imx: serial: use tty_encode_baud_rate to set true rate

real baud rate may be different from the one requested.
for upper layers, set the nearest value to the real rate
in favour of the rate previously requested.

Signed-off-by: Oskar Schirmer <os@emlix.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/serial/imx.c b/drivers/serial/imx.c
index 8c79e8c2fd4e7d79569bec10f4d49b1559b484c2..7b5d1de9cfe39c3436d1074bb3b9c77933743507 100644 (file)
--- a/drivers/serial/imx.c
+++ b/drivers/serial/imx.c
@@ -818,6 +818,7 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios,
        unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
        unsigned int div, ufcr;
        unsigned long num, denom;
+       uint64_t tdiv64;
 
        /*
         * If we don't support modem control lines, don't allow
@@ -930,6 +931,12 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios,
        rational_best_approximation(16 * div * baud, sport->port.uartclk,
                1 << 16, 1 << 16, &num, &denom);
 
+       tdiv64 = sport->port.uartclk;
+       tdiv64 *= num;
+       do_div(tdiv64, denom * 16 * div);
+       tty_encode_baud_rate(sport->port.info->port.tty,
+               (speed_t)tdiv64, (speed_t)tdiv64);
+
        num -= 1;
        denom -= 1;