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_...@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_...@aspeedtech.com>
+L:     linux-asp...@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.ch...@gmail.com>
 L:     acpi4asus-u...@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_...@aspeedtech.com>");
+MODULE_LICENSE("GPL");
-- 
2.25.1

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