1 files changed, 157 insertions, 0 deletions

diff --git a/arch/arm/plat-s3c24xx/sleep.S b/arch/arm/plat-s3c24xx/sleep.S
new file mode 100644
index 000000000000..435349dc3243
--- /dev/null
+++ b/arch/arm/plat-s3c24xx/sleep.S
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+/* linux/arch/arm/mach-s3c2410/sleep.S
+ *
+ * Copyright (c) 2004 Simtec Electronics
+ *      Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C2410 Power Manager (Suspend-To-RAM) support
+ *
+ * Based on PXA/SA1100 sleep code by:
+ *      Nicolas Pitre, (c) 2002 Monta Vista Software Inc
+ *      Cliff Brake, (c) 2001
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/hardware.h>
+#include <asm/arch/map.h>
+
+#include <asm/arch/regs-gpio.h>
+#include <asm/arch/regs-clock.h>
+#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, c13, c0, 0  @ PID
+        mrc     p15, 0, r5, c3, c0, 0   @ Domain ID
+        mrc     p15, 0, r6, c2, c0, 0   @ translation table base address
+        mrc     p15, 0, r7, 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
+         *
+         * 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)
+        */
+
+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, c13, c0, 0          @ PID
+        mcr     p15, 0, r5, c3, c0, 0           @ Domain ID
+        mcr     p15, 0, r6, 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, r7, c1, c0, 0           @ turn on MMU, etc
+        nop                                     @ second-to-last before mmu
+        mov     pc, r2                          @ go back to virtual address
+
+        .ltorg