From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64892C432BE for ; Thu, 2 Sep 2021 11:03:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37D2860FDA for ; Thu, 2 Sep 2021 11:03:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233828AbhIBLEv (ORCPT ); Thu, 2 Sep 2021 07:04:51 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:39710 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S232113AbhIBLEu (ORCPT ); Thu, 2 Sep 2021 07:04:50 -0400 X-UUID: 86b3d324245c45f1b14f9e8fb3201383-20210902 X-UUID: 86b3d324245c45f1b14f9e8fb3201383-20210902 Received: from mtkmbs10n1.mediatek.inc [(172.21.101.34)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 1238895030; Thu, 02 Sep 2021 19:03:49 +0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs05n1.mediatek.inc (172.21.101.15) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 2 Sep 2021 19:03:47 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Thu, 2 Sep 2021 19:03:47 +0800 From: YP WU To: CC: , , , , , , , , Subject: Re: How to use "DTV_FE_CAPABILITY" command for Frontend.h of Linux DVB Date: Thu, 2 Sep 2021 19:03:47 +0800 Message-ID: <20210902110347.14939-1-yp.wu@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20210715095933.63dbcd31@coco.lan> References: <20210715095933.63dbcd31@coco.lan> MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hello, Mr.Mauro, Frist of all, thanks for your reply and Sorry to reply late. We know that everything is controlled by /dev/dvb/frontend. It is assumed that the device node "dvb/frontend0", "dvb/frontend1" and "dvb/frontend2" use the input signal from the same satellite antenna. In addition, "dvb/frontend0", "dvb/frontend1", and "dvb/frontend2" are premised on receiving broadcast signals at the same time under the condition that the same voltage is always supplied to the satellite antenna. Therefore, Our TV uses an HW circuit equipped with only one LNB IC. Since only one LNB IC is installed, the design policy of including and controlling the same LNB IC in "dvb/frontend0", "dvb/frontend1" and "dvb/frontend2" is complicated and difficult to understand. It is more simpler and easier to design to separate the LNB IC into "dvb/frontend3" and control the LNB IC from "dvb0.frontend3". Therefore, we want to separate LNB to different device node. BRs, YP