sfc: Stop the TX queues during loopback self-tests
[linux-2.6.git] / arch / mips / jazz / reset.c
1 /*
2  * Reset a Jazz machine.
3  *
4  * We don't trust the firmware so we do it the classic way by poking and
5  * stabbing at the keyboard controller ...
6  */
7 #include <linux/jiffies.h>
8 #include <asm/jazz.h>
9
10 #define KBD_STAT_IBF            0x02    /* Keyboard input buffer full */
11
12 static void jazz_write_output(unsigned char val)
13 {
14         int status;
15
16         do {
17                 status = jazz_kh->command;
18         } while (status & KBD_STAT_IBF);
19         jazz_kh->data = val;
20 }
21
22 static void jazz_write_command(unsigned char val)
23 {
24         int status;
25
26         do {
27                 status = jazz_kh->command;
28         } while (status & KBD_STAT_IBF);
29         jazz_kh->command = val;
30 }
31
32 static unsigned char jazz_read_status(void)
33 {
34         return jazz_kh->command;
35 }
36
37 static inline void kb_wait(void)
38 {
39         unsigned long start = jiffies;
40         unsigned long timeout = start + HZ/2;
41
42         do {
43                 if (! (jazz_read_status() & 0x02))
44                         return;
45         } while (time_before_eq(jiffies, timeout));
46 }
47
48 void jazz_machine_restart(char *command)
49 {
50         while(1) {
51                 kb_wait();
52                 jazz_write_command(0xd1);
53                 kb_wait();
54                 jazz_write_output(0x00);
55         }
56 }