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#include "project.h"
#define KBCLK (1UL << 0)
#define KBCLK_PORT GPIOA
#define KBCLK_IRQ NVIC_EXTI0_IRQ
#define KBDAT (1UL << 1)
#define KBDAT_PORT GPIOA
/*Cope with lost sync */
/*If we've had no bits for this long, it's definately the start of a new word, 72MHz units */
#define RESYNC_GAP (7200000) /* 100ms */
#define ATKBD_TIMEOUT 1000 /*how long to wait for the keyboard to respond to a command in ms */
typedef enum {
STATE_START=0,
STATE_BIT0,
STATE_BIT1,
STATE_BIT2,
STATE_BIT3,
STATE_BIT4,
STATE_BIT5,
STATE_BIT6,
STATE_BIT7,
STATE_PARITY,
STATE_STOP,
} atkbd_state;
#define ATKBD_CMD_SETLEDS 0xed
#define ATKBD_CMD_GSCANSET 0xf0
#define ATKBD_CMD_SSCANSET 0xf0
#define ATKBD_CMD_GETID 0xf2
#define ATKBD_CMD_SETREP 0xf3
#define ATKBD_CMD_ENABLE 0xf4
#define ATKBD_CMD_RESET_DIS 0xf5
#define ATKBD_CMD_RESET_DEF 0xf6
#define ATKBD_CMD_SETALL_MB 0xf8
#define ATKBD_CMD_SETALL_MBR 0xfa
#define ATKBD_CMD_RESET_BAT 0xff
#define ATKBD_CMD_RESEND 0xfe
#define ATKBD_CMD_EX_ENABLE 0xea
#define ATKBD_CMD_EX_SETLEDS 0xeb
#define ATKBD_CMD_OK_GETID 0xe8
#define ATKBD_RET_ECHO 0xee
#define ATKBD_RET_ACK 0xfa
#define ATKBD_RET_NAK 0xfe
#define ATKBD_RET_BAT 0xaa
#define ATKBD_RET_EMUL0 0xe0
#define ATKBD_RET_EMUL1 0xe1
#define ATKBD_RET_RELEASE 0xf0
#define ATKBD_RET_HANJA 0xf1
#define ATKBD_RET_HANGEUL 0xf2
#define ATKBD_RET_ERR 0xff
#define ATKBD_KEY_UNKNOWN 0
#define ATKBD_KEY_NULL 255
static int atkbd_ack;
static int atkbd_nack;
static int atkbd_bat;
static int atkbd_echo;
static uint32_t cycle_diff(uint32_t a,uint32_t b)
{
return b-a;
}
static void atkbd_dispatch(int emul,int key,int updown)
{
printf("KEY> %x %x %x\r\n",emul,key,updown);
}
static void atkbd_data_dispatch(uint8_t byte)
{
static int release;
static int emul;
printf("ATKBD < 0x%02x\r\n",byte);
switch (byte) {
case ATKBD_RET_ACK:
atkbd_ack++;
break;
case ATKBD_RET_NAK:
atkbd_nack++;
break;
case ATKBD_RET_BAT:
atkbd_bat++;
break;
case ATKBD_RET_ECHO:
atkbd_echo++;
break;
case ATKBD_RET_ERR:
case ATKBD_KEY_UNKNOWN:
case ATKBD_RET_HANJA: /*Don't handle japanese or korean for the moment*/
case ATKBD_RET_HANGEUL: /*Don't handle japanese or korean for the moment*/
/*All these need no action */
break;
case ATKBD_RET_EMUL0:
emul=1;
break;
case ATKBD_RET_EMUL1:
emul=2;
break;
case ATKBD_RET_RELEASE:
release=1;
break;
default:
atkbd_dispatch(emul,byte,release);
emul=0;
release=0;
}
}
void exti0_isr(void)
{
static uint32_t last_interrupt=0;
static atkbd_state state=STATE_START;
static uint8_t atkbd_byte;
static int parity;
uint32_t now,diff;
int d;
d=!!GET(KBDAT);
exti_reset_request(KBCLK);
now=dwt_read_cycle_counter();
diff=cycle_diff(last_interrupt,now);
last_interrupt=now;
if (diff>RESYNC_GAP) state=STATE_START;
switch (state) {
case STATE_START:
atkbd_byte=0;
parity=0;
if (!d) state++;
break;
case STATE_BIT0:
case STATE_BIT1:
case STATE_BIT2:
case STATE_BIT3:
case STATE_BIT4:
case STATE_BIT5:
case STATE_BIT6:
case STATE_BIT7:
atkbd_byte|=d<<(state-STATE_BIT0);
/* fall through*/
case STATE_PARITY:
parity ^= d;
state++;
break;
case STATE_STOP:
if (d && parity) atkbd_data_dispatch(atkbd_byte);
state=STATE_START;
break;
}
}
void atkbd_set(int clk,int dat)
{
if (clk) {
MAP_INPUT_PU(KBCLK);
} else {
CLEAR(KBCLK);
MAP_OUTPUT_PP(KBCLK);
}
if (dat) {
MAP_INPUT_PU(KBDAT);
} else {
CLEAR(KBDAT);
MAP_OUTPUT_PP(KBDAT);
}
}
int atkbd_send(uint8_t d)
{
uint32_t then=ticks;
int parity=1;
uint32_t c;
nvic_disable_irq(KBCLK_IRQ);
#define PS2_CLOCK_SEIZE_DELAY 200
#define PS2_BIT_DELAY 10
atkbd_set(0,1);
delay_us(PS2_CLOCK_SEIZE_DELAY);
atkbd_set(0,0);
delay_us(PS2_BIT_DELAY);
atkbd_set(1,0);
delay_us(PS2_BIT_DELAY);
for (c=1;c<0x100;c<<=1) {
while (GET(KBCLK)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
atkbd_set(1,c&d);
parity^=!!(c&d);
while (!GET(KBCLK)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
}
while (GET(KBCLK)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
atkbd_set(1,parity);
while (!GET(KBCLK)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
while (GET(KBCLK)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
while (!GET(KBCLK)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
atkbd_set(1,1);
while (GET(KBDAT)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
while (GET(KBCLK)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
while (!GET(KBDAT)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
while (!GET(KBCLK)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
exti_reset_request(KBCLK);
nvic_enable_irq(KBCLK_IRQ);
printf("ATKBD > 0x%02x\r\n",d);
return 0;
err:
atkbd_set(1,1);
while (!GET(KBDAT)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
while (!GET(KBCLK)) if (timed_out(then,ATKBD_TIMEOUT)) goto err;
exti_reset_request(KBCLK);
nvic_enable_irq(KBCLK_IRQ);
printf("ATKBD >! 0x%02x\r\n",d);
return -1;
}
static int atkbd_reset(void)
{
uint32_t then=ticks;
atkbd_bat=0;
atkbd_send(ATKBD_CMD_RESET_BAT);
while (!atkbd_bat) if (timed_out(then,ATKBD_TIMEOUT)) return -1;
then=ticks;
atkbd_ack=0;
atkbd_send(ATKBD_CMD_SETALL_MBR);
while (!atkbd_ack) if (timed_out(then,ATKBD_TIMEOUT)) return -1;
return 0;
}
int atkbd_request_echo(void)
{
uint32_t then=ticks;
atkbd_ack=0;
atkbd_send(ATKBD_CMD_ECHO);
while (!atkbd_echo) if (timed_out(then,ATKBD_TIMEOUT)) return -1;
return 0;
}
int atkbd_set_leds(uint8_t leds)
{
uint32_t then=ticks;
atkbd_ack=0;
atkbd_send(ATKBD_CMD_SETLEDS);
while (!atkbd_ack) if (timed_out(then,ATKBD_TIMEOUT)) return -1;
then=ticks;
atkbd_ack=0;
atkbd_send(leds);
while (!atkbd_ack) if (timed_out(then,ATKBD_TIMEOUT)) return -1;
return 0;
}
void atkbd_init(void)
{
atkbd_set(1,1);
delay_ms(200);
nvic_enable_irq(NVIC_EXTI0_IRQ);
exti_select_source(KBCLK, KBCLK_PORT);
exti_set_trigger(KBCLK, EXTI_TRIGGER_FALLING);
exti_enable_request(KBCLK);
exti_reset_request(KBCLK);
nvic_enable_irq(KBCLK_IRQ);
atkbd_reset();
atkbd_request_echo();
atkbd_set_leds(0x07);
}
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