[PATCH 2/3] phy: qcom: qmp-combo: Select LFPS detect only when SS link is confirmed present

[Tapas Rana]

qmp_combo_enable_autonomous_mode() selects the autonomous-mode wake
interrupt mask by comparing qmp->phy_mode against
PHY_MODE_USB_HOST_SS/PHY_MODE_USB_DEVICE_SS. However, this driver's
set_mode() only ever stores PHY_MODE_USB_HOST or PHY_MODE_USB_DEVICE,
since dwc3 core and dwc3-qcom never pass the _SS variants. As a
result, the comparison is always false and the PHY always falls back
to the ARCVR_DTCT_EN | ARCVR_DTCT_EVENT_SEL mask instead of also
enabling ALFPS_DTCT_EN, regardless of whether a SuperSpeed device is
attached.

Store the qcom_usb_ss_state submode (added in the previous patch)
alongside phy_mode in qmp_combo_usb_set_mode(), and switch
qmp_combo_enable_autonomous_mode() on it instead of on phy_mode, so
LFPS detection is selected only when a SuperSpeed link is confirmed
present.

Signed-off-by: Tapas Rana <tapas.rana@xxxxxxxxxxxxxxxx>
---
 drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 27 ++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
index aa9dc9716574..813a0955c591 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
@@ -27,6 +27,7 @@
 #include <drm/bridge/aux-bridge.h>
 
 #include <dt-bindings/phy/phy-qcom-qmp.h>
+#include <linux/phy/phy-qcom-qmp-usb-ss.h>
 
 #include "phy-qcom-qmp-common.h"
 
@@ -2630,6 +2631,7 @@ struct qmp_combo {
 
 	struct phy *usb_phy;
 	enum phy_mode phy_mode;
+	enum qcom_usb_ss_state  ss_state;
 	unsigned int usb_init_count;
 
 	struct phy *dp_phy;
@@ -4518,6 +4520,16 @@ static int qmp_combo_usb_set_mode(struct phy *phy, enum phy_mode mode, int submo
 
 	qmp->phy_mode = mode;
 
+	switch (submode) {
+	case QCOM_USB_SS_PRESENT:
+	case QCOM_USB_SS_ABSENT:
+		qmp->ss_state = submode;
+		break;
+	default:
+		qmp->ss_state = QCOM_USB_SS_UNKNOWN;
+		break;
+	}
+
 	return 0;
 }
 
@@ -4672,11 +4684,20 @@ static void qmp_combo_enable_autonomous_mode(struct qmp_combo *qmp)
 	void __iomem *pcs_aon = qmp->pcs_aon;
 	u32 intr_mask;
 
-	if (qmp->phy_mode == PHY_MODE_USB_HOST_SS ||
-	    qmp->phy_mode == PHY_MODE_USB_DEVICE_SS)
+	/*
+	 * Use LFPS detection only when a SuperSpeed device is known to be
+	 * present. For absent or unknown state, use receiver detection.
+	 */
+	switch (qmp->ss_state) {
+	case QCOM_USB_SS_PRESENT:
 		intr_mask = ARCVR_DTCT_EN | ALFPS_DTCT_EN;
-	else
+		break;
+	case QCOM_USB_SS_ABSENT:
+	case QCOM_USB_SS_UNKNOWN:
+	default:
 		intr_mask = ARCVR_DTCT_EN | ARCVR_DTCT_EVENT_SEL;
+		break;
+	}
 
 	/* Clear any pending interrupts status */
 	qphy_setbits(pcs_usb, cfg->regs[QPHY_PCS_LFPS_RXTERM_IRQ_CLEAR], IRQ_CLEAR);
-- 
2.43.0