xref: /openbmc/linux/arch/mips/sni/reset.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/arch/mips/sni/process.c
4  *
5  *  Reset a SNI machine.
6  */
7 #include <linux/delay.h>
8 
9 #include <asm/io.h>
10 #include <asm/reboot.h>
11 #include <asm/sni.h>
12 
13 /*
14  * This routine reboots the machine by asking the keyboard
15  * controller to pulse the reset-line low. We try that for a while,
16  * and if it doesn't work, we do some other stupid things.
17  */
18 static inline void kb_wait(void)
19 {
20 	int i;
21 
22 	for (i = 0; i < 0x10000; i++)
23 		if ((inb_p(0x64) & 0x02) == 0)
24 			break;
25 }
26 
27 /* XXX This ends up at the ARC firmware prompt ...  */
28 void sni_machine_restart(char *command)
29 {
30 	int i;
31 
32 	/* This does a normal via the keyboard controller like a PC.
33 	   We can do that easier ...  */
34 	local_irq_disable();
35 	for (;;) {
36 		for (i = 0; i < 100; i++) {
37 			kb_wait();
38 			udelay(50);
39 			outb_p(0xfe, 0x64);	 /* pulse reset low */
40 			udelay(50);
41 		}
42 	}
43 }
44 
45 void sni_machine_power_off(void)
46 {
47 	*(volatile unsigned char *)PCIMT_CSWCSM = 0xfd;
48 }
49