[linux-block.git] / drivers / rtc / rtc-s3c.c

// SPDX-License-Identifier: GPL-2.0-only
/* 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/
 *
 * 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 alarm_enabled;

	const struct s3c_rtc_data *data;

	int irq_alarm;
	spinlock_t alarm_lock;

	bool wake_en;
};

struct s3c_rtc_data {
	bool needs_src_clk;

	void (*irq_handler) (struct s3c_rtc *info, int mask);
	void (*enable) (struct s3c_rtc *info);
	void (*disable) (struct s3c_rtc *info);
};

static int s3c_rtc_enable_clk(struct s3c_rtc *info)
{
	int ret;

	ret = clk_enable(info->rtc_clk);
	if (ret)
		return ret;

	if (info->data->needs_src_clk) {
		ret = clk_enable(info->rtc_src_clk);
		if (ret) {
			clk_disable(info->rtc_clk);
			return ret;
		}
	}
	return 0;
}

static void s3c_rtc_disable_clk(struct s3c_rtc *info)
{
	if (info->data->needs_src_clk)
		clk_disable(info->rtc_src_clk);
	clk_disable(info->rtc_clk);
}

/* IRQ Handler */
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 long flags;
	unsigned int tmp;
	int ret;

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

	ret = s3c_rtc_enable_clk(info);
	if (ret)
		return ret;

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

	if (enabled)
		tmp |= S3C2410_RTCALM_ALMEN;

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

	spin_lock_irqsave(&info->alarm_lock, flags);

	if (info->alarm_enabled && !enabled)
		s3c_rtc_disable_clk(info);
	else if (!info->alarm_enabled && enabled)
		ret = s3c_rtc_enable_clk(info);

	info->alarm_enabled = enabled;
	spin_unlock_irqrestore(&info->alarm_lock, flags);

	s3c_rtc_disable_clk(info);

	return ret;
}

/* Read time from RTC and convert it from BCD */
static int s3c_rtc_read_time(struct s3c_rtc *info, struct rtc_time *tm)
{
	unsigned int have_retried = 0;
	int ret;

	ret = s3c_rtc_enable_clk(info);
	if (ret)
		return ret;

retry_get_time:
	tm->tm_min  = readb(info->base + S3C2410_RTCMIN);
	tm->tm_hour = readb(info->base + S3C2410_RTCHOUR);
	tm->tm_mday = readb(info->base + S3C2410_RTCDATE);
	tm->tm_mon  = readb(info->base + S3C2410_RTCMON);
	tm->tm_year = readb(info->base + S3C2410_RTCYEAR);
	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 (tm->tm_sec == 0 && !have_retried) {
		have_retried = 1;
		goto retry_get_time;
	}

	s3c_rtc_disable_clk(info);

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

	return 0;
}

/* Convert time to BCD and write it to RTC */
static int s3c_rtc_write_time(struct s3c_rtc *info, const struct rtc_time *tm)
{
	int ret;

	ret = s3c_rtc_enable_clk(info);
	if (ret)
		return ret;

	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),  info->base + S3C2410_RTCMON);
	writeb(bin2bcd(tm->tm_year), info->base + S3C2410_RTCYEAR);

	s3c_rtc_disable_clk(info);

	return 0;
}

static int s3c_rtc_gettime(struct device *dev, struct rtc_time *tm)
{
	struct s3c_rtc *info = dev_get_drvdata(dev);
	int ret;

	ret = s3c_rtc_read_time(info, tm);
	if (ret)
		return ret;

	/* Convert internal representation to actual date/time */
	tm->tm_year += 100;
	tm->tm_mon -= 1;

	dev_dbg(dev, "read time %ptR\n", tm);
	return 0;
}

static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
{
	struct s3c_rtc *info = dev_get_drvdata(dev);
	struct rtc_time rtc_tm = *tm;

	dev_dbg(dev, "set time %ptR\n", tm);

	/*
	 * Convert actual date/time to internal representation.
	 * We get around Y2K by simply not supporting it.
	 */
	rtc_tm.tm_year -= 100;
	rtc_tm.tm_mon += 1;

	return s3c_rtc_write_time(info, &rtc_tm);
}

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;
	int ret;

	ret = s3c_rtc_enable_clk(info);
	if (ret)
		return ret;

	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, %ptR\n", alm_en, alm_tm);

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

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

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

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

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

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

	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;
	int ret;

	dev_dbg(dev, "s3c_rtc_setalarm: %d, %ptR\n", alrm->enabled, tm);

	ret = s3c_rtc_enable_clk(info);
	if (ret)
		return ret;

	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);
	}

	if (tm->tm_mon < 12 && tm->tm_mon >= 0) {
		alrm_en |= S3C2410_RTCALM_MONEN;
		writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_ALMMON);
	}

	if (tm->tm_mday <= 31 && tm->tm_mday >= 1) {
		alrm_en |= S3C2410_RTCALM_DAYEN;
		writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_ALMDATE);
	}

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

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

	s3c_rtc_setaie(dev, alrm->enabled);

	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,
	.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\n");

		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\n");

		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\n");

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

	s3c_rtc_setaie(info->dev, 0);

	if (info->data->needs_src_clk)
		clk_unprepare(info->rtc_src_clk);
	clk_unprepare(info->rtc_clk);
}

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

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

	info->dev = &pdev->dev;
	info->data = of_device_get_match_data(&pdev->dev);
	if (!info->data) {
		dev_err(&pdev->dev, "failed getting s3c_rtc_data\n");
		return -EINVAL;
	}
	spin_lock_init(&info->alarm_lock);

	platform_set_drvdata(pdev, info);

	info->irq_alarm = platform_get_irq(pdev, 0);
	if (info->irq_alarm < 0)
		return info->irq_alarm;

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

	/* get the memory region */
	info->base = devm_platform_ioremap_resource(pdev, 0);
	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))
		return dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_clk),
				     "failed to find rtc clock\n");
	ret = clk_prepare_enable(info->rtc_clk);
	if (ret)
		return ret;

	if (info->data->needs_src_clk) {
		info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");
		if (IS_ERR(info->rtc_src_clk)) {
			ret = dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_src_clk),
					    "failed to find rtc source clock\n");
			goto err_src_clk;
		}
		ret = clk_prepare_enable(info->rtc_src_clk);
		if (ret)
			goto err_src_clk;
	}

	/* disable RTC enable bits potentially set by the bootloader */
	if (info->data->disable)
		info->data->disable(info);

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

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

	device_init_wakeup(&pdev->dev, true);

	info->rtc = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(info->rtc)) {
		ret = PTR_ERR(info->rtc);
		goto err_nortc;
	}

	info->rtc->ops = &s3c_rtcops;
	info->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
	info->rtc->range_max = RTC_TIMESTAMP_END_2099;

	ret = devm_rtc_register_device(info->rtc);
	if (ret)
		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\n", info->irq_alarm, ret);
		goto err_nortc;
	}

	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);
err_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);
	int ret;

	ret = s3c_rtc_enable_clk(info);
	if (ret)
		return ret;

	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\n");
	}

	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);

	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 struct s3c_rtc_data const s3c2410_rtc_data = {
	.irq_handler		= s3c24xx_rtc_irq,
	.enable			= s3c24xx_rtc_enable,
	.disable		= s3c24xx_rtc_disable,
};

static struct s3c_rtc_data const s3c2416_rtc_data = {
	.irq_handler		= s3c24xx_rtc_irq,
	.enable			= s3c24xx_rtc_enable,
	.disable		= s3c24xx_rtc_disable,
};

static struct s3c_rtc_data const s3c2443_rtc_data = {
	.irq_handler		= s3c24xx_rtc_irq,
	.enable			= s3c24xx_rtc_enable,
	.disable		= s3c24xx_rtc_disable,
};

static struct s3c_rtc_data const s3c6410_rtc_data = {
	.needs_src_clk		= true,
	.irq_handler		= s3c6410_rtc_irq,
	.enable			= s3c24xx_rtc_enable,
	.disable		= s3c6410_rtc_disable,
};

static const __maybe_unused struct of_device_id s3c_rtc_dt_match[] = {
	{
		.compatible = "samsung,s3c2410-rtc",
		.data = &s3c2410_rtc_data,
	}, {
		.compatible = "samsung,s3c2416-rtc",
		.data = &s3c2416_rtc_data,
	}, {
		.compatible = "samsung,s3c2443-rtc",
		.data = &s3c2443_rtc_data,
	}, {
		.compatible = "samsung,s3c6410-rtc",
		.data = &s3c6410_rtc_data,
	}, {
		.compatible = "samsung,exynos3250-rtc",
		.data = &s3c6410_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");
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/* drivers/rtc/rtc-s3c.c
	3	*
	4	* Copyright (c) 2010 Samsung Electronics Co., Ltd.
	5	* http://www.samsung.com/
	6	*
	7	* Copyright (c) 2004,2006 Simtec Electronics
	8	* Ben Dooks, <ben@simtec.co.uk>
	9	* http://armlinux.simtec.co.uk/
	10	*
	11	* S3C2410/S3C2440/S3C24XX Internal RTC Driver
	12	*/
	13
	14	#include <linux/module.h>
	15	#include <linux/fs.h>
	16	#include <linux/string.h>
	17	#include <linux/init.h>
	18	#include <linux/platform_device.h>
	19	#include <linux/interrupt.h>
	20	#include <linux/rtc.h>
	21	#include <linux/bcd.h>
	22	#include <linux/clk.h>
	23	#include <linux/log2.h>
	24	#include <linux/slab.h>
	25	#include <linux/of.h>
	26	#include <linux/uaccess.h>
	27	#include <linux/io.h>
	28
	29	#include <asm/irq.h>
	30	#include "rtc-s3c.h"
	31
	32	struct s3c_rtc {
	33	struct device *dev;
	34	struct rtc_device *rtc;
	35
	36	void __iomem *base;
	37	struct clk *rtc_clk;
	38	struct clk *rtc_src_clk;
	39	bool alarm_enabled;
	40
	41	const struct s3c_rtc_data *data;
	42
	43	int irq_alarm;
	44	spinlock_t alarm_lock;
	45
	46	bool wake_en;
	47	};
	48
	49	struct s3c_rtc_data {
	50	bool needs_src_clk;
	51
	52	void (irq_handler) (struct s3c_rtc info, int mask);
	53	void (enable) (struct s3c_rtc info);
	54	void (disable) (struct s3c_rtc info);
	55	};
	56
	57	static int s3c_rtc_enable_clk(struct s3c_rtc *info)
	58	{
	59	int ret;
	60
	61	ret = clk_enable(info->rtc_clk);
	62	if (ret)
	63	return ret;
	64
	65	if (info->data->needs_src_clk) {
	66	ret = clk_enable(info->rtc_src_clk);
	67	if (ret) {
	68	clk_disable(info->rtc_clk);
	69	return ret;
	70	}
	71	}
	72	return 0;
	73	}
	74
	75	static void s3c_rtc_disable_clk(struct s3c_rtc *info)
	76	{
	77	if (info->data->needs_src_clk)
	78	clk_disable(info->rtc_src_clk);
	79	clk_disable(info->rtc_clk);
	80	}
	81
	82	/* IRQ Handler */
	83	static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
	84	{
	85	struct s3c_rtc info = (struct s3c_rtc )id;
	86
	87	if (info->data->irq_handler)
	88	info->data->irq_handler(info, S3C2410_INTP_ALM);
	89
	90	return IRQ_HANDLED;
	91	}
	92
	93	/* Update control registers */
	94	static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
	95	{
	96	struct s3c_rtc *info = dev_get_drvdata(dev);
	97	unsigned long flags;
	98	unsigned int tmp;
	99	int ret;
	100
	101	dev_dbg(info->dev, "%s: aie=%d\n", __func__, enabled);
	102
	103	ret = s3c_rtc_enable_clk(info);
	104	if (ret)
	105	return ret;
	106
	107	tmp = readb(info->base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
	108
	109	if (enabled)
	110	tmp \|= S3C2410_RTCALM_ALMEN;
	111
	112	writeb(tmp, info->base + S3C2410_RTCALM);
	113
	114	spin_lock_irqsave(&info->alarm_lock, flags);
	115
	116	if (info->alarm_enabled && !enabled)
	117	s3c_rtc_disable_clk(info);
	118	else if (!info->alarm_enabled && enabled)
	119	ret = s3c_rtc_enable_clk(info);
	120
	121	info->alarm_enabled = enabled;
	122	spin_unlock_irqrestore(&info->alarm_lock, flags);
	123
	124	s3c_rtc_disable_clk(info);
	125
	126	return ret;
	127	}
	128
	129	/* Read time from RTC and convert it from BCD */
	130	static int s3c_rtc_read_time(struct s3c_rtc info, struct rtc_time tm)
	131	{
	132	unsigned int have_retried = 0;
	133	int ret;
	134
	135	ret = s3c_rtc_enable_clk(info);
	136	if (ret)
	137	return ret;
	138
	139	retry_get_time:
	140	tm->tm_min = readb(info->base + S3C2410_RTCMIN);
	141	tm->tm_hour = readb(info->base + S3C2410_RTCHOUR);
	142	tm->tm_mday = readb(info->base + S3C2410_RTCDATE);
	143	tm->tm_mon = readb(info->base + S3C2410_RTCMON);
	144	tm->tm_year = readb(info->base + S3C2410_RTCYEAR);
	145	tm->tm_sec = readb(info->base + S3C2410_RTCSEC);
	146
	147	/*
	148	* The only way to work out whether the system was mid-update
	149	* when we read it is to check the second counter, and if it
	150	* is zero, then we re-try the entire read
	151	*/
	152	if (tm->tm_sec == 0 && !have_retried) {
	153	have_retried = 1;
	154	goto retry_get_time;
	155	}
	156
	157	s3c_rtc_disable_clk(info);
	158
	159	tm->tm_sec = bcd2bin(tm->tm_sec);
	160	tm->tm_min = bcd2bin(tm->tm_min);
	161	tm->tm_hour = bcd2bin(tm->tm_hour);
	162	tm->tm_mday = bcd2bin(tm->tm_mday);
	163	tm->tm_mon = bcd2bin(tm->tm_mon);
	164	tm->tm_year = bcd2bin(tm->tm_year);
	165
	166	return 0;
	167	}
	168
	169	/* Convert time to BCD and write it to RTC */
	170	static int s3c_rtc_write_time(struct s3c_rtc info, const struct rtc_time tm)
	171	{
	172	int ret;
	173
	174	ret = s3c_rtc_enable_clk(info);
	175	if (ret)
	176	return ret;
	177
	178	writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_RTCSEC);
	179	writeb(bin2bcd(tm->tm_min), info->base + S3C2410_RTCMIN);
	180	writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_RTCHOUR);
	181	writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_RTCDATE);
	182	writeb(bin2bcd(tm->tm_mon), info->base + S3C2410_RTCMON);
	183	writeb(bin2bcd(tm->tm_year), info->base + S3C2410_RTCYEAR);
	184
	185	s3c_rtc_disable_clk(info);
	186
	187	return 0;
	188	}
	189
	190	static int s3c_rtc_gettime(struct device dev, struct rtc_time tm)
	191	{
	192	struct s3c_rtc *info = dev_get_drvdata(dev);
	193	int ret;
	194
	195	ret = s3c_rtc_read_time(info, tm);
	196	if (ret)
	197	return ret;
	198
	199	/* Convert internal representation to actual date/time */
	200	tm->tm_year += 100;
	201	tm->tm_mon -= 1;
	202
	203	dev_dbg(dev, "read time %ptR\n", tm);
	204	return 0;
	205	}
	206
	207	static int s3c_rtc_settime(struct device dev, struct rtc_time tm)
	208	{
	209	struct s3c_rtc *info = dev_get_drvdata(dev);
	210	struct rtc_time rtc_tm = *tm;
	211
	212	dev_dbg(dev, "set time %ptR\n", tm);
	213
	214	/*
	215	* Convert actual date/time to internal representation.
	216	* We get around Y2K by simply not supporting it.
	217	*/
	218	rtc_tm.tm_year -= 100;
	219	rtc_tm.tm_mon += 1;
	220
	221	return s3c_rtc_write_time(info, &rtc_tm);
	222	}
	223
	224	static int s3c_rtc_getalarm(struct device dev, struct rtc_wkalrm alrm)
	225	{
	226	struct s3c_rtc *info = dev_get_drvdata(dev);
	227	struct rtc_time *alm_tm = &alrm->time;
	228	unsigned int alm_en;
	229	int ret;
	230
	231	ret = s3c_rtc_enable_clk(info);
	232	if (ret)
	233	return ret;
	234
	235	alm_tm->tm_sec = readb(info->base + S3C2410_ALMSEC);
	236	alm_tm->tm_min = readb(info->base + S3C2410_ALMMIN);
	237	alm_tm->tm_hour = readb(info->base + S3C2410_ALMHOUR);
	238	alm_tm->tm_mon = readb(info->base + S3C2410_ALMMON);
	239	alm_tm->tm_mday = readb(info->base + S3C2410_ALMDATE);
	240	alm_tm->tm_year = readb(info->base + S3C2410_ALMYEAR);
	241
	242	alm_en = readb(info->base + S3C2410_RTCALM);
	243
	244	s3c_rtc_disable_clk(info);
	245
	246	alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
	247
	248	dev_dbg(dev, "read alarm %d, %ptR\n", alm_en, alm_tm);
	249
	250	/* decode the alarm enable field */
	251	if (alm_en & S3C2410_RTCALM_SECEN)
	252	alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
	253
	254	if (alm_en & S3C2410_RTCALM_MINEN)
	255	alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
	256
	257	if (alm_en & S3C2410_RTCALM_HOUREN)
	258	alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
	259
	260	if (alm_en & S3C2410_RTCALM_DAYEN)
	261	alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
	262
	263	if (alm_en & S3C2410_RTCALM_MONEN) {
	264	alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
	265	alm_tm->tm_mon -= 1;
	266	}
	267
	268	if (alm_en & S3C2410_RTCALM_YEAREN)
	269	alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
	270
	271	return 0;
	272	}
	273
	274	static int s3c_rtc_setalarm(struct device dev, struct rtc_wkalrm alrm)
	275	{
	276	struct s3c_rtc *info = dev_get_drvdata(dev);
	277	struct rtc_time *tm = &alrm->time;
	278	unsigned int alrm_en;
	279	int ret;
	280
	281	dev_dbg(dev, "s3c_rtc_setalarm: %d, %ptR\n", alrm->enabled, tm);
	282
	283	ret = s3c_rtc_enable_clk(info);
	284	if (ret)
	285	return ret;
	286
	287	alrm_en = readb(info->base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
	288	writeb(0x00, info->base + S3C2410_RTCALM);
	289
	290	if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
	291	alrm_en \|= S3C2410_RTCALM_SECEN;
	292	writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_ALMSEC);
	293	}
	294
	295	if (tm->tm_min < 60 && tm->tm_min >= 0) {
	296	alrm_en \|= S3C2410_RTCALM_MINEN;
	297	writeb(bin2bcd(tm->tm_min), info->base + S3C2410_ALMMIN);
	298	}
	299
	300	if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
	301	alrm_en \|= S3C2410_RTCALM_HOUREN;
	302	writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_ALMHOUR);
	303	}
	304
	305	if (tm->tm_mon < 12 && tm->tm_mon >= 0) {
	306	alrm_en \|= S3C2410_RTCALM_MONEN;
	307	writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_ALMMON);
	308	}
	309
	310	if (tm->tm_mday <= 31 && tm->tm_mday >= 1) {
	311	alrm_en \|= S3C2410_RTCALM_DAYEN;
	312	writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_ALMDATE);
	313	}
	314
	315	dev_dbg(dev, "setting S3C2410_RTCALM to %08x\n", alrm_en);
	316
	317	writeb(alrm_en, info->base + S3C2410_RTCALM);
	318
	319	s3c_rtc_setaie(dev, alrm->enabled);
	320
	321	s3c_rtc_disable_clk(info);
	322
	323	return 0;
	324	}
	325
	326	static const struct rtc_class_ops s3c_rtcops = {
	327	.read_time = s3c_rtc_gettime,
	328	.set_time = s3c_rtc_settime,
	329	.read_alarm = s3c_rtc_getalarm,
	330	.set_alarm = s3c_rtc_setalarm,
	331	.alarm_irq_enable = s3c_rtc_setaie,
	332	};
	333
	334	static void s3c24xx_rtc_enable(struct s3c_rtc *info)
	335	{
	336	unsigned int con, tmp;
	337
	338	con = readw(info->base + S3C2410_RTCCON);
	339	/* re-enable the device, and check it is ok */
	340	if ((con & S3C2410_RTCCON_RTCEN) == 0) {
	341	dev_info(info->dev, "rtc disabled, re-enabling\n");
	342
	343	tmp = readw(info->base + S3C2410_RTCCON);
	344	writew(tmp \| S3C2410_RTCCON_RTCEN, info->base + S3C2410_RTCCON);
	345	}
	346
	347	if (con & S3C2410_RTCCON_CNTSEL) {
	348	dev_info(info->dev, "removing RTCCON_CNTSEL\n");
	349
	350	tmp = readw(info->base + S3C2410_RTCCON);
	351	writew(tmp & ~S3C2410_RTCCON_CNTSEL,
	352	info->base + S3C2410_RTCCON);
	353	}
	354
	355	if (con & S3C2410_RTCCON_CLKRST) {
	356	dev_info(info->dev, "removing RTCCON_CLKRST\n");
	357
	358	tmp = readw(info->base + S3C2410_RTCCON);
	359	writew(tmp & ~S3C2410_RTCCON_CLKRST,
	360	info->base + S3C2410_RTCCON);
	361	}
	362	}
	363
	364	static void s3c24xx_rtc_disable(struct s3c_rtc *info)
	365	{
	366	unsigned int con;
	367
	368	con = readw(info->base + S3C2410_RTCCON);
	369	con &= ~S3C2410_RTCCON_RTCEN;
	370	writew(con, info->base + S3C2410_RTCCON);
	371
	372	con = readb(info->base + S3C2410_TICNT);
	373	con &= ~S3C2410_TICNT_ENABLE;
	374	writeb(con, info->base + S3C2410_TICNT);
	375	}
	376
	377	static void s3c6410_rtc_disable(struct s3c_rtc *info)
	378	{
	379	unsigned int con;
	380
	381	con = readw(info->base + S3C2410_RTCCON);
	382	con &= ~S3C64XX_RTCCON_TICEN;
	383	con &= ~S3C2410_RTCCON_RTCEN;
	384	writew(con, info->base + S3C2410_RTCCON);
	385	}
	386
	387	static void s3c_rtc_remove(struct platform_device *pdev)
	388	{
	389	struct s3c_rtc *info = platform_get_drvdata(pdev);
	390
	391	s3c_rtc_setaie(info->dev, 0);
	392
	393	if (info->data->needs_src_clk)
	394	clk_unprepare(info->rtc_src_clk);
	395	clk_unprepare(info->rtc_clk);
	396	}
	397
	398	static int s3c_rtc_probe(struct platform_device *pdev)
	399	{
	400	struct s3c_rtc *info = NULL;
	401	int ret;
	402
	403	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
	404	if (!info)
	405	return -ENOMEM;
	406
	407	info->dev = &pdev->dev;
	408	info->data = of_device_get_match_data(&pdev->dev);
	409	if (!info->data) {
	410	dev_err(&pdev->dev, "failed getting s3c_rtc_data\n");
	411	return -EINVAL;
	412	}
	413	spin_lock_init(&info->alarm_lock);
	414
	415	platform_set_drvdata(pdev, info);
	416
	417	info->irq_alarm = platform_get_irq(pdev, 0);
	418	if (info->irq_alarm < 0)
	419	return info->irq_alarm;
	420
	421	dev_dbg(&pdev->dev, "s3c2410_rtc: alarm irq %d\n", info->irq_alarm);
	422
	423	/* get the memory region */
	424	info->base = devm_platform_ioremap_resource(pdev, 0);
	425	if (IS_ERR(info->base))
	426	return PTR_ERR(info->base);
	427
	428	info->rtc_clk = devm_clk_get(&pdev->dev, "rtc");
	429	if (IS_ERR(info->rtc_clk))
	430	return dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_clk),
	431	"failed to find rtc clock\n");
	432	ret = clk_prepare_enable(info->rtc_clk);
	433	if (ret)
	434	return ret;
	435
	436	if (info->data->needs_src_clk) {
	437	info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");
	438	if (IS_ERR(info->rtc_src_clk)) {
	439	ret = dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_src_clk),
	440	"failed to find rtc source clock\n");
	441	goto err_src_clk;
	442	}
	443	ret = clk_prepare_enable(info->rtc_src_clk);
	444	if (ret)
	445	goto err_src_clk;
	446	}
	447
	448	/* disable RTC enable bits potentially set by the bootloader */
	449	if (info->data->disable)
	450	info->data->disable(info);
	451
	452	/* check to see if everything is setup correctly */
	453	if (info->data->enable)
	454	info->data->enable(info);
	455
	456	dev_dbg(&pdev->dev, "s3c2410_rtc: RTCCON=%02x\n",
	457	readw(info->base + S3C2410_RTCCON));
	458
	459	device_init_wakeup(&pdev->dev, true);
	460
	461	info->rtc = devm_rtc_allocate_device(&pdev->dev);
	462	if (IS_ERR(info->rtc)) {
	463	ret = PTR_ERR(info->rtc);
	464	goto err_nortc;
	465	}
	466
	467	info->rtc->ops = &s3c_rtcops;
	468	info->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
	469	info->rtc->range_max = RTC_TIMESTAMP_END_2099;
	470
	471	ret = devm_rtc_register_device(info->rtc);
	472	if (ret)
	473	goto err_nortc;
	474
	475	ret = devm_request_irq(&pdev->dev, info->irq_alarm, s3c_rtc_alarmirq,
	476	0, "s3c2410-rtc alarm", info);
	477	if (ret) {
	478	dev_err(&pdev->dev, "IRQ%d error %d\n", info->irq_alarm, ret);
	479	goto err_nortc;
	480	}
	481
	482	s3c_rtc_disable_clk(info);
	483
	484	return 0;
	485
	486	err_nortc:
	487	if (info->data->disable)
	488	info->data->disable(info);
	489
	490	if (info->data->needs_src_clk)
	491	clk_disable_unprepare(info->rtc_src_clk);
	492	err_src_clk:
	493	clk_disable_unprepare(info->rtc_clk);
	494
	495	return ret;
	496	}
	497
	498	#ifdef CONFIG_PM_SLEEP
	499
	500	static int s3c_rtc_suspend(struct device *dev)
	501	{
	502	struct s3c_rtc *info = dev_get_drvdata(dev);
	503	int ret;
	504
	505	ret = s3c_rtc_enable_clk(info);
	506	if (ret)
	507	return ret;
	508
	509	if (info->data->disable)
	510	info->data->disable(info);
	511
	512	if (device_may_wakeup(dev) && !info->wake_en) {
	513	if (enable_irq_wake(info->irq_alarm) == 0)
	514	info->wake_en = true;
	515	else
	516	dev_err(dev, "enable_irq_wake failed\n");
	517	}
	518
	519	return 0;
	520	}
	521
	522	static int s3c_rtc_resume(struct device *dev)
	523	{
	524	struct s3c_rtc *info = dev_get_drvdata(dev);
	525
	526	if (info->data->enable)
	527	info->data->enable(info);
	528
	529	s3c_rtc_disable_clk(info);
	530
	531	if (device_may_wakeup(dev) && info->wake_en) {
	532	disable_irq_wake(info->irq_alarm);
	533	info->wake_en = false;
	534	}
	535
	536	return 0;
	537	}
	538	#endif
	539	static SIMPLE_DEV_PM_OPS(s3c_rtc_pm_ops, s3c_rtc_suspend, s3c_rtc_resume);
	540
	541	static void s3c24xx_rtc_irq(struct s3c_rtc *info, int mask)
	542	{
	543	rtc_update_irq(info->rtc, 1, RTC_AF \| RTC_IRQF);
	544	}
	545
	546	static void s3c6410_rtc_irq(struct s3c_rtc *info, int mask)
	547	{
	548	rtc_update_irq(info->rtc, 1, RTC_AF \| RTC_IRQF);
	549	writeb(mask, info->base + S3C2410_INTP);
	550	}
	551
	552	static struct s3c_rtc_data const s3c2410_rtc_data = {
	553	.irq_handler = s3c24xx_rtc_irq,
	554	.enable = s3c24xx_rtc_enable,
	555	.disable = s3c24xx_rtc_disable,
	556	};
	557
	558	static struct s3c_rtc_data const s3c2416_rtc_data = {
	559	.irq_handler = s3c24xx_rtc_irq,
	560	.enable = s3c24xx_rtc_enable,
	561	.disable = s3c24xx_rtc_disable,
	562	};
	563
	564	static struct s3c_rtc_data const s3c2443_rtc_data = {
	565	.irq_handler = s3c24xx_rtc_irq,
	566	.enable = s3c24xx_rtc_enable,
	567	.disable = s3c24xx_rtc_disable,
	568	};
	569
	570	static struct s3c_rtc_data const s3c6410_rtc_data = {
	571	.needs_src_clk = true,
	572	.irq_handler = s3c6410_rtc_irq,
	573	.enable = s3c24xx_rtc_enable,
	574	.disable = s3c6410_rtc_disable,
	575	};
	576
	577	static const __maybe_unused struct of_device_id s3c_rtc_dt_match[] = {
	578	{
	579	.compatible = "samsung,s3c2410-rtc",
	580	.data = &s3c2410_rtc_data,
	581	}, {
	582	.compatible = "samsung,s3c2416-rtc",
	583	.data = &s3c2416_rtc_data,
	584	}, {
	585	.compatible = "samsung,s3c2443-rtc",
	586	.data = &s3c2443_rtc_data,
	587	}, {
	588	.compatible = "samsung,s3c6410-rtc",
	589	.data = &s3c6410_rtc_data,
	590	}, {
	591	.compatible = "samsung,exynos3250-rtc",
	592	.data = &s3c6410_rtc_data,
	593	},
	594	{ /* sentinel */ },
	595	};
	596	MODULE_DEVICE_TABLE(of, s3c_rtc_dt_match);
	597
	598	static struct platform_driver s3c_rtc_driver = {
	599	.probe = s3c_rtc_probe,
	600	.remove = s3c_rtc_remove,
	601	.driver = {
	602	.name = "s3c-rtc",
	603	.pm = &s3c_rtc_pm_ops,
	604	.of_match_table = of_match_ptr(s3c_rtc_dt_match),
	605	},
	606	};
	607	module_platform_driver(s3c_rtc_driver);
	608
	609	MODULE_DESCRIPTION("Samsung S3C RTC Driver");
	610	MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
	611	MODULE_LICENSE("GPL");