arch/arm/mach-imx/pm-imx27.c

   1 /*
   2  * i.MX27 Power Management Routines
   3  *
   4  * Based on Freescale's BSP
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License.
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/suspend.h>
  12 #include <linux/io.h>
  13
  14 #include "hardware.h"
  15
  16 static int mx27_suspend_enter(suspend_state_t state)
  17 {
  18         u32 cscr;
  19         switch (state) {
  20         case PM_SUSPEND_MEM:
  21                 /* Clear MPEN and SPEN to disable MPLL/SPLL */
  22                 cscr = imx_readl(MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR));
  23                 cscr &= 0xFFFFFFFC;
  24                 imx_writel(cscr, MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR));
  25                 /* Executes WFI */
  26                 cpu_do_idle();
  27                 break;
  28
  29         default:
  30                 return -EINVAL;
  31         }
  32         return 0;
  33 }
  34
  35 static const struct platform_suspend_ops mx27_suspend_ops = {
  36         .enter = mx27_suspend_enter,
  37         .valid = suspend_valid_only_mem,
  38 };
  39
  40 static int __init mx27_pm_init(void)
  41 {
  42         if (!cpu_is_mx27())
  43                 return 0;
  44
  45         suspend_set_ops(&mx27_suspend_ops);
  46         return 0;
  47 }
  48
  49 device_initcall(mx27_pm_init);