1 /*
2  * linux/arch/unicore32/kernel/pm.c
3  *
4  * Code specific to PKUnity SoC and UniCore ISA
5  *
6  *	Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
7  *	Copyright (C) 2001-2010 Guan Xuetao
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
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 #include <linux/io.h>
19 
20 #include <mach/hardware.h>
21 #include <mach/pm.h>
22 
23 #include "setup.h"
24 
25 struct puv3_cpu_pm_fns *puv3_cpu_pm_fns;
26 static unsigned long *sleep_save;
27 
puv3_pm_enter(suspend_state_t state)28 int puv3_pm_enter(suspend_state_t state)
29 {
30 	unsigned long sleep_save_checksum = 0, checksum = 0;
31 	int i;
32 
33 	/* skip registers saving for standby */
34 	if (state != PM_SUSPEND_STANDBY) {
35 		puv3_cpu_pm_fns->save(sleep_save);
36 		/* before sleeping, calculate and save a checksum */
37 		for (i = 0; i < puv3_cpu_pm_fns->save_count - 1; i++)
38 			sleep_save_checksum += sleep_save[i];
39 	}
40 
41 	/* *** go zzz *** */
42 	puv3_cpu_pm_fns->enter(state);
43 	cpu_init();
44 #ifdef CONFIG_INPUT_KEYBOARD
45 	puv3_ps2_init();
46 #endif
47 #ifdef CONFIG_PCI
48 	pci_puv3_preinit();
49 #endif
50 	if (state != PM_SUSPEND_STANDBY) {
51 		/* after sleeping, validate the checksum */
52 		for (i = 0; i < puv3_cpu_pm_fns->save_count - 1; i++)
53 			checksum += sleep_save[i];
54 
55 		/* if invalid, display message and wait for a hardware reset */
56 		if (checksum != sleep_save_checksum) {
57 			while (1)
58 				puv3_cpu_pm_fns->enter(state);
59 		}
60 		puv3_cpu_pm_fns->restore(sleep_save);
61 	}
62 
63 	pr_debug("*** made it back from resume\n");
64 
65 	return 0;
66 }
67 EXPORT_SYMBOL_GPL(puv3_pm_enter);
68 
sleep_phys_sp(void * sp)69 unsigned long sleep_phys_sp(void *sp)
70 {
71 	return virt_to_phys(sp);
72 }
73 
puv3_pm_valid(suspend_state_t state)74 static int puv3_pm_valid(suspend_state_t state)
75 {
76 	if (puv3_cpu_pm_fns)
77 		return puv3_cpu_pm_fns->valid(state);
78 
79 	return -EINVAL;
80 }
81 
puv3_pm_prepare(void)82 static int puv3_pm_prepare(void)
83 {
84 	int ret = 0;
85 
86 	if (puv3_cpu_pm_fns && puv3_cpu_pm_fns->prepare)
87 		ret = puv3_cpu_pm_fns->prepare();
88 
89 	return ret;
90 }
91 
puv3_pm_finish(void)92 static void puv3_pm_finish(void)
93 {
94 	if (puv3_cpu_pm_fns && puv3_cpu_pm_fns->finish)
95 		puv3_cpu_pm_fns->finish();
96 }
97 
98 static struct platform_suspend_ops puv3_pm_ops = {
99 	.valid		= puv3_pm_valid,
100 	.enter		= puv3_pm_enter,
101 	.prepare	= puv3_pm_prepare,
102 	.finish		= puv3_pm_finish,
103 };
104 
puv3_pm_init(void)105 static int __init puv3_pm_init(void)
106 {
107 	if (!puv3_cpu_pm_fns) {
108 		printk(KERN_ERR "no valid puv3_cpu_pm_fns defined\n");
109 		return -EINVAL;
110 	}
111 
112 	sleep_save = kmalloc(puv3_cpu_pm_fns->save_count
113 				* sizeof(unsigned long), GFP_KERNEL);
114 	if (!sleep_save) {
115 		printk(KERN_ERR "failed to alloc memory for pm save\n");
116 		return -ENOMEM;
117 	}
118 
119 	suspend_set_ops(&puv3_pm_ops);
120 	return 0;
121 }
122 
123 device_initcall(puv3_pm_init);
124