From patchwork Thu Jan 3 16:41:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Petazzoni X-Patchwork-Id: 1020397 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=bootlin.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43VtwG0mvyz9s9G for ; Fri, 4 Jan 2019 03:41:18 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731625AbfACQlO (ORCPT ); Thu, 3 Jan 2019 11:41:14 -0500 Received: from mail.bootlin.com ([62.4.15.54]:59900 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729889AbfACQlN (ORCPT ); Thu, 3 Jan 2019 11:41:13 -0500 Received: by mail.bootlin.com (Postfix, from userid 110) id 17983207AD; Thu, 3 Jan 2019 17:41:12 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on mail.bootlin.com X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,SHORTCIRCUIT, URIBL_BLOCKED shortcircuit=ham autolearn=disabled version=3.4.2 Received: from localhost (mat33-2-88-189-187-82.fbx.proxad.net [88.189.187.82]) by mail.bootlin.com (Postfix) with ESMTPSA id C2EA7206DC; Thu, 3 Jan 2019 17:41:11 +0100 (CET) From: Thomas Petazzoni To: Linus Walleij , Bartosz Golaszewski , Rob Herring , Mark Rutland Cc: Frank Rowand , linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, Marek Vasut , Thomas Petazzoni Subject: [PATCH 3/4] gpio: add core support for pull-up/pull-down configuration Date: Thu, 3 Jan 2019 17:41:01 +0100 Message-Id: <20190103164102.31437-4-thomas.petazzoni@bootlin.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190103164102.31437-1-thomas.petazzoni@bootlin.com> References: <20190103164102.31437-1-thomas.petazzoni@bootlin.com> MIME-Version: 1.0 Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org This commit adds support for configuring the pull-up and pull-down resistors available in some GPIO controllers. While configuring pull-up/pull-down is already possible through the pinctrl subsystem, some GPIO controllers, especially simple ones such as GPIO expanders on I2C, don't have any pinmuxing capability and therefore do not use the pinctrl subsystem. This commit implements the GPIO_PULL_UP and GPIO_PULL_DOWN flags, which can be used from the Device Tree, to enable a pull-up or pull-down resistor on a given GPIO. The flag is simply propagated all the way to the core GPIO subsystem, where it is used to call the gpio_chip ->set_config callback with the appropriate existing PIN_CONFIG_BIAS_* values. Signed-off-by: Thomas Petazzoni Acked-by: Rob Herring --- drivers/gpio/gpiolib-of.c | 5 +++++ drivers/gpio/gpiolib.c | 12 ++++++++++++ drivers/gpio/gpiolib.h | 2 ++ include/dt-bindings/gpio/gpio.h | 6 ++++++ include/linux/gpio/machine.h | 2 ++ include/linux/of_gpio.h | 2 ++ 6 files changed, 29 insertions(+) diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 7f1260c78270..6518dc8c7c4c 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -323,6 +323,11 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, if (of_flags & OF_GPIO_TRANSITORY) *flags |= GPIO_TRANSITORY; + if (of_flags & OF_GPIO_PULL_UP) + *flags |= GPIO_PULL_UP; + else if (of_flags & OF_GPIO_PULL_DOWN) + *flags |= GPIO_PULL_DOWN; + return desc; } diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index b07e4f6ee641..20887c62fbb3 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2585,6 +2585,13 @@ int gpiod_direction_input(struct gpio_desc *desc) if (status == 0) clear_bit(FLAG_IS_OUT, &desc->flags); + if (test_bit(FLAG_PULL_UP, &desc->flags)) + gpio_set_config(chip, gpio_chip_hwgpio(desc), + PIN_CONFIG_BIAS_PULL_UP); + else if (test_bit(FLAG_PULL_DOWN, &desc->flags)) + gpio_set_config(chip, gpio_chip_hwgpio(desc), + PIN_CONFIG_BIAS_PULL_DOWN); + trace_gpio_direction(desc_to_gpio(desc), 1, status); return status; @@ -4054,6 +4061,11 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, if (lflags & GPIO_OPEN_SOURCE) set_bit(FLAG_OPEN_SOURCE, &desc->flags); + if (lflags & GPIO_PULL_UP) + set_bit(FLAG_PULL_UP, &desc->flags); + else if (lflags & GPIO_PULL_DOWN) + set_bit(FLAG_PULL_DOWN, &desc->flags); + status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY)); if (status < 0) return status; diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 087d865286a0..0b0cf213c45a 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -225,6 +225,8 @@ struct gpio_desc { #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */ #define FLAG_IS_HOGGED 11 /* GPIO is hogged */ #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */ +#define FLAG_PULL_UP 13 /* GPIO has pull up enabled */ +#define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */ /* Connection label */ const char *label; diff --git a/include/dt-bindings/gpio/gpio.h b/include/dt-bindings/gpio/gpio.h index 2cc10ae4bbb7..c029467e828b 100644 --- a/include/dt-bindings/gpio/gpio.h +++ b/include/dt-bindings/gpio/gpio.h @@ -33,4 +33,10 @@ #define GPIO_PERSISTENT 0 #define GPIO_TRANSITORY 8 +/* Bit 4 express pull up */ +#define GPIO_PULL_UP 16 + +/* Bit 5 express pull down */ +#define GPIO_PULL_DOWN 32 + #endif diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h index daa44eac9241..69673be10213 100644 --- a/include/linux/gpio/machine.h +++ b/include/linux/gpio/machine.h @@ -12,6 +12,8 @@ enum gpio_lookup_flags { GPIO_OPEN_SOURCE = (1 << 2), GPIO_PERSISTENT = (0 << 3), GPIO_TRANSITORY = (1 << 3), + GPIO_PULL_UP = (1 << 4), + GPIO_PULL_DOWN = (1 << 5), }; /** diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h index 163b79ecd01a..f9737dea9d1f 100644 --- a/include/linux/of_gpio.h +++ b/include/linux/of_gpio.h @@ -28,6 +28,8 @@ enum of_gpio_flags { OF_GPIO_SINGLE_ENDED = 0x2, OF_GPIO_OPEN_DRAIN = 0x4, OF_GPIO_TRANSITORY = 0x8, + OF_GPIO_PULL_UP = 0x10, + OF_GPIO_PULL_DOWN = 0x20, }; #ifdef CONFIG_OF_GPIO