From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:43364 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752053Ab2FSR3P (ORCPT ); Tue, 19 Jun 2012 13:29:15 -0400 Message-ID: <4FE0B802.3080703@redhat.com> Date: Tue, 19 Jun 2012 19:33:54 +0200 From: Hans de Goede MIME-Version: 1.0 To: Mauro Carvalho Chehab CC: Hans Verkuil , linux-media@vger.kernel.org, halli manjunatha , Hans Verkuil Subject: Re: [RFCv2 PATCH 4/6] videodev2.h: add frequency band information. References: <1338202005-10208-1-git-send-email-hverkuil@xs4all.nl> <005651489cd5c9f832df2d5d90e19e2eee07c9b9.1338201853.git.hans.verkuil@cisco.com> <4FDFCC0F.9000208@redhat.com> <4FE037FE.7030804@redhat.com> <4FE05DF4.7030905@redhat.com> <4FE07255.6050606@redhat.com> <4FE08942.8020603@redhat.com> <4FE0AD29.4070300@redhat.com> In-Reply-To: <4FE0AD29.4070300@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi, On 06/19/2012 06:47 PM, Hans de Goede wrote: > Hi, > > a way to enumerate bands, including their rangelow, rangehigh > and capabilities> > > Ok, you've convinced me. I agree that having a way to actually > enumerate ranges, rather then having a fixed set of ranges, is > better. > > Which brings us back many weeks to the proposal for making > it possible to enumerate bands on radio devices. Rather > then digging up the old mails lets start anew, I propose > the following API for this: > > 1. A radio device can have multiple tuners, but only 1 can > be active (streaming audio to the associated audio input) > at the same time. > > 2. Radio device tuners are enumerated by calling G_TUNER > with an increasing index until EINVAL gets returned > > 3. G_FREQUENCY will always return the frequency and index > of the currently active tuner > > 4. When calling S_TUNER on a radio device, the active > tuner will be set to the v4l2_tuner index field > > 5. When calling S_FREQUENCY on a radio device, the active > tuner will be set to the v4l2_frequency tuner field > > 6. On a G_TUNER call on a radio device the rxsubchans, > audmode, signal and afc v4l2_tuner fields are only > filled on for the active tuner (as returned by > G_FREQUENCY) for inactive tuners these fields are reported > as 0. p.s. I forgot: 7. When calling VIDIOC_S_HW_FREQ_SEEK on a radio device, the active tuner will be set to the v4l2_hw_freq_seek tuner field 8. When changing the active tuner with S_TUNER or S_HW_FREQ_SEEK, the current frequency may be changed to fit in the range of the new active tuner 9. For backwards compatibility reasons tuner 0 should be the tuner with the broadest possible FM range Regards, Hans