This patch adds an extra operation in ns16550.c to suuport MediaTek SoCs as we have a highspeed register which influences the calcualtion of the divisor.
Note that we don't support the baudrate greater than 115200 currently.
Signed-off-by: Ryder Lee ryder.lee@mediatek.com Tested-by: Matthias Brugger matthias.bgg@gmail.com --- drivers/serial/ns16550.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c index f9041aa..f5410af 100644 --- a/drivers/serial/ns16550.c +++ b/drivers/serial/ns16550.c @@ -148,6 +148,13 @@ int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
static void NS16550_setbrg(NS16550_t com_port, int baud_divisor) { +#ifdef CONFIG_ARCH_MEDIATEK + /* + * MediaTek UARTs has an extra highspeed register. + * We need to clear it if baudrate <= 115200. + */ + serial_out(0, &com_port->reg9); +#endif serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr); serial_out(baud_divisor & 0xff, &com_port->dll); serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm); @@ -261,6 +268,9 @@ static inline void _debug_uart_init(void) serial_dout(&com_port->mcr, UART_MCRVAL); serial_dout(&com_port->fcr, UART_FCR_DEFVAL);
+#ifdef CONFIG_ARCH_MEDIATEK + serial_dout(&com_port->reg9, 0); +#endif serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL); serial_dout(&com_port->dll, baud_divisor & 0xff); serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);