Hi Jonathan,
On Sun, 11 Oct 2020 18:07:40 +0100
Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
>
> I'm not sure vdd-supply absolutely has to be provided if vref-supply
> is, but as the previous binding docs stated it was required it seems
> reasonable to leave it as such.
Good catch. Vdd is useless on MCP4726 if Vref is specified. The driver
requires Vdd...
How to proceed there?
Thanks,
Tomas
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Cc: Tomas Novotny <tomas@xxxxxxxxxx>
> ---
> .../devicetree/bindings/iio/dac/mcp4725.txt | 35 ---------
> .../bindings/iio/dac/microchip,mcp4725.yaml | 71 +++++++++++++++++++
> 2 files changed, 71 insertions(+), 35 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/iio/dac/mcp4725.txt b/Documentation/devicetree/bindings/iio/dac/mcp4725.txt
> deleted file mode 100644
> index 1bc6c093fbfe..000000000000
> --- a/Documentation/devicetree/bindings/iio/dac/mcp4725.txt
> +++ /dev/null
> @@ -1,35 +0,0 @@
> -Microchip mcp4725 and mcp4726 DAC device driver
> -
> -Required properties:
> - - compatible: Must be "microchip,mcp4725" or "microchip,mcp4726"
> - - reg: Should contain the DAC I2C address
> - - vdd-supply: Phandle to the Vdd power supply. This supply is used as a
> - voltage reference on mcp4725. It is used as a voltage reference on
> - mcp4726 if there is no vref-supply specified.
> -
> -Optional properties (valid only for mcp4726):
> - - vref-supply: Optional phandle to the Vref power supply. Vref pin is
> - used as a voltage reference when this supply is specified.
> - - microchip,vref-buffered: Boolean to enable buffering of the external
> - Vref pin. This boolean is not valid without the vref-supply. Quoting
> - the datasheet: This is offered in cases where the reference voltage
> - does not have the current capability not to drop its voltage when
> - connected to the internal resistor ladder circuit.
> -
> -Examples:
> -
> - /* simple mcp4725 */
> - mcp4725@60 {
> - compatible = "microchip,mcp4725";
> - reg = <0x60>;
> - vdd-supply = <&vdac_vdd>;
> - };
> -
> - /* mcp4726 with the buffered external reference voltage */
> - mcp4726@60 {
> - compatible = "microchip,mcp4726";
> - reg = <0x60>;
> - vdd-supply = <&vdac_vdd>;
> - vref-supply = <&vdac_vref>;
> - microchip,vref-buffered;
> - };
> diff --git a/Documentation/devicetree/bindings/iio/dac/microchip,mcp4725.yaml b/Documentation/devicetree/bindings/iio/dac/microchip,mcp4725.yaml
> new file mode 100644
> index 000000000000..271998610ceb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/microchip,mcp4725.yaml
> @@ -0,0 +1,71 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/dac/microchip,mcp4725.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Microchip mcp4725 and mcp4726 DAC
> +
> +maintainers:
> + - Tomas Novotny <tomas@xxxxxxxxxx>
> +
> +properties:
> + compatible:
> + enum:
> + - microchip,mcp4725
> + - microchip,mcp4726
> +
> + reg:
> + maxItems: 1
> +
> + vdd-supply:
> + description: |
> + Provides both power and acts as the reference supply on the mcp4725.
> + For the mcp4726 it will be used as the reference voltage if vref-supply
> + is not provided.
> +
> + vref-supply:
> + description:
> + Vref pin is used as a voltage reference when this supply is specified.
> +
> + microchip,vref-buffered:
> + type: boolean
> + description: |
> + Enable buffering of the external Vref pin. This boolean is not valid
> + without the vref-supply. Quoting the datasheet: This is offered in
> + cases where the reference voltage does not have the current
> + capability not to drop its voltage when connected to the internal
> + resistor ladder circuit.
> +
> +allOf:
> + - if:
> + not:
> + properties:
> + compatible:
> + contains:
> + const: microchip,mcp4726
> + then:
> + properties:
> + vref-supply: false
> + microchip,vref-buffered: false
> +
> +required:
> + - compatible
> + - reg
> + - vdd-supply
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + mcp4725@60 {
> + compatible = "microchip,mcp4725";
> + reg = <0x60>;
> + vdd-supply = <&vdac_vdd>;
> + };
> + };
> +...
