From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BFD1722FDE7; Fri, 9 May 2025 15:48:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746805710; cv=none; b=GFH9P10SXVLfVZfx2sPgZJ3Vb0xhu8oCUn4/R3E62N3JMCp0N1sv8OhBEzDWLes0FQucZMomQX4Ei2gIun/giI/eUTzhiI/BZRUPcakUl8hLkx3q38Dal4ckgwG/jq9e8dGlLIIcPx3xUt+18y8CJplzW6WZBdcf7bgujTknLrQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746805710; c=relaxed/simple; bh=Z/ccOXoCEaNihcY6p2Y764mYYL45MJ+rALkM+IUwoe8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rdw9WDRV0EbmW1ioT8/bnTUcgYXO3nPJQ4/d2VE/6jX48am8Yb9NYsPuHzsfDTF6dcK1GDNpFvLqUHu3hRTMS/WilZ2VfnjKMqwD37+c5s91/4YEVP50Y/MBk9AkQkwOFeQu5iM/nb7UApEGvduE0/MXzvX5ugRdavfLgYBnP64= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IjWuvd9r; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IjWuvd9r" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4622BC4CEEF; Fri, 9 May 2025 15:48:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746805710; bh=Z/ccOXoCEaNihcY6p2Y764mYYL45MJ+rALkM+IUwoe8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IjWuvd9r7Fii+94cxA3vTZy6O0PSohuktwLs/ESa7TAcScbshAHwHs+MDfGMN9PVd BJ0HrtDxDkBmtM5aG2mnm5wIJ1ChHyEbib3TTm+SzK3Hxbl9pujKshBEc7prGkOy50 CID/LqIok0SbvO4EEdzg6HtOBUQiAitMycu6crVcCR7JVMgu/yxWcVMqg5n732JzcZ DWPwwxiRINKNdw15G1mj+PL4iXMjYDanwJYKywWQ87f+2BhFruV/AQYq+RRtlC8XPr G5WRcy1j3I60HqaINX+pm2woaQQ6IeSxLI4zEBO0+xQf5/SszHTgKxtz9QCBRXTcIV qkjGGUqNjB9/g== Date: Fri, 9 May 2025 16:48:25 +0100 From: Conor Dooley To: Mike Looijmans Cc: linux-usb@vger.kernel.org, Alexander Stein , Conor Dooley , Greg Kroah-Hartman , Krzysztof Kozlowski , Rob Herring , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] dt-bindings: usb: ti,usb8041: Add binding for TI USB8044 hub controller Message-ID: <20250509-flagman-bootleg-ad27822f7d53@spud> References: <20250507131143.2243079-1-mike.looijmans@topic.nl> <1b153bce-a66a-45ee-a5c6-963ea6fb1c82.949ef384-8293-46b8-903f-40a477c056ae.3e03400f-766d-4690-8f43-cbea2cac93d8@emailsignatures365.codetwo.com> <20250507131143.2243079-2-mike.looijmans@topic.nl> <20250508-prewashed-jawline-37f53c0f9429@spud> <583dc73e-23d3-4c8a-a457-f2bf71190e6a@topic.nl> <20250508-waving-sustainer-28fe228e01f8@spud> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="n9g9I+OmmxWn4iaj" Content-Disposition: inline In-Reply-To: --n9g9I+OmmxWn4iaj Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, May 09, 2025 at 07:56:35AM +0200, Mike Looijmans wrote: > On 08-05-2025 17:53, Conor Dooley wrote: > > On Thu, May 08, 2025 at 05:19:03PM +0200, Mike Looijmans wrote: > > > On 08-05-2025 16:58, Conor Dooley wrote: > > > > On Wed, May 07, 2025 at 03:11:43PM +0200, Mike Looijmans wrote: > > > > > The TI USB8044 is similar to the USB8041. > > > > Similar how? Why's a fallback not suitable? > > > I don't quite understand what is meant by "fallback" here? > > A fallback compatible, since you;re using the same match data as the > > 8041. >=20 > I think it would work. It would look strange though, having to put an > additional vid/pid in the devicetree to make it work. That's how a huge number of other devices work in devicetree when handling differs between devices. > > > It's similar in that the USB8044 provides the same functionality and = can use > > > the same driver as the USB8041, all that is needed is to add the PID/= VID > > > values. > > Is this onboard_dev_id_table table with the vid/pid used in combination > > with dt, or in-place of dt when device detection is dynamic? If the > > latter, why can't dt use a fallback compatible since the handling is > > identical to the 8041? >=20 > My basic understanding is: >=20 > The devicetree match creates a platform device that controls the reset pin > of the hub. It's basic task is to de-assert the reset, so the hub starts > negotiating. This part also works with the 8041 devicetree entry (which is > how I first tried to get it up and running). >=20 > The VID/PID table then matches the hub on the USB bus, which can then be > associated with its platform device. Since the 8044 reports a different > VID/PID, this part only worked when I added the entries to the tables. Right, so you do actually need to use the dt entry /and/ the dynamic data? In that case, there's little value in a fallback, since you need non-fallback information in the driver for things to work. If that's a correct understanding, Acked-by: Conor Dooley --n9g9I+OmmxWn4iaj Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCaB4jyQAKCRB4tDGHoIJi 0pfCAQCGCGWallUTglxaL9aGMoqKHpRUBAoqvKbvaSLxA9HlwwEAwOUAI1MU7toT 1VyheNOnj9KtDpaBM0yYX5amE/4BHAA= =hpeN -----END PGP SIGNATURE----- --n9g9I+OmmxWn4iaj--