usb: mtu3: power down port when power down device IP

When power down device IP, we can also power down device port,
then power on the port again when power on device ip, it's helpful
to make device ip enter ip sleep mode.
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1623139069-8173-7-git-send-email-chunfeng.yun@mediatek.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/mtu3/mtu3_core.c

@@ -334,6 +334,10 @@ void mtu3_start(struct mtu3 *mtu)
 		mtu3_readl(mbase, U3D_DEVICE_CONTROL));
 
 	mtu3_clrbits(mtu->ippc_base, U3D_SSUSB_IP_PW_CTRL2, SSUSB_IP_DEV_PDN);
+	if (mtu->is_u3_ip)
+		mtu3_clrbits(mtu->ippc_base, SSUSB_U3_CTRL(0), SSUSB_U3_PORT_PDN);
+
+	mtu3_clrbits(mtu->ippc_base, SSUSB_U2_CTRL(0), SSUSB_U2_PORT_PDN);
 
 	mtu3_csr_init(mtu);
 	mtu3_set_speed(mtu, mtu->speed);
@@ -356,6 +360,11 @@ void mtu3_stop(struct mtu3 *mtu)
 		mtu3_dev_on_off(mtu, 0);
 
 	mtu->is_active = 0;
+
+	if (mtu->is_u3_ip)
+		mtu3_setbits(mtu->ippc_base, SSUSB_U3_CTRL(0), SSUSB_U3_PORT_PDN);
+
+	mtu3_setbits(mtu->ippc_base, SSUSB_U2_CTRL(0), SSUSB_U2_PORT_PDN);
 	mtu3_setbits(mtu->ippc_base, U3D_SSUSB_IP_PW_CTRL2, SSUSB_IP_DEV_PDN);
 }