1/* linux/arch/arm/plat-s3c/pm.c
2 *
3 * Copyright 2008 Openmoko, Inc.
4 * Copyright 2004-2008 Simtec Electronics
5 *	Ben Dooks <ben@simtec.co.uk>
6 *	http://armlinux.simtec.co.uk/
7 *
8 * S3C common power management (suspend to ram) support.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13*/
14
15#include <linux/init.h>
16#include <linux/suspend.h>
17#include <linux/errno.h>
18#include <linux/delay.h>
19#include <linux/of.h>
20#include <linux/serial_s3c.h>
21#include <linux/io.h>
22
23#include <asm/cacheflush.h>
24#include <asm/suspend.h>
25
26#ifdef CONFIG_SAMSUNG_ATAGS
27#include <mach/map.h>
28#ifndef CONFIG_ARCH_EXYNOS
29#include <mach/regs-clock.h>
30#include <mach/regs-irq.h>
31#endif
32#include <mach/irqs.h>
33#endif
34
35#include <asm/irq.h>
36
37#include <plat/pm.h>
38#include <mach/pm-core.h>
39
40/* for external use */
41
42unsigned long s3c_pm_flags;
43
44/* The IRQ ext-int code goes here, it is too small to currently bother
45 * with its own file. */
46
47unsigned long s3c_irqwake_intmask	= 0xffffffffL;
48unsigned long s3c_irqwake_eintmask	= 0xffffffffL;
49
50int s3c_irqext_wake(struct irq_data *data, unsigned int state)
51{
52	unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
53
54	if (!(s3c_irqwake_eintallow & bit))
55		return -ENOENT;
56
57	printk(KERN_INFO "wake %s for irq %d\n",
58	       state ? "enabled" : "disabled", data->irq);
59
60	if (!state)
61		s3c_irqwake_eintmask |= bit;
62	else
63		s3c_irqwake_eintmask &= ~bit;
64
65	return 0;
66}
67
68/* s3c2410_pm_show_resume_irqs
69 *
70 * print any IRQs asserted at resume time (ie, we woke from)
71*/
72static void __maybe_unused s3c_pm_show_resume_irqs(int start,
73						   unsigned long which,
74						   unsigned long mask)
75{
76	int i;
77
78	which &= ~mask;
79
80	for (i = 0; i <= 31; i++) {
81		if (which & (1L<<i)) {
82			S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
83		}
84	}
85}
86
87
88void (*pm_cpu_prep)(void);
89int (*pm_cpu_sleep)(unsigned long);
90
91#define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
92
93/* s3c_pm_enter
94 *
95 * central control for sleep/resume process
96*/
97
98static int s3c_pm_enter(suspend_state_t state)
99{
100	int ret;
101	/* ensure the debug is initialised (if enabled) */
102
103	s3c_pm_debug_init();
104
105	S3C_PMDBG("%s(%d)\n", __func__, state);
106
107	if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
108		printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
109		return -EINVAL;
110	}
111
112	/* check if we have anything to wake-up with... bad things seem
113	 * to happen if you suspend with no wakeup (system will often
114	 * require a full power-cycle)
115	*/
116
117	if (!of_have_populated_dt() &&
118	    !any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
119	    !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
120		printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
121		printk(KERN_ERR "%s: Aborting sleep\n", __func__);
122		return -EINVAL;
123	}
124
125	/* save all necessary core registers not covered by the drivers */
126
127	if (!of_have_populated_dt()) {
128		samsung_pm_save_gpios();
129		samsung_pm_saved_gpios();
130	}
131
132	s3c_pm_save_uarts();
133	s3c_pm_save_core();
134
135	/* set the irq configuration for wake */
136
137	s3c_pm_configure_extint();
138
139	S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
140	    s3c_irqwake_intmask, s3c_irqwake_eintmask);
141
142	s3c_pm_arch_prepare_irqs();
143
144	/* call cpu specific preparation */
145
146	pm_cpu_prep();
147
148	/* flush cache back to ram */
149
150	flush_cache_all();
151
152	s3c_pm_check_store();
153
154	/* send the cpu to sleep... */
155
156	s3c_pm_arch_stop_clocks();
157
158	/* this will also act as our return point from when
159	 * we resume as it saves its own register state and restores it
160	 * during the resume.  */
161
162	ret = cpu_suspend(0, pm_cpu_sleep);
163	if (ret)
164		return ret;
165
166	/* restore the system state */
167
168	s3c_pm_restore_core();
169	s3c_pm_restore_uarts();
170
171	if (!of_have_populated_dt()) {
172		samsung_pm_restore_gpios();
173		s3c_pm_restored_gpios();
174	}
175
176	s3c_pm_debug_init();
177
178	/* check what irq (if any) restored the system */
179
180	s3c_pm_arch_show_resume_irqs();
181
182	S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
183
184	/* LEDs should now be 1110 */
185	s3c_pm_debug_smdkled(1 << 1, 0);
186
187	s3c_pm_check_restore();
188
189	/* ok, let's return from sleep */
190
191	S3C_PMDBG("S3C PM Resume (post-restore)\n");
192	return 0;
193}
194
195static int s3c_pm_prepare(void)
196{
197	/* prepare check area if configured */
198
199	s3c_pm_check_prepare();
200	return 0;
201}
202
203static void s3c_pm_finish(void)
204{
205	s3c_pm_check_cleanup();
206}
207
208static const struct platform_suspend_ops s3c_pm_ops = {
209	.enter		= s3c_pm_enter,
210	.prepare	= s3c_pm_prepare,
211	.finish		= s3c_pm_finish,
212	.valid		= suspend_valid_only_mem,
213};
214
215/* s3c_pm_init
216 *
217 * Attach the power management functions. This should be called
218 * from the board specific initialisation if the board supports
219 * it.
220*/
221
222int __init s3c_pm_init(void)
223{
224	printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
225
226	suspend_set_ops(&s3c_pm_ops);
227	return 0;
228}
229