usb/gadget: Add driver for Aspeed SoC virtual hub

The Aspeed BMC SoCs support a "virtual hub" function. It provides some
HW support for a top-level USB2 hub behind which sit 5 gadget "ports".

This driver adds support for the full functionality, emulating the
hub standard requests and exposing 5 UDC gadget drivers corresponding
to the ports.

The hub itself has HW provided dedicated EP0 and EP1 (the latter for
hub interrupts). It also has dedicated EP0s for each function. For
other endpoints, there's a pool of 15 "generic" endpoints that are
shared among the ports.

The driver relies on my previous patch adding a "dispose" EP op to
handle EP allocation between ports. EPs are allocated from the shared
pool in the UDC "match_ep" callback and assigned to the UDC instance
(added to the gadget ep_list).

When the composite driver gets unbound, the new hook will allow the UDC
to clean things up and return those EPs to the shared pool.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/udc/Kconfig

@@ -438,6 +438,8 @@ config USB_GADGET_XILINX
 	  dynamically linked module called "udc-xilinx" and force all
 	  gadget drivers to also be dynamically linked.
 
+source "drivers/usb/gadget/udc/aspeed-vhub/Kconfig"
+
 #
 # LAST -- dummy/emulated controller
 #

drivers/usb/gadget/udc/Makefile

@@ -39,4 +39,5 @@ obj-$(CONFIG_USB_MV_U3D)	+= mv_u3d_core.o
 obj-$(CONFIG_USB_GR_UDC)	+= gr_udc.o
 obj-$(CONFIG_USB_GADGET_XILINX)	+= udc-xilinx.o
 obj-$(CONFIG_USB_SNP_UDC_PLAT) += snps_udc_plat.o
+obj-$(CONFIG_USB_ASPEED_VHUB)	+= aspeed-vhub/
 obj-$(CONFIG_USB_BDC_UDC)	+= bdc/

drivers/usb/gadget/udc/aspeed-vhub/Kconfig

+# SPDX-License-Identifier: GPL-2.0+
+config USB_ASPEED_VHUB
+	tristate "Aspeed vHub UDC driver"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	help
+	  USB peripheral controller for the Aspeed AST2500 family
+	  SoCs supporting the "vHub" functionality and USB2.0

drivers/usb/gadget/udc/aspeed-vhub/Makefile

+# 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
+

drivers/usb/gadget/udc/aspeed-vhub/core.c

+// 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;
+
+	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(&ep->dev->gadget,
+						 &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");

drivers/usb/gadget/udc/aspeed-vhub/dev.c

+// 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;
+}

drivers/usb/gadget/udc/aspeed-vhub/ep0.c

+// 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, 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);
+
+	/* 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 + AST_VHUB_EP0_CTRL);
+}
+
+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;
+	}
+}

drivers/usb/gadget/udc/aspeed-vhub/epn.c

+// 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);
+		writel(ep->buf_dma, ep->epn.regs + AST_VHUB_EP_DESC_BASE);
+	} else
+		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)
+{
+	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) {
+		struct ast_vhub_desc *desc;
+		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;
+	}
+
+	/* 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(&ep->dev->gadget, 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 */
+	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;
+}

drivers/usb/gadget/udc/aspeed-vhub/hub.c

+// 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);
+}
+

drivers/usb/gadget/udc/aspeed-vhub/vhub.h

+/* 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
+
+/* 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 */