]>
Commit | Line | Data |
---|---|---|
a074364c | 1 | /* |
2 | Copyright 2010,2011,2012,2013 Jun WAKO <wakojun@gmail.com> | |
3 | ||
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. | |
8 | ||
9 | ||
10 | Redistribution and use in source and binary forms, with or without | |
11 | modification, are permitted provided that the following conditions are met: | |
12 | ||
13 | * Redistributions of source code must retain the above copyright | |
14 | notice, this list of conditions and the following disclaimer. | |
15 | ||
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 | |
19 | distribution. | |
20 | ||
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. | |
24 | ||
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. | |
36 | */ | |
37 | ||
38 | /* | |
39 | * PS/2 protocol Pin interrupt version | |
40 | */ | |
41 | ||
42 | #include <stdbool.h> | |
43 | #include <avr/interrupt.h> | |
44 | #include <util/delay.h> | |
3def1c30 | 45 | #include "pbuff.h" |
a074364c | 46 | #include "ps2.h" |
47 | #include "ps2_io.h" | |
48 | #include "print.h" | |
49 | ||
50 | ||
51 | #define WAIT(stat, us, err) do { \ | |
52 | if (!wait_##stat(us)) { \ | |
53 | ps2_error = err; \ | |
54 | goto ERROR; \ | |
55 | } \ | |
56 | } while (0) | |
57 | ||
58 | ||
59 | uint8_t ps2_error = PS2_ERR_NONE; | |
60 | ||
a074364c | 61 | void ps2_host_init(void) |
62 | { | |
63 | idle(); | |
64 | PS2_INT_INIT(); | |
65 | PS2_INT_ON(); | |
66 | // POR(150-2000ms) plus BAT(300-500ms) may take 2.5sec([3]p.20) | |
67 | //_delay_ms(2500); | |
68 | } | |
69 | ||
70 | uint8_t ps2_host_send(uint8_t data) | |
71 | { | |
72 | bool parity = true; | |
73 | ps2_error = PS2_ERR_NONE; | |
74 | ||
75 | PS2_INT_OFF(); | |
76 | ||
77 | /* terminate a transmission if we have */ | |
78 | inhibit(); | |
79 | _delay_us(100); // 100us [4]p.13, [5]p.50 | |
80 | ||
81 | /* 'Request to Send' and Start bit */ | |
82 | data_lo(); | |
83 | clock_hi(); | |
84 | WAIT(clock_lo, 10000, 10); // 10ms [5]p.50 | |
85 | ||
86 | /* Data bit[2-9] */ | |
87 | for (uint8_t i = 0; i < 8; i++) { | |
88 | _delay_us(15); | |
89 | if (data&(1<<i)) { | |
90 | parity = !parity; | |
91 | data_hi(); | |
92 | } else { | |
93 | data_lo(); | |
94 | } | |
95 | WAIT(clock_hi, 50, 2); | |
96 | WAIT(clock_lo, 50, 3); | |
97 | } | |
98 | ||
99 | /* Parity bit */ | |
100 | _delay_us(15); | |
101 | if (parity) { data_hi(); } else { data_lo(); } | |
102 | WAIT(clock_hi, 50, 4); | |
103 | WAIT(clock_lo, 50, 5); | |
104 | ||
105 | /* Stop bit */ | |
106 | _delay_us(15); | |
107 | data_hi(); | |
108 | ||
109 | /* Ack */ | |
110 | WAIT(data_lo, 50, 6); | |
111 | WAIT(clock_lo, 50, 7); | |
112 | ||
113 | /* wait for idle state */ | |
114 | WAIT(clock_hi, 50, 8); | |
115 | WAIT(data_hi, 50, 9); | |
116 | ||
117 | idle(); | |
118 | PS2_INT_ON(); | |
119 | return ps2_host_recv_response(); | |
120 | ERROR: | |
121 | idle(); | |
122 | PS2_INT_ON(); | |
123 | return 0; | |
124 | } | |
125 | ||
126 | uint8_t ps2_host_recv_response(void) | |
127 | { | |
128 | // Command may take 25ms/20ms at most([5]p.46, [3]p.21) | |
129 | uint8_t retry = 25; | |
130 | while (retry-- && !pbuf_has_data()) { | |
131 | _delay_ms(1); | |
132 | } | |
133 | return pbuf_dequeue(); | |
134 | } | |
135 | ||
136 | /* get data received by interrupt */ | |
137 | uint8_t ps2_host_recv(void) | |
138 | { | |
139 | if (pbuf_has_data()) { | |
140 | ps2_error = PS2_ERR_NONE; | |
141 | return pbuf_dequeue(); | |
142 | } else { | |
143 | ps2_error = PS2_ERR_NODATA; | |
144 | return 0; | |
145 | } | |
146 | } | |
147 | ||
148 | ISR(PS2_INT_VECT) | |
149 | { | |
150 | static enum { | |
151 | INIT, | |
152 | START, | |
153 | BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7, | |
154 | PARITY, | |
155 | STOP, | |
156 | } state = INIT; | |
157 | static uint8_t data = 0; | |
158 | static uint8_t parity = 1; | |
159 | ||
160 | // TODO: abort if elapse 100us from previous interrupt | |
161 | ||
162 | // return unless falling edge | |
163 | if (clock_in()) { | |
164 | goto RETURN; | |
165 | } | |
166 | ||
167 | state++; | |
168 | switch (state) { | |
169 | case START: | |
170 | if (data_in()) | |
171 | goto ERROR; | |
172 | break; | |
173 | case BIT0: | |
174 | case BIT1: | |
175 | case BIT2: | |
176 | case BIT3: | |
177 | case BIT4: | |
178 | case BIT5: | |
179 | case BIT6: | |
180 | case BIT7: | |
181 | data >>= 1; | |
182 | if (data_in()) { | |
183 | data |= 0x80; | |
184 | parity++; | |
185 | } | |
186 | break; | |
187 | case PARITY: | |
188 | if (data_in()) { | |
189 | if (!(parity & 0x01)) | |
190 | goto ERROR; | |
191 | } else { | |
192 | if (parity & 0x01) | |
193 | goto ERROR; | |
194 | } | |
195 | break; | |
196 | case STOP: | |
197 | if (!data_in()) | |
198 | goto ERROR; | |
199 | pbuf_enqueue(data); | |
200 | goto DONE; | |
201 | break; | |
202 | default: | |
203 | goto ERROR; | |
204 | } | |
205 | goto RETURN; | |
206 | ERROR: | |
207 | ps2_error = state; | |
208 | DONE: | |
209 | state = INIT; | |
210 | data = 0; | |
211 | parity = 1; | |
212 | RETURN: | |
213 | return; | |
214 | } | |
215 | ||
216 | /* send LED state to keyboard */ | |
217 | void ps2_host_set_led(uint8_t led) | |
218 | { | |
219 | ps2_host_send(0xED); | |
220 | ps2_host_send(led); | |
221 | } |