From patchwork Wed Feb 14 06:36:12 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Winklhofer via B4 Relay X-Patchwork-Id: 20355 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:7300:bc8a:b0:106:860b:bbdd with SMTP id dn10csp1025872dyb; Tue, 13 Feb 2024 22:40:50 -0800 (PST) X-Forwarded-Encrypted: i=3; AJvYcCVOsvqo5SMOasT8si2EZss0MPAyfmvVDDEV1hv3S++O8KM8KQHyghmOE5VHfnaTikFOL9kSsS0w6Ms9YSr7jZJcx9Tyrw== X-Google-Smtp-Source: AGHT+IGpmlxxUXcqNOBQ//3x0ftokEwg8MEn1vKcx63Ta3Tx6njnpILH9oqunsva4jjeCVkbUtpL X-Received: by 2002:a05:6808:18a1:b0:3bf:f3d2:df11 with SMTP id bi33-20020a05680818a100b003bff3d2df11mr1910465oib.33.1707892850789; Tue, 13 Feb 2024 22:40:50 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1707892850; cv=pass; d=google.com; s=arc-20160816; b=yBSpeKp4LvriEHOBKLYfAJuLKhnV++4it49lP+n07f15cqKu/8q9JLTTOrbOQ4HOHH jKKMVPLLrxdnEiWGOzSoIFo6CM8Ge5g6hnhM0IdflRKr1dp8T5PWORXDW1ygvtmHvgHd HFrGs+WKXs6r0PO1XbDmh6S8XcHqiMqAwsGQdiu+6BG8Eexml0esCZvGqhBBTg2f3KRl swDqhwCmZi7BaqUZHOuyC8PuLnHxkgwyLG35w8pDx73mzMR27D1l3RjjFAeoKRJR/qF8 94tMKN3dja8r1mPpLJLDv4IYHwc5HrpQ2Ji8CyKR5vrpGLbbFcBC4EIgldBOaOuqPls/ vt3g== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=reply-to:cc:to:content-transfer-encoding:mime-version :list-unsubscribe:list-subscribe:list-id:precedence:message-id:date :subject:from:dkim-signature; bh=mSnXwzkw7TxZz72DJRdK5pSwlsfg1G8QbxV7w403wXk=; fh=7lzDI2Fgt04fN9WHZougnOX2mtzFf0pyNZgRJUcly5k=; b=zvOssSbNH31Uj2/CdTlPJKTiId2UByV5V1V/7D5fkhK7rq6P5hCkTyl+Gg6pcyMgbh 4m2/d/h716pc6jMkhb5k4OlYVl4UZbUJHrrwp4CvUGTgBylBPWdkgGafgXMZhFCFwAH6 3K6qruYCcgDakOCVhMhCI22ZLDPJ4O89zo37b4vSvLgL6H8ZE2zp2emTly+u+J9FdLKm 4O0BPJikLejisXcqtIlAoZ/LSqVqhg8Dy8dzPXmqFCZ//0qZREed/wjt4dSZjCwJQsad fYUctzMKlGJFA4g/A/UmWjre9Iw/S1hd4JUhyGVRE6PziAEcpQqxssXZEaDTYN6k/Wxn 9jPA==; dara=google.com ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=eV7XWZGg; arc=pass (i=1 dkim=pass dkdomain=kernel.org); spf=pass (google.com: domain of linux-kernel+bounces-64792-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-64792-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org X-Forwarded-Encrypted: i=2; AJvYcCXIMClTa3vIur8rXL35l7YZwmb5Z0VJcWjTUhydoxNvlPefUkFckfasqcsbVlo6vkxBqNArxbfCSFbSVTzhmdWky926Vg== Received: from sy.mirrors.kernel.org (sy.mirrors.kernel.org. [2604:1380:40f1:3f00::1]) by mx.google.com with ESMTPS id fb3-20020a056a002d8300b006e10bfd6a85si613875pfb.56.2024.02.13.22.40.50 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Feb 2024 22:40:50 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-64792-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=eV7XWZGg; arc=pass (i=1 dkim=pass dkdomain=kernel.org); spf=pass (google.com: domain of linux-kernel+bounces-64792-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-64792-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sy.mirrors.kernel.org (Postfix) with ESMTPS id 7697DB2893B for ; Wed, 14 Feb 2024 06:37:30 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 950D5134A0; Wed, 14 Feb 2024 06:36:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eV7XWZGg" Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 37D6310A36; Wed, 14 Feb 2024 06:36:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707892584; cv=none; b=WUULtdto2OwOC90rTzjjcflFdP7nQAVZq0iGPCnt+vDfRQXTnU+7JFR8OlpntXevD62aaronM25Dno/KqfJbHBfNPAPHUm3foDHHdgIz7dhsNGWhkBIyCzV5Mnl/3jWLzZepUA2fk+Ma8fXLq9qV4Zl1C5eTXqN2sEvHX1FgdRU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707892584; c=relaxed/simple; bh=WpkvpKeOfNBGl3s6SIPd42Jru7SBxmJQ0eeopGKSBh0=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=su+PzvbOm9M+m2TwYB6K95K7+zcYnHDiWj7oS/HAEv2Bwmll/R0KiHGYumHMoSVnWewPxQSJQX65GYsOS3CVx+M3fpsnY9gfwNcvSQ9WDLLWTRfwCkyEYJVskfVcNykN1+U5uh6XkhFYS339TDrwPVcYkxo42CLDvnUh5jQ6AxM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eV7XWZGg; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPS id AF834C433F1; Wed, 14 Feb 2024 06:36:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707892583; bh=WpkvpKeOfNBGl3s6SIPd42Jru7SBxmJQ0eeopGKSBh0=; h=From:Subject:Date:To:Cc:Reply-To:From; b=eV7XWZGgcsCBWCzbwnWFvwhtnkFdx9lheIXn+t6XALWjWJ/cuAq8dcWZcnBsvWx7r +9sO0OoBQL3KVHuEM6pckQjRbkrdKjj6ofZ3t7FNO2bqZn1aZR+XMsl19E0HALUvuN ZNECPLVkUvzxAFRKl68feMOv94jvnRf+tveOLBEhgOBKGTOBzxTPt9QXntvBMTALaU A5LHbv9HFPrl/8cNhn2VwlXvNT7ObWCjVk81qHPfw1rykH9RUcX3kIWqOcsGfYN+5u fHey70CLrw0ZZwiRngcaKTMxOBcjtwbxKTjypmxjZAfhVrl0ZM5T/VM/Wty7UL8QMi qHEgAMykJ/P/w== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93E91C4829A; Wed, 14 Feb 2024 06:36:23 +0000 (UTC) From: Christoph Winklhofer via B4 Relay Subject: [PATCH v7 0/3] w1: add UART w1 bus driver Date: Wed, 14 Feb 2024 07:36:12 +0100 Message-Id: <20240214-w1-uart-v7-0-6e21fa24e066@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAF1fzGUC/13OTW6DMBCG4atEXtdo/G+66j2qLIwZB7cBV4aQV hF3r4mUQrPwYiQ/n94bGTFHHMnr4UYyznGMaSiHeTkQ37nhhDS25SYcuAQGkl4Zvbg8UUSrrXJ MOQWk/P7KGOL3fen9WO6QU0+nLqN7eMF4eQASbCUlKE0Z9R/VNQ6f5y4FzG+n3sVz5VO/DnZxn FL+uZfNYp19RKi/iFlQoKXDQC0ajkbvJtaIWe6d3pwszgRkwlhnG4HPTu0c3zlVHGstb0LrucP 62enNcag3p4sTaJTwTNas/te5LMsvFCMkVIcBAAA= To: Krzysztof Kozlowski , Rob Herring , Conor Dooley , Christoph Winklhofer , Rob Herring , Greg Kroah-Hartman , Jiri Slaby , Krzysztof Kozlowski , Jonathan Corbet Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, linux-doc@vger.kernel.org X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1707892581; l=5348; i=cj.winklhofer@gmail.com; s=20240104; h=from:subject:message-id; bh=WpkvpKeOfNBGl3s6SIPd42Jru7SBxmJQ0eeopGKSBh0=; b=/uU0jMlHsz8KXluEL7g+eEFniKD6PeJMvlDOYz0JZZVc1Om2voISol0iky4T3FOmNFvn6HalV VQFyi3MZIGDANmui+wyhL1sWAAH685itWvlVFU3U2fMWRLS6hN9Unh8 X-Developer-Key: i=cj.winklhofer@gmail.com; a=ed25519; pk=lgjGjOt7hFKJT9UXhgUyrdthxvZ7DJ5F1U/7d9qdAsk= X-Endpoint-Received: by B4 Relay for cj.winklhofer@gmail.com/20240104 with auth_id=111 X-Original-From: Christoph Winklhofer Reply-To: X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1790855454202050081 X-GMAIL-MSGID: 1790855454202050081 Hello! This patch contains a driver for a 1-Wire bus over UART. The driver utilizes the UART interface via the Serial Device Bus to create the 1-Wire timing patterns. Changes in v7: - rename mutex to rx_mutex and comment its usage - fix comments and use kerneldoc for internal structs - Link to v6: https://lore.kernel.org/r/20240209-w1-uart-v6-0-3e753c149196@gmail.com Thanks Krzysztof for the review. Changes in v6: - change order of patches for dt-binding - remove unnecessary lock in remove - delay for 1-Wire cycle without mutex lock - fix comment style and add some more comments - Link to v5: https://lore.kernel.org/r/20240126-w1-uart-v5-0-1d82bfdc2ae9@gmail.com Thanks Krzysztof and Rob for the review. Changes in v5: - dt-binding: allow child object for onewire and use prefix -bps for baud rate configuration. - use type u8 for a byte, instead of unsigned char - use constants (NSEC_PER_SEC, BITS_PER_BYTE) - make delay computation from packet time more coherent - Link to v4: https://lore.kernel.org/r/20240106-w1-uart-v4-0-7fe1378a8b3e@gmail.com Thanks Jiri, Krzysztof and Rob for the review. Changes in v4: - rework baud-rate configuration: also check max bit-time, support higher baud-rates by adding a delay to complete 1-Wire cycle. - dt-binding w1-uart: specify baud-rates for 1-Wire operations - Link to v3: https://lore.kernel.org/r/20240105-w1-uart-v3-0-8687093b2e76@gmail.com Changes in v3: - improve baud-rate configuration: use specific limits for 1-Wire reset, touch-0 and touch-1 operation, compute in nanoseconds. - remove unused header atomic.h - use function instead of macro to compute bit-time from baud-rate - switch to b4 util to publish patch: missing recipients - Link to v2: https://lore.kernel.org/lkml/20231223100408.44056-1-cj.winklhofer@gmail.com Changes in v2: - add documentation for dt-binding - allow onewire as serial child node - support different baud-rates: The driver requests a baud-rate (9600 for reset and 115200 for write/read) and tries to adapt the transmitted byte according to the actual baud-rate returned from serdev. - fix locking problem for serdev-receive and w1-master reset/touch: The received byte is now protected with a mutex - instead of the atomic, which was used before due to the concurrent store and load. - explicit error in serdev-receive: Receiving more than one byte results in an error, since the w1-uart driver is the only writer, it writes a single-byte and should receive a single byte. - fix variable names, errno-returns, wrong define CONFIG_OF - fix log flooding - fix driver remove (error-path for rxtx-function) - Link to v1: https://lore.kernel.org/all/20231217122004.42795-1-cj.winklhofer@gmail.com Krzysztof, thank your very much for your feedback! It was tested on a "Raspberry Pi 3 Model B+" with a DS18B20 and on a "Variscite DART-6UL" with a DS18S20 temperature sensor. Content: - Patch 1: device tree binding 1-Wire - Patch 2: allow onewire as serial child node - Patch 3: driver and documentation The patch was created against the w1 subsytem tree (branch w1-next): Link: https://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux-w1.git/ The checkpatch.pl script reported the following error - which I am not sure how to fix: WARNING: added, moved or deleted file(s), does MAINTAINERS need updating? The technical details for 1-Wire over UART are in the document: Link: https://www.analog.com/en/technical-articles/using-a-uart-to-implement-a-1wire-bus-master.html In short, the UART peripheral must support full-duplex and operate in open-drain mode. The timing patterns are generated by a specific combination of baud-rate and transmitted byte, which corresponds to a 1-Wire read bit, write bit or reset pulse. For instance the timing pattern for a 1-Wire reset and presence detect uses the baud-rate 9600, i.e. 104.2 us per bit. The transmitted byte 0xf0 over UART (least significant bit first, start-bit low) sets the reset low time for 1-Wire to 521 us. A present 1-Wire device changes the received byte by pulling the line low, which is used by the driver to evaluate the result of the 1-Wire operation. Similar for a 1-Wire read bit or write bit, which uses the baud-rate 115200, i.e. 8.7 us per bit. The transmitted byte 0x00 is used for a Write-0 operation and the byte 0xff for Read-0, Read-1 and Write-1. Hope the driver is helpful. Thanks, Christoph --- Christoph Winklhofer (3): dt-bindings: serial: allow onewire as child node dt-bindings: w1: UART 1-Wire bus w1: add UART w1 bus driver .../devicetree/bindings/serial/serial.yaml | 2 +- Documentation/devicetree/bindings/w1/w1-uart.yaml | 60 +++ Documentation/w1/masters/index.rst | 1 + Documentation/w1/masters/w1-uart.rst | 54 +++ drivers/w1/masters/Kconfig | 10 + drivers/w1/masters/Makefile | 1 + drivers/w1/masters/w1-uart.c | 415 +++++++++++++++++++++ 7 files changed, 542 insertions(+), 1 deletion(-) --- base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d change-id: 20240104-w1-uart-ee8685a15a50 Best regards,