[PATCH] phy: mediatek: xsphy: clear U2 DTM0 force bits during init

[Nikolai Burov via B4 Relay <devnull+nikolai.burov.jolla.com@kernel.org>]

From: Nikolai Burov <nikolai.burov@jolla.com>

On mobile SoCs, the USB PHY is completely powered off during bootup.
As a result, various bits in the DTM0 register are set that prevent
the USB 2.0 PHY from functioning. Clear them as part of the
initialization sequence.

Signed-off-by: Nikolai Burov <nikolai.burov@jolla.com>
---
 drivers/phy/mediatek/phy-mtk-xsphy.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/phy/mediatek/phy-mtk-xsphy.c b/drivers/phy/mediatek/phy-mtk-xsphy.c
index cc1d66954212..b29220bc5592 100644
--- a/drivers/phy/mediatek/phy-mtk-xsphy.c
+++ b/drivers/phy/mediatek/phy-mtk-xsphy.c
@@ -62,6 +62,14 @@
 #define P2A6_RG_BC11_SW_EN	BIT(23)
 #define P2A6_RG_OTG_VBUSCMP_EN	BIT(20)
 
+#define XSP_U2PHYDTM0		((SSUSB_SIFSLV_U2PHY_COM) + 0x068)
+#define P2D_FORCE_DATAIN	BIT(23)
+#define P2D_FORCE_DM_PULLDOWN	BIT(21)
+#define P2D_FORCE_DP_PULLDOWN	BIT(20)
+#define P2D_FORCE_XCVRSEL	BIT(19)
+#define P2D_FORCE_SUSPENDM	BIT(18)
+#define P2D_FORCE_TERMSEL	BIT(17)
+
 #define XSP_U2PHYDTM1		((SSUSB_SIFSLV_U2PHY_COM) + 0x06C)
 #define P2D_FORCE_IDDIG		BIT(9)
 #define P2D_RG_VBUSVALID	BIT(5)
@@ -181,6 +189,11 @@ static void u2_phy_instance_init(struct mtk_xsphy *xsphy,
 {
 	void __iomem *pbase = inst->port_base;
 
+	mtk_phy_clear_bits(pbase + XSP_U2PHYDTM0,
+			   P2D_FORCE_DATAIN | P2D_FORCE_DM_PULLDOWN |
+			   P2D_FORCE_DP_PULLDOWN | P2D_FORCE_XCVRSEL |
+			   P2D_FORCE_SUSPENDM | P2D_FORCE_TERMSEL);
+
 	/* DP/DM BC1.1 path Disable */
 	mtk_phy_clear_bits(pbase + XSP_USBPHYACR6, P2A6_RG_BC11_SW_EN);
 

---
base-commit: bee763d5f341b99cf472afeb508d4988f62a6ca1
change-id: 20260710-mt6858-xsphy-poweron-ccafba09b4c2

Best regards,
--  
Nikolai Burov <nikolai.burov@jolla.com>