xref: /openbmc/linux/arch/arm/mach-s3c/pm.c (revision 236bdb88)
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 
34 unsigned 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 
39 unsigned long s3c_irqwake_intmask	= 0xffffffffL;
40 unsigned long s3c_irqwake_eintmask	= 0xffffffffL;
41 
42 int 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 
60 void (*pm_cpu_prep)(void);
61 int (*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 
70 static 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 
163 static int s3c_pm_prepare(void)
164 {
165 	/* prepare check area if configured */
166 
167 	s3c_pm_check_prepare();
168 	return 0;
169 }
170 
171 static void s3c_pm_finish(void)
172 {
173 	s3c_pm_check_cleanup();
174 }
175 
176 static 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 
190 int __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 }
197