From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 38357C55182 for ; Tue, 21 Apr 2020 12:58:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 130192076C for ; Tue, 21 Apr 2020 12:58:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=st.com header.i=@st.com header.b="Fu+lvdF4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728524AbgDUM6v (ORCPT ); Tue, 21 Apr 2020 08:58:51 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:39826 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728337AbgDUM6v (ORCPT ); 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Tue, 21 Apr 2020 14:58:36 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 31A3410002A; Tue, 21 Apr 2020 14:58:36 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag5node3.st.com [10.75.127.15]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 1BAFA2B188F; Tue, 21 Apr 2020 14:58:36 +0200 (CEST) Received: from [10.211.6.179] (10.75.127.44) by SFHDAG5NODE3.st.com (10.75.127.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 21 Apr 2020 14:58:34 +0200 Subject: Re: [PATCH v3 2/2] tty: serial: Add modem control gpio support for STM32 UART To: CC: , , , , , , , , , References: <20200420170204.24541-1-mani@kernel.org> <20200420170204.24541-3-mani@kernel.org> From: Fabrice Gasnier Message-ID: <035edfe7-1799-51c1-58aa-2498e5991aee@st.com> Date: Tue, 21 Apr 2020 14:58:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200420170204.24541-3-mani@kernel.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.75.127.44] X-ClientProxiedBy: SFHDAG7NODE1.st.com (10.75.127.19) To SFHDAG5NODE3.st.com (10.75.127.15) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.676 definitions=2020-04-21_05:2020-04-20,2020-04-21 signatures=0 Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On 4/20/20 7:02 PM, mani@kernel.org wrote: > From: Manivannan Sadhasivam > > STM32 UART controllers have the built in modem control support using > dedicated gpios which can be enabled using 'st,hw-flow-ctrl' flag in DT. > But there might be cases where the board design need to use different > gpios for modem control. > > For supporting such cases, this commit adds modem control gpio support > to STM32 UART controller using mctrl_gpio driver. > > Reviewed-by: Andy Shevchenko > Signed-off-by: Manivannan Sadhasivam > --- > drivers/tty/serial/Kconfig | 1 + > drivers/tty/serial/stm32-usart.c | 53 ++++++++++++++++++++++++++++++-- > drivers/tty/serial/stm32-usart.h | 1 + > 3 files changed, 53 insertions(+), 2 deletions(-) Hi Mani, You can add my: Acked-by: Fabrice Gasnier Thanks, Fabrice > > diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig > index 0aea76cd67ff..e7a6f2130684 100644 > --- a/drivers/tty/serial/Kconfig > +++ b/drivers/tty/serial/Kconfig > @@ -1462,6 +1462,7 @@ config SERIAL_STM32 > tristate "STMicroelectronics STM32 serial port support" > select SERIAL_CORE > depends on ARCH_STM32 || COMPILE_TEST > + select SERIAL_MCTRL_GPIO if GPIOLIB > help > This driver is for the on-chip Serial Controller on > STMicroelectronics STM32 MCUs. > diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c > index 5e93e8d40f59..17c2f3276888 100644 > --- a/drivers/tty/serial/stm32-usart.c > +++ b/drivers/tty/serial/stm32-usart.c > @@ -31,6 +31,7 @@ > #include > #include > > +#include "serial_mctrl_gpio.h" > #include "stm32-usart.h" > > static void stm32_stop_tx(struct uart_port *port); > @@ -510,12 +511,29 @@ static void stm32_set_mctrl(struct uart_port *port, unsigned int mctrl) > stm32_set_bits(port, ofs->cr3, USART_CR3_RTSE); > else > stm32_clr_bits(port, ofs->cr3, USART_CR3_RTSE); > + > + mctrl_gpio_set(stm32_port->gpios, mctrl); > } > > static unsigned int stm32_get_mctrl(struct uart_port *port) > { > + struct stm32_port *stm32_port = to_stm32_port(port); > + unsigned int ret; > + > /* This routine is used to get signals of: DCD, DSR, RI, and CTS */ > - return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; > + ret = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; > + > + return mctrl_gpio_get(stm32_port->gpios, &ret); > +} > + > +static void stm32_enable_ms(struct uart_port *port) > +{ > + mctrl_gpio_enable_ms(to_stm32_port(port)->gpios); > +} > + > +static void stm32_disable_ms(struct uart_port *port) > +{ > + mctrl_gpio_disable_ms(to_stm32_port(port)->gpios); > } > > /* Transmit stop */ > @@ -626,6 +644,9 @@ static void stm32_shutdown(struct uart_port *port) > u32 val, isr; > int ret; > > + /* Disable modem control interrupts */ > + stm32_disable_ms(port); > + > val = USART_CR1_TXEIE | USART_CR1_TE; > val |= stm32_port->cr1_irq | USART_CR1_RE; > val |= BIT(cfg->uart_enable_bit); > @@ -764,6 +785,12 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios, > cr3 |= USART_CR3_CTSE | USART_CR3_RTSE; > } > > + /* Handle modem control interrupts */ > + if (UART_ENABLE_MS(port, termios->c_cflag)) > + stm32_enable_ms(port); > + else > + stm32_disable_ms(port); > + > usartdiv = DIV_ROUND_CLOSEST(port->uartclk, baud); > > /* > @@ -898,6 +925,7 @@ static const struct uart_ops stm32_uart_ops = { > .throttle = stm32_throttle, > .unthrottle = stm32_unthrottle, > .stop_rx = stm32_stop_rx, > + .enable_ms = stm32_enable_ms, > .break_ctl = stm32_break_ctl, > .startup = stm32_startup, > .shutdown = stm32_shutdown, > @@ -960,10 +988,31 @@ static int stm32_init_port(struct stm32_port *stm32port, > > stm32port->port.uartclk = clk_get_rate(stm32port->clk); > if (!stm32port->port.uartclk) { > - clk_disable_unprepare(stm32port->clk); > ret = -EINVAL; > + goto err_clk; > + } > + > + stm32port->gpios = mctrl_gpio_init(&stm32port->port, 0); > + if (IS_ERR(stm32port->gpios)) { > + ret = PTR_ERR(stm32port->gpios); > + goto err_clk; > } > > + /* Both CTS/RTS gpios and "st,hw-flow-ctrl" should not be specified */ > + if (stm32port->hw_flow_control) { > + if (mctrl_gpio_to_gpiod(stm32port->gpios, UART_GPIO_CTS) || > + mctrl_gpio_to_gpiod(stm32port->gpios, UART_GPIO_RTS)) { > + dev_err(&pdev->dev, "Conflicting RTS/CTS config\n"); > + ret = -EINVAL; > + goto err_clk; > + } > + } > + > + return ret; > + > +err_clk: > + clk_disable_unprepare(stm32port->clk); > + > return ret; > } > > diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h > index db8bf0d4982d..d4c916e78d40 100644 > --- a/drivers/tty/serial/stm32-usart.h > +++ b/drivers/tty/serial/stm32-usart.h > @@ -274,6 +274,7 @@ struct stm32_port { > bool fifoen; > int wakeirq; > int rdr_mask; /* receive data register mask */ > + struct mctrl_gpios *gpios; /* modem control gpios */ > }; > > static struct stm32_port stm32_ports[STM32_MAX_PORTS]; >