1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
/*
* Copyright (C) 2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2009 PetaLogix
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/of_platform.h>
#include <asm/prom.h>
/* Trigger specific functions */
#ifdef CONFIG_GPIOLIB
#include <linux/of_gpio.h>
static int handle; /* reset pin handle */
static unsigned int reset_val;
static int of_reset_gpio_handle(void)
{
int ret; /* variable which stored handle reset gpio pin */
struct device_node *root; /* root node */
struct device_node *gpio; /* gpio node */
struct gpio_chip *gc;
u32 flags;
const void *gpio_spec;
/* find out root node */
root = of_find_node_by_path("/");
/* give me handle for gpio node to be possible allocate pin */
ret = of_parse_phandles_with_args(root, "hard-reset-gpios",
"#gpio-cells", 0, &gpio, &gpio_spec);
if (ret) {
pr_debug("%s: can't parse gpios property\n", __func__);
goto err0;
}
gc = gpio->data;
if (!gc) {
pr_debug("%s: gpio controller %s isn't registered\n",
root->full_name, gpio->full_name);
ret = -ENODEV;
goto err1;
}
ret = gc->of_xlate(gc, root, gpio_spec, &flags);
if (ret < 0)
goto err1;
ret += gc->base;
err1:
of_node_put(gpio);
err0:
pr_debug("%s exited with status %d\n", __func__, ret);
return ret;
}
void of_platform_reset_gpio_probe(void)
{
int ret;
handle = of_reset_gpio_handle();
if (!gpio_is_valid(handle)) {
printk(KERN_INFO "Skipping unavailable RESET gpio %d (%s)\n",
handle, "reset");
}
ret = gpio_request(handle, "reset");
if (ret < 0) {
printk(KERN_INFO "GPIO pin is already allocated\n");
return;
}
/* get current setup value */
reset_val = gpio_get_value(handle);
/* FIXME maybe worth to perform any action */
pr_debug("Reset: Gpio output state: 0x%x\n", reset_val);
/* Setup GPIO as output */
ret = gpio_direction_output(handle, 0);
if (ret < 0)
goto err;
/* Setup output direction */
gpio_set_value(handle, 0);
printk(KERN_INFO "RESET: Registered gpio device: %d, current val: %d\n",
handle, reset_val);
return;
err:
gpio_free(handle);
return;
}
static void gpio_system_reset(void)
{
gpio_set_value(handle, 1 - reset_val);
}
#else
#define gpio_system_reset() do {} while (0)
void of_platform_reset_gpio_probe(void)
{
return;
}
#endif
void machine_restart(char *cmd)
{
printk(KERN_NOTICE "Machine restart...\n");
gpio_system_reset();
dump_stack();
while (1)
;
}
void machine_shutdown(void)
{
printk(KERN_NOTICE "Machine shutdown...\n");
while (1)
;
}
void machine_halt(void)
{
printk(KERN_NOTICE "Machine halt...\n");
while (1)
;
}
void machine_power_off(void)
{
printk(KERN_NOTICE "Machine power off...\n");
while (1)
;
}
|
