From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934216AbcLBOLj (ORCPT ); Fri, 2 Dec 2016 09:11:39 -0500 Received: from mail-wm0-f41.google.com ([74.125.82.41]:37186 "EHLO mail-wm0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934154AbcLBOLf (ORCPT ); Fri, 2 Dec 2016 09:11:35 -0500 From: Lee Jones To: gregkh@linuxfoundation.org, jslaby@suse.com, patrice.chotard@st.com Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@stlinux.com, linux-serial@vger.kernel.org, Lee Jones Subject: [PATCH 2/3] serial: st-asc: Provide RTS functionality Date: Fri, 2 Dec 2016 14:11:45 +0000 Message-Id: <20161202141146.31281-2-lee.jones@linaro.org> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161202141146.31281-1-lee.jones@linaro.org> References: <20161202141146.31281-1-lee.jones@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Until this point, it has not been possible for serial applications to toggle the UART RTS line. This can be useful with certain configurations. For example, when using a Mezzanine on a Linaro 96board, RTS line is used to take the the on-board microcontroller in and out of reset. Signed-off-by: Lee Jones --- drivers/tty/serial/st-asc.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c index 379e5bd..ce46898 100644 --- a/drivers/tty/serial/st-asc.c +++ b/drivers/tty/serial/st-asc.c @@ -30,6 +30,7 @@ #include #include #include +#include #define DRIVER_NAME "st-asc" #define ASC_SERIAL_NAME "ttyAS" @@ -38,6 +39,7 @@ struct asc_port { struct uart_port port; + struct gpio_desc *rts; struct clk *clk; unsigned int hw_flow_control:1; unsigned int force_m1:1; @@ -381,12 +383,16 @@ static unsigned int asc_tx_empty(struct uart_port *port) static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl) { + struct asc_port *ascport = to_asc_port(port); + /* * This routine is used for seting signals of: DTR, DCD, CTS/RTS * We use ASC's hardware for CTS/RTS, so don't need any for that. * Some boards have DTR and DCD implemented using PIO pins, * code to do this should be hooked in here. */ + + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS); } static unsigned int asc_get_mctrl(struct uart_port *port) @@ -731,12 +737,20 @@ MODULE_DEVICE_TABLE(of, asc_match); static int asc_serial_probe(struct platform_device *pdev) { int ret; + struct device_node *np = pdev->dev.of_node; struct asc_port *ascport; + struct gpio_desc *gpiod; ascport = asc_of_get_asc_port(pdev); if (!ascport) return -ENODEV; + gpiod = devm_get_gpiod_from_child(&pdev->dev, "rts", &np->fwnode); + if (!IS_ERR(gpiod)) { + gpiod_direction_output(gpiod, 0); + ascport->rts = gpiod; + } + ret = asc_init_port(ascport, pdev); if (ret) return ret; -- 2.10.2