1 /*
2 * Copyright (C) 2013 Samsung Electronics Co., Ltd.
3 * Tomasz Figa <t.figa@samsung.com>
4 * Copyright (C) 2008 Openmoko, Inc.
5 * Copyright (C) 2004-2008 Simtec Electronics
6 * Ben Dooks <ben@simtec.co.uk>
7 * http://armlinux.simtec.co.uk/
8 *
9 * Samsung common power management helper functions.
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16 #include <linux/io.h>
17 #include <linux/kernel.h>
18
19 #include <plat/pm-common.h>
20
21 /* helper functions to save and restore register state */
22
23 /**
24 * s3c_pm_do_save() - save a set of registers for restoration on resume.
25 * @ptr: Pointer to an array of registers.
26 * @count: Size of the ptr array.
27 *
28 * Run through the list of registers given, saving their contents in the
29 * array for later restoration when we wakeup.
30 */
s3c_pm_do_save(struct sleep_save * ptr,int count)31 void s3c_pm_do_save(struct sleep_save *ptr, int count)
32 {
33 for (; count > 0; count--, ptr++) {
34 ptr->val = __raw_readl(ptr->reg);
35 S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
36 }
37 }
38
39 /**
40 * s3c_pm_do_restore() - restore register values from the save list.
41 * @ptr: Pointer to an array of registers.
42 * @count: Size of the ptr array.
43 *
44 * Restore the register values saved from s3c_pm_do_save().
45 *
46 * Note, we do not use S3C_PMDBG() in here, as the system may not have
47 * restore the UARTs state yet
48 */
49
s3c_pm_do_restore(const struct sleep_save * ptr,int count)50 void s3c_pm_do_restore(const struct sleep_save *ptr, int count)
51 {
52 for (; count > 0; count--, ptr++) {
53 pr_debug("restore %p (restore %08lx, was %08x)\n",
54 ptr->reg, ptr->val, __raw_readl(ptr->reg));
55
56 __raw_writel(ptr->val, ptr->reg);
57 }
58 }
59
60 /**
61 * s3c_pm_do_restore_core() - early restore register values from save list.
62 *
63 * This is similar to s3c_pm_do_restore() except we try and minimise the
64 * side effects of the function in case registers that hardware might need
65 * to work has been restored.
66 *
67 * WARNING: Do not put any debug in here that may effect memory or use
68 * peripherals, as things may be changing!
69 */
70
s3c_pm_do_restore_core(const struct sleep_save * ptr,int count)71 void s3c_pm_do_restore_core(const struct sleep_save *ptr, int count)
72 {
73 for (; count > 0; count--, ptr++)
74 __raw_writel(ptr->val, ptr->reg);
75 }
76