From patchwork Wed May 12 14:12:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Walle X-Patchwork-Id: 436053 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 449A9C43616 for ; Wed, 12 May 2021 14:13:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1AC056127A for ; Wed, 12 May 2021 14:13:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231373AbhELOOl (ORCPT ); Wed, 12 May 2021 10:14:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231438AbhELOOT (ORCPT ); Wed, 12 May 2021 10:14:19 -0400 Received: from ssl.serverraum.org (ssl.serverraum.org [IPv6:2a01:4f8:151:8464::1:2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3E54EC061574; Wed, 12 May 2021 07:13:10 -0700 (PDT) Received: from mwalle01.fritz.box (unknown [IPv6:2a02:810c:c200:2e91:fa59:71ff:fe9b:b851]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id 87B312224E; Wed, 12 May 2021 16:13:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1620828788; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2uhIH+O4D664Cx/PV6KT/9KkEON+ziodtCiUccB2ePE=; b=Z0CJfNkSlQBCiP+nCQiJfQWjxq9PTAbqwt6rnrMOTMXxAgeN5EfhfoVnOp65aH5bzdmZ/9 Rs5bIwxXvwlVNUs7jz52ajKaMbpBkCqcFZsmaXeQyDNGaTJRvwCak44PTKo1MTSJydxfRH wUpToJuMm8Qmy/CykOROHUi9SIUT050= From: Michael Walle To: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , Jiri Slaby , Angelo Dureghello , Johan Hovold , Philippe Schenker , Michael Walle Subject: [PATCH v2 8/9] serial: fsl_lpuart: add loopback support Date: Wed, 12 May 2021 16:12:54 +0200 Message-Id: <20210512141255.18277-9-michael@walle.cc> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210512141255.18277-1-michael@walle.cc> References: <20210512141255.18277-1-michael@walle.cc> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org The LPUART can loop the RX and TX signal. Add support for it. Please note, this was only tested on the 32 bit version of the LPUART. Signed-off-by: Michael Walle --- drivers/tty/serial/fsl_lpuart.c | 36 +++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index ad1fe8cf63f2..1ed019d91177 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1403,22 +1403,54 @@ static int lpuart32_config_rs485(struct uart_port *port, static unsigned int lpuart_get_mctrl(struct uart_port *port) { - return 0; + unsigned int mctrl = 0; + u8 reg; + + reg = readb(port->membase + UARTCR1); + if (reg & UARTCR1_LOOPS) + mctrl |= TIOCM_LOOP; + + return mctrl; } static unsigned int lpuart32_get_mctrl(struct uart_port *port) { - return 0; + unsigned int mctrl = 0; + u32 reg; + + reg = lpuart32_read(port, UARTCTRL); + if (reg & UARTCTRL_LOOPS) + mctrl |= TIOCM_LOOP; + + return mctrl; } static void lpuart_set_mctrl(struct uart_port *port, unsigned int mctrl) { + u8 reg; + + reg = readb(port->membase + UARTCR1); + + /* for internal loopback we need LOOPS=1 and RSRC=0 */ + reg &= ~(UARTCR1_LOOPS | UARTCR1_RSRC); + if (mctrl & TIOCM_LOOP) + reg |= UARTCR1_LOOPS; + writeb(reg, port->membase + UARTCR1); } static void lpuart32_set_mctrl(struct uart_port *port, unsigned int mctrl) { + u32 reg; + + reg = lpuart32_read(port, UARTCTRL); + + /* for internal loopback we need LOOPS=1 and RSRC=0 */ + reg &= ~(UARTCTRL_LOOPS | UARTCTRL_RSRC); + if (mctrl & TIOCM_LOOP) + reg |= UARTCTRL_LOOPS; + lpuart32_write(port, reg, UARTCTRL); } static void lpuart_break_ctl(struct uart_port *port, int break_state)