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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: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hifive-unleashed-5.1
Soren Brinkmann 2016-01-11 17:41:41 -08:00 committed by Greg Kroah-Hartman
parent a8df6a5160
commit 07986580d0
1 changed files with 40 additions and 57 deletions
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97
drivers/tty/serial/xilinx_uartps.c
View File

@ -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);
}
/**