Pull output-switch into test branch

Documentation/video-output.txt

+
+		Video Output Switcher Control
+		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+		2006 luming.yu@intel.com
+
+The output sysfs class driver provides an abstract video output layer that
+can be used to hook platform specific methods to enable/disable video output
+device through common sysfs interface. For example, on my IBM ThinkPad T42
+laptop, The ACPI video driver registered its output devices and read/write
+method for 'state' with output sysfs class. The user interface under sysfs is:
+
+linux:/sys/class/video_output # tree .
+.
+|-- CRT0
+|   |-- device -> ../../../devices/pci0000:00/0000:00:01.0
+|   |-- state
+|   |-- subsystem -> ../../../class/video_output
+|   `-- uevent
+|-- DVI0
+|   |-- device -> ../../../devices/pci0000:00/0000:00:01.0
+|   |-- state
+|   |-- subsystem -> ../../../class/video_output
+|   `-- uevent
+|-- LCD0
+|   |-- device -> ../../../devices/pci0000:00/0000:00:01.0
+|   |-- state
+|   |-- subsystem -> ../../../class/video_output
+|   `-- uevent
+`-- TV0
+   |-- device -> ../../../devices/pci0000:00/0000:00:01.0
+   |-- state
+   |-- subsystem -> ../../../class/video_output
+   `-- uevent
+

drivers/video/output.c

+/*
+ *  output.c - Display Output Switch driver
+ *
+ *  Copyright (C) 2006 Luming Yu <luming.yu@intel.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/module.h>
+#include <linux/video_output.h>
+#include <linux/err.h>
+#include <linux/ctype.h>
+
+
+MODULE_DESCRIPTION("Display Output Switcher Lowlevel Control Abstraction");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Luming Yu <luming.yu@intel.com>");
+
+static ssize_t video_output_show_state(struct class_device *dev,char *buf)
+{
+	ssize_t ret_size = 0;
+	struct output_device *od = to_output_device(dev);
+	if (od->props)
+		ret_size = sprintf(buf,"%.8x\n",od->props->get_status(od));
+	return ret_size;
+}
+
+static ssize_t video_output_store_state(struct class_device *dev,
+	const char *buf,size_t count)
+{
+	char *endp;
+	struct output_device *od = to_output_device(dev);
+	int request_state = simple_strtoul(buf,&endp,0);
+	size_t size = endp - buf;
+
+	if (*endp && isspace(*endp))
+		size++;
+	if (size != count)
+		return -EINVAL;
+
+	if (od->props) {
+		od->request_state = request_state;
+		od->props->set_state(od);
+	}
+	return count;
+}
+
+static void video_output_class_release(struct class_device *dev)
+{
+	struct output_device *od = to_output_device(dev);
+	kfree(od);
+}
+
+static struct class_device_attribute video_output_attributes[] = {
+	__ATTR(state, 0644, video_output_show_state, video_output_store_state),
+	__ATTR_NULL,
+};
+
+static struct class video_output_class = {
+	.name = "video_output",
+	.release = video_output_class_release,
+	.class_dev_attrs = video_output_attributes,
+};
+
+struct output_device *video_output_register(const char *name,
+	struct device *dev,
+	void *devdata,
+	struct output_properties *op)
+{
+	struct output_device *new_dev;
+	int ret_code = 0;
+
+	new_dev = kzalloc(sizeof(struct output_device),GFP_KERNEL);
+	if (!new_dev) {
+		ret_code = -ENOMEM;
+		goto error_return;
+	}
+	new_dev->props = op;
+	new_dev->class_dev.class = &video_output_class;
+	new_dev->class_dev.dev = dev;
+	strlcpy(new_dev->class_dev.class_id,name,KOBJ_NAME_LEN);
+	class_set_devdata(&new_dev->class_dev,devdata);
+	ret_code = class_device_register(&new_dev->class_dev);
+	if (ret_code) {
+		kfree(new_dev);
+		goto error_return;
+	}
+	return new_dev;
+
+error_return:
+	return ERR_PTR(ret_code);
+}
+EXPORT_SYMBOL(video_output_register);
+
+void video_output_unregister(struct output_device *dev)
+{
+	if (!dev)
+		return;
+	class_device_unregister(&dev->class_dev);
+}
+EXPORT_SYMBOL(video_output_unregister);
+
+static void __exit video_output_class_exit(void)
+{
+	class_unregister(&video_output_class);
+}
+
+static int __init video_output_class_init(void)
+{
+	return class_register(&video_output_class);
+}
+
+postcore_initcall(video_output_class_init);
+module_exit(video_output_class_exit);

include/linux/video_output.h

+/*
+ *
+ *  Copyright (C) 2006 Luming Yu <luming.yu@intel.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#ifndef _LINUX_VIDEO_OUTPUT_H
+#define _LINUX_VIDEO_OUTPUT_H
+#include <linux/device.h>
+struct output_device;
+struct output_properties {
+	int (*set_state)(struct output_device *);
+	int (*get_status)(struct output_device *);
+};
+struct output_device {
+	int request_state;
+	struct output_properties *props;
+	struct class_device class_dev;
+};
+#define to_output_device(obj) container_of(obj, struct output_device, class_dev)
+struct output_device *video_output_register(const char *name,
+	struct device *dev,
+	void *devdata,
+	struct output_properties *op);
+void video_output_unregister(struct output_device *dev);
+#endif