From patchwork Wed Nov 6 09:25:39 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linus Walleij X-Patchwork-Id: 21352 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-vb0-f69.google.com (mail-vb0-f69.google.com [209.85.212.69]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id 2108F20DB9 for ; Wed, 6 Nov 2013 09:25:50 +0000 (UTC) Received: by mail-vb0-f69.google.com with SMTP id w5sf8618483vbf.8 for ; Wed, 06 Nov 2013 01:25:49 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:delivered-to:from:to:cc:subject :date:message-id:x-original-sender:x-original-authentication-results :precedence:mailing-list:list-id:list-post:list-help:list-archive :list-unsubscribe; bh=aZVg/xLNIyj+mtOwc9tIyJzyjS8wSjywUY8mc3BU3+M=; b=dLlCeyckwcOtXnY+JWG2z0jzqpODY6DmT3jLpVtfbTidkNGs92E60aLoye9JqUAfoz Y+5ecpyo7Y7LaIPD8tfB+NPWpETmdBLMdHLL9/DmMVprurN3/6pwJfi/YsP1kBABnPgg rPJvbc0Xw/eBWHmJAlGFvHbpPAPDHX0kldiion6R7Za8nIHAC40d63GZvPlz57xw1dcS lv55xF2vubWNaBjfdIBq7qeP7Sj8C3NbcW959pkYw3d8v7+o2cQ8Mv5ibm4DYR3+8yqk RQtdFKGJBL34v/mGwEN5nVdreZmGDTZbRJDec8Tmy7k/G5TgZGboEMMCTWb2fqhM8BMt ZPsA== X-Gm-Message-State: ALoCoQm9m+6/CD/LpWxnC6mOFLyDBkMTYBV3OlT0GV8NZmRUL5hcOaAGx5ApUa3Ukhv0x3t3siGh X-Received: by 10.52.108.166 with SMTP id hl6mr1364303vdb.0.1383729949704; Wed, 06 Nov 2013 01:25:49 -0800 (PST) MIME-Version: 1.0 X-BeenThere: patchwork-forward@linaro.org Received: by 10.49.60.68 with SMTP id f4ls603848qer.72.gmail; Wed, 06 Nov 2013 01:25:49 -0800 (PST) X-Received: by 10.58.254.200 with SMTP id ak8mr1588119ved.12.1383729949602; Wed, 06 Nov 2013 01:25:49 -0800 (PST) Received: from mail-ve0-f180.google.com (mail-ve0-f180.google.com [209.85.128.180]) by mx.google.com with ESMTPS id j9si8116746vcg.10.2013.11.06.01.25.49 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 06 Nov 2013 01:25:49 -0800 (PST) Received-SPF: neutral (google.com: 209.85.128.180 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) client-ip=209.85.128.180; Received: by mail-ve0-f180.google.com with SMTP id oy12so3440920veb.11 for ; Wed, 06 Nov 2013 01:25:49 -0800 (PST) X-Received: by 10.58.186.173 with SMTP id fl13mr1545311vec.31.1383729949478; Wed, 06 Nov 2013 01:25:49 -0800 (PST) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patches@linaro.org Received: by 10.220.174.196 with SMTP id u4csp270460vcz; Wed, 6 Nov 2013 01:25:48 -0800 (PST) X-Received: by 10.180.37.227 with SMTP id b3mr1657044wik.24.1383729947651; Wed, 06 Nov 2013 01:25:47 -0800 (PST) Received: from mail-wi0-f173.google.com (mail-wi0-f173.google.com [209.85.212.173]) by mx.google.com with ESMTPS id dl2si10540937wjb.157.2013.11.06.01.25.47 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 06 Nov 2013 01:25:47 -0800 (PST) Received-SPF: neutral (google.com: 209.85.212.173 is neither permitted nor denied by best guess record for domain of linus.walleij@linaro.org) client-ip=209.85.212.173; Received: by mail-wi0-f173.google.com with SMTP id ey11so3409364wid.12 for ; Wed, 06 Nov 2013 01:25:47 -0800 (PST) X-Received: by 10.180.106.133 with SMTP id gu5mr20629861wib.0.1383729947077; Wed, 06 Nov 2013 01:25:47 -0800 (PST) Received: from localhost.localdomain ([85.235.11.236]) by mx.google.com with ESMTPSA id w10sm22322089wia.4.2013.11.06.01.25.45 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 06 Nov 2013 01:25:46 -0800 (PST) From: Linus Walleij To: linux-gpio@vger.kernel.org, Andrew Victor , Nicolas Ferre , Jean-Christophe Plagniol-Villard , linux-serial@vger.kernel.org, Greg Kroah-Hartman Cc: Alexandre Courbot , linux-arm-kernel@lists.infradead.org, Linus Walleij Subject: [PATCH v2] ARM/serial: at91: switch atmel serial to use gpiolib Date: Wed, 6 Nov 2013 10:25:39 +0100 Message-Id: <1383729939-10269-1-git-send-email-linus.walleij@linaro.org> X-Mailer: git-send-email 1.8.3.1 X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: linus.walleij@linaro.org X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.128.180 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Precedence: list Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org List-ID: X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , This passes the errata fix using a GPIO to control the RTS pin on one of the AT91 chips to use gpiolib instead of the AT91-specific interfaces. Also remove the reliance on compile-time #defines and the cpu_* check and rely on the platform passing down the proper GPIO pin through platform data. This is a prerequisite for getting rid of the local GPIO implementation in the AT91 platform and move toward multiplatform. The patch also adds device tree support for getting the RTS GPIO pin from the device tree on DT boot paths. Signed-off-by: Nicolas Ferre Signed-off-by: Linus Walleij --- ChangeLog v1->v2: - Skip check for UART base address from leftover hack, if we have an RTS GPIO we just use it. - Set default error value on GPIO pin to -EINVAL - Fold in a device tree support patch from Nicolas Ferre --- .../devicetree/bindings/serial/atmel-usart.txt | 3 ++ arch/arm/mach-at91/at91rm9200_devices.c | 1 + drivers/tty/serial/atmel_serial.c | 55 +++++++++++++++------- include/linux/platform_data/atmel.h | 1 + 4 files changed, 42 insertions(+), 18 deletions(-) diff --git a/Documentation/devicetree/bindings/serial/atmel-usart.txt b/Documentation/devicetree/bindings/serial/atmel-usart.txt index 2191dcb9f1da..3adc61c2e4ca 100644 --- a/Documentation/devicetree/bindings/serial/atmel-usart.txt +++ b/Documentation/devicetree/bindings/serial/atmel-usart.txt @@ -10,6 +10,8 @@ Required properties: Optional properties: - atmel,use-dma-rx: use of PDC or DMA for receiving data - atmel,use-dma-tx: use of PDC or DMA for transmitting data +- rts-gpios: specify a GPIO for RTS line. It will use specified PIO instead of the peripheral + function pin for the USART RTS feature. If unsure, don't specify this property. - add dma bindings for dma transfer: - dmas: DMA specifier, consisting of a phandle to DMA controller node, memory peripheral interface and USART DMA channel ID, FIFO configuration. @@ -28,6 +30,7 @@ Example: interrupts = <7>; atmel,use-dma-rx; atmel,use-dma-tx; + rts-gpios = <&pioD 15 0>; }; - use DMA: diff --git a/arch/arm/mach-at91/at91rm9200_devices.c b/arch/arm/mach-at91/at91rm9200_devices.c index c721e9b08066..51d4c08962f6 100644 --- a/arch/arm/mach-at91/at91rm9200_devices.c +++ b/arch/arm/mach-at91/at91rm9200_devices.c @@ -961,6 +961,7 @@ static struct resource uart0_resources[] = { static struct atmel_uart_data uart0_data = { .use_dma_tx = 1, .use_dma_rx = 1, + .rts_gpio = AT91_PIN_PA21, }; static u64 uart0_dmamask = DMA_BIT_MASK(32); diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index d067285a2d20..e31f3319be64 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -35,21 +35,18 @@ #include #include #include +#include #include #include #include #include #include #include +#include #include #include -#ifdef CONFIG_ARM -#include -#include -#endif - #define PDC_BUFFER_SIZE 512 /* Revisit: We should calculate this based on the actual port settings */ #define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */ @@ -167,6 +164,7 @@ struct atmel_uart_port { struct circ_buf rx_ring; struct serial_rs485 rs485; /* rs485 settings */ + int rts_gpio; /* optional RTS GPIO */ unsigned int tx_done_mask; bool is_usart; /* usart or uart */ struct timer_list uart_timer; /* uart timer */ @@ -300,20 +298,16 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) unsigned int mode; struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); -#ifdef CONFIG_ARCH_AT91RM9200 - if (cpu_is_at91rm9200()) { - /* - * AT91RM9200 Errata #39: RTS0 is not internally connected - * to PA21. We need to drive the pin manually. - */ - if (port->mapbase == AT91RM9200_BASE_US0) { - if (mctrl & TIOCM_RTS) - at91_set_gpio_value(AT91_PIN_PA21, 0); - else - at91_set_gpio_value(AT91_PIN_PA21, 1); - } + /* + * AT91RM9200 Errata #39: RTS0 is not internally connected + * to PA21. We need to drive the pin as a GPIO. + */ + if (gpio_is_valid(atmel_port->rts_gpio)) { + if (mctrl & TIOCM_RTS) + gpio_set_value(atmel_port->rts_gpio, 0); + else + gpio_set_value(atmel_port->rts_gpio, 1); } -#endif if (mctrl & TIOCM_RTS) control |= ATMEL_US_RTSEN; @@ -2365,6 +2359,31 @@ static int atmel_serial_probe(struct platform_device *pdev) port = &atmel_ports[ret]; port->backup_imr = 0; port->uart.line = ret; + port->rts_gpio = -EINVAL; /* Invalid, zero could be valid */ + /* + * In theory the GPIO pin controlling RTS could be zero and + * this would be an improper check, but we know that the only + * existing case is != 0 and it's nice to use the zero-initialized + * structs to indicate "no RTS GPIO" instead of open-coding some + * invalid value everywhere. + */ + if (pdata && pdata->rts_gpio > 0) + port->rts_gpio = pdata->rts_gpio; + else if (np) + port->rts_gpio = of_get_named_gpio(np, "rts-gpios", 0); + + if (gpio_is_valid(port->rts_gpio)) { + ret = devm_gpio_request(&pdev->dev, port->rts_gpio, "RTS"); + if (ret) { + dev_err(&pdev->dev, "error requesting RTS GPIO\n"); + goto err; + } + ret = gpio_direction_output(port->rts_gpio, 0); + if (ret) { + dev_err(&pdev->dev, "error setting up RTS GPIO\n"); + goto err; + } + } ret = atmel_init_port(port, pdev); if (ret) diff --git a/include/linux/platform_data/atmel.h b/include/linux/platform_data/atmel.h index cea9f70133c5..e26b0c14edea 100644 --- a/include/linux/platform_data/atmel.h +++ b/include/linux/platform_data/atmel.h @@ -84,6 +84,7 @@ struct atmel_uart_data { short use_dma_rx; /* use receive DMA? */ void __iomem *regs; /* virt. base address, if any */ struct serial_rs485 rs485; /* rs485 settings */ + int rts_gpio; /* optional RTS GPIO */ }; /* Touchscreen Controller */