[PATCH 1/2] dt-bindings: net: bluetooth: Add MediaTek MT7921S SDIO Bluetooth

[Chen-Yu Tsai <wenst@chromium.org>]

The MediaTek MT7921S is a WiFi/Bluetooth combo chip that works over
SDIO. While the Bluetooth function is fully discoverable, the chip
has a pin that can reset just the Bluetooth side, as opposed to the
full chip. This needs to be described in the device tree.

Add a device tree binding for MT7921S Bluetooth over SDIO specifically
ot document the reset line.

Cc: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
 .../bluetooth/mediatek,mt7921s-bluetooth.yaml | 49 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 50 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/bluetooth/mediatek,mt7921s-bluetooth.yaml

diff --git a/Documentation/devicetree/bindings/net/bluetooth/mediatek,mt7921s-bluetooth.yaml b/Documentation/devicetree/bindings/net/bluetooth/mediatek,mt7921s-bluetooth.yaml
new file mode 100644
index 000000000000..bbe240e7cc40
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/bluetooth/mediatek,mt7921s-bluetooth.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/bluetooth/mediatek,mt7921s-bluetooth.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek MT7921S Bluetooth
+
+description:
+  This binding describes the Bluetooth side of the SDIO-attached MT7921S
+  WiFi+Bluetooth combo chips. These chips are dual-radio chips supporting
+  WiFi and Bluetooth. Bluetooth works over SDIO just like WiFi. Bluetooth
+  has its own reset line, separate from WiFi, which can be used to reset
+  the Bluetooth core.
+
+maintainers:
+  - Sean Wang <sean.wang@mediatek.com>
+
+properties:
+  compatible:
+    enum:
+      - mediatek,mt7921s-bluetooth
+  reg:
+    const: 2
+
+  reset-gpios:
+    maxItems: 1
+    description: A GPIO line connected to the Bluetooth subsystem reset line.
+      Typically the W_DISABLE2# pin on M.2 E-key modules. If present this
+      shall be flagged as active low.
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    mmc {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        bluetooth@2 {
+            compatible = "mediatek,mt7921s-bluetooth";
+            reg = <2>;
+            reset-gpios = <&pio 8 GPIO_ACTIVE_LOW>;
+        };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index b64a64ca7916..662957146852 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13657,6 +13657,7 @@ M:	Sean Wang <sean.wang@mediatek.com>
 L:	linux-bluetooth@vger.kernel.org
 L:	linux-mediatek@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
+F:	Documentation/devicetree/bindings/net/bluetooth/mediatek,mt7921s-bluetooth.yaml
 F:	Documentation/devicetree/bindings/net/mediatek-bluetooth.txt
 F:	drivers/bluetooth/btmtkuart.c
 
-- 
2.43.0.429.g432eaa2c6b-goog