Add documentation for ltc2664.
Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
---
.../bindings/iio/dac/adi,ltc2664.yaml | 167 ++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 168 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
new file mode 100644
index 000000000000..517a96808ee0
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
@@ -0,0 +1,167 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/dac/adi,ltc2664.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices LTC2664 DAC
+
+maintainers:
+ - Michael Hennerich <michael.hennerich@analog.com>
+ - Kim Seer Paller <kimseer.paller@analog.com>
+
+description: |
+ Analog Devices LTC2664 4 channel, 16 bit, +-10V DAC
+ https://www.analog.com/media/en/technical-documentation/data-sheets/2664fa.pdf
+
+properties:
+ compatible:
+ enum:
+ - adi,ltc2664
+
+ reg:
+ maxItems: 1
+
+ spi-max-frequency:
+ maximum: 50000000
+
+ vcc-supply:
+ description: Analog Supply Voltage Input.
+
+ v-pos-supply:
+ description: Positive Supply Voltage Input.
+
+ v-neg-supply:
+ description: Negative Supply Voltage Input.
+
+ iovcc-supply:
+ description: Digital Input/Output Supply Voltage.
+
+ ref-supply:
+ description:
+ Reference Input/Output. The voltage at the REF pin sets the full-scale
+ range of all channels. If not provided the internal reference is used and
+ also provided on the VREF pin.
+
+ clr-gpios:
+ description:
+ Active-low Asynchronous Clear Input. A logic low at this level-triggered
+ input clears the part to the reset code and range determined by the
+ hardwired option chosen using the MSPAN pins. The control registers are
+ cleared to zero.
+ maxItems: 1
+
+ adi,manual-span-operation-config:
+ description:
+ This property must mimic the MSPAN pin configurations. By tying the MSPAN
+ pins (MSP2, MSP1 and MSP0) to GND and/or VCC, any output range can be
+ hardware-configured with different mid-scale or zero-scale reset options.
+ The hardware configuration is latched during power on reset for proper
+ operation.
+ 0 - MPS2=GND, MPS1=GND, MSP0=GND
+ 1 - MPS2=GND, MPS1=GND, MSP0=VCC
+ 2 - MPS2=GND, MPS1=VCC, MSP0=GND
+ 3 - MPS2=GND, MPS1=VCC, MSP0=VCC
+ 4 - MPS2=VCC, MPS1=GND, MSP0=GND
+ 5 - MPS2=VCC, MPS1=GND, MSP0=VCC
+ 6 - MPS2=VCC, MPS1=VCC, MSP0=GND
+ 7 - MPS2=VCC, MPS1=VCC, MSP0=VCC (enables SoftSpan feature)
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [0, 1, 2, 3, 4, 5, 6, 7]
+ default: 7
+
+ io-channels:
+ description:
+ Analog multiplexer output. VOUT0-VOUT3, MUXIN0-MUXIN3, REFLO, REF, V+, V-,
+ and a temperature monitor output can be internally routed to the MUXOUT pin.
+
+ '#address-cells':
+ const: 1
+
+ '#size-cells':
+ const: 0
+
+patternProperties:
+ "^channel@[0-3]$":
+ type: object
+ additionalProperties: false
+
+ properties:
+ reg:
+ description: The channel number representing the DAC output channel.
+ maximum: 3
+
+ adi,toggle-mode:
+ description:
+ Set the channel as a toggle enabled channel. Toggle operation enables
+ fast switching of a DAC output between two different DAC codes without
+ any SPI transaction.
+ type: boolean
+
+ adi,output-range-microvolt:
+ description: Specify the channel output full scale range.
+ oneOf:
+ - items:
+ - const: 0
+ - enum: [5000000, 10000000]
+ - items:
+ - const: -5000000
+ - const: 5000000
+ - items:
+ - const: -10000000
+ - const: 10000000
+ - items:
+ - const: -2500000
+ - const: 2500000
+
+ required:
+ - reg
+ - adi,output-range-microvolt
+
+required:
+ - compatible
+ - reg
+ - spi-max-frequency
+ - vcc-supply
+ - iovcc-supply
+ - v-pos-supply
+ - v-neg-supply
+
+allOf:
+ - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+additionalProperties: false
+
+examples:
+ - |
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ dac@0 {
+ compatible = "adi,ltc2664";
+ reg = <0>;
+ spi-max-frequency = <10000000>;
+
+ vcc-supply = <&vcc>;
+ iovcc-supply = <&vcc>;
+ ref-supply = <&vref>;
+ v-pos-supply = <&vpos>;
+ v-neg-supply = <&vneg>;
+
+ io-channels = <&adc 0>;
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+ channel@0 {
+ reg = <0>;
+ adi,toggle-mode;
+ adi,output-range-microvolt = <(-10000000) 10000000>;
+ };
+
+ channel@1 {
+ reg = <1>;
+ adi,output-range-microvolt = <0 10000000>;
+ };
+ };
+ };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index b3be54c09159..7becbdf7d1df 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12857,6 +12857,7 @@ L: linux-iio@vger.kernel.org
S: Supported
W: https://ez.analog.com/linux-software-drivers
F: Documentation/ABI/testing/sysfs-bus-iio-dac
+F: Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
LTC2688 IIO DAC DRIVER
M: Nuno Sá <nuno.sa@analog.com>
--
2.34.1
A few comments inline.
> + adi,manual-span-operation-config:
> + description:
> + This property must mimic the MSPAN pin configurations. By tying the MSPAN
> + pins (MSP2, MSP1 and MSP0) to GND and/or VCC, any output range can be
> + hardware-configured with different mid-scale or zero-scale reset options.
> + The hardware configuration is latched during power on reset for proper
> + operation.
> + 0 - MPS2=GND, MPS1=GND, MSP0=GND
> + 1 - MPS2=GND, MPS1=GND, MSP0=VCC
> + 2 - MPS2=GND, MPS1=VCC, MSP0=GND
> + 3 - MPS2=GND, MPS1=VCC, MSP0=VCC
> + 4 - MPS2=VCC, MPS1=GND, MSP0=GND
> + 5 - MPS2=VCC, MPS1=GND, MSP0=VCC
> + 6 - MPS2=VCC, MPS1=VCC, MSP0=GND
> + 7 - MPS2=VCC, MPS1=VCC, MSP0=VCC (enables SoftSpan feature)
Could you add to the description to say what results of the entries are
(like you have done for 7)
e.g.
0 - MSP2=GND, MPS1=GND, MSP0=GND (+-10V, reset to 0V)
at least I think that's what reset to mid scale means.
This seems like a reasonable level of information to convey here.
I was going to suggest making this a 3 value array, but that would
make ti hard to add such docs, so perhaps what you have here
is the right approach.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [0, 1, 2, 3, 4, 5, 6, 7]
> + default: 7
> +
> + io-channels:
> + description:
> + Analog multiplexer output. VOUT0-VOUT3, MUXIN0-MUXIN3, REFLO, REF, V+, V-,
> + and a temperature monitor output can be internally routed to the MUXOUT pin.
> +
That's a little confusing. What you are specifying here is the ADC
channels that is connected to. This description sort of suggests it's about
what is routed there.
On 23/05/2024 05:19, Kim Seer Paller wrote: > Add documentation for ltc2664. > > + > + ref-supply: > + description: > + Reference Input/Output. The voltage at the REF pin sets the full-scale > + range of all channels. If not provided the internal reference is used and > + also provided on the VREF pin. > + > + clr-gpios: > + description: > + Active-low Asynchronous Clear Input. A logic low at this level-triggered > + input clears the part to the reset code and range determined by the > + hardwired option chosen using the MSPAN pins. The control registers are > + cleared to zero. So this is a reset gpio? > + maxItems: 1 > + > + adi,manual-span-operation-config: > + description: > + This property must mimic the MSPAN pin configurations. By tying the MSPAN > + pins (MSP2, MSP1 and MSP0) to GND and/or VCC, any output range can be > + hardware-configured with different mid-scale or zero-scale reset options. > + The hardware configuration is latched during power on reset for proper > + operation. > + 0 - MPS2=GND, MPS1=GND, MSP0=GND > + 1 - MPS2=GND, MPS1=GND, MSP0=VCC > + 2 - MPS2=GND, MPS1=VCC, MSP0=GND > + 3 - MPS2=GND, MPS1=VCC, MSP0=VCC > + 4 - MPS2=VCC, MPS1=GND, MSP0=GND > + 5 - MPS2=VCC, MPS1=GND, MSP0=VCC > + 6 - MPS2=VCC, MPS1=VCC, MSP0=GND > + 7 - MPS2=VCC, MPS1=VCC, MSP0=VCC (enables SoftSpan feature) > + $ref: /schemas/types.yaml#/definitions/uint32 > + enum: [0, 1, 2, 3, 4, 5, 6, 7] > + default: 7 > + > + io-channels: > + description: > + Analog multiplexer output. VOUT0-VOUT3, MUXIN0-MUXIN3, REFLO, REF, V+, V-, That's not output but input. > + and a temperature monitor output can be internally routed to the MUXOUT pin. Needs maxItems > + > + '#address-cells': > + const: 1 > + > + '#size-cells': > + const: 0 > + Best regards, Krzysztof
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