On Wed, May 18, 2022 at 1:59 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Wed, May 18, 2022 at 01:41:18PM +0200, Belisko Marek wrote: > > Hello, > > > > I'm writing serial tty driver (it's SPI/UART converter) and I get > > inspired by this driver: > > https://github.com/raspberrypi/linux/blob/rpi-5.15.y/drivers/tty/serial/sc16is7xx.c > > > > I have driver probed and also added port to driver which I see in console: > > [ 2616.826105] spi0.0: ttyTX0 at I/O 0x1 (irq = 0, base_baud = 9375) > > is a test_driver > > > > so I should see it in /dev/ttyTX0 but it seems node is not created. > > Udev is running on a platform. > > Any ideas what can cause this? > > Without seeing the code itself, it's almost impossible to guess. > > Also note that udev does not create device nodes (hasn't for over a > decade). devtmpfs in the kernel does that, udev just helps with > managing the permissions of created nodes if needed. OK thanks for clarification. > > And why did you pick the ttyTX name? That's already reserved for that > driver, you should use a new one, right? I've should used also others like ttyTEST but result was same. > > And what hardware are you writing this driver for that we don't already > have a driver for it? I'm writing a driver for the following model: Linux CPU is connected with SPI with another CPU (Cortex M3) and this other CPU performs UART handling based on data which comes over SPI. I would like to expose Cortex M3 UARTS on linux as tty ports so it will act as standar serial device. Code can be found here: https://pastebin.com/6qpUw2Jt Thanks, marek > > thanks, > > greg k-h
