xref: /openbmc/linux/arch/sh/kernel/cpu/shmobile/pm.c (revision be709d48)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * arch/sh/kernel/cpu/shmobile/pm.c
4  *
5  * Power management support code for SuperH Mobile
6  *
7  *  Copyright (C) 2009 Magnus Damm
8  */
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/io.h>
12 #include <linux/suspend.h>
13 #include <asm/suspend.h>
14 #include <linux/uaccess.h>
15 #include <asm/cacheflush.h>
16 #include <asm/bl_bit.h>
17 
18 /*
19  * Notifier lists for pre/post sleep notification
20  */
21 ATOMIC_NOTIFIER_HEAD(sh_mobile_pre_sleep_notifier_list);
22 ATOMIC_NOTIFIER_HEAD(sh_mobile_post_sleep_notifier_list);
23 
24 /*
25  * Sleep modes available on SuperH Mobile:
26  *
27  * Sleep mode is just plain "sleep" instruction
28  * Sleep Self-Refresh mode is above plus RAM put in Self-Refresh
29  * Standby Self-Refresh mode is above plus stopped clocks
30  */
31 #define SUSP_MODE_SLEEP		(SUSP_SH_SLEEP)
32 #define SUSP_MODE_SLEEP_SF	(SUSP_SH_SLEEP | SUSP_SH_SF)
33 #define SUSP_MODE_STANDBY_SF	(SUSP_SH_STANDBY | SUSP_SH_SF)
34 #define SUSP_MODE_RSTANDBY_SF \
35 	(SUSP_SH_RSTANDBY | SUSP_SH_MMU | SUSP_SH_REGS | SUSP_SH_SF)
36  /*
37   * U-standby mode is unsupported since it needs bootloader hacks
38   */
39 
40 #ifdef CONFIG_CPU_SUBTYPE_SH7724
41 #define RAM_BASE 0xfd800000 /* RSMEM */
42 #else
43 #define RAM_BASE 0xe5200000 /* ILRAM */
44 #endif
45 
46 void sh_mobile_call_standby(unsigned long mode)
47 {
48 	void *onchip_mem = (void *)RAM_BASE;
49 	struct sh_sleep_data *sdp = onchip_mem;
50 	void (*standby_onchip_mem)(unsigned long, unsigned long);
51 
52 	/* code located directly after data structure */
53 	standby_onchip_mem = (void *)(sdp + 1);
54 
55 	atomic_notifier_call_chain(&sh_mobile_pre_sleep_notifier_list,
56 				   mode, NULL);
57 
58 	/* flush the caches if MMU flag is set */
59 	if (mode & SUSP_SH_MMU)
60 		flush_cache_all();
61 
62 	/* Let assembly snippet in on-chip memory handle the rest */
63 	standby_onchip_mem(mode, RAM_BASE);
64 
65 	atomic_notifier_call_chain(&sh_mobile_post_sleep_notifier_list,
66 				   mode, NULL);
67 }
68 
69 extern char sh_mobile_sleep_enter_start;
70 extern char sh_mobile_sleep_enter_end;
71 
72 extern char sh_mobile_sleep_resume_start;
73 extern char sh_mobile_sleep_resume_end;
74 
75 unsigned long sh_mobile_sleep_supported = SUSP_SH_SLEEP;
76 
77 void sh_mobile_register_self_refresh(unsigned long flags,
78 				     void *pre_start, void *pre_end,
79 				     void *post_start, void *post_end)
80 {
81 	void *onchip_mem = (void *)RAM_BASE;
82 	void *vp;
83 	struct sh_sleep_data *sdp;
84 	int n;
85 
86 	/* part 0: data area */
87 	sdp = onchip_mem;
88 	sdp->addr.stbcr = 0xa4150020; /* STBCR */
89 	sdp->addr.bar = 0xa4150040; /* BAR */
90 	sdp->addr.pteh = 0xff000000; /* PTEH */
91 	sdp->addr.ptel = 0xff000004; /* PTEL */
92 	sdp->addr.ttb = 0xff000008; /* TTB */
93 	sdp->addr.tea = 0xff00000c; /* TEA */
94 	sdp->addr.mmucr = 0xff000010; /* MMUCR */
95 	sdp->addr.ptea = 0xff000034; /* PTEA */
96 	sdp->addr.pascr = 0xff000070; /* PASCR */
97 	sdp->addr.irmcr = 0xff000078; /* IRMCR */
98 	sdp->addr.ccr = 0xff00001c; /* CCR */
99 	sdp->addr.ramcr = 0xff000074; /* RAMCR */
100 	vp = sdp + 1;
101 
102 	/* part 1: common code to enter sleep mode */
103 	n = &sh_mobile_sleep_enter_end - &sh_mobile_sleep_enter_start;
104 	memcpy(vp, &sh_mobile_sleep_enter_start, n);
105 	vp += roundup(n, 4);
106 
107 	/* part 2: board specific code to enter self-refresh mode */
108 	n = pre_end - pre_start;
109 	memcpy(vp, pre_start, n);
110 	sdp->sf_pre = (unsigned long)vp;
111 	vp += roundup(n, 4);
112 
113 	/* part 3: board specific code to resume from self-refresh mode */
114 	n = post_end - post_start;
115 	memcpy(vp, post_start, n);
116 	sdp->sf_post = (unsigned long)vp;
117 	vp += roundup(n, 4);
118 
119 	/* part 4: common code to resume from sleep mode */
120 	WARN_ON(vp > (onchip_mem + 0x600));
121 	vp = onchip_mem + 0x600; /* located at interrupt vector */
122 	n = &sh_mobile_sleep_resume_end - &sh_mobile_sleep_resume_start;
123 	memcpy(vp, &sh_mobile_sleep_resume_start, n);
124 	sdp->resume = (unsigned long)vp;
125 
126 	sh_mobile_sleep_supported |= flags;
127 }
128 
129 static int sh_pm_enter(suspend_state_t state)
130 {
131 	if (!(sh_mobile_sleep_supported & SUSP_MODE_STANDBY_SF))
132 		return -ENXIO;
133 
134 	local_irq_disable();
135 	set_bl_bit();
136 	sh_mobile_call_standby(SUSP_MODE_STANDBY_SF);
137 	local_irq_disable();
138 	clear_bl_bit();
139 	return 0;
140 }
141 
142 static const struct platform_suspend_ops sh_pm_ops = {
143 	.enter          = sh_pm_enter,
144 	.valid          = suspend_valid_only_mem,
145 };
146 
147 static int __init sh_pm_init(void)
148 {
149 	suspend_set_ops(&sh_pm_ops);
150 	return sh_mobile_setup_cpuidle();
151 }
152 
153 late_initcall(sh_pm_init);
154