projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| c7c28b0f MS |
1 | /* |
| 2 | * Copyright (C) 2012-2013 Xilinx | |
| 3 | * | |
| 4 | * based on linux/arch/arm/mach-realview/hotplug.c | |
| 5 | * | |
| 6 | * Copyright (C) 2002 ARM Ltd. | |
| 7 | * All Rights Reserved | |
| 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 | ||
| 17 | #include <asm/cacheflush.h> | |
| 18 | #include <asm/cp15.h> | |
| 19 | #include "common.h" | |
| 20 | ||
| 21 | static inline void zynq_cpu_enter_lowpower(void) | |
| 22 | { | |
| 23 | unsigned int v; | |
| 24 | ||
| 25 | flush_cache_all(); | |
| 26 | asm volatile( | |
| 27 | " mcr p15, 0, %1, c7, c5, 0\n" | |
| 28 | " dsb\n" | |
| 29 | /* | |
| 30 | * Turn off coherency | |
| 31 | */ | |
| 32 | " mrc p15, 0, %0, c1, c0, 1\n" | |
| 33 | " bic %0, %0, #0x40\n" | |
| 34 | " mcr p15, 0, %0, c1, c0, 1\n" | |
| 35 | " mrc p15, 0, %0, c1, c0, 0\n" | |
| 36 | " bic %0, %0, %2\n" | |
| 37 | " mcr p15, 0, %0, c1, c0, 0\n" | |
| 38 | : "=&r" (v) | |
| 39 | : "r" (0), "Ir" (CR_C) | |
| 40 | : "cc"); | |
| 41 | } | |
| 42 | ||
| 43 | static inline void zynq_cpu_leave_lowpower(void) | |
| 44 | { | |
| 45 | unsigned int v; | |
| 46 | ||
| 47 | asm volatile( | |
| 48 | " 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, #0x40\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 zynq_platform_do_lowpower(unsigned int cpu, int *spurious) | |
| 60 | { | |
| 61 | /* | |
| 62 | * there is no power-control hardware on this platform, so all | |
| 63 | * we can do is put the core into WFI; this is safe as the calling | |
| 64 | * code will have already disabled interrupts | |
| 65 | */ | |
| 66 | for (;;) { | |
| 67 | dsb(); | |
| 68 | wfi(); | |
| 69 | ||
| 70 | /* | |
| 71 | * Getting here, means that we have come out of WFI without | |
| 72 | * having been woken up - this shouldn't happen | |
| 73 | * | |
| 74 | * Just note it happening - when we're woken, we can report | |
| 75 | * its occurrence. | |
| 76 | */ | |
| 77 | (*spurious)++; | |
| 78 | } | |
| 79 | } | |
| 80 | ||
| 81 | /* | |
| 82 | * platform-specific code to shutdown a CPU | |
| 83 | * | |
| 84 | * Called with IRQs disabled | |
| 85 | */ | |
| 86 | void zynq_platform_cpu_die(unsigned int cpu) | |
| 87 | { | |
| 88 | int spurious = 0; | |
| 89 | ||
| 90 | /* | |
| 91 | * we're ready for shutdown now, so do it | |
| 92 | */ | |
| 93 | zynq_cpu_enter_lowpower(); | |
| 94 | zynq_platform_do_lowpower(cpu, &spurious); | |
| 95 | ||
| 96 | /* | |
| 97 | * bring this CPU back into the world of cache | |
| 98 | * coherency, and then restore interrupts | |
| 99 | */ | |
| 100 | zynq_cpu_leave_lowpower(); | |
| 101 | ||
| 102 | if (spurious) | |
| 103 | pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious); | |
| 104 | } |