rp2040-playground/composite/usb_buffered_ep.c

142 lines
3.6 KiB
C

/****************************************************************************
* buffered endpoint
****************************************************************************/
/* USB buffer library
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include "tusb.h"
#include "device/usbd_pvt.h"
#include "trace.h"
#include <libsimtrace/usb_buffered_ep.h>
#include <errno.h>
#include <osmocom/core/linuxlist.h>
#include <osmocom/core/msgb.h>
#define USB_MAX_QLEN 3
#define USB_ALLOC_SIZE 280
#define USB_HEADROOM_SIZE 8
void bep_init(struct usb_buffered_ep *bep, uint8_t ep)
{
bep->ep = ep;
bep->msg_in_progress = NULL;
INIT_LLIST_HEAD(&bep->queue);
bep->queue_len = 0;
}
struct msgb *bep_msgb_alloc(struct usb_buffered_ep *bep)
{
struct msgb *msg = msgb_alloc_headroom(USB_ALLOC_SIZE, USB_HEADROOM_SIZE, "USB");
if (!msg)
return NULL;
msg->dst = bep;
return msg;
}
void bep_msgb_free(struct msgb *msg)
{
msgb_free(msg);
}
/* IN/IRQ EP: dequeue next pending message and send it to host */
int bep_refill_to_host(struct usb_buffered_ep *bep, bool is_out_ep)
{
unsigned long x;
const uint8_t rhport = 0;
unsigned int len;
if (usbd_edpt_busy(rhport, bep->ep)) {
LOGBEP(bep, "skipping: edpt_busy\r\n");
return 0;
}
local_irq_save(x);
if (bep->msg_in_progress) {
local_irq_restore(x);
LOGBEP(bep, "skipping: msg_in_progress\r\n");
return 0;
}
if (llist_empty(&bep->queue)) {
local_irq_restore(x);
LOGBEP(bep, "skipping: queue empty\r\n");
return 0;
}
bep->msg_in_progress = msgb_dequeue_count(&bep->queue, &bep->queue_len);
local_irq_restore(x);
if (is_out_ep)
len = msgb_tailroom(bep->msg_in_progress);
else
len = msgb_length(bep->msg_in_progress);
TU_VERIFY(usbd_edpt_xfer(rhport, bep->ep, msgb_data(bep->msg_in_progress), len));
LOGBEP(bep, "success (msg=%p, data=%p/%u)!\r\n", bep->msg_in_progress, msgb_data(bep->msg_in_progress), len);
return 1;
}
/* assume the last in-progress msgb has completed + return it */
struct msgb *bep_get_completed(struct usb_buffered_ep *bep)
{
unsigned long x;
struct msgb *msg;
local_irq_save(x);
msg = bep->msg_in_progress;
bep->msg_in_progress = NULL;
local_irq_restore(x);
LOGBEP(bep, "(msg=%p)\r\n", msg);
return msg;
}
/* assume the last in-progress msgb has completed + free it */
void bep_complete_in_progress(struct usb_buffered_ep *bep)
{
struct msgb *msg = bep_get_completed(bep);
LOGBEP(bep, "(msg=%p)\r\n", msg);
bep_msgb_free(msg);
}
/* enqueue a USB buffer for transmission to host */
int bep_enqueue_msgb(struct msgb *msg)
{
struct usb_buffered_ep *ep = msg->dst;
if (!msg->dst) {
TRACE_ERROR("%s: msg without dst\r\n", __func__);
bep_msgb_free(msg);
return -EINVAL;
}
/* no need for irqsafe operation, as the usb_tx_queue is
* processed only by the main loop context */
if (ep->queue_len >= USB_MAX_QLEN) {
struct msgb *evict;
/* free the first pending buffer in the queue */
TRACE_INFO("EP%02x: dropping first queue element (qlen=%u)\r\n",
ep->ep, ep->queue_len);
evict = msgb_dequeue_count(&ep->queue, &ep->queue_len);
OSMO_ASSERT(evict);
bep_msgb_free(evict);
}
LOGBEP(ep, "(msg=%p)\r\n", msg);
msgb_enqueue_count(&ep->queue, msg, &ep->queue_len);
return 0;
}