summaryrefslogtreecommitdiff
path: root/arch/arm/mach-spear/hotplug.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2013-05-02 09:38:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-02 09:38:16 -0700
commit99c6bcf46d2233d33e441834e958ed0bc22b190a (patch)
tree25abf5e856bc0f08d75e623715eb5acc4d4de2b2 /arch/arm/mach-spear/hotplug.c
parent97b1007a2924aaa9126398623f6755a8c3c6a616 (diff)
parent2fdfe1c26fb9f24cfdf124384abb35396ca2cd3f (diff)
Merge tag 'multiplatform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC multiplatform updates from Olof Johansson: "More multiplatform enablement for ARM platforms. The ones converted in this branch are: - bcm2835 - cns3xxx - sirf - nomadik - msx - spear - tegra - ux500 We're getting close to having most of them converted! One of the larger platforms remaining is Samsung Exynos, and there are a bunch of supporting patches in this merge window for it. There was a patch in this branch to a early version of multiplatform conversion, but it ended up being reverted due to need of more bake time. The revert commit is part of the branch since it would have required rebasing multiple dependent branches and they were stable by then" * tag 'multiplatform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (70 commits) mmc: sdhci-s3c: Fix operation on non-single image Samsung platforms clocksource: nomadik-mtu: fix up clocksource/timer Revert "ARM: exynos: enable multiplatform support" ARM: SPEAr13xx: Fix typo "ARCH_HAVE_CPUFREQ" ARM: exynos: enable multiplatform support rtc: s3c: make header file local mtd: onenand/samsung: make regs-onenand.h file local thermal/exynos: remove unnecessary header inclusions mmc: sdhci-s3c: remove platform dependencies ARM: samsung: move mfc device definition to s5p-dev-mfc.c ARM: exynos: move debug-macro.S to include/debug/ ARM: exynos: prepare for sparse IRQ ARM: exynos: introduce EXYNOS_ATAGS symbol ARM: tegra: build assembly files with -march=armv7-a ARM: Push selects for TWD/SCU into machine entries ARM: ux500: build hotplug.o for ARMv7-a ARM: ux500: move to multiplatform ARM: ux500: make remaining headers local ARM: ux500: make irqs.h local to platform ARM: ux500: get rid of <mach/[hardware|db8500-regs].h> ...
Diffstat (limited to 'arch/arm/mach-spear/hotplug.c')
-rw-r--r--arch/arm/mach-spear/hotplug.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/arm/mach-spear/hotplug.c b/arch/arm/mach-spear/hotplug.c
new file mode 100644
index 000000000000..a7d2dd11a4f2
--- /dev/null
+++ b/arch/arm/mach-spear/hotplug.c
@@ -0,0 +1,103 @@
+/*
+ * 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>
+
+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 spear13xx_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)++;
+ }
+}
+
+/*
+ * platform-specific code to shutdown a CPU
+ *
+ * Called with IRQs disabled
+ */
+void __ref spear13xx_cpu_die(unsigned int cpu)
+{
+ int spurious = 0;
+
+ /*
+ * we're ready for shutdown now, so do it
+ */
+ cpu_enter_lowpower();
+ spear13xx_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);
+}