diff options
Diffstat (limited to 'target/image/generic/lzma-loader/src/uart16550.c')
| -rw-r--r-- | target/image/generic/lzma-loader/src/uart16550.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/target/image/generic/lzma-loader/src/uart16550.c b/target/image/generic/lzma-loader/src/uart16550.c new file mode 100644 index 0000000..7df5727 --- /dev/null +++ b/target/image/generic/lzma-loader/src/uart16550.c @@ -0,0 +1,86 @@ +/* + * Copyright (C) 2001 MontaVista Software Inc. + * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + */ + + +#include "uart16550.h" + +/* === CONFIG === */ + +#define BASE 0xb8058000 +#define MAX_BAUD 1152000 +#define REG_OFFSET 4 + +/* === END OF CONFIG === */ + +/* register offset */ +#define OFS_RCV_BUFFER (0*REG_OFFSET) +#define OFS_TRANS_HOLD (0*REG_OFFSET) +#define OFS_SEND_BUFFER (0*REG_OFFSET) +#define OFS_INTR_ENABLE (1*REG_OFFSET) +#define OFS_INTR_ID (2*REG_OFFSET) +#define OFS_DATA_FORMAT (3*REG_OFFSET) +#define OFS_LINE_CONTROL (3*REG_OFFSET) +#define OFS_MODEM_CONTROL (4*REG_OFFSET) +#define OFS_RS232_OUTPUT (4*REG_OFFSET) +#define OFS_LINE_STATUS (5*REG_OFFSET) +#define OFS_MODEM_STATUS (6*REG_OFFSET) +#define OFS_RS232_INPUT (6*REG_OFFSET) +#define OFS_SCRATCH_PAD (7*REG_OFFSET) + +#define OFS_DIVISOR_LSB (0*REG_OFFSET) +#define OFS_DIVISOR_MSB (1*REG_OFFSET) + + +/* memory-mapped read/write of the port */ +#define UART16550_READ(y) (*((volatile uint32*)(BASE + y))) +#define UART16550_WRITE(y, z) ((*((volatile uint32*)(BASE + y))) = z) + +#define DEBUG_LED (*(unsigned short*)0xb7ffffc0) +#define OutputLED(x) (DEBUG_LED = x) + +void Uart16550Init(uint32 baud, uint8 data, uint8 parity, uint8 stop) +{ + /* disable interrupts */ + UART16550_WRITE(OFS_INTR_ENABLE, 0); + + /* set up buad rate */ + { + uint32 divisor; + + /* set DIAB bit */ + UART16550_WRITE(OFS_LINE_CONTROL, 0x80); + + /* set divisor */ + divisor = MAX_BAUD / baud; + UART16550_WRITE(OFS_DIVISOR_LSB, divisor & 0xff); + UART16550_WRITE(OFS_DIVISOR_MSB, (divisor & 0xff00)>>8); + + /* clear DIAB bit */ + UART16550_WRITE(OFS_LINE_CONTROL, 0x0); + } + + /* set data format */ + UART16550_WRITE(OFS_DATA_FORMAT, data | parity | stop); +} + +uint8 Uart16550GetPoll() +{ + while((UART16550_READ(OFS_LINE_STATUS) & 0x1) == 0); + return UART16550_READ(OFS_RCV_BUFFER); +} + + +void Uart16550Put(uint8 byte) +{ + while ((UART16550_READ(OFS_LINE_STATUS) &0x20) == 0); + UART16550_WRITE(OFS_SEND_BUFFER, byte); +} + |