From patchwork Mon Nov 21 09:25:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Scally X-Patchwork-Id: 13050530 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 26EF8C4332F for ; Mon, 21 Nov 2022 09:25:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230201AbiKUJZs (ORCPT ); Mon, 21 Nov 2022 04:25:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230197AbiKUJZq (ORCPT ); Mon, 21 Nov 2022 04:25:46 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44EB427DE4 for ; Mon, 21 Nov 2022 01:25:45 -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 BFADD1905; Mon, 21 Nov 2022 10:25:38 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1669022739; bh=28K8LD+f0JZGAxJz0Tf5aEHpV0AcAjYiab70NsIvnbY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cB3ph/tjBIrTRmuqZpxGQ55HWxVSVGKefYwgJkia6Gqa5ZxB+D9JdnIM0IQxduf5v 5LLZ4oEKaL1eNtxEQCp37+WMeJMsLQjq4oSFNh3/vFmMJS+SPiyNG5MAsJIRdzet0r p00VZeu5tRShNq/CZKojhgDgt5Dls3ppvoPKiss0= From: Daniel Scally To: linux-usb@vger.kernel.org Cc: balbi@kernel.org, gregkh@linuxfoundation.org, laurent.pinchart@ideasonboard.com, kieran.bingham@ideasonboard.com, torleiv@huddly.com, mgr@pengutronix.de, Daniel Scally Subject: [PATCH v2 6/9] usb: gadget: uvc: Allow linking XUs to string descriptors Date: Mon, 21 Nov 2022 09:25:14 +0000 Message-Id: <20221121092517.225242-7-dan.scally@ideasonboard.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221121092517.225242-1-dan.scally@ideasonboard.com> References: <20221121092517.225242-1-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 v2: - New patch drivers/usb/gadget/function/uvc_configfs.c | 60 ++++++++++++++++++++++ drivers/usb/gadget/function/uvc_configfs.h | 1 + 2 files changed, 61 insertions(+) diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c index da2f70036993..5c51862150c4 100644 --- a/drivers/usb/gadget/function/uvc_configfs.c +++ b/drivers/usb/gadget/function/uvc_configfs.c @@ -1053,8 +1053,68 @@ 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 *strings; + struct uvcg_string *string; + struct config_item *opts_item; + struct f_uvc_opts *opts; + int ret = 0; + + mutex_lock(su_mutex); /* for navigating configfs hierarchy */ + + /* Validate that the target of the link is an entry in strings/ */ + opts_item = src->ci_parent->ci_parent->ci_parent; + + strings = config_group_find_item(to_config_group(opts_item), "strings"); + if (!strings || tgt->ci_parent->ci_parent != strings) { + ret = -EINVAL; + goto put_strings; + } + + string = to_uvcg_string(tgt); + opts = to_f_uvc_opts(opts_item); + + mutex_lock(&opts->lock); + + xu->string_descriptor_index = string->usb_string.id; + + mutex_unlock(&opts->lock); + +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 a714426a174a..e1308026aed6 100644 --- a/drivers/usb/gadget/function/uvc_configfs.h +++ b/drivers/usb/gadget/function/uvc_configfs.h @@ -183,6 +183,7 @@ 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; };