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author | Arnd Bergmann <arnd@arndb.de> | 2012-05-14 17:59:18 +0400 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2012-05-14 19:35:50 +0400 |
commit | 090a80cba39f2763a488b6f7c65e38922d5aa17a (patch) | |
tree | ba3797eeca74c42be95bc592ed2db1be99e329d2 /arch/arm/mach-spear13xx/hotplug.c | |
parent | 36be50515fe2aef61533b516fa2576a2c7fe7664 (diff) | |
parent | eb3f995d7e73fd78b8fcdc55cfbf01a74a09a6e8 (diff) | |
download | linux-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.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 @@ +/* + * 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; +} |