> You might want to add the "flash" functionality within the kernel > driver > itself, so you can get a bit tighter timing than relying on a > userspace/kernelspace turn around to provide an accurate timing loop.
I was already considering this. At this point we fork a process to handle the GPIO functionality for us, so we can get reasonable timing on being able to flash the LED. Another process is worring about moving bytes. This is causing lockups in the and stalls in the communications. I've fixed the lockup issue, but I still am dealing with LED process stalling the two comms process. I was definitely considering changing the code so that all the user app would have to do is set the GPIO mode to off, on, and blink, and the Kernel would do all the dirty work. > > That would be interesting to find out. In the past, the company that > made this chip has been very unhelpful, going so far as to publish a > driver that violated the GPL and my copyright :( > Yeah that sucks. I talked to my manager (who did the first run at modifying the driver for GPIO support). He said that he sniffed out the packet with a usb protocol sniffer. He used the dev-kit and toggled the GPIOs to capture the packet with the sniffer. After I complete the changes I'm going to make to the driver, I can definitely forward them on if people are interested in them. I will likely need some guidance on coding standards and the like. > There are lots of other good and documented chips that work very well > with Linux that you might want to look into in the future for stuff > like > this (ftdi_sio is one, and there are others.) > Our hardware manager mentioned this today. That everyone has been giving us the gears for not using the ftdi part in the design. The problem is that their parts aren't rated for industrial temperature range. The cp210x family however is. Hardware requirements were more important than software requirements on that front. If I had my choice the cp210x parts would never be in any of our products. Andrew - To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
