[linux-2.6-block.git] / drivers / rtc / rtc-sun6i.c

/*
 * An RTC driver for Allwinner A31/A23
 *
 * Copyright (c) 2014, Chen-Yu Tsai <wens@csie.org>
 *
 * based on rtc-sunxi.c
 *
 * An RTC driver for Allwinner A10/A20
 *
 * Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/delay.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/types.h>

/* Control register */
#define SUN6I_LOSC_CTRL				0x0000
#define SUN6I_LOSC_CTRL_ALM_DHMS_ACC		BIT(9)
#define SUN6I_LOSC_CTRL_RTC_HMS_ACC		BIT(8)
#define SUN6I_LOSC_CTRL_RTC_YMD_ACC		BIT(7)
#define SUN6I_LOSC_CTRL_ACC_MASK		GENMASK(9, 7)

/* RTC */
#define SUN6I_RTC_YMD				0x0010
#define SUN6I_RTC_HMS				0x0014

/* Alarm 0 (counter) */
#define SUN6I_ALRM_COUNTER			0x0020
#define SUN6I_ALRM_CUR_VAL			0x0024
#define SUN6I_ALRM_EN				0x0028
#define SUN6I_ALRM_EN_CNT_EN			BIT(0)
#define SUN6I_ALRM_IRQ_EN			0x002c
#define SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN		BIT(0)
#define SUN6I_ALRM_IRQ_STA			0x0030
#define SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND		BIT(0)

/* Alarm 1 (wall clock) */
#define SUN6I_ALRM1_EN				0x0044
#define SUN6I_ALRM1_IRQ_EN			0x0048
#define SUN6I_ALRM1_IRQ_STA			0x004c
#define SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND	BIT(0)

/* Alarm config */
#define SUN6I_ALARM_CONFIG			0x0050
#define SUN6I_ALARM_CONFIG_WAKEUP		BIT(0)

/*
 * Get date values
 */
#define SUN6I_DATE_GET_DAY_VALUE(x)		((x)  & 0x0000001f)
#define SUN6I_DATE_GET_MON_VALUE(x)		(((x) & 0x00000f00) >> 8)
#define SUN6I_DATE_GET_YEAR_VALUE(x)		(((x) & 0x003f0000) >> 16)
#define SUN6I_LEAP_GET_VALUE(x)			(((x) & 0x00400000) >> 22)

/*
 * Get time values
 */
#define SUN6I_TIME_GET_SEC_VALUE(x)		((x)  & 0x0000003f)
#define SUN6I_TIME_GET_MIN_VALUE(x)		(((x) & 0x00003f00) >> 8)
#define SUN6I_TIME_GET_HOUR_VALUE(x)		(((x) & 0x001f0000) >> 16)

/*
 * Set date values
 */
#define SUN6I_DATE_SET_DAY_VALUE(x)		((x)       & 0x0000001f)
#define SUN6I_DATE_SET_MON_VALUE(x)		((x) <<  8 & 0x00000f00)
#define SUN6I_DATE_SET_YEAR_VALUE(x)		((x) << 16 & 0x003f0000)
#define SUN6I_LEAP_SET_VALUE(x)			((x) << 22 & 0x00400000)

/*
 * Set time values
 */
#define SUN6I_TIME_SET_SEC_VALUE(x)		((x)       & 0x0000003f)
#define SUN6I_TIME_SET_MIN_VALUE(x)		((x) <<  8 & 0x00003f00)
#define SUN6I_TIME_SET_HOUR_VALUE(x)		((x) << 16 & 0x001f0000)

/*
 * The year parameter passed to the driver is usually an offset relative to
 * the year 1900. This macro is used to convert this offset to another one
 * relative to the minimum year allowed by the hardware.
 *
 * The year range is 1970 - 2033. This range is selected to match Allwinner's
 * driver, even though it is somewhat limited.
 */
#define SUN6I_YEAR_MIN				1970
#define SUN6I_YEAR_MAX				2033
#define SUN6I_YEAR_OFF				(SUN6I_YEAR_MIN - 1900)

struct sun6i_rtc_dev {
	struct rtc_device *rtc;
	struct device *dev;
	void __iomem *base;
	int irq;
	unsigned long alarm;
};

static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id)
{
	struct sun6i_rtc_dev *chip = (struct sun6i_rtc_dev *) id;
	u32 val;

	val = readl(chip->base + SUN6I_ALRM_IRQ_STA);

	if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) {
		val |= SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND;
		writel(val, chip->base + SUN6I_ALRM_IRQ_STA);

		rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);

		return IRQ_HANDLED;
	}

	return IRQ_NONE;
}

static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip)
{
	u32 alrm_val = 0;
	u32 alrm_irq_val = 0;
	u32 alrm_wake_val = 0;

	if (to) {
		alrm_val = SUN6I_ALRM_EN_CNT_EN;
		alrm_irq_val = SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN;
		alrm_wake_val = SUN6I_ALARM_CONFIG_WAKEUP;
	} else {
		writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
		       chip->base + SUN6I_ALRM_IRQ_STA);
	}

	writel(alrm_val, chip->base + SUN6I_ALRM_EN);
	writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN);
	writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG);
}

static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
{
	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
	u32 date, time;

	/*
	 * read again in case it changes
	 */
	do {
		date = readl(chip->base + SUN6I_RTC_YMD);
		time = readl(chip->base + SUN6I_RTC_HMS);
	} while ((date != readl(chip->base + SUN6I_RTC_YMD)) ||
		 (time != readl(chip->base + SUN6I_RTC_HMS)));

	rtc_tm->tm_sec  = SUN6I_TIME_GET_SEC_VALUE(time);
	rtc_tm->tm_min  = SUN6I_TIME_GET_MIN_VALUE(time);
	rtc_tm->tm_hour = SUN6I_TIME_GET_HOUR_VALUE(time);

	rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);
	rtc_tm->tm_mon  = SUN6I_DATE_GET_MON_VALUE(date);
	rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);

	rtc_tm->tm_mon  -= 1;

	/*
	 * switch from (data_year->min)-relative offset to
	 * a (1900)-relative one
	 */
	rtc_tm->tm_year += SUN6I_YEAR_OFF;

	return rtc_valid_tm(rtc_tm);
}

static int sun6i_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
	u32 alrm_st;
	u32 alrm_en;

	alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN);
	alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA);
	wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN);
	wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN);
	rtc_time_to_tm(chip->alarm, &wkalrm->time);

	return 0;
}

static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
	struct rtc_time *alrm_tm = &wkalrm->time;
	struct rtc_time tm_now;
	unsigned long time_now = 0;
	unsigned long time_set = 0;
	unsigned long time_gap = 0;
	int ret = 0;

	ret = sun6i_rtc_gettime(dev, &tm_now);
	if (ret < 0) {
		dev_err(dev, "Error in getting time\n");
		return -EINVAL;
	}

	rtc_tm_to_time(alrm_tm, &time_set);
	rtc_tm_to_time(&tm_now, &time_now);
	if (time_set <= time_now) {
		dev_err(dev, "Date to set in the past\n");
		return -EINVAL;
	}

	time_gap = time_set - time_now;

	if (time_gap > U32_MAX) {
		dev_err(dev, "Date too far in the future\n");
		return -EINVAL;
	}

	sun6i_rtc_setaie(0, chip);
	writel(0, chip->base + SUN6I_ALRM_COUNTER);
	usleep_range(100, 300);

	writel(time_gap, chip->base + SUN6I_ALRM_COUNTER);
	chip->alarm = time_set;

	sun6i_rtc_setaie(wkalrm->enabled, chip);

	return 0;
}

static int sun6i_rtc_wait(struct sun6i_rtc_dev *chip, int offset,
			  unsigned int mask, unsigned int ms_timeout)
{
	const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout);
	u32 reg;

	do {
		reg = readl(chip->base + offset);
		reg &= mask;

		if (!reg)
			return 0;

	} while (time_before(jiffies, timeout));

	return -ETIMEDOUT;
}

static int sun6i_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)
{
	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
	u32 date = 0;
	u32 time = 0;
	int year;

	year = rtc_tm->tm_year + 1900;
	if (year < SUN6I_YEAR_MIN || year > SUN6I_YEAR_MAX) {
		dev_err(dev, "rtc only supports year in range %d - %d\n",
			SUN6I_YEAR_MIN, SUN6I_YEAR_MAX);
		return -EINVAL;
	}

	rtc_tm->tm_year -= SUN6I_YEAR_OFF;
	rtc_tm->tm_mon += 1;

	date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |
		SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon)  |
		SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);

	if (is_leap_year(year))
		date |= SUN6I_LEAP_SET_VALUE(1);

	time = SUN6I_TIME_SET_SEC_VALUE(rtc_tm->tm_sec)  |
		SUN6I_TIME_SET_MIN_VALUE(rtc_tm->tm_min)  |
		SUN6I_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);

	/* Check whether registers are writable */
	if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
			   SUN6I_LOSC_CTRL_ACC_MASK, 50)) {
		dev_err(dev, "rtc is still busy.\n");
		return -EBUSY;
	}

	writel(time, chip->base + SUN6I_RTC_HMS);

	/*
	 * After writing the RTC HH-MM-SS register, the
	 * SUN6I_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not
	 * be cleared until the real writing operation is finished
	 */

	if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
			   SUN6I_LOSC_CTRL_RTC_HMS_ACC, 50)) {
		dev_err(dev, "Failed to set rtc time.\n");
		return -ETIMEDOUT;
	}

	writel(date, chip->base + SUN6I_RTC_YMD);

	/*
	 * After writing the RTC YY-MM-DD register, the
	 * SUN6I_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not
	 * be cleared until the real writing operation is finished
	 */

	if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
			   SUN6I_LOSC_CTRL_RTC_YMD_ACC, 50)) {
		dev_err(dev, "Failed to set rtc time.\n");
		return -ETIMEDOUT;
	}

	return 0;
}

static int sun6i_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);

	if (!enabled)
		sun6i_rtc_setaie(enabled, chip);

	return 0;
}

static const struct rtc_class_ops sun6i_rtc_ops = {
	.read_time		= sun6i_rtc_gettime,
	.set_time		= sun6i_rtc_settime,
	.read_alarm		= sun6i_rtc_getalarm,
	.set_alarm		= sun6i_rtc_setalarm,
	.alarm_irq_enable	= sun6i_rtc_alarm_irq_enable
};

static int sun6i_rtc_probe(struct platform_device *pdev)
{
	struct sun6i_rtc_dev *chip;
	struct resource *res;
	int ret;

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

	platform_set_drvdata(pdev, chip);
	chip->dev = &pdev->dev;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	chip->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(chip->base))
		return PTR_ERR(chip->base);

	chip->irq = platform_get_irq(pdev, 0);
	if (chip->irq < 0) {
		dev_err(&pdev->dev, "No IRQ resource\n");
		return chip->irq;
	}

	ret = devm_request_irq(&pdev->dev, chip->irq, sun6i_rtc_alarmirq,
			       0, dev_name(&pdev->dev), chip);
	if (ret) {
		dev_err(&pdev->dev, "Could not request IRQ\n");
		return ret;
	}

	/* clear the alarm counter value */
	writel(0, chip->base + SUN6I_ALRM_COUNTER);

	/* disable counter alarm */
	writel(0, chip->base + SUN6I_ALRM_EN);

	/* disable counter alarm interrupt */
	writel(0, chip->base + SUN6I_ALRM_IRQ_EN);

	/* disable week alarm */
	writel(0, chip->base + SUN6I_ALRM1_EN);

	/* disable week alarm interrupt */
	writel(0, chip->base + SUN6I_ALRM1_IRQ_EN);

	/* clear counter alarm pending interrupts */
	writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
	       chip->base + SUN6I_ALRM_IRQ_STA);

	/* clear week alarm pending interrupts */
	writel(SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND,
	       chip->base + SUN6I_ALRM1_IRQ_STA);

	/* disable alarm wakeup */
	writel(0, chip->base + SUN6I_ALARM_CONFIG);

	chip->rtc = rtc_device_register("rtc-sun6i", &pdev->dev,
					&sun6i_rtc_ops, THIS_MODULE);
	if (IS_ERR(chip->rtc)) {
		dev_err(&pdev->dev, "unable to register device\n");
		return PTR_ERR(chip->rtc);
	}

	dev_info(&pdev->dev, "RTC enabled\n");

	return 0;
}

static int sun6i_rtc_remove(struct platform_device *pdev)
{
	struct sun6i_rtc_dev *chip = platform_get_drvdata(pdev);

	rtc_device_unregister(chip->rtc);

	return 0;
}

static const struct of_device_id sun6i_rtc_dt_ids[] = {
	{ .compatible = "allwinner,sun6i-a31-rtc" },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);

static struct platform_driver sun6i_rtc_driver = {
	.probe		= sun6i_rtc_probe,
	.remove		= sun6i_rtc_remove,
	.driver		= {
		.name		= "sun6i-rtc",
		.of_match_table = sun6i_rtc_dt_ids,
	},
};

module_platform_driver(sun6i_rtc_driver);

MODULE_DESCRIPTION("sun6i RTC driver");
MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
MODULE_LICENSE("GPL");
Commit	Line	Data
9765d2d9 CYT	1	/*
	2	* An RTC driver for Allwinner A31/A23
	3	*
	4	* Copyright (c) 2014, Chen-Yu Tsai <wens@csie.org>
	5	*
	6	* based on rtc-sunxi.c
	7	*
	8	* An RTC driver for Allwinner A10/A20
	9	*
	10	* Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com>
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License as published by
	14	* the Free Software Foundation; either version 2 of the License, or
	15	* (at your option) any later version.
	16	*
	17	* This program is distributed in the hope that it will be useful, but WITHOUT
	18	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	19	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	20	* more details.
	21	*/
	22
	23	#include <linux/delay.h>
	24	#include <linux/err.h>
	25	#include <linux/fs.h>
	26	#include <linux/init.h>
	27	#include <linux/interrupt.h>
	28	#include <linux/io.h>
	29	#include <linux/kernel.h>
	30	#include <linux/module.h>
	31	#include <linux/of.h>
	32	#include <linux/of_address.h>
	33	#include <linux/of_device.h>
	34	#include <linux/platform_device.h>
	35	#include <linux/rtc.h>
	36	#include <linux/types.h>
	37
	38	/* Control register */
	39	#define SUN6I_LOSC_CTRL 0x0000
	40	#define SUN6I_LOSC_CTRL_ALM_DHMS_ACC BIT(9)
	41	#define SUN6I_LOSC_CTRL_RTC_HMS_ACC BIT(8)
	42	#define SUN6I_LOSC_CTRL_RTC_YMD_ACC BIT(7)
	43	#define SUN6I_LOSC_CTRL_ACC_MASK GENMASK(9, 7)
	44
	45	/* RTC */
	46	#define SUN6I_RTC_YMD 0x0010
	47	#define SUN6I_RTC_HMS 0x0014
	48
	49	/* Alarm 0 (counter) */
	50	#define SUN6I_ALRM_COUNTER 0x0020
	51	#define SUN6I_ALRM_CUR_VAL 0x0024
	52	#define SUN6I_ALRM_EN 0x0028
	53	#define SUN6I_ALRM_EN_CNT_EN BIT(0)
	54	#define SUN6I_ALRM_IRQ_EN 0x002c
	55	#define SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN BIT(0)
	56	#define SUN6I_ALRM_IRQ_STA 0x0030
	57	#define SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND BIT(0)
	58
	59	/* Alarm 1 (wall clock) */
	60	#define SUN6I_ALRM1_EN 0x0044
	61	#define SUN6I_ALRM1_IRQ_EN 0x0048
	62	#define SUN6I_ALRM1_IRQ_STA 0x004c
	63	#define SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND BIT(0)
	64
65	/* Alarm config */
66	#define SUN6I_ALARM_CONFIG 0x0050
67	#define SUN6I_ALARM_CONFIG_WAKEUP BIT(0)
68
69	/*
70	* Get date values
71	*/
72	#define SUN6I_DATE_GET_DAY_VALUE(x) ((x) & 0x0000001f)
73	#define SUN6I_DATE_GET_MON_VALUE(x) (((x) & 0x00000f00) >> 8)
74	#define SUN6I_DATE_GET_YEAR_VALUE(x) (((x) & 0x003f0000) >> 16)
75	#define SUN6I_LEAP_GET_VALUE(x) (((x) & 0x00400000) >> 22)
76
77	/*
78	* Get time values
79	*/
80	#define SUN6I_TIME_GET_SEC_VALUE(x) ((x) & 0x0000003f)
81	#define SUN6I_TIME_GET_MIN_VALUE(x) (((x) & 0x00003f00) >> 8)
82	#define SUN6I_TIME_GET_HOUR_VALUE(x) (((x) & 0x001f0000) >> 16)
83
84	/*
85	* Set date values
86	*/
87	#define SUN6I_DATE_SET_DAY_VALUE(x) ((x) & 0x0000001f)
88	#define SUN6I_DATE_SET_MON_VALUE(x) ((x) << 8 & 0x00000f00)
89	#define SUN6I_DATE_SET_YEAR_VALUE(x) ((x) << 16 & 0x003f0000)
90	#define SUN6I_LEAP_SET_VALUE(x) ((x) << 22 & 0x00400000)
91
92	/*
93	* Set time values
94	*/
95	#define SUN6I_TIME_SET_SEC_VALUE(x) ((x) & 0x0000003f)
96	#define SUN6I_TIME_SET_MIN_VALUE(x) ((x) << 8 & 0x00003f00)
97	#define SUN6I_TIME_SET_HOUR_VALUE(x) ((x) << 16 & 0x001f0000)
98
99	/*
100	* The year parameter passed to the driver is usually an offset relative to
101	* the year 1900. This macro is used to convert this offset to another one
102	* relative to the minimum year allowed by the hardware.
103	*
104	* The year range is 1970 - 2033. This range is selected to match Allwinner's
105	* driver, even though it is somewhat limited.
106	*/
107	#define SUN6I_YEAR_MIN 1970
108	#define SUN6I_YEAR_MAX 2033
109	#define SUN6I_YEAR_OFF (SUN6I_YEAR_MIN - 1900)
110
111	struct sun6i_rtc_dev {
112	struct rtc_device *rtc;
113	struct device *dev;
114	void __iomem *base;
115	int irq;
116	unsigned long alarm;
117	};
118
119	static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id)
120	{
121	struct sun6i_rtc_dev chip = (struct sun6i_rtc_dev ) id;
122	u32 val;
123
124	val = readl(chip->base + SUN6I_ALRM_IRQ_STA);
125
126	if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) {
127	val \|= SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND;
128	writel(val, chip->base + SUN6I_ALRM_IRQ_STA);
129
130	rtc_update_irq(chip->rtc, 1, RTC_AF \| RTC_IRQF);
131
132	return IRQ_HANDLED;
133	}
134
135	return IRQ_NONE;
136	}
137
138	static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip)
139	{
140	u32 alrm_val = 0;
141	u32 alrm_irq_val = 0;
142	u32 alrm_wake_val = 0;
143
144	if (to) {
145	alrm_val = SUN6I_ALRM_EN_CNT_EN;
146	alrm_irq_val = SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN;
147	alrm_wake_val = SUN6I_ALARM_CONFIG_WAKEUP;
148	} else {
149	writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
150	chip->base + SUN6I_ALRM_IRQ_STA);
151	}
152
153	writel(alrm_val, chip->base + SUN6I_ALRM_EN);
154	writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN);
155	writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG);
156	}
157
158	static int sun6i_rtc_gettime(struct device dev, struct rtc_time rtc_tm)
159	{
160	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
161	u32 date, time;
162
163	/*
164	* read again in case it changes
165	*/
166	do {
167	date = readl(chip->base + SUN6I_RTC_YMD);
168	time = readl(chip->base + SUN6I_RTC_HMS);
169	} while ((date != readl(chip->base + SUN6I_RTC_YMD)) \|\|
170	(time != readl(chip->base + SUN6I_RTC_HMS)));
171
172	rtc_tm->tm_sec = SUN6I_TIME_GET_SEC_VALUE(time);
173	rtc_tm->tm_min = SUN6I_TIME_GET_MIN_VALUE(time);
174	rtc_tm->tm_hour = SUN6I_TIME_GET_HOUR_VALUE(time);
175
176	rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);
177	rtc_tm->tm_mon = SUN6I_DATE_GET_MON_VALUE(date);
178	rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);
179
180	rtc_tm->tm_mon -= 1;
181
182	/*
183	* switch from (data_year->min)-relative offset to
184	* a (1900)-relative one
185	*/
186	rtc_tm->tm_year += SUN6I_YEAR_OFF;
187
188	return rtc_valid_tm(rtc_tm);
189	}
190
191	static int sun6i_rtc_getalarm(struct device dev, struct rtc_wkalrm wkalrm)
192	{
193	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
194	u32 alrm_st;
195	u32 alrm_en;
196
197	alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN);
198	alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA);
199	wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN);
200	wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN);
201	rtc_time_to_tm(chip->alarm, &wkalrm->time);
202
203	return 0;
204	}
205
206	static int sun6i_rtc_setalarm(struct device dev, struct rtc_wkalrm wkalrm)
207	{
208	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
209	struct rtc_time *alrm_tm = &wkalrm->time;
210	struct rtc_time tm_now;
211	unsigned long time_now = 0;
212	unsigned long time_set = 0;
213	unsigned long time_gap = 0;
214	int ret = 0;
215
216	ret = sun6i_rtc_gettime(dev, &tm_now);
217	if (ret < 0) {
218	dev_err(dev, "Error in getting time\n");
219	return -EINVAL;
220	}
221
222	rtc_tm_to_time(alrm_tm, &time_set);
223	rtc_tm_to_time(&tm_now, &time_now);
224	if (time_set <= time_now) {
225	dev_err(dev, "Date to set in the past\n");
226	return -EINVAL;
227	}
228
229	time_gap = time_set - time_now;
230
231	if (time_gap > U32_MAX) {
232	dev_err(dev, "Date too far in the future\n");
233	return -EINVAL;
234	}
235
236	sun6i_rtc_setaie(0, chip);
237	writel(0, chip->base + SUN6I_ALRM_COUNTER);
238	usleep_range(100, 300);
239
240	writel(time_gap, chip->base + SUN6I_ALRM_COUNTER);
241	chip->alarm = time_set;
242
243	sun6i_rtc_setaie(wkalrm->enabled, chip);
244
245	return 0;
246	}
247
248	static int sun6i_rtc_wait(struct sun6i_rtc_dev *chip, int offset,
249	unsigned int mask, unsigned int ms_timeout)
250	{
251	const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout);
252	u32 reg;
253
254	do {
255	reg = readl(chip->base + offset);
256	reg &= mask;
257
258	if (!reg)
259	return 0;
260
261	} while (time_before(jiffies, timeout));
262
263	return -ETIMEDOUT;
264	}
265
266	static int sun6i_rtc_settime(struct device dev, struct rtc_time rtc_tm)
267	{
268	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
269	u32 date = 0;
270	u32 time = 0;
271	int year;
272
273	year = rtc_tm->tm_year + 1900;
274	if (year < SUN6I_YEAR_MIN \|\| year > SUN6I_YEAR_MAX) {
275	dev_err(dev, "rtc only supports year in range %d - %d\n",
276	SUN6I_YEAR_MIN, SUN6I_YEAR_MAX);
277	return -EINVAL;
278	}
279
280	rtc_tm->tm_year -= SUN6I_YEAR_OFF;
281	rtc_tm->tm_mon += 1;
282
283	date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) \|
284	SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon) \|
285	SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);
286
287	if (is_leap_year(year))
288	date \|= SUN6I_LEAP_SET_VALUE(1);
289
290	time = SUN6I_TIME_SET_SEC_VALUE(rtc_tm->tm_sec) \|
291	SUN6I_TIME_SET_MIN_VALUE(rtc_tm->tm_min) \|
292	SUN6I_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);
293
294	/* Check whether registers are writable */
295	if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
296	SUN6I_LOSC_CTRL_ACC_MASK, 50)) {
297	dev_err(dev, "rtc is still busy.\n");
298	return -EBUSY;
299	}
300
301	writel(time, chip->base + SUN6I_RTC_HMS);
302
303	/*
304	* After writing the RTC HH-MM-SS register, the
305	* SUN6I_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not
306	* be cleared until the real writing operation is finished
307	*/
308
309	if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
310	SUN6I_LOSC_CTRL_RTC_HMS_ACC, 50)) {
311	dev_err(dev, "Failed to set rtc time.\n");
312	return -ETIMEDOUT;
313	}
314
315	writel(date, chip->base + SUN6I_RTC_YMD);
316
317	/*
318	* After writing the RTC YY-MM-DD register, the
319	* SUN6I_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not
320	* be cleared until the real writing operation is finished
321	*/
322
323	if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
324	SUN6I_LOSC_CTRL_RTC_YMD_ACC, 50)) {
325	dev_err(dev, "Failed to set rtc time.\n");
326	return -ETIMEDOUT;
327	}
328
329	return 0;
330	}
331
332	static int sun6i_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
333	{
334	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
335
336	if (!enabled)
337	sun6i_rtc_setaie(enabled, chip);
338
339	return 0;
340	}
341
342	static const struct rtc_class_ops sun6i_rtc_ops = {
343	.read_time = sun6i_rtc_gettime,
344	.set_time = sun6i_rtc_settime,
345	.read_alarm = sun6i_rtc_getalarm,
346	.set_alarm = sun6i_rtc_setalarm,
347	.alarm_irq_enable = sun6i_rtc_alarm_irq_enable
348	};
349
350	static int sun6i_rtc_probe(struct platform_device *pdev)
351	{
352	struct sun6i_rtc_dev *chip;
353	struct resource *res;
354	int ret;
355
356	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
357	if (!chip)
358	return -ENOMEM;
359
360	platform_set_drvdata(pdev, chip);
361	chip->dev = &pdev->dev;
362
363	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
364	chip->base = devm_ioremap_resource(&pdev->dev, res);
365	if (IS_ERR(chip->base))
366	return PTR_ERR(chip->base);
367
368	chip->irq = platform_get_irq(pdev, 0);
369	if (chip->irq < 0) {
370	dev_err(&pdev->dev, "No IRQ resource\n");
371	return chip->irq;
372	}
373
374	ret = devm_request_irq(&pdev->dev, chip->irq, sun6i_rtc_alarmirq,
375	0, dev_name(&pdev->dev), chip);
376	if (ret) {
377	dev_err(&pdev->dev, "Could not request IRQ\n");
378	return ret;
379	}
380
381	/* clear the alarm counter value */
382	writel(0, chip->base + SUN6I_ALRM_COUNTER);
383
384	/* disable counter alarm */
385	writel(0, chip->base + SUN6I_ALRM_EN);
386
387	/* disable counter alarm interrupt */
388	writel(0, chip->base + SUN6I_ALRM_IRQ_EN);
389
390	/* disable week alarm */
391	writel(0, chip->base + SUN6I_ALRM1_EN);
392
393	/* disable week alarm interrupt */
394	writel(0, chip->base + SUN6I_ALRM1_IRQ_EN);
395
396	/* clear counter alarm pending interrupts */
397	writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
398	chip->base + SUN6I_ALRM_IRQ_STA);
399
400	/* clear week alarm pending interrupts */
401	writel(SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND,
402	chip->base + SUN6I_ALRM1_IRQ_STA);
403
404	/* disable alarm wakeup */
405	writel(0, chip->base + SUN6I_ALARM_CONFIG);
406
407	chip->rtc = rtc_device_register("rtc-sun6i", &pdev->dev,
408	&sun6i_rtc_ops, THIS_MODULE);
409	if (IS_ERR(chip->rtc)) {
410	dev_err(&pdev->dev, "unable to register device\n");
411	return PTR_ERR(chip->rtc);
412	}
413
414	dev_info(&pdev->dev, "RTC enabled\n");
415
416	return 0;
417	}
418
419	static int sun6i_rtc_remove(struct platform_device *pdev)
420	{
421	struct sun6i_rtc_dev *chip = platform_get_drvdata(pdev);
422
423	rtc_device_unregister(chip->rtc);
424
425	return 0;
426	}
427
428	static const struct of_device_id sun6i_rtc_dt_ids[] = {
429	{ .compatible = "allwinner,sun6i-a31-rtc" },
430	{ /* sentinel */ },
431	};
432	MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);
433
434	static struct platform_driver sun6i_rtc_driver = {
435	.probe = sun6i_rtc_probe,
436	.remove = sun6i_rtc_remove,
437	.driver = {
438	.name = "sun6i-rtc",
439	.of_match_table = sun6i_rtc_dt_ids,
440	},
441	};
442
443	module_platform_driver(sun6i_rtc_driver);
444
445	MODULE_DESCRIPTION("sun6i RTC driver");
446	MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
447	MODULE_LICENSE("GPL");