root/arch/arm/mach-s3c24xx/sleep-s3c2412.S

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Copyright (c) 2007 Simtec Electronics
   4  *      Ben Dooks <ben@simtec.co.uk>
   5  *
   6  * S3C2412 Power Manager low-level sleep support
   7  */
   8 
   9 #include <linux/linkage.h>
  10 #include <asm/assembler.h>
  11 #include <mach/hardware.h>
  12 #include <mach/map.h>
  13 
  14 #include <mach/regs-irq.h>
  15 
  16         .text
  17 
  18         .global s3c2412_sleep_enter
  19 
  20 s3c2412_sleep_enter:
  21         mov     r0, #0                  /* argument for coprocessors */
  22         ldr     r1, =S3C2410_INTPND
  23         ldr     r2, =S3C2410_SRCPND
  24         ldr     r3, =S3C2410_EINTPEND
  25 
  26         teq     r0, r0
  27         bl      s3c2412_sleep_enter1
  28         teq     pc, r0
  29         bl      s3c2412_sleep_enter1
  30 
  31         .align  5
  32 
  33         /* this is called twice, first with the Z flag to ensure that the
  34          * instructions have been loaded into the cache, and the second
  35          * time to try and suspend the system.
  36         */
  37 s3c2412_sleep_enter1:
  38         mcr     p15, 0, r0, c7, c10, 4
  39         mcrne   p15, 0, r0, c7, c0, 4
  40 
  41         /* if we return from here, it is because an interrupt was
  42          * active when we tried to shutdown. Try and ack the IRQ and
  43          * retry, as simply returning causes the system to lock.
  44         */
  45 
  46         ldrne   r9, [r1]
  47         strne   r9, [r1]
  48         ldrne   r9, [r2]
  49         strne   r9, [r2]
  50         ldrne   r9, [r3]
  51         strne   r9, [r3]
  52         bne     s3c2412_sleep_enter1
  53 
  54         ret     lr