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 #include <mach/hardware.h>
  14
  15 static int mx27_suspend_enter(suspend_state_t state)
  16 {
  17         u32 cscr;
  18         switch (state) {
  19         case PM_SUSPEND_MEM:
  20                 /* Clear MPEN and SPEN to disable MPLL/SPLL */
  21                 cscr = __raw_readl(MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR));
  22                 cscr &= 0xFFFFFFFC;
  23                 __raw_writel(cscr, MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR));
  24                 /* Executes WFI */
  25                 cpu_do_idle();
  26                 break;
  27
  28         default:
  29                 return -EINVAL;
  30         }
  31         return 0;
  32 }
  33
  34 static const struct platform_suspend_ops mx27_suspend_ops = {
  35         .enter = mx27_suspend_enter,
  36         .valid = suspend_valid_only_mem,
  37 };
  38
  39 static int __init mx27_pm_init(void)
  40 {
  41         if (!cpu_is_mx27())
  42                 return 0;
  43
  44         suspend_set_ops(&mx27_suspend_ops);
  45         return 0;
  46 }
  47
  48 device_initcall(mx27_pm_init);