[PATCH v1 1/2] dt-bindings: power: supply: Add Qualcomm SMB1351 charger

[Adrian Nguyen <thenguyen1024@gmail.com>]

The Qualcomm SMB1351 is a switch-mode battery charger with an I2C
interface. Some phones use it as a parallel charger next to the charger
in their PMIC: both take power from the same USB input and charge the
same battery. On the Vsmart Active 1 (SDM660, PM660) the SMB1351 is
powered from that input alone, so it does not respond on I2C while the
input is absent.

The SMB1350 has the same programming interface, and the two can be told
apart by their version register, so the SMB1350 gets its own compatible
with qcom,smb1351 as the fallback. The version register of the chip on
the Vsmart Active 1 identifies it as an SMB1350.

Document the chip with the battery it charges and its STAT output,
which it can drive as an interrupt line. On a parallel charger,
power-supplies refers to the PMIC charger whose USB input also powers
the SMB1351. The SMB1351 can also be the only charger of a board, with
no PMIC charger to refer to, so that property is optional.

Assisted-by: LLM
Signed-off-by: Adrian Nguyen <thenguyen1024@gmail.com>
---
 .../bindings/power/supply/qcom,smb1351.yaml   | 71 +++++++++++++++++++
 1 file changed, 71 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/supply/qcom,smb1351.yaml

diff --git a/Documentation/devicetree/bindings/power/supply/qcom,smb1351.yaml b/Documentation/devicetree/bindings/power/supply/qcom,smb1351.yaml
new file mode 100644
index 000000000000..e08aeb4775e8
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/supply/qcom,smb1351.yaml
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/supply/qcom,smb1351.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm SMB1351 battery charger
+
+maintainers:
+  - Adrian Nguyen <thenguyen1024@gmail.com>
+
+description:
+  The Qualcomm SMB1351 is a switch-mode single-cell battery charger with an
+  I2C interface. Some boards use it as a parallel charger next to the
+  charger in a PMIC, taking power from the same USB input and charging the
+  same battery. On some of them it is powered from that input only, so it
+  does not respond on I2C and loses its configuration while the input is
+  absent. The SMB1350 has the same programming interface, and the two can be
+  told apart by their version register.
+
+allOf:
+  - $ref: power-supply.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - const: qcom,smb1351
+      - items:
+          - const: qcom,smb1350
+          - const: qcom,smb1351
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    description:
+      The STAT output, which the chip can drive as an interrupt line.
+    maxItems: 1
+
+  monitored-battery: true
+
+  power-supplies:
+    description:
+      The PMIC charger whose USB input (VBUS) also powers this charger, on
+      boards that use it as a parallel charger.
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - monitored-battery
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        charger@1d {
+            compatible = "qcom,smb1350", "qcom,smb1351";
+            reg = <0x1d>;
+            interrupts = <61 IRQ_TYPE_LEVEL_LOW>;
+
+            monitored-battery = <&battery>;
+            power-supplies = <&pm660_charger>;
+        };
+    };
-- 
2.43.0