2 Copyright 2010,2011,2012,2013,2019 Jun WAKO <wakojun@gmail.com>
4 This software is licensed with a Modified BSD License.
5 All of this is supposed to be Free Software, Open Source, DFSG-free,
6 GPL-compatible, and OK to use in both free and proprietary applications.
7 Additions and corrections to this file are welcome.
10 Redistribution and use in source and binary forms, with or without
11 modification, are permitted provided that the following conditions are met:
13 * Redistributions of source code must retain the above copyright
14 notice, this list of conditions and the following disclaimer.
16 * Redistributions in binary form must reproduce the above copyright
17 notice, this list of conditions and the following disclaimer in
18 the documentation and/or other materials provided with the
21 * Neither the name of the copyright holders nor the names of
22 contributors may be used to endorse or promote products derived
23 from this software without specific prior written permission.
25 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
26 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
29 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 POSSIBILITY OF SUCH DAMAGE.
39 * IBM PC keyboard protocol
43 #include <avr/interrupt.h>
51 #define WAIT(stat, us, err) do { \
52 if (!wait_##stat(us)) { \
60 static uint8_t buf[BUF_SIZE];
61 static ringbuf_t rb = {
65 .size_mask = BUF_SIZE - 1
68 volatile uint8_t ibmpc_protocol = IBMPC_PROTOCOL_AT;
69 volatile uint8_t ibmpc_error = IBMPC_ERR_NONE;
71 void ibmpc_host_init(void)
73 // initialize reset pin
74 IBMPC_RST_PORT |= (1<<IBMPC_RST_BIT1);
75 IBMPC_RST_DDR |= (1<<IBMPC_RST_BIT1);
76 IBMPC_RST_PORT |= (1<<IBMPC_RST_BIT2);
77 IBMPC_RST_DDR |= (1<<IBMPC_RST_BIT2);
83 void ibmpc_host_enable(void)
89 void ibmpc_host_disable(void)
95 int16_t ibmpc_host_send(uint8_t data)
98 ibmpc_error = IBMPC_ERR_NONE;
100 if (ibmpc_protocol == IBMPC_PROTOCOL_XT) return -1;
102 dprintf("w%02X ", data);
106 /* terminate a transmission if we have */
108 wait_us(100); // 100us [4]p.13, [5]p.50
110 /* 'Request to Send' and Start bit */
113 WAIT(clock_lo, 10000, 1); // 10ms [5]p.50
116 for (uint8_t i = 0; i < 8; i++) {
124 WAIT(clock_hi, 50, 2);
125 WAIT(clock_lo, 50, 3);
130 if (parity) { data_hi(); } else { data_lo(); }
131 WAIT(clock_hi, 50, 4);
132 WAIT(clock_lo, 50, 5);
139 WAIT(data_lo, 50, 6);
140 WAIT(clock_lo, 50, 7);
142 /* wait for idle state */
143 WAIT(clock_hi, 50, 8);
144 WAIT(data_hi, 50, 9);
148 return ibmpc_host_recv_response();
150 ibmpc_error |= IBMPC_ERR_SEND;
156 int16_t ibmpc_host_recv_response(void)
158 // Command may take 25ms/20ms at most([5]p.46, [3]p.21)
160 while (retry-- && ringbuf_is_empty(&rb)) {
163 int16_t data = ringbuf_get(&rb);
164 if (data != -1) dprintf("r%02X ", data);
168 /* get data received by interrupt */
169 int16_t ibmpc_host_recv(void)
171 int16_t data = ringbuf_get(&rb);
172 if (data != -1) dprintf("r%02X ", data);
178 static uint16_t last_time = 0;
181 BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7,
185 static uint8_t data = 0;
186 static uint8_t parity = 1;
188 uint8_t dbit = IBMPC_DATA_PIN&(1<<IBMPC_DATA_BIT);
190 // Reset state when taking more than 1ms
191 if (last_time && timer_elapsed(last_time) > 10) {
192 ibmpc_error = IBMPC_ERR_TIMEOUT | IBMPC_ERR_RECV | state;
197 last_time = timer_read();
201 if (ibmpc_protocol == IBMPC_PROTOCOL_XT) {
202 // ignore start(0) bit
222 if (state == BIT7 && ibmpc_protocol == IBMPC_PROTOCOL_XT) {
223 if (!ringbuf_put(&rb, data)) {
224 ibmpc_error = IBMPC_ERR_FULL;
227 ibmpc_error = IBMPC_ERR_NONE;
233 if (!(parity & 0x01))
243 if (!ringbuf_put(&rb, data)) {
244 ibmpc_error = IBMPC_ERR_FULL;
247 ibmpc_error = IBMPC_ERR_NONE;
256 ibmpc_error |= state;
257 ibmpc_error |= IBMPC_ERR_RECV;
270 /* send LED state to keyboard */
271 void ibmpc_host_set_led(uint8_t led)
273 ibmpc_host_send(0xED);
274 ibmpc_host_send(led);