diff options
Diffstat (limited to 'arch/arm/mach-s3c2410/sleep.S')
| -rw-r--r-- | arch/arm/mach-s3c2410/sleep.S | 151 |
1 files changed, 30 insertions, 121 deletions
diff --git a/arch/arm/mach-s3c2410/sleep.S b/arch/arm/mach-s3c2410/sleep.S index 2018c2e..9179a10 100644 --- a/arch/arm/mach-s3c2410/sleep.S +++ b/arch/arm/mach-s3c2410/sleep.S @@ -1,4 +1,4 @@ -/* linux/arch/arm/mach-s3c2410/sleep.S +/* linux/arch/arm/mach-s3c2410/s3c2410-sleep.S * * Copyright (c) 2004 Simtec Electronics * Ben Dooks <ben@simtec.co.uk> @@ -34,126 +34,35 @@ #include <asm/arch/regs-mem.h> #include <asm/arch/regs-serial.h> -/* CONFIG_DEBUG_RESUME is dangerous if your bootloader does not - * reset the UART configuration, only enable if you really need this! -*/ -//#define CONFIG_DEBUG_RESUME - - .text - - /* s3c2410_cpu_save - * - * save enough of the CPU state to allow us to re-start - * pm.c code. as we store items like the sp/lr, we will - * end up returning from this function when the cpu resumes - * so the return value is set to mark this. - * - * This arangement means we avoid having to flush the cache - * from this code. - * - * entry: - * r0 = pointer to save block - * - * exit: - * r0 = 0 => we stored everything - * 1 => resumed from sleep - */ - -ENTRY(s3c2410_cpu_save) - stmfd sp!, { r4 - r12, lr } - - @@ store co-processor registers - - mrc p15, 0, r4, c15, c1, 0 @ CP access register - 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 address - mrc p15, 0, r8, c1, c0, 0 @ control register - - stmia r0, { r4 - r13 } - - mov r0, #0 - ldmfd sp, { r4 - r12, pc } - - @@ return to the caller, after having the MMU - @@ turned on, this restores the last bits from the - @@ stack -resume_with_mmu: - mov r0, #1 - ldmfd sp!, { r4 - r12, pc } - - .ltorg - - @@ the next bits sit in the .data segment, even though they - @@ happen to be code... the s3c2410_sleep_save_phys needs to be - @@ accessed by the resume code before it can restore the MMU. - @@ This means that the variable has to be close enough for the - @@ code to read it... since the .text segment needs to be RO, - @@ the data segment can be the only place to put this code. - - .data - - .global s3c2410_sleep_save_phys -s3c2410_sleep_save_phys: - .word 0 - - /* s3c2410_cpu_resume + /* s3c2410_cpu_suspend * - * resume code entry for bootloader to call - * - * we must put this code here in the data segment as we have no - * other way of restoring the stack pointer after sleep, and we - * must not write to the code segment (code is read-only) + * put the cpu into sleep mode */ -ENTRY(s3c2410_cpu_resume) - mov r0, #PSR_I_BIT | PSR_F_BIT | SVC_MODE - msr cpsr_c, r0 - - @@ load UART to allow us to print the two characters for - @@ resume debug - - mov r2, #S3C24XX_PA_UART & 0xff000000 - orr r2, r2, #S3C24XX_PA_UART & 0xff000 - -#if 0 - /* SMDK2440 LED set */ - mov r14, #S3C24XX_PA_GPIO - ldr r12, [ r14, #0x54 ] - bic r12, r12, #3<<4 - orr r12, r12, #1<<7 - str r12, [ r14, #0x54 ] -#endif - -#ifdef CONFIG_DEBUG_RESUME - mov r3, #'L' - strb r3, [ r2, #S3C2410_UTXH ] -1001: - ldrb r14, [ r3, #S3C2410_UTRSTAT ] - tst r14, #S3C2410_UTRSTAT_TXE - beq 1001b -#endif /* CONFIG_DEBUG_RESUME */ - - 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 - - ldr r0, s3c2410_sleep_save_phys @ address of restore block - ldmia r0, { r4 - r13 } - - mcr p15, 0, r4, c15, c1, 0 @ CP access register - 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 - -#ifdef CONFIG_DEBUG_RESUME - mov r3, #'R' - strb r3, [ r2, #S3C2410_UTXH ] -#endif - - ldr r2, =resume_with_mmu - mcr p15, 0, r8, c1, c0, 0 @ turn on MMU, etc - nop @ second-to-last before mmu - mov pc, r2 @ go back to virtual address - - .ltorg +ENTRY(s3c2410_cpu_suspend) + @@ prepare cpu to sleep + + ldr r4, =S3C2410_REFRESH + ldr r5, =S3C24XX_MISCCR + ldr r6, =S3C2410_CLKCON + ldr r7, [ r4 ] @ get REFRESH (and ensure in TLB) + ldr r8, [ r5 ] @ get MISCCR (and ensure in TLB) + ldr r9, [ r6 ] @ get CLKCON (and ensure in TLB) + + orr r7, r7, #S3C2410_REFRESH_SELF @ SDRAM sleep command + orr r8, r8, #S3C2410_MISCCR_SDSLEEP @ SDRAM power-down signals + orr r9, r9, #S3C2410_CLKCON_POWER @ power down command + + teq pc, #0 @ first as a trial-run to load cache + bl s3c2410_do_sleep + teq r0, r0 @ now do it for real + b s3c2410_do_sleep @ + + @@ align next bit of code to cache line + .align 8 +s3c2410_do_sleep: + streq r7, [ r4 ] @ SDRAM sleep command + streq r8, [ r5 ] @ SDRAM power-down config + streq r9, [ r6 ] @ CPU sleep +1: beq 1b + mov pc, r14 |
