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 <mach/map.h>
22 #include <mach/regs-clock.h>
23 #include <mach/regs-irq.h>
24 #include <mach/irqs.h>
25
26 #include <asm/irq.h>
27
28 #include <plat/pm.h>
29 #include <mach/pm-core.h>
30
31 /* for external use */
32
33 unsigned long s3c_pm_flags;
34
35 /* The IRQ ext-int code goes here, it is too small to currently bother
36 * with its own file. */
37
38 unsigned long s3c_irqwake_intmask = 0xffffffffL;
39 unsigned long s3c_irqwake_eintmask = 0xffffffffL;
40
s3c_irqext_wake(struct irq_data * data,unsigned int state)41 int s3c_irqext_wake(struct irq_data *data, unsigned int state)
42 {
43 unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
44
45 if (!(s3c_irqwake_eintallow & bit))
46 return -ENOENT;
47
48 printk(KERN_INFO "wake %s for irq %d\n",
49 state ? "enabled" : "disabled", data->irq);
50
51 if (!state)
52 s3c_irqwake_eintmask |= bit;
53 else
54 s3c_irqwake_eintmask &= ~bit;
55
56 return 0;
57 }
58
59 void (*pm_cpu_prep)(void);
60 int (*pm_cpu_sleep)(unsigned long);
61
62 #define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
63
64 /* s3c_pm_enter
65 *
66 * central control for sleep/resume process
67 */
68
s3c_pm_enter(suspend_state_t state)69 static int s3c_pm_enter(suspend_state_t state)
70 {
71 int ret;
72 /* ensure the debug is initialised (if enabled) */
73
74 s3c_pm_debug_init();
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();
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();
141
142 if (!of_have_populated_dt()) {
143 samsung_pm_restore_gpios();
144 s3c_pm_restored_gpios();
145 }
146
147 s3c_pm_debug_init();
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 /* LEDs should now be 1110 */
156 s3c_pm_debug_smdkled(1 << 1, 0);
157
158 s3c_pm_check_restore();
159
160 /* ok, let's return from sleep */
161
162 S3C_PMDBG("S3C PM Resume (post-restore)\n");
163 return 0;
164 }
165
s3c_pm_prepare(void)166 static int s3c_pm_prepare(void)
167 {
168 /* prepare check area if configured */
169
170 s3c_pm_check_prepare();
171 return 0;
172 }
173
s3c_pm_finish(void)174 static void s3c_pm_finish(void)
175 {
176 s3c_pm_check_cleanup();
177 }
178
179 static const struct platform_suspend_ops s3c_pm_ops = {
180 .enter = s3c_pm_enter,
181 .prepare = s3c_pm_prepare,
182 .finish = s3c_pm_finish,
183 .valid = suspend_valid_only_mem,
184 };
185
186 /* s3c_pm_init
187 *
188 * Attach the power management functions. This should be called
189 * from the board specific initialisation if the board supports
190 * it.
191 */
192
s3c_pm_init(void)193 int __init s3c_pm_init(void)
194 {
195 printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
196
197 suspend_set_ops(&s3c_pm_ops);
198 return 0;
199 }
200