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/*
* SA11x0 Assembler Sleep/WakeUp Management Routines
*
* Copyright (c) 2001 Cliff Brake <cbrake@accelent.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License.
*
* History:
*
* 2001-02-06: Cliff Brake Initial code
*
* 2001-08-29: Nicolas Pitre Simplified.
*
* 2002-05-27: Nicolas Pitre Revisited, more cleanup and simplification.
* Storage is on the stack now.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <mach/hardware.h>
.text
/*
* sa1100_cpu_suspend()
*
* Causes sa11x0 to enter sleep state
*
*/
ENTRY(sa1100_cpu_suspend)
stmfd sp!, {r4 - r12, lr} @ save registers on stack
mov r1, r0
ldr r3, =sa1100_cpu_resume @ return function
bl cpu_suspend
@ disable clock switching
mcr p15, 0, r1, c15, c2, 2
@ Adjust memory timing before lowering CPU clock
@ Clock speed adjustment without changing memory timing makes
@ CPU hang in some cases
ldr r0, =MDREFR
ldr r1, [r0]
orr r1, r1, #MDREFR_K1DB2
str r1, [r0]
@ delay 90us and set CPU PLL to lowest speed
@ fixes resume problem on high speed SA1110
mov r0, #90
bl __udelay
ldr r0, =PPCR
mov r1, #0
str r1, [r0]
mov r0, #90
bl __udelay
/*
* SA1110 SDRAM controller workaround. register values:
*
* r0 = &MSC0
* r1 = &MSC1
* r2 = &MSC2
* r3 = MSC0 value
* r4 = MSC1 value
* r5 = MSC2 value
* r6 = &MDREFR
* r7 = first MDREFR value
* r8 = second MDREFR value
* r9 = &MDCNFG
* r10 = MDCNFG value
* r11 = third MDREFR value
* r12 = &PMCR
* r13 = PMCR value (1)
*/
ldr r0, =MSC0
ldr r1, =MSC1
ldr r2, =MSC2
ldr r3, [r0]
bic r3, r3, #FMsk(MSC_RT)
bic r3, r3, #FMsk(MSC_RT)<<16
ldr r4, [r1]
bic r4, r4, #FMsk(MSC_RT)
bic r4, r4, #FMsk(MSC_RT)<<16
ldr r5, [r2]
bic r5, r5, #FMsk(MSC_RT)
bic r5, r5, #FMsk(MSC_RT)<<16
ldr r6, =MDREFR
ldr r7, [r6]
bic r7, r7, #0x0000FF00
bic r7, r7, #0x000000F0
orr r8, r7, #MDREFR_SLFRSH
ldr r9, =MDCNFG
ldr r10, [r9]
bic r10, r10, #(MDCNFG_DE0+MDCNFG_DE1)
bic r10, r10, #(MDCNFG_DE2+MDCNFG_DE3)
bic r11, r8, #MDREFR_SLFRSH
bic r11, r11, #MDREFR_E1PIN
ldr r12, =PMCR
mov r13, #PMCR_SF
b sa1110_sdram_controller_fix
.align 5
sa1110_sdram_controller_fix:
@ Step 1 clear RT field of all MSCx registers
str r3, [r0]
str r4, [r1]
str r5, [r2]
@ Step 2 clear DRI field in MDREFR
str r7, [r6]
@ Step 3 set SLFRSH bit in MDREFR
str r8, [r6]
@ Step 4 clear DE bis in MDCNFG
str r10, [r9]
@ Step 5 clear DRAM refresh control register
str r11, [r6]
@ Wow, now the hardware suspend request pins can be used, that makes them functional for
@ about 7 ns out of the entire time that the CPU is running!
@ Step 6 set force sleep bit in PMCR
str r13, [r12]
20: b 20b @ loop waiting for sleep
/*
* cpu_sa1100_resume()
*
* entry point from bootloader into kernel during resume
*/
.align 5
sa1100_cpu_resume:
ldmfd sp!, {r4 - r12, pc} @ return to caller
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