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/*
* sysirq_mask.c - System-interrupt masking
*
* Copyright (C) 2013 Johan Hovold <jhovold@gmail.com>
*
* Functions to disable system interrupts from backup-powered peripherals.
*
* The RTC and RTT-peripherals are generally powered by backup power (VDDBU)
* and are not reset on wake-up, user, watchdog or software reset. This means
* that their interrupts may be enabled during early boot (e.g. after a user
* reset).
*
* As the RTC and RTT share the system-interrupt line with the PIT, an
* interrupt occurring before a handler has been installed would lead to the
* system interrupt being disabled and prevent the system from booting.
*
* 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.
*/
#include <linux/io.h>
#include "generic.h"
#define AT91_RTC_IDR 0x24 /* Interrupt Disable Register */
#define AT91_RTC_IMR 0x28 /* Interrupt Mask Register */
void __init at91_sysirq_mask_rtc(u32 rtc_base)
{
void __iomem *base;
u32 mask;
base = ioremap(rtc_base, 64);
if (!base)
return;
mask = readl_relaxed(base + AT91_RTC_IMR);
if (mask) {
pr_info("AT91: Disabling rtc irq\n");
writel_relaxed(mask, base + AT91_RTC_IDR);
(void)readl_relaxed(base + AT91_RTC_IMR); /* flush */
}
iounmap(base);
}
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