[PATCH 1/5] irqchip: atmel-aic: add irq fixup for RTT block

[Boris BREZILLON]

Add a new fixup function for the RTT (Real Time Timer) block.

This fixup function was previously implemented in
arch/arm/mach-at91/sysirq_mask.c, but is now moved to the AIC driver so
that we can remove SoC specific hooks in arch/arm/mach-at91/ when booting
a DT kernel.

Signed-off-by: Boris BREZILLON <boris.brezillon at free-electrons.com>
---
 drivers/irqchip/irq-atmel-aic-common.c | 26 ++++++++++++++++++++++++++
 drivers/irqchip/irq-atmel-aic-common.h |  2 ++
 2 files changed, 28 insertions(+)

diff --git a/drivers/irqchip/irq-atmel-aic-common.c b/drivers/irqchip/irq-atmel-aic-common.c
index 6ae3cdee..656cfe3 100644
--- a/drivers/irqchip/irq-atmel-aic-common.c
+++ b/drivers/irqchip/irq-atmel-aic-common.c
@@ -167,6 +167,32 @@ void __init aic_common_rtc_irq_fixup(struct device_node *root)
 	iounmap(regs);
 }
 
+#define AT91_RTT_MR		0x00			/* Real-time Mode Register */
+#define AT91_RTT_ALMIEN		(1 << 16)		/* Alarm Interrupt Enable */
+#define AT91_RTT_RTTINCIEN	(1 << 17)		/* Real Time Timer Increment Interrupt Enable */
+
+void __init aic_common_rtt_irq_fixup(struct device_node *root)
+{
+	struct device_node *np;
+	void __iomem *regs;
+
+	/*
+	 * The at91sam9263 SoC has 2 instances of the RTT block, hence we
+	 * iterate over the DT to find each occurrence.
+	 */
+	for_each_compatible_node(np, NULL, "atmel,at91sam9260-rtt") {
+		regs = of_iomap(np, 0);
+		if (!regs)
+			continue;
+
+		writel(readl(regs + AT91_RTT_MR) &
+		       ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN),
+		       regs + AT91_RTT_MR);
+
+		iounmap(regs);
+	}
+}
+
 void __init aic_common_irq_fixup(const struct of_device_id *matches)
 {
 	struct device_node *root = of_find_node_by_path("/");
diff --git a/drivers/irqchip/irq-atmel-aic-common.h b/drivers/irqchip/irq-atmel-aic-common.h
index 90aa00e..603f0a9 100644
--- a/drivers/irqchip/irq-atmel-aic-common.h
+++ b/drivers/irqchip/irq-atmel-aic-common.h
@@ -34,6 +34,8 @@ struct irq_domain *__init aic_common_of_init(struct device_node *node,
 
 void __init aic_common_rtc_irq_fixup(struct device_node *root);
 
+void __init aic_common_rtt_irq_fixup(struct device_node *root);
+
 void __init aic_common_irq_fixup(const struct of_device_id *matches);
 
 #endif /* __IRQ_ATMEL_AIC_COMMON_H */
-- 
1.9.1