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-rw-r--r--arch/arm/mach-s3c24xx/include/mach/entry-macro.S70
1 files changed, 70 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c24xx/include/mach/entry-macro.S b/arch/arm/mach-s3c24xx/include/mach/entry-macro.S
new file mode 100644
index 0000000..7615a14
--- /dev/null
+++ b/arch/arm/mach-s3c24xx/include/mach/entry-macro.S
@@ -0,0 +1,70 @@
+/*
+ * arch/arm/mach-s3c2410/include/mach/entry-macro.S
+ *
+ * Low-level IRQ helper macros for S3C2410-based platforms
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+*/
+
+/* We have a problem that the INTOFFSET register does not always
+ * show one interrupt. Occasionally we get two interrupts through
+ * the prioritiser, and this causes the INTOFFSET register to show
+ * what looks like the logical-or of the two interrupt numbers.
+ *
+ * Thanks to Klaus, Shannon, et al for helping to debug this problem
+*/
+
+#define INTPND (0x10)
+#define INTOFFSET (0x14)
+
+#include <mach/hardware.h>
+#include <asm/irq.h>
+
+ .macro get_irqnr_preamble, base, tmp
+ .endm
+
+ .macro get_irqnr_and_base, irqnr, irqstat, base, tmp
+
+ mov \base, #S3C24XX_VA_IRQ
+
+ @@ try the interrupt offset register, since it is there
+
+ ldr \irqstat, [ \base, #INTPND ]
+ teq \irqstat, #0
+ beq 1002f
+ ldr \irqnr, [ \base, #INTOFFSET ]
+ mov \tmp, #1
+ tst \irqstat, \tmp, lsl \irqnr
+ bne 1001f
+
+ @@ the number specified is not a valid irq, so try
+ @@ and work it out for ourselves
+
+ mov \irqnr, #0 @@ start here
+
+ @@ work out which irq (if any) we got
+
+ movs \tmp, \irqstat, lsl#16
+ addeq \irqnr, \irqnr, #16
+ moveq \irqstat, \irqstat, lsr#16
+ tst \irqstat, #0xff
+ addeq \irqnr, \irqnr, #8
+ moveq \irqstat, \irqstat, lsr#8
+ tst \irqstat, #0xf
+ addeq \irqnr, \irqnr, #4
+ moveq \irqstat, \irqstat, lsr#4
+ tst \irqstat, #0x3
+ addeq \irqnr, \irqnr, #2
+ moveq \irqstat, \irqstat, lsr#2
+ tst \irqstat, #0x1
+ addeq \irqnr, \irqnr, #1
+
+ @@ we have the value
+1001:
+ adds \irqnr, \irqnr, #IRQ_EINT0
+1002:
+ @@ exit here, Z flag unset if IRQ
+
+ .endm