linux/arch/arm/mach-omap2/omap-hotplug.c
Santosh Shilimkar b5b4f2881f ARM: OMAP4: PM: Program CPU1 to hit OFF when off-lined
Program non-boot CPUs to hit lowest supported power state
when it is off-lined using cpu hotplug framework.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
2011-12-08 11:29:00 -08:00

73 lines
1.5 KiB
C

/*
* OMAP4 SMP cpu-hotplug support
*
* Copyright (C) 2010 Texas Instruments, Inc.
* Author:
* Santosh Shilimkar <santosh.shilimkar@ti.com>
*
* Platform file needed for the OMAP4 SMP. This file is based on arm
* realview smp platform.
* Copyright (c) 2002 ARM Limited.
*
* 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 "common.h"
#include "powerdomain.h"
int platform_cpu_kill(unsigned int cpu)
{
return 1;
}
/*
* platform-specific code to shutdown a CPU
* Called with IRQs disabled
*/
void platform_cpu_die(unsigned int cpu)
{
unsigned int this_cpu;
flush_cache_all();
dsb();
/*
* we're ready for shutdown now, so do it
*/
if (omap_modify_auxcoreboot0(0x0, 0x200) != 0x0)
pr_err("Secure clear status failed\n");
for (;;) {
/*
* Enter into low power state
*/
omap4_hotplug_cpu(cpu, PWRDM_POWER_OFF);
this_cpu = smp_processor_id();
if (omap_read_auxcoreboot0() == this_cpu) {
/*
* OK, proper wakeup, we're done
*/
break;
}
pr_debug("CPU%u: spurious wakeup call\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;
}