Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754889Ab0KRUCk (ORCPT ); Thu, 18 Nov 2010 15:02:40 -0500 Received: from cantor2.suse.de ([195.135.220.15]:56937 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753878Ab0KRUCi (ORCPT ); Thu, 18 Nov 2010 15:02:38 -0500 Date: Thu, 18 Nov 2010 12:02:30 -0800 From: Greg KH To: Timur Tabi Cc: Arnd Bergmann , Linux Kernel Mailing List , Scott Wood , Stuart Yoder Subject: Re: How do I choose an arbitrary minor number for my tty device? Message-ID: <20101118200230.GA25715@suse.de> References: <20101118153912.GA1443@suse.de> <4CE54E40.9040503@freescale.com> <20101118163321.GA2723@suse.de> <4CE5562B.8080604@freescale.com> <20101118165136.GA3103@suse.de> <4CE55ACB.80207@freescale.com> <20101118171856.GA4283@suse.de> <4CE5647F.5000203@freescale.com> <20101118175832.GA4931@suse.de> <4CE58005.7040308@freescale.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4CE58005.7040308@freescale.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2891 Lines: 73 On Thu, Nov 18, 2010 at 01:35:33PM -0600, Timur Tabi wrote: > Greg KH wrote: > >> I just booted a Linux kernel with the driver I just emailed you, and there's no > >> > /dev/serial/ directory. The only directories under /dev/ are 'shm' and 'pts', > >> > both of which are empty. > > > Then plug in a serial port device and see what happens. You didn't hook > > everything up in your driver correctly it seems, do your devices show up > > under /sys/class/tty? > > If I delete the call to device_create() in ehv_bc_init() (so that it creates the > TTY devices only, and not the character devices), I get this: > > # ls -l /sys/class/tty/ttyEHV* > lrwxrwxrwx 1 root root 0 Jan 1 00:04 /sys/class/tty/ttyEHV0 > -> ../../devices/virtual/tty/ttyEHV0 > lrwxrwxrwx 1 root root 0 Jan 1 00:04 /sys/class/tty/ttyEHV1 > -> ../../devices/virtual/tty/ttyEHV1 > lrwxrwxrwx 1 root root 0 Jan 1 00:04 /sys/class/tty/ttyEHV2 > -> ../../devices/virtual/tty/ttyEHV2 > > >> > I'm also running a Fedora 13 x86 system, just to see if I need a full modern OS > >> > to see these files. Again, there is no /dev/serial/, even though I have serial > >> > ports. > > Dynamic ones like a usb to serial device? > > No, not dynamic ones. > > >> > Also not that since I'm not registering the byte channels as serial devices, I > >> > wouldn't expect anything in /dev/serial/ to reference them. > >> > > >> > What does my driver need to do in order for these /dev/xxxx/ entries to contain > >> > that information? > > > See the udev rules for details. > > udev rules still need some way for the driver to tell user-space that > /dev/ttyEHV0 is associated with byte channel handle 73. I still don't know what > mechanism my driver is supposed to use to make that information available to > user space. > > I could fake it by doing this: > > for (i = 0; i < num_byte_channels; i++) { > bc->handle = get_the_byte_channel_handle(i); > ehv_bc_driver->name_base = bc->handle - i; > tty_register_device(ehv_bc_driver, i, NULL); Why are you not setting up a parent device of your tty device? That should be essencial. > } > > This actually works and does what I want, but I seriously doubt it's acceptable. > When I do this, I get: > > # ls -l /dev/ttyEH* > crw-rw---- 1 root uucp 253, 0 Jan 1 00:00 /dev/ttyEHV73 > crw-rw---- 1 root uucp 253, 1 Jan 1 00:00 /dev/ttyEHV76 > crw-rw---- 1 root uucp 253, 2 Jan 1 00:00 /dev/ttyEHV79 Does that work for you? Looks fine to me :) But again, you really should get the driver model portion right... thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/