1/*
 2 * sysirq_mask.c - System-interrupt masking
 3 *
 4 * Copyright (C) 2013 Johan Hovold <jhovold@gmail.com>
 5 *
 6 * Functions to disable system interrupts from backup-powered peripherals.
 7 *
 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
11 * reset).
12 *
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.
16 *
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.
21 */
22
23#include <linux/io.h>
24#include <mach/at91_rtt.h>
25
26#include "generic.h"
27
28#define AT91_RTC_IDR	0x24	/* Interrupt Disable Register */
29#define AT91_RTC_IMR	0x28	/* Interrupt Mask Register */
30
31void __init at91_sysirq_mask_rtc(u32 rtc_base)
32{
33	void __iomem *base;
34	u32 mask;
35
36	base = ioremap(rtc_base, 64);
37	if (!base)
38		return;
39
40	mask = readl_relaxed(base + AT91_RTC_IMR);
41	if (mask) {
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 */
45	}
46
47	iounmap(base);
48}
49
50void __init at91_sysirq_mask_rtt(u32 rtt_base)
51{
52	void __iomem *base;
53	void __iomem *reg;
54	u32 mode;
55
56	base = ioremap(rtt_base, 16);
57	if (!base)
58		return;
59
60	reg = base + AT91_RTT_MR;
61
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 */
68	}
69
70	iounmap(base);
71}