arch/arm/mach-msm/idle.c

   1 /* arch/arm/mach-msm/idle.c
   2  *
   3  * Idle processing for MSM7K - work around bugs with SWFI.
   4  *
   5  * Copyright (c) 2007 QUALCOMM Incorporated.
   6  * Copyright (C) 2007 Google, Inc.
   7  *
   8  * This software is licensed under the terms of the GNU General Public
   9  * License version 2, as published by the Free Software Foundation, and
  10  * may be copied, distributed, and modified under those terms.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  */
  18
  19 #include <linux/init.h>
  20 #include <asm/system.h>
  21
  22 static void msm_idle(void)
  23 {
  24 #ifdef CONFIG_MSM7X00A_IDLE
  25         asm volatile (
  26
  27         "mrc     p15, 0, r1, c1, c0, 0    /* read current CR    */ \n\t"
  28         "bic     r0, r1, #(1 << 2)        /* clear dcache bit   */ \n\t"
  29         "bic     r0, r0, #(1 << 12)       /* clear icache bit   */ \n\t"
  30         "mcr     p15, 0, r0, c1, c0, 0    /* disable d/i cache  */ \n\t"
  31
  32         "mov     r0, #0                   /* prepare wfi value  */ \n\t"
  33         "mcr     p15, 0, r0, c7, c10, 0   /* flush the cache    */ \n\t"
  34         "mcr     p15, 0, r0, c7, c10, 4   /* memory barrier     */ \n\t"
  35         "mcr     p15, 0, r0, c7, c0, 4    /* wait for interrupt */ \n\t"
  36
  37         "mcr     p15, 0, r1, c1, c0, 0    /* restore d/i cache  */ \n\t"
  38
  39         : : : "r0","r1" );
  40 #endif
  41 }
  42
  43 static int __init msm_idle_init(void)
  44 {
  45         arm_pm_idle = msm_idle;
  46         return 0;
  47 }
  48
  49 arch_initcall(msm_idle_init);