Alexander Hentschel / PS2

Fork of PS/2 Keyboard lib.

Dependents:   C64Synth

Fork of PS2 by Pallavi Prasad

PS2KB_INIT.cpp@0:62b62530a82f, 2012-10-11 (annotated)

Committer:
pprasad7
Date:
Thu Oct 11 20:15:09 2012 +0000
Revision:
0:62b62530a82f
Child:
1:f290d8dc0afc
PS/2 Input;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
pprasad7 0:62b62530a82f 1 /**
pprasad7 0:62b62530a82f 2 * PS/2 keyboard interface control class (Version 0.0.1)
pprasad7 0:62b62530a82f 3 *
pprasad7 0:62b62530a82f 4 * Copyright (C) 2010 Shinichiro Nakamura (CuBeatSystems)
pprasad7 0:62b62530a82f 5 * http://shinta.main.jp/
pprasad7 0:62b62530a82f 6 */
pprasad7 0:62b62530a82f 7 #include "PS2KB_INIT.h"
pprasad7 0:62b62530a82f 8
pprasad7 0:62b62530a82f 9 /**
pprasad7 0:62b62530a82f 10 * Create.
pprasad7 0:62b62530a82f 11 */
pprasad7 0:62b62530a82f 12 PS2KB_INIT::PS2KB_INIT(PinName clk_pin, PinName dat_pin)
pprasad7 0:62b62530a82f 13 : clk(clk_pin), dat(dat_pin) {
pprasad7 0:62b62530a82f 14 clk.input();
pprasad7 0:62b62530a82f 15 dat.input();
pprasad7 0:62b62530a82f 16 clk.write(1);
pprasad7 0:62b62530a82f 17 dat.write(1);
pprasad7 0:62b62530a82f 18
pprasad7 0:62b62530a82f 19 /*
pprasad7 0:62b62530a82f 20 * 0xFF: Reset.
pprasad7 0:62b62530a82f 21 * 0xED: Set/Reset status indicators.
pprasad7 0:62b62530a82f 22 * 0xF2: Read ID.
pprasad7 0:62b62530a82f 23 * 0xF3: Set typematic rate/delay.
pprasad7 0:62b62530a82f 24 * 0xF4: Enable.
pprasad7 0:62b62530a82f 25 */
pprasad7 0:62b62530a82f 26 char txdat[12] = "\xFF\xED\x07\xF2\xED\x00\xF3\x20\xF3\x00\xF4";
pprasad7 0:62b62530a82f 27 const int n = sizeof(txdat);
pprasad7 0:62b62530a82f 28 int txerrcnt = 0;
pprasad7 0:62b62530a82f 29 int rxerrcnt = 0;
pprasad7 0:62b62530a82f 30 for (int i = 0; i < n; i++) {
pprasad7 0:62b62530a82f 31 if (send(txdat[i]) != 0) {
pprasad7 0:62b62530a82f 32 txerrcnt++;
pprasad7 0:62b62530a82f 33 }
pprasad7 0:62b62530a82f 34 if (recv() < 0) {
pprasad7 0:62b62530a82f 35 rxerrcnt++;
pprasad7 0:62b62530a82f 36 }
pprasad7 0:62b62530a82f 37 if (txdat[i] == 0xF2) {
pprasad7 0:62b62530a82f 38 if (recv() < 0) {
pprasad7 0:62b62530a82f 39 rxerrcnt++;
pprasad7 0:62b62530a82f 40 }
pprasad7 0:62b62530a82f 41 }
pprasad7 0:62b62530a82f 42 }
pprasad7 0:62b62530a82f 43
pprasad7 0:62b62530a82f 44 if (txerrcnt > 0) {
pprasad7 0:62b62530a82f 45 // printf("TX %d errors occured.\n", txerrcnt);
pprasad7 0:62b62530a82f 46 }
pprasad7 0:62b62530a82f 47 if (rxerrcnt > 0) {
pprasad7 0:62b62530a82f 48 // printf("RX %d errors occured.\n", rxerrcnt);
pprasad7 0:62b62530a82f 49 }
pprasad7 0:62b62530a82f 50 }
pprasad7 0:62b62530a82f 51
pprasad7 0:62b62530a82f 52 /**
pprasad7 0:62b62530a82f 53 * Destroy.
pprasad7 0:62b62530a82f 54 */
pprasad7 0:62b62530a82f 55 PS2KB_INIT::~PS2KB_INIT() {
pprasad7 0:62b62530a82f 56 }
pprasad7 0:62b62530a82f 57
pprasad7 0:62b62530a82f 58 /**
pprasad7 0:62b62530a82f 59 * Send a byte data.
pprasad7 0:62b62530a82f 60 *
pprasad7 0:62b62530a82f 61 * @param c a character.
pprasad7 0:62b62530a82f 62 *
pprasad7 0:62b62530a82f 63 * @return Negative value is a error number.
pprasad7 0:62b62530a82f 64 */
pprasad7 0:62b62530a82f 65 int PS2KB_INIT::send(uint8_t c) {
pprasad7 0:62b62530a82f 66 clk.output();
pprasad7 0:62b62530a82f 67 dat.output();
pprasad7 0:62b62530a82f 68
pprasad7 0:62b62530a82f 69 clk.write(0);
pprasad7 0:62b62530a82f 70 wait_us(200);
pprasad7 0:62b62530a82f 71
pprasad7 0:62b62530a82f 72 dat.write(0);
pprasad7 0:62b62530a82f 73 wait_us(10);
pprasad7 0:62b62530a82f 74 clk.write(1);
pprasad7 0:62b62530a82f 75 wait_us(10);
pprasad7 0:62b62530a82f 76
pprasad7 0:62b62530a82f 77 clk.input();
pprasad7 0:62b62530a82f 78 int parcnt = 0;
pprasad7 0:62b62530a82f 79 for (int i = 0; i < 10; i++) {
pprasad7 0:62b62530a82f 80 if (!waitClockDownEdge()) {
pprasad7 0:62b62530a82f 81 return -1;
pprasad7 0:62b62530a82f 82 }
pprasad7 0:62b62530a82f 83 if ((0 <= i) && (i <= 7)) {
pprasad7 0:62b62530a82f 84 /*
pprasad7 0:62b62530a82f 85 * Data bit.
pprasad7 0:62b62530a82f 86 */
pprasad7 0:62b62530a82f 87 if ((c & (1 << i)) == 0) {
pprasad7 0:62b62530a82f 88 dat.write(0);
pprasad7 0:62b62530a82f 89 } else {
pprasad7 0:62b62530a82f 90 dat.write(1);
pprasad7 0:62b62530a82f 91 parcnt++;
pprasad7 0:62b62530a82f 92 }
pprasad7 0:62b62530a82f 93 }
pprasad7 0:62b62530a82f 94 if (i == 8) {
pprasad7 0:62b62530a82f 95 /*
pprasad7 0:62b62530a82f 96 * Parity bit.
pprasad7 0:62b62530a82f 97 */
pprasad7 0:62b62530a82f 98 if ((parcnt % 2) == 0) {
pprasad7 0:62b62530a82f 99 dat.write(1);
pprasad7 0:62b62530a82f 100 } else {
pprasad7 0:62b62530a82f 101 dat.write(0);
pprasad7 0:62b62530a82f 102 }
pprasad7 0:62b62530a82f 103 }
pprasad7 0:62b62530a82f 104 if (i == 9) {
pprasad7 0:62b62530a82f 105 /*
pprasad7 0:62b62530a82f 106 * Stop bit.
pprasad7 0:62b62530a82f 107 */
pprasad7 0:62b62530a82f 108 dat.write(1);
pprasad7 0:62b62530a82f 109 }
pprasad7 0:62b62530a82f 110 }
pprasad7 0:62b62530a82f 111 dat.input();
pprasad7 0:62b62530a82f 112
pprasad7 0:62b62530a82f 113 /*
pprasad7 0:62b62530a82f 114 * Check a ACK.
pprasad7 0:62b62530a82f 115 */
pprasad7 0:62b62530a82f 116 if (!waitClockDownEdge()) {
pprasad7 0:62b62530a82f 117 return -2;
pprasad7 0:62b62530a82f 118 }
pprasad7 0:62b62530a82f 119 if (dat.read() != 0) {
pprasad7 0:62b62530a82f 120 return -3;
pprasad7 0:62b62530a82f 121 }
pprasad7 0:62b62530a82f 122
pprasad7 0:62b62530a82f 123 if (!waitClockUpLevel()) {
pprasad7 0:62b62530a82f 124 return -4;
pprasad7 0:62b62530a82f 125 }
pprasad7 0:62b62530a82f 126
pprasad7 0:62b62530a82f 127 return 0;
pprasad7 0:62b62530a82f 128 }
pprasad7 0:62b62530a82f 129
pprasad7 0:62b62530a82f 130 /**
pprasad7 0:62b62530a82f 131 * Receive a byte data.
pprasad7 0:62b62530a82f 132 *
pprasad7 0:62b62530a82f 133 * @return return a data. Negative value is a error number.
pprasad7 0:62b62530a82f 134 */
pprasad7 0:62b62530a82f 135 int PS2KB_INIT::recv(void) {
pprasad7 0:62b62530a82f 136 uint8_t c = 0;
pprasad7 0:62b62530a82f 137 clk.input();
pprasad7 0:62b62530a82f 138 dat.input();
pprasad7 0:62b62530a82f 139 int parcnt = 0;
pprasad7 0:62b62530a82f 140 for (int i = 0; i < 11; i++) {
pprasad7 0:62b62530a82f 141 if (!waitClockDownEdge()) {
pprasad7 0:62b62530a82f 142 return -1;
pprasad7 0:62b62530a82f 143 }
pprasad7 0:62b62530a82f 144 if (i == 0) {
pprasad7 0:62b62530a82f 145 /*
pprasad7 0:62b62530a82f 146 * Start bit.
pprasad7 0:62b62530a82f 147 */
pprasad7 0:62b62530a82f 148 if (dat.read() != 0) {
pprasad7 0:62b62530a82f 149 return -2;
pprasad7 0:62b62530a82f 150 }
pprasad7 0:62b62530a82f 151 }
pprasad7 0:62b62530a82f 152 if ((1 <= i) && (i <= 8)) {
pprasad7 0:62b62530a82f 153 /*
pprasad7 0:62b62530a82f 154 * Data bit.
pprasad7 0:62b62530a82f 155 */
pprasad7 0:62b62530a82f 156 if (dat.read() == 0) {
pprasad7 0:62b62530a82f 157 c &= ~(1 << (i - 1));
pprasad7 0:62b62530a82f 158 } else {
pprasad7 0:62b62530a82f 159 c |= (1 << (i - 1));
pprasad7 0:62b62530a82f 160 parcnt++;
pprasad7 0:62b62530a82f 161 }
pprasad7 0:62b62530a82f 162 }
pprasad7 0:62b62530a82f 163 if (i == 9) {
pprasad7 0:62b62530a82f 164 /*
pprasad7 0:62b62530a82f 165 * Parity bit.
pprasad7 0:62b62530a82f 166 */
pprasad7 0:62b62530a82f 167 if (dat.read() == 0) {
pprasad7 0:62b62530a82f 168 if ((parcnt % 2) != 1) {
pprasad7 0:62b62530a82f 169 return -3;
pprasad7 0:62b62530a82f 170 }
pprasad7 0:62b62530a82f 171 } else {
pprasad7 0:62b62530a82f 172 if ((parcnt % 2) != 0) {
pprasad7 0:62b62530a82f 173 return -4;
pprasad7 0:62b62530a82f 174 }
pprasad7 0:62b62530a82f 175 }
pprasad7 0:62b62530a82f 176 }
pprasad7 0:62b62530a82f 177 if (i == 10) {
pprasad7 0:62b62530a82f 178 /*
pprasad7 0:62b62530a82f 179 * Stop bit.
pprasad7 0:62b62530a82f 180 */
pprasad7 0:62b62530a82f 181 if (dat.read() != 1) {
pprasad7 0:62b62530a82f 182 return -5;
pprasad7 0:62b62530a82f 183 }
pprasad7 0:62b62530a82f 184 }
pprasad7 0:62b62530a82f 185 }
pprasad7 0:62b62530a82f 186 return (int)c;
pprasad7 0:62b62530a82f 187 }
pprasad7 0:62b62530a82f 188
pprasad7 0:62b62530a82f 189 /**
pprasad7 0:62b62530a82f 190 * Wait a clock down edge.
pprasad7 0:62b62530a82f 191 *
pprasad7 0:62b62530a82f 192 * @return true if wait done.
pprasad7 0:62b62530a82f 193 */
pprasad7 0:62b62530a82f 194 bool PS2KB_INIT::waitClockDownEdge(void) {
pprasad7 0:62b62530a82f 195 int cnt;
pprasad7 0:62b62530a82f 196 /*
pprasad7 0:62b62530a82f 197 * Wait until clock is low.
pprasad7 0:62b62530a82f 198 */
pprasad7 0:62b62530a82f 199 cnt = 0;
pprasad7 0:62b62530a82f 200 while (clk.read() == 0) {
pprasad7 0:62b62530a82f 201 cnt++;
pprasad7 0:62b62530a82f 202 if (MAX_RETRY < cnt) {
pprasad7 0:62b62530a82f 203 return false;
pprasad7 0:62b62530a82f 204 }
pprasad7 0:62b62530a82f 205 wait_us(1);
pprasad7 0:62b62530a82f 206 }
pprasad7 0:62b62530a82f 207 /*
pprasad7 0:62b62530a82f 208 * Wait until clock is high.
pprasad7 0:62b62530a82f 209 */
pprasad7 0:62b62530a82f 210 cnt = 0;
pprasad7 0:62b62530a82f 211 while (clk.read() == 1) {
pprasad7 0:62b62530a82f 212 cnt++;
pprasad7 0:62b62530a82f 213 if (MAX_RETRY < cnt) {
pprasad7 0:62b62530a82f 214 return false;
pprasad7 0:62b62530a82f 215 }
pprasad7 0:62b62530a82f 216 wait_us(1);
pprasad7 0:62b62530a82f 217 }
pprasad7 0:62b62530a82f 218 return true;
pprasad7 0:62b62530a82f 219 }
pprasad7 0:62b62530a82f 220
pprasad7 0:62b62530a82f 221 /**
pprasad7 0:62b62530a82f 222 * Wait a clock up level.
pprasad7 0:62b62530a82f 223 *
pprasad7 0:62b62530a82f 224 * @return true if wait done.
pprasad7 0:62b62530a82f 225 */
pprasad7 0:62b62530a82f 226 bool PS2KB_INIT::waitClockUpLevel(void) {
pprasad7 0:62b62530a82f 227 int cnt;
pprasad7 0:62b62530a82f 228 /*
pprasad7 0:62b62530a82f 229 * Wait until clock is low.
pprasad7 0:62b62530a82f 230 */
pprasad7 0:62b62530a82f 231 cnt = 0;
pprasad7 0:62b62530a82f 232 while (clk.read() == 0) {
pprasad7 0:62b62530a82f 233 cnt++;
pprasad7 0:62b62530a82f 234 if (MAX_RETRY < cnt) {
pprasad7 0:62b62530a82f 235 return false;
pprasad7 0:62b62530a82f 236 }
pprasad7 0:62b62530a82f 237 wait_us(1);
pprasad7 0:62b62530a82f 238 }
pprasad7 0:62b62530a82f 239 return true;
pprasad7 0:62b62530a82f 240 }