arm64: dts: qcom: sm7225-fairphone-fp4: Add Bluetooth

The device has a WCN3988 chip for WiFi and Bluetooth. Configure the
Bluetooth node and enable the UART it is connected to, plus the
necessary pinctrl that has been borrowed with comments from
sc7280-idp.dtsi.
Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230421-fp4-bluetooth-v2-4-3de840d5483e@fairphone.com

arch/arm64/boot/dts/qcom/sm7225-fairphone-fp4.dts

@@ -31,6 +31,7 @@ / {
 
 	aliases {
 		serial0 = &uart9;
+		serial1 = &uart1;
 	};
 
 	chosen {
@@ -524,6 +525,39 @@ adc-chan@644 {
 	};
 };
 
+&qup_uart1_cts {
+	/*
+	 * Configure a bias-bus-hold on CTS to lower power
+	 * usage when Bluetooth is turned off. Bus hold will
+	 * maintain a low power state regardless of whether
+	 * the Bluetooth module drives the pin in either
+	 * direction or leaves the pin fully unpowered.
+	 */
+	bias-bus-hold;
+};
+
+&qup_uart1_rts {
+	/* We'll drive RTS, so no pull */
+	drive-strength = <2>;
+	bias-disable;
+};
+
+&qup_uart1_rx {
+	/*
+	 * Configure a pull-up on RX. This is needed to avoid
+	 * garbage data when the TX pin of the Bluetooth module is
+	 * in tri-state (module powered off or not driving the
+	 * signal yet).
+	 */
+	bias-pull-up;
+};
+
+&qup_uart1_tx {
+	/* We'll drive TX, so no pull */
+	drive-strength = <2>;
+	bias-disable;
+};
+
 &qupv3_id_0 {
 	status = "okay";
 };
@@ -561,6 +595,75 @@ &sdhc_2 {
 
 &tlmm {
 	gpio-reserved-ranges = <13 4>, <56 2>;
+
+	qup_uart1_sleep_cts: qup-uart1-sleep-cts-state {
+		pins = "gpio61";
+		function = "gpio";
+		/*
+		 * Configure a bias-bus-hold on CTS to lower power
+		 * usage when Bluetooth is turned off. Bus hold will
+		 * maintain a low power state regardless of whether
+		 * the Bluetooth module drives the pin in either
+		 * direction or leaves the pin fully unpowered.
+		 */
+		bias-bus-hold;
+	};
+
+	qup_uart1_sleep_rts: qup-uart1-sleep-rts-state {
+		pins = "gpio62";
+		function = "gpio";
+		/*
+		 * Configure pull-down on RTS. As RTS is active low
+		 * signal, pull it low to indicate the BT SoC that it
+		 * can wakeup the system anytime from suspend state by
+		 * pulling RX low (by sending wakeup bytes).
+		 */
+		bias-pull-down;
+	};
+
+	qup_uart1_sleep_rx: qup-uart1-sleep-rx-state {
+		pins = "gpio64";
+		function = "gpio";
+		/*
+		 * Configure a pull-up on RX. This is needed to avoid
+		 * garbage data when the TX pin of the Bluetooth module
+		 * is floating which may cause spurious wakeups.
+		 */
+		bias-pull-up;
+	};
+
+	qup_uart1_sleep_tx: qup-uart1-sleep-tx-state {
+		pins = "gpio63";
+		function = "gpio";
+		/*
+		 * Configure pull-up on TX when it isn't actively driven
+		 * to prevent BT SoC from receiving garbage during sleep.
+		 */
+		bias-pull-up;
+	};
+};
+
+&uart1 {
+	/delete-property/ interrupts;
+	interrupts-extended = <&intc GIC_SPI 602 IRQ_TYPE_LEVEL_HIGH>,
+			      <&tlmm 64 IRQ_TYPE_EDGE_FALLING>;
+
+	pinctrl-names = "default", "sleep";
+	pinctrl-1 = <&qup_uart1_sleep_cts>, <&qup_uart1_sleep_rts>, <&qup_uart1_sleep_tx>, <&qup_uart1_sleep_rx>;
+
+	status = "okay";
+
+	bluetooth {
+		compatible = "qcom,wcn3988-bt";
+
+		vddio-supply = <&vreg_l11a>;
+		vddxo-supply = <&vreg_l7a>;
+		vddrf-supply = <&vreg_l2e>;
+		vddch0-supply = <&vreg_l10e>;
+		swctrl-gpios = <&tlmm 69 GPIO_ACTIVE_HIGH>;
+
+		max-speed = <3200000>;
+	};
 };
 
 &uart9 {