aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/laptops/hpfall.c
blob: b85dbbac049933dd9dc6f6f45568f3725246f032 (plain) (blame)
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
141
142
143
144
145
146
/* Disk protection for HP machines.
 *
 * Copyright 2008 Eric Piel
 * Copyright 2009 Pavel Machek <pavel@ucw.cz>
 *
 * GPLv2.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <string.h>
#include <stdint.h>
#include <errno.h>
#include <signal.h>
#include <sys/mman.h>
#include <sched.h>

char unload_heads_path[64];

int set_unload_heads_path(char *device)
{
	char devname[64];

	if (strlen(device) <= 5 || strncmp(device, "/dev/", 5) != 0)
		return -EINVAL;
	strncpy(devname, device + 5, sizeof(devname));

	snprintf(unload_heads_path, sizeof(unload_heads_path) - 1,
				"/sys/block/%s/device/unload_heads", devname);
	return 0;
}
int valid_disk(void)
{
	int fd = open(unload_heads_path, O_RDONLY);
	if (fd < 0) {
		perror(unload_heads_path);
		return 0;
	}

	close(fd);
	return 1;
}

void write_int(char *path, int i)
{
	char buf[1024];
	int fd = open(path, O_RDWR);
	if (fd < 0) {
		perror("open");
		exit(1);
	}
	sprintf(buf, "%d", i);
	if (write(fd, buf, strlen(buf)) != strlen(buf)) {
		perror("write");
		exit(1);
	}
	close(fd);
}

void set_led(int on)
{
	write_int("/sys/class/leds/hp::hddprotect/brightness", on);
}

void protect(int seconds)
{
	write_int(unload_heads_path, seconds*1000);
}

int on_ac(void)
{
//	/sys/class/power_supply/AC0/online
}

int lid_open(void)
{
//	/proc/acpi/button/lid/LID/state
}

void ignore_me(void)
{
	protect(0);
	set_led(0);
}

int main(int argc, char **argv)
{
	int fd, ret;
	struct sched_param param;

	if (argc == 1)
		ret = set_unload_heads_path("/dev/sda");
	else if (argc == 2)
		ret = set_unload_heads_path(argv[1]);
	else
		ret = -EINVAL;

	if (ret || !valid_disk()) {
		fprintf(stderr, "usage: %s <device> (default: /dev/sda)\n",
				argv[0]);
		exit(1);
	}

	fd = open("/dev/freefall", O_RDONLY);
	if (fd < 0) {
		perror("/dev/freefall");
		return EXIT_FAILURE;
	}

	daemon(0, 0);
	param.sched_priority = sched_get_priority_max(SCHED_FIFO);
	sched_setscheduler(0, SCHED_FIFO, &param);
	mlockall(MCL_CURRENT|MCL_FUTURE);

	signal(SIGALRM, ignore_me);

	for (;;) {
		unsigned char count;

		ret = read(fd, &count, sizeof(count));
		alarm(0);
		if ((ret == -1) && (errno == EINTR)) {
			/* Alarm expired, time to unpark the heads */
			continue;
		}

		if (ret != sizeof(count)) {
			perror("read");
			break;
		}

		protect(21);
		set_led(1);
		if (1 || on_ac() || lid_open())
			alarm(2);
		else
			alarm(20);
	}

	close(fd);
	return EXIT_SUCCESS;
}