arm64: dts: qcom: sc7280: Configure uart7 to support bluetooth on sc7280-idp

Add bluetooth uart pin configuration for sc7280-idp.
Signed-off-by: Rajesh Patil <rajpat@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1632399378-12229-7-git-send-email-rajpat@codeaurora.org

arch/arm64/boot/dts/qcom/sc7280-idp.dtsi

@@ -322,6 +322,16 @@ &usb_2_hsphy {
 	vdda18-supply = <&vreg_l1c_1p8>;
 };
 
+&uart7 {
+	status = "okay";
+
+	/delete-property/interrupts;
+	interrupts-extended = <&intc GIC_SPI 608 IRQ_TYPE_LEVEL_HIGH>,
+				<&tlmm 31 IRQ_TYPE_EDGE_FALLING>;
+	pinctrl-names = "default", "sleep";
+	pinctrl-1 = <&qup_uart7_sleep_cts>, <&qup_uart7_sleep_rts>, <&qup_uart7_sleep_tx>, <&qup_uart7_sleep_rx>;
+};
+
 /* PINCTRL - additions to nodes defined in sc7280.dtsi */
 
 &pm7325_gpios {
@@ -358,6 +368,81 @@ &qup_uart5_rx {
 	bias-pull-up;
 };
 
+&qup_uart7_cts {
+	/*
+	 * Configure a pull-down on CTS to match the pull of
+	 * the Bluetooth module.
+	 */
+	bias-pull-down;
+};
+
+&qup_uart7_rts {
+	/* We'll drive RTS, so no pull */
+	drive-strength = <2>;
+	bias-disable;
+};
+
+&qup_uart7_tx {
+	/* We'll drive TX, so no pull */
+	drive-strength = <2>;
+	bias-disable;
+};
+
+&qup_uart7_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;
+};
+
+&tlmm {
+	qup_uart7_sleep_cts: qup-uart7-sleep-cts {
+		pins = "gpio28";
+		function = "gpio";
+		/*
+		 * Configure a pull-down on CTS to match the pull of
+		 * the Bluetooth module.
+		 */
+		bias-pull-down;
+	};
+
+	qup_uart7_sleep_rts: qup-uart7-sleep-rts {
+		pins = "gpio29";
+		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_uart7_sleep_tx: qup-uart7-sleep-tx {
+		pins = "gpio30";
+		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;
+	};
+
+	qup_uart7_sleep_rx: qup-uart7-sleep-rx {
+		pins = "gpio31";
+		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;
+	};
+};
+
 &sdc1_on {
 	clk {
 		bias-disable;