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From: florin.leotescu@oss.nxp.com
To: Guenter Roeck <linux@roeck-us.net>, Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Michael Shych <michaelsh@nvidia.com>,
	linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: daniel.baluta@nxp.com, viorel.suman@nxp.com,
	linux-arm-kernel@lists.infradead.org, imx@lists.linux.dev,
	festevam@gmail.com, Florin Leotescu <florin.leotescu@nxp.com>
Subject: [PATCH v7 2/3] dt-bindings: hwmon: emc2305: Add fan-shutdown-percent property
Date: Wed, 29 Apr 2026 09:59:54 +0300	[thread overview]
Message-ID: <20260429065955.2113012-3-florin.leotescu@oss.nxp.com> (raw)
In-Reply-To: <20260429065955.2113012-1-florin.leotescu@oss.nxp.com>

From: Florin Leotescu <florin.leotescu@nxp.com>

The EMC2305 fan controller supports multiple independent PWM fan
outputs. Some systems require fans to enter a defined safe state
during system shutdown or reboot handoff, until firmware or the next
boot stage reconfigures the controller.

Add an optional "fan-shutdown-percent" property to fan child nodes
allowing the PWM duty cycle applied during shutdown to be configured
per fan output.

Signed-off-by: Florin Leotescu <florin.leotescu@nxp.com>
---
 .../devicetree/bindings/hwmon/microchip,emc2305.yaml      | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml b/Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml
index d3f06ebc19fa..8c2548539d7f 100644
--- a/Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml
+++ b/Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml
@@ -54,6 +54,12 @@ patternProperties:
           The fan number used to determine the associated PWM channel.
         maxItems: 1
 
+      fan-shutdown-percent:
+        description:
+          PWM duty cycle in percent applied to the fan during shutdown.
+        minimum: 0
+        maximum: 100
+
     required:
       - reg
 
@@ -80,12 +86,14 @@ examples:
             fan@0 {
                 reg = <0x0>;
                 pwms = <&fan_controller 26000 PWM_POLARITY_INVERTED 1>;
+                fan-shutdown-percent = <100>;
                 #cooling-cells = <2>;
             };
 
             fan@1 {
                 reg = <0x1>;
                 pwms = <&fan_controller 26000 0 1>;
+                fan-shutdown-percent = <50>;
                 #cooling-cells = <2>;
             };
 
-- 
2.34.1


  parent reply	other threads:[~2026-04-29  6:45 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-29  6:59 [PATCH v7 0/3] Support configurable fan PWM at shutdown florin.leotescu
2026-04-29  6:59 ` [PATCH v7 1/3] hwmon: emc2305: Fix fan channel index handling florin.leotescu
2026-04-30 23:13   ` Guenter Roeck
2026-04-29  6:59 ` florin.leotescu [this message]
2026-04-29 18:18   ` [PATCH v7 2/3] dt-bindings: hwmon: emc2305: Add fan-shutdown-percent property Conor Dooley
2026-04-30 12:02     ` Florin Leotescu
2026-04-30 18:53       ` Conor Dooley
2026-04-30 23:14   ` Guenter Roeck
2026-04-29  6:59 ` [PATCH v7 3/3] hwmon: emc2305: Support configurable fan PWM at shutdown florin.leotescu
2026-04-30 23:17   ` Guenter Roeck

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