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 */
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
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
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
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