xref: /openbmc/linux/arch/arm/mach-pxa/pm.c (revision a1e58bbd)
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/time.h>
18 
19 #include <asm/hardware.h>
20 #include <asm/memory.h>
21 #include <asm/system.h>
22 #include <asm/arch/pm.h>
23 #include <asm/arch/pxa-regs.h>
24 #include <asm/arch/lubbock.h>
25 #include <asm/mach/time.h>
26 
27 struct pxa_cpu_pm_fns *pxa_cpu_pm_fns;
28 static unsigned long *sleep_save;
29 
30 int pxa_pm_enter(suspend_state_t state)
31 {
32 	unsigned long sleep_save_checksum = 0, checksum = 0;
33 	int i;
34 
35 #ifdef CONFIG_IWMMXT
36 	/* force any iWMMXt context to ram **/
37 	if (elf_hwcap & HWCAP_IWMMXT)
38 		iwmmxt_task_disable(NULL);
39 #endif
40 
41 	/* skip registers saving for standby */
42 	if (state != PM_SUSPEND_STANDBY) {
43 		pxa_cpu_pm_fns->save(sleep_save);
44 		/* before sleeping, calculate and save a checksum */
45 		for (i = 0; i < pxa_cpu_pm_fns->save_size - 1; i++)
46 			sleep_save_checksum += sleep_save[i];
47 	}
48 
49 	/* Clear sleep reset status */
50 	RCSR = RCSR_SMR;
51 
52 	/* *** go zzz *** */
53 	pxa_cpu_pm_fns->enter(state);
54 	cpu_init();
55 
56 	if (state != PM_SUSPEND_STANDBY) {
57 		/* after sleeping, validate the checksum */
58 		for (i = 0; i < pxa_cpu_pm_fns->save_size - 1; i++)
59 			checksum += sleep_save[i];
60 
61 		/* if invalid, display message and wait for a hardware reset */
62 		if (checksum != sleep_save_checksum) {
63 #ifdef CONFIG_ARCH_LUBBOCK
64 			LUB_HEXLED = 0xbadbadc5;
65 #endif
66 			while (1)
67 				pxa_cpu_pm_fns->enter(state);
68 		}
69 		pxa_cpu_pm_fns->restore(sleep_save);
70 	}
71 
72 	pr_debug("*** made it back from resume\n");
73 
74 	return 0;
75 }
76 
77 EXPORT_SYMBOL_GPL(pxa_pm_enter);
78 
79 unsigned long sleep_phys_sp(void *sp)
80 {
81 	return virt_to_phys(sp);
82 }
83 
84 static int pxa_pm_valid(suspend_state_t state)
85 {
86 	if (pxa_cpu_pm_fns)
87 		return pxa_cpu_pm_fns->valid(state);
88 
89 	return -EINVAL;
90 }
91 
92 static struct platform_suspend_ops pxa_pm_ops = {
93 	.valid		= pxa_pm_valid,
94 	.enter		= pxa_pm_enter,
95 };
96 
97 static int __init pxa_pm_init(void)
98 {
99 	if (!pxa_cpu_pm_fns) {
100 		printk(KERN_ERR "no valid pxa_cpu_pm_fns defined\n");
101 		return -EINVAL;
102 	}
103 
104 	sleep_save = kmalloc(pxa_cpu_pm_fns->save_size, GFP_KERNEL);
105 	if (!sleep_save) {
106 		printk(KERN_ERR "failed to alloc memory for pm save\n");
107 		return -ENOMEM;
108 	}
109 
110 	suspend_set_ops(&pxa_pm_ops);
111 	return 0;
112 }
113 
114 device_initcall(pxa_pm_init);
115