usb: mtu3: clear SOFTCONN when clear USB3_EN if work as HS mode

When the controller supports SS mode, but works as HS mode, the
SOFTCONN will not be cleared automatically when clear USB3_EN
by default, this cause an issue that can't disconnect from host,
so clear SOFTCONN when clear USB3_EN when the class driver want
to disable the D+ pullup.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/mtu3/mtu3_core.c

@@ -586,6 +586,8 @@ static void mtu3_regs_init(struct mtu3 *mtu)
 		mtu3_clrbits(mbase, U3D_LTSSM_CTRL, SOFT_U3_EXIT_EN);
 		/* automatically build U2 link when U3 detect fail */
 		mtu3_setbits(mbase, U3D_USB2_TEST_MODE, U2U3_AUTO_SWITCH);
+		/* auto clear SOFT_CONN when clear USB3_EN if work as HS */
+		mtu3_setbits(mbase, U3D_U3U2_SWITCH_CTRL, SOFTCON_CLR_AUTO_EN);
 	}
 
 	mtu3_set_speed(mtu);

drivers/usb/mtu3/mtu3_hw_regs.h

@@ -268,6 +268,8 @@
 #define U3D_LTSSM_INTR_ENABLE	(SSUSB_USB3_MAC_CSR_BASE + 0x013C)
 #define U3D_LTSSM_INTR		(SSUSB_USB3_MAC_CSR_BASE + 0x0140)
 
+#define U3D_U3U2_SWITCH_CTRL	(SSUSB_USB3_MAC_CSR_BASE + 0x0170)
+
 /*---------------- SSUSB_USB3_MAC_CSR FIELD DEFINITION ----------------*/
 
 /* U3D_LTSSM_CTRL */
@@ -302,6 +304,9 @@
 #define SS_DISABLE_INTR		BIT(1)
 #define SS_INACTIVE_INTR	BIT(0)
 
+/* U3D_U3U2_SWITCH_CTRL */
+#define SOFTCON_CLR_AUTO_EN	BIT(0)
+
 /*---------------- SSUSB_USB3_SYS_CSR REGISTER DEFINITION ----------------*/
 
 #define U3D_LINK_UX_INACT_TIMER	(SSUSB_USB3_SYS_CSR_BASE + 0x020C)