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/*
* Copyright © 2012 Intel Corporation
*
* Permission to use, copy, modify, distribute, and sell this software and
* its documentation for any purpose is hereby granted without fee, provided
* that the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of the copyright holders not be used in
* advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. The copyright holders make
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
* RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
* CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS 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 <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <xf86drm.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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