1// SPDX-License-Identifier: GPL-2.0
  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#include <linux/init.h>
 11#include <linux/suspend.h>
 12#include <linux/errno.h>
 13#include <linux/delay.h>
 14#include <linux/of.h>
 15#include <linux/serial_s3c.h>
 16#include <linux/io.h>
 17
 18#include <asm/cacheflush.h>
 19#include <asm/suspend.h>
 20
 21#include "map.h"
 22#include "regs-clock.h"
 23#include "regs-irq.h"
 24#include "irqs.h"
 25
 26#include <asm/irq.h>
 27
 28#include "cpu.h"
 29#include "pm.h"
 30#include "pm-core.h"
 31
 32/* for external use */
 33
 34unsigned long s3c_pm_flags;
 35
 36/* The IRQ ext-int code goes here, it is too small to currently bother
 37 * with its own file. */
 38
 39unsigned long s3c_irqwake_intmask	= 0xffffffffL;
 40unsigned long s3c_irqwake_eintmask	= 0xffffffffL;
 41
 42int s3c_irqext_wake(struct irq_data *data, unsigned int state)
 43{
 44	unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
 45
 46	if (!(s3c_irqwake_eintallow & bit))
 47		return -ENOENT;
 48
 49	printk(KERN_INFO "wake %s for irq %d\n",
 50	       state ? "enabled" : "disabled", data->irq);
 51
 52	if (!state)
 53		s3c_irqwake_eintmask |= bit;
 54	else
 55		s3c_irqwake_eintmask &= ~bit;
 56
 57	return 0;
 58}
 59
 60void (*pm_cpu_prep)(void);
 61int (*pm_cpu_sleep)(unsigned long);
 62
 63#define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
 64
 65/* s3c_pm_enter
 66 *
 67 * central control for sleep/resume process
 68*/
 69
 70static int s3c_pm_enter(suspend_state_t state)
 71{
 72	int ret;
 73	/* ensure the debug is initialised (if enabled) */
 74	s3c_pm_debug_init_uart();
 75
 76	S3C_PMDBG("%s(%d)\n", __func__, state);
 77
 78	if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
 79		printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
 80		return -EINVAL;
 81	}
 82
 83	/* check if we have anything to wake-up with... bad things seem
 84	 * to happen if you suspend with no wakeup (system will often
 85	 * require a full power-cycle)
 86	*/
 87
 88	if (!of_have_populated_dt() &&
 89	    !any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
 90	    !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
 91		printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
 92		printk(KERN_ERR "%s: Aborting sleep\n", __func__);
 93		return -EINVAL;
 94	}
 95
 96	/* save all necessary core registers not covered by the drivers */
 97
 98	if (!of_have_populated_dt()) {
 99		samsung_pm_save_gpios();
100		samsung_pm_saved_gpios();
101	}
102
103	s3c_pm_save_uarts(false);
104	s3c_pm_save_core();
105
106	/* set the irq configuration for wake */
107
108	s3c_pm_configure_extint();
109
110	S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
111	    s3c_irqwake_intmask, s3c_irqwake_eintmask);
112
113	s3c_pm_arch_prepare_irqs();
114
115	/* call cpu specific preparation */
116
117	pm_cpu_prep();
118
119	/* flush cache back to ram */
120
121	flush_cache_all();
122
123	s3c_pm_check_store();
124
125	/* send the cpu to sleep... */
126
127	s3c_pm_arch_stop_clocks();
128
129	/* this will also act as our return point from when
130	 * we resume as it saves its own register state and restores it
131	 * during the resume.  */
132
133	ret = cpu_suspend(0, pm_cpu_sleep);
134	if (ret)
135		return ret;
136
137	/* restore the system state */
138
139	s3c_pm_restore_core();
140	s3c_pm_restore_uarts(false);
141
142	if (!of_have_populated_dt()) {
143		samsung_pm_restore_gpios();
144		s3c_pm_restored_gpios();
145	}
146
147	s3c_pm_debug_init_uart();
148
149	/* check what irq (if any) restored the system */
150
151	s3c_pm_arch_show_resume_irqs();
152
153	S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
154
155	s3c_pm_check_restore();
156
157	/* ok, let's return from sleep */
158
159	S3C_PMDBG("S3C PM Resume (post-restore)\n");
160	return 0;
161}
162
163static int s3c_pm_prepare(void)
164{
165	/* prepare check area if configured */
166
167	s3c_pm_check_prepare();
168	return 0;
169}
170
171static void s3c_pm_finish(void)
172{
173	s3c_pm_check_cleanup();
174}
175
176static const struct platform_suspend_ops s3c_pm_ops = {
177	.enter		= s3c_pm_enter,
178	.prepare	= s3c_pm_prepare,
179	.finish		= s3c_pm_finish,
180	.valid		= suspend_valid_only_mem,
181};
182
183/* s3c_pm_init
184 *
185 * Attach the power management functions. This should be called
186 * from the board specific initialisation if the board supports
187 * it.
188*/
189
190int __init s3c_pm_init(void)
191{
192	printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
193
194	suspend_set_ops(&s3c_pm_ops);
195	return 0;
196}