void serial8250_rx_dma_flush(struct uart_8250_port *p)
{
struct uart_8250_dma *dma = p->dma;
if (dma->rx_running) {
dmaengine_pause(dma->rxchan);
__dma_rx_complete(p);
dmaengine_terminate_async(dma->rxchan);
}
}
int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir)
{
struct uart_8250_dma *dma = p->dma;
struct dma_async_tx_descriptor *desc;
struct dma_tx_state state;
int dma_status;
dma_status = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
switch (iir & 0x3f) {
case UART_IIR_RLSI:
/* 8250_core handles errors and break interrupts */
return -EIO;
case UART_IIR_RX_TIMEOUT:
/*
* If RCVR FIFO trigger level was not reached, complete the
* transfer and let 8250_core copy the remaining data.
*/
if (dma_status == DMA_IN_PROGRESS) {
dmaengine_pause(dma->rxchan);
__dma_rx_complete(p);
}
return -ETIMEDOUT;
default:
break;
}
if (dma_status)
return 0;
desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
dma->rx_size, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc)
return -EBUSY;
desc->callback = __dma_rx_complete;
desc->callback_param = p;
dma->rx_cookie = dmaengine_submit(desc);
dma_sync_single_for_device(dma->rxchan->device->dev, dma->rx_addr,
dma->rx_size, DMA_FROM_DEVICE);
dma_async_issue_pending(dma->rxchan);
return 0;
}
