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path: root/drivers/usb/host/xhci-ring.c
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Diffstat (limited to 'drivers/usb/host/xhci-ring.c')
-rw-r--r--drivers/usb/host/xhci-ring.c939
1 files changed, 939 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
new file mode 100644
index 0000000..19c3ec6
--- /dev/null
+++ b/drivers/usb/host/xhci-ring.c
@@ -0,0 +1,939 @@
+/*
+ * 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 <asm-generic/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((uint32_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((uint32_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((uint32_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 = udev->controller;
+
+ /*
+ * 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((uint32_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((uint32_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 = udev->controller;
+ 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 -
+ 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 = udev->controller;
+ 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((uint32_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((uint32_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((uint32_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 = udev->controller;
+ 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((uint32_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((uint32_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((uint32_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;
+}