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Commit 07986580 authored by Soren Brinkmann's avatar Soren Brinkmann Committed by Greg Kroah-Hartman
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tty: xuartps: Consolidate TX handling 



start_tx and the ISR used largely identical code to transmit data.
Consolidate that in one place.

Signed-off-by: default avatarSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a8df6a51

drivers/tty/serial/xilinx_uartps.c

+40 −57
Original line number Diff line number Diff line
@@ -239,6 +239,41 @@ static void cdns_uart_handle_rx(struct uart_port *port, unsigned int isrstatus) 
	tty_flip_buffer_push(&port->state->port);

}



static void cdns_uart_handle_tx(struct uart_port *port)

{

	unsigned int numbytes;



	if (uart_circ_empty(&port->state->xmit)) {

		writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IDR);

		return;

	}



	numbytes = port->fifosize;

	while (numbytes && !uart_circ_empty(&port->state->xmit) &&

	       !(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)) {

		/*

		 * Get the data from the UART circular buffer

		 * and write it to the cdns_uart's TX_FIFO

		 * register.

		 */

		writel(port->state->xmit.buf[port->state->xmit.tail],

			port->membase + CDNS_UART_FIFO);

		port->icount.tx++;



		/*

		 * Adjust the tail of the UART buffer and wrap

		 * the buffer if it reaches limit.

		 */

		port->state->xmit.tail =

			(port->state->xmit.tail + 1) & (UART_XMIT_SIZE - 1);



		numbytes--;

	}



	if (uart_circ_chars_pending(&port->state->xmit) < WAKEUP_CHARS)

		uart_write_wakeup(port);

}



/**

 * cdns_uart_isr - Interrupt handler

 * @irq: Irq number
@@ -250,7 +285,7 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id) 
{

	struct uart_port *port = (struct uart_port *)dev_id;

	unsigned long flags;

	unsigned int isrstatus, numbytes;

	unsigned int isrstatus;



	spin_lock_irqsave(&port->lock, flags);
@@ -262,40 +297,8 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id) 
	if (isrstatus & CDNS_UART_RX_IRQS)

		cdns_uart_handle_rx(port, isrstatus);



	/* Dispatch an appropriate handler */

	if ((isrstatus & CDNS_UART_IXR_TXEMPTY) == CDNS_UART_IXR_TXEMPTY) {

		if (uart_circ_empty(&port->state->xmit)) {

			writel(CDNS_UART_IXR_TXEMPTY,

					port->membase + CDNS_UART_IDR);

		} else {

			numbytes = port->fifosize;

			/* Break if no more data available in the UART buffer */

			while (numbytes--) {

				if (uart_circ_empty(&port->state->xmit))

					break;

				/* Get the data from the UART circular buffer

				 * and write it to the cdns_uart's TX_FIFO

				 * register.

				 */

				writel(port->state->xmit.buf[

						port->state->xmit.tail],

					port->membase + CDNS_UART_FIFO);



				port->icount.tx++;



				/* Adjust the tail of the UART buffer and wrap

				 * the buffer if it reaches limit.

				 */

				port->state->xmit.tail =

					(port->state->xmit.tail + 1) &

						(UART_XMIT_SIZE - 1);

			}



			if (uart_circ_chars_pending(

					&port->state->xmit) < WAKEUP_CHARS)

				uart_write_wakeup(port);

		}

	}

	if ((isrstatus & CDNS_UART_IXR_TXEMPTY) == CDNS_UART_IXR_TXEMPTY)

		cdns_uart_handle_tx(port);



	writel(isrstatus, port->membase + CDNS_UART_ISR);
@@ -502,7 +505,7 @@ static int cdns_uart_clk_notifier_cb(struct notifier_block *nb, 
 */

static void cdns_uart_start_tx(struct uart_port *port)

{

	unsigned int status, numbytes = port->fifosize;

	unsigned int status;



	if (uart_tx_stopped(port))

		return;
@@ -519,31 +522,11 @@ static void cdns_uart_start_tx(struct uart_port *port) 
	if (uart_circ_empty(&port->state->xmit))

		return;



	while (numbytes-- && ((readl(port->membase + CDNS_UART_SR) &

				CDNS_UART_SR_TXFULL)) != CDNS_UART_SR_TXFULL) {

		/* Break if no more data available in the UART buffer */

		if (uart_circ_empty(&port->state->xmit))

			break;

	cdns_uart_handle_tx(port);



		/* Get the data from the UART circular buffer and

		 * write it to the cdns_uart's TX_FIFO register.

		 */

		writel(port->state->xmit.buf[port->state->xmit.tail],

				port->membase + CDNS_UART_FIFO);

		port->icount.tx++;



		/* Adjust the tail of the UART buffer and wrap

		 * the buffer if it reaches limit.

		 */

		port->state->xmit.tail = (port->state->xmit.tail + 1) &

					(UART_XMIT_SIZE - 1);

	}

	writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_ISR);

	/* Enable the TX Empty interrupt */

	writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IER);



	if (uart_circ_chars_pending(&port->state->xmit) < WAKEUP_CHARS)

		uart_write_wakeup(port);

}



/**