diff options
author | Viresh Kumar <viresh.kumar@st.com> | 2012-04-19 12:53:13 -0400 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2012-05-14 11:34:05 -0400 |
commit | e3978dc7dfcb9e7b022bda775929943b43bdefd8 (patch) | |
tree | c37d37291c0b7df7c3207d2e042d2f1253af2afd /arch/arm/mach-spear13xx/hotplug.c | |
parent | b31e23726bb9d6cd8848fc539b23330769830110 (diff) |
SPEAr13xx: Add source files
This patch adds source files for SPEAr13xx Machines.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Deepak Sikri <deepak.sikri@st.com>
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
Diffstat (limited to 'arch/arm/mach-spear13xx/hotplug.c')
-rw-r--r-- | arch/arm/mach-spear13xx/hotplug.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/arch/arm/mach-spear13xx/hotplug.c b/arch/arm/mach-spear13xx/hotplug.c new file mode 100644 index 000000000000..5c6867b46d09 --- /dev/null +++ b/arch/arm/mach-spear13xx/hotplug.c | |||
@@ -0,0 +1,119 @@ | |||
1 | /* | ||
2 | * linux/arch/arm/mach-spear13xx/hotplug.c | ||
3 | * | ||
4 | * Copyright (C) 2012 ST Microelectronics Ltd. | ||
5 | * Deepak Sikri <deepak.sikri@st.com> | ||
6 | * | ||
7 | * based upon linux/arch/arm/mach-realview/hotplug.c | ||
8 | * | ||
9 | * This program is free software; you can redistribute it and/or modify | ||
10 | * it under the terms of the GNU General Public License version 2 as | ||
11 | * published by the Free Software Foundation. | ||
12 | */ | ||
13 | #include <linux/kernel.h> | ||
14 | #include <linux/errno.h> | ||
15 | #include <linux/smp.h> | ||
16 | #include <asm/cacheflush.h> | ||
17 | #include <asm/cp15.h> | ||
18 | #include <asm/smp_plat.h> | ||
19 | |||
20 | extern volatile int pen_release; | ||
21 | |||
22 | static inline void cpu_enter_lowpower(void) | ||
23 | { | ||
24 | unsigned int v; | ||
25 | |||
26 | flush_cache_all(); | ||
27 | asm volatile( | ||
28 | " mcr p15, 0, %1, c7, c5, 0\n" | ||
29 | " dsb\n" | ||
30 | /* | ||
31 | * Turn off coherency | ||
32 | */ | ||
33 | " mrc p15, 0, %0, c1, c0, 1\n" | ||
34 | " bic %0, %0, #0x20\n" | ||
35 | " mcr p15, 0, %0, c1, c0, 1\n" | ||
36 | " mrc p15, 0, %0, c1, c0, 0\n" | ||
37 | " bic %0, %0, %2\n" | ||
38 | " mcr p15, 0, %0, c1, c0, 0\n" | ||
39 | : "=&r" (v) | ||
40 | : "r" (0), "Ir" (CR_C) | ||
41 | : "cc", "memory"); | ||
42 | } | ||
43 | |||
44 | static inline void cpu_leave_lowpower(void) | ||
45 | { | ||
46 | unsigned int v; | ||
47 | |||
48 | asm volatile("mrc p15, 0, %0, c1, c0, 0\n" | ||
49 | " orr %0, %0, %1\n" | ||
50 | " mcr p15, 0, %0, c1, c0, 0\n" | ||
51 | " mrc p15, 0, %0, c1, c0, 1\n" | ||
52 | " orr %0, %0, #0x20\n" | ||
53 | " mcr p15, 0, %0, c1, c0, 1\n" | ||
54 | : "=&r" (v) | ||
55 | : "Ir" (CR_C) | ||
56 | : "cc"); | ||
57 | } | ||
58 | |||
59 | static inline void platform_do_lowpower(unsigned int cpu, int *spurious) | ||
60 | { | ||
61 | for (;;) { | ||
62 | wfi(); | ||
63 | |||
64 | if (pen_release == cpu) { | ||
65 | /* | ||
66 | * OK, proper wakeup, we're done | ||
67 | */ | ||
68 | break; | ||
69 | } | ||
70 | |||
71 | /* | ||
72 | * Getting here, means that we have come out of WFI without | ||
73 | * having been woken up - this shouldn't happen | ||
74 | * | ||
75 | * Just note it happening - when we're woken, we can report | ||
76 | * its occurrence. | ||
77 | */ | ||
78 | (*spurious)++; | ||
79 | } | ||
80 | } | ||
81 | |||
82 | int platform_cpu_kill(unsigned int cpu) | ||
83 | { | ||
84 | return 1; | ||
85 | } | ||
86 | |||
87 | /* | ||
88 | * platform-specific code to shutdown a CPU | ||
89 | * | ||
90 | * Called with IRQs disabled | ||
91 | */ | ||
92 | void __cpuinit platform_cpu_die(unsigned int cpu) | ||
93 | { | ||
94 | int spurious = 0; | ||
95 | |||
96 | /* | ||
97 | * we're ready for shutdown now, so do it | ||
98 | */ | ||
99 | cpu_enter_lowpower(); | ||
100 | platform_do_lowpower(cpu, &spurious); | ||
101 | |||
102 | /* | ||
103 | * bring this CPU back into the world of cache | ||
104 | * coherency, and then restore interrupts | ||
105 | */ | ||
106 | cpu_leave_lowpower(); | ||
107 | |||
108 | if (spurious) | ||
109 | pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious); | ||
110 | } | ||
111 | |||
112 | int platform_cpu_disable(unsigned int cpu) | ||
113 | { | ||
114 | /* | ||
115 | * we don't allow CPU 0 to be shutdown (it is still too special | ||
116 | * e.g. clock tick interrupts) | ||
117 | */ | ||
118 | return cpu == 0 ? -EPERM : 0; | ||
119 | } | ||