Commit d10ee1d1 authored by Vabhav Sharma's avatar Vabhav Sharma Committed by Greg Kroah-Hartman
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tty: serial: fsl_lpuart: minimum baud rate support 



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: default avatarVabhav Sharma <vabhav.sharma@nxp.com>
Link: https://lore.kernel.org/r/1593170434-13524-1-git-send-email-vabhav.sharma@oss.nxp.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3550f897

drivers/tty/serial/fsl_lpuart.c

+3 −0
Original line number Diff line number Diff line
@@ -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;