From 07986580d0ad14433021b709c6c005e2757c5a68 Mon Sep 17 00:00:00 2001 From: Soren Brinkmann Date: Mon, 11 Jan 2016 17:41:41 -0800 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/xilinx_uartps.c | 97 ++++++++++++------------------ 1 file changed, 40 insertions(+), 57 deletions(-) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 3ff6e3c2347c..131a3117fbbb 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -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; - - /* 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++; + cdns_uart_handle_tx(port); - /* 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); } /** -- 2.30.2