From 7ec8bb15ee368ea54d48d64867767a704d9ab4c2 Mon Sep 17 00:00:00 2001 From: Wolfgang Denk Date: Thu, 27 Dec 2007 10:56:54 +0100 Subject: OMAP5912: fix FIFO handling in UART driver According to the OMAP5912 Serial Interfaces Reference Guide (see http://focus.ti.com/lit/ug/spru760c/spru760c.pdf, page 150), the FIFO_EN enable bit in the FIFO Control Register (FCR) can only be changed when the baud clock is not running, i. e. when both DLL and DLH are set to 0. Thus make sure that DLL and DLH are 0 when writing the FCR. Signed-off-by: Wolfgang Denk --- drivers/serial/ns16550.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) (limited to 'drivers/serial') diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c index 2429464d89..6b3f60eb57 100644 --- a/drivers/serial/ns16550.c +++ b/drivers/serial/ns16550.c @@ -21,11 +21,15 @@ void NS16550_init (NS16550_t com_port, int baud_divisor) com_port->mdr1 = 0x7; /* mode select reset TL16C750*/ #endif com_port->lcr = LCR_BKSE | LCRVAL; - com_port->dll = baud_divisor & 0xff; - com_port->dlm = (baud_divisor >> 8) & 0xff; + com_port->dll = 0; + com_port->dlm = 0; com_port->lcr = LCRVAL; com_port->mcr = MCRVAL; com_port->fcr = FCRVAL; + com_port->lcr = LCR_BKSE | LCRVAL; + com_port->dll = baud_divisor & 0xff; + com_port->dlm = (baud_divisor >> 8) & 0xff; + com_port->lcr = LCRVAL; #if defined(CONFIG_OMAP) #if defined(CONFIG_APTIX) com_port->mdr1 = 3; /* /13 mode so Aptix 6MHz can hit 115200 */ @@ -38,12 +42,16 @@ void NS16550_init (NS16550_t com_port, int baud_divisor) void NS16550_reinit (NS16550_t com_port, int baud_divisor) { com_port->ier = 0x00; + com_port->lcr = LCR_BKSE | LCRVAL; + com_port->dll = 0; + com_port->dlm = 0; + com_port->lcr = LCRVAL; + com_port->mcr = MCRVAL; + com_port->fcr = FCRVAL; com_port->lcr = LCR_BKSE; com_port->dll = baud_divisor & 0xff; com_port->dlm = (baud_divisor >> 8) & 0xff; com_port->lcr = LCRVAL; - com_port->mcr = MCRVAL; - com_port->fcr = FCRVAL; } void NS16550_putc (NS16550_t com_port, char c) -- cgit v1.2.3