usb: mtu3: use FORCE/RG_IDDIG to implement manual DRD switch

In order to keep manual DRD switch independent on IDDIG interrupt,
make use of FORCE/RG_IDDIG instead of IDDIG EINT interrupt to
implement manual DRD switch function.
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/mtu3/mtu3.h

@@ -114,6 +114,19 @@ enum mtu3_g_ep0_state {
 	MU3D_EP0_STATE_STALL,
 };
 
+/**
+ * MTU3_DR_FORCE_NONE: automatically switch host and periperal mode
+ *		by IDPIN signal.
+ * MTU3_DR_FORCE_HOST: force to enter host mode and override OTG
+ *		IDPIN signal.
+ * MTU3_DR_FORCE_DEVICE: force to enter peripheral mode.
+ */
+enum mtu3_dr_force_mode {
+	MTU3_DR_FORCE_NONE = 0,
+	MTU3_DR_FORCE_HOST,
+	MTU3_DR_FORCE_DEVICE,
+};
+
 /**
  * @base: the base address of fifo
  * @limit: the bitmap size in bits
@@ -196,7 +209,6 @@ struct mtu3_gpd_ring {
 *		xHCI driver initialization, it's necessary for system bootup
 *		as device.
 * @is_u3_drd: whether port0 supports usb3.0 dual-role device or not
-* @id_*: used to maually switch between host and device modes by idpin
 * @manual_drd_enabled: it's true when supports dual-role device by debugfs
 *		to switch host/device modes depending on user input.
 */
@@ -207,10 +219,6 @@ struct otg_switch_mtk {
 	struct notifier_block id_nb;
 	struct delayed_work extcon_reg_dwork;
 	bool is_u3_drd;
-	/* dual-role switch by debugfs */
-	struct pinctrl *id_pinctrl;
-	struct pinctrl_state *id_float;
-	struct pinctrl_state *id_ground;
 	bool manual_drd_enabled;
 };
 

drivers/usb/mtu3/mtu3_dr.c

@@ -261,21 +261,22 @@ static void extcon_register_dwork(struct work_struct *work)
  * depending on user input.
  * This is useful in special cases, such as uses TYPE-A receptacle but also
  * wants to support dual-role mode.
- * It generates cable state changes by pulling up/down IDPIN and
- * notifies driver to switch mode by "extcon-usb-gpio".
- * NOTE: when use MICRO receptacle, should not enable this interface.
  */
 static void ssusb_mode_manual_switch(struct ssusb_mtk *ssusb, int to_host)
 {
 	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
 
-	if (to_host)
-		pinctrl_select_state(otg_sx->id_pinctrl, otg_sx->id_ground);
-	else
-		pinctrl_select_state(otg_sx->id_pinctrl, otg_sx->id_float);
+	if (to_host) {
+		ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
+		ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);
+		ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
+	} else {
+		ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
+		ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
+		ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
+	}
 }
 
-
 static int ssusb_mode_show(struct seq_file *sf, void *unused)
 {
 	struct ssusb_mtk *ssusb = sf->private;
@@ -388,17 +389,45 @@ static void ssusb_debugfs_exit(struct ssusb_mtk *ssusb)
 	debugfs_remove_recursive(ssusb->dbgfs_root);
 }
 
+void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
+			  enum mtu3_dr_force_mode mode)
+{
+	u32 value;
+
+	value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0));
+	switch (mode) {
+	case MTU3_DR_FORCE_DEVICE:
+		value |= SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG;
+		break;
+	case MTU3_DR_FORCE_HOST:
+		value |= SSUSB_U2_PORT_FORCE_IDDIG;
+		value &= ~SSUSB_U2_PORT_RG_IDDIG;
+		break;
+	case MTU3_DR_FORCE_NONE:
+		value &= ~(SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG);
+		break;
+	default:
+		return;
+	}
+	mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
+}
+
 int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
 {
 	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
 
-	INIT_DELAYED_WORK(&otg_sx->extcon_reg_dwork, extcon_register_dwork);
-
-	if (otg_sx->manual_drd_enabled)
+	if (otg_sx->manual_drd_enabled) {
 		ssusb_debugfs_init(ssusb);
-
-	/* It is enough to delay 1s for waiting for host initialization */
-	schedule_delayed_work(&otg_sx->extcon_reg_dwork, HZ);
+	} else {
+		INIT_DELAYED_WORK(&otg_sx->extcon_reg_dwork,
+				  extcon_register_dwork);
+
+		/*
+		 * It is enough to delay 1s for waiting for
+		 * host initialization
+		 */
+		schedule_delayed_work(&otg_sx->extcon_reg_dwork, HZ);
+	}
 
 	return 0;
 }
@@ -407,8 +436,8 @@ void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
 {
 	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
 
-	cancel_delayed_work(&otg_sx->extcon_reg_dwork);
-
 	if (otg_sx->manual_drd_enabled)
 		ssusb_debugfs_exit(ssusb);
+	else
+		cancel_delayed_work(&otg_sx->extcon_reg_dwork);
 }

drivers/usb/mtu3/mtu3_dr.h

@@ -87,6 +87,8 @@ static inline void ssusb_gadget_exit(struct ssusb_mtk *ssusb)
 int ssusb_otg_switch_init(struct ssusb_mtk *ssusb);
 void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb);
 int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on);
+void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
+			  enum mtu3_dr_force_mode mode);
 
 #else
 
@@ -103,6 +105,10 @@ static inline int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
 	return 0;
 }
 
+static inline void
+ssusb_set_force_mode(struct ssusb_mtk *ssusb, enum mtu3_dr_force_mode mode)
+{}
+
 #endif
 
 #endif		/* _MTU3_DR_H_ */

drivers/usb/mtu3/mtu3_host.c

@@ -189,6 +189,8 @@ int ssusb_host_disable(struct ssusb_mtk *ssusb, bool suspend)
 
 static void ssusb_host_setup(struct ssusb_mtk *ssusb)
 {
+	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
+
 	host_ports_num_get(ssusb);
 
 	/*
@@ -197,6 +199,9 @@ static void ssusb_host_setup(struct ssusb_mtk *ssusb)
 	 */
 	ssusb_host_enable(ssusb);
 
+	if (otg_sx->manual_drd_enabled)
+		ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
+
 	/* if port0 supports dual-role, works as host mode by default */
 	ssusb_set_vbus(&ssusb->otg_switch, 1);
 }

drivers/usb/mtu3/mtu3_hw_regs.h

@@ -472,6 +472,8 @@
 #define SSUSB_U3_PORT_DIS		BIT(0)
 
 /* U3D_SSUSB_U2_CTRL_0P */
+#define SSUSB_U2_PORT_RG_IDDIG		BIT(12)
+#define SSUSB_U2_PORT_FORCE_IDDIG	BIT(11)
 #define SSUSB_U2_PORT_VBUSVALID	BIT(9)
 #define SSUSB_U2_PORT_OTG_SEL		BIT(7)
 #define SSUSB_U2_PORT_HOST		BIT(2)

drivers/usb/mtu3/mtu3_plat.c

@@ -21,7 +21,6 @@
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
-#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 
 #include "mtu3.h"
@@ -212,33 +211,6 @@ static void ssusb_ip_sw_reset(struct ssusb_mtk *ssusb)
 	mtu3_clrbits(ssusb->ippc_base, U3D_SSUSB_IP_PW_CTRL0, SSUSB_IP_SW_RST);
 }
 
-static int get_iddig_pinctrl(struct ssusb_mtk *ssusb)
-{
-	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
-
-	otg_sx->id_pinctrl = devm_pinctrl_get(ssusb->dev);
-	if (IS_ERR(otg_sx->id_pinctrl)) {
-		dev_err(ssusb->dev, "Cannot find id pinctrl!\n");
-		return PTR_ERR(otg_sx->id_pinctrl);
-	}
-
-	otg_sx->id_float =
-		pinctrl_lookup_state(otg_sx->id_pinctrl, "id_float");
-	if (IS_ERR(otg_sx->id_float)) {
-		dev_err(ssusb->dev, "Cannot find pinctrl id_float!\n");
-		return PTR_ERR(otg_sx->id_float);
-	}
-
-	otg_sx->id_ground =
-		pinctrl_lookup_state(otg_sx->id_pinctrl, "id_ground");
-	if (IS_ERR(otg_sx->id_ground)) {
-		dev_err(ssusb->dev, "Cannot find pinctrl id_ground!\n");
-		return PTR_ERR(otg_sx->id_ground);
-	}
-
-	return 0;
-}
-
 /* ignore the error if the clock does not exist */
 static struct clk *get_optional_clk(struct device *dev, const char *id)
 {
@@ -349,15 +321,11 @@ static int get_ssusb_rscs(struct platform_device *pdev, struct ssusb_mtk *ssusb)
 			dev_err(ssusb->dev, "couldn't get extcon device\n");
 			return -EPROBE_DEFER;
 		}
-		if (otg_sx->manual_drd_enabled) {
-			ret = get_iddig_pinctrl(ssusb);
-			if (ret)
-				return ret;
-		}
 	}
 
-	dev_info(dev, "dr_mode: %d, is_u3_dr: %d, u3p_dis_msk:%x\n",
-		ssusb->dr_mode, otg_sx->is_u3_drd, ssusb->u3p_dis_msk);
+	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,
+		otg_sx->manual_drd_enabled ? "manual" : "auto");
 
 	return 0;
 }