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/*
* arch/blackfin/kernel/reboot.c - handle shutdown/reboot
*
* Copyright 2004-2007 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#include <linux/interrupt.h>
#include <asm/bfin-global.h>
#include <asm/reboot.h>
#include <asm/system.h>
/* A system soft reset makes external memory unusable so force
* this function into L1. We use the compiler ssync here rather
* than SSYNC() because it's safe (no interrupts and such) and
* we save some L1. We do not need to force sanity in the SYSCR
* register as the BMODE selection bit is cleared by the soft
* reset while the Core B bit (on dual core parts) is cleared by
* the core reset.
*/
__attribute__((l1_text))
void bfin_reset(void)
{
/* Wait for completion of "system" events such as cache line
* line fills so that we avoid infinite stalls later on as
* much as possible. This code is in L1, so it won't trigger
* any such event after this point in time.
*/
__builtin_bfin_ssync();
while (1) {
/* Initiate System software reset. */
bfin_write_SWRST(0x7);
/* Due to the way reset is handled in the hardware, we need
* to delay for 7 SCLKS. The only reliable way to do this is
* to calculate the CCLK/SCLK ratio and multiply 7. For now,
* we'll assume worse case which is a 1:15 ratio.
*/
asm(
"LSETUP (1f, 1f) LC0 = %0\n"
"1: nop;"
:
: "a" (15 * 7)
: "LC0", "LB0", "LT0"
);
/* Clear System software reset */
bfin_write_SWRST(0);
/* Wait for the SWRST write to complete. Cannot rely on SSYNC
* though as the System state is all reset now.
*/
asm(
"LSETUP (1f, 1f) LC1 = %0\n"
"1: nop;"
:
: "a" (15 * 1)
: "LC1", "LB1", "LT1"
);
/* Issue core reset */
asm("raise 1");
}
}
__attribute__((weak))
void native_machine_restart(char *cmd)
{
}
void machine_restart(char *cmd)
{
native_machine_restart(cmd);
local_irq_disable();
bfin_reset();
}
__attribute__((weak))
void native_machine_halt(void)
{
idle_with_irq_disabled();
}
void machine_halt(void)
{
native_machine_halt();
}
__attribute__((weak))
void native_machine_power_off(void)
{
idle_with_irq_disabled();
}
void machine_power_off(void)
{
native_machine_power_off();
}
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