1 /*
2  * SMP support for R-Mobile / SH-Mobile - r8a7779 portion
3  *
4  * Copyright (C) 2011  Renesas Solutions Corp.
5  * Copyright (C) 2011  Magnus Damm
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 <mach/r8a7779.h>
28 #include <asm/cacheflush.h>
29 #include <asm/smp_plat.h>
30 #include <asm/smp_scu.h>
31 #include <asm/smp_twd.h>
32 
33 #define AVECR IOMEM(0xfe700040)
34 #define R8A7779_SCU_BASE 0xf0000000
35 
36 static struct r8a7779_pm_ch r8a7779_ch_cpu1 = {
37 	.chan_offs = 0x40, /* PWRSR0 .. PWRER0 */
38 	.chan_bit = 1, /* ARM1 */
39 	.isr_bit = 1, /* ARM1 */
40 };
41 
42 static struct r8a7779_pm_ch r8a7779_ch_cpu2 = {
43 	.chan_offs = 0x40, /* PWRSR0 .. PWRER0 */
44 	.chan_bit = 2, /* ARM2 */
45 	.isr_bit = 2, /* ARM2 */
46 };
47 
48 static struct r8a7779_pm_ch r8a7779_ch_cpu3 = {
49 	.chan_offs = 0x40, /* PWRSR0 .. PWRER0 */
50 	.chan_bit = 3, /* ARM3 */
51 	.isr_bit = 3, /* ARM3 */
52 };
53 
54 static struct r8a7779_pm_ch *r8a7779_ch_cpu[4] = {
55 	[1] = &r8a7779_ch_cpu1,
56 	[2] = &r8a7779_ch_cpu2,
57 	[3] = &r8a7779_ch_cpu3,
58 };
59 
60 #ifdef CONFIG_HAVE_ARM_TWD
61 static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, R8A7779_SCU_BASE + 0x600, 29);
62 void __init r8a7779_register_twd(void)
63 {
64 	twd_local_timer_register(&twd_local_timer);
65 }
66 #endif
67 
68 static int r8a7779_platform_cpu_kill(unsigned int cpu)
69 {
70 	struct r8a7779_pm_ch *ch = NULL;
71 	int ret = -EIO;
72 
73 	cpu = cpu_logical_map(cpu);
74 
75 	if (cpu < ARRAY_SIZE(r8a7779_ch_cpu))
76 		ch = r8a7779_ch_cpu[cpu];
77 
78 	if (ch)
79 		ret = r8a7779_sysc_power_down(ch);
80 
81 	return ret ? ret : 1;
82 }
83 
84 static int r8a7779_boot_secondary(unsigned int cpu, struct task_struct *idle)
85 {
86 	struct r8a7779_pm_ch *ch = NULL;
87 	unsigned int lcpu = cpu_logical_map(cpu);
88 	int ret;
89 
90 	if (lcpu < ARRAY_SIZE(r8a7779_ch_cpu))
91 		ch = r8a7779_ch_cpu[lcpu];
92 
93 	if (ch)
94 		ret = r8a7779_sysc_power_up(ch);
95 	else
96 		ret = -EIO;
97 
98 	return ret;
99 }
100 
101 static void __init r8a7779_smp_prepare_cpus(unsigned int max_cpus)
102 {
103 	/* Map the reset vector (in headsmp-scu.S, headsmp.S) */
104 	__raw_writel(__pa(shmobile_boot_vector), AVECR);
105 	shmobile_boot_fn = virt_to_phys(shmobile_boot_scu);
106 	shmobile_boot_arg = (unsigned long)shmobile_scu_base;
107 
108 	/* setup r8a7779 specific SCU bits */
109 	shmobile_scu_base = IOMEM(R8A7779_SCU_BASE);
110 	shmobile_smp_scu_prepare_cpus(max_cpus);
111 
112 	r8a7779_pm_init();
113 
114 	/* power off secondary CPUs */
115 	r8a7779_platform_cpu_kill(1);
116 	r8a7779_platform_cpu_kill(2);
117 	r8a7779_platform_cpu_kill(3);
118 }
119 
120 #ifdef CONFIG_HOTPLUG_CPU
121 static int r8a7779_cpu_kill(unsigned int cpu)
122 {
123 	if (shmobile_smp_scu_cpu_kill(cpu))
124 		return r8a7779_platform_cpu_kill(cpu);
125 
126 	return 0;
127 }
128 
129 static int r8a7779_cpu_disable(unsigned int cpu)
130 {
131 	/* only CPU1->3 have power domains, do not allow hotplug of CPU0 */
132 	return cpu == 0 ? -EPERM : 0;
133 }
134 #endif /* CONFIG_HOTPLUG_CPU */
135 
136 struct smp_operations r8a7779_smp_ops  __initdata = {
137 	.smp_prepare_cpus	= r8a7779_smp_prepare_cpus,
138 	.smp_boot_secondary	= r8a7779_boot_secondary,
139 #ifdef CONFIG_HOTPLUG_CPU
140 	.cpu_disable		= r8a7779_cpu_disable,
141 	.cpu_die		= shmobile_smp_scu_cpu_die,
142 	.cpu_kill		= r8a7779_cpu_kill,
143 #endif
144 };
145