/*
-Copyright (c) 2010 Jun WAKO <wakojun@gmail.com>
+Copyright (c) 2010,2011 Jun WAKO <wakojun@gmail.com>
This software is licensed with a Modified BSD License.
All of this is supposed to be Free Software, Open Source, DFSG-free,
*/
#include <stdbool.h>
#include <avr/io.h>
+#include <avr/interrupt.h>
#include <util/delay.h>
#include "ps2.h"
-#include "print.h"
#include "debug.h"
+static uint8_t recv_data(void);
static inline void clock_lo(void);
static inline void clock_hi(void);
static inline bool clock_in(void);
static inline uint16_t wait_clock_hi(uint16_t us);
static inline uint16_t wait_data_lo(uint16_t us);
static inline uint16_t wait_data_hi(uint16_t us);
+static inline void idle(void);
+static inline void inhibit(void);
/*
} \
} while (0)
-#define WAIT_NORETRY(stat, us, err) do { \
- if (!wait_##stat(us)) { \
- ps2_error = err; \
- return 0; \
- } \
-} while (0)
-
uint8_t ps2_error = PS2_ERR_NONE;
void ps2_host_init(void)
{
- /* inhibit */
- clock_lo();
- data_hi();
+#ifdef PS2_INT_ENABLE
+ PS2_INT_ENABLE();
+ idle();
+#else
+ inhibit();
+#endif
}
+// TODO: send using interrupt if available
uint8_t ps2_host_send(uint8_t data)
{
+ uint8_t res = 0;
bool parity = true;
- ps2_error = 0;
-
- /* request to send */
- clock_lo();
+ ps2_error = PS2_ERR_NONE;
+#ifdef PS2_INT_DISABLE
+ PS2_INT_DISABLE();
+#endif
+ /* terminate a transmission if we have */
+ inhibit();
_delay_us(100);
+
/* start bit [1] */
data_lo();
clock_hi();
WAIT(clock_lo, 15000, 1);
/* data [2-9] */
for (uint8_t i = 0; i < 8; i++) {
+ _delay_us(15);
if (data&(1<<i)) {
parity = !parity;
data_hi();
WAIT(clock_lo, 50, 3);
}
/* parity [10] */
+ _delay_us(15);
if (parity) { data_hi(); } else { data_lo(); }
WAIT(clock_hi, 50, 4);
WAIT(clock_lo, 50, 5);
/* stop bit [11] */
+ _delay_us(15);
data_hi();
/* ack [12] */
WAIT(data_lo, 50, 6);
WAIT(clock_lo, 50, 7);
+
+ /* wait for idle state */
WAIT(clock_hi, 50, 8);
WAIT(data_hi, 50, 9);
- /* inhibit device to send */
- clock_lo();
-
- return 1;
+ res = ps2_host_recv_response();
ERROR:
- /* inhibit device to send */
- data_hi();
- clock_lo();
- return 0;
+#ifdef PS2_INT_ENABLE
+ PS2_INT_ENABLE();
+ idle();
+#else
+ inhibit();
+#endif
+ return res;
}
-uint8_t ps2_host_recv(void)
+/* receive data when host want else inhibit communication */
+uint8_t ps2_host_recv_response(void)
{
uint8_t data = 0;
- bool parity = true;
- ps2_error = 0;
/* terminate a transmission if we have */
- clock_lo();
+ inhibit();
_delay_us(100);
/* release lines(idle state) */
- clock_hi();
- data_hi();
+ idle();
+
+ /* wait start bit */
+ wait_clock_lo(2000);
+ data = recv_data();
+
+ inhibit();
+ return data;
+}
+
+#ifndef PS2_INT_VECT
+uint8_t ps2_host_recv(void)
+{
+ return ps2_host_recv_response();
+}
+#else
+/* ring buffer to store ps/2 key data */
+#define PBUF_SIZE 8
+static uint8_t pbuf[PBUF_SIZE];
+static uint8_t pbuf_head = 0;
+static uint8_t pbuf_tail = 0;
+static inline void pbuf_enqueue(uint8_t data)
+{
+ if (!data)
+ return;
+
+ uint8_t sreg = SREG;
+ cli();
+ uint8_t next = (pbuf_head + 1) % PBUF_SIZE;
+ if (next != pbuf_tail) {
+ pbuf[pbuf_head] = data;
+ pbuf_head = next;
+ } else {
+ debug("pbuf: full\n");
+ }
+ SREG = sreg;
+}
+static inline uint8_t pbuf_dequeue(void)
+{
+ uint8_t val = 0;
+
+ uint8_t sreg = SREG;
+ cli();
+ if (pbuf_head != pbuf_tail) {
+ val = pbuf[pbuf_tail];
+ pbuf_tail = (pbuf_tail + 1) % PBUF_SIZE;
+ }
+ SREG = sreg;
+
+ return val;
+}
+
+/* get data received by interrupt */
+uint8_t ps2_host_recv(void)
+{
+ if (ps2_error) {
+ print("x");
+ phex(ps2_error);
+ ps2_host_send(0xFE); // request to resend
+ ps2_error = PS2_ERR_NONE;
+ }
+ idle();
+ return pbuf_dequeue();
+}
+
+#if 0
+#define DEBUGP_INIT() do { DDRC = 0xFF; } while (0)
+#define DEBUGP(x) do { PORTC = x; } while (0)
+#else
+#define DEBUGP_INIT()
+#define DEBUGP(x)
+#endif
+ISR(PS2_INT_VECT)
+{
+ 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;
+ }
+
+ 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(0x0F);
+ inhibit();
+ ps2_error = state;
+DONE:
+ state = INIT;
+ data = 0;
+ parity = 1;
+RETURN:
+ return;
+}
+#endif
+
+
+static void ps2_reset(void)
+{
+ ps2_host_send(0xFF);
+}
+
+/* send LED state to keyboard */
+void ps2_host_set_led(uint8_t led)
+{
+ ps2_host_send(0xED);
+ ps2_host_send(led);
+}
+
+
+/* called after start bit comes */
+static uint8_t recv_data(void)
+{
+ uint8_t data = 0;
+ bool parity = true;
+ ps2_error = PS2_ERR_NONE;
/* start bit [1] */
- WAIT(clock_lo, 2000, 1); // How long should we wait?
+ WAIT(clock_lo, 1, 1);
WAIT(data_lo, 1, 2);
WAIT(clock_hi, 50, 3);
WAIT(data_hi, 1, 9);
WAIT(clock_hi, 50, 10);
- /* inhibit device to send */
- clock_lo();
-
return data;
ERROR:
- /* inhibit device to send */
- data_hi();
- clock_lo();
return 0;
}
-
static inline void clock_lo()
{
PS2_CLOCK_PORT &= ~(1<<PS2_CLOCK_BIT);
{
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()
{
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);
}
while (!data_in() && us) { asm(""); _delay_us(1); us--; }
return us;
}
+
+/* idle state that device can send */
+static inline void idle(void)
+{
+ clock_hi();
+ data_hi();
+}
+
+/* inhibit device to send */
+static inline void inhibit(void)
+{
+ clock_lo();
+ data_hi();
+}
projects / max / tmk_keyboard.git / blobdiff