arch/arm/mach-imx/pm-imx6q.c

   1 /*
   2  * Copyright 2011 Freescale Semiconductor, Inc.
   3  * Copyright 2011 Linaro Ltd.
   4  *
   5  * The code contained herein is licensed under the GNU General Public
   6  * License. You may obtain a copy of the GNU General Public License
   7  * Version 2 or later at the following locations:
   8  *
   9  * http://www.opensource.org/licenses/gpl-license.html
  10  * http://www.gnu.org/copyleft/gpl.html
  11  */
  12
  13 #include <linux/init.h>
  14 #include <linux/io.h>
  15 #include <linux/of.h>
  16 #include <linux/suspend.h>
  17 #include <asm/cacheflush.h>
  18 #include <asm/proc-fns.h>
  19 #include <asm/suspend.h>
  20 #include <asm/hardware/cache-l2x0.h>
  21 #include <mach/common.h>
  22 #include <mach/hardware.h>
  23
  24 extern unsigned long phys_l2x0_saved_regs;
  25
  26 static int imx6q_suspend_finish(unsigned long val)
  27 {
  28         cpu_do_idle();
  29         return 0;
  30 }
  31
  32 static int imx6q_pm_enter(suspend_state_t state)
  33 {
  34         switch (state) {
  35         case PM_SUSPEND_MEM:
  36                 imx6q_set_lpm(STOP_POWER_OFF);
  37                 imx_gpc_pre_suspend();
  38                 imx_set_cpu_jump(0, v7_cpu_resume);
  39                 /* Zzz ... */
  40                 cpu_suspend(0, imx6q_suspend_finish);
  41                 imx_smp_prepare();
  42                 imx_gpc_post_resume();
  43                 break;
  44         default:
  45                 return -EINVAL;
  46         }
  47
  48         return 0;
  49 }
  50
  51 static const struct platform_suspend_ops imx6q_pm_ops = {
  52         .enter = imx6q_pm_enter,
  53         .valid = suspend_valid_only_mem,
  54 };
  55
  56 void __init imx6q_pm_init(void)
  57 {
  58         /*
  59          * The l2x0 core code provides an infrastucture to save and restore
  60          * l2x0 registers across suspend/resume cycle.  But because imx6q
  61          * retains L2 content during suspend and needs to resume L2 before
  62          * MMU is enabled, it can only utilize register saving support and
  63          * have to take care of restoring on its own.  So we save physical
  64          * address of the data structure used by l2x0 core to save registers,
  65          * and later restore the necessary ones in imx6q resume entry.
  66          */
  67         phys_l2x0_saved_regs = __pa(&l2x0_saved_regs);
  68
  69         suspend_set_ops(&imx6q_pm_ops);
  70 }