From patchwork Mon Feb 20 17:49:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?UmFmYcWCIE1pxYJlY2tp?= X-Patchwork-Id: 655178 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 6414DC636D6 for ; Mon, 20 Feb 2023 17:49:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232072AbjBTRts (ORCPT ); Mon, 20 Feb 2023 12:49:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43716 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232467AbjBTRtr (ORCPT ); Mon, 20 Feb 2023 12:49:47 -0500 Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [IPv6:2a00:1450:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 714371EBF8; Mon, 20 Feb 2023 09:49:42 -0800 (PST) Received: by mail-lj1-x234.google.com with SMTP id u15so3007718ljo.5; Mon, 20 Feb 2023 09:49:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=BFDJegi5uTYwdkZXr42aNBwxRD/vvuGUyK4suapHfLE=; b=pNp4F+WC3OYbrn5ogI5MzgDCG/M7DsThUP1JveuJQchDIP5pr5gJjrONCAEm5MCqJ6 0mBiEWGY46umgI+IlFdYRaS5MTRSpJUFNUe+xvnDAl+8vDi99y8Q2A1AZG1xHQzYz2x3 hR6HOaZ1fdpqnGjv9Sm46+HtmEffVa4Be2BeaVcJw/5LHmzf61gj0dY+KkLayoJkSyNa oyfyQCi+vLKoWyAqNd6ZSxZ6+z2jrLoW9p3dBXdVm+zc6ddqsGfAp8zkX7utEKpQ4MIp KpYDrFrUx4v9+fRGS/N3FEAHWFq1KIKJ9pr6VVjYuhjomasoHeKG0VDVwE94iWwKTEMh QHTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=BFDJegi5uTYwdkZXr42aNBwxRD/vvuGUyK4suapHfLE=; b=qVswGQXkdPrisN07Wf5/Pne/rsAxnN/4m2H5JhVXr8m1l80tVNuhPUHmvfmwRgQyiN lJjaKD8YOiKW+J4qSHXGD2M/XjdE5187TtvmUZDWQk0oxecx84S5wbxvf4bDJyCvOpCn 5lg0R4GB0ZNNkdanKAvIl6hUj4ITvt1Y1MwePiaZJj5VnyJobXssDwbLBNoTJO2tkEQ6 +cmrIrKdWQN3hVyCuOdMv3NZ9qkjDWConViukkdyNp6jd1/AhB2v5+LfjX5SmpMZkmqw vi/vXOV0eOHz9YcyUkQ4Z8jbGAzdAe8tadmgY+HAGHOqDbrjLc13XLWZjqav0ZYwFOrU xNhA== X-Gm-Message-State: AO0yUKXMCCu04YnOl9GGcIlBw58wpwMNPbVl7tN2fRv805i6zihFXja5 oFz6bvoQyCWUVCyBeFI/y5c= X-Google-Smtp-Source: AK7set+Sh6RcNPNBI8AkSmYzzOk7NOMz/GoQ61Hr+5GGqp7LrngcaXhxl712WiDfdg5IZOKgCEhe0w== X-Received: by 2002:a05:651c:10aa:b0:28e:a8aa:6f95 with SMTP id k10-20020a05651c10aa00b0028ea8aa6f95mr832063ljn.8.1676915380580; Mon, 20 Feb 2023 09:49:40 -0800 (PST) Received: from localhost.lan (ip-194-187-74-233.konfederacka.maverick.com.pl. [194.187.74.233]) by smtp.gmail.com with ESMTPSA id u22-20020a2e9f16000000b0029353491df6sm294695ljk.48.2023.02.20.09.49.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Feb 2023 09:49:40 -0800 (PST) From: =?utf-8?b?UmFmYcWCIE1pxYJlY2tp?= To: Srinivas Kandagatla , Rob Herring , Krzysztof Kozlowski Cc: Matthias Brugger , Kunihiko Hayashi , Masami Hiramatsu , linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?b?UmFmYcWCIE1pxYJlY2tp?= Subject: [PATCH V3 1/2] dt-bindings: nvmem: mmio: new binding for MMIO accessible NVMEM devices Date: Mon, 20 Feb 2023 18:49:29 +0100 Message-Id: <20230220174930.7440-2-zajec5@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230220174930.7440-1-zajec5@gmail.com> References: <20230220174930.7440-1-zajec5@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org From: Rafał Miłecki Content of some NVMEM devices can be read using MMIO. Some of them (probably very few though) may be also programmable that way. Add generic binding to allow describing such hardware. This *doesn't* apply to any more complicated devices that need more complex interface e.g. for writing. While such devices could be supported for reading purposes by the same driver - they should get their own binding. This binding will gain even more usability once we fully support NVMEM layouts (describing content of NVMEM devices in an independent way). Signed-off-by: Rafał Miłecki Reviewed-by: Rob Herring --- V3: Make it clear this binding should NOT be used for more complex devices --- .../devicetree/bindings/nvmem/mmio.yaml | 50 +++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 Documentation/devicetree/bindings/nvmem/mmio.yaml diff --git a/Documentation/devicetree/bindings/nvmem/mmio.yaml b/Documentation/devicetree/bindings/nvmem/mmio.yaml new file mode 100644 index 000000000000..9ca96b7a4856 --- /dev/null +++ b/Documentation/devicetree/bindings/nvmem/mmio.yaml @@ -0,0 +1,50 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/nvmem/mmio.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: MMIO access based NVMEM + +description: | + This binding describes simple NVMEM devices with content that can be accessed + using MMIO (memory-mapped I/O access). + + More complex devices that support any other access than a simple memory + mapping should use a custom binding. In such cases this binding's compatible + should NOT be used even as a fallback. + + This binding is designed to describe just an NVMEM content access method. The + way of handling actual content should be described independently (on top of + this binding). + +maintainers: + - Rafał Miłecki + +allOf: + - $ref: nvmem.yaml# + +properties: + compatible: + const: mmio-nvmem + + reg: + maxItems: 1 + + reg-io-width: + description: | + The size (in bytes) of the IO accesses that should be performed + on the device. + enum: [1, 2, 4, 8] + +required: + - reg + +unevaluatedProperties: false + +examples: + - | + nvmem@10000 { + compatible = "mmio-nvmem"; + reg = <0x10000000 0x10000>; + };