From patchwork Mon Jan 30 09:34:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Scally X-Patchwork-Id: 648909 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 99BFAC54EAA for ; Mon, 30 Jan 2023 09:38:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235349AbjA3Jih (ORCPT ); Mon, 30 Jan 2023 04:38:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231455AbjA3Jif (ORCPT ); Mon, 30 Jan 2023 04:38:35 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E6761164F for ; Mon, 30 Jan 2023 01:38:03 -0800 (PST) Received: from mail.ideasonboard.com (cpc141996-chfd3-2-0-cust928.12-3.cable.virginm.net [86.13.91.161]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id AB2E4192D; Mon, 30 Jan 2023 10:35:06 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1675071307; bh=3VjcWjQDoupM5MTqgg81P+flMEsJDKLq1YR0103cqew=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=stGba8gCQevgbOh0hImDHbVadtyN+weR2y5UUc1eNm7IiNXNKmuzTDzniZSgzQnYr ERfZCMeJbKEA+kk9g9C+XcmO0f8OP4R017z67STiStpkCiNuHuSawbZ5g8c9KWnHT2 edfXqWgC3CnJoampAo7EtqdwNnqPQ8ODDQyxvBBE= From: Daniel Scally To: linux-usb@vger.kernel.org, gregkh@linuxfoundation.org, laurent.pinchart@ideasonboard.com Cc: mgr@pengutronix.de, balbi@kernel.org, kieran.bingham@ideasonboard.com, torleiv@huddly.com, stern@rowland.harvard.edu, Daniel Scally Subject: [PATCH v3 08/11] usb: gadget: uvc: Allow linking XUs to string descriptors Date: Mon, 30 Jan 2023 09:34:40 +0000 Message-Id: <20230130093443.25644-9-dan.scally@ideasonboard.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230130093443.25644-1-dan.scally@ideasonboard.com> References: <20230130093443.25644-1-dan.scally@ideasonboard.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Add .allow_link() and .drop_link() callbacks to allow users to link an extension unit descriptor to a string descriptor. Signed-off-by: Daniel Scally --- Changes in v3: - Changed the target of the links to in /strings Changes in v2: - New patch drivers/usb/gadget/function/uvc_configfs.c | 52 ++++++++++++++++++++++ drivers/usb/gadget/function/uvc_configfs.h | 1 + 2 files changed, 53 insertions(+) diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c index a81613e9652d..9da3b784f954 100644 --- a/drivers/usb/gadget/function/uvc_configfs.c +++ b/drivers/usb/gadget/function/uvc_configfs.c @@ -1063,8 +1063,60 @@ static void uvcg_extension_release(struct config_item *item) kfree(xu); } +static int uvcg_extension_allow_link(struct config_item *src, struct config_item *tgt) +{ + struct mutex *su_mutex = &src->ci_group->cg_subsys->su_mutex; + struct uvcg_extension *xu = to_uvcg_extension(src); + struct config_item *gadget_item; + struct gadget_string *string; + struct config_item *strings; + int ret = 0; + + mutex_lock(su_mutex); /* for navigating configfs hierarchy */ + + /* Validate that the target of the link is an entry in strings/ */ + gadget_item = src->ci_parent->ci_parent->ci_parent->ci_parent->ci_parent; + strings = config_group_find_item(to_config_group(gadget_item), "strings"); + if (!strings || tgt->ci_parent->ci_parent != strings) { + ret = -EINVAL; + goto put_strings; + } + + string = to_gadget_string(tgt); + xu->string_descriptor_index = string->usb_string.id; + +put_strings: + config_item_put(strings); + mutex_unlock(su_mutex); + + return ret; +} + +static void uvcg_extension_drop_link(struct config_item *src, struct config_item *tgt) +{ + struct mutex *su_mutex = &src->ci_group->cg_subsys->su_mutex; + struct uvcg_extension *xu = to_uvcg_extension(src); + struct config_item *opts_item; + struct f_uvc_opts *opts; + + mutex_lock(su_mutex); /* for navigating configfs hierarchy */ + + opts_item = src->ci_parent->ci_parent->ci_parent; + opts = to_f_uvc_opts(opts_item); + + mutex_lock(&opts->lock); + + xu->string_descriptor_index = 0; + + mutex_unlock(&opts->lock); + + mutex_unlock(su_mutex); +} + static struct configfs_item_operations uvcg_extension_item_ops = { .release = uvcg_extension_release, + .allow_link = uvcg_extension_allow_link, + .drop_link = uvcg_extension_drop_link, }; static const struct config_item_type uvcg_extension_type = { diff --git a/drivers/usb/gadget/function/uvc_configfs.h b/drivers/usb/gadget/function/uvc_configfs.h index c9a4182fb26f..bf188080034c 100644 --- a/drivers/usb/gadget/function/uvc_configfs.h +++ b/drivers/usb/gadget/function/uvc_configfs.h @@ -153,6 +153,7 @@ struct uvcg_extension_unit_descriptor { struct uvcg_extension { struct config_item item; struct list_head list; + u8 string_descriptor_index; struct uvcg_extension_unit_descriptor desc; };