xref: /openbmc/linux/arch/arm/mach-imx/pm-imx27.c (revision 779b56bb)
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 
mx27_suspend_enter(suspend_state_t state)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 
imx27_pm_init(void)49 void __init imx27_pm_init(void)
50 {
51 	suspend_set_ops(&mx27_suspend_ops);
52 }
53