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