xref: /linux/arch/sh/kernel/cpu/shmobile/pm.c (revision bcefe12eff5dca6fdfa94ed85e5bee66380d5cd9)
1 /*
2  * arch/sh/kernel/cpu/shmobile/pm.c
3  *
4  * Power management support code for SuperH Mobile
5  *
6  *  Copyright (C) 2009 Magnus Damm
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file "COPYING" in the main directory of this archive
10  * for more details.
11  */
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/io.h>
15 #include <linux/suspend.h>
16 #include <asm/suspend.h>
17 #include <asm/uaccess.h>
18 
19 /*
20  * Sleep modes available on SuperH Mobile:
21  *
22  * Sleep mode is just plain "sleep" instruction
23  * Sleep Self-Refresh mode is above plus RAM put in Self-Refresh
24  * Standby Self-Refresh mode is above plus stopped clocks
25  */
26 #define SUSP_MODE_SLEEP		(SUSP_SH_SLEEP)
27 #define SUSP_MODE_SLEEP_SF	(SUSP_SH_SLEEP | SUSP_SH_SF)
28 #define SUSP_MODE_STANDBY_SF	(SUSP_SH_STANDBY | SUSP_SH_SF)
29 
30 /*
31  * The following modes are not there yet:
32  *
33  * R-standby mode is unsupported, but will be added in the future
34  * U-standby mode is low priority since it needs bootloader hacks
35  */
36 
37 #define ILRAM_BASE 0xe5200000
38 
39 extern const unsigned char sh_mobile_standby[];
40 extern const unsigned int sh_mobile_standby_size;
41 
42 void sh_mobile_call_standby(unsigned long mode)
43 {
44 	void *onchip_mem = (void *)ILRAM_BASE;
45 	void (*standby_onchip_mem)(unsigned long, unsigned long) = onchip_mem;
46 
47 	/* Let assembly snippet in on-chip memory handle the rest */
48 	standby_onchip_mem(mode, ILRAM_BASE);
49 }
50 
51 static int sh_pm_enter(suspend_state_t state)
52 {
53 	local_irq_disable();
54 	set_bl_bit();
55 	sh_mobile_call_standby(SUSP_MODE_STANDBY_SF);
56 	local_irq_disable();
57 	clear_bl_bit();
58 	return 0;
59 }
60 
61 static struct platform_suspend_ops sh_pm_ops = {
62 	.enter          = sh_pm_enter,
63 	.valid          = suspend_valid_only_mem,
64 };
65 
66 static int __init sh_pm_init(void)
67 {
68 	void *onchip_mem = (void *)ILRAM_BASE;
69 
70 	/* Copy the assembly snippet to the otherwise ununsed ILRAM */
71 	memcpy(onchip_mem, sh_mobile_standby, sh_mobile_standby_size);
72 	wmb();
73 	ctrl_barrier();
74 
75 	suspend_set_ops(&sh_pm_ops);
76 	sh_mobile_setup_cpuidle();
77 	return 0;
78 }
79 
80 late_initcall(sh_pm_init);
81