From 948cd8c18c466fdcbe707bb2a42a148796bfccdd Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 9 Oct 2013 17:19:29 +0200 Subject: usbfs: Add support for bulk stream ids This patch makes it possible to specify a bulk stream id when submitting an urb using the async usbfs API. It overloads the number_of_packets usbdevfs_urb field for this. This is not pretty, but given other constraints it is the best we can do. The reasoning leading to this goes as follows: 1) We want to support bulk streams in the usbfs API 2) We do not want to extend the usbdevfs_urb struct with a new member, as that would mean defining new ioctl numbers for all async API ioctls + adding compat versions for the old ones (times 2 for 32 bit support) 3) 1 + 2 means we need to re-use an existing field 4) number_of_packets is only used for isoc urbs, and streams are bulk only so it is the best (and only) candidate for re-using Note that: 1) This patch only uses number_of_packets as stream_id if the app has actually allocated streams on the ep, so that old apps which may have garbage in there (as it was unused until now in the bulk case), will not break 2) This patch does not add support for allocating / freeing bulk-streams, that is done in a follow up patch Signed-off-by: Hans de Goede Signed-off-by: Sarah Sharp --- include/uapi/linux/usbdevice_fs.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/usbdevice_fs.h b/include/uapi/linux/usbdevice_fs.h index 0c65e4b12617..cbf122db56bc 100644 --- a/include/uapi/linux/usbdevice_fs.h +++ b/include/uapi/linux/usbdevice_fs.h @@ -102,7 +102,10 @@ struct usbdevfs_urb { int buffer_length; int actual_length; int start_frame; - int number_of_packets; + union { + int number_of_packets; /* Only used for isoc urbs */ + unsigned int stream_id; /* Only used with bulk streams */ + }; int error_count; unsigned int signr; /* signal to be sent on completion, or 0 if none should be sent. */ -- cgit v1.2.3 From bcf7f6e39335af4f03da8c26a98185fd49754fcc Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 9 Oct 2013 17:19:31 +0200 Subject: usbfs: Add support for allocating / freeing streams This allows userspace to use bulk-streams, just like in kernel drivers, see Documentation/usb/bulk-streams.txt for details on the in kernel API. This is exported pretty much one on one to userspace. To use streams an app must first make a USBDEVFS_ALLOC_STREAMS ioctl, on success this will return the number of streams available (which may be less then requested). If there are n streams the app can then submit usbdevfs_urb-s with their stream_id member set to 1-n to use a specific stream. IE if USBDEVFS_ALLOC_STREAMS returns 4 then stream_id 1-4 can be used. When the app is done using streams it should call USBDEVFS_FREE_STREAMS Note applications are advised to use libusb rather then using the usbdevfs api directly. The latest version of libusb has support for streams. Signed-off-by: Hans de Goede Signed-off-by: Sarah Sharp --- include/uapi/linux/usbdevice_fs.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/usbdevice_fs.h b/include/uapi/linux/usbdevice_fs.h index cbf122db56bc..abe5f4bd4d82 100644 --- a/include/uapi/linux/usbdevice_fs.h +++ b/include/uapi/linux/usbdevice_fs.h @@ -147,6 +147,11 @@ struct usbdevfs_disconnect_claim { char driver[USBDEVFS_MAXDRIVERNAME + 1]; }; +struct usbdevfs_streams { + unsigned int num_streams; /* Not used by USBDEVFS_FREE_STREAMS */ + unsigned int num_eps; + unsigned char eps[0]; +}; #define USBDEVFS_CONTROL _IOWR('U', 0, struct usbdevfs_ctrltransfer) #define USBDEVFS_CONTROL32 _IOWR('U', 0, struct usbdevfs_ctrltransfer32) @@ -179,5 +184,7 @@ struct usbdevfs_disconnect_claim { #define USBDEVFS_RELEASE_PORT _IOR('U', 25, unsigned int) #define USBDEVFS_GET_CAPABILITIES _IOR('U', 26, __u32) #define USBDEVFS_DISCONNECT_CLAIM _IOR('U', 27, struct usbdevfs_disconnect_claim) +#define USBDEVFS_ALLOC_STREAMS _IOR('U', 28, struct usbdevfs_streams) +#define USBDEVFS_FREE_STREAMS _IOR('U', 29, struct usbdevfs_streams) #endif /* _UAPI_LINUX_USBDEVICE_FS_H */ -- cgit v1.2.3