// SPDX-License-Identifier: GPL-2.0-or-later/* * An RTC driver for Allwinner A10/A20 * * Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com> */ #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/platform_device.h>#include <linux/rtc.h>#include <linux/types.h> #define SUNXI_LOSC_CTRL				0x0000#define SUNXI_LOSC_CTRL_RTC_HMS_ACC		BIT(8)#define SUNXI_LOSC_CTRL_RTC_YMD_ACC		BIT(7) #define SUNXI_RTC_YMD				0x0004 #define SUNXI_RTC_HMS				0x0008 #define SUNXI_ALRM_DHMS				0x000c #define SUNXI_ALRM_EN				0x0014#define SUNXI_ALRM_EN_CNT_EN			BIT(8) #define SUNXI_ALRM_IRQ_EN			0x0018#define SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN		BIT(0) #define SUNXI_ALRM_IRQ_STA			0x001c#define SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND		BIT(0) #define SUNXI_MASK_DH				0x0000001f#define SUNXI_MASK_SM				0x0000003f#define SUNXI_MASK_M				0x0000000f#define SUNXI_MASK_LY				0x00000001#define SUNXI_MASK_D				0x00000ffe#define SUNXI_MASK_M				0x0000000f #define SUNXI_GET(x, mask, shift)		(((x) & ((mask) << (shift))) \							>> (shift)) #define SUNXI_SET(x, mask, shift)		(((x) & (mask)) << (shift)) /* * Get date values */#define SUNXI_DATE_GET_DAY_VALUE(x)		SUNXI_GET(x, SUNXI_MASK_DH, 0)#define SUNXI_DATE_GET_MON_VALUE(x)		SUNXI_GET(x, SUNXI_MASK_M, 8)#define SUNXI_DATE_GET_YEAR_VALUE(x, mask)	SUNXI_GET(x, mask, 16) /* * Get time values */#define SUNXI_TIME_GET_SEC_VALUE(x)		SUNXI_GET(x, SUNXI_MASK_SM, 0)#define SUNXI_TIME_GET_MIN_VALUE(x)		SUNXI_GET(x, SUNXI_MASK_SM, 8)#define SUNXI_TIME_GET_HOUR_VALUE(x)		SUNXI_GET(x, SUNXI_MASK_DH, 16) /* * Get alarm values */#define SUNXI_ALRM_GET_SEC_VALUE(x)		SUNXI_GET(x, SUNXI_MASK_SM, 0)#define SUNXI_ALRM_GET_MIN_VALUE(x)		SUNXI_GET(x, SUNXI_MASK_SM, 8)#define SUNXI_ALRM_GET_HOUR_VALUE(x)		SUNXI_GET(x, SUNXI_MASK_DH, 16) /* * Set date values */#define SUNXI_DATE_SET_DAY_VALUE(x)		SUNXI_DATE_GET_DAY_VALUE(x)#define SUNXI_DATE_SET_MON_VALUE(x)		SUNXI_SET(x, SUNXI_MASK_M, 8)#define SUNXI_DATE_SET_YEAR_VALUE(x, mask)	SUNXI_SET(x, mask, 16)#define SUNXI_LEAP_SET_VALUE(x, shift)		SUNXI_SET(x, SUNXI_MASK_LY, shift) /* * Set time values */#define SUNXI_TIME_SET_SEC_VALUE(x)		SUNXI_TIME_GET_SEC_VALUE(x)#define SUNXI_TIME_SET_MIN_VALUE(x)		SUNXI_SET(x, SUNXI_MASK_SM, 8)#define SUNXI_TIME_SET_HOUR_VALUE(x)		SUNXI_SET(x, SUNXI_MASK_DH, 16) /* * Set alarm values */#define SUNXI_ALRM_SET_SEC_VALUE(x)		SUNXI_ALRM_GET_SEC_VALUE(x)#define SUNXI_ALRM_SET_MIN_VALUE(x)		SUNXI_SET(x, SUNXI_MASK_SM, 8)#define SUNXI_ALRM_SET_HOUR_VALUE(x)		SUNXI_SET(x, SUNXI_MASK_DH, 16)#define SUNXI_ALRM_SET_DAY_VALUE(x)		SUNXI_SET(x, SUNXI_MASK_D, 21) /* * Time unit conversions */#define SEC_IN_MIN				60#define SEC_IN_HOUR				(60 * SEC_IN_MIN)#define SEC_IN_DAY				(24 * SEC_IN_HOUR) /* * 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. */#define SUNXI_YEAR_OFF(x)			((x)->min - 1900) /* * min and max year are arbitrary set considering the limited range of the * hardware register field */struct sunxi_rtc_data_year {	unsigned int min;		/* min year allowed */	unsigned int max;		/* max year allowed */	unsigned int mask;		/* mask for the year field */	unsigned char leap_shift;	/* bit shift to get the leap year */}; static const struct sunxi_rtc_data_year data_year_param[] = {	[0] = {		.min		= 2010,		.max		= 2073,		.mask		= 0x3f,		.leap_shift	= 22,	},	[1] = {		.min		= 1970,		.max		= 2225,		.mask		= 0xff,		.leap_shift	= 24,	},}; struct sunxi_rtc_dev {	struct rtc_device *rtc;	struct device *dev;	const struct sunxi_rtc_data_year *data_year;	void __iomem *base;	int irq;}; static irqreturn_t sunxi_rtc_alarmirq(int irq, void *id){	struct sunxi_rtc_dev *chip = (struct sunxi_rtc_dev *) id;	u32 val; 	val = readl(chip->base + SUNXI_ALRM_IRQ_STA); 	if (val & SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND) {		val |= SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND;		writel(val, chip->base + SUNXI_ALRM_IRQ_STA); 		rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF); 		return IRQ_HANDLED;	} 	return IRQ_NONE;} static void sunxi_rtc_setaie(unsigned int to, struct sunxi_rtc_dev *chip){	u32 alrm_val = 0;	u32 alrm_irq_val = 0; 	if (to) {		alrm_val = readl(chip->base + SUNXI_ALRM_EN);		alrm_val |= SUNXI_ALRM_EN_CNT_EN; 		alrm_irq_val = readl(chip->base + SUNXI_ALRM_IRQ_EN);		alrm_irq_val |= SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN;	} else {		writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND,				chip->base + SUNXI_ALRM_IRQ_STA);	} 	writel(alrm_val, chip->base + SUNXI_ALRM_EN);	writel(alrm_irq_val, chip->base + SUNXI_ALRM_IRQ_EN);} static int sunxi_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm){	struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);	struct rtc_time *alrm_tm = &wkalrm->time;	u32 alrm;	u32 alrm_en;	u32 date; 	alrm = readl(chip->base + SUNXI_ALRM_DHMS);	date = readl(chip->base + SUNXI_RTC_YMD); 	alrm_tm->tm_sec = SUNXI_ALRM_GET_SEC_VALUE(alrm);	alrm_tm->tm_min = SUNXI_ALRM_GET_MIN_VALUE(alrm);	alrm_tm->tm_hour = SUNXI_ALRM_GET_HOUR_VALUE(alrm); 	alrm_tm->tm_mday = SUNXI_DATE_GET_DAY_VALUE(date);	alrm_tm->tm_mon = SUNXI_DATE_GET_MON_VALUE(date);	alrm_tm->tm_year = SUNXI_DATE_GET_YEAR_VALUE(date,			chip->data_year->mask); 	alrm_tm->tm_mon -= 1; 	/*	 * switch from (data_year->min)-relative offset to	 * a (1900)-relative one	 */	alrm_tm->tm_year += SUNXI_YEAR_OFF(chip->data_year); 	alrm_en = readl(chip->base + SUNXI_ALRM_IRQ_EN);	if (alrm_en & SUNXI_ALRM_EN_CNT_EN)		wkalrm->enabled = 1; 	return 0;} static int sunxi_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm){	struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);	u32 date, time; 	/*	 * read again in case it changes	 */	do {		date = readl(chip->base + SUNXI_RTC_YMD);		time = readl(chip->base + SUNXI_RTC_HMS);	} while ((date != readl(chip->base + SUNXI_RTC_YMD)) ||		 (time != readl(chip->base + SUNXI_RTC_HMS))); 	rtc_tm->tm_sec  = SUNXI_TIME_GET_SEC_VALUE(time);	rtc_tm->tm_min  = SUNXI_TIME_GET_MIN_VALUE(time);	rtc_tm->tm_hour = SUNXI_TIME_GET_HOUR_VALUE(time); 	rtc_tm->tm_mday = SUNXI_DATE_GET_DAY_VALUE(date);	rtc_tm->tm_mon  = SUNXI_DATE_GET_MON_VALUE(date);	rtc_tm->tm_year = SUNXI_DATE_GET_YEAR_VALUE(date,					chip->data_year->mask); 	rtc_tm->tm_mon  -= 1; 	/*	 * switch from (data_year->min)-relative offset to	 * a (1900)-relative one	 */	rtc_tm->tm_year += SUNXI_YEAR_OFF(chip->data_year); 	return 0;} static int sunxi_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm){	struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);	struct rtc_time *alrm_tm = &wkalrm->time;	struct rtc_time tm_now;	u32 alrm;	time64_t diff;	unsigned long time_gap;	unsigned long time_gap_day;	unsigned long time_gap_hour;	unsigned long time_gap_min;	int ret; 	ret = sunxi_rtc_gettime(dev, &tm_now);	if (ret < 0) {		dev_err(dev, "Error in getting time\n");		return -EINVAL;	} 	diff = rtc_tm_sub(alrm_tm, &tm_now);	if (diff <= 0) {		dev_err(dev, "Date to set in the past\n");		return -EINVAL;	} 	if (diff > 255 * SEC_IN_DAY) {		dev_err(dev, "Day must be in the range 0 - 255\n");		return -EINVAL;	} 	time_gap = diff;	time_gap_day = time_gap / SEC_IN_DAY;	time_gap -= time_gap_day * SEC_IN_DAY;	time_gap_hour = time_gap / SEC_IN_HOUR;	time_gap -= time_gap_hour * SEC_IN_HOUR;	time_gap_min = time_gap / SEC_IN_MIN;	time_gap -= time_gap_min * SEC_IN_MIN; 	sunxi_rtc_setaie(0, chip);	writel(0, chip->base + SUNXI_ALRM_DHMS);	usleep_range(100, 300); 	alrm = SUNXI_ALRM_SET_SEC_VALUE(time_gap) |		SUNXI_ALRM_SET_MIN_VALUE(time_gap_min) |		SUNXI_ALRM_SET_HOUR_VALUE(time_gap_hour) |		SUNXI_ALRM_SET_DAY_VALUE(time_gap_day);	writel(alrm, chip->base + SUNXI_ALRM_DHMS); 	writel(0, chip->base + SUNXI_ALRM_IRQ_EN);	writel(SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN, chip->base + SUNXI_ALRM_IRQ_EN); 	sunxi_rtc_setaie(wkalrm->enabled, chip); 	return 0;} static int sunxi_rtc_wait(struct sunxi_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 == mask)			return 0; 	} while (time_before(jiffies, timeout)); 	return -ETIMEDOUT;} static int sunxi_rtc_settime(struct device *dev, struct rtc_time *rtc_tm){	struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);	u32 date = 0;	u32 time = 0;	unsigned int year; 	/*	 * the input rtc_tm->tm_year is the offset relative to 1900. We use	 * the SUNXI_YEAR_OFF macro to rebase it with respect to the min year	 * allowed by the hardware	 */ 	year = rtc_tm->tm_year + 1900;	if (year < chip->data_year->min || year > chip->data_year->max) {		dev_err(dev, "rtc only supports year in range %u - %u\n",			chip->data_year->min, chip->data_year->max);		return -EINVAL;	} 	rtc_tm->tm_year -= SUNXI_YEAR_OFF(chip->data_year);	rtc_tm->tm_mon += 1; 	date = SUNXI_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |		SUNXI_DATE_SET_MON_VALUE(rtc_tm->tm_mon)  |		SUNXI_DATE_SET_YEAR_VALUE(rtc_tm->tm_year,				chip->data_year->mask); 	if (is_leap_year(year))		date |= SUNXI_LEAP_SET_VALUE(1, chip->data_year->leap_shift); 	time = SUNXI_TIME_SET_SEC_VALUE(rtc_tm->tm_sec)  |		SUNXI_TIME_SET_MIN_VALUE(rtc_tm->tm_min)  |		SUNXI_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour); 	writel(0, chip->base + SUNXI_RTC_HMS);	writel(0, chip->base + SUNXI_RTC_YMD); 	writel(time, chip->base + SUNXI_RTC_HMS); 	/*	 * After writing the RTC HH-MM-SS register, the	 * SUNXI_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not	 * be cleared until the real writing operation is finished	 */ 	if (sunxi_rtc_wait(chip, SUNXI_LOSC_CTRL,				SUNXI_LOSC_CTRL_RTC_HMS_ACC, 50)) {		dev_err(dev, "Failed to set rtc time.\n");		return -1;	} 	writel(date, chip->base + SUNXI_RTC_YMD); 	/*	 * After writing the RTC YY-MM-DD register, the	 * SUNXI_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not	 * be cleared until the real writing operation is finished	 */ 	if (sunxi_rtc_wait(chip, SUNXI_LOSC_CTRL,				SUNXI_LOSC_CTRL_RTC_YMD_ACC, 50)) {		dev_err(dev, "Failed to set rtc time.\n");		return -1;	} 	return 0;} static int sunxi_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled){	struct sunxi_rtc_dev *chip = dev_get_drvdata(dev); 	if (!enabled)		sunxi_rtc_setaie(enabled, chip); 	return 0;} static const struct rtc_class_ops sunxi_rtc_ops = {	.read_time		= sunxi_rtc_gettime,	.set_time		= sunxi_rtc_settime,	.read_alarm		= sunxi_rtc_getalarm,	.set_alarm		= sunxi_rtc_setalarm,	.alarm_irq_enable	= sunxi_rtc_alarm_irq_enable}; static const struct of_device_id sunxi_rtc_dt_ids[] = {	{ .compatible = "allwinner,sun4i-a10-rtc", .data = &data_year_param[0] },	{ .compatible = "allwinner,sun7i-a20-rtc", .data = &data_year_param[1] },	{ /* sentinel */ },};MODULE_DEVICE_TABLE(of, sunxi_rtc_dt_ids); static int sunxi_rtc_probe(struct platform_device *pdev){	struct sunxi_rtc_dev *chip;	int ret; 	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);	if (!chip)		return -ENOMEM; 	platform_set_drvdata(pdev, chip);	chip->dev = &pdev->dev; 	chip->rtc = devm_rtc_allocate_device(&pdev->dev);	if (IS_ERR(chip->rtc))		return PTR_ERR(chip->rtc); 	chip->base = devm_platform_ioremap_resource(pdev, 0);	if (IS_ERR(chip->base))		return PTR_ERR(chip->base); 	chip->irq = platform_get_irq(pdev, 0);	if (chip->irq < 0)		return chip->irq;	ret = devm_request_irq(&pdev->dev, chip->irq, sunxi_rtc_alarmirq,			0, dev_name(&pdev->dev), chip);	if (ret) {		dev_err(&pdev->dev, "Could not request IRQ\n");		return ret;	} 	chip->data_year = of_device_get_match_data(&pdev->dev);	if (!chip->data_year) {		dev_err(&pdev->dev, "Unable to setup RTC data\n");		return -ENODEV;	} 	/* clear the alarm count value */	writel(0, chip->base + SUNXI_ALRM_DHMS); 	/* disable alarm, not generate irq pending */	writel(0, chip->base + SUNXI_ALRM_EN); 	/* disable alarm week/cnt irq, unset to cpu */	writel(0, chip->base + SUNXI_ALRM_IRQ_EN); 	/* clear alarm week/cnt irq pending */	writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base +			SUNXI_ALRM_IRQ_STA); 	chip->rtc->ops = &sunxi_rtc_ops; 	return devm_rtc_register_device(chip->rtc);} static struct platform_driver sunxi_rtc_driver = {	.probe		= sunxi_rtc_probe,	.driver		= {		.name		= "sunxi-rtc",		.of_match_table = sunxi_rtc_dt_ids,	},}; module_platform_driver(sunxi_rtc_driver); MODULE_DESCRIPTION("sunxi RTC driver");MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");MODULE_LICENSE("GPL");