1 // SPDX-License-Identifier: GPL-2.0
3 * Reset a Jazz machine.
5 * We don't trust the firmware so we do it the classic way by poking and
6 * stabbing at the keyboard controller ...
8 #include <linux/jiffies.h>
11 #define KBD_STAT_IBF 0x02 /* Keyboard input buffer full */
13 static void jazz_write_output(unsigned char val)
18 status = jazz_kh->command;
19 } while (status & KBD_STAT_IBF);
23 static void jazz_write_command(unsigned char val)
28 status = jazz_kh->command;
29 } while (status & KBD_STAT_IBF);
30 jazz_kh->command = val;
33 static unsigned char jazz_read_status(void)
35 return jazz_kh->command;
38 static inline void kb_wait(void)
40 unsigned long start = jiffies;
41 unsigned long timeout = start + HZ/2;
44 if (! (jazz_read_status() & 0x02))
46 } while (time_before_eq(jiffies, timeout));
49 void jazz_machine_restart(char *command)
53 jazz_write_command(0xd1);
55 jazz_write_output(0x00);