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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 19FA6E77188 for ; Fri, 20 Dec 2024 19:43:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ECbYktccaIa1QdXtSBa1Z1RFkYlF/wIkrmasp+itWD4=; b=yIiZhlaTW8qB6b//UZ1jkcLBDF Eblfd7QUCxLgTxwNwncXWpkjtETHVYNZKjNJXAkvV6S7/FqflVgbopF5hD6+22SIZ+NlAPUK4RAzR H+6LXwBJyXJKI6acDk6F5qZP7U1wzmt/1cI2dDbjQAPOl/UpaH+OerTm9QawN+P+/EwjDPgoJizPY H+Vbar0IehPiR/beCj3mR6Lrp+CX5118PzJ1tioXWDy5ad/IC6P8KkUv5CE6YYc1gTvKGq92UGLfK wqf/xDGb+ydXEyzkDBCjbSPU9unD+9kOQXf2I8VdKn+swkuDxEJJmIXGg/Tp4R5KDJj+DPYcN5rly rqKt1sSw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tOiu5-00000005yBc-0GTl; Fri, 20 Dec 2024 19:43:17 +0000 Received: from nyc.source.kernel.org ([147.75.193.91]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tOisu-00000005y0z-3CXF for linux-arm-kernel@lists.infradead.org; Fri, 20 Dec 2024 19:42:05 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id DA1B9A41FF8; Fri, 20 Dec 2024 19:40:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4AB6C4CECD; Fri, 20 Dec 2024 19:41:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1734723723; bh=CxGn7Klj0NZdQ41qkc+OiHDFz7q57MzEMRCe/qwiymU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lt5IWLQ1xcngwDOu5pq0XeOMh232j0L6VZGYBxEJTWjGu8/lfocZhtaJO9X9DJQfL 4PS/FBtvRLEl8KACH0uhdhlZ6ZC3tyTIlyP57RkYMDLJeuE6oqiYyY8eFgrhYq0E+j gKWgr7ke+r2lq/CucEnF3dDuKeUcjdOwIEze4K/b2N9jV1Br26dJYOGEjEhQ+Jl1li 2+3U0lezZq/4FzoThBnVuGb3hJ7TwtTIbDlEwWhNfx6wZP0Q1ffBSGs2y5R2IuCd7M TlbGQc33qLdjwYi7hyP/g1rXaLmJdQ9yPfaNq3eWXSCmX8THkEzfM8ahSf3620wceo 7hYgFfFGd4N7Q== Date: Fri, 20 Dec 2024 19:41:57 +0000 From: Conor Dooley To: Tudor Ambarus Cc: Conor Dooley , Jassi Brar , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, andre.draszik@linaro.org, peter.griffin@linaro.org, kernel-team@android.com, willmcvicker@google.com, daniel.lezcano@linaro.org, vincent.guittot@linaro.org, ulf.hansson@linaro.org, arnd@arndb.de Subject: Re: [PATCH 1/2] dt-bindings: mailbox: add support for referencing controllers solely by node Message-ID: <20241220-carving-diagram-a27c04aafb10@spud> References: <20241219-mbox_request_channel_by_args-v1-0-617a6910f842@linaro.org> <20241219-mbox_request_channel_by_args-v1-1-617a6910f842@linaro.org> <20241219-recent-everyone-865b19864693@wendy> <20241219-strum-cheese-89e5e60d22c3@spud> <463d5955-a056-40e1-a46e-f89ac0dadccf@linaro.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Xx+aca69A1IHgTcv" Content-Disposition: inline In-Reply-To: <463d5955-a056-40e1-a46e-f89ac0dadccf@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241220_114204_936587_2882B102 X-CRM114-Status: GOOD ( 21.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --Xx+aca69A1IHgTcv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Dec 20, 2024 at 07:51:32AM +0000, Tudor Ambarus wrote: >=20 >=20 > On 12/19/24 6:58 PM, Conor Dooley wrote: > > On Thu, Dec 19, 2024 at 03:42:11PM +0000, Tudor Ambarus wrote: > >> Hi, Conor, > >> > >> On 12/19/24 2:11 PM, Conor Dooley wrote: > >>>> There are mailbox clients that can discover the mailbox channel ID at > >>>> run-time. For such cases passing the channel identifier via DT is > >>>> redundant. Add support for referencing controllers solely by node. > >>> I don't really get your implementation, why not just allow #mbox-cell= s =3D 0? > >>> That's what's done for things like fixed frequency clocks that only h= ave > >>> a single output. > >> > >> Ah, indeed! > >> > >> instead of: > >> of_parse_phandle(dev->of_node, "mbox", 0); > >> I can do a: > >> of_parse_phandle_with_args(dev->of_node, "mboxes", > >> "#mbox-cells", 0, &of_args) > >> where #mbox-cells =3D 0; > >> > >> Or ... can I pass NULL for cells_name and make the #mbox-cells property > >> optional and still keeping its requirement of being at least 1? > >=20 > > I think the mbox-cells =3D 0 approach is preferred, that property is wh= at > > marks it as a mailbox controller after all. Perhaps Rob or Krzysztof can > > comment? >=20 > I think using mbox-cells =3D 0 is better indeed. In my proposal I > considered the list to always have a single phandle, thus a reference to > a single mailbox controller, whereas it may be possible that clients to > reference multiple mailbox controllers. If so, #mbox-cells needs to be > defined in all the controllers, for consistency reasons, similar to what > happens with fixed clocks, as you already mentioned. Oh right, I had totally forgotten about that, that's a solid argument for the mbox-cells =3D 0 approach for sure. --Xx+aca69A1IHgTcv Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZ2XIhQAKCRB4tDGHoIJi 0sK+AQDCcx/lgCTv+Omz3fHAepr8BVUseHHBs+4WzmyKpR3V4AEAqX3itqXBhmyZ 9veirorpUjlotYZvKUMvTmoTRZswTgA= =SG7R -----END PGP SIGNATURE----- --Xx+aca69A1IHgTcv--