/*
* This is mostly serial8250_handle_irq(). We have a slightly different DMA
* hoook for RX/TX and need different logic for them in the ISR. Therefore we
* use the default routine in the non-DMA case and this one for with DMA.
*/
static int omap_8250_dma_handle_irq(struct uart_port *port)
{
struct uart_8250_port *up = up_to_u8250p(port);
unsigned char status;
unsigned long flags;
u8 iir;
int dma_err = 0;
serial8250_rpm_get(up);
iir = serial_port_in(port, UART_IIR);
if (iir & UART_IIR_NO_INT) {
serial8250_rpm_put(up);
return 0;
}
spin_lock_irqsave(&port->lock, flags);
status = serial_port_in(port, UART_LSR);
if (status & (UART_LSR_DR | UART_LSR_BI)) {
dma_err = omap_8250_rx_dma(up, iir);
if (dma_err) {
status = serial8250_rx_chars(up, status);
omap_8250_rx_dma(up, 0);
}
}
serial8250_modem_status(up);
if (status & UART_LSR_THRE && up->dma->tx_err) {
if (uart_tx_stopped(&up->port) ||
uart_circ_empty(&up->port.state->xmit)) {
up->dma->tx_err = 0;
serial8250_tx_chars(up);
} else {
/*
* try again due to an earlier failer which
* might have been resolved by now.
*/
dma_err = omap_8250_tx_dma(up);
if (dma_err)
serial8250_tx_chars(up);
}
}
spin_unlock_irqrestore(&port->lock, flags);
serial8250_rpm_put(up);
return 1;
}
static irqreturn_t omap8250_irq(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct uart_8250_port *up = up_to_u8250p(port);
unsigned int iir;
int ret;
#ifdef CONFIG_SERIAL_8250_DMA
if (up->dma) {
ret = omap_8250_dma_handle_irq(port);
return IRQ_RETVAL(ret);
}
#endif
serial8250_rpm_get(up);
iir = serial_port_in(port, UART_IIR);
ret = serial8250_handle_irq(port, iir);
serial8250_rpm_put(up);
return IRQ_RETVAL(ret);
}