From patchwork Tue May 12 12:40:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 213992 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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 DEF4FC54E4A for ; Tue, 12 May 2020 12:44:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB5F020674 for ; Tue, 12 May 2020 12:44:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729436AbgELMos (ORCPT ); Tue, 12 May 2020 08:44:48 -0400 Received: from mailout2.hostsharing.net ([83.223.78.233]:56311 "EHLO mailout2.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727783AbgELMor (ORCPT ); Tue, 12 May 2020 08:44:47 -0400 Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.hostsharing.net", Issuer "COMODO RSA Domain Validation Secure Server CA" (not verified)) by mailout2.hostsharing.net (Postfix) with ESMTPS id 87C6F1037031D; Tue, 12 May 2020 14:44:45 +0200 (CEST) Received: from localhost (unknown [87.130.102.138]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 49227627549D; Tue, 12 May 2020 14:44:45 +0200 (CEST) X-Mailbox-Line: From 271e814af4b0db3bffbbb74abf2b46b75add4516 Mon Sep 17 00:00:00 2001 Message-Id: <271e814af4b0db3bffbbb74abf2b46b75add4516.1589285873.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Tue, 12 May 2020 14:40:02 +0200 Subject: [PATCH v2 2/4] serial: Allow uart_get_rs485_mode() to return errno To: Greg Kroah-Hartman , Jiri Slaby Cc: "Matwey V. Kornilov" , Giulio Benetti , Heiko Stuebner , Andy Shevchenko , Christoph Muellner , linux-serial@vger.kernel.org Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org We're about to amend uart_get_rs485_mode() to support a GPIO pin for rs485 bus termination. Retrieving the GPIO descriptor may fail, so allow uart_get_rs485_mode() to return an errno and change all callers to check for failure. The GPIO descriptor is going to be stored in struct uart_port. Pass that struct to uart_get_rs485_mode() in lieu of a struct device and struct serial_rs485, both of which are directly accessible from struct uart_port. A few drivers call uart_get_rs485_mode() before setting the struct device pointer in struct uart_port. Shuffle those calls around where necessary. [Heiko Stuebner did the ar933x_uart.c portion, hence his Signed-off-by.] Signed-off-by: Heiko Stuebner Signed-off-by: Lukas Wunner --- drivers/tty/serial/8250/8250_core.c | 4 +++- drivers/tty/serial/ar933x_uart.c | 6 ++++-- drivers/tty/serial/atmel_serial.c | 6 ++++-- drivers/tty/serial/fsl_lpuart.c | 5 ++++- drivers/tty/serial/imx.c | 6 +++++- drivers/tty/serial/omap-serial.c | 4 +++- drivers/tty/serial/serial_core.c | 6 +++++- drivers/tty/serial/stm32-usart.c | 8 ++++---- include/linux/serial_core.h | 2 +- 9 files changed, 33 insertions(+), 14 deletions(-) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 9548d3f8fc8e..fc118f649887 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -1026,7 +1026,9 @@ int serial8250_register_8250_port(struct uart_8250_port *up) if (up->port.dev) { uart->port.dev = up->port.dev; - uart_get_rs485_mode(uart->port.dev, &uart->port.rs485); + ret = uart_get_rs485_mode(&uart->port); + if (ret) + goto err; } if (up->port.flags & UPF_FIXED_TYPE) diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c index 7e7f1398019f..0c80a79d7442 100644 --- a/drivers/tty/serial/ar933x_uart.c +++ b/drivers/tty/serial/ar933x_uart.c @@ -766,8 +766,6 @@ static int ar933x_uart_probe(struct platform_device *pdev) goto err_disable_clk; } - uart_get_rs485_mode(&pdev->dev, &port->rs485); - port->mapbase = mem_res->start; port->line = id; port->irq = irq_res->start; @@ -786,6 +784,10 @@ static int ar933x_uart_probe(struct platform_device *pdev) baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP); up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD); + ret = uart_get_rs485_mode(port); + if (ret) + goto err_disable_clk; + up->gpios = mctrl_gpio_init(port, 0); if (IS_ERR(up->gpios) && PTR_ERR(up->gpios) != -ENOSYS) return PTR_ERR(up->gpios); diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 8d7080efad9b..e43471b33710 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -2491,8 +2491,6 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port, atmel_init_property(atmel_port, pdev); atmel_set_ops(port); - uart_get_rs485_mode(&mpdev->dev, &port->rs485); - port->iotype = UPIO_MEM; port->flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP; port->ops = &atmel_pops; @@ -2506,6 +2504,10 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port, memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring)); + ret = uart_get_rs485_mode(port); + if (ret) + return ret; + /* for console, the clock could already be configured */ if (!atmel_port->clk) { atmel_port->clk = clk_get(&mpdev->dev, "usart"); diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 6a9909e56449..029324c77cd7 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -2619,7 +2619,9 @@ static int lpuart_probe(struct platform_device *pdev) if (ret) goto failed_attach_port; - uart_get_rs485_mode(&pdev->dev, &sport->port.rs485); + ret = uart_get_rs485_mode(&sport->port); + if (ret) + goto failed_get_rs485; if (sport->port.rs485.flags & SER_RS485_RX_DURING_TX) dev_err(&pdev->dev, "driver doesn't support RX during TX\n"); @@ -2632,6 +2634,7 @@ static int lpuart_probe(struct platform_device *pdev) return 0; +failed_get_rs485: failed_attach_port: failed_irq_request: lpuart_disable_clks(sport); diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index f4d68109bc8b..91f3910d6c44 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -2302,7 +2302,11 @@ static int imx_uart_probe(struct platform_device *pdev) sport->ucr4 = readl(sport->port.membase + UCR4); sport->ufcr = readl(sport->port.membase + UFCR); - uart_get_rs485_mode(&pdev->dev, &sport->port.rs485); + ret = uart_get_rs485_mode(&sport->port); + if (ret) { + clk_disable_unprepare(sport->clk_ipg); + return ret; + } if (sport->port.rs485.flags & SER_RS485_ENABLED && (!sport->have_rtscts && !sport->have_rtsgpio)) diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index c71c1a2266dc..8573fc9cb0cd 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -1608,7 +1608,9 @@ static int serial_omap_probe_rs485(struct uart_omap_port *up, if (!np) return 0; - uart_get_rs485_mode(up->dev, rs485conf); + ret = uart_get_rs485_mode(&up->port); + if (ret) + return ret; if (of_property_read_bool(np, "rs485-rts-active-high")) { rs485conf->flags |= SER_RS485_RTS_ON_SEND; diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 66a5e2faf57e..43b6682877d5 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -3295,8 +3295,10 @@ EXPORT_SYMBOL(uart_remove_one_port); * This function implements the device tree binding described in * Documentation/devicetree/bindings/serial/rs485.txt. */ -void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf) +int uart_get_rs485_mode(struct uart_port *port) { + struct serial_rs485 *rs485conf = &port->rs485; + struct device *dev = port->dev; u32 rs485_delay[2]; int ret; @@ -3328,6 +3330,8 @@ void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf) rs485conf->flags &= ~SER_RS485_RTS_ON_SEND; rs485conf->flags |= SER_RS485_RTS_AFTER_SEND; } + + return 0; } EXPORT_SYMBOL_GPL(uart_get_rs485_mode); diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 5e93e8d40f59..e3db54398159 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -158,9 +158,7 @@ static int stm32_init_rs485(struct uart_port *port, if (!pdev->dev.of_node) return -ENODEV; - uart_get_rs485_mode(&pdev->dev, rs485conf); - - return 0; + return uart_get_rs485_mode(port); } static int stm32_pending_rx(struct uart_port *port, u32 *sr, int *last_res, @@ -931,7 +929,9 @@ static int stm32_init_port(struct stm32_port *stm32port, port->rs485_config = stm32_config_rs485; - stm32_init_rs485(port, pdev); + ret = stm32_init_rs485(port, pdev); + if (ret) + return ret; if (stm32port->info->cfg.has_wakeup) { stm32port->wakeirq = platform_get_irq(pdev, 1); diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 92f5eba86052..b649a2b894e7 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -472,5 +472,5 @@ extern int uart_handle_break(struct uart_port *port); (cflag) & CRTSCTS || \ !((cflag) & CLOCAL)) -void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf); +int uart_get_rs485_mode(struct uart_port *port); #endif /* LINUX_SERIAL_CORE_H */ From patchwork Tue May 12 12:40:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 213991 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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 AECD2C54E8B for ; Tue, 12 May 2020 12:47:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E22D20674 for ; Tue, 12 May 2020 12:47:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729880AbgELMru (ORCPT ); Tue, 12 May 2020 08:47:50 -0400 Received: from mailout3.hostsharing.net ([176.9.242.54]:54785 "EHLO mailout3.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729626AbgELMru (ORCPT ); Tue, 12 May 2020 08:47:50 -0400 Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.hostsharing.net", Issuer "COMODO RSA Domain Validation Secure Server CA" (not verified)) by mailout3.hostsharing.net (Postfix) with ESMTPS id B829C101C01C0; Tue, 12 May 2020 14:47:47 +0200 (CEST) Received: from localhost (unknown [87.130.102.138]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 14486627549D; Tue, 12 May 2020 14:47:46 +0200 (CEST) X-Mailbox-Line: From 3d32e182ebefce6144844adf12fe481a35580633 Mon Sep 17 00:00:00 2001 Message-Id: <3d32e182ebefce6144844adf12fe481a35580633.1589285874.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Tue, 12 May 2020 14:40:03 +0200 Subject: [PATCH v2 3/4] dt-bindings: serial: Add binding for rs485 bus termination GPIO To: Greg Kroah-Hartman , Jiri Slaby , Rob Herring Cc: "Matwey V. Kornilov" , Giulio Benetti , Heiko Stuebner , Andy Shevchenko , Christoph Muellner , linux-serial@vger.kernel.org, devicetree@vger.kernel.org Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Commit e8759ad17d41 ("serial: uapi: Add support for bus termination") introduced the ability to enable rs485 bus termination from user space. So far the feature is only used by a single driver, 8250_exar.c, using a hardcoded GPIO pin specific to Siemens IOT2040 products. Provide for a more generic solution by allowing specification of an rs485 bus termination GPIO pin in the device tree. An upcoming commit implements support for this pin for any 8250 driver. The binding is used in device trees of the "Revolution Pi" PLCs offered by KUNBUS. [Heiko Stuebner converted the binding to YAML, hence his Signed-off-by.] Signed-off-by: Heiko Stuebner Signed-off-by: Lukas Wunner Cc: Jan Kiszka --- Documentation/devicetree/bindings/serial/rs485.yaml | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Documentation/devicetree/bindings/serial/rs485.yaml b/Documentation/devicetree/bindings/serial/rs485.yaml index d4beaf11222d..a9ad17864889 100644 --- a/Documentation/devicetree/bindings/serial/rs485.yaml +++ b/Documentation/devicetree/bindings/serial/rs485.yaml @@ -43,3 +43,7 @@ properties: rs485-rx-during-tx: description: enables the receiving of data even while sending data. $ref: /schemas/types.yaml#/definitions/flag + + rs485-term-gpios: + description: GPIO pin to enable RS485 bus termination. + maxItems: 1