[U-Boot] [PATCH 1/1 v2] omap3_beagle: Enabling UART3 first allows the Transmitter to be empty

Manfred Huber
2013-03-25T22:02:47Z

From: Manfred Huber

Due to a Bug in the ROM code of some OMAP3 devices, the TEMT bit is not
set if UART3 is configured before (only THRE is set). Reason is the
disabling of UART3 even though the Transmitter is not empty. Enabling
UART3 allows the Transmitter to be empty.

Signed-off-by: Manfred Huber <man.huber@arcor.de>
---
drivers/serial/ns16550.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index b2da8b3..24ff84f 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -36,10 +36,18 @@

void NS16550_init(NS16550_t com_port, int baud_divisor)
{
-#if (!defined(CONFIG_SYS_NS16550_BROKEN_TEMT))
+#if (defined(CONFIG_SPL_BUILD) && defined(CONFIG_OMAP34XX))
+ if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE)) ==
UART_LSR_THRE) {
+ serial_out(UART_LCR_DLAB, &com_port->lcr);
+ serial_out(baud_divisor & 0xff, &com_port->dll);
+ serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
+ serial_out(UART_LCRVAL, &com_port->lcr);
+ serial_out(0, &com_port->mdr1);
+ }
+#endif
+
while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
;
-#endif

serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
#if (defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)) || \