From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH v3 1/3] devicetree: of: Add bindings for chosen node, stdout-path Date: Wed, 3 Dec 2014 15:12:03 +0000 Message-ID: References: <1417110967-16284-1-git-send-email-leif.lindholm@linaro.org> <1417110967-16284-2-git-send-email-leif.lindholm@linaro.org> <547E7455.6090009@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: In-Reply-To: <547E7455.6090009-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Frank Rowand Cc: Leif Lindholm , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , Linux Kernel Mailing List , Mark Rutland , Andrew Lunn , "s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org" , Rob Herring , Ian Campbell , Jean-Christophe PLAGNIOL-VILLARD List-Id: devicetree@vger.kernel.org On Wed, Dec 3, 2014 at 2:24 AM, Frank Rowand wrote: > 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) ... ] I don't understand what you mean here. Are you suggesting a change to this patch? Is there something deficient in it? g. > >> +-------------------- >> + >> +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