From patchwork Wed Jun 7 14:05:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hugo Villeneuve X-Patchwork-Id: 690470 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4299C8300C for ; Wed, 7 Jun 2023 14:05:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240726AbjFGOFu (ORCPT ); Wed, 7 Jun 2023 10:05:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240205AbjFGOFs (ORCPT ); Wed, 7 Jun 2023 10:05:48 -0400 Received: from mail.hugovil.com (mail.hugovil.com [162.243.120.170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7B561BEC; Wed, 7 Jun 2023 07:05:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hugovil.com ; s=x; h=Subject:Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=SuJQI5JxUPzY+H5j7N6gL+Df0hCmvZbTgQvKUtpTEpg=; b=lxFwyIRPR7jlhJYI5I55AmpVI1 gAMwRwqqutMusoc4NIPYpZbkF1M26ebBw0gEUOSlQxlavN6C7bxU5cOTEd7hCHI8o00GfO90E4QDV vu9EaHRkeqC3GfkHlFFtY6ls+SYXM9rkdsxoUkfZf+ktJOZuHTQak0VeOU+9cQtAGVoU=; Received: from modemcable168.174-80-70.mc.videotron.ca ([70.80.174.168]:57832 helo=pettiford.lan) by mail.hugovil.com with esmtpa (Exim 4.92) (envelope-from ) id 1q6tn9-0005dF-1m; Wed, 07 Jun 2023 10:05:39 -0400 From: Hugo Villeneuve To: gregkh@linuxfoundation.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, jirislaby@kernel.org, jringle@gridpoint.com, jesse.sung@canonical.com, isaac.true@canonical.com, l.perczak@camlintechnologies.com, tomasz.mon@camlingroup.com Cc: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, hugo@hugovil.com, linux-gpio@vger.kernel.org, Hugo Villeneuve , stable@vger.kernel.org, Conor Dooley , Lech Perczak Date: Wed, 7 Jun 2023 10:05:19 -0400 Message-Id: <20230607140525.833982-6-hugo@hugovil.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230607140525.833982-1-hugo@hugovil.com> References: <20230607140525.833982-1-hugo@hugovil.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 70.80.174.168 X-SA-Exim-Mail-From: hugo@hugovil.com Subject: [PATCH v8 05/10] dt-bindings: sc16is7xx: Add property to change GPIO function X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.hugovil.com) Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: Hugo Villeneuve Some variants in this series of UART controllers have GPIO pins that are shared between GPIO and modem control lines. The pin mux mode (GPIO or modem control lines) can be set for each ports (channels) supported by the variant. This adds a property to the device tree to set the GPIO pin mux to modem control lines on selected ports if needed. Cc: # 6.1.x Signed-off-by: Hugo Villeneuve Acked-by: Conor Dooley Reviewed-by: Lech Perczak --- .../bindings/serial/nxp,sc16is7xx.txt | 46 +++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/Documentation/devicetree/bindings/serial/nxp,sc16is7xx.txt b/Documentation/devicetree/bindings/serial/nxp,sc16is7xx.txt index 0fa8e3e43bf8..1a7e4bff0456 100644 --- a/Documentation/devicetree/bindings/serial/nxp,sc16is7xx.txt +++ b/Documentation/devicetree/bindings/serial/nxp,sc16is7xx.txt @@ -23,6 +23,9 @@ Optional properties: 1 = active low. - irda-mode-ports: An array that lists the indices of the port that should operate in IrDA mode. +- nxp,modem-control-line-ports: An array that lists the indices of the port that + should have shared GPIO lines configured as + modem control lines. Example: sc16is750: sc16is750@51 { @@ -35,6 +38,26 @@ Example: #gpio-cells = <2>; }; + sc16is752: sc16is752@53 { + compatible = "nxp,sc16is752"; + reg = <0x53>; + clocks = <&clk20m>; + interrupt-parent = <&gpio3>; + interrupts = <7 IRQ_TYPE_EDGE_FALLING>; + nxp,modem-control-line-ports = <1>; /* Port 1 as modem control lines */ + gpio-controller; /* Port 0 as GPIOs */ + #gpio-cells = <2>; + }; + + sc16is752: sc16is752@54 { + compatible = "nxp,sc16is752"; + reg = <0x54>; + clocks = <&clk20m>; + interrupt-parent = <&gpio3>; + interrupts = <7 IRQ_TYPE_EDGE_FALLING>; + nxp,modem-control-line-ports = <0 1>; /* Ports 0 and 1 as modem control lines */ + }; + * spi as bus Required properties: @@ -59,6 +82,9 @@ Optional properties: 1 = active low. - irda-mode-ports: An array that lists the indices of the port that should operate in IrDA mode. +- nxp,modem-control-line-ports: An array that lists the indices of the port that + should have shared GPIO lines configured as + modem control lines. Example: sc16is750: sc16is750@0 { @@ -70,3 +96,23 @@ Example: gpio-controller; #gpio-cells = <2>; }; + + sc16is752: sc16is752@1 { + compatible = "nxp,sc16is752"; + reg = <1>; + clocks = <&clk20m>; + interrupt-parent = <&gpio3>; + interrupts = <7 IRQ_TYPE_EDGE_FALLING>; + nxp,modem-control-line-ports = <1>; /* Port 1 as modem control lines */ + gpio-controller; /* Port 0 as GPIOs */ + #gpio-cells = <2>; + }; + + sc16is752: sc16is752@2 { + compatible = "nxp,sc16is752"; + reg = <2>; + clocks = <&clk20m>; + interrupt-parent = <&gpio3>; + interrupts = <7 IRQ_TYPE_EDGE_FALLING>; + nxp,modem-control-line-ports = <0 1>; /* Ports 0 and 1 as modem control lines */ + }; From patchwork Wed Jun 7 14:05:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hugo Villeneuve X-Patchwork-Id: 690466 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D4C1C7EE29 for ; Wed, 7 Jun 2023 14:07:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241030AbjFGOHc (ORCPT ); Wed, 7 Jun 2023 10:07:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241033AbjFGOHN (ORCPT ); Wed, 7 Jun 2023 10:07:13 -0400 Received: from mail.hugovil.com (mail.hugovil.com [162.243.120.170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 275F81BF8; Wed, 7 Jun 2023 07:06:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hugovil.com ; s=x; h=Subject:Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=50p/zLaeMpKRWmAB6TSo0KVng1B728/hNk2tudhv+As=; b=IAY/E7e23qeM3CII6ORjATKc0M hpx1APb8hpjceyDyFBdNDsb0lmeDIboY7KT38TGbte9yJowwNBCrlG+TTafI9jSoaJiWU6I3aIb1Y kmz8sCnlJ/MrFf6W5Q/Sv95GCdYbaAs0OqQumdtZ31CHzdeNuxX9eZ1vLhb73q7YqjeA=; Received: from modemcable168.174-80-70.mc.videotron.ca ([70.80.174.168]:57832 helo=pettiford.lan) by mail.hugovil.com with esmtpa (Exim 4.92) (envelope-from ) id 1q6tnA-0005dF-PD; Wed, 07 Jun 2023 10:05:41 -0400 From: Hugo Villeneuve To: gregkh@linuxfoundation.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, jirislaby@kernel.org, jringle@gridpoint.com, jesse.sung@canonical.com, isaac.true@canonical.com, l.perczak@camlintechnologies.com, tomasz.mon@camlingroup.com Cc: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, hugo@hugovil.com, linux-gpio@vger.kernel.org, Hugo Villeneuve , stable@vger.kernel.org, Andy Shevchenko Date: Wed, 7 Jun 2023 10:05:20 -0400 Message-Id: <20230607140525.833982-7-hugo@hugovil.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230607140525.833982-1-hugo@hugovil.com> References: <20230607140525.833982-1-hugo@hugovil.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 70.80.174.168 X-SA-Exim-Mail-From: hugo@hugovil.com Subject: [PATCH v8 06/10] serial: sc16is7xx: fix regression with GPIO configuration X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.hugovil.com) Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: Hugo Villeneuve Commit 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines") and commit 21144bab4f11 ("sc16is7xx: Handle modem status lines") changed the function of the GPIOs pins to act as modem control lines without any possibility of selecting GPIO function. As a consequence, applications that depends on GPIO lines configured by default as GPIO pins no longer work as expected. Also, the change to select modem control lines function was done only for channel A of dual UART variants (752/762). This was not documented in the log message. Allow to specify GPIO or modem control line function in the device tree, and for each of the ports (A or B). Do so by using the new device-tree property named "modem-control-line-ports" (property added in separate patch). When registering GPIO chip controller, mask-out GPIO pins declared as modem control lines according to this new "modem-control-line-ports" DT property. Boards that need to have GPIOS configured as modem control lines should add that property to their device tree. Here is a list of boards using the sc16is7xx driver in their device tree and that may need to be modified: arm64/boot/dts/freescale/fsl-ls1012a-frdm.dts mips/boot/dts/ingenic/cu1830-neo.dts mips/boot/dts/ingenic/cu1000-neo.dts Fixes: 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines") Fixes: 21144bab4f11 ("sc16is7xx: Handle modem status lines") Cc: # 6.1.x: 95982fad dt-bindings: sc16is7xx: Add property to change GPIO function Cc: # 6.1.x: 1584d572 serial: sc16is7xx: refactor GPIO controller registration Cc: # 6.1.x: ac2caa5a serial: sc16is7xx: remove obsolete out_thread label Cc: # 6.1.x: d90961ad serial: sc16is7xx: mark IOCONTROL register as volatile Cc: # 6.1.x: 6dae3bad serial: sc16is7xx: fix broken port 0 uart init Cc: # 6.1.x Signed-off-by: Hugo Villeneuve Reviewed-by: Andy Shevchenko --- drivers/tty/serial/sc16is7xx.c | 104 +++++++++++++++++++++++++++------ 1 file changed, 85 insertions(+), 19 deletions(-) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index f5b4d2d18a71..11edbebe8fa2 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -236,7 +236,8 @@ /* IOControl register bits (Only 750/760) */ #define SC16IS7XX_IOCONTROL_LATCH_BIT (1 << 0) /* Enable input latching */ -#define SC16IS7XX_IOCONTROL_MODEM_BIT (1 << 1) /* Enable GPIO[7:4] as modem pins */ +#define SC16IS7XX_IOCONTROL_MODEM_A_BIT (1 << 1) /* Enable GPIO[7:4] as modem A pins */ +#define SC16IS7XX_IOCONTROL_MODEM_B_BIT (1 << 2) /* Enable GPIO[3:0] as modem B pins */ #define SC16IS7XX_IOCONTROL_SRESET_BIT (1 << 3) /* Software Reset */ /* EFCR register bits */ @@ -301,12 +302,12 @@ /* Misc definitions */ #define SC16IS7XX_FIFO_SIZE (64) #define SC16IS7XX_REG_SHIFT 2 +#define SC16IS7XX_GPIOS_PER_BANK 4 struct sc16is7xx_devtype { char name[10]; int nr_gpio; int nr_uart; - int has_mctrl; }; #define SC16IS7XX_RECONF_MD (1 << 0) @@ -337,7 +338,9 @@ struct sc16is7xx_port { struct clk *clk; #ifdef CONFIG_GPIOLIB struct gpio_chip gpio; + unsigned long gpio_valid_mask; #endif + u8 mctrl_mask; unsigned char buf[SC16IS7XX_FIFO_SIZE]; struct kthread_worker kworker; struct task_struct *kworker_task; @@ -448,35 +451,30 @@ static const struct sc16is7xx_devtype sc16is74x_devtype = { .name = "SC16IS74X", .nr_gpio = 0, .nr_uart = 1, - .has_mctrl = 0, }; static const struct sc16is7xx_devtype sc16is750_devtype = { .name = "SC16IS750", - .nr_gpio = 4, + .nr_gpio = 8, .nr_uart = 1, - .has_mctrl = 1, }; static const struct sc16is7xx_devtype sc16is752_devtype = { .name = "SC16IS752", - .nr_gpio = 0, + .nr_gpio = 8, .nr_uart = 2, - .has_mctrl = 1, }; static const struct sc16is7xx_devtype sc16is760_devtype = { .name = "SC16IS760", - .nr_gpio = 4, + .nr_gpio = 8, .nr_uart = 1, - .has_mctrl = 1, }; static const struct sc16is7xx_devtype sc16is762_devtype = { .name = "SC16IS762", - .nr_gpio = 0, + .nr_gpio = 8, .nr_uart = 2, - .has_mctrl = 1, }; static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg) @@ -1351,14 +1349,43 @@ static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip, return 0; } +static int sc16is7xx_gpio_init_valid_mask(struct gpio_chip *chip, + unsigned long *valid_mask, + unsigned int ngpios) +{ + struct sc16is7xx_port *s = gpiochip_get_data(chip); + + *valid_mask = s->gpio_valid_mask; + + return 0; +} + static int sc16is7xx_setup_gpio_chip(struct sc16is7xx_port *s) { if (!s->devtype->nr_gpio) return 0; + switch (s->mctrl_mask) { + case 0: + s->gpio_valid_mask = GENMASK(7, 0); + break; + case SC16IS7XX_IOCONTROL_MODEM_A_BIT: + s->gpio_valid_mask = GENMASK(3, 0); + break; + case SC16IS7XX_IOCONTROL_MODEM_B_BIT: + s->gpio_valid_mask = GENMASK(7, 4); + break; + default: + break; + } + + if (s->gpio_valid_mask == 0) + return 0; + s->gpio.owner = THIS_MODULE; s->gpio.parent = s->dev; s->gpio.label = dev_name(s->dev); + s->gpio.init_valid_mask = sc16is7xx_gpio_init_valid_mask; s->gpio.direction_input = sc16is7xx_gpio_direction_input; s->gpio.get = sc16is7xx_gpio_get; s->gpio.direction_output = sc16is7xx_gpio_direction_output; @@ -1371,6 +1398,47 @@ static int sc16is7xx_setup_gpio_chip(struct sc16is7xx_port *s) } #endif +/* + * Configure ports designated to operate as modem control lines. + */ +static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s) +{ + int i; + int ret; + int count; + u32 mctrl_port[2]; + + count = device_property_count_u32(s->dev, + "nxp,modem-control-line-ports"); + if (count < 0 || count > ARRAY_SIZE(mctrl_port)) + return 0; + + ret = device_property_read_u32_array(s->dev, + "nxp,modem-control-line-ports", + mctrl_port, count); + if (ret) + return ret; + + s->mctrl_mask = 0; + + for (i = 0; i < count; i++) { + /* Use GPIO lines as modem control lines */ + if (mctrl_port[i] == 0) + s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_A_BIT; + else if (mctrl_port[i] == 1) + s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_B_BIT; + } + + if (s->mctrl_mask) + regmap_update_bits( + s->regmap, + SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT, + SC16IS7XX_IOCONTROL_MODEM_A_BIT | + SC16IS7XX_IOCONTROL_MODEM_B_BIT, s->mctrl_mask); + + return 0; +} + static const struct serial_rs485 sc16is7xx_rs485_supported = { .flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND, .delay_rts_before_send = 1, @@ -1479,12 +1547,6 @@ static int sc16is7xx_probe(struct device *dev, SC16IS7XX_EFCR_RXDISABLE_BIT | SC16IS7XX_EFCR_TXDISABLE_BIT); - /* Use GPIO lines as modem status registers */ - if (devtype->has_mctrl) - sc16is7xx_port_write(&s->p[i].port, - SC16IS7XX_IOCONTROL_REG, - SC16IS7XX_IOCONTROL_MODEM_BIT); - /* Initialize kthread work structs */ kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc); kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc); @@ -1522,6 +1584,10 @@ static int sc16is7xx_probe(struct device *dev, s->p[u].irda_mode = true; } + ret = sc16is7xx_setup_mctrl_ports(s); + if (ret) + goto out_ports; + #ifdef CONFIG_GPIOLIB ret = sc16is7xx_setup_gpio_chip(s); if (ret) @@ -1548,7 +1614,7 @@ static int sc16is7xx_probe(struct device *dev, return 0; #ifdef CONFIG_GPIOLIB - if (devtype->nr_gpio) + if (s->gpio_valid_mask) gpiochip_remove(&s->gpio); #endif @@ -1572,7 +1638,7 @@ static void sc16is7xx_remove(struct device *dev) int i; #ifdef CONFIG_GPIOLIB - if (s->devtype->nr_gpio) + if (s->gpio_valid_mask) gpiochip_remove(&s->gpio); #endif From patchwork Wed Jun 7 14:05:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hugo Villeneuve X-Patchwork-Id: 690469 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 864E0C87FE7 for ; Wed, 7 Jun 2023 14:05:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240878AbjFGOFx (ORCPT ); Wed, 7 Jun 2023 10:05:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240759AbjFGOFu (ORCPT ); Wed, 7 Jun 2023 10:05:50 -0400 Received: from mail.hugovil.com (mail.hugovil.com [162.243.120.170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4250A1BE6; Wed, 7 Jun 2023 07:05:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hugovil.com ; s=x; h=Subject:Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=y5I58H4JZdxt5KQmeeMGWVEFZi9VwZ11ibHuDz0qvxg=; b=k/Hdo5EmzF6vURXJeqHLFQnpFc LwR0ZnW7sRUPGh1GA4d8pPF7zM7/xW2/QMur9CifkjlSMxpfMHcONqJU2YftMsKRvU+44C49RitMk vlDqd2CKNlAAtcQbYzaThPvQ0FqUEHw0lxMfd0OaIeL+48IvjuYpF7HdRGNyH4gre13M=; Received: from modemcable168.174-80-70.mc.videotron.ca ([70.80.174.168]:57832 helo=pettiford.lan) by mail.hugovil.com with esmtpa (Exim 4.92) (envelope-from ) id 1q6tnC-0005dF-NP; Wed, 07 Jun 2023 10:05:43 -0400 From: Hugo Villeneuve To: gregkh@linuxfoundation.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, jirislaby@kernel.org, jringle@gridpoint.com, jesse.sung@canonical.com, isaac.true@canonical.com, l.perczak@camlintechnologies.com, tomasz.mon@camlingroup.com Cc: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, hugo@hugovil.com, linux-gpio@vger.kernel.org, Hugo Villeneuve , stable@vger.kernel.org, Lech Perczak Date: Wed, 7 Jun 2023 10:05:21 -0400 Message-Id: <20230607140525.833982-8-hugo@hugovil.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230607140525.833982-1-hugo@hugovil.com> References: <20230607140525.833982-1-hugo@hugovil.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 70.80.174.168 X-SA-Exim-Mail-From: hugo@hugovil.com Subject: [PATCH v8 07/10] serial: sc16is7xx: fix bug when first setting GPIO direction X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.hugovil.com) Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: Hugo Villeneuve When configuring a pin as an output pin with a value of logic 0, we end up as having a value of logic 1 on the output pin. Setting a logic 0 a second time (or more) after that will correctly output a logic 0 on the output pin. By default, all GPIO pins are configured as inputs. When we enter sc16is7xx_gpio_direction_output() for the first time, we first set the desired value in IOSTATE, and then we configure the pin as an output. The datasheet states that writing to IOSTATE register will trigger a transfer of the value to the I/O pin configured as output, so if the pin is configured as an input, nothing will be transferred. Therefore, set the direction first in IODIR, and then set the desired value in IOSTATE. This is what is done in NXP application note AN10587. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: Signed-off-by: Hugo Villeneuve Reviewed-by: Lech Perczak Tested-by: Lech Perczak --- drivers/tty/serial/sc16is7xx.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 11edbebe8fa2..98c520ef4a02 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1342,9 +1342,18 @@ static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip, state |= BIT(offset); else state &= ~BIT(offset); - sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state); + + /* + * If we write IOSTATE first, and then IODIR, the output value is not + * transferred to the corresponding I/O pin. + * The datasheet states that each register bit will be transferred to + * the corresponding I/O pin programmed as output when writing to + * IOSTATE. Therefore, configure direction first with IODIR, and then + * set value after with IOSTATE. + */ sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), BIT(offset)); + sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state); return 0; } From patchwork Wed Jun 7 14:05:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Hugo Villeneuve X-Patchwork-Id: 690468 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37232C7EE23 for ; Wed, 7 Jun 2023 14:06:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240934AbjFGOGC (ORCPT ); Wed, 7 Jun 2023 10:06:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240871AbjFGOFw (ORCPT ); Wed, 7 Jun 2023 10:05:52 -0400 Received: from mail.hugovil.com (mail.hugovil.com [162.243.120.170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B16251BEC; Wed, 7 Jun 2023 07:05:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hugovil.com ; s=x; h=Subject:Content-Transfer-Encoding:Content-Type:MIME-Version: References:In-Reply-To:Message-Id:Date:Cc:To:From:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=TFnTYj33J3Uv6zn3iG50TL/Xr9i/wbGF60DwHjFumoc=; b=E2ks1+Mv+fHVk2eONNn10G6Kh4 VnwLMlhRvtIHT5gzvtVF49BWP/LGr9OrWI5CwVkJ7CX7W1+NSPAOmIIMdWvgXShQniTm3TTMmXhdH a4WGn3Cad/6Kmn+PCbJNUdR2QGgvTddOpivqPfPDhKf429P/Yx8f7I2WzE1fJfRFGzH0=; Received: from modemcable168.174-80-70.mc.videotron.ca ([70.80.174.168]:57832 helo=pettiford.lan) by mail.hugovil.com with esmtpa (Exim 4.92) (envelope-from ) id 1q6tnE-0005dF-Ah; Wed, 07 Jun 2023 10:05:44 -0400 From: Hugo Villeneuve To: gregkh@linuxfoundation.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, jirislaby@kernel.org, jringle@gridpoint.com, jesse.sung@canonical.com, isaac.true@canonical.com, l.perczak@camlintechnologies.com, tomasz.mon@camlingroup.com Cc: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, hugo@hugovil.com, linux-gpio@vger.kernel.org, Hugo Villeneuve , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , Lech Perczak Date: Wed, 7 Jun 2023 10:05:22 -0400 Message-Id: <20230607140525.833982-9-hugo@hugovil.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230607140525.833982-1-hugo@hugovil.com> References: <20230607140525.833982-1-hugo@hugovil.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 70.80.174.168 X-SA-Exim-Mail-From: hugo@hugovil.com Subject: [PATCH v8 08/10] serial: sc16is7xx: add call to get rs485 DT flags and properties X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.hugovil.com) Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: Hugo Villeneuve Add call to uart_get_rs485_mode() to probe for RS485 flags and properties from device tree. Signed-off-by: Hugo Villeneuve Reviewed-by: Ilpo Järvinen Reviewed-by: Lech Perczak Tested-by: Lech Perczak --- drivers/tty/serial/sc16is7xx.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 98c520ef4a02..7246f8997fda 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1549,6 +1549,10 @@ static int sc16is7xx_probe(struct device *dev, goto out_ports; } + ret = uart_get_rs485_mode(&s->p[i].port); + if (ret) + goto out_ports; + /* Disable all interrupts */ sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0); /* Disable TX/RX */