[PATCH v3] dt-bindings: pwm: st,pwm: convert to DT schema

From: Charan Pedumuru

Date: Thu Jun 25 2026 - 06:49:53 EST


Convert STMicroelectronics STiH41x PWM/Capture controller binding
to DT schema.
Changes during conversion:
- Fix compatible string from "st,pwm" to "st,sti-pwm" to match the
actual hardware variant naming convention used across STi bindings.
- Drop pinctrl-names from the required list as pinctrl properties are
inherited and validated by the pinctrl schema.

Signed-off-by: Charan Pedumuru <charan.pedumuru@xxxxxxxxx>
---
Changes in v3:
- Fix compatible to "st,sti-pwm".
- Drop pinctrl-names from required.
- Modify the commit message to explain the changes made.
- Change maintainer to "Lee Jones <lee.jones@xxxxxxxxxx>".
- Link to v2: https://patch.msgid.link/20260618-st-pwm-v2-1-c792d5795ce2@xxxxxxxxx

Changes in v2:
- Add the missing interrupts to the required following the old binding.
- Modify the commit message to explain the changes made.
- Link to v1: https://patch.msgid.link/20260613-st-pwm-v1-1-458c2c89709a@xxxxxxxxx
---
Documentation/devicetree/bindings/pwm/pwm-st.txt | 43 ----------
.../devicetree/bindings/pwm/st,sti-pwm.yaml | 92 ++++++++++++++++++++++
2 files changed, 92 insertions(+), 43 deletions(-)

diff --git a/Documentation/devicetree/bindings/pwm/pwm-st.txt b/Documentation/devicetree/bindings/pwm/pwm-st.txt
deleted file mode 100644
index 19fce774cafa..000000000000
--- a/Documentation/devicetree/bindings/pwm/pwm-st.txt
+++ /dev/null
@@ -1,43 +0,0 @@
-STMicroelectronics PWM driver bindings
---------------------------------------
-
-Required parameters:
-- compatible : "st,pwm"
-- #pwm-cells : Number of cells used to specify a PWM. First cell
- specifies the per-chip index of the PWM to use and the
- second cell is the period in nanoseconds - fixed to 2
- for STiH41x.
-- reg : Physical base address and length of the controller's
- registers.
-- pinctrl-names: Set to "default".
-- pinctrl-0: List of phandles pointing to pin configuration nodes
- for PWM module.
- For Pinctrl properties, please refer to [1].
-- clock-names: Valid entries are "pwm" and/or "capture".
-- clocks: phandle of the clock used by the PWM module.
- For Clk properties, please refer to [2].
-- interrupts: IRQ for the Capture device
-
-Optional properties:
-- st,pwm-num-chan: Number of available PWM channels. Default is 0.
-- st,capture-num-chan: Number of available Capture channels. Default is 0.
-
-[1] Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
-[2] Documentation/devicetree/bindings/clock/clock-bindings.txt
-
-Example:
-
-pwm1: pwm@fe510000 {
- compatible = "st,pwm";
- reg = <0xfe510000 0x68>;
- #pwm-cells = <2>;
- pinctrl-names = "default";
- pinctrl-0 = <&pinctrl_pwm1_chan0_default
- &pinctrl_pwm1_chan1_default
- &pinctrl_pwm1_chan2_default
- &pinctrl_pwm1_chan3_default>;
- clocks = <&clk_sysin>;
- clock-names = "pwm";
- st,pwm-num-chan = <4>;
- st,capture-num-chan = <2>;
-};
diff --git a/Documentation/devicetree/bindings/pwm/st,sti-pwm.yaml b/Documentation/devicetree/bindings/pwm/st,sti-pwm.yaml
new file mode 100644
index 000000000000..c69073e79ce9
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/st,sti-pwm.yaml
@@ -0,0 +1,92 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/st,sti-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: STMicroelectronics STiH41x PWM/Capture controller
+
+maintainers:
+ - Lee Jones <lee.jones@xxxxxxxxxx>
+
+description:
+ The STiH41x PWM controller supports both PWM output and input capture
+ functionality. It provides multiple PWM output channels for generating
+ variable duty-cycle waveforms, and multiple input capture channels for
+ measuring external signal periods and pulse widths. PWM output channels
+ and input capture channels are configured independently via
+ st,pwm-num-chan and st,capture-num-chan respectively.
+
+allOf:
+ - $ref: pwm.yaml#
+
+properties:
+ compatible:
+ const: st,sti-pwm
+
+ reg:
+ maxItems: 1
+
+ "#pwm-cells":
+ const: 2
+
+ pinctrl-names:
+ const: default
+
+ clock-names:
+ items:
+ enum: [pwm, capture]
+ minItems: 1
+ maxItems: 2
+
+ clocks:
+ minItems: 1
+ maxItems: 2
+
+ interrupts:
+ description: IRQ line for the capture device.
+ maxItems: 1
+
+ st,pwm-num-chan:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Number of available PWM output channels.
+ minimum: 0
+ maximum: 4
+ default: 0
+
+ st,capture-num-chan:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Number of available input capture channels.
+ minimum: 0
+ maximum: 4
+ default: 0
+
+required:
+ - reg
+ - compatible
+ - "#pwm-cells"
+ - clock-names
+ - clocks
+ - interrupts
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ pwm@fe510000 {
+ compatible = "st,pwm";
+ reg = <0xfe510000 0x68>;
+ interrupts = <GIC_SPI 128 IRQ_TYPE_LEVEL_HIGH>;
+ #pwm-cells = <2>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_pwm1_chan0_default
+ &pinctrl_pwm1_chan1_default
+ &pinctrl_pwm1_chan2_default
+ &pinctrl_pwm1_chan3_default>;
+ clocks = <&clk_sysin>;
+ clock-names = "pwm";
+ st,pwm-num-chan = <4>;
+ st,capture-num-chan = <2>;
+ };
+...

---
base-commit: c425609d6ac4012c8bbf01ec2e10e801b1923a7b
change-id: 20260613-st-pwm-1feade6cfea3

Best regards,
--
Charan Pedumuru <charan.pedumuru@xxxxxxxxx>