Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 3752 insertions, 0 deletions

diff --git a/drivers/usb/gadget/udc/aspeed-vhub/Kconfig b/drivers/usb/gadget/udc/aspeed-vhub/Kconfig
new file mode 100644
index 000000000..83ba8a2eb
--- /dev/null
+++ b/drivers/usb/gadget/udc/aspeed-vhub/Kconfig
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0+
+config USB_ASPEED_VHUB
+	tristate "Aspeed vHub UDC driver"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	depends on USB_LIBCOMPOSITE
+	help
+	  USB peripheral controller for the Aspeed AST2500 family
+	  SoCs supporting the "vHub" functionality and USB2.0
diff --git a/drivers/usb/gadget/udc/aspeed-vhub/Makefile b/drivers/usb/gadget/udc/aspeed-vhub/Makefile
new file mode 100644
index 000000000..9f3add605
--- /dev/null
+++ b/drivers/usb/gadget/udc/aspeed-vhub/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0+
+obj-$(CONFIG_USB_ASPEED_VHUB)	+= aspeed-vhub.o
+aspeed-vhub-y	:= core.o ep0.o epn.o dev.o hub.o
+
diff --git a/drivers/usb/gadget/udc/aspeed-vhub/core.c b/drivers/usb/gadget/udc/aspeed-vhub/core.c
new file mode 100644
index 000000000..902e61be4
--- /dev/null
+++ b/drivers/usb/gadget/udc/aspeed-vhub/core.c
@@ -0,0 +1,426 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * aspeed-vhub -- Driver for Aspeed SoC "vHub" USB gadget
+ *
+ * core.c - Top level support
+ *
+ * Copyright 2017 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/prefetch.h>
+#include <linux/clk.h>
+#include <linux/usb/gadget.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regmap.h>
+#include <linux/dma-mapping.h>
+
+#include "vhub.h"
+
+void ast_vhub_done(struct ast_vhub_ep *ep, struct ast_vhub_req *req,
+		   int status)
+{
+	bool internal = req->internal;
+	struct ast_vhub *vhub = ep->vhub;
+
+	EPVDBG(ep, "completing request @%p, status %d\n", req, status);
+
+	list_del_init(&req->queue);
+
+	if (req->req.status == -EINPROGRESS)
+		req->req.status = status;
+
+	if (req->req.dma) {
+		if (!WARN_ON(!ep->dev))
+			usb_gadget_unmap_request_by_dev(&vhub->pdev->dev,
+						 &req->req, ep->epn.is_in);
+		req->req.dma = 0;
+	}
+
+	/*
+	 * If this isn't an internal EP0 request, call the core
+	 * to call the gadget completion.
+	 */
+	if (!internal) {
+		spin_unlock(&ep->vhub->lock);
+		usb_gadget_giveback_request(&ep->ep, &req->req);
+		spin_lock(&ep->vhub->lock);
+	}
+}
+
+void ast_vhub_nuke(struct ast_vhub_ep *ep, int status)
+{
+	struct ast_vhub_req *req;
+
+	EPDBG(ep, "Nuking\n");
+
+	/* Beware, lock will be dropped & req-acquired by done() */
+	while (!list_empty(&ep->queue)) {
+		req = list_first_entry(&ep->queue, struct ast_vhub_req, queue);
+		ast_vhub_done(ep, req, status);
+	}
+}
+
+struct usb_request *ast_vhub_alloc_request(struct usb_ep *u_ep,
+					   gfp_t gfp_flags)
+{
+	struct ast_vhub_req *req;
+
+	req = kzalloc(sizeof(*req), gfp_flags);
+	if (!req)
+		return NULL;
+	return &req->req;
+}
+
+void ast_vhub_free_request(struct usb_ep *u_ep, struct usb_request *u_req)
+{
+	struct ast_vhub_req *req = to_ast_req(u_req);
+
+	kfree(req);
+}
+
+static irqreturn_t ast_vhub_irq(int irq, void *data)
+{
+	struct ast_vhub *vhub = data;
+	irqreturn_t iret = IRQ_NONE;
+	u32 istat;
+
+	/* Stale interrupt while tearing down */
+	if (!vhub->ep0_bufs)
+		return IRQ_NONE;
+
+	spin_lock(&vhub->lock);
+
+	/* Read and ACK interrupts */
+	istat = readl(vhub->regs + AST_VHUB_ISR);
+	if (!istat)
+		goto bail;
+	writel(istat, vhub->regs + AST_VHUB_ISR);
+	iret = IRQ_HANDLED;
+
+	UDCVDBG(vhub, "irq status=%08x, ep_acks=%08x ep_nacks=%08x\n",
+	       istat,
+	       readl(vhub->regs + AST_VHUB_EP_ACK_ISR),
+	       readl(vhub->regs + AST_VHUB_EP_NACK_ISR));
+
+	/* Handle generic EPs first */
+	if (istat & VHUB_IRQ_EP_POOL_ACK_STALL) {
+		u32 i, ep_acks = readl(vhub->regs + AST_VHUB_EP_ACK_ISR);
+		writel(ep_acks, vhub->regs + AST_VHUB_EP_ACK_ISR);
+
+		for (i = 0; ep_acks && i < AST_VHUB_NUM_GEN_EPs; i++) {
+			u32 mask = VHUB_EP_IRQ(i);
+			if (ep_acks & mask) {
+				ast_vhub_epn_ack_irq(&vhub->epns[i]);
+				ep_acks &= ~mask;
+			}
+		}
+	}
+
+	/* Handle device interrupts */
+	if (istat & (VHUB_IRQ_DEVICE1 |
+		     VHUB_IRQ_DEVICE2 |
+		     VHUB_IRQ_DEVICE3 |
+		     VHUB_IRQ_DEVICE4 |
+		     VHUB_IRQ_DEVICE5)) {
+		if (istat & VHUB_IRQ_DEVICE1)
+			ast_vhub_dev_irq(&vhub->ports[0].dev);
+		if (istat & VHUB_IRQ_DEVICE2)
+			ast_vhub_dev_irq(&vhub->ports[1].dev);
+		if (istat & VHUB_IRQ_DEVICE3)
+			ast_vhub_dev_irq(&vhub->ports[2].dev);
+		if (istat & VHUB_IRQ_DEVICE4)
+			ast_vhub_dev_irq(&vhub->ports[3].dev);
+		if (istat & VHUB_IRQ_DEVICE5)
+			ast_vhub_dev_irq(&vhub->ports[4].dev);
+	}
+
+	/* Handle top-level vHub EP0 interrupts */
+	if (istat & (VHUB_IRQ_HUB_EP0_OUT_ACK_STALL |
+		     VHUB_IRQ_HUB_EP0_IN_ACK_STALL |
+		     VHUB_IRQ_HUB_EP0_SETUP)) {
+		if (istat & VHUB_IRQ_HUB_EP0_IN_ACK_STALL)
+			ast_vhub_ep0_handle_ack(&vhub->ep0, true);
+		if (istat & VHUB_IRQ_HUB_EP0_OUT_ACK_STALL)
+			ast_vhub_ep0_handle_ack(&vhub->ep0, false);
+		if (istat & VHUB_IRQ_HUB_EP0_SETUP)
+			ast_vhub_ep0_handle_setup(&vhub->ep0);
+	}
+
+	/* Various top level bus events */
+	if (istat & (VHUB_IRQ_BUS_RESUME |
+		     VHUB_IRQ_BUS_SUSPEND |
+		     VHUB_IRQ_BUS_RESET)) {
+		if (istat & VHUB_IRQ_BUS_RESUME)
+			ast_vhub_hub_resume(vhub);
+		if (istat & VHUB_IRQ_BUS_SUSPEND)
+			ast_vhub_hub_suspend(vhub);
+		if (istat & VHUB_IRQ_BUS_RESET)
+			ast_vhub_hub_reset(vhub);
+	}
+
+ bail:
+	spin_unlock(&vhub->lock);
+	return iret;
+}
+
+void ast_vhub_init_hw(struct ast_vhub *vhub)
+{
+	u32 ctrl;
+
+	UDCDBG(vhub,"(Re)Starting HW ...\n");
+
+	/* Enable PHY */
+	ctrl = VHUB_CTRL_PHY_CLK |
+		VHUB_CTRL_PHY_RESET_DIS;
+
+       /*
+	* We do *NOT* set the VHUB_CTRL_CLK_STOP_SUSPEND bit
+	* to stop the logic clock during suspend because
+	* it causes the registers to become inaccessible and
+	* we haven't yet figured out a good wayt to bring the
+	* controller back into life to issue a wakeup.
+	*/
+
+	/*
+	 * Set some ISO & split control bits according to Aspeed
+	 * recommendation
+	 *
+	 * VHUB_CTRL_ISO_RSP_CTRL: When set tells the HW to respond
+	 * with 0 bytes data packet to ISO IN endpoints when no data
+	 * is available.
+	 *
+	 * VHUB_CTRL_SPLIT_IN: This makes a SOF complete a split IN
+	 * transaction.
+	 */
+	ctrl |= VHUB_CTRL_ISO_RSP_CTRL | VHUB_CTRL_SPLIT_IN;
+	writel(ctrl, vhub->regs + AST_VHUB_CTRL);
+	udelay(1);
+
+	/* Set descriptor ring size */
+	if (AST_VHUB_DESCS_COUNT == 256) {
+		ctrl |= VHUB_CTRL_LONG_DESC;
+		writel(ctrl, vhub->regs + AST_VHUB_CTRL);
+	} else {
+		BUILD_BUG_ON(AST_VHUB_DESCS_COUNT != 32);
+	}
+
+	/* Reset all devices */
+	writel(VHUB_SW_RESET_ALL, vhub->regs + AST_VHUB_SW_RESET);
+	udelay(1);
+	writel(0, vhub->regs + AST_VHUB_SW_RESET);
+
+	/* Disable and cleanup EP ACK/NACK interrupts */
+	writel(0, vhub->regs + AST_VHUB_EP_ACK_IER);
+	writel(0, vhub->regs + AST_VHUB_EP_NACK_IER);
+	writel(VHUB_EP_IRQ_ALL, vhub->regs + AST_VHUB_EP_ACK_ISR);
+	writel(VHUB_EP_IRQ_ALL, vhub->regs + AST_VHUB_EP_NACK_ISR);
+
+	/* Default settings for EP0, enable HW hub EP1 */
+	writel(0, vhub->regs + AST_VHUB_EP0_CTRL);
+	writel(VHUB_EP1_CTRL_RESET_TOGGLE |
+	       VHUB_EP1_CTRL_ENABLE,
+	       vhub->regs + AST_VHUB_EP1_CTRL);
+	writel(0, vhub->regs + AST_VHUB_EP1_STS_CHG);
+
+	/* Configure EP0 DMA buffer */
+	writel(vhub->ep0.buf_dma, vhub->regs + AST_VHUB_EP0_DATA);
+
+	/* Clear address */
+	writel(0, vhub->regs + AST_VHUB_CONF);
+
+	/* Pullup hub (activate on host) */
+	if (vhub->force_usb1)
+		ctrl |= VHUB_CTRL_FULL_SPEED_ONLY;
+
+	ctrl |= VHUB_CTRL_UPSTREAM_CONNECT;
+	writel(ctrl, vhub->regs + AST_VHUB_CTRL);
+
+	/* Enable some interrupts */
+	writel(VHUB_IRQ_HUB_EP0_IN_ACK_STALL |
+	       VHUB_IRQ_HUB_EP0_OUT_ACK_STALL |
+	       VHUB_IRQ_HUB_EP0_SETUP |
+	       VHUB_IRQ_EP_POOL_ACK_STALL |
+	       VHUB_IRQ_BUS_RESUME |
+	       VHUB_IRQ_BUS_SUSPEND |
+	       VHUB_IRQ_BUS_RESET,
+	       vhub->regs + AST_VHUB_IER);
+}
+
+static int ast_vhub_remove(struct platform_device *pdev)
+{
+	struct ast_vhub *vhub = platform_get_drvdata(pdev);
+	unsigned long flags;
+	int i;
+
+	if (!vhub || !vhub->regs)
+		return 0;
+
+	/* Remove devices */
+	for (i = 0; i < AST_VHUB_NUM_PORTS; i++)
+		ast_vhub_del_dev(&vhub->ports[i].dev);
+
+	spin_lock_irqsave(&vhub->lock, flags);
+
+	/* Mask & ack all interrupts  */
+	writel(0, vhub->regs + AST_VHUB_IER);
+	writel(VHUB_IRQ_ACK_ALL, vhub->regs + AST_VHUB_ISR);
+
+	/* Pull device, leave PHY enabled */
+	writel(VHUB_CTRL_PHY_CLK |
+	       VHUB_CTRL_PHY_RESET_DIS,
+	       vhub->regs + AST_VHUB_CTRL);
+
+	if (vhub->clk)
+		clk_disable_unprepare(vhub->clk);
+
+	spin_unlock_irqrestore(&vhub->lock, flags);
+
+	if (vhub->ep0_bufs)
+		dma_free_coherent(&pdev->dev,
+				  AST_VHUB_EP0_MAX_PACKET *
+				  (AST_VHUB_NUM_PORTS + 1),
+				  vhub->ep0_bufs,
+				  vhub->ep0_bufs_dma);
+	vhub->ep0_bufs = NULL;
+
+	return 0;
+}
+
+static int ast_vhub_probe(struct platform_device *pdev)
+{
+	enum usb_device_speed max_speed;
+	struct ast_vhub *vhub;
+	struct resource *res;
+	int i, rc = 0;
+
+	vhub = devm_kzalloc(&pdev->dev, sizeof(*vhub), GFP_KERNEL);
+	if (!vhub)
+		return -ENOMEM;
+
+	spin_lock_init(&vhub->lock);
+	vhub->pdev = pdev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	vhub->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(vhub->regs)) {
+		dev_err(&pdev->dev, "Failed to map resources\n");
+		return PTR_ERR(vhub->regs);
+	}
+	UDCDBG(vhub, "vHub@%pR mapped @%p\n", res, vhub->regs);
+
+	platform_set_drvdata(pdev, vhub);
+
+	vhub->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(vhub->clk)) {
+		rc = PTR_ERR(vhub->clk);
+		goto err;
+	}
+	rc = clk_prepare_enable(vhub->clk);
+	if (rc) {
+		dev_err(&pdev->dev, "Error couldn't enable clock (%d)\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)
+		vhub->force_usb1 = true;
+
+	/* Mask & ack all interrupts before installing the handler */
+	writel(0, vhub->regs + AST_VHUB_IER);
+	writel(VHUB_IRQ_ACK_ALL, vhub->regs + AST_VHUB_ISR);
+
+	/* Find interrupt and install handler */
+	vhub->irq = platform_get_irq(pdev, 0);
+	if (vhub->irq < 0) {
+		dev_err(&pdev->dev, "Failed to get interrupt\n");
+		rc = vhub->irq;
+		goto err;
+	}
+	rc = devm_request_irq(&pdev->dev, vhub->irq, ast_vhub_irq, 0,
+			      KBUILD_MODNAME, vhub);
+	if (rc) {
+		dev_err(&pdev->dev, "Failed to request interrupt\n");
+		goto err;
+	}
+
+	/*
+	 * Allocate DMA buffers for all EP0s in one chunk,
+	 * one per port and one for the vHub itself
+	 */
+	vhub->ep0_bufs = dma_alloc_coherent(&pdev->dev,
+					    AST_VHUB_EP0_MAX_PACKET *
+					    (AST_VHUB_NUM_PORTS + 1),
+					    &vhub->ep0_bufs_dma, GFP_KERNEL);
+	if (!vhub->ep0_bufs) {
+		dev_err(&pdev->dev, "Failed to allocate EP0 DMA buffers\n");
+		rc = -ENOMEM;
+		goto err;
+	}
+	UDCVDBG(vhub, "EP0 DMA buffers @%p (DMA 0x%08x)\n",
+		vhub->ep0_bufs, (u32)vhub->ep0_bufs_dma);
+
+	/* Init vHub EP0 */
+	ast_vhub_init_ep0(vhub, &vhub->ep0, NULL);
+
+	/* Init devices */
+	for (i = 0; i < AST_VHUB_NUM_PORTS && rc == 0; i++)
+		rc = ast_vhub_init_dev(vhub, i);
+	if (rc)
+		goto err;
+
+	/* Init hub emulation */
+	ast_vhub_init_hub(vhub);
+
+	/* Initialize HW */
+	ast_vhub_init_hw(vhub);
+
+	dev_info(&pdev->dev, "Initialized virtual hub in USB%d mode\n",
+		 vhub->force_usb1 ? 1 : 2);
+
+	return 0;
+ err:
+	ast_vhub_remove(pdev);
+	return rc;
+}
+
+static const struct of_device_id ast_vhub_dt_ids[] = {
+	{
+		.compatible = "aspeed,ast2400-usb-vhub",
+	},
+	{
+		.compatible = "aspeed,ast2500-usb-vhub",
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ast_vhub_dt_ids);
+
+static struct platform_driver ast_vhub_driver = {
+	.probe		= ast_vhub_probe,
+	.remove		= ast_vhub_remove,
+	.driver		= {
+		.name	= KBUILD_MODNAME,
+		.of_match_table	= ast_vhub_dt_ids,
+	},
+};
+module_platform_driver(ast_vhub_driver);
+
+MODULE_DESCRIPTION("Aspeed vHub udc driver");
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/usb/gadget/udc/aspeed-vhub/dev.c b/drivers/usb/gadget/udc/aspeed-vhub/dev.c
new file mode 100644
index 000000000..f0233912b
--- /dev/null
+++ b/drivers/usb/gadget/udc/aspeed-vhub/dev.c
@@ -0,0 +1,589 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * aspeed-vhub -- Driver for Aspeed SoC "vHub" USB gadget
+ *
+ * dev.c - Individual device/gadget management (ie, a port = a gadget)
+ *
+ * Copyright 2017 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/prefetch.h>
+#include <linux/clk.h>
+#include <linux/usb/gadget.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regmap.h>
+#include <linux/dma-mapping.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+
+#include "vhub.h"
+
+void ast_vhub_dev_irq(struct ast_vhub_dev *d)
+{
+	u32 istat = readl(d->regs + AST_VHUB_DEV_ISR);
+
+	writel(istat, d->regs + AST_VHUB_DEV_ISR);
+
+	if (istat & VHUV_DEV_IRQ_EP0_IN_ACK_STALL)
+		ast_vhub_ep0_handle_ack(&d->ep0, true);
+	if (istat & VHUV_DEV_IRQ_EP0_OUT_ACK_STALL)
+		ast_vhub_ep0_handle_ack(&d->ep0, false);
+	if (istat & VHUV_DEV_IRQ_EP0_SETUP)
+		ast_vhub_ep0_handle_setup(&d->ep0);
+}
+
+static void ast_vhub_dev_enable(struct ast_vhub_dev *d)
+{
+	u32 reg, hmsk;
+
+	if (d->enabled)
+		return;
+
+	/* Enable device and its EP0 interrupts */
+	reg = VHUB_DEV_EN_ENABLE_PORT |
+		VHUB_DEV_EN_EP0_IN_ACK_IRQEN |
+		VHUB_DEV_EN_EP0_OUT_ACK_IRQEN |
+		VHUB_DEV_EN_EP0_SETUP_IRQEN;
+	if (d->gadget.speed == USB_SPEED_HIGH)
+		reg |= VHUB_DEV_EN_SPEED_SEL_HIGH;
+	writel(reg, d->regs + AST_VHUB_DEV_EN_CTRL);
+
+	/* Enable device interrupt in the hub as well */
+	hmsk = VHUB_IRQ_DEVICE1 << d->index;
+	reg = readl(d->vhub->regs + AST_VHUB_IER);
+	reg |= hmsk;
+	writel(reg, d->vhub->regs + AST_VHUB_IER);
+
+	/* Set EP0 DMA buffer address */
+	writel(d->ep0.buf_dma, d->regs + AST_VHUB_DEV_EP0_DATA);
+
+	d->enabled = true;
+}
+
+static void ast_vhub_dev_disable(struct ast_vhub_dev *d)
+{
+	u32 reg, hmsk;
+
+	if (!d->enabled)
+		return;
+
+	/* Disable device interrupt in the hub */
+	hmsk = VHUB_IRQ_DEVICE1 << d->index;
+	reg = readl(d->vhub->regs + AST_VHUB_IER);
+	reg &= ~hmsk;
+	writel(reg, d->vhub->regs + AST_VHUB_IER);
+
+	/* Then disable device */
+	writel(0, d->regs + AST_VHUB_DEV_EN_CTRL);
+	d->gadget.speed = USB_SPEED_UNKNOWN;
+	d->enabled = false;
+	d->suspended = false;
+}
+
+static int ast_vhub_dev_feature(struct ast_vhub_dev *d,
+				u16 wIndex, u16 wValue,
+				bool is_set)
+{
+	DDBG(d, "%s_FEATURE(dev val=%02x)\n",
+	     is_set ? "SET" : "CLEAR", wValue);
+
+	if (wValue != USB_DEVICE_REMOTE_WAKEUP)
+		return std_req_driver;
+
+	d->wakeup_en = is_set;
+
+	return std_req_complete;
+}
+
+static int ast_vhub_ep_feature(struct ast_vhub_dev *d,
+			       u16 wIndex, u16 wValue, bool is_set)
+{
+	struct ast_vhub_ep *ep;
+	int ep_num;
+
+	ep_num = wIndex & USB_ENDPOINT_NUMBER_MASK;
+	DDBG(d, "%s_FEATURE(ep%d val=%02x)\n",
+	     is_set ? "SET" : "CLEAR", ep_num, wValue);
+	if (ep_num == 0)
+		return std_req_complete;
+	if (ep_num >= AST_VHUB_NUM_GEN_EPs || !d->epns[ep_num - 1])
+		return std_req_stall;
+	if (wValue != USB_ENDPOINT_HALT)
+		return std_req_driver;
+
+	ep = d->epns[ep_num - 1];
+	if (WARN_ON(!ep))
+		return std_req_stall;
+
+	if (!ep->epn.enabled || !ep->ep.desc || ep->epn.is_iso ||
+	    ep->epn.is_in != !!(wIndex & USB_DIR_IN))
+		return std_req_stall;
+
+	DDBG(d, "%s stall on EP %d\n",
+	     is_set ? "setting" : "clearing", ep_num);
+	ep->epn.stalled = is_set;
+	ast_vhub_update_epn_stall(ep);
+
+	return std_req_complete;
+}
+
+static int ast_vhub_dev_status(struct ast_vhub_dev *d,
+			       u16 wIndex, u16 wValue)
+{
+	u8 st0;
+
+	DDBG(d, "GET_STATUS(dev)\n");
+
+	st0 = d->gadget.is_selfpowered << USB_DEVICE_SELF_POWERED;
+	if (d->wakeup_en)
+		st0 |= 1 << USB_DEVICE_REMOTE_WAKEUP;
+
+	return ast_vhub_simple_reply(&d->ep0, st0, 0);
+}
+
+static int ast_vhub_ep_status(struct ast_vhub_dev *d,
+			      u16 wIndex, u16 wValue)
+{
+	int ep_num = wIndex & USB_ENDPOINT_NUMBER_MASK;
+	struct ast_vhub_ep *ep;
+	u8 st0 = 0;
+
+	DDBG(d, "GET_STATUS(ep%d)\n", ep_num);
+
+	if (ep_num >= AST_VHUB_NUM_GEN_EPs)
+		return std_req_stall;
+	if (ep_num != 0) {
+		ep = d->epns[ep_num - 1];
+		if (!ep)
+			return std_req_stall;
+		if (!ep->epn.enabled || !ep->ep.desc || ep->epn.is_iso ||
+		    ep->epn.is_in != !!(wIndex & USB_DIR_IN))
+			return std_req_stall;
+		if (ep->epn.stalled)
+			st0 |= 1 << USB_ENDPOINT_HALT;
+	}
+
+	return ast_vhub_simple_reply(&d->ep0, st0, 0);
+}
+
+static void ast_vhub_dev_set_address(struct ast_vhub_dev *d, u8 addr)
+{
+	u32 reg;
+
+	DDBG(d, "SET_ADDRESS: Got address %x\n", addr);
+
+	reg = readl(d->regs + AST_VHUB_DEV_EN_CTRL);
+	reg &= ~VHUB_DEV_EN_ADDR_MASK;
+	reg |= VHUB_DEV_EN_SET_ADDR(addr);
+	writel(reg, d->regs + AST_VHUB_DEV_EN_CTRL);
+}
+
+int ast_vhub_std_dev_request(struct ast_vhub_ep *ep,
+			     struct usb_ctrlrequest *crq)
+{
+	struct ast_vhub_dev *d = ep->dev;
+	u16 wValue, wIndex;
+
+	/* No driver, we shouldn't be enabled ... */
+	if (!d->driver || !d->enabled || d->suspended) {
+		EPDBG(ep,
+		      "Device is wrong state driver=%p enabled=%d"
+		      " suspended=%d\n",
+		      d->driver, d->enabled, d->suspended);
+		return std_req_stall;
+	}
+
+	/* First packet, grab speed */
+	if (d->gadget.speed == USB_SPEED_UNKNOWN) {
+		d->gadget.speed = ep->vhub->speed;
+		if (d->gadget.speed > d->driver->max_speed)
+			d->gadget.speed = d->driver->max_speed;
+		DDBG(d, "fist packet, captured speed %d\n",
+		     d->gadget.speed);
+	}
+
+	wValue = le16_to_cpu(crq->wValue);
+	wIndex = le16_to_cpu(crq->wIndex);
+
+	switch ((crq->bRequestType << 8) | crq->bRequest) {
+		/* SET_ADDRESS */
+	case DeviceOutRequest | USB_REQ_SET_ADDRESS:
+		ast_vhub_dev_set_address(d, wValue);
+		return std_req_complete;
+
+		/* GET_STATUS */
+	case DeviceRequest | USB_REQ_GET_STATUS:
+		return ast_vhub_dev_status(d, wIndex, wValue);
+	case InterfaceRequest | USB_REQ_GET_STATUS:
+		return ast_vhub_simple_reply(ep, 0, 0);
+	case EndpointRequest | USB_REQ_GET_STATUS:
+		return ast_vhub_ep_status(d, wIndex, wValue);
+
+		/* SET/CLEAR_FEATURE */
+	case DeviceOutRequest | USB_REQ_SET_FEATURE:
+		return ast_vhub_dev_feature(d, wIndex, wValue, true);
+	case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
+		return ast_vhub_dev_feature(d, wIndex, wValue, false);
+	case EndpointOutRequest | USB_REQ_SET_FEATURE:
+		return ast_vhub_ep_feature(d, wIndex, wValue, true);
+	case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
+		return ast_vhub_ep_feature(d, wIndex, wValue, false);
+	}
+	return std_req_driver;
+}
+
+static int ast_vhub_udc_wakeup(struct usb_gadget* gadget)
+{
+	struct ast_vhub_dev *d = to_ast_dev(gadget);
+	unsigned long flags;
+	int rc = -EINVAL;
+
+	spin_lock_irqsave(&d->vhub->lock, flags);
+	if (!d->wakeup_en)
+		goto err;
+
+	DDBG(d, "Device initiated wakeup\n");
+
+	/* Wakeup the host */
+	ast_vhub_hub_wake_all(d->vhub);
+	rc = 0;
+ err:
+	spin_unlock_irqrestore(&d->vhub->lock, flags);
+	return rc;
+}
+
+static int ast_vhub_udc_get_frame(struct usb_gadget* gadget)
+{
+	struct ast_vhub_dev *d = to_ast_dev(gadget);
+
+	return (readl(d->vhub->regs + AST_VHUB_USBSTS) >> 16) & 0x7ff;
+}
+
+static void ast_vhub_dev_nuke(struct ast_vhub_dev *d)
+{
+	unsigned int i;
+
+	for (i = 0; i < AST_VHUB_NUM_GEN_EPs; i++) {
+		if (!d->epns[i])
+			continue;
+		ast_vhub_nuke(d->epns[i], -ESHUTDOWN);
+	}
+}
+
+static int ast_vhub_udc_pullup(struct usb_gadget* gadget, int on)
+{
+	struct ast_vhub_dev *d = to_ast_dev(gadget);
+	unsigned long flags;
+
+	spin_lock_irqsave(&d->vhub->lock, flags);
+
+	DDBG(d, "pullup(%d)\n", on);
+
+	/* Mark disconnected in the hub */
+	ast_vhub_device_connect(d->vhub, d->index, on);
+
+	/*
+	 * If enabled, nuke all requests if any (there shouldn't be)
+	 * and disable the port. This will clear the address too.
+	 */
+	if (d->enabled) {
+		ast_vhub_dev_nuke(d);
+		ast_vhub_dev_disable(d);
+	}
+
+	spin_unlock_irqrestore(&d->vhub->lock, flags);
+
+	return 0;
+}
+
+static int ast_vhub_udc_start(struct usb_gadget *gadget,
+			      struct usb_gadget_driver *driver)
+{
+	struct ast_vhub_dev *d = to_ast_dev(gadget);
+	unsigned long flags;
+
+	spin_lock_irqsave(&d->vhub->lock, flags);
+
+	DDBG(d, "start\n");
+
+	/* We don't do much more until the hub enables us */
+	d->driver = driver;
+	d->gadget.is_selfpowered = 1;
+
+	spin_unlock_irqrestore(&d->vhub->lock, flags);
+
+	return 0;
+}
+
+static struct usb_ep *ast_vhub_udc_match_ep(struct usb_gadget *gadget,
+					    struct usb_endpoint_descriptor *desc,
+					    struct usb_ss_ep_comp_descriptor *ss)
+{
+	struct ast_vhub_dev *d = to_ast_dev(gadget);
+	struct ast_vhub_ep *ep;
+	struct usb_ep *u_ep;
+	unsigned int max, addr, i;
+
+	DDBG(d, "Match EP type %d\n", usb_endpoint_type(desc));
+
+	/*
+	 * First we need to look for an existing unclaimed EP as another
+	 * configuration may have already associated a bunch of EPs with
+	 * this gadget. This duplicates the code in usb_ep_autoconfig_ss()
+	 * unfortunately.
+	 */
+	list_for_each_entry(u_ep, &gadget->ep_list, ep_list) {
+		if (usb_gadget_ep_match_desc(gadget, u_ep, desc, ss)) {
+			DDBG(d, " -> using existing EP%d\n",
+			     to_ast_ep(u_ep)->d_idx);
+			return u_ep;
+		}
+	}
+
+	/*
+	 * We didn't find one, we need to grab one from the pool.
+	 *
+	 * First let's do some sanity checking
+	 */
+	switch(usb_endpoint_type(desc)) {
+	case USB_ENDPOINT_XFER_CONTROL:
+		/* Only EP0 can be a control endpoint */
+		return NULL;
+	case USB_ENDPOINT_XFER_ISOC:
+		/* ISO:	 limit 1023 bytes full speed, 1024 high/super speed */
+		if (gadget_is_dualspeed(gadget))
+			max = 1024;
+		else
+			max = 1023;
+		break;
+	case USB_ENDPOINT_XFER_BULK:
+		if (gadget_is_dualspeed(gadget))
+			max = 512;
+		else
+			max = 64;
+		break;
+	case USB_ENDPOINT_XFER_INT:
+		if (gadget_is_dualspeed(gadget))
+			max = 1024;
+		else
+			max = 64;
+		break;
+	}
+	if (usb_endpoint_maxp(desc) > max)
+		return NULL;
+
+	/*
+	 * Find a free EP address for that device. We can't
+	 * let the generic code assign these as it would
+	 * create overlapping numbers for IN and OUT which
+	 * we don't support, so also create a suitable name
+	 * that will allow the generic code to use our
+	 * assigned address.
+	 */
+	for (i = 0; i < AST_VHUB_NUM_GEN_EPs; i++)
+		if (d->epns[i] == NULL)
+			break;
+	if (i >= AST_VHUB_NUM_GEN_EPs)
+		return NULL;
+	addr = i + 1;
+
+	/*
+	 * Now grab an EP from the shared pool and associate
+	 * it with our device
+	 */
+	ep = ast_vhub_alloc_epn(d, addr);
+	if (!ep)
+		return NULL;
+	DDBG(d, "Allocated epn#%d for port EP%d\n",
+	     ep->epn.g_idx, addr);
+
+	return &ep->ep;
+}
+
+static int ast_vhub_udc_stop(struct usb_gadget *gadget)
+{
+	struct ast_vhub_dev *d = to_ast_dev(gadget);
+	unsigned long flags;
+
+	spin_lock_irqsave(&d->vhub->lock, flags);
+
+	DDBG(d, "stop\n");
+
+	d->driver = NULL;
+	d->gadget.speed = USB_SPEED_UNKNOWN;
+
+	ast_vhub_dev_nuke(d);
+
+	if (d->enabled)
+		ast_vhub_dev_disable(d);
+
+	spin_unlock_irqrestore(&d->vhub->lock, flags);
+
+	return 0;
+}
+
+static struct usb_gadget_ops ast_vhub_udc_ops = {
+	.get_frame	= ast_vhub_udc_get_frame,
+	.wakeup		= ast_vhub_udc_wakeup,
+	.pullup		= ast_vhub_udc_pullup,
+	.udc_start	= ast_vhub_udc_start,
+	.udc_stop	= ast_vhub_udc_stop,
+	.match_ep	= ast_vhub_udc_match_ep,
+};
+
+void ast_vhub_dev_suspend(struct ast_vhub_dev *d)
+{
+	d->suspended = true;
+	if (d->driver) {
+		spin_unlock(&d->vhub->lock);
+		d->driver->suspend(&d->gadget);
+		spin_lock(&d->vhub->lock);
+	}
+}
+
+void ast_vhub_dev_resume(struct ast_vhub_dev *d)
+{
+	d->suspended = false;
+	if (d->driver) {
+		spin_unlock(&d->vhub->lock);
+		d->driver->resume(&d->gadget);
+		spin_lock(&d->vhub->lock);
+	}
+}
+
+void ast_vhub_dev_reset(struct ast_vhub_dev *d)
+{
+	/*
+	 * If speed is not set, we enable the port. If it is,
+	 * send reset to the gadget and reset "speed".
+	 *
+	 * Speed is an indication that we have got the first
+	 * setup packet to the device.
+	 */
+	if (d->gadget.speed == USB_SPEED_UNKNOWN && !d->enabled) {
+		DDBG(d, "Reset at unknown speed of disabled device, enabling...\n");
+		ast_vhub_dev_enable(d);
+		d->suspended = false;
+	}
+	if (d->gadget.speed != USB_SPEED_UNKNOWN && d->driver) {
+		unsigned int i;
+
+		DDBG(d, "Reset at known speed of bound device, resetting...\n");
+		spin_unlock(&d->vhub->lock);
+		d->driver->reset(&d->gadget);
+		spin_lock(&d->vhub->lock);
+
+		/*
+		 * Disable/re-enable HW, this will clear the address
+		 * and speed setting.
+		 */
+		ast_vhub_dev_disable(d);
+		ast_vhub_dev_enable(d);
+
+		/* Clear stall on all EPs */
+		for (i = 0; i < AST_VHUB_NUM_GEN_EPs; i++) {
+			struct ast_vhub_ep *ep = d->epns[i];
+
+			if (ep && ep->epn.stalled) {
+				ep->epn.stalled = false;
+				ast_vhub_update_epn_stall(ep);
+			}
+		}
+
+		/* Additional cleanups */
+		d->wakeup_en = false;
+		d->suspended = false;
+	}
+}
+
+void ast_vhub_del_dev(struct ast_vhub_dev *d)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&d->vhub->lock, flags);
+	if (!d->registered) {
+		spin_unlock_irqrestore(&d->vhub->lock, flags);
+		return;
+	}
+	d->registered = false;
+	spin_unlock_irqrestore(&d->vhub->lock, flags);
+
+	usb_del_gadget_udc(&d->gadget);
+	device_unregister(d->port_dev);
+}
+
+static void ast_vhub_dev_release(struct device *dev)
+{
+	kfree(dev);
+}
+
+int ast_vhub_init_dev(struct ast_vhub *vhub, unsigned int idx)
+{
+	struct ast_vhub_dev *d = &vhub->ports[idx].dev;
+	struct device *parent = &vhub->pdev->dev;
+	int rc;
+
+	d->vhub = vhub;
+	d->index = idx;
+	d->name = devm_kasprintf(parent, GFP_KERNEL, "port%d", idx+1);
+	d->regs = vhub->regs + 0x100 + 0x10 * idx;
+
+	ast_vhub_init_ep0(vhub, &d->ep0, d);
+
+	/*
+	 * The UDC core really needs us to have separate and uniquely
+	 * named "parent" devices for each port so we create a sub device
+	 * here for that purpose
+	 */
+	d->port_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
+	if (!d->port_dev)
+		return -ENOMEM;
+	device_initialize(d->port_dev);
+	d->port_dev->release = ast_vhub_dev_release;
+	d->port_dev->parent = parent;
+	dev_set_name(d->port_dev, "%s:p%d", dev_name(parent), idx + 1);
+	rc = device_add(d->port_dev);
+	if (rc)
+		goto fail_add;
+
+	/* Populate gadget */
+	INIT_LIST_HEAD(&d->gadget.ep_list);
+	d->gadget.ops = &ast_vhub_udc_ops;
+	d->gadget.ep0 = &d->ep0.ep;
+	d->gadget.name = KBUILD_MODNAME;
+	if (vhub->force_usb1)
+		d->gadget.max_speed = USB_SPEED_FULL;
+	else
+		d->gadget.max_speed = USB_SPEED_HIGH;
+	d->gadget.speed = USB_SPEED_UNKNOWN;
+	d->gadget.dev.of_node = vhub->pdev->dev.of_node;
+
+	rc = usb_add_gadget_udc(d->port_dev, &d->gadget);
+	if (rc != 0)
+		goto fail_udc;
+	d->registered = true;
+
+	return 0;
+ fail_udc:
+	device_del(d->port_dev);
+ fail_add:
+	put_device(d->port_dev);
+
+	return rc;
+}
diff --git a/drivers/usb/gadget/udc/aspeed-vhub/ep0.c b/drivers/usb/gadget/udc/aspeed-vhub/ep0.c
new file mode 100644
index 000000000..e2927fb08
--- /dev/null
+++ b/drivers/usb/gadget/udc/aspeed-vhub/ep0.c
@@ -0,0 +1,495 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * aspeed-vhub -- Driver for Aspeed SoC "vHub" USB gadget
+ *
+ * ep0.c - Endpoint 0 handling
+ *
+ * Copyright 2017 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/prefetch.h>
+#include <linux/clk.h>
+#include <linux/usb/gadget.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regmap.h>
+#include <linux/dma-mapping.h>
+
+#include "vhub.h"
+
+int ast_vhub_reply(struct ast_vhub_ep *ep, char *ptr, int len)
+{
+	struct usb_request *req = &ep->ep0.req.req;
+	int rc;
+
+	if (WARN_ON(ep->d_idx != 0))
+		return std_req_stall;
+	if (WARN_ON(!ep->ep0.dir_in))
+		return std_req_stall;
+	if (WARN_ON(len > AST_VHUB_EP0_MAX_PACKET))
+		return std_req_stall;
+	if (WARN_ON(req->status == -EINPROGRESS))
+		return std_req_stall;
+
+	req->buf = ptr;
+	req->length = len;
+	req->complete = NULL;
+	req->zero = true;
+
+	/*
+	 * Call internal queue directly after dropping the lock. This is
+	 * safe to do as the reply is always the last thing done when
+	 * processing a SETUP packet, usually as a tail call
+	 */
+	spin_unlock(&ep->vhub->lock);
+	if (ep->ep.ops->queue(&ep->ep, req, GFP_ATOMIC))
+		rc = std_req_stall;
+	else
+		rc = std_req_data;
+	spin_lock(&ep->vhub->lock);
+	return rc;
+}
+
+int __ast_vhub_simple_reply(struct ast_vhub_ep *ep, int len, ...)
+{
+	u8 *buffer = ep->buf;
+	unsigned int i;
+	va_list args;
+
+	va_start(args, len);
+
+	/* Copy data directly into EP buffer */
+	for (i = 0; i < len; i++)
+		buffer[i] = va_arg(args, int);
+	va_end(args);
+
+	/* req->buf NULL means data is already there */
+	return ast_vhub_reply(ep, NULL, len);
+}
+
+void ast_vhub_ep0_handle_setup(struct ast_vhub_ep *ep)
+{
+	struct usb_ctrlrequest crq;
+	enum std_req_rc std_req_rc;
+	int rc = -ENODEV;
+
+	if (WARN_ON(ep->d_idx != 0))
+		return;
+
+	/*
+	 * Grab the setup packet from the chip and byteswap
+	 * interesting fields
+	 */
+	memcpy_fromio(&crq, ep->ep0.setup, sizeof(crq));
+
+	EPDBG(ep, "SETUP packet %02x/%02x/%04x/%04x/%04x [%s] st=%d\n",
+	      crq.bRequestType, crq.bRequest,
+	       le16_to_cpu(crq.wValue),
+	       le16_to_cpu(crq.wIndex),
+	       le16_to_cpu(crq.wLength),
+	       (crq.bRequestType & USB_DIR_IN) ? "in" : "out",
+	       ep->ep0.state);
+
+	/* Check our state, cancel pending requests if needed */
+	if (ep->ep0.state != ep0_state_token) {
+		EPDBG(ep, "wrong state\n");
+		ast_vhub_nuke(ep, -EIO);
+
+		/*
+		 * Accept the packet regardless, this seems to happen
+		 * when stalling a SETUP packet that has an OUT data
+		 * phase.
+		 */
+		ast_vhub_nuke(ep, 0);
+		goto stall;
+	}
+
+	/* Calculate next state for EP0 */
+	ep->ep0.state = ep0_state_data;
+	ep->ep0.dir_in = !!(crq.bRequestType & USB_DIR_IN);
+
+	/* If this is the vHub, we handle requests differently */
+	std_req_rc = std_req_driver;
+	if (ep->dev == NULL) {
+		if ((crq.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
+			std_req_rc = ast_vhub_std_hub_request(ep, &crq);
+		else if ((crq.bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
+			std_req_rc = ast_vhub_class_hub_request(ep, &crq);
+		else
+			std_req_rc = std_req_stall;
+	} else if ((crq.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
+		std_req_rc = ast_vhub_std_dev_request(ep, &crq);
+
+	/* Act upon result */
+	switch(std_req_rc) {
+	case std_req_complete:
+		goto complete;
+	case std_req_stall:
+		goto stall;
+	case std_req_driver:
+		break;
+	case std_req_data:
+		return;
+	}
+
+	/* Pass request up to the gadget driver */
+	if (WARN_ON(!ep->dev))
+		goto stall;
+	if (ep->dev->driver) {
+		EPDBG(ep, "forwarding to gadget...\n");
+		spin_unlock(&ep->vhub->lock);
+		rc = ep->dev->driver->setup(&ep->dev->gadget, &crq);
+		spin_lock(&ep->vhub->lock);
+		EPDBG(ep, "driver returned %d\n", rc);
+	} else {
+		EPDBG(ep, "no gadget for request !\n");
+	}
+	if (rc >= 0)
+		return;
+
+ stall:
+	EPDBG(ep, "stalling\n");
+	writel(VHUB_EP0_CTRL_STALL, ep->ep0.ctlstat);
+	ep->ep0.state = ep0_state_status;
+	ep->ep0.dir_in = false;
+	return;
+
+ complete:
+	EPVDBG(ep, "sending [in] status with no data\n");
+	writel(VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
+	ep->ep0.state = ep0_state_status;
+	ep->ep0.dir_in = false;
+}
+
+
+static void ast_vhub_ep0_do_send(struct ast_vhub_ep *ep,
+				 struct ast_vhub_req *req)
+{
+	unsigned int chunk;
+	u32 reg;
+
+	/* If this is a 0-length request, it's the gadget trying to
+	 * send a status on our behalf. We take it from here.
+	 */
+	if (req->req.length == 0)
+		req->last_desc = 1;
+
+	/* Are we done ? Complete request, otherwise wait for next interrupt */
+	if (req->last_desc >= 0) {
+		EPVDBG(ep, "complete send %d/%d\n",
+		       req->req.actual, req->req.length);
+		ep->ep0.state = ep0_state_status;
+		writel(VHUB_EP0_RX_BUFF_RDY, ep->ep0.ctlstat);
+		ast_vhub_done(ep, req, 0);
+		return;
+	}
+
+	/*
+	 * Next chunk cropped to max packet size. Also check if this
+	 * is the last packet
+	 */
+	chunk = req->req.length - req->req.actual;
+	if (chunk > ep->ep.maxpacket)
+		chunk = ep->ep.maxpacket;
+	else if ((chunk < ep->ep.maxpacket) || !req->req.zero)
+		req->last_desc = 1;
+
+	EPVDBG(ep, "send chunk=%d last=%d, req->act=%d mp=%d\n",
+	       chunk, req->last_desc, req->req.actual, ep->ep.maxpacket);
+
+	/*
+	 * Copy data if any (internal requests already have data
+	 * in the EP buffer)
+	 */
+	if (chunk && req->req.buf)
+		memcpy(ep->buf, req->req.buf + req->req.actual, chunk);
+
+	vhub_dma_workaround(ep->buf);
+
+	/* Remember chunk size and trigger send */
+	reg = VHUB_EP0_SET_TX_LEN(chunk);
+	writel(reg, ep->ep0.ctlstat);
+	writel(reg | VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
+	req->req.actual += chunk;
+}
+
+static void ast_vhub_ep0_rx_prime(struct ast_vhub_ep *ep)
+{
+	EPVDBG(ep, "rx prime\n");
+
+	/* Prime endpoint for receiving data */
+	writel(VHUB_EP0_RX_BUFF_RDY, ep->ep0.ctlstat);
+}
+
+static void ast_vhub_ep0_do_receive(struct ast_vhub_ep *ep, struct ast_vhub_req *req,
+				    unsigned int len)
+{
+	unsigned int remain;
+	int rc = 0;
+
+	/* We are receiving... grab request */
+	remain = req->req.length - req->req.actual;
+
+	EPVDBG(ep, "receive got=%d remain=%d\n", len, remain);
+
+	/* Are we getting more than asked ? */
+	if (len > remain) {
+		EPDBG(ep, "receiving too much (ovf: %d) !\n",
+		      len - remain);
+		len = remain;
+		rc = -EOVERFLOW;
+	}
+	if (len && req->req.buf)
+		memcpy(req->req.buf + req->req.actual, ep->buf, len);
+	req->req.actual += len;
+
+	/* Done ? */
+	if (len < ep->ep.maxpacket || len == remain) {
+		ep->ep0.state = ep0_state_status;
+		writel(VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
+		ast_vhub_done(ep, req, rc);
+	} else
+		ast_vhub_ep0_rx_prime(ep);
+}
+
+void ast_vhub_ep0_handle_ack(struct ast_vhub_ep *ep, bool in_ack)
+{
+	struct ast_vhub_req *req;
+	struct ast_vhub *vhub = ep->vhub;
+	struct device *dev = &vhub->pdev->dev;
+	bool stall = false;
+	u32 stat;
+
+	/* Read EP0 status */
+	stat = readl(ep->ep0.ctlstat);
+
+	/* Grab current request if any */
+	req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
+
+	EPVDBG(ep, "ACK status=%08x,state=%d is_in=%d in_ack=%d req=%p\n",
+		stat, ep->ep0.state, ep->ep0.dir_in, in_ack, req);
+
+	switch(ep->ep0.state) {
+	case ep0_state_token:
+		/* There should be no request queued in that state... */
+		if (req) {
+			dev_warn(dev, "request present while in TOKEN state\n");
+			ast_vhub_nuke(ep, -EINVAL);
+		}
+		dev_warn(dev, "ack while in TOKEN state\n");
+		stall = true;
+		break;
+	case ep0_state_data:
+		/* Check the state bits corresponding to our direction */
+		if ((ep->ep0.dir_in && (stat & VHUB_EP0_TX_BUFF_RDY)) ||
+		    (!ep->ep0.dir_in && (stat & VHUB_EP0_RX_BUFF_RDY)) ||
+		    (ep->ep0.dir_in != in_ack)) {
+			dev_warn(dev, "irq state mismatch");
+			stall = true;
+			break;
+		}
+		/*
+		 * We are in data phase and there's no request, something is
+		 * wrong, stall
+		 */
+		if (!req) {
+			dev_warn(dev, "data phase, no request\n");
+			stall = true;
+			break;
+		}
+
+		/* We have a request, handle data transfers */
+		if (ep->ep0.dir_in)
+			ast_vhub_ep0_do_send(ep, req);
+		else
+			ast_vhub_ep0_do_receive(ep, req, VHUB_EP0_RX_LEN(stat));
+		return;
+	case ep0_state_status:
+		/* Nuke stale requests */
+		if (req) {
+			dev_warn(dev, "request present while in STATUS state\n");
+			ast_vhub_nuke(ep, -EINVAL);
+		}
+
+		/*
+		 * If the status phase completes with the wrong ack, stall
+		 * the endpoint just in case, to abort whatever the host
+		 * was doing.
+		 */
+		if (ep->ep0.dir_in == in_ack) {
+			dev_warn(dev, "status direction mismatch\n");
+			stall = true;
+		}
+	}
+
+	/* Reset to token state */
+	ep->ep0.state = ep0_state_token;
+	if (stall)
+		writel(VHUB_EP0_CTRL_STALL, ep->ep0.ctlstat);
+}
+
+static int ast_vhub_ep0_queue(struct usb_ep* u_ep, struct usb_request *u_req,
+			      gfp_t gfp_flags)
+{
+	struct ast_vhub_req *req = to_ast_req(u_req);
+	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
+	struct ast_vhub *vhub = ep->vhub;
+	struct device *dev = &vhub->pdev->dev;
+	unsigned long flags;
+
+	/* Paranoid cheks */
+	if (!u_req || (!u_req->complete && !req->internal)) {
+		dev_warn(dev, "Bogus EP0 request ! u_req=%p\n", u_req);
+		if (u_req) {
+			dev_warn(dev, "complete=%p internal=%d\n",
+				 u_req->complete, req->internal);
+		}
+		return -EINVAL;
+	}
+
+	/* Not endpoint 0 ? */
+	if (WARN_ON(ep->d_idx != 0))
+		return -EINVAL;
+
+	/* Disabled device */
+	if (ep->dev && (!ep->dev->enabled || ep->dev->suspended))
+		return -ESHUTDOWN;
+
+	/* Data, no buffer and not internal ? */
+	if (u_req->length && !u_req->buf && !req->internal) {
+		dev_warn(dev, "Request with no buffer !\n");
+		return -EINVAL;
+	}
+
+	EPVDBG(ep, "enqueue req @%p\n", req);
+	EPVDBG(ep, "  l=%d zero=%d noshort=%d is_in=%d\n",
+	       u_req->length, u_req->zero,
+	       u_req->short_not_ok, ep->ep0.dir_in);
+
+	/* Initialize request progress fields */
+	u_req->status = -EINPROGRESS;
+	u_req->actual = 0;
+	req->last_desc = -1;
+	req->active = false;
+
+	spin_lock_irqsave(&vhub->lock, flags);
+
+	/* EP0 can only support a single request at a time */
+	if (!list_empty(&ep->queue) || ep->ep0.state == ep0_state_token) {
+		dev_warn(dev, "EP0: Request in wrong state\n");
+		spin_unlock_irqrestore(&vhub->lock, flags);
+		return -EBUSY;
+	}
+
+	/* Add request to list and kick processing if empty */
+	list_add_tail(&req->queue, &ep->queue);
+
+	if (ep->ep0.dir_in) {
+		/* IN request, send data */
+		ast_vhub_ep0_do_send(ep, req);
+	} else if (u_req->length == 0) {
+		/* 0-len request, send completion as rx */
+		EPVDBG(ep, "0-length rx completion\n");
+		ep->ep0.state = ep0_state_status;
+		writel(VHUB_EP0_TX_BUFF_RDY, ep->ep0.ctlstat);
+		ast_vhub_done(ep, req, 0);
+	} else {
+		/* OUT request, start receiver */
+		ast_vhub_ep0_rx_prime(ep);
+	}
+
+	spin_unlock_irqrestore(&vhub->lock, flags);
+
+	return 0;
+}
+
+static int ast_vhub_ep0_dequeue(struct usb_ep* u_ep, struct usb_request *u_req)
+{
+	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
+	struct ast_vhub *vhub = ep->vhub;
+	struct ast_vhub_req *req;
+	unsigned long flags;
+	int rc = -EINVAL;
+
+	spin_lock_irqsave(&vhub->lock, flags);
+
+	/* Only one request can be in the queue */
+	req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
+
+	/* Is it ours ? */
+	if (req && u_req == &req->req) {
+		EPVDBG(ep, "dequeue req @%p\n", req);
+
+		/*
+		 * We don't have to deal with "active" as all
+		 * DMAs go to the EP buffers, not the request.
+		 */
+		ast_vhub_done(ep, req, -ECONNRESET);
+
+		/* We do stall the EP to clean things up in HW */
+		writel(VHUB_EP0_CTRL_STALL, ep->ep0.ctlstat);
+		ep->ep0.state = ep0_state_status;
+		ep->ep0.dir_in = false;
+		rc = 0;
+	}
+	spin_unlock_irqrestore(&vhub->lock, flags);
+	return rc;
+}
+
+
+static const struct usb_ep_ops ast_vhub_ep0_ops = {
+	.queue		= ast_vhub_ep0_queue,
+	.dequeue	= ast_vhub_ep0_dequeue,
+	.alloc_request	= ast_vhub_alloc_request,
+	.free_request	= ast_vhub_free_request,
+};
+
+void ast_vhub_init_ep0(struct ast_vhub *vhub, struct ast_vhub_ep *ep,
+		       struct ast_vhub_dev *dev)
+{
+	memset(ep, 0, sizeof(*ep));
+
+	INIT_LIST_HEAD(&ep->ep.ep_list);
+	INIT_LIST_HEAD(&ep->queue);
+	ep->ep.ops = &ast_vhub_ep0_ops;
+	ep->ep.name = "ep0";
+	ep->ep.caps.type_control = true;
+	usb_ep_set_maxpacket_limit(&ep->ep, AST_VHUB_EP0_MAX_PACKET);
+	ep->d_idx = 0;
+	ep->dev = dev;
+	ep->vhub = vhub;
+	ep->ep0.state = ep0_state_token;
+	INIT_LIST_HEAD(&ep->ep0.req.queue);
+	ep->ep0.req.internal = true;
+
+	/* Small difference between vHub and devices */
+	if (dev) {
+		ep->ep0.ctlstat = dev->regs + AST_VHUB_DEV_EP0_CTRL;
+		ep->ep0.setup = vhub->regs +
+			AST_VHUB_SETUP0 + 8 * (dev->index + 1);
+		ep->buf = vhub->ep0_bufs +
+			AST_VHUB_EP0_MAX_PACKET * (dev->index + 1);
+		ep->buf_dma = vhub->ep0_bufs_dma +
+			AST_VHUB_EP0_MAX_PACKET * (dev->index + 1);
+	} else {
+		ep->ep0.ctlstat = vhub->regs + AST_VHUB_EP0_CTRL;
+		ep->ep0.setup = vhub->regs + AST_VHUB_SETUP0;
+		ep->buf = vhub->ep0_bufs;
+		ep->buf_dma = vhub->ep0_bufs_dma;
+	}
+}
diff --git a/drivers/usb/gadget/udc/aspeed-vhub/epn.c b/drivers/usb/gadget/udc/aspeed-vhub/epn.c
new file mode 100644
index 000000000..931f540a7
--- /dev/null
+++ b/drivers/usb/gadget/udc/aspeed-vhub/epn.c
@@ -0,0 +1,854 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * aspeed-vhub -- Driver for Aspeed SoC "vHub" USB gadget
+ *
+ * epn.c - Generic endpoints management
+ *
+ * Copyright 2017 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/prefetch.h>
+#include <linux/clk.h>
+#include <linux/usb/gadget.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regmap.h>
+#include <linux/dma-mapping.h>
+
+#include "vhub.h"
+
+#define EXTRA_CHECKS
+
+#ifdef EXTRA_CHECKS
+#define CHECK(ep, expr, fmt...)					\
+	do {							\
+		if (!(expr)) EPDBG(ep, "CHECK:" fmt);		\
+	} while(0)
+#else
+#define CHECK(ep, expr, fmt...)	do { } while(0)
+#endif
+
+static void ast_vhub_epn_kick(struct ast_vhub_ep *ep, struct ast_vhub_req *req)
+{
+	unsigned int act = req->req.actual;
+	unsigned int len = req->req.length;
+	unsigned int chunk;
+
+	/* There should be no DMA ongoing */
+	WARN_ON(req->active);
+
+	/* Calculate next chunk size */
+	chunk = len - act;
+	if (chunk > ep->ep.maxpacket)
+		chunk = ep->ep.maxpacket;
+	else if ((chunk < ep->ep.maxpacket) || !req->req.zero)
+		req->last_desc = 1;
+
+	EPVDBG(ep, "kick req %p act=%d/%d chunk=%d last=%d\n",
+	       req, act, len, chunk, req->last_desc);
+
+	/* If DMA unavailable, using staging EP buffer */
+	if (!req->req.dma) {
+
+		/* For IN transfers, copy data over first */
+		if (ep->epn.is_in) {
+			memcpy(ep->buf, req->req.buf + act, chunk);
+			vhub_dma_workaround(ep->buf);
+		}
+		writel(ep->buf_dma, ep->epn.regs + AST_VHUB_EP_DESC_BASE);
+	} else {
+		if (ep->epn.is_in)
+			vhub_dma_workaround(req->req.buf);
+		writel(req->req.dma + act, ep->epn.regs + AST_VHUB_EP_DESC_BASE);
+	}
+
+	/* Start DMA */
+	req->active = true;
+	writel(VHUB_EP_DMA_SET_TX_SIZE(chunk),
+	       ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
+	writel(VHUB_EP_DMA_SET_TX_SIZE(chunk) | VHUB_EP_DMA_SINGLE_KICK,
+	       ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
+}
+
+static void ast_vhub_epn_handle_ack(struct ast_vhub_ep *ep)
+{
+	struct ast_vhub_req *req;
+	unsigned int len;
+	u32 stat;
+
+	/* Read EP status */
+	stat = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
+
+	/* Grab current request if any */
+	req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
+
+	EPVDBG(ep, "ACK status=%08x is_in=%d, req=%p (active=%d)\n",
+	       stat, ep->epn.is_in, req, req ? req->active : 0);
+
+	/* In absence of a request, bail out, must have been dequeued */
+	if (!req)
+		return;
+
+	/*
+	 * Request not active, move on to processing queue, active request
+	 * was probably dequeued
+	 */
+	if (!req->active)
+		goto next_chunk;
+
+	/* Check if HW has moved on */
+	if (VHUB_EP_DMA_RPTR(stat) != 0) {
+		EPDBG(ep, "DMA read pointer not 0 !\n");
+		return;
+	}
+
+	/* No current DMA ongoing */
+	req->active = false;
+
+	/* Grab lenght out of HW */
+	len = VHUB_EP_DMA_TX_SIZE(stat);
+
+	/* If not using DMA, copy data out if needed */
+	if (!req->req.dma && !ep->epn.is_in && len)
+		memcpy(req->req.buf + req->req.actual, ep->buf, len);
+
+	/* Adjust size */
+	req->req.actual += len;
+
+	/* Check for short packet */
+	if (len < ep->ep.maxpacket)
+		req->last_desc = 1;
+
+	/* That's it ? complete the request and pick a new one */
+	if (req->last_desc >= 0) {
+		ast_vhub_done(ep, req, 0);
+		req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req,
+					       queue);
+
+		/*
+		 * Due to lock dropping inside "done" the next request could
+		 * already be active, so check for that and bail if needed.
+		 */
+		if (!req || req->active)
+			return;
+	}
+
+ next_chunk:
+	ast_vhub_epn_kick(ep, req);
+}
+
+static inline unsigned int ast_vhub_count_free_descs(struct ast_vhub_ep *ep)
+{
+	/*
+	 * d_next == d_last means descriptor list empty to HW,
+	 * thus we can only have AST_VHUB_DESCS_COUNT-1 descriptors
+	 * in the list
+	 */
+	return (ep->epn.d_last + AST_VHUB_DESCS_COUNT - ep->epn.d_next - 1) &
+		(AST_VHUB_DESCS_COUNT - 1);
+}
+
+static void ast_vhub_epn_kick_desc(struct ast_vhub_ep *ep,
+				   struct ast_vhub_req *req)
+{
+	struct ast_vhub_desc *desc = NULL;
+	unsigned int act = req->act_count;
+	unsigned int len = req->req.length;
+	unsigned int chunk;
+
+	/* Mark request active if not already */
+	req->active = true;
+
+	/* If the request was already completely written, do nothing */
+	if (req->last_desc >= 0)
+		return;
+
+	EPVDBG(ep, "kick act=%d/%d chunk_max=%d free_descs=%d\n",
+	       act, len, ep->epn.chunk_max, ast_vhub_count_free_descs(ep));
+
+	/* While we can create descriptors */
+	while (ast_vhub_count_free_descs(ep) && req->last_desc < 0) {
+		unsigned int d_num;
+
+		/* Grab next free descriptor */
+		d_num = ep->epn.d_next;
+		desc = &ep->epn.descs[d_num];
+		ep->epn.d_next = (d_num + 1) & (AST_VHUB_DESCS_COUNT - 1);
+
+		/* Calculate next chunk size */
+		chunk = len - act;
+		if (chunk <= ep->epn.chunk_max) {
+			/*
+			 * Is this the last packet ? Because of having up to 8
+			 * packets in a descriptor we can't just compare "chunk"
+			 * with ep.maxpacket. We have to see if it's a multiple
+			 * of it to know if we have to send a zero packet.
+			 * Sadly that involves a modulo which is a bit expensive
+			 * but probably still better than not doing it.
+			 */
+			if (!chunk || !req->req.zero || (chunk % ep->ep.maxpacket) != 0)
+				req->last_desc = d_num;
+		} else {
+			chunk = ep->epn.chunk_max;
+		}
+
+		EPVDBG(ep, " chunk: act=%d/%d chunk=%d last=%d desc=%d free=%d\n",
+		       act, len, chunk, req->last_desc, d_num,
+		       ast_vhub_count_free_descs(ep));
+
+		/* Populate descriptor */
+		desc->w0 = cpu_to_le32(req->req.dma + act);
+
+		/* Interrupt if end of request or no more descriptors */
+
+		/*
+		 * TODO: Be smarter about it, if we don't have enough
+		 * descriptors request an interrupt before queue empty
+		 * or so in order to be able to populate more before
+		 * the HW runs out. This isn't a problem at the moment
+		 * as we use 256 descriptors and only put at most one
+		 * request in the ring.
+		 */
+		desc->w1 = cpu_to_le32(VHUB_DSC1_IN_SET_LEN(chunk));
+		if (req->last_desc >= 0 || !ast_vhub_count_free_descs(ep))
+			desc->w1 |= cpu_to_le32(VHUB_DSC1_IN_INTERRUPT);
+
+		/* Account packet */
+		req->act_count = act = act + chunk;
+	}
+
+	if (likely(desc))
+		vhub_dma_workaround(desc);
+
+	/* Tell HW about new descriptors */
+	writel(VHUB_EP_DMA_SET_CPU_WPTR(ep->epn.d_next),
+	       ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
+
+	EPVDBG(ep, "HW kicked, d_next=%d dstat=%08x\n",
+	       ep->epn.d_next, readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS));
+}
+
+static void ast_vhub_epn_handle_ack_desc(struct ast_vhub_ep *ep)
+{
+	struct ast_vhub_req *req;
+	unsigned int len, d_last;
+	u32 stat, stat1;
+
+	/* Read EP status, workaround HW race */
+	do {
+		stat = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
+		stat1 = readl(ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
+	} while(stat != stat1);
+
+	/* Extract RPTR */
+	d_last = VHUB_EP_DMA_RPTR(stat);
+
+	/* Grab current request if any */
+	req = list_first_entry_or_null(&ep->queue, struct ast_vhub_req, queue);
+
+	EPVDBG(ep, "ACK status=%08x is_in=%d ep->d_last=%d..%d\n",
+	       stat, ep->epn.is_in, ep->epn.d_last, d_last);
+
+	/* Check all completed descriptors */
+	while (ep->epn.d_last != d_last) {
+		struct ast_vhub_desc *desc;
+		unsigned int d_num;
+		bool is_last_desc;
+
+		/* Grab next completed descriptor */
+		d_num = ep->epn.d_last;
+		desc = &ep->epn.descs[d_num];
+		ep->epn.d_last = (d_num + 1) & (AST_VHUB_DESCS_COUNT - 1);
+
+		/* Grab len out of descriptor */
+		len = VHUB_DSC1_IN_LEN(le32_to_cpu(desc->w1));
+
+		EPVDBG(ep, " desc %d len=%d req=%p (act=%d)\n",
+		       d_num, len, req, req ? req->active : 0);
+
+		/* If no active request pending, move on */
+		if (!req || !req->active)
+			continue;
+
+		/* Adjust size */
+		req->req.actual += len;
+
+		/* Is that the last chunk ? */
+		is_last_desc = req->last_desc == d_num;
+		CHECK(ep, is_last_desc == (len < ep->ep.maxpacket ||
+					   (req->req.actual >= req->req.length &&
+					    !req->req.zero)),
+		      "Last packet discrepancy: last_desc=%d len=%d r.act=%d "
+		      "r.len=%d r.zero=%d mp=%d\n",
+		      is_last_desc, len, req->req.actual, req->req.length,
+		      req->req.zero, ep->ep.maxpacket);
+
+		if (is_last_desc) {
+			/*
+			 * Because we can only have one request at a time
+			 * in our descriptor list in this implementation,
+			 * d_last and ep->d_last should now be equal
+			 */
+			CHECK(ep, d_last == ep->epn.d_last,
+			      "DMA read ptr mismatch %d vs %d\n",
+			      d_last, ep->epn.d_last);
+
+			/* Note: done will drop and re-acquire the lock */
+			ast_vhub_done(ep, req, 0);
+			req = list_first_entry_or_null(&ep->queue,
+						       struct ast_vhub_req,
+						       queue);
+			break;
+		}
+	}
+
+	/* More work ? */
+	if (req)
+		ast_vhub_epn_kick_desc(ep, req);
+}
+
+void ast_vhub_epn_ack_irq(struct ast_vhub_ep *ep)
+{
+	if (ep->epn.desc_mode)
+		ast_vhub_epn_handle_ack_desc(ep);
+	else
+		ast_vhub_epn_handle_ack(ep);
+}
+
+static int ast_vhub_epn_queue(struct usb_ep* u_ep, struct usb_request *u_req,
+			      gfp_t gfp_flags)
+{
+	struct ast_vhub_req *req = to_ast_req(u_req);
+	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
+	struct ast_vhub *vhub = ep->vhub;
+	unsigned long flags;
+	bool empty;
+	int rc;
+
+	/* Paranoid checks */
+	if (!u_req || !u_req->complete || !u_req->buf) {
+		dev_warn(&vhub->pdev->dev, "Bogus EPn request ! u_req=%p\n", u_req);
+		if (u_req) {
+			dev_warn(&vhub->pdev->dev, "complete=%p internal=%d\n",
+				 u_req->complete, req->internal);
+		}
+		return -EINVAL;
+	}
+
+	/* Endpoint enabled ? */
+	if (!ep->epn.enabled || !u_ep->desc || !ep->dev || !ep->d_idx ||
+	    !ep->dev->enabled || ep->dev->suspended) {
+		EPDBG(ep,"Enqueing request on wrong or disabled EP\n");
+		return -ESHUTDOWN;
+	}
+
+	/* Map request for DMA if possible. For now, the rule for DMA is
+	 * that:
+	 *
+	 *  * For single stage mode (no descriptors):
+	 *
+	 *   - The buffer is aligned to a 8 bytes boundary (HW requirement)
+	 *   - For a OUT endpoint, the request size is a multiple of the EP
+	 *     packet size (otherwise the controller will DMA past the end
+	 *     of the buffer if the host is sending a too long packet).
+	 *
+	 *  * For descriptor mode (tx only for now), always.
+	 *
+	 * We could relax the latter by making the decision to use the bounce
+	 * buffer based on the size of a given *segment* of the request rather
+	 * than the whole request.
+	 */
+	if (ep->epn.desc_mode ||
+	    ((((unsigned long)u_req->buf & 7) == 0) &&
+	     (ep->epn.is_in || !(u_req->length & (u_ep->maxpacket - 1))))) {
+		rc = usb_gadget_map_request_by_dev(&vhub->pdev->dev, u_req,
+					    ep->epn.is_in);
+		if (rc) {
+			dev_warn(&vhub->pdev->dev,
+				 "Request mapping failure %d\n", rc);
+			return rc;
+		}
+	} else
+		u_req->dma = 0;
+
+	EPVDBG(ep, "enqueue req @%p\n", req);
+	EPVDBG(ep, " l=%d dma=0x%x zero=%d noshort=%d noirq=%d is_in=%d\n",
+	       u_req->length, (u32)u_req->dma, u_req->zero,
+	       u_req->short_not_ok, u_req->no_interrupt,
+	       ep->epn.is_in);
+
+	/* Initialize request progress fields */
+	u_req->status = -EINPROGRESS;
+	u_req->actual = 0;
+	req->act_count = 0;
+	req->active = false;
+	req->last_desc = -1;
+	spin_lock_irqsave(&vhub->lock, flags);
+	empty = list_empty(&ep->queue);
+
+	/* Add request to list and kick processing if empty */
+	list_add_tail(&req->queue, &ep->queue);
+	if (empty) {
+		if (ep->epn.desc_mode)
+			ast_vhub_epn_kick_desc(ep, req);
+		else
+			ast_vhub_epn_kick(ep, req);
+	}
+	spin_unlock_irqrestore(&vhub->lock, flags);
+
+	return 0;
+}
+
+static void ast_vhub_stop_active_req(struct ast_vhub_ep *ep,
+				     bool restart_ep)
+{
+	u32 state, reg, loops;
+
+	/* Stop DMA activity */
+	if (ep->epn.desc_mode)
+		writel(VHUB_EP_DMA_CTRL_RESET, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+	else
+		writel(0, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+
+	/* Wait for it to complete */
+	for (loops = 0; loops < 1000; loops++) {
+		state = readl(ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+		state = VHUB_EP_DMA_PROC_STATUS(state);
+		if (state == EP_DMA_PROC_RX_IDLE ||
+		    state == EP_DMA_PROC_TX_IDLE)
+			break;
+		udelay(1);
+	}
+	if (loops >= 1000)
+		dev_warn(&ep->vhub->pdev->dev, "Timeout waiting for DMA\n");
+
+	/* If we don't have to restart the endpoint, that's it */
+	if (!restart_ep)
+		return;
+
+	/* Restart the endpoint */
+	if (ep->epn.desc_mode) {
+		/*
+		 * Take out descriptors by resetting the DMA read
+		 * pointer to be equal to the CPU write pointer.
+		 *
+		 * Note: If we ever support creating descriptors for
+		 * requests that aren't the head of the queue, we
+		 * may have to do something more complex here,
+		 * especially if the request being taken out is
+		 * not the current head descriptors.
+		 */
+		reg = VHUB_EP_DMA_SET_RPTR(ep->epn.d_next) |
+			VHUB_EP_DMA_SET_CPU_WPTR(ep->epn.d_next);
+		writel(reg, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
+
+		/* Then turn it back on */
+		writel(ep->epn.dma_conf,
+		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+	} else {
+		/* Single mode: just turn it back on */
+		writel(ep->epn.dma_conf,
+		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+	}
+}
+
+static int ast_vhub_epn_dequeue(struct usb_ep* u_ep, struct usb_request *u_req)
+{
+	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
+	struct ast_vhub *vhub = ep->vhub;
+	struct ast_vhub_req *req;
+	unsigned long flags;
+	int rc = -EINVAL;
+
+	spin_lock_irqsave(&vhub->lock, flags);
+
+	/* Make sure it's actually queued on this endpoint */
+	list_for_each_entry (req, &ep->queue, queue) {
+		if (&req->req == u_req)
+			break;
+	}
+
+	if (&req->req == u_req) {
+		EPVDBG(ep, "dequeue req @%p active=%d\n",
+		       req, req->active);
+		if (req->active)
+			ast_vhub_stop_active_req(ep, true);
+		ast_vhub_done(ep, req, -ECONNRESET);
+		rc = 0;
+	}
+
+	spin_unlock_irqrestore(&vhub->lock, flags);
+	return rc;
+}
+
+void ast_vhub_update_epn_stall(struct ast_vhub_ep *ep)
+{
+	u32 reg;
+
+	if (WARN_ON(ep->d_idx == 0))
+		return;
+	reg = readl(ep->epn.regs + AST_VHUB_EP_CONFIG);
+	if (ep->epn.stalled || ep->epn.wedged)
+		reg |= VHUB_EP_CFG_STALL_CTRL;
+	else
+		reg &= ~VHUB_EP_CFG_STALL_CTRL;
+	writel(reg, ep->epn.regs + AST_VHUB_EP_CONFIG);
+
+	if (!ep->epn.stalled && !ep->epn.wedged)
+		writel(VHUB_EP_TOGGLE_SET_EPNUM(ep->epn.g_idx),
+		       ep->vhub->regs + AST_VHUB_EP_TOGGLE);
+}
+
+static int ast_vhub_set_halt_and_wedge(struct usb_ep* u_ep, bool halt,
+				      bool wedge)
+{
+	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
+	struct ast_vhub *vhub = ep->vhub;
+	unsigned long flags;
+
+	EPDBG(ep, "Set halt (%d) & wedge (%d)\n", halt, wedge);
+
+	if (!u_ep || !u_ep->desc)
+		return -EINVAL;
+	if (ep->d_idx == 0)
+		return 0;
+	if (ep->epn.is_iso)
+		return -EOPNOTSUPP;
+
+	spin_lock_irqsave(&vhub->lock, flags);
+
+	/* Fail with still-busy IN endpoints */
+	if (halt && ep->epn.is_in && !list_empty(&ep->queue)) {
+		spin_unlock_irqrestore(&vhub->lock, flags);
+		return -EAGAIN;
+	}
+	ep->epn.stalled = halt;
+	ep->epn.wedged = wedge;
+	ast_vhub_update_epn_stall(ep);
+
+	spin_unlock_irqrestore(&vhub->lock, flags);
+
+	return 0;
+}
+
+static int ast_vhub_epn_set_halt(struct usb_ep *u_ep, int value)
+{
+	return ast_vhub_set_halt_and_wedge(u_ep, value != 0, false);
+}
+
+static int ast_vhub_epn_set_wedge(struct usb_ep *u_ep)
+{
+	return ast_vhub_set_halt_and_wedge(u_ep, true, true);
+}
+
+static int ast_vhub_epn_disable(struct usb_ep* u_ep)
+{
+	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
+	struct ast_vhub *vhub = ep->vhub;
+	unsigned long flags;
+	u32 imask, ep_ier;
+
+	EPDBG(ep, "Disabling !\n");
+
+	spin_lock_irqsave(&vhub->lock, flags);
+
+	ep->epn.enabled = false;
+
+	/* Stop active DMA if any */
+	ast_vhub_stop_active_req(ep, false);
+
+	/* Disable endpoint */
+	writel(0, ep->epn.regs + AST_VHUB_EP_CONFIG);
+
+	/* Disable ACK interrupt */
+	imask = VHUB_EP_IRQ(ep->epn.g_idx);
+	ep_ier = readl(vhub->regs + AST_VHUB_EP_ACK_IER);
+	ep_ier &= ~imask;
+	writel(ep_ier, vhub->regs + AST_VHUB_EP_ACK_IER);
+	writel(imask, vhub->regs + AST_VHUB_EP_ACK_ISR);
+
+	/* Nuke all pending requests */
+	ast_vhub_nuke(ep, -ESHUTDOWN);
+
+	/* No more descriptor associated with request */
+	ep->ep.desc = NULL;
+
+	spin_unlock_irqrestore(&vhub->lock, flags);
+
+	return 0;
+}
+
+static int ast_vhub_epn_enable(struct usb_ep* u_ep,
+			       const struct usb_endpoint_descriptor *desc)
+{
+	static const char *ep_type_string[] __maybe_unused = { "ctrl",
+							       "isoc",
+							       "bulk",
+							       "intr" };
+	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
+	struct ast_vhub_dev *dev;
+	struct ast_vhub *vhub;
+	u16 maxpacket, type;
+	unsigned long flags;
+	u32 ep_conf, ep_ier, imask;
+
+	/* Check arguments */
+	if (!u_ep || !desc)
+		return -EINVAL;
+
+	maxpacket = usb_endpoint_maxp(desc);
+	if (!ep->d_idx || !ep->dev ||
+	    desc->bDescriptorType != USB_DT_ENDPOINT ||
+	    maxpacket == 0 || maxpacket > ep->ep.maxpacket) {
+		EPDBG(ep, "Invalid EP enable,d_idx=%d,dev=%p,type=%d,mp=%d/%d\n",
+		      ep->d_idx, ep->dev, desc->bDescriptorType,
+		      maxpacket, ep->ep.maxpacket);
+		return -EINVAL;
+	}
+	if (ep->d_idx != usb_endpoint_num(desc)) {
+		EPDBG(ep, "EP number mismatch !\n");
+		return -EINVAL;
+	}
+
+	if (ep->epn.enabled) {
+		EPDBG(ep, "Already enabled\n");
+		return -EBUSY;
+	}
+	dev = ep->dev;
+	vhub = ep->vhub;
+
+	/* Check device state */
+	if (!dev->driver) {
+		EPDBG(ep, "Bogus device state: driver=%p speed=%d\n",
+		       dev->driver, dev->gadget.speed);
+		return -ESHUTDOWN;
+	}
+
+	/* Grab some info from the descriptor */
+	ep->epn.is_in = usb_endpoint_dir_in(desc);
+	ep->ep.maxpacket = maxpacket;
+	type = usb_endpoint_type(desc);
+	ep->epn.d_next = ep->epn.d_last = 0;
+	ep->epn.is_iso = false;
+	ep->epn.stalled = false;
+	ep->epn.wedged = false;
+
+	EPDBG(ep, "Enabling [%s] %s num %d maxpacket=%d\n",
+	      ep->epn.is_in ? "in" : "out", ep_type_string[type],
+	      usb_endpoint_num(desc), maxpacket);
+
+	/* Can we use DMA descriptor mode ? */
+	ep->epn.desc_mode = ep->epn.descs && ep->epn.is_in;
+	if (ep->epn.desc_mode)
+		memset(ep->epn.descs, 0, 8 * AST_VHUB_DESCS_COUNT);
+
+	/*
+	 * Large send function can send up to 8 packets from
+	 * one descriptor with a limit of 4095 bytes.
+	 */
+	ep->epn.chunk_max = ep->ep.maxpacket;
+	if (ep->epn.is_in) {
+		ep->epn.chunk_max <<= 3;
+		while (ep->epn.chunk_max > 4095)
+			ep->epn.chunk_max -= ep->ep.maxpacket;
+	}
+
+	switch(type) {
+	case USB_ENDPOINT_XFER_CONTROL:
+		EPDBG(ep, "Only one control endpoint\n");
+		return -EINVAL;
+	case USB_ENDPOINT_XFER_INT:
+		ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_INT);
+		break;
+	case USB_ENDPOINT_XFER_BULK:
+		ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_BULK);
+		break;
+	case USB_ENDPOINT_XFER_ISOC:
+		ep_conf = VHUB_EP_CFG_SET_TYPE(EP_TYPE_ISO);
+		ep->epn.is_iso = true;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Encode the rest of the EP config register */
+	if (maxpacket < 1024)
+		ep_conf |= VHUB_EP_CFG_SET_MAX_PKT(maxpacket);
+	if (!ep->epn.is_in)
+		ep_conf |= VHUB_EP_CFG_DIR_OUT;
+	ep_conf |= VHUB_EP_CFG_SET_EP_NUM(usb_endpoint_num(desc));
+	ep_conf |= VHUB_EP_CFG_ENABLE;
+	ep_conf |= VHUB_EP_CFG_SET_DEV(dev->index + 1);
+	EPVDBG(ep, "config=%08x\n", ep_conf);
+
+	spin_lock_irqsave(&vhub->lock, flags);
+
+	/* Disable HW and reset DMA */
+	writel(0, ep->epn.regs + AST_VHUB_EP_CONFIG);
+	writel(VHUB_EP_DMA_CTRL_RESET,
+	       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+
+	/* Configure and enable */
+	writel(ep_conf, ep->epn.regs + AST_VHUB_EP_CONFIG);
+
+	if (ep->epn.desc_mode) {
+		/* Clear DMA status, including the DMA read ptr */
+		writel(0, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
+
+		/* Set descriptor base */
+		writel(ep->epn.descs_dma,
+		       ep->epn.regs + AST_VHUB_EP_DESC_BASE);
+
+		/* Set base DMA config value */
+		ep->epn.dma_conf = VHUB_EP_DMA_DESC_MODE;
+		if (ep->epn.is_in)
+			ep->epn.dma_conf |= VHUB_EP_DMA_IN_LONG_MODE;
+
+		/* First reset and disable all operations */
+		writel(ep->epn.dma_conf | VHUB_EP_DMA_CTRL_RESET,
+		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+
+		/* Enable descriptor mode */
+		writel(ep->epn.dma_conf,
+		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+	} else {
+		/* Set base DMA config value */
+		ep->epn.dma_conf = VHUB_EP_DMA_SINGLE_STAGE;
+
+		/* Reset and switch to single stage mode */
+		writel(ep->epn.dma_conf | VHUB_EP_DMA_CTRL_RESET,
+		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+		writel(ep->epn.dma_conf,
+		       ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+		writel(0, ep->epn.regs + AST_VHUB_EP_DESC_STATUS);
+	}
+
+	/* Cleanup data toggle just in case */
+	writel(VHUB_EP_TOGGLE_SET_EPNUM(ep->epn.g_idx),
+	       vhub->regs + AST_VHUB_EP_TOGGLE);
+
+	/* Cleanup and enable ACK interrupt */
+	imask = VHUB_EP_IRQ(ep->epn.g_idx);
+	writel(imask, vhub->regs + AST_VHUB_EP_ACK_ISR);
+	ep_ier = readl(vhub->regs + AST_VHUB_EP_ACK_IER);
+	ep_ier |= imask;
+	writel(ep_ier, vhub->regs + AST_VHUB_EP_ACK_IER);
+
+	/* Woot, we are online ! */
+	ep->epn.enabled = true;
+
+	spin_unlock_irqrestore(&vhub->lock, flags);
+
+	return 0;
+}
+
+static void ast_vhub_epn_dispose(struct usb_ep *u_ep)
+{
+	struct ast_vhub_ep *ep = to_ast_ep(u_ep);
+
+	if (WARN_ON(!ep->dev || !ep->d_idx))
+		return;
+
+	EPDBG(ep, "Releasing endpoint\n");
+
+	/* Take it out of the EP list */
+	list_del_init(&ep->ep.ep_list);
+
+	/* Mark the address free in the device */
+	ep->dev->epns[ep->d_idx - 1] = NULL;
+
+	/* Free name & DMA buffers */
+	kfree(ep->ep.name);
+	ep->ep.name = NULL;
+	dma_free_coherent(&ep->vhub->pdev->dev,
+			  AST_VHUB_EPn_MAX_PACKET +
+			  8 * AST_VHUB_DESCS_COUNT,
+			  ep->buf, ep->buf_dma);
+	ep->buf = NULL;
+	ep->epn.descs = NULL;
+
+	/* Mark free */
+	ep->dev = NULL;
+}
+
+static const struct usb_ep_ops ast_vhub_epn_ops = {
+	.enable		= ast_vhub_epn_enable,
+	.disable	= ast_vhub_epn_disable,
+	.dispose	= ast_vhub_epn_dispose,
+	.queue		= ast_vhub_epn_queue,
+	.dequeue	= ast_vhub_epn_dequeue,
+	.set_halt	= ast_vhub_epn_set_halt,
+	.set_wedge	= ast_vhub_epn_set_wedge,
+	.alloc_request	= ast_vhub_alloc_request,
+	.free_request	= ast_vhub_free_request,
+};
+
+struct ast_vhub_ep *ast_vhub_alloc_epn(struct ast_vhub_dev *d, u8 addr)
+{
+	struct ast_vhub *vhub = d->vhub;
+	struct ast_vhub_ep *ep;
+	unsigned long flags;
+	int i;
+
+	/* Find a free one (no device) */
+	spin_lock_irqsave(&vhub->lock, flags);
+	for (i = 0; i < AST_VHUB_NUM_GEN_EPs; i++)
+		if (vhub->epns[i].dev == NULL)
+			break;
+	if (i >= AST_VHUB_NUM_GEN_EPs) {
+		spin_unlock_irqrestore(&vhub->lock, flags);
+		return NULL;
+	}
+
+	/* Set it up */
+	ep = &vhub->epns[i];
+	ep->dev = d;
+	spin_unlock_irqrestore(&vhub->lock, flags);
+
+	DDBG(d, "Allocating gen EP %d for addr %d\n", i, addr);
+	INIT_LIST_HEAD(&ep->queue);
+	ep->d_idx = addr;
+	ep->vhub = vhub;
+	ep->ep.ops = &ast_vhub_epn_ops;
+	ep->ep.name = kasprintf(GFP_KERNEL, "ep%d", addr);
+	d->epns[addr-1] = ep;
+	ep->epn.g_idx = i;
+	ep->epn.regs = vhub->regs + 0x200 + (i * 0x10);
+
+	ep->buf = dma_alloc_coherent(&vhub->pdev->dev,
+				     AST_VHUB_EPn_MAX_PACKET +
+				     8 * AST_VHUB_DESCS_COUNT,
+				     &ep->buf_dma, GFP_KERNEL);
+	if (!ep->buf) {
+		kfree(ep->ep.name);
+		ep->ep.name = NULL;
+		return NULL;
+	}
+	ep->epn.descs = ep->buf + AST_VHUB_EPn_MAX_PACKET;
+	ep->epn.descs_dma = ep->buf_dma + AST_VHUB_EPn_MAX_PACKET;
+
+	usb_ep_set_maxpacket_limit(&ep->ep, AST_VHUB_EPn_MAX_PACKET);
+	list_add_tail(&ep->ep.ep_list, &d->gadget.ep_list);
+	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;
+
+	return ep;
+}
diff --git a/drivers/usb/gadget/udc/aspeed-vhub/hub.c b/drivers/usb/gadget/udc/aspeed-vhub/hub.c
new file mode 100644
index 000000000..35ba0e55a
--- /dev/null
+++ b/drivers/usb/gadget/udc/aspeed-vhub/hub.c
@@ -0,0 +1,829 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * aspeed-vhub -- Driver for Aspeed SoC "vHub" USB gadget
+ *
+ * hub.c - virtual hub handling
+ *
+ * Copyright 2017 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/prefetch.h>
+#include <linux/clk.h>
+#include <linux/usb/gadget.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regmap.h>
+#include <linux/dma-mapping.h>
+#include <linux/bcd.h>
+#include <linux/version.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+
+#include "vhub.h"
+
+/* usb 2.0 hub device descriptor
+ *
+ * A few things we may want to improve here:
+ *
+ *    - We may need to indicate TT support
+ *    - We may need a device qualifier descriptor
+ *	as devices can pretend to be usb1 or 2
+ *    - Make vid/did overridable
+ *    - make it look like usb1 if usb1 mode forced
+ */
+#define KERNEL_REL	bin2bcd(((LINUX_VERSION_CODE >> 16) & 0x0ff))
+#define KERNEL_VER	bin2bcd(((LINUX_VERSION_CODE >> 8) & 0x0ff))
+
+enum {
+	AST_VHUB_STR_MANUF = 3,
+	AST_VHUB_STR_PRODUCT = 2,
+	AST_VHUB_STR_SERIAL = 1,
+};
+
+static const struct usb_device_descriptor ast_vhub_dev_desc = {
+	.bLength		= USB_DT_DEVICE_SIZE,
+	.bDescriptorType	= USB_DT_DEVICE,
+	.bcdUSB			= cpu_to_le16(0x0200),
+	.bDeviceClass		= USB_CLASS_HUB,
+	.bDeviceSubClass	= 0,
+	.bDeviceProtocol	= 1,
+	.bMaxPacketSize0	= 64,
+	.idVendor		= cpu_to_le16(0x1d6b),
+	.idProduct		= cpu_to_le16(0x0107),
+	.bcdDevice		= cpu_to_le16(0x0100),
+	.iManufacturer		= AST_VHUB_STR_MANUF,
+	.iProduct		= AST_VHUB_STR_PRODUCT,
+	.iSerialNumber		= AST_VHUB_STR_SERIAL,
+	.bNumConfigurations	= 1,
+};
+
+/* Patches to the above when forcing USB1 mode */
+static void ast_vhub_patch_dev_desc_usb1(struct usb_device_descriptor *desc)
+{
+	desc->bcdUSB = cpu_to_le16(0x0100);
+	desc->bDeviceProtocol = 0;
+}
+
+/*
+ * Configuration descriptor: same comments as above
+ * regarding handling USB1 mode.
+ */
+
+/*
+ * We don't use sizeof() as Linux definition of
+ * struct usb_endpoint_descriptor contains 2
+ * extra bytes
+ */
+#define AST_VHUB_CONF_DESC_SIZE	(USB_DT_CONFIG_SIZE + \
+				 USB_DT_INTERFACE_SIZE + \
+				 USB_DT_ENDPOINT_SIZE)
+
+static const struct ast_vhub_full_cdesc {
+	struct usb_config_descriptor	cfg;
+	struct usb_interface_descriptor intf;
+	struct usb_endpoint_descriptor	ep;
+} __attribute__ ((packed)) ast_vhub_conf_desc = {
+	.cfg = {
+		.bLength		= USB_DT_CONFIG_SIZE,
+		.bDescriptorType	= USB_DT_CONFIG,
+		.wTotalLength		= cpu_to_le16(AST_VHUB_CONF_DESC_SIZE),
+		.bNumInterfaces		= 1,
+		.bConfigurationValue	= 1,
+		.iConfiguration		= 0,
+		.bmAttributes		= USB_CONFIG_ATT_ONE |
+					  USB_CONFIG_ATT_SELFPOWER |
+					  USB_CONFIG_ATT_WAKEUP,
+		.bMaxPower		= 0,
+	},
+	.intf = {
+		.bLength		= USB_DT_INTERFACE_SIZE,
+		.bDescriptorType	= USB_DT_INTERFACE,
+		.bInterfaceNumber	= 0,
+		.bAlternateSetting	= 0,
+		.bNumEndpoints		= 1,
+		.bInterfaceClass	= USB_CLASS_HUB,
+		.bInterfaceSubClass	= 0,
+		.bInterfaceProtocol	= 0,
+		.iInterface		= 0,
+	},
+	.ep = {
+		.bLength		= USB_DT_ENDPOINT_SIZE,
+		.bDescriptorType	= USB_DT_ENDPOINT,
+		.bEndpointAddress	= 0x81,
+		.bmAttributes		= USB_ENDPOINT_XFER_INT,
+		.wMaxPacketSize		= cpu_to_le16(1),
+		.bInterval		= 0x0c,
+	},
+};
+
+#define AST_VHUB_HUB_DESC_SIZE	(USB_DT_HUB_NONVAR_SIZE + 2)
+
+static const struct usb_hub_descriptor ast_vhub_hub_desc = {
+	.bDescLength			= AST_VHUB_HUB_DESC_SIZE,
+	.bDescriptorType		= USB_DT_HUB,
+	.bNbrPorts			= AST_VHUB_NUM_PORTS,
+	.wHubCharacteristics		= cpu_to_le16(HUB_CHAR_NO_LPSM),
+	.bPwrOn2PwrGood			= 10,
+	.bHubContrCurrent		= 0,
+	.u.hs.DeviceRemovable[0]	= 0,
+	.u.hs.DeviceRemovable[1]	= 0xff,
+};
+
+/*
+ * These strings converted to UTF-16 must be smaller than
+ * our EP0 buffer.
+ */
+static const struct usb_string ast_vhub_str_array[] = {
+	{
+		.id = AST_VHUB_STR_SERIAL,
+		.s = "00000000"
+	},
+	{
+		.id = AST_VHUB_STR_PRODUCT,
+		.s = "USB Virtual Hub"
+	},
+	{
+		.id = AST_VHUB_STR_MANUF,
+		.s = "Aspeed"
+	},
+	{ }
+};
+
+static const struct usb_gadget_strings ast_vhub_strings = {
+	.language = 0x0409,
+	.strings = (struct usb_string *)ast_vhub_str_array
+};
+
+static int ast_vhub_hub_dev_status(struct ast_vhub_ep *ep,
+				   u16 wIndex, u16 wValue)
+{
+	u8 st0;
+
+	EPDBG(ep, "GET_STATUS(dev)\n");
+
+	/*
+	 * Mark it as self-powered, I doubt the BMC is powered off
+	 * the USB bus ...
+	 */
+	st0 = 1 << USB_DEVICE_SELF_POWERED;
+
+	/*
+	 * Need to double check how remote wakeup actually works
+	 * on that chip and what triggers it.
+	 */
+	if (ep->vhub->wakeup_en)
+		st0 |= 1 << USB_DEVICE_REMOTE_WAKEUP;
+
+	return ast_vhub_simple_reply(ep, st0, 0);
+}
+
+static int ast_vhub_hub_ep_status(struct ast_vhub_ep *ep,
+				  u16 wIndex, u16 wValue)
+{
+	int ep_num;
+	u8 st0 = 0;
+
+	ep_num = wIndex & USB_ENDPOINT_NUMBER_MASK;
+	EPDBG(ep, "GET_STATUS(ep%d)\n", ep_num);
+
+	/* On the hub we have only EP 0 and 1 */
+	if (ep_num == 1) {
+		if (ep->vhub->ep1_stalled)
+			st0 |= 1 << USB_ENDPOINT_HALT;
+	} else if (ep_num != 0)
+		return std_req_stall;
+
+	return ast_vhub_simple_reply(ep, st0, 0);
+}
+
+static int ast_vhub_hub_dev_feature(struct ast_vhub_ep *ep,
+				    u16 wIndex, u16 wValue,
+				    bool is_set)
+{
+	EPDBG(ep, "%s_FEATURE(dev val=%02x)\n",
+	      is_set ? "SET" : "CLEAR", wValue);
+
+	if (wValue != USB_DEVICE_REMOTE_WAKEUP)
+		return std_req_stall;
+
+	ep->vhub->wakeup_en = is_set;
+	EPDBG(ep, "Hub remote wakeup %s\n",
+	      is_set ? "enabled" : "disabled");
+
+	return std_req_complete;
+}
+
+static int ast_vhub_hub_ep_feature(struct ast_vhub_ep *ep,
+				   u16 wIndex, u16 wValue,
+				   bool is_set)
+{
+	int ep_num;
+	u32 reg;
+
+	ep_num = wIndex & USB_ENDPOINT_NUMBER_MASK;
+	EPDBG(ep, "%s_FEATURE(ep%d val=%02x)\n",
+	      is_set ? "SET" : "CLEAR", ep_num, wValue);
+
+	if (ep_num > 1)
+		return std_req_stall;
+	if (wValue != USB_ENDPOINT_HALT)
+		return std_req_stall;
+	if (ep_num == 0)
+		return std_req_complete;
+
+	EPDBG(ep, "%s stall on EP 1\n",
+	      is_set ? "setting" : "clearing");
+
+	ep->vhub->ep1_stalled = is_set;
+	reg = readl(ep->vhub->regs + AST_VHUB_EP1_CTRL);
+	if (is_set) {
+		reg |= VHUB_EP1_CTRL_STALL;
+	} else {
+		reg &= ~VHUB_EP1_CTRL_STALL;
+		reg |= VHUB_EP1_CTRL_RESET_TOGGLE;
+	}
+	writel(reg, ep->vhub->regs + AST_VHUB_EP1_CTRL);
+
+	return std_req_complete;
+}
+
+static int ast_vhub_rep_desc(struct ast_vhub_ep *ep,
+			     u8 desc_type, u16 len)
+{
+	size_t dsize;
+
+	EPDBG(ep, "GET_DESCRIPTOR(type:%d)\n", desc_type);
+
+	/*
+	 * Copy first to EP buffer and send from there, so
+	 * we can do some in-place patching if needed. We know
+	 * the EP buffer is big enough but ensure that doesn't
+	 * change. We do that now rather than later after we
+	 * have checked sizes etc... to avoid a gcc bug where
+	 * it thinks len is constant and barfs about read
+	 * overflows in memcpy.
+	 */
+	switch(desc_type) {
+	case USB_DT_DEVICE:
+		dsize = USB_DT_DEVICE_SIZE;
+		memcpy(ep->buf, &ast_vhub_dev_desc, dsize);
+		BUILD_BUG_ON(dsize > sizeof(ast_vhub_dev_desc));
+		BUILD_BUG_ON(USB_DT_DEVICE_SIZE >= AST_VHUB_EP0_MAX_PACKET);
+		break;
+	case USB_DT_CONFIG:
+		dsize = AST_VHUB_CONF_DESC_SIZE;
+		memcpy(ep->buf, &ast_vhub_conf_desc, dsize);
+		BUILD_BUG_ON(dsize > sizeof(ast_vhub_conf_desc));
+		BUILD_BUG_ON(AST_VHUB_CONF_DESC_SIZE >= AST_VHUB_EP0_MAX_PACKET);
+		break;
+	case USB_DT_HUB:
+		dsize = AST_VHUB_HUB_DESC_SIZE;
+		memcpy(ep->buf, &ast_vhub_hub_desc, dsize);
+		BUILD_BUG_ON(dsize > sizeof(ast_vhub_hub_desc));
+	BUILD_BUG_ON(AST_VHUB_HUB_DESC_SIZE >= AST_VHUB_EP0_MAX_PACKET);
+		break;
+	default:
+		return std_req_stall;
+	}
+
+	/* Crop requested length */
+	if (len > dsize)
+		len = dsize;
+
+	/* Patch it if forcing USB1 */
+	if (desc_type == USB_DT_DEVICE && ep->vhub->force_usb1)
+		ast_vhub_patch_dev_desc_usb1(ep->buf);
+
+	/* Shoot it from the EP buffer */
+	return ast_vhub_reply(ep, NULL, len);
+}
+
+static int ast_vhub_rep_string(struct ast_vhub_ep *ep,
+			       u8 string_id, u16 lang_id,
+			       u16 len)
+{
+	int rc = usb_gadget_get_string (&ast_vhub_strings, string_id, ep->buf);
+
+	/*
+	 * This should never happen unless we put too big strings in
+	 * the array above
+	 */
+	BUG_ON(rc >= AST_VHUB_EP0_MAX_PACKET);
+
+	if (rc < 0)
+		return std_req_stall;
+
+	/* Shoot it from the EP buffer */
+	return ast_vhub_reply(ep, NULL, min_t(u16, rc, len));
+}
+
+enum std_req_rc ast_vhub_std_hub_request(struct ast_vhub_ep *ep,
+					 struct usb_ctrlrequest *crq)
+{
+	struct ast_vhub *vhub = ep->vhub;
+	u16 wValue, wIndex, wLength;
+
+	wValue = le16_to_cpu(crq->wValue);
+	wIndex = le16_to_cpu(crq->wIndex);
+	wLength = le16_to_cpu(crq->wLength);
+
+	/* First packet, grab speed */
+	if (vhub->speed == USB_SPEED_UNKNOWN) {
+		u32 ustat = readl(vhub->regs + AST_VHUB_USBSTS);
+		if (ustat & VHUB_USBSTS_HISPEED)
+			vhub->speed = USB_SPEED_HIGH;
+		else
+			vhub->speed = USB_SPEED_FULL;
+		UDCDBG(vhub, "USB status=%08x speed=%s\n", ustat,
+		       vhub->speed == USB_SPEED_HIGH ? "high" : "full");
+	}
+
+	switch ((crq->bRequestType << 8) | crq->bRequest) {
+		/* SET_ADDRESS */
+	case DeviceOutRequest | USB_REQ_SET_ADDRESS:
+		EPDBG(ep, "SET_ADDRESS: Got address %x\n", wValue);
+		writel(wValue, vhub->regs + AST_VHUB_CONF);
+		return std_req_complete;
+
+		/* GET_STATUS */
+	case DeviceRequest | USB_REQ_GET_STATUS:
+		return ast_vhub_hub_dev_status(ep, wIndex, wValue);
+	case InterfaceRequest | USB_REQ_GET_STATUS:
+		return ast_vhub_simple_reply(ep, 0, 0);
+	case EndpointRequest | USB_REQ_GET_STATUS:
+		return ast_vhub_hub_ep_status(ep, wIndex, wValue);
+
+		/* SET/CLEAR_FEATURE */
+	case DeviceOutRequest | USB_REQ_SET_FEATURE:
+		return ast_vhub_hub_dev_feature(ep, wIndex, wValue, true);
+	case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
+		return ast_vhub_hub_dev_feature(ep, wIndex, wValue, false);
+	case EndpointOutRequest | USB_REQ_SET_FEATURE:
+		return ast_vhub_hub_ep_feature(ep, wIndex, wValue, true);
+	case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
+		return ast_vhub_hub_ep_feature(ep, wIndex, wValue, false);
+
+		/* GET/SET_CONFIGURATION */
+	case DeviceRequest | USB_REQ_GET_CONFIGURATION:
+		return ast_vhub_simple_reply(ep, 1);
+	case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
+		if (wValue != 1)
+			return std_req_stall;
+		return std_req_complete;
+
+		/* GET_DESCRIPTOR */
+	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
+		switch (wValue >> 8) {
+		case USB_DT_DEVICE:
+		case USB_DT_CONFIG:
+			return ast_vhub_rep_desc(ep, wValue >> 8,
+						 wLength);
+		case USB_DT_STRING:
+			return ast_vhub_rep_string(ep, wValue & 0xff,
+						   wIndex, wLength);
+		}
+		return std_req_stall;
+
+		/* GET/SET_INTERFACE */
+	case DeviceRequest | USB_REQ_GET_INTERFACE:
+		return ast_vhub_simple_reply(ep, 0);
+	case DeviceOutRequest | USB_REQ_SET_INTERFACE:
+		if (wValue != 0 || wIndex != 0)
+			return std_req_stall;
+		return std_req_complete;
+	}
+	return std_req_stall;
+}
+
+static void ast_vhub_update_hub_ep1(struct ast_vhub *vhub,
+				    unsigned int port)
+{
+	/* Update HW EP1 response */
+	u32 reg = readl(vhub->regs + AST_VHUB_EP1_STS_CHG);
+	u32 pmask = (1 << (port + 1));
+	if (vhub->ports[port].change)
+		reg |= pmask;
+	else
+		reg &= ~pmask;
+	writel(reg, vhub->regs + AST_VHUB_EP1_STS_CHG);
+}
+
+static void ast_vhub_change_port_stat(struct ast_vhub *vhub,
+				      unsigned int port,
+				      u16 clr_flags,
+				      u16 set_flags,
+				      bool set_c)
+{
+	struct ast_vhub_port *p = &vhub->ports[port];
+	u16 prev;
+
+	/* Update port status */
+	prev = p->status;
+	p->status = (prev & ~clr_flags) | set_flags;
+	DDBG(&p->dev, "port %d status %04x -> %04x (C=%d)\n",
+	     port + 1, prev, p->status, set_c);
+
+	/* Update change bits if needed */
+	if (set_c) {
+		u16 chg = p->status ^ prev;
+
+		/* Only these are relevant for change */
+		chg &= USB_PORT_STAT_C_CONNECTION |
+		       USB_PORT_STAT_C_ENABLE |
+		       USB_PORT_STAT_C_SUSPEND |
+		       USB_PORT_STAT_C_OVERCURRENT |
+		       USB_PORT_STAT_C_RESET |
+		       USB_PORT_STAT_C_L1;
+		p->change |= chg;
+
+		ast_vhub_update_hub_ep1(vhub, port);
+	}
+}
+
+static void ast_vhub_send_host_wakeup(struct ast_vhub *vhub)
+{
+	u32 reg = readl(vhub->regs + AST_VHUB_CTRL);
+	UDCDBG(vhub, "Waking up host !\n");
+	reg |= VHUB_CTRL_MANUAL_REMOTE_WAKEUP;
+	writel(reg, vhub->regs + AST_VHUB_CTRL);
+}
+
+void ast_vhub_device_connect(struct ast_vhub *vhub,
+			     unsigned int port, bool on)
+{
+	if (on)
+		ast_vhub_change_port_stat(vhub, port, 0,
+					  USB_PORT_STAT_CONNECTION, true);
+	else
+		ast_vhub_change_port_stat(vhub, port,
+					  USB_PORT_STAT_CONNECTION |
+					  USB_PORT_STAT_ENABLE,
+					  0, true);
+
+	/*
+	 * If the hub is set to wakup the host on connection events
+	 * then send a wakeup.
+	 */
+	if (vhub->wakeup_en)
+		ast_vhub_send_host_wakeup(vhub);
+}
+
+static void ast_vhub_wake_work(struct work_struct *work)
+{
+	struct ast_vhub *vhub = container_of(work,
+					     struct ast_vhub,
+					     wake_work);
+	unsigned long flags;
+	unsigned int i;
+
+	/*
+	 * Wake all sleeping ports. If a port is suspended by
+	 * the host suspend (without explicit state suspend),
+	 * we let the normal host wake path deal with it later.
+	 */
+	spin_lock_irqsave(&vhub->lock, flags);
+	for (i = 0; i < AST_VHUB_NUM_PORTS; i++) {
+		struct ast_vhub_port *p = &vhub->ports[i];
+
+		if (!(p->status & USB_PORT_STAT_SUSPEND))
+			continue;
+		ast_vhub_change_port_stat(vhub, i,
+					  USB_PORT_STAT_SUSPEND,
+					  0, true);
+		ast_vhub_dev_resume(&p->dev);
+	}
+	ast_vhub_send_host_wakeup(vhub);
+	spin_unlock_irqrestore(&vhub->lock, flags);
+}
+
+void ast_vhub_hub_wake_all(struct ast_vhub *vhub)
+{
+	/*
+	 * 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(&vhub->wake_work);
+}
+
+static void ast_vhub_port_reset(struct ast_vhub *vhub, u8 port)
+{
+	struct ast_vhub_port *p = &vhub->ports[port];
+	u16 set, clr, speed;
+
+	/* First mark disabled */
+	ast_vhub_change_port_stat(vhub, port,
+				  USB_PORT_STAT_ENABLE |
+				  USB_PORT_STAT_SUSPEND,
+				  USB_PORT_STAT_RESET,
+				  false);
+
+	if (!p->dev.driver)
+		return;
+
+	/*
+	 * This will either "start" the port or reset the
+	 * device if already started...
+	 */
+	ast_vhub_dev_reset(&p->dev);
+
+	/* Grab the right speed */
+	speed = p->dev.driver->max_speed;
+	if (speed == USB_SPEED_UNKNOWN || speed > vhub->speed)
+		speed = vhub->speed;
+
+	switch (speed) {
+	case USB_SPEED_LOW:
+		set = USB_PORT_STAT_LOW_SPEED;
+		clr = USB_PORT_STAT_HIGH_SPEED;
+		break;
+	case USB_SPEED_FULL:
+		set = 0;
+		clr = USB_PORT_STAT_LOW_SPEED |
+			USB_PORT_STAT_HIGH_SPEED;
+		break;
+	case USB_SPEED_HIGH:
+		set = USB_PORT_STAT_HIGH_SPEED;
+		clr = USB_PORT_STAT_LOW_SPEED;
+		break;
+	default:
+		UDCDBG(vhub, "Unsupported speed %d when"
+		       " connecting device\n",
+		       speed);
+		return;
+	}
+	clr |= USB_PORT_STAT_RESET;
+	set |= USB_PORT_STAT_ENABLE;
+
+	/* This should ideally be delayed ... */
+	ast_vhub_change_port_stat(vhub, port, clr, set, true);
+}
+
+static enum std_req_rc ast_vhub_set_port_feature(struct ast_vhub_ep *ep,
+						 u8 port, u16 feat)
+{
+	struct ast_vhub *vhub = ep->vhub;
+	struct ast_vhub_port *p;
+
+	if (port == 0 || port > AST_VHUB_NUM_PORTS)
+		return std_req_stall;
+	port--;
+	p = &vhub->ports[port];
+
+	switch(feat) {
+	case USB_PORT_FEAT_SUSPEND:
+		if (!(p->status & USB_PORT_STAT_ENABLE))
+			return std_req_complete;
+		ast_vhub_change_port_stat(vhub, port,
+					  0, USB_PORT_STAT_SUSPEND,
+					  false);
+		ast_vhub_dev_suspend(&p->dev);
+		return std_req_complete;
+	case USB_PORT_FEAT_RESET:
+		EPDBG(ep, "Port reset !\n");
+		ast_vhub_port_reset(vhub, port);
+		return std_req_complete;
+	case USB_PORT_FEAT_POWER:
+		/*
+		 * On Power-on, we mark the connected flag changed,
+		 * if there's a connected device, some hosts will
+		 * otherwise fail to detect it.
+		 */
+		if (p->status & USB_PORT_STAT_CONNECTION) {
+			p->change |= USB_PORT_STAT_C_CONNECTION;
+			ast_vhub_update_hub_ep1(vhub, port);
+		}
+		return std_req_complete;
+	case USB_PORT_FEAT_TEST:
+	case USB_PORT_FEAT_INDICATOR:
+		/* We don't do anything with these */
+		return std_req_complete;
+	}
+	return std_req_stall;
+}
+
+static enum std_req_rc ast_vhub_clr_port_feature(struct ast_vhub_ep *ep,
+						 u8 port, u16 feat)
+{
+	struct ast_vhub *vhub = ep->vhub;
+	struct ast_vhub_port *p;
+
+	if (port == 0 || port > AST_VHUB_NUM_PORTS)
+		return std_req_stall;
+	port--;
+	p = &vhub->ports[port];
+
+	switch(feat) {
+	case USB_PORT_FEAT_ENABLE:
+		ast_vhub_change_port_stat(vhub, port,
+					  USB_PORT_STAT_ENABLE |
+					  USB_PORT_STAT_SUSPEND, 0,
+					  false);
+		ast_vhub_dev_suspend(&p->dev);
+		return std_req_complete;
+	case USB_PORT_FEAT_SUSPEND:
+		if (!(p->status & USB_PORT_STAT_SUSPEND))
+			return std_req_complete;
+		ast_vhub_change_port_stat(vhub, port,
+					  USB_PORT_STAT_SUSPEND, 0,
+					  false);
+		ast_vhub_dev_resume(&p->dev);
+		return std_req_complete;
+	case USB_PORT_FEAT_POWER:
+		/* We don't do power control */
+		return std_req_complete;
+	case USB_PORT_FEAT_INDICATOR:
+		/* We don't have indicators */
+		return std_req_complete;
+	case USB_PORT_FEAT_C_CONNECTION:
+	case USB_PORT_FEAT_C_ENABLE:
+	case USB_PORT_FEAT_C_SUSPEND:
+	case USB_PORT_FEAT_C_OVER_CURRENT:
+	case USB_PORT_FEAT_C_RESET:
+		/* Clear state-change feature */
+		p->change &= ~(1u << (feat - 16));
+		ast_vhub_update_hub_ep1(vhub, port);
+		return std_req_complete;
+	}
+	return std_req_stall;
+}
+
+static enum std_req_rc ast_vhub_get_port_stat(struct ast_vhub_ep *ep,
+					      u8 port)
+{
+	struct ast_vhub *vhub = ep->vhub;
+	u16 stat, chg;
+
+	if (port == 0 || port > AST_VHUB_NUM_PORTS)
+		return std_req_stall;
+	port--;
+
+	stat = vhub->ports[port].status;
+	chg = vhub->ports[port].change;
+
+	/* We always have power */
+	stat |= USB_PORT_STAT_POWER;
+
+	EPDBG(ep, " port status=%04x change=%04x\n", stat, chg);
+
+	return ast_vhub_simple_reply(ep,
+				     stat & 0xff,
+				     stat >> 8,
+				     chg & 0xff,
+				     chg >> 8);
+}
+
+enum std_req_rc ast_vhub_class_hub_request(struct ast_vhub_ep *ep,
+					   struct usb_ctrlrequest *crq)
+{
+	u16 wValue, wIndex, wLength;
+
+	wValue = le16_to_cpu(crq->wValue);
+	wIndex = le16_to_cpu(crq->wIndex);
+	wLength = le16_to_cpu(crq->wLength);
+
+	switch ((crq->bRequestType << 8) | crq->bRequest) {
+	case GetHubStatus:
+		EPDBG(ep, "GetHubStatus\n");
+		return ast_vhub_simple_reply(ep, 0, 0, 0, 0);
+	case GetPortStatus:
+		EPDBG(ep, "GetPortStatus(%d)\n", wIndex & 0xff);
+		return ast_vhub_get_port_stat(ep, wIndex & 0xf);
+	case GetHubDescriptor:
+		if (wValue != (USB_DT_HUB << 8))
+			return std_req_stall;
+		EPDBG(ep, "GetHubDescriptor(%d)\n", wIndex & 0xff);
+		return ast_vhub_rep_desc(ep, USB_DT_HUB, wLength);
+	case SetHubFeature:
+	case ClearHubFeature:
+		EPDBG(ep, "Get/SetHubFeature(%d)\n", wValue);
+		/* No feature, just complete the requests */
+		if (wValue == C_HUB_LOCAL_POWER ||
+		    wValue == C_HUB_OVER_CURRENT)
+			return std_req_complete;
+		return std_req_stall;
+	case SetPortFeature:
+		EPDBG(ep, "SetPortFeature(%d,%d)\n", wIndex & 0xf, wValue);
+		return ast_vhub_set_port_feature(ep, wIndex & 0xf, wValue);
+	case ClearPortFeature:
+		EPDBG(ep, "ClearPortFeature(%d,%d)\n", wIndex & 0xf, wValue);
+		return ast_vhub_clr_port_feature(ep, wIndex & 0xf, wValue);
+	default:
+		EPDBG(ep, "Unknown class request\n");
+	}
+	return std_req_stall;
+}
+
+void ast_vhub_hub_suspend(struct ast_vhub *vhub)
+{
+	unsigned int i;
+
+	UDCDBG(vhub, "USB bus suspend\n");
+
+	if (vhub->suspended)
+		return;
+
+	vhub->suspended = true;
+
+	/*
+	 * Forward to unsuspended ports without changing
+	 * their connection status.
+	 */
+	for (i = 0; i < AST_VHUB_NUM_PORTS; i++) {
+		struct ast_vhub_port *p = &vhub->ports[i];
+
+		if (!(p->status & USB_PORT_STAT_SUSPEND))
+			ast_vhub_dev_suspend(&p->dev);
+	}
+}
+
+void ast_vhub_hub_resume(struct ast_vhub *vhub)
+{
+	unsigned int i;
+
+	UDCDBG(vhub, "USB bus resume\n");
+
+	if (!vhub->suspended)
+		return;
+
+	vhub->suspended = false;
+
+	/*
+	 * Forward to unsuspended ports without changing
+	 * their connection status.
+	 */
+	for (i = 0; i < AST_VHUB_NUM_PORTS; i++) {
+		struct ast_vhub_port *p = &vhub->ports[i];
+
+		if (!(p->status & USB_PORT_STAT_SUSPEND))
+			ast_vhub_dev_resume(&p->dev);
+	}
+}
+
+void ast_vhub_hub_reset(struct ast_vhub *vhub)
+{
+	unsigned int i;
+
+	UDCDBG(vhub, "USB bus reset\n");
+
+	/*
+	 * Is the speed known ? If not we don't care, we aren't
+	 * initialized yet and ports haven't been enabled.
+	 */
+	if (vhub->speed == USB_SPEED_UNKNOWN)
+		return;
+
+	/* We aren't suspended anymore obviously */
+	vhub->suspended = false;
+
+	/* No speed set */
+	vhub->speed = USB_SPEED_UNKNOWN;
+
+	/* Wakeup not enabled anymore */
+	vhub->wakeup_en = false;
+
+	/*
+	 * Clear all port status, disable gadgets and "suspend"
+	 * them. They will be woken up by a port reset.
+	 */
+	for (i = 0; i < AST_VHUB_NUM_PORTS; i++) {
+		struct ast_vhub_port *p = &vhub->ports[i];
+
+		/* Only keep the connected flag */
+		p->status &= USB_PORT_STAT_CONNECTION;
+		p->change = 0;
+
+		/* Suspend the gadget if any */
+		ast_vhub_dev_suspend(&p->dev);
+	}
+
+	/* Cleanup HW */
+	writel(0, vhub->regs + AST_VHUB_CONF);
+	writel(0, vhub->regs + AST_VHUB_EP0_CTRL);
+	writel(VHUB_EP1_CTRL_RESET_TOGGLE |
+	       VHUB_EP1_CTRL_ENABLE,
+	       vhub->regs + AST_VHUB_EP1_CTRL);
+	writel(0, vhub->regs + AST_VHUB_EP1_STS_CHG);
+}
+
+void ast_vhub_init_hub(struct ast_vhub *vhub)
+{
+	vhub->speed = USB_SPEED_UNKNOWN;
+	INIT_WORK(&vhub->wake_work, ast_vhub_wake_work);
+}
+
diff --git a/drivers/usb/gadget/udc/aspeed-vhub/vhub.h b/drivers/usb/gadget/udc/aspeed-vhub/vhub.h
new file mode 100644
index 000000000..4ed03d33a
--- /dev/null
+++ b/drivers/usb/gadget/udc/aspeed-vhub/vhub.h
@@ -0,0 +1,547 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef __ASPEED_VHUB_H
+#define __ASPEED_VHUB_H
+
+/*****************************
+ *                           *
+ * VHUB register definitions *
+ *                           *
+ *****************************/
+
+#define	AST_VHUB_CTRL		0x00	/* Root Function Control & Status Register */
+#define	AST_VHUB_CONF		0x04	/* Root Configuration Setting Register */
+#define	AST_VHUB_IER		0x08	/* Interrupt Ctrl Register */
+#define	AST_VHUB_ISR		0x0C	/* Interrupt Status Register */
+#define	AST_VHUB_EP_ACK_IER	0x10	/* Programmable Endpoint Pool ACK Interrupt Enable Register */
+#define	AST_VHUB_EP_NACK_IER	0x14	/* Programmable Endpoint Pool NACK Interrupt Enable Register  */
+#define AST_VHUB_EP_ACK_ISR	0x18	/* Programmable Endpoint Pool ACK Interrupt Status Register  */
+#define AST_VHUB_EP_NACK_ISR	0x1C	/* Programmable Endpoint Pool NACK Interrupt Status Register  */
+#define AST_VHUB_SW_RESET	0x20	/* Device Controller Soft Reset Enable Register */
+#define AST_VHUB_USBSTS		0x24	/* USB Status Register */
+#define AST_VHUB_EP_TOGGLE	0x28	/* Programmable Endpoint Pool Data Toggle Value Set */
+#define AST_VHUB_ISO_FAIL_ACC	0x2C	/* Isochronous Transaction Fail Accumulator */
+#define AST_VHUB_EP0_CTRL	0x30	/* Endpoint 0 Contrl/Status Register */
+#define AST_VHUB_EP0_DATA	0x34	/* Base Address of Endpoint 0 In/OUT Data Buffer Register */
+#define AST_VHUB_EP1_CTRL	0x38	/* Endpoint 1 Contrl/Status Register */
+#define AST_VHUB_EP1_STS_CHG	0x3C	/* Endpoint 1 Status Change Bitmap Data */
+#define AST_VHUB_SETUP0		0x80	/* Root Device Setup Data Buffer0 */
+#define AST_VHUB_SETUP1		0x84	/* Root Device Setup Data Buffer1 */
+
+/* Main control reg */
+#define VHUB_CTRL_PHY_CLK			(1 << 31)
+#define VHUB_CTRL_PHY_LOOP_TEST			(1 << 25)
+#define VHUB_CTRL_DN_PWN			(1 << 24)
+#define VHUB_CTRL_DP_PWN			(1 << 23)
+#define VHUB_CTRL_LONG_DESC			(1 << 18)
+#define VHUB_CTRL_ISO_RSP_CTRL			(1 << 17)
+#define VHUB_CTRL_SPLIT_IN			(1 << 16)
+#define VHUB_CTRL_LOOP_T_RESULT			(1 << 15)
+#define VHUB_CTRL_LOOP_T_STS			(1 << 14)
+#define VHUB_CTRL_PHY_BIST_RESULT		(1 << 13)
+#define VHUB_CTRL_PHY_BIST_CTRL			(1 << 12)
+#define VHUB_CTRL_PHY_RESET_DIS			(1 << 11)
+#define VHUB_CTRL_SET_TEST_MODE(x)		((x) << 8)
+#define VHUB_CTRL_MANUAL_REMOTE_WAKEUP		(1 << 4)
+#define VHUB_CTRL_AUTO_REMOTE_WAKEUP		(1 << 3)
+#define VHUB_CTRL_CLK_STOP_SUSPEND		(1 << 2)
+#define VHUB_CTRL_FULL_SPEED_ONLY		(1 << 1)
+#define VHUB_CTRL_UPSTREAM_CONNECT		(1 << 0)
+
+/* IER & ISR */
+#define VHUB_IRQ_USB_CMD_DEADLOCK		(1 << 18)
+#define VHUB_IRQ_EP_POOL_NAK			(1 << 17)
+#define VHUB_IRQ_EP_POOL_ACK_STALL		(1 << 16)
+#define VHUB_IRQ_DEVICE5			(1 << 13)
+#define VHUB_IRQ_DEVICE4			(1 << 12)
+#define VHUB_IRQ_DEVICE3			(1 << 11)
+#define VHUB_IRQ_DEVICE2			(1 << 10)
+#define VHUB_IRQ_DEVICE1			(1 << 9)
+#define VHUB_IRQ_BUS_RESUME			(1 << 8)
+#define VHUB_IRQ_BUS_SUSPEND 			(1 << 7)
+#define VHUB_IRQ_BUS_RESET 			(1 << 6)
+#define VHUB_IRQ_HUB_EP1_IN_DATA_ACK		(1 << 5)
+#define VHUB_IRQ_HUB_EP0_IN_DATA_NAK		(1 << 4)
+#define VHUB_IRQ_HUB_EP0_IN_ACK_STALL		(1 << 3)
+#define VHUB_IRQ_HUB_EP0_OUT_NAK		(1 << 2)
+#define VHUB_IRQ_HUB_EP0_OUT_ACK_STALL		(1 << 1)
+#define VHUB_IRQ_HUB_EP0_SETUP			(1 << 0)
+#define VHUB_IRQ_ACK_ALL			0x1ff
+
+/* SW reset reg */
+#define VHUB_SW_RESET_EP_POOL			(1 << 9)
+#define VHUB_SW_RESET_DMA_CONTROLLER		(1 << 8)
+#define VHUB_SW_RESET_DEVICE5			(1 << 5)
+#define VHUB_SW_RESET_DEVICE4			(1 << 4)
+#define VHUB_SW_RESET_DEVICE3			(1 << 3)
+#define VHUB_SW_RESET_DEVICE2			(1 << 2)
+#define VHUB_SW_RESET_DEVICE1			(1 << 1)
+#define VHUB_SW_RESET_ROOT_HUB			(1 << 0)
+#define VHUB_SW_RESET_ALL			(VHUB_SW_RESET_EP_POOL | \
+						 VHUB_SW_RESET_DMA_CONTROLLER | \
+						 VHUB_SW_RESET_DEVICE5 | \
+						 VHUB_SW_RESET_DEVICE4 | \
+						 VHUB_SW_RESET_DEVICE3 | \
+						 VHUB_SW_RESET_DEVICE2 | \
+						 VHUB_SW_RESET_DEVICE1 | \
+						 VHUB_SW_RESET_ROOT_HUB)
+/* EP ACK/NACK IRQ masks */
+#define VHUB_EP_IRQ(n)				(1 << (n))
+#define VHUB_EP_IRQ_ALL				0x7fff	/* 15 EPs */
+
+/* USB status reg */
+#define VHUB_USBSTS_HISPEED			(1 << 27)
+
+/* EP toggle */
+#define VHUB_EP_TOGGLE_VALUE			(1 << 8)
+#define VHUB_EP_TOGGLE_SET_EPNUM(x)		((x) & 0x1f)
+
+/* HUB EP0 control */
+#define VHUB_EP0_CTRL_STALL			(1 << 0)
+#define VHUB_EP0_TX_BUFF_RDY			(1 << 1)
+#define VHUB_EP0_RX_BUFF_RDY			(1 << 2)
+#define VHUB_EP0_RX_LEN(x)			(((x) >> 16) & 0x7f)
+#define VHUB_EP0_SET_TX_LEN(x)			(((x) & 0x7f) << 8)
+
+/* HUB EP1 control */
+#define VHUB_EP1_CTRL_RESET_TOGGLE		(1 << 2)
+#define VHUB_EP1_CTRL_STALL			(1 << 1)
+#define VHUB_EP1_CTRL_ENABLE			(1 << 0)
+
+/***********************************
+ *                                 *
+ * per-device register definitions *
+ *                                 *
+ ***********************************/
+#define AST_VHUB_DEV_EN_CTRL		0x00
+#define AST_VHUB_DEV_ISR		0x04
+#define AST_VHUB_DEV_EP0_CTRL		0x08
+#define AST_VHUB_DEV_EP0_DATA		0x0c
+
+/* Device enable control */
+#define VHUB_DEV_EN_SET_ADDR(x)			((x) << 8)
+#define VHUB_DEV_EN_ADDR_MASK			((0xff) << 8)
+#define VHUB_DEV_EN_EP0_NAK_IRQEN		(1 << 6)
+#define VHUB_DEV_EN_EP0_IN_ACK_IRQEN		(1 << 5)
+#define VHUB_DEV_EN_EP0_OUT_NAK_IRQEN		(1 << 4)
+#define VHUB_DEV_EN_EP0_OUT_ACK_IRQEN		(1 << 3)
+#define VHUB_DEV_EN_EP0_SETUP_IRQEN		(1 << 2)
+#define VHUB_DEV_EN_SPEED_SEL_HIGH		(1 << 1)
+#define VHUB_DEV_EN_ENABLE_PORT			(1 << 0)
+
+/* Interrupt status */
+#define VHUV_DEV_IRQ_EP0_IN_DATA_NACK		(1 << 4)
+#define VHUV_DEV_IRQ_EP0_IN_ACK_STALL		(1 << 3)
+#define VHUV_DEV_IRQ_EP0_OUT_DATA_NACK		(1 << 2)
+#define VHUV_DEV_IRQ_EP0_OUT_ACK_STALL		(1 << 1)
+#define VHUV_DEV_IRQ_EP0_SETUP			(1 << 0)
+
+/* Control bits.
+ *
+ * Note: The driver relies on the bulk of those bits
+ *       matching corresponding vHub EP0 control bits
+ */
+#define VHUB_DEV_EP0_CTRL_STALL			VHUB_EP0_CTRL_STALL
+#define VHUB_DEV_EP0_TX_BUFF_RDY		VHUB_EP0_TX_BUFF_RDY
+#define VHUB_DEV_EP0_RX_BUFF_RDY		VHUB_EP0_RX_BUFF_RDY
+#define VHUB_DEV_EP0_RX_LEN(x)			VHUB_EP0_RX_LEN(x)
+#define VHUB_DEV_EP0_SET_TX_LEN(x)		VHUB_EP0_SET_TX_LEN(x)
+
+/*************************************
+ *                                   *
+ * per-endpoint register definitions *
+ *                                   *
+ *************************************/
+
+#define AST_VHUB_EP_CONFIG		0x00
+#define AST_VHUB_EP_DMA_CTLSTAT		0x04
+#define AST_VHUB_EP_DESC_BASE		0x08
+#define AST_VHUB_EP_DESC_STATUS		0x0C
+
+/* EP config reg */
+#define VHUB_EP_CFG_SET_MAX_PKT(x)	(((x) & 0x3ff) << 16)
+#define VHUB_EP_CFG_AUTO_DATA_DISABLE	(1 << 13)
+#define VHUB_EP_CFG_STALL_CTRL		(1 << 12)
+#define VHUB_EP_CFG_SET_EP_NUM(x)	(((x) & 0xf) << 8)
+#define VHUB_EP_CFG_SET_TYPE(x)		((x) << 5)
+#define   EP_TYPE_OFF			0
+#define   EP_TYPE_BULK			1
+#define   EP_TYPE_INT			2
+#define   EP_TYPE_ISO			3
+#define VHUB_EP_CFG_DIR_OUT		(1 << 4)
+#define VHUB_EP_CFG_SET_DEV(x)		((x) << 1)
+#define VHUB_EP_CFG_ENABLE		(1 << 0)
+
+/* EP DMA control */
+#define VHUB_EP_DMA_PROC_STATUS(x)	(((x) >> 4) & 0xf)
+#define   EP_DMA_PROC_RX_IDLE		0
+#define   EP_DMA_PROC_TX_IDLE		8
+#define VHUB_EP_DMA_IN_LONG_MODE	(1 << 3)
+#define VHUB_EP_DMA_OUT_CONTIG_MODE	(1 << 3)
+#define VHUB_EP_DMA_CTRL_RESET		(1 << 2)
+#define VHUB_EP_DMA_SINGLE_STAGE	(1 << 1)
+#define VHUB_EP_DMA_DESC_MODE		(1 << 0)
+
+/* EP DMA status */
+#define VHUB_EP_DMA_SET_TX_SIZE(x)	((x) << 16)
+#define VHUB_EP_DMA_TX_SIZE(x)		(((x) >> 16) & 0x7ff)
+#define VHUB_EP_DMA_RPTR(x)		(((x) >> 8) & 0xff)
+#define VHUB_EP_DMA_SET_RPTR(x)		(((x) & 0xff) << 8)
+#define VHUB_EP_DMA_SET_CPU_WPTR(x)	(x)
+#define VHUB_EP_DMA_SINGLE_KICK		(1 << 0) /* WPTR = 1 for single mode */
+
+/*******************************
+ *                             *
+ * DMA descriptors definitions *
+ *                             *
+ *******************************/
+
+/* Desc W1 IN */
+#define VHUB_DSC1_IN_INTERRUPT		(1 << 31)
+#define VHUB_DSC1_IN_SPID_DATA0		(0 << 14)
+#define VHUB_DSC1_IN_SPID_DATA2		(1 << 14)
+#define VHUB_DSC1_IN_SPID_DATA1		(2 << 14)
+#define VHUB_DSC1_IN_SPID_MDATA		(3 << 14)
+#define VHUB_DSC1_IN_SET_LEN(x)		((x) & 0xfff)
+#define VHUB_DSC1_IN_LEN(x)		((x) & 0xfff)
+
+/****************************************
+ *                                      *
+ * Data structures and misc definitions *
+ *                                      *
+ ****************************************/
+
+#define AST_VHUB_NUM_GEN_EPs	15	/* Generic non-0 EPs */
+#define AST_VHUB_NUM_PORTS	5	/* vHub ports */
+#define AST_VHUB_EP0_MAX_PACKET	64	/* EP0's max packet size */
+#define AST_VHUB_EPn_MAX_PACKET	1024	/* Generic EPs max packet size */
+#define AST_VHUB_DESCS_COUNT	256	/* Use 256 descriptor mode (valid
+					 * values are 256 and 32)
+					 */
+
+struct ast_vhub;
+struct ast_vhub_dev;
+
+/*
+ * DMA descriptor (generic EPs only, currently only used
+ * for IN endpoints
+ */
+struct ast_vhub_desc {
+	__le32	w0;
+	__le32	w1;
+};
+
+/* A transfer request, either core-originated or internal */
+struct ast_vhub_req {
+	struct usb_request	req;
+	struct list_head	queue;
+
+	/* Actual count written to descriptors (desc mode only) */
+	unsigned int		act_count;
+
+	/*
+	 * Desc number of the final packet or -1. For non-desc
+	 * mode (or ep0), any >= 0 value means "last packet"
+	 */
+	int			last_desc;
+
+	/* Request active (pending DMAs) */
+	bool			active  : 1;
+
+	/* Internal request (don't call back core) */
+	bool			internal : 1;
+};
+#define to_ast_req(__ureq) container_of(__ureq, struct ast_vhub_req, req)
+
+/* Current state of an EP0 */
+enum ep0_state {
+	ep0_state_token,
+	ep0_state_data,
+	ep0_state_status,
+};
+
+/*
+ * An endpoint, either generic, ep0, actual gadget EP
+ * or internal use vhub EP0. vhub EP1 doesn't have an
+ * associated structure as it's mostly HW managed.
+ */
+struct ast_vhub_ep {
+	struct usb_ep		ep;
+
+	/* Request queue */
+	struct list_head	queue;
+
+	/* EP index in the device, 0 means this is an EP0 */
+	unsigned int		d_idx;
+
+	/* Dev pointer or NULL for vHub EP0 */
+	struct ast_vhub_dev	*dev;
+
+	/* vHub itself */
+	struct ast_vhub		*vhub;
+
+	/*
+	 * DMA buffer for EP0, fallback DMA buffer for misaligned
+	 * OUT transfers for generic EPs
+	 */
+	void			*buf;
+	dma_addr_t		buf_dma;
+
+	/* The rest depends on the EP type */
+	union {
+		/* EP0 (either device or vhub) */
+		struct {
+			/*
+			 * EP0 registers are "similar" for
+			 * vHub and devices but located in
+			 * different places.
+			 */
+			void __iomem		*ctlstat;
+			void __iomem		*setup;
+
+			/* Current state & direction */
+			enum ep0_state		state;
+			bool			dir_in;
+
+			/* Internal use request */
+			struct ast_vhub_req	req;
+		} ep0;
+
+		/* Generic endpoint (aka EPn) */
+		struct {
+			/* Registers */
+			void __iomem   		*regs;
+
+			/* Index in global pool (0..14) */
+			unsigned int		g_idx;
+
+			/* DMA Descriptors */
+			struct ast_vhub_desc	*descs;
+			dma_addr_t		descs_dma;
+			unsigned int		d_next;
+			unsigned int		d_last;
+			unsigned int		dma_conf;
+
+			/* Max chunk size for IN EPs */
+			unsigned int		chunk_max;
+
+			/* State flags */
+			bool			is_in :  1;
+			bool			is_iso : 1;
+			bool			stalled : 1;
+			bool			wedged : 1;
+			bool			enabled : 1;
+			bool			desc_mode : 1;
+		} epn;
+	};
+};
+#define to_ast_ep(__uep) container_of(__uep, struct ast_vhub_ep, ep)
+
+/* A device attached to a vHub port */
+struct ast_vhub_dev {
+	struct ast_vhub			*vhub;
+	void __iomem			*regs;
+
+	/* Device index (0...4) and name string */
+	unsigned int			index;
+	const char			*name;
+
+	/* sysfs enclosure for the gadget gunk */
+	struct device			*port_dev;
+
+	/* Link to gadget core */
+	struct usb_gadget		gadget;
+	struct usb_gadget_driver	*driver;
+	bool				registered : 1;
+	bool				wakeup_en : 1;
+	bool				suspended : 1;
+	bool				enabled : 1;
+
+	/* Endpoint structures */
+	struct ast_vhub_ep		ep0;
+	struct ast_vhub_ep		*epns[AST_VHUB_NUM_GEN_EPs];
+
+};
+#define to_ast_dev(__g) container_of(__g, struct ast_vhub_dev, gadget)
+
+/* Per vhub port stateinfo structure */
+struct ast_vhub_port {
+	/* Port status & status change registers */
+	u16			status;
+	u16			change;
+
+	/* Associated device slot */
+	struct ast_vhub_dev	dev;
+};
+
+/* Global vhub structure */
+struct ast_vhub {
+	struct platform_device		*pdev;
+	void __iomem			*regs;
+	int				irq;
+	spinlock_t			lock;
+	struct work_struct		wake_work;
+	struct clk			*clk;
+
+	/* EP0 DMA buffers allocated in one chunk */
+	void				*ep0_bufs;
+	dma_addr_t			ep0_bufs_dma;
+
+	/* EP0 of the vhub itself */
+	struct ast_vhub_ep		ep0;
+
+	/* State of vhub ep1 */
+	bool				ep1_stalled : 1;
+
+	/* Per-port info */
+	struct ast_vhub_port		ports[AST_VHUB_NUM_PORTS];
+
+	/* Generic EP data structures */
+	struct ast_vhub_ep		epns[AST_VHUB_NUM_GEN_EPs];
+
+	/* Upstream bus is suspended ? */
+	bool				suspended : 1;
+
+	/* Hub itself can signal remote wakeup */
+	bool				wakeup_en : 1;
+
+	/* Force full speed only */
+	bool				force_usb1 : 1;
+
+	/* Upstream bus speed captured at bus reset */
+	unsigned int			speed;
+};
+
+/* Standard request handlers result codes */
+enum std_req_rc {
+	std_req_stall = -1,	/* Stall requested */
+	std_req_complete = 0,	/* Request completed with no data */
+	std_req_data = 1,	/* Request completed with data */
+	std_req_driver = 2,	/* Pass to driver pls */
+};
+
+#ifdef CONFIG_USB_GADGET_VERBOSE
+#define UDCVDBG(u, fmt...)	dev_dbg(&(u)->pdev->dev, fmt)
+
+#define EPVDBG(ep, fmt, ...)	do {			\
+	dev_dbg(&(ep)->vhub->pdev->dev,			\
+		"%s:EP%d " fmt,				\
+		(ep)->dev ? (ep)->dev->name : "hub",	\
+		(ep)->d_idx, ##__VA_ARGS__);		\
+	} while(0)
+
+#define DVDBG(d, fmt, ...)	do {			\
+	dev_dbg(&(d)->vhub->pdev->dev,			\
+		"%s " fmt, (d)->name,			\
+		##__VA_ARGS__);				\
+	} while(0)
+
+#else
+#define UDCVDBG(u, fmt...)	do { } while(0)
+#define EPVDBG(ep, fmt, ...)	do { } while(0)
+#define DVDBG(d, fmt, ...)	do { } while(0)
+#endif
+
+#ifdef CONFIG_USB_GADGET_DEBUG
+#define UDCDBG(u, fmt...)	dev_dbg(&(u)->pdev->dev, fmt)
+
+#define EPDBG(ep, fmt, ...)	do {			\
+	dev_dbg(&(ep)->vhub->pdev->dev,			\
+		"%s:EP%d " fmt,				\
+		(ep)->dev ? (ep)->dev->name : "hub",	\
+		(ep)->d_idx, ##__VA_ARGS__);		\
+	} while(0)
+
+#define DDBG(d, fmt, ...)	do {			\
+	dev_dbg(&(d)->vhub->pdev->dev,			\
+		"%s " fmt, (d)->name,			\
+		##__VA_ARGS__);				\
+	} while(0)
+#else
+#define UDCDBG(u, fmt...)	do { } while(0)
+#define EPDBG(ep, fmt, ...)	do { } while(0)
+#define DDBG(d, fmt, ...)	do { } while(0)
+#endif
+
+static inline void vhub_dma_workaround(void *addr)
+{
+	/*
+	 * This works around a confirmed HW issue with the Aspeed chip.
+	 *
+	 * The core uses a different bus to memory than the AHB going to
+	 * the USB device controller. Due to the latter having a higher
+	 * priority than the core for arbitration on that bus, it's
+	 * possible for an MMIO to the device, followed by a DMA by the
+	 * device from memory to all be performed and services before
+	 * a previous store to memory gets completed.
+	 *
+	 * This the following scenario can happen:
+	 *
+	 *    - Driver writes to a DMA descriptor (Mbus)
+	 *    - Driver writes to the MMIO register to start the DMA (AHB)
+	 *    - The gadget sees the second write and sends a read of the
+	 *      descriptor to the memory controller (Mbus)
+	 *    - The gadget hits memory before the descriptor write
+	 *      causing it to read an obsolete value.
+	 *
+	 * Thankfully the problem is limited to the USB gadget device, other
+	 * masters in the SoC all have a lower priority than the core, thus
+	 * ensuring that the store by the core arrives first.
+	 *
+	 * The workaround consists of using a dummy read of the memory before
+	 * doing the MMIO writes. This will ensure that the previous writes
+	 * have been "pushed out".
+	 */
+	mb();
+	(void)__raw_readl((void __iomem *)addr);
+}
+
+/* core.c */
+void ast_vhub_done(struct ast_vhub_ep *ep, struct ast_vhub_req *req,
+		   int status);
+void ast_vhub_nuke(struct ast_vhub_ep *ep, int status);
+struct usb_request *ast_vhub_alloc_request(struct usb_ep *u_ep,
+					   gfp_t gfp_flags);
+void ast_vhub_free_request(struct usb_ep *u_ep, struct usb_request *u_req);
+void ast_vhub_init_hw(struct ast_vhub *vhub);
+
+/* ep0.c */
+void ast_vhub_ep0_handle_ack(struct ast_vhub_ep *ep, bool in_ack);
+void ast_vhub_ep0_handle_setup(struct ast_vhub_ep *ep);
+void ast_vhub_init_ep0(struct ast_vhub *vhub, struct ast_vhub_ep *ep,
+		       struct ast_vhub_dev *dev);
+int ast_vhub_reply(struct ast_vhub_ep *ep, char *ptr, int len);
+int __ast_vhub_simple_reply(struct ast_vhub_ep *ep, int len, ...);
+#define ast_vhub_simple_reply(udc, ...)					       \
+	__ast_vhub_simple_reply((udc),					       \
+			       sizeof((u8[]) { __VA_ARGS__ })/sizeof(u8),      \
+			       __VA_ARGS__)
+
+/* hub.c */
+void ast_vhub_init_hub(struct ast_vhub *vhub);
+enum std_req_rc ast_vhub_std_hub_request(struct ast_vhub_ep *ep,
+					 struct usb_ctrlrequest *crq);
+enum std_req_rc ast_vhub_class_hub_request(struct ast_vhub_ep *ep,
+					   struct usb_ctrlrequest *crq);
+void ast_vhub_device_connect(struct ast_vhub *vhub, unsigned int port,
+			     bool on);
+void ast_vhub_hub_suspend(struct ast_vhub *vhub);
+void ast_vhub_hub_resume(struct ast_vhub *vhub);
+void ast_vhub_hub_reset(struct ast_vhub *vhub);
+void ast_vhub_hub_wake_all(struct ast_vhub *vhub);
+
+/* dev.c */
+int ast_vhub_init_dev(struct ast_vhub *vhub, unsigned int idx);
+void ast_vhub_del_dev(struct ast_vhub_dev *d);
+void ast_vhub_dev_irq(struct ast_vhub_dev *d);
+int ast_vhub_std_dev_request(struct ast_vhub_ep *ep,
+			     struct usb_ctrlrequest *crq);
+
+/* epn.c */
+void ast_vhub_epn_ack_irq(struct ast_vhub_ep *ep);
+void ast_vhub_update_epn_stall(struct ast_vhub_ep *ep);
+struct ast_vhub_ep *ast_vhub_alloc_epn(struct ast_vhub_dev *d, u8 addr);
+void ast_vhub_dev_suspend(struct ast_vhub_dev *d);
+void ast_vhub_dev_resume(struct ast_vhub_dev *d);
+void ast_vhub_dev_reset(struct ast_vhub_dev *d);
+
+#endif /* __ASPEED_VHUB_H */