diff options
Diffstat (limited to 'arch/mips/galileo-boards/ev96100/uart.S')
| -rw-r--r-- | arch/mips/galileo-boards/ev96100/uart.S | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/mips/galileo-boards/ev96100/uart.S b/arch/mips/galileo-boards/ev96100/uart.S new file mode 100644 index 000000000..549bbb68d --- /dev/null +++ b/arch/mips/galileo-boards/ev96100/uart.S @@ -0,0 +1,92 @@ + +/* + * Low level serial I/O routines. + */ +#include <asm/asm.h> +#include <linux/errno.h> +#include <asm/current.h> +#include <asm/mipsregs.h> +#include <asm/regdef.h> +#include <asm/stackframe.h> +#include <asm/isadep.h> +#include <asm/unistd.h> + +#define SERIAL_BASE 0xbd000020 +#define SERB_DLABLO 0 +#define SERB_DLABHI 1 +#define SERB_FIFO 2 +#define SERB_DATA 0 +#define SERB_LCR 3 +#define SERB_MCR 4 +#define SERB_CMD 5 + +#define SERA_DLABLO 0x08 +#define SERA_DLABHI 0x09 +#define SERA_DATA 0x08 +#define SERA_LCR 0x0B +#define SERA_MCR 0x0C +#define SERA_CMD 0x0D + +#define TX_BUSY 0x20 + +/* + * To calculate divisor for different baud rates: + * divisor = 3686400/(baud rate x 16), where 3686400 is our + * 3.6864MHz clock input. + */ + +/* + * routine to initialize the serial DUART. Channel A only + */ + .set noreorder + .global init_serial + .ent init_serial +init_serial: + li a0,SERIAL_BASE + +#if 0 + # init channel A + li t0,0x0083 + sb t0,SERA_LCR(a0) # set DLAB + +# li t0,24 # 9600 baud + li t0,2 # 115200 baud + sb t0,SERA_DLABLO(a0) # set divisor + + li t0,0 + sb t0,SERA_DLABHI(a0) + + li t0,0x0003 # 8 data bits + sb t0,SERA_LCR(a0) +#endif + +#if 1 + # init channel B + li t0,0x0083 + sb t0,SERB_LCR(a0) # set DLAB + + li t0,24 + sb t0,SERB_DLABLO(a0) # set divisor for 115200 baud + + li t0,0 + sb t0,SERB_DLABHI(a0) + + li t0,0x0003 # 8 data bits + sb t0,SERB_LCR(a0) + + li t0,0 # no fifo + sb t0,SERB_FIFO(a0) +#endif + + li a0, 0xB4000000 + li t0, 0x002fffff + sw t0, 0x464(a0) + + + jr ra + nop + + .size init_serial, . - init_serial; + .end init_serial + + .set reorder |