+ /*
+ * note that the error handling code is
+ * out of the main execution path
+ */
+ if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
+ | ATMEL_US_OVRE | ATMEL_US_RXBRK)
+ || atmel_port->break_active)) {
+
+ /* clear error */
+ UART_PUT_CR(port, ATMEL_US_RSTSTA);
+
+ if (status & ATMEL_US_RXBRK
+ && !atmel_port->break_active) {
+ atmel_port->break_active = 1;
+ UART_PUT_IER(port, ATMEL_US_RXBRK);
+ } else {
+ /*
+ * This is either the end-of-break
+ * condition or we've received at
+ * least one character without RXBRK
+ * being set. In both cases, the next
+ * RXBRK will indicate start-of-break.
+ */
+ UART_PUT_IDR(port, ATMEL_US_RXBRK);
+ status &= ~ATMEL_US_RXBRK;
+ atmel_port->break_active = 0;
+ }
+ }
+
+ atmel_buffer_rx_char(port, status, ch);
+ status = UART_GET_CSR(port);
+ }
+
+ tasklet_schedule(&atmel_port->tasklet);
+}
+
+/*
+ * Transmit characters (called from tasklet with TXRDY interrupt
+ * disabled)
+ */
+static void atmel_tx_chars(struct uart_port *port)
+{
+ struct circ_buf *xmit = &port->state->xmit;
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+ if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) {
+ UART_PUT_CHAR(port, port->x_char);
+ port->icount.tx++;
+ port->x_char = 0;
+ }
+ if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+ return;
+
+ while (UART_GET_CSR(port) & atmel_port->tx_done_mask) {
+ UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ port->icount.tx++;
+ if (uart_circ_empty(xmit))
+ break;
+ }
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+
+ if (!uart_circ_empty(xmit))
+ /* Enable interrupts */
+ UART_PUT_IER(port, atmel_port->tx_done_mask);
+}
+
+/*
+ * receive interrupt handler.
+ */
+static void
+atmel_handle_receive(struct uart_port *port, unsigned int pending)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+ if (atmel_use_dma_rx(port)) {
+ /*
+ * PDC receive. Just schedule the tasklet and let it
+ * figure out the details.
+ *
+ * TODO: We're not handling error flags correctly at
+ * the moment.
+ */
+ if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) {
+ UART_PUT_IDR(port, (ATMEL_US_ENDRX
+ | ATMEL_US_TIMEOUT));
+ tasklet_schedule(&atmel_port->tasklet);
+ }
+
+ if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE |
+ ATMEL_US_FRAME | ATMEL_US_PARE))
+ atmel_pdc_rxerr(port, pending);
+ }
+
+ /* Interrupt receive */
+ if (pending & ATMEL_US_RXRDY)
+ atmel_rx_chars(port);
+ else if (pending & ATMEL_US_RXBRK) {
+ /*
+ * End of break detected. If it came along with a
+ * character, atmel_rx_chars will handle it.
+ */
+ UART_PUT_CR(port, ATMEL_US_RSTSTA);
+ UART_PUT_IDR(port, ATMEL_US_RXBRK);
+ atmel_port->break_active = 0;
+ }
+}
+
+/*
+ * transmit interrupt handler. (Transmit is IRQF_NODELAY safe)
+ */
+static void
+atmel_handle_transmit(struct uart_port *port, unsigned int pending)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+ if (pending & atmel_port->tx_done_mask) {
+ /* Either PDC or interrupt transmission */
+ UART_PUT_IDR(port, atmel_port->tx_done_mask);
+ tasklet_schedule(&atmel_port->tasklet);
+ }
+}
+
+/*
+ * status flags interrupt handler.
+ */
+static void
+atmel_handle_status(struct uart_port *port, unsigned int pending,
+ unsigned int status)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+ if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC
+ | ATMEL_US_CTSIC)) {
+ atmel_port->irq_status = status;
+ tasklet_schedule(&atmel_port->tasklet);
+ }
+}