RCR2);
    tmp &= ~RCR2_RESET;
    tmp |= RCR2_RTCEN | RCR2_START;
    writeb(tmp, rtc->regbase + RCR2);

    spin_unlock_irq(&rtc->lock);

    return 0;
}

static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
{
    unsigned int byte;
    int value = 0xff;   /* return 0xff for ignored values */

    byte = readb(rtc->regbase + reg_off);
    if (byte & AR_ENB) {
        byte &= ~AR_ENB;    /* strip the enable bit */
        value = bcd2bin(byte);
    }

    return value;
}

static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct sh_rtc *rtc = platform_get_drvdata(pdev);
    struct rtc_time *tm = &wkalrm->time;

    spin_lock_irq(&rtc->lock);

    tm->tm_sec  = sh_rtc_read_alarm_value(rtc, RSECAR);
    tm->tm_min  = sh_rtc_read_alarm_value(rtc, RMINAR);
    tm->tm_hour = sh_rtc_read_alarm_value(rtc, RHRAR);
    tm->tm_wday = sh_rtc_read_alarm_value(rtc, RWKAR);
    tm->tm_mday = sh_rtc_read_alarm_value(rtc, RDAYAR);
    tm->tm_mon  = sh_rtc_read_alarm_value(rtc, RMONAR);
    if (tm->tm_mon > 0)
        tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
    tm->tm_year     = 0xffff;

    wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;

    spin_unlock_irq(&rtc->lock);

    return 0;
}

static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
                        int value, int reg_off)
{
    /* < 0 for a value that is ignored */
    if (value < 0)
        writeb(0, rtc->regbase + reg_off);
    else
        writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
}

static int sh_rtc_check_alarm(struct rtc_time *tm)
{
    /*
     * The original rtc says anything > 0xc0 is "don't care" or "match
     * all" - most users use 0xff but rtc-dev uses -1 for the same thing.
     * The original rtc doesn't support years - some things use -1 and
     * some 0xffff. We use -1 to make out tests easier.
     */
    if (tm->tm_year == 0xffff)
        tm->tm_year = -1;
    if (tm->tm_mon >= 0xff)
        tm->tm_mon = -1;
    if (tm->tm_mday >= 0xff)
        tm->tm_mday = -1;
    if (tm->tm_wday >= 0xff)
        tm->tm_wday = -1;
    if (tm->tm_hour >= 0xff)
        tm->tm_hour = -1;
    if (tm->tm_min >= 0xff)
        tm->tm_min = -1;
    if (tm->tm_sec >= 0xff)
        tm->tm_sec = -1;

    if (tm->tm_year > 9999 ||
        tm->tm_mon >= 12 ||
        tm->tm_mday == 0 || tm->tm_mday >= 32 ||
        tm->tm_wday >= 7 ||
        tm->tm_hour >= 24 ||
        tm->tm_min >= 60 ||
        tm->tm_sec >= 60)
        return -EINVAL;

    return 0;
}

static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct sh_rtc *rtc = platform_get_drvdata(pdev);
    unsigned int rcr1;
    struct rtc_time *tm = &wkalrm->time;
    int mon, err;

    err = sh_rtc_check_alarm(tm);
    if (unlikely(err < 0))
        return err;

    spin_lock_irq(&rtc->lock);

    /* disable alarm interrupt and clear the alarm flag */
    rcr1 = readb(rtc->regbase + RCR1);
    rcr1 &= ~(RCR1_AF | RCR1_AIE);
    writeb(rcr1, rtc->regbase + RCR1);

    /* set alarm time */
    sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
    sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
    sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
    sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
    sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
    mon = tm->tm_mon;
    if (mon >= 0)
        mon += 1;
    sh_rtc_write_alarm_value(rtc, mon, RMONAR);

    if (wkalrm->enabled) {
        rcr1 |= RCR1_AIE;
        writeb(rcr1, rtc->regbase + RCR1);
    }

    spin_unlock_irq(&rtc->lock);

    return 0;
}

static struct rtc_class_ops sh_rtc_ops = {
    .read_time  = sh_rtc_read_time,
    .set_time   = sh_rtc_set_time,
    .read_alarm = sh_rtc_read_alarm,
    .set_alarm  = sh_rtc_set_alarm,
    .proc       = sh_rtc_proc,
    .alarm_irq_enable = sh_rtc_alarm_irq_enable,
};

static int __init sh_rtc_probe(struct platform_device *pdev)
{
    struct sh_rtc *rtc;
    struct resource *res;
    struct rtc_time r;
    char clk_name[6];
    int clk_id, ret;

    rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
    if (unlikely(!rtc))
        return -ENOMEM;

    spin_lock_init(&rtc->lock);

    /* get periodic/carry/alarm irqs */
    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);
    rtc->alarm_irq = platform_get_irq(pdev, 2);

    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 = resource_size(res);

    rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
    if (unlikely(!rtc->res)) {
        ret = -EBUSY;
        goto err_badres;
    }

    rtc->regbase = ioremap_nocache(rtc->res->start, rtc->regsize);
    if (unlikely(!rtc->regbase)) {
        ret = -EINVAL;
        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;

        /*
         * Some CPUs have special capabilities in addition to the
         * default set. Add those in here.
         */
        rtc->capabilities |= pinfo->capabilities;
    }

    if (rtc->carry_irq <= 0) {
        /* register shared periodic/carry/alarm irq */
        ret = request_irq(rtc->periodic_irq, sh_rtc_shared,
                  0, "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,
                  0, "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;
        }

        ret = request_irq(rtc->carry_irq, sh_rtc_interrupt,
                  0, "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;
        }

        ret = request_irq(rtc->alarm_irq, sh_rtc_alarm,
                  0, "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;
        }
    }

    platform_set_drvdata(pdev, 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);
        free_irq(rtc->carry_irq, rtc);
        free_irq(rtc->alarm_irq, rtc);
        goto err_unmap;
    }

    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_mem_region(rtc->res->start, rtc->regsize);
err_badres:
    kfree(rtc);

    return ret;
}

static int __exit sh_rtc_remove(struct platform_device *pdev)
{
    struct sh_rtc *rtc = platform_get_drvdata(pdev);

    rtc_device_unregister(rtc->rtc_dev);
    sh_rtc_irq_set_state(&pdev->dev, 0);

    sh_rtc_setaie(&pdev->dev, 0);
    sh_rtc_setcie(&pdev->dev, 0);

    free_irq(rtc->periodic_irq, rtc);

    if (rtc->carry_irq > 0) {
        free_irq(rtc->carry_irq, rtc);
        free_irq(rtc->alarm_irq, rtc);
    }

    iounmap(rtc->regbase);
    release_mem_region(rtc->res->start, rtc->regsize);

    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);

    irq_set_irq_wake(rtc->periodic_irq, enabled);

    if (rtc->carry_irq > 0) {
        irq_set_irq_wake(rtc->carry_irq, enabled);
        irq_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,
    },
    .remove     = __exit_p(sh_rtc_remove),
};

static int __init sh_rtc_init(void)
{
    return platform_driver_probe(&sh_rtc_platform_driver, sh_rtc_probe);
}

static void __exit sh_rtc_exit(void)
{
    platform_driver_unregister(&sh_rtc_platform_driver);
}

module_init(sh_rtc_init);
module_exit(sh_rtc_exit);

MODULE_DESCRIPTION("SuperH on-chip RTC driver");
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR("Paul Mundt <[email protected]>, "
          "Jamie Lenehan <[email protected]>, "
          "Angelo Castello <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);