From: Alan Cox Subject: Re: [RFC PATCH 1/3] UART: Add UART subsystem as a bus. Date: Thu, 6 Dec 2012 13:53:41 +0000 Message-ID: <20121206135341.148b325e@pyramind.ukuu.org.uk> References: <6d5fc2e0799c12554aa8acdb2d7782ba8643902b.1354505472.git.lv.zheng@intel.com> <20121204185404.GQ3117@intel.com> <20121204195030.238d1b71@bob.linux.org.uk> <20121205062015.GR3117@intel.com> <20121205094343.09d653c5@pyramind.ukuu.org.uk> <1AE640813FDE7649BE1B193DEA596E88BD6C94@SHSMSX101.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:54879 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755026Ab2LFNs2 (ORCPT ); Thu, 6 Dec 2012 08:48:28 -0500 In-Reply-To: <1AE640813FDE7649BE1B193DEA596E88BD6C94@SHSMSX101.ccr.corp.intel.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: "Zheng, Lv" Cc: Mika Westerberg , Alan Cox , "Brown, Len" , "Wysocki, Rafael J" , Greg Kroah-Hartman , "linux-acpi@vger.kernel.org" , "linux-serial@vger.kernel.org" , Heikki Krogerus , Mathias Nyman , "Huang, Ying" > > We just need a set of type names for the sysfs node I think "bluetooth", "ups", > > "loconet", "serial", "modem", "cir" etc... > > Is it a good idea to introduce uart_device driver in the kernel to fill a new 'ldisc' member in the uart_device or to load ldisc by default for the corresponding tty_port? No but it can provide information to help user space. In many cases the decision isn't about a line discipline but about automatically setting permissions or linking ports to the right driver. The hints need to be generic - they can come from open firmware, from pci identifiers, from ACPI and so on. > Shall we change the uart_bus to the tty_bus, then introduce tty_host / tty_target for the bus? We have a tty class - is that not sufficient ? Alan