u-boot/drivers/usb/host/xhci-ring.c

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/*
* 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+
*/
#include <common.h>
#include <asm/byteorder.h>
#include <usb.h>
#include <asm/unaligned.h>
#include <linux/errno.h>
#include "xhci.h"
/**
* Is this TRB a link TRB or was the last TRB the last TRB in this event ring
* segment? I.e. would the updated event TRB pointer step off the end of the
* event seg ?
*
* @param ctrl Host controller data structure
* @param ring pointer to the ring
* @param seg poniter to the segment to which TRB belongs
* @param trb poniter to the ring trb
* @return 1 if this TRB a link TRB else 0
*/
static int last_trb(struct xhci_ctrl *ctrl, struct xhci_ring *ring,
struct xhci_segment *seg, union xhci_trb *trb)
{
if (ring == ctrl->event_ring)
return trb == &seg->trbs[TRBS_PER_SEGMENT];
else
return TRB_TYPE_LINK_LE32(trb->link.control);
}
/**
* Does this link TRB point to the first segment in a ring,
* or was the previous TRB the last TRB on the last segment in the ERST?
*
* @param ctrl Host controller data structure
* @param ring pointer to the ring
* @param seg poniter to the segment to which TRB belongs
* @param trb poniter to the ring trb
* @return 1 if this TRB is the last TRB on the last segment else 0
*/
static bool last_trb_on_last_seg(struct xhci_ctrl *ctrl,
struct xhci_ring *ring,
struct xhci_segment *seg,
union xhci_trb *trb)
{
if (ring == ctrl->event_ring)
return ((trb == &seg->trbs[TRBS_PER_SEGMENT]) &&
(seg->next == ring->first_seg));
else
return le32_to_cpu(trb->link.control) & LINK_TOGGLE;
}
/**
* See Cycle bit rules. SW is the consumer for the event ring only.
* Don't make a ring full of link TRBs. That would be dumb and this would loop.
*
* If we've just enqueued a TRB that is in the middle of a TD (meaning the
* chain bit is set), then set the chain bit in all the following link TRBs.
* If we've enqueued the last TRB in a TD, make sure the following link TRBs
* have their chain bit cleared (so that each Link TRB is a separate TD).
*
* Section 6.4.4.1 of the 0.95 spec says link TRBs cannot have the chain bit
* set, but other sections talk about dealing with the chain bit set. This was
* fixed in the 0.96 specification errata, but we have to assume that all 0.95
* xHCI hardware can't handle the chain bit being cleared on a link TRB.
*
* @param ctrl Host controller data structure
* @param ring pointer to the ring
* @param more_trbs_coming flag to indicate whether more trbs
* are expected or NOT.
* Will you enqueue more TRBs before calling
* prepare_ring()?
* @return none
*/
static void inc_enq(struct xhci_ctrl *ctrl, struct xhci_ring *ring,
bool more_trbs_coming)
{
u32 chain;
union xhci_trb *next;
chain = le32_to_cpu(ring->enqueue->generic.field[3]) & TRB_CHAIN;
next = ++(ring->enqueue);
/*
* Update the dequeue pointer further if that was a link TRB or we're at
* the end of an event ring segment (which doesn't have link TRBS)
*/
while (last_trb(ctrl, ring, ring->enq_seg, next)) {
if (ring != ctrl->event_ring) {
/*
* If the caller doesn't plan on enqueueing more
* TDs before ringing the doorbell, then we
* don't want to give the link TRB to the
* hardware just yet. We'll give the link TRB
* back in prepare_ring() just before we enqueue
* the TD at the top of the ring.
*/
if (!chain && !more_trbs_coming)
break;
/*
* If we're not dealing with 0.95 hardware or
* isoc rings on AMD 0.96 host,
* carry over the chain bit of the previous TRB
* (which may mean the chain bit is cleared).
*/
next->link.control &= cpu_to_le32(~TRB_CHAIN);
next->link.control |= cpu_to_le32(chain);
next->link.control ^= cpu_to_le32(TRB_CYCLE);
xhci_flush_cache((uintptr_t)next,
sizeof(union xhci_trb));
}
/* Toggle the cycle bit after the last ring segment. */
if (last_trb_on_last_seg(ctrl, ring,
ring->enq_seg, next))
ring->cycle_state = (ring->cycle_state ? 0 : 1);
ring->enq_seg = ring->enq_seg->next;
ring->enqueue = ring->enq_seg->trbs;
next = ring->enqueue;
}
}
/**
* See Cycle bit rules. SW is the consumer for the event ring only.
* Don't make a ring full of link TRBs. That would be dumb and this would loop.
*
* @param ctrl Host controller data structure
* @param ring Ring whose Dequeue TRB pointer needs to be incremented.
* return none
*/
static void inc_deq(struct xhci_ctrl *ctrl, struct xhci_ring *ring)
{
do {
/*
* Update the dequeue pointer further if that was a link TRB or
* we're at the end of an event ring segment (which doesn't have
* link TRBS)
*/
if (last_trb(ctrl, ring, ring->deq_seg, ring->dequeue)) {
if (ring == ctrl->event_ring &&
last_trb_on_last_seg(ctrl, ring,
ring->deq_seg, ring->dequeue)) {
ring->cycle_state = (ring->cycle_state ? 0 : 1);
}
ring->deq_seg = ring->deq_seg->next;
ring->dequeue = ring->deq_seg->trbs;
} else {
ring->dequeue++;
}
} while (last_trb(ctrl, ring, ring->deq_seg, ring->dequeue));
}
/**
* Generic function for queueing a TRB on a ring.
* The caller must have checked to make sure there's room on the ring.
*
* @param more_trbs_coming: Will you enqueue more TRBs before calling
* prepare_ring()?
* @param ctrl Host controller data structure
* @param ring pointer to the ring
* @param more_trbs_coming flag to indicate whether more trbs
* @param trb_fields pointer to trb field array containing TRB contents
* @return pointer to the enqueued trb
*/
static struct xhci_generic_trb *queue_trb(struct xhci_ctrl *ctrl,
struct xhci_ring *ring,
bool more_trbs_coming,
unsigned int *trb_fields)
{
struct xhci_generic_trb *trb;
int i;
trb = &ring->enqueue->generic;
for (i = 0; i < 4; i++)
trb->field[i] = cpu_to_le32(trb_fields[i]);
xhci_flush_cache((uintptr_t)trb, sizeof(struct xhci_generic_trb));
inc_enq(ctrl, ring, more_trbs_coming);
return trb;
}
/**
* Does various checks on the endpoint ring, and makes it ready
* to queue num_trbs.
*
* @param ctrl Host controller data structure
* @param ep_ring pointer to the EP Transfer Ring
* @param ep_state State of the End Point
* @return error code in case of invalid ep_state, 0 on success
*/
static int prepare_ring(struct xhci_ctrl *ctrl, struct xhci_ring *ep_ring,
u32 ep_state)
{
union xhci_trb *next = ep_ring->enqueue;
/* Make sure the endpoint has been added to xHC schedule */
switch (ep_state) {
case EP_STATE_DISABLED:
/*
* USB core changed config/interfaces without notifying us,
* or hardware is reporting the wrong state.
*/
puts("WARN urb submitted to disabled ep\n");
return -ENOENT;
case EP_STATE_ERROR:
puts("WARN waiting for error on ep to be cleared\n");
return -EINVAL;
case EP_STATE_HALTED:
puts("WARN halted endpoint, queueing URB anyway.\n");
case EP_STATE_STOPPED:
case EP_STATE_RUNNING:
debug("EP STATE RUNNING.\n");
break;
default:
puts("ERROR unknown endpoint state for ep\n");
return -EINVAL;
}
while (last_trb(ctrl, ep_ring, ep_ring->enq_seg, next)) {
/*
* If we're not dealing with 0.95 hardware or isoc rings
* on AMD 0.96 host, clear the chain bit.
*/
next->link.control &= cpu_to_le32(~TRB_CHAIN);
next->link.control ^= cpu_to_le32(TRB_CYCLE);
xhci_flush_cache((uintptr_t)next, sizeof(union xhci_trb));
/* Toggle the cycle bit after the last ring segment. */
if (last_trb_on_last_seg(ctrl, ep_ring,
ep_ring->enq_seg, next))
ep_ring->cycle_state = (ep_ring->cycle_state ? 0 : 1);
ep_ring->enq_seg = ep_ring->enq_seg->next;
ep_ring->enqueue = ep_ring->enq_seg->trbs;
next = ep_ring->enqueue;
}
return 0;
}
/**
* Generic function for queueing a command TRB on the command ring.
* Check to make sure there's room on the command ring for one command TRB.
*
* @param ctrl Host controller data structure
* @param ptr Pointer address to write in the first two fields (opt.)
* @param slot_id Slot ID to encode in the flags field (opt.)
* @param ep_index Endpoint index to encode in the flags field (opt.)
* @param cmd Command type to enqueue
* @return none
*/
void xhci_queue_command(struct xhci_ctrl *ctrl, u8 *ptr, u32 slot_id,
u32 ep_index, trb_type cmd)
{
u32 fields[4];
u64 val_64 = (uintptr_t)ptr;
BUG_ON(prepare_ring(ctrl, ctrl->cmd_ring, EP_STATE_RUNNING));
fields[0] = lower_32_bits(val_64);
fields[1] = upper_32_bits(val_64);
fields[2] = 0;
fields[3] = TRB_TYPE(cmd) | EP_ID_FOR_TRB(ep_index) |
SLOT_ID_FOR_TRB(slot_id) | ctrl->cmd_ring->cycle_state;
queue_trb(ctrl, ctrl->cmd_ring, false, fields);
/* Ring the command ring doorbell */
xhci_writel(&ctrl->dba->doorbell[0], DB_VALUE_HOST);
}
/**
* The TD size is the number of bytes remaining in the TD (including this TRB),
* right shifted by 10.
* It must fit in bits 21:17, so it can't be bigger than 31.
*
* @param remainder remaining packets to be sent
* @return remainder if remainder is less than max else max
*/
static u32 xhci_td_remainder(unsigned int remainder)
{
u32 max = (1 << (21 - 17 + 1)) - 1;
if ((remainder >> 10) >= max)
return max << 17;
else
return (remainder >> 10) << 17;
}
/**
* Finds out the remanining packets to be sent
*
* @param running_total total size sent so far
* @param trb_buff_len length of the TRB Buffer
* @param total_packet_count total packet count
* @param maxpacketsize max packet size of current pipe
* @param num_trbs_left number of TRBs left to be processed
* @return 0 if running_total or trb_buff_len is 0, else remainder
*/
static u32 xhci_v1_0_td_remainder(int running_total,
int trb_buff_len,
unsigned int total_packet_count,
int maxpacketsize,
unsigned int num_trbs_left)
{
int packets_transferred;
/* One TRB with a zero-length data packet. */
if (num_trbs_left == 0 || (running_total == 0 && trb_buff_len == 0))
return 0;
/*
* All the TRB queueing functions don't count the current TRB in
* running_total.
*/
packets_transferred = (running_total + trb_buff_len) / maxpacketsize;
if ((total_packet_count - packets_transferred) > 31)
return 31 << 17;
return (total_packet_count - packets_transferred) << 17;
}
/**
* Ring the doorbell of the End Point
*
* @param udev pointer to the USB device structure
* @param ep_index index of the endpoint
* @param start_cycle cycle flag of the first TRB
* @param start_trb pionter to the first TRB
* @return none
*/
static void giveback_first_trb(struct usb_device *udev, int ep_index,
int start_cycle,
struct xhci_generic_trb *start_trb)
{
struct xhci_ctrl *ctrl = xhci_get_ctrl(udev);
/*
* Pass all the TRBs to the hardware at once and make sure this write
* isn't reordered.
*/
if (start_cycle)
start_trb->field[3] |= cpu_to_le32(start_cycle);
else
start_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
xhci_flush_cache((uintptr_t)start_trb, sizeof(struct xhci_generic_trb));
/* Ringing EP doorbell here */
xhci_writel(&ctrl->dba->doorbell[udev->slot_id],
DB_VALUE(ep_index, 0));
return;
}
/**** POLLING mechanism for XHCI ****/
/**
* Finalizes a handled event TRB by advancing our dequeue pointer and giving
* the TRB back to the hardware for recycling. Must call this exactly once at
* the end of each event handler, and not touch the TRB again afterwards.
*
* @param ctrl Host controller data structure
* @return none
*/
void xhci_acknowledge_event(struct xhci_ctrl *ctrl)
{
/* Advance our dequeue pointer to the next event */
inc_deq(ctrl, ctrl->event_ring);
/* Inform the hardware */
xhci_writeq(&ctrl->ir_set->erst_dequeue,
(uintptr_t)ctrl->event_ring->dequeue | ERST_EHB);
}
/**
* Checks if there is a new event to handle on the event ring.
*
* @param ctrl Host controller data structure
* @return 0 if failure else 1 on success
*/
static int event_ready(struct xhci_ctrl *ctrl)
{
union xhci_trb *event;
xhci_inval_cache((uintptr_t)ctrl->event_ring->dequeue,
sizeof(union xhci_trb));
event = ctrl->event_ring->dequeue;
/* Does the HC or OS own the TRB? */
if ((le32_to_cpu(event->event_cmd.flags) & TRB_CYCLE) !=
ctrl->event_ring->cycle_state)
return 0;
return 1;
}
/**
* Waits for a specific type of event and returns it. Discards unexpected
* events. Caller *must* call xhci_acknowledge_event() after it is finished
* processing the event, and must not access the returned pointer afterwards.
*
* @param ctrl Host controller data structure
* @param expected TRB type expected from Event TRB
* @return pointer to event trb
*/
union xhci_trb *xhci_wait_for_event(struct xhci_ctrl *ctrl, trb_type expected)
{
trb_type type;
unsigned long ts = get_timer(0);
do {
union xhci_trb *event = ctrl->event_ring->dequeue;
if (!event_ready(ctrl))
continue;
type = TRB_FIELD_TO_TYPE(le32_to_cpu(event->event_cmd.flags));
if (type == expected)
return event;
if (type == TRB_PORT_STATUS)
/* TODO: remove this once enumeration has been reworked */
/*
* Port status change events always have a
* successful completion code
*/
BUG_ON(GET_COMP_CODE(
le32_to_cpu(event->generic.field[2])) !=
COMP_SUCCESS);
else
printf("Unexpected XHCI event TRB, skipping... "
"(%08x %08x %08x %08x)\n",
le32_to_cpu(event->generic.field[0]),
le32_to_cpu(event->generic.field[1]),
le32_to_cpu(event->generic.field[2]),
le32_to_cpu(event->generic.field[3]));
xhci_acknowledge_event(ctrl);
} while (get_timer(ts) < XHCI_TIMEOUT);
if (expected == TRB_TRANSFER)
return NULL;
printf("XHCI timeout on event type %d... cannot recover.\n", expected);
BUG();
}
/*
* Stops transfer processing for an endpoint and throws away all unprocessed
* TRBs by setting the xHC's dequeue pointer to our enqueue pointer. The next
* xhci_bulk_tx/xhci_ctrl_tx on this enpoint will add new transfers there and
* ring the doorbell, causing this endpoint to start working again.
* (Careful: This will BUG() when there was no transfer in progress. Shouldn't
* happen in practice for current uses and is too complicated to fix right now.)
*/
static void abort_td(struct usb_device *udev, int ep_index)
{
struct xhci_ctrl *ctrl = xhci_get_ctrl(udev);
struct xhci_ring *ring = ctrl->devs[udev->slot_id]->eps[ep_index].ring;
union xhci_trb *event;
u32 field;
xhci_queue_command(ctrl, NULL, udev->slot_id, ep_index, TRB_STOP_RING);
event = xhci_wait_for_event(ctrl, TRB_TRANSFER);
field = le32_to_cpu(event->trans_event.flags);
BUG_ON(TRB_TO_SLOT_ID(field) != udev->slot_id);
BUG_ON(TRB_TO_EP_INDEX(field) != ep_index);
BUG_ON(GET_COMP_CODE(le32_to_cpu(event->trans_event.transfer_len
!= COMP_STOP)));
xhci_acknowledge_event(ctrl);
event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
BUG_ON(TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags))
!= udev->slot_id || GET_COMP_CODE(le32_to_cpu(
event->event_cmd.status)) != COMP_SUCCESS);
xhci_acknowledge_event(ctrl);
xhci_queue_command(ctrl, (void *)((uintptr_t)ring->enqueue |
ring->cycle_state), udev->slot_id, ep_index, TRB_SET_DEQ);
event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
BUG_ON(TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags))
!= udev->slot_id || GET_COMP_CODE(le32_to_cpu(
event->event_cmd.status)) != COMP_SUCCESS);
xhci_acknowledge_event(ctrl);
}
static void record_transfer_result(struct usb_device *udev,
union xhci_trb *event, int length)
{
udev->act_len = min(length, length -
(int)EVENT_TRB_LEN(le32_to_cpu(event->trans_event.transfer_len)));
switch (GET_COMP_CODE(le32_to_cpu(event->trans_event.transfer_len))) {
case COMP_SUCCESS:
BUG_ON(udev->act_len != length);
/* fallthrough */
case COMP_SHORT_TX:
udev->status = 0;
break;
case COMP_STALL:
udev->status = USB_ST_STALLED;
break;
case COMP_DB_ERR:
case COMP_TRB_ERR:
udev->status = USB_ST_BUF_ERR;
break;
case COMP_BABBLE:
udev->status = USB_ST_BABBLE_DET;
break;
default:
udev->status = 0x80; /* USB_ST_TOO_LAZY_TO_MAKE_A_NEW_MACRO */
}
}
/**** Bulk and Control transfer methods ****/
/**
* Queues up the BULK Request
*
* @param udev pointer to the USB device structure
* @param pipe contains the DIR_IN or OUT , devnum
* @param length length of the buffer
* @param buffer buffer to be read/written based on the request
* @return returns 0 if successful else -1 on failure
*/
int xhci_bulk_tx(struct usb_device *udev, unsigned long pipe,
int length, void *buffer)
{
int num_trbs = 0;
struct xhci_generic_trb *start_trb;
bool first_trb = 0;
int start_cycle;
u32 field = 0;
u32 length_field = 0;
struct xhci_ctrl *ctrl = xhci_get_ctrl(udev);
int slot_id = udev->slot_id;
int ep_index;
struct xhci_virt_device *virt_dev;
struct xhci_ep_ctx *ep_ctx;
struct xhci_ring *ring; /* EP transfer ring */
union xhci_trb *event;
int running_total, trb_buff_len;
unsigned int total_packet_count;
int maxpacketsize;
u64 addr;
int ret;
u32 trb_fields[4];
u64 val_64 = (uintptr_t)buffer;
debug("dev=%p, pipe=%lx, buffer=%p, length=%d\n",
udev, pipe, buffer, length);
ep_index = usb_pipe_ep_index(pipe);
virt_dev = ctrl->devs[slot_id];
xhci_inval_cache((uintptr_t)virt_dev->out_ctx->bytes,
virt_dev->out_ctx->size);
ep_ctx = xhci_get_ep_ctx(ctrl, virt_dev->out_ctx, ep_index);
ring = virt_dev->eps[ep_index].ring;
/*
* How much data is (potentially) left before the 64KB boundary?
* XHCI Spec puts restriction( TABLE 49 and 6.4.1 section of XHCI Spec)
* that the buffer should not span 64KB boundary. if so
* we send request in more than 1 TRB by chaining them.
*/
running_total = TRB_MAX_BUFF_SIZE -
(lower_32_bits(val_64) & (TRB_MAX_BUFF_SIZE - 1));
trb_buff_len = running_total;
running_total &= TRB_MAX_BUFF_SIZE - 1;
/*
* If there's some data on this 64KB chunk, or we have to send a
* zero-length transfer, we need at least one TRB
*/
if (running_total != 0 || length == 0)
num_trbs++;
/* How many more 64KB chunks to transfer, how many more TRBs? */
while (running_total < length) {
num_trbs++;
running_total += TRB_MAX_BUFF_SIZE;
}
/*
* XXX: Calling routine prepare_ring() called in place of
* prepare_trasfer() as there in 'Linux' since we are not
* maintaining multiple TDs/transfer at the same time.
*/
ret = prepare_ring(ctrl, ring,
le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK);
if (ret < 0)
return ret;
/*
* Don't give the first TRB to the hardware (by toggling the cycle bit)
* until we've finished creating all the other TRBs. The ring's cycle
* state may change as we enqueue the other TRBs, so save it too.
*/
start_trb = &ring->enqueue->generic;
start_cycle = ring->cycle_state;
running_total = 0;
maxpacketsize = usb_maxpacket(udev, pipe);
total_packet_count = DIV_ROUND_UP(length, maxpacketsize);
/* How much data is in the first TRB? */
/*
* How much data is (potentially) left before the 64KB boundary?
* XHCI Spec puts restriction( TABLE 49 and 6.4.1 section of XHCI Spec)
* that the buffer should not span 64KB boundary. if so
* we send request in more than 1 TRB by chaining them.
*/
addr = val_64;
if (trb_buff_len > length)
trb_buff_len = length;
first_trb = true;
/* flush the buffer before use */
xhci_flush_cache((uintptr_t)buffer, length);
/* Queue the first TRB, even if it's zero-length */
do {
u32 remainder = 0;
field = 0;
/* Don't change the cycle bit of the first TRB until later */
if (first_trb) {
first_trb = false;
if (start_cycle == 0)
field |= TRB_CYCLE;
} else {
field |= ring->cycle_state;
}
/*
* Chain all the TRBs together; clear the chain bit in the last
* TRB to indicate it's the last TRB in the chain.
*/
if (num_trbs > 1)
field |= TRB_CHAIN;
else
field |= TRB_IOC;
/* Only set interrupt on short packet for IN endpoints */
if (usb_pipein(pipe))
field |= TRB_ISP;
/* Set the TRB length, TD size, and interrupter fields. */
if (HC_VERSION(xhci_readl(&ctrl->hccr->cr_capbase)) < 0x100)
remainder = xhci_td_remainder(length - running_total);
else
remainder = xhci_v1_0_td_remainder(running_total,
trb_buff_len,
total_packet_count,
maxpacketsize,
num_trbs - 1);
length_field = ((trb_buff_len & TRB_LEN_MASK) |
remainder |
((0 & TRB_INTR_TARGET_MASK) <<
TRB_INTR_TARGET_SHIFT));
trb_fields[0] = lower_32_bits(addr);
trb_fields[1] = upper_32_bits(addr);
trb_fields[2] = length_field;
trb_fields[3] = field | (TRB_NORMAL << TRB_TYPE_SHIFT);
queue_trb(ctrl, ring, (num_trbs > 1), trb_fields);
--num_trbs;
running_total += trb_buff_len;
/* Calculate length for next transfer */
addr += trb_buff_len;
trb_buff_len = min((length - running_total), TRB_MAX_BUFF_SIZE);
} while (running_total < length);
giveback_first_trb(udev, ep_index, start_cycle, start_trb);
event = xhci_wait_for_event(ctrl, TRB_TRANSFER);
if (!event) {
debug("XHCI bulk transfer timed out, aborting...\n");
abort_td(udev, ep_index);
udev->status = USB_ST_NAK_REC; /* closest thing to a timeout */
udev->act_len = 0;
return -ETIMEDOUT;
}
field = le32_to_cpu(event->trans_event.flags);
BUG_ON(TRB_TO_SLOT_ID(field) != slot_id);
BUG_ON(TRB_TO_EP_INDEX(field) != ep_index);
BUG_ON(*(void **)(uintptr_t)le64_to_cpu(event->trans_event.buffer) -
buffer > (size_t)length);
record_transfer_result(udev, event, length);
xhci_acknowledge_event(ctrl);
xhci_inval_cache((uintptr_t)buffer, length);
return (udev->status != USB_ST_NOT_PROC) ? 0 : -1;
}
/**
* Queues up the Control Transfer Request
*
* @param udev pointer to the USB device structure
* @param pipe contains the DIR_IN or OUT , devnum
* @param req request type
* @param length length of the buffer
* @param buffer buffer to be read/written based on the request
* @return returns 0 if successful else error code on failure
*/
int xhci_ctrl_tx(struct usb_device *udev, unsigned long pipe,
struct devrequest *req, int length,
void *buffer)
{
int ret;
int start_cycle;
int num_trbs;
u32 field;
u32 length_field;
u64 buf_64 = 0;
struct xhci_generic_trb *start_trb;
struct xhci_ctrl *ctrl = xhci_get_ctrl(udev);
int slot_id = udev->slot_id;
int ep_index;
u32 trb_fields[4];
struct xhci_virt_device *virt_dev = ctrl->devs[slot_id];
struct xhci_ring *ep_ring;
union xhci_trb *event;
debug("req=%u (%#x), type=%u (%#x), value=%u (%#x), index=%u\n",
req->request, req->request,
req->requesttype, req->requesttype,
le16_to_cpu(req->value), le16_to_cpu(req->value),
le16_to_cpu(req->index));
ep_index = usb_pipe_ep_index(pipe);
ep_ring = virt_dev->eps[ep_index].ring;
/*
* Check to see if the max packet size for the default control
* endpoint changed during FS device enumeration
*/
if (udev->speed == USB_SPEED_FULL) {
ret = xhci_check_maxpacket(udev);
if (ret < 0)
return ret;
}
xhci_inval_cache((uintptr_t)virt_dev->out_ctx->bytes,
virt_dev->out_ctx->size);
struct xhci_ep_ctx *ep_ctx = NULL;
ep_ctx = xhci_get_ep_ctx(ctrl, virt_dev->out_ctx, ep_index);
/* 1 TRB for setup, 1 for status */
num_trbs = 2;
/*
* Don't need to check if we need additional event data and normal TRBs,
* since data in control transfers will never get bigger than 16MB
* XXX: can we get a buffer that crosses 64KB boundaries?
*/
if (length > 0)
num_trbs++;
/*
* XXX: Calling routine prepare_ring() called in place of
* prepare_trasfer() as there in 'Linux' since we are not
* maintaining multiple TDs/transfer at the same time.
*/
ret = prepare_ring(ctrl, ep_ring,
le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK);
if (ret < 0)
return ret;
/*
* Don't give the first TRB to the hardware (by toggling the cycle bit)
* until we've finished creating all the other TRBs. The ring's cycle
* state may change as we enqueue the other TRBs, so save it too.
*/
start_trb = &ep_ring->enqueue->generic;
start_cycle = ep_ring->cycle_state;
debug("start_trb %p, start_cycle %d\n", start_trb, start_cycle);
/* Queue setup TRB - see section 6.4.1.2.1 */
/* FIXME better way to translate setup_packet into two u32 fields? */
field = 0;
field |= TRB_IDT | (TRB_SETUP << TRB_TYPE_SHIFT);
if (start_cycle == 0)
field |= 0x1;
/* xHCI 1.0 6.4.1.2.1: Transfer Type field */
if (HC_VERSION(xhci_readl(&ctrl->hccr->cr_capbase)) == 0x100) {
if (length > 0) {
if (req->requesttype & USB_DIR_IN)
field |= (TRB_DATA_IN << TRB_TX_TYPE_SHIFT);
else
field |= (TRB_DATA_OUT << TRB_TX_TYPE_SHIFT);
}
}
debug("req->requesttype = %d, req->request = %d,"
"le16_to_cpu(req->value) = %d,"
"le16_to_cpu(req->index) = %d,"
"le16_to_cpu(req->length) = %d\n",
req->requesttype, req->request, le16_to_cpu(req->value),
le16_to_cpu(req->index), le16_to_cpu(req->length));
trb_fields[0] = req->requesttype | req->request << 8 |
le16_to_cpu(req->value) << 16;
trb_fields[1] = le16_to_cpu(req->index) |
le16_to_cpu(req->length) << 16;
/* TRB_LEN | (TRB_INTR_TARGET) */
trb_fields[2] = (8 | ((0 & TRB_INTR_TARGET_MASK) <<
TRB_INTR_TARGET_SHIFT));
/* Immediate data in pointer */
trb_fields[3] = field;
queue_trb(ctrl, ep_ring, true, trb_fields);
/* Re-initializing field to zero */
field = 0;
/* If there's data, queue data TRBs */
/* Only set interrupt on short packet for IN endpoints */
if (usb_pipein(pipe))
field = TRB_ISP | (TRB_DATA << TRB_TYPE_SHIFT);
else
field = (TRB_DATA << TRB_TYPE_SHIFT);
length_field = (length & TRB_LEN_MASK) | xhci_td_remainder(length) |
((0 & TRB_INTR_TARGET_MASK) << TRB_INTR_TARGET_SHIFT);
debug("length_field = %d, length = %d,"
"xhci_td_remainder(length) = %d , TRB_INTR_TARGET(0) = %d\n",
length_field, (length & TRB_LEN_MASK),
xhci_td_remainder(length), 0);
if (length > 0) {
if (req->requesttype & USB_DIR_IN)
field |= TRB_DIR_IN;
buf_64 = (uintptr_t)buffer;
trb_fields[0] = lower_32_bits(buf_64);
trb_fields[1] = upper_32_bits(buf_64);
trb_fields[2] = length_field;
trb_fields[3] = field | ep_ring->cycle_state;
xhci_flush_cache((uintptr_t)buffer, length);
queue_trb(ctrl, ep_ring, true, trb_fields);
}
/*
* Queue status TRB -
* see Table 7 and sections 4.11.2.2 and 6.4.1.2.3
*/
/* If the device sent data, the status stage is an OUT transfer */
field = 0;
if (length > 0 && req->requesttype & USB_DIR_IN)
field = 0;
else
field = TRB_DIR_IN;
trb_fields[0] = 0;
trb_fields[1] = 0;
trb_fields[2] = ((0 & TRB_INTR_TARGET_MASK) << TRB_INTR_TARGET_SHIFT);
/* Event on completion */
trb_fields[3] = field | TRB_IOC |
(TRB_STATUS << TRB_TYPE_SHIFT) |
ep_ring->cycle_state;
queue_trb(ctrl, ep_ring, false, trb_fields);
giveback_first_trb(udev, ep_index, start_cycle, start_trb);
event = xhci_wait_for_event(ctrl, TRB_TRANSFER);
if (!event)
goto abort;
field = le32_to_cpu(event->trans_event.flags);
BUG_ON(TRB_TO_SLOT_ID(field) != slot_id);
BUG_ON(TRB_TO_EP_INDEX(field) != ep_index);
record_transfer_result(udev, event, length);
xhci_acknowledge_event(ctrl);
/* Invalidate buffer to make it available to usb-core */
if (length > 0)
xhci_inval_cache((uintptr_t)buffer, length);
if (GET_COMP_CODE(le32_to_cpu(event->trans_event.transfer_len))
== COMP_SHORT_TX) {
/* Short data stage, clear up additional status stage event */
event = xhci_wait_for_event(ctrl, TRB_TRANSFER);
if (!event)
goto abort;
BUG_ON(TRB_TO_SLOT_ID(field) != slot_id);
BUG_ON(TRB_TO_EP_INDEX(field) != ep_index);
xhci_acknowledge_event(ctrl);
}
return (udev->status != USB_ST_NOT_PROC) ? 0 : -1;
abort:
debug("XHCI control transfer timed out, aborting...\n");
abort_td(udev, ep_index);
udev->status = USB_ST_NAK_REC;
udev->act_len = 0;
return -ETIMEDOUT;
}