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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=unavailable 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 1F3ADC43610 for ; Mon, 12 Nov 2018 21:19:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7C322243E for ; Mon, 12 Nov 2018 21:19:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D7C322243E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goldelico.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730500AbeKMHOR convert rfc822-to-8bit (ORCPT ); Tue, 13 Nov 2018 02:14:17 -0500 Received: from mo4-p01-ob.smtp.rzone.de ([81.169.146.164]:17371 "EHLO mo4-p01-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727267AbeKMHOR (ORCPT ); Tue, 13 Nov 2018 02:14:17 -0500 X-RZG-AUTH: ":JGIXVUS7cutRB/49FwqZ7WcJeFKiMgPgp8VKxflSZ1P34KBj5Qpw97WFDlSUXA0LOA==" X-RZG-CLASS-ID: mo00 Received: from imac.fritz.box by smtp.strato.de (RZmta 44.3 AUTH) with ESMTPSA id J0aaaduACLJ3xGQ (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (curve secp521r1 with 521 ECDH bits, eq. 15360 bits RSA)) (Client did not present a certificate); Mon, 12 Nov 2018 22:19:03 +0100 (CET) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Subject: Re: [Letux-kernel] [PATCH RFC] bluetooth: add uart h4 devices via serdev/devicetree From: "H. Nikolaus Schaller" In-Reply-To: <20181112215812.18ebca35@aktux> Date: Mon, 12 Nov 2018 22:19:02 +0100 Cc: Sebastian Reichel , devicetree , Johan Hedberg , Marcel Holtmann , LKML , "open list:BLUETOOTH DRIVERS" , Discussions about the Letux Kernel Content-Transfer-Encoding: 8BIT Message-Id: <2C74C837-A6D3-47C9-BE59-CCA594289B94@goldelico.com> References: <20181110232034.17277-1-andreas@kemnade.info> <20181111024648.7rt7rlhaqihtqecv@earth.universe> <20181112215812.18ebca35@aktux> To: Andreas Kemnade X-Mailer: Apple Mail (2.3124) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Am 12.11.2018 um 21:59 schrieb Andreas Kemnade : > > Hi, > > On Sun, 11 Nov 2018 03:46:48 +0100 > Sebastian Reichel wrote: > >> Hi, >> >> On Sun, Nov 11, 2018 at 12:20:34AM +0100, Andreas Kemnade wrote: >>> This is a first try to be able to use h4 devices specified in >>> the devicetree, so you do not need to call hciattach and >>> it can be automatically probed. >>> >>> Of course, proper devicetree bindings documentation is >>> missing. And also you would extend that by regulator/ >>> enable gpio settings. >>> >>> But before proceeding further it should be checked if the >>> general way of doing things is right. >>> >>> Signed-off-by: Andreas Kemnade >>> --- >> >> Patch looks good to me, just one note >> > I found one thing myself: > Shouldn't we have a generic compatible string like "generic-h4". > ehci-platform.c has for example: > { .compatible = "generic-ehci", }, There might be differences in h4 compatible devices (e.g. default baud rate) so that I would not bet there a "generic-h4" suffices in the long run. And, shouldn't there be a vendor prefix anyways? I.e. something like "bluetooth,h4"? Because it seems to be defined in https://www.bluetooth.org/docman/handlers/DownloadDoc.ashx?doc_id=41266 On the other hand, with hci-ll protocol the compatible strings are chip variants. Well, this seems to be required to decide which firmware to download. So it boils down to if DT compatibility should be compatible to generic functions or specific chips? AFAI see this is more or less random and there seems to be no general rule. Just some thoughts but no strong preference. BR, Nikolaus