From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 C9350182BD for ; Fri, 3 Nov 2023 13:29:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=hefring-com.20230601.gappssmtp.com header.i=@hefring-com.20230601.gappssmtp.com header.b="1QTz2NOu" Received: from mail-qt1-x82f.google.com (mail-qt1-x82f.google.com [IPv6:2607:f8b0:4864:20::82f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1E6519D for ; Fri, 3 Nov 2023 06:29:24 -0700 (PDT) Received: by mail-qt1-x82f.google.com with SMTP id d75a77b69052e-41cc0e9d92aso11002781cf.3 for ; Fri, 03 Nov 2023 06:29:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=hefring-com.20230601.gappssmtp.com; s=20230601; t=1699018164; x=1699622964; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=f5hQXxQSZxO3OZcCJDZkPQHyyuV8tvUWsRYcmXkePgE=; b=1QTz2NOuMb1GC999v0VIP/ms1+ewVvw8xJSWBTX+BNW5YCmjVPrnEJbcfFOHuoc/i9 7zt4rHuTxk+A4q2Tnjh0i54oVTg+qjhfKRSPLjktiKP1N48/gL3uOVtQNOOU0HzCo+op N2673Gdfri+agbHMg1afdfAnJoCzWqJw91ISlbbTKb/BVCO5x7yxVRCvV87mh4gfxzkK LjryHTCPHbMXuVykUqxd24u5Vjq9XcjKiRj+d1CzdABAr9cUYPQQewJKtRxLdG3PS8Kg IDXRorZJ/iXuyrRNXaykP45r7El/3TlsBAlOo6yhOjkGrTOaHiHUw5UobXGOqSTTei0u Mnyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699018164; x=1699622964; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=f5hQXxQSZxO3OZcCJDZkPQHyyuV8tvUWsRYcmXkePgE=; b=dUL0r++Hw1N+3xysznbwhDz/FI2I6jaql70Hyn+g1a7tR8OBT6xF6GcMdS7SXqkXJk 5h0859rr3w7Mhxdr5rcfRE68uHOW+geCGd+5HnZVHLx3kiYp2LO932uStP5H6E4aYfCt 9kBcx6a+wZbIAOyTeAQn34qRGAJoAujeBKnhg3OQgUSX90e8Jvuhzr8q9wtIsIg5vSuv DyXvJ4wTRJxiAbQG0cXYVMw7d6haR+yOGUW5jht6jytcVDDoVcWXh0F1vGYKkCg8Pqcc pBrENFF5wKn+TjwiINBBAslqyOFG+TiBwyqUaE1Ntq8SYorK0aMCdTJeM/nJGcZbA1JZ B0og== X-Gm-Message-State: AOJu0YzK55d3KB3ASfK2znYeQN7udY6bElufeUWZoSvIBn3lIQ71MqEC iiF36P4SeVqEIi5FyJxBl1UsKQ== X-Google-Smtp-Source: AGHT+IEn5wRuUs2lNs9myO4AF2zBH6YUvvrm/OBfPI7RX6oZHVthZK736BXDD9Z+YCw0VljCX13Q1Q== X-Received: by 2002:ac8:5b89:0:b0:417:b901:91a7 with SMTP id a9-20020ac85b89000000b00417b90191a7mr27765637qta.24.1699018164054; Fri, 03 Nov 2023 06:29:24 -0700 (PDT) Received: from dell-precision-5540 ([50.212.55.89]) by smtp.gmail.com with ESMTPSA id gb7-20020a05622a598700b00418189b689csm723217qtb.10.2023.11.03.06.29.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Nov 2023 06:29:23 -0700 (PDT) Date: Fri, 3 Nov 2023 09:29:12 -0400 From: Ben Wolsieffer To: Conor Dooley Cc: linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Mark Brown , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Maxime Coquelin , Alexandre Torgue , Alain Volmat , Erwan Leray , Fabrice Gasnier Subject: Re: [PATCH v2 3/5] dt-bindings: spi: add stm32f7-spi compatible Message-ID: References: <20231102193722.3042245-1-ben.wolsieffer@hefring.com> <20231102193722.3042245-4-ben.wolsieffer@hefring.com> <20231103-recognize-unwashed-b8f1a83fe851@spud> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231103-recognize-unwashed-b8f1a83fe851@spud> Hi Conor, On Fri, Nov 03, 2023 at 12:50:53PM +0000, Conor Dooley wrote: > On Thu, Nov 02, 2023 at 03:37:20PM -0400, Ben Wolsieffer wrote: > A wider range of supported word sizes and some additional buffers, > implies that the F4 could be used as a fallback compatible. Does the > register map change incompatibly in the process of widening the FIFOs or > something like that? Yes, the F4 has a single bit to select 8 or 16 bit word size, while the F7 uses four bits to select an arbitrary word size from 4 to 16 bits. This series supports the packing mode, to allow sending two <=8 bit words with a single write to the FIFO, but even if we didn't want to support this feature, the F7 would require setting the FRXTH bit (not present in the F4) when using <=8 bit word sizes. > > Cheers, > Conor.