Re: [PATCH 2.6] Class support for ppdev.c

[sebek64@post.cz (Marcel Sebek)]

On Sat, Apr 10, 2004 at 09:28:59PM +0100, viro@parcelfarce.linux.theplanet.co.uk wrote:
> On Sat, Apr 10, 2004 at 09:46:01PM +0200, Marcel Sebek wrote:
> > And new updated patch. partport_find_number() needs to decrement refcount
> > by parport_put_port().
> 
> And it's still broken.  New parports can appear at any point - hell, we even
> have USB->parport converters.  IOW, if you want to do something useful here -
> use ->attach()/->detach() of parport_driver.
> 
Ok. Here's new one. It uses attach()/detach() callbacks for creating
udev and devfs files.


diff -urN linux-2.6/drivers/char/ppdev.c linux-2.6-new/drivers/char/ppdev.c
--- linux-2.6/drivers/char/ppdev.c	2004-04-11 10:11:32.000000000 +0200
+++ linux-2.6-new/drivers/char/ppdev.c	2004-04-11 10:11:57.000000000 +0200
@@ -59,6 +59,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/sched.h>
+#include <linux/device.h>
 #include <linux/devfs_fs_kernel.h>
 #include <linux/ioctl.h>
 #include <linux/parport.h>
@@ -739,6 +740,8 @@
 	return mask;
 }
 
+static struct class_simple *ppdev_class;
+
 static struct file_operations pp_fops = {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
@@ -750,32 +753,64 @@
 	.release	= pp_release,
 };
 
+static void pp_attach(struct parport *port)
+{
+	class_simple_device_add(ppdev_class, MKDEV(PP_MAJOR, port->number),
+			NULL, "parport%d", port->number);
+	devfs_mk_cdev(MKDEV(PP_MAJOR, port->number), S_IFCHR | S_IRUGO | S_IWUGO,
+			"parports/%d", port->number);
+}
+
+static void pp_detach(struct parport *port)
+{
+	devfs_remove("parports/%d", port->number);
+	class_simple_device_remove(MKDEV(PP_MAJOR, port->number));
+}
+
+static struct parport_driver pp_driver = {
+	.name		= CHRDEV,
+	.attach		= pp_attach,
+	.detach		= pp_detach,
+};
+
 static int __init ppdev_init (void)
 {
-	int i;
+	int err = 0;
 
 	if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
 		printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
 			PP_MAJOR);
 		return -EIO;
 	}
+	ppdev_class = class_simple_create(THIS_MODULE, CHRDEV);
+	if (IS_ERR(ppdev_class)) {
+		err = PTR_ERR(ppdev_class);
+		goto out_chrdev;
+	}
 	devfs_mk_dir("parports");
-	for (i = 0; i < PARPORT_MAX; i++) {
-		devfs_mk_cdev(MKDEV(PP_MAJOR, i),
-				S_IFCHR | S_IRUGO | S_IWUGO, "parports/%d", i);
+	if (parport_register_driver(&pp_driver)) {
+		printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
+		goto out_class;
 	}
 
 	printk (KERN_INFO PP_VERSION "\n");
-	return 0;
+	goto out;
+
+out_class:
+	class_simple_destroy(ppdev_class);
+	devfs_remove("parports");
+out_chrdev:
+	unregister_chrdev(PP_MAJOR, CHRDEV);
+out:
+	return err;
 }
 
 static void __exit ppdev_cleanup (void)
 {
-	int i;
 	/* Clean up all parport stuff */
-	for (i = 0; i < PARPORT_MAX; i++)
-		devfs_remove("parports/%d", i);
+	parport_unregister_driver(&pp_driver);
 	devfs_remove("parports");
+	class_simple_destroy(ppdev_class);
 	unregister_chrdev (PP_MAJOR, CHRDEV);
 }
 

-- 
Marcel Sebek
jabber: sebek@jabber.cz                     ICQ: 279852819
linux user number: 307850                 GPG ID: 5F88735E
GPG FP: 0F01 BAB8 3148 94DB B95D  1FCA 8B63 CA06 5F88 735E