From patchwork Mon Apr 20 17:02:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Manivannan Sadhasivam X-Patchwork-Id: 214086 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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=no 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 C1BE5C3815B for ; Mon, 20 Apr 2020 17:02:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91FFA21D79 for ; Mon, 20 Apr 2020 17:02:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587402138; bh=aksiYpWTvag3k42u0M1b1NrjxY8yKocMPEw91TQYxEU=; h=From:To:Cc:Subject:Date:List-ID:From; b=fyQVSxDa0qxj5ka+0M85mJ7Omzcxmy1No2fwFCz0tCgOmKFo6q8fpwRdFF0wT1++N 6gg/4zQ1H0qXHaAKONZDhZV7jgz3cNTzLcsQA05atK79KTWtO9PkbffMaZ2RcQz5HC yGruAnZOvTZm7cvXiOrUnEi5S1J+YAyaD0EHHNhk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726434AbgDTRCS (ORCPT ); Mon, 20 Apr 2020 13:02:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:38260 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725784AbgDTRCS (ORCPT ); Mon, 20 Apr 2020 13:02:18 -0400 Received: from localhost.localdomain (unknown [157.46.94.248]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A2FB820CC7; Mon, 20 Apr 2020 17:02:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587402137; bh=aksiYpWTvag3k42u0M1b1NrjxY8yKocMPEw91TQYxEU=; h=From:To:Cc:Subject:Date:From; b=bM5TEFM6C5MJE7Kcy6aNRoG0fjnGHLSHqXpkrnuuYUVe4H9Ivr7WigZ0IzlLMZ5R6 ggHj/GRUmCAAiaBJmz95FdNW6UpXR1wn4Io//QLjuSabgrWzfYKpzwBhnFUWkdRS0S 7PcmuXjFHlv/Vt6tf5kpQEzocBySnhWsaLV7oqtE= From: mani@kernel.org To: gregkh@linuxfoundation.org, robh+dt@kernel.org, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com Cc: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, fabrice.gasnier@st.com, andy.shevchenko@gmail.com, Manivannan Sadhasivam Subject: [PATCH v3 0/2] Add CTS/RTS gpio support to STM32 UART Date: Mon, 20 Apr 2020 22:32:02 +0530 Message-Id: <20200420170204.24541-1-mani@kernel.org> X-Mailer: git-send-email 2.17.1 Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: Manivannan Sadhasivam Hello, This patchset adds CTS/RTS gpio support to STM32 UART controller. Eventhough the UART controller supports using dedicated CTS/RTS gpios, sometimes we need to use different set of gpios for flow control. This is necessary for the upcoming STM32MP1 based board called Stinger96 IoT-Box. On that board, a bluetooth chip is connected to one of the UART controller but the CTS/RTS lines got swapped mistakenly. So this patchset serves as a workaround for that hardware bug and also supports the usecase of using any gpio for CTS/RTS functionality. As per the sugggestion provided by Andy for v1, I've now switched to mctrl_gpio driver. This patchset has been validated with Stinger96 IoT-Box connected to Murata WiFi-BT combo chip. Thanks, Mani Changes in v3: * Added Andy's reviewed-by tag * Fixed minor issues spotted by Fabrice Changes in v2: As per the review by Andy: * Switched to mctrl_gpio driver instead of using custom CTS/RTS implementation * Removed the use of software flow control terminology. Manivannan Sadhasivam (2): dt-bindings: serial: Document CTS/RTS gpios in STM32 UART tty: serial: Add modem control gpio support for STM32 UART .../bindings/serial/st,stm32-uart.yaml | 14 +++++ drivers/tty/serial/Kconfig | 1 + drivers/tty/serial/stm32-usart.c | 53 ++++++++++++++++++- drivers/tty/serial/stm32-usart.h | 1 + 4 files changed, 67 insertions(+), 2 deletions(-)