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authorWill Deacon <will.deacon@arm.com>2012-07-06 15:47:17 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-07-09 17:42:23 +0100
commitd0a533b18235d36206b9b422efadb7cee444dfdb (patch)
tree43dcdcf9eebd9c88430df031305ca4eb5c2346f4 /arch/arm/mach-sa1100
parent923df96b9f31b7d08d8438ff9677326d9537accf (diff)
downloadop-kernel-dev-d0a533b18235d36206b9b422efadb7cee444dfdb.zip
op-kernel-dev-d0a533b18235d36206b9b422efadb7cee444dfdb.tar.gz
ARM: 7452/1: delay: allow timer-based delay implementation to be selected
This patch allows a timer-based delay implementation to be selected by switching the delay routines over to use get_cycles, which is implemented in terms of read_current_timer. This further allows us to skip the loop calibration and have a consistent delay function in the face of core frequency scaling. To avoid the pain of dealing with memory-mapped counters, this implementation uses the co-processor interface to the architected timers when they are available. The previous loop-based implementation is kept around for CPUs without the architected timers and we retain both the maximum delay (2ms) and the corresponding conversion factors for determining the number of loops required for a given interval. Since the indirection of the timer routines will only work when called from C, the sa1100 sleep routines are modified to branch to the loop-based delay functions directly. Tested-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-sa1100')
-rw-r--r--arch/arm/mach-sa1100/sleep.S8
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/arm/mach-sa1100/sleep.S b/arch/arm/mach-sa1100/sleep.S
index 30cc672..8586374 100644
--- a/arch/arm/mach-sa1100/sleep.S
+++ b/arch/arm/mach-sa1100/sleep.S
@@ -38,9 +38,9 @@ ENTRY(sa1100_finish_suspend)
orr r4, r4, #MDREFR_K1DB2
ldr r5, =PPCR
- @ Pre-load __udelay into the I-cache
+ @ Pre-load __loop_udelay into the I-cache
mov r0, #1
- bl __udelay
+ bl __loop_udelay
mov r0, r0
@ The following must all exist in a single cache line to
@@ -53,11 +53,11 @@ ENTRY(sa1100_finish_suspend)
@ delay 90us and set CPU PLL to lowest speed
@ fixes resume problem on high speed SA1110
mov r0, #90
- bl __udelay
+ bl __loop_udelay
mov r1, #0
str r1, [r5]
mov r0, #90
- bl __udelay
+ bl __loop_udelay
/*
* SA1110 SDRAM controller workaround. register values:
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