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 */
30 #define AT91_RTC_IRQ_MASK 0x1f /* Available IRQs mask */
32 void __init
at91_sysirq_mask_rtc(u32 rtc_base
)
36 base
= ioremap(rtc_base
, 64);
41 * sam9x5 SoCs have the following errata:
42 * "RTC: Interrupt Mask Register cannot be used
43 * Interrupt Mask Register read always returns 0."
45 * Hence we're not relying on IMR values to disable
48 writel_relaxed(AT91_RTC_IRQ_MASK
, base
+ AT91_RTC_IDR
);
49 (void)readl_relaxed(base
+ AT91_RTC_IMR
); /* flush */
54 void __init
at91_sysirq_mask_rtt(u32 rtt_base
)
60 base
= ioremap(rtt_base
, 16);
64 reg
= base
+ AT91_RTT_MR
;
66 mode
= readl_relaxed(reg
);
67 if (mode
& (AT91_RTT_ALMIEN
| AT91_RTT_RTTINCIEN
)) {
68 pr_info("AT91: Disabling rtt irq\n");
69 mode
&= ~(AT91_RTT_ALMIEN
| AT91_RTT_RTTINCIEN
);
70 writel_relaxed(mode
, reg
);
71 (void)readl_relaxed(reg
); /* flush */