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From:   Bryan Brattlof <bb@ti.com>
To:     Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
CC:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Amit Kucheria <amitk@kernel.org>,
        Zhang Rui <rui.zhang@intel.com>, Nishanth Menon <nm@ti.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Tero Kristo <kristo@kernel.org>, Keerthy <j-keerthy@ti.com>,
        Linux Thermal <linux-pm@vger.kernel.org>,
        Linux Device Tree <devicetree@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Bryan Brattlof <bb@ti.com>
Subject: [PATCH 05/11] dt-bindings: thermal: k3-j72xx: elaborate on binding descriptions
Date:   Tue, 11 Oct 2022 18:17:21 -0500
Message-ID: <20221011231727.8090-6-bb@ti.com>
In-Reply-To: <20221011231727.8090-1-bb@ti.com>
References: <20221011231727.8090-1-bb@ti.com>
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Elaborate on the function of this device node as well as some of the
properties that this node uses.

Signed-off-by: Bryan Brattlof <bb@ti.com>
---
 .../bindings/thermal/ti,j72xx-thermal.yaml    | 27 ++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/thermal/ti,j72xx-thermal.yaml b/Documentation/devicetree/bindings/thermal/ti,j72xx-thermal.yaml
index c74f124ebfc00..0b6a6fa07a532 100644
--- a/Documentation/devicetree/bindings/thermal/ti,j72xx-thermal.yaml
+++ b/Documentation/devicetree/bindings/thermal/ti,j72xx-thermal.yaml
@@ -9,6 +9,24 @@ title: Texas Instruments J72XX VTM (DTS) binding
 maintainers:
   - Keerthy <j-keerthy@ti.com>
 
+description: |
+  The TI K3 family of SoCs typically have a Voltage & Thermal
+  Management (VTM) device to control up to 8 temperature diode
+  sensors to measure silicon junction temperatures from different
+  hotspots of the chip as well as provide temperature, interrupt
+  and alerting information.
+
+  The VTM device will periodically enable these temperature sensors
+  to make a temperature measurement and store the reported data
+  allowing the sensors to stay in a reset state when not in use
+  to maximize the sensor's life.
+
+  This VTM driver will then use the following polynomial equation to
+  calculate the temperature from the value stored in the VTM device.
+
+  Temp = (-9.2627e-12) * x^4 + (6.0373e-08) * x^3 + \
+         (-1.7058e-04) * x^2 + (3.2512e-01) * x   + (-4.9003e+01)
+
 properties:
   compatible:
     enum:
@@ -19,9 +37,16 @@ properties:
     items:
       - description: VTM cfg1 register space
       - description: VTM cfg2 register space
-      - description: VTM efuse register space
+      - description: |
+          A software trimming method must be applied to some Jacinto
+          devices to function properly. This eFuse region provides
+          the information needed for these SoCs to report
+          temperatures accurately.
 
   power-domains:
+    description: |
+      Should contain the phandle to a power management (PM) domain
+      node and the device-id of this device.
     maxItems: 1
 
   "#thermal-sensor-cells":
-- 
2.38.0