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Diffstat (limited to 'arch/arm/mach-pxa/sleep.S')
| -rw-r--r-- | arch/arm/mach-pxa/sleep.S | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/arch/arm/mach-pxa/sleep.S b/arch/arm/mach-pxa/sleep.S new file mode 100644 index 0000000..16cad2c --- /dev/null +++ b/arch/arm/mach-pxa/sleep.S @@ -0,0 +1,194 @@ +/* + * Low-level PXA250/210 sleep/wakeUp support + * + * Initial SA1110 code: + * Copyright (c) 2001 Cliff Brake <cbrake@accelent.com> + * + * Adapted for PXA by Nicolas Pitre: + * Copyright (c) 2002 Monta Vista Software, Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License. + */ + +#include <linux/config.h> +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/hardware.h> + +#include <asm/arch/pxa-regs.h> + + .text + +/* + * pxa_cpu_suspend() + * + * Forces CPU into sleep state + */ + +ENTRY(pxa_cpu_suspend) + + mra r2, r3, acc0 + stmfd sp!, {r2 - r12, lr} @ save registers on stack + + @ get coprocessor registers + mrc p14, 0, r3, c6, c0, 0 @ clock configuration, for turbo mode + mrc p15, 0, r4, c15, c1, 0 @ CP access reg + mrc p15, 0, r5, c13, c0, 0 @ PID + mrc p15, 0, r6, c3, c0, 0 @ domain ID + mrc p15, 0, r7, c2, c0, 0 @ translation table base addr + mrc p15, 0, r8, c1, c1, 0 @ auxiliary control reg + mrc p15, 0, r9, c1, c0, 0 @ control reg + + bic r3, r3, #2 @ clear frequency change bit + + @ store them plus current virtual stack ptr on stack + mov r10, sp + stmfd sp!, {r3 - r10} + + @ preserve phys address of stack + mov r0, sp + bl sleep_phys_sp + ldr r1, =sleep_save_sp + str r0, [r1] + + @ clean data cache + bl xscale_flush_kern_cache_all + + @ Put the processor to sleep + @ (also workaround for sighting 28071) + + @ prepare value for sleep mode + mov r1, #3 @ sleep mode + + @ prepare to put SDRAM into self-refresh manually + ldr r4, =MDREFR + ldr r5, [r4] + orr r5, r5, #MDREFR_SLFRSH + + @ prepare pointer to physical address 0 (virtual mapping in generic.c) + mov r2, #UNCACHED_PHYS_0 + + @ Intel PXA255 Specification Update notes problems + @ about suspending with PXBus operating above 133MHz + @ (see Errata 31, GPIO output signals, ... unpredictable in sleep + @ + @ We keep the change-down close to the actual suspend on SDRAM + @ as possible to eliminate messing about with the refresh clock + @ as the system will restore with the original speed settings + @ + @ Ben Dooks, 13-Sep-2004 + + ldr r6, =CCCR + ldr r8, [r6] @ keep original value for resume + + @ ensure x1 for run and turbo mode with memory clock + bic r7, r8, #CCCR_M_MASK | CCCR_N_MASK + orr r7, r7, #(1<<5) | (2<<7) + + @ check that the memory frequency is within limits + and r14, r7, #CCCR_L_MASK + teq r14, #1 + bicne r7, r7, #CCCR_L_MASK + orrne r7, r7, #1 @@ 99.53MHz + + @ get ready for the change + + @ note, turbo is not preserved over sleep so there is no + @ point in preserving it here. we save it on the stack with the + @ other CP registers instead. + mov r0, #0 + mcr p14, 0, r0, c6, c0, 0 + orr r0, r0, #2 @ initiate change bit + + @ align execution to a cache line + b 1f + + .ltorg + .align 5 +1: + + @ All needed values are now in registers. + @ These last instructions should be in cache + + @ initiate the frequency change... + str r7, [r6] + mcr p14, 0, r0, c6, c0, 0 + + @ restore the original cpu speed value for resume + str r8, [r6] + + @ put SDRAM into self-refresh + str r5, [r4] + + @ force address lines low by reading at physical address 0 + ldr r3, [r2] + + @ enter sleep mode + mcr p14, 0, r1, c7, c0, 0 + +20: b 20b @ loop waiting for sleep + +/* + * cpu_pxa_resume() + * + * entry point from bootloader into kernel during resume + * + * Note: Yes, part of the following code is located into the .data section. + * This is to allow sleep_save_sp to be accessed with a relative load + * while we can't rely on any MMU translation. We could have put + * sleep_save_sp in the .text section as well, but some setups might + * insist on it to be truly read-only. + */ + + .data + .align 5 +ENTRY(pxa_cpu_resume) + mov r0, #PSR_I_BIT | PSR_F_BIT | MODE_SVC @ set SVC, irqs off + msr cpsr_c, r0 + + ldr r0, sleep_save_sp @ stack phys addr + ldr r2, =resume_after_mmu @ its absolute virtual address + ldmfd r0, {r3 - r9, sp} @ CP regs + virt stack ptr + + mov r1, #0 + mcr p15, 0, r1, c8, c7, 0 @ invalidate I & D TLBs + mcr p15, 0, r1, c7, c7, 0 @ invalidate I & D caches, BTB + +#ifdef CONFIG_XSCALE_CACHE_ERRATA + bic r9, r9, #0x0004 @ see cpu_xscale_proc_init +#endif + + mcr p14, 0, r3, c6, c0, 0 @ clock configuration, turbo mode. + mcr p15, 0, r4, c15, c1, 0 @ CP access reg + mcr p15, 0, r5, c13, c0, 0 @ PID + mcr p15, 0, r6, c3, c0, 0 @ domain ID + mcr p15, 0, r7, c2, c0, 0 @ translation table base addr + mcr p15, 0, r8, c1, c1, 0 @ auxiliary control reg + b resume_turn_on_mmu @ cache align execution + + .align 5 +resume_turn_on_mmu: + mcr p15, 0, r9, c1, c0, 0 @ turn on MMU, caches, etc. + + @ Let us ensure we jump to resume_after_mmu only when the mcr above + @ actually took effect. They call it the "cpwait" operation. + mrc p15, 0, r1, c2, c0, 0 @ queue a dependency on CP15 + sub pc, r2, r1, lsr #32 @ jump to virtual addr + nop + nop + nop + +sleep_save_sp: + .word 0 @ preserve stack phys ptr here + + .text +resume_after_mmu: +#ifdef CONFIG_XSCALE_CACHE_ERRATA + bl cpu_xscale_proc_init +#endif + ldmfd sp!, {r2, r3} + mar acc0, r2, r3 + ldmfd sp!, {r4 - r12, pc} @ return to caller + + |