int mite_sync_output_dma(struct mite_channel *mite_chan, comedi_async * async)
{
int count;
u32 nbytes_ub, nbytes_lb;
unsigned int old_alloc_count;
u32 stop_count =
async->cmd.stop_arg * cfc_bytes_per_scan(async->subdevice);
old_alloc_count = async->buf_read_alloc_count;
// read alloc as much as we can
comedi_buf_read_alloc(async, async->prealloc_bufsz);
nbytes_lb = mite_bytes_read_from_memory_lb(mite_chan);
if (async->cmd.stop_src == TRIG_COUNT &&
(int)(nbytes_lb - stop_count) > 0)
nbytes_lb = stop_count;
nbytes_ub = mite_bytes_read_from_memory_ub(mite_chan);
if (async->cmd.stop_src == TRIG_COUNT &&
(int)(nbytes_ub - stop_count) > 0)
nbytes_ub = stop_count;
if ((int)(nbytes_ub - old_alloc_count) > 0) {
rt_printk("mite: DMA underrun\n");
async->events |= COMEDI_CB_OVERFLOW;
return -1;
}
count = nbytes_lb - async->buf_read_count;
if (count <= 0) {
return 0;
}
if (count) {
comedi_buf_read_free(async, count);
async->events |= COMEDI_CB_BLOCK;
}
return 0;
}
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;
}
void cfc_inc_scan_progress(struct comedi_subdevice *s, unsigned int num_bytes)
{
struct comedi_async *async = s->async;
unsigned int scan_length = cfc_bytes_per_scan(s);
async->scan_progress += num_bytes;
if (async->scan_progress >= scan_length) {
async->scan_progress %= scan_length;
async->events |= COMEDI_CB_EOS;
}
}
static void increment_scan_progress(comedi_subdevice *subd,
unsigned int num_bytes)
{
comedi_async *async = subd->async;
unsigned int scan_length = cfc_bytes_per_scan(subd);
async->scan_progress += num_bytes;
if (async->scan_progress >= scan_length) {
async->scan_progress %= scan_length;
async->events |= COMEDI_CB_EOS;
}
}
