Add a suitable sleep configuration for uart3 to support Bluetooth wakeup.
If QUP function is selected in sleep state, UART RTS/RFR is pulled high
during suspend and BT SoC not able to send wakeup bytes. So, configure
GPIO mode in sleep state to keep it low during suspend.
Signed-off-by: satya priya <skakit@xxxxxxxxxxxxxx>
Reviewed-by: Akash Asthana <akashast@xxxxxxxxxxxxxx>
---
Changes in V2:
- This patch adds sleep state for BT UART. Newly added in V2.
Changes in V3:
- Remove "output-high" for TX from both sleep and default states
as it is not required. Configure pull-up for TX in sleep state.
Changes in V4:
- As per Matthias's comment, removed drive-strength for sleep state
and fixed nit-pick.
Changes in V5:
- As per Matthias's comments, moved pinmux change for sleep state,
pinctrl and interrupt config to the board specific file.
arch/arm64/boot/dts/qcom/sc7180-idp.dts | 48 +++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)
diff --git a/arch/arm64/boot/dts/qcom/sc7180-idp.dts b/arch/arm64/boot/dts/qcom/sc7180-idp.dts
index 04888df..e529a41 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-idp.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-idp.dts
@@ -344,6 +344,10 @@
};
&uart3 {
+ pinctrl-names = "default", "sleep";
+ pinctrl-1 = <&qup_uart3_sleep>;
+ interrupts-extended = <&intc GIC_SPI 604 IRQ_TYPE_LEVEL_HIGH>,
+ <&tlmm 41 IRQ_TYPE_EDGE_FALLING>;
status = "okay";
bluetooth: wcn3990-bt {
@@ -545,3 +549,47 @@
};
};
+&tlmm {
+ qup_uart3_sleep: qup-uart3-sleep {
+ pinmux {
+ pins = "gpio38", "gpio39",
+ "gpio40", "gpio41";
+ function = "gpio";
+ };
+
+ pinconf-cts {
+ /*
+ * Configure a pull-down on CTS to match the pull of
+ * the Bluetooth module.
+ */
+ pins = "gpio38";
+ bias-pull-down;
+ };
+
+ pinconf-rts {
+ /*
+ * Configure pull-down on RTS to make sure that the BT SoC can
+ * wake up the system by sending wakeup bytes during suspend.
+ */
+ pins = "gpio39";
+ bias-pull-down;
+ };
+
+ pinconf-tx {
+ /* Configure pull-up on TX when it isn't actively driven */
+ pins = "gpio40";
+ bias-pull-up;
+ };
+
+ pinconf-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).
+ */
+ pins = "gpio41";
+ bias-pull-up;
+ };
+ };
+};
--
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