[PATCH v2 - dt-bindings: maxim-ds1302: Convert to dt schema v2] dt-bindings: maxim-ds1302: Convert to dt schema

[PATCH v2 - dt-bindings: maxim-ds1302: Convert to dt schema v2] dt-bindings: maxim-ds1302: Convert to dt schema

[Sudheendra Sampath]

Convert Maxim DS1302 real-time clock binding to DT schema.
Changes based on code review comments.

Signed-off-by: Sudheendra Sampath <giveback4fun@gmail.com>
---
 .../devicetree/bindings/rtc/maxim-ds1302.txt  | 46 -----------------
 .../devicetree/bindings/rtc/maxim-ds1302.yaml | 50 +++++++++++++++++++
 2 files changed, 50 insertions(+), 46 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/rtc/maxim-ds1302.txt
 create mode 100644 Documentation/devicetree/bindings/rtc/maxim-ds1302.yaml

diff --git a/Documentation/devicetree/bindings/rtc/maxim-ds1302.txt b/Documentation/devicetree/bindings/rtc/maxim-ds1302.txt
deleted file mode 100644
index ba470c56cdec..000000000000
--- a/Documentation/devicetree/bindings/rtc/maxim-ds1302.txt
+++ /dev/null
@@ -1,46 +0,0 @@
-* Maxim/Dallas Semiconductor DS-1302 RTC
-
-Simple device which could be used to store date/time between reboots.
-
-The device uses the standard MicroWire half-duplex transfer timing.
-Master output is set on low clock and sensed by the RTC on the rising
-edge. Master input is set by the RTC on the trailing edge and is sensed
-by the master on low clock.
-
-Required properties:
-
-- compatible : Should be "maxim,ds1302"
-
-Required SPI properties:
-
-- reg : Should be address of the device chip select within
-  the controller.
-
-- spi-max-frequency : DS-1302 has 500 kHz if powered at 2.2V,
-  and 2MHz if powered at 5V.
-
-- spi-3wire : The device has a shared signal IN/OUT line.
-
-- spi-lsb-first : DS-1302 requires least significant bit first
-  transfers.
-
-- spi-cs-high: DS-1302 has active high chip select line. This is
-  required unless inverted in hardware.
-
-Example:
-
-spi@901c {
-	#address-cells = <1>;
-	#size-cells = <0>;
-	compatible = "icpdas,lp8841-spi-rtc";
-	reg = <0x901c 0x1>;
-
-	rtc@0 {
-		compatible = "maxim,ds1302";
-		reg = <0>;
-		spi-max-frequency = <500000>;
-		spi-3wire;
-		spi-lsb-first;
-		spi-cs-high;
-	};
-};
diff --git a/Documentation/devicetree/bindings/rtc/maxim-ds1302.yaml b/Documentation/devicetree/bindings/rtc/maxim-ds1302.yaml
new file mode 100644
index 000000000000..54a2fcf7f8e7
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/maxim-ds1302.yaml
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/maxim-ds1302.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Maxim/Dallas Semiconductor DS-1302 RTC
+
+maintainers:
+  - Alexandre Belloni <alexandre.belloni@bootlin.com>
+  - Sergey Yanovich <ynvich@gmail.com>
+
+description: |
+  Simple device which could be used to store date/time between reboots.
+
+  The device uses the standard MicroWire half-duplex transfer timing.
+  Master output is set on low clock and sensed by the RTC on the rising
+  edge. Master input is set by the RTC on the trailing edge and is sensed
+  by the master on low clock.
+
+properties:
+  compatible:
+    items:
+      - const: maxim,ds1302
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: DS-1302 has 500 kHz if powered at 2.2V, and 2MHz if powered at 5V
+    enum:
+      - 500000
+      - 2000000
+
+  spi-3wire: true
+
+  spi-lsb-first: true
+
+  spi-cs-high: true
+
+required:
+  - compatible
+  - reg
+  - spi-max-frequency
+  - spi-3wire
+  - spi-lsb-first
+  - spi-cs-high
+
+additionalProperties: false
-- 
2.47.3

Re: [PATCH v2 - dt-bindings: maxim-ds1302: Convert to dt schema v2] dt-bindings: maxim-ds1302: Convert to dt schema

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 4 potential issue(s) to consider:
- [Medium] spi-max-frequency is incorrectly restricted to an enum of exact values, preventing valid lower frequencies.
- [Medium] spi-cs-high is unconditionally required, breaking setups with inverted hardware CS.
- [Medium] The binding defines an SPI peripheral and RTC but fails to reference standard core schemas.
- [Low] The YAML conversion silently removes the device tree example section.
--

commit 4b0cc4e2d5ae6befdb10a7457cde3f6698ee83c7
Author: Sudheendra Sampath <giveback4fun@gmail.com>

dt-bindings: maxim-ds1302: Convert to dt schema

This commit converts the Maxim DS1302 real-time clock text binding to the DT
schema format based on code review comments.

> diff --git a/Documentation/devicetree/bindings/rtc/maxim-ds1302.yaml b/Documentation/devicetree/bindings/rtc/maxim-ds1302.yaml
> new file mode 100644
> index 0000000000000..54a2fcf7f8e7b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/maxim-ds1302.yaml
> @@ -0,0 +1,50 @@
[ ... ]
> +  spi-max-frequency:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: DS-1302 has 500 kHz if powered at 2.2V, and 2MHz if powered at 5V
> +    enum:
> +      - 500000
> +      - 2000000

[Severity: Medium]
Does this restrict spi-max-frequency too strictly? Schema validation might
fail for perfectly valid device trees that specify frequencies other than
500kHz or 2MHz (e.g., 250000) to ensure signal integrity.

Should this use a constraint like maximum: 2000000 rather than an exact enum?

[ ... ]
> +required:
> +  - compatible
> +  - reg
> +  - spi-max-frequency
> +  - spi-3wire
> +  - spi-lsb-first
> +  - spi-cs-high

[Severity: Medium]
Will this unconditionally require spi-cs-high and break backwards
compatibility for existing setups?

The original text binding noted that this property is required unless inverted
in hardware. Forcing it globally in the required list might reject legitimate
hardware configurations where the chip select is hardware-inverted.

> +
> +additionalProperties: false

[Severity: Medium]
Does additionalProperties: false incorrectly reject standard SPI peripheral
properties here?

If a device tree uses properties like spi-cs-setup-delay-ns or
spi-rx-delay-us, dt_binding_check will throw an error. Should the schema
include references to /schemas/spi/spi-peripheral-props.yaml# and rtc.yaml#,
and then use unevaluatedProperties: false instead to properly inherit standard
capabilities?

[Severity: Low]
Is the examples block missing from the end of the schema file?

The original text file included an example demonstrating node placement.
Without it, dt_binding_check cannot validate the schema against a concrete
instance, and the usage documentation is lost.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260908190137.1168904-1-giveback4fun@gmail.com?part=1

Re: [PATCH v2 - dt-bindings: maxim-ds1302: Convert to dt schema v2] dt-bindings: maxim-ds1302: Convert to dt schema

[Krzysztof Kozlowski]

On Tue, Sep 08, 2026 at 12:01:37PM -0700, Sudheendra Sampath wrote:
> Convert Maxim DS1302 real-time clock binding to DT schema.
> Changes based on code review comments.
> 
> Signed-off-by: Sudheendra Sampath <giveback4fun@gmail.com>
> ---

Your subject PATCH prefix is odd. Please use git format-patch -v2 or b4.


>  .../devicetree/bindings/rtc/maxim-ds1302.txt  | 46 -----------------
>  .../devicetree/bindings/rtc/maxim-ds1302.yaml | 50 +++++++++++++++++++
>  2 files changed, 50 insertions(+), 46 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/rtc/maxim-ds1302.txt
>  create mode 100644 Documentation/devicetree/bindings/rtc/maxim-ds1302.yaml
> 
> diff --git a/Documentation/devicetree/bindings/rtc/maxim-ds1302.txt b/Documentation/devicetree/bindings/rtc/maxim-ds1302.txt
> deleted file mode 100644
> index ba470c56cdec..000000000000
> --- a/Documentation/devicetree/bindings/rtc/maxim-ds1302.txt
> +++ /dev/null
> @@ -1,46 +0,0 @@
> -* Maxim/Dallas Semiconductor DS-1302 RTC
> -
> -Simple device which could be used to store date/time between reboots.
> -
> -The device uses the standard MicroWire half-duplex transfer timing.
> -Master output is set on low clock and sensed by the RTC on the rising
> -edge. Master input is set by the RTC on the trailing edge and is sensed
> -by the master on low clock.
> -
> -Required properties:
> -
> -- compatible : Should be "maxim,ds1302"
> -
> -Required SPI properties:
> -
> -- reg : Should be address of the device chip select within
> -  the controller.
> -
> -- spi-max-frequency : DS-1302 has 500 kHz if powered at 2.2V,
> -  and 2MHz if powered at 5V.
> -
> -- spi-3wire : The device has a shared signal IN/OUT line.
> -
> -- spi-lsb-first : DS-1302 requires least significant bit first
> -  transfers.
> -
> -- spi-cs-high: DS-1302 has active high chip select line. This is
> -  required unless inverted in hardware.
> -
> -Example:
> -
> -spi@901c {
> -	#address-cells = <1>;
> -	#size-cells = <0>;
> -	compatible = "icpdas,lp8841-spi-rtc";
> -	reg = <0x901c 0x1>;
> -
> -	rtc@0 {
> -		compatible = "maxim,ds1302";
> -		reg = <0>;
> -		spi-max-frequency = <500000>;
> -		spi-3wire;
> -		spi-lsb-first;
> -		spi-cs-high;
> -	};
> -};
> diff --git a/Documentation/devicetree/bindings/rtc/maxim-ds1302.yaml b/Documentation/devicetree/bindings/rtc/maxim-ds1302.yaml
> new file mode 100644
> index 000000000000..54a2fcf7f8e7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/maxim-ds1302.yaml

Filename should match compatible.

> @@ -0,0 +1,50 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/rtc/maxim-ds1302.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Maxim/Dallas Semiconductor DS-1302 RTC
> +
> +maintainers:
> +  - Alexandre Belloni <alexandre.belloni@bootlin.com>
> +  - Sergey Yanovich <ynvich@gmail.com>
> +
> +description: |
> +  Simple device which could be used to store date/time between reboots.
> +
> +  The device uses the standard MicroWire half-duplex transfer timing.
> +  Master output is set on low clock and sensed by the RTC on the rising
> +  edge. Master input is set by the RTC on the trailing edge and is sensed
> +  by the master on low clock.
> +
> +properties:
> +  compatible:
> +    items:

No need for items.

> +      - const: maxim,ds1302
> +
> +  reg:
> +    maxItems: 1
> +
> +  spi-max-frequency:
> +    $ref: /schemas/types.yaml#/definitions/uint32

Why do you need the type? Please look at other bindings.

> +    description: DS-1302 has 500 kHz if powered at 2.2V, and 2MHz if powered at 5V
> +    enum:
> +      - 500000
> +      - 2000000
> +
> +  spi-3wire: true
> +
> +  spi-lsb-first: true
> +
> +  spi-cs-high: true
> +
> +required:
> +  - compatible
> +  - reg
> +  - spi-max-frequency
> +  - spi-3wire
> +  - spi-lsb-first
> +  - spi-cs-high
> +
> +additionalProperties: false

Missing example. Please follow standard rules, expressed in writing
bindings and writing schema docs, DTS101 slides or just look how other
people do it. Otherwise explain why doing this differently?

Best regards,
Krzysztof

Re: [PATCH v2 - dt-bindings: maxim-ds1302: Convert to dt schema v2] dt-bindings: maxim-ds1302: Convert to dt schema

[Krzysztof Kozlowski]

On Tue, Sep 08, 2026 at 12:01:37PM -0700, Sudheendra Sampath wrote:
> Convert Maxim DS1302 real-time clock binding to DT schema.
> Changes based on code review comments.
> 
> Signed-off-by: Sudheendra Sampath <giveback4fun@gmail.com>
> ---

Where is changelog?

And more importantly, how did you figure out the address list without
using get_maintainers.pl script?

Please use scripts/get_maintainers.pl to get a list of necessary people
and lists to CC (and consider --no-git-fallback argument, so you will
not CC people just because they made one commit years ago). It might
happen, that command when run on an older kernel, gives you outdated
entries. Therefore please be sure you base your patches on recent Linux
kernel.

Tools like b4 or scripts/get_maintainer.pl provide you proper list of
people, so fix your workflow. Tools might also fail if you work on some
ancient tree (don't, instead use mainline) or work on fork of kernel
(don't, instead use mainline). Just use b4 and everything should be
fine, although remember about 'b4 prep --auto-to-cc' if you added new
patches to the patchset.

Best regards,
Krzysztof