346 lines
		
	
	
	
		
			8.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			346 lines
		
	
	
	
		
			8.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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| Copyright 2010,2011,2012,2013 Jun WAKO <wakojun@gmail.com>
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| 
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| This software is licensed with a Modified BSD License.
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| All of this is supposed to be Free Software, Open Source, DFSG-free,
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| GPL-compatible, and OK to use in both free and proprietary applications.
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| Additions and corrections to this file are welcome.
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| 
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| 
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| Redistribution and use in source and binary forms, with or without
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| modification, are permitted provided that the following conditions are met:
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| 
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| * Redistributions of source code must retain the above copyright
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|   notice, this list of conditions and the following disclaimer.
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| 
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| * Redistributions in binary form must reproduce the above copyright
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|   notice, this list of conditions and the following disclaimer in
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|   the documentation and/or other materials provided with the
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|   distribution.
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| 
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| * Neither the name of the copyright holders nor the names of
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|   contributors may be used to endorse or promote products derived
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|   from this software without specific prior written permission.
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| 
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| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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| LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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| INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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| CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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| ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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| POSSIBILITY OF SUCH DAMAGE.
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| */
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| 
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| /*
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|  * PS/2 protocol Pin interrupt version
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|  */
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| 
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| #include <stdbool.h>
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| 
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| #if defined(__AVR__)
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| #    include <avr/interrupt.h>
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| #elif defined(PROTOCOL_CHIBIOS) // TODO: or STM32 ?
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| // chibiOS headers
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| #    include "ch.h"
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| #    include "hal.h"
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| #    include "gpio.h"
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| #endif
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| 
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| #include "ps2.h"
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| #include "ps2_io.h"
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| #include "print.h"
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| #include "wait.h"
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| 
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| #define WAIT(stat, us, err)     \
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|     do {                        \
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|         if (!wait_##stat(us)) { \
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|             ps2_error = err;    \
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|             goto ERROR;         \
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|         }                       \
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|     } while (0)
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| 
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| uint8_t ps2_error = PS2_ERR_NONE;
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| 
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| static inline uint8_t pbuf_dequeue(void);
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| static inline void    pbuf_enqueue(uint8_t data);
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| static inline void    pbuf_clear(void);
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| bool                  pbuf_has_data(void);
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| 
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| #if defined(PROTOCOL_CHIBIOS)
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| void ps2_interrupt_service_routine(void);
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| void palCallback(void *arg) {
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|     ps2_interrupt_service_routine();
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| }
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| 
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| #    define PS2_INT_INIT()                                 \
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|         do {                                               \
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|             palSetLineMode(PS2_CLOCK_PIN, PAL_MODE_INPUT); \
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|         } while (0)
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| #    define PS2_INT_ON()                                                    \
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|         do {                                                                \
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|             palEnableLineEvent(PS2_CLOCK_PIN, PAL_EVENT_MODE_FALLING_EDGE); \
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|             palSetLineCallback(PS2_CLOCK_PIN, palCallback, NULL);           \
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|         } while (0)
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| #    define PS2_INT_OFF()                       \
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|         do {                                    \
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|             palDisableLineEvent(PS2_CLOCK_PIN); \
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|         } while (0)
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| #endif // PROTOCOL_CHIBIOS
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| 
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| void ps2_host_init(void) {
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|     idle();
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|     PS2_INT_INIT();
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|     PS2_INT_ON();
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|     // POR(150-2000ms) plus BAT(300-500ms) may take 2.5sec([3]p.20)
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|     // wait_ms(2500);
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| }
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| 
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| uint8_t ps2_host_send(uint8_t data) {
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|     bool parity = true;
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|     ps2_error   = PS2_ERR_NONE;
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| 
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|     PS2_INT_OFF();
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| 
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|     /* terminate a transmission if we have */
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|     inhibit();
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|     wait_us(100); // 100us [4]p.13, [5]p.50
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| 
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|     /* 'Request to Send' and Start bit */
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|     data_lo();
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|     clock_hi();
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|     WAIT(clock_lo, 10000, 10); // 10ms [5]p.50
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| 
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|     /* Data bit[2-9] */
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|     for (uint8_t i = 0; i < 8; i++) {
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|         if (data & (1 << i)) {
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|             parity = !parity;
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|             data_hi();
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|         } else {
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|             data_lo();
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|         }
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|         WAIT(clock_hi, 50, 2);
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|         WAIT(clock_lo, 50, 3);
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|     }
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| 
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|     /* Parity bit */
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|     wait_us(15);
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|     if (parity) {
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|         data_hi();
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|     } else {
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|         data_lo();
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|     }
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|     WAIT(clock_hi, 50, 4);
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|     WAIT(clock_lo, 50, 5);
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| 
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|     /* Stop bit */
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|     wait_us(15);
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|     data_hi();
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| 
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|     /* Ack */
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|     WAIT(data_lo, 50, 6);
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|     WAIT(clock_lo, 50, 7);
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| 
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|     /* wait for idle state */
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|     WAIT(clock_hi, 50, 8);
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|     WAIT(data_hi, 50, 9);
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| 
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|     idle();
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|     PS2_INT_ON();
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|     return ps2_host_recv_response();
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| ERROR:
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|     idle();
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|     PS2_INT_ON();
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|     return 0;
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| }
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| 
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| uint8_t ps2_host_recv_response(void) {
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|     // Command may take 25ms/20ms at most([5]p.46, [3]p.21)
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|     uint8_t retry = 25;
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|     while (retry-- && !pbuf_has_data()) {
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|         wait_ms(1);
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|     }
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|     return pbuf_dequeue();
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| }
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| 
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| /* get data received by interrupt */
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| uint8_t ps2_host_recv(void) {
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|     if (pbuf_has_data()) {
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|         ps2_error = PS2_ERR_NONE;
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|         return pbuf_dequeue();
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|     } else {
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|         ps2_error = PS2_ERR_NODATA;
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|         return 0;
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|     }
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| }
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| 
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| void ps2_interrupt_service_routine(void) {
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|     static enum {
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|         INIT,
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|         START,
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|         BIT0,
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|         BIT1,
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|         BIT2,
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|         BIT3,
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|         BIT4,
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|         BIT5,
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|         BIT6,
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|         BIT7,
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|         PARITY,
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|         STOP,
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|     } state               = INIT;
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|     static uint8_t data   = 0;
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|     static uint8_t parity = 1;
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| 
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|     // TODO: abort if elapse 100us from previous interrupt
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| 
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|     // return unless falling edge
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|     if (clock_in()) {
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|         goto RETURN;
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|     }
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| 
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|     state++;
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|     switch (state) {
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|         case START:
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|             if (data_in()) goto ERROR;
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|             break;
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|         case BIT0:
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|         case BIT1:
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|         case BIT2:
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|         case BIT3:
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|         case BIT4:
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|         case BIT5:
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|         case BIT6:
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|         case BIT7:
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|             data >>= 1;
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|             if (data_in()) {
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|                 data |= 0x80;
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|                 parity++;
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|             }
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|             break;
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|         case PARITY:
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|             if (data_in()) {
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|                 if (!(parity & 0x01)) goto ERROR;
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|             } else {
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|                 if (parity & 0x01) goto ERROR;
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|             }
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|             break;
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|         case STOP:
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|             if (!data_in()) goto ERROR;
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|             pbuf_enqueue(data);
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|             goto DONE;
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|             break;
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|         default:
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|             goto ERROR;
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|     }
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|     goto RETURN;
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| ERROR:
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|     ps2_error = state;
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| DONE:
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|     state  = INIT;
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|     data   = 0;
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|     parity = 1;
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| RETURN:
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|     return;
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| }
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| 
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| #if defined(__AVR__)
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| ISR(PS2_INT_VECT) {
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|     ps2_interrupt_service_routine();
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| }
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| #endif
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| 
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| /* send LED state to keyboard */
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| void ps2_host_set_led(uint8_t led) {
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|     ps2_host_send(0xED);
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|     ps2_host_send(led);
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| }
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| 
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| /*--------------------------------------------------------------------
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|  * Ring buffer to store scan codes from keyboard
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|  *------------------------------------------------------------------*/
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| #define PBUF_SIZE 32
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| static uint8_t     pbuf[PBUF_SIZE];
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| static uint8_t     pbuf_head = 0;
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| static uint8_t     pbuf_tail = 0;
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| static inline void pbuf_enqueue(uint8_t data) {
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| #if defined(__AVR__)
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|     uint8_t sreg = SREG;
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|     cli();
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| #elif defined(PROTOCOL_CHIBIOS)
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|     chSysLockFromISR();
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| #endif
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| 
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|     uint8_t next = (pbuf_head + 1) % PBUF_SIZE;
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|     if (next != pbuf_tail) {
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|         pbuf[pbuf_head] = data;
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|         pbuf_head       = next;
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|     } else {
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|         print("pbuf: full\n");
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|     }
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| 
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| #if defined(__AVR__)
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|     SREG = sreg;
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| #elif defined(PROTOCOL_CHIBIOS)
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|     chSysUnlockFromISR();
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| #endif
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| }
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| static inline uint8_t pbuf_dequeue(void) {
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|     uint8_t val = 0;
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| 
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| #if defined(__AVR__)
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|     uint8_t sreg = SREG;
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|     cli();
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| #elif defined(PROTOCOL_CHIBIOS)
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|     chSysLock();
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| #endif
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| 
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|     if (pbuf_head != pbuf_tail) {
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|         val       = pbuf[pbuf_tail];
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|         pbuf_tail = (pbuf_tail + 1) % PBUF_SIZE;
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|     }
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| 
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| #if defined(__AVR__)
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|     SREG = sreg;
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| #elif defined(PROTOCOL_CHIBIOS)
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|     chSysUnlock();
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| #endif
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| 
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|     return val;
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| }
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| bool pbuf_has_data(void) {
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| #if defined(__AVR__)
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|     uint8_t sreg = SREG;
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|     cli();
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| #elif defined(PROTOCOL_CHIBIOS)
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|     chSysLock();
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| #endif
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| 
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|     bool has_data = (pbuf_head != pbuf_tail);
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| 
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| #if defined(__AVR__)
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|     SREG = sreg;
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| #elif defined(PROTOCOL_CHIBIOS)
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|     chSysUnlock();
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| #endif
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|     return has_data;
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| }
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| static inline void pbuf_clear(void) {
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| #if defined(__AVR__)
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|     uint8_t sreg = SREG;
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|     cli();
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| #elif defined(PROTOCOL_CHIBIOS)
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|     chSysLock();
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| #endif
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| 
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|     pbuf_head = pbuf_tail = 0;
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| 
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| #if defined(__AVR__)
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|     SREG = sreg;
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| #elif defined(PROTOCOL_CHIBIOS)
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|     chSysUnlock();
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| #endif
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| }
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