mirror of
https://github.com/adulau/aha.git
synced 2024-12-27 03:06:10 +00:00
DOC: A couple corrections and clarifications in USB doc.
A couple of corrections and clarifications in USB documentation. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
This commit is contained in:
parent
37679011c5
commit
838cb6aba4
1 changed files with 7 additions and 7 deletions
|
@ -100,8 +100,8 @@
|
|||
useful documents, at the USB home page (see Resources). An excellent
|
||||
introduction to the Linux USB subsystem can be found at the USB Working
|
||||
Devices List (see Resources). It explains how the Linux USB subsystem is
|
||||
structured and introduces the reader to the concept of USB urbs, which
|
||||
are essential to USB drivers.
|
||||
structured and introduces the reader to the concept of USB urbs
|
||||
(USB Request Blocks), which are essential to USB drivers.
|
||||
</para>
|
||||
<para>
|
||||
The first thing a Linux USB driver needs to do is register itself with
|
||||
|
@ -162,8 +162,8 @@ static int __init usb_skel_init(void)
|
|||
module_init(usb_skel_init);
|
||||
</programlisting>
|
||||
<para>
|
||||
When the driver is unloaded from the system, it needs to unregister
|
||||
itself with the USB subsystem. This is done with the usb_unregister
|
||||
When the driver is unloaded from the system, it needs to deregister
|
||||
itself with the USB subsystem. This is done with the usb_deregister
|
||||
function:
|
||||
</para>
|
||||
<programlisting>
|
||||
|
@ -232,7 +232,7 @@ static int skel_probe(struct usb_interface *interface,
|
|||
were passed to the USB subsystem will be called from a user program trying
|
||||
to talk to the device. The first function called will be open, as the
|
||||
program tries to open the device for I/O. We increment our private usage
|
||||
count and save off a pointer to our internal structure in the file
|
||||
count and save a pointer to our internal structure in the file
|
||||
structure. This is done so that future calls to file operations will
|
||||
enable the driver to determine which device the user is addressing. All
|
||||
of this is done with the following code:
|
||||
|
@ -252,8 +252,8 @@ file->private_data = dev;
|
|||
send to the device based on the size of the write urb it has created (this
|
||||
size depends on the size of the bulk out end point that the device has).
|
||||
Then it copies the data from user space to kernel space, points the urb to
|
||||
the data and submits the urb to the USB subsystem. This can be shown in
|
||||
he following code:
|
||||
the data and submits the urb to the USB subsystem. This can be seen in
|
||||
the following code:
|
||||
</para>
|
||||
<programlisting>
|
||||
/* we can only write as much as 1 urb will hold */
|
||||
|
|
Loading…
Reference in a new issue