From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.kapsi.fi ([217.30.184.167]:36715 "EHLO mail.kapsi.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752087Ab2GTBnX (ORCPT ); Thu, 19 Jul 2012 21:43:23 -0400 Message-ID: <5008B7B0.1020602@iki.fi> Date: Fri, 20 Jul 2012 04:43:12 +0300 From: Antti Palosaari MIME-Version: 1.0 To: Steven Toth CC: linux-media Subject: Re: GPIO interface between DVB sub-drivers (bridge, demod, tuner) References: <4FFF327A.9080300@iki.fi> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 07/13/2012 12:07 AM, Steven Toth wrote: > On Thu, Jul 12, 2012 at 4:49 PM, Steven Toth wrote: >> Nobody understands the relationship between the bridge and the >> sub-component as well as the bridge driver. The current interfaces are >> limiting in many ways. We solve that today with rather ugly 'attach' >> structures that are inflexible, for example to set gpios to a default state. >> Then, once that interface is attached, the bridge effectively loses most of >> the control to the tuner and/or demod. The result is a large disconnect >> between the bridge and subcomponents. >> >> Why limit any interface extension to GPIOs? Why not make something a >> little more flexible so we can pass custom messages around? >> What did you ever decide about the enable/disable of the LNA? And, how >> would the bridge do that in your proposed solution? Via the proposed GPIO >> interface? GPIO / LNA is ready, see following patches: add LNA support for DVB API cxd2820r: use Kernel GPIO for GPIO access em28xx: implement FE set_lna() callback from: http://git.linuxtv.org/anttip/media_tree.git/shortlog/refs/heads/dvb_core Kernel GPIOs were quite easy to implement and use - when needed knowledge was gathered after all the testing and study. I wonder why none was done that earlier for DVB... It also offer nice debug/devel feature as you can mount those GPIOs via sysfs and use directly. Next-step: DVB power management. regards Antti -- http://palosaari.fi/