linux4.1.36 2440 启用 RTC 支持

/drivers/rtc/rtc-s3c.c
822行
static struct platform_driver s3c_rtc_driver = {
    .probe        = s3c_rtc_probe,
    .remove        = s3c_rtc_remove,
    .driver        = {
        .name    = "s3c-rtc",
        .pm    = &s3c_rtc_pm_ops,
        .of_match_table    = of_match_ptr(s3c_rtc_dt_match),
    },
};
module_platform_driver(s3c_rtc_driver);

/arch/arm/plat-samsung/devs.c
836行
static struct resource s3c_rtc_resource[] = {
    [0] = DEFINE_RES_MEM(S3C24XX_PA_RTC, SZ_256),
    [1] = DEFINE_RES_IRQ(IRQ_RTC),
    [2] = DEFINE_RES_IRQ(IRQ_TICK),
};

struct platform_device s3c_device_rtc = {
    .name        = "s3c-rtc", //修改此处 和 s3c_rtc_driver 中的 .name 相同
    .id        = -1,
    .num_resources    = ARRAY_SIZE(s3c_rtc_resource),
    .resource    = s3c_rtc_resource,
};

修改 mach-smdk2440.c 中添加设备
static struct platform_device *smdk2440_devices[] __initdata = {
    &s3c_device_ohci,
    &s3c_device_lcd,
    &s3c_device_wdt,
    &s3c_device_i2c0,
    &s3c_device_iis,
    &dm9000_device_eth,
    &s3c_device_rtc, //添加此项
};

make uImage 使用新内核 启动
错误信息
Unable to handle kernel NULL pointer dereference at virtual address 000000c0
pgd = c0004000
[000000c0] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.1.36 #73
Hardware name: SMDK2440
task: c381faa0 ti: c3822000 task.ti: c3822000
PC is at s3c_rtc_probe+0x4c/0x3f0
LR is at s3c_rtc_probe+0x38/0x3f0

经过 printk 大法以后定位到 s3c_rtc_get_data() 出现空指针问题

static const struct of_device_id s3c_rtc_dt_match[];

static struct s3c_rtc_data *s3c_rtc_get_data(struct platform_device *pdev)
{
    const struct of_device_id *match;

    match = of_match_node(s3c_rtc_dt_match, pdev->dev.of_node);
    return (struct s3c_rtc_data *)match->data;
}

改为
static struct s3c_rtc_data *s3c_rtc_get_data(struct platform_device *pdev)
{
    const struct of_device_id *match;
    match = of_match_node(s3c_rtc_dt_match, pdev->dev.of_node);
    if(NULL != match)
    {
        return (struct s3c_rtc_data *)match->data;
    }
    return NULL;
}

改了以后，启动不报空指针错误了。但是还是不能用rtc 。

要自己实现这么一个函数
添加一个函数声明
static struct s3c_rtc_data *get_s3c_2410_data(void);

在最下面添加实现
static struct s3c_rtc_data *get_s3c_2410_data(void)
{
    return (struct s3c_rtc_data *)&s3c2410_rtc_data;
}

rtc-s3c.c

/* drivers/rtc/rtc-s3c.c
 *
 * Copyright (c) 2010 Samsung Electronics Co., Ltd.
 *        http://www.samsung.com/
 *
 * Copyright (c) 2004,2006 Simtec Electronics
 *    Ben Dooks, <ben@simtec.co.uk>
 *    http://armlinux.simtec.co.uk/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * S3C2410/S3C2440/S3C24XX Internal RTC Driver
*/

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/clk.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/uaccess.h>
#include <linux/io.h>

#include <asm/irq.h>
#include "rtc-s3c.h"

struct s3c_rtc {
    struct device *dev;
    struct rtc_device *rtc;

    void __iomem *base;
    struct clk *rtc_clk;
    struct clk *rtc_src_clk;
    bool clk_disabled;

    struct s3c_rtc_data *data;

    int irq_alarm;
    int irq_tick;

    spinlock_t pie_lock;
    spinlock_t alarm_clk_lock;

    int ticnt_save, ticnt_en_save;
    bool wake_en;
};

struct s3c_rtc_data {
    int max_user_freq;
    bool needs_src_clk;

    void (*irq_handler) (struct s3c_rtc *info, int mask);
    void (*set_freq) (struct s3c_rtc *info, int freq);
    void (*enable_tick) (struct s3c_rtc *info, struct seq_file *seq);
    void (*select_tick_clk) (struct s3c_rtc *info);
    void (*save_tick_cnt) (struct s3c_rtc *info);
    void (*restore_tick_cnt) (struct s3c_rtc *info);
    void (*enable) (struct s3c_rtc *info);
    void (*disable) (struct s3c_rtc *info);
};
static struct s3c_rtc_data *get_s3c_2410_data(void);
static void s3c_rtc_enable_clk(struct s3c_rtc *info)
{
    unsigned long irq_flags;

    spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
    if (info->clk_disabled) {
        clk_enable(info->rtc_clk);
        if (info->data->needs_src_clk)
            clk_enable(info->rtc_src_clk);
        info->clk_disabled = false;
    }
    spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
}

static void s3c_rtc_disable_clk(struct s3c_rtc *info)
{
    unsigned long irq_flags;

    spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
    if (!info->clk_disabled) {
        if (info->data->needs_src_clk)
            clk_disable(info->rtc_src_clk);
        clk_disable(info->rtc_clk);
        info->clk_disabled = true;
    }
    spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
}

/* IRQ Handlers */
static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
{
    struct s3c_rtc *info = (struct s3c_rtc *)id;

    if (info->data->irq_handler)
        info->data->irq_handler(info, S3C2410_INTP_TIC);

    return IRQ_HANDLED;
}

static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
{
    struct s3c_rtc *info = (struct s3c_rtc *)id;

    if (info->data->irq_handler)
        info->data->irq_handler(info, S3C2410_INTP_ALM);

    return IRQ_HANDLED;
}

/* Update control registers */
static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
{
    struct s3c_rtc *info = dev_get_drvdata(dev);
    unsigned int tmp;

    dev_dbg(info->dev, "%s: aie=%d
", __func__, enabled);

    s3c_rtc_enable_clk(info);

    tmp = readb(info->base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;

    if (enabled)
        tmp |= S3C2410_RTCALM_ALMEN;

    writeb(tmp, info->base + S3C2410_RTCALM);

    s3c_rtc_disable_clk(info);

    if (enabled)
        s3c_rtc_enable_clk(info);
    else
        s3c_rtc_disable_clk(info);

    return 0;
}

/* Set RTC frequency */
static int s3c_rtc_setfreq(struct s3c_rtc *info, int freq)
{
    if (!is_power_of_2(freq))
        return -EINVAL;

    s3c_rtc_enable_clk(info);
    spin_lock_irq(&info->pie_lock);

    if (info->data->set_freq)
        info->data->set_freq(info, freq);

    spin_unlock_irq(&info->pie_lock);
    s3c_rtc_disable_clk(info);

    return 0;
}

/* Time read/write */
static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
{
    struct s3c_rtc *info = dev_get_drvdata(dev);
    unsigned int have_retried = 0;

    s3c_rtc_enable_clk(info);

 retry_get_time:
    rtc_tm->tm_min  = readb(info->base + S3C2410_RTCMIN);
    rtc_tm->tm_hour = readb(info->base + S3C2410_RTCHOUR);
    rtc_tm->tm_mday = readb(info->base + S3C2410_RTCDATE);
    rtc_tm->tm_mon  = readb(info->base + S3C2410_RTCMON);
    rtc_tm->tm_year = readb(info->base + S3C2410_RTCYEAR);
    rtc_tm->tm_sec  = readb(info->base + S3C2410_RTCSEC);

    /* the only way to work out whether the system was mid-update
     * when we read it is to check the second counter, and if it
     * is zero, then we re-try the entire read
     */

    if (rtc_tm->tm_sec == 0 && !have_retried) {
        have_retried = 1;
        goto retry_get_time;
    }

    rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
    rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
    rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
    rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
    rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
    rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);

    s3c_rtc_disable_clk(info);

    rtc_tm->tm_year += 100;

    dev_dbg(dev, "read time %04d.%02d.%02d %02d:%02d:%02d
",
         1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
         rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);

    rtc_tm->tm_mon -= 1;

    return rtc_valid_tm(rtc_tm);
}

static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
{
    struct s3c_rtc *info = dev_get_drvdata(dev);
    int year = tm->tm_year - 100;

    dev_dbg(dev, "set time %04d.%02d.%02d %02d:%02d:%02d
",
         1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
         tm->tm_hour, tm->tm_min, tm->tm_sec);

    /* we get around y2k by simply not supporting it */

    if (year < 0 || year >= 100) {
        dev_err(dev, "rtc only supports 100 years
");
        return -EINVAL;
    }

    s3c_rtc_enable_clk(info);

    writeb(bin2bcd(tm->tm_sec),  info->base + S3C2410_RTCSEC);
    writeb(bin2bcd(tm->tm_min),  info->base + S3C2410_RTCMIN);
    writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_RTCHOUR);
    writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_RTCDATE);
    writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_RTCMON);
    writeb(bin2bcd(year), info->base + S3C2410_RTCYEAR);

    s3c_rtc_disable_clk(info);

    return 0;
}

static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
    struct s3c_rtc *info = dev_get_drvdata(dev);
    struct rtc_time *alm_tm = &alrm->time;
    unsigned int alm_en;

    s3c_rtc_enable_clk(info);

    alm_tm->tm_sec  = readb(info->base + S3C2410_ALMSEC);
    alm_tm->tm_min  = readb(info->base + S3C2410_ALMMIN);
    alm_tm->tm_hour = readb(info->base + S3C2410_ALMHOUR);
    alm_tm->tm_mon  = readb(info->base + S3C2410_ALMMON);
    alm_tm->tm_mday = readb(info->base + S3C2410_ALMDATE);
    alm_tm->tm_year = readb(info->base + S3C2410_ALMYEAR);

    alm_en = readb(info->base + S3C2410_RTCALM);

    s3c_rtc_disable_clk(info);

    alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;

    dev_dbg(dev, "read alarm %d, %04d.%02d.%02d %02d:%02d:%02d
",
         alm_en,
         1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
         alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);

    /* decode the alarm enable field */
    if (alm_en & S3C2410_RTCALM_SECEN)
        alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
    else
        alm_tm->tm_sec = -1;

    if (alm_en & S3C2410_RTCALM_MINEN)
        alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
    else
        alm_tm->tm_min = -1;

    if (alm_en & S3C2410_RTCALM_HOUREN)
        alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
    else
        alm_tm->tm_hour = -1;

    if (alm_en & S3C2410_RTCALM_DAYEN)
        alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
    else
        alm_tm->tm_mday = -1;

    if (alm_en & S3C2410_RTCALM_MONEN) {
        alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
        alm_tm->tm_mon -= 1;
    } else {
        alm_tm->tm_mon = -1;
    }

    if (alm_en & S3C2410_RTCALM_YEAREN)
        alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
    else
        alm_tm->tm_year = -1;

    return 0;
}

static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
    struct s3c_rtc *info = dev_get_drvdata(dev);
    struct rtc_time *tm = &alrm->time;
    unsigned int alrm_en;

    dev_dbg(dev, "s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d
",
         alrm->enabled,
         1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
         tm->tm_hour, tm->tm_min, tm->tm_sec);

    s3c_rtc_enable_clk(info);

    alrm_en = readb(info->base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
    writeb(0x00, info->base + S3C2410_RTCALM);

    if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
        alrm_en |= S3C2410_RTCALM_SECEN;
        writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_ALMSEC);
    }

    if (tm->tm_min < 60 && tm->tm_min >= 0) {
        alrm_en |= S3C2410_RTCALM_MINEN;
        writeb(bin2bcd(tm->tm_min), info->base + S3C2410_ALMMIN);
    }

    if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
        alrm_en |= S3C2410_RTCALM_HOUREN;
        writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_ALMHOUR);
    }

    dev_dbg(dev, "setting S3C2410_RTCALM to %08x
", alrm_en);

    writeb(alrm_en, info->base + S3C2410_RTCALM);

    s3c_rtc_disable_clk(info);

    s3c_rtc_setaie(dev, alrm->enabled);

    return 0;
}

static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
{
    struct s3c_rtc *info = dev_get_drvdata(dev);

    s3c_rtc_enable_clk(info);

    if (info->data->enable_tick)
        info->data->enable_tick(info, seq);

    s3c_rtc_disable_clk(info);

    return 0;
}

static const struct rtc_class_ops s3c_rtcops = {
    .read_time    = s3c_rtc_gettime,
    .set_time    = s3c_rtc_settime,
    .read_alarm    = s3c_rtc_getalarm,
    .set_alarm    = s3c_rtc_setalarm,
    .proc        = s3c_rtc_proc,
    .alarm_irq_enable = s3c_rtc_setaie,
};

static void s3c24xx_rtc_enable(struct s3c_rtc *info)
{
    unsigned int con, tmp;

    con = readw(info->base + S3C2410_RTCCON);
    /* re-enable the device, and check it is ok */
    if ((con & S3C2410_RTCCON_RTCEN) == 0) {
        dev_info(info->dev, "rtc disabled, re-enabling
");

        tmp = readw(info->base + S3C2410_RTCCON);
        writew(tmp | S3C2410_RTCCON_RTCEN,
            info->base + S3C2410_RTCCON);
    }

    if (con & S3C2410_RTCCON_CNTSEL) {
        dev_info(info->dev, "removing RTCCON_CNTSEL
");

        tmp = readw(info->base + S3C2410_RTCCON);
        writew(tmp & ~S3C2410_RTCCON_CNTSEL,
            info->base + S3C2410_RTCCON);
    }

    if (con & S3C2410_RTCCON_CLKRST) {
        dev_info(info->dev, "removing RTCCON_CLKRST
");

        tmp = readw(info->base + S3C2410_RTCCON);
        writew(tmp & ~S3C2410_RTCCON_CLKRST,
            info->base + S3C2410_RTCCON);
    }
}

static void s3c24xx_rtc_disable(struct s3c_rtc *info)
{
    unsigned int con;

    con = readw(info->base + S3C2410_RTCCON);
    con &= ~S3C2410_RTCCON_RTCEN;
    writew(con, info->base + S3C2410_RTCCON);

    con = readb(info->base + S3C2410_TICNT);
    con &= ~S3C2410_TICNT_ENABLE;
    writeb(con, info->base + S3C2410_TICNT);
}

static void s3c6410_rtc_disable(struct s3c_rtc *info)
{
    unsigned int con;

    con = readw(info->base + S3C2410_RTCCON);
    con &= ~S3C64XX_RTCCON_TICEN;
    con &= ~S3C2410_RTCCON_RTCEN;
    writew(con, info->base + S3C2410_RTCCON);
}

static int s3c_rtc_remove(struct platform_device *pdev)
{
    struct s3c_rtc *info = platform_get_drvdata(pdev);

    s3c_rtc_setaie(info->dev, 0);

    clk_unprepare(info->rtc_clk);
    info->rtc_clk = NULL;

    return 0;
}

static const struct of_device_id s3c_rtc_dt_match[];

static struct s3c_rtc_data *s3c_rtc_get_data(struct platform_device *pdev)
{
    const struct of_device_id *match;

    match = of_match_node(s3c_rtc_dt_match, pdev->dev.of_node);
    if(NULL != match)
    {
        return (struct s3c_rtc_data *)match->data;
    }
    return NULL;
}

static int s3c_rtc_probe(struct platform_device *pdev)
{
    struct s3c_rtc *info = NULL;
    struct rtc_time rtc_tm;
    struct resource *res;
    int ret;

    info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
    if (!info)
        return -ENOMEM;

    /* find the IRQs */
    info->irq_tick = platform_get_irq(pdev, 1);
    if (info->irq_tick < 0) {
        dev_err(&pdev->dev, "no irq for rtc tick
");
        return info->irq_tick;
    }

    info->dev = &pdev->dev;
    //改为自己实现的函数
    //info->data = s3c_rtc_get_data(pdev);
    info->data = get_s3c_2410_data();
    if (!info->data) {
        dev_err(&pdev->dev, "failed getting s3c_rtc_data
");
        return -EINVAL;
    }
    spin_lock_init(&info->pie_lock);
    spin_lock_init(&info->alarm_clk_lock);

    platform_set_drvdata(pdev, info);

    info->irq_alarm = platform_get_irq(pdev, 0);
    if (info->irq_alarm < 0) {
        dev_err(&pdev->dev, "no irq for alarm
");
        return info->irq_alarm;
    }

    dev_dbg(&pdev->dev, "s3c2410_rtc: tick irq %d, alarm irq %d
",
         info->irq_tick, info->irq_alarm);

    /* get the memory region */
    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    info->base = devm_ioremap_resource(&pdev->dev, res);
    if (IS_ERR(info->base))
        return PTR_ERR(info->base);

    info->rtc_clk = devm_clk_get(&pdev->dev, "rtc");
    if (IS_ERR(info->rtc_clk)) {
        dev_err(&pdev->dev, "failed to find rtc clock
");
        return PTR_ERR(info->rtc_clk);
    }
    clk_prepare_enable(info->rtc_clk);

    if (info->data->needs_src_clk) {
        info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");
        if (IS_ERR(info->rtc_src_clk)) {
            dev_err(&pdev->dev,
                "failed to find rtc source clock
");
            return PTR_ERR(info->rtc_src_clk);
        }
        clk_prepare_enable(info->rtc_src_clk);
    }

    /* check to see if everything is setup correctly */
    if (info->data->enable)
        info->data->enable(info);

    dev_dbg(&pdev->dev, "s3c2410_rtc: RTCCON=%02x
",
         readw(info->base + S3C2410_RTCCON));

    device_init_wakeup(&pdev->dev, 1);

    /* Check RTC Time */
    if (s3c_rtc_gettime(&pdev->dev, &rtc_tm)) {
        rtc_tm.tm_year    = 100;
        rtc_tm.tm_mon    = 0;
        rtc_tm.tm_mday    = 1;
        rtc_tm.tm_hour    = 0;
        rtc_tm.tm_min    = 0;
        rtc_tm.tm_sec    = 0;

        s3c_rtc_settime(&pdev->dev, &rtc_tm);

        dev_warn(&pdev->dev, "warning: invalid RTC value so initializing it
");
    }

    /* register RTC and exit */
    info->rtc = devm_rtc_device_register(&pdev->dev, "s3c", &s3c_rtcops,
                  THIS_MODULE);
    if (IS_ERR(info->rtc)) {
        dev_err(&pdev->dev, "cannot attach rtc
");
        ret = PTR_ERR(info->rtc);
        goto err_nortc;
    }

    ret = devm_request_irq(&pdev->dev, info->irq_alarm, s3c_rtc_alarmirq,
              0,  "s3c2410-rtc alarm", info);
    if (ret) {
        dev_err(&pdev->dev, "IRQ%d error %d
", info->irq_alarm, ret);
        goto err_nortc;
    }

    ret = devm_request_irq(&pdev->dev, info->irq_tick, s3c_rtc_tickirq,
              0,  "s3c2410-rtc tick", info);
    if (ret) {
        dev_err(&pdev->dev, "IRQ%d error %d
", info->irq_tick, ret);
        goto err_nortc;
    }

    if (info->data->select_tick_clk)
        info->data->select_tick_clk(info);

    s3c_rtc_setfreq(info, 1);

    s3c_rtc_disable_clk(info);

    return 0;

 err_nortc:
    if (info->data->disable)
        info->data->disable(info);

    if (info->data->needs_src_clk)
        clk_disable_unprepare(info->rtc_src_clk);
    clk_disable_unprepare(info->rtc_clk);

    return ret;
}

#ifdef CONFIG_PM_SLEEP

static int s3c_rtc_suspend(struct device *dev)
{
    struct s3c_rtc *info = dev_get_drvdata(dev);

    s3c_rtc_enable_clk(info);

    /* save TICNT for anyone using periodic interrupts */
    if (info->data->save_tick_cnt)
        info->data->save_tick_cnt(info);

    if (info->data->disable)
        info->data->disable(info);

    if (device_may_wakeup(dev) && !info->wake_en) {
        if (enable_irq_wake(info->irq_alarm) == 0)
            info->wake_en = true;
        else
            dev_err(dev, "enable_irq_wake failed
");
    }

    return 0;
}

static int s3c_rtc_resume(struct device *dev)
{
    struct s3c_rtc *info = dev_get_drvdata(dev);

    if (info->data->enable)
        info->data->enable(info);

    if (info->data->restore_tick_cnt)
        info->data->restore_tick_cnt(info);

    s3c_rtc_disable_clk(info);

    if (device_may_wakeup(dev) && info->wake_en) {
        disable_irq_wake(info->irq_alarm);
        info->wake_en = false;
    }

    return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(s3c_rtc_pm_ops, s3c_rtc_suspend, s3c_rtc_resume);

static void s3c24xx_rtc_irq(struct s3c_rtc *info, int mask)
{
    rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
}

static void s3c6410_rtc_irq(struct s3c_rtc *info, int mask)
{
    rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
    writeb(mask, info->base + S3C2410_INTP);
}

static void s3c2410_rtc_setfreq(struct s3c_rtc *info, int freq)
{
    unsigned int tmp = 0;
    int val;

    tmp = readb(info->base + S3C2410_TICNT);
    tmp &= S3C2410_TICNT_ENABLE;

    val = (info->rtc->max_user_freq / freq) - 1;
    tmp |= val;

    writel(tmp, info->base + S3C2410_TICNT);
}

static void s3c2416_rtc_setfreq(struct s3c_rtc *info, int freq)
{
    unsigned int tmp = 0;
    int val;

    tmp = readb(info->base + S3C2410_TICNT);
    tmp &= S3C2410_TICNT_ENABLE;

    val = (info->rtc->max_user_freq / freq) - 1;

    tmp |= S3C2443_TICNT_PART(val);
    writel(S3C2443_TICNT1_PART(val), info->base + S3C2443_TICNT1);

    writel(S3C2416_TICNT2_PART(val), info->base + S3C2416_TICNT2);

    writel(tmp, info->base + S3C2410_TICNT);
}

static void s3c2443_rtc_setfreq(struct s3c_rtc *info, int freq)
{
    unsigned int tmp = 0;
    int val;

    tmp = readb(info->base + S3C2410_TICNT);
    tmp &= S3C2410_TICNT_ENABLE;

    val = (info->rtc->max_user_freq / freq) - 1;

    tmp |= S3C2443_TICNT_PART(val);
    writel(S3C2443_TICNT1_PART(val), info->base + S3C2443_TICNT1);

    writel(tmp, info->base + S3C2410_TICNT);
}

static void s3c6410_rtc_setfreq(struct s3c_rtc *info, int freq)
{
    int val;

    val = (info->rtc->max_user_freq / freq) - 1;
    writel(val, info->base + S3C2410_TICNT);
}

static void s3c24xx_rtc_enable_tick(struct s3c_rtc *info, struct seq_file *seq)
{
    unsigned int ticnt;

    ticnt = readb(info->base + S3C2410_TICNT);
    ticnt &= S3C2410_TICNT_ENABLE;

    seq_printf(seq, "periodic_IRQ	: %s
", ticnt  ? "yes" : "no");
}

static void s3c2416_rtc_select_tick_clk(struct s3c_rtc *info)
{
    unsigned int con;

    con = readw(info->base + S3C2410_RTCCON);
    con |= S3C2443_RTCCON_TICSEL;
    writew(con, info->base + S3C2410_RTCCON);
}

static void s3c6410_rtc_enable_tick(struct s3c_rtc *info, struct seq_file *seq)
{
    unsigned int ticnt;

    ticnt = readw(info->base + S3C2410_RTCCON);
    ticnt &= S3C64XX_RTCCON_TICEN;

    seq_printf(seq, "periodic_IRQ	: %s
", ticnt  ? "yes" : "no");
}

static void s3c24xx_rtc_save_tick_cnt(struct s3c_rtc *info)
{
    info->ticnt_save = readb(info->base + S3C2410_TICNT);
}

static void s3c24xx_rtc_restore_tick_cnt(struct s3c_rtc *info)
{
    writeb(info->ticnt_save, info->base + S3C2410_TICNT);
}

static void s3c6410_rtc_save_tick_cnt(struct s3c_rtc *info)
{
    info->ticnt_en_save = readw(info->base + S3C2410_RTCCON);
    info->ticnt_en_save &= S3C64XX_RTCCON_TICEN;
    info->ticnt_save = readl(info->base + S3C2410_TICNT);
}

static void s3c6410_rtc_restore_tick_cnt(struct s3c_rtc *info)
{
    unsigned int con;

    writel(info->ticnt_save, info->base + S3C2410_TICNT);
    if (info->ticnt_en_save) {
        con = readw(info->base + S3C2410_RTCCON);
        writew(con | info->ticnt_en_save,
                info->base + S3C2410_RTCCON);
    }
}

static struct s3c_rtc_data const s3c2410_rtc_data = {
    .max_user_freq        = 128,
    .irq_handler        = s3c24xx_rtc_irq,
    .set_freq        = s3c2410_rtc_setfreq,
    .enable_tick        = s3c24xx_rtc_enable_tick,
    .save_tick_cnt        = s3c24xx_rtc_save_tick_cnt,
    .restore_tick_cnt    = s3c24xx_rtc_restore_tick_cnt,
    .enable            = s3c24xx_rtc_enable,
    .disable        = s3c24xx_rtc_disable,
};

static struct s3c_rtc_data const s3c2416_rtc_data = {
    .max_user_freq        = 32768,
    .irq_handler        = s3c24xx_rtc_irq,
    .set_freq        = s3c2416_rtc_setfreq,
    .enable_tick        = s3c24xx_rtc_enable_tick,
    .select_tick_clk    = s3c2416_rtc_select_tick_clk,
    .save_tick_cnt        = s3c24xx_rtc_save_tick_cnt,
    .restore_tick_cnt    = s3c24xx_rtc_restore_tick_cnt,
    .enable            = s3c24xx_rtc_enable,
    .disable        = s3c24xx_rtc_disable,
};

static struct s3c_rtc_data const s3c2443_rtc_data = {
    .max_user_freq        = 32768,
    .irq_handler        = s3c24xx_rtc_irq,
    .set_freq        = s3c2443_rtc_setfreq,
    .enable_tick        = s3c24xx_rtc_enable_tick,
    .select_tick_clk    = s3c2416_rtc_select_tick_clk,
    .save_tick_cnt        = s3c24xx_rtc_save_tick_cnt,
    .restore_tick_cnt    = s3c24xx_rtc_restore_tick_cnt,
    .enable            = s3c24xx_rtc_enable,
    .disable        = s3c24xx_rtc_disable,
};

static struct s3c_rtc_data const s3c6410_rtc_data = {
    .max_user_freq        = 32768,
    .needs_src_clk        = true,
    .irq_handler        = s3c6410_rtc_irq,
    .set_freq        = s3c6410_rtc_setfreq,
    .enable_tick        = s3c6410_rtc_enable_tick,
    .save_tick_cnt        = s3c6410_rtc_save_tick_cnt,
    .restore_tick_cnt    = s3c6410_rtc_restore_tick_cnt,
    .enable            = s3c24xx_rtc_enable,
    .disable        = s3c6410_rtc_disable,
};

static struct s3c_rtc_data const exynos3250_rtc_data = {
    .max_user_freq        = 32768,
    .needs_src_clk        = true,
    .irq_handler        = s3c6410_rtc_irq,
    .set_freq        = s3c6410_rtc_setfreq,
    .enable_tick        = s3c6410_rtc_enable_tick,
    .save_tick_cnt        = s3c6410_rtc_save_tick_cnt,
    .restore_tick_cnt    = s3c6410_rtc_restore_tick_cnt,
    .enable            = s3c24xx_rtc_enable,
    .disable        = s3c6410_rtc_disable,
};
static struct s3c_rtc_data *get_s3c_2410_data(void)
{
    return (struct s3c_rtc_data *)&s3c2410_rtc_data;
}
static const struct of_device_id s3c_rtc_dt_match[] = {
    {
        .compatible = "samsung,s3c2410-rtc",
        .data = (void *)&s3c2410_rtc_data,
    }, {
        .compatible = "samsung,s3c2416-rtc",
        .data = (void *)&s3c2416_rtc_data,
    }, {
        .compatible = "samsung,s3c2443-rtc",
        .data = (void *)&s3c2443_rtc_data,
    }, {
        .compatible = "samsung,s3c6410-rtc",
        .data = (void *)&s3c6410_rtc_data,
    }, {
        .compatible = "samsung,exynos3250-rtc",
        .data = (void *)&exynos3250_rtc_data,
    },
    { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, s3c_rtc_dt_match);

static struct platform_driver s3c_rtc_driver = {
    .probe        = s3c_rtc_probe,
    .remove        = s3c_rtc_remove,
    .driver        = {
        .name    = "s3c-rtc",
        .pm    = &s3c_rtc_pm_ops,
        .of_match_table    = of_match_ptr(s3c_rtc_dt_match),
    },
};
module_platform_driver(s3c_rtc_driver);

MODULE_DESCRIPTION("Samsung S3C RTC Driver");
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:s3c2410-rtc");