From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.kapsi.fi ([217.30.184.167]:44478 "EHLO mail.kapsi.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753057Ab3KURFJ (ORCPT ); Thu, 21 Nov 2013 12:05:09 -0500 Message-ID: <528E3D41.5010508@iki.fi> Date: Thu, 21 Nov 2013 19:05:05 +0200 From: Antti Palosaari MIME-Version: 1.0 To: LMML , Mauro Carvalho Chehab , Hans Verkuil , Hans de Goede Subject: SDR sampling rate - control or IOCTL? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hello I am adding new property for sampling rate that is ideally the only obligatory parameter required by SDR. It is value that could be only positive and bigger the better, lets say unsigned 64 bit is quite ideal. That value sets maximum radio frequency possible to receive (ideal SDR). Valid values are not always in some single range from X to Y, there could be some multiple value ranges. For example possible values: 1000-2000, 23459, 900001-2800000 Reading possible values from device could be nice, but not necessary. Reading current value is more important. Here is what I though earlier as a requirements: sampling rate * values: 1 - infinity (unit: Hz, samples per second) currently 500 MHz is more than enough * operations GET, inquire what HW supports GET, get current value SET, set desired value I am not sure what is best way to implement that kind of thing. IOCTL like frequency V4L2 Control? put it into stream format request? Sampling rate is actually frequency of ADC. As there devices has almost always tuner too (practical SDR) there is need for tuner frequency too. As tuner is still own entity, is it possible to use same frequency parameter for both ADC and RF tuner in same device? regards Antti -- http://palosaari.fi/