kernel-ark/arch/blackfin/kernel/reboot.c
Michael Hennerich 444ad82bc3 [Blackfin] arch: Add proper SW System Reset delay sequence
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
2008-01-22 18:38:02 +08:00

90 lines
1.8 KiB
C

/*
* 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>
#if defined(BF537_FAMILY) || defined(BF533_FAMILY) || defined(BF527_FAMILY)
#define SYSCR_VAL 0x0
#elif defined(BF561_FAMILY)
#define SYSCR_VAL 0x20
#elif defined(BF548_FAMILY)
#define SYSCR_VAL 0x10
#endif
/*
* Delay min 5 SCLK cycles using worst case CCLK/SCLK ratio (15)
*/
#define SWRST_DELAY (5 * 15)
/* A system soft reset makes external memory unusable
* so force this function into L1.
*/
__attribute__((l1_text))
void bfin_reset(void)
{
/* force BMODE and disable Core B (as needed) */
bfin_write_SYSCR(SYSCR_VAL);
/* we use asm ssync here because it's save and we save some L1 */
asm("ssync;");
while (1) {
/* initiate system soft reset with magic 0x7 */
bfin_write_SWRST(0x7);
/* Wait for System reset to actually reset, needs to be 5 SCLKs, */
/* Assume CCLK / SCLK ratio is worst case (15), and use 5*15 */
asm("LSETUP(.Lfoo,.Lfoo) LC0 = %0\n .Lfoo: NOP;\n"
: : "a" (SWRST_DELAY) : "LC0", "LT0", "LB0");
/* clear system soft reset */
bfin_write_SWRST(0);
asm("ssync;");
/* 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();
}