usbmon: Add class for binary interface

Add a class which allows for an easier integration with udev.

This code was originally written by Paolo Abeni, and arrived to my tree
as a part of big patch to add binary API on December 18. As I understand,
Paolo always meant the class to be a part of the whole thing. This is his
udev rule to go along with the patch:

KERNEL=="usbmon[0-9]*", NAME="usbmon%n", MODE="0440",OWNER="root",GROUP="bin"

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 66 insertions, 18 deletions

diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c
index 0af11a6620..c03dfd7a9d 100644
--- a/drivers/usb/mon/mon_bin.c
+++ b/drivers/usb/mon/mon_bin.c
@@ -4,7 +4,7 @@
  * This is a binary format reader.
  *
  * Copyright (C) 2006 Paolo Abeni (paolo.abeni@email.it)
- * Copyright (C) 2006 Pete Zaitcev (zaitcev@redhat.com)
+ * Copyright (C) 2006,2007 Pete Zaitcev (zaitcev@redhat.com)
  */
 
 #include <linux/kernel.h>
@@ -172,6 +172,7 @@ static inline struct mon_bin_hdr *MON_OFF2HDR(const struct mon_reader_bin *rp,
 
 #define MON_RING_EMPTY(rp)      ((rp)->b_cnt == 0)
 
+static struct class *mon_bin_class;
 static dev_t mon_bin_dev0;
 static struct cdev mon_bin_cdev;
 
@@ -1144,10 +1145,38 @@ static void mon_free_buff(struct mon_pgmap *map, int npages)
                 free_page((unsigned long) map[n].ptr);
 }
 
+int mon_bin_add(struct mon_bus *mbus, const struct usb_bus *ubus)
+{
+        struct device *dev;
+        unsigned minor = ubus? ubus->busnum: 0;
+
+        if (minor >= MON_BIN_MAX_MINOR)
+                return 0;
+
+        dev = device_create(mon_bin_class, ubus? ubus->controller: NULL,
+                        MKDEV(MAJOR(mon_bin_dev0), minor), "usbmon%d", minor);
+        if (IS_ERR(dev))
+                return 0;
+
+        mbus->classdev = dev;
+        return 1;
+}
+
+void mon_bin_del(struct mon_bus *mbus)
+{
+        device_destroy(mon_bin_class, mbus->classdev->devt);
+}
+
 int __init mon_bin_init(void)
 {
         int rc;
 
+        mon_bin_class = class_create(THIS_MODULE, "usbmon");
+        if (IS_ERR(mon_bin_class)) {
+                rc = PTR_ERR(mon_bin_class);
+                goto err_class;
+        }
+
         rc = alloc_chrdev_region(&mon_bin_dev0, 0, MON_BIN_MAX_MINOR, "usbmon");
         if (rc < 0)
                 goto err_dev;
@@ -1164,6 +1193,8 @@ int __init mon_bin_init(void)
 err_add:
         unregister_chrdev_region(mon_bin_dev0, MON_BIN_MAX_MINOR);
 err_dev:
+        class_destroy(mon_bin_class);
+err_class:
         return rc;
 }
 
@@ -1171,4 +1202,5 @@ void mon_bin_exit(void)
 {
         cdev_del(&mon_bin_cdev);
         unregister_chrdev_region(mon_bin_dev0, MON_BIN_MAX_MINOR);
+        class_destroy(mon_bin_class);
 }
diff --git a/drivers/usb/mon/mon_main.c b/drivers/usb/mon/mon_main.c
index 8977ec0d0f..ce61d8b0fd 100644
--- a/drivers/usb/mon/mon_main.c
+++ b/drivers/usb/mon/mon_main.c
@@ -220,6 +220,8 @@ static void mon_bus_remove(struct usb_bus *ubus)
         list_del(&mbus->bus_link);
         if (mbus->text_inited)
                 mon_text_del(mbus);
+        if (mbus->bin_inited)
+                mon_bin_del(mbus);
 
         mon_dissolve(mbus, ubus);
         kref_put(&mbus->ref, mon_bus_drop);
@@ -301,8 +303,8 @@ static void mon_bus_init(struct usb_bus *ubus)
         mbus->u_bus = ubus;
         ubus->mon_bus = mbus;
 
-        mbus->text_inited = mon_text_add(mbus, ubus->busnum);
-        // mon_bin_add(...)
+        mbus->text_inited = mon_text_add(mbus, ubus);
+        mbus->bin_inited = mon_bin_add(mbus, ubus);
 
         mutex_lock(&mon_lock);
         list_add_tail(&mbus->bus_link, &mon_buses);
@@ -321,8 +323,8 @@ static void mon_bus0_init(void)
         spin_lock_init(&mbus->lock);
         INIT_LIST_HEAD(&mbus->r_list);
 
-        mbus->text_inited = mon_text_add(mbus, 0);
-        // mbus->bin_inited = mon_bin_add(mbus, 0);
+        mbus->text_inited = mon_text_add(mbus, NULL);
+        mbus->bin_inited = mon_bin_add(mbus, NULL);
 }
 
 /*
@@ -403,6 +405,8 @@ static void __exit mon_exit(void)
 
                 if (mbus->text_inited)
                         mon_text_del(mbus);
+                if (mbus->bin_inited)
+                        mon_bin_del(mbus);
 
                 /*
                  * This never happens, because the open/close paths in
@@ -423,6 +427,8 @@ static void __exit mon_exit(void)
         mbus = &mon_bus0;
         if (mbus->text_inited)
                 mon_text_del(mbus);
+        if (mbus->bin_inited)
+                mon_bin_del(mbus);
 
         mutex_unlock(&mon_lock);
 
diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c
index ec0cc51e39..982b773d71 100644
--- a/drivers/usb/mon/mon_text.c
+++ b/drivers/usb/mon/mon_text.c
@@ -655,20 +655,24 @@ static const struct file_operations mon_fops_text_u = {
         .release =      mon_text_release,
 };
 
-int mon_text_add(struct mon_bus *mbus, int busnum)
+int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus)
 {
         struct dentry *d;
         enum { NAMESZ = 10 };
         char name[NAMESZ];
+        int busnum = ubus? ubus->busnum: 0;
         int rc;
 
-        rc = snprintf(name, NAMESZ, "%dt", busnum);
-        if (rc <= 0 || rc >= NAMESZ)
-                goto err_print_t;
-        d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_t);
-        if (d == NULL)
-                goto err_create_t;
-        mbus->dent_t = d;
+        if (ubus != NULL) {
+                rc = snprintf(name, NAMESZ, "%dt", busnum);
+                if (rc <= 0 || rc >= NAMESZ)
+                        goto err_print_t;
+                d = debugfs_create_file(name, 0600, mon_dir, mbus,
+                                                             &mon_fops_text_t);
+                if (d == NULL)
+                        goto err_create_t;
+                mbus->dent_t = d;
+        }
 
         rc = snprintf(name, NAMESZ, "%du", busnum);
         if (rc <= 0 || rc >= NAMESZ)
@@ -694,8 +698,10 @@ err_print_s:
         mbus->dent_u = NULL;
 err_create_u:
 err_print_u:
-        debugfs_remove(mbus->dent_t);
-        mbus->dent_t = NULL;
+        if (ubus != NULL) {
+                debugfs_remove(mbus->dent_t);
+                mbus->dent_t = NULL;
+        }
 err_create_t:
 err_print_t:
         return 0;
@@ -704,7 +710,8 @@ err_print_t:
 void mon_text_del(struct mon_bus *mbus)
 {
         debugfs_remove(mbus->dent_u);
-        debugfs_remove(mbus->dent_t);
+        if (mbus->dent_t != NULL)
+                debugfs_remove(mbus->dent_t);
         debugfs_remove(mbus->dent_s);
 }
 
diff --git a/drivers/usb/mon/usb_mon.h b/drivers/usb/mon/usb_mon.h
index 13d6325528..f68ad6d99a 100644
--- a/drivers/usb/mon/usb_mon.h
+++ b/drivers/usb/mon/usb_mon.h
@@ -20,9 +20,11 @@ struct mon_bus {
         struct usb_bus *u_bus;
 
         int text_inited;
+        int bin_inited;
         struct dentry *dent_s;          /* Debugging file */
         struct dentry *dent_t;          /* Text interface file */
         struct dentry *dent_u;          /* Second text interface file */
+        struct device *classdev;        /* Device in usbmon class */
 
         /* Ref */
         int nreaders;                   /* Under mon_lock AND mbus->lock */
@@ -52,9 +54,10 @@ void mon_reader_del(struct mon_bus *mbus, struct mon_reader *r);
 
 struct mon_bus *mon_bus_lookup(unsigned int num);
 
-int /*bool*/ mon_text_add(struct mon_bus *mbus, int busnum);
+int /*bool*/ mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus);
 void mon_text_del(struct mon_bus *mbus);
-// void mon_bin_add(struct mon_bus *);
+int /*bool*/ mon_bin_add(struct mon_bus *mbus, const struct usb_bus *ubus);
+void mon_bin_del(struct mon_bus *mbus);
 
 int __init mon_text_init(void);
 void mon_text_exit(void);