diff options
Diffstat (limited to 'arch/arm/mach-imx/hotplug.c')
-rw-r--r-- | arch/arm/mach-imx/hotplug.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/hotplug.c b/arch/arm/mach-imx/hotplug.c new file mode 100644 index 00000000..20ed2d56 --- /dev/null +++ b/arch/arm/mach-imx/hotplug.c @@ -0,0 +1,84 @@ +/* + * Copyright 2011 Freescale Semiconductor, Inc. + * Copyright 2011 Linaro Ltd. + * + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +#include <linux/errno.h> +#include <asm/cacheflush.h> +#include <asm/cp15.h> +#include <mach/common.h> + +int platform_cpu_kill(unsigned int cpu) +{ + return 1; +} + +static inline void cpu_enter_lowpower(void) +{ + unsigned int v; + + flush_cache_all(); + asm volatile( + "mcr p15, 0, %1, c7, c5, 0\n" + " mcr p15, 0, %1, c7, c10, 4\n" + /* + * Turn off coherency + */ + " mrc p15, 0, %0, c1, c0, 1\n" + " bic %0, %0, %3\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), "Ir" (0x40) + : "cc"); +} + +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, %2\n" + " mcr p15, 0, %0, c1, c0, 1\n" + : "=&r" (v) + : "Ir" (CR_C), "Ir" (0x40) + : "cc"); +} + +/* + * platform-specific code to shutdown a CPU + * + * Called with IRQs disabled + */ +void platform_cpu_die(unsigned int cpu) +{ + cpu_enter_lowpower(); + imx_enable_cpu(cpu, false); + cpu_do_idle(); + cpu_leave_lowpower(); + + /* We should never return from idle */ + panic("cpu %d unexpectedly exit from shutdown\n", cpu); +} + +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; +} |