From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krishna Yarlagadda Subject: [PATCH 01/14] serial: tegra: add internal loopback functionality Date: Mon, 12 Aug 2019 16:58:10 +0530 Message-ID: <1565609303-27000-2-git-send-email-kyarlagadda@nvidia.com> References: <1565609303-27000-1-git-send-email-kyarlagadda@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1565609303-27000-1-git-send-email-kyarlagadda@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: gregkh@linuxfoundation.org, robh+dt@kernel.org, mark.rutland@arm.com, thierry.reding@gmail.com, jonathanh@nvidia.com, ldewangan@nvidia.com, jslaby@suse.com Cc: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, Andreas Abel , Krishna Yarlagadda List-Id: linux-serial@vger.kernel.org From: Andreas Abel Add the internal loopback functionality that can be enabled with TIOCM_LOOP. Signed-off-by: Andreas Abel Signed-off-by: Krishna Yarlagadda --- drivers/tty/serial/serial-tegra.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c index d5269aa..19f4c24 100644 --- a/drivers/tty/serial/serial-tegra.c +++ b/drivers/tty/serial/serial-tegra.c @@ -4,7 +4,7 @@ * * High-speed serial driver for NVIDIA Tegra SoCs * - * Copyright (c) 2012-2013, NVIDIA CORPORATION. All rights reserved. + * Copyright (c) 2012-2019, NVIDIA CORPORATION. All rights reserved. * * Author: Laxman Dewangan */ @@ -192,16 +192,34 @@ static void set_dtr(struct tegra_uart_port *tup, bool active) } } +static void set_loopbk(struct tegra_uart_port *tup, bool active) +{ + unsigned long mcr = tup->mcr_shadow; + + if (active) + mcr |= UART_MCR_LOOP; + else + mcr &= ~UART_MCR_LOOP; + + if (mcr != tup->mcr_shadow) { + tegra_uart_write(tup, mcr, UART_MCR); + tup->mcr_shadow = mcr; + } +} + static void tegra_uart_set_mctrl(struct uart_port *u, unsigned int mctrl) { struct tegra_uart_port *tup = to_tegra_uport(u); - int dtr_enable; + int enable; tup->rts_active = !!(mctrl & TIOCM_RTS); set_rts(tup, tup->rts_active); - dtr_enable = !!(mctrl & TIOCM_DTR); - set_dtr(tup, dtr_enable); + enable = !!(mctrl & TIOCM_DTR); + set_dtr(tup, enable); + + enable = !!(mctrl & TIOCM_LOOP); + set_loopbk(tup, enable); } static void tegra_uart_break_ctl(struct uart_port *u, int break_ctl) -- 2.7.4