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// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/drivers/rtc/rtc-pl030.c
*
* Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
*/
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/amba/bus.h>
#include <linux/io.h>
#include <linux/slab.h>
#define RTC_DR (0)
#define RTC_MR (4)
#define RTC_STAT (8)
#define RTC_EOI (8)
#define RTC_LR (12)
#define RTC_CR (16)
#define RTC_CR_MIE (1 << 0)
struct pl030_rtc {
struct rtc_device *rtc;
void __iomem *base;
};
static irqreturn_t pl030_interrupt(int irq, void *dev_id)
{
struct pl030_rtc *rtc = dev_id;
writel(0, rtc->base + RTC_EOI);
return IRQ_HANDLED;
}
static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct pl030_rtc *rtc = dev_get_drvdata(dev);
rtc_time64_to_tm(readl(rtc->base + RTC_MR), &alrm->time);
return 0;
}
static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct pl030_rtc *rtc = dev_get_drvdata(dev);
writel(rtc_tm_to_time64(&alrm->time), rtc->base + RTC_MR);
return 0;
}
static int pl030_read_time(struct device *dev, struct rtc_time *tm)
{
struct pl030_rtc *rtc = dev_get_drvdata(dev);
rtc_time64_to_tm(readl(rtc->base + RTC_DR), tm);
return 0;
}
/*
* Set the RTC time. Unfortunately, we can't accurately set
* the point at which the counter updates.
*
* Also, since RTC_LR is transferred to RTC_CR on next rising
* edge of the 1Hz clock, we must write the time one second
* in advance.
*/
static int pl030_set_time(struct device *dev, struct rtc_time *tm)
{
struct pl030_rtc *rtc = dev_get_drvdata(dev);
writel(rtc_tm_to_time64(tm) + 1, rtc->base + RTC_LR);
return 0;
}
static const struct rtc_class_ops pl030_ops = {
.read_time = pl030_read_time,
.set_time = pl030_set_time,
.read_alarm = pl030_read_alarm,
.set_alarm = pl030_set_alarm,
};
static int pl030_probe(struct amba_device *dev, const struct amba_id *id)
{
struct pl030_rtc *rtc;
int ret;
ret = amba_request_regions(dev, NULL);
if (ret)
goto err_req;
rtc = devm_kzalloc(&dev->dev, sizeof(*rtc), GFP_KERNEL);
if (!rtc) {
ret = -ENOMEM;
goto err_rtc;
}
rtc->rtc = devm_rtc_allocate_device(&dev->dev);
if (IS_ERR(rtc->rtc)) {
ret = PTR_ERR(rtc->rtc);
goto err_rtc;
}
rtc->rtc->ops = &pl030_ops;
rtc->rtc->range_max = U32_MAX;
rtc->base = ioremap(dev->res.start, resource_size(&dev->res));
if (!rtc->base) {
ret = -ENOMEM;
goto err_rtc;
}
__raw_writel(0, rtc->base + RTC_CR);
__raw_writel(0, rtc->base + RTC_EOI);
amba_set_drvdata(dev, rtc);
ret = request_irq(dev->irq[0], pl030_interrupt, 0,
"rtc-pl030", rtc);
if (ret)
goto err_irq;
ret = rtc_register_device(rtc->rtc);
if (ret)
goto err_reg;
return 0;
err_reg:
free_irq(dev->irq[0], rtc);
err_irq:
iounmap(rtc->base);
err_rtc:
amba_release_regions(dev);
err_req:
return ret;
}
static int pl030_remove(struct amba_device *dev)
{
struct pl030_rtc *rtc = amba_get_drvdata(dev);
writel(0, rtc->base + RTC_CR);
free_irq(dev->irq[0], rtc);
iounmap(rtc->base);
amba_release_regions(dev);
return 0;
}
static struct amba_id pl030_ids[] = {
{
.id = 0x00041030,
.mask = 0x000fffff,
},
{ 0, 0 },
};
MODULE_DEVICE_TABLE(amba, pl030_ids);
static struct amba_driver pl030_driver = {
.drv = {
.name = "rtc-pl030",
},
.probe = pl030_probe,
.remove = pl030_remove,
.id_table = pl030_ids,
};
module_amba_driver(pl030_driver);
MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver");
MODULE_LICENSE("GPL");
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