From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751729AbcLEONq (ORCPT ); Mon, 5 Dec 2016 09:13:46 -0500 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:62011 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751134AbcLEONl (ORCPT ); Mon, 5 Dec 2016 09:13:41 -0500 Subject: Re: [PATCH 2/3] serial: st-asc: Provide RTS functionality To: Lee Jones , , References: <20161202141146.31281-1-lee.jones@linaro.org> <20161202141146.31281-2-lee.jones@linaro.org> CC: , , , From: Patrice Chotard Message-ID: <5e652529-8dcb-568e-a748-0ec745099211@st.com> Date: Mon, 5 Dec 2016 15:11:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20161202141146.31281-2-lee.jones@linaro.org> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.48.1.66] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-12-05_10:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Lee On 12/02/2016 03:11 PM, Lee Jones wrote: > 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 typo "the the on" > 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; >