V4L/DVB (5507): Pvrusb2: Gather USB bus address info and report it

The V4L2 API requires a unique bus_info string returned as part of the
v4l2_capability structure.  These changes gather up the USB address
information, from the underlying device, into a string and report that
out through v4l2 and via sysfs (for completeness).
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/pvrusb2/pvrusb2-hdw-internal.h

@@ -283,6 +283,8 @@ struct pvr2_hdw {
 	int unit_number;             /* ID for driver instance */
 	unsigned long serial_number; /* ID for hardware itself */
 
+	char bus_info[32]; /* Bus location info */
+
 	/* Minor numbers used by v4l logic (yes, this is a hack, as there
 	   should be no v4l junk here).  Probably a better way to do this. */
 	int v4l_minor_number_video;

drivers/media/video/pvrusb2/pvrusb2-hdw.c

@@ -1008,6 +1008,13 @@ unsigned long pvr2_hdw_get_sn(struct pvr2_hdw *hdw)
 	return hdw->serial_number;
 }
 
+
+const char *pvr2_hdw_get_bus_info(struct pvr2_hdw *hdw)
+{
+	return hdw->bus_info;
+}
+
+
 unsigned long pvr2_hdw_get_cur_freq(struct pvr2_hdw *hdw)
 {
 	return hdw->freqSelector ? hdw->freqValTelevision : hdw->freqValRadio;
@@ -2105,6 +2112,11 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf,
 	hdw->usb_intf = intf;
 	hdw->usb_dev = interface_to_usbdev(intf);
 
+	scnprintf(hdw->bus_info,sizeof(hdw->bus_info),
+		  "usb %s address %d",
+		  hdw->usb_dev->dev.bus_id,
+		  hdw->usb_dev->devnum);
+
 	ifnum = hdw->usb_intf->cur_altsetting->desc.bInterfaceNumber;
 	usb_set_interface(hdw->usb_dev,ifnum,0);
 

drivers/media/video/pvrusb2/pvrusb2-hdw.h

@@ -124,6 +124,9 @@ struct usb_device *pvr2_hdw_get_dev(struct pvr2_hdw *);
 /* Retrieve serial number of device */
 unsigned long pvr2_hdw_get_sn(struct pvr2_hdw *);
 
+/* Retrieve bus location info of device */
+const char *pvr2_hdw_get_bus_info(struct pvr2_hdw *);
+
 /* Called when hardware has been unplugged */
 void pvr2_hdw_disconnect(struct pvr2_hdw *);
 

drivers/media/video/pvrusb2/pvrusb2-sysfs.c

@@ -42,9 +42,11 @@ struct pvr2_sysfs {
 	struct class_device_attribute attr_v4l_minor_number;
 	struct class_device_attribute attr_v4l_radio_minor_number;
 	struct class_device_attribute attr_unit_number;
+	struct class_device_attribute attr_bus_info;
 	int v4l_minor_number_created_ok;
 	int v4l_radio_minor_number_created_ok;
 	int unit_number_created_ok;
+	int bus_info_created_ok;
 };
 
 #ifdef CONFIG_VIDEO_PVRUSB2_DEBUGIFC
@@ -705,6 +707,10 @@ static void class_dev_destroy(struct pvr2_sysfs *sfp)
 	pvr2_sysfs_tear_down_debugifc(sfp);
 #endif /* CONFIG_VIDEO_PVRUSB2_DEBUGIFC */
 	pvr2_sysfs_tear_down_controls(sfp);
+	if (sfp->bus_info_created_ok) {
+		class_device_remove_file(sfp->class_dev,
+					 &sfp->attr_bus_info);
+	}
 	if (sfp->v4l_minor_number_created_ok) {
 		class_device_remove_file(sfp->class_dev,
 					 &sfp->attr_v4l_minor_number);
@@ -735,6 +741,16 @@ static ssize_t v4l_minor_number_show(struct class_device *class_dev,char *buf)
 }
 
 
+static ssize_t bus_info_show(struct class_device *class_dev,char *buf)
+{
+	struct pvr2_sysfs *sfp;
+	sfp = (struct pvr2_sysfs *)class_dev->class_data;
+	if (!sfp) return -EINVAL;
+	return scnprintf(buf,PAGE_SIZE,"%s\n",
+			 pvr2_hdw_get_bus_info(sfp->channel.hdw));
+}
+
+
 static ssize_t v4l_radio_minor_number_show(struct class_device *class_dev,
 					   char *buf)
 {
@@ -836,6 +852,20 @@ static void class_dev_create(struct pvr2_sysfs *sfp,
 		sfp->unit_number_created_ok = !0;
 	}
 
+	sfp->attr_bus_info.attr.owner = THIS_MODULE;
+	sfp->attr_bus_info.attr.name = "bus_info_str";
+	sfp->attr_bus_info.attr.mode = S_IRUGO;
+	sfp->attr_bus_info.show = bus_info_show;
+	sfp->attr_bus_info.store = NULL;
+	ret = class_device_create_file(sfp->class_dev,
+				       &sfp->attr_bus_info);
+	if (ret < 0) {
+		printk(KERN_WARNING "%s: class_device_create_file error: %d\n",
+		       __FUNCTION__, ret);
+	} else {
+		sfp->bus_info_created_ok = !0;
+	}
+
 	pvr2_sysfs_add_controls(sfp);
 #ifdef CONFIG_VIDEO_PVRUSB2_DEBUGIFC
 	pvr2_sysfs_add_debugifc(sfp);

drivers/media/video/pvrusb2/pvrusb2-v4l2.c

@@ -203,6 +203,8 @@ static int pvr2_v4l2_do_ioctl(struct inode *inode, struct file *file,
 		struct v4l2_capability *cap = arg;
 
 		memcpy(cap, &pvr_capability, sizeof(struct v4l2_capability));
+		strlcpy(cap->bus_info,pvr2_hdw_get_bus_info(hdw),
+			sizeof(cap->bus_info));
 
 		ret = 0;
 		break;