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+/* 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