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_prepare(void)
  23 {
  24         return clk_enable(gpc_dvfs_clk);
  25 }
  26
  27 static int mx5_suspend_enter(suspend_state_t state)
  28 {
  29         switch (state) {
  30         case PM_SUSPEND_MEM:
  31                 mx5_cpu_lp_set(STOP_POWER_OFF);
  32                 break;
  33         case PM_SUSPEND_STANDBY:
  34                 mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
  35                 break;
  36         default:
  37                 return -EINVAL;
  38         }
  39
  40         if (state == PM_SUSPEND_MEM) {
  41                 local_flush_tlb_all();
  42                 flush_cache_all();
  43
  44                 /*clear the EMPGC0/1 bits */
  45                 __raw_writel(0, MXC_SRPG_EMPGC0_SRPGCR);
  46                 __raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
  47         }
  48         cpu_do_idle();
  49         return 0;
  50 }
  51
  52 static void mx5_suspend_finish(void)
  53 {
  54         clk_disable(gpc_dvfs_clk);
  55 }
  56
  57 static int mx5_pm_valid(suspend_state_t state)
  58 {
  59         return (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX);
  60 }
  61
  62 static const struct platform_suspend_ops mx5_suspend_ops = {
  63         .valid = mx5_pm_valid,
  64         .prepare = mx5_suspend_prepare,
  65         .enter = mx5_suspend_enter,
  66         .finish = mx5_suspend_finish,
  67 };
  68
  69 static int __init mx5_pm_init(void)
  70 {
  71         if (gpc_dvfs_clk == NULL)
  72                 gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
  73
  74         if (!IS_ERR(gpc_dvfs_clk)) {
  75                 if (cpu_is_mx51())
  76                         suspend_set_ops(&mx5_suspend_ops);
  77         } else
  78                 return -EPERM;
  79
  80         return 0;
  81 }
  82 device_initcall(mx5_pm_init);