From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Zabel Subject: Re: [PATCH v4 1/1] USB: core: let USB device know device node Date: Fri, 05 Feb 2016 10:37:00 +0100 Message-ID: <1454665020.6406.21.camel@pengutronix.de> References: <1453706679-18948-1-git-send-email-peter.chen@freescale.com> <1454582690.3356.18.camel@pengutronix.de> <20160205061124.GB1858@shlinux2> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160205061124.GB1858@shlinux2> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peter Chen Cc: Peter Chen , gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, balbi-l0cyMroinI0@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, valentin.longchamp-SkAbAL50j+5BDgjK7y7TUQ@public.gmane.org, s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, stillcompiling-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: devicetree@vger.kernel.org Am Freitag, den 05.02.2016, 14:11 +0800 schrieb Peter Chen: [...] > > The reference recommendation states that for single-configuration USB > > devices the compatible should contain all of the applicable strings from > > the list starting with 2) "usbVID,PID.REV" and ending with 11) > > "usb,device". Are we going to ignore this? > > I have not seen benefits if we write several compatibles in dts, > the information of compatibles listed in doc can be got during > the enumeration. > > I suggest we use the simple pattern for this compatible, in that > case, every one can be easy to follow it, and will not be confused > which compatibles should be used, and the style can be unify. Just pointing it out, a comment why this differs from the recommendation would be nice to avoid confusion. [...] > > > + compatible = "usb05e3,0608"; > > > + reg = <0x1>; > > > + }; > > > > I'd have written this node as: > > > > hub: hub@1 { > > compatible = "usb5e3,608", "usb5e3,class9", > > "usb,class9", "usb,device"; > > reg = <1>; > > }; > > The reg should be hexadecimal, do we need to add "0x" before the value? The unit-address name part should be hexadecimal, the reg property value doesn't have to be. As long as the value is < 10 I don't see a problem. > > As another example, I'd like to introduce the USB WLAN Adapter soldered > > onto the imx6q-gk802 board to its power enable GPIO via the device tree: > > > > /* Internal USB port (USBH1) */ > > &usbh1 { > > #address-cells = <1>; > > #size-cells = <0>; > > status = "okay"; > > > > /* RTL8192CU 802.11n WLAN Adapter */ > > device@1 { > > compatible = "usbbda,8176.200", "usbbda,8176", > > "usb,device"; > > reg = <1>; > > > > enable-gpios = <&gpio2 0 GPIO_ACTIVE_LOW>; > > }; > > }; > > > > It is okay to use your example, but I still insist like below: Sorry for being imprecise. The hub example is fine for the documentation. I just wanted to illustrate how and why I am interested in this discussion. best regards Philipp -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html