android_kernel_motorola_sm6225/include/asm-arm/arch-s3c2410/entry-macro.S
Ben Dooks 26f91fd54d [ARM] 3443/1: [S3C2410] Improve IRQ entry code
Patch from Ben Dooks

Remove the old debug from the IRQ entry code,
update the comments on the handling of the
IRQ registers.

The message "bad interrupt offset" is removed
as it is only helpful for debugging, and can
cause printk() flooding when under load.

Make the code to deal with GPIO interrupts
faster, and use the same path to deal with
unexplained results from the IRQ registers.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-04-02 00:09:26 +01:00

88 lines
2.1 KiB
ArmAsm

/*
* include/asm-arm/arch-s3c2410/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)
#define EXTINTPEND (0xa8)
#define EXTINTMASK (0xa4)
#include <asm/hardware.h>
#include <asm/arch/irqs.h>
.macro get_irqnr_and_base, irqnr, irqstat, base, tmp
mov \base, #S3C24XX_VA_IRQ
ldr \irqstat, [ \base, #INTPND]
bics \irqnr, \irqstat, #3<<4 @@ only an GPIO IRQ
beq 2000f
@@ try the interrupt offset register, since it is there
ldr \irqnr, [ \base, #INTOFFSET ]
mov \tmp, #1
tst \irqstat, \tmp, lsl \irqnr
addne \irqnr, \irqnr, #IRQ_EINT0
bne 1001f
@@ the number specified is not a valid irq, so try
@@ and work it out for ourselves
mov \irqnr, #IRQ_EINT0 @@ start here
b 3000f
2000:
@@ load the GPIO interrupt register, and check it
add \tmp, \base, #S3C24XX_VA_GPIO - S3C24XX_VA_IRQ
ldr \irqstat, [ \tmp, # EXTINTPEND ]
ldr \irqnr, [ \tmp, # EXTINTMASK ]
bics \irqstat, \irqstat, \irqnr
beq 1001f
mov \irqnr, #(IRQ_EINT4 - 4)
@@ work out which irq (if any) we got
3000:
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
movs \irqnr, \irqnr
1001:
@@ exit here, Z flag unset if IRQ
.endm
/* currently don't need an disable_fiq macro */
.macro disable_fiq
.endm