/*
* STK1160 driver
*
* Copyright (C) 2012 Ezequiel Garcia
* <elezegarcia--a.t--gmail.com>
*
* Based on Easycap driver by R.M. Thomas
* Copyright (C) 2010 R.M. Thomas
* <rmthomas--a.t--sciolus.org>
*
* 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 <linux/module.h>
#include <linux/usb.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include "stk1160.h"
static unsigned int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "enable debug messages");
static inline void print_err_status(struct stk1160 *dev,
int packet, int status)
{
char *errmsg = "Unknown";
switch (status) {
case -ENOENT:
errmsg = "unlinked synchronously";
break;
case -ECONNRESET:
errmsg = "unlinked asynchronously";
break;
case -ENOSR:
errmsg = "Buffer error (overrun)";
break;
case -EPIPE:
errmsg = "Stalled (device not responding)";
break;
case -EOVERFLOW:
errmsg = "Babble (bad cable?)";
break;
case -EPROTO:
errmsg = "Bit-stuff error (bad cable?)";
break;
case -EILSEQ:
errmsg = "CRC/Timeout (could be anything)";
break;
case -ETIME:
errmsg = "Device does not respond";
break;
}
if (packet < 0)
printk_ratelimited(KERN_WARNING "URB status %d [%s].\n",
status, errmsg);
else
printk_ratelimited(KERN_INFO "URB packet %d, status %d [%s].\n",
packet, status, errmsg);
}
static inline
struct stk1160_buffer *stk1160_next_buffer(struct stk1160 *dev)
{
struct stk1160_buffer *buf = NULL;
unsigned long flags = 0;
/* Current buffer must be NULL when this functions gets called */
WARN_ON(dev->isoc_ctl.buf);
spin_lock_irqsave(&dev->buf_lock, flags);
if (!list_empty(&dev->avail_bufs)) {
buf = list_first_entry(&dev->avail_bufs,
struct stk1160_buffer, list);
list_del(&buf->list);
}
spin_unlock_irqrestore(&dev->buf_lock, flags);
return buf;
}
static inline
void stk1160_buffer_done(struct stk1160 *dev)
{
struct stk1160_buffer *buf = dev->isoc_ctl.buf;
buf->vb.sequence = dev->sequence++;
buf->vb.field = V4L2_FIELD_INTERLACED;
buf->vb.vb2_buf.timestamp = ktime_get_ns();
vb2_set_plane_payload(&buf->vb.vb2_buf, 0, buf->bytesused);
vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
dev->isoc_ctl.buf = NULL;
}
static inline
void stk1160_copy_video(struct stk1160 *dev, u8 *src, int len)
{
int linesdone, lineoff, lencopy;
int bytesperline = dev->width * 2;
struct stk1160_buffer *buf = dev->isoc_ctl.buf;
u8 *dst = buf->mem;
int remain;
/*
* TODO: These stk1160_dbg are very spammy!
* We should 1) check why we are getting them
* and 2) add ratelimit.
*
* UPDATE: One of the reasons (the only one?) for getting these
* is incorrect standard (mismatch between expected and configured).
* So perhaps, we could add a counter for errors. When the counter
* reaches some value, we simply stop streaming.
*/
len -= 4;
src += 4;
remain = len;
linesdone = buf->pos / bytesperline;
lineoff = buf->pos % bytesperline; /* offset in current line */
if (!buf->odd)
dst += bytesperline;
/* Multiply linesdone by two, to take account of the other field */
dst += linesdone * bytesperline * 2 + lineoff;
/* Copy the remaining of current line */
if (remain < (bytesperline - lineoff))
lencopy = remain;
else
lencopy = bytesperline - lineoff;
/*
* Check if we have enough space left in the buffer.
* In that case, we force loop exit after copy.
*/
if (lencopy > buf->bytesused - buf->length) {
lencopy = buf->bytesused - buf->length;
remain = lencopy;
}
/* Check if the copy is done */
if (lencopy == 0 || remain == 0)
return;
/* Let the bug hunt begin! sanity checks! */
if (lencopy < 0) {
stk1160_dbg("copy skipped: negative lencopy\n");
return;
}
if ((unsigned long)dst + lencopy >
(unsigned long)buf->mem + buf->length) {
printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
return;
}
memcpy(dst, src, lencopy);
buf->bytesused += lencopy;
buf->pos += lencopy;
remain -= lencopy;
/* Copy current field line by line, interlacing with the other field */
while (remain > 0) {
dst += lencopy + bytesperline;
src += lencopy;
/* Copy one line at a time */
if (remain < bytesperline)
lencopy = remain;
else
lencopy = bytesperline;
/*
* Check if we have enough space left in the buffer.
* In that case, we force loop exit after copy.
*/
if (lencopy > buf->bytesused - buf->length) {
lencopy = buf->bytesused - buf->length;
remain = lencopy;
}
/* Check if the copy is done */
if (lencopy == 0 || remain == 0)
return;
if (lencopy < 0) {
printk_ratelimited(KERN_WARNING "stk1160: negative lencopy detected\n");
return;
}
if ((unsigned long)dst + lencopy >
(unsigned long)buf->mem + buf->length) {
printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
return;
}
memcpy(dst, src, lencopy);
remain -= lencopy;
buf->bytesused += lencopy;
buf->pos += lencopy;
}
}
/*
* Controls the isoc copy of each urb packet
*/
static void stk1160_process_isoc(struct stk1160 *dev, struct urb *urb)
{
int i, len, status;
u8 *p;
if (!dev) {
stk1160_warn("%s called with null device\n", __func__);
return;
}
if (urb->status < 0) {
/* Print status and drop current packet (or field?) */
print_err_status(dev, -1, urb->status);
return;
}
for (i = 0; i < urb->number_of_packets; i++) {
status = urb->iso_frame_desc[i].status;
if (status < 0) {
print_err_status(dev, i, status);
continue;
}
/* Get packet actual length and pointer to data */
p = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
len = urb->iso_frame_desc[i].actual_length;
/* Empty packet */
if (len <= 4)
continue;
/*
* An 8-byte packet sequence means end of field.
* So if we don't have any packet, we start receiving one now
* and if we do have a packet, then we are done with it.
*
* These end of field packets are always 0xc0 or 0x80,
* but not always 8-byte long so we don't check packet length.
*/
if (p[0] == 0xc0) {
/*
* If first byte is 0xc0 then we received
* second field, and frame has ended.
*/
if (dev->isoc_ctl.buf != NULL)
stk1160_buffer_done(dev);
dev->isoc_ctl.buf = stk1160_next_buffer(dev);
if (dev->isoc_ctl.buf == NULL)
return;
}
/*
* If we don't have a buffer here, then it means we
* haven't found the start mark sequence.
*/
if (dev->isoc_ctl.buf == NULL)
continue;
if (p[0] == 0xc0 || p[0] == 0x80) {
/* We set next packet parity and
* continue to get next one
*/
dev->isoc_ctl.buf->odd = *p & 0x40;
dev->isoc_ctl.buf->pos = 0;
continue;
}
stk1160_copy_video(dev, p, len);
}
}
/*
* IRQ callback, called by URB callback
*/
static void stk1160_isoc_irq(struct urb *urb)
{
int i, rc;
struct stk1160 *dev = urb->context;
switch (urb->status) {
case 0:
break;
case -ECONNRESET: /* kill */
case -ENOENT:
case -ESHUTDOWN:
/* TODO: check uvc driver: he frees the queue here */
return;
default:
stk1160_err("urb error! status %d\n", urb->status);
return;
}
stk1160_process_isoc(dev, urb);
/* Reset urb buffers */
for (i = 0; i < urb->number_of_packets; i++) {
urb->iso_frame_desc[i].status = 0;
urb->iso_frame_desc[i].actual_length = 0;
}
rc = usb_submit_urb(urb, GFP_ATOMIC);
if (rc)
stk1160_err("urb re-submit failed (%d)\n", rc);
}
/*
* Cancel urbs
* This function can't be called in atomic context
*/
void stk1160_cancel_isoc(struct stk1160 *dev)
{
int i, num_bufs = dev->isoc_ctl.num_bufs;
/*
* This check is not necessary, but we add it
* to avoid a spurious debug message
*/
if (!num_bufs)
return;
stk1160_dbg("killing %d urbs...\n", num_bufs);
for (i = 0; i < num_bufs; i++) {
/*
* To kill urbs we can't be in atomic context.
* We don't care for NULL pointer since
* usb_kill_urb allows it.
*/
usb_kill_urb(dev->isoc_ctl.urb[i]);
}
stk1160_dbg("all urbs killed\n");
}
/*
* Releases urb and transfer buffers
* Obviusly, associated urb must be killed before releasing it.
*/
void stk1160_free_isoc(struct stk1160 *dev)
{
struct urb *urb;
int i, num_bufs = dev->isoc_ctl.num_bufs;
stk1160_dbg("freeing %d urb buffers...\n", num_bufs);
for (i = 0; i < num_bufs; i++) {
urb = dev->isoc_ctl.urb[i];
if (urb) {
if (dev->isoc_ctl.transfer_buffer[i]) {
#ifndef CONFIG_DMA_NONCOHERENT
usb_free_coherent(dev->udev,
urb->transfer_buffer_length,
dev->isoc_ctl.transfer_buffer[i],
urb->transfer_dma);
#else
kfree(dev->isoc_ctl.transfer_buffer[i]);
#endif
}
usb_free_urb(urb);
dev->isoc_ctl.urb[i] = NULL;
}
dev->isoc_ctl.transfer_buffer[i] = NULL;
}
kfree(dev->isoc_ctl.urb);
kfree(dev->isoc_ctl.transfer_buffer);
dev->isoc_ctl.urb = NULL;
dev->isoc_ctl.transfer_buffer = NULL;
dev->isoc_ctl.num_bufs = 0;
stk1160_dbg("all urb buffers freed\n");
}
/*
* Helper for cancelling and freeing urbs
* This function can't be called in atomic context
*/
void stk1160_uninit_isoc(struct stk1160 *dev)
{
stk1160_cancel_isoc(dev);
stk1160_free_isoc(dev);
}
/*
* Allocate URBs
*/
int stk1160_alloc_isoc(struct stk1160 *dev)
{
struct urb *urb;
int i, j, k, sb_size, max_packets, num_bufs;
/*
* It may be necessary to release isoc here,
* since isoc are only released on disconnection.
* (see new_pkt_size flag)
*/
if (dev->isoc_ctl.num_bufs)
stk1160_uninit_isoc(dev);
stk1160_dbg("allocating urbs...\n");
num_bufs = STK1160_NUM_BUFS;
max_packets = STK1160_NUM_PACKETS;
sb_size = max_packets * dev->max_pkt_size;
dev->isoc_ctl.buf = NULL;
dev->isoc_ctl.max_pkt_size = dev->max_pkt_size;
dev->isoc_ctl.urb = kzalloc(sizeof(void *)*num_bufs, GFP_KERNEL);
if (!dev->isoc_ctl.urb) {
stk1160_err("out of memory for urb array\n");
return -ENOMEM;
}
dev->isoc_ctl.transfer_buffer = kzalloc(sizeof(void *)*num_bufs,
GFP_KERNEL);
if (!dev->isoc_ctl.transfer_buffer) {
stk1160_err("out of memory for usb transfers\n");
kfree(dev->isoc_ctl.urb);
return -ENOMEM;
}
/* allocate urbs and transfer buffers */
for (i = 0; i < num_bufs; i++) {
urb = usb_alloc_urb(max_packets, GFP_KERNEL);
if (!urb)
goto free_i_bufs;
dev->isoc_ctl.urb[i] = urb;
#ifndef CONFIG_DMA_NONCOHERENT
dev->isoc_ctl.transfer_buffer[i] = usb_alloc_coherent(dev->udev,
sb_size, GFP_KERNEL, &urb->transfer_dma);
#else
dev->isoc_ctl.transfer_buffer[i] = kmalloc(sb_size, GFP_KERNEL);
#endif
if (!dev->isoc_ctl.transfer_buffer[i]) {
stk1160_err("cannot alloc %d bytes for tx[%d] buffer\n",
sb_size, i);
/* Not enough transfer buffers, so just give up */
if (i < STK1160_MIN_BUFS)
goto free_i_bufs;
goto nomore_tx_bufs;
}
memset(dev->isoc_ctl.transfer_buffer[i], 0, sb_size);
/*
* FIXME: Where can I get the endpoint?
*/
urb->dev = dev->udev;
urb->pipe = usb_rcvisocpipe(dev->udev, STK1160_EP_VIDEO);
urb->transfer_buffer = dev->isoc_ctl.transfer_buffer[i];
urb->transfer_buffer_length = sb_size;
urb->complete = stk1160_isoc_irq;
urb->context = dev;
urb->interval = 1;
urb->start_frame = 0;
urb->number_of_packets = max_packets;
#ifndef CONFIG_DMA_NONCOHERENT
urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
#else
urb->transfer_flags = URB_ISO_ASAP;
#endif
k = 0;
for (j = 0; j < max_packets; j++) {
urb->iso_frame_desc[j].offset = k;
urb->iso_frame_desc[j].length =
dev->isoc_ctl.max_pkt_size;
k += dev->isoc_ctl.max_pkt_size;
}
}
stk1160_dbg("%d urbs allocated\n", num_bufs);
/* At last we can say we have some buffers */
dev->isoc_ctl.num_bufs = num_bufs;
return 0;
nomore_tx_bufs:
/*
* Failed to allocate desired buffer count. However, we may have
* enough to work fine, so we just free the extra urb,
* store the allocated count and keep going, fingers crossed!
*/
usb_free_urb(dev->isoc_ctl.urb[i]);
dev->isoc_ctl.urb[i] = NULL;
stk1160_warn("%d urbs allocated. Trying to continue...\n", i - 1);
dev->isoc_ctl.num_bufs = i - 1;
return 0;
free_i_bufs:
/* Save the allocated buffers so far, so we can properly free them */
dev->isoc_ctl.num_bufs = i+1;
stk1160_free_isoc(dev);
return -ENOMEM;
}
