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Diffstat (limited to 'arch/arm/mach-at91/sysirq_mask.c')
-rw-r--r--arch/arm/mach-at91/sysirq_mask.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/sysirq_mask.c b/arch/arm/mach-at91/sysirq_mask.c
new file mode 100644
index 00000000000..2ba694f9626
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+++ b/arch/arm/mach-at91/sysirq_mask.c
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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 <mach/at91_rtt.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);
+}
+
+void __init at91_sysirq_mask_rtt(u32 rtt_base)
+{
+ void __iomem *base;
+ void __iomem *reg;
+ u32 mode;
+
+ base = ioremap(rtt_base, 16);
+ if (!base)
+ return;
+
+ reg = base + AT91_RTT_MR;
+
+ mode = readl_relaxed(reg);
+ if (mode & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN)) {
+ pr_info("AT91: Disabling rtt irq\n");
+ mode &= ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
+ writel_relaxed(mode, reg);
+ (void)readl_relaxed(reg); /* flush */
+ }
+
+ iounmap(base);
+}