linux/arch/mips/jazz/reset.c

70 lines
1.2 KiB
C

/*
* Reset a Jazz machine.
*
* We don't trust the firmware so we do it the classic way by poking and
* stabbing at the keyboard controller ...
*/
#include <linux/jiffies.h>
#include <asm/jazz.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/reboot.h>
#include <asm/delay.h>
#define KBD_STAT_IBF 0x02 /* Keyboard input buffer full */
static void jazz_write_output(unsigned char val)
{
int status;
do {
status = jazz_kh->command;
} while (status & KBD_STAT_IBF);
jazz_kh->data = val;
}
static void jazz_write_command(unsigned char val)
{
int status;
do {
status = jazz_kh->command;
} while (status & KBD_STAT_IBF);
jazz_kh->command = val;
}
static unsigned char jazz_read_status(void)
{
return jazz_kh->command;
}
static inline void kb_wait(void)
{
unsigned long start = jiffies;
unsigned long timeout = start + HZ/2;
do {
if (! (jazz_read_status() & 0x02))
return;
} while (time_before_eq(jiffies, timeout));
}
void jazz_machine_restart(char *command)
{
while(1) {
kb_wait();
jazz_write_command (0xd1);
kb_wait();
jazz_write_output (0x00);
}
}
void jazz_machine_halt(void)
{
}
void jazz_machine_power_off(void)
{
/* Jazz machines don't have a software power switch */
}