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authorViresh Kumar <viresh.kumar@st.com>2012-04-19 12:53:13 -0400
committerArnd Bergmann <arnd@arndb.de>2012-05-14 11:34:05 -0400
commite3978dc7dfcb9e7b022bda775929943b43bdefd8 (patch)
treec37d37291c0b7df7c3207d2e042d2f1253af2afd /arch/arm/mach-spear13xx/hotplug.c
parentb31e23726bb9d6cd8848fc539b23330769830110 (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.c119
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
20extern volatile int pen_release;
21
22static 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
44static 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
59static 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
82int 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 */
92void __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
112int 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}