From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Quadros Subject: Re: [PATCH v2 4/4] Documentation: extcon: usb-gpio: update usb-gpio binding description Date: Wed, 1 Apr 2015 14:33:23 +0300 Message-ID: <551BD783.9060109@ti.com> References: <1427873005-24024-1-git-send-email-r.baldyga@samsung.com> <1427873005-24024-5-git-send-email-r.baldyga@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1427873005-24024-5-git-send-email-r.baldyga@samsung.com> Sender: linux-kernel-owner@vger.kernel.org To: Robert Baldyga , cw00.choi@samsung.com Cc: myungjoo.ham@samsung.com, linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, m.szyprowski@samsung.com List-Id: devicetree@vger.kernel.org On 01/04/15 10:23, Robert Baldyga wrote: > Add information about VBUS pin detection support, 'debounce' property > and some other details. > > Signed-off-by: Robert Baldyga Acked-by: Roger Quadros cheers, -roger > --- > .../devicetree/bindings/extcon/extcon-usb-gpio.txt | 28 ++++++++++++++++++++-- > 1 file changed, 26 insertions(+), 2 deletions(-) > > diff --git a/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt b/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt > index af0b903..7096f39 100644 > --- a/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt > +++ b/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt > @@ -1,16 +1,40 @@ > USB GPIO Extcon device > > -This is a virtual device used to generate USB cable states from the USB ID pin > -connected to a GPIO pin. > +This is a virtual device used to generate USB cable states from the USB > +ID and VBUS signals connected to GPIO pins. > + > +The extcon cable states USB and USB_HOST are actually VBUS and !ID > +pin states and do not indicate what mode the USB needs to operate in. > +That decision is done by the USB stack. > + > +Some devices have only one of these GPIO pins, so we support cases when > +only one of them is present. Hence properties 'id-gpio' and 'vbus-gpio' > +are described as optional, but at least one of them has to be present > +in extcon-usb-gpio node. > + > +In general we have three cases: > +1. If VBUS and ID gpios are present we pass them as is > + USB-HOST = !ID, USB = VBUS > +2. If only VBUS gpio is present we assume that ID pin is always High. > + USB-HOST = false, USB = VBUS. > +3. If only ID pin is available we infer the VBUS pin states based on ID. > + USB-HOST = !ID, USB = ID > > Required properties: > - compatible: Should be "linux,extcon-usb-gpio" > + > +Optional properties > - id-gpio: gpio for USB ID pin. See gpio binding. > +- vbus-gpio: gpio for USB VBUS pin. See gpio binding. > +- debounce: gpio debounce time in milliseconds (u32). > + > > Example: Examples of extcon-usb-gpio node in dra7-evm.dts as listed below: > extcon_usb1 { > compatible = "linux,extcon-usb-gpio"; > id-gpio = <&gpio6 1 GPIO_ACTIVE_HIGH>; > + vbus-gpio = <&gpio6 2 GPIO_ACTIVE_HIGH>; > + debounce = <25>; > } > > &omap_dwc3_1 { >