Re: Linux USB Documentation

On Fri, Nov 16, 2007 at 02:35:06PM +0530, Srinivas G. wrote:
> Dear All,
> 
> I am a Linux device driver developer. I have developed the USB client
> driver in the Linux environment.

Great, which one?  Do you have a pointer to the code somewhere so we can
add it to the main Linux kernel source tree?

> For this, I have followed the Rubini's
> 3rd Edition LLD book. Now I want to know the interaction among the Linux
> OS, USB Stack and HCD (Host Controller Driver). I mean, what are the
> modules exists in the stack and how they interacts with the OS as well
> as HCD?

They _are_ the OS, there is nothing separating them from the kernel at
all.

And they can interact with the rest of the kernel in whatever way you
want them to, that is their responsibility.

> Suppose, how the HCD driver intimates the stack about when a new
> device attached to the host controller? I think, it is through some
> event mechanism, but I need code flow.

As Oliver pointed out, it is started by the hub driver's kernel thread,
not really an "event mechanism", but just a process that gets woken up.

> I have some experience in HCD development in the Nucleus and it looks
> like as shown below.
> 
> Application
> 	|
> Nucleus OS
> 	|
> Class Drivers
> 	|
> USB Core (USB Stack)
> 	|
> Host Controller Driver (HCD)
> 	|
> Host Controller (Hardware)
> 	|
> USB Device
> 
> Here, in Nucleus, the HCD driver intimates the stack about a new device
> attachment through pending IRP mechanism. 
> 
> I have gone through the following links.
> http://www.linux-usb.org
> http://www.linux-usb.org/USB-guide/book1.html
> http://it.linux-usb.org/FAQ.html
> http://tldp.org/
> http://www.tux.org/lkml/index.html
> http://www.linux-usb.org/usb2.html
> 
> I did not get the information that I need (that is flow among OS, Stack
> and HCD). All these links have old information and I am looking into the
> latest kernel version 2.6.22.

I suggest reading the code itself, that's the best documentation :)

If you have specific questions, please let us know.

thanks,

greg k-h

-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2005.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
[email protected]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel