xref: /openbmc/linux/arch/arm/mach-sa1100/pm.c (revision 95c96174)
1 /*
2  * SA1100 Power Management Routines
3  *
4  * Copyright (c) 2001 Cliff Brake <cbrake@accelent.com>
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License.
8  *
9  * History:
10  *
11  * 2001-02-06:	Cliff Brake         Initial code
12  *
13  * 2001-02-25:	Sukjae Cho <sjcho@east.isi.edu> &
14  * 		Chester Kuo <chester@linux.org.tw>
15  * 			Save more value for the resume function! Support
16  * 			Bitsy/Assabet/Freebird board
17  *
18  * 2001-08-29:	Nicolas Pitre <nico@fluxnic.net>
19  * 			Cleaned up, pushed platform dependent stuff
20  * 			in the platform specific files.
21  *
22  * 2002-05-27:	Nicolas Pitre	Killed sleep.h and the kmalloced save array.
23  * 				Storage is local on the stack now.
24  */
25 #include <linux/init.h>
26 #include <linux/suspend.h>
27 #include <linux/errno.h>
28 #include <linux/time.h>
29 
30 #include <mach/hardware.h>
31 #include <asm/memory.h>
32 #include <asm/suspend.h>
33 #include <asm/mach/time.h>
34 
35 extern int sa1100_finish_suspend(unsigned long);
36 
37 #define SAVE(x)		sleep_save[SLEEP_SAVE_##x] = x
38 #define RESTORE(x)	x = sleep_save[SLEEP_SAVE_##x]
39 
40 /*
41  * List of global SA11x0 peripheral registers to preserve.
42  * More ones like CP and general purpose register values are preserved
43  * on the stack and then the stack pointer is stored last in sleep.S.
44  */
45 enum {	SLEEP_SAVE_GPDR, SLEEP_SAVE_GAFR,
46 	SLEEP_SAVE_PPDR, SLEEP_SAVE_PPSR, SLEEP_SAVE_PPAR, SLEEP_SAVE_PSDR,
47 
48 	SLEEP_SAVE_Ser1SDCR0,
49 
50 	SLEEP_SAVE_COUNT
51 };
52 
53 
54 static int sa11x0_pm_enter(suspend_state_t state)
55 {
56 	unsigned long gpio, sleep_save[SLEEP_SAVE_COUNT];
57 
58 	gpio = GPLR;
59 
60 	/* save vital registers */
61 	SAVE(GPDR);
62 	SAVE(GAFR);
63 
64 	SAVE(PPDR);
65 	SAVE(PPSR);
66 	SAVE(PPAR);
67 	SAVE(PSDR);
68 
69 	SAVE(Ser1SDCR0);
70 
71 	/* Clear previous reset status */
72 	RCSR = RCSR_HWR | RCSR_SWR | RCSR_WDR | RCSR_SMR;
73 
74 	/* set resume return address */
75 	PSPR = virt_to_phys(cpu_resume);
76 
77 	/* go zzz */
78 	cpu_suspend(0, sa1100_finish_suspend);
79 
80 	/*
81 	 * Ensure not to come back here if it wasn't intended
82 	 */
83 	PSPR = 0;
84 
85 	/*
86 	 * Ensure interrupt sources are disabled; we will re-init
87 	 * the interrupt subsystem via the device manager.
88 	 */
89 	ICLR = 0;
90 	ICCR = 1;
91 	ICMR = 0;
92 
93 	/* restore registers */
94 	RESTORE(GPDR);
95 	RESTORE(GAFR);
96 
97 	RESTORE(PPDR);
98 	RESTORE(PPSR);
99 	RESTORE(PPAR);
100 	RESTORE(PSDR);
101 
102 	RESTORE(Ser1SDCR0);
103 
104 	GPSR = gpio;
105 	GPCR = ~gpio;
106 
107 	/*
108 	 * Clear the peripheral sleep-hold bit.
109 	 */
110 	PSSR = PSSR_PH;
111 
112 	return 0;
113 }
114 
115 static const struct platform_suspend_ops sa11x0_pm_ops = {
116 	.enter		= sa11x0_pm_enter,
117 	.valid		= suspend_valid_only_mem,
118 };
119 
120 static int __init sa11x0_pm_init(void)
121 {
122 	suspend_set_ops(&sa11x0_pm_ops);
123 	return 0;
124 }
125 
126 late_initcall(sa11x0_pm_init);
127