From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frank Rowand Subject: Re: [PATCH v3 1/3] devicetree: of: Add bindings for chosen node, stdout-path Date: Tue, 02 Dec 2014 18:24:21 -0800 Message-ID: <547E7455.6090009@gmail.com> References: <1417110967-16284-1-git-send-email-leif.lindholm@linaro.org> <1417110967-16284-2-git-send-email-leif.lindholm@linaro.org> Reply-To: frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1417110967-16284-2-git-send-email-leif.lindholm-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Leif Lindholm Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, andrew-g2DYL2Zd6BY@public.gmane.org, s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, ijc-8fiUuRrzOP0dnm+yROfE0A@public.gmane.org, grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org, frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: devicetree@vger.kernel.org On 11/27/2014 9:56 AM, Leif Lindholm wrote: > Add a global binding for the chosen node. > Include a description of the stdout-path, and an explicit statement on > its extra options in the context of a UART console. > > Opening description stolen from www.devicetree.org, and part of the > remaining text provided by Mark Rutland. > > Signed-off-by: Leif Lindholm > --- > Documentation/devicetree/bindings/chosen.txt | 42 ++++++++++++++++++++++++++ > 1 file changed, 42 insertions(+) > create mode 100644 Documentation/devicetree/bindings/chosen.txt > > diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt > new file mode 100644 > index 0000000..9cd74e9 > --- /dev/null > +++ b/Documentation/devicetree/bindings/chosen.txt > @@ -0,0 +1,42 @@ > +The chosen node > +--------------- > + > +The chosen node does not represent a real device, but serves as a place > +for passing data between firmware and the operating system, like boot > +arguments. Data in the chosen node does not represent the hardware. > + > + > +stdout-path property The code in patch 3/3 adds the extra options feature to the properties: stdout-path linux,stdout-path stdout [if (IS_ENABLED(CONFIG_PPC) ... ] > +-------------------- > + > +Device trees may specify the device to be used for boot console output > +with a stdout-path property under /chosen, as described in ePAPR, e.g. > + > +/ { > + chosen { > + stdout-path = "/serial@f00:115200"; > + }; > + > + serial@f00 { > + compatible = "vendor,some-uart"; > + reg = <0xf00 0x10>; > + }; > +}; > + > +If the character ":" is present in the value, this terminates the path. > +The meaning of any characters following the ":" is device-specific, and > +must be specified in the relevant binding documentation. > + > +For UART devices, the format supported by uart_parse_options() is the > +expected one. In this case, the format of the string is: > + > + {{{}}} > + > +where > + > + baud - baud rate in decimal > + parity - 'n' (none), 'o', (odd) or 'e' (even) > + bits - number of data bits > + flow - 'r' (rts) > + > +For example: 115200n8r > -- 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