// SPDX-License-Identifier: GPL-2.0 /* * 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> #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); } }