Alan, > -----Original Message----- > From: Alan Cox [mailto:alan@xxxxxxxxxxxxxxxxxxx] > Sent: Thursday, October 07, 2010 2:38 PM > To: Savoy, Pavan > Cc: Jiri Slaby; gregkh@xxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > devel@xxxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH 1/2] drivers:staging:ti-st: move TI_ST from staging > > > The situation here was to access the UART from a kernel driver. Say we have > > a V4L2 FM radio over the UART, How can I write a v4L2 driver? I has to be a > > line discipline driver correct? > > Why would you want to ? you can just control it from user space. If you > did want to drive it from the kernel then an ldisc would be one way to do > it I guess. ldisc is the ONLY way to do it, isn't it? Do I have any other option? The situation was something similar here. What I was trying to get to is how we can have a per-device context if a driver is just a line discipline driver? Few months ago, something similar was discussed.... I have 3 sub-devices if you will on a device which is interfaced over UART, One of them is Bluetooth which requires any UART Bluetooth device to have its Own line discipline - N_HCI. Another is FM, which needs to be a V4L2 device. Now being V4L2 device, I need to access the UART from kernel, but I cannot since BT would be using it via the N_HCI ldisc. Coming to what Jiri, was commenting was about the ldisc_ops structure, which Just needs to be static and not really kmalloc-ed in heap. I did it because, I imagined some day TTY ldisc drivers had capability to have It's own per-device context/private_data (in addition to) tty driver_data or Something like tty ldisc_data would be good. > Alan _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
