diff options
Diffstat (limited to 'arch/arm/mach-s3c64xx/sleep.S')
| -rw-r--r-- | arch/arm/mach-s3c64xx/sleep.S | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c64xx/sleep.S b/arch/arm/mach-s3c64xx/sleep.S new file mode 100644 index 00000000000..b2ef4431736 --- /dev/null +++ b/arch/arm/mach-s3c64xx/sleep.S @@ -0,0 +1,144 @@ +/* linux/arch/arm/plat-s3c64xx/sleep.S + * + * Copyright 2008 Openmoko, Inc. + * Copyright 2008 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk> + * http://armlinux.simtec.co.uk/ + * + * S3C64XX CPU sleep code + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <mach/map.h> + +#undef S3C64XX_VA_GPIO +#define S3C64XX_VA_GPIO (0x0) + +#include <mach/regs-gpio.h> +#include <mach/gpio-bank-n.h> + +#define LL_UART (S3C_PA_UART + (0x400 * CONFIG_S3C_LOWLEVEL_UART_PORT)) + + .text + + /* s3c_cpu_save + * + * Save enough processor state to allow the restart of the pm.c + * code after resume. + * + * entry: + * r0 = pointer to the save block + */ + +ENTRY(s3c_cpu_save) + stmfd sp!, { r4 - r12, lr } + + mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID + mrc p15, 0, r5, c3, c0, 0 @ Domain ID + mrc p15, 0, r6, c2, c0, 0 @ Translation Table BASE0 + mrc p15, 0, r7, c2, c0, 1 @ Translation Table BASE1 + mrc p15, 0, r8, c2, c0, 2 @ Translation Table Control + mrc p15, 0, r9, c1, c0, 0 @ Control register + mrc p15, 0, r10, c1, c0, 1 @ Auxiliary control register + mrc p15, 0, r11, c1, c0, 2 @ Co-processor access controls + + stmia r0, { r4 - r13 } @ Save CP registers and SP + + @@ save our state to ram + bl s3c_pm_cb_flushcache + + @@ call final suspend code + ldr r0, =pm_cpu_sleep + ldr pc, [r0] + + @@ return to the caller, after the MMU is turned on. + @@ restore the last bits of the stack and return. +resume_with_mmu: + ldmfd sp!, { r4 - r12, pc } @ return, from sp from s3c_cpu_save + + .data + + /* the next bit is code, but it requires easy access to the + * s3c_sleep_save_phys data before the MMU is switched on, so + * we store the code that needs this variable in the .data where + * the value can be written to (the .text segment is RO). + */ + + .global s3c_sleep_save_phys +s3c_sleep_save_phys: + .word 0 + + /* Sleep magic, the word before the resume entry point so that the + * bootloader can check for a resumeable image. */ + + .word 0x2bedf00d + + /* s3c_cpu_reusme + * + * This is the entry point, stored by whatever method the bootloader + * requires to get the kernel runnign again. This code expects to be + * entered with no caches live and the MMU disabled. It will then + * restore the MMU and other basic CP registers saved and restart + * the kernel C code to finish the resume code. + */ + +ENTRY(s3c_cpu_resume) + msr cpsr_c, #PSR_I_BIT | PSR_F_BIT | SVC_MODE + ldr r2, =LL_UART /* for debug */ + +#ifdef CONFIG_S3C_PM_DEBUG_LED_SMDK + /* Initialise the GPIO state if we are debugging via the SMDK LEDs, + * as the uboot version supplied resets these to inputs during the + * resume checks. + */ + + ldr r3, =S3C64XX_PA_GPIO + ldr r0, [ r3, #S3C64XX_GPNCON ] + bic r0, r0, #(S3C64XX_GPN_CONMASK(12) | S3C64XX_GPN_CONMASK(13) | \ + S3C64XX_GPN_CONMASK(14) | S3C64XX_GPN_CONMASK(15)) + orr r0, r0, #(S3C64XX_GPN_OUTPUT(12) | S3C64XX_GPN_OUTPUT(13) | \ + S3C64XX_GPN_OUTPUT(14) | S3C64XX_GPN_OUTPUT(15)) + str r0, [ r3, #S3C64XX_GPNCON ] + + ldr r0, [ r3, #S3C64XX_GPNDAT ] + bic r0, r0, #0xf << 12 @ GPN12..15 + orr r0, r0, #1 << 15 @ GPN15 + str r0, [ r3, #S3C64XX_GPNDAT ] +#endif + + /* __v6_setup from arch/arm/mm/proc-v6.S, ensure that the caches + * are thoroughly cleaned just in case the bootloader didn't do it + * for us. */ + mov r0, #0 + mcr p15, 0, r0, c7, c14, 0 @ clean+invalidate D cache + mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache + mcr p15, 0, r0, c7, c15, 0 @ clean+invalidate cache + mcr p15, 0, r0, c7, c10, 4 @ drain write buffer + @@mcr p15, 0, r0, c8, c7, 0 @ invalidate I + D TLBs + @@mcr p15, 0, r0, c7, c7, 0 @ Invalidate I + D caches + + ldr r0, s3c_sleep_save_phys + ldmia r0, { r4 - r13 } + + mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID + mcr p15, 0, r5, c3, c0, 0 @ Domain ID + mcr p15, 0, r6, c2, c0, 0 @ Translation Table BASE0 + mcr p15, 0, r7, c2, c0, 1 @ Translation Table BASE1 + mcr p15, 0, r8, c2, c0, 2 @ Translation Table Control + mcr p15, 0, r10, c1, c0, 1 @ Auxiliary control register + + mov r0, #0 @ restore copro access controls + mcr p15, 0, r11, c1, c0, 2 @ Co-processor access controls + mcr p15, 0, r0, c7, c5, 4 + + ldr r2, =resume_with_mmu + mcr p15, 0, r9, c1, c0, 0 /* turn mmu back on */ + nop + mov pc, r2 /* jump back */ + + .end |