diff options
Diffstat (limited to 'drivers/ns16550.c')
| -rw-r--r-- | drivers/ns16550.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/ns16550.c b/drivers/ns16550.c new file mode 100644 index 0000000..6f818d7 --- /dev/null +++ b/drivers/ns16550.c @@ -0,0 +1,56 @@ +/* + * COM1 NS16550 support + * originally from linux source (arch/ppc/boot/ns16550.c) + * modified to use CFG_ISA_MEM and new defines + */ + +#include <config.h> + +#ifdef CFG_NS16550 + +#include <ns16550.h> + +#define LCRVAL LCR_8N1 /* 8 data, 1 stop, no parity */ +#define MCRVAL (MCR_DTR | MCR_RTS) /* RTS/DTR */ +#define FCRVAL (FCR_FIFO_EN | FCR_RXSR | FCR_TXSR) /* Clear & enable FIFOs */ + +void NS16550_init (NS16550_t com_port, int baud_divisor) +{ + com_port->ier = 0x00; + com_port->lcr = LCR_BKSE | LCRVAL; + 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_reinit (NS16550_t com_port, int baud_divisor) +{ + com_port->ier = 0x00; + 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) +{ + while ((com_port->lsr & LSR_THRE) == 0); + com_port->thr = c; +} + +char NS16550_getc (NS16550_t com_port) +{ + while ((com_port->lsr & LSR_DR) == 0); + return (com_port->rbr); +} + +int NS16550_tstc (NS16550_t com_port) +{ + return ((com_port->lsr & LSR_DR) != 0); +} + +#endif |