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/common.h>
  18 #include <mach/hardware.h>
  19 #include "crm_regs.h"
  20
  21 static struct clk *gpc_dvfs_clk;
  22
  23 static int mx5_suspend_prepare(void)
  24 {
  25         return clk_enable(gpc_dvfs_clk);
  26 }
  27
  28 static int mx5_suspend_enter(suspend_state_t state)
  29 {
  30         switch (state) {
  31         case PM_SUSPEND_MEM:
  32                 mx5_cpu_lp_set(STOP_POWER_OFF);
  33                 break;
  34         case PM_SUSPEND_STANDBY:
  35                 mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
  36                 break;
  37         default:
  38                 return -EINVAL;
  39         }
  40
  41         if (state == PM_SUSPEND_MEM) {
  42                 local_flush_tlb_all();
  43                 flush_cache_all();
  44
  45                 /*clear the EMPGC0/1 bits */
  46                 __raw_writel(0, MXC_SRPG_EMPGC0_SRPGCR);
  47                 __raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
  48         }
  49         cpu_do_idle();
  50         return 0;
  51 }
  52
  53 static void mx5_suspend_finish(void)
  54 {
  55         clk_disable(gpc_dvfs_clk);
  56 }
  57
  58 static int mx5_pm_valid(suspend_state_t state)
  59 {
  60         return (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX);
  61 }
  62
  63 static const struct platform_suspend_ops mx5_suspend_ops = {
  64         .valid = mx5_pm_valid,
  65         .prepare = mx5_suspend_prepare,
  66         .enter = mx5_suspend_enter,
  67         .finish = mx5_suspend_finish,
  68 };
  69
  70 static int __init mx5_pm_init(void)
  71 {
  72         if (gpc_dvfs_clk == NULL)
  73                 gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
  74
  75         if (!IS_ERR(gpc_dvfs_clk)) {
  76                 if (cpu_is_mx51())
  77                         suspend_set_ops(&mx5_suspend_ops);
  78         } else
  79                 return -EPERM;
  80
  81         return 0;
  82 }
  83 device_initcall(mx5_pm_init);