[PATCH v5 1/3] usb: gadget: add Aspeed ast2600 udc driver

[Neal Liu <neal_liu@aspeedtech.com>]

Aspeed udc is compliant with USB2.0, supports USB High Speed
and Full Speed, backward compatible with USB1.1.

Supports independent DMA channel for each generic endpoint.
Supports 32/256 stages descriptor mode for all generic endpoints.

This driver supports full functionality including single/multiple
stages descriptor mode, and exposes 1 UDC gadget driver.

Signed-off-by: Neal Liu <neal_liu@aspeedtech.com>
---
 MAINTAINERS                         |    7 +
 drivers/usb/gadget/udc/Kconfig      |   13 +
 drivers/usb/gadget/udc/Makefile     |    1 +
 drivers/usb/gadget/udc/aspeed_udc.c | 1596 +++++++++++++++++++++++++++
 4 files changed, 1617 insertions(+)
 create mode 100644 drivers/usb/gadget/udc/aspeed_udc.c

diff --git a/MAINTAINERS b/MAINTAINERS
index e8c52d0192a6..784d8d8e7b22 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3109,6 +3109,13 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/media/aspeed-video.txt
 F:	drivers/media/platform/aspeed/
 
+ASPEED USB UDC DRIVER
+M:	Neal Liu <neal_liu@aspeedtech.com>
+L:	linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
+S:	Maintained
+F:	Documentation/devicetree/bindings/usb/aspeed,udc.yaml
+F:	drivers/usb/gadget/udc/aspeed_udc.c
+
 ASUS NOTEBOOKS AND EEEPC ACPI/WMI EXTRAS DRIVERS
 M:	Corentin Chary <corentin.chary@gmail.com>
 L:	acpi4asus-user@lists.sourceforge.net
diff --git a/drivers/usb/gadget/udc/Kconfig b/drivers/usb/gadget/udc/Kconfig
index 69394dc1cdfb..03535f33511b 100644
--- a/drivers/usb/gadget/udc/Kconfig
+++ b/drivers/usb/gadget/udc/Kconfig
@@ -463,6 +463,19 @@ config USB_TEGRA_XUDC
 	 dynamically linked module called "tegra_xudc" and force all
 	 gadget drivers to also be dynamically linked.
 
+config USB_ASPEED_UDC
+	tristate "Aspeed UDC driver support"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	depends on USB_LIBCOMPOSITE
+	help
+	  Enables Aspeed USB2.0 Device Controller driver for AST260x
+	  family SoCs. The controller supports 1 control endpoint and
+	  4 programmable endpoints.
+
+	  Say "y" to link the driver statically, or "m" to build a
+	  dynamically linked module called "aspeed_udc" and force all
+	  gadget drivers to also be dynamically linked.
+
 source "drivers/usb/gadget/udc/aspeed-vhub/Kconfig"
 
 #
diff --git a/drivers/usb/gadget/udc/Makefile b/drivers/usb/gadget/udc/Makefile
index a21f2224e7eb..12f9e4c9eb0c 100644
--- a/drivers/usb/gadget/udc/Makefile
+++ b/drivers/usb/gadget/udc/Makefile
@@ -40,5 +40,6 @@ obj-$(CONFIG_USB_GR_UDC)	+= gr_udc.o
 obj-$(CONFIG_USB_GADGET_XILINX)	+= udc-xilinx.o
 obj-$(CONFIG_USB_SNP_UDC_PLAT) += snps_udc_plat.o
 obj-$(CONFIG_USB_ASPEED_VHUB)	+= aspeed-vhub/
+obj-$(CONFIG_USB_ASPEED_UDC)	+= aspeed_udc.o
 obj-$(CONFIG_USB_BDC_UDC)	+= bdc/
 obj-$(CONFIG_USB_MAX3420_UDC)	+= max3420_udc.o
diff --git a/drivers/usb/gadget/udc/aspeed_udc.c b/drivers/usb/gadget/udc/aspeed_udc.c
new file mode 100644
index 000000000000..1fc15228ff15
--- /dev/null
+++ b/drivers/usb/gadget/udc/aspeed_udc.c
@@ -0,0 +1,1596 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2021 Aspeed Technology Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/prefetch.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/slab.h>
+
+#define AST_UDC_NUM_ENDPOINTS		(1 + 4)
+#define AST_UDC_EP0_MAX_PACKET		64	/* EP0's max packet size */
+#define AST_UDC_EPn_MAX_PACKET		1024	/* Generic EPs max packet size */
+#define AST_UDC_DESCS_COUNT		256	/* Use 256 stages descriptor mode (32/256) */
+#define AST_UDC_DESC_MODE		1	/* Single/Multiple Stage(s) Descriptor Mode */
+
+#define AST_UDC_EP_DMA_SIZE		(AST_UDC_EPn_MAX_PACKET + 8 * AST_UDC_DESCS_COUNT)
+
+/*****************************
+ *                           *
+ * UDC register definitions  *
+ *                           *
+ *****************************/
+
+#define AST_UDC_FUNC_CTRL		0x00	/* Root Function Control & Status Register */
+#define AST_UDC_CONFIG			0x04	/* Root Configuration Setting Register */
+#define AST_UDC_IER			0x08	/* Interrupt Control Register */
+#define AST_UDC_ISR			0x0C	/* Interrupt Status Register */
+#define AST_UDC_EP_ACK_IER		0x10	/* Programmable ep Pool ACK Interrupt Enable Reg */
+#define AST_UDC_EP_NAK_IER		0x14	/* Programmable ep Pool NAK Interrupt Enable Reg */
+#define AST_UDC_EP_ACK_ISR		0x18	/* Programmable ep Pool ACK Interrupt Status Reg */
+#define AST_UDC_EP_NAK_ISR		0x1C	/* Programmable ep Pool NAK Interrupt Status Reg */
+#define AST_UDC_DEV_RESET		0x20	/* Device Controller Soft Reset Enable Register */
+#define AST_UDC_STS			0x24	/* USB Status Register */
+#define AST_VHUB_EP_DATA		0x28	/* Programmable ep Pool Data Toggle Value Set */
+#define AST_VHUB_ISO_TX_FAIL		0x2C	/* Isochronous Transaction Fail Accumulator */
+#define AST_UDC_EP0_CTRL		0x30	/* Endpoint 0 Control/Status Register */
+#define AST_UDC_EP0_DATA_BUFF		0x34	/* Base Address of ep0 IN/OUT Data Buffer Reg */
+#define AST_UDC_SETUP0			0x80    /* Root Device Setup Data Buffer0 */
+#define AST_UDC_SETUP1			0x84    /* Root Device Setup Data Buffer1 */
+
+
+/* Main control reg */
+#define USB_PHY_CLK_EN			BIT(31)
+#define USB_FIFO_DYN_PWRD_EN		BIT(19)
+#define USB_EP_LONG_DESC		BIT(18)
+#define USB_BIST_TEST_PASS		BIT(13)
+#define USB_BIST_TURN_ON		BIT(12)
+#define USB_PHY_RESET_DIS		BIT(11)
+#define USB_TEST_MODE(x)		((x) << 8)
+#define USB_FORCE_TIMER_HS		BIT(7)
+#define USB_FORCE_HS			BIT(6)
+#define USB_REMOTE_WAKEUP_12MS		BIT(5)
+#define USB_REMOTE_WAKEUP_EN		BIT(4)
+#define USB_AUTO_REMOTE_WAKEUP_EN	BIT(3)
+#define USB_STOP_CLK_IN_SUPEND		BIT(2)
+#define USB_UPSTREAM_FS			BIT(1)
+#define USB_UPSTREAM_EN			BIT(0)
+
+/* Main config reg */
+#define UDC_CFG_SET_ADDR(x)		((x) & 0x3f)
+#define UDC_CFG_ADDR_MASK		(0x3f)
+
+/* Interrupt ctrl & status reg */
+#define UDC_IRQ_EP_POOL_NAK		BIT(17)
+#define UDC_IRQ_EP_POOL_ACK_STALL	BIT(16)
+#define UDC_IRQ_BUS_RESUME		BIT(8)
+#define UDC_IRQ_BUS_SUSPEND		BIT(7)
+#define UDC_IRQ_BUS_RESET		BIT(6)
+#define UDC_IRQ_EP0_IN_DATA_NAK		BIT(4)
+#define UDC_IRQ_EP0_IN_ACK_STALL	BIT(3)
+#define UDC_IRQ_EP0_OUT_NAK		BIT(2)
+#define UDC_IRQ_EP0_OUT_ACK_STALL	BIT(1)
+#define UDC_IRQ_EP0_SETUP		BIT(0)
+#define UDC_IRQ_ACK_ALL			(0x1ff)
+
+/* EP isr reg */
+#define USB_EP3_ISR			BIT(3)
+#define USB_EP2_ISR			BIT(2)
+#define USB_EP1_ISR			BIT(1)
+#define USB_EP0_ISR			BIT(0)
+#define UDC_IRQ_EP_ACK_ALL		(0xf)
+
+/*Soft reset reg */
+#define ROOT_UDC_SOFT_RESET		BIT(0)
+
+/* USB status reg */
+#define UDC_STS_HIGHSPEED		BIT(27)
+
+/* Programmable EP data toggle */
+#define EP_TOGGLE_SET_EPNUM(x)		((x) & 0x3)
+
+/* EP0 ctrl reg */
+#define EP0_GET_RX_LEN(x)		((x >> 16) & 0x7f)
+#define EP0_TX_LEN(x)			((x & 0x7f) << 8)
+#define EP0_RX_BUFF_RDY			BIT(2)
+#define EP0_TX_BUFF_RDY			BIT(1)
+#define EP0_STALL			BIT(0)
+
+/*************************************
+ *                                   *
+ * per-endpoint register definitions *
+ *                                   *
+ *************************************/
+
+#define AST_UDC_EP_CONFIG		0x00	/* Endpoint Configuration Register */
+#define AST_UDC_EP_DMA_CTRL		0x04	/* DMA Descriptor List Control/Status Register */
+#define AST_UDC_EP_DMA_BUFF		0x08	/* DMA Descriptor/Buffer Base Address */
+#define AST_UDC_EP_DMA_STS		0x0C	/* DMA Descriptor List R/W Pointer and Status */
+
+#define AST_UDC_EP_BASE			0x200
+#define AST_UDC_EP_OFFSET		0x10
+
+/* EP config reg */
+#define EP_SET_MAX_PKT(x)		((x & 0x3ff) << 16)
+#define EP_DATA_FETCH_CTRL(x)		((x & 0x3) << 14)
+#define EP_AUTO_DATA_DISABLE		(0x1 << 13)
+#define EP_SET_EP_STALL			(0x1 << 12)
+#define EP_SET_EP_NUM(x)		((x & 0xf) << 8)
+#define EP_SET_TYPE_MASK(x)		((x) << 5)
+#define EP_TYPE_BULK			(0x1)
+#define EP_TYPE_INT			(0x2)
+#define EP_TYPE_ISO			(0x3)
+#define EP_DIR_OUT			(0x1 << 4)
+#define EP_ALLOCATED_MASK		(0x7 << 1)
+#define EP_ENABLE			BIT(0)
+
+/* EP DMA ctrl reg */
+#define EP_DMA_CTRL_GET_PROC_STS(x)	((x >> 4) & 0xf)
+#define EP_DMA_CTRL_STS_RX_IDLE		0x0
+#define EP_DMA_CTRL_STS_TX_IDLE		0x8
+#define EP_DMA_CTRL_IN_LONG_MODE	(0x1 << 3)
+#define EP_DMA_CTRL_RESET		(0x1 << 2)
+#define EP_DMA_SINGLE_STAGE		(0x1 << 1)
+#define EP_DMA_DESC_MODE		(0x1 << 0)
+
+/* EP DMA status reg */
+#define EP_DMA_SET_TX_SIZE(x)		((x & 0x7ff) << 16)
+#define EP_DMA_GET_TX_SIZE(x)		(((x) >> 16) & 0x7ff)
+#define EP_DMA_GET_RPTR(x)		(((x) >> 8) & 0xff)
+#define EP_DMA_GET_WPTR(x)		((x) & 0xff)
+#define EP_DMA_SINGLE_KICK		(1 << 0) /* WPTR = 1 for single mode */
+
+/* EP desc reg */
+#define AST_EP_DMA_DESC_INTR_ENABLE	BIT(31)
+#define AST_EP_DMA_DESC_PID_DATA0	(0 << 14)
+#define AST_EP_DMA_DESC_PID_DATA2	BIT(14)
+#define AST_EP_DMA_DESC_PID_DATA1	(2 << 14)
+#define AST_EP_DMA_DESC_PID_MDATA	(3 << 14)
+#define EP_DESC1_IN_LEN(x)		((x) & 0x1fff)
+#define AST_EP_DMA_DESC_MAX_LEN		(7680) /* Max packet length for trasmit in 1 desc */
+
+struct ast_udc_request {
+	struct usb_request	req;
+	struct list_head	queue;
+	unsigned		mapped:1;
+	unsigned int		actual_dma_length;
+	u32			saved_dma_wptr;
+};
+
+#define to_ast_req(__req) container_of(__req, struct ast_udc_request, req)
+
+struct ast_dma_desc {
+	u32	des_0;
+	u32	des_1;
+};
+
+struct ast_udc_ep {
+	struct usb_ep			ep;
+
+	/* Request queue */
+	struct list_head		queue;
+
+	struct ast_udc_dev		*udc;
+	void __iomem			*ep_reg;
+	void				*epn_buf;
+	dma_addr_t			epn_buf_dma;
+	const struct usb_endpoint_descriptor	*desc;
+
+	/* DMA Descriptors */
+	struct ast_dma_desc		*descs;
+	dma_addr_t			descs_dma;
+	u32				descs_wptr;
+	u32				chunk_max;
+
+	bool				dir_in:1;
+	unsigned			stopped:1;
+	bool				desc_mode:1;
+};
+
+#define to_ast_ep(__ep) container_of(__ep, struct ast_udc_ep, ep)
+
+struct ast_udc_dev {
+	struct platform_device		*pdev;
+	void __iomem			*reg;
+	int				irq;
+	spinlock_t			lock;
+	struct clk			*clk;
+	struct work_struct		wake_work;
+
+	/* EP0 DMA buffers allocated in one chunk */
+	void				*ep0_buf;
+	dma_addr_t			ep0_buf_dma;
+	struct ast_udc_ep		ep[AST_UDC_NUM_ENDPOINTS];
+
+	struct usb_gadget		gadget;
+	struct usb_gadget_driver	*driver;
+	void __iomem			*creq;
+	enum usb_device_state		suspended_from;
+	int				desc_mode;
+
+	/* Force full speed only */
+	bool				force_usb1:1;
+	unsigned			is_control_tx:1;
+	bool				wakeup_en:1;
+};
+
+#define to_ast_dev(__g) container_of(__g, struct ast_udc_dev, gadget)
+
+static const char * const ast_ep_name[] = {
+	"ep0", "ep1", "ep2", "ep3", "ep4"
+};
+
+#ifdef AST_UDC_DEBUG_ALL
+#define AST_UDC_DEBUG
+#define AST_SETUP_DEBUG
+#define AST_EP_DEBUG
+#define AST_ISR_DEBUG
+#endif
+
+#ifdef AST_SETUP_DEBUG
+#define SETUP_DBG(u, fmt, ...)	\
+	dev_dbg(&(u)->pdev->dev, "%s() " fmt, __func__, ##__VA_ARGS__)
+#else
+#define SETUP_DBG(u, fmt, ...)
+#endif
+
+#ifdef AST_EP_DEBUG
+#define EP_DBG(e, fmt, ...)	\
+	dev_dbg(&(e)->udc->pdev->dev, "%s():%s " fmt, __func__,	\
+		 (e)->ep.name, ##__VA_ARGS__)
+#else
+#define EP_DBG(ep, fmt, ...)	((void)(ep))
+#endif
+
+#ifdef AST_UDC_DEBUG
+#define UDC_DBG(u, fmt, ...)	\
+	dev_dbg(&(u)->pdev->dev, "%s() " fmt, __func__, ##__VA_ARGS__)
+#else
+#define UDC_DBG(u, fmt, ...)
+#endif
+
+#ifdef AST_ISR_DEBUG
+#define ISR_DBG(u, fmt, ...)	\
+	dev_dbg(&(u)->pdev->dev, "%s() " fmt, __func__, ##__VA_ARGS__)
+#else
+#define ISR_DBG(u, fmt, ...)
+#endif
+
+/*-------------------------------------------------------------------------*/
+#define ast_udc_read(udc, offset) \
+	readl((udc)->reg + (offset))
+#define ast_udc_write(udc, val, offset) \
+	writel((val), (udc)->reg + (offset))
+
+#define ast_ep_read(ep, reg) \
+	readl((ep)->ep_reg + (reg))
+#define ast_ep_write(ep, val, reg) \
+	writel((val), (ep)->ep_reg + (reg))
+
+/*-------------------------------------------------------------------------*/
+
+static void ast_udc_done(struct ast_udc_ep *ep, struct ast_udc_request *req,
+			 int status)
+{
+	struct ast_udc_dev *udc = ep->udc;
+
+	EP_DBG(ep, "req @%p, len (%d/%d), buf:0x%x, dir:0x%x\n",
+	       req, req->req.actual, req->req.length,
+	       (u32)req->req.buf, ep->dir_in);
+
+	list_del(&req->queue);
+
+	if (req->req.status == -EINPROGRESS)
+		req->req.status = status;
+	else
+		status = req->req.status;
+
+	if (status && status != -ESHUTDOWN)
+		EP_DBG(ep, "done req:%p, status:%d\n", req, status);
+
+	spin_unlock(&udc->lock);
+	usb_gadget_giveback_request(&ep->ep, &req->req);
+	spin_lock(&udc->lock);
+}
+
+static void ast_udc_nuke(struct ast_udc_ep *ep, int status)
+{
+	int count = 0;
+
+	while (!list_empty(&ep->queue)) {
+		struct ast_udc_request *req;
+
+		req = list_entry(ep->queue.next, struct ast_udc_request,
+				 queue);
+		ast_udc_done(ep, req, status);
+		count++;
+	}
+
+	if (count)
+		EP_DBG(ep, "Nuked %d request(s)\n", count);
+}
+
+/*
+ * Stop activity on all endpoints.
+ * Device controller for which EP activity is to be stopped.
+ *
+ * All the endpoints are stopped and any pending transfer requests if any on
+ * the endpoint are terminated.
+ */
+static void ast_udc_stop_activity(struct ast_udc_dev *udc)
+{
+	struct ast_udc_ep *ep;
+	int i;
+
+	for (i = 0; i < AST_UDC_NUM_ENDPOINTS; i++) {
+		ep = &udc->ep[i];
+		ep->stopped = 1;
+		ast_udc_nuke(ep, -ESHUTDOWN);
+	}
+}
+
+static int ast_udc_ep_enable(struct usb_ep *_ep,
+			     const struct usb_endpoint_descriptor *desc)
+{
+	u16 maxpacket = usb_endpoint_maxp(desc);
+	struct ast_udc_ep *ep = to_ast_ep(_ep);
+	struct ast_udc_dev *udc = ep->udc;
+	u8 epnum = usb_endpoint_num(desc);
+	unsigned long flags;
+	u32 ep_conf = 0;
+	u8 dir_in;
+	u8 type;
+
+	if (!_ep || !ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT ||
+	    maxpacket == 0 || maxpacket > ep->ep.maxpacket) {
+		EP_DBG(ep, "Failed, invalid EP enable param\n");
+		return -EINVAL;
+	}
+
+	if (!udc->driver) {
+		EP_DBG(ep, "bogus device state\n");
+		return -ESHUTDOWN;
+	}
+
+	EP_DBG(ep, "maxpacket:0x%x\n", maxpacket);
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	ep->desc = desc;
+	ep->stopped = 0;
+	ep->ep.maxpacket = maxpacket;
+	ep->chunk_max = AST_EP_DMA_DESC_MAX_LEN;
+
+	if (maxpacket < AST_UDC_EPn_MAX_PACKET)
+		ep_conf = EP_SET_MAX_PKT(maxpacket);
+
+	ep_conf |= EP_SET_EP_NUM(epnum);
+
+	type = usb_endpoint_type(desc);
+	dir_in = usb_endpoint_dir_in(desc);
+	ep->dir_in = dir_in;
+	if (!ep->dir_in)
+		ep_conf |= EP_DIR_OUT;
+
+	EP_DBG(ep, "type %d, dir_in %d\n", type, dir_in);
+	switch (type) {
+	case USB_ENDPOINT_XFER_ISOC:
+		ep_conf |= EP_SET_TYPE_MASK(EP_TYPE_ISO);
+		break;
+
+	case USB_ENDPOINT_XFER_BULK:
+		ep_conf |= EP_SET_TYPE_MASK(EP_TYPE_BULK);
+		break;
+
+	case USB_ENDPOINT_XFER_INT:
+		ep_conf |= EP_SET_TYPE_MASK(EP_TYPE_INT);
+		break;
+	}
+
+	ep->desc_mode = udc->desc_mode && ep->descs_dma && ep->dir_in;
+	if (ep->desc_mode) {
+		ast_ep_write(ep, EP_DMA_CTRL_RESET, AST_UDC_EP_DMA_CTRL);
+		ast_ep_write(ep, 0, AST_UDC_EP_DMA_STS);
+		ast_ep_write(ep, ep->descs_dma, AST_UDC_EP_DMA_BUFF);
+
+		/* Enable Long Descriptor Mode */
+		ast_ep_write(ep, EP_DMA_CTRL_IN_LONG_MODE | EP_DMA_DESC_MODE,
+			     AST_UDC_EP_DMA_CTRL);
+
+		ep->descs_wptr = 0;
+
+	} else {
+		ast_ep_write(ep, EP_DMA_CTRL_RESET, AST_UDC_EP_DMA_CTRL);
+		ast_ep_write(ep, EP_DMA_SINGLE_STAGE, AST_UDC_EP_DMA_CTRL);
+		ast_ep_write(ep, 0, AST_UDC_EP_DMA_STS);
+	}
+
+	/* Cleanup data toggle just in case */
+	ast_udc_write(udc, EP_TOGGLE_SET_EPNUM(epnum), AST_VHUB_EP_DATA);
+
+	/* Enable EP */
+	ast_ep_write(ep, ep_conf | EP_ENABLE, AST_UDC_EP_CONFIG);
+
+	EP_DBG(ep, "ep_config: 0x%x\n", ast_ep_read(ep, AST_UDC_EP_CONFIG));
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+
+static int ast_udc_ep_disable(struct usb_ep *_ep)
+{
+	struct ast_udc_ep *ep = to_ast_ep(_ep);
+	struct ast_udc_dev *udc = ep->udc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	ep->ep.desc = NULL;
+	ep->stopped = 1;
+
+	ast_udc_nuke(ep, -ESHUTDOWN);
+	ast_ep_write(ep, 0, AST_UDC_EP_CONFIG);
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+
+static struct usb_request *ast_udc_ep_alloc_request(struct usb_ep *_ep,
+						    gfp_t gfp_flags)
+{
+	struct ast_udc_ep *ep = to_ast_ep(_ep);
+	struct ast_udc_request *req;
+
+	req = kzalloc(sizeof(struct ast_udc_request), gfp_flags);
+	if (!req) {
+		EP_DBG(ep, "request allocation failed\n");
+		return NULL;
+	}
+
+	INIT_LIST_HEAD(&req->queue);
+
+	return &req->req;
+}
+
+static void ast_udc_ep_free_request(struct usb_ep *_ep,
+				    struct usb_request *_req)
+{
+	struct ast_udc_request *req = to_ast_req(_req);
+
+	kfree(req);
+}
+
+static int ast_dma_descriptor_setup(struct ast_udc_ep *ep, u32 dma_buf,
+				    u16 tx_len, struct ast_udc_request *req)
+{
+	struct ast_udc_dev *udc = ep->udc;
+	struct device *dev = &udc->pdev->dev;
+	u32 offset, chunk;
+	int count, last;
+
+	if (!ep->descs) {
+		dev_warn(dev, "%s: Empty DMA descs list failure\n",
+			 ep->ep.name);
+		return -EINVAL;
+	}
+
+	chunk = tx_len;
+	offset = count = last = 0;
+
+	EP_DBG(ep, "req @%p, %s:%d, %s:0x%x, %s:0x%x\n", req,
+	       "wptr", ep->descs_wptr, "dma_buf", dma_buf,
+	       "tx_len", tx_len);
+
+	/* Create Descriptor Lists */
+	while (chunk >= 0 && !last && count < AST_UDC_DESCS_COUNT) {
+
+		ep->descs[ep->descs_wptr].des_0 = dma_buf + offset;
+
+		if (chunk <= ep->chunk_max) {
+			ep->descs[ep->descs_wptr].des_1 = chunk;
+			last = 1;
+		} else {
+			ep->descs[ep->descs_wptr].des_1 = ep->chunk_max;
+			chunk -= ep->chunk_max;
+		}
+
+		EP_DBG(ep, "descs[%d]: 0x%x 0x%x, last:%d\n",
+		       ep->descs_wptr,
+		       ep->descs[ep->descs_wptr].des_0,
+		       ep->descs[ep->descs_wptr].des_1,
+		       last);
+
+		if (count == 0)
+			req->saved_dma_wptr = ep->descs_wptr;
+
+		ep->descs_wptr++;
+		count++;
+
+		if (ep->descs_wptr >= AST_UDC_DESCS_COUNT)
+			ep->descs_wptr = 0;
+
+		offset = ep->chunk_max * count;
+	}
+
+	return 0;
+}
+
+static void ast_udc_epn_kick(struct ast_udc_ep *ep, struct ast_udc_request *req)
+{
+	u32 tx_len;
+	u32 last;
+
+	last = req->req.length - req->req.actual;
+	tx_len = last > ep->ep.maxpacket ? ep->ep.maxpacket : last;
+
+	EP_DBG(ep, "kick req @%p, len:%d, dir:%d\n",
+	       req, tx_len, ep->dir_in);
+
+	ast_ep_write(ep, req->req.dma + req->req.actual, AST_UDC_EP_DMA_BUFF);
+
+	/* Start DMA */
+	ast_ep_write(ep, EP_DMA_SET_TX_SIZE(tx_len), AST_UDC_EP_DMA_STS);
+	ast_ep_write(ep, EP_DMA_SET_TX_SIZE(tx_len) | EP_DMA_SINGLE_KICK,
+		     AST_UDC_EP_DMA_STS);
+}
+
+static void ast_udc_epn_kick_desc(struct ast_udc_ep *ep,
+				  struct ast_udc_request *req)
+{
+	u32 descs_max_size;
+	u32 tx_len;
+	u32 last;
+
+	descs_max_size = AST_EP_DMA_DESC_MAX_LEN * AST_UDC_DESCS_COUNT;
+
+	last = req->req.length - req->req.actual;
+	tx_len = last > descs_max_size ? descs_max_size : last;
+
+	EP_DBG(ep, "kick req @%p, %s:%d, %s:0x%x, %s:0x%x (%d/%d), %s:0x%x\n",
+	       req, "tx_len", tx_len, "dir_in", ep->dir_in,
+	       "dma", req->req.dma + req->req.actual,
+	       req->req.actual, req->req.length,
+	       "descs_max_size", descs_max_size);
+
+	if (!ast_dma_descriptor_setup(ep, req->req.dma + req->req.actual,
+				      tx_len, req))
+		req->actual_dma_length += tx_len;
+
+	/* make sure CPU done everything before triggering DMA */
+	mb();
+
+	ast_ep_write(ep, ep->descs_wptr, AST_UDC_EP_DMA_STS);
+
+	EP_DBG(ep, "descs_wptr:%d, dstat:0x%x, dctrl:0x%x\n",
+	       ep->descs_wptr,
+	       ast_ep_read(ep, AST_UDC_EP_DMA_STS),
+	       ast_ep_read(ep, AST_UDC_EP_DMA_CTRL));
+}
+
+static void ast_udc_ep0_queue(struct ast_udc_ep *ep,
+			      struct ast_udc_request *req)
+{
+	struct ast_udc_dev *udc = ep->udc;
+	u32 tx_len;
+	u32 last;
+
+	last = req->req.length - req->req.actual;
+	tx_len = last > ep->ep.maxpacket ? ep->ep.maxpacket : last;
+
+	ast_udc_write(udc, req->req.dma + req->req.actual,
+		      AST_UDC_EP0_DATA_BUFF);
+
+	if (ep->dir_in) {
+		/* IN requests, send data */
+		SETUP_DBG(udc, "IN: %s:0x%x, %s:0x%x, %s:%d (%d/%d), %s:%d\n",
+			  "buf", (u32)req->req.buf,
+			  "dma", req->req.dma + req->req.actual,
+			  "tx_len", tx_len,
+			  req->req.actual, req->req.length,
+			  "dir_in", ep->dir_in);
+
+		req->req.actual += tx_len;
+		ast_udc_write(udc, EP0_TX_LEN(tx_len), AST_UDC_EP0_CTRL);
+		ast_udc_write(udc, EP0_TX_LEN(tx_len) | EP0_TX_BUFF_RDY,
+			      AST_UDC_EP0_CTRL);
+
+	} else {
+		/* OUT requests, receive data */
+		SETUP_DBG(udc, "OUT: %s:%x, %s:%x, %s:(%d/%d), %s:%d\n",
+			  "buf", (u32)req->req.buf,
+			  "dma", req->req.dma + req->req.actual,
+			  "len", req->req.actual, req->req.length,
+			  "dir_in", ep->dir_in);
+
+		if (!req->req.length) {
+			/* 0 len request, send tx as completion */
+			ast_udc_write(udc, EP0_TX_BUFF_RDY, AST_UDC_EP0_CTRL);
+			ep->dir_in = 0x1;
+		} else
+			ast_udc_write(udc, EP0_RX_BUFF_RDY, AST_UDC_EP0_CTRL);
+	}
+}
+
+static int ast_udc_ep_queue(struct usb_ep *_ep, struct usb_request *_req,
+			    gfp_t gfp_flags)
+{
+	struct ast_udc_request *req = to_ast_req(_req);
+	struct ast_udc_ep *ep = to_ast_ep(_ep);
+	struct ast_udc_dev *udc = ep->udc;
+	struct device *dev = &udc->pdev->dev;
+	unsigned long flags;
+	int rc;
+
+	if (unlikely(!_req || !_req->complete || !_req->buf || !_ep)) {
+		dev_warn(dev, "Invalid EP request !\n");
+		return -EINVAL;
+	}
+
+	if (ep->stopped) {
+		dev_warn(dev, "%s is already stopped !\n", _ep->name);
+		return -ESHUTDOWN;
+	}
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	list_add_tail(&req->queue, &ep->queue);
+
+	req->req.actual = 0;
+	req->req.status = -EINPROGRESS;
+	req->actual_dma_length = 0;
+
+	rc = usb_gadget_map_request(&udc->gadget, &req->req, ep->dir_in);
+	if (rc) {
+		EP_DBG(ep, "Request mapping failure %d\n", rc);
+		dev_warn(dev, "Request mapping failure %d\n", rc);
+		goto end;
+	}
+
+	EP_DBG(ep, "enqueue req @%p\n", req);
+	EP_DBG(ep, "l=%d, dma:0x%x, zero:%d, is_in:%d\n",
+		_req->length, _req->dma, _req->zero, ep->dir_in);
+
+	/* EP0 request enqueue */
+	if (ep->ep.desc == NULL) {
+		if ((req->req.dma % 4) != 0) {
+			dev_warn(dev, "EP0 req dma alignment error\n");
+			return -ESHUTDOWN;
+		}
+
+		ast_udc_ep0_queue(ep, req);
+		goto end;
+	}
+
+	/* EPn request enqueue */
+	if (list_is_singular(&ep->queue)) {
+		if (ep->desc_mode)
+			ast_udc_epn_kick_desc(ep, req);
+		else
+			ast_udc_epn_kick(ep, req);
+	}
+
+end:
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return rc;
+}
+
+static int ast_udc_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
+{
+	struct ast_udc_ep *ep = to_ast_ep(_ep);
+	struct ast_udc_dev *udc = ep->udc;
+	struct ast_udc_request *req;
+	unsigned long flags;
+	int rc = 0;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	/* make sure it's actually queued on this endpoint */
+	list_for_each_entry(req, &ep->queue, queue) {
+		if (&req->req == _req) {
+			list_del_init(&req->queue);
+			ast_udc_done(ep, req, -ESHUTDOWN);
+			_req->status = -ECONNRESET;
+			break;
+		}
+	}
+
+	/* dequeue request not found */
+	if (&req->req != _req)
+		rc = -EINVAL;
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return rc;
+}
+
+static int ast_udc_ep_set_halt(struct usb_ep *_ep, int value)
+{
+	struct ast_udc_ep *ep = to_ast_ep(_ep);
+	struct ast_udc_dev *udc = ep->udc;
+	unsigned long flags;
+	int epnum;
+	u32 ctrl;
+
+	EP_DBG(ep, "val:%d\n", value);
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	epnum = usb_endpoint_num(ep->desc);
+
+	/* EP0 */
+	if (epnum == 0) {
+		ctrl = ast_udc_read(udc, AST_UDC_EP0_CTRL);
+		if (value)
+			ctrl |= EP0_STALL;
+		else
+			ctrl &= ~EP0_STALL;
+
+		ast_udc_write(udc, ctrl, AST_UDC_EP0_CTRL);
+
+	} else {
+	/* EPn */
+		ctrl = ast_udc_read(udc, AST_UDC_EP_CONFIG);
+		if (value)
+			ctrl |= EP_SET_EP_STALL;
+		else
+			ctrl &= ~EP_SET_EP_STALL;
+
+		ast_ep_write(ep, ctrl, AST_UDC_EP_CONFIG);
+
+		/* only epn is stopped and waits for clear */
+		ep->stopped = value ? 1 : 0;
+	}
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+
+static const struct usb_ep_ops ast_udc_ep_ops = {
+	.enable		= ast_udc_ep_enable,
+	.disable	= ast_udc_ep_disable,
+	.alloc_request	= ast_udc_ep_alloc_request,
+	.free_request	= ast_udc_ep_free_request,
+	.queue		= ast_udc_ep_queue,
+	.dequeue	= ast_udc_ep_dequeue,
+	.set_halt	= ast_udc_ep_set_halt,
+	/* there's only imprecise fifo status reporting */
+};
+
+static void ast_udc_ep0_rx(struct ast_udc_dev *udc)
+{
+	ast_udc_write(udc, udc->ep0_buf_dma, AST_UDC_EP0_DATA_BUFF);
+	ast_udc_write(udc, EP0_RX_BUFF_RDY, AST_UDC_EP0_CTRL);
+}
+
+static void ast_udc_ep0_tx(struct ast_udc_dev *udc)
+{
+	ast_udc_write(udc, udc->ep0_buf_dma, AST_UDC_EP0_DATA_BUFF);
+	ast_udc_write(udc, EP0_TX_BUFF_RDY, AST_UDC_EP0_CTRL);
+}
+
+static void ast_udc_ep0_out(struct ast_udc_dev *udc)
+{
+	struct device *dev = &udc->pdev->dev;
+	struct ast_udc_ep *ep = &udc->ep[0];
+	struct ast_udc_request *req;
+	u16 rx_len;
+
+	if (list_empty(&ep->queue))
+		return;
+
+	req = list_entry(ep->queue.next, struct ast_udc_request, queue);
+
+	rx_len = EP0_GET_RX_LEN(ast_udc_read(udc, AST_UDC_EP0_CTRL));
+	req->req.actual += rx_len;
+
+	SETUP_DBG(udc, "req %p (%d/%d)\n", req,
+		  req->req.actual, req->req.length);
+
+	if ((rx_len < ep->ep.maxpacket) ||
+	    (req->req.actual == req->req.length)) {
+		ast_udc_ep0_tx(udc);
+		if (!ep->dir_in)
+			ast_udc_done(ep, req, 0);
+
+	} else {
+		if (rx_len > req->req.length) {
+			// Issue Fix
+			dev_warn(dev, "Something wrong (%d/%d)\n",
+				 req->req.actual, req->req.length);
+			ast_udc_ep0_tx(udc);
+			ast_udc_done(ep, req, 0);
+			return;
+		}
+
+		ep->dir_in = 0;
+
+		/* More works */
+		ast_udc_ep0_queue(ep, req);
+	}
+}
+
+static void ast_udc_ep0_in(struct ast_udc_dev *udc)
+{
+	struct ast_udc_ep *ep = &udc->ep[0];
+	struct ast_udc_request *req;
+
+	if (list_empty(&ep->queue)) {
+		if (udc->is_control_tx) {
+			ast_udc_ep0_rx(udc);
+			udc->is_control_tx = 0;
+		}
+
+		return;
+	}
+
+	req = list_entry(ep->queue.next, struct ast_udc_request, queue);
+
+	SETUP_DBG(udc, "req %p (%d/%d)\n", req,
+		  req->req.actual, req->req.length);
+
+	if (req->req.length == req->req.actual) {
+		if (req->req.length)
+			ast_udc_ep0_rx(udc);
+
+		if (ep->dir_in)
+			ast_udc_done(ep, req, 0);
+
+	} else {
+		/* More works */
+		ast_udc_ep0_queue(ep, req);
+	}
+}
+
+static void ast_udc_epn_handle(struct ast_udc_dev *udc, u16 ep_num)
+{
+	struct ast_udc_ep *ep = &udc->ep[ep_num];
+	struct ast_udc_request *req;
+	u16 len = 0;
+
+	if (list_empty(&ep->queue))
+		return;
+
+	req = list_first_entry(&ep->queue, struct ast_udc_request, queue);
+
+	len = EP_DMA_GET_TX_SIZE(ast_ep_read(ep, AST_UDC_EP_DMA_STS));
+	req->req.actual += len;
+
+	EP_DBG(ep, "req @%p, length:(%d/%d), %s:0x%x\n", req,
+		req->req.actual, req->req.length, "len", len);
+
+	/* Done this request */
+	if (req->req.length == req->req.actual) {
+		ast_udc_done(ep, req, 0);
+		req = list_first_entry_or_null(&ep->queue,
+					       struct ast_udc_request,
+					       queue);
+
+	} else {
+		/* Check for short packet */
+		if (len < ep->ep.maxpacket) {
+			ast_udc_done(ep, req, 0);
+			req = list_first_entry_or_null(&ep->queue,
+						       struct ast_udc_request,
+						       queue);
+		}
+	}
+
+	/* More requests */
+	if (req)
+		ast_udc_epn_kick(ep, req);
+}
+
+static void ast_udc_epn_handle_desc(struct ast_udc_dev *udc, u16 ep_num)
+{
+	struct ast_udc_ep *ep = &udc->ep[ep_num];
+	struct device *dev = &udc->pdev->dev;
+	struct ast_udc_request *req;
+	u32 proc_sts, wr_ptr, rd_ptr;
+	u32 len_in_desc, ctrl;
+	u16 total_len = 0;
+	int i;
+
+	if (list_empty(&ep->queue)) {
+		dev_warn(dev, "%s reqest queue empty !\n", ep->ep.name);
+		return;
+	}
+
+	req = list_first_entry(&ep->queue, struct ast_udc_request, queue);
+
+	ctrl = ast_ep_read(ep, AST_UDC_EP_DMA_CTRL);
+	proc_sts = EP_DMA_CTRL_GET_PROC_STS(ctrl);
+
+	/* Check processing status is idle */
+	if (proc_sts != EP_DMA_CTRL_STS_RX_IDLE &&
+	    proc_sts != EP_DMA_CTRL_STS_TX_IDLE) {
+		dev_warn(dev, "EP DMA CTRL: 0x%x, PS:0x%x\n",
+			 ast_ep_read(ep, AST_UDC_EP_DMA_CTRL),
+			 proc_sts);
+		return;
+	}
+
+	ctrl = ast_ep_read(ep, AST_UDC_EP_DMA_STS);
+	rd_ptr = EP_DMA_GET_RPTR(ctrl);
+	wr_ptr = EP_DMA_GET_WPTR(ctrl);
+
+	if (rd_ptr != wr_ptr) {
+		dev_warn(dev, "desc list is not empty ! %s:%d, %s:%d\n",
+		"rptr", rd_ptr, "wptr", wr_ptr);
+		return;
+	}
+
+	EP_DBG(ep, "rd_ptr:%d, wr_ptr:%d\n", rd_ptr, wr_ptr);
+	i = req->saved_dma_wptr;
+
+	do {
+		len_in_desc = EP_DESC1_IN_LEN(ep->descs[i].des_1);
+		EP_DBG(ep, "desc[%d] len: %d\n", i, len_in_desc);
+		total_len += len_in_desc;
+		i++;
+		if (i >= AST_UDC_DESCS_COUNT)
+			i = 0;
+
+	} while (i != wr_ptr);
+
+	req->req.actual += total_len;
+
+	EP_DBG(ep, "req @%p, length:(%d/%d), %s:0x%x\n", req,
+		req->req.actual, req->req.length, "len", total_len);
+
+	/* Done this request */
+	if (req->req.length == req->req.actual) {
+		ast_udc_done(ep, req, 0);
+		req = list_first_entry_or_null(&ep->queue,
+					       struct ast_udc_request,
+					       queue);
+
+	} else {
+		/* Check for short packet */
+		if (total_len < ep->ep.maxpacket) {
+			ast_udc_done(ep, req, 0);
+			req = list_first_entry_or_null(&ep->queue,
+						       struct ast_udc_request,
+						       queue);
+		}
+	}
+
+	/* More requests & dma descs not setup yet */
+	if (req && (req->actual_dma_length == req->req.actual)) {
+		EP_DBG(ep, "More requests\n");
+		ast_udc_epn_kick_desc(ep, req);
+	}
+}
+
+static void ast_udc_ep0_data_tx(struct ast_udc_dev *udc, u8 *tx_data, u32 len)
+{
+	if (len) {
+		memcpy(udc->ep0_buf, tx_data, len);
+
+		ast_udc_write(udc, udc->ep0_buf_dma, AST_UDC_EP0_DATA_BUFF);
+		ast_udc_write(udc, EP0_TX_LEN(len), AST_UDC_EP0_CTRL);
+		ast_udc_write(udc, EP0_TX_LEN(len) | EP0_TX_BUFF_RDY,
+			      AST_UDC_EP0_CTRL);
+		udc->is_control_tx = 1;
+
+	} else
+		ast_udc_write(udc, EP0_TX_BUFF_RDY, AST_UDC_EP0_CTRL);
+}
+
+static void ast_udc_getstatus(struct ast_udc_dev *udc)
+{
+	struct usb_ctrlrequest crq;
+	struct ast_udc_ep *ep;
+	u16 status = 0;
+	u16 epnum = 0;
+
+	memcpy_fromio(&crq, udc->creq, sizeof(crq));
+
+	switch (crq.bRequestType & USB_RECIP_MASK) {
+	case USB_RECIP_DEVICE:
+		/* Get device status */
+		status = 1 << USB_DEVICE_SELF_POWERED;
+		break;
+	case USB_RECIP_INTERFACE:
+		break;
+	case USB_RECIP_ENDPOINT:
+		epnum = crq.wIndex & USB_ENDPOINT_NUMBER_MASK;
+		status = udc->ep[epnum].stopped;
+		break;
+	default:
+		goto stall;
+	}
+
+	ep = &udc->ep[epnum];
+	EP_DBG(ep, "status: 0x%x\n", status);
+	ast_udc_ep0_data_tx(udc, (u8 *)&status, sizeof(status));
+
+	return;
+
+stall:
+	EP_DBG(ep, "Can't respond request\n");
+	ast_udc_write(udc, ast_udc_read(udc, AST_UDC_EP0_CTRL) | EP0_STALL,
+		      AST_UDC_EP0_CTRL);
+}
+
+static void ast_udc_ep0_handle_setup(struct ast_udc_dev *udc)
+{
+	struct ast_udc_ep *ep = &udc->ep[0];
+	struct ast_udc_request *req;
+	struct usb_ctrlrequest crq;
+	int req_num = 0;
+	int rc = 0;
+	u32 reg;
+
+	memcpy_fromio(&crq, udc->creq, sizeof(crq));
+
+	SETUP_DBG(udc, "SETEUP packet: %02x/%02x/%04x/%04x/%04x\n",
+		  crq.bRequestType, crq.bRequest, le16_to_cpu(crq.wValue),
+		  le16_to_cpu(crq.wIndex), le16_to_cpu(crq.wLength));
+
+	/*
+	 * Cleanup ep0 request(s) in queue because
+	 * there is a new control setup comes.
+	 */
+	list_for_each_entry(req, &udc->ep[0].queue, queue) {
+		req_num++;
+		EP_DBG(ep, "there is req %p in ep0 queue !\n", req);
+	}
+
+	if (req_num)
+		ast_udc_nuke(&udc->ep[0], -ETIMEDOUT);
+
+	udc->ep[0].dir_in = crq.bRequestType & USB_DIR_IN;
+
+	if ((crq.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
+		switch (crq.bRequest) {
+		case USB_REQ_SET_ADDRESS:
+			if (ast_udc_read(udc, AST_UDC_STS) & UDC_STS_HIGHSPEED)
+				udc->gadget.speed = USB_SPEED_HIGH;
+			else
+				udc->gadget.speed = USB_SPEED_FULL;
+
+			SETUP_DBG(udc, "set addr: 0x%x\n", crq.wValue);
+			reg = ast_udc_read(udc, AST_UDC_CONFIG);
+			reg &= ~UDC_CFG_ADDR_MASK;
+			reg |= UDC_CFG_SET_ADDR(crq.wValue);
+			ast_udc_write(udc, reg, AST_UDC_CONFIG);
+			goto req_complete;
+
+		case USB_REQ_CLEAR_FEATURE:
+			SETUP_DBG(udc, "ep0: CLEAR FEATURE\n");
+			goto req_driver;
+
+		case USB_REQ_SET_FEATURE:
+			SETUP_DBG(udc, "ep0: SET FEATURE\n");
+			goto req_driver;
+
+		case USB_REQ_GET_STATUS:
+			ast_udc_getstatus(udc);
+			return;
+
+		default:
+			goto req_driver;
+		}
+
+	}
+
+req_driver:
+	if (udc->driver) {
+		SETUP_DBG(udc, "Forwarding %s to gadget...\n",
+			  udc->gadget.name);
+
+		spin_unlock(&udc->lock);
+		rc = udc->driver->setup(&udc->gadget, &crq);
+		spin_lock(&udc->lock);
+
+	} else {
+		SETUP_DBG(udc, "No gadget for request !\n");
+	}
+
+	if (rc >= 0)
+		return;
+
+	/* Stall if gadget failed */
+	SETUP_DBG(udc, "Stalling, rc:0x%x\n", rc);
+	ast_udc_write(udc, ast_udc_read(udc, AST_UDC_EP0_CTRL) | EP0_STALL,
+		      AST_UDC_EP0_CTRL);
+	return;
+
+req_complete:
+	SETUP_DBG(udc, "ep0: Sending IN status without data\n");
+	ast_udc_write(udc, EP0_TX_BUFF_RDY, AST_UDC_EP0_CTRL);
+}
+
+static irqreturn_t ast_udc_isr(int irq, void *data)
+{
+	struct ast_udc_dev *udc = (struct ast_udc_dev *)data;
+	struct ast_udc_ep *ep;
+	u32 isr, ep_isr;
+	int i;
+
+	spin_lock(&udc->lock);
+
+	isr = ast_udc_read(udc, AST_UDC_ISR);
+	if (!isr)
+		goto done;
+
+	/* Ack interrupts */
+	ast_udc_write(udc, isr, AST_UDC_ISR);
+
+	if (isr & UDC_IRQ_BUS_RESET) {
+		ISR_DBG(udc, "UDC_IRQ_BUS_RESET\n");
+		udc->gadget.speed = USB_SPEED_UNKNOWN;
+
+		ep = &udc->ep[1];
+		EP_DBG(ep, "dctrl:0x%x\n",
+		       ast_ep_read(ep, AST_UDC_EP_DMA_CTRL));
+
+		if (udc->driver && udc->driver->reset) {
+			spin_unlock(&udc->lock);
+			udc->driver->reset(&udc->gadget);
+			spin_lock(&udc->lock);
+		}
+	}
+
+	if (isr & UDC_IRQ_BUS_SUSPEND) {
+		ISR_DBG(udc, "UDC_IRQ_BUS_SUSPEND\n");
+		udc->suspended_from = udc->gadget.state;
+		usb_gadget_set_state(&udc->gadget, USB_STATE_SUSPENDED);
+
+		if (udc->driver && udc->driver->suspend) {
+			spin_unlock(&udc->lock);
+			udc->driver->suspend(&udc->gadget);
+			spin_lock(&udc->lock);
+		}
+	}
+
+	if (isr & UDC_IRQ_BUS_RESUME) {
+		ISR_DBG(udc, "UDC_IRQ_BUS_RESUME\n");
+		usb_gadget_set_state(&udc->gadget, udc->suspended_from);
+
+		if (udc->driver && udc->driver->resume) {
+			spin_unlock(&udc->lock);
+			udc->driver->resume(&udc->gadget);
+			spin_lock(&udc->lock);
+		}
+	}
+
+	if (isr & UDC_IRQ_EP0_IN_ACK_STALL) {
+		ISR_DBG(udc, "UDC_IRQ_EP0_IN_ACK_STALL\n");
+		ast_udc_ep0_in(udc);
+	}
+
+	if (isr & UDC_IRQ_EP0_OUT_ACK_STALL) {
+		ISR_DBG(udc, "UDC_IRQ_EP0_OUT_ACK_STALL\n");
+		ast_udc_ep0_out(udc);
+	}
+
+	if (isr & UDC_IRQ_EP0_SETUP) {
+		ISR_DBG(udc, "UDC_IRQ_EP0_SETUP\n");
+		ast_udc_ep0_handle_setup(udc);
+	}
+
+	if (isr & UDC_IRQ_EP_POOL_ACK_STALL) {
+		ISR_DBG(udc, "UDC_IRQ_EP_POOL_ACK_STALL\n");
+		ep_isr = ast_udc_read(udc, AST_UDC_EP_ACK_ISR);
+
+		/* Ack EP interrupts */
+		ast_udc_write(udc, ep_isr, AST_UDC_EP_ACK_ISR);
+
+		/* Handle each EP */
+		for (i = 0; i < AST_UDC_NUM_ENDPOINTS - 1; i++) {
+			if (ep_isr & (0x1 << i)) {
+				ep = &udc->ep[i + 1];
+				if (ep->desc_mode)
+					ast_udc_epn_handle_desc(udc, i + 1);
+				else
+					ast_udc_epn_handle(udc, i + 1);
+			}
+		}
+	}
+
+done:
+	spin_unlock(&udc->lock);
+	return IRQ_HANDLED;
+}
+
+static int ast_udc_gadget_getframe(struct usb_gadget *gadget)
+{
+	struct ast_udc_dev *udc = to_ast_dev(gadget);
+
+	return (ast_udc_read(udc, AST_UDC_STS) >> 16) & 0x7ff;
+}
+
+static void ast_udc_wake_work(struct work_struct *work)
+{
+	struct ast_udc_dev *udc = container_of(work, struct ast_udc_dev,
+					       wake_work);
+	unsigned long flags;
+	u32 ctrl;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	UDC_DBG(udc, "Wakeup Host !\n");
+	ctrl = ast_udc_read(udc, AST_UDC_FUNC_CTRL);
+	ast_udc_write(udc, ctrl | USB_REMOTE_WAKEUP_EN, AST_UDC_FUNC_CTRL);
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+}
+
+static void ast_udc_wakeup_all(struct ast_udc_dev *udc)
+{
+	/*
+	 * A device is trying to wake the world, because this
+	 * can recurse into the device, we break the call chain
+	 * using a work queue
+	 */
+	schedule_work(&udc->wake_work);
+}
+
+static int ast_udc_wakeup(struct usb_gadget *gadget)
+{
+	struct ast_udc_dev *udc = to_ast_dev(gadget);
+	unsigned long flags;
+	int rc = 0;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	if (!udc->wakeup_en) {
+		UDC_DBG(udc, "Remote Wakeup is disabled\n");
+		rc = -EINVAL;
+		goto err;
+	}
+
+	UDC_DBG(udc, "Device initiated wakeup\n");
+	ast_udc_wakeup_all(udc);
+
+err:
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return rc;
+}
+
+/*
+ * Activate/Deactivate link with host
+ */
+static int ast_udc_pullup(struct usb_gadget *gadget, int is_on)
+{
+	struct ast_udc_dev *udc = to_ast_dev(gadget);
+	unsigned long flags;
+	u32 ctrl;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	UDC_DBG(udc, "is_on: %d\n", is_on);
+	if (is_on)
+		ctrl = ast_udc_read(udc, AST_UDC_FUNC_CTRL) | USB_UPSTREAM_EN;
+	else
+		ctrl = ast_udc_read(udc, AST_UDC_FUNC_CTRL) & ~USB_UPSTREAM_EN;
+
+	ast_udc_write(udc, ctrl, AST_UDC_FUNC_CTRL);
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+
+static int ast_udc_start(struct usb_gadget *gadget,
+			 struct usb_gadget_driver *driver)
+{
+	struct ast_udc_dev *udc = to_ast_dev(gadget);
+	struct ast_udc_ep *ep;
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	UDC_DBG(udc, "\n");
+	udc->driver = driver;
+	udc->gadget.dev.of_node = udc->pdev->dev.of_node;
+
+	for (i = 0; i < AST_UDC_NUM_ENDPOINTS; i++) {
+		ep = &udc->ep[i];
+		ep->stopped = 0;
+	}
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+
+static int ast_udc_stop(struct usb_gadget *gadget)
+{
+	struct ast_udc_dev *udc = to_ast_dev(gadget);
+	unsigned long flags;
+	u32 ctrl;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	UDC_DBG(udc, "\n");
+	ctrl = ast_udc_read(udc, AST_UDC_FUNC_CTRL) & ~USB_UPSTREAM_EN;
+	ast_udc_write(udc, ctrl, AST_UDC_FUNC_CTRL);
+
+	udc->gadget.speed = USB_SPEED_UNKNOWN;
+	udc->driver = NULL;
+
+	ast_udc_stop_activity(udc);
+	usb_gadget_set_state(&udc->gadget, USB_STATE_NOTATTACHED);
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return 0;
+}
+
+static const struct usb_gadget_ops ast_udc_ops = {
+	.get_frame		= ast_udc_gadget_getframe,
+	.wakeup			= ast_udc_wakeup,
+	.pullup			= ast_udc_pullup,
+	.udc_start		= ast_udc_start,
+	.udc_stop		= ast_udc_stop,
+};
+
+/*
+ * Support 1 Control Endpoint.
+ * Support multiple programmable endpoints that can be configured to
+ * Bulk IN/OUT, Interrupt IN/OUT, and Isochronous IN/OUT type endpoint.
+ */
+static void ast_udc_init_ep(struct ast_udc_dev *udc)
+{
+	struct ast_udc_ep *ep;
+	int i;
+
+	for (i = 0; i < AST_UDC_NUM_ENDPOINTS; i++) {
+		ep = &udc->ep[i];
+		ep->ep.name = ast_ep_name[i];
+		if (i == 0) {
+			ep->ep.caps.type_control = true;
+		} else {
+			ep->ep.caps.type_iso = true;
+			ep->ep.caps.type_bulk = true;
+			ep->ep.caps.type_int = true;
+		}
+		ep->ep.caps.dir_in = true;
+		ep->ep.caps.dir_out = true;
+
+		ep->ep.ops = &ast_udc_ep_ops;
+		ep->udc = udc;
+
+		INIT_LIST_HEAD(&ep->queue);
+
+		if (i == 0) {
+			usb_ep_set_maxpacket_limit(&ep->ep,
+						   AST_UDC_EP0_MAX_PACKET);
+			continue;
+		}
+
+		ep->ep_reg = udc->reg + AST_UDC_EP_BASE +
+				(AST_UDC_EP_OFFSET * (i - 1));
+
+		ep->epn_buf = udc->ep0_buf + (i * AST_UDC_EP_DMA_SIZE);
+		ep->epn_buf_dma = udc->ep0_buf_dma + (i * AST_UDC_EP_DMA_SIZE);
+		usb_ep_set_maxpacket_limit(&ep->ep, AST_UDC_EPn_MAX_PACKET);
+
+		ep->descs = ep->epn_buf + AST_UDC_EPn_MAX_PACKET;
+		ep->descs_dma = ep->epn_buf_dma + AST_UDC_EPn_MAX_PACKET;
+		ep->descs_wptr = 0;
+
+		list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);
+	}
+}
+
+static void ast_udc_init_dev(struct ast_udc_dev *udc)
+{
+	INIT_WORK(&udc->wake_work, ast_udc_wake_work);
+}
+
+static void ast_udc_init_hw(struct ast_udc_dev *udc)
+{
+	u32 ctrl;
+
+	/* Enable PHY */
+	ctrl = USB_PHY_CLK_EN | USB_PHY_RESET_DIS;
+	ast_udc_write(udc, ctrl, AST_UDC_FUNC_CTRL);
+
+	udelay(1);
+	ast_udc_write(udc, 0, AST_UDC_DEV_RESET);
+
+	/* Set descriptor ring size */
+	if (AST_UDC_DESCS_COUNT == 256) {
+		ctrl |= USB_EP_LONG_DESC;
+		ast_udc_write(udc, ctrl, AST_UDC_FUNC_CTRL);
+	}
+
+	/* Mask & ack all interrupts before installing the handler */
+	ast_udc_write(udc, 0, AST_UDC_IER);
+	ast_udc_write(udc, UDC_IRQ_ACK_ALL, AST_UDC_ISR);
+
+	/* Enable some interrupts */
+	ctrl = UDC_IRQ_EP_POOL_ACK_STALL | UDC_IRQ_BUS_RESUME |
+	       UDC_IRQ_BUS_SUSPEND | UDC_IRQ_BUS_RESET |
+	       UDC_IRQ_EP0_IN_ACK_STALL | UDC_IRQ_EP0_OUT_ACK_STALL |
+	       UDC_IRQ_EP0_SETUP;
+	ast_udc_write(udc, ctrl, AST_UDC_IER);
+
+	/* Cleanup and enable ep ACK interrupts */
+	ast_udc_write(udc, UDC_IRQ_EP_ACK_ALL, AST_UDC_EP_ACK_IER);
+	ast_udc_write(udc, UDC_IRQ_EP_ACK_ALL, AST_UDC_EP_ACK_ISR);
+
+	ast_udc_write(udc, 0, AST_UDC_EP0_CTRL);
+}
+
+static int ast_udc_remove(struct platform_device *pdev)
+{
+	struct ast_udc_dev *udc = platform_get_drvdata(pdev);
+	unsigned long flags;
+	u32 ctrl;
+
+	usb_del_gadget_udc(&udc->gadget);
+	if (udc->driver)
+		return -EBUSY;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	/* Disable upstream port connection */
+	ctrl = ast_udc_read(udc, AST_UDC_FUNC_CTRL) & ~USB_UPSTREAM_EN;
+	ast_udc_write(udc, ctrl, AST_UDC_FUNC_CTRL);
+
+	clk_disable_unprepare(udc->clk);
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	if (udc->ep0_buf)
+		dma_free_coherent(&pdev->dev,
+				  AST_UDC_EP_DMA_SIZE * AST_UDC_NUM_ENDPOINTS,
+				  udc->ep0_buf,
+				  udc->ep0_buf_dma);
+
+	udc->ep0_buf = NULL;
+
+	return 0;
+}
+
+static int ast_udc_probe(struct platform_device *pdev)
+{
+	enum usb_device_speed max_speed;
+	struct device *dev = &pdev->dev;
+	struct ast_udc_dev *udc;
+	struct resource *res;
+	int rc;
+
+	udc = devm_kzalloc(&pdev->dev, sizeof(struct ast_udc_dev), GFP_KERNEL);
+	if (!udc)
+		return -ENOMEM;
+
+	udc->gadget.dev.parent = dev;
+	udc->pdev = pdev;
+	spin_lock_init(&udc->lock);
+
+	udc->gadget.ops = &ast_udc_ops;
+	udc->gadget.ep0 = &udc->ep[0].ep;
+	udc->gadget.name = "aspeed-udc";
+	udc->gadget.dev.init_name = "gadget";
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	udc->reg = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(udc->reg)) {
+		dev_err(&pdev->dev, "Failed to map resources\n");
+		return PTR_ERR(udc->reg);
+	}
+
+	platform_set_drvdata(pdev, udc);
+
+	udc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(udc->clk)) {
+		rc = PTR_ERR(udc->clk);
+		goto err;
+	}
+	rc = clk_prepare_enable(udc->clk);
+	if (rc) {
+		dev_err(&pdev->dev, "Failed to enable clock (0x%x)\n", rc);
+		goto err;
+	}
+
+	/* Check if we need to limit the HW to USB1 */
+	max_speed = usb_get_maximum_speed(&pdev->dev);
+	if (max_speed != USB_SPEED_UNKNOWN && max_speed < USB_SPEED_HIGH)
+		udc->force_usb1 = true;
+
+	/*
+	 * Allocate DMA buffers for all EPs in one chunk
+	 */
+	udc->ep0_buf = dma_alloc_coherent(&pdev->dev,
+					  AST_UDC_EP_DMA_SIZE *
+					  AST_UDC_NUM_ENDPOINTS,
+					  &udc->ep0_buf_dma, GFP_KERNEL);
+
+	udc->gadget.speed = USB_SPEED_UNKNOWN;
+	udc->gadget.max_speed = USB_SPEED_HIGH;
+	udc->creq = udc->reg + AST_UDC_SETUP0;
+
+	/*
+	 * Support single stage mode or 32/256 stages descriptor mode.
+	 * Set default as Descriptor Mode.
+	 */
+	udc->desc_mode = AST_UDC_DESC_MODE;
+
+	dev_info(&pdev->dev, "DMA %s\n", udc->desc_mode ?
+		 "descriptor mode" : "single mode");
+
+	INIT_LIST_HEAD(&udc->gadget.ep_list);
+	INIT_LIST_HEAD(&udc->gadget.ep0->ep_list);
+
+	/* Initialized udc ep */
+	ast_udc_init_ep(udc);
+
+	/* Initialized udc device */
+	ast_udc_init_dev(udc);
+
+	/* Initialized udc hardware */
+	ast_udc_init_hw(udc);
+
+	/* Find interrupt and install handler */
+	udc->irq = platform_get_irq(pdev, 0);
+	if (udc->irq < 0) {
+		dev_err(&pdev->dev, "Failed to get interrupt\n");
+		rc = udc->irq;
+		goto err;
+	}
+
+	rc = devm_request_irq(&pdev->dev, udc->irq, ast_udc_isr, 0,
+			      KBUILD_MODNAME, udc);
+	if (rc) {
+		dev_err(&pdev->dev, "Failed to request interrupt\n");
+		goto err;
+	}
+
+	rc = usb_add_gadget_udc(&pdev->dev, &udc->gadget);
+	if (rc) {
+		dev_err(&pdev->dev, "Failed to add gadget udc\n");
+		goto err;
+	}
+
+	dev_info(&pdev->dev, "Initialized udc in USB%s mode\n",
+		 udc->force_usb1 ? "1" : "2");
+
+	return 0;
+
+err:
+	dev_err(&pdev->dev, "Failed to udc probe, rc:0x%x\n", rc);
+	ast_udc_remove(pdev);
+
+	return rc;
+}
+
+static const struct of_device_id ast_udc_of_dt_ids[] = {
+	{ .compatible = "aspeed,ast2600-udc", },
+	{}
+};
+
+MODULE_DEVICE_TABLE(of, ast_udc_of_dt_ids);
+
+static struct platform_driver ast_udc_driver = {
+	.probe			= ast_udc_probe,
+	.remove			= ast_udc_remove,
+	.driver			= {
+		.name			= KBUILD_MODNAME,
+		.of_match_table		= ast_udc_of_dt_ids,
+	},
+};
+
+module_platform_driver(ast_udc_driver);
+
+MODULE_DESCRIPTION("ASPEED UDC driver");
+MODULE_AUTHOR("Neal Liu <neal_liu@aspeedtech.com>");
+MODULE_LICENSE("GPL");
-- 
2.25.1