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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACF89C46467 for ; Tue, 10 Jan 2023 22:01:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231136AbjAJWB3 (ORCPT ); Tue, 10 Jan 2023 17:01:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57480 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231808AbjAJWBV (ORCPT ); Tue, 10 Jan 2023 17:01:21 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB547183A4; Tue, 10 Jan 2023 14:01:19 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8E9C9B819B6; Tue, 10 Jan 2023 22:01:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3819AC433D2; Tue, 10 Jan 2023 22:01:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673388077; bh=M5rts+D30gn+VWBW52xohLqDKxs2pcijUxIUeXZGA1U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PliotbDymRLYIkcaTmlGbbwKLVSGDgWxgLy8o/JeEYOU1sCncW4M1p+Y5krZKt75o p5+QLMiwo9Fbp1GugcLkut7w5jhPRVNMJQkkv4TyG/krRkAPHj7StmYpT7CSDPIVxA uc2FTsrW4qZCGgiw/zuJsQegcumY+oxYq5uAUiDLDcs7+1xYpPXsdwTmxL8bYDgosd IsP//3x0a3THLQssrE1BqJPSw4KcyYTXoLtoORduuniDF6+YbAEq3pNRXO3MgSfmr5 d2Aym4psoCiVAtwFHIFldXrTkje+YZa5E6Rke65dMX58VdSm1wOayfb0NmfuYM/x9U tpIOpon3+yrJA== Date: Tue, 10 Jan 2023 22:01:10 +0000 From: Mark Brown To: William Zhang Cc: Rob Herring , Linux SPI List , Broadcom Kernel List , anand.gore@broadcom.com, tomer.yacoby@broadcom.com, dan.beygelman@broadcom.com, joel.peshkin@broadcom.com, f.fainelli@gmail.com, jonas.gorski@gmail.com, kursad.oney@broadcom.com, dregan@mail.com, Krzysztof Kozlowski , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 03/16] dt-bindings: spi: Add spi peripheral specific property Message-ID: References: <20230106200809.330769-1-william.zhang@broadcom.com> <20230106200809.330769-4-william.zhang@broadcom.com> <3ff9a7fa-25dd-701c-078e-03e47bd3c08b@broadcom.com> <6720e3a4-dbbb-f490-98db-511a52b9a2ab@broadcom.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="8k6YxWNEbCoXLS2/" Content-Disposition: inline In-Reply-To: X-Cookie: Live free or die. Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --8k6YxWNEbCoXLS2/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Jan 09, 2023 at 12:18:09PM -0800, William Zhang wrote: > This setting is set per spi message for particular chip select of the device > when starting the message through bcm63xx_hsspi_set_clk function and restore > to default(clock gating) when message is done through > bcm63xx_hsspi_restore_clk_gate. In that case I am extremely confused about what the feature is supposed to do. The description says: + brcm,no-clk-gate: + $ref: /schemas/types.yaml#/definitions/flag + description: + Some SPI device such as Broadcom ISI based voice daughtercard requires +SPI + clock running even when chip select is deasserted. By default the + controller turns off or gate the clock when cs is not active to save + power. This flag tells the controller driver to keep the clock running + when chip select is not active. which to me sounds like the clock should never be turned off and instead left running at all times. Switching back to clock gating after sending the message doesn't seem to correspond to the above at all, the message being done would normally also be the point at which chip select is deasserted. --8k6YxWNEbCoXLS2/ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmO94CUACgkQJNaLcl1U h9CdJAf/QI6A4fWPY4QxulQZlgN08+3prwWv5cDXiANd7ma60ajOD9YwY0ajx9gb iM6BzxPjLHgbRvvR0WtDxt47NWLBJr2rf9B4hBTjr5EZdX2fWurcx3aJTnD+eNG2 x7zASz234aU7ZEPr3jNsm/JAs2nJYJDiAVBSNPuplyX4fDmPUZQmrDBP3uaAhdO9 7WzWvaPY8ZomdB4V1Onv0oz9x8xXX/c0Ngx36V4XR1zsOqbnbzValVoHDJ6y3geu d6ejtbA1wtuowzV3csuYVq/tkw3Az9h9idivu3UW7qaTmvjIUL374AHeSUUG+b1C Dr4pP7nqnpJkzBu179zn+QlTBB/j0A== =qE5i -----END PGP SIGNATURE----- --8k6YxWNEbCoXLS2/--