tests/setbacklight.c

   1 /*
   2  * Copyright © 2012 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining
   5  * a copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sublicense, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the
  13  * next paragraph) shall be included in all copies or substantial
  14  * portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  19  * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  20  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  21  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  *
  25  * Author: Tiago Vignatti
  26  */
  27 /*
  28  * \file setbacklight.c
  29  * Test program to get a backlight connector and set its brightness value.
  30  * Queries for the connectors id can be performed using drm/tests/modeprint
  31  * program.
  32  */
  33
  34 #include "config.h"
  35
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <stdint.h>
  39 #include <unistd.h>
  40 #include <fcntl.h>
  41 #include <xf86drmMode.h>
  42
  43 #include "libbacklight.h"
  44
  45 static uint32_t
  46 get_drm_connector_type(struct udev_device *drm_device, uint32_t connector_id)
  47 {
  48         const char *filename;
  49         int fd, i, connector_type;
  50         drmModeResPtr res;
  51         drmModeConnectorPtr connector;
  52
  53         filename = udev_device_get_devnode(drm_device);
  54         fd = open(filename, O_RDWR | O_CLOEXEC);
  55         if (fd < 0) {
  56                 printf("couldn't open drm_device\n");
  57                 return -1;
  58         }
  59
  60         res = drmModeGetResources(fd);
  61         if (res == 0) {
  62                 printf("Failed to get resources from card\n");
  63                 close(fd);
  64                 return -1;
  65         }
  66
  67         for (i = 0; i < res->count_connectors; i++) {
  68                 connector = drmModeGetConnector(fd, res->connectors[i]);
  69                 if (!connector)
  70                         continue;
  71
  72                 if ((connector->connection == DRM_MODE_DISCONNECTED) ||
  73                     (connector->connector_id != connector_id)) {
  74                         drmModeFreeConnector(connector);
  75                         continue;
  76                 }
  77
  78                 connector_type = connector->connector_type;
  79                 drmModeFreeConnector(connector);
  80                 drmModeFreeResources(res);
  81
  82                 close(fd);
  83                 return connector_type;
  84         }
  85
  86         close(fd);
  87         drmModeFreeResources(res);
  88         return -1;
  89 }
  90
  91 /* returns a value between 0-255 range, where higher is brighter */
  92 static uint32_t
  93 get_normalized_backlight(struct backlight *backlight)
  94 {
  95         long brightness, max_brightness;
  96         long norm;
  97
  98         brightness = backlight_get_brightness(backlight);
  99         max_brightness = backlight_get_max_brightness(backlight);
 100
 101         /* convert it to a scale of 0 to 255 */
 102         norm = (brightness * 255)/(max_brightness);
 103
 104         return (int) norm;
 105 }
 106
 107 static void
 108 set_backlight(struct udev_device *drm_device, int connector_id, int blight)
 109 {
 110         int connector_type;
 111         long max_brightness, brightness, actual_brightness;
 112         struct backlight *backlight;
 113         long new_blight;
 114
 115         connector_type = get_drm_connector_type(drm_device, connector_id);
 116         if (connector_type < 0)
 117                 return;
 118
 119         backlight = backlight_init(drm_device, connector_type);
 120         if (!backlight) {
 121                 printf("backlight adjust failed\n");
 122                 return;
 123         }
 124
 125         max_brightness = backlight_get_max_brightness(backlight);
 126         printf("Max backlight: %ld\n", max_brightness);
 127
 128         brightness = backlight_get_brightness(backlight);
 129         printf("Cached backlight: %ld\n", brightness);
 130
 131         actual_brightness = backlight_get_actual_brightness(backlight);
 132         printf("Hardware backlight: %ld\n", actual_brightness);
 133
 134         printf("normalized current brightness: %d\n",
 135                get_normalized_backlight(backlight));
 136
 137         /* denormalized value */
 138         new_blight = (blight * max_brightness) / 255;
 139
 140         backlight_set_brightness(backlight, new_blight);
 141         printf("Setting brightness to: %ld (norm: %d)\n", new_blight, blight);
 142
 143         backlight_destroy(backlight);
 144 }
 145
 146 int
 147 main(int argc, char **argv)
 148 {
 149         int blight, connector_id;
 150         const char *path;
 151         struct udev *udev;
 152         struct udev_enumerate *e;
 153         struct udev_list_entry *entry;
 154         struct udev_device *drm_device;
 155
 156         if (argc < 3) {
 157                 printf("Please add connector_id and brightness values from 0-255\n");
 158                 return 1;
 159         }
 160
 161         connector_id = atoi(argv[1]);
 162         blight = atoi(argv[2]);
 163
 164         udev = udev_new();
 165         if (udev == NULL) {
 166                 printf("failed to initialize udev context\n");
 167                 return 1;
 168         }
 169
 170         e = udev_enumerate_new(udev);
 171         udev_enumerate_add_match_subsystem(e, "drm");
 172         udev_enumerate_add_match_sysname(e, "card[0-9]*");
 173
 174         udev_enumerate_scan_devices(e);
 175         drm_device = NULL;
 176         udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(e)) {
 177                 path = udev_list_entry_get_name(entry);
 178                 drm_device = udev_device_new_from_syspath(udev, path);
 179                 break;
 180         }
 181
 182         if (drm_device == NULL) {
 183                 printf("no drm device found\n");
 184                 return 1;
 185         }
 186
 187         set_backlight(drm_device, connector_id, blight);
 188
 189         udev_device_unref(drm_device);
 190         return 0;
 191 }