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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 09B11C4320A for ; Mon, 2 Aug 2021 04:12:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DAE2E60243 for ; Mon, 2 Aug 2021 04:12:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229792AbhHBENA (ORCPT ); Mon, 2 Aug 2021 00:13:00 -0400 Received: from pi.codeconstruct.com.au ([203.29.241.158]:37312 "EHLO codeconstruct.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229637AbhHBEM7 (ORCPT ); Mon, 2 Aug 2021 00:12:59 -0400 Received: by codeconstruct.com.au (Postfix, from userid 10001) id 5AB022094C; Mon, 2 Aug 2021 12:05:04 +0800 (AWST) From: Matt Johnston To: devicetree@vger.kernel.org Cc: Wolfram Sang , Jeremy Kerr , Matt Johnston Subject: [RFC PATCH 2/2] dt-bindings: net: Add mctp-i2c bus-attach property Date: Mon, 2 Aug 2021 12:04:58 +0800 Message-Id: <20210802040458.334732-3-matt@codeconstruct.com.au> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210802040458.334732-1-matt@codeconstruct.com.au> References: <20210802040458.334732-1-matt@codeconstruct.com.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Allows attaching multiple child busses in a mux topology to an mctp-i2c instance on the root bus. In general I2C slave mode does not make sense for mux busses, but the MCTP request/response protocol means the the root can switch between child muxes for incoming I2C messages. Signed-off-by: Matt Johnston --- .../devicetree/bindings/net/mctp-i2c.yaml | 42 +++++++++++++++++-- 1 file changed, 38 insertions(+), 4 deletions(-) diff --git a/Documentation/devicetree/bindings/net/mctp-i2c.yaml b/Documentation/devicetree/bindings/net/mctp-i2c.yaml index f9378cd845d4..45429cbcc6a1 100644 --- a/Documentation/devicetree/bindings/net/mctp-i2c.yaml +++ b/Documentation/devicetree/bindings/net/mctp-i2c.yaml @@ -12,11 +12,10 @@ maintainers: description: The MCTP I2C binding defines an MCTP endpoint on the I2C bus to communicate with I2C peripherals using MCTP (DMTF specification DSP0237). - - An mctp-i2c device must be attached to a hardware bus adapter which supports + A single binding node can attach to multiple child busses in a mux topology. + An mctp-i2c node's parent must be a hardware bus adapter which supports slave functionality. The reg address must include I2C_OWN_SLAVE_ADDRESS. - properties: compatible: const: mctp-i2c @@ -24,6 +23,17 @@ properties: reg: maxItems: 1 + bus-attach: + $ref: "/schemas/types.yaml#/definitions/phandle-array" + description: | + List of phandles of I2C busses to attach to. I2C mux busses may only + be attached to an mctp-i2c binding on their parent root adapter in the + mux topology. + If no bus-attach property is specified then only the direct parent + I2C bus is attached. Otherwise to include a direct parent bus it + must be included in the bus-attach list if needed. + + additionalProperties: true required: @@ -33,12 +43,36 @@ required: examples: - | #include - i2c { + + // simple attaching to a root adapter i2c0 + i2c0: i2cbus0 { + #address-cells = <1>; + #size-cells = <0>; + + mctp@50 { + compatible = "mctp-i2c"; + reg = <(0x50 | I2C_OWN_SLAVE_ADDRESS)>; + }; + }; + + // attaching to a root adapter i2c5 and a child mux bus i2c14 + i2c5: i2cbus5 { #address-cells = <1>; #size-cells = <0>; mctp@50 { compatible = "mctp-i2c"; reg = <(0x50 | I2C_OWN_SLAVE_ADDRESS)>; + attach-bus = <&i2c5 &i2c14>; }; }; + + i2cmux0 { + compatible = "i2c-mux-gpio"; + #address-cells = <1>; + #size-cells = <0>; + i2c-parent = <&i2c0>; + i2c14: i2c@5 { + reg = <0>; + }; + }; -- 2.30.2