// SPDX-License-Identifier: GPL-2.0/* drivers/rtc/rtc-goldfish.c * * Copyright (C) 2007 Google, Inc. * Copyright (C) 2017 Imagination Technologies Ltd. */ #include <linux/io.h>#include <linux/module.h>#include <linux/of.h>#include <linux/platform_device.h>#include <linux/rtc.h> #define TIMER_TIME_LOW		0x00	/* get low bits of current time  */					/*   and update TIMER_TIME_HIGH  */#define TIMER_TIME_HIGH	0x04	/* get high bits of time at last */					/*   TIMER_TIME_LOW read         */#define TIMER_ALARM_LOW	0x08	/* set low bits of alarm and     */					/*   activate it                 */#define TIMER_ALARM_HIGH	0x0c	/* set high bits of next alarm   */#define TIMER_IRQ_ENABLED	0x10#define TIMER_CLEAR_ALARM	0x14#define TIMER_ALARM_STATUS	0x18#define TIMER_CLEAR_INTERRUPT	0x1c struct goldfish_rtc {	void __iomem *base;	int irq;	struct rtc_device *rtc;}; static int goldfish_rtc_read_alarm(struct device *dev,				   struct rtc_wkalrm *alrm){	u64 rtc_alarm;	u64 rtc_alarm_low;	u64 rtc_alarm_high;	void __iomem *base;	struct goldfish_rtc *rtcdrv; 	rtcdrv = dev_get_drvdata(dev);	base = rtcdrv->base; 	rtc_alarm_low = readl(base + TIMER_ALARM_LOW);	rtc_alarm_high = readl(base + TIMER_ALARM_HIGH);	rtc_alarm = (rtc_alarm_high << 32) | rtc_alarm_low; 	do_div(rtc_alarm, NSEC_PER_SEC);	memset(alrm, 0, sizeof(struct rtc_wkalrm)); 	rtc_time64_to_tm(rtc_alarm, &alrm->time); 	if (readl(base + TIMER_ALARM_STATUS))		alrm->enabled = 1;	else		alrm->enabled = 0; 	return 0;} static int goldfish_rtc_set_alarm(struct device *dev,				  struct rtc_wkalrm *alrm){	struct goldfish_rtc *rtcdrv;	u64 rtc_alarm64;	u64 rtc_status_reg;	void __iomem *base; 	rtcdrv = dev_get_drvdata(dev);	base = rtcdrv->base; 	if (alrm->enabled) {		rtc_alarm64 = rtc_tm_to_time64(&alrm->time) * NSEC_PER_SEC;		writel((rtc_alarm64 >> 32), base + TIMER_ALARM_HIGH);		writel(rtc_alarm64, base + TIMER_ALARM_LOW);		writel(1, base + TIMER_IRQ_ENABLED);	} else {		/*		 * if this function was called with enabled=0		 * then it could mean that the application is		 * trying to cancel an ongoing alarm		 */		rtc_status_reg = readl(base + TIMER_ALARM_STATUS);		if (rtc_status_reg)			writel(1, base + TIMER_CLEAR_ALARM);	} 	return 0;} static int goldfish_rtc_alarm_irq_enable(struct device *dev,					 unsigned int enabled){	void __iomem *base;	struct goldfish_rtc *rtcdrv; 	rtcdrv = dev_get_drvdata(dev);	base = rtcdrv->base; 	if (enabled)		writel(1, base + TIMER_IRQ_ENABLED);	else		writel(0, base + TIMER_IRQ_ENABLED); 	return 0;} static irqreturn_t goldfish_rtc_interrupt(int irq, void *dev_id){	struct goldfish_rtc *rtcdrv = dev_id;	void __iomem *base = rtcdrv->base; 	writel(1, base + TIMER_CLEAR_INTERRUPT); 	rtc_update_irq(rtcdrv->rtc, 1, RTC_IRQF | RTC_AF); 	return IRQ_HANDLED;} static int goldfish_rtc_read_time(struct device *dev, struct rtc_time *tm){	struct goldfish_rtc *rtcdrv;	void __iomem *base;	u64 time_high;	u64 time_low;	u64 time; 	rtcdrv = dev_get_drvdata(dev);	base = rtcdrv->base; 	time_low = readl(base + TIMER_TIME_LOW);	time_high = readl(base + TIMER_TIME_HIGH);	time = (time_high << 32) | time_low; 	do_div(time, NSEC_PER_SEC); 	rtc_time64_to_tm(time, tm); 	return 0;} static int goldfish_rtc_set_time(struct device *dev, struct rtc_time *tm){	struct goldfish_rtc *rtcdrv;	void __iomem *base;	u64 now64; 	rtcdrv = dev_get_drvdata(dev);	base = rtcdrv->base; 	now64 = rtc_tm_to_time64(tm) * NSEC_PER_SEC;	writel((now64 >> 32), base + TIMER_TIME_HIGH);	writel(now64, base + TIMER_TIME_LOW); 	return 0;} static const struct rtc_class_ops goldfish_rtc_ops = {	.read_time	= goldfish_rtc_read_time,	.set_time	= goldfish_rtc_set_time,	.read_alarm	= goldfish_rtc_read_alarm,	.set_alarm	= goldfish_rtc_set_alarm,	.alarm_irq_enable = goldfish_rtc_alarm_irq_enable}; static int goldfish_rtc_probe(struct platform_device *pdev){	struct goldfish_rtc *rtcdrv;	int err; 	rtcdrv = devm_kzalloc(&pdev->dev, sizeof(*rtcdrv), GFP_KERNEL);	if (!rtcdrv)		return -ENOMEM; 	platform_set_drvdata(pdev, rtcdrv);	rtcdrv->base = devm_platform_ioremap_resource(pdev, 0);	if (IS_ERR(rtcdrv->base))		return PTR_ERR(rtcdrv->base); 	rtcdrv->irq = platform_get_irq(pdev, 0);	if (rtcdrv->irq < 0)		return -ENODEV; 	rtcdrv->rtc = devm_rtc_allocate_device(&pdev->dev);	if (IS_ERR(rtcdrv->rtc))		return PTR_ERR(rtcdrv->rtc); 	rtcdrv->rtc->ops = &goldfish_rtc_ops;	rtcdrv->rtc->range_max = U64_MAX / NSEC_PER_SEC; 	err = devm_request_irq(&pdev->dev, rtcdrv->irq,			       goldfish_rtc_interrupt,			       0, pdev->name, rtcdrv);	if (err)		return err; 	return devm_rtc_register_device(rtcdrv->rtc);} static const struct of_device_id goldfish_rtc_of_match[] = {	{ .compatible = "google,goldfish-rtc", },	{},};MODULE_DEVICE_TABLE(of, goldfish_rtc_of_match); static struct platform_driver goldfish_rtc = {	.probe = goldfish_rtc_probe,	.driver = {		.name = "goldfish_rtc",		.of_match_table = goldfish_rtc_of_match,	}}; module_platform_driver(goldfish_rtc); MODULE_LICENSE("GPL v2");