--- On Thu, 1/14/10, Greg KH <greg@xxxxxxxxx> wrote: > From: Greg KH <greg@xxxxxxxxx> > Subject: Re: Simple USB raw data drivers or APIs > To: "Ron Madrid" <ron_madrid@xxxxxxxxxxxxx> > Cc: linux-usb@xxxxxxxxxxxxxxx > Date: Thursday, January 14, 2010, 3:04 PM > On Thu, Jan 14, 2010 at 02:21:55PM > -0800, Ron Madrid wrote: > > Hello all, > > > > I am working with a custom MPC8313 based board > running > > linux and want to have USB communication between my > board > > and a host machine. I would like to make a few > > statements and find out if my assumptions are > correct. > > > > 1. I need to write a gadget driver for my > board. > > Yes, if the existing ones do not work with your hardware. I take it you are talking about the ethernet and serial ones? If not I don't know what you mean by existing ones? > > 2. I need to write a device driver for my host > > machine. > > That depends on the type of usb device you wish your device > to be. > If you pick a "class" device, then no, you will not, as the > host driver > will already be written (usb storage is an example of > this.) > > > 3. I need to write application programs that > open > > each (respective) driver in order to define the > > communication between each device. > > No, it depends on what type of USB device you create. > If it's a storage > device, you access it through the "normal" file apis on the > host > computer. That makes sense. > > Basically, what I want to be able to do is access data > from > > my board and send it back to my host machine via USB, > in a > > similar fashion as send() recv() in socket > > programming. Does there already exist any > drivers that > > implement a generic raw data transfer capability that > can be > > interfaced in this manner? > > Yes, the ethernet gadget device, or the serial one should > work. > > > I do already know about the ethernet over usb drivers > and > > have tried them in the past. I want something > more > > direct and with less overhead. > > Why do you feel the ethernet gadget has too much overhead? I was under the impression that after calling send() or recv() ethernet packets get assembled with the data and these would then be put into the urbs. Am I wrong? > Have you tried the serial one? I have not. But I think I'll give it a go. Worst case it'll be a good exercise. I'm mostly worried about speed. I just want to be able to dump data as quickly as possible. If the ethernet or serial drivers are just as fast as writing my own I can go with those, but I don't know if that is the case. If there are speed benefits from writing my own, that's the route I'll take. Ron -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
