bd117bd161
Add the initial support for the S3C64XX based systems to use suspend-to-RAM to sleep. Includes basic debugging for use with the SMDK6410 usign the LEDs on the baseboard. Signed-off-by: Ben Dooks <ben-linux@fluff.org>
145 lines
4.2 KiB
ArmAsm
145 lines
4.2 KiB
ArmAsm
/* linux/0arch/arm/plat-s3c64xx/sleep.S
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*
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* Copyright 2008 Openmoko, Inc.
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* Copyright 2008 Simtec Electronics
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* Ben Dooks <ben@simtec.co.uk>
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* http://armlinux.simtec.co.uk/
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*
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* S3C64XX CPU sleep code
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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#include <mach/map.h>
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#undef S3C64XX_VA_GPIO
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#define S3C64XX_VA_GPIO (0x0)
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#include <plat/regs-gpio.h>
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#include <plat/gpio-bank-n.h>
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#define LL_UART (S3C_PA_UART + (0x400 * CONFIG_S3C_LOWLEVEL_UART_PORT))
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.text
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/* s3c_cpu_save
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*
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* Save enough processor state to allow the restart of the pm.c
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* code after resume.
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*
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* entry:
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* r0 = pointer to the save block
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*/
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ENTRY(s3c_cpu_save)
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stmfd sp!, { r4 - r12, lr }
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mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
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mrc p15, 0, r5, c3, c0, 0 @ Domain ID
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mrc p15, 0, r6, c2, c0, 0 @ Translation Table BASE0
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mrc p15, 0, r7, c2, c0, 1 @ Translation Table BASE1
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mrc p15, 0, r8, c2, c0, 2 @ Translation Table Control
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mrc p15, 0, r9, c1, c0, 0 @ Control register
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mrc p15, 0, r10, c1, c0, 1 @ Auxiliary control register
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mrc p15, 0, r11, c1, c0, 2 @ Co-processor access controls
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stmia r0, { r4 - r13 } @ Save CP registers and SP
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@@ save our state to ram
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bl s3c_pm_cb_flushcache
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@@ call final suspend code
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ldr r0, =pm_cpu_sleep
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ldr pc, [r0]
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@@ return to the caller, after the MMU is turned on.
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@@ restore the last bits of the stack and return.
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resume_with_mmu:
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ldmfd sp!, { r4 - r12, pc } @ return, from sp from s3c_cpu_save
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.data
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/* the next bit is code, but it requires easy access to the
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* s3c_sleep_save_phys data before the MMU is switched on, so
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* we store the code that needs this variable in the .data where
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* the value can be written to (the .text segment is RO).
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*/
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.global s3c_sleep_save_phys
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s3c_sleep_save_phys:
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.word 0
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/* Sleep magic, the word before the resume entry point so that the
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* bootloader can check for a resumeable image. */
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.word 0x2bedf00d
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/* s3c_cpu_reusme
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*
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* This is the entry point, stored by whatever method the bootloader
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* requires to get the kernel runnign again. This code expects to be
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* entered with no caches live and the MMU disabled. It will then
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* restore the MMU and other basic CP registers saved and restart
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* the kernel C code to finish the resume code.
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*/
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ENTRY(s3c_cpu_resume)
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msr cpsr_c, #PSR_I_BIT | PSR_F_BIT | SVC_MODE
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ldr r2, =LL_UART /* for debug */
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#ifdef CONFIG_S3C_PM_DEBUG_LED_SMDK
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/* Initialise the GPIO state if we are debugging via the SMDK LEDs,
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* as the uboot version supplied resets these to inputs during the
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* resume checks.
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*/
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ldr r3, =S3C64XX_PA_GPIO
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ldr r0, [ r3, #S3C64XX_GPNCON ]
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bic r0, r0, #(S3C64XX_GPN_CONMASK(12) | S3C64XX_GPN_CONMASK(13) | \
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S3C64XX_GPN_CONMASK(14) | S3C64XX_GPN_CONMASK(15))
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orr r0, r0, #(S3C64XX_GPN_OUTPUT(12) | S3C64XX_GPN_OUTPUT(13) | \
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S3C64XX_GPN_OUTPUT(14) | S3C64XX_GPN_OUTPUT(15))
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str r0, [ r3, #S3C64XX_GPNCON ]
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ldr r0, [ r3, #S3C64XX_GPNDAT ]
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bic r0, r0, #0xf << 12 @ GPN12..15
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orr r0, r0, #1 << 15 @ GPN15
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str r0, [ r3, #S3C64XX_GPNDAT ]
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#endif
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/* __v6_setup from arch/arm/mm/proc-v6.S, ensure that the caches
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* are thoroughly cleaned just in case the bootloader didn't do it
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* for us. */
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mov r0, #0
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mcr p15, 0, r0, c7, c14, 0 @ clean+invalidate D cache
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mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
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mcr p15, 0, r0, c7, c15, 0 @ clean+invalidate cache
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mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
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@@mcr p15, 0, r0, c8, c7, 0 @ invalidate I + D TLBs
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@@mcr p15, 0, r0, c7, c7, 0 @ Invalidate I + D caches
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ldr r0, s3c_sleep_save_phys
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ldmia r0, { r4 - r13 }
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mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
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mcr p15, 0, r5, c3, c0, 0 @ Domain ID
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mcr p15, 0, r6, c2, c0, 0 @ Translation Table BASE0
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mcr p15, 0, r7, c2, c0, 1 @ Translation Table BASE1
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mcr p15, 0, r8, c2, c0, 2 @ Translation Table Control
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mcr p15, 0, r10, c1, c0, 1 @ Auxiliary control register
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mov r0, #0 @ restore copro access controls
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mcr p15, 0, r11, c1, c0, 2 @ Co-processor access controls
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mcr p15, 0, r0, c7, c5, 4
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ldr r2, =resume_with_mmu
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mcr p15, 0, r9, c1, c0, 0 /* turn mmu back on */
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nop
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mov pc, r2 /* jump back */
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.end
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