drivers/usb/gadget/udc/aspeed-vhub/core.c - manifest_repos/kernel - Git at Google

 // 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;
 	int count = 0;

 	/* 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);
 		count++;
 	}
 	if (count)
 		EPDBG(ep, "Nuked %d request(s)\n", count);
 }

 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) {
 		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");
	// 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;
	int count = 0;

	/* 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);
	count++;
	}
	if (count)
	EPDBG(ep, "Nuked %d request(s)\n", count);
	}

	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) {
	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");