| 1 | # |
| 2 | /* |
| 3 | */ |
| 4 | |
| 5 | /* |
| 6 | * DP-11 Synchronous interface driver |
| 7 | * This driver is rather insensitive to the remote |
| 8 | * device it talks to, which is to say most of the protocol |
| 9 | * must be supplied by the calling program. |
| 10 | * Exceptions: parity is even; 7 data bits per character; |
| 11 | * max. of 512 characters per record; 10 second timeout |
| 12 | * on waiting to receive; half-duplex transmission. |
| 13 | */ |
| 14 | |
| 15 | #include "../param.h" |
| 16 | #include "../conf.h" |
| 17 | #include "../user.h" |
| 18 | #include "../buf.h" |
| 19 | |
| 20 | /* control info */ |
| 21 | struct { |
| 22 | char *dp_buf; |
| 23 | char *dp_bufp; |
| 24 | int dp_nxmit; |
| 25 | char dp_state; |
| 26 | char dp_timer; |
| 27 | int dp_proc; |
| 28 | } dp11; |
| 29 | |
| 30 | /* device registers */ |
| 31 | struct { |
| 32 | int dprcsr; |
| 33 | char dprbuf; |
| 34 | char dpsyn0; |
| 35 | int dptcsr; |
| 36 | char dptbuf; |
| 37 | char dpsyn1; |
| 38 | }; |
| 39 | |
| 40 | /* bits */ |
| 41 | #define ODDPAR 010000 |
| 42 | #define IENABLE 0100 |
| 43 | #define HDUPLX 02 |
| 44 | |
| 45 | #define CTRANS 0100000 |
| 46 | #define RORUN 040000 |
| 47 | #define RING 020000 |
| 48 | #define DSRDY 010000 |
| 49 | #define CARRIER 04000 |
| 50 | #define DONE 0200 |
| 51 | #define IENABLE 0100 |
| 52 | #define SIENABL 040 |
| 53 | |
| 54 | #define WRITE 1 |
| 55 | #define READ 0 |
| 56 | |
| 57 | #define DTRDY 01 |
| 58 | #define RCVACT 04000 |
| 59 | |
| 60 | #define DPADDR 0174770 |
| 61 | #define DPPRI 5 |
| 62 | #define SYN 026 /* (receive) sync character */ |
| 63 | |
| 64 | /* |
| 65 | * The open fails unless the device is not open or |
| 66 | * the opening process is the one that has it open already. |
| 67 | */ |
| 68 | dpopen(dev, flag) |
| 69 | { |
| 70 | int dptimeout(); |
| 71 | |
| 72 | if (dp11.dp_proc!=0 && dp11.dp_proc!=u.u_procp) { |
| 73 | u.u_error = ENXIO; |
| 74 | return; |
| 75 | } |
| 76 | dp11.dp_proc = u.u_procp; |
| 77 | dp11.dp_state = READ; |
| 78 | if (dp11.dp_buf==0) { |
| 79 | dp11.dp_buf = getblk(NODEV); |
| 80 | dp11.dp_bufp = dp11.dp_buf->b_addr; |
| 81 | dp11.dp_timer = HZ; |
| 82 | timeout(dptimeout, 0, HZ); |
| 83 | } |
| 84 | DPADDR->dpsyn0 = SYN; |
| 85 | DPADDR->dprcsr = HDUPLX|IENABLE; |
| 86 | DPADDR->dptcsr = IENABLE|SIENABL|DTRDY; |
| 87 | } |
| 88 | |
| 89 | dpclose() |
| 90 | { |
| 91 | DPADDR->dprcsr = 0; |
| 92 | DPADDR->dptcsr = 0; |
| 93 | dp11.dp_timer = 0; |
| 94 | dp11.dp_proc = 0; |
| 95 | if (dp11.dp_buf != 0) { |
| 96 | brelse(dp11.dp_buf); |
| 97 | dp11.dp_buf = 0; |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | /* |
| 102 | * Read waits until: |
| 103 | * there is loss of "data set ready", or |
| 104 | * a timeout occurs, or |
| 105 | * a full record has been received. |
| 106 | * The former two result in an error. |
| 107 | */ |
| 108 | dpread() |
| 109 | { |
| 110 | register char *bp, **epp; |
| 111 | |
| 112 | bp = dp11.dp_buf->b_addr; |
| 113 | epp = &dp11.dp_bufp; |
| 114 | for(;;) { |
| 115 | if(dpwait()) |
| 116 | return; |
| 117 | if (*epp > bp) |
| 118 | break; |
| 119 | spl6(); |
| 120 | if (dp11.dp_timer <= 1) { |
| 121 | spl0(); |
| 122 | return; |
| 123 | } |
| 124 | sleep(&dp11, DPPRI); |
| 125 | spl0(); |
| 126 | } |
| 127 | iomove(dp11.dp_buf, 0, min(u.u_count, *epp-bp), B_READ); |
| 128 | } |
| 129 | |
| 130 | /* |
| 131 | * write checks to make sure that the data set is not reading, |
| 132 | * and that it is ready. Then the record is copied |
| 133 | * and transmission started. |
| 134 | */ |
| 135 | dpwrite() |
| 136 | { |
| 137 | register char *bp; |
| 138 | |
| 139 | if (u.u_count==0 || dpwait()) |
| 140 | return; |
| 141 | dp11.dp_state = WRITE; |
| 142 | bp = dp11.dp_buf->b_addr; |
| 143 | dp11.dp_bufp = bp; |
| 144 | if (u.u_count>512) |
| 145 | u.u_count = 512; |
| 146 | dp11.dp_nxmit = u.u_count; |
| 147 | iomove(dp11.dp_buf, 0, u.u_count, B_WRITE); |
| 148 | dpstart(); |
| 149 | } |
| 150 | |
| 151 | /* |
| 152 | * If "data set ready" is down return an error; otherwise |
| 153 | * wait until the dataset is in read state with no carrier, |
| 154 | * which means a record has just been received. |
| 155 | */ |
| 156 | dpwait() |
| 157 | { |
| 158 | for(;;) { |
| 159 | if ((DPADDR->dptcsr&DSRDY)==0 || dp11.dp_buf==0) { |
| 160 | u.u_error = EIO; |
| 161 | return(1); |
| 162 | } |
| 163 | spl6(); |
| 164 | if (dp11.dp_state==READ && (DPADDR->dptcsr&CARRIER)==0) { |
| 165 | spl0(); |
| 166 | return(0); |
| 167 | } |
| 168 | sleep(&dp11, DPPRI); |
| 169 | spl0(); |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | /* |
| 174 | * Start off the next character to be transmitted; |
| 175 | * when the record is done, drop back into read state. |
| 176 | */ |
| 177 | dpstart() |
| 178 | { |
| 179 | register int c; |
| 180 | extern char partab[]; |
| 181 | |
| 182 | dp11.dp_timer = 10; |
| 183 | if (--dp11.dp_nxmit >= 0) { |
| 184 | c = (*dp11.dp_bufp++) & 0177; |
| 185 | DPADDR->dptbuf = c | ~partab[c]&0200; |
| 186 | } else { |
| 187 | dp11.dp_bufp = dp11.dp_buf->b_addr; |
| 188 | dp11.dp_state = READ; |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * Count down the DP timer (once per second) |
| 194 | * If it runs out, it presumably means the other station |
| 195 | * won't speak. |
| 196 | */ |
| 197 | dptimeout() |
| 198 | { |
| 199 | if (dp11.dp_timer==0) |
| 200 | return; |
| 201 | if (--dp11.dp_timer==0) { |
| 202 | dpturnaround(); |
| 203 | dp11.dp_timer = 1; |
| 204 | } |
| 205 | timeout(dptimeout, 0, HZ); |
| 206 | } |
| 207 | |
| 208 | /* |
| 209 | * Receiver interrupt: if reading, stash character |
| 210 | * unless there is an overrun. |
| 211 | */ |
| 212 | dprint() |
| 213 | { |
| 214 | register int c; |
| 215 | |
| 216 | c = DPADDR->dprbuf & 0177; |
| 217 | if (dp11.dp_state==READ) { |
| 218 | if ((DPADDR->dprcsr&ODDPAR) == 0) |
| 219 | c =| 0200; |
| 220 | if (dp11.dp_bufp < dp11.dp_buf->b_addr+512) |
| 221 | *dp11.dp_bufp++ = c; |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | /* |
| 226 | * Transmitter interrupt: |
| 227 | * Knock down hardware bits. |
| 228 | * If carrier has dropped, the record is done, so turn the line around; |
| 229 | * otherwise start another character. |
| 230 | */ |
| 231 | dpxint() |
| 232 | { |
| 233 | register int dpstat; |
| 234 | |
| 235 | dpstat = DPADDR->dptcsr; |
| 236 | DPADDR->dptcsr =& ~(CTRANS|RORUN|RING|DONE); |
| 237 | if (dpstat & (CTRANS|RORUN)) |
| 238 | dpturnaround(); |
| 239 | else if (dpstat&DONE && dp11.dp_state==WRITE) |
| 240 | dpstart(); |
| 241 | } |
| 242 | |
| 243 | /* |
| 244 | * Change the state from writing to reading at the end of a record. |
| 245 | */ |
| 246 | dpturnaround() |
| 247 | { |
| 248 | DPADDR->dprcsr =& ~RCVACT; |
| 249 | if (dp11.dp_state==WRITE) { |
| 250 | dp11.dp_timer = 10; |
| 251 | dp11.dp_state = READ; |
| 252 | dp11.dp_bufp = dp11.dp_buf->b_addr; |
| 253 | } |
| 254 | wakeup(&dp11); |
| 255 | } |