1 /*
2  * SMP support for R-Mobile / SH-Mobile - sh73a0 portion
3  *
4  * Copyright (C) 2010  Magnus Damm
5  * Copyright (C) 2010  Takashi Yoshii
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; version 2 of the License.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19  */
20 #include <linux/kernel.h>
21 #include <linux/init.h>
22 #include <linux/smp.h>
23 #include <linux/spinlock.h>
24 #include <linux/io.h>
25 #include <linux/delay.h>
26 #include <mach/common.h>
27 #include <asm/cacheflush.h>
28 #include <asm/smp_plat.h>
29 #include <mach/sh73a0.h>
30 #include <asm/smp_scu.h>
31 #include <asm/smp_twd.h>
32 
33 #define WUPCR		IOMEM(0xe6151010)
34 #define SRESCR		IOMEM(0xe6151018)
35 #define PSTR		IOMEM(0xe6151040)
36 #define SBAR		IOMEM(0xe6180020)
37 #define APARMBAREA	IOMEM(0xe6f10020)
38 
39 #define PSTR_SHUTDOWN_MODE	3
40 
41 #define SH73A0_SCU_BASE 0xf0000000
42 
43 #ifdef CONFIG_HAVE_ARM_TWD
44 static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, SH73A0_SCU_BASE + 0x600, 29);
45 void __init sh73a0_register_twd(void)
46 {
47 	twd_local_timer_register(&twd_local_timer);
48 }
49 #endif
50 
51 static int sh73a0_boot_secondary(unsigned int cpu, struct task_struct *idle)
52 {
53 	cpu = cpu_logical_map(cpu);
54 
55 	if (((__raw_readl(PSTR) >> (4 * cpu)) & 3) == 3)
56 		__raw_writel(1 << cpu, WUPCR);	/* wake up */
57 	else
58 		__raw_writel(1 << cpu, SRESCR);	/* reset */
59 
60 	return 0;
61 }
62 
63 static void __init sh73a0_smp_prepare_cpus(unsigned int max_cpus)
64 {
65 	scu_enable(shmobile_scu_base);
66 
67 	/* Map the reset vector (in headsmp-scu.S, headsmp.S) */
68 	__raw_writel(0, APARMBAREA);      /* 4k */
69 	__raw_writel(__pa(shmobile_boot_vector), SBAR);
70 	shmobile_boot_fn = virt_to_phys(shmobile_boot_scu);
71 	shmobile_boot_arg = (unsigned long)shmobile_scu_base;
72 
73 	/* enable cache coherency on booting CPU */
74 	scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL);
75 }
76 
77 static void __init sh73a0_smp_init_cpus(void)
78 {
79 	/* setup sh73a0 specific SCU base */
80 	shmobile_scu_base = IOMEM(SH73A0_SCU_BASE);
81 
82 	shmobile_smp_init_cpus(scu_get_core_count(shmobile_scu_base));
83 }
84 
85 #ifdef CONFIG_HOTPLUG_CPU
86 static int sh73a0_cpu_kill(unsigned int cpu)
87 {
88 
89 	int k;
90 	u32 pstr;
91 
92 	/*
93 	 * wait until the power status register confirms the shutdown of the
94 	 * offline target
95 	 */
96 	for (k = 0; k < 1000; k++) {
97 		pstr = (__raw_readl(PSTR) >> (4 * cpu)) & 3;
98 		if (pstr == PSTR_SHUTDOWN_MODE)
99 			return 1;
100 
101 		mdelay(1);
102 	}
103 
104 	return 0;
105 }
106 
107 static void sh73a0_cpu_die(unsigned int cpu)
108 {
109 	/* Set power off mode. This takes the CPU out of the MP cluster */
110 	scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF);
111 
112 	/* Enter shutdown mode */
113 	cpu_do_idle();
114 }
115 
116 static int sh73a0_cpu_disable(unsigned int cpu)
117 {
118 	return 0; /* CPU0 and CPU1 supported */
119 }
120 #endif /* CONFIG_HOTPLUG_CPU */
121 
122 struct smp_operations sh73a0_smp_ops __initdata = {
123 	.smp_init_cpus		= sh73a0_smp_init_cpus,
124 	.smp_prepare_cpus	= sh73a0_smp_prepare_cpus,
125 	.smp_boot_secondary	= sh73a0_boot_secondary,
126 #ifdef CONFIG_HOTPLUG_CPU
127 	.cpu_kill		= sh73a0_cpu_kill,
128 	.cpu_die		= sh73a0_cpu_die,
129 	.cpu_disable		= sh73a0_cpu_disable,
130 #endif
131 };
132