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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 6194DC433E3 for ; Thu, 25 Mar 2021 12:30:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4816961A26 for ; Thu, 25 Mar 2021 12:30:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230155AbhCYM3f (ORCPT ); Thu, 25 Mar 2021 08:29:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230204AbhCYM3Y (ORCPT ); Thu, 25 Mar 2021 08:29:24 -0400 Received: from mail.kapsi.fi (mail.kapsi.fi [IPv6:2001:67c:1be8::25]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BDE5AC06174A for ; Thu, 25 Mar 2021 05:29:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kapsi.fi; s=20161220; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject: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=To/IbCmae+7r3GZ+mwza5PKigW3IoMiD3wBa9D4YBzY=; b=blHc6JqEFKfNjefr9PYdzFC9oP y4cJxCyPPgH61q/9OllneSNc8W7P9Y0YZ0UwbPDOu61moLK+8kr6GvOj6C20vScjNosWRF4/KSLkt qUY72JIVA9ZfnM6+BKy3UtNbGQaeLSJ6+QUns7vd3PehjXnUB2OQj4DJZcuW1n+bfMlj1Gjyyok1y Qugehexv+btevveu9Jbao9V0q4GxfuQP4Sq6mrTZi8cuZLs+tF1r2mrfZbE/HYZ7KSDpA36BOFGjw kSRuZIiKPn/oxebAMU+Zun9pOemuyNwgmKdAIkaHNUbjnTFddP+W5W1j0gCIcKzWC1kn1Ya48IEgI KcudNzxA==; Received: from 97-173-191-90.dyn.estpak.ee ([90.191.173.97] helo=ubuntu) by mail.kapsi.fi with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1lPP73-00036j-Fa; Thu, 25 Mar 2021 14:29:22 +0200 Received: by ubuntu (sSMTP sendmail emulation); Thu, 25 Mar 2021 14:29:20 +0200 From: Mauri Sandberg To: linux-gpio@vger.kernel.org Cc: andy.shevchenko@gmail.com, linus.walleij@linaro.org, bgolaszewski@baylibre.com, geert+renesas@glider.be, Mauri Sandberg Subject: [RFC gpio/for-next 2/2] gpio: gpio-mux-input: add generic gpio input multiplexer Date: Thu, 25 Mar 2021 14:28:32 +0200 Message-Id: <20210325122832.119147-3-sandberg@mailfence.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210325122832.119147-1-sandberg@mailfence.com> References: <20210325122832.119147-1-sandberg@mailfence.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 90.191.173.97 X-SA-Exim-Mail-From: sandberg@mailfence.com X-SA-Exim-Scanned: No (on mail.kapsi.fi); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Suppport for a general GPIO multiplexer. To drive the multiplexer a mux-controller is needed. The output pin of the multiplexer is a GPIO pin. Signed-off-by: Mauri Sandberg --- drivers/gpio/Kconfig | 11 +++ drivers/gpio/Makefile | 1 + drivers/gpio/gpio-mux-input.c | 143 ++++++++++++++++++++++++++++++++++ 3 files changed, 155 insertions(+) create mode 100644 drivers/gpio/gpio-mux-input.c diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index c70f46e80a3b..41062d8f7d93 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -1641,4 +1641,15 @@ config GPIO_MOCKUP endmenu +comment "Other GPIO expanders" + +config GPIO_MUX_INPUT + tristate "General GPIO input multiplexer" + select MULTIPLEXER + select MUX_GPIO + depends on OF_GPIO + help + Say yes here to enable support for generic GPIO input multiplexer. This + needs a multiplexer controller to drive the select pins. + endif diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 35e3b6026665..00f7576ce23f 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -105,6 +105,7 @@ obj-$(CONFIG_GPIO_MPC8XXX) += gpio-mpc8xxx.o obj-$(CONFIG_GPIO_MSC313) += gpio-msc313.o obj-$(CONFIG_GPIO_MSIC) += gpio-msic.o obj-$(CONFIG_GPIO_MT7621) += gpio-mt7621.o +obj-$(CONFIG_GPIO_MUX_INPUT) += gpio-mux-input.o obj-$(CONFIG_GPIO_MVEBU) += gpio-mvebu.o obj-$(CONFIG_GPIO_MXC) += gpio-mxc.o obj-$(CONFIG_GPIO_MXS) += gpio-mxs.o diff --git a/drivers/gpio/gpio-mux-input.c b/drivers/gpio/gpio-mux-input.c new file mode 100644 index 000000000000..ec0c7acbab2f --- /dev/null +++ b/drivers/gpio/gpio-mux-input.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * A generic GPIO input multiplexer driver + * + * Copyright (C) 2021 Mauri Sandberg + * + */ + +#include +#include +#include +#include +#include +#include + +struct gpio_mux_input { + struct device *parent; + struct gpio_chip gpio_chip; + struct mux_control *mux_control; + struct gpio_desc *mux_pin; +}; + +static struct gpio_mux_input *gpio_to_mux(struct gpio_chip *gc) +{ + return container_of(gc, struct gpio_mux_input, gpio_chip); +} + +static int gpio_mux_input_direction_input(struct gpio_chip *gc, + unsigned int offset) +{ + return 0; +} + +static int gpio_mux_input_direction_output(struct gpio_chip *gc, + unsigned int offset, int val) +{ + return -EINVAL; +} + +static int gpio_mux_input_get_value(struct gpio_chip *gc, unsigned int offset) +{ + struct gpio_mux_input *mux; + int ret; + + mux = gpio_to_mux(gc); + ret = mux_control_select(mux->mux_control, offset); + if (ret) + return ret; + + ret = gpiod_get_value(mux->mux_pin); + mux_control_deselect(mux->mux_control); + return ret; +} + +static void gpio_mux_input_set_value(struct gpio_chip *gc, + unsigned int offset, int val) +{ + /* not supported */ +} + +static int gpio_mux_input_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct gpio_mux_input *mux; + struct gpio_chip *gc; + struct mux_control *mc; + struct gpio_desc *pin; + int err; + + mux = kzalloc(sizeof(struct gpio_mux_input), GFP_KERNEL); + if (mux == NULL) + return -ENOMEM; + + mc = mux_control_get(&pdev->dev, NULL); + if (IS_ERR(mc)) { + err = (int) PTR_ERR(mc); + if (err != -EPROBE_DEFER) + dev_err(&pdev->dev, "unable to get mux-control: %d\n", + err); + goto err_free_mux; + } + + mux->mux_control = mc; + pin = gpiod_get(&pdev->dev, "pin", GPIOD_IN); + if (IS_ERR(pin)) { + err = (int) PTR_ERR(pin); + dev_err(&pdev->dev, "unable to claim pin GPIOs: %d\n", err); + goto err_free_mc; + } + + mux->mux_pin = pin; + mux->parent = &pdev->dev; + + gc = &mux->gpio_chip; + gc->direction_input = gpio_mux_input_direction_input; + gc->direction_output = gpio_mux_input_direction_output; + gc->get = gpio_mux_input_get_value; + gc->set = gpio_mux_input_set_value; + gc->can_sleep = 1; + + gc->base = -1; + gc->ngpio = mux_control_states(mc); + gc->label = dev_name(mux->parent); + gc->parent = mux->parent; + gc->owner = THIS_MODULE; + gc->of_node = np; + + err = gpiochip_add(&mux->gpio_chip); + if (err) { + dev_err(&pdev->dev, "unable to add gpio chip, err=%d\n", err); + goto err_free_pin; + } + + platform_set_drvdata(pdev, mux); + return 0; + +err_free_pin: + gpiod_put(pin); +err_free_mc: + mux_control_put(mc); +err_free_mux: + kfree(mux); + return err; +} + +static const struct of_device_id gpio_mux_input_id[] = { + { + .compatible = "gpio-mux-input", + .data = NULL, + }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, gpio_mux_input_id); + +static struct platform_driver gpio_mux_input_driver = { + .driver = { + .name = "gpio-mux-input", + .owner = THIS_MODULE, + .of_match_table = gpio_mux_input_id, + }, + .probe = gpio_mux_input_probe, +}; +module_platform_driver(gpio_mux_input_driver); -- 2.25.1