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PS/2: request to resend when error is occured.

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This commit is contained in:
tmk 2011-02-15 21:14:55 +09:00
parent 3015f191a5
commit 239bdbf419
4 changed files with 93 additions and 110 deletions
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123
ps2.c
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@ -96,13 +96,15 @@ void ps2_host_init(void)
#endif
}
// TODO: send using interrupt if available
uint8_t ps2_host_send(uint8_t data)
{
bool parity;
RETRY:
parity = true;
ps2_error = 0;
uint8_t res = 0;
bool parity = true;
ps2_error = PS2_ERR_NONE;
#ifdef PS2_INT_DISABLE
PS2_INT_DISABLE();
#endif
/* terminate a transmission if we have */
inhibit();
_delay_us(100);
@ -139,15 +141,15 @@ RETRY:
WAIT(clock_hi, 50, 8);
WAIT(data_hi, 50, 9);
uint8_t res = ps2_host_recv_response();
if (res == 0xFE && data != 0xFE)
goto RETRY;
inhibit();
return res;
res = ps2_host_recv_response();
ERROR:
#ifdef PS2_INT_ENABLE
PS2_INT_ENABLE();
idle();
#else
inhibit();
return 0;
#endif
return res;
}
/* receive data when host want else inhibit communication */
@ -209,46 +211,99 @@ static inline uint8_t pbuf_dequeue(void)
/* get data received by interrupt */
uint8_t ps2_host_recv(void)
{
// TODO: release clock line after 100us when inhibited by error
if (ps2_error) {
ps2_host_send(0xFE); // request to resend
ps2_error = PS2_ERR_NONE;
}
return pbuf_dequeue();
}
#define DEBUGP_INIT() do { DDRC = 0xFF; } while (0)
#define DEBUGP(x) do { PORTC = x; } while (0)
ISR(PS2_INT_VECT)
{
/* interrupt means start bit comes */
pbuf_enqueue(recv_data());
static enum {
INIT,
START,
BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7,
PARITY,
STOP,
} state = INIT;
static uint8_t data = 0;
static uint8_t parity = 1;
/* release lines(idle state) */
idle();
_delay_us(5);
// TODO: abort if elapse 100us from previous interrupt
// return unless falling edge
if (clock_in()) {
goto RETURN;
}
state++;
DEBUGP(state);
switch (state) {
case START:
if (data_in())
goto ERROR;
break;
case BIT0:
case BIT1:
case BIT2:
case BIT3:
case BIT4:
case BIT5:
case BIT6:
case BIT7:
data >>= 1;
if (data_in()) {
data |= 0x80;
parity++;
}
break;
case PARITY:
if (data_in()) {
if (!(parity & 0x01))
goto ERROR;
} else {
if (parity & 0x01)
goto ERROR;
}
break;
case STOP:
if (!data_in())
goto ERROR;
pbuf_enqueue(data);
goto DONE;
break;
default:
goto ERROR;
}
goto RETURN;
ERROR:
DEBUGP(0xFF);
inhibit();
ps2_error = state;
DONE:
state = INIT;
data = 0;
parity = 1;
RETURN:
return;
}
#endif
/*
static void ps2_reset(void)
{
ps2_host_send(0xFF);
if (ps2_host_recv_response() == 0xFA) {
_delay_ms(1000);
ps2_host_recv_response();
}
}
*/
/* send LED state to keyboard */
void ps2_host_set_led(uint8_t led)
{
#ifdef PS2_INT_DISABLE
PS2_INT_DISABLE();
#endif
ps2_host_send(0xED);
ps2_host_recv_response();
ps2_host_send(led);
ps2_host_recv_response();
#ifdef PS2_INT_ENABLE
PS2_INT_ENABLE();
idle();
#endif
}
@ -257,7 +312,7 @@ static uint8_t recv_data(void)
{
uint8_t data = 0;
bool parity = true;
ps2_error = 0;
ps2_error = PS2_ERR_NONE;
/* start bit [1] */
WAIT(clock_lo, 1, 1);
@ -307,6 +362,7 @@ static inline bool clock_in()
{
PS2_CLOCK_DDR &= ~(1<<PS2_CLOCK_BIT);
PS2_CLOCK_PORT |= (1<<PS2_CLOCK_BIT);
_delay_us(1);
return PS2_CLOCK_PIN&(1<<PS2_CLOCK_BIT);
}
static inline void data_lo()
@ -324,6 +380,7 @@ static inline bool data_in()
{
PS2_DATA_DDR &= ~(1<<PS2_DATA_BIT);
PS2_DATA_PORT |= (1<<PS2_DATA_BIT);
_delay_us(1);
return PS2_DATA_PIN&(1<<PS2_DATA_BIT);
}