diff options
| -rw-r--r-- | drivers/tty/serial/imx.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 3215ecbfeb93..7506a8dad88b 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1372,12 +1372,38 @@ static void imx_shutdown(struct uart_port *port) static void imx_flush_buffer(struct uart_port *port) { + int i, temp; struct imx_port *sport = (struct imx_port *)port; if (sport->dma_is_enabled) { sport->tx_bytes = 0; dmaengine_terminate_all(sport->dma_chan_tx); } + + /* + * UCR2_SRST will reset the transmit and receive state machines, + * all FIFOs and register UBIR, UBMR, UBRC, + * and UTS[6-3], so save the required registers + */ + sport->saved_reg[0] = readl(sport->port.membase + UBIR); + sport->saved_reg[1] = readl(sport->port.membase + UBMR); + sport->saved_reg[2] = readl(sport->port.membase + UBRC); + sport->saved_reg[3] = readl(sport->port.membase + IMX21_UTS); + + i = 100; + + temp = readl(sport->port.membase + UCR2); + temp &= ~UCR2_SRST; + writel(temp, sport->port.membase + UCR2); + + while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0)) + udelay(1); + + /* Restore the registers */ + writel(sport->saved_reg[0], sport->port.membase + UBIR); + writel(sport->saved_reg[1], sport->port.membase + UBMR); + writel(sport->saved_reg[2], sport->port.membase + UBRC); + writel(sport->saved_reg[3], sport->port.membase + IMX21_UTS); } static void |