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/*
* Copyright © 2012 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* Author: Tiago Vignatti
*/
/*
* \file setbacklight.c
* Test program to get a backlight connector and set its brightness value.
* Queries for the connectors id can be performed using drm/tests/modeprint
* program.
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <fcntl.h>
#include <xf86drmMode.h>
#include "libbacklight.h"
static uint32_t
get_drm_connector_type(struct udev_device *drm_device, uint32_t connector_id)
{
const char *filename;
int fd, i, connector_type;
drmModeResPtr res;
drmModeConnectorPtr connector;
filename = udev_device_get_devnode(drm_device);
fd = open(filename, O_RDWR | O_CLOEXEC);
if (fd < 0) {
printf("couldn't open drm_device\n");
return -1;
}
res = drmModeGetResources(fd);
if (res == 0) {
printf("Failed to get resources from card\n");
close(fd);
return -1;
}
for (i = 0; i < res->count_connectors; i++) {
connector = drmModeGetConnector(fd, res->connectors[i]);
if (!connector)
continue;
if ((connector->connection == DRM_MODE_DISCONNECTED) ||
(connector->connector_id != connector_id)) {
drmModeFreeConnector(connector);
continue;
}
connector_type = connector->connector_type;
drmModeFreeConnector(connector);
drmModeFreeResources(res);
close(fd);
return connector_type;
}
close(fd);
drmModeFreeResources(res);
return -1;
}
/* returns a value between 0-255 range, where higher is brighter */
static uint32_t
get_normalized_backlight(struct backlight *backlight)
{
long brightness, max_brightness;
long norm;
brightness = backlight_get_brightness(backlight);
max_brightness = backlight_get_max_brightness(backlight);
/* convert it to a scale of 0 to 255 */
norm = (brightness * 255)/(max_brightness);
return (int) norm;
}
static void
set_backlight(struct udev_device *drm_device, int connector_id, int blight)
{
int connector_type;
long max_brightness, brightness, actual_brightness;
struct backlight *backlight;
long new_blight;
connector_type = get_drm_connector_type(drm_device, connector_id);
if (connector_type < 0)
return;
backlight = backlight_init(drm_device, connector_type);
if (!backlight) {
printf("backlight adjust failed\n");
return;
}
max_brightness = backlight_get_max_brightness(backlight);
printf("Max backlight: %ld\n", max_brightness);
brightness = backlight_get_brightness(backlight);
printf("Cached backlight: %ld\n", brightness);
actual_brightness = backlight_get_actual_brightness(backlight);
printf("Hardware backlight: %ld\n", actual_brightness);
printf("normalized current brightness: %d\n",
get_normalized_backlight(backlight));
/* denormalized value */
new_blight = (blight * max_brightness) / 255;
backlight_set_brightness(backlight, new_blight);
printf("Setting brightness to: %ld (norm: %d)\n", new_blight, blight);
backlight_destroy(backlight);
}
int
main(int argc, char **argv)
{
int blight, connector_id;
const char *path;
struct udev *udev;
struct udev_enumerate *e;
struct udev_list_entry *entry;
struct udev_device *drm_device;
if (argc < 3) {
printf("Please add connector_id and brightness values from 0-255\n");
return 1;
}
connector_id = atoi(argv[1]);
blight = atoi(argv[2]);
udev = udev_new();
if (udev == NULL) {
printf("failed to initialize udev context\n");
return 1;
}
e = udev_enumerate_new(udev);
udev_enumerate_add_match_subsystem(e, "drm");
udev_enumerate_add_match_sysname(e, "card[0-9]*");
udev_enumerate_scan_devices(e);
drm_device = NULL;
udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(e)) {
path = udev_list_entry_get_name(entry);
drm_device = udev_device_new_from_syspath(udev, path);
break;
}
if (drm_device == NULL) {
printf("no drm device found\n");
return 1;
}
set_backlight(drm_device, connector_id, blight);
udev_device_unref(drm_device);
return 0;
}
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