diff options
Diffstat (limited to 'arch/arm/mach-mx51/suspend.S')
| -rw-r--r-- | arch/arm/mach-mx51/suspend.S | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/arm/mach-mx51/suspend.S b/arch/arm/mach-mx51/suspend.S new file mode 100644 index 000000000000..5cfd9be91eab --- /dev/null +++ b/arch/arm/mach-mx51/suspend.S @@ -0,0 +1,153 @@ +/* + * 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 |