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/*
* Copyright 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
*/
/*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/linkage.h>
#define ARM_CTRL_DCACHE 1 << 2
#define ARM_CTRL_ICACHE 1 << 12
#define ARM_AUXCR_L2EN 1 << 1
/*
* cpu_do_suspend_workaround()
*
* Suspend the processor (eg, wait for interrupt).
*
* IRQs are already disabled.
*/
ENTRY(cpu_do_suspend_workaround)
stmfd sp!, {r4,r5,r6,r7,r9,r10,r11} @ Save registers
mov r6, r0 @save iomux address
/* Disable L1 caches */
mrc p15, 0, r0, c1, c0, 0 @ R0 = system control reg
bic r0, r0, #ARM_CTRL_ICACHE @ Disable ICache
bic r0, r0, #ARM_CTRL_DCACHE @ Disable DCache
mcr p15, 0, r0, c1, c0, 0 @ Update system control reg
mrc p15, 1, r0, c0, c0, 1 @ Read CLIDR
ands r3, r0, #0x7000000 @ Isolate level of coherency
mov r3, r3, lsr #23 @ Cache level value (naturally aligned)
beq FinishedClean
mov r10, #0
Loop1Clean:
add r2, r10, r10, lsr #1 @ Work out cache level
mov r1, r0, lsr r2 @ R0 bottom 3 bits = Cache Type for this level
and r1, r1, #7 @ Get those 3 bits alone
cmp r1, #2
blt SkipClean @ No cache or only instruction cache at this level
mcr p15, 2, r10, c0, c0, 0 @ Write the Cache Size selection register
mov r1, #0
.long 0xF57FF06F @ ISB
mrc p15, 1, r1, c0, c0, 0 @ Reads current Cache Size ID register
and r2, r1, #7 @ Extract the line length field
add r2, r2, #4 @ Add 4 for the line length offset (log2 16 bytes)
ldr r4, =0x3FF
ands r4, r4, r1, lsr #3 @ R4 is the max number on the way size (right aligned)
clz r5, r4 @ R5 is the bit position of the way size increment
ldr r7, =0x00007FFF
ands r7, r7, r1, lsr #13 @ R7 is the max number of the index size (right aligned)
Loop2Clean:
mov r9, r4 @ R9 working copy of the max way size (right aligned)
Loop3Clean:
orr r11, r10, r9, lsl r5 @ Factor in the way number and cache number into R11
orr r11, r11, r7, lsl r2 @ Factor in the index number
mcr p15, 0, r11, c7, c14, 2 @ Clean and invalidate by set/way
subs r9, r9, #1 @ Decrement the way number
bge Loop3Clean
subs r7, r7, #1 @ Decrement the index
bge Loop2Clean
SkipClean:
add r10, r10, #2 @ Increment the cache number
cmp r3, r10
bgt Loop1Clean
FinishedClean:
/* Disable L2 cache */
mrc p15, 0, r0, c1, c0, 1 @ R0 = auxiliary control reg
bic r0, r0, #ARM_AUXCR_L2EN @ Disable L2 cache
mcr p15, 0, r0, c1, c0, 1 @ Update aux control reg
/*Set the DDR drive strength to low */
ldr r10, [r6]
and r10, r10, #0xF1 @ clear bits 2-1
str r10, [r6]
.long 0xe320f003 @ Opcode for WFI
/*Set the DDR drive strength to max */
orr r10, r10, #0x06 @ set bits 2-1
str r10, [r6]
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ Invalidate inst cache
/* Invalidate data caches */
mrc p15, 1, r0, c0, c0, 1 @ Read CLIDR
ands r3, r0, #0x7000000 @ Isolate level of coherency
mov r3, r3, lsr #23 @ Cache level value (naturally aligned)
beq FinishedInvalidate
mov r10, #0
Loop1Invalidate:
add r2, r10, r10, lsr #1 @ Work out cache level
mov r1, r0, lsr r2 @ R0 bottom 3 bits = Cache Type for this level
and r1, r1, #7 @ Get those 3 bits alone
cmp r1, #2
blt SkipInvalidate @ No cache or only instruction cache at this level
mcr p15, 2, r10, c0, c0, 0 @ Write the Cache Size selection register
mov r1, #0
.long 0xF57FF06F @ ISB
mrc p15, 1, r1, c0, c0, 0 @ Reads current Cache Size ID register
and r2, r1, #7 @ Extract the line length field
add r2, r2, #4 @ Add 4 for the line length offset (log2 16 bytes)
ldr r4, =0x3FF
ands r4, r4, r1, lsr #3 @ R4 is the max number on the way size (right aligned)
clz r5, r4 @ R5 is the bit position of the way size increment
ldr r7, =0x00007FFF
ands r7, r7, r1, lsr #13 @ R7 is the max number of the index size (right aligned)
Loop2Invalidate:
mov r9, r4 @ R9 working copy of the max way size (right aligned)
Loop3Invalidate:
orr r11, r10, r9, lsl r5 @ Factor in the way number and cache number into R11
orr r11, r11, r7, lsl r2 @ Factor in the index number
mcr p15, 0, r11, c7, c6, 2 @ Invalidate by set/way
subs r9, r9, #1 @ Decrement the way number
bge Loop3Invalidate
subs r7, r7, #1 @ Decrement the index
bge Loop2Invalidate
SkipInvalidate:
add r10, r10, #2 @ Increment the cache number
cmp r3, r10
bgt Loop1Invalidate
FinishedInvalidate:
/* Enable L2 cache */
mrc p15, 0, r0, c1, c0, 1 @ R0 = auxiliary control reg
orr r0, r0, #ARM_AUXCR_L2EN @ Enable L2 cache
mcr p15, 0, r0, c1, c0, 1 @ Update aux control reg
/* Enable L1 caches */
mrc p15, 0, r0, c1, c0, 0 @ R0 = system control reg
orr r0, r0, #ARM_CTRL_ICACHE @ Enable ICache
orr r0, r0, #ARM_CTRL_DCACHE @ Enable DCache
mcr p15, 0, r0, c1, c0, 0 @ Update system control reg
/* Restore registers */
ldmfd sp!, {r4,r5,r6,r7,r9,r10,r11}
mov pc, lr
.type cpu_do_suspend, #object
ENTRY(cpu_do_suspend)
.word cpu_do_suspend_workaround
.size cpu_do_suspend_workaround, . - cpu_do_suspend_workaround
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