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/*
* Copyright 2012 Canonical Ltd.
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 3, as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranties of
* MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Authors:
* Renato Araujo Oliveira Filho <renato@canonical.com>
*/
#include <gudev/gudev.h>
#include <errno.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include "ib-brightness-control.h"
struct _IbBrightnessControl
{
gchar *path;
};
IbBrightnessControl*
ib_brightness_control_new (void)
{
IbBrightnessControl *control;
GUdevClient *client;
gchar *path = NULL;
GList *devices;
// detect device
client = g_udev_client_new (NULL);
devices = g_udev_client_query_by_subsystem (client, "backlight");
if (devices != NULL) {
GList *device;
const gchar *device_type;
for (device = devices; device != NULL; device = device->next) {
device_type = g_udev_device_get_sysfs_attr (device->data, "type");
if ((g_strcmp0 (device_type, "firmware") == 0) ||
(g_strcmp0 (device_type, "platform") == 0) ||
(g_strcmp0 (device_type, "raw") == 0)) {
path = g_strdup (g_udev_device_get_sysfs_path (device->data));
g_debug ("found: %s", path);
break;
}
}
g_list_free_full (devices, g_object_unref);
}
else {
g_warning ("Fail to query backlight devices.");
}
control = g_new0 (IbBrightnessControl, 1);
control->path = path;
g_object_unref (client);
return control;
}
void
ib_brightness_control_set_value (IbBrightnessControl* self, gint value)
{
gint fd;
gchar *filename;
gchar *svalue;
size_t length;
gint err;
if (self->path == NULL)
return;
filename = g_build_filename (self->path, "brightness", NULL);
fd = open(filename, O_WRONLY);
if (fd < 0) {
g_warning ("Fail to set brightness.");
g_free (filename);
return;
}
svalue = g_strdup_printf ("%i", value);
length = strlen (svalue);
err = errno;
errno = 0;
if (write (fd, svalue, length) != (ssize_t)length) {
g_warning ("Fail to write brightness information: %s", g_strerror(errno));
}
errno = err;
close (fd);
g_free (svalue);
g_free (filename);
}
static gint
ib_brightness_control_get_value_from_file (IbBrightnessControl *self, const gchar *file)
{
GError *error;
gchar *svalue;
gint value;
gchar *filename;
if (self->path == NULL)
return 0;
svalue = NULL;
error = NULL;
filename = g_build_filename (self->path, file, NULL);
g_file_get_contents (filename, &svalue, NULL, &error);
if (error) {
g_warning ("Fail to get brightness value: %s", error->message);
value = -1;
g_error_free (error);
} else {
value = atoi (svalue);
g_free (svalue);
}
g_free (filename);
return value;
}
gint
ib_brightness_control_get_value (IbBrightnessControl* self)
{
return ib_brightness_control_get_value_from_file (self, "brightness");
}
gint
ib_brightness_control_get_max_value (IbBrightnessControl* self)
{
return ib_brightness_control_get_value_from_file (self, "max_brightness");
}
void
ib_brightness_control_free (IbBrightnessControl *self)
{
g_free (self->path);
g_free (self);
}
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