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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4370EC433EF for ; Thu, 11 Nov 2021 15:01:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2835E61252 for ; Thu, 11 Nov 2021 15:01:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233716AbhKKPEL (ORCPT ); Thu, 11 Nov 2021 10:04:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:41050 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230177AbhKKPEH (ORCPT ); Thu, 11 Nov 2021 10:04:07 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0CBC1610A2; Thu, 11 Nov 2021 15:01:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636642878; bh=uS7AjnXMAtTTLK2QXT7jX014gaj/3UVYVDR6aRPON98=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=W5ovTJil3ubv82wwqLB2yw9MZ3IehldRT16BUotCXwAerMxBegV1j1cFwKBho2lVP QdNvgIHtBd4JA1W+FZ8Po7F1yz0RNmx8WSxykS6/IMoiBl6boZWXC/wqqntQ5Om+z8 jsmQ0wzQbVdcMRKNF+jiN8oewSCzSZCJ1c7W1E14RaLbYZZBTWMf3SL1lydAG3e1Bb w9OZPkxydOKU94CwSJ7XS2JmheEy1iFBGnWFk3XdSh280A1kghB7IqeLMbtuDCuqhC WdaTF28E5D2F7mjlpkYZY5qflopmvCXXmGcS/m2keY+DZQJik8/DkKbuhQv0CKU3yK TI+/qiMTAku5g== Date: Thu, 11 Nov 2021 15:01:12 +0000 From: Mark Brown To: Serge Semin Cc: nandhini.srikandan@intel.com, Serge Semin , robh+dt@kernel.org, linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, mgross@linux.intel.com, kris.pan@intel.com, kenchappa.demakkanavar@intel.com, furong.zhou@intel.com, mallikarjunappa.sangannavar@intel.com, mahesh.r.vaidya@intel.com, rashmi.a@intel.com Subject: Re: [PATCH v3 1/5] dt-bindings: spi: Add SSTE support for DWC SSI controller Message-ID: References: <20211111065201.10249-1-nandhini.srikandan@intel.com> <20211111065201.10249-2-nandhini.srikandan@intel.com> <20211111143108.pxovseqvm2ywmoc2@mobilestation> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="msY2aCMFe/FNn5o4" Content-Disposition: inline In-Reply-To: <20211111143108.pxovseqvm2ywmoc2@mobilestation> X-Cookie: Teutonic: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --msY2aCMFe/FNn5o4 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Nov 11, 2021 at 05:31:08PM +0300, Serge Semin wrote: > BTW Mark, why not to have a generic DT-property which would set that > flag automatically by the SPI-core subsystem seeing it's indeed a > client device-property? For instance there can be some property like > "spi-cs-toggle" DT-property which when specified for the particular > SPI-client DT-node will make the SPI-core subsystem to set the Anything like this is fundamentally part of the wire protocol for the device, there's no need for an extra property on top of the compatible for the device and the driver really, really needs to know what's going on to avoid data corruption. You could also use this feature together with varying the word size as an optimisation at runtime (eg, do long sequences of register writes in a single hardware operation by setting an appropriate word length to cause the controller to bounce chip select between writes). > SPI_CS_WORD flag of the device mode? Like it has already been done for > "spi-cs-high"/"spi-lsb-first"/etc. I don't think either of those properties was a good idea, there's a bunch of stuff in the older SPI bindings that don't make much sense. --msY2aCMFe/FNn5o4 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmGNMDgACgkQJNaLcl1U h9A69wf8DefUDl1wuH91X13IzD3bwWUOzWSPEV4LGsq2YCdUNo9VfRJ9L7e+J4Br /1tkwFSlJhOVlrRAp66Ov/kVhM+Br8h+yCrLNuOHrBqDZFPIh2N5j6MSn0+QjZNB SN2WX7vH2FErJLjvb4iMu+6cvYKes1K9X2yXWrHvdhvQ27EgOp+BcmrF14MtDh2Y Y/zsuW/fYHAXqeRWPSghPLiU/mLM8Rk2Uy4nlmOPm3OB34otL2OCvo2n5hZlKr8b VQVxRlA3iDMNi5dyaqKXWgupLo0CiVbY6FsdBM3DXm121jLoYFOoqbm46EEBbunq MjOILfeaeIW0pK9oK3KIaiwhMFmyLA== =kf7P -----END PGP SIGNATURE----- --msY2aCMFe/FNn5o4--