From patchwork Fri Nov 11 22:19:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Torokhov X-Patchwork-Id: 624452 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 6A0CFC43217 for ; Fri, 11 Nov 2022 22:19:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234666AbiKKWTs (ORCPT ); Fri, 11 Nov 2022 17:19:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234612AbiKKWTY (ORCPT ); Fri, 11 Nov 2022 17:19:24 -0500 Received: from mail-pl1-x631.google.com (mail-pl1-x631.google.com [IPv6:2607:f8b0:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 327E39FF3; Fri, 11 Nov 2022 14:19:23 -0800 (PST) Received: by mail-pl1-x631.google.com with SMTP id k7so5277944pll.6; Fri, 11 Nov 2022 14:19:23 -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=8e9qt1EThZ8DxhiWWBzObBNLU7s1JE4dLO1Y/7HqnGA=; b=la77TJAPgqsJGHCt1tRPnBp6TO/wknDaKOMIAU0HQ677C5OX7mGcET+dVn4SpT1Kfy MckhDcY0IUeY3XWu7Iy9dEXKGyGHDn42/DlZZkOd7DM4oh2uo7K+CM8AoYKTSYXB6WpF X5VYmsGyUkO2jkYP3pcIqd6f8H4udTPzfRExYdRX5Ix8CObDxJgTT9D368XaGkR8Kbuc PKxBTfLk+MaV7k8RzfJta5Cv6ew6i3xb8y29RkNJYpCiq3fneUFf/k15biV/OxeNpocf d1rtE40hk2ce1GQ6P3CZm1e8rzCAfiCINXlhx69ehORrZCQrf2dOzf+FNKog5Rv/BfvZ ei4g== 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=8e9qt1EThZ8DxhiWWBzObBNLU7s1JE4dLO1Y/7HqnGA=; b=Px9AkceT4mvQycnzxwgY/njfahGKSMll2F4uLngaiSoexCqKCAJkdY51DpNm4x6y+v wfzlSXscf66UR2lYfxlQth3VASeEz5Dd7tsFXiDbP9JuipFkWC9Te5yTsG5Yya1GUjxK 1bKL16noUrNHXpogBNawVNq2LVhcun4BnztnSmzOa3YOnQfNuQzBnjqWK+pX0oif8hjC MFqVOhB4nLdi/OS8eHJczPvNfwvZqD45iR9FTEPGPwQVZ3fYqAV1TFxVkwrNqXc4JJKM gHHvJSMIx1PdqnduUi4o5WFdUzFYM1ejlWVtfErqBtExQqM5yP6VJF68h3K3BUym/9Lc hB9g== X-Gm-Message-State: ANoB5pkunNeV7ZBCwQ7hvBkHHYHZ+ufJEi2X2RMb8TJAneeLBRboCOBK ZU7SzcNOM4Cn+niVH6z+PbE= X-Google-Smtp-Source: AA0mqf6JFu3NdHAl9ynWlwiXLiCenaaQREKQsMlK4py6nS55dkkLBaUKJBPiMvitH10IGm5z6PC9Bg== X-Received: by 2002:a17:903:2442:b0:186:e8bd:9c14 with SMTP id l2-20020a170903244200b00186e8bd9c14mr4428835pls.174.1668205162520; Fri, 11 Nov 2022 14:19:22 -0800 (PST) Received: from dtor-ws.mtv.corp.google.com ([2620:15c:9d:2:de05:ad1e:65ae:ea4d]) by smtp.gmail.com with ESMTPSA id q9-20020a170902bd8900b00180daa59314sm2201109pls.125.2022.11.11.14.19.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Nov 2022 14:19:21 -0800 (PST) From: Dmitry Torokhov To: Bartosz Golaszewski , Andy Shevchenko , Linus Walleij Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Subject: [PATCH v4 6/6] gpiolib: add support for software nodes Date: Fri, 11 Nov 2022 14:19:08 -0800 Message-Id: <20221031-gpiolib-swnode-v4-6-6c1671890027@gmail.com> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221031-gpiolib-swnode-v4-0-6c1671890027@gmail.com> References: <20221031-gpiolib-swnode-v4-0-6c1671890027@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 Reviewed-by: Andy Shevchenko Signed-off-by: Dmitry Torokhov --- drivers/gpio/Makefile | 1 + drivers/gpio/gpiolib-swnode.c | 123 ++++++++++++++++++++++++++++++++++++++++++ drivers/gpio/gpiolib-swnode.h | 14 +++++ drivers/gpio/gpiolib.c | 7 +++ include/linux/gpio/property.h | 11 ++++ 5 files changed, 156 insertions(+) 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..dd9ccac214d1 --- /dev/null +++ b/drivers/gpio/gpiolib-swnode.c @@ -0,0 +1,123 @@ +// 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); + return chip ?: ERR_PTR(-EPROBE_DEFER); +} + +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(const 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..af849e56f6bc --- /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(const 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 7f739096c4cf..7936d54a2e30 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" @@ -3870,6 +3871,10 @@ static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode, dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, con_id); desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags); + } else if (is_software_node(fwnode)) { + dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", + fwnode, con_id); + desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags); } return desc; @@ -3987,6 +3992,8 @@ int gpiod_count(struct device *dev, const char *con_id) 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); 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..6c75c8bd44a0 --- /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 /* for GPIO_* flags */ +#include + +#define PROPERTY_ENTRY_GPIO(_name_, _chip_node_, _idx_, _flags_) \ + PROPERTY_ENTRY_REF(_name_, _chip_node_, _idx_, _flags_) + +#endif /* __LINUX_GPIO_PROPERTY_H */