429 lines
9.5 KiB
C
429 lines
9.5 KiB
C
/*
|
|
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,
|
|
GPL-compatible, and OK to use in both free and proprietary applications.
|
|
Additions and corrections to this file are welcome.
|
|
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
|
|
* Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in
|
|
the documentation and/or other materials provided with the
|
|
distribution.
|
|
|
|
* Neither the name of the copyright holders nor the names of
|
|
contributors may be used to endorse or promote products derived
|
|
from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
#include <stdbool.h>
|
|
#include <avr/io.h>
|
|
#include <avr/interrupt.h>
|
|
#include <util/delay.h>
|
|
#include "ps2.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 void data_lo(void);
|
|
static inline void data_hi(void);
|
|
static inline bool data_in(void);
|
|
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);
|
|
|
|
|
|
/*
|
|
Primitive PS/2 Library for AVR
|
|
==============================
|
|
Host side is only supported now.
|
|
|
|
|
|
I/O control
|
|
-----------
|
|
High state is asserted by input with pull up.
|
|
|
|
|
|
PS/2 References
|
|
---------------
|
|
http://www.computer-engineering.org/ps2protocol/
|
|
http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
|
|
*/
|
|
|
|
|
|
#define WAIT(stat, us, err) do { \
|
|
if (!wait_##stat(us)) { \
|
|
ps2_error = err; \
|
|
goto ERROR; \
|
|
} \
|
|
} while (0)
|
|
|
|
|
|
uint8_t ps2_error = PS2_ERR_NONE;
|
|
|
|
|
|
void ps2_host_init(void)
|
|
{
|
|
#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 = 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();
|
|
} else {
|
|
data_lo();
|
|
}
|
|
WAIT(clock_hi, 50, 2);
|
|
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);
|
|
|
|
res = ps2_host_recv_response();
|
|
ERROR:
|
|
#ifdef PS2_INT_ENABLE
|
|
PS2_INT_ENABLE();
|
|
idle();
|
|
#else
|
|
inhibit();
|
|
#endif
|
|
return res;
|
|
}
|
|
|
|
/* 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 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();
|
|
}
|
|
|
|
#define DEBUGP_INIT() do { DDRC = 0xFF; } while (0)
|
|
#define DEBUGP(x) do { PORTC = x; } while (0)
|
|
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, 1, 1);
|
|
WAIT(data_lo, 1, 2);
|
|
WAIT(clock_hi, 50, 3);
|
|
|
|
/* data [2-9] */
|
|
for (uint8_t i = 0; i < 8; i++) {
|
|
WAIT(clock_lo, 50, 4);
|
|
if (data_in()) {
|
|
parity = !parity;
|
|
data |= (1<<i);
|
|
}
|
|
WAIT(clock_hi, 50, 5);
|
|
}
|
|
|
|
/* parity [10] */
|
|
WAIT(clock_lo, 50, 6);
|
|
if (data_in() != parity) {
|
|
ps2_error = PS2_ERR_PARITY;
|
|
goto ERROR;
|
|
}
|
|
WAIT(clock_hi, 50, 7);
|
|
|
|
/* stop bit [11] */
|
|
WAIT(clock_lo, 50, 8);
|
|
WAIT(data_hi, 1, 9);
|
|
WAIT(clock_hi, 50, 10);
|
|
|
|
return data;
|
|
ERROR:
|
|
return 0;
|
|
}
|
|
|
|
static inline void clock_lo()
|
|
{
|
|
PS2_CLOCK_PORT &= ~(1<<PS2_CLOCK_BIT);
|
|
PS2_CLOCK_DDR |= (1<<PS2_CLOCK_BIT);
|
|
}
|
|
static inline void clock_hi()
|
|
{
|
|
/* input with pull up */
|
|
PS2_CLOCK_DDR &= ~(1<<PS2_CLOCK_BIT);
|
|
PS2_CLOCK_PORT |= (1<<PS2_CLOCK_BIT);
|
|
}
|
|
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()
|
|
{
|
|
PS2_DATA_PORT &= ~(1<<PS2_DATA_BIT);
|
|
PS2_DATA_DDR |= (1<<PS2_DATA_BIT);
|
|
}
|
|
static inline void data_hi()
|
|
{
|
|
/* input with pull up */
|
|
PS2_DATA_DDR &= ~(1<<PS2_DATA_BIT);
|
|
PS2_DATA_PORT |= (1<<PS2_DATA_BIT);
|
|
}
|
|
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);
|
|
}
|
|
|
|
static inline uint16_t wait_clock_lo(uint16_t us)
|
|
{
|
|
while (clock_in() && us) { asm(""); _delay_us(1); us--; }
|
|
return us;
|
|
}
|
|
static inline uint16_t wait_clock_hi(uint16_t us)
|
|
{
|
|
while (!clock_in() && us) { asm(""); _delay_us(1); us--; }
|
|
return us;
|
|
}
|
|
static inline uint16_t wait_data_lo(uint16_t us)
|
|
{
|
|
while (data_in() && us) { asm(""); _delay_us(1); us--; }
|
|
return us;
|
|
}
|
|
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();
|
|
}
|