From patchwork Fri Dec 14 06:20:41 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yash Shah X-Patchwork-Id: 1013355 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pwm-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=sifive.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=sifive.com header.i=@sifive.com header.b="X8t8L5Lr"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43GL6R4vH0z9s3q for ; Fri, 14 Dec 2018 17:21:35 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727212AbeLNGVf (ORCPT ); Fri, 14 Dec 2018 01:21:35 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:32884 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727206AbeLNGVf (ORCPT ); Fri, 14 Dec 2018 01:21:35 -0500 Received: by mail-pf1-f195.google.com with SMTP id c123so2336913pfb.0 for ; Thu, 13 Dec 2018 22:21:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Y2uFCXiJuXowKbjYO6BVNjHU6wQk1zGPwNY0PMaxB4A=; b=X8t8L5Lrcf998Ry9QkXcSsKXXfFvEcQOFPFvGwzZDNgzkrIqTm0c2/FAw6oLntUu8V HFX/Wm7lBcAHONkBQ7Ph5YpFxaQt8TbHa/g8ua5shT8ij4yvqmZuAAnwH78DaIeQ/GbX 7QZ8usiAxLusob+tkP4d8GQM5tvEOlg+Bxs1MsS93IzKzhWmnOXu0wEthqULHK7W/nfG vdNAChftTblNo0hRsa0x95hTxYoaXmrjNoQMO/Dbj5yZrPvnbqkhwcAaM7gzufjnn41N BaCI74p8ySBF66WrCW8fiOLJtsfdk5BnepjMRsJR8nf/DGyNfpD8iI3HGNJJm1VoIwMJ R64g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Y2uFCXiJuXowKbjYO6BVNjHU6wQk1zGPwNY0PMaxB4A=; b=clFcgH4Y3FntXAotvAe8MtiyKmlqs3elL8kUKc/zQ7gPTbqMUvRXdYSm8Ore+dnQh0 6f21oIMM0ztuIF68iZU+7vslkPUoj/9mTdIEwVFbF8C4mZgDlW6ObYezVVgpaRng+w+W FY/OmM0FJGozWzAEqIP0n67tEwJ5bq2gZK0HeZ9GA75N8pmSxb2WbrcZ828keQfSQw72 0wrRTK9u0hUQj89XUhnDqRWMBOQ6nokFsXobgpQaVD9Mprkz9zJ4Hm7GrCGEk4pRwLGh bDl3E6BZVU4frCQDDdEO4JDN+ipxzAasQIVv2TnhV8Ht2HBKP6b4fc9ZrXydwExfPYTt rIgA== X-Gm-Message-State: AA+aEWan7sZsJuoxZ0QtwKVpjotPLyPqZ5j926Hh3E/olYnv7+BxENHC NYafCOzdgcolvPYGVS2eHtxzMg== X-Google-Smtp-Source: AFSGD/VEStnIFYNojR+jlGrPT+98KR2dnXiG+KSAOGn8gu0KsUA+RHRAZrEFQr6S7RO5wyTqB/RP4w== X-Received: by 2002:a62:69c4:: with SMTP id e187mr1740518pfc.50.1544768494383; Thu, 13 Dec 2018 22:21:34 -0800 (PST) Received: from buildserver-90.open-silicon.com ([114.143.65.226]) by smtp.googlemail.com with ESMTPSA id i1sm4841703pgb.46.2018.12.13.22.21.30 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 13 Dec 2018 22:21:33 -0800 (PST) From: Yash Shah To: palmer@sifive.com, linux-pwm@vger.kernel.org, linux-riscv@lists.infradead.org Cc: thierry.reding@gmail.com, robh+dt@kernel.org, mark.rutland@arm.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, sachin.ghadi@sifive.com, paul.walmsley@sifive.com, Yash Shah Subject: [RFC v2 1/2] pwm: sifive: Add DT documentation for SiFive PWM Controller Date: Fri, 14 Dec 2018 11:50:41 +0530 Message-Id: <1544768442-12530-2-git-send-email-yash.shah@sifive.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1544768442-12530-1-git-send-email-yash.shah@sifive.com> References: <1544768442-12530-1-git-send-email-yash.shah@sifive.com> Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org DT documentation for PWM controller added with updated compatible string. Signed-off-by: Wesley W. Terpstra [Atish: Compatible string update] Signed-off-by: Atish Patra Signed-off-by: Yash Shah --- .../devicetree/bindings/pwm/pwm-sifive.txt | 44 ++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 Documentation/devicetree/bindings/pwm/pwm-sifive.txt diff --git a/Documentation/devicetree/bindings/pwm/pwm-sifive.txt b/Documentation/devicetree/bindings/pwm/pwm-sifive.txt new file mode 100644 index 0000000..250d8ee --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/pwm-sifive.txt @@ -0,0 +1,44 @@ +SiFive PWM controller + +Unlike most other PWM controllers, the SiFive PWM controller currently only +supports one period for all channels in the PWM. This is set globally in DTS. +The period also has significant restrictions on the values it can achieve, +which the driver rounds to the nearest achievable frequency. + +Required properties: +- compatible: should be something similar to "sifive,-pwm" for + the PWM as integrated on a particular chip, and + "sifive,pwm" for the general PWM IP block + programming model. Supported compatible strings are: + "sifive,fu540-c000-pwm" for the SiFive PWM v0 as + integrated onto the SiFive FU540 chip, and "sifive,pwm0" + for the SiFive PWM v0 IP block with no chip integration + tweaks. +- reg: physical base address and length of the controller's registers +- clocks: The frequency the controller runs at +- #pwm-cells: Should be 2. + The first cell is the PWM channel number + The second cell is the PWM polarity +- sifive,approx-period: the driver will get as close to this period as it can +- interrupts: one interrupt per PWM channel + +PWM RTL that corresponds to the IP block version numbers can be found +here: + +https://github.com/sifive/sifive-blocks/tree/master/src/main/scala/devices/pwm + +Further information on the format of the IP +block-specific version numbers can be found in +Documentation/devicetree/bindings/sifive/sifive-blocks-ip-versioning.txt + +Examples: + +pwm: pwm@10020000 { + compatible = "sifive,fu540-c000-pwm","sifive,pwm0"; + reg = <0x0 0x10020000 0x0 0x1000>; + clocks = <&tlclk>; + interrupt-parent = <&plic>; + interrupts = <42 43 44 45>; + #pwm-cells = <2>; + sifive,approx-period = <1000000>; +};