usb: mtu3: support option to disable usb2 ports

Add support to disable specific usb2 host ports, it's useful when
a usb2 port is disabled on some platforms, but enabled on others
for the same SoC.
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1626340078-29111-9-git-send-email-chunfeng.yun@mediatek.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/mtu3/mtu3.h

@@ -228,6 +228,9 @@ struct otg_switch_mtk {
  *		host only, device only or dual-role mode
  * @u2_ports: number of usb2.0 host ports
  * @u3_ports: number of usb3.0 host ports
+ * @u2p_dis_msk: mask of disabling usb2 ports, e.g. bit0==1 to
+ *		disable u2port0, bit1==1 to disable u2port1,... etc,
+ *		but when use dual-role mode, can't disable u2port0
  * @u3p_dis_msk: mask of disabling usb3 ports, for example, bit0==1 to
  *		disable u3port0, bit1==1 to disable u3port1,... etc
  * @dbgfs_root: only used when supports manual dual-role switch via debugfs
@@ -252,6 +255,7 @@ struct ssusb_mtk {
 	bool is_host;
 	int u2_ports;
 	int u3_ports;
+	int u2p_dis_msk;
 	int u3p_dis_msk;
 	struct dentry *dbgfs_root;
 	/* usb wakeup for host mode */

drivers/usb/mtu3/mtu3_host.c

@@ -155,6 +155,9 @@ int ssusb_host_enable(struct ssusb_mtk *ssusb)
 
 	/* power on and enable all u2 ports */
 	for (i = 0; i < num_u2p; i++) {
+		if ((0x1 << i) & ssusb->u2p_dis_msk)
+			continue;
+
 		value = mtu3_readl(ibase, SSUSB_U2_CTRL(i));
 		value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
 		value |= SSUSB_U2_PORT_HOST_SEL;
@@ -188,8 +191,11 @@ int ssusb_host_disable(struct ssusb_mtk *ssusb, bool suspend)
 		mtu3_writel(ibase, SSUSB_U3_CTRL(i), value);
 	}
 
-	/* power down and disable all u2 ports */
+	/* power down and disable u2 ports except skipped ones */
 	for (i = 0; i < num_u2p; i++) {
+		if ((0x1 << i) & ssusb->u2p_dis_msk)
+			continue;
+
 		value = mtu3_readl(ibase, SSUSB_U2_CTRL(i));
 		value |= SSUSB_U2_PORT_PDN;
 		value |= suspend ? 0 : SSUSB_U2_PORT_DIS;

drivers/usb/mtu3/mtu3_plat.c

@@ -225,6 +225,8 @@ static int get_ssusb_rscs(struct platform_device *pdev, struct ssusb_mtk *ssusb)
 	/* optional property, ignore the error if it does not exist */
 	of_property_read_u32(node, "mediatek,u3p-dis-msk",
 			     &ssusb->u3p_dis_msk);
+	of_property_read_u32(node, "mediatek,u2p-dis-msk",
+			     &ssusb->u2p_dis_msk);
 
 	otg_sx->vbus = devm_regulator_get(dev, "vbus");
 	if (IS_ERR(otg_sx->vbus)) {
@@ -241,6 +243,9 @@ static int get_ssusb_rscs(struct platform_device *pdev, struct ssusb_mtk *ssusb)
 		of_property_read_bool(node, "enable-manual-drd");
 	otg_sx->role_sw_used = of_property_read_bool(node, "usb-role-switch");
 
+	/* can't disable port0 when use dual-role mode */
+	ssusb->u2p_dis_msk &= ~0x1;
+
 	if (otg_sx->role_sw_used || otg_sx->manual_drd_enabled)
 		goto out;
 
@@ -253,9 +258,11 @@ static int get_ssusb_rscs(struct platform_device *pdev, struct ssusb_mtk *ssusb)
 	}
 
 out:
-	dev_info(dev, "dr_mode: %d, is_u3_dr: %d, u3p_dis_msk: %x, drd: %s\n",
-		ssusb->dr_mode, otg_sx->is_u3_drd, ssusb->u3p_dis_msk,
+	dev_info(dev, "dr_mode: %d, is_u3_dr: %d, drd: %s\n",
+		 ssusb->dr_mode, otg_sx->is_u3_drd,
 		otg_sx->manual_drd_enabled ? "manual" : "auto");
+	dev_info(dev, "u2p_dis_msk: %x, u3p_dis_msk: %x\n",
+		 ssusb->u2p_dis_msk, ssusb->u3p_dis_msk);
 
 	return 0;
 }