int mite_sync_input_dma(struct mite_channel *mite_chan, comedi_async * async)
{
int count;
unsigned int nbytes, old_alloc_count;
const unsigned bytes_per_scan = cfc_bytes_per_scan(async->subdevice);
old_alloc_count = async->buf_write_alloc_count;
// write alloc as much as we can
comedi_buf_write_alloc(async, async->prealloc_bufsz);
nbytes = mite_bytes_written_to_memory_lb(mite_chan);
if ((int)(mite_bytes_written_to_memory_ub(mite_chan) -
old_alloc_count) > 0) {
rt_printk("mite: DMA overwrite of free area\n");
async->events |= COMEDI_CB_OVERFLOW;
return -1;
}
count = nbytes - async->buf_write_count;
/* it's possible count will be negative due to
* conservative value returned by mite_bytes_written_to_memory_lb */
if (count <= 0) {
return 0;
}
comedi_buf_write_free(async, count);
async->scan_progress += count;
if (async->scan_progress >= bytes_per_scan) {
async->scan_progress %= bytes_per_scan;
async->events |= COMEDI_CB_EOS;
}
async->events |= COMEDI_CB_BLOCK;
return 0;
}
int mite_sync_input_dma(struct mite_channel *mite_chan,
struct comedi_subdevice *s)
{
struct comedi_async *async = s->async;
int count;
unsigned int nbytes, old_alloc_count;
old_alloc_count = async->buf_write_alloc_count;
/* write alloc as much as we can */
comedi_buf_write_alloc(s, async->prealloc_bufsz);
nbytes = mite_bytes_written_to_memory_lb(mite_chan);
if ((int)(mite_bytes_written_to_memory_ub(mite_chan) -
old_alloc_count) > 0) {
dev_warn(s->device->class_dev,
"mite: DMA overwrite of free area\n");
async->events |= COMEDI_CB_OVERFLOW;
return -1;
}
count = nbytes - async->buf_write_count;
/*
* it's possible count will be negative due to conservative value
* returned by mite_bytes_written_to_memory_lb
*/
if (count <= 0)
return 0;
comedi_buf_write_free(s, count);
comedi_inc_scan_progress(s, count);
async->events |= COMEDI_CB_BLOCK;
return 0;
}
