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authortmk2011-02-15 21:14:55 +0900
committertmk2011-02-22 03:09:09 +0900
commit239bdbf41936566c0ae5b0cbd8c6bf7dd824f7fb (patch)
tree2a906df667e523d8b24b01e23ffae0c9bc815250 /ps2.c
parent3015f191a5d9268cb5ca7a0256597d3d76f4d200 (diff)
PS/2: request to resend when error is occured.
Diffstat (limited to 'ps2.c')
-rw-r--r--ps2.c123
1 files changed, 90 insertions, 33 deletions
diff --git a/ps2.c b/ps2.c
index 6d76538fe..52ee1691f 100644
--- a/ps2.c
+++ b/ps2.c
@@ -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;
+
+ // TODO: abort if elapse 100us from previous interrupt
+
+ // return unless falling edge
+ if (clock_in()) {
+ goto RETURN;
+ }
- /* release lines(idle state) */
- idle();
- _delay_us(5);
+ 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);
}