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/*
* Copyright (C) 2010 Michael Buesch <m@bues.ch>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include "backlight_class.h"
#include "fileaccess.h"
#include "log.h"
#include "util.h"
#include "conf.h"
#include "main.h"
#include <string.h>
#include <limits.h>
#include <errno.h>
#define BASEPATH "/class/backlight"
static int backlight_class_max_brightness(struct backlight *b)
{
struct backlight_class *bc = container_of(b, struct backlight_class, backlight);
return bc->max_brightness;
}
static int backlight_class_current_brightness(struct backlight *b)
{
struct backlight_class *bc = container_of(b, struct backlight_class, backlight);
return bc->brightness;
}
static int backlight_class_set_brightness(struct backlight *b, int value)
{
struct backlight_class *bc = container_of(b, struct backlight_class, backlight);
int err;
value = min(b->max_brightness(b), value);
value = max(b->min_brightness(b), value);
if (bc->brightness == value)
return 0;
err = file_write_int(bc->set_br_file, value, 10);
if (err)
return err;
bc->brightness = value;
backlight_notify_state_change(b);
return 0;
}
static int backlight_class_read_file(struct backlight_class *bc)
{
int err, value;
err = file_read_int(bc->actual_br_file, &value, 0);
if (err) {
logerr("WARNING: Failed to read actual backlight brightness\n");
return -abs(err);
}
return value;
}
static int backlight_class_update(struct backlight *b)
{
struct backlight_class *bc = container_of(b, struct backlight_class, backlight);
int expected_brightness, cur_brightness, err, res;
expected_brightness = bc->brightness;
res = backlight_class_read_file(bc);
if (res < 0)
return res;
cur_brightness = res;
if (cur_brightness != expected_brightness &&
cur_brightness != b->min_brightness(b)) {
logdebug("Amending backlight brightness from %d to %d\n",
cur_brightness, expected_brightness);
err = backlight_class_set_brightness(b, expected_brightness);
if (err)
return err;
}
return 0;
}
static void backlight_class_destroy(struct backlight *b)
{
struct backlight_class *bc = container_of(b, struct backlight_class, backlight);
file_close(bc->actual_br_file);
file_close(bc->set_br_file);
free(bc);
}
static const char * backlight_select_sysfs_dir(struct list_head *dir_entries)
{
struct dir_entry *ent;
const char *prefer_dir, *selection = NULL;
/* Use the preferred device, if any. */
prefer_dir = config_get(backend.config,
"BACKLIGHT_CLASS",
"prefer_device",
NULL);
if (prefer_dir) {
list_for_each_entry(ent, dir_entries, list) {
if ((ent->type & (DT_LNK | DT_DIR)) &&
strcmp(ent->name, prefer_dir) == 0) {
selection = ent->name;
break;
}
}
if (!selection) {
logerr("class backlight: Failed to find preferred "
"device '%s'\n", prefer_dir);
}
}
if (!selection) {
/* Return first entry, otherwise. */
list_for_each_entry(ent, dir_entries, list) {
if (ent->type & (DT_LNK | DT_DIR)) {
selection = ent->name;
break;
}
}
}
return selection;
}
static struct backlight * backlight_class_probe(void)
{
struct backlight_class *bc;
struct fileaccess *file, *actual_br_file = NULL, *set_br_file = NULL;
LIST_HEAD(dir_entries);
int err, res, max_brightness;
const char *dirname;
err = list_sysfs_directory(&dir_entries, BASEPATH);
if (err <= 0)
return NULL;
dirname = backlight_select_sysfs_dir(&dir_entries);
if (!dirname)
goto err_ent_free;
logdebug("class backlight: Using '%s' for brightness adjustment\n",
dirname);
file = sysfs_file_open(O_RDONLY, "%s/%s/max_brightness",
BASEPATH, dirname);
if (!file)
goto err_files_close;
err = file_read_int(file, &max_brightness, 0);
file_close(file);
if (err)
goto err_files_close;
actual_br_file = sysfs_file_open(O_RDONLY, "%s/%s/actual_brightness",
BASEPATH, dirname);
if (!actual_br_file)
goto err_files_close;
set_br_file = sysfs_file_open(O_RDWR, "%s/%s/brightness",
BASEPATH, dirname);
if (!set_br_file)
goto err_files_close;
bc = zalloc(sizeof(*bc));
if (!bc)
goto err_files_close;
bc->actual_br_file = actual_br_file;
bc->set_br_file = set_br_file;
bc->max_brightness = max_brightness;
backlight_init(&bc->backlight, "class");
bc->backlight.max_brightness = backlight_class_max_brightness;
bc->backlight.current_brightness = backlight_class_current_brightness;
bc->backlight.set_brightness = backlight_class_set_brightness;
bc->backlight.destroy = backlight_class_destroy;
bc->backlight.update = backlight_class_update;
bc->backlight.poll_interval = 2000;
res = backlight_class_read_file(bc);
if (res < 0)
goto err_free;
bc->brightness = res;
backlight_notify_state_change(&bc->backlight);
dir_entries_free(&dir_entries);
return &bc->backlight;
err_free:
free(bc);
err_files_close:
file_close(set_br_file);
file_close(actual_br_file);
err_ent_free:
dir_entries_free(&dir_entries);
return NULL;
}
BACKLIGHT_PROBE(class, backlight_class_probe);
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