ARM: orion: switch to a per-platform handle_irq() function

Moving to the Device Tree implies having CONFIG_MULTI_IRQ_HANDLER
enabled, even for non-DT platforms (if we want both DT and non-DT
platforms to be supported in a single kernel).

However, the common CONFIG_MULTI_IRQ_HANDLER handler for non-DT
platforms in plat-orion/irq.c doesn't match the needs of
Orion5x. Also, it doesn't make much sense for orion_irq_init() to
register the multi-IRQ handler: orion_irq_init() is called once for
each IRQ cause/mask tuple, while the multi-IRQ handler only needs to
be registered once.

To solve this problem, we move the multi-IRQ handle in per-platform
code: mach-kirkwood/irq.c and mach-dove/irq.c. The Orion5x variant
will be introduced in a followup commit. Of course, this code will
ultimately be completely removed once all boards are converted to the
Device Tree.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: https://lkml.kernel.org/r/1398202002-28530-23-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

1 files changed, 37 insertions, 0 deletions

diff --git a/arch/arm/mach-kirkwood/irq.c b/arch/arm/mach-kirkwood/irq.c
index 2a97a2e..2c47a8a 100644
--- a/arch/arm/mach-kirkwood/irq.c
+++ b/arch/arm/mach-kirkwood/irq.c
@@ -7,6 +7,7 @@
  * License version 2.  This program is licensed "as is" without any
  * warranty of any kind, whether express or implied.
  */
+#include <asm/exception.h>
 #include <linux/gpio.h>
 #include <linux/kernel.h>
 #include <linux/irq.h>
@@ -30,11 +31,47 @@ static int __initdata gpio1_irqs[4] = {
 	0,
 };
 
+#ifdef CONFIG_MULTI_IRQ_HANDLER
+/*
+ * Compiling with both non-DT and DT support enabled, will
+ * break asm irq handler used by non-DT boards. Therefore,
+ * we provide a C-style irq handler even for non-DT boards,
+ * if MULTI_IRQ_HANDLER is set.
+ */
+
+static void __iomem *kirkwood_irq_base = IRQ_VIRT_BASE;
+
+asmlinkage void
+__exception_irq_entry kirkwood_legacy_handle_irq(struct pt_regs *regs)
+{
+	u32 stat;
+
+	stat = readl_relaxed(kirkwood_irq_base + IRQ_CAUSE_LOW_OFF);
+	stat &= readl_relaxed(kirkwood_irq_base + IRQ_MASK_LOW_OFF);
+	if (stat) {
+		unsigned int hwirq = __fls(stat);
+		handle_IRQ(hwirq, regs);
+		return;
+	}
+	stat = readl_relaxed(kirkwood_irq_base + IRQ_CAUSE_HIGH_OFF);
+	stat &= readl_relaxed(kirkwood_irq_base + IRQ_MASK_HIGH_OFF);
+	if (stat) {
+		unsigned int hwirq = 32 + __fls(stat);
+		handle_IRQ(hwirq, regs);
+		return;
+	}
+}
+#endif
+
 void __init kirkwood_init_irq(void)
 {
 	orion_irq_init(0, IRQ_VIRT_BASE + IRQ_MASK_LOW_OFF);
 	orion_irq_init(32, IRQ_VIRT_BASE + IRQ_MASK_HIGH_OFF);
 
+#ifdef CONFIG_MULTI_IRQ_HANDLER
+	set_handle_irq(kirkwood_legacy_handle_irq);
+#endif
+
 	/*
 	 * Initialize gpiolib for GPIOs 0-49.
 	 */