usb: Add MediaTek USB3 DRD driver

This patch adds support for the MediaTek USB3 controller
integrated into MT8173. It currently supports High-Speed
Peripheral Only mode.

Super-Speed Peripheral, Dual-Role Device and Host Only (xHCI)
modes will be added in the next patchs.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

10 files changed, 3857 insertions, 0 deletions

diff --git a/drivers/usb/mtu3/Kconfig b/drivers/usb/mtu3/Kconfig
new file mode 100644
index 000000000000..54dadee36f4d
--- /dev/null
+++ b/drivers/usb/mtu3/Kconfig
@@ -0,0 +1,32 @@
+# For MTK USB3.0 IP
+
+config USB_MTU3
+	tristate "MediaTek USB3 Dual Role controller"
+	depends on (USB || USB_GADGET) && HAS_DMA
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	help
+	  Say Y or M here if your system runs on MediaTek SoCs with
+	  Dual Role SuperSpeed USB controller. You can select usb
+	  mode as peripheral role or host role, or both.
+
+	  If you don't know what this is, please say N.
+
+	  Choose M here to compile this driver as a module, and it
+	  will be called mtu3.ko.
+
+
+if USB_MTU3
+choice
+	bool "MTU3 Mode Selection"
+	default USB_MTU3_GADGET if (!USB && USB_GADGET)
+
+config USB_MTU3_GADGET
+	bool "Gadget only mode"
+	depends on USB_GADGET=y || USB_GADGET=USB_MTU3
+	help
+	  Select this when you want to use MTU3 in gadget mode only,
+	  thereby the host feature will be regressed.
+
+endchoice
+
+endif
diff --git a/drivers/usb/mtu3/Makefile b/drivers/usb/mtu3/Makefile
new file mode 100644
index 000000000000..532c2570c58b
--- /dev/null
+++ b/drivers/usb/mtu3/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_USB_MTU3)	+= mtu3.o
+mtu3-y	:= mtu3_plat.o mtu3_core.o mtu3_gadget_ep0.o mtu3_gadget.o mtu3_qmu.o
diff --git a/drivers/usb/mtu3/mtu3.h b/drivers/usb/mtu3/mtu3.h
new file mode 100644
index 000000000000..ad1a1338bff1
--- /dev/null
+++ b/drivers/usb/mtu3/mtu3.h
@@ -0,0 +1,341 @@
+/*
+ * mtu3.h - MediaTek USB3 DRD header
+ *
+ * Copyright (C) 2016 MediaTek Inc.
+ *
+ * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef __MTU3_H__
+#define __MTU3_H__
+
+#include <linux/device.h>
+#include <linux/dmapool.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/phy/phy.h>
+#include <linux/regulator/consumer.h>
+#include <linux/usb.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/otg.h>
+
+struct mtu3;
+struct mtu3_ep;
+struct mtu3_request;
+
+#include "mtu3_hw_regs.h"
+#include "mtu3_qmu.h"
+
+#define	MU3D_EP_TXCR0(epnum)	(U3D_TX1CSR0 + (((epnum) - 1) * 0x10))
+#define	MU3D_EP_TXCR1(epnum)	(U3D_TX1CSR1 + (((epnum) - 1) * 0x10))
+#define	MU3D_EP_TXCR2(epnum)	(U3D_TX1CSR2 + (((epnum) - 1) * 0x10))
+
+#define	MU3D_EP_RXCR0(epnum)	(U3D_RX1CSR0 + (((epnum) - 1) * 0x10))
+#define	MU3D_EP_RXCR1(epnum)	(U3D_RX1CSR1 + (((epnum) - 1) * 0x10))
+#define	MU3D_EP_RXCR2(epnum)	(U3D_RX1CSR2 + (((epnum) - 1) * 0x10))
+
+#define USB_QMU_RQCSR(epnum)	(U3D_RXQCSR1 + (((epnum) - 1) * 0x10))
+#define USB_QMU_RQSAR(epnum)	(U3D_RXQSAR1 + (((epnum) - 1) * 0x10))
+#define USB_QMU_RQCPR(epnum)	(U3D_RXQCPR1 + (((epnum) - 1) * 0x10))
+
+#define USB_QMU_TQCSR(epnum)	(U3D_TXQCSR1 + (((epnum) - 1) * 0x10))
+#define USB_QMU_TQSAR(epnum)	(U3D_TXQSAR1 + (((epnum) - 1) * 0x10))
+#define USB_QMU_TQCPR(epnum)	(U3D_TXQCPR1 + (((epnum) - 1) * 0x10))
+
+#define SSUSB_U2_CTRL(p)	(U3D_SSUSB_U2_CTRL_0P + ((p) * 0x08))
+
+#define MTU3_DRIVER_NAME	"mtu3"
+#define	DMA_ADDR_INVALID	(~(dma_addr_t)0)
+
+#define MTU3_EP_ENABLED		BIT(0)
+#define MTU3_EP_STALL		BIT(1)
+#define MTU3_EP_WEDGE		BIT(2)
+#define MTU3_EP_BUSY		BIT(3)
+
+#define MTU3_U2_IP_SLOT_DEFAULT 1
+
+/**
+ * Normally the device works on HS or SS, to simplify fifo management,
+ * devide fifo into some 512B parts, use bitmap to manage it; And
+ * 128 bits size of bitmap is large enough, that means it can manage
+ * up to 64KB fifo size.
+ * NOTE: MTU3_EP_FIFO_UNIT should be power of two
+ */
+#define MTU3_EP_FIFO_UNIT		(1 << 9)
+#define MTU3_FIFO_BIT_SIZE		128
+#define MTU3_U2_IP_EP0_FIFO_SIZE	64
+
+/**
+ * Maximum size of ep0 response buffer for ch9 requests,
+ * the SET_SEL request uses 6 so far, and GET_STATUS is 2
+ */
+#define EP0_RESPONSE_BUF  6
+
+/* device operated link and speed got from DEVICE_CONF register */
+enum mtu3_speed {
+	MTU3_SPEED_INACTIVE = 0,
+	MTU3_SPEED_FULL = 1,
+	MTU3_SPEED_HIGH = 3,
+};
+
+/**
+ * @MU3D_EP0_STATE_SETUP: waits for SETUP or received a SETUP
+ *		without data stage.
+ * @MU3D_EP0_STATE_TX: IN data stage
+ * @MU3D_EP0_STATE_RX: OUT data stage
+ * @MU3D_EP0_STATE_TX_END: the last IN data is transferred, and
+ *		waits for its completion interrupt
+ * @MU3D_EP0_STATE_STALL: ep0 is in stall status, will be auto-cleared
+ *		after receives a SETUP.
+ */
+enum mtu3_g_ep0_state {
+	MU3D_EP0_STATE_SETUP = 1,
+	MU3D_EP0_STATE_TX,
+	MU3D_EP0_STATE_RX,
+	MU3D_EP0_STATE_TX_END,
+	MU3D_EP0_STATE_STALL,
+};
+
+/**
+ * @base: the base address of fifo
+ * @limit: the bitmap size in bits
+ * @bitmap: fifo bitmap in unit of @MTU3_EP_FIFO_UNIT
+ */
+struct mtu3_fifo_info {
+	u32 base;
+	u32 limit;
+	DECLARE_BITMAP(bitmap, MTU3_FIFO_BIT_SIZE);
+};
+
+/**
+ * General Purpose Descriptor (GPD):
+ *	The format of TX GPD is a little different from RX one.
+ *	And the size of GPD is 16 bytes.
+ *
+ * @flag:
+ *	bit0: Hardware Own (HWO)
+ *	bit1: Buffer Descriptor Present (BDP), always 0, BD is not supported
+ *	bit2: Bypass (BPS), 1: HW skips this GPD if HWO = 1
+ *	bit7: Interrupt On Completion (IOC)
+ * @chksum: This is used to validate the contents of this GPD;
+ *	If TXQ_CS_EN / RXQ_CS_EN bit is set, an interrupt is issued
+ *	when checksum validation fails;
+ *	Checksum value is calculated over the 16 bytes of the GPD by default;
+ * @data_buf_len (RX ONLY): This value indicates the length of
+ *	the assigned data buffer
+ * @next_gpd: Physical address of the next GPD
+ * @buffer: Physical address of the data buffer
+ * @buf_len:
+ *	(TX): This value indicates the length of the assigned data buffer
+ *	(RX): The total length of data received
+ * @ext_len: reserved
+ * @ext_flag:
+ *	bit5 (TX ONLY): Zero Length Packet (ZLP),
+ */
+struct qmu_gpd {
+	__u8 flag;
+	__u8 chksum;
+	__le16 data_buf_len;
+	__le32 next_gpd;
+	__le32 buffer;
+	__le16 buf_len;
+	__u8 ext_len;
+	__u8 ext_flag;
+} __packed;
+
+/**
+* dma: physical base address of GPD segment
+* start: virtual base address of GPD segment
+* end: the last GPD element
+* enqueue: the first empty GPD to use
+* dequeue: the first completed GPD serviced by ISR
+* NOTE: the size of GPD ring should be >= 2
+*/
+struct mtu3_gpd_ring {
+	dma_addr_t dma;
+	struct qmu_gpd *start;
+	struct qmu_gpd *end;
+	struct qmu_gpd *enqueue;
+	struct qmu_gpd *dequeue;
+};
+
+/**
+ * @fifo_size: it is (@slot + 1) * @fifo_seg_size
+ * @fifo_seg_size: it is roundup_pow_of_two(@maxp)
+ */
+struct mtu3_ep {
+	struct usb_ep ep;
+	char name[12];
+	struct mtu3 *mtu;
+	u8 epnum;
+	u8 type;
+	u8 is_in;
+	u16 maxp;
+	int slot;
+	u32 fifo_size;
+	u32 fifo_addr;
+	u32 fifo_seg_size;
+	struct mtu3_fifo_info *fifo;
+
+	struct list_head req_list;
+	struct mtu3_gpd_ring gpd_ring;
+	const struct usb_endpoint_descriptor *desc;
+
+	int flags;
+	u8 wedged;
+	u8 busy;
+};
+
+struct mtu3_request {
+	struct usb_request request;
+	struct list_head list;
+	struct mtu3_ep *mep;
+	struct mtu3 *mtu;
+	struct qmu_gpd *gpd;
+	int epnum;
+};
+
+/**
+ * struct mtu3 - device driver instance data.
+ * @slot: MTU3_U2_IP_SLOT_DEFAULT for U2 IP
+ * @may_wakeup: means device's remote wakeup is enabled
+ * @is_self_powered: is reported in device status and the config descriptor
+ * @ep0_req: dummy request used while handling standard USB requests
+ *		for GET_STATUS and SET_SEL
+ * @setup_buf: ep0 response buffer for GET_STATUS and SET_SEL requests
+ */
+struct mtu3 {
+	spinlock_t lock;
+	struct device *dev;
+	void __iomem *mac_base;
+	void __iomem *ippc_base;
+	struct phy *phy;
+	struct regulator *vusb33;
+	struct clk *sys_clk;
+	int irq;
+
+	struct mtu3_fifo_info tx_fifo;
+	struct mtu3_fifo_info rx_fifo;
+
+	struct mtu3_ep *ep_array;
+	struct mtu3_ep *in_eps;
+	struct mtu3_ep *out_eps;
+	struct mtu3_ep *ep0;
+	int num_eps;
+	int slot;
+	int active_ep;
+
+	struct dma_pool	*qmu_gpd_pool;
+	enum mtu3_g_ep0_state ep0_state;
+	struct usb_gadget g;	/* the gadget */
+	struct usb_gadget_driver *gadget_driver;
+	struct mtu3_request ep0_req;
+	u8 setup_buf[EP0_RESPONSE_BUF];
+
+	unsigned is_active:1;
+	unsigned may_wakeup:1;
+	unsigned is_self_powered:1;
+	unsigned test_mode:1;
+	unsigned softconnect:1;
+
+	u8 address;
+	u8 test_mode_nr;
+	u32 hw_version;
+};
+
+static inline struct mtu3 *gadget_to_mtu3(struct usb_gadget *g)
+{
+	return container_of(g, struct mtu3, g);
+}
+
+static inline int is_first_entry(const struct list_head *list,
+	const struct list_head *head)
+{
+	return list_is_last(head, list);
+}
+
+static inline struct mtu3_request *to_mtu3_request(struct usb_request *req)
+{
+	return req ? container_of(req, struct mtu3_request, request) : NULL;
+}
+
+static inline struct mtu3_ep *to_mtu3_ep(struct usb_ep *ep)
+{
+	return ep ? container_of(ep, struct mtu3_ep, ep) : NULL;
+}
+
+static inline struct mtu3_request *next_request(struct mtu3_ep *mep)
+{
+	struct list_head *queue = &mep->req_list;
+
+	if (list_empty(queue))
+		return NULL;
+
+	return list_first_entry(queue, struct mtu3_request, list);
+}
+
+static inline void mtu3_writel(void __iomem *base, u32 offset, u32 data)
+{
+	writel(data, base + offset);
+}
+
+static inline u32 mtu3_readl(void __iomem *base, u32 offset)
+{
+	return readl(base + offset);
+}
+
+static inline void mtu3_setbits(void __iomem *base, u32 offset, u32 bits)
+{
+	void __iomem *addr = base + offset;
+	u32 tmp = readl(addr);
+
+	writel((tmp | (bits)), addr);
+}
+
+static inline void mtu3_clrbits(void __iomem *base, u32 offset, u32 bits)
+{
+	void __iomem *addr = base + offset;
+	u32 tmp = readl(addr);
+
+	writel((tmp & ~(bits)), addr);
+}
+
+int ssusb_check_clocks(struct mtu3 *mtu, u32 ex_clks);
+struct usb_request *mtu3_alloc_request(struct usb_ep *ep, gfp_t gfp_flags);
+void mtu3_free_request(struct usb_ep *ep, struct usb_request *req);
+void mtu3_req_complete(struct mtu3_ep *mep,
+		struct usb_request *req, int status);
+
+int mtu3_config_ep(struct mtu3 *mtu, struct mtu3_ep *mep,
+		int interval, int burst, int mult);
+void mtu3_deconfig_ep(struct mtu3 *mtu, struct mtu3_ep *mep);
+void mtu3_ep_stall_set(struct mtu3_ep *mep, bool set);
+void mtu3_ep0_setup(struct mtu3 *mtu);
+void mtu3_start(struct mtu3 *mtu);
+void mtu3_stop(struct mtu3 *mtu);
+void mtu3_hs_softconn_set(struct mtu3 *mtu, bool enable);
+
+int mtu3_gadget_setup(struct mtu3 *mtu);
+void mtu3_gadget_cleanup(struct mtu3 *mtu);
+void mtu3_gadget_reset(struct mtu3 *mtu);
+void mtu3_gadget_suspend(struct mtu3 *mtu);
+void mtu3_gadget_resume(struct mtu3 *mtu);
+void mtu3_gadget_disconnect(struct mtu3 *mtu);
+int ssusb_gadget_init(struct mtu3 *mtu);
+void ssusb_gadget_exit(struct mtu3 *mtu);
+
+irqreturn_t mtu3_ep0_isr(struct mtu3 *mtu);
+extern const struct usb_ep_ops mtu3_ep0_ops;
+
+#endif
diff --git a/drivers/usb/mtu3/mtu3_core.c b/drivers/usb/mtu3/mtu3_core.c
new file mode 100644
index 000000000000..33d21dddb8a0
--- /dev/null
+++ b/drivers/usb/mtu3/mtu3_core.c
@@ -0,0 +1,675 @@
+/*
+ * mtu3_core.c - hardware access layer and gadget init/exit of
+ *                     MediaTek usb3 Dual-Role Controller Driver
+ *
+ * Copyright (C) 2016 MediaTek Inc.
+ *
+ * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+#include "mtu3.h"
+
+static int ep_fifo_alloc(struct mtu3_ep *mep, u32 seg_size)
+{
+	struct mtu3_fifo_info *fifo = mep->fifo;
+	u32 num_bits = DIV_ROUND_UP(seg_size, MTU3_EP_FIFO_UNIT);
+	u32 start_bit;
+
+	/* ensure that @mep->fifo_seg_size is power of two */
+	num_bits = roundup_pow_of_two(num_bits);
+	if (num_bits > fifo->limit)
+		return -EINVAL;
+
+	mep->fifo_seg_size = num_bits * MTU3_EP_FIFO_UNIT;
+	num_bits = num_bits * (mep->slot + 1);
+	start_bit = bitmap_find_next_zero_area(fifo->bitmap,
+			fifo->limit, 0, num_bits, 0);
+	if (start_bit >= fifo->limit)
+		return -EOVERFLOW;
+
+	bitmap_set(fifo->bitmap, start_bit, num_bits);
+	mep->fifo_size = num_bits * MTU3_EP_FIFO_UNIT;
+	mep->fifo_addr = fifo->base + MTU3_EP_FIFO_UNIT * start_bit;
+
+	dev_dbg(mep->mtu->dev, "%s fifo:%#x/%#x, start_bit: %d\n",
+		__func__, mep->fifo_seg_size, mep->fifo_size, start_bit);
+
+	return mep->fifo_addr;
+}
+
+static void ep_fifo_free(struct mtu3_ep *mep)
+{
+	struct mtu3_fifo_info *fifo = mep->fifo;
+	u32 addr = mep->fifo_addr;
+	u32 bits = mep->fifo_size / MTU3_EP_FIFO_UNIT;
+	u32 start_bit;
+
+	if (unlikely(addr < fifo->base || bits > fifo->limit))
+		return;
+
+	start_bit = (addr - fifo->base) / MTU3_EP_FIFO_UNIT;
+	bitmap_clear(fifo->bitmap, start_bit, bits);
+	mep->fifo_size = 0;
+	mep->fifo_seg_size = 0;
+
+	dev_dbg(mep->mtu->dev, "%s size:%#x/%#x, start_bit: %d\n",
+		__func__, mep->fifo_seg_size, mep->fifo_size, start_bit);
+}
+
+/* set/clear U3D HS device soft connect */
+void mtu3_hs_softconn_set(struct mtu3 *mtu, bool enable)
+{
+	if (enable) {
+		mtu3_setbits(mtu->mac_base, U3D_POWER_MANAGEMENT,
+			SOFT_CONN | SUSPENDM_ENABLE);
+	} else {
+		mtu3_clrbits(mtu->mac_base, U3D_POWER_MANAGEMENT,
+			SOFT_CONN | SUSPENDM_ENABLE);
+	}
+	dev_dbg(mtu->dev, "SOFTCONN = %d\n", !!enable);
+}
+
+/* only port0 of U2/U3 supports device mode */
+static int mtu3_device_enable(struct mtu3 *mtu)
+{
+	void __iomem *ibase = mtu->ippc_base;
+	u32 check_clk = 0;
+
+	mtu3_clrbits(ibase, U3D_SSUSB_IP_PW_CTRL2, SSUSB_IP_DEV_PDN);
+	mtu3_clrbits(ibase, SSUSB_U2_CTRL(0),
+		(SSUSB_U2_PORT_DIS | SSUSB_U2_PORT_PDN |
+		SSUSB_U2_PORT_HOST_SEL));
+	mtu3_setbits(ibase, SSUSB_U2_CTRL(0), SSUSB_U2_PORT_OTG_SEL);
+
+	return ssusb_check_clocks(mtu, check_clk);
+}
+
+static void mtu3_device_disable(struct mtu3 *mtu)
+{
+	void __iomem *ibase = mtu->ippc_base;
+
+	mtu3_setbits(ibase, SSUSB_U2_CTRL(0),
+		SSUSB_U2_PORT_DIS | SSUSB_U2_PORT_PDN);
+	mtu3_clrbits(ibase, SSUSB_U2_CTRL(0), SSUSB_U2_PORT_OTG_SEL);
+	mtu3_setbits(ibase, U3D_SSUSB_IP_PW_CTRL2, SSUSB_IP_DEV_PDN);
+}
+
+/* reset U3D's device module. */
+static void mtu3_device_reset(struct mtu3 *mtu)
+{
+	void __iomem *ibase = mtu->ippc_base;
+
+	mtu3_setbits(ibase, U3D_SSUSB_DEV_RST_CTRL, SSUSB_DEV_SW_RST);
+	udelay(1);
+	mtu3_clrbits(ibase, U3D_SSUSB_DEV_RST_CTRL, SSUSB_DEV_SW_RST);
+}
+
+/* disable all interrupts */
+static void mtu3_intr_disable(struct mtu3 *mtu)
+{
+	void __iomem *mbase = mtu->mac_base;
+
+	/* Disable level 1 interrupts */
+	mtu3_writel(mbase, U3D_LV1IECR, ~0x0);
+
+	/* Disable endpoint interrupts */
+	mtu3_writel(mbase, U3D_EPIECR, ~0x0);
+}
+
+static void mtu3_intr_status_clear(struct mtu3 *mtu)
+{
+	void __iomem *mbase = mtu->mac_base;
+
+	/* Clear EP0 and Tx/Rx EPn interrupts status */
+	mtu3_writel(mbase, U3D_EPISR, ~0x0);
+
+	/* Clear U2 USB common interrupts status */
+	mtu3_writel(mbase, U3D_COMMON_USB_INTR, ~0x0);
+
+	/* Clear speed change interrupt status */
+	mtu3_writel(mbase, U3D_DEV_LINK_INTR, ~0x0);
+}
+
+/* enable system global interrupt */
+static void mtu3_intr_enable(struct mtu3 *mtu)
+{
+	void __iomem *mbase = mtu->mac_base;
+	u32 value;
+
+	/*Enable level 1 interrupts (BMU, QMU, MAC3, DMA, MAC2, EPCTL) */
+	value = BMU_INTR | QMU_INTR | MAC2_INTR | EP_CTRL_INTR;
+	mtu3_writel(mbase, U3D_LV1IESR, value);
+
+	/* Enable U2 common USB interrupts */
+	value = SUSPEND_INTR | RESUME_INTR | RESET_INTR;
+	mtu3_writel(mbase, U3D_COMMON_USB_INTR_ENABLE, value);
+
+	/* Enable QMU interrupts. */
+	value = TXQ_CSERR_INT | TXQ_LENERR_INT | RXQ_CSERR_INT |
+			RXQ_LENERR_INT | RXQ_ZLPERR_INT;
+	mtu3_writel(mbase, U3D_QIESR1, value);
+
+	/* Enable speed change interrupt */
+	mtu3_writel(mbase, U3D_DEV_LINK_INTR_ENABLE, SSUSB_DEV_SPEED_CHG_INTR);
+}
+
+/* set/clear the stall and toggle bits for non-ep0 */
+void mtu3_ep_stall_set(struct mtu3_ep *mep, bool set)
+{
+	struct mtu3 *mtu = mep->mtu;
+	void __iomem *mbase = mtu->mac_base;
+	u8 epnum = mep->epnum;
+	u32 csr;
+
+	if (mep->is_in) {	/* TX */
+		csr = mtu3_readl(mbase, MU3D_EP_TXCR0(epnum)) & TX_W1C_BITS;
+		if (set)
+			csr |= TX_SENDSTALL;
+		else
+			csr = (csr & (~TX_SENDSTALL)) | TX_SENTSTALL;
+		mtu3_writel(mbase, MU3D_EP_TXCR0(epnum), csr);
+	} else {	/* RX */
+		csr = mtu3_readl(mbase, MU3D_EP_RXCR0(epnum)) & RX_W1C_BITS;
+		if (set)
+			csr |= RX_SENDSTALL;
+		else
+			csr = (csr & (~RX_SENDSTALL)) | RX_SENTSTALL;
+		mtu3_writel(mbase, MU3D_EP_RXCR0(epnum), csr);
+	}
+
+	if (!set) {
+		mtu3_setbits(mbase, U3D_EP_RST, EP_RST(mep->is_in, epnum));
+		mtu3_clrbits(mbase, U3D_EP_RST, EP_RST(mep->is_in, epnum));
+		mep->flags &= ~MTU3_EP_STALL;
+	} else {
+		mep->flags |= MTU3_EP_STALL;
+	}
+
+	dev_dbg(mtu->dev, "%s: %s\n", mep->name,
+		set ? "SEND STALL" : "CLEAR STALL, with EP RESET");
+}
+
+void mtu3_start(struct mtu3 *mtu)
+{
+	void __iomem *mbase = mtu->mac_base;
+
+	dev_dbg(mtu->dev, "%s devctl 0x%x\n", __func__,
+		mtu3_readl(mbase, U3D_DEVICE_CONTROL));
+
+	mtu3_clrbits(mtu->ippc_base, U3D_SSUSB_IP_PW_CTRL2, SSUSB_IP_DEV_PDN);
+
+	/* Initialize the default interrupts */
+	mtu3_intr_enable(mtu);
+
+	mtu->is_active = 1;
+
+	if (mtu->softconnect)
+		mtu3_hs_softconn_set(mtu, 1);
+}
+
+void mtu3_stop(struct mtu3 *mtu)
+{
+	dev_dbg(mtu->dev, "%s\n", __func__);
+
+	mtu3_intr_disable(mtu);
+	mtu3_intr_status_clear(mtu);
+
+	if (mtu->softconnect)
+		mtu3_hs_softconn_set(mtu, 0);
+
+	mtu->is_active = 0;
+	mtu3_setbits(mtu->ippc_base, U3D_SSUSB_IP_PW_CTRL2, SSUSB_IP_DEV_PDN);
+}
+
+/* for non-ep0 */
+int mtu3_config_ep(struct mtu3 *mtu, struct mtu3_ep *mep,
+			int interval, int burst, int mult)
+{
+	void __iomem *mbase = mtu->mac_base;
+	int epnum = mep->epnum;
+	u32 csr0, csr1, csr2;
+	int fifo_sgsz, fifo_addr;
+	int num_pkts;
+
+	fifo_addr = ep_fifo_alloc(mep, mep->maxp);
+	if (fifo_addr < 0) {
+		dev_err(mtu->dev, "alloc ep fifo failed(%d)\n", mep->maxp);
+		return -ENOMEM;
+	}
+	fifo_sgsz = ilog2(mep->fifo_seg_size);
+	dev_dbg(mtu->dev, "%s fifosz: %x(%x/%x)\n", __func__, fifo_sgsz,
+		mep->fifo_seg_size, mep->fifo_size);
+
+	if (mep->is_in) {
+		csr0 = TX_TXMAXPKTSZ(mep->maxp);
+		csr0 |= TX_DMAREQEN;
+
+		num_pkts = (burst + 1) * (mult + 1) - 1;
+		csr1 = TX_SS_BURST(burst) | TX_SLOT(mep->slot);
+		csr1 |= TX_MAX_PKT(num_pkts) | TX_MULT(mult);
+
+		csr2 = TX_FIFOADDR(fifo_addr >> 4);
+		csr2 |= TX_FIFOSEGSIZE(fifo_sgsz);
+
+		switch (mep->type) {
+		case USB_ENDPOINT_XFER_BULK:
+			csr1 |= TX_TYPE(TYPE_BULK);
+			break;
+		case USB_ENDPOINT_XFER_ISOC:
+			csr1 |= TX_TYPE(TYPE_ISO);
+			csr2 |= TX_BINTERVAL(interval);
+			break;
+		case USB_ENDPOINT_XFER_INT:
+			csr1 |= TX_TYPE(TYPE_INT);
+			csr2 |= TX_BINTERVAL(interval);
+			break;
+		}
+
+		/* Enable QMU Done interrupt */
+		mtu3_setbits(mbase, U3D_QIESR0, QMU_TX_DONE_INT(epnum));
+
+		mtu3_writel(mbase, MU3D_EP_TXCR0(epnum), csr0);
+		mtu3_writel(mbase, MU3D_EP_TXCR1(epnum), csr1);
+		mtu3_writel(mbase, MU3D_EP_TXCR2(epnum), csr2);
+
+		dev_dbg(mtu->dev, "U3D_TX%d CSR0:%#x, CSR1:%#x, CSR2:%#x\n",
+			epnum, mtu3_readl(mbase, MU3D_EP_TXCR0(epnum)),
+			mtu3_readl(mbase, MU3D_EP_TXCR1(epnum)),
+			mtu3_readl(mbase, MU3D_EP_TXCR2(epnum)));
+	} else {
+		csr0 = RX_RXMAXPKTSZ(mep->maxp);
+		csr0 |= RX_DMAREQEN;
+
+		num_pkts = (burst + 1) * (mult + 1) - 1;
+		csr1 = RX_SS_BURST(burst) | RX_SLOT(mep->slot);
+		csr1 |= RX_MAX_PKT(num_pkts) | RX_MULT(mult);
+
+		csr2 = RX_FIFOADDR(fifo_addr >> 4);
+		csr2 |= RX_FIFOSEGSIZE(fifo_sgsz);
+
+		switch (mep->type) {
+		case USB_ENDPOINT_XFER_BULK:
+			csr1 |= RX_TYPE(TYPE_BULK);
+			break;
+		case USB_ENDPOINT_XFER_ISOC:
+			csr1 |= RX_TYPE(TYPE_ISO);
+			csr2 |= RX_BINTERVAL(interval);
+			break;
+		case USB_ENDPOINT_XFER_INT:
+			csr1 |= RX_TYPE(TYPE_INT);
+			csr2 |= RX_BINTERVAL(interval);
+			break;
+		}
+
+		/*Enable QMU Done interrupt */
+		mtu3_setbits(mbase, U3D_QIESR0, QMU_RX_DONE_INT(epnum));
+
+		mtu3_writel(mbase, MU3D_EP_RXCR0(epnum), csr0);
+		mtu3_writel(mbase, MU3D_EP_RXCR1(epnum), csr1);
+		mtu3_writel(mbase, MU3D_EP_RXCR2(epnum), csr2);
+
+		dev_dbg(mtu->dev, "U3D_RX%d CSR0:%#x, CSR1:%#x, CSR2:%#x\n",
+			epnum, mtu3_readl(mbase, MU3D_EP_RXCR0(epnum)),
+			mtu3_readl(mbase, MU3D_EP_RXCR1(epnum)),
+			mtu3_readl(mbase, MU3D_EP_RXCR2(epnum)));
+	}
+
+	dev_dbg(mtu->dev, "csr0:%#x, csr1:%#x, csr2:%#x\n", csr0, csr1, csr2);
+	dev_dbg(mtu->dev, "%s: %s, fifo-addr:%#x, fifo-size:%#x(%#x/%#x)\n",
+		__func__, mep->name, mep->fifo_addr, mep->fifo_size,
+		fifo_sgsz, mep->fifo_seg_size);
+
+	return 0;
+}
+
+/* for non-ep0 */
+void mtu3_deconfig_ep(struct mtu3 *mtu, struct mtu3_ep *mep)
+{
+	void __iomem *mbase = mtu->mac_base;
+	int epnum = mep->epnum;
+
+	if (mep->is_in) {
+		mtu3_writel(mbase, MU3D_EP_TXCR0(epnum), 0);
+		mtu3_writel(mbase, MU3D_EP_TXCR1(epnum), 0);
+		mtu3_writel(mbase, MU3D_EP_TXCR2(epnum), 0);
+		mtu3_setbits(mbase, U3D_QIECR0, QMU_TX_DONE_INT(epnum));
+	} else {
+		mtu3_writel(mbase, MU3D_EP_RXCR0(epnum), 0);
+		mtu3_writel(mbase, MU3D_EP_RXCR1(epnum), 0);
+		mtu3_writel(mbase, MU3D_EP_RXCR2(epnum), 0);
+		mtu3_setbits(mbase, U3D_QIECR0, QMU_RX_DONE_INT(epnum));
+	}
+
+	ep_fifo_free(mep);
+
+	dev_dbg(mtu->dev, "%s: %s\n", __func__, mep->name);
+}
+
+/*
+ * 1. when supports only HS, the fifo is shared for all EPs, and
+ *	the capability registers of @EPNTXFFSZ or @EPNRXFFSZ indicate
+ *	the total fifo size of non-ep0, and ep0's is fixed to 64B,
+ *	so the total fifo size is 64B + @EPNTXFFSZ;
+ *	Due to the first 64B should be reserved for EP0, non-ep0's fifo
+ *	starts from offset 64 and are divided into two equal parts for
+ *	TX or RX EPs for simplification.
+ */
+static void get_ep_fifo_config(struct mtu3 *mtu)
+{
+	struct mtu3_fifo_info *tx_fifo;
+	struct mtu3_fifo_info *rx_fifo;
+	u32 fifosize;
+
+	fifosize = mtu3_readl(mtu->mac_base, U3D_CAP_EPNTXFFSZ);
+	tx_fifo = &mtu->tx_fifo;
+	tx_fifo->base = MTU3_U2_IP_EP0_FIFO_SIZE;
+	tx_fifo->limit = (fifosize / MTU3_EP_FIFO_UNIT) >> 1;
+	bitmap_zero(tx_fifo->bitmap, MTU3_FIFO_BIT_SIZE);
+
+	rx_fifo = &mtu->rx_fifo;
+	rx_fifo->base =
+		tx_fifo->base + tx_fifo->limit * MTU3_EP_FIFO_UNIT;
+	rx_fifo->limit = tx_fifo->limit;
+	bitmap_zero(rx_fifo->bitmap, MTU3_FIFO_BIT_SIZE);
+	mtu->slot = MTU3_U2_IP_SLOT_DEFAULT;
+
+	dev_dbg(mtu->dev, "%s, TX: base-%d, limit-%d; RX: base-%d, limit-%d\n",
+		__func__, tx_fifo->base, tx_fifo->limit,
+		rx_fifo->base, rx_fifo->limit);
+}
+
+void mtu3_ep0_setup(struct mtu3 *mtu)
+{
+	u32 maxpacket = mtu->g.ep0->maxpacket;
+	u32 csr;
+
+	dev_dbg(mtu->dev, "%s maxpacket: %d\n", __func__, maxpacket);
+
+	csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR);
+	csr &= ~EP0_MAXPKTSZ_MSK;
+	csr |= EP0_MAXPKTSZ(maxpacket);
+	csr &= EP0_W1C_BITS;
+	mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr);
+
+	/* Enable EP0 interrupt */
+	mtu3_writel(mtu->mac_base, U3D_EPIESR, EP0ISR);
+}
+
+static int mtu3_mem_alloc(struct mtu3 *mtu)
+{
+	void __iomem *mbase = mtu->mac_base;
+	struct mtu3_ep *ep_array;
+	int in_ep_num, out_ep_num;
+	u32 cap_epinfo;
+	int ret;
+	int i;
+
+	mtu->hw_version = mtu3_readl(mtu->ippc_base, U3D_SSUSB_HW_ID);
+
+	cap_epinfo = mtu3_readl(mbase, U3D_CAP_EPINFO);
+	in_ep_num = CAP_TX_EP_NUM(cap_epinfo);
+	out_ep_num = CAP_RX_EP_NUM(cap_epinfo);
+
+	dev_info(mtu->dev, "IP version 0x%x\n", mtu->hw_version);
+	dev_info(mtu->dev, "fifosz/epnum: Tx=%#x/%d, Rx=%#x/%d\n",
+		 mtu3_readl(mbase, U3D_CAP_EPNTXFFSZ), in_ep_num,
+		 mtu3_readl(mbase, U3D_CAP_EPNRXFFSZ), out_ep_num);
+
+	/* one for ep0, another is reserved */
+	mtu->num_eps = min(in_ep_num, out_ep_num) + 1;
+	ep_array = kcalloc(mtu->num_eps * 2, sizeof(*ep_array), GFP_KERNEL);
+	if (ep_array == NULL)
+		return -ENOMEM;
+
+	mtu->ep_array = ep_array;
+	mtu->in_eps = ep_array;
+	mtu->out_eps = &ep_array[mtu->num_eps];
+	/* ep0 uses in_eps[0], out_eps[0] is reserved */
+	mtu->ep0 = mtu->in_eps;
+
+	mtu->ep0->mtu = mtu;
+	mtu->ep0->epnum = 0;
+
+	for (i = 1; i < mtu->num_eps; i++) {
+		struct mtu3_ep *mep = mtu->in_eps + i;
+
+		mep->fifo = &mtu->tx_fifo;
+		mep = mtu->out_eps + i;
+		mep->fifo = &mtu->rx_fifo;
+	}
+
+	get_ep_fifo_config(mtu);
+
+	ret = mtu3_qmu_init(mtu);
+	if (ret)
+		kfree(mtu->ep_array);
+
+	return ret;
+}
+
+static void mtu3_mem_free(struct mtu3 *mtu)
+{
+	mtu3_qmu_exit(mtu);
+	kfree(mtu->ep_array);
+}
+
+static void mtu3_regs_init(struct mtu3 *mtu)
+{
+
+	void __iomem *mbase = mtu->mac_base;
+
+	/* be sure interrupts are disabled before registration of ISR */
+	mtu3_intr_disable(mtu);
+	mtu3_intr_status_clear(mtu);
+
+	mtu3_clrbits(mbase, U3D_USB3_CONFIG, USB3_EN);
+	/* HS/FS detected by HW */
+	mtu3_setbits(mbase, U3D_POWER_MANAGEMENT, HS_ENABLE);
+
+	/* delay about 0.1us from detecting reset to send chirp-K */
+	mtu3_clrbits(mbase, U3D_LINK_RESET_INFO, WTCHRP_MSK);
+
+	/* U2/U3 detected by HW */
+	mtu3_writel(mbase, U3D_DEVICE_CONF, 0);
+
+	/* enable QMU 16B checksum */
+	mtu3_setbits(mbase, U3D_QCR0, QMU_CS16B_EN);
+
+	/* vbus detected by HW */
+	mtu3_clrbits(mbase, U3D_MISC_CTRL, VBUS_FRC_EN | VBUS_ON);
+}
+
+static irqreturn_t mtu3_link_isr(struct mtu3 *mtu)
+{
+	void __iomem *mbase = mtu->mac_base;
+	enum usb_device_speed udev_speed;
+	u32 maxpkt = 64;
+	u32 link;
+	u32 speed;
+
+	link = mtu3_readl(mbase, U3D_DEV_LINK_INTR);
+	link &= mtu3_readl(mbase, U3D_DEV_LINK_INTR_ENABLE);
+	mtu3_writel(mbase, U3D_DEV_LINK_INTR, link); /* W1C */
+	dev_dbg(mtu->dev, "=== LINK[%x] ===\n", link);
+
+	if (!(link & SSUSB_DEV_SPEED_CHG_INTR))
+		return IRQ_NONE;
+
+	speed = SSUSB_DEV_SPEED(mtu3_readl(mbase, U3D_DEVICE_CONF));
+
+	switch (speed) {
+	case MTU3_SPEED_FULL:
+		udev_speed = USB_SPEED_FULL;
+		/*BESLCK = 4 < BESLCK_U3 = 10 < BESLDCK = 15 */
+		mtu3_writel(mbase, U3D_USB20_LPM_PARAMETER, LPM_BESLDCK(0xf)
+				| LPM_BESLCK(4) | LPM_BESLCK_U3(0xa));
+		mtu3_setbits(mbase, U3D_POWER_MANAGEMENT,
+				LPM_BESL_STALL | LPM_BESLD_STALL);
+		break;
+	case MTU3_SPEED_HIGH:
+		udev_speed = USB_SPEED_HIGH;
+		/*BESLCK = 4 < BESLCK_U3 = 10 < BESLDCK = 15 */
+		mtu3_writel(mbase, U3D_USB20_LPM_PARAMETER, LPM_BESLDCK(0xf)
+				| LPM_BESLCK(4) | LPM_BESLCK_U3(0xa));
+		mtu3_setbits(mbase, U3D_POWER_MANAGEMENT,
+				LPM_BESL_STALL | LPM_BESLD_STALL);
+		break;
+	default:
+		udev_speed = USB_SPEED_UNKNOWN;
+		break;
+	}
+	dev_dbg(mtu->dev, "%s: %s\n", __func__, usb_speed_string(udev_speed));
+
+	mtu->g.speed = udev_speed;
+	mtu->g.ep0->maxpacket = maxpkt;
+	mtu->ep0_state = MU3D_EP0_STATE_SETUP;
+
+	if (udev_speed == USB_SPEED_UNKNOWN)
+		mtu3_gadget_disconnect(mtu);
+	else
+		mtu3_ep0_setup(mtu);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mtu3_u2_common_isr(struct mtu3 *mtu)
+{
+	void __iomem *mbase = mtu->mac_base;
+	u32 u2comm;
+
+	u2comm = mtu3_readl(mbase, U3D_COMMON_USB_INTR);
+	u2comm &= mtu3_readl(mbase, U3D_COMMON_USB_INTR_ENABLE);
+	mtu3_writel(mbase, U3D_COMMON_USB_INTR, u2comm); /* W1C */
+	dev_dbg(mtu->dev, "=== U2COMM[%x] ===\n", u2comm);
+
+	if (u2comm & SUSPEND_INTR)
+		mtu3_gadget_suspend(mtu);
+
+	if (u2comm & RESUME_INTR)
+		mtu3_gadget_resume(mtu);
+
+	if (u2comm & RESET_INTR)
+		mtu3_gadget_reset(mtu);
+
+	return IRQ_HANDLED;
+}
+
+irqreturn_t mtu3_irq(int irq, void *data)
+{
+	struct mtu3 *mtu = (struct mtu3 *)data;
+	unsigned long flags;
+	u32 level1;
+
+	spin_lock_irqsave(&mtu->lock, flags);
+
+	/* U3D_LV1ISR is RU */
+	level1 = mtu3_readl(mtu->mac_base, U3D_LV1ISR);
+	level1 &= mtu3_readl(mtu->mac_base, U3D_LV1IER);
+
+	if (level1 & EP_CTRL_INTR)
+		mtu3_link_isr(mtu);
+
+	if (level1 & MAC2_INTR)
+		mtu3_u2_common_isr(mtu);
+
+	if (level1 & BMU_INTR)
+		mtu3_ep0_isr(mtu);
+
+	if (level1 & QMU_INTR)
+		mtu3_qmu_isr(mtu);
+
+	spin_unlock_irqrestore(&mtu->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static int mtu3_hw_init(struct mtu3 *mtu)
+{
+	int ret;
+
+	mtu3_device_reset(mtu);
+
+	ret = mtu3_device_enable(mtu);
+	if (ret) {
+		dev_err(mtu->dev, "device enable failed %d\n", ret);
+		return ret;
+	}
+
+	ret = mtu3_mem_alloc(mtu);
+	if (ret)
+		return -ENOMEM;
+
+	mtu3_regs_init(mtu);
+
+	return 0;
+}
+
+static void mtu3_hw_exit(struct mtu3 *mtu)
+{
+	mtu3_device_disable(mtu);
+	mtu3_mem_free(mtu);
+}
+
+/*-------------------------------------------------------------------------*/
+
+int ssusb_gadget_init(struct mtu3 *mtu)
+{
+	struct device *dev = mtu->dev;
+	int ret;
+
+	ret = mtu3_hw_init(mtu);
+	if (ret) {
+		dev_err(dev, "mtu3 hw init failed:%d\n", ret);
+		return ret;
+	}
+
+	ret = devm_request_irq(dev, mtu->irq, mtu3_irq, 0, dev_name(dev), mtu);
+	if (ret) {
+		dev_err(dev, "request irq %d failed!\n", mtu->irq);
+		goto irq_err;
+	}
+
+	device_init_wakeup(dev, true);
+
+	ret = mtu3_gadget_setup(mtu);
+	if (ret) {
+		dev_err(dev, "mtu3 gadget init failed:%d\n", ret);
+		goto gadget_err;
+	}
+
+	dev_dbg(dev, " %s() done...\n", __func__);
+
+	return 0;
+
+gadget_err:
+	device_init_wakeup(dev, false);
+
+irq_err:
+	mtu3_hw_exit(mtu);
+	dev_err(dev, " %s() fail...\n", __func__);
+
+	return ret;
+}
+
+void ssusb_gadget_exit(struct mtu3 *mtu)
+{
+	mtu3_gadget_cleanup(mtu);
+	device_init_wakeup(mtu->dev, false);
+	mtu3_hw_exit(mtu);
+}
diff --git a/drivers/usb/mtu3/mtu3_gadget.c b/drivers/usb/mtu3/mtu3_gadget.c
new file mode 100644
index 000000000000..0e25e0f9e605
--- /dev/null
+++ b/drivers/usb/mtu3/mtu3_gadget.c
@@ -0,0 +1,709 @@
+/*
+ * mtu3_gadget.c - MediaTek usb3 DRD peripheral support
+ *
+ * Copyright (C) 2016 MediaTek Inc.
+ *
+ * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the