serial: uniphier: flush transmitter before changing hardware settings

Ensure the transmitter is empty when chaining the baudrate or any
hardware settings. If a character is remaining in the transmitter,
the console will be garbled.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This commit is contained in:
Masahiro Yamada 2020-07-10 01:12:07 +09:00
parent 70434ab9de
commit 26f7a7deab

View file

@ -43,6 +43,10 @@ static int uniphier_serial_setbrg(struct udevice *dev, int baudrate)
divisor = DIV_ROUND_CLOSEST(priv->uartclk, mode_x_div * baudrate);
/* flush the trasmitter before changing hw setting */
while (!(readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_TEMT))
;
writel(divisor, priv->membase + UNIPHIER_UART_DLR);
return 0;
@ -132,6 +136,10 @@ static int uniphier_serial_probe(struct udevice *dev)
priv->uartclk = clk_data->clk_rate;
/* flush the trasmitter empty before changing hw setting */
while (!(readl(priv->membase + UNIPHIER_UART_LSR) & UART_LSR_TEMT))
;
tmp = readl(priv->membase + UNIPHIER_UART_LCR_MCR);
tmp &= ~UNIPHIER_UART_LCR_MASK;
tmp |= FIELD_PREP(UNIPHIER_UART_LCR_MASK, UART_LCR_WLEN8);