[PATCH 1/3] dt-bindings: hwmon: ltc4283: add ltc4284

[Alexis Czezar Torreno <alexisczezar.torreno@analog.com>]

The LTC4284 is a negative voltage hot swap controller that drives an
external N-channel MOSFET to allow a board to be safely inserted and
removed from a live backplane.

Note that this device has a MODE pin that is determined by differing
voltage levels (VEE, VIN, INTVCC, or left open) and cannot be
controlled via software or GPIO.

Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
---
 .../devicetree/bindings/hwmon/adi,ltc4283.yaml     | 57 ++++++++++++++++++++--
 1 file changed, 53 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml b/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml
index 05e2132ad4d8621ab76ee89aa166c131fed08e85..c850390ddc4a33ed3fd877bf4620f7f009366ff5 100644
--- a/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml
+++ b/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml
@@ -10,22 +10,42 @@ maintainers:
   - Nuno Sá <nuno.sa@analog.com>
 
 description: |
-  The LTC4283 negative voltage hot swap controller drives an external N-channel
-  MOSFET to allow a board to be safely inserted and removed from a live
-  backplane.
+  The LTC4283 and LTC4284 are negative voltage hot swap controllers that drive
+  external N-channel MOSFETs to allow a board to be safely inserted and removed
+  from a live backplane.
+
+  The LTC4284 features dual-gate drivers with four operating modes (single
+  driver, parallel, high stress staged start, and low stress staged start)
+  configured via the hardware MODE pin. The MODE pin must be connected to the
+  appropriate voltage level (VEE, VIN, INTVCC, or left open) and cannot be
+  controlled via software or GPIO.
 
   https://www.analog.com/media/en/technical-documentation/data-sheets/ltc4283.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ltc4284.pdf
 
 properties:
   compatible:
     enum:
       - adi,ltc4283
+      - adi,ltc4284
 
   reg:
     maxItems: 1
 
   adi,rsense-nano-ohms:
-    description: Value of the sense resistor.
+    description:
+      Value of the sense resistor. For LTC4283, this is the resistor connected
+      between SENSE+/SENSE- pins. For LTC4284, this is the resistor connected
+      between SENSE1+/SENSE1- pins.
+
+  adi,rsense2-nano-ohms:
+    description:
+      Value of the SENSE2 current sense resistor. This resistor is connected
+      between SENSE2+ and SENSE2- pins.
+
+  adi,radc-nano-ohms:
+    description:
+      Value of the effective resistance seen by the ADC+/ADC- pins.
 
   adi,current-limit-sense-microvolt:
     description:
@@ -195,6 +215,20 @@ required:
   - adi,rsense-nano-ohms
 
 allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: adi,ltc4284
+    then:
+      required:
+        - adi,rsense2-nano-ohms
+        - adi,radc-nano-ohms
+    else:
+      properties:
+        adi,rsense2-nano-ohms: false
+        adi,radc-nano-ohms: false
+
   - if:
       properties:
         adi,pgio1-func:
@@ -269,4 +303,19 @@ examples:
             #gpio-cells = <2>;
         };
     };
+
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        swap-controller@20 {
+            compatible = "adi,ltc4284";
+            reg = <0x20>;
+
+            adi,rsense-nano-ohms = <1000>;
+            adi,rsense2-nano-ohms = <1000>;
+            adi,radc-nano-ohms = <500>;
+        };
+    };
 ...

-- 
2.34.1