From patchwork Thu Apr 16 04:56:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: rishi gupta X-Patchwork-Id: 214097 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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 87D90C352BE for ; Thu, 16 Apr 2020 04:56:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6429220771 for ; Thu, 16 Apr 2020 04:56:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="l9ukk57M" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404751AbgDPE4b (ORCPT ); Thu, 16 Apr 2020 00:56:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404729AbgDPE4a (ORCPT ); Thu, 16 Apr 2020 00:56:30 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25DD7C061A0C; Wed, 15 Apr 2020 21:56:30 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id u65so1131858pfb.4; Wed, 15 Apr 2020 21:56:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=SzP7bHD5Hc4jVvputS81h7AwLyVMTVzgcy2Av2iBbno=; b=l9ukk57MXClJMRH+oZYY1IMPAWfCKffwTD/MRHif0/vKJsYekb3MIVZgfvcgkEHoYa 4sMiA4FxoPD/1hgm9NXfi3Lluo/tYMsdUiul3pPyUeQxLQ7v9ntrttcNADiP4u9rARgB HZWncVdEYBU8T3Jyq9egkIVT7SJ3kaBznGu2t0k1Uh9ZBcXJY/OQrFdM18Z2Yausafrq qB67/H1wyWEqeasZs6jHiBnly5SGVtnKvHxyD+Uu+xU+lAhmt7y+s89mzhMeXxL3Dla8 SBSxEV8WYkh8j93pGCSUvcDMtS6NJyBO/FQZ0Nl0JsIoSYxDBAdfxG4pGFkEcp12Mky+ 9jqA== 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; bh=SzP7bHD5Hc4jVvputS81h7AwLyVMTVzgcy2Av2iBbno=; b=FolfxKY8xP183t8qmeVu2ZSBHrntfq/TwUNfW8GvNnmYEzkSgs1Xf6C342IjGshWlg FAgsq3Ev3jV9HUyt74B+Z73eS5tF9yfd965hZUf8FTBBJGpHKa+6rv02DrugoJe9ec7S gBImCiYHzsvZBGMKiYOBhdOCjZYm9S4npYClDGR5mA8/WbJG0lNzPZA6p86Txxvdr1eK v0rOCyFqaR6sApOkRqvtFpP2EiOOWql8+3YABiK08zYiHumz2HyQD/xrjg4EAq/L0WFg m9Vs5UAkLUoAwaf66kykOUsfYGf3v1OOYKV37pVspeb5q1pDQIyM20rS7ZbybP8qsAjY CJ3w== X-Gm-Message-State: AGi0PuaewoDe47H60DQm8QYZW1EiQOG+zPrM/cL5VPUQvVTMtkrJ5as+ nHlVEpbXyeC1nvGMH/i2S6h592aTiNY= X-Google-Smtp-Source: APiQypJa7VvdT4JFQmvU9sh/Orly6zGOEZqw9Ndxdm2WZL5BeFtsHXB+ih3k/RAX44DLyazVdVVF4Q== X-Received: by 2002:a63:c149:: with SMTP id p9mr29292799pgi.389.1587012989254; Wed, 15 Apr 2020 21:56:29 -0700 (PDT) Received: from localhost.localdomain ([183.82.182.213]) by smtp.gmail.com with ESMTPSA id 3sm4749198pgh.75.2020.04.15.21.56.26 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 15 Apr 2020 21:56:28 -0700 (PDT) From: Rishi Gupta To: gregkh@linuxfoundation.org, jslaby@suse.com, robh+dt@kernel.org, corbet@lwn.net, andriy.shevchenko@linux.intel.com Cc: devicetree@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Rishi Gupta Subject: [PATCH v3 1/4] dt-bindings: ttyvs: document serial null modem driver bindings Date: Thu, 16 Apr 2020 10:26:11 +0530 Message-Id: <1587012974-21219-1-git-send-email-gupt21@gmail.com> X-Mailer: git-send-email 2.7.4 Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org The ttyvs driver creates virtual tty devices. These devices can also be created through device tree. This commit document this. Signed-off-by: Rishi Gupta --- Changes in v3: - Rebased on top of v5.7-rc1 Changes in v2: - Made dev-num property mandatory - Removed descriptions not needed due to driver changes .../devicetree/bindings/serial/ttyvs.yaml | 165 +++++++++++++++++++++ 1 file changed, 165 insertions(+) create mode 100644 Documentation/devicetree/bindings/serial/ttyvs.yaml diff --git a/Documentation/devicetree/bindings/serial/ttyvs.yaml b/Documentation/devicetree/bindings/serial/ttyvs.yaml new file mode 100644 index 0000000..c919424 --- /dev/null +++ b/Documentation/devicetree/bindings/serial/ttyvs.yaml @@ -0,0 +1,165 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/serial/ttyvs.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Virtual multi-port serial card DT bindings + +maintainers: + - Rishi Gupta + +description: | + The ttyvs driver creates a virtual card which can have 0 to 65535 + virtual tty devices. The card is modelled as a node with zero or more + child nodes each representing a virtual tty device. These devices + can be configured to be a loop-back type device or it can be part of + a null-modem pair. + + Devices can be created by defining properties required to instantiate + a device (see examples Ex1/2/3 at the end). More information about + how to use this driver is here Documentation/virtual/tty-ttyvs.rst + +properties: + compatible: + const: ttyvs,virtual-uart-card + + max-num-vs-devs: + allOf: + - $ref: /schemas/types.yaml#/definitions/uint32 + - minimum: 0 + - maximum: 0xffff + maxItems: 1 + description: + By default, the driver can create upto 64 devices. This number can + be changed by passing 'max_num_vs_devs' module parameter to the driver + or by defining 'max-num-vs-devs' DT property. If both are used then + driver updates itself to support total number of devices as defined + by max-num-vs-devs property. + +patternProperties: + "^ttyvs@[0-9]+$": + type: object + description: + Node representing one virtual tty device. This describes, device + number and its configuration. + + properties: + dev-num: + allOf: + - $ref: /schemas/types.yaml#/definitions/uint32 + - minimum: 0 + - maximum: 65534 + maxItems: 1 + description: + Specifies index (N in /dev/ttyvsN) to use for creating device. + Valid value for dev-num is from 0 to 65534. + + rtsmap: + allOf: + - $ref: /schemas/types.yaml#/definitions/uint32-array + items: + - enum: [1, 6, 8, 9] + maxItems: 1 + description: + Specifies to which pin(s) RTS pin of this device should be + connected. Valid values are pin 1 (DCD), pin 6 (DSR), pin 8 + (CTS) and pin 9 (RI). If this is not used then RTS pin is + left unconnected. + + dtrmap: + allOf: + - $ref: /schemas/types.yaml#/definitions/uint32-array + items: + - enum: [1, 6, 8, 9] + maxItems: 1 + description: + Specifies to which pin(s) DTR pin of this device should be + connected. Valid values are pin 1 (DCD), pin 6 (DSR), pin 8 + (CTS) and pin 9 (RI). If this is not used then DTR pin is + left unconnected. + + set-dtr-at-open: + type: boolean + description: + If used, DTR signal will be asserted by driver when device + node is opened by user space application. + + peer-dev: + $ref: /schemas/types.yaml#definitions/phandle + description: + Phandle to the peer DT node if this node is part of a null + modem pair. + +required: + - compatible + - dev-num + +examples: + - | + # Ex1; Null-modem pair only TX/RX connected + # /dev/ttvs0 <---> /dev/ttyvs1 + # TX (3) ----> (2) RX + # RX (2) <---- (3) TX + + ttyvs-card@0 { + compatible = "ttyvs,virtual-uart-card"; + + ttyvs0: ttyvs0 { + dev-num = <0>; + peer-dev = <&ttyvs1>; + }; + + ttyvs1: ttyvs1 { + dev-num = <1>; + peer-dev = <&ttyvs0>; + }; + }; + + - | + # Ex2; Standard loop-back device + # TX (3) -->| + # RX (2) <--| + + ttyvs-card@0 { + compatible = "ttyvs,virtual-uart-card"; + ttyvs2 { + dev-num = <2>; + rtsmap = <8>; + dtrmap = <1 6>; + set-dtr-at-open; + }; + }; + + - | + # Ex3; Standard null-modem pair for hardware flow control + # TX (3) ----> (2) RX + # RX (2) <---- (3) TX + # RTS (7) ----> (8) CTS + # DTR (4) --+-> (1) DCD + # +-> (6) DSR + # CTS (8) <---- (7) RTS + # DCD (1) <-+-- (4) DTR + # DSR (6) <-+ + + ttyvs-card@0 { + compatible = "ttyvs,virtual-uart-card"; + max-num-vs-devs = <128>; + + ttyvs3: ttyvs3 { + dev-num = <3>; + rtsmap = <8>; + dtrmap = <1 6>; + set-dtr-at-open; + peer-dev = <&ttyvs4>; + }; + + ttyvs4: ttyvs4 { + dev-num = <4>; + rtsmap = <8>; + dtrmap = <1 6>; + set-dtr-at-open; + peer-dev = <&ttyvs3>; + }; + }; +...