linux-kernel - [PATCH v4 11/13] phy: qcom: qmp-usbc: Add USB/DP mutex handling

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Message-Id: <20250911-add-displayport-support-for-qcs615-platform-v4-11-2702bdda14ed@oss.qualcomm.com>
Date: Thu, 11 Sep 2025 22:55:08 +0800
From: Xiangxu Yin <xiangxu.yin@....qualcomm.com>
To: Vinod Koul <vkoul@...nel.org>, Kishon Vijay Abraham I <kishon@...nel.org>,
        Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Rob Clark <robin.clark@....qualcomm.com>,
        Dmitry Baryshkov <lumag@...nel.org>,
        Abhinav Kumar <abhinav.kumar@...ux.dev>,
        Jessica Zhang <jessica.zhang@....qualcomm.com>,
        Sean Paul <sean@...rly.run>,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>
Cc: linux-arm-msm@...r.kernel.org, linux-phy@...ts.infradead.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, freedreno@...ts.freedesktop.org,
        fange.zhang@....qualcomm.com, yongxing.mou@....qualcomm.com,
        li.liu@....qualcomm.com, tingwei.zhang@....qualcomm.com,
        Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>,
        Xiangxu Yin <xiangxu.yin@....qualcomm.com>
Subject: [PATCH v4 11/13] phy: qcom: qmp-usbc: Add USB/DP mutex handling

Introduce mutual exclusion between USB and DP PHY modes to prevent
simultaneous activation.

Signed-off-by: Xiangxu Yin <xiangxu.yin@....qualcomm.com>
---
 drivers/phy/qualcomm/phy-qcom-qmp-usbc.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c b/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
index 613239d15a6a3bba47a647db4e663713f127c93e..866277036089c588cf0c63204efb91bbec5430ae 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
@@ -1061,6 +1061,19 @@ static int qmp_usbc_usb_power_off(struct phy *phy)
 	return 0;
 }
 
+static int qmp_check_mutex_phy(struct qmp_usbc *qmp, bool is_dp)
+{
+	if ((is_dp && qmp->usb_init_count) ||
+	    (!is_dp && qmp->dp_init_count)) {
+		dev_err(qmp->dev,
+			"PHY is configured for %s, can not enable %s\n",
+			is_dp ? "USB" : "DP", is_dp ? "DP" : "USB");
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
 static int qmp_usbc_usb_enable(struct phy *phy)
 {
 	struct qmp_usbc *qmp = phy_get_drvdata(phy);
@@ -1068,6 +1081,10 @@ static int qmp_usbc_usb_enable(struct phy *phy)
 
 	mutex_lock(&qmp->phy_mutex);
 
+	ret = qmp_check_mutex_phy(qmp, false);
+	if (ret)
+		goto out_unlock;
+
 	ret = qmp_usbc_com_init(phy);
 	if (ret)
 		goto out_unlock;
@@ -1121,6 +1138,10 @@ static int qmp_usbc_dp_enable(struct phy *phy)
 
 	mutex_lock(&qmp->phy_mutex);
 
+	ret = qmp_check_mutex_phy(qmp, true);
+	if (ret)
+		goto dp_init_unlock;
+
 	ret = qmp_usbc_com_init(phy);
 	if (ret)
 		goto dp_init_unlock;

-- 
2.34.1