1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (C) 2013 Samsung Electronics Co., Ltd.
4 //	Tomasz Figa <t.figa@samsung.com>
5 // Copyright (C) 2008 Openmoko, Inc.
6 // Copyright (C) 2004-2008 Simtec Electronics
7 //	Ben Dooks <ben@simtec.co.uk>
8 //	http://armlinux.simtec.co.uk/
9 //
10 // Samsung common power management helper functions.
11 
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 
15 #include "pm-common.h"
16 
17 /* helper functions to save and restore register state */
18 
19 /**
20  * s3c_pm_do_save() - save a set of registers for restoration on resume.
21  * @ptr: Pointer to an array of registers.
22  * @count: Size of the ptr array.
23  *
24  * Run through the list of registers given, saving their contents in the
25  * array for later restoration when we wakeup.
26  */
s3c_pm_do_save(struct sleep_save * ptr,int count)27 void s3c_pm_do_save(struct sleep_save *ptr, int count)
28 {
29 	for (; count > 0; count--, ptr++) {
30 		ptr->val = readl_relaxed(ptr->reg);
31 		S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
32 	}
33 }
34 
35 /**
36  * s3c_pm_do_restore() - restore register values from the save list.
37  * @ptr: Pointer to an array of registers.
38  * @count: Size of the ptr array.
39  *
40  * Restore the register values saved from s3c_pm_do_save().
41  *
42  * Note, we do not use S3C_PMDBG() in here, as the system may not have
43  * restore the UARTs state yet
44 */
45 
s3c_pm_do_restore(const struct sleep_save * ptr,int count)46 void s3c_pm_do_restore(const struct sleep_save *ptr, int count)
47 {
48 	for (; count > 0; count--, ptr++) {
49 		pr_debug("restore %p (restore %08lx, was %08x)\n",
50 				ptr->reg, ptr->val, readl_relaxed(ptr->reg));
51 
52 		writel_relaxed(ptr->val, ptr->reg);
53 	}
54 }
55 
56 /**
57  * s3c_pm_do_restore_core() - early restore register values from save list.
58  * @ptr: Pointer to an array of registers.
59  * @count: Size of the ptr array.
60  *
61  * This is similar to s3c_pm_do_restore() except we try and minimise the
62  * side effects of the function in case registers that hardware might need
63  * to work has been restored.
64  *
65  * WARNING: Do not put any debug in here that may effect memory or use
66  * peripherals, as things may be changing!
67 */
68 
s3c_pm_do_restore_core(const struct sleep_save * ptr,int count)69 void s3c_pm_do_restore_core(const struct sleep_save *ptr, int count)
70 {
71 	for (; count > 0; count--, ptr++)
72 		writel_relaxed(ptr->val, ptr->reg);
73 }
74