Add support for controlling leds keyboard backlights

Add a new DBus interface based on the QoS one to provide for controlling a
keyboard backlight via the Linux leds interface.

Signed-off-by: Richard Hughes <richard@hughsie.com>

1 files changed, 319 insertions, 0 deletions

diff --git a/src/up-kbd-backlight.c b/src/up-kbd-backlight.c
new file mode 100644
index 0000000..249b93d
--- /dev/null
+++ b/src/up-kbd-backlight.c
@@ -0,0 +1,319 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2008 Richard Hughes <richard@hughsie.com>
+ *               2010 Alex Murray <murray.alex@gmail.com>
+ *
+ * Licensed under the GNU General Public License Version 2
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+
+#include <glib.h>
+#include <dbus/dbus-glib.h>
+#include <dbus/dbus-glib-lowlevel.h>
+#include <glib/gi18n.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <dirent.h>
+
+#include "egg-debug.h"
+
+#include "up-kbd-backlight.h"
+#include "up-marshal.h"
+#include "up-daemon.h"
+#include "up-kbd-backlight-glue.h"
+#include "up-types.h"
+
+static void     up_kbd_backlight_finalize   (GObject	*object);
+
+#define UP_KBD_BACKLIGHT_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), UP_TYPE_KBD_BACKLIGHT, UpKbdBacklightPrivate))
+
+struct UpKbdBacklightPrivate
+{
+	gint			 fd;
+	gint			 brightness;
+	gint			 max_brightness;
+	DBusGConnection		*connection;
+};
+
+enum {
+	BRIGHTNESS_CHANGED,
+	LAST_SIGNAL
+};
+
+static guint signals [LAST_SIGNAL] = { 0 };
+
+G_DEFINE_TYPE (UpKbdBacklight, up_kbd_backlight, G_TYPE_OBJECT)
+
+/**
+ * up_kbd_backlight_brightness_write:
+ **/
+static gboolean
+up_kbd_backlight_brightness_write (UpKbdBacklight *kbd_backlight, gint value)
+{
+	gchar *text = NULL;
+	gint retval;
+	gint length;
+	gboolean ret = TRUE;
+
+	/* write new values to backlight */
+	if (kbd_backlight->priv->fd < 0) {
+		egg_warning ("cannot write to kbd_backlight as file not open");
+		ret = FALSE;
+		goto out;
+	}
+
+	/* limit to between 0 and max */
+	value = CLAMP (value, 0, kbd_backlight->priv->max_brightness);
+
+	/* convert to text */
+	text = g_strdup_printf ("%i", value);
+	length = strlen (text);
+
+	/* write to file */
+	lseek (kbd_backlight->priv->fd, 0, SEEK_SET);
+	retval = write (kbd_backlight->priv->fd, text, length);
+	if (retval != length) {
+		egg_warning ("writing '%s' to device failed", text);
+		ret = FALSE;
+		goto out;
+	}
+
+	/* emit signal */
+	kbd_backlight->priv->brightness = value;
+	g_signal_emit (kbd_backlight, signals [BRIGHTNESS_CHANGED], 0,
+		       kbd_backlight->priv->brightness);
+
+out:
+	g_free (text);
+	return ret;
+}
+
+/**
+ * up_kbd_backlight_get_brightness:
+ *
+ * Gets the current brightness
+ **/
+gboolean
+up_kbd_backlight_get_brightness (UpKbdBacklight *kbd_backlight, gint *value, GError **error)
+{
+	g_return_val_if_fail (value != NULL, FALSE);
+	*value = kbd_backlight->priv->brightness;
+	return TRUE;
+}
+
+/**
+ * up_kbd_backlight_get_max_brightness:
+ *
+ * Gets the max brightness
+ **/
+gboolean
+up_kbd_backlight_get_max_brightness (UpKbdBacklight *kbd_backlight, gint *value, GError **error)
+{
+	g_return_val_if_fail (value != NULL, FALSE);
+	*value = kbd_backlight->priv->max_brightness;
+	return TRUE;
+}
+
+/**
+ * up_kbd_backlight_set_brightness:
+ **/
+gboolean
+up_kbd_backlight_set_brightness (UpKbdBacklight *kbd_backlight, gint value, GError **error)
+{
+	gboolean ret = FALSE;
+
+	egg_debug ("setting brightness to %i", value);
+	ret = up_kbd_backlight_brightness_write(kbd_backlight, value);
+
+	if (!ret) {
+		*error = g_error_new (UP_DAEMON_ERROR, UP_DAEMON_ERROR_GENERAL, "error writing brightness %d", value);
+	}
+	return ret;
+}
+
+/**
+ * up_kbd_backlight_class_init:
+ **/
+static void
+up_kbd_backlight_class_init (UpKbdBacklightClass *klass)
+{
+	GObjectClass *object_class = G_OBJECT_CLASS (klass);
+	object_class->finalize = up_kbd_backlight_finalize;
+
+	signals [BRIGHTNESS_CHANGED] =
+		g_signal_new ("brightness-changed",
+			      G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST,
+			      G_STRUCT_OFFSET (UpKbdBacklightClass, brightness_changed),
+			      NULL, NULL, g_cclosure_marshal_VOID__INT,
+			      G_TYPE_NONE, 1, G_TYPE_INT);
+
+	/* introspection */
+	dbus_g_object_type_install_info (UP_TYPE_KBD_BACKLIGHT, &dbus_glib_up_kbd_backlight_object_info);
+
+	g_type_class_add_private (klass, sizeof (UpKbdBacklightPrivate));
+}
+
+/**
+ * up_kbd_backlight_find:
+ **/
+static gboolean
+up_kbd_backlight_find (UpKbdBacklight *kbd_backlight)
+{
+	gboolean ret;
+	gboolean found = FALSE;
+	GDir *dir;
+	const gchar *filename;
+	gchar *dir_path = NULL;
+	gchar *path_max = NULL;
+	gchar *path_now = NULL;
+	gchar *buf_max = NULL;
+	gchar *buf_now = NULL;
+	GError *error = NULL;
+
+	kbd_backlight->priv->fd = -1;
+
+	/* open directory */
+	dir = g_dir_open ("/sys/class/leds", 0, &error);
+	if (dir == NULL) {
+		egg_warning ("failed to get directory: %s", error->message);
+		g_error_free (error);
+		goto out;
+	}
+
+	/* find a led device that is a keyboard device */
+	while ((filename = g_dir_read_name (dir)) != NULL) {
+		if (g_strstr_len (filename, -1, "kbd_backlight") != NULL) {
+			dir_path = g_build_filename ("/sys/class/leds",
+						    filename, NULL);
+			break;
+		}
+	}
+
+	/* nothing found */
+	if (dir_path == NULL)
+		goto out;
+
+	/* read max brightness */
+	path_max = g_build_filename (dir_path, "max_brightness", NULL);
+	ret = g_file_get_contents (path_max, &buf_max, NULL, &error);
+	if (!ret) {
+		egg_warning ("failed to get max brightness: %s", error->message);
+		g_error_free (error);
+		goto out;
+	}
+	kbd_backlight->priv->max_brightness = g_ascii_strtoull (buf_max, NULL, 10);
+	if (kbd_backlight->priv->max_brightness <= 0) {
+		egg_warning ("failed to convert max brightness: %s", buf_max);
+		goto out;
+	}
+
+	/* read brightness */
+	path_now = g_build_filename (dir_path, "brightness", NULL);
+	ret = g_file_get_contents (path_now, &buf_now, NULL, &error);
+	if (!ret) {
+		egg_warning ("failed to get brightness: %s", error->message);
+		g_error_free (error);
+		goto out;
+	}
+	kbd_backlight->priv->brightness = g_ascii_strtoull (buf_now, NULL, 10);
+	if (kbd_backlight->priv->brightness <= 0) {
+		egg_warning ("failed to convert brightness: %s", buf_now);
+		goto out;
+	}
+
+	/* open the file for writing */
+	kbd_backlight->priv->fd = open (path_now, O_RDWR);
+	if (kbd_backlight->priv->fd < 0)
+		goto out;
+
+	/* success */
+	found = TRUE;
+out:
+	if (dir != NULL)
+		g_dir_close (dir);
+	g_free (dir_path);
+	g_free (path_max);
+	g_free (path_now);
+	g_free (buf_max);
+	g_free (buf_now);
+	return found;
+}
+
+/**
+ * up_kbd_backlight_init:
+ **/
+static void
+up_kbd_backlight_init (UpKbdBacklight *kbd_backlight)
+{
+	GError *error = NULL;
+
+	kbd_backlight->priv = UP_KBD_BACKLIGHT_GET_PRIVATE (kbd_backlight);
+
+	/* find a kbd backlight in sysfs */
+	if (!up_kbd_backlight_find (kbd_backlight)) {
+		egg_debug ("cannot find a keyboard backlight");
+		return;
+	}
+
+	kbd_backlight->priv->connection = dbus_g_bus_get (DBUS_BUS_SYSTEM, &error);
+	if (error != NULL) {
+		egg_warning ("Cannot connect to bus: %s", error->message);
+		g_error_free (error);
+		return;
+	}
+
+	/* register on the bus */
+	dbus_g_connection_register_g_object (kbd_backlight->priv->connection, "/org/freedesktop/UPower/KbdBacklight", G_OBJECT (kbd_backlight));
+
+}
+
+/**
+ * up_kbd_backlight_finalize:
+ **/
+static void
+up_kbd_backlight_finalize (GObject *object)
+{
+	UpKbdBacklight *kbd_backlight;
+
+	g_return_if_fail (object != NULL);
+	g_return_if_fail (UP_IS_KBD_BACKLIGHT (object));
+
+	kbd_backlight = UP_KBD_BACKLIGHT (object);
+	kbd_backlight->priv = UP_KBD_BACKLIGHT_GET_PRIVATE (kbd_backlight);
+
+	/* close file */
+	close (kbd_backlight->priv->fd);
+
+	G_OBJECT_CLASS (up_kbd_backlight_parent_class)->finalize (object);
+}
+
+/**
+ * up_kbd_backlight_new:
+ **/
+UpKbdBacklight *
+up_kbd_backlight_new (void)
+{
+	UpKbdBacklight *kbd_backlight;
+	kbd_backlight = g_object_new (UP_TYPE_KBD_BACKLIGHT, NULL);
+	return UP_KBD_BACKLIGHT (kbd_backlight);
+}
+