+++ /dev/null
-/*
-Copyright 2010,2011,2012,2013 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 <util/delay.h>
-#include "ps2.h"
-#include "debug.h"
-
-
-/*
- * PS/2 protocol busywait version
- */
-
-#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)
-{
- // POR(150-2000ms) plus BAT(300-500ms) may take 2.5sec([3]p.20)
- _delay_ms(2500);
-
- inhibit();
-}
-
-uint8_t ps2_host_send(uint8_t data)
-{
- uint8_t res = 0;
- bool parity = true;
- ps2_error = PS2_ERR_NONE;
- /* terminate a transmission if we have */
- inhibit();
- _delay_us(200); // at least 100us
-
- /* start bit [1] */
- data_lo();
- clock_hi();
- WAIT(clock_lo, 20000, 10); // may take 15ms at most until device starts clocking
- /* 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:
- inhibit();
- return res;
-}
-
-/* receive data when host want else inhibit communication */
-uint8_t ps2_host_recv_response(void)
-{
- // TODO:
- // Command might take 20ms to response([3]p.21)
- // TrackPoint might take 25ms ([5]2.7)
- uint8_t data = 0;
- uint8_t try = 200;
- while (try-- && (data = ps2_host_recv())) ;
- return data;
-}
-
-/* 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 */
-uint8_t ps2_host_recv(void)
-{
- uint8_t data = 0;
- bool parity = true;
- ps2_error = PS2_ERR_NONE;
-
- /* release lines(idle state) */
- idle();
-
- /* start bit [1] */
- WAIT(clock_lo, 100, 1); // TODO: this is enough?
- 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();
- return data;
-ERROR:
- if (ps2_error > PS2_ERR_STARTBIT3) {
- printf("x%02X\n", ps2_error);
- }
- inhibit();
- return 0;
-}