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From:   satya priya <skakit@codeaurora.org>
To:     Bjorn Andersson <bjorn.andersson@linaro.org>
Cc:     Matthias Kaehlcke <mka@chromium.org>, gregkh@linuxfoundation.org,
        Andy Gross <agross@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, akashast@codeaurora.org,
        rojay@codeaurora.org, msavaliy@qti.qualcomm.com,
        satya priya <skakit@codeaurora.org>
Subject: [PATCH V4 3/4] arm64: dts: qcom: sc7180: Add sleep state for BT UART
Date:   Thu,  3 Sep 2020 20:34:57 +0530
Message-Id: <1599145498-20707-4-git-send-email-skakit@codeaurora.org>
In-Reply-To: <1599145498-20707-1-git-send-email-skakit@codeaurora.org>
References: <1599145498-20707-1-git-send-email-skakit@codeaurora.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add sleep state for BT uart to support the wakeup feature.

Signed-off-by: satya priya <skakit@codeaurora.org>
Reviewed-by: Akash Asthana <akashast@codeaurora.org>
---
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.

 arch/arm64/boot/dts/qcom/sc7180-idp.dts | 37 +++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sc7180-idp.dts b/arch/arm64/boot/dts/qcom/sc7180-idp.dts
index cecac3e..77e3523 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-idp.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-idp.dts
@@ -507,6 +507,43 @@
 	};
 };
 
+&qup_uart3_sleep {
+	pinconf-cts {
+		/*
+		 * Configure no-pull on CTS. As this is driven by BT, do not
+		 * specify any pull in order to not conflict with BT pulls.
+		 */
+		pins = "gpio38";
+		bias-disable;
+	};
+
+	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;
+	};
+};
+
 &qup_uart8_default {
 	pinconf-tx {
 		pins = "gpio44";
-- 
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