xref: /openbmc/linux/arch/microblaze/kernel/reset.c (revision 12eb4683)
1 /*
2  * Copyright (C) 2009 Michal Simek <monstr@monstr.eu>
3  * Copyright (C) 2009 PetaLogix
4  *
5  * This file is subject to the terms and conditions of the GNU General Public
6  * License. See the file "COPYING" in the main directory of this archive
7  * for more details.
8  */
9 
10 #include <linux/init.h>
11 #include <linux/of_platform.h>
12 #include <asm/prom.h>
13 
14 /* Trigger specific functions */
15 #ifdef CONFIG_GPIOLIB
16 
17 #include <linux/of_gpio.h>
18 
19 static int handle; /* reset pin handle */
20 static unsigned int reset_val;
21 
22 void of_platform_reset_gpio_probe(void)
23 {
24 	int ret;
25 	handle = of_get_named_gpio(of_find_node_by_path("/"),
26 				   "hard-reset-gpios", 0);
27 
28 	if (!gpio_is_valid(handle)) {
29 		pr_info("Skipping unavailable RESET gpio %d (%s)\n",
30 				handle, "reset");
31 		return;
32 	}
33 
34 	ret = gpio_request(handle, "reset");
35 	if (ret < 0) {
36 		pr_info("GPIO pin is already allocated\n");
37 		return;
38 	}
39 
40 	/* get current setup value */
41 	reset_val = gpio_get_value(handle);
42 	/* FIXME maybe worth to perform any action */
43 	pr_debug("Reset: Gpio output state: 0x%x\n", reset_val);
44 
45 	/* Setup GPIO as output */
46 	ret = gpio_direction_output(handle, 0);
47 	if (ret < 0)
48 		goto err;
49 
50 	/* Setup output direction */
51 	gpio_set_value(handle, 0);
52 
53 	pr_info("RESET: Registered gpio device: %d, current val: %d\n",
54 							handle, reset_val);
55 	return;
56 err:
57 	gpio_free(handle);
58 	return;
59 }
60 
61 
62 static void gpio_system_reset(void)
63 {
64 	if (gpio_is_valid(handle))
65 		gpio_set_value(handle, 1 - reset_val);
66 	else
67 		pr_notice("Reset GPIO unavailable - halting!\n");
68 }
69 #else
70 static void gpio_system_reset(void)
71 {
72 	pr_notice("No reset GPIO present - halting!\n");
73 }
74 
75 void of_platform_reset_gpio_probe(void)
76 {
77 	return;
78 }
79 #endif
80 
81 void machine_restart(char *cmd)
82 {
83 	pr_notice("Machine restart...\n");
84 	gpio_system_reset();
85 	while (1)
86 		;
87 }
88 
89 void machine_shutdown(void)
90 {
91 	pr_notice("Machine shutdown...\n");
92 	while (1)
93 		;
94 }
95 
96 void machine_halt(void)
97 {
98 	pr_notice("Machine halt...\n");
99 	while (1)
100 		;
101 }
102 
103 void machine_power_off(void)
104 {
105 	pr_notice("Machine power off...\n");
106 	while (1)
107 		;
108 }
109