arch/arm/mach-mx5/pm-imx5.c

   1 /*
   2  *  Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
   3  *
   4  * The code contained herein is licensed under the GNU General Public
   5  * License. You may obtain a copy of the GNU General Public License
   6  * Version 2 or later at the following locations:
   7  *
   8  * http://www.opensource.org/licenses/gpl-license.html
   9  * http://www.gnu.org/copyleft/gpl.html
  10  */
  11 #include <linux/suspend.h>
  12 #include <linux/clk.h>
  13 #include <linux/io.h>
  14 #include <linux/err.h>
  15 #include <asm/cacheflush.h>
  16 #include <asm/tlbflush.h>
  17 #include <mach/system.h>
  18 #include "crm_regs.h"
  19
  20 static struct clk *gpc_dvfs_clk;
  21
  22 static int mx5_suspend_enter(suspend_state_t state)
  23 {
  24         clk_enable(gpc_dvfs_clk);
  25         switch (state) {
  26         case PM_SUSPEND_MEM:
  27                 mx5_cpu_lp_set(STOP_POWER_OFF);
  28                 break;
  29         case PM_SUSPEND_STANDBY:
  30                 mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
  31                 break;
  32         default:
  33                 return -EINVAL;
  34         }
  35
  36         if (state == PM_SUSPEND_MEM) {
  37                 local_flush_tlb_all();
  38                 flush_cache_all();
  39
  40                 /*clear the EMPGC0/1 bits */
  41                 __raw_writel(0, MXC_SRPG_EMPGC0_SRPGCR);
  42                 __raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
  43         }
  44         cpu_do_idle();
  45         clk_disable(gpc_dvfs_clk);
  46
  47         return 0;
  48 }
  49
  50 static int mx5_pm_valid(suspend_state_t state)
  51 {
  52         return (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX);
  53 }
  54
  55 static const struct platform_suspend_ops mx5_suspend_ops = {
  56         .valid = mx5_pm_valid,
  57         .enter = mx5_suspend_enter,
  58 };
  59
  60 static int __init mx5_pm_init(void)
  61 {
  62         if (gpc_dvfs_clk == NULL)
  63                 gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
  64
  65         if (!IS_ERR(gpc_dvfs_clk)) {
  66                 if (cpu_is_mx51())
  67                         suspend_set_ops(&mx5_suspend_ops);
  68         } else
  69                 return -EPERM;
  70
  71         return 0;
  72 }
  73 device_initcall(mx5_pm_init);