123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254 |
- /*
- Copyright (c) 2010 Jun WAKO <[email protected]>
-
- 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 <util/delay.h>
- #include "ps2.h"
- #include "print.h"
- #include "debug.h"
-
-
- 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);
-
-
- /*
- 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)
-
- #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();
- }
-
- uint8_t ps2_host_send(uint8_t data)
- {
- bool parity = true;
- ps2_error = 0;
-
- /* request to send */
- clock_lo();
- _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++) {
- if (data&(1<<i)) {
- parity = !parity;
- data_hi();
- } else {
- data_lo();
- }
- WAIT(clock_hi, 50, 2);
- WAIT(clock_lo, 50, 3);
- }
- /* parity [10] */
- if (parity) { data_hi(); } else { data_lo(); }
- WAIT(clock_hi, 50, 4);
- WAIT(clock_lo, 50, 5);
- /* stop bit [11] */
- data_hi();
- /* ack [12] */
- WAIT(data_lo, 50, 6);
- WAIT(clock_lo, 50, 7);
- WAIT(clock_hi, 50, 8);
- WAIT(data_hi, 50, 9);
-
- /* inhibit device to send */
- clock_lo();
-
- return 1;
- ERROR:
- /* inhibit device to send */
- data_hi();
- clock_lo();
- return 0;
- }
-
- uint8_t ps2_host_recv(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(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);
-
- /* 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);
- }
- 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);
- 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);
- 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;
- }
|