Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 1148 insertions, 0 deletions

diff --git a/drivers/usb/c67x00/c67x00-sched.c b/drivers/usb/c67x00/c67x00-sched.c
new file mode 100644
index 0000000000..a09fa68a6c
--- /dev/null
+++ b/drivers/usb/c67x00/c67x00-sched.c
@@ -0,0 +1,1148 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * c67x00-sched.c: Cypress C67X00 USB Host Controller Driver - TD scheduling
+ *
+ * Copyright (C) 2006-2008 Barco N.V.
+ *    Derived from the Cypress cy7c67200/300 ezusb linux driver and
+ *    based on multiple host controller drivers inside the linux kernel.
+ */
+
+#include <linux/kthread.h>
+#include <linux/slab.h>
+
+#include "c67x00.h"
+#include "c67x00-hcd.h"
+
+/*
+ * These are the stages for a control urb, they are kept
+ * in both urb->interval and td->privdata.
+ */
+#define SETUP_STAGE		0
+#define DATA_STAGE		1
+#define STATUS_STAGE		2
+
+/* -------------------------------------------------------------------------- */
+
+/*
+ * struct c67x00_ep_data: Host endpoint data structure
+ */
+struct c67x00_ep_data {
+	struct list_head queue;
+	struct list_head node;
+	struct usb_host_endpoint *hep;
+	struct usb_device *dev;
+	u16 next_frame;		/* For int/isoc transactions */
+};
+
+/*
+ * struct c67x00_td
+ *
+ * Hardware parts are little endiannes, SW in CPU endianess.
+ */
+struct c67x00_td {
+	/* HW specific part */
+	__le16 ly_base_addr;	/* Bytes 0-1 */
+	__le16 port_length;	/* Bytes 2-3 */
+	u8 pid_ep;		/* Byte 4 */
+	u8 dev_addr;		/* Byte 5 */
+	u8 ctrl_reg;		/* Byte 6 */
+	u8 status;		/* Byte 7 */
+	u8 retry_cnt;		/* Byte 8 */
+#define TT_OFFSET		2
+#define TT_CONTROL		0
+#define TT_ISOCHRONOUS		1
+#define TT_BULK			2
+#define TT_INTERRUPT		3
+	u8 residue;		/* Byte 9 */
+	__le16 next_td_addr;	/* Bytes 10-11 */
+	/* SW part */
+	struct list_head td_list;
+	u16 td_addr;
+	void *data;
+	struct urb *urb;
+	unsigned long privdata;
+
+	/* These are needed for handling the toggle bits:
+	 * an urb can be dequeued while a td is in progress
+	 * after checking the td, the toggle bit might need to
+	 * be fixed */
+	struct c67x00_ep_data *ep_data;
+	unsigned int pipe;
+};
+
+struct c67x00_urb_priv {
+	struct list_head hep_node;
+	struct urb *urb;
+	int port;
+	int cnt;		/* packet number for isoc */
+	int status;
+	struct c67x00_ep_data *ep_data;
+};
+
+#define td_udev(td)	((td)->ep_data->dev)
+
+#define CY_TD_SIZE		12
+
+#define TD_PIDEP_OFFSET		0x04
+#define TD_PIDEPMASK_PID	0xF0
+#define TD_PIDEPMASK_EP		0x0F
+#define TD_PORTLENMASK_DL	0x03FF
+#define TD_PORTLENMASK_PN	0xC000
+
+#define TD_STATUS_OFFSET	0x07
+#define TD_STATUSMASK_ACK	0x01
+#define TD_STATUSMASK_ERR	0x02
+#define TD_STATUSMASK_TMOUT	0x04
+#define TD_STATUSMASK_SEQ	0x08
+#define TD_STATUSMASK_SETUP	0x10
+#define TD_STATUSMASK_OVF	0x20
+#define TD_STATUSMASK_NAK	0x40
+#define TD_STATUSMASK_STALL	0x80
+
+#define TD_ERROR_MASK		(TD_STATUSMASK_ERR | TD_STATUSMASK_TMOUT | \
+				 TD_STATUSMASK_STALL)
+
+#define TD_RETRYCNT_OFFSET	0x08
+#define TD_RETRYCNTMASK_ACT_FLG	0x10
+#define TD_RETRYCNTMASK_TX_TYPE	0x0C
+#define TD_RETRYCNTMASK_RTY_CNT	0x03
+
+#define TD_RESIDUE_OVERFLOW	0x80
+
+#define TD_PID_IN		0x90
+
+/* Residue: signed 8bits, neg -> OVERFLOW, pos -> UNDERFLOW */
+#define td_residue(td)		((__s8)(td->residue))
+#define td_ly_base_addr(td)	(__le16_to_cpu((td)->ly_base_addr))
+#define td_port_length(td)	(__le16_to_cpu((td)->port_length))
+#define td_next_td_addr(td)	(__le16_to_cpu((td)->next_td_addr))
+
+#define td_active(td)		((td)->retry_cnt & TD_RETRYCNTMASK_ACT_FLG)
+#define td_length(td)		(td_port_length(td) & TD_PORTLENMASK_DL)
+
+#define td_sequence_ok(td)	(!td->status || \
+				 (!(td->status & TD_STATUSMASK_SEQ) ==	\
+				  !(td->ctrl_reg & SEQ_SEL)))
+
+#define td_acked(td)		(!td->status || \
+				 (td->status & TD_STATUSMASK_ACK))
+#define td_actual_bytes(td)	(td_length(td) - td_residue(td))
+
+/* -------------------------------------------------------------------------- */
+
+/*
+ * dbg_td - Dump the contents of the TD
+ */
+static void dbg_td(struct c67x00_hcd *c67x00, struct c67x00_td *td, char *msg)
+{
+	struct device *dev = c67x00_hcd_dev(c67x00);
+
+	dev_dbg(dev, "### %s at 0x%04x\n", msg, td->td_addr);
+	dev_dbg(dev, "urb:      0x%p\n", td->urb);
+	dev_dbg(dev, "endpoint:   %4d\n", usb_pipeendpoint(td->pipe));
+	dev_dbg(dev, "pipeout:    %4d\n", usb_pipeout(td->pipe));
+	dev_dbg(dev, "ly_base_addr: 0x%04x\n", td_ly_base_addr(td));
+	dev_dbg(dev, "port_length:  0x%04x\n", td_port_length(td));
+	dev_dbg(dev, "pid_ep:         0x%02x\n", td->pid_ep);
+	dev_dbg(dev, "dev_addr:       0x%02x\n", td->dev_addr);
+	dev_dbg(dev, "ctrl_reg:       0x%02x\n", td->ctrl_reg);
+	dev_dbg(dev, "status:         0x%02x\n", td->status);
+	dev_dbg(dev, "retry_cnt:      0x%02x\n", td->retry_cnt);
+	dev_dbg(dev, "residue:        0x%02x\n", td->residue);
+	dev_dbg(dev, "next_td_addr: 0x%04x\n", td_next_td_addr(td));
+	dev_dbg(dev, "data: %*ph\n", td_length(td), td->data);
+}
+
+/* -------------------------------------------------------------------------- */
+/* Helper functions */
+
+static inline u16 c67x00_get_current_frame_number(struct c67x00_hcd *c67x00)
+{
+	return c67x00_ll_husb_get_frame(c67x00->sie) & HOST_FRAME_MASK;
+}
+
+/*
+ * frame_add
+ * Software wraparound for framenumbers.
+ */
+static inline u16 frame_add(u16 a, u16 b)
+{
+	return (a + b) & HOST_FRAME_MASK;
+}
+
+/*
+ * frame_after - is frame a after frame b
+ */
+static inline int frame_after(u16 a, u16 b)
+{
+	return ((HOST_FRAME_MASK + a - b) & HOST_FRAME_MASK) <
+	    (HOST_FRAME_MASK / 2);
+}
+
+/*
+ * frame_after_eq - is frame a after or equal to frame b
+ */
+static inline int frame_after_eq(u16 a, u16 b)
+{
+	return ((HOST_FRAME_MASK + 1 + a - b) & HOST_FRAME_MASK) <
+	    (HOST_FRAME_MASK / 2);
+}
+
+/* -------------------------------------------------------------------------- */
+
+/*
+ * c67x00_release_urb - remove link from all tds to this urb
+ * Disconnects the urb from it's tds, so that it can be given back.
+ * pre: urb->hcpriv != NULL
+ */
+static void c67x00_release_urb(struct c67x00_hcd *c67x00, struct urb *urb)
+{
+	struct c67x00_td *td;
+	struct c67x00_urb_priv *urbp;
+
+	BUG_ON(!urb);
+
+	c67x00->urb_count--;
+
+	if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
+		c67x00->urb_iso_count--;
+		if (c67x00->urb_iso_count == 0)
+			c67x00->max_frame_bw = MAX_FRAME_BW_STD;
+	}
+
+	/* TODO this might be not so efficient when we've got many urbs!
+	 * Alternatives:
+	 *   * only clear when needed
+	 *   * keep a list of tds with each urbp
+	 */
+	list_for_each_entry(td, &c67x00->td_list, td_list)
+		if (urb == td->urb)
+			td->urb = NULL;
+
+	urbp = urb->hcpriv;
+	urb->hcpriv = NULL;
+	list_del(&urbp->hep_node);
+	kfree(urbp);
+}
+
+/* -------------------------------------------------------------------------- */
+
+static struct c67x00_ep_data *
+c67x00_ep_data_alloc(struct c67x00_hcd *c67x00, struct urb *urb)
+{
+	struct usb_host_endpoint *hep = urb->ep;
+	struct c67x00_ep_data *ep_data;
+	int type;
+
+	c67x00->current_frame = c67x00_get_current_frame_number(c67x00);
+
+	/* Check if endpoint already has a c67x00_ep_data struct allocated */
+	if (hep->hcpriv) {
+		ep_data = hep->hcpriv;
+		if (frame_after(c67x00->current_frame, ep_data->next_frame))
+			ep_data->next_frame =
+			    frame_add(c67x00->current_frame, 1);
+		return hep->hcpriv;
+	}
+
+	/* Allocate and initialize a new c67x00 endpoint data structure */
+	ep_data = kzalloc(sizeof(*ep_data), GFP_ATOMIC);
+	if (!ep_data)
+		return NULL;
+
+	INIT_LIST_HEAD(&ep_data->queue);
+	INIT_LIST_HEAD(&ep_data->node);
+	ep_data->hep = hep;
+
+	/* hold a reference to udev as long as this endpoint lives,
+	 * this is needed to possibly fix the data toggle */
+	ep_data->dev = usb_get_dev(urb->dev);
+	hep->hcpriv = ep_data;
+
+	/* For ISOC and INT endpoints, start ASAP: */
+	ep_data->next_frame = frame_add(c67x00->current_frame, 1);
+
+	/* Add the endpoint data to one of the pipe lists; must be added
+	   in order of endpoint address */
+	type = usb_pipetype(urb->pipe);
+	if (list_empty(&ep_data->node)) {
+		list_add(&ep_data->node, &c67x00->list[type]);
+	} else {
+		struct c67x00_ep_data *prev;
+
+		list_for_each_entry(prev, &c67x00->list[type], node) {
+			if (prev->hep->desc.bEndpointAddress >
+			    hep->desc.bEndpointAddress) {
+				list_add(&ep_data->node, prev->node.prev);
+				break;
+			}
+		}
+	}
+
+	return ep_data;
+}
+
+static int c67x00_ep_data_free(struct usb_host_endpoint *hep)
+{
+	struct c67x00_ep_data *ep_data = hep->hcpriv;
+
+	if (!ep_data)
+		return 0;
+
+	if (!list_empty(&ep_data->queue))
+		return -EBUSY;
+
+	usb_put_dev(ep_data->dev);
+	list_del(&ep_data->queue);
+	list_del(&ep_data->node);
+
+	kfree(ep_data);
+	hep->hcpriv = NULL;
+
+	return 0;
+}
+
+void c67x00_endpoint_disable(struct usb_hcd *hcd, struct usb_host_endpoint *ep)
+{
+	struct c67x00_hcd *c67x00 = hcd_to_c67x00_hcd(hcd);
+	unsigned long flags;
+
+	if (!list_empty(&ep->urb_list))
+		dev_warn(c67x00_hcd_dev(c67x00), "error: urb list not empty\n");
+
+	spin_lock_irqsave(&c67x00->lock, flags);
+
+	/* loop waiting for all transfers in the endpoint queue to complete */
+	while (c67x00_ep_data_free(ep)) {
+		/* Drop the lock so we can sleep waiting for the hardware */
+		spin_unlock_irqrestore(&c67x00->lock, flags);
+
+		/* it could happen that we reinitialize this completion, while
+		 * somebody was waiting for that completion.  The timeout and
+		 * while loop handle such cases, but this might be improved */
+		reinit_completion(&c67x00->endpoint_disable);
+		c67x00_sched_kick(c67x00);
+		wait_for_completion_timeout(&c67x00->endpoint_disable, 1 * HZ);
+
+		spin_lock_irqsave(&c67x00->lock, flags);
+	}
+
+	spin_unlock_irqrestore(&c67x00->lock, flags);
+}
+
+/* -------------------------------------------------------------------------- */
+
+static inline int get_root_port(struct usb_device *dev)
+{
+	while (dev->parent->parent)
+		dev = dev->parent;
+	return dev->portnum;
+}
+
+int c67x00_urb_enqueue(struct usb_hcd *hcd,
+		       struct urb *urb, gfp_t mem_flags)
+{
+	int ret;
+	unsigned long flags;
+	struct c67x00_urb_priv *urbp;
+	struct c67x00_hcd *c67x00 = hcd_to_c67x00_hcd(hcd);
+	int port = get_root_port(urb->dev)-1;
+
+	/* Allocate and initialize urb private data */
+	urbp = kzalloc(sizeof(*urbp), mem_flags);
+	if (!urbp) {
+		ret = -ENOMEM;
+		goto err_urbp;
+	}
+
+	spin_lock_irqsave(&c67x00->lock, flags);
+
+	/* Make sure host controller is running */
+	if (!HC_IS_RUNNING(hcd->state)) {
+		ret = -ENODEV;
+		goto err_not_linked;
+	}
+
+	ret = usb_hcd_link_urb_to_ep(hcd, urb);
+	if (ret)
+		goto err_not_linked;
+
+	INIT_LIST_HEAD(&urbp->hep_node);
+	urbp->urb = urb;
+	urbp->port = port;
+
+	urbp->ep_data = c67x00_ep_data_alloc(c67x00, urb);
+
+	if (!urbp->ep_data) {
+		ret = -ENOMEM;
+		goto err_epdata;
+	}
+
+	/* TODO claim bandwidth with usb_claim_bandwidth?
+	 * also release it somewhere! */
+
+	urb->hcpriv = urbp;
+
+	urb->actual_length = 0;	/* Nothing received/transmitted yet */
+
+	switch (usb_pipetype(urb->pipe)) {
+	case PIPE_CONTROL:
+		urb->interval = SETUP_STAGE;
+		break;
+	case PIPE_INTERRUPT:
+		break;
+	case PIPE_BULK:
+		break;
+	case PIPE_ISOCHRONOUS:
+		if (c67x00->urb_iso_count == 0)
+			c67x00->max_frame_bw = MAX_FRAME_BW_ISO;
+		c67x00->urb_iso_count++;
+		/* Assume always URB_ISO_ASAP, FIXME */
+		if (list_empty(&urbp->ep_data->queue))
+			urb->start_frame = urbp->ep_data->next_frame;
+		else {
+			/* Go right after the last one */
+			struct urb *last_urb;
+
+			last_urb = list_entry(urbp->ep_data->queue.prev,
+					      struct c67x00_urb_priv,
+					      hep_node)->urb;
+			urb->start_frame =
+			    frame_add(last_urb->start_frame,
+				      last_urb->number_of_packets *
+				      last_urb->interval);
+		}
+		urbp->cnt = 0;
+		break;
+	}
+
+	/* Add the URB to the endpoint queue */
+	list_add_tail(&urbp->hep_node, &urbp->ep_data->queue);
+
+	/* If this is the only URB, kick start the controller */
+	if (!c67x00->urb_count++)
+		c67x00_ll_hpi_enable_sofeop(c67x00->sie);
+
+	c67x00_sched_kick(c67x00);
+	spin_unlock_irqrestore(&c67x00->lock, flags);
+
+	return 0;
+
+err_epdata:
+	usb_hcd_unlink_urb_from_ep(hcd, urb);
+err_not_linked:
+	spin_unlock_irqrestore(&c67x00->lock, flags);
+	kfree(urbp);
+err_urbp:
+
+	return ret;
+}
+
+int c67x00_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
+{
+	struct c67x00_hcd *c67x00 = hcd_to_c67x00_hcd(hcd);
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(&c67x00->lock, flags);
+	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
+	if (rc)
+		goto done;
+
+	c67x00_release_urb(c67x00, urb);
+	usb_hcd_unlink_urb_from_ep(hcd, urb);
+
+	spin_unlock(&c67x00->lock);
+	usb_hcd_giveback_urb(hcd, urb, status);
+	spin_lock(&c67x00->lock);
+
+	spin_unlock_irqrestore(&c67x00->lock, flags);
+
+	return 0;
+
+ done:
+	spin_unlock_irqrestore(&c67x00->lock, flags);
+	return rc;
+}
+
+/* -------------------------------------------------------------------------- */
+
+/*
+ * pre: c67x00 locked, urb unlocked
+ */
+static void
+c67x00_giveback_urb(struct c67x00_hcd *c67x00, struct urb *urb, int status)
+{
+	struct c67x00_urb_priv *urbp;
+
+	if (!urb)
+		return;
+
+	urbp = urb->hcpriv;
+	urbp->status = status;
+
+	list_del_init(&urbp->hep_node);
+
+	c67x00_release_urb(c67x00, urb);
+	usb_hcd_unlink_urb_from_ep(c67x00_hcd_to_hcd(c67x00), urb);
+	spin_unlock(&c67x00->lock);
+	usb_hcd_giveback_urb(c67x00_hcd_to_hcd(c67x00), urb, status);
+	spin_lock(&c67x00->lock);
+}
+
+/* -------------------------------------------------------------------------- */
+
+static int c67x00_claim_frame_bw(struct c67x00_hcd *c67x00, struct urb *urb,
+				 int len, int periodic)
+{
+	struct c67x00_urb_priv *urbp = urb->hcpriv;
+	int bit_time;
+
+	/* According to the C67x00 BIOS user manual, page 3-18,19, the
+	 * following calculations provide the full speed bit times for
+	 * a transaction.
+	 *
+	 * FS(in)	= 112.5 +  9.36*BC + HOST_DELAY
+	 * FS(in,iso)	=  90.5 +  9.36*BC + HOST_DELAY
+	 * FS(out)	= 112.5 +  9.36*BC + HOST_DELAY
+	 * FS(out,iso)	=  78.4 +  9.36*BC + HOST_DELAY
+	 * LS(in)	= 802.4 + 75.78*BC + HOST_DELAY
+	 * LS(out)	= 802.6 + 74.67*BC + HOST_DELAY
+	 *
+	 * HOST_DELAY == 106 for the c67200 and c67300.
+	 */
+
+	/* make calculations in 1/100 bit times to maintain resolution */
+	if (urbp->ep_data->dev->speed == USB_SPEED_LOW) {
+		/* Low speed pipe */
+		if (usb_pipein(urb->pipe))
+			bit_time = 80240 + 7578*len;
+		else
+			bit_time = 80260 + 7467*len;
+	} else {
+		/* FS pipes */
+		if (usb_pipeisoc(urb->pipe))
+			bit_time = usb_pipein(urb->pipe) ? 9050 : 7840;
+		else
+			bit_time = 11250;
+		bit_time += 936*len;
+	}
+
+	/* Scale back down to integer bit times.  Use a host delay of 106.
+	 * (this is the only place it is used) */
+	bit_time = ((bit_time+50) / 100) + 106;
+
+	if (unlikely(bit_time + c67x00->bandwidth_allocated >=
+		     c67x00->max_frame_bw))
+		return -EMSGSIZE;
+
+	if (unlikely(c67x00->next_td_addr + CY_TD_SIZE >=
+		     c67x00->td_base_addr + SIE_TD_SIZE))
+		return -EMSGSIZE;
+
+	if (unlikely(c67x00->next_buf_addr + len >=
+		     c67x00->buf_base_addr + SIE_TD_BUF_SIZE))
+		return -EMSGSIZE;
+
+	if (periodic) {
+		if (unlikely(bit_time + c67x00->periodic_bw_allocated >=
+			     MAX_PERIODIC_BW(c67x00->max_frame_bw)))
+			return -EMSGSIZE;
+		c67x00->periodic_bw_allocated += bit_time;
+	}
+
+	c67x00->bandwidth_allocated += bit_time;
+	return 0;
+}
+
+/* -------------------------------------------------------------------------- */
+
+/*
+ * td_addr and buf_addr must be word aligned
+ */
+static int c67x00_create_td(struct c67x00_hcd *c67x00, struct urb *urb,
+			    void *data, int len, int pid, int toggle,
+			    unsigned long privdata)
+{
+	struct c67x00_td *td;
+	struct c67x00_urb_priv *urbp = urb->hcpriv;
+	const __u8 active_flag = 1, retry_cnt = 3;
+	__u8 cmd = 0;
+	int tt = 0;
+
+	if (c67x00_claim_frame_bw(c67x00, urb, len, usb_pipeisoc(urb->pipe)
+				  || usb_pipeint(urb->pipe)))
+		return -EMSGSIZE;	/* Not really an error, but expected */
+
+	td = kzalloc(sizeof(*td), GFP_ATOMIC);
+	if (!td)
+		return -ENOMEM;
+
+	td->pipe = urb->pipe;
+	td->ep_data = urbp->ep_data;
+
+	if ((td_udev(td)->speed == USB_SPEED_LOW) &&
+	    !(c67x00->low_speed_ports & (1 << urbp->port)))
+		cmd |= PREAMBLE_EN;
+
+	switch (usb_pipetype(td->pipe)) {
+	case PIPE_ISOCHRONOUS:
+		tt = TT_ISOCHRONOUS;
+		cmd |= ISO_EN;
+		break;
+	case PIPE_CONTROL:
+		tt = TT_CONTROL;
+		break;
+	case PIPE_BULK:
+		tt = TT_BULK;
+		break;
+	case PIPE_INTERRUPT:
+		tt = TT_INTERRUPT;
+		break;
+	}
+
+	if (toggle)
+		cmd |= SEQ_SEL;
+
+	cmd |= ARM_EN;
+
+	/* SW part */
+	td->td_addr = c67x00->next_td_addr;
+	c67x00->next_td_addr = c67x00->next_td_addr + CY_TD_SIZE;
+
+	/* HW part */
+	td->ly_base_addr = __cpu_to_le16(c67x00->next_buf_addr);
+	td->port_length = __cpu_to_le16((c67x00->sie->sie_num << 15) |
+					(urbp->port << 14) | (len & 0x3FF));
+	td->pid_ep = ((pid & 0xF) << TD_PIDEP_OFFSET) |
+	    (usb_pipeendpoint(td->pipe) & 0xF);
+	td->dev_addr = usb_pipedevice(td->pipe) & 0x7F;
+	td->ctrl_reg = cmd;
+	td->status = 0;
+	td->retry_cnt = (tt << TT_OFFSET) | (active_flag << 4) | retry_cnt;
+	td->residue = 0;
+	td->next_td_addr = __cpu_to_le16(c67x00->next_td_addr);
+
+	/* SW part */
+	td->data = data;
+	td->urb = urb;
+	td->privdata = privdata;
+
+	c67x00->next_buf_addr += (len + 1) & ~0x01;	/* properly align */
+
+	list_add_tail(&td->td_list, &c67x00->td_list);
+	return 0;
+}
+
+static inline void c67x00_release_td(struct c67x00_td *td)
+{
+	list_del_init(&td->td_list);
+	kfree(td);
+}
+
+/* -------------------------------------------------------------------------- */
+
+static int c67x00_add_data_urb(struct c67x00_hcd *c67x00, struct urb *urb)
+{
+	int remaining;
+	int toggle;
+	int pid;
+	int ret = 0;
+	int maxps;
+	int need_empty;
+
+	toggle = usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
+			       usb_pipeout(urb->pipe));
+	remaining = urb->transfer_buffer_length - urb->actual_length;
+
+	maxps = usb_maxpacket(urb->dev, urb->pipe);
+
+	need_empty = (urb->transfer_flags & URB_ZERO_PACKET) &&
+	    usb_pipeout(urb->pipe) && !(remaining % maxps);
+
+	while (remaining || need_empty) {
+		int len;
+		char *td_buf;
+
+		len = (remaining > maxps) ? maxps : remaining;
+		if (!len)
+			need_empty = 0;
+
+		pid = usb_pipeout(urb->pipe) ? USB_PID_OUT : USB_PID_IN;
+		td_buf = urb->transfer_buffer + urb->transfer_buffer_length -
+		    remaining;
+		ret = c67x00_create_td(c67x00, urb, td_buf, len, pid, toggle,
+				       DATA_STAGE);
+		if (ret)
+			return ret;	/* td wasn't created */
+
+		toggle ^= 1;
+		remaining -= len;
+		if (usb_pipecontrol(urb->pipe))
+			break;
+	}
+
+	return 0;
+}
+
+/*
+ * return 0 in case more bandwidth is available, else errorcode
+ */
+static int c67x00_add_ctrl_urb(struct c67x00_hcd *c67x00, struct urb *urb)
+{
+	int ret;
+	int pid;
+
+	switch (urb->interval) {
+	default:
+	case SETUP_STAGE:
+		ret = c67x00_create_td(c67x00, urb, urb->setup_packet,
+				       8, USB_PID_SETUP, 0, SETUP_STAGE);
+		if (ret)
+			return ret;
+		urb->interval = SETUP_STAGE;
+		usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
+			      usb_pipeout(urb->pipe), 1);
+		break;
+	case DATA_STAGE:
+		if (urb->transfer_buffer_length) {
+			ret = c67x00_add_data_urb(c67x00, urb);
+			if (ret)
+				return ret;
+			break;
+		}
+		fallthrough;
+	case STATUS_STAGE:
+		pid = !usb_pipeout(urb->pipe) ? USB_PID_OUT : USB_PID_IN;
+		ret = c67x00_create_td(c67x00, urb, NULL, 0, pid, 1,
+				       STATUS_STAGE);
+		if (ret)
+			return ret;
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * return 0 in case more bandwidth is available, else errorcode
+ */
+static int c67x00_add_int_urb(struct c67x00_hcd *c67x00, struct urb *urb)
+{
+	struct c67x00_urb_priv *urbp = urb->hcpriv;
+
+	if (frame_after_eq(c67x00->current_frame, urbp->ep_data->next_frame)) {
+		urbp->ep_data->next_frame =
+		    frame_add(urbp->ep_data->next_frame, urb->interval);
+		return c67x00_add_data_urb(c67x00, urb);
+	}
+	return 0;
+}
+
+static int c67x00_add_iso_urb(struct c67x00_hcd *c67x00, struct urb *urb)
+{
+	struct c67x00_urb_priv *urbp = urb->hcpriv;
+
+	if (frame_after_eq(c67x00->current_frame, urbp->ep_data->next_frame)) {
+		char *td_buf;
+		int len, pid, ret;
+
+		BUG_ON(urbp->cnt >= urb->number_of_packets);
+
+		td_buf = urb->transfer_buffer +
+		    urb->iso_frame_desc[urbp->cnt].offset;
+		len = urb->iso_frame_desc[urbp->cnt].length;
+		pid = usb_pipeout(urb->pipe) ? USB_PID_OUT : USB_PID_IN;
+
+		ret = c67x00_create_td(c67x00, urb, td_buf, len, pid, 0,
+				       urbp->cnt);
+		if (ret) {
+			dev_dbg(c67x00_hcd_dev(c67x00), "create failed: %d\n",
+				ret);
+			urb->iso_frame_desc[urbp->cnt].actual_length = 0;
+			urb->iso_frame_desc[urbp->cnt].status = ret;
+			if (urbp->cnt + 1 == urb->number_of_packets)
+				c67x00_giveback_urb(c67x00, urb, 0);
+		}
+
+		urbp->ep_data->next_frame =
+		    frame_add(urbp->ep_data->next_frame, urb->interval);
+		urbp->cnt++;
+	}
+	return 0;
+}
+
+/* -------------------------------------------------------------------------- */
+
+static void c67x00_fill_from_list(struct c67x00_hcd *c67x00, int type,
+				  int (*add)(struct c67x00_hcd *, struct urb *))
+{
+	struct c67x00_ep_data *ep_data;
+	struct urb *urb;
+
+	/* traverse every endpoint on the list */
+	list_for_each_entry(ep_data, &c67x00->list[type], node) {
+		if (!list_empty(&ep_data->queue)) {
+			/* and add the first urb */
+			/* isochronous transfer rely on this */
+			urb = list_entry(ep_data->queue.next,
+					 struct c67x00_urb_priv,
+					 hep_node)->urb;
+			add(c67x00, urb);
+		}
+	}
+}
+
+static void c67x00_fill_frame(struct c67x00_hcd *c67x00)
+{
+	struct c67x00_td *td, *ttd;
+
+	/* Check if we can proceed */
+	if (!list_empty(&c67x00->td_list)) {
+		dev_warn(c67x00_hcd_dev(c67x00),
+			 "TD list not empty! This should not happen!\n");
+		list_for_each_entry_safe(td, ttd, &c67x00->td_list, td_list) {
+			dbg_td(c67x00, td, "Unprocessed td");
+			c67x00_release_td(td);
+		}
+	}
+
+	/* Reinitialize variables */
+	c67x00->bandwidth_allocated = 0;
+	c67x00->periodic_bw_allocated = 0;
+
+	c67x00->next_td_addr = c67x00->td_base_addr;
+	c67x00->next_buf_addr = c67x00->buf_base_addr;
+
+	/* Fill the list */
+	c67x00_fill_from_list(c67x00, PIPE_ISOCHRONOUS, c67x00_add_iso_urb);
+	c67x00_fill_from_list(c67x00, PIPE_INTERRUPT, c67x00_add_int_urb);
+	c67x00_fill_from_list(c67x00, PIPE_CONTROL, c67x00_add_ctrl_urb);
+	c67x00_fill_from_list(c67x00, PIPE_BULK, c67x00_add_data_urb);
+}
+
+/* -------------------------------------------------------------------------- */
+
+/*
+ * Get TD from C67X00
+ */
+static inline void
+c67x00_parse_td(struct c67x00_hcd *c67x00, struct c67x00_td *td)
+{
+	c67x00_ll_read_mem_le16(c67x00->sie->dev,
+				td->td_addr, td, CY_TD_SIZE);
+
+	if (usb_pipein(td->pipe) && td_actual_bytes(td))
+		c67x00_ll_read_mem_le16(c67x00->sie->dev, td_ly_base_addr(td),
+					td->data, td_actual_bytes(td));
+}
+
+static int c67x00_td_to_error(struct c67x00_hcd *c67x00, struct c67x00_td *td)
+{
+	if (td->status & TD_STATUSMASK_ERR) {
+		dbg_td(c67x00, td, "ERROR_FLAG");
+		return -EILSEQ;
+	}
+	if (td->status & TD_STATUSMASK_STALL) {
+		/* dbg_td(c67x00, td, "STALL"); */
+		return -EPIPE;
+	}
+	if (td->status & TD_STATUSMASK_TMOUT) {
+		dbg_td(c67x00, td, "TIMEOUT");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static inline int c67x00_end_of_data(struct c67x00_td *td)
+{
+	int maxps, need_empty, remaining;
+	struct urb *urb = td->urb;
+	int act_bytes;
+
+	act_bytes = td_actual_bytes(td);
+
+	if (unlikely(!act_bytes))
+		return 1;	/* This was an empty packet */
+
+	maxps = usb_maxpacket(td_udev(td), td->pipe);
+
+	if (unlikely(act_bytes < maxps))
+		return 1;	/* Smaller then full packet */
+
+	remaining = urb->transfer_buffer_length - urb->actual_length;
+	need_empty = (urb->transfer_flags & URB_ZERO_PACKET) &&
+	    usb_pipeout(urb->pipe) && !(remaining % maxps);
+
+	if (unlikely(!remaining && !need_empty))
+		return 1;
+
+	return 0;
+}
+
+/* -------------------------------------------------------------------------- */
+
+/* Remove all td's from the list which come
+ * after last_td and are meant for the same pipe.
+ * This is used when a short packet has occurred */
+static inline void c67x00_clear_pipe(struct c67x00_hcd *c67x00,
+				     struct c67x00_td *last_td)
+{
+	struct c67x00_td *td, *tmp;
+	td = last_td;
+	tmp = last_td;
+	while (td->td_list.next != &c67x00->td_list) {
+		td = list_entry(td->td_list.next, struct c67x00_td, td_list);
+		if (td->pipe == last_td->pipe) {
+			c67x00_release_td(td);
+			td = tmp;
+		}
+		tmp = td;
+	}
+}
+
+/* -------------------------------------------------------------------------- */
+
+static void c67x00_handle_successful_td(struct c67x00_hcd *c67x00,
+					struct c67x00_td *td)
+{
+	struct urb *urb = td->urb;
+
+	if (!urb)
+		return;
+
+	urb->actual_length += td_actual_bytes(td);
+
+	switch (usb_pipetype(td->pipe)) {
+		/* isochronous tds are handled separately */
+	case PIPE_CONTROL:
+		switch (td->privdata) {
+		case SETUP_STAGE:
+			urb->interval =
+			    urb->transfer_buffer_length ?
+			    DATA_STAGE : STATUS_STAGE;
+			/* Don't count setup_packet with normal data: */
+			urb->actual_length = 0;
+			break;
+
+		case DATA_STAGE:
+			if (c67x00_end_of_data(td)) {
+				urb->interval = STATUS_STAGE;
+				c67x00_clear_pipe(c67x00, td);
+			}
+			break;
+
+		case STATUS_STAGE:
+			urb->interval = 0;
+			c67x00_giveback_urb(c67x00, urb, 0);
+			break;
+		}
+		break;
+
+	case PIPE_INTERRUPT:
+	case PIPE_BULK:
+		if (unlikely(c67x00_end_of_data(td))) {
+			c67x00_clear_pipe(c67x00, td);
+			c67x00_giveback_urb(c67x00, urb, 0);
+		}
+		break;
+	}
+}
+
+static void c67x00_handle_isoc(struct c67x00_hcd *c67x00, struct c67x00_td *td)
+{
+	struct urb *urb = td->urb;
+	int cnt;
+
+	if (!urb)
+		return;
+
+	cnt = td->privdata;
+
+	if (td->status & TD_ERROR_MASK)
+		urb->error_count++;
+
+	urb->iso_frame_desc[cnt].actual_length = td_actual_bytes(td);
+	urb->iso_frame_desc[cnt].status = c67x00_td_to_error(c67x00, td);
+	if (cnt + 1 == urb->number_of_packets)	/* Last packet */
+		c67x00_giveback_urb(c67x00, urb, 0);
+}
+
+/* -------------------------------------------------------------------------- */
+
+/*
+ * c67x00_check_td_list - handle tds which have been processed by the c67x00
+ * pre: current_td == 0
+ */
+static inline void c67x00_check_td_list(struct c67x00_hcd *c67x00)
+{
+	struct c67x00_td *td, *tmp;
+	struct urb *urb;
+	int ack_ok;
+	int clear_endpoint;
+
+	list_for_each_entry_safe(td, tmp, &c67x00->td_list, td_list) {
+		/* get the TD */
+		c67x00_parse_td(c67x00, td);
+		urb = td->urb;	/* urb can be NULL! */
+		ack_ok = 0;
+		clear_endpoint = 1;
+
+		/* Handle isochronous transfers separately */
+		if (usb_pipeisoc(td->pipe)) {
+			clear_endpoint = 0;
+			c67x00_handle_isoc(c67x00, td);
+			goto cont;
+		}
+
+		/* When an error occurs, all td's for that pipe go into an
+		 * inactive state. This state matches successful transfers so
+		 * we must make sure not to service them. */
+		if (td->status & TD_ERROR_MASK) {
+			c67x00_giveback_urb(c67x00, urb,
+					    c67x00_td_to_error(c67x00, td));
+			goto cont;
+		}
+
+		if ((td->status & TD_STATUSMASK_NAK) || !td_sequence_ok(td) ||
+		    !td_acked(td))
+			goto cont;
+
+		/* Sequence ok and acked, don't need to fix toggle */
+		ack_ok = 1;
+
+		if (unlikely(td->status & TD_STATUSMASK_OVF)) {
+			if (td_residue(td) & TD_RESIDUE_OVERFLOW) {
+				/* Overflow */
+				c67x00_giveback_urb(c67x00, urb, -EOVERFLOW);
+				goto cont;
+			}
+		}
+
+		clear_endpoint = 0;
+		c67x00_handle_successful_td(c67x00, td);
+
+cont:
+		if (clear_endpoint)
+			c67x00_clear_pipe(c67x00, td);
+		if (ack_ok)
+			usb_settoggle(td_udev(td), usb_pipeendpoint(td->pipe),
+				      usb_pipeout(td->pipe),
+				      !(td->ctrl_reg & SEQ_SEL));
+		/* next in list could have been removed, due to clear_pipe! */
+		tmp = list_entry(td->td_list.next, typeof(*td), td_list);
+		c67x00_release_td(td);
+	}
+}
+
+/* -------------------------------------------------------------------------- */
+
+static inline int c67x00_all_tds_processed(struct c67x00_hcd *c67x00)
+{
+	/* If all tds are processed, we can check the previous frame (if
+	 * there was any) and start our next frame.
+	 */
+	return !c67x00_ll_husb_get_current_td(c67x00->sie);
+}
+
+/*
+ * Send td to C67X00
+ */
+static void c67x00_send_td(struct c67x00_hcd *c67x00, struct c67x00_td *td)
+{
+	int len = td_length(td);
+
+	if (len && ((td->pid_ep & TD_PIDEPMASK_PID) != TD_PID_IN))
+		c67x00_ll_write_mem_le16(c67x00->sie->dev, td_ly_base_addr(td),
+					 td->data, len);
+
+	c67x00_ll_write_mem_le16(c67x00->sie->dev,
+				 td->td_addr, td, CY_TD_SIZE);
+}
+
+static void c67x00_send_frame(struct c67x00_hcd *c67x00)
+{
+	struct c67x00_td *td;
+
+	if (list_empty(&c67x00->td_list))
+		dev_warn(c67x00_hcd_dev(c67x00),
+			 "%s: td list should not be empty here!\n",
+			 __func__);
+
+	list_for_each_entry(td, &c67x00->td_list, td_list) {
+		if (td->td_list.next == &c67x00->td_list)
+			td->next_td_addr = 0;	/* Last td in list */
+
+		c67x00_send_td(c67x00, td);
+	}
+
+	c67x00_ll_husb_set_current_td(c67x00->sie, c67x00->td_base_addr);
+}
+
+/* -------------------------------------------------------------------------- */
+
+/*
+ * c67x00_do_work - Schedulers state machine
+ */
+static void c67x00_do_work(struct c67x00_hcd *c67x00)
+{
+	spin_lock(&c67x00->lock);
+	/* Make sure all tds are processed */
+	if (!c67x00_all_tds_processed(c67x00))
+		goto out;
+
+	c67x00_check_td_list(c67x00);
+
+	/* no td's are being processed (current == 0)
+	 * and all have been "checked" */
+	complete(&c67x00->endpoint_disable);
+
+	if (!list_empty(&c67x00->td_list))
+		goto out;
+
+	c67x00->current_frame = c67x00_get_current_frame_number(c67x00);
+	if (c67x00->current_frame == c67x00->last_frame)
+		goto out;	/* Don't send tds in same frame */
+	c67x00->last_frame = c67x00->current_frame;
+
+	/* If no urbs are scheduled, our work is done */
+	if (!c67x00->urb_count) {
+		c67x00_ll_hpi_disable_sofeop(c67x00->sie);
+		goto out;
+	}
+
+	c67x00_fill_frame(c67x00);
+	if (!list_empty(&c67x00->td_list))
+		/* TD's have been added to the frame */
+		c67x00_send_frame(c67x00);
+
+ out:
+	spin_unlock(&c67x00->lock);
+}
+
+/* -------------------------------------------------------------------------- */
+
+static void c67x00_sched_work(struct work_struct *work)
+{
+	struct c67x00_hcd *c67x00;
+
+	c67x00 = container_of(work, struct c67x00_hcd, work);
+	c67x00_do_work(c67x00);
+}
+
+void c67x00_sched_kick(struct c67x00_hcd *c67x00)
+{
+	queue_work(system_highpri_wq, &c67x00->work);
+}
+
+int c67x00_sched_start_scheduler(struct c67x00_hcd *c67x00)
+{
+	INIT_WORK(&c67x00->work, c67x00_sched_work);
+	return 0;
+}
+
+void c67x00_sched_stop_scheduler(struct c67x00_hcd *c67x00)
+{
+	cancel_work_sync(&c67x00->work);
+}