xref: /rk3399_rockchip-uboot/drivers/usb/host/xhci.c (revision 25d1936a192ac62b8df5dc33e37455dcaeb19fae)

/*
 * USB HOST XHCI Controller stack
 *
 * Based on xHCI host controller driver in linux-kernel
 * by Sarah Sharp.
 *
 * Copyright (C) 2008 Intel Corp.
 * Author: Sarah Sharp
 *
 * Copyright (C) 2013 Samsung Electronics Co.Ltd
 * Authors: Vivek Gautam <gautam.vivek@samsung.com>
 *	    Vikas Sajjan <vikas.sajjan@samsung.com>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/**
 * This file gives the xhci stack for usb3.0 looking into
 * xhci specification Rev1.0 (5/21/10).
 * The quirk devices support hasn't been given yet.
 */

#include <common.h>
#include <asm/byteorder.h>
#include <usb.h>
#include <malloc.h>
#include <watchdog.h>
#include <asm/cache.h>
#include <asm/unaligned.h>
#include <asm-generic/errno.h>
#include "xhci.h"

#ifndef CONFIG_USB_MAX_CONTROLLER_COUNT
#define CONFIG_USB_MAX_CONTROLLER_COUNT 1
#endif

static struct descriptor {
	struct usb_hub_descriptor hub;
	struct usb_device_descriptor device;
	struct usb_config_descriptor config;
	struct usb_interface_descriptor interface;
	struct usb_endpoint_descriptor endpoint;
	struct usb_ss_ep_comp_descriptor ep_companion;
} __attribute__ ((packed)) descriptor = {
	{
		0xc,		/* bDescLength */
		0x2a,		/* bDescriptorType: hub descriptor */
		2,		/* bNrPorts -- runtime modified */
		cpu_to_le16(0x8), /* wHubCharacteristics */
		10,		/* bPwrOn2PwrGood */
		0,		/* bHubCntrCurrent */
		{},		/* Device removable */
		{}		/* at most 7 ports! XXX */
	},
	{
		0x12,		/* bLength */
		1,		/* bDescriptorType: UDESC_DEVICE */
		cpu_to_le16(0x0300), /* bcdUSB: v3.0 */
		9,		/* bDeviceClass: UDCLASS_HUB */
		0,		/* bDeviceSubClass: UDSUBCLASS_HUB */
		3,		/* bDeviceProtocol: UDPROTO_SSHUBSTT */
		9,		/* bMaxPacketSize: 512 bytes  2^9 */
		0x0000,		/* idVendor */
		0x0000,		/* idProduct */
		cpu_to_le16(0x0100), /* bcdDevice */
		1,		/* iManufacturer */
		2,		/* iProduct */
		0,		/* iSerialNumber */
		1		/* bNumConfigurations: 1 */
	},
	{
		0x9,
		2,		/* bDescriptorType: UDESC_CONFIG */
		cpu_to_le16(0x1f), /* includes SS endpoint descriptor */
		1,		/* bNumInterface */
		1,		/* bConfigurationValue */
		0,		/* iConfiguration */
		0x40,		/* bmAttributes: UC_SELF_POWER */
		0		/* bMaxPower */
	},
	{
		0x9,		/* bLength */
		4,		/* bDescriptorType: UDESC_INTERFACE */
		0,		/* bInterfaceNumber */
		0,		/* bAlternateSetting */
		1,		/* bNumEndpoints */
		9,		/* bInterfaceClass: UICLASS_HUB */
		0,		/* bInterfaceSubClass: UISUBCLASS_HUB */
		0,		/* bInterfaceProtocol: UIPROTO_HSHUBSTT */
		0		/* iInterface */
	},
	{
		0x7,		/* bLength */
		5,		/* bDescriptorType: UDESC_ENDPOINT */
		0x81,		/* bEndpointAddress: IN endpoint 1 */
		3,		/* bmAttributes: UE_INTERRUPT */
		8,		/* wMaxPacketSize */
		255		/* bInterval */
	},
	{
		0x06,		/* ss_bLength */
		0x30,		/* ss_bDescriptorType: SS EP Companion */
		0x00,		/* ss_bMaxBurst: allows 1 TX between ACKs */
		/* ss_bmAttributes: 1 packet per service interval */
		0x00,
		/* ss_wBytesPerInterval: 15 bits for max 15 ports */
		cpu_to_le16(0x02),
	},
};

static struct xhci_ctrl xhcic[CONFIG_USB_MAX_CONTROLLER_COUNT];

/**
 * Waits for as per specified amount of time
 * for the "result" to match with "done"
 *
 * @param ptr	pointer to the register to be read
 * @param mask	mask for the value read
 * @param done	value to be campared with result
 * @param usec	time to wait till
 * @return 0 if handshake is success else < 0 on failure
 */
static int handshake(uint32_t volatile *ptr, uint32_t mask,
					uint32_t done, int usec)
{
	uint32_t result;

	do {
		result = xhci_readl(ptr);
		if (result == ~(uint32_t)0)
			return -ENODEV;
		result &= mask;
		if (result == done)
			return 0;
		usec--;
		udelay(1);
	} while (usec > 0);

	return -ETIMEDOUT;
}

/**
 * Set the run bit and wait for the host to be running.
 *
 * @param hcor	pointer to host controller operation registers
 * @return status of the Handshake
 */
static int xhci_start(struct xhci_hcor *hcor)
{
	u32 temp;
	int ret;

	puts("Starting the controller\n");
	temp = xhci_readl(&hcor->or_usbcmd);
	temp |= (CMD_RUN);
	xhci_writel(&hcor->or_usbcmd, temp);

	/*
	 * Wait for the HCHalted Status bit to be 0 to indicate the host is
	 * running.
	 */
	ret = handshake(&hcor->or_usbsts, STS_HALT, 0, XHCI_MAX_HALT_USEC);
	if (ret)
		debug("Host took too long to start, "
				"waited %u microseconds.\n",
				XHCI_MAX_HALT_USEC);
	return ret;
}

/**
 * Resets the XHCI Controller
 *
 * @param hcor	pointer to host controller operation registers
 * @return -EBUSY if XHCI Controller is not halted else status of handshake
 */
int xhci_reset(struct xhci_hcor *hcor)
{
	u32 cmd;
	u32 state;
	int ret;

	/* Halting the Host first */
	debug("// Halt the HC\n");
	state = xhci_readl(&hcor->or_usbsts) & STS_HALT;
	if (!state) {
		cmd = xhci_readl(&hcor->or_usbcmd);
		cmd &= ~CMD_RUN;
		xhci_writel(&hcor->or_usbcmd, cmd);
	}

	ret = handshake(&hcor->or_usbsts,
			STS_HALT, STS_HALT, XHCI_MAX_HALT_USEC);
	if (ret) {
		printf("Host not halted after %u microseconds.\n",
				XHCI_MAX_HALT_USEC);
		return -EBUSY;
	}

	debug("// Reset the HC\n");
	cmd = xhci_readl(&hcor->or_usbcmd);
	cmd |= CMD_RESET;
	xhci_writel(&hcor->or_usbcmd, cmd);

	ret = handshake(&hcor->or_usbcmd, CMD_RESET, 0, XHCI_MAX_RESET_USEC);
	if (ret)
		return ret;

	/*
	 * xHCI cannot write to any doorbells or operational registers other
	 * than status until the "Controller Not Ready" flag is cleared.
	 */
	return handshake(&hcor->or_usbsts, STS_CNR, 0, XHCI_MAX_RESET_USEC);
}

/**
 * Used for passing endpoint bitmasks between the core and HCDs.
 * Find the index for an endpoint given its descriptor.
 * Use the return value to right shift 1 for the bitmask.
 *
 * Index  = (epnum * 2) + direction - 1,
 * where direction = 0 for OUT, 1 for IN.
 * For control endpoints, the IN index is used (OUT index is unused), so
 * index = (epnum * 2) + direction - 1 = (epnum * 2) + 1 - 1 = (epnum * 2)
 *
 * @param desc	USB enpdoint Descriptor
 * @return index of the Endpoint
 */
static unsigned int xhci_get_ep_index(struct usb_endpoint_descriptor *desc)
{
	unsigned int index;

	if (usb_endpoint_xfer_control(desc))
		index = (unsigned int)(usb_endpoint_num(desc) * 2);
	else
		index = (unsigned int)((usb_endpoint_num(desc) * 2) -
				(usb_endpoint_dir_in(desc) ? 0 : 1));

	return index;
}

/**
 * Issue a configure endpoint command or evaluate context command
 * and wait for it to finish.
 *
 * @param udev	pointer to the Device Data Structure
 * @param ctx_change	flag to indicate the Context has changed or NOT
 * @return 0 on success, -1 on failure
 */
static int xhci_configure_endpoints(struct usb_device *udev, bool ctx_change)
{
	struct xhci_container_ctx *in_ctx;
	struct xhci_virt_device *virt_dev;
	struct xhci_ctrl *ctrl = udev->controller;
	union xhci_trb *event;

	virt_dev = ctrl->devs[udev->slot_id];
	in_ctx = virt_dev->in_ctx;

	xhci_flush_cache((uint32_t)in_ctx->bytes, in_ctx->size);
	xhci_queue_command(ctrl, in_ctx->bytes, udev->slot_id, 0,
			   ctx_change ? TRB_EVAL_CONTEXT : TRB_CONFIG_EP);
	event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
	BUG_ON(TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags))
		!= udev->slot_id);

	switch (GET_COMP_CODE(le32_to_cpu(event->event_cmd.status))) {
	case COMP_SUCCESS:
		debug("Successful %s command\n",
			ctx_change ? "Evaluate Context" : "Configure Endpoint");
		break;
	default:
		printf("ERROR: %s command returned completion code %d.\n",
			ctx_change ? "Evaluate Context" : "Configure Endpoint",
			GET_COMP_CODE(le32_to_cpu(event->event_cmd.status)));
		return -EINVAL;
	}

	xhci_acknowledge_event(ctrl);

	return 0;
}

/**
 * Configure the endpoint, programming the device contexts.
 *
 * @param udev	pointer to the USB device structure
 * @return returns the status of the xhci_configure_endpoints
 */
static int xhci_set_configuration(struct usb_device *udev)
{
	struct xhci_container_ctx *in_ctx;
	struct xhci_container_ctx *out_ctx;
	struct xhci_input_control_ctx *ctrl_ctx;
	struct xhci_slot_ctx *slot_ctx;
	struct xhci_ep_ctx *ep_ctx[MAX_EP_CTX_NUM];
	int cur_ep;
	int max_ep_flag = 0;
	int ep_index;
	unsigned int dir;
	unsigned int ep_type;
	struct xhci_ctrl *ctrl = udev->controller;
	int num_of_ep;
	int ep_flag = 0;
	u64 trb_64 = 0;
	int slot_id = udev->slot_id;
	struct xhci_virt_device *virt_dev = ctrl->devs[slot_id];
	struct usb_interface *ifdesc;

	out_ctx = virt_dev->out_ctx;
	in_ctx = virt_dev->in_ctx;

	num_of_ep = udev->config.if_desc[0].no_of_ep;
	ifdesc = &udev->config.if_desc[0];

	ctrl_ctx = xhci_get_input_control_ctx(in_ctx);
	/* Zero the input context control */
	ctrl_ctx->add_flags = 0;
	ctrl_ctx->drop_flags = 0;

	/* EP_FLAG gives values 1 & 4 for EP1OUT and EP2IN */
	for (cur_ep = 0; cur_ep < num_of_ep; cur_ep++) {
		ep_flag = xhci_get_ep_index(&ifdesc->ep_desc[cur_ep]);
		ctrl_ctx->add_flags |= cpu_to_le32(1 << (ep_flag + 1));
		if (max_ep_flag < ep_flag)
			max_ep_flag = ep_flag;
	}

	xhci_inval_cache((uint32_t)out_ctx->bytes, out_ctx->size);

	/* slot context */
	xhci_slot_copy(ctrl, in_ctx, out_ctx);
	slot_ctx = xhci_get_slot_ctx(ctrl, in_ctx);
	slot_ctx->dev_info &= ~(LAST_CTX_MASK);
	slot_ctx->dev_info |= cpu_to_le32(LAST_CTX(max_ep_flag + 1) | 0);

	xhci_endpoint_copy(ctrl, in_ctx, out_ctx, 0);

	/* filling up ep contexts */
	for (cur_ep = 0; cur_ep < num_of_ep; cur_ep++) {
		struct usb_endpoint_descriptor *endpt_desc = NULL;

		endpt_desc = &ifdesc->ep_desc[cur_ep];
		trb_64 = 0;

		ep_index = xhci_get_ep_index(endpt_desc);
		ep_ctx[ep_index] = xhci_get_ep_ctx(ctrl, in_ctx, ep_index);

		/* Allocate the ep rings */
		virt_dev->eps[ep_index].ring = xhci_ring_alloc(1, true);
		if (!virt_dev->eps[ep_index].ring)
			return -ENOMEM;

		/*NOTE: ep_desc[0] actually represents EP1 and so on */
		dir = (((endpt_desc->bEndpointAddress) & (0x80)) >> 7);
		ep_type = (((endpt_desc->bmAttributes) & (0x3)) | (dir << 2));
		ep_ctx[ep_index]->ep_info2 =
			cpu_to_le32(ep_type << EP_TYPE_SHIFT);
		ep_ctx[ep_index]->ep_info2 |=
			cpu_to_le32(MAX_PACKET
			(get_unaligned(&endpt_desc->wMaxPacketSize)));

		ep_ctx[ep_index]->ep_info2 |=
			cpu_to_le32(((0 & MAX_BURST_MASK) << MAX_BURST_SHIFT) |
			((3 & ERROR_COUNT_MASK) << ERROR_COUNT_SHIFT));

		trb_64 = (uintptr_t)
				virt_dev->eps[ep_index].ring->enqueue;
		ep_ctx[ep_index]->deq = cpu_to_le64(trb_64 |
				virt_dev->eps[ep_index].ring->cycle_state);
	}

	return xhci_configure_endpoints(udev, false);
}

/**
 * Issue an Address Device command (which will issue a SetAddress request to
 * the device).
 *
 * @param udev pointer to the Device Data Structure
 * @return 0 if successful else error code on failure
 */
static int xhci_address_device(struct usb_device *udev)
{
	int ret = 0;
	struct xhci_ctrl *ctrl = udev->controller;
	struct xhci_slot_ctx *slot_ctx;
	struct xhci_input_control_ctx *ctrl_ctx;
	struct xhci_virt_device *virt_dev;
	int slot_id = udev->slot_id;
	union xhci_trb *event;

	virt_dev = ctrl->devs[slot_id];

	/*
	 * This is the first Set Address since device plug-in
	 * so setting up the slot context.
	 */
	debug("Setting up addressable devices\n");
	xhci_setup_addressable_virt_dev(udev);

	ctrl_ctx = xhci_get_input_control_ctx(virt_dev->in_ctx);
	ctrl_ctx->add_flags = cpu_to_le32(SLOT_FLAG | EP0_FLAG);
	ctrl_ctx->drop_flags = 0;

	xhci_queue_command(ctrl, (void *)ctrl_ctx, slot_id, 0, TRB_ADDR_DEV);
	event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
	BUG_ON(TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags)) != slot_id);

	switch (GET_COMP_CODE(le32_to_cpu(event->event_cmd.status))) {
	case COMP_CTX_STATE:
	case COMP_EBADSLT:
		printf("Setup ERROR: address device command for slot %d.\n",
								slot_id);
		ret = -EINVAL;
		break;
	case COMP_TX_ERR:
		puts("Device not responding to set address.\n");
		ret = -EPROTO;
		break;
	case COMP_DEV_ERR:
		puts("ERROR: Incompatible device"
					"for address device command.\n");
		ret = -ENODEV;
		break;
	case COMP_SUCCESS:
		debug("Successful Address Device command\n");
		udev->status = 0;
		break;
	default:
		printf("ERROR: unexpected command completion code 0x%x.\n",
			GET_COMP_CODE(le32_to_cpu(event->event_cmd.status)));
		ret = -EINVAL;
		break;
	}

	xhci_acknowledge_event(ctrl);

	if (ret < 0)
		/*
		 * TODO: Unsuccessful Address Device command shall leave the
		 * slot in default state. So, issue Disable Slot command now.
		 */
		return ret;

	xhci_inval_cache((uint32_t)virt_dev->out_ctx->bytes,
				virt_dev->out_ctx->size);
	slot_ctx = xhci_get_slot_ctx(ctrl, virt_dev->out_ctx);

	debug("xHC internal address is: %d\n",
		le32_to_cpu(slot_ctx->dev_state) & DEV_ADDR_MASK);

	return 0;
}

/**
 * Issue Enable slot command to the controller to allocate
 * device slot and assign the slot id. It fails if the xHC
 * ran out of device slots, the Enable Slot command timed out,
 * or allocating memory failed.
 *
 * @param udev	pointer to the Device Data Structure
 * @return Returns 0 on succes else return error code on failure
 */
int usb_alloc_device(struct usb_device *udev)
{
	union xhci_trb *event;
	struct xhci_ctrl *ctrl = udev->controller;
	int ret;

	/*
	 * Root hub will be first device to be initailized.
	 * If this device is root-hub, don't do any xHC related
	 * stuff.
	 */
	if (ctrl->rootdev == 0) {
		udev->speed = USB_SPEED_SUPER;
		return 0;
	}

	xhci_queue_command(ctrl, NULL, 0, 0, TRB_ENABLE_SLOT);
	event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
	BUG_ON(GET_COMP_CODE(le32_to_cpu(event->event_cmd.status))
		!= COMP_SUCCESS);

	udev->slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags));

	xhci_acknowledge_event(ctrl);

	ret = xhci_alloc_virt_device(udev);
	if (ret < 0) {
		/*
		 * TODO: Unsuccessful Address Device command shall leave
		 * the slot in default. So, issue Disable Slot command now.
		 */
		puts("Could not allocate xHCI USB device data structures\n");
		return ret;
	}

	return 0;
}

/*
 * Full speed devices may have a max packet size greater than 8 bytes, but the
 * USB core doesn't know that until it reads the first 8 bytes of the
 * descriptor.  If the usb_device's max packet size changes after that point,
 * we need to issue an evaluate context command and wait on it.
 *
 * @param udev	pointer to the Device Data Structure
 * @return returns the status of the xhci_configure_endpoints
 */
int xhci_check_maxpacket(struct usb_device *udev)
{
	struct xhci_ctrl *ctrl = udev->controller;
	unsigned int slot_id = udev->slot_id;
	int ep_index = 0;	/* control endpoint */
	struct xhci_container_ctx *in_ctx;
	struct xhci_container_ctx *out_ctx;
	struct xhci_input_control_ctx *ctrl_ctx;
	struct xhci_ep_ctx *ep_ctx;
	int max_packet_size;
	int hw_max_packet_size;
	int ret = 0;
	struct usb_interface *ifdesc;

	ifdesc = &udev->config.if_desc[0];

	out_ctx = ctrl->devs[slot_id]->out_ctx;
	xhci_inval_cache((uint32_t)out_ctx->bytes, out_ctx->size);

	ep_ctx = xhci_get_ep_ctx(ctrl, out_ctx, ep_index);
	hw_max_packet_size = MAX_PACKET_DECODED(le32_to_cpu(ep_ctx->ep_info2));
	max_packet_size = usb_endpoint_maxp(&ifdesc->ep_desc[0]);
	if (hw_max_packet_size != max_packet_size) {
		debug("Max Packet Size for ep 0 changed.\n");
		debug("Max packet size in usb_device = %d\n", max_packet_size);
		debug("Max packet size in xHCI HW = %d\n", hw_max_packet_size);
		debug("Issuing evaluate context command.\n");

		/* Set up the modified control endpoint 0 */
		xhci_endpoint_copy(ctrl, ctrl->devs[slot_id]->in_ctx,
				ctrl->devs[slot_id]->out_ctx, ep_index);
		in_ctx = ctrl->devs[slot_id]->in_ctx;
		ep_ctx = xhci_get_ep_ctx(ctrl, in_ctx, ep_index);
		ep_ctx->ep_info2 &= cpu_to_le32(~MAX_PACKET_MASK);
		ep_ctx->ep_info2 |= cpu_to_le32(MAX_PACKET(max_packet_size));

		/*
		 * Set up the input context flags for the command
		 * FIXME: This won't work if a non-default control endpoint
		 * changes max packet sizes.
		 */
		ctrl_ctx = xhci_get_input_control_ctx(in_ctx);
		ctrl_ctx->add_flags = cpu_to_le32(EP0_FLAG);
		ctrl_ctx->drop_flags = 0;

		ret = xhci_configure_endpoints(udev, true);
	}
	return ret;
}

/**
 * Clears the Change bits of the Port Status Register
 *
 * @param wValue	request value
 * @param wIndex	request index
 * @param addr		address of posrt status register
 * @param port_status	state of port status register
 * @return none
 */
static void xhci_clear_port_change_bit(u16 wValue,
		u16 wIndex, volatile uint32_t *addr, u32 port_status)
{
	char *port_change_bit;
	u32 status;

	switch (wValue) {
	case USB_PORT_FEAT_C_RESET:
		status = PORT_RC;
		port_change_bit = "reset";
		break;
	case USB_PORT_FEAT_C_CONNECTION:
		status = PORT_CSC;
		port_change_bit = "connect";
		break;
	case USB_PORT_FEAT_C_OVER_CURRENT:
		status = PORT_OCC;
		port_change_bit = "over-current";
		break;
	case USB_PORT_FEAT_C_ENABLE:
		status = PORT_PEC;
		port_change_bit = "enable/disable";
		break;
	case USB_PORT_FEAT_C_SUSPEND:
		status = PORT_PLC;
		port_change_bit = "suspend/resume";
		break;
	default:
		/* Should never happen */
		return;
	}

	/* Change bits are all write 1 to clear */
	xhci_writel(addr, port_status | status);

	port_status = xhci_readl(addr);
	debug("clear port %s change, actual port %d status  = 0x%x\n",
			port_change_bit, wIndex, port_status);
}

/**
 * Save Read Only (RO) bits and save read/write bits where
 * writing a 0 clears the bit and writing a 1 sets the bit (RWS).
 * For all other types (RW1S, RW1CS, RW, and RZ), writing a '0' has no effect.
 *
 * @param state	state of the Port Status and Control Regsiter
 * @return a value that would result in the port being in the
 *	   same state, if the value was written to the port
 *	   status control register.
 */
static u32 xhci_port_state_to_neutral(u32 state)
{
	/* Save read-only status and port state */
	return (state & XHCI_PORT_RO) | (state & XHCI_PORT_RWS);
}

/**
 * Submits the Requests to the XHCI Host Controller
 *
 * @param udev pointer to the USB device structure
 * @param pipe contains the DIR_IN or OUT , devnum
 * @param buffer buffer to be read/written based on the request
 * @return returns 0 if successful else -1 on failure
 */
static int xhci_submit_root(struct usb_device *udev, unsigned long pipe,
			void *buffer, struct devrequest *req)
{
	uint8_t tmpbuf[4];
	u16 typeReq;
	void *srcptr = NULL;
	int len, srclen;
	uint32_t reg;
	volatile uint32_t *status_reg;
	struct xhci_ctrl *ctrl = udev->controller;
	struct xhci_hcor *hcor = ctrl->hcor;

	if ((req->requesttype & USB_RT_PORT) &&
	    le16_to_cpu(req->index) > CONFIG_SYS_USB_XHCI_MAX_ROOT_PORTS) {
		printf("The request port(%d) is not configured\n",
			le16_to_cpu(req->index) - 1);
		return -EINVAL;
	}

	status_reg = (volatile uint32_t *)
		     (&hcor->portregs[le16_to_cpu(req->index) - 1].or_portsc);
	srclen = 0;

	typeReq = req->request | req->requesttype << 8;

	switch (typeReq) {
	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
		switch (le16_to_cpu(req->value) >> 8) {
		case USB_DT_DEVICE:
			debug("USB_DT_DEVICE request\n");
			srcptr = &descriptor.device;
			srclen = 0x12;
			break;
		case USB_DT_CONFIG:
			debug("USB_DT_CONFIG config\n");
			srcptr = &descriptor.config;
			srclen = 0x19;
			break;
		case USB_DT_STRING:
			debug("USB_DT_STRING config\n");
			switch (le16_to_cpu(req->value) & 0xff) {
			case 0:	/* Language */
				srcptr = "\4\3\11\4";
				srclen = 4;
				break;
			case 1:	/* Vendor String  */
				srcptr = "\16\3u\0-\0b\0o\0o\0t\0";
				srclen = 14;
				break;
			case 2:	/* Product Name */
				srcptr = "\52\3X\0H\0C\0I\0 "
					 "\0H\0o\0s\0t\0 "
					 "\0C\0o\0n\0t\0r\0o\0l\0l\0e\0r\0";
				srclen = 42;
				break;
			default:
				printf("unknown value DT_STRING %x\n",
					le16_to_cpu(req->value));
				goto unknown;
			}
			break;
		default:
			printf("unknown value %x\n", le16_to_cpu(req->value));
			goto unknown;
		}
		break;
	case USB_REQ_GET_DESCRIPTOR | ((USB_DIR_IN | USB_RT_HUB) << 8):
		switch (le16_to_cpu(req->value) >> 8) {
		case USB_DT_HUB:
			debug("USB_DT_HUB config\n");
			srcptr = &descriptor.hub;
			srclen = 0x8;
			break;
		default:
			printf("unknown value %x\n", le16_to_cpu(req->value));
			goto unknown;
		}
		break;
	case USB_REQ_SET_ADDRESS | (USB_RECIP_DEVICE << 8):
		debug("USB_REQ_SET_ADDRESS\n");
		ctrl->rootdev = le16_to_cpu(req->value);
		break;
	case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
		/* Do nothing */
		break;
	case USB_REQ_GET_STATUS | ((USB_DIR_IN | USB_RT_HUB) << 8):
		tmpbuf[0] = 1;	/* USB_STATUS_SELFPOWERED */
		tmpbuf[1] = 0;
		srcptr = tmpbuf;
		srclen = 2;
		break;
	case USB_REQ_GET_STATUS | ((USB_RT_PORT | USB_DIR_IN) << 8):
		memset(tmpbuf, 0, 4);
		reg = xhci_readl(status_reg);
		if (reg & PORT_CONNECT) {
			tmpbuf[0] |= USB_PORT_STAT_CONNECTION;
			switch (reg & DEV_SPEED_MASK) {
			case XDEV_FS:
				debug("SPEED = FULLSPEED\n");
				break;
			case XDEV_LS:
				debug("SPEED = LOWSPEED\n");
				tmpbuf[1] |= USB_PORT_STAT_LOW_SPEED >> 8;
				break;
			case XDEV_HS:
				debug("SPEED = HIGHSPEED\n");
				tmpbuf[1] |= USB_PORT_STAT_HIGH_SPEED >> 8;
				break;
			case XDEV_SS:
				debug("SPEED = SUPERSPEED\n");
				tmpbuf[1] |= USB_PORT_STAT_SUPER_SPEED >> 8;
				break;
			}
		}
		if (reg & PORT_PE)
			tmpbuf[0] |= USB_PORT_STAT_ENABLE;
		if ((reg & PORT_PLS_MASK) == XDEV_U3)
			tmpbuf[0] |= USB_PORT_STAT_SUSPEND;
		if (reg & PORT_OC)
			tmpbuf[0] |= USB_PORT_STAT_OVERCURRENT;
		if (reg & PORT_RESET)
			tmpbuf[0] |= USB_PORT_STAT_RESET;
		if (reg & PORT_POWER)
			/*
			 * XXX: This Port power bit (for USB 3.0 hub)
			 * we are faking in USB 2.0 hub port status;
			 * since there's a change in bit positions in
			 * two:
			 * USB 2.0 port status PP is at position[8]
			 * USB 3.0 port status PP is at position[9]
			 * So, we are still keeping it at position [8]
			 */
			tmpbuf[1] |= USB_PORT_STAT_POWER >> 8;
		if (reg & PORT_CSC)
			tmpbuf[2] |= USB_PORT_STAT_C_CONNECTION;
		if (reg & PORT_PEC)
			tmpbuf[2] |= USB_PORT_STAT_C_ENABLE;
		if (reg & PORT_OCC)
			tmpbuf[2] |= USB_PORT_STAT_C_OVERCURRENT;
		if (reg & PORT_RC)
			tmpbuf[2] |= USB_PORT_STAT_C_RESET;

		srcptr = tmpbuf;
		srclen = 4;
		break;
	case USB_REQ_SET_FEATURE | ((USB_DIR_OUT | USB_RT_PORT) << 8):
		reg = xhci_readl(status_reg);
		reg = xhci_port_state_to_neutral(reg);
		switch (le16_to_cpu(req->value)) {
		case USB_PORT_FEAT_ENABLE:
			reg |= PORT_PE;
			xhci_writel(status_reg, reg);
			break;
		case USB_PORT_FEAT_POWER:
			reg |= PORT_POWER;
			xhci_writel(status_reg, reg);
			break;
		case USB_PORT_FEAT_RESET:
			reg |= PORT_RESET;
			xhci_writel(status_reg, reg);
			break;
		default:
			printf("unknown feature %x\n", le16_to_cpu(req->value));
			goto unknown;
		}
		break;
	case USB_REQ_CLEAR_FEATURE | ((USB_DIR_OUT | USB_RT_PORT) << 8):
		reg = xhci_readl(status_reg);
		reg = xhci_port_state_to_neutral(reg);
		switch (le16_to_cpu(req->value)) {
		case USB_PORT_FEAT_ENABLE:
			reg &= ~PORT_PE;
			break;
		case USB_PORT_FEAT_POWER:
			reg &= ~PORT_POWER;
			break;
		case USB_PORT_FEAT_C_RESET:
		case USB_PORT_FEAT_C_CONNECTION:
		case USB_PORT_FEAT_C_OVER_CURRENT:
		case USB_PORT_FEAT_C_ENABLE:
			xhci_clear_port_change_bit((le16_to_cpu(req->value)),
							le16_to_cpu(req->index),
							status_reg, reg);
			break;
		default:
			printf("unknown feature %x\n", le16_to_cpu(req->value));
			goto unknown;
		}
		xhci_writel(status_reg, reg);
		break;
	default:
		puts("Unknown request\n");
		goto unknown;
	}

	debug("scrlen = %d\n req->length = %d\n",
		srclen, le16_to_cpu(req->length));

	len = min(srclen, le16_to_cpu(req->length));

	if (srcptr != NULL && len > 0)
		memcpy(buffer, srcptr, len);
	else
		debug("Len is 0\n");

	udev->act_len = len;
	udev->status = 0;

	return 0;

unknown:
	udev->act_len = 0;
	udev->status = USB_ST_STALLED;

	return -ENODEV;
}

/**
 * Submits the INT request to XHCI Host cotroller
 *
 * @param udev	pointer to the USB device
 * @param pipe		contains the DIR_IN or OUT , devnum
 * @param buffer	buffer to be read/written based on the request
 * @param length	length of the buffer
 * @param interval	interval of the interrupt
 * @return 0
 */
int
submit_int_msg(struct usb_device *udev, unsigned long pipe, void *buffer,
						int length, int interval)
{
	/*
	 * TODO: Not addressing any interrupt type transfer requests
	 * Add support for it later.
	 */
	return -EINVAL;
}

/**
 * submit the BULK type of request to the USB Device
 *
 * @param udev	pointer to the USB device
 * @param pipe		contains the DIR_IN or OUT , devnum
 * @param buffer	buffer to be read/written based on the request
 * @param length	length of the buffer
 * @return returns 0 if successful else -1 on failure
 */
int
submit_bulk_msg(struct usb_device *udev, unsigned long pipe, void *buffer,
								int length)
{
	if (usb_pipetype(pipe) != PIPE_BULK) {
		printf("non-bulk pipe (type=%lu)", usb_pipetype(pipe));
		return -EINVAL;
	}

	return xhci_bulk_tx(udev, pipe, length, buffer);
}

/**
 * submit the control type of request to the Root hub/Device based on the devnum
 *
 * @param udev	pointer to the USB device
 * @param pipe		contains the DIR_IN or OUT , devnum
 * @param buffer	buffer to be read/written based on the request
 * @param length	length of the buffer
 * @param setup		Request type
 * @return returns 0 if successful else -1 on failure
 */
int
submit_control_msg(struct usb_device *udev, unsigned long pipe, void *buffer,
					int length, struct devrequest *setup)
{
	struct xhci_ctrl *ctrl = udev->controller;
	int ret = 0;

	if (usb_pipetype(pipe) != PIPE_CONTROL) {
		printf("non-control pipe (type=%lu)", usb_pipetype(pipe));
		return -EINVAL;
	}

	if (usb_pipedevice(pipe) == ctrl->rootdev)
		return xhci_submit_root(udev, pipe, buffer, setup);

	if (setup->request == USB_REQ_SET_ADDRESS)
		return xhci_address_device(udev);

	if (setup->request == USB_REQ_SET_CONFIGURATION) {
		ret = xhci_set_configuration(udev);
		if (ret) {
			puts("Failed to configure xHCI endpoint\n");
			return ret;
		}
	}

	return xhci_ctrl_tx(udev, pipe, setup, length, buffer);
}

/**
 * Intialises the XHCI host controller
 * and allocates the necessary data structures
 *
 * @param index	index to the host controller data structure
 * @return pointer to the intialised controller
 */
int usb_lowlevel_init(int index, enum usb_init_type init, void **controller)
{
	uint32_t val;
	uint32_t val2;
	uint32_t reg;
	struct xhci_hccr *hccr;
	struct xhci_hcor *hcor;
	struct xhci_ctrl *ctrl;

	if (xhci_hcd_init(index, &hccr, (struct xhci_hcor **)&hcor) != 0)
		return -ENODEV;

	if (xhci_reset(hcor) != 0)
		return -ENODEV;

	ctrl = &xhcic[index];

	ctrl->hccr = hccr;
	ctrl->hcor = hcor;

	/*
	 * Program the Number of Device Slots Enabled field in the CONFIG
	 * register with the max value of slots the HC can handle.
	 */
	val = (xhci_readl(&hccr->cr_hcsparams1) & HCS_SLOTS_MASK);
	val2 = xhci_readl(&hcor->or_config);
	val |= (val2 & ~HCS_SLOTS_MASK);
	xhci_writel(&hcor->or_config, val);

	/* initializing xhci data structures */
	if (xhci_mem_init(ctrl, hccr, hcor) < 0)
		return -ENOMEM;

	reg = xhci_readl(&hccr->cr_hcsparams1);
	descriptor.hub.bNbrPorts = ((reg & HCS_MAX_PORTS_MASK) >>
						HCS_MAX_PORTS_SHIFT);
	printf("Register %x NbrPorts %d\n", reg, descriptor.hub.bNbrPorts);

	/* Port Indicators */
	reg = xhci_readl(&hccr->cr_hccparams);
	if (HCS_INDICATOR(reg))
		put_unaligned(get_unaligned(&descriptor.hub.wHubCharacteristics)
				| 0x80, &descriptor.hub.wHubCharacteristics);

	/* Port Power Control */
	if (HCC_PPC(reg))
		put_unaligned(get_unaligned(&descriptor.hub.wHubCharacteristics)
				| 0x01, &descriptor.hub.wHubCharacteristics);

	if (xhci_start(hcor)) {
		xhci_reset(hcor);
		return -ENODEV;
	}

	/* Zero'ing IRQ control register and IRQ pending register */
	xhci_writel(&ctrl->ir_set->irq_control, 0x0);
	xhci_writel(&ctrl->ir_set->irq_pending, 0x0);

	reg = HC_VERSION(xhci_readl(&hccr->cr_capbase));
	printf("USB XHCI %x.%02x\n", reg >> 8, reg & 0xff);

	*controller = &xhcic[index];

	return 0;
}

/**
 * Stops the XHCI host controller
 * and cleans up all the related data structures
 *
 * @param index	index to the host controller data structure
 * @return none
 */
int usb_lowlevel_stop(int index)
{
	struct xhci_ctrl *ctrl = (xhcic + index);
	u32 temp;

	xhci_reset(ctrl->hcor);

	debug("// Disabling event ring interrupts\n");
	temp = xhci_readl(&ctrl->hcor->or_usbsts);
	xhci_writel(&ctrl->hcor->or_usbsts, temp & ~STS_EINT);
	temp = xhci_readl(&ctrl->ir_set->irq_pending);
	xhci_writel(&ctrl->ir_set->irq_pending, ER_IRQ_DISABLE(temp));

	xhci_hcd_stop(index);

	xhci_cleanup(ctrl);

	return 0;
}