Re: [PATCH]

On Wed, 2007-02-21 at 21:23 +0000, James Simmons wrote:

This is the new display intreface. Its goal is to provide a standard 
interface to various types of displays. Currently we have auxdisplay, 
output acpi device and the now defunct lcd class in the backlight directory.
Please apply.

Is this an attempt to consolidate all display hardware and drivers?

[snip]

+struct class *display_class;
+EXPORT_SYMBOL(display_class);
+static int index;
+
+struct display_device *display_device_register(struct display_driver *driver,
+						struct device *dev, void *devdata)
+{
+	struct display_device *new_dev = NULL;
+	int ret = -EINVAL;
+
+	if (unlikely(!driver))
+		return ERR_PTR(ret);
+
+	new_dev = kzalloc(sizeof(struct display_device), GFP_KERNEL);
+	if (likely(new_dev) && unlikely(driver->probe(new_dev, devdata))) {
+		new_dev->dev = device_create(display_class, dev, 0,
+						"display%d", index);
+
+		if (!IS_ERR(new_dev->dev)) {
+			dev_set_drvdata(new_dev->dev, new_dev);
+			new_dev->driver = driver;
+			new_dev->parent = dev;
+			mutex_init(&new_dev->lock);
+			index++;
+		} else {
+			new_dev->dev = NULL;
+			kfree(new_dev);

Set new_dev to NULL on failure.

+		}
+	}
+	return new_dev;
+}
+EXPORT_SYMBOL(display_device_register);
+
+void display_device_unregister(struct display_device *ddev)
+{
+	if (!ddev)
+		return;
+	mutex_lock(&ddev->lock);
+	device_del(ddev->dev);
+	ddev->driver = NULL;
+	index--;

display0
display1
index = 2
unregister display0
index = 1
display_device_register() as device1
device1 <-- BUG, already used.

[snip]

+
+struct display_device;
+
+/* This structure defines all the properties of a Display. */
+struct display_driver {
+	int  (*set_contrast)(struct display_device *, unsigned int);
+	int  (*get_contrast)(struct display_device *);
+	void (*suspend)(struct display_device *, pm_message_t state);
+	void (*resume)(struct display_device *);
+	int  (*probe)(struct display_device *, void *);
+	int  (*remove)(struct display_device *);
+	int  max_contrast;

If this is an attempt to consolidate, I don't see the 'brightness'
hook of backlight and lcd.

If this is not a consolidation, why don't we just extend the lcd class?

Tony 



-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys-and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV