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Diffstat (limited to 'recipes/backsaver/files/backsaver.c')
| -rw-r--r-- | recipes/backsaver/files/backsaver.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/recipes/backsaver/files/backsaver.c b/recipes/backsaver/files/backsaver.c new file mode 100644 index 0000000000..3f030b9dd9 --- /dev/null +++ b/recipes/backsaver/files/backsaver.c @@ -0,0 +1,256 @@ +/* + * 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); +} |