arm/mach-imx/pm-imx27.c

0001 /*
0002  * i.MX27 Power Management Routines
0003  *
0004  * Based on Freescale's BSP
0005  *
0006  * This program is free software; you can redistribute it and/or
0007  * modify it under the terms of the GNU General Public License.
0008  */
0009
0010 #include <linux/of_address.h>
0011 #include <linux/kernel.h>
0012 #include <linux/suspend.h>
0013 #include <linux/io.h>
0014
0015 #include "common.h"
0016 #include "hardware.h"
0017
0018 static int mx27_suspend_enter(suspend_state_t state)
0019 {
0020     void __iomem *ccm_base;
0021     struct device_node *np;
0022     u32 cscr;
0023
0024     np = of_find_compatible_node(NULL, NULL, "fsl,imx27-ccm");
0025     ccm_base = of_iomap(np, 0);
0026     BUG_ON(!ccm_base);
0027
0028     switch (state) {
0029     case PM_SUSPEND_MEM:
0030         /* Clear MPEN and SPEN to disable MPLL/SPLL */
0031         cscr = imx_readl(ccm_base);
0032         cscr &= 0xFFFFFFFC;
0033         imx_writel(cscr, ccm_base);
0034         /* Executes WFI */
0035         cpu_do_idle();
0036         break;
0037
0038     default:
0039         return -EINVAL;
0040     }
0041     return 0;
0042 }
0043
0044 static const struct platform_suspend_ops mx27_suspend_ops = {
0045     .enter = mx27_suspend_enter,
0046     .valid = suspend_valid_only_mem,
0047 };
0048
0049 void __init imx27_pm_init(void)
0050 {
0051     suspend_set_ops(&mx27_suspend_ops);
0052 }