| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <7836f862-5320-4a81-b15b-4ada08e78077@baylibre.com>
Date: Mon, 22 Sep 2025 16:59:17 -0500
From: David Lechner <dlechner@...libre.com>
To: Ariana Lazar <ariana.lazar@...rochip.com>,
Jonathan Cameron <jic23@...nel.org>, Nuno Sá
<nuno.sa@...log.com>, Andy Shevchenko <andy@...nel.org>,
Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>
Cc: linux-iio@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] dt-bindings: iio: dac: adding support for Microchip
MCP47FEB02
On 9/22/25 6:30 AM, Ariana Lazar wrote:
> This is the device tree schema for iio driver for Microchip
> MCP47F(E/V)B(0/1/2)1, MCP47F(E/V)B(0/1/2)2, MCP47F(E/V)B(0/1/2)4 and
> MCP47F(E/V)B(0/1/2)8 series of buffered voltage output Digital-to-Analog
> Converters with nonvolatile or volatile memory and an I2C Interface.
>
> The families support up to 8 output channels.
>
> The devices can be 8-bit, 10-bit and 12-bit.
>
> Signed-off-by: Ariana Lazar <ariana.lazar@...rochip.com>
> ---
> .../bindings/iio/dac/microchip,mcp47feb02.yaml | 305 +++++++++++++++++++++
> MAINTAINERS | 6 +
> 2 files changed, 311 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml b/Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..d05ddafa37540bc1f6b6ce65a466b95913925c10
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml
> @@ -0,0 +1,305 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/dac/microchip,mcp47feb02.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Microchip MCP47F(E/V)B(0/1/2)(1/2/4/8) DAC with I2C Interface Families
> +
> +maintainers:
> + - Ariana Lazar <ariana.lazar@...rochip.com>
> +
> +description: |
> + Datasheet for MCP47FEB01, MCP47FEB11, MCP47FEB21, MCP47FEB02, MCP47FEB12,
> + MCP47FEB22 can be found here:
> + https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005375A.pdf
> + Datasheet for MCP47FVBXX can be found here:
> + https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005405A.pdf
> + Datasheet for MCP47FEB04, MCP47FEB14, MCP47FEB24, MCP47FEB08, MCP47FEB18,
> + MCP47FEB28, MCP47FVB04, MCP47FVB14, MCP47FVB24, MCP47FVB08, MCP47FVB18,
> + MCP47FVB28 can be found here:
> + https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP47FXBX48-Data-Sheet-DS200006368A.pdf
> +
> + +------------+--------------+-------------+-------------+------------+
> + | Device | Resolution | Channels | Vref number | Memory |
> + |------------|--------------|-------------|-------------|------------|
> + | MCP47FEB01 | 8-bit | 1 | 1 | EEPROM |
> + | MCP47FEB11 | 10-bit | 1 | 1 | EEPROM |
> + | MCP47FEB21 | 12-bit | 1 | 1 | EEPROM |
> + |------------|--------------|-------------|-------------|------------|
> + | MCP47FEB02 | 8-bit | 2 | 1 | EEPROM |
> + | MCP47FEB12 | 10-bit | 2 | 1 | EEPROM |
> + | MCP47FEB22 | 12-bit | 2 | 1 | EEPROM |
> + |------------|--------------|-------------|-------------|------------|
> + | MCP47FVB01 | 8-bit | 1 | 1 | RAM |
> + | MCP47FVB11 | 10-bit | 1 | 1 | RAM |
> + | MCP47FVB21 | 12-bit | 1 | 1 | RAM |
> + |------------|--------------|-------------|-------------|------------|
> + | MCP47FVB02 | 8-bit | 2 | 1 | RAM |
> + | MCP47FVB12 | 10-bit | 2 | 1 | RAM |
> + | MCP47FVB22 | 12-bit | 2 | 1 | RAM |
> + |------------|--------------|-------------|-------------|------------|
> + | MCP47FVB04 | 8-bit | 4 | 2 | RAM |
> + | MCP47FVB14 | 10-bit | 4 | 2 | RAM |
> + | MCP47FVB24 | 12-bit | 4 | 2 | RAM |
> + |------------|--------------|-------------|-------------|------------|
> + | MCP47FVB08 | 8-bit | 8 | 2 | RAM |
> + | MCP47FVB18 | 10-bit | 8 | 2 | RAM |
> + | MCP47FVB28 | 12-bit | 8 | 2 | RAM |
> + |------------|--------------|-------------|-------------|------------|
> + | MCP47FEB04 | 8-bit | 4 | 2 | EEPROM |
> + | MCP47FEB14 | 10-bit | 4 | 2 | EEPROM |
> + | MCP47FEB24 | 12-bit | 4 | 2 | EEPROM |
> + |------------|--------------|-------------|-------------|------------|
> + | MCP47FEB08 | 8-bit | 8 | 2 | EEPROM |
> + | MCP47FEB18 | 10-bit | 8 | 2 | EEPROM |
> + | MCP47FEB28 | 12-bit | 8 | 2 | EEPROM |
> + +------------+--------------+-------------+-------------+------------+
> +
> +properties:
> + compatible:
> + enum:
> + - microchip,mcp47feb01
> + - microchip,mcp47feb11
> + - microchip,mcp47feb21
> + - microchip,mcp47feb02
> + - microchip,mcp47feb12
> + - microchip,mcp47feb22
> + - microchip,mcp47fvb01
> + - microchip,mcp47fvb11
> + - microchip,mcp47fvb21
> + - microchip,mcp47fvb02
> + - microchip,mcp47fvb12
> + - microchip,mcp47fvb22
> + - microchip,mcp47fvb04
> + - microchip,mcp47fvb14
> + - microchip,mcp47fvb24
> + - microchip,mcp47fvb08
> + - microchip,mcp47fvb18
> + - microchip,mcp47fvb28
> + - microchip,mcp47feb04
> + - microchip,mcp47feb14
> + - microchip,mcp47feb24
> + - microchip,mcp47feb08
> + - microchip,mcp47feb18
> + - microchip,mcp47feb28
> +
> + reg:
> + maxItems: 1
> +
> + "#address-cells":
> + const: 1
> +
> + "#size-cells":
> + const: 0
> +
> + vdd-supply:
> + description: |
Don't need `|` unless formatting needs to be preserved, like for the table in
the description above or the bullet lists below.
> + Provides power and 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.
> + Into the datasheet it could be found as a Vref0.
> + If it does not exists the internal reference will be used.
It looks like there is also the possibility to use V_DD as the reference
voltage. Not sure the best way to handle that though.
> + This will be used as a reference voltage for the following outputs:
> + - for single-channel device: Vout0;
> + - for dual-channel device: Vout0, Vout1;
> + - for quad-channel device: Vout0, Vout2;
> + - for octal-channel device: Vout0, Vout2, Vout6, Vout8;
> +
> + vref1-supply:
> + description: |
> + Vref1 pin is used as a voltage reference when this supply is specified.
> + If it does not exists the internal reference will be used.
> + This will be used as a reference voltage for the following outputs:
> + - for quad-channel device: Vout1, Vout3;
> + - for octal-channel device: Vout1, Vout3, Vout5, Vout7;
> +
> + lat-gpios:
> + description: |
> + LAT pin to be used as a hardware trigger to synchronously update the DAC
> + channels and the pin is active Low. It could be also found as lat0 in
> + datasheet.
> + maxItems: 1
> +
> + lat1-gpios:
> + description: |
> + LAT1 pin to be used as a hardware trigger to synchronously update the odd
> + DAC channels on devices with 4 and 8 channels. The pin is active Low.
> + maxItems: 1
> +
> + microchip,vref-buffered:
> + type: boolean
> + description: |
> + Enable buffering of the external Vref/Vref0 pin in cases where the
> + external reference voltage does not have sufficient current capability in
> + order not to drop it’s voltage when connected to the internal resistor
> + ladder circuit.
> +
> + microchip,vref1-buffered:
> + type: boolean
> + description: |
> + Enable buffering of the external Vref1 pin in cases where the external
> + reference voltage does not have sufficient current capability in order not
> + to drop it’s voltage when connected to the internal resistor ladder
> + circuit.
> +
> + microchip,output-gain-2x:
> + type: boolean
> + description: |
> +
> +patternProperties:
> + "^channel@[0-7]$":
> + $ref: dac.yaml
> + type: object
> + description: Voltage output channel.
> +
> + properties:
> + reg:
> + description: The channel number.
> + minimum: 1
> + maximum: 7
> +
> + label:
> + description: Unique name to identify which channel this is.
> +
> + required:
> + - reg
> +
> + unevaluatedProperties: false
> +
> +required:
> + - compatible
> + - reg
> + - vdd-supply
> +
> +allOf:
> + - if:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - microchip,mcp47feb01
> + - microchip,mcp47feb11
> + - microchip,mcp47feb21
> + - microchip,mcp47fvb01
> + - microchip,mcp47fvb11
> + - microchip,mcp47fvb21
> + then:
> + properties:
> + lat-gpios: true
> + lat1-gpios: false
> + vref-supply: true
> + vref1-supply: false
> + microchip,vref-buffered: true
Everything is already true, so we can leave out all of those
lines. It make it hard to see what is actually being modified.
> + microchip,vref1-buffered: false
> + patternProperties:
> + "^channel@[1]$":
> + properties:
> + reg:
> + items:
No items: here.
> + maximum: 1
> + "^channel@[2-7]$": false
> + - if:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - microchip,mcp47feb02
> + - microchip,mcp47feb12
> + - microchip,mcp47feb22
> + - microchip,mcp47fvb02
> + - microchip,mcp47fvb12
> + - microchip,mcp47fvb22
> + then:
> + properties:
> + lat-gpios: true
> + lat1-gpios: false
> + vref-supply: true
> + vref1-supply: false
> + microchip,vref-buffered: true
> + microchip,vref1-buffered: false
> + patternProperties:
> + "^channel@[1-2]$":
> + properties:
> + reg:
> + items:
> + maximum: 1
Isn't maximum 2 in this case?
> + "^channel@[3-7]$": false
> + - if:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - microchip,mcp47fvb04
> + - microchip,mcp47fvb14
> + - microchip,mcp47fvb24
> + - microchip,mcp47fvb08
> + - microchip,mcp47fvb18
> + - microchip,mcp47fvb28
> + - microchip,mcp47feb04
> + - microchip,mcp47feb14
> + - microchip,mcp47feb24
> + - microchip,mcp47feb08
> + - microchip,mcp47feb18
> + - microchip,mcp47feb28
Should the 8-channel chips be include here? This
limits the channel@ to 1-4, so that doesn't jive
with having 8 channels.
> + then:
> + properties:
> + lat-gpios: true
> + lat1-gpios: true
> + vref-supply: true
> + vref1-supply: true
> + microchip,vref-buffered: true
> + microchip,vref1-buffered: true
> + patternProperties:
> + "^channel@[1-4]$":
> + properties:
> + reg:
> + items:
> + maximum: 1
And 4 here?
> + "^channel@[5-7]$": false
> + - if:
> + not:
> + required:
> + - vref-supply
> + then:
> + properties:
> + microchip,vref-buffered: false
> + - if:
> + not:
> + required:
> + - vref1-supply
> + then:
> + properties:
> + microchip,vref1-buffered: false
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + i2c {
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> + dac@0 {
> + compatible = "microchip,mcp47feb02";
> + reg = <0>;
> + vdd-supply = <&vdac_vdd>;
> + vref-supply = <&vref_reg>;
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> + channel@0 {
> + reg = <0>;
> + label = "DAC_OUTPUT_0";
These aren't particularly useful labels. It gives
the same info as the register number.
> + };
> +
> + channel@1 {
> + reg = <0x1>;
> + label = "DAC_OUTPUT_1";
> + };
> + };
> + };
> +...
Powered by blists - more mailing lists