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#include <mach/map.h>
 27#include <mach/regs-clock.h>
 28#include <mach/regs-irq.h>
 29#include <mach/irqs.h>
 30
 31#include <asm/irq.h>
 32
 33#include <plat/pm.h>
 34#include <mach/pm-core.h>
 35
 36/* for external use */
 37
 38unsigned long s3c_pm_flags;
 39
 40/* The IRQ ext-int code goes here, it is too small to currently bother
 41 * with its own file. */
 42
 43unsigned long s3c_irqwake_intmask	= 0xffffffffL;
 44unsigned long s3c_irqwake_eintmask	= 0xffffffffL;
 45
 46int s3c_irqext_wake(struct irq_data *data, unsigned int state)
 47{
 48	unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
 49
 50	if (!(s3c_irqwake_eintallow & bit))
 51		return -ENOENT;
 52
 53	printk(KERN_INFO "wake %s for irq %d\n",
 54	       state ? "enabled" : "disabled", data->irq);
 55
 56	if (!state)
 57		s3c_irqwake_eintmask |= bit;
 58	else
 59		s3c_irqwake_eintmask &= ~bit;
 60
 61	return 0;
 62}
 63
 64void (*pm_cpu_prep)(void);
 65int (*pm_cpu_sleep)(unsigned long);
 66
 67#define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
 68
 69/* s3c_pm_enter
 70 *
 71 * central control for sleep/resume process
 72*/
 73
 74static int s3c_pm_enter(suspend_state_t state)
 75{
 76	int ret;
 77	/* ensure the debug is initialised (if enabled) */
 78
 79	s3c_pm_debug_init();
 80
 81	S3C_PMDBG("%s(%d)\n", __func__, state);
 82
 83	if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
 84		printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
 85		return -EINVAL;
 86	}
 87
 88	/* check if we have anything to wake-up with... bad things seem
 89	 * to happen if you suspend with no wakeup (system will often
 90	 * require a full power-cycle)
 91	*/
 92
 93	if (!of_have_populated_dt() &&
 94	    !any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
 95	    !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
 96		printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
 97		printk(KERN_ERR "%s: Aborting sleep\n", __func__);
 98		return -EINVAL;
 99	}
100
101	/* save all necessary core registers not covered by the drivers */
102
103	if (!of_have_populated_dt()) {
104		samsung_pm_save_gpios();
105		samsung_pm_saved_gpios();
106	}
107
108	s3c_pm_save_uarts();
109	s3c_pm_save_core();
110
111	/* set the irq configuration for wake */
112
113	s3c_pm_configure_extint();
114
115	S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
116	    s3c_irqwake_intmask, s3c_irqwake_eintmask);
117
118	s3c_pm_arch_prepare_irqs();
119
120	/* call cpu specific preparation */
121
122	pm_cpu_prep();
123
124	/* flush cache back to ram */
125
126	flush_cache_all();
127
128	s3c_pm_check_store();
129
130	/* send the cpu to sleep... */
131
132	s3c_pm_arch_stop_clocks();
133
134	/* this will also act as our return point from when
135	 * we resume as it saves its own register state and restores it
136	 * during the resume.  */
137
138	ret = cpu_suspend(0, pm_cpu_sleep);
139	if (ret)
140		return ret;
141
142	/* restore the system state */
143
144	s3c_pm_restore_core();
145	s3c_pm_restore_uarts();
146
147	if (!of_have_populated_dt()) {
148		samsung_pm_restore_gpios();
149		s3c_pm_restored_gpios();
150	}
151
152	s3c_pm_debug_init();
153
154	/* check what irq (if any) restored the system */
155
156	s3c_pm_arch_show_resume_irqs();
157
158	S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
159
160	/* LEDs should now be 1110 */
161	s3c_pm_debug_smdkled(1 << 1, 0);
162
163	s3c_pm_check_restore();
164
165	/* ok, let's return from sleep */
166
167	S3C_PMDBG("S3C PM Resume (post-restore)\n");
168	return 0;
169}
170
171static int s3c_pm_prepare(void)
172{
173	/* prepare check area if configured */
174
175	s3c_pm_check_prepare();
176	return 0;
177}
178
179static void s3c_pm_finish(void)
180{
181	s3c_pm_check_cleanup();
182}
183
184static const struct platform_suspend_ops s3c_pm_ops = {
185	.enter		= s3c_pm_enter,
186	.prepare	= s3c_pm_prepare,
187	.finish		= s3c_pm_finish,
188	.valid		= suspend_valid_only_mem,
189};
190
191/* s3c_pm_init
192 *
193 * Attach the power management functions. This should be called
194 * from the board specific initialisation if the board supports
195 * it.
196*/
197
198int __init s3c_pm_init(void)
199{
200	printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
201
202	suspend_set_ops(&s3c_pm_ops);
203	return 0;
204}