From d10ee1d1917b082f0008a840cde5aeaad11b396b Mon Sep 17 00:00:00 2001 From: Vabhav Sharma Date: Fri, 26 Jun 2020 16:50:34 +0530 Subject: tty: serial: fsl_lpuart: minimum baud rate support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The formula for the baud rate is baud rate = "baud clock / ((OSR+1) × SBR) Algorithm used in function lpuart32_serial_setbrg() only changes the SBR. Even with maxmum value put in, OSR stays at 0x7 and the lowest baud rate would be ~ 2600 bps Update the algorithm to allow driver operation at 1200,2400 or 600 bps Signed-off-by: Vabhav Sharma Link: https://lore.kernel.org/r/1593170434-13524-1-git-send-email-vabhav.sharma@oss.nxp.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/fsl_lpuart.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/tty/serial/fsl_lpuart.c') diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 90298c403042..7ca642249224 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1925,6 +1925,9 @@ static void __lpuart32_serial_setbrg(struct uart_port *port, tmp_sbr++; } + if (tmp_sbr > UARTBAUD_SBR_MASK) + continue; + if (tmp_diff <= baud_diff) { baud_diff = tmp_diff; osr = tmp_osr; -- cgit v1.2.3