ARM: dts: bcm27xx: Enable kernel Bluetooth

Change the base Device Tree files so that by default the kernel is responsible for initialisation of the onboard Bluetooth modems. Use dtparam=krnbt=off to revert to the old behaviour. Signed-off-by: Phil Elwell <phil@raspberrypi.com>
raspberrypi · Apr 26, 2023 · ec08e93 · ec08e93
1 parent 49dc409
commit ec08e93
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Showing 5 changed files with 46 additions and 28 deletions.
diff --git a/arch/arm/boot/dts/bcm2708-rpi-bt.dtsi b/arch/arm/boot/dts/bcm2708-rpi-bt.dtsi
@@ -5,22 +5,34 @@
 		compatible = "brcm,bcm43438-bt";
 		max-speed = <3000000>;
 		shutdown-gpios = <&gpio 45 GPIO_ACTIVE_HIGH>;
-		status = "disabled";
+		local-bd-address = [ 00 00 00 00 00 00 ];
+		fallback-bd-address; // Don't override a valid address
+		status = "okay";
 	};
 };
 
 &uart1 {
 	minibt: bluetooth {
 		compatible = "brcm,bcm43438-bt";
-		max-speed = <460800>;
+		max-speed = <230400>;
 		shutdown-gpios = <&gpio 45 GPIO_ACTIVE_HIGH>;
+		local-bd-address = [ 00 00 00 00 00 00 ];
+		fallback-bd-address; // Don't override a valid address
 		status = "disabled";
 	};
 };
 
 / {
+	aliases {
+		bluetooth = &bt;
+	};
+
 	__overrides__ {
+		bdaddr = <&bt>,"local-bd-address[",
+		       <&bt>,"fallback-bd-address?=0",
+		       <&minibt>,"local-bd-address[",
+		       <&minibt>,"fallback-bd-address?=0";
 		krnbt = <&bt>,"status";
-		krnbt_baudrate = <&bt>,"max-speed:0";
+		krnbt_baudrate = <&bt>,"max-speed:0", <&minibt>,"max-speed:0";
 	};
 };
diff --git a/arch/arm/boot/dts/bcm271x-rpi-bt.dtsi b/arch/arm/boot/dts/bcm271x-rpi-bt.dtsi
@@ -5,22 +5,34 @@
 		compatible = "brcm,bcm43438-bt";
 		max-speed = <3000000>;
 		shutdown-gpios = <&expgpio 0 GPIO_ACTIVE_HIGH>;
-		status = "disabled";
+		local-bd-address = [ 00 00 00 00 00 00 ];
+		fallback-bd-address; // Don't override a valid address
+		status = "okay";
 	};
 };
 
 &uart1 {
 	minibt: bluetooth {
 		compatible = "brcm,bcm43438-bt";
-		max-speed = <460800>;
+		max-speed = <230400>;
 		shutdown-gpios = <&expgpio 0 GPIO_ACTIVE_HIGH>;
+		local-bd-address = [ 00 00 00 00 00 00 ];
+		fallback-bd-address; // Don't override a valid address
 		status = "disabled";
 	};
 };
 
 / {
+	aliases {
+		bluetooth = &bt;
+	};
+
 	__overrides__ {
+		bdaddr = <&bt>,"local-bd-address[",
+		       <&bt>,"fallback-bd-address?=0",
+		       <&minibt>,"local-bd-address[",
+		       <&minibt>,"fallback-bd-address?=0";
 		krnbt = <&bt>,"status";
-		krnbt_baudrate = <&bt>,"max-speed:0";
+		krnbt_baudrate = <&bt>,"max-speed:0", <&minibt>,"max-speed:0";
 	};
 };
diff --git a/arch/arm/boot/dts/overlays/README b/arch/arm/boot/dts/overlays/README
@@ -144,6 +144,13 @@ Params:
                                 See /sys/kernel/debug/raspberrypi_axi_monitor
                                 for the results.
 
+        bdaddr                  Set an alternative Bluetooth address (BDADDR).
+                                The value should be a 6-byte hexadecimal value,
+                                with or without colon separators, written least-
+                                significant-byte first. For example,
+                                bdaddr=06:05:04:03:02:01
+                                will set the BDADDR to 01:02:03:04:05:06.
+
         cam0_reg                Enables CAM 0 regulator.
                                 Only required on CM1 & 3.
 
@@ -219,9 +226,9 @@ Params:
         i2s                     Set to "on" to enable the i2s interface
                                 (default "off")
 
-        krnbt                   Set to "on" to enable autoprobing of Bluetooth
+        krnbt                   Set to "off" to disable autoprobing of Bluetooth
                                 driver without need of hciattach/btattach
-                                (default "off")
+                                (default "on")
 
         krnbt_baudrate          Set the baudrate of the PL011 UART when used
                                 with krnbt=on

diff --git a/arch/arm/boot/dts/overlays/disable-bt-overlay.dts b/arch/arm/boot/dts/overlays/disable-bt-overlay.dts
@@ -1,12 +1,7 @@
 /dts-v1/;
 /plugin/;
 
-/* Disable Bluetooth and restore UART0/ttyAMA0 over GPIOs 14 & 15.
-   To disable the systemd service that initialises the modem so it doesn't use
-   the UART:
-
-       sudo systemctl disable hciuart
-*/
+/* Disable Bluetooth and restore UART0/ttyAMA0 over GPIOs 14 & 15. */
 
 #include <dt-bindings/gpio/gpio.h>
 

diff --git a/arch/arm/boot/dts/overlays/miniuart-bt-overlay.dts b/arch/arm/boot/dts/overlays/miniuart-bt-overlay.dts
@@ -40,7 +40,7 @@
 		target = <&uart1>;
 		__overlay__ {
 			pinctrl-names = "default";
-			pinctrl-0 = <&uart1_pins &bt_pins &fake_bt_cts>;
+			pinctrl-0 = <&uart1_pins>;
 			status = "okay";
 		};
 	};
@@ -57,37 +57,29 @@
 	fragment@4 {
 		target = <&uart1_pins>;
 		__overlay__ {
-			brcm,pins = <32 33>;
+			brcm,pins = <32 33 30 31>;
 			brcm,function = <2>; /* alt5=UART1 */
-			brcm,pull = <0 2>;
+			brcm,pull = <0 2 2 0>;
 		};
 	};
 
 	fragment@5 {
-		target = <&gpio>;
-		__overlay__ {
-			fake_bt_cts: fake_bt_cts {
-				brcm,pins = <31>;
-				brcm,function = <1>; /* output */
-			};
-		};
-	};
-
-	fragment@6 {
 		target-path = "/aliases";
 		__overlay__ {
 			serial0 = "/soc/serial@7e201000";
 			serial1 = "/soc/serial@7e215040";
 		};
 	};
 
-	fragment@7 {
+	fragment@6 {
 		target = <&minibt>;
 		minibt_frag: __overlay__ {
+			status = "okay";
 		};
 	};
 
 	__overrides__ {
 		krnbt = <&minibt_frag>,"status";
+		krnbt_baudrate = <&minibt_frag>,"max-speed:0";
 	};
 };