On Fri, Jan 04, 2019 at 06:09:44PM +0200, Ranran wrote: > On Fri, Jan 4, 2019 at 9:57 AM Greg KH <greg@xxxxxxxxx> wrote: > > > > On Fri, Jan 04, 2019 at 08:48:25AM +0200, Ranran wrote: > > > Hello, > > > > > > I would like to ask if it make sense to create pty for a serial real device. > > > > > > The full story: > > > I have FPGA behind PCIe with several devices: serial, i2c and others. > > > I thought of implementing in userspace the device driver using > > > uio_pci_generic (it's basically memory access and interrupts for > > > serial). > > > Now if we need the serial to be like a regular serial in Linux, then I > > > can use the pty with the serial userspace implementation, and then the > > > we get pty device node which can be treated just as a regular tty, > > > Right ? > > > > > > Does it make sense to use pty this way with a real device ? > > > > If your fpga has a uart on it, why not just use a real kernel driver to > > control it? It will be much easier in the long-run that way instead of > > trying to fake it all in userspace. > > > The FPGA has several devices mapped to pci with one vector table for > all these fpga devices. So individual PCI devices? Or one PCI device with different BARs for the different devices? If it's a FPGA, you should be able to reprogram it to look like a standard UART device, that way no kernel changes are needed at all. I recommend doing that as it's the easiest way in the long-term. > Is a platform driver should be used to connect tha uart and the > canbus, each to its pci driver or is it best to write one single pci > driver for all these devices and register each device (uart, canbus) > seperately in the custom pci driver? It all depends on how you have to talk to your device, but if it is PCI, it's not a platform device, it's a PCI device. Don't abuse platform devices :) good luck, greg k-h
