2 * sysirq_mask.c - System-interrupt masking
4 * Copyright (C) 2013 Johan Hovold <jhovold@gmail.com>
6 * Functions to disable system interrupts from backup-powered peripherals.
8 * The RTC and RTT-peripherals are generally powered by backup power (VDDBU)
9 * and are not reset on wake-up, user, watchdog or software reset. This means
10 * that their interrupts may be enabled during early boot (e.g. after a user
13 * As the RTC and RTT share the system-interrupt line with the PIT, an
14 * interrupt occurring before a handler has been installed would lead to the
15 * system interrupt being disabled and prevent the system from booting.
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
24 #include <mach/at91_rtt.h>
28 #define AT91_RTC_IDR 0x24 /* Interrupt Disable Register */
29 #define AT91_RTC_IMR 0x28 /* Interrupt Mask Register */
31 void __init at91_sysirq_mask_rtc(u32 rtc_base)
36 base = ioremap(rtc_base, 64);
40 mask = readl_relaxed(base + AT91_RTC_IMR);
42 pr_info("AT91: Disabling rtc irq\n");
43 writel_relaxed(mask, base + AT91_RTC_IDR);
44 (void)readl_relaxed(base + AT91_RTC_IMR); /* flush */
50 void __init at91_sysirq_mask_rtt(u32 rtt_base)
56 base = ioremap(rtt_base, 16);
60 reg = base + AT91_RTT_MR;
62 mode = readl_relaxed(reg);
63 if (mode & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN)) {
64 pr_info("AT91: Disabling rtt irq\n");
65 mode &= ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
66 writel_relaxed(mode, reg);
67 (void)readl_relaxed(reg); /* flush */