--- /dev/null
+/*
+ * backsaver - Small backlight power saver daemon
+ *
+ * This app relies on contemporary Linux 2.6 intefaces, like
+ * backlight class dev and generic input devices. Legacy interfaces
+ * are not supported by design.
+ *
+ * Copyright (C) 2007, 2008 Paul Sokolovsky <pmiscml@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <getopt.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int opt_verbose;
+int opt_timeout = 2;
+int opt_power;
+int opt_brightness = -1;
+
+char readbuf[256];
+fd_set read_fds;
+fd_set work_fds;
+int fds[32];
+
+int bl_state = 1;
+
+#define BL_PATH "/sys/class/backlight/"
+
+/* Backlight device properties */
+char bldev_brightness_path[256] = BL_PATH;
+char bldev_power_path[256] = BL_PATH;
+int bldev_max_brightness;
+int bldev_saved_brightness;
+int bldev_dim_brightness;
+
+void fatal(char *msg)
+{
+ fprintf(stderr, "%s\n", msg);
+ exit(1);
+}
+
+int sysfs_get_value(char *fname)
+{
+ char buf[64];
+ int fd = open(fname, O_RDONLY);
+ int sz = read(fd, buf, sizeof(buf) - 1);
+ buf[sz] = 0;
+ close(fd);
+ return atoi(buf);
+}
+
+void sysfs_set_value(char *fname, int val)
+{
+ char buf[64];
+ int fd = open(fname, O_WRONLY);
+ int sz = sprintf(buf, "%d\n", val);
+ write(fd, buf, sz);
+ close(fd);
+}
+
+char *bldev_scan()
+{
+ static char name[256];
+ DIR *dir;
+ struct dirent *de;
+ int more_than_one = 0;
+
+ dir = opendir(BL_PATH);
+ if (!dir)
+ fatal("Backlight device class does not seem to be support by kernel (" BL_PATH " is absent)");
+
+ *name = 0;
+ while (de = readdir(dir)) {
+ if (de->d_name[0] == '.')
+ continue;
+ if (*name == 0) {
+ strcpy(name, de->d_name);
+ } else {
+ more_than_one = 1;
+ break;
+ }
+ }
+
+ closedir(dir);
+ if (*name == 0)
+ fatal("There does not seem to be any backlight device available (" BL_PATH " is empty)");
+ if (more_than_one)
+ fatal("There seems to be several backlight devices available, use --device= option");
+
+ return name;
+}
+
+void bldev_init(char *bldev)
+{
+ strcat(bldev_brightness_path, bldev);
+ strcat(bldev_brightness_path, "/brightness");
+ strcat(bldev_power_path, bldev);
+ strcat(bldev_power_path, "/power");
+
+ char buf[PATH_MAX];
+ memcpy(buf, BL_PATH, sizeof(BL_PATH));
+ strcat(buf, bldev);
+ strcat(buf, "/max_brightness");
+ bldev_max_brightness = sysfs_get_value(buf);
+
+ bldev_dim_brightness = bldev_max_brightness * opt_brightness / 100;
+}
+
+void set_backlight(int state)
+{
+ if (!bl_state) {
+ if (opt_verbose)
+ printf("BL off\n");
+ if (opt_power) {
+ sysfs_set_value(bldev_power_path, 4);
+ } else {
+ bldev_saved_brightness = sysfs_get_value(bldev_brightness_path);
+ sysfs_set_value(bldev_brightness_path, bldev_dim_brightness);
+ }
+ } else {
+ if (opt_verbose)
+ printf("BL on\n");
+ if (opt_power) {
+ sysfs_set_value(bldev_power_path, 0);
+ } else {
+ sysfs_set_value(bldev_brightness_path, bldev_saved_brightness);
+ }
+ }
+}
+
+#define INPUT_PATH "/dev/input/"
+
+int main_loop(int argc, char *argv[], int argstart)
+{
+ fd_set read_fds;
+ struct timeval timeout;
+ int i, maxfd = 0, numfd = 0;
+
+ FD_ZERO(&read_fds);
+
+ if (argstart == argc) {
+ static char path[256] = INPUT_PATH;
+ DIR *dir;
+ struct dirent *de;
+ struct stat stat;
+
+ dir = opendir(INPUT_PATH);
+ if (!dir)
+ fatal("Cannot open generic input device directory (" INPUT_PATH " is absent)");
+
+ while (de = readdir(dir)) {
+ if (de->d_name[0] == '.')
+ continue;
+ strcpy(path + sizeof(INPUT_PATH) - 1, de->d_name);
+
+ if (lstat(path, &stat))
+ fatal("Cannot stat input device to monitor");
+ if (S_ISLNK(stat.st_mode)) {
+ if (opt_verbose)
+ printf("Skipping symlink %s\n", path);
+ continue;
+ }
+ if (opt_verbose)
+ printf("Using %s\n", path);
+
+ int fd = open(path, O_RDONLY);
+ if (fd == -1)
+ fatal("Cannot open input device to monitor");
+ if (fd > maxfd)
+ maxfd = fd;
+ fds[numfd++] = fd;
+ FD_SET(fd, &read_fds);
+ }
+
+ closedir(dir);
+ } else {
+ for (i = argstart; i < argc; i++) {
+ if (opt_verbose)
+ printf("Using: %s\n", argv[i]);
+ int fd = open(argv[i], O_RDONLY);
+ if (fd == -1)
+ fatal("Cannot open input device to monitor");
+ if (fd > maxfd)
+ maxfd = fd;
+ fds[numfd++] = fd;
+ FD_SET(fd, &read_fds);
+ }
+ }
+
+ timeout.tv_usec = 0;
+
+ while (1) {
+ memcpy(&work_fds, &read_fds, sizeof(read_fds));
+ timeout.tv_sec = opt_timeout;
+ i = select(maxfd + 1, &work_fds, NULL, NULL, &timeout);
+ if (opt_verbose)
+ printf("Select returned: %d\n", i);
+ if (i > 0) {
+ if (!bl_state) {
+ bl_state = 1;
+ set_backlight(bl_state);
+ }
+ for (i = 0; i < numfd; i++) {
+ if (FD_ISSET(fds[i], &work_fds)) {
+ int sz = read(fds[i], readbuf, sizeof(readbuf));
+ if (opt_verbose)
+ printf("Discarded %d bytes from fd %d\n", sz, fds[i]);
+ }
+ }
+ } else {
+ if (bl_state) {
+ bl_state = 0;
+ set_backlight(bl_state);
+ }
+ }
+
+ }
+}
+
+struct option options[] = {
+ { "verbose", no_argument, &opt_verbose, 1 },
+ { "timeout", required_argument, NULL, 't' },
+ { "power", no_argument, &opt_power, 1 },
+ { "brightness", required_argument, NULL, 'b' },
+ NULL
+};
+int main(int argc, char *argv[])
+{
+ int opt;
+ while ((opt = getopt_long(argc, argv, "?h", options, NULL)) != -1) {
+ switch (opt) {
+ case 't':
+ opt_timeout = atoi(optarg);
+ break;
+ case 'b':
+ opt_brightness = atoi(optarg);
+ break;
+ }
+ }
+ printf("%d\n", optind);
+
+ char *bldev = bldev_scan();
+ bldev_init(bldev);
+
+ return main_loop(argc, argv, optind);
+}
git.openpandora.org / openembedded.git / commitdiff