From patchwork Wed Nov 9 00:26:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Torokhov X-Patchwork-Id: 13037000 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 C50AAC4332F for ; Wed, 9 Nov 2022 00:27:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229953AbiKIA1d (ORCPT ); Tue, 8 Nov 2022 19:27:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229576AbiKIA1a (ORCPT ); Tue, 8 Nov 2022 19:27:30 -0500 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76BC661746; Tue, 8 Nov 2022 16:27:07 -0800 (PST) Received: by mail-pj1-x102c.google.com with SMTP id m14-20020a17090a3f8e00b00212dab39bcdso410331pjc.0; Tue, 08 Nov 2022 16:27:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=0Ijc7x8fTPDGZNvBUT+idDBJ96j7Q8JpBhejyZkqpOE=; b=cno7Z9azlDI6o85fEz8MD2y/a8szxhVEbZY6MEh6gZBL/HphROAHhLzvsJCRI80MoE aqTCiO6+fj+O8UytedhuuTc3mA7WLJeEHv0igHqHpz4YpjKwSElnXEmhStte6ro6aTkY rLgPj221M3z+N+65Hk/BGHAMtEZI5SPBraZFsv8ATL/8mhe3RbcmrfW5HxWqQrpwABLz +4m5BQ7AonG4CL0y1Vx+iEWG6dP85VlgmiTTK+Q+yI/aP2bWyS3WJ3A+HlqKgDmz+h/F mb89E5qBHZ8G2HwECBGE6ULIg4JeCDp4L/35vqTLrsjyn6ztfwisBzJJ+YM+9UsBoqz/ +7JQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=0Ijc7x8fTPDGZNvBUT+idDBJ96j7Q8JpBhejyZkqpOE=; b=S5SdAI2pjLdU+I/lpnse7pN+e6xjAjHnVNusGTpRpas2IcMLrSTVOFkWg3JQrZZ9GJ +mMoNwiJKaHRtI++8qit5W4rJa1hmFfOIpvHBoWurtAkbB+RULx/wIF4ZqfmqDRGwxKP 1LxWNS5Vtm8JKLeS4Cz2h97ezdBvWuSIjkL2iUiDs4uEIq7Eh7YAyjRBFfnVqbA+2SND I/Xb9Fv3LT99yN+xeg1XhIxtj0OoREodZqURRyA8VNZEmUhSn753voEkWvy1ibmBiC6F swO8HlWQa8jMW8BztO10P5ODpOM9yAe0wiXPZ1eVhGKZ59E3lmcxkjEL+Xett12+zhYq 509Q== X-Gm-Message-State: ACrzQf0eP3JzRMnb7fvcrm0FupOrm2yNwzZWvHLJBajo6ogyYfQbZZGF 16IM1dfBDx1CvBp5eeP8ufU= X-Google-Smtp-Source: AMsMyM5C5riJ1nVd+Rtkgzz6gmb2zCxGgtA8Ic5C4bQw2CZdCRWTFvM5ZL1aVP1hHeVJmLwuWA2Tmw== X-Received: by 2002:a17:90b:1212:b0:213:a3a4:4d97 with SMTP id gl18-20020a17090b121200b00213a3a44d97mr58093759pjb.225.1667953626621; Tue, 08 Nov 2022 16:27:06 -0800 (PST) Received: from dtor-ws.mtv.corp.google.com ([2620:15c:9d:2:9f46:7242:26:f220]) by smtp.gmail.com with ESMTPSA id i65-20020a626d44000000b0056bd737fdf3sm6907324pfc.123.2022.11.08.16.27.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Nov 2022 16:27:05 -0800 (PST) From: Dmitry Torokhov To: Linus Walleij , Andy Shevchenko , Bartosz Golaszewski Cc: linux-acpi@vger.kernel.org, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 6/6] gpiolib: add support for software nodes Date: Tue, 8 Nov 2022 16:26:51 -0800 Message-Id: <20221031-gpiolib-swnode-v2-6-81f55af5fa0e@gmail.com> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221031-gpiolib-swnode-v2-0-81f55af5fa0e@gmail.com> References: <20221031-gpiolib-swnode-v2-0-81f55af5fa0e@gmail.com> MIME-Version: 1.0 X-Mailer: b4 0.11.0-dev-28747 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Now that static device properties understand notion of child nodes and references, let's teach gpiolib to handle them: - GPIOs are represented as a references to software nodes representing gpiochip - references must have 2 arguments - GPIO number within the chip and GPIO flags (GPIO_ACTIVE_LOW/GPIO_ACTIVE_HIGH, etc) - a new PROPERTY_ENTRY_GPIO() macro is supplied to ensure the above - name of the software node representing gpiochip must match label of the gpiochip, as we use it to locate gpiochip structure at runtime The following illustrates use of software nodes to describe a "System" button that is currently specified via use of gpio_keys_platform_data in arch/mips/alchemy/board-mtx1.c. It follows bindings specified in Documentation/devicetree/bindings/input/gpio-keys.yaml. static const struct software_node mxt1_gpiochip2_node = { .name = "alchemy-gpio2", }; static const struct property_entry mtx1_gpio_button_props[] = { PROPERTY_ENTRY_U32("linux,code", BTN_0), PROPERTY_ENTRY_STRING("label", "System button"), PROPERTY_ENTRY_GPIO("gpios", &mxt1_gpiochip2_node, 7, GPIO_ACTIVE_LOW), { } }; Similarly, arch/arm/mach-tegra/board-paz00.c can be converted to: static const struct software_node tegra_gpiochip_node = { .name = "tegra-gpio", }; static struct property_entry wifi_rfkill_prop[] __initdata = { PROPERTY_ENTRY_STRING("name", "wifi_rfkill"), PROPERTY_ENTRY_STRING("type", "wlan"), PROPERTY_ENTRY_GPIO("reset-gpios", &tegra_gpiochip_node, 25, GPIO_ACTIVE_HIGH); PROPERTY_ENTRY_GPIO("shutdown-gpios", &tegra_gpiochip_node, 85, GPIO_ACTIVE_HIGH); { }, }; static struct platform_device wifi_rfkill_device = { .name = "rfkill_gpio", .id = -1, }; ... software_node_register(&tegra_gpiochip_node); device_create_managed_software_node(&wifi_rfkill_device.dev, wifi_rfkill_prop, NULL); Acked-by: Linus Walleij Signed-off-by: Dmitry Torokhov --- drivers/gpio/Makefile | 1 + drivers/gpio/gpiolib-swnode.c | 128 ++++++++++++++++++++++++++++++++++++++++++ drivers/gpio/gpiolib-swnode.h | 14 +++++ drivers/gpio/gpiolib.c | 12 +++- include/linux/gpio/property.h | 11 ++++ 5 files changed, 164 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 8629e9eaf79e..010587025fc8 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_OF_GPIO) += gpiolib-of.o obj-$(CONFIG_GPIO_CDEV) += gpiolib-cdev.o obj-$(CONFIG_GPIO_SYSFS) += gpiolib-sysfs.o obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o +obj-$(CONFIG_GPIOLIB) += gpiolib-swnode.o # Device drivers. Generally keep list sorted alphabetically obj-$(CONFIG_GPIO_REGMAP) += gpio-regmap.o diff --git a/drivers/gpio/gpiolib-swnode.c b/drivers/gpio/gpiolib-swnode.c new file mode 100644 index 000000000000..4cf41234bfc6 --- /dev/null +++ b/drivers/gpio/gpiolib-swnode.c @@ -0,0 +1,128 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Software Node helpers for the GPIO API + * + * Copyright 2022 Google LLC + */ +#include +#include +#include +#include +#include +#include +#include +#include + +#include "gpiolib.h" +#include "gpiolib-swnode.h" + +static void swnode_format_propname(const char *con_id, char *propname, + size_t max_size) +{ + /* + * Note we do not need to try both -gpios and -gpio suffixes, + * as, unlike OF and ACPI, we can fix software nodes to conform + * to the proper binding. + */ + if (con_id) + snprintf(propname, max_size, "%s-gpios", con_id); + else + strscpy(propname, "gpios", max_size); +} + +static int swnode_gpiochip_match_name(struct gpio_chip *chip, void *data) +{ + return !strcmp(chip->label, data); +} + +static struct gpio_chip *swnode_get_chip(struct fwnode_handle *fwnode) +{ + const struct software_node *chip_node; + struct gpio_chip *chip; + + chip_node = to_software_node(fwnode); + if (!chip_node || !chip_node->name) + return ERR_PTR(-EINVAL); + + chip = gpiochip_find((void *)chip_node->name, + swnode_gpiochip_match_name); + if (!chip) + return ERR_PTR(-EPROBE_DEFER); + + return chip; +} + +struct gpio_desc *swnode_find_gpio(struct fwnode_handle *fwnode, + const char *con_id, unsigned int idx, + unsigned long *flags) +{ + const struct software_node *swnode; + struct fwnode_reference_args args; + struct gpio_chip *chip; + struct gpio_desc *desc; + char propname[32]; /* 32 is max size of property name */ + int error; + + swnode = to_software_node(fwnode); + if (!swnode) + return ERR_PTR(-EINVAL); + + swnode_format_propname(con_id, propname, sizeof(propname)); + + /* + * We expect all swnode-described GPIOs have GPIO number and + * polarity arguments, hence nargs is set to 2. + */ + error = fwnode_property_get_reference_args(fwnode, propname, NULL, + 2, idx, &args); + if (error) { + pr_debug("%s: can't parse '%s' property of node '%pfwP[%d]'\n", + __func__, propname, fwnode, idx); + return ERR_PTR(error); + } + + chip = swnode_get_chip(args.fwnode); + fwnode_handle_put(args.fwnode); + if (IS_ERR(chip)) + return ERR_CAST(chip); + + desc = gpiochip_get_desc(chip, args.args[0]); + *flags = args.args[1]; /* We expect native GPIO flags */ + + pr_debug("%s: parsed '%s' property of node '%pfwP[%d]' - status (%d)\n", + __func__, propname, fwnode, idx, PTR_ERR_OR_ZERO(desc)); + + return desc; +} + +/** + * swnode_gpio_count - count the GPIOs associated with a device / function + * @fwnode: firmware node of the GPIO consumer, can be %NULL for + * system-global GPIOs + * @con_id: function within the GPIO consumer + * + * Return: + * The number of GPIOs associated with a device / function or %-ENOENT, + * if no GPIO has been assigned to the requested function. + */ +int swnode_gpio_count(struct fwnode_handle *fwnode, const char *con_id) +{ + struct fwnode_reference_args args; + char propname[32]; + int count; + + swnode_format_propname(con_id, propname, sizeof(propname)); + + /* + * This is not very efficient, but GPIO lists usually have only + * 1 or 2 entries. + */ + count = 0; + while (fwnode_property_get_reference_args(fwnode, propname, NULL, + 0, count, &args) == 0) { + fwnode_handle_put(args.fwnode); + count++; + } + + return count ?: -ENOENT; +} diff --git a/drivers/gpio/gpiolib-swnode.h b/drivers/gpio/gpiolib-swnode.h new file mode 100644 index 000000000000..4e07be56ed9f --- /dev/null +++ b/drivers/gpio/gpiolib-swnode.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef GPIOLIB_SWNODE_H +#define GPIOLIB_SWNODE_H + +struct fwnode_handle; +struct gpio_desc; + +struct gpio_desc *swnode_find_gpio(struct fwnode_handle *fwnode, + const char *con_id, unsigned int idx, + unsigned long *flags); +int swnode_gpio_count(struct fwnode_handle *fwnode, const char *con_id); + +#endif /* GPIOLIB_SWNODE_H */ diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index c33ffdd47667..bf5c072206da 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -26,6 +26,7 @@ #include "gpiolib.h" #include "gpiolib-of.h" #include "gpiolib-acpi.h" +#include "gpiolib-swnode.h" #include "gpiolib-cdev.h" #include "gpiolib-sysfs.h" @@ -3821,6 +3822,9 @@ static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode, } else if (is_acpi_node(fwnode)) { dev_dbg(consumer, "using ACPI for GPIO lookup\n"); desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags); + } else if (is_software_node(fwnode)) { + dev_dbg(consumer, "using software node for GPIO lookup\n"); + desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags); } else { desc = ERR_PTR(-ENOENT); } @@ -3934,13 +3938,17 @@ EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index); */ int gpiod_count(struct device *dev, const char *con_id) { - const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL; - int count = -ENOENT; + struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL; + int count; if (is_of_node(fwnode)) count = of_gpio_get_count(dev, con_id); else if (is_acpi_node(fwnode)) count = acpi_gpio_count(dev, con_id); + else if (is_software_node(fwnode)) + count = swnode_gpio_count(fwnode, con_id); + else + count = -ENOENT; if (count < 0) count = platform_gpio_count(dev, con_id); diff --git a/include/linux/gpio/property.h b/include/linux/gpio/property.h new file mode 100644 index 000000000000..f76a46469f66 --- /dev/null +++ b/include/linux/gpio/property.h @@ -0,0 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0+ +#ifndef __LINUX_GPIO_PROPERTY_H +#define __LINUX_GPIO_PROPERTY_H + +#include +#include + +#define PROPERTY_ENTRY_GPIO(_name_, _chip_node_, _idx_, _flags_) \ + PROPERTY_ENTRY_REF(_name_, _chip_node_, _idx_, _flags_) + +#endif /* __LINUX_GPIO_PROPERTY_H */