/*
* 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 <linux/jiffies.h>
#include <asm/cp15.h>
#include <asm/proc-fns.h>
#include "common.h"
static inline void cpu_enter_lowpower(void)
{
unsigned int v;
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");
}
/*
* platform-specific code to shutdown a CPU
*
* Called with IRQs disabled
*/
void imx_cpu_die(unsigned int cpu)
{
cpu_enter_lowpower();
/*
* We use the cpu jumping argument register to sync with
* imx_cpu_kill() which is running on cpu0 and waiting for
* the register being cleared to kill the cpu.
*/
imx_set_cpu_arg(cpu, ~0);
while (1)
cpu_do_idle();
}
int imx_cpu_kill(unsigned int cpu)
{
unsigned long timeout = jiffies + msecs_to_jiffies(50);
while (imx_get_cpu_arg(cpu) == 0)
if (time_after(jiffies, timeout))
return 0;
imx_enable_cpu(cpu, false);
imx_set_cpu_arg(cpu, 0);
return 1;
}
