PS/2 library receives data partially by interrupt

This commit is contained in:
tmk 2011-02-07 14:59:07 +09:00
parent 0632618d29
commit 04f351b802
11 changed files with 277 additions and 108 deletions

185
ps2.c
View file

@ -1,5 +1,5 @@
/*
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,
@ -36,12 +36,13 @@ POSSIBILITY OF SUCH DAMAGE.
*/
#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);
@ -52,6 +53,8 @@ static inline uint16_t wait_clock_lo(uint16_t us);
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);
/*
@ -79,38 +82,38 @@ http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
} \
} 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
}
uint8_t ps2_host_send(uint8_t data)
{
bool parity = true;
bool parity;
RETRY:
parity = true;
ps2_error = 0;
/* request to send */
clock_lo();
/* 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();
@ -121,44 +124,145 @@ uint8_t ps2_host_send(uint8_t data)
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();
uint8_t res = ps2_host_recv_response();
if (res == 0xFE && data != 0xFE)
goto RETRY;
return 1;
inhibit();
return res;
ERROR:
/* inhibit device to send */
data_hi();
clock_lo();
inhibit();
return 0;
}
/* receive data when host want else inhibit communication */
uint8_t ps2_host_recv_response(void)
{
uint8_t data = 0;
/* terminate a transmission if we have */
inhibit();
_delay_us(100);
/* release lines(idle state) */
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 next = (pbuf_head + 1) % PBUF_SIZE;
if (next != pbuf_tail) {
pbuf[pbuf_head] = data;
pbuf_head = next;
} else {
print("pbuf: full\n");
}
}
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)
{
return pbuf_dequeue();
}
ISR(PS2_INT_VECT)
{
PORTC = 0xFF;
/* interrupt means start bit comes */
pbuf_enqueue(recv_data());
/* release lines(idle state) */
idle();
_delay_us(5);
PORTC = 0x00;
}
#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
}
/* called after start bit comes */
static uint8_t recv_data(void)
{
uint8_t data = 0;
bool parity = true;
ps2_error = 0;
/* terminate a transmission if we have */
clock_lo();
_delay_us(100);
/* release lines(idle state) */
clock_hi();
data_hi();
/* 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);
@ -185,18 +289,11 @@ uint8_t ps2_host_recv(void)
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);
@ -252,3 +349,17 @@ static inline uint16_t wait_data_hi(uint16_t us)
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();
}