static void __dma_rx_complete(void *param)
{
struct uart_8250_port *p = param;
struct omap8250_priv *priv = p->port.private_data;
struct uart_8250_dma *dma = p->dma;
struct dma_tx_state state;
unsigned long flags;
spin_lock_irqsave(&p->port.lock, flags);
/*
* If the tx status is not DMA_COMPLETE, then this is a delayed
* completion callback. A previous RX timeout flush would have
* already pushed the data, so exit.
*/
if (dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state) !=
DMA_COMPLETE) {
spin_unlock_irqrestore(&p->port.lock, flags);
return;
}
__dma_rx_do_complete(p);
if (!priv->throttled)
omap_8250_rx_dma(p);
spin_unlock_irqrestore(&p->port.lock, flags);
}
static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
{
struct omap8250_priv *priv = p->port.private_data;
struct uart_8250_dma *dma = p->dma;
struct dma_tx_state state;
unsigned long flags;
int ret;
spin_lock_irqsave(&priv->rx_dma_lock, flags);
if (!dma->rx_running) {
spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
return;
}
ret = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
if (ret == DMA_IN_PROGRESS) {
ret = dmaengine_pause(dma->rxchan);
if (WARN_ON_ONCE(ret))
priv->rx_dma_broken = true;
}
spin_unlock_irqrestore(&priv->rx_dma_lock, flags);
__dma_rx_do_complete(p);
dmaengine_terminate_all(dma->rxchan);
}
static int omap_8250_rx_dma(struct uart_8250_port *p, unsigned int iir)
{
struct uart_8250_dma *dma = p->dma;
struct dma_async_tx_descriptor *desc;
switch (iir & 0x3f) {
case UART_IIR_RLSI:
/* 8250_core handles errors and break interrupts */
if (dma->rx_running) {
dmaengine_pause(dma->rxchan);
__dma_rx_do_complete(p, true);
}
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->rx_running) {
dmaengine_pause(dma->rxchan);
__dma_rx_do_complete(p, true);
}
return -ETIMEDOUT;
case UART_IIR_RDI:
/*
* The OMAP UART is a special BEAST. If we receive RDI we _have_
* a DMA transfer programmed but it didn't work. One reason is
* that we were too slow and there were too many bytes in the
* FIFO, the UART counted wrong and never kicked the DMA engine
* to do anything. That means once we receive RDI on OMAP then
* the DMA won't do anything soon so we have to cancel the DMA
* transfer and purge the FIFO manually.
*/
if (dma->rx_running) {
dmaengine_pause(dma->rxchan);
__dma_rx_do_complete(p, true);
}
return -ETIMEDOUT;
default:
break;
}
if (dma->rx_running)
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;
dma->rx_running = 1;
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;
}
static void __dma_rx_complete(void *param)
{
__dma_rx_do_complete(param, false);
}
static void __dma_rx_complete(void *param)
{
__dma_rx_do_complete(param);
omap_8250_rx_dma(param);
}