xref: /linux/arch/arm/mach-omap2/pm.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  * linux/arch/arm/mach-omap2/pm.c
3  *
4  * OMAP2 Power Management Routines
5  *
6  * Copyright (C) 2006 Nokia Corporation
7  * Tony Lindgren <tony@atomide.com>
8  *
9  * Copyright (C) 2005 Texas Instruments, Inc.
10  * Richard Woodruff <r-woodruff2@ti.com>
11  *
12  * Based on pm.c for omap1
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License version 2 as
16  * published by the Free Software Foundation.
17  */
18 
19 #include <linux/pm.h>
20 #include <linux/sched.h>
21 #include <linux/proc_fs.h>
22 #include <linux/pm.h>
23 #include <linux/interrupt.h>
24 #include <linux/sysfs.h>
25 #include <linux/module.h>
26 
27 #include <asm/io.h>
28 #include <asm/irq.h>
29 #include <asm/atomic.h>
30 #include <asm/mach/time.h>
31 #include <asm/mach/irq.h>
32 #include <asm/mach-types.h>
33 
34 #include <asm/arch/irqs.h>
35 #include <asm/arch/clock.h>
36 #include <asm/arch/sram.h>
37 #include <asm/arch/pm.h>
38 
39 static struct clk *vclk;
40 static void (*omap2_sram_idle)(void);
41 static void (*omap2_sram_suspend)(int dllctrl, int cpu_rev);
42 static void (*saved_idle)(void);
43 
44 void omap2_pm_idle(void)
45 {
46 	local_irq_disable();
47 	local_fiq_disable();
48 	if (need_resched()) {
49 		local_fiq_enable();
50 		local_irq_enable();
51 		return;
52 	}
53 
54 	/*
55 	 * Since an interrupt may set up a timer, we don't want to
56 	 * reprogram the hardware timer with interrupts enabled.
57 	 * Re-enable interrupts only after returning from idle.
58 	 */
59 	timer_dyn_reprogram();
60 
61 	omap2_sram_idle();
62 	local_fiq_enable();
63 	local_irq_enable();
64 }
65 
66 static int omap2_pm_prepare(suspend_state_t state)
67 {
68 	int error = 0;
69 
70 	/* We cannot sleep in idle until we have resumed */
71 	saved_idle = pm_idle;
72 	pm_idle = NULL;
73 
74 	switch (state)
75 	{
76 	case PM_SUSPEND_STANDBY:
77 	case PM_SUSPEND_MEM:
78 		break;
79 
80 	case PM_SUSPEND_DISK:
81 		return -ENOTSUPP;
82 
83 	default:
84 		return -EINVAL;
85 	}
86 
87 	return error;
88 }
89 
90 static int omap2_pm_enter(suspend_state_t state)
91 {
92 	switch (state)
93 	{
94 	case PM_SUSPEND_STANDBY:
95 	case PM_SUSPEND_MEM:
96 		/* FIXME: Add suspend */
97 		break;
98 
99 	case PM_SUSPEND_DISK:
100 		return -ENOTSUPP;
101 
102 	default:
103 		return -EINVAL;
104 	}
105 
106 	return 0;
107 }
108 
109 static int omap2_pm_finish(suspend_state_t state)
110 {
111 	pm_idle = saved_idle;
112 	return 0;
113 }
114 
115 static struct pm_ops omap_pm_ops = {
116 	.pm_disk_mode	= 0,
117 	.prepare	= omap2_pm_prepare,
118 	.enter		= omap2_pm_enter,
119 	.finish		= omap2_pm_finish,
120 };
121 
122 int __init omap2_pm_init(void)
123 {
124 	printk("Power Management for TI OMAP.\n");
125 
126 	vclk = clk_get(NULL, "virt_prcm_set");
127 	if (IS_ERR(vclk)) {
128 		printk(KERN_ERR "Could not get PM vclk\n");
129 		return -ENODEV;
130 	}
131 
132 	/*
133 	 * We copy the assembler sleep/wakeup routines to SRAM.
134 	 * These routines need to be in SRAM as that's the only
135 	 * memory the MPU can see when it wakes up.
136 	 */
137 	omap2_sram_idle = omap_sram_push(omap24xx_idle_loop_suspend,
138 					 omap24xx_idle_loop_suspend_sz);
139 
140 	omap2_sram_suspend = omap_sram_push(omap24xx_cpu_suspend,
141 					    omap24xx_cpu_suspend_sz);
142 
143 	pm_set_ops(&omap_pm_ops);
144 	pm_idle = omap2_pm_idle;
145 
146 	return 0;
147 }
148 
149 __initcall(omap2_pm_init);
150