ok6410 -- uart & led

;/*************************************************************************************
;
; Project Name : OK6410 Uart & Led
;*************************************************************************************/
.globl main
.globl _start

_start:
    ldr r0,=0x70000000
    orr r0, r0, #0x13
    mcr p15, 0, r0, c15, c2, 4

    ldr r0, =0x7E004000
    mov r1, #0
    str r1, [r0]

    ldr r0, =0x7F008820
    ldr r1, =0x00221111
    str r1, [r0]

    ldr r1, =0x7F008828
    mov r0, #0
    str r0, [r1]
    bl delay

    ldr r1, =0x7F008824
    mov r0, #0
    str r0, [r1]
    bl delay

loop:
    mov r0, #0xE
    str r0, [r1]
    bl delay

    mov r0, #0xD
    str r0, [r1]
    bl delay

    mov r0, #0xB
    str r0, [r1]
    bl delay

    mov r0, #0x7
    str r0, [r1]
    bl delay

bl sys_clk_init
    bl        main

delay:
    ldr r2, =0x500000

delay_loop:
    sub r2, r2, #1
    cmp r2, #0
    bne delay_loop
    mov pc, lr

;-------------------------- clock init
sys_clk_init:
ldr r0, =0x7E00F000
ldr r1, [r0, #0x900]
mov r2, #0x40
orr r1, r1, r2
str r1, [r0, #0x900]
nop
nop
nop
nop

ldr r2, =0x80
orr r1, r1, r2
str r1, [r0, #0x900]

check_sync_ack:
ldr r1, [r0, #0x900]
ldr r2, =0xF00
and r1, r1, r2
cmp r1, #0xF00
bne check_sync_ack

set_lock_time:
mov r1, #0xFF00
orr r1, r1, #0xFF
str r1, [r0, #0x0]
str r1, [r0, #0x4]
str r1, [r0, #0x8]

set_div_clock:
ldr r1, [r0, #0x20]
bic r1, r1, #0xFF00
bic r1, r1, #0xFF
ldr r2, =0x3300
orr r1, r1, r2
str r1, [r0, #0x20]

set_uart_clock:
ldr r1, [r0, #0x28]
bic r1, r1, #0x70000
orr r1, r1, #0x30000
str r1, [r0, #0x28]

enable_apll_epll:
ldr r1, =0x810A0301
str r1, [r0, #0x0c]
ldr r1, =0x810A0302
str r1, [r0, #0x10]

selete_clk_src:
ldr r1, [r0, #0x1c]
ldr r2, =0x2005
orr r1, r1, r2
str r1, [r0, #0x1c]

mov pc, lr

halt:
b halt

;-------------------------------------------------------------------------------

;uart

#define ULCON0     (*((volatile unsigned long *)0x7F005000))
#define UCON0      (*((volatile unsigned long *)0x7F005004))
#define UFCON0     (*((volatile unsigned long *)0x7F005008))
#define UMCON0     (*((volatile unsigned long *)0x7F00500C))
#define UTRSTAT0   (*((volatile unsigned long *)0x7F005010))
#define UFSTAT0    (*((volatile unsigned long *)0x7F005018))
#define UTXH0      (*((volatile unsigned char *)0x7F005020))
#define URXH0      (*((volatile unsigned char *)0x7F005024))
#define UBRDIV0    (*((volatile unsigned short *)0x7F005028))
#define UDIVSLOT0 (*((volatile unsigned short *)0x7F00502C))
#define GPACON     (*((volatile unsigned long *)0x7F008000))

void init_uart(void)
{
GPACON &= ~0xff;
GPACON |= 0x22; /* ULCON0 */
ULCON0 = 0x3; /* 數據位:8, 無較驗, 停止位: 1, 8n1 */
UCON0 = 0x5; /* 使能UART發送、接收 */
UFCON0 = 0x01; /* FIFO ENABLE */
UMCON0 = 0; /* 波特率 */
/* DIV_VAL = (PCLK / (bps x 16 ) ) - 1
* PCLK = 66.5MHz
* bps = 115200
* DIV_VAL = (66500000 / (115200 x 16 ) ) - 1
*         = 35.08
*/
UBRDIV0   = 35;
/* x/16 = 0.08
* x = 1
*/
UDIVSLOT0 = 0x1;
}