1 files changed, 329 insertions, 0 deletions

diff --git a/drivers/usb/mtu3/mtu3_dr.c b/drivers/usb/mtu3/mtu3_dr.c
new file mode 100644
index 000000000..9b8aded3d
--- /dev/null
+++ b/drivers/usb/mtu3/mtu3_dr.c
@@ -0,0 +1,329 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * mtu3_dr.c - dual role switch and host glue layer
+ *
+ * Copyright (C) 2016 MediaTek Inc.
+ *
+ * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
+ */
+
+#include "mtu3.h"
+#include "mtu3_dr.h"
+#include "mtu3_debug.h"
+
+#define USB2_PORT 2
+#define USB3_PORT 3
+
+static inline struct ssusb_mtk *otg_sx_to_ssusb(struct otg_switch_mtk *otg_sx)
+{
+	return container_of(otg_sx, struct ssusb_mtk, otg_switch);
+}
+
+static void toggle_opstate(struct ssusb_mtk *ssusb)
+{
+	mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
+	mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
+}
+
+/* only port0 supports dual-role mode */
+static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
+	int version, bool tohost)
+{
+	void __iomem *ibase = ssusb->ippc_base;
+	u32 value;
+
+	dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
+		version, tohost ? "host" : "device");
+
+	if (version == USB2_PORT) {
+		/* 1. power off and disable u2 port0 */
+		value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
+		value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS;
+		mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
+
+		/* 2. power on, enable u2 port0 and select its mode */
+		value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
+		value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
+		value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) :
+			(value & (~SSUSB_U2_PORT_HOST_SEL));
+		mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
+	} else {
+		/* 1. power off and disable u3 port0 */
+		value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
+		value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS;
+		mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
+
+		/* 2. power on, enable u3 port0 and select its mode */
+		value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
+		value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS);
+		value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) :
+			(value & (~SSUSB_U3_PORT_HOST_SEL));
+		mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
+	}
+
+	return 0;
+}
+
+static void switch_port_to_host(struct ssusb_mtk *ssusb)
+{
+	u32 check_clk = 0;
+
+	dev_dbg(ssusb->dev, "%s\n", __func__);
+
+	ssusb_port0_switch(ssusb, USB2_PORT, true);
+
+	if (ssusb->otg_switch.is_u3_drd) {
+		ssusb_port0_switch(ssusb, USB3_PORT, true);
+		check_clk = SSUSB_U3_MAC_RST_B_STS;
+	}
+
+	ssusb_check_clocks(ssusb, check_clk);
+
+	/* after all clocks are stable */
+	toggle_opstate(ssusb);
+}
+
+static void switch_port_to_device(struct ssusb_mtk *ssusb)
+{
+	u32 check_clk = 0;
+
+	dev_dbg(ssusb->dev, "%s\n", __func__);
+
+	ssusb_port0_switch(ssusb, USB2_PORT, false);
+
+	if (ssusb->otg_switch.is_u3_drd) {
+		ssusb_port0_switch(ssusb, USB3_PORT, false);
+		check_clk = SSUSB_U3_MAC_RST_B_STS;
+	}
+
+	ssusb_check_clocks(ssusb, check_clk);
+}
+
+int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
+{
+	struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
+	struct regulator *vbus = otg_sx->vbus;
+	int ret;
+
+	/* vbus is optional */
+	if (!vbus)
+		return 0;
+
+	dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");
+
+	if (is_on) {
+		ret = regulator_enable(vbus);
+		if (ret) {
+			dev_err(ssusb->dev, "vbus regulator enable failed\n");
+			return ret;
+		}
+	} else {
+		regulator_disable(vbus);
+	}
+
+	return 0;
+}
+
+static void ssusb_mode_sw_work(struct work_struct *work)
+{
+	struct otg_switch_mtk *otg_sx =
+		container_of(work, struct otg_switch_mtk, dr_work);
+	struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
+	struct mtu3 *mtu = ssusb->u3d;
+	enum usb_role desired_role = otg_sx->desired_role;
+	enum usb_role current_role;
+
+	current_role = ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
+
+	if (desired_role == USB_ROLE_NONE) {
+		/* the default mode is host as probe does */
+		desired_role = USB_ROLE_HOST;
+		if (otg_sx->default_role == USB_ROLE_DEVICE)
+			desired_role = USB_ROLE_DEVICE;
+	}
+
+	if (current_role == desired_role)
+		return;
+
+	dev_dbg(ssusb->dev, "set role : %s\n", usb_role_string(desired_role));
+	mtu3_dbg_trace(ssusb->dev, "set role : %s", usb_role_string(desired_role));
+	pm_runtime_get_sync(ssusb->dev);
+
+	switch (desired_role) {
+	case USB_ROLE_HOST:
+		ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
+		mtu3_stop(mtu);
+		switch_port_to_host(ssusb);
+		ssusb_set_vbus(otg_sx, 1);
+		ssusb->is_host = true;
+		break;
+	case USB_ROLE_DEVICE:
+		ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
+		ssusb->is_host = false;
+		ssusb_set_vbus(otg_sx, 0);
+		switch_port_to_device(ssusb);
+		mtu3_start(mtu);
+		break;
+	case USB_ROLE_NONE:
+	default:
+		dev_err(ssusb->dev, "invalid role\n");
+	}
+	pm_runtime_put(ssusb->dev);
+}
+
+static void ssusb_set_mode(struct otg_switch_mtk *otg_sx, enum usb_role role)
+{
+	struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
+
+	if (ssusb->dr_mode != USB_DR_MODE_OTG)
+		return;
+
+	otg_sx->desired_role = role;
+	queue_work(system_freezable_wq, &otg_sx->dr_work);
+}
+
+static int ssusb_id_notifier(struct notifier_block *nb,
+	unsigned long event, void *ptr)
+{
+	struct otg_switch_mtk *otg_sx =
+		container_of(nb, struct otg_switch_mtk, id_nb);
+
+	ssusb_set_mode(otg_sx, event ? USB_ROLE_HOST : USB_ROLE_DEVICE);
+
+	return NOTIFY_DONE;
+}
+
+static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
+{
+	struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
+	struct extcon_dev *edev = otg_sx->edev;
+	int ret;
+
+	/* extcon is optional */
+	if (!edev)
+		return 0;
+
+	otg_sx->id_nb.notifier_call = ssusb_id_notifier;
+	ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
+					&otg_sx->id_nb);
+	if (ret < 0) {
+		dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");
+		return ret;
+	}
+
+	ret = extcon_get_state(edev, EXTCON_USB_HOST);
+	dev_dbg(ssusb->dev, "EXTCON_USB_HOST: %d\n", ret);
+
+	/* default as host, switch to device mode if needed */
+	if (!ret)
+		ssusb_set_mode(otg_sx, USB_ROLE_DEVICE);
+
+	return 0;
+}
+
+/*
+ * We provide an interface via debugfs to switch between host and device modes
+ * depending on user input.
+ * This is useful in special cases, such as uses TYPE-A receptacle but also
+ * wants to support dual-role mode.
+ */
+void ssusb_mode_switch(struct ssusb_mtk *ssusb, int to_host)
+{
+	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
+
+	ssusb_set_mode(otg_sx, to_host ? USB_ROLE_HOST : USB_ROLE_DEVICE);
+}
+
+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);
+}
+
+static int ssusb_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
+{
+	struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
+	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
+
+	ssusb_set_mode(otg_sx, role);
+
+	return 0;
+}
+
+static enum usb_role ssusb_role_sw_get(struct usb_role_switch *sw)
+{
+	struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
+
+	return ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
+}
+
+static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx)
+{
+	struct usb_role_switch_desc role_sx_desc = { 0 };
+	struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
+	struct device *dev = ssusb->dev;
+	enum usb_dr_mode mode;
+
+	if (!otg_sx->role_sw_used)
+		return 0;
+
+	mode = usb_get_role_switch_default_mode(dev);
+	if (mode == USB_DR_MODE_PERIPHERAL)
+		otg_sx->default_role = USB_ROLE_DEVICE;
+	else
+		otg_sx->default_role = USB_ROLE_HOST;
+
+	role_sx_desc.set = ssusb_role_sw_set;
+	role_sx_desc.get = ssusb_role_sw_get;
+	role_sx_desc.fwnode = dev_fwnode(dev);
+	role_sx_desc.driver_data = ssusb;
+	otg_sx->role_sw = usb_role_switch_register(dev, &role_sx_desc);
+	if (IS_ERR(otg_sx->role_sw))
+		return PTR_ERR(otg_sx->role_sw);
+
+	ssusb_set_mode(otg_sx, otg_sx->default_role);
+
+	return 0;
+}
+
+int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
+{
+	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
+	int ret = 0;
+
+	INIT_WORK(&otg_sx->dr_work, ssusb_mode_sw_work);
+
+	if (otg_sx->manual_drd_enabled)
+		ssusb_dr_debugfs_init(ssusb);
+	else if (otg_sx->role_sw_used)
+		ret = ssusb_role_sw_register(otg_sx);
+	else
+		ret = ssusb_extcon_register(otg_sx);
+
+	return ret;
+}
+
+void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
+{
+	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
+
+	cancel_work_sync(&otg_sx->dr_work);
+	usb_role_switch_unregister(otg_sx->role_sw);
+}