From patchwork Mon Nov 21 09:25:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Scally X-Patchwork-Id: 13050533 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 33F5EC433FE for ; Mon, 21 Nov 2022 09:25:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230211AbiKUJZv (ORCPT ); Mon, 21 Nov 2022 04:25:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230207AbiKUJZt (ORCPT ); Mon, 21 Nov 2022 04:25:49 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D76B29359 for ; Mon, 21 Nov 2022 01:25:48 -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 063292D9; Mon, 21 Nov 2022 10:25:39 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1669022740; bh=8gN8M4WanXpSSG/9fB+2p0usCZzFfitjbtVpmKrLjFM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Yb87Gdxg5T1l1+mlZpStoa3auYQ+k4V6NJTwSO2lHn/ygsXkKs4eM+jWPjrmx+i+i GCqjVaqYv+/zpT6MwrzgHpTAvEDJ3grM23sl7dYZe2VMCBF097t0GSOjjOTMIRjVwS LJ785JFR9KoHBI3OvFXFnvKRKIOwvqW9GVdbDiwo= 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 8/9] usb: gadget: uvc: Allow linking function to string descs Date: Mon, 21 Nov 2022 09:25:16 +0000 Message-Id: <20221121092517.225242-9-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 Currently the string descriptors for the IAD, VideoControl Interface and VideoStreaming Interfaces are hardcoded into f_uvc. Now that we can create arbitrary string descriptors, add a mechanism to define string descriptors for the IAD, VC and VS interfaces by linking to the appropriate directory at function level. Signed-off-by: Daniel Scally --- Changes in v2: - New patch drivers/usb/gadget/function/u_uvc.h | 8 +++ drivers/usb/gadget/function/uvc_configfs.c | 59 ++++++++++++++++++++++ 2 files changed, 67 insertions(+) diff --git a/drivers/usb/gadget/function/u_uvc.h b/drivers/usb/gadget/function/u_uvc.h index c1c9ea5931d3..331cdf5ba9c8 100644 --- a/drivers/usb/gadget/function/u_uvc.h +++ b/drivers/usb/gadget/function/u_uvc.h @@ -88,6 +88,14 @@ struct f_uvc_opts { struct list_head languages; unsigned int nlangs; + /* + * Indexes into the function's string descriptors allowing users to set + * custom descriptions rather than the hard-coded defaults. + */ + u8 iad_index; + u8 vs0_index; + u8 vs1_index; + /* * Read/write access to configfs attributes is handled by configfs. * diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c index 5c51862150c4..e8faa31998fa 100644 --- a/drivers/usb/gadget/function/uvc_configfs.c +++ b/drivers/usb/gadget/function/uvc_configfs.c @@ -3197,8 +3197,67 @@ static void uvc_func_item_release(struct config_item *item) usb_put_function_instance(&opts->func_inst); } +static int uvc_func_allow_link(struct config_item *src, struct config_item *tgt) +{ + struct mutex *su_mutex = &src->ci_group->cg_subsys->su_mutex; + struct config_item *strings; + struct uvcg_string *string; + struct f_uvc_opts *opts; + int ret = 0; + + mutex_lock(su_mutex); /* for navigating configfs hierarchy */ + + /* Validate that the target is an entry in strings/ */ + strings = config_group_find_item(to_config_group(src), "strings"); + if (!strings || tgt->ci_parent->ci_parent != strings) { + ret = -EINVAL; + goto put_strings; + } + + string = to_uvcg_string(tgt); + + opts = to_f_uvc_opts(src); + mutex_lock(&opts->lock); + + if (!strcmp(tgt->ci_name, "iad_desc")) + opts->iad_index = string->usb_string.id; + else if (!strcmp(tgt->ci_name, "vs0_desc")) + opts->vs0_index = string->usb_string.id; + else if (!strcmp(tgt->ci_name, "vs1_desc")) + opts->vs1_index = string->usb_string.id; + else + ret = -EINVAL; + + mutex_unlock(&opts->lock); + +put_strings: + config_item_put(strings); + mutex_unlock(su_mutex); + + return ret; +} + +static void uvc_func_drop_link(struct config_item *src, struct config_item *tgt) +{ + struct f_uvc_opts *opts; + + opts = to_f_uvc_opts(src); + mutex_lock(&opts->lock); + + if (!strcmp(tgt->ci_name, "iad_desc")) + opts->iad_index = 0; + else if (!strcmp(tgt->ci_name, "vs0_desc")) + opts->vs0_index = 0; + else if (!strcmp(tgt->ci_name, "vs1_desc")) + opts->vs1_index = 0; + + mutex_unlock(&opts->lock); +} + static struct configfs_item_operations uvc_func_item_ops = { .release = uvc_func_item_release, + .allow_link = uvc_func_allow_link, + .drop_link = uvc_func_drop_link, }; #define UVCG_OPTS_ATTR(cname, aname, limit) \