arm: vf610: lpuart: disable FIFO on initializaton

UART does not use the UART FIFO, but we should also not rely that
the UART FIFO is diabled by default. For instance, when loading
U-Boot using the boot ROMs serial downloader protocol over UART,
FIFO is enabled at U-Boot start time.

This patch disables the RX and TX FIFO, sets back their thresholds
and flushes them.

Signed-off-by: Stefan Agner <stefan@agner.ch>
This commit is contained in:
Stefan Agner 2014-08-19 17:54:28 +02:00 committed by Stefano Babic
parent a3db78d887
commit 89e69fd4a9

View File

@ -17,6 +17,10 @@
#define US1_OR (1 << 3)
#define UC2_TE (1 << 3)
#define UC2_RE (1 << 2)
#define CFIFO_TXFLUSH (1 << 7)
#define CFIFO_RXFLUSH (1 << 6)
#define SFIFO_RXOF (1 << 2)
#define SFIFO_RXUF (1 << 0)
DECLARE_GLOBAL_DATA_PTR;
@ -85,6 +89,12 @@ static int lpuart_serial_init(void)
__raw_writeb(0, &base->umodem);
__raw_writeb(0, &base->uc1);
/* Disable FIFO and flush buffer */
__raw_writeb(0x0, &base->upfifo);
__raw_writeb(0x0, &base->utwfifo);
__raw_writeb(0x1, &base->urwfifo);
__raw_writeb(CFIFO_TXFLUSH | CFIFO_RXFLUSH, &base->ucfifo);
/* provide data bits, parity, stop bit, etc */
serial_setbrg();