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 "common.h"
  16 #include "hardware.h"
  17
  18 static int mx27_suspend_enter(suspend_state_t state)
  19 {
  20         void __iomem *ccm_base;
  21         struct device_node *np;
  22         u32 cscr;
  23
  24         np = of_find_compatible_node(NULL, NULL, "fsl,imx27-ccm");
  25         ccm_base = of_iomap(np, 0);
  26         BUG_ON(!ccm_base);
  27
  28         switch (state) {
  29         case PM_SUSPEND_MEM:
  30                 /* Clear MPEN and SPEN to disable MPLL/SPLL */
  31                 cscr = imx_readl(ccm_base);
  32                 cscr &= 0xFFFFFFFC;
  33                 imx_writel(cscr, ccm_base);
  34                 /* Executes WFI */
  35                 cpu_do_idle();
  36                 break;
  37
  38         default:
  39                 return -EINVAL;
  40         }
  41         return 0;
  42 }
  43
  44 static const struct platform_suspend_ops mx27_suspend_ops = {
  45         .enter = mx27_suspend_enter,
  46         .valid = suspend_valid_only_mem,
  47 };
  48
  49 void __init imx27_pm_init(void)
  50 {
  51         suspend_set_ops(&mx27_suspend_ops);
  52 }