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authorArnd Bergmann <arnd@arndb.de>2012-05-14 17:59:18 +0400
committerArnd Bergmann <arnd@arndb.de>2012-05-14 19:35:50 +0400
commit090a80cba39f2763a488b6f7c65e38922d5aa17a (patch)
treeba3797eeca74c42be95bc592ed2db1be99e329d2 /arch/arm/mach-spear13xx/hotplug.c
parent36be50515fe2aef61533b516fa2576a2c7fe7664 (diff)
parenteb3f995d7e73fd78b8fcdc55cfbf01a74a09a6e8 (diff)
downloadlinux-090a80cba39f2763a488b6f7c65e38922d5aa17a.tar.xz
Merge branch 'spear/13xx' into next/soc2
* spear/13xx: pinctrl: SPEAr1310: Fix pin numbers for clcd_high_res SPEAr: Update MAINTAINERS and Documentation SPEAr13xx: Add defconfig SPEAr13xx: Add compilation support SPEAr13xx: Add dts and dtsi files pinctrl: Add SPEAr13xx pinctrl drivers pinctrl: SPEAr: Create macro for declaring GPIO PINS SPEAr13xx: Add common clock framework support SPEAr13xx: Add source files SPEAr13xx: Add header files Depends on clock, pinctrl and dt branches to go first. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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 @@
+/*
+ * linux/arch/arm/mach-spear13xx/hotplug.c
+ *
+ * Copyright (C) 2012 ST Microelectronics Ltd.
+ * Deepak Sikri <deepak.sikri@st.com>
+ *
+ * based upon linux/arch/arm/mach-realview/hotplug.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/smp.h>
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/smp_plat.h>
+
+extern volatile int pen_release;
+
+static inline void cpu_enter_lowpower(void)
+{
+ unsigned int v;
+
+ flush_cache_all();
+ asm volatile(
+ " mcr p15, 0, %1, c7, c5, 0\n"
+ " dsb\n"
+ /*
+ * Turn off coherency
+ */
+ " mrc p15, 0, %0, c1, c0, 1\n"
+ " bic %0, %0, #0x20\n"
+ " mcr p15, 0, %0, c1, c0, 1\n"
+ " mrc p15, 0, %0, c1, c0, 0\n"
+ " bic %0, %0, %2\n"
+ " mcr p15, 0, %0, c1, c0, 0\n"
+ : "=&r" (v)
+ : "r" (0), "Ir" (CR_C)
+ : "cc", "memory");
+}
+
+static inline void cpu_leave_lowpower(void)
+{
+ unsigned int v;
+
+ asm volatile("mrc p15, 0, %0, c1, c0, 0\n"
+ " orr %0, %0, %1\n"
+ " mcr p15, 0, %0, c1, c0, 0\n"
+ " mrc p15, 0, %0, c1, c0, 1\n"
+ " orr %0, %0, #0x20\n"
+ " mcr p15, 0, %0, c1, c0, 1\n"
+ : "=&r" (v)
+ : "Ir" (CR_C)
+ : "cc");
+}
+
+static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
+{
+ for (;;) {
+ wfi();
+
+ if (pen_release == cpu) {
+ /*
+ * OK, proper wakeup, we're done
+ */
+ break;
+ }
+
+ /*
+ * Getting here, means that we have come out of WFI without
+ * having been woken up - this shouldn't happen
+ *
+ * Just note it happening - when we're woken, we can report
+ * its occurrence.
+ */
+ (*spurious)++;
+ }
+}
+
+int platform_cpu_kill(unsigned int cpu)
+{
+ return 1;
+}
+
+/*
+ * platform-specific code to shutdown a CPU
+ *
+ * Called with IRQs disabled
+ */
+void __cpuinit platform_cpu_die(unsigned int cpu)
+{
+ int spurious = 0;
+
+ /*
+ * we're ready for shutdown now, so do it
+ */
+ cpu_enter_lowpower();
+ platform_do_lowpower(cpu, &spurious);
+
+ /*
+ * bring this CPU back into the world of cache
+ * coherency, and then restore interrupts
+ */
+ cpu_leave_lowpower();
+
+ if (spurious)
+ pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
+}
+
+int platform_cpu_disable(unsigned int cpu)
+{
+ /*
+ * we don't allow CPU 0 to be shutdown (it is still too special
+ * e.g. clock tick interrupts)
+ */
+ return cpu == 0 ? -EPERM : 0;
+}