From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:40873 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754597Ab2FSTOd (ORCPT ); Tue, 19 Jun 2012 15:14:33 -0400 Message-ID: <4FE0D0AF.40801@redhat.com> Date: Tue, 19 Jun 2012 21:19:11 +0200 From: Hans de Goede MIME-Version: 1.0 To: halli manjunatha CC: Mauro Carvalho Chehab , Hans Verkuil , linux-media@vger.kernel.org, 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> <4FE0B802.3080703@redhat.com> 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: Hi, On 06/19/2012 07:43 PM, halli manjunatha wrote: > On Tue, Jun 19, 2012 at 12:33 PM, Hans de Goede wrote: >> 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 > > So with this approach every time during S_FREQ/S_HW_SEEK/S_TUNER > driver will check which tuner mode it is set to and change the tuner > mode (or band) according to tuner field. > > So in my case I will have to support 5 tuner modes (EUROPE, JAPAN, > RUSSIAN, WEATHER and DEFAULT) just like bands. Correct. Regards, Hans