xref: /openbmc/linux/arch/arm/mach-pxa/pm.c (revision aac28965)
1 /*
2  * PXA250/210 Power Management Routines
3  *
4  * Original code for the SA11x0:
5  * Copyright (c) 2001 Cliff Brake <cbrake@accelent.com>
6  *
7  * Modified for the PXA250 by Nicolas Pitre:
8  * Copyright (c) 2002 Monta Vista Software, Inc.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License.
12  */
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/suspend.h>
16 #include <linux/errno.h>
17 #include <linux/slab.h>
18 
19 #include "pm.h"
20 
21 struct pxa_cpu_pm_fns *pxa_cpu_pm_fns;
22 static unsigned long *sleep_save;
23 
24 int pxa_pm_enter(suspend_state_t state)
25 {
26 	unsigned long sleep_save_checksum = 0, checksum = 0;
27 	int i;
28 
29 #ifdef CONFIG_IWMMXT
30 	/* force any iWMMXt context to ram **/
31 	if (elf_hwcap & HWCAP_IWMMXT)
32 		iwmmxt_task_disable(NULL);
33 #endif
34 
35 	/* skip registers saving for standby */
36 	if (state != PM_SUSPEND_STANDBY && pxa_cpu_pm_fns->save) {
37 		pxa_cpu_pm_fns->save(sleep_save);
38 		/* before sleeping, calculate and save a checksum */
39 		for (i = 0; i < pxa_cpu_pm_fns->save_count - 1; i++)
40 			sleep_save_checksum += sleep_save[i];
41 	}
42 
43 	/* *** go zzz *** */
44 	pxa_cpu_pm_fns->enter(state);
45 
46 	if (state != PM_SUSPEND_STANDBY && pxa_cpu_pm_fns->restore) {
47 		/* after sleeping, validate the checksum */
48 		for (i = 0; i < pxa_cpu_pm_fns->save_count - 1; i++)
49 			checksum += sleep_save[i];
50 
51 		/* if invalid, display message and wait for a hardware reset */
52 		if (checksum != sleep_save_checksum) {
53 
54 			lubbock_set_hexled(0xbadbadc5);
55 
56 			while (1)
57 				pxa_cpu_pm_fns->enter(state);
58 		}
59 		pxa_cpu_pm_fns->restore(sleep_save);
60 	}
61 
62 	pr_debug("*** made it back from resume\n");
63 
64 	return 0;
65 }
66 
67 EXPORT_SYMBOL_GPL(pxa_pm_enter);
68 
69 static int pxa_pm_valid(suspend_state_t state)
70 {
71 	if (pxa_cpu_pm_fns)
72 		return pxa_cpu_pm_fns->valid(state);
73 
74 	return -EINVAL;
75 }
76 
77 int pxa_pm_prepare(void)
78 {
79 	int ret = 0;
80 
81 	if (pxa_cpu_pm_fns && pxa_cpu_pm_fns->prepare)
82 		ret = pxa_cpu_pm_fns->prepare();
83 
84 	return ret;
85 }
86 
87 void pxa_pm_finish(void)
88 {
89 	if (pxa_cpu_pm_fns && pxa_cpu_pm_fns->finish)
90 		pxa_cpu_pm_fns->finish();
91 }
92 
93 static const struct platform_suspend_ops pxa_pm_ops = {
94 	.valid		= pxa_pm_valid,
95 	.enter		= pxa_pm_enter,
96 	.prepare	= pxa_pm_prepare,
97 	.finish		= pxa_pm_finish,
98 };
99 
100 static int __init pxa_pm_init(void)
101 {
102 	if (!pxa_cpu_pm_fns) {
103 		printk(KERN_ERR "no valid pxa_cpu_pm_fns defined\n");
104 		return -EINVAL;
105 	}
106 
107 	sleep_save = kmalloc_array(pxa_cpu_pm_fns->save_count,
108 				   sizeof(*sleep_save),
109 				   GFP_KERNEL);
110 	if (!sleep_save)
111 		return -ENOMEM;
112 
113 	suspend_set_ops(&pxa_pm_ops);
114 	return 0;
115 }
116 
117 device_initcall(pxa_pm_init);
118