xref: /OK3568_Linux_fs/kernel/arch/arm/mach-imx/pm-imx27.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * i.MX27 Power Management Routines
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * Based on Freescale's BSP
5*4882a593Smuzhiyun  *
6*4882a593Smuzhiyun  * This program is free software; you can redistribute it and/or
7*4882a593Smuzhiyun  * modify it under the terms of the GNU General Public License.
8*4882a593Smuzhiyun  */
9*4882a593Smuzhiyun 
10*4882a593Smuzhiyun #include <linux/of_address.h>
11*4882a593Smuzhiyun #include <linux/kernel.h>
12*4882a593Smuzhiyun #include <linux/suspend.h>
13*4882a593Smuzhiyun #include <linux/io.h>
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun #include "hardware.h"
16*4882a593Smuzhiyun 
mx27_suspend_enter(suspend_state_t state)17*4882a593Smuzhiyun static int mx27_suspend_enter(suspend_state_t state)
18*4882a593Smuzhiyun {
19*4882a593Smuzhiyun 	void __iomem *ccm_base;
20*4882a593Smuzhiyun 	struct device_node *np;
21*4882a593Smuzhiyun 	u32 cscr;
22*4882a593Smuzhiyun 
23*4882a593Smuzhiyun 	np = of_find_compatible_node(NULL, NULL, "fsl,imx27-ccm");
24*4882a593Smuzhiyun 	ccm_base = of_iomap(np, 0);
25*4882a593Smuzhiyun 	BUG_ON(!ccm_base);
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun 	switch (state) {
28*4882a593Smuzhiyun 	case PM_SUSPEND_MEM:
29*4882a593Smuzhiyun 		/* Clear MPEN and SPEN to disable MPLL/SPLL */
30*4882a593Smuzhiyun 		cscr = imx_readl(ccm_base);
31*4882a593Smuzhiyun 		cscr &= 0xFFFFFFFC;
32*4882a593Smuzhiyun 		imx_writel(cscr, ccm_base);
33*4882a593Smuzhiyun 		/* Executes WFI */
34*4882a593Smuzhiyun 		cpu_do_idle();
35*4882a593Smuzhiyun 		break;
36*4882a593Smuzhiyun 
37*4882a593Smuzhiyun 	default:
38*4882a593Smuzhiyun 		return -EINVAL;
39*4882a593Smuzhiyun 	}
40*4882a593Smuzhiyun 	return 0;
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun 
43*4882a593Smuzhiyun static const struct platform_suspend_ops mx27_suspend_ops = {
44*4882a593Smuzhiyun 	.enter = mx27_suspend_enter,
45*4882a593Smuzhiyun 	.valid = suspend_valid_only_mem,
46*4882a593Smuzhiyun };
47*4882a593Smuzhiyun 
imx27_pm_init(void)48*4882a593Smuzhiyun void __init imx27_pm_init(void)
49*4882a593Smuzhiyun {
50*4882a593Smuzhiyun 	suspend_set_ops(&mx27_suspend_ops);
51*4882a593Smuzhiyun }
52