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/of_address.h>
  11 #include <linux/kernel.h>
  12 #include <linux/suspend.h>
  13 #include <linux/io.h>
  14
  15 #include "hardware.h"
  16
  17 static int mx27_suspend_enter(suspend_state_t state)
  18 {
  19         void __iomem *ccm_base;
  20         struct device_node *np;
  21         u32 cscr;
  22
  23         np = of_find_compatible_node(NULL, NULL, "fsl,imx27-ccm");
  24         ccm_base = of_iomap(np, 0);
  25         BUG_ON(!ccm_base);
  26
  27         switch (state) {
  28         case PM_SUSPEND_MEM:
  29                 /* Clear MPEN and SPEN to disable MPLL/SPLL */
  30                 cscr = imx_readl(ccm_base);
  31                 cscr &= 0xFFFFFFFC;
  32                 imx_writel(cscr, ccm_base);
  33                 /* Executes WFI */
  34                 cpu_do_idle();
  35                 break;
  36
  37         default:
  38                 return -EINVAL;
  39         }
  40         return 0;
  41 }
  42
  43 static const struct platform_suspend_ops mx27_suspend_ops = {
  44         .enter = mx27_suspend_enter,
  45         .valid = suspend_valid_only_mem,
  46 };
  47
  48 void __init imx27_pm_init(void)
  49 {
  50         suspend_set_ops(&mx27_suspend_ops);
  51 }