| Message ID | 20240106-w1-uart-v4-1-7fe1378a8b3e@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | w1: add UART w1 bus driver | expand |
On Sat, Jan 06, 2024 at 05:02:24PM +0100, Christoph Winklhofer wrote: > Add device tree binding for UART 1-Wire bus. > > Signed-off-by: Christoph Winklhofer <cj.winklhofer@gmail.com> > --- > Documentation/devicetree/bindings/w1/w1-uart.yaml | 62 +++++++++++++++++++++++ > 1 file changed, 62 insertions(+) > > diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml > new file mode 100644 > index 000000000000..6b90693b2ca0 > --- /dev/null > +++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml > @@ -0,0 +1,62 @@ > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/w1/w1-uart.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: UART 1-Wire Bus > + > +maintainers: > + - Christoph Winklhofer <cj.winklhofer@gmail.com> > + > +description: | > + UART 1-wire bus. Utilizes the UART interface via the Serial Device Bus > + to create the 1-Wire timing patterns. > + > + The UART peripheral must support full-duplex and operate in open-drain > + mode. The timing patterns are generated by a specific combination of > + baud-rate and transmitted byte, which corresponds to a 1-Wire read bit, > + write bit or reset pulse. > + > + The default baud-rate for reset and presence detection is 9600 and for > + a 1-Wire read or write operation 115200. In case the actual baud-rate > + is different from the requested one, the transmitted byte is adapted > + to generate the 1-Wire timing patterns. > + > + https://www.analog.com/en/technical-articles/using-a-uart-to-implement-a-1wire-bus-master.html > + > + > +properties: > + compatible: > + const: w1-uart > + > + reset-speed: > + $ref: /schemas/types.yaml#/definitions/uint32 > + default: 9600 > + description: | Don't need '|' if no formatting > + The baud rate for the 1-Wire reset and presence detect. > + > + touch_0-speed: Don't use '_' in property names. I'm somewhat familar with 1-wire, but I don't get what 'touch' means here. I assume these are low and high times which are a function of the baudrate. > + $ref: /schemas/types.yaml#/definitions/uint32 > + default: 115200 > + description: | > + The baud rate for the 1-Wire write-0 cycle (touch bit 0). > + > + touch_1-speed: > + $ref: /schemas/types.yaml#/definitions/uint32 > + default: 115200 > + description: | > + The baud rate for the 1-Wire write-1 and read cycle (touch bit 1). > + > +required: > + - compatible > + > +additionalProperties: false w1.txt says there can be a child node for the 1-wire device. You need 'type: object'. Or w1.txt needs to be converted to schema and referenced here (along with using unevaluatedProperties here instead). Rob
On Fri, Jan 12, 2024 at 07:39:17PM -0600, Rob Herring wrote: > On Sat, Jan 06, 2024 at 05:02:24PM +0100, Christoph Winklhofer wrote: > > Add device tree binding for UART 1-Wire bus. > > > > Signed-off-by: Christoph Winklhofer <cj.winklhofer@gmail.com> > > --- > > Documentation/devicetree/bindings/w1/w1-uart.yaml | 62 +++++++++++++++++++++++ > > 1 file changed, 62 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml > > new file mode 100644 > > index 000000000000..6b90693b2ca0 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml > > @@ -0,0 +1,62 @@ > > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/w1/w1-uart.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# ... > > +properties: > > + compatible: > > + const: w1-uart > > + > > + reset-speed: > > + $ref: /schemas/types.yaml#/definitions/uint32 > > + default: 9600 > > + description: | > > Don't need '|' if no formatting > Ok. > > + The baud rate for the 1-Wire reset and presence detect. > > + > > + touch_0-speed: > > Don't use '_' in property names. > > I'm somewhat familar with 1-wire, but I don't get what 'touch' means > here. I assume these are low and high times which are a function of the > baudrate. > I change the name to 'write-0-speed' and 'write-1-speed'. The function in the w1-framework is named 'touch_bit' - therefore the previous naming. It is the baud-rate used in the 1-Wire cycle to write a 0-Bit (write-0-speed) and to perform a 1-Wire cycle that writes a 1-Bit and reads a 0-Bit or 1-Bit (write-1-speed). > > + $ref: /schemas/types.yaml#/definitions/uint32 > > + default: 115200 > > + description: | > > + The baud rate for the 1-Wire write-0 cycle (touch bit 0). > > + > > + touch_1-speed: > > + $ref: /schemas/types.yaml#/definitions/uint32 > > + default: 115200 > > + description: | > > + The baud rate for the 1-Wire write-1 and read cycle (touch bit 1). > > + > > +required: > > + - compatible > > + > > +additionalProperties: false > > w1.txt says there can be a child node for the 1-wire device. You need > 'type: object'. Or w1.txt needs to be converted to schema and referenced > here (along with using unevaluatedProperties here instead). > > Rob Will change it to type object. However, I also tried to convert w1.txt to w1.yaml - I am not quite sure, so I add an excerpt of my attempt. The example in w1.txt builds fine. Is oneOf allowed as a top-level property, the documentation only mentions allOf? Only one child should be allowed, but I did not find a way to restrict this. # w1-uart.yaml: unevaluatedProperties: $ref: w1.yaml # w1.yaml: properties: compatible: enum: - maxim,ds2760 oneOf: - $ref: /schemas/power/supply/maxim,ds2760.yaml unevaluatedProperties: false # Thank you for the review! Kind regards, Christoph
On 13/01/2024 19:04, Christoph Winklhofer wrote: > On Fri, Jan 12, 2024 at 07:39:17PM -0600, Rob Herring wrote: >> On Sat, Jan 06, 2024 at 05:02:24PM +0100, Christoph Winklhofer wrote: >>> Add device tree binding for UART 1-Wire bus. >>> >>> Signed-off-by: Christoph Winklhofer <cj.winklhofer@gmail.com> >>> --- >>> Documentation/devicetree/bindings/w1/w1-uart.yaml | 62 +++++++++++++++++++++++ >>> 1 file changed, 62 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml >>> new file mode 100644 >>> index 000000000000..6b90693b2ca0 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml >>> @@ -0,0 +1,62 @@ >>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause >>> +%YAML 1.2 >>> +--- >>> +$id: http://devicetree.org/schemas/w1/w1-uart.yaml# >>> +$schema: http://devicetree.org/meta-schemas/core.yaml# > ... >>> +properties: >>> + compatible: >>> + const: w1-uart >>> + >>> + reset-speed: >>> + $ref: /schemas/types.yaml#/definitions/uint32 >>> + default: 9600 >>> + description: | >> >> Don't need '|' if no formatting >> > > Ok. > >>> + The baud rate for the 1-Wire reset and presence detect. >>> + >>> + touch_0-speed: >> >> Don't use '_' in property names. >> >> I'm somewhat familar with 1-wire, but I don't get what 'touch' means >> here. I assume these are low and high times which are a function of the >> baudrate. >> > > I change the name to 'write-0-speed' and 'write-1-speed'. The function > in the w1-framework is named 'touch_bit' - therefore the previous > naming. > > It is the baud-rate used in the 1-Wire cycle to write a 0-Bit > (write-0-speed) and to perform a 1-Wire cycle that writes a 1-Bit and > reads a 0-Bit or 1-Bit (write-1-speed). Then probably -bps: https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml > >>> + $ref: /schemas/types.yaml#/definitions/uint32 >>> + default: 115200 >>> + description: | >>> + The baud rate for the 1-Wire write-0 cycle (touch bit 0). >>> + >>> + touch_1-speed: >>> + $ref: /schemas/types.yaml#/definitions/uint32 >>> + default: 115200 >>> + description: | >>> + The baud rate for the 1-Wire write-1 and read cycle (touch bit 1). >>> + >>> +required: >>> + - compatible >>> + >>> +additionalProperties: false >> >> w1.txt says there can be a child node for the 1-wire device. You need >> 'type: object'. Or w1.txt needs to be converted to schema and referenced >> here (along with using unevaluatedProperties here instead). >> >> Rob > > Will change it to type object. However, I also tried to convert w1.txt > to w1.yaml - I am not quite sure, so I add an excerpt of my attempt. > The example in w1.txt builds fine. Is oneOf allowed as a top-level > property, the documentation only mentions allOf? > Only one child should be allowed, but I did not find a way to restrict > this. > > # w1-uart.yaml: > unevaluatedProperties: > $ref: w1.yaml > > # w1.yaml: > properties: > compatible: > enum: > - maxim,ds2760 w1 describes entire class of the devices, so it should not have compatibles. Look how other buses do it. > > oneOf: > - $ref: /schemas/power/supply/maxim,ds2760.yaml > > unevaluatedProperties: false Best regards, Krzysztof
On Sun, Jan 14, 2024 at 11:54:48AM +0100, Krzysztof Kozlowski wrote: > On 13/01/2024 19:04, Christoph Winklhofer wrote: > > On Fri, Jan 12, 2024 at 07:39:17PM -0600, Rob Herring wrote: > >> On Sat, Jan 06, 2024 at 05:02:24PM +0100, Christoph Winklhofer wrote: > >>> Add device tree binding for UART 1-Wire bus. > >>> > >>> Signed-off-by: Christoph Winklhofer <cj.winklhofer@gmail.com> > >>> --- > >>> Documentation/devicetree/bindings/w1/w1-uart.yaml | 62 +++++++++++++++++++++++ > >>> 1 file changed, 62 insertions(+) > >>> > >>> diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml > >>> new file mode 100644 > >>> index 000000000000..6b90693b2ca0 > >>> --- /dev/null > >>> +++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml > >>> @@ -0,0 +1,62 @@ > >>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause > >>> +%YAML 1.2 > >>> +--- > >>> +$id: http://devicetree.org/schemas/w1/w1-uart.yaml# > >>> +$schema: http://devicetree.org/meta-schemas/core.yaml# > > ... > >>> +properties: > >>> + compatible: > >>> + const: w1-uart > >>> + > >>> + reset-speed: > >>> + $ref: /schemas/types.yaml#/definitions/uint32 > >>> + default: 9600 > >>> + description: | > >> > >> Don't need '|' if no formatting > >> > > > > Ok. > > > >>> + The baud rate for the 1-Wire reset and presence detect. > >>> + > >>> + touch_0-speed: > >> > >> Don't use '_' in property names. > >> > >> I'm somewhat familar with 1-wire, but I don't get what 'touch' means > >> here. I assume these are low and high times which are a function of the > >> baudrate. > >> > > > > I change the name to 'write-0-speed' and 'write-1-speed'. The function > > in the w1-framework is named 'touch_bit' - therefore the previous > > naming. > > > > It is the baud-rate used in the 1-Wire cycle to write a 0-Bit > > (write-0-speed) and to perform a 1-Wire cycle that writes a 1-Bit and > > reads a 0-Bit or 1-Bit (write-1-speed). > > > Then probably -bps: > https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml The serial.yaml uses prefix -speed for the baud rate but I can change it to -bps. > > > > >>> + $ref: /schemas/types.yaml#/definitions/uint32 > >>> + default: 115200 > >>> + description: | > >>> + The baud rate for the 1-Wire write-0 cycle (touch bit 0). > >>> + > >>> + touch_1-speed: > >>> + $ref: /schemas/types.yaml#/definitions/uint32 > >>> + default: 115200 > >>> + description: | > >>> + The baud rate for the 1-Wire write-1 and read cycle (touch bit 1). > >>> + > >>> +required: > >>> + - compatible > >>> + > >>> +additionalProperties: false > >> > >> w1.txt says there can be a child node for the 1-wire device. You need > >> 'type: object'. Or w1.txt needs to be converted to schema and referenced > >> here (along with using unevaluatedProperties here instead). > >> > >> Rob > > > > Will change it to type object. However, I also tried to convert w1.txt > > to w1.yaml - I am not quite sure, so I add an excerpt of my attempt. > > The example in w1.txt builds fine. Is oneOf allowed as a top-level > > property, the documentation only mentions allOf? > > Only one child should be allowed, but I did not find a way to restrict > > this. > > > > # w1-uart.yaml: > > unevaluatedProperties: > > $ref: w1.yaml > > > > # w1.yaml: > > properties: > > compatible: > > enum: > > - maxim,ds2760 > > w1 describes entire class of the devices, so it should not have > compatibles. Look how other buses do it. Thanks for the hint, looked at serial.yaml and usb.yaml. Hence w1.yaml should describe the properties common to all w1 bus controllers (property for child device) and w1-uart.yaml references it in allOf, like: # w1.yaml patternProperties: ".*": if: type: object then: description: Devices are listed... properties: compatible: required: - compatible additionalProperties: true # w1-uart.yaml allOf: - $ref: w1.yaml# unevaluatedProperties: false Kind regards, Christoph
On 14/01/2024 15:47, Christoph Winklhofer wrote: > On Sun, Jan 14, 2024 at 11:54:48AM +0100, Krzysztof Kozlowski wrote: >> On 13/01/2024 19:04, Christoph Winklhofer wrote: >>> On Fri, Jan 12, 2024 at 07:39:17PM -0600, Rob Herring wrote: >>>> On Sat, Jan 06, 2024 at 05:02:24PM +0100, Christoph Winklhofer wrote: >>>>> Add device tree binding for UART 1-Wire bus. >>>>> >>>>> Signed-off-by: Christoph Winklhofer <cj.winklhofer@gmail.com> >>>>> --- >>>>> Documentation/devicetree/bindings/w1/w1-uart.yaml | 62 +++++++++++++++++++++++ >>>>> 1 file changed, 62 insertions(+) >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml >>>>> new file mode 100644 >>>>> index 000000000000..6b90693b2ca0 >>>>> --- /dev/null >>>>> +++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml >>>>> @@ -0,0 +1,62 @@ >>>>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause >>>>> +%YAML 1.2 >>>>> +--- >>>>> +$id: http://devicetree.org/schemas/w1/w1-uart.yaml# >>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>> ... >>>>> +properties: >>>>> + compatible: >>>>> + const: w1-uart >>>>> + >>>>> + reset-speed: >>>>> + $ref: /schemas/types.yaml#/definitions/uint32 >>>>> + default: 9600 >>>>> + description: | >>>> >>>> Don't need '|' if no formatting >>>> >>> >>> Ok. >>> >>>>> + The baud rate for the 1-Wire reset and presence detect. >>>>> + >>>>> + touch_0-speed: >>>> >>>> Don't use '_' in property names. >>>> >>>> I'm somewhat familar with 1-wire, but I don't get what 'touch' means >>>> here. I assume these are low and high times which are a function of the >>>> baudrate. >>>> >>> >>> I change the name to 'write-0-speed' and 'write-1-speed'. The function >>> in the w1-framework is named 'touch_bit' - therefore the previous >>> naming. >>> >>> It is the baud-rate used in the 1-Wire cycle to write a 0-Bit >>> (write-0-speed) and to perform a 1-Wire cycle that writes a 1-Bit and >>> reads a 0-Bit or 1-Bit (write-1-speed). >> >> >> Then probably -bps: >> https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml > > The serial.yaml uses prefix -speed for the baud rate but I can change it > to -bps. Do you reference serial.yaml? > Best regards, Krzysztof
On Sun, Jan 14, 2024 at 04:55:42PM +0100, Krzysztof Kozlowski wrote: > On 14/01/2024 15:47, Christoph Winklhofer wrote: > > On Sun, Jan 14, 2024 at 11:54:48AM +0100, Krzysztof Kozlowski wrote: > >> On 13/01/2024 19:04, Christoph Winklhofer wrote: > >>> On Fri, Jan 12, 2024 at 07:39:17PM -0600, Rob Herring wrote: > >>>> On Sat, Jan 06, 2024 at 05:02:24PM +0100, Christoph Winklhofer wrote: > >>>>> Add device tree binding for UART 1-Wire bus. > >>>>> > >>>>> Signed-off-by: Christoph Winklhofer <cj.winklhofer@gmail.com> > >>>>> --- > >>>>> Documentation/devicetree/bindings/w1/w1-uart.yaml | 62 +++++++++++++++++++++++ > >>>>> 1 file changed, 62 insertions(+) > >>>>> > >>>>> diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml > >>>>> new file mode 100644 > >>>>> index 000000000000..6b90693b2ca0 > >>>>> --- /dev/null > >>>>> +++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml > >>>>> @@ -0,0 +1,62 @@ > >>>>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause > >>>>> +%YAML 1.2 > >>>>> +--- > >>>>> +$id: http://devicetree.org/schemas/w1/w1-uart.yaml# > >>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# > >>> ... > >>>>> +properties: > >>>>> + compatible: > >>>>> + const: w1-uart > >>>>> + > >>>>> + reset-speed: > >>>>> + $ref: /schemas/types.yaml#/definitions/uint32 > >>>>> + default: 9600 > >>>>> + description: | > >>>> > >>>> Don't need '|' if no formatting > >>>> > >>> > >>> Ok. > >>> > >>>>> + The baud rate for the 1-Wire reset and presence detect. > >>>>> + > >>>>> + touch_0-speed: > >>>> > >>>> Don't use '_' in property names. > >>>> > >>>> I'm somewhat familar with 1-wire, but I don't get what 'touch' means > >>>> here. I assume these are low and high times which are a function of the > >>>> baudrate. > >>>> > >>> > >>> I change the name to 'write-0-speed' and 'write-1-speed'. The function > >>> in the w1-framework is named 'touch_bit' - therefore the previous > >>> naming. > >>> > >>> It is the baud-rate used in the 1-Wire cycle to write a 0-Bit > >>> (write-0-speed) and to perform a 1-Wire cycle that writes a 1-Bit and > >>> reads a 0-Bit or 1-Bit (write-1-speed). > >> > >> > >> Then probably -bps: > >> https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml > > > > The serial.yaml uses prefix -speed for the baud rate but I can change it > > to -bps. > > Do you reference serial.yaml? > No, serial.yaml is not referenced but 'onewire' will be a child-node of a serial-device which already defines baud rate related properties with -speed (e.g. max-speed although not used in w1-uart). Hence, I thought -speed is typically used for baud rates. Thanks, Christoph
On 15/01/2024 18:36, Christoph Winklhofer wrote: > On Sun, Jan 14, 2024 at 04:55:42PM +0100, Krzysztof Kozlowski wrote: >> On 14/01/2024 15:47, Christoph Winklhofer wrote: >>> On Sun, Jan 14, 2024 at 11:54:48AM +0100, Krzysztof Kozlowski wrote: >>>> On 13/01/2024 19:04, Christoph Winklhofer wrote: >>>>> On Fri, Jan 12, 2024 at 07:39:17PM -0600, Rob Herring wrote: >>>>>> On Sat, Jan 06, 2024 at 05:02:24PM +0100, Christoph Winklhofer wrote: >>>>>>> Add device tree binding for UART 1-Wire bus. >>>>>>> >>>>>>> Signed-off-by: Christoph Winklhofer <cj.winklhofer@gmail.com> >>>>>>> --- >>>>>>> Documentation/devicetree/bindings/w1/w1-uart.yaml | 62 +++++++++++++++++++++++ >>>>>>> 1 file changed, 62 insertions(+) >>>>>>> >>>>>>> diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml >>>>>>> new file mode 100644 >>>>>>> index 000000000000..6b90693b2ca0 >>>>>>> --- /dev/null >>>>>>> +++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml >>>>>>> @@ -0,0 +1,62 @@ >>>>>>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause >>>>>>> +%YAML 1.2 >>>>>>> +--- >>>>>>> +$id: http://devicetree.org/schemas/w1/w1-uart.yaml# >>>>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>>>> ... >>>>>>> +properties: >>>>>>> + compatible: >>>>>>> + const: w1-uart >>>>>>> + >>>>>>> + reset-speed: >>>>>>> + $ref: /schemas/types.yaml#/definitions/uint32 >>>>>>> + default: 9600 >>>>>>> + description: | >>>>>> >>>>>> Don't need '|' if no formatting >>>>>> >>>>> >>>>> Ok. >>>>> >>>>>>> + The baud rate for the 1-Wire reset and presence detect. >>>>>>> + >>>>>>> + touch_0-speed: >>>>>> >>>>>> Don't use '_' in property names. >>>>>> >>>>>> I'm somewhat familar with 1-wire, but I don't get what 'touch' means >>>>>> here. I assume these are low and high times which are a function of the >>>>>> baudrate. >>>>>> >>>>> >>>>> I change the name to 'write-0-speed' and 'write-1-speed'. The function >>>>> in the w1-framework is named 'touch_bit' - therefore the previous >>>>> naming. >>>>> >>>>> It is the baud-rate used in the 1-Wire cycle to write a 0-Bit >>>>> (write-0-speed) and to perform a 1-Wire cycle that writes a 1-Bit and >>>>> reads a 0-Bit or 1-Bit (write-1-speed). >>>> >>>> >>>> Then probably -bps: >>>> https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml >>> >>> The serial.yaml uses prefix -speed for the baud rate but I can change it >>> to -bps. >> >> Do you reference serial.yaml? >> > > No, serial.yaml is not referenced but 'onewire' will be a child-node of > a serial-device which already defines baud rate related properties > with -speed (e.g. max-speed although not used in w1-uart). Hence, I > thought -speed is typically used for baud rates. Ah, it defines max-speed for childre, so for onewire. Re-using that property would make sense, but since you are defining completely new properties, let's use proper (-bps) naming. I still wonder, why would you use different baud rates for these three different operations? Best regards, Krzysztof
diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml new file mode 100644 index 000000000000..6b90693b2ca0 --- /dev/null +++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml @@ -0,0 +1,62 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/w1/w1-uart.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: UART 1-Wire Bus + +maintainers: + - Christoph Winklhofer <cj.winklhofer@gmail.com> + +description: | + UART 1-wire bus. Utilizes the UART interface via the Serial Device Bus + to create the 1-Wire timing patterns. + + The UART peripheral must support full-duplex and operate in open-drain + mode. The timing patterns are generated by a specific combination of + baud-rate and transmitted byte, which corresponds to a 1-Wire read bit, + write bit or reset pulse. + + The default baud-rate for reset and presence detection is 9600 and for + a 1-Wire read or write operation 115200. In case the actual baud-rate + is different from the requested one, the transmitted byte is adapted + to generate the 1-Wire timing patterns. + + https://www.analog.com/en/technical-articles/using-a-uart-to-implement-a-1wire-bus-master.html + + +properties: + compatible: + const: w1-uart + + reset-speed: + $ref: /schemas/types.yaml#/definitions/uint32 + default: 9600 + description: | + The baud rate for the 1-Wire reset and presence detect. + + touch_0-speed: + $ref: /schemas/types.yaml#/definitions/uint32 + default: 115200 + description: | + The baud rate for the 1-Wire write-0 cycle (touch bit 0). + + touch_1-speed: + $ref: /schemas/types.yaml#/definitions/uint32 + default: 115200 + description: | + The baud rate for the 1-Wire write-1 and read cycle (touch bit 1). + +required: + - compatible + +additionalProperties: false + +examples: + - | + serial { + onewire { + compatible = "w1-uart"; + }; + };