-/* 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>
#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 5
+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
git.openpandora.org / pandora-kernel.git / blobdiff