From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C90EC04AB4 for ; Mon, 20 May 2019 02:39:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 34B2D2082C for ; Mon, 20 May 2019 02:39:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729598AbfETCjT (ORCPT ); Sun, 19 May 2019 22:39:19 -0400 Received: from Mailgw01.mediatek.com ([1.203.163.78]:35115 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727720AbfETCjT (ORCPT ); Sun, 19 May 2019 22:39:19 -0400 X-UUID: e9d19da9f5d54130adf050cc20d5151b-20190520 X-UUID: e9d19da9f5d54130adf050cc20d5151b-20190520 Received: from mtkcas32.mediatek.inc [(172.27.4.253)] by mailgw01.mediatek.com (envelope-from ) (mailgw01.mediatek.com ESMTP with TLS) with ESMTP id 849597756; Mon, 20 May 2019 10:39:15 +0800 Received: from MTKCAS32.mediatek.inc (172.27.4.184) by MTKMBS31DR.mediatek.inc (172.27.6.102) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Mon, 20 May 2019 10:39:13 +0800 Received: from [10.17.3.153] (172.27.4.253) by MTKCAS32.mediatek.inc (172.27.4.170) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Mon, 20 May 2019 10:39:11 +0800 Message-ID: <1558319951.10179.352.camel@mhfsdcap03> Subject: Re: [PATCH v5 4/6] usb: roles: add API to get usb_role_switch by node From: Chunfeng Yun To: Heikki Krogerus CC: Rob Herring , Greg Kroah-Hartman , Mark Rutland , "Matthias Brugger" , Adam Thomson , Li Jun , "Badhri Jagan Sridharan" , Hans de Goede , Andy Shevchenko , Min Guo , , , , , , Biju Das , Linus Walleij Date: Mon, 20 May 2019 10:39:11 +0800 In-Reply-To: <20190517130511.GA1887@kuha.fi.intel.com> References: <1557823643-8616-1-git-send-email-chunfeng.yun@mediatek.com> <1557823643-8616-5-git-send-email-chunfeng.yun@mediatek.com> <20190517103736.GA1490@kuha.fi.intel.com> <20190517130511.GA1887@kuha.fi.intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Hi, On Fri, 2019-05-17 at 16:05 +0300, Heikki Krogerus wrote: > Hi, > > On Fri, May 17, 2019 at 01:37:36PM +0300, Heikki Krogerus wrote: > > On Tue, May 14, 2019 at 04:47:21PM +0800, Chunfeng Yun wrote: > > > Add fwnode_usb_role_switch_get() to make easier to get > > > usb_role_switch by fwnode which register it. > > > It's useful when there is not device_connection registered > > > between two drivers and only knows the fwnode which register > > > usb_role_switch. > > > > > > Signed-off-by: Chunfeng Yun > > > Tested-by: Biju Das > > > > Acked-by: Heikki Krogerus > > Hold on. I just noticed Rob's comment on patch 2/6, where he points out > that you don't need to use device graph since the controller is the > parent of the connector. Doesn't that mean you don't really need this > API? No, I still need it. The change is about the way how to get fwnode; when use device graph, get fwnode by of_graph_get_remote_node(); but now will get fwnode by of_get_parent(); > > > > --- > > > v5 changes: > > > 1. remove linux/of.h suggested by Biju > > > 2. add tested by Biju > > > > > > Note: still depends on [1] > > > [1]: [v6,08/13] usb: roles: Introduce stubs for the exiting functions in role.h > > > https://patchwork.kernel.org/patch/10909971/ > > > > > > v4 changes: > > > 1. use switch_fwnode_match() to find fwnode suggested by Heikki > > > 2. this patch now depends on [1] > > > > > > [1] [v6,08/13] usb: roles: Introduce stubs for the exiting functions in role.h > > > https://patchwork.kernel.org/patch/10909971/ > > > > > > v3 changes: > > > 1. use fwnodes instead of node suggested by Andy > > > 2. rebuild the API suggested by Heikki > > > > > > v2 no changes > > > --- > > > drivers/usb/roles/class.c | 24 ++++++++++++++++++++++++ > > > include/linux/usb/role.h | 8 ++++++++ > > > 2 files changed, 32 insertions(+) > > > > > > diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c > > > index f45d8df5cfb8..4a1f09a41ec0 100644 > > > --- a/drivers/usb/roles/class.c > > > +++ b/drivers/usb/roles/class.c > > > @@ -135,6 +135,30 @@ struct usb_role_switch *usb_role_switch_get(struct device *dev) > > > } > > > EXPORT_SYMBOL_GPL(usb_role_switch_get); > > > > > > +/** > > > + * fwnode_usb_role_switch_get - Find USB role switch by it's parent fwnode > > > + * @fwnode: The fwnode that register USB role switch > > > + * > > > + * Finds and returns role switch registered by @fwnode. The reference count > > > + * for the found switch is incremented. > > > + */ > > > +struct usb_role_switch * > > > +fwnode_usb_role_switch_get(struct fwnode_handle *fwnode) > > > +{ > > > + struct usb_role_switch *sw; > > > + struct device *dev; > > > + > > > + dev = class_find_device(role_class, NULL, fwnode, switch_fwnode_match); > > > + if (!dev) > > > + return ERR_PTR(-EPROBE_DEFER); > > > + > > > + sw = to_role_switch(dev); > > > + WARN_ON(!try_module_get(sw->dev.parent->driver->owner)); > > > + > > > + return sw; > > > +} > > > +EXPORT_SYMBOL_GPL(fwnode_usb_role_switch_get); > > This function only basically converts the fwnode to usb_role_switch, > but I would actually prefer that we walked through the device graph > here instead of expecting the caller to do that. > > So this function should probable be called fwnode_to_usb_role_switch() > and not fwnode_usb_role_switch_get(), but I guess you don't need it > at all, right? > > > thanks, >