From patchwork Thu Apr 16 17:57:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Manivannan Sadhasivam X-Patchwork-Id: 214094 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 3E508C2BB55 for ; Thu, 16 Apr 2020 17:58:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1688A20786 for ; Thu, 16 Apr 2020 17:58:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587059906; bh=uob6JmhQsIuVSxn6LknqVxhOVd73KK6UiP0jt6GPlzk=; h=From:To:Cc:Subject:Date:List-ID:From; b=ObggAcB1Ewz6yYJ9S9ovY05lVwzTOLsvzpZK2GKQYqxELLsB0PyeDCJFgkk2G8+/+ pn2B3+J2izKfv5PnLeuXscjQ5Z3tWefji0aiziCpGe6UhDY5SMifoY9DJGmVTY+fhZ L8Woxh3IlXS0incAnbUpkscCl5JS/fmwAwLg0Fqw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728203AbgDPR6W (ORCPT ); Thu, 16 Apr 2020 13:58:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:50818 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727794AbgDPR6U (ORCPT ); Thu, 16 Apr 2020 13:58:20 -0400 Received: from localhost.localdomain (unknown [157.50.106.138]) (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 806A120786; Thu, 16 Apr 2020 17:58:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587059900; bh=uob6JmhQsIuVSxn6LknqVxhOVd73KK6UiP0jt6GPlzk=; h=From:To:Cc:Subject:Date:From; b=aNPdJIx5+vDQui9jyo5c0PQmu3LjohwVttopU8ZmKeKBHx8mi2M+Edq5DRSaNbXm5 n5/4lsaW/h65mCndQWun1ybG2cdAe33Ryq18d5sNBIei7V6QbUDHrj6dod5utxYXLQ O9BSXR/p24p2y4RGMqv9laLGn3wUa0rlNVPbcNVw= 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 v2 0/2] Add CTS/RTS gpio support to STM32 UART Date: Thu, 16 Apr 2020 23:27:27 +0530 Message-Id: <20200416175729.5550-1-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 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): tty: serial: Add modem control gpio support for STM32 UART dt-bindings: serial: Document CTS/RTS gpios in STM32 UART .../bindings/serial/st,stm32-uart.yaml | 14 ++++++ drivers/tty/serial/Kconfig | 1 + drivers/tty/serial/stm32-usart.c | 43 ++++++++++++++++++- drivers/tty/serial/stm32-usart.h | 1 + 4 files changed, 58 insertions(+), 1 deletion(-)