| Message ID | 1417110967-16284-2-git-send-email-leif.lindholm@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thu, 27 Nov 2014 18:41:33 +0000 , Mark Rutland <mark.rutland@arm.com> wrote: > On Thu, Nov 27, 2014 at 05:56:05PM +0000, 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 <leif.lindholm@linaro.org> > > --- > > 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 > > +-------------------- > > + > > +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: > > Please drop the mention of uart_parse_options and just describe the > format. Linux internal details are irrelevant to the contract of the > binding. > > Otherwise this looks good to me! I've fixed it up and merged it. No need to respin. Thanks! g. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On Wed, Dec 3, 2014 at 2:24 AM, Frank Rowand <frowand.list@gmail.com> 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 <leif.lindholm@linaro.org> >> --- >> 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: >> + >> + <baud>{<parity>{<bits>{<flow>}}} >> + >> +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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Dec 3, 2014 at 7:46 PM, Frank Rowand <frowand.list@gmail.com> wrote: > On 12/3/2014 7:12 AM, Grant Likely wrote: >> On Wed, Dec 3, 2014 at 2:24 AM, Frank Rowand <frowand.list@gmail.com> 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 <leif.lindholm@linaro.org> >>>> --- >>>> 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? > > Assuming that the code change in patch 3 is as desired, then the chosen.txt > documentation applies to all three properties, not just stdout-path. So > yes, a change is suggested for the documentation. how about if this is added: Implementation note: Linux will look for the property "linux,stdout-path" or on PowerPC "stdout" if "stdout-path" is not found. However, the "linux,stdout-path" and "stdout" properties are deprecated. New platforms should only use the "stdout-path" property. g. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On Wed, 03 Dec 2014 15:07:49 -0800 , Frank Rowand <frowand.list@gmail.com> wrote: > On 12/3/2014 1:45 PM, Grant Likely wrote: > > On Wed, Dec 3, 2014 at 7:46 PM, Frank Rowand <frowand.list@gmail.com> wrote: > >> On 12/3/2014 7:12 AM, Grant Likely wrote: > >>> On Wed, Dec 3, 2014 at 2:24 AM, Frank Rowand <frowand.list@gmail.com> 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 <leif.lindholm@linaro.org> > >>>>> --- > >>>>> 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? > >> > >> Assuming that the code change in patch 3 is as desired, then the chosen.txt > >> documentation applies to all three properties, not just stdout-path. So > >> yes, a change is suggested for the documentation. > > > > how about if this is added: > > > > Implementation note: Linux will look for the property "linux,stdout-path" or > > on PowerPC "stdout" if "stdout-path" is not found. However, the > > "linux,stdout-path" and "stdout" properties are deprecated. New platforms > > should only use the "stdout-path" property. > > > > g. > > > > Yep, perfect. Great, thanks. Merged. g. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 +-------------------- + +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: + + <baud>{<parity>{<bits>{<flow>}}} + +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
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 <leif.lindholm@linaro.org> --- Documentation/devicetree/bindings/chosen.txt | 42 ++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 Documentation/devicetree/bindings/chosen.txt