From patchwork Wed Oct 26 13:15:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Schiffer X-Patchwork-Id: 618907 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 D431DFA3742 for ; Wed, 26 Oct 2022 13:16:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234036AbiJZNQm (ORCPT ); Wed, 26 Oct 2022 09:16:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234034AbiJZNQh (ORCPT ); Wed, 26 Oct 2022 09:16:37 -0400 Received: from mx1.tq-group.com (mx1.tq-group.com [93.104.207.81]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 548118306F; Wed, 26 Oct 2022 06:16:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tq-group.com; i=@tq-group.com; q=dns/txt; s=key1; t=1666790196; x=1698326196; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=rmV74reOQIhMVx3wfFt0WNHhPTZ+EE2t0X4nueZsE3E=; b=lwV9B2/GGH8BD3LR4e9svhvvx7RNQizqm6gj1u8lWwh2uS3mbd2h7m77 fFIeenw0jw/sk36Jn7aB0/3WrSp0hL8FXfH2ZmWULWIKn+xthB/wfu0o+ ZBsxG0dMlFqe2vKriIiEh9HpznGjM3EH8yUW1KIryzddTvbzCcTwpW7MJ NF7GBKeuu/1t0Cinlw6WPO1PYp5Jvbv9lpEOZkAP0uBqIMbpc0lL3Rk4I dZlsGK1d153gvSVyeNXgRCb1NPTwDbtBfJtG0cofHZfv5BNuWtn0A0PW5 f7weVBgDd80tPnUa8YQLJgSzJCqUt9KtMF+Wg70X6SeXKVXrXJCCscCTv A==; X-IronPort-AV: E=Sophos;i="5.95,214,1661810400"; d="scan'208";a="26988469" Received: from unknown (HELO tq-pgp-pr1.tq-net.de) ([192.168.6.15]) by mx1-pgp.tq-group.com with ESMTP; 26 Oct 2022 15:16:31 +0200 Received: from mx1.tq-group.com ([192.168.6.7]) by tq-pgp-pr1.tq-net.de (PGP Universal service); Wed, 26 Oct 2022 15:16:31 +0200 X-PGP-Universal: processed; by tq-pgp-pr1.tq-net.de on Wed, 26 Oct 2022 15:16:31 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tq-group.com; i=@tq-group.com; q=dns/txt; s=key1; t=1666790191; x=1698326191; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=rmV74reOQIhMVx3wfFt0WNHhPTZ+EE2t0X4nueZsE3E=; b=FXDp8xAAIqGd6/RL9y8KrOnNq0i/vgBaqMYdKGbnkXh0qoMQa68LPoQ3 5JBbE5FQHNkEgB0edF+VAwEUnlpvFXIynS+aBvLjzFu9ClGKITol5aLab Ndh6731IPrB2/3d+OG5sVUbsWvU1m+RVoRpmf0Te2jM0r7qI/AbPip9n6 vIT5zrl4QaS8x9eUdclxXUnA52znNWj8c64Y1PODYEuhDJQbzJxOyxBEb sfl/JUUIDDL5qJ9wr+Wo2UCO8p3YPG5kx2eclsonv9VPs9hEOMxZnvT44 CD2caRrZVFM8riiFR/i0e115nWeWRJjm7jJyc6udD37yC8gx/F7vDMAyU g==; X-IronPort-AV: E=Sophos;i="5.95,214,1661810400"; d="scan'208";a="26988468" Received: from vtuxmail01.tq-net.de ([10.115.0.20]) by mx1.tq-group.com with ESMTP; 26 Oct 2022 15:16:31 +0200 Received: from localhost.localdomain (SCHIFFERM-M2.tq-net.de [10.121.49.14]) by vtuxmail01.tq-net.de (Postfix) with ESMTPA id 21BFC280072; Wed, 26 Oct 2022 15:16:30 +0200 (CEST) From: Matthias Schiffer To: Arnd Bergmann , Greg Kroah-Hartman , Rob Herring , Krzysztof Kozlowski Cc: Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz , Amitkumar Karwar , Ganapathi Bhat , Sharvari Harisangam , Xinming Hu , Kalle Valo , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux@ew.tq-group.com, Matthias Schiffer Subject: [RFC 1/5] misc: introduce notify-device driver Date: Wed, 26 Oct 2022 15:15:30 +0200 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org A notify-device is a synchronization facility that allows to query "readiness" across drivers, without creating a direct dependency between the driver modules. The notify-device can also be used to trigger deferred probes. Signed-off-by: Matthias Schiffer --- drivers/misc/Kconfig | 4 ++ drivers/misc/Makefile | 1 + drivers/misc/notify-device.c | 109 ++++++++++++++++++++++++++++++++++ include/linux/notify-device.h | 33 ++++++++++ 4 files changed, 147 insertions(+) create mode 100644 drivers/misc/notify-device.c create mode 100644 include/linux/notify-device.h diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 358ad56f6524..63559e9f854c 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -496,6 +496,10 @@ config VCPU_STALL_DETECTOR If you do not intend to run this kernel as a guest, say N. +config NOTIFY_DEVICE + tristate "Notify device" + depends on OF + source "drivers/misc/c2port/Kconfig" source "drivers/misc/eeprom/Kconfig" source "drivers/misc/cb710/Kconfig" diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index ac9b3e757ba1..1e8012112b43 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -62,3 +62,4 @@ obj-$(CONFIG_HI6421V600_IRQ) += hi6421v600-irq.o obj-$(CONFIG_OPEN_DICE) += open-dice.o obj-$(CONFIG_GP_PCI1XXXX) += mchp_pci1xxxx/ obj-$(CONFIG_VCPU_STALL_DETECTOR) += vcpu_stall_detector.o +obj-$(CONFIG_NOTIFY_DEVICE) += notify-device.o diff --git a/drivers/misc/notify-device.c b/drivers/misc/notify-device.c new file mode 100644 index 000000000000..42e0980394ea --- /dev/null +++ b/drivers/misc/notify-device.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include +#include +#include +#include +#include +#include + +static void notify_device_release(struct device *dev) +{ + of_node_put(dev->of_node); + kfree(dev); +} + +static struct class notify_device_class = { + .name = "notify-device", + .owner = THIS_MODULE, + .dev_release = notify_device_release, +}; + +static struct platform_driver notify_device_driver = { + .driver = { + .name = "notify-device", + }, +}; + +struct device *notify_device_create(struct device *parent, const char *child) +{ + struct device_node *node; + struct device *dev; + int err; + + if (!parent->of_node) + return ERR_PTR(-EINVAL); + + node = of_get_child_by_name(parent->of_node, child); + if (!node) + return NULL; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) { + of_node_put(node); + return ERR_PTR(-ENOMEM); + } + + dev_set_name(dev, "%s:%s", dev_name(parent), child); + dev->class = ¬ify_device_class; + dev->parent = parent; + dev->of_node = node; + err = device_register(dev); + if (err) { + put_device(dev); + return ERR_PTR(err); + } + + dev->driver = ¬ify_device_driver.driver; + err = device_bind_driver(dev); + if (err) { + device_unregister(dev); + return ERR_PTR(err); + } + + return dev; +} +EXPORT_SYMBOL_GPL(notify_device_create); + +void notify_device_destroy(struct device *dev) +{ + if (!dev) + return; + + device_release_driver(dev); + device_unregister(dev); +} +EXPORT_SYMBOL_GPL(notify_device_destroy); + +struct device *notify_device_find_by_of_node(struct device_node *node) +{ + return class_find_device_by_of_node(¬ify_device_class, node); +} +EXPORT_SYMBOL_GPL(notify_device_find_by_of_node); + +static int __init notify_device_init(void) +{ + int err; + + err = class_register(¬ify_device_class); + if (err) + return err; + + err = platform_driver_register(¬ify_device_driver); + if (err) { + class_unregister(¬ify_device_class); + return err; + } + + return 0; +} + +static void __exit notify_device_exit(void) +{ + platform_driver_unregister(¬ify_device_driver); + class_unregister(¬ify_device_class); +} + +module_init(notify_device_init); +module_exit(notify_device_exit); +MODULE_LICENSE("GPL"); diff --git a/include/linux/notify-device.h b/include/linux/notify-device.h new file mode 100644 index 000000000000..f8c3e15d3b8f --- /dev/null +++ b/include/linux/notify-device.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_NOTIFY_DEVICE_H +#define _LINUX_NOTIFY_DEVICE_H +#include +#include + +#ifdef CONFIG_NOTIFY_DEVICE + +struct device *notify_device_create(struct device *parent, const char *child); +void notify_device_destroy(struct device *dev); +struct device *notify_device_find_by_of_node(struct device_node *node); + +#else + +static inline struct device *notify_device_create(struct device *parent, + const char *child) +{ + return NULL; +} + +static inline void notify_device_destroy(struct device *dev) +{ +} + +static inline struct device *notify_device_find_by_of_node(struct device_node *node) +{ + return NULL; +} + +#endif + +#endif /* _LINUX_NOTIFY_DEVICE_H */