serial: 8250_mtk: support big baud rate.

mediatek can support baud rate up to 4M.
the 'uart_get_baud_rate' function will limit the max baud rate.
Modify max baud to remove the limit.

Signed-off-by: Long Cheng <long.cheng@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 3611ec9..ce0cc47 100644 (file)
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -62,7 +62,7 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
         */
        baud = uart_get_baud_rate(port, termios, old,
                                  port->uartclk / 16 / 0xffff,
-                                 port->uartclk / 16);
+                                 port->uartclk);
 
        if (baud <= 115200) {
                serial_port_out(port, UART_MTK_HIGHS, 0x0);
@@ -76,10 +76,6 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
                quot = DIV_ROUND_UP(port->uartclk, 4 * baud);
        } else {
                serial_port_out(port, UART_MTK_HIGHS, 0x3);
-
-               /* Set to highest baudrate supported */
-               if (baud >= 1152000)
-                       baud = 921600;
                quot = DIV_ROUND_UP(port->uartclk, 256 * baud);
        }
 

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 7481b95..c45c1e3 100644 (file)
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2504,8 +2504,6 @@ static unsigned int serial8250_get_baud_rate(struct uart_port *port,
                                             struct ktermios *termios,
                                             struct ktermios *old)
 {
-       unsigned int tolerance = port->uartclk / 100;
-
        /*
         * Ask the core to calculate the divisor for us.
         * Allow 1% tolerance at the upper limit so uart clks marginally
@@ -2514,7 +2512,7 @@ static unsigned int serial8250_get_baud_rate(struct uart_port *port,
         */
        return uart_get_baud_rate(port, termios, old,
                                  port->uartclk / 16 / 0xffff,
-                                 (port->uartclk + tolerance) / 16);
+                                 port->uartclk);
 }
 
 void