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_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED autolearn=ham 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 DD039C43381 for ; Fri, 15 Mar 2019 07:53:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A401E21872 for ; Fri, 15 Mar 2019 07:53:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728475AbfCOHxG (ORCPT ); Fri, 15 Mar 2019 03:53:06 -0400 Received: from Mailgw01.mediatek.com ([1.203.163.78]:26469 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727557AbfCOHxG (ORCPT ); Fri, 15 Mar 2019 03:53:06 -0400 X-UUID: 74200d71c15b4ddb9fc49abef31b0c0a-20190315 X-UUID: 74200d71c15b4ddb9fc49abef31b0c0a-20190315 Received: from mtkcas35.mediatek.inc [(172.27.4.253)] by mailgw01.mediatek.com (envelope-from ) (mailgw01.mediatek.com ESMTP with TLS) with ESMTP id 1407047240; Fri, 15 Mar 2019 15:52:56 +0800 Received: from MTKCAS36.mediatek.inc (172.27.4.186) by MTKMBS31N2.mediatek.inc (172.27.4.87) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Fri, 15 Mar 2019 15:52:55 +0800 Received: from [10.17.3.153] (172.27.4.253) by MTKCAS36.mediatek.inc (172.27.4.170) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Fri, 15 Mar 2019 15:52:54 +0800 Message-ID: <1552636374.10179.121.camel@mhfsdcap03> Subject: Re: [PATCH v2 2/6] dt-bindings: usb: add binding for Type-B dual role switch by GPIO From: Chunfeng Yun To: Rob Herring CC: Greg Kroah-Hartman , Heikki Krogerus , Mark Rutland , Matthias Brugger , Adam Thomson , Li Jun , "Badhri Jagan Sridharan" , Hans de Goede , Andy Shevchenko , Min Guo , , , , , Date: Fri, 15 Mar 2019 15:52:54 +0800 In-Reply-To: <1552635513-2378-3-git-send-email-chunfeng.yun@mediatek.com> References: <1552635513-2378-1-git-send-email-chunfeng.yun@mediatek.com> <1552635513-2378-3-git-send-email-chunfeng.yun@mediatek.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-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rob, There are two ways that I think out to support type-B GPIO based dual role switch. The first one, as the series used: &mtu3 { status = "okay"; connector@0 { compatible = "usb-b-connector", "linux,typeb-switch-gpio"; label = "micro-USB"; type = "micro"; id-gpio = <&pio 12 GPIO_ACTIVE_HIGH>; vbus-supply = <&usb_p0_vbus>; }; }; but there are some shortcomings: 1. It's not transparent, USB controller driver should be modified, and call of_platform_populate() to create platform device for connector, this is not friendly when the controller driver hasn't child node before, and also not compatible with other cases, such as Type-C 2. It doesn't keep format consistent with the case using Type-C, or using PMIC to detect ID pin. 3. vbus-supply will be got by USB controller driver if it aready supports it another way as following: role_sw_iddig { compatible = "linux,typeb-switch-gpio"; status = "okay"; connector { compatible = "usb-b-connector"; label = "micro-USB"; type = "micro"; id-gpios = <&pio 12 GPIO_ACTIVE_HIGH>; vbus-supply = <&usb_p0_vbus>; }; port { bsw_ep: endpoint@0 { remote-endpoint = <&usb_role_sw>; }; }; }; &mtu3 { status = "okay"; port { usb_role_sw: endpoint@0 { remote-endpoint = <&bsw_ep>; }; }; }; strength: avoid the shortcomings of the first way shortcoming: it's a virtual device and seems not following graph.txt binding, Do you have any suggestion? Thanks On Fri, 2019-03-15 at 15:38 +0800, Chunfeng Yun wrote: > It's used to support dual role switch via GPIO when use Type-B > receptacle > > Signed-off-by: Chunfeng Yun > --- > v2 changes: > 1. new patch to make binding clear suggested by Hans > --- > .../bindings/usb/typeb-switch-gpio.txt | 26 +++++++++++++++++++ > 1 file changed, 26 insertions(+) > create mode 100644 Documentation/devicetree/bindings/usb/typeb-switch-gpio.txt > > diff --git a/Documentation/devicetree/bindings/usb/typeb-switch-gpio.txt b/Documentation/devicetree/bindings/usb/typeb-switch-gpio.txt > new file mode 100644 > index 000000000000..d46d83bc6500 > --- /dev/null > +++ b/Documentation/devicetree/bindings/usb/typeb-switch-gpio.txt > @@ -0,0 +1,26 @@ > +USB Type-B dual role switch via a GPIO > + > +This is a virtual device used to switch dual role mode from the USB ID pin > +connected to a GPIO pin. > + > +Required properties: > +- compatible: Should be "linux,typeb-switch-gpio" > + > +Either one of id-gpios or vbus-gpios must be present, and both can be present > +as well. > +vbus-supply could be present if needed when support dual role mode. > + see connector/usb-connector.txt > + > +Example: > + > +&mtu3 { > + status = "okay"; > + > + connector@0 { > + compatible = "usb-b-connector", "linux,typeb-switch-gpio"; > + label = "micro-USB"; > + type = "micro"; > + id-gpio = <&pio 12 GPIO_ACTIVE_HIGH>; > + vbus-supply = <&usb_p0_vbus>; > + }; > +};