linux/arch/arm/mach-s3c24xx/include/mach/entry-macro.S

71 lines
1.7 KiB
ArmAsm

/*
* 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