From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: [PATCH 1/5] dt-bindings: connector: add optional properties for Type-B Date: Wed, 13 Mar 2019 11:18:37 +0100 Message-ID: <0c3ca095-9077-0b9d-839f-61ebc066e3f9@redhat.com> References: <1552025622-15582-1-git-send-email-chunfeng.yun@mediatek.com> <1552025622-15582-2-git-send-email-chunfeng.yun@mediatek.com> <693b11e7-fa9e-ab1f-561a-beb758b1872f@redhat.com> <1552282383.10179.21.camel@mhfsdcap03> <1552360688.10179.55.camel@mhfsdcap03> <464f1021-4c5e-9137-489d-65fd578575d3@redhat.com> <1552472109.10179.103.camel@mhfsdcap03> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1552472109.10179.103.camel@mhfsdcap03> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Chunfeng Yun Cc: Rob Herring , Greg Kroah-Hartman , Heikki Krogerus , Mark Rutland , Matthias Brugger , Adam Thomson , Li Jun , Badhri Jagan Sridharan , Andy Shevchenko , Min Guo , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org List-Id: devicetree@vger.kernel.org Hi, On 3/13/19 11:15 AM, Chunfeng Yun wrote: > Hi, > On Tue, 2019-03-12 at 13:45 +0100, Hans de Goede wrote: >> Hi, >> On 12-03-19 04:18, Chunfeng Yun wrote: >>> Hi, >>> On Mon, 2019-03-11 at 09:06 +0100, Hans de Goede wrote: >>>> Hi, >>>> >>>> On 11-03-19 06:33, Chunfeng Yun wrote: >>>>> Hi, >>>>> >>>>> On Fri, 2019-03-08 at 13:07 +0100, Hans de Goede wrote: >>>>>> Hi, >>>>>> >>>>>> On 08-03-19 07:13, Chunfeng Yun wrote: >>>>>>> Add id-gpios, vbus-gpios, vbus-supply and pinctrl properties for >>>>>>> usb-b-connector >>>>>>> >>>>>>> Signed-off-by: Chunfeng Yun >>>>>>> --- >>>>>>> .../devicetree/bindings/connector/usb-connector.txt | 10 ++++++++++ >>>>>>> 1 file changed, 10 insertions(+) >>>>>>> >>>>>>> diff --git a/Documentation/devicetree/bindings/connector/usb-connector.txt b/Documentation/devicetree/bindings/connector/usb-connector.txt >>>>>>> index a9a2f2fc44f2..7a07b0f4f973 100644 >>>>>>> --- a/Documentation/devicetree/bindings/connector/usb-connector.txt >>>>>>> +++ b/Documentation/devicetree/bindings/connector/usb-connector.txt >>>>>>> @@ -17,6 +17,16 @@ Optional properties: >>>>>>> - self-powered: Set this property if the usb device that has its own power >>>>>>> source. >>>>>>> >>>>>>> +Optional properties for usb-b-connector: >>>>>>> +- id-gpios: gpio for USB ID pin. >>>>>> >>>>>> What about boards where the ID pin is *not* connected to a GPIO, >>>>>> but e.g. to a special pin on the PMIC which can also detect >>>>>> an ACA adapter ? Currently this case is handled by extcon >>>>>> drivers, but we have no way to set e.g. vbus-supply for the >>>>>> connector. Maybe in this case the usb-connector node should >>>>>> be a child of the PMIC node ? >>>>> Yes, it would be, PMIC is in charger of detecting the status of ID pin >>>> >>>> Ok, then I think this should be documented too. >>>> >>>>>> And in many cases there also is a mux to switch the datalines >>>>>> between the host and device(gadget) controllers, how should >>>>>> that be described in this model? See the new usb-role-switch >>>>>> code under drivers/usb/roles >>>>>> >>>>>> In some cases the mux is controlled through a gpio, so we >>>>>> may want to add a "mux-gpios" here in which case we also >>>>>> need to define what 0/1 means. >>>>> I'm not sure, the mux seems not belong to this connector, >>>>> and may need another driver to register usb-role-switch, >>>>> similar to: >>>>> >>>>> [v2,2/2] usb: typec: add typec switch via GPIO control >>>>> https://patchwork.kernel.org/patch/10834327/ >>>> >>>> Right the mux/role-switch will need a driver, but the "owner" >>>> of the usb_connector, e.g. the PMIC or the owner of the >>>> id GPIO pin needs to know which device is the role-switch so >>>> that it can set the role correctly based on the id-pin. >>>> >>>> Your binding already contains Vbus info, allowing the owner >>>> of the usb_connector to enable/disable Vbus based on the id-pin, >>>> but the owner will also be responsible for setting the role-switch. >>> In this patch series, I make usb_connector driver enable/disable Vbus, >>> but not the parent(USB controller) of usb_connector which registers a >>> usb-role-switch, which way do you think it is better? >> >> IMHO there should not be a driver for the usb_connector child-node, >> only for the parent-device of that child-node. > If so, each USB controller driver should process this special case by > itself when use a gpio to detect the status of ID pin, it's not a > friendly way. And it's easy by using extcon-usb-gpio driver before, so > we also want to provide a simple way when support usb_connector, no > matter what method we choose. > > Ideally, the only one thing that USB controller driver need to do, just > register a usb-role-switch, and leave decision when switch the role to > other drivers, such as type-C, PMIC/charger, also include gpio > >> >> There are going to be too many specific setups surrounding PMICs to >> be able to do a single generic driver for the connector. >> > Fortunately, these patches only focus on the simplest gpio driven role > switch :) In that case there should be an extra compatible added to the usb_b_connector node to which the "simple gpio" driver binds, so that not all devicetree-s declaring a usb_b_connector child-node automatically get that driver bound, and the gpio / vbus properties should be mandatory properties for usb_b_connector child nodes declaring the extra compatible, rather then being optional for the generic compatible. Regards, Hans