From patchwork Fri Mar 17 14:54:39 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lars-Peter Clausen X-Patchwork-Id: 664658 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 A8F4EC7618E for ; Fri, 17 Mar 2023 14:56:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230185AbjCQO4S (ORCPT ); Fri, 17 Mar 2023 10:56:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230163AbjCQO4R (ORCPT ); Fri, 17 Mar 2023 10:56:17 -0400 Received: from www381.your-server.de (www381.your-server.de [78.46.137.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9C1D3524E; Fri, 17 Mar 2023 07:55:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=metafoo.de; s=default2002; h=Content-Transfer-Encoding:MIME-Version:Message-Id:Date: Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References; bh=N8AQvUD4CkJRTp9l4/aTKO2hzAyj5DrZ3kdV7fLxNxU=; b=Aj5FldAmifl1mnpVGpPCDwuFRa anpISlwySB74lEODIJG7A5DJW8RUNoWrutqOXvG5JvnZFDHXeOZ0qwUNzT5Np9gt2LDUWkbsY9AWj icogAE5MWHO0Knav31rtjqYAzs+6GZB7n63CY3JlJCspUP3Q0L2rSrNjPNKP1ehWLOCxVph/agfMd tGGkiz2fOZ9rC5W2bnyS5u+Ua+2kc1J/XxkkgFyPFVocAkcYhF2/JstTI9DK+EOgv9VW0OdnI3IQH M0ZIGT4EukgYNUBT8Hp07WTWZqqmQEQisXpaiaU3OCgMbPwl8wpr36bY+D/+Gx4fJDQhPjM+P5y1O 6YlEPfpQ==; Received: from sslproxy06.your-server.de ([78.46.172.3]) by www381.your-server.de with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1pdBUX-000LQ7-P0; Fri, 17 Mar 2023 15:55:37 +0100 Received: from [2604:5500:c0e5:eb00:da5e:d3ff:feff:933b] (helo=lars-desktop.lan) by sslproxy06.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1pdBUX-000E4A-7C; Fri, 17 Mar 2023 15:55:37 +0100 From: Lars-Peter Clausen To: Wolfram Sang Cc: Michal Simek , Shubhrajyoti Datta , Rob Herring , Krzysztof Kozlowski , linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, Lars-Peter Clausen Subject: [PATCH v2 1/3] dt-bindings: i2c: cadence: Document `fifo-depth` property Date: Fri, 17 Mar 2023 07:54:39 -0700 Message-Id: <20230317145441.156880-1-lars@metafoo.de> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Authenticated-Sender: lars@metafoo.de X-Virus-Scanned: Clear (ClamAV 0.103.8/26846/Fri Mar 17 08:22:57 2023) Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org The depth of the FIFO of the Cadence I2C controller IP is a synthesis configuration parameter. Different instances of the IP can have different values. For correct operation software needs to be aware of the size of the FIFO. Add the documentation for the devicetree property that describes the FIFO depth of the IP core. The default value of 16 is for backwards compatibility reasons with existing hardware descriptions where this property is not specified and software has assumed that the FIFO depth is 16. Signed-off-by: Lars-Peter Clausen Acked-by: Michal Simek Acked-by: Michal Simek Reviewed-by: Rob Herring --- Changes since v1: * Remove quotes around "/schemas/types.yaml#/definitions/uint32" * Add `enum` describing valid values * Use `fifo-depth` instead of `cdns,fifo-depth` * Use `bytes` instead of `words` for the property unit --- Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml b/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml index 2e95cda7262a..2401d1e19916 100644 --- a/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml +++ b/Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml @@ -38,6 +38,13 @@ properties: description: | Input clock name. + fifo-depth: + description: + Size of the data FIFO in bytes. + $ref: /schemas/types.yaml#/definitions/uint32 + default: 16 + enum: [2, 4, 8, 16, 32, 64, 128, 256] + required: - compatible - reg @@ -57,4 +64,5 @@ examples: clock-frequency = <400000>; #address-cells = <1>; #size-cells = <0>; + fifo-depth = <8>; };