From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Zabel Subject: Re: [PATCH 1/6] binding-doc: power: pwrseq-generic: add binding doc for generic power sequence library Date: Thu, 07 Jul 2016 11:47:14 +0200 Message-ID: <1467884834.4236.36.camel@pengutronix.de> References: <1467882892-27589-1-git-send-email-peter.chen@nxp.com> <1467882892-27589-2-git-send-email-peter.chen@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1467882892-27589-2-git-send-email-peter.chen-3arQi8VN3Tc@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peter Chen Cc: gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz@public.gmane.org, ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, sre-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, shawnguo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, mail-APzI5cXaD1zVlRWJc41N0YvC60bnQu0Y@public.gmane.org, troy.kisky-Q5RJGjKts06CY9SHAMCTRUEOCMrvLtNR@public.gmane.org, festevam-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, oscar-Bdbr4918Nnnk1uMJSBkQmQ@public.gmane.org, stephen.boyd-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-pm@vger.kernel.org Am Donnerstag, den 07.07.2016, 17:14 +0800 schrieb Peter Chen: > Add binding doc for generic power sequence library. > > Signed-off-by: Peter Chen > --- > .../bindings/power/pwrseq/pwrseq-generic.txt | 56 ++++++++++++++++++++++ > 1 file changed, 56 insertions(+) > create mode 100644 Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt > > diff --git a/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt > new file mode 100644 > index 0000000..4b23834 > --- /dev/null > +++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt > @@ -0,0 +1,56 @@ > +The generic power sequence library > + > +Some hard-wired USB/MMC devices need to do power sequence to let the > +device work normally, the typical power sequence like: enable USB > +PHY clock, toggle reset pin, etc. But current Linux USB driver > +lacks of such code to do it, it may cause some hard-wired USB devices > +works abnormal or can't be recognized by controller at all. The > +power sequence will be done before this device can be found at USB > +bus. > + > +The power sequence properties is under the device node. > + > +Required properties: > +- power-sequence: this device needs to do power sequence before enumeration > + > +Optional properties: > +- clocks: the input clock for device. > +- clock-name: must be "pwrseq-clk" The "-clk" in the clock name is redundant. > +- pwrseq-reset-gpios: Should specify the GPIO for reset. > +- pwrseq-reset-duration-us: the duration in microsecond for assert reset signal. I understand you want to make it explicit that this GPIO is for the pwrseq library, but are we really gaining anything over just calling these reset-gpios and reset-duration-us? The same applies to the clock name above. > +Below is the example of USB power sequence properties on USB device > +nodes which have two level USB hubs. > + > +&usbotg1 { > + vbus-supply = <®_usb_otg1_vbus>; > + pinctrl-names = "default"; > + pinctrl-0 = <&pinctrl_usb_otg1_id>; > + status = "okay"; > + > + #address-cells = <1>; > + #size-cells = <0>; > + hub: genesys@1 { > + compatible = "usb5e3,608"; > + reg = <1>; > + > + power-sequence; > + clocks = <&clks IMX6SX_CLK_CKO>; > + clock-names = "pwrseq-clk"; > + pwrseq-reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>; /* hub reset pin */ > + pwrseq-reset-duration-us = <10>; > + > + #address-cells = <1>; > + #size-cells = <0>; > + ethernet: asix@1 { > + compatible = "usbb95,1708"; > + reg = <1>; > + > + power-sequence; > + clocks = <&clks IMX6SX_CLK_IPG>; > + clock-names = "pwrseq-clk"; > + pwrseq-reset-gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; /* ethernet_rst */ > + pwrseq-reset-duration-us = <15>; > + }; This looks weird. The hub and ethernet chips don't have "pwrseq" clock and reset input pins. I'd remove the clock-names and pwrseq- reset prefix. 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