1 /* 2 * drivers/s390/char/sclp_vt220.c 3 * SCLP VT220 terminal driver. 4 * 5 * S390 version 6 * Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation 7 * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com> 8 */ 9 10 #include <linux/config.h> 11 #include <linux/module.h> 12 #include <linux/spinlock.h> 13 #include <linux/list.h> 14 #include <linux/wait.h> 15 #include <linux/timer.h> 16 #include <linux/kernel.h> 17 #include <linux/tty.h> 18 #include <linux/tty_driver.h> 19 #include <linux/sched.h> 20 #include <linux/errno.h> 21 #include <linux/mm.h> 22 #include <linux/major.h> 23 #include <linux/console.h> 24 #include <linux/kdev_t.h> 25 #include <linux/bootmem.h> 26 #include <linux/interrupt.h> 27 #include <linux/init.h> 28 #include <asm/uaccess.h> 29 #include "sclp.h" 30 31 #define SCLP_VT220_PRINT_HEADER "sclp vt220 tty driver: " 32 #define SCLP_VT220_MAJOR TTY_MAJOR 33 #define SCLP_VT220_MINOR 65 34 #define SCLP_VT220_DRIVER_NAME "sclp_vt220" 35 #define SCLP_VT220_DEVICE_NAME "ttysclp" 36 #define SCLP_VT220_CONSOLE_NAME "ttyS" 37 #define SCLP_VT220_CONSOLE_INDEX 1 /* console=ttyS1 */ 38 #define SCLP_VT220_BUF_SIZE 80 39 40 /* Representation of a single write request */ 41 struct sclp_vt220_request { 42 struct list_head list; 43 struct sclp_req sclp_req; 44 int retry_count; 45 }; 46 47 /* VT220 SCCB */ 48 struct sclp_vt220_sccb { 49 struct sccb_header header; 50 struct evbuf_header evbuf; 51 }; 52 53 #define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \ 54 sizeof(struct sclp_vt220_request) - \ 55 sizeof(struct sclp_vt220_sccb)) 56 57 /* Structures and data needed to register tty driver */ 58 static struct tty_driver *sclp_vt220_driver; 59 60 /* The tty_struct that the kernel associated with us */ 61 static struct tty_struct *sclp_vt220_tty; 62 63 /* Lock to protect internal data from concurrent access */ 64 static spinlock_t sclp_vt220_lock; 65 66 /* List of empty pages to be used as write request buffers */ 67 static struct list_head sclp_vt220_empty; 68 69 /* List of pending requests */ 70 static struct list_head sclp_vt220_outqueue; 71 72 /* Number of requests in outqueue */ 73 static int sclp_vt220_outqueue_count; 74 75 /* Wait queue used to delay write requests while we've run out of buffers */ 76 static wait_queue_head_t sclp_vt220_waitq; 77 78 /* Timer used for delaying write requests to merge subsequent messages into 79 * a single buffer */ 80 static struct timer_list sclp_vt220_timer; 81 82 /* Pointer to current request buffer which has been partially filled but not 83 * yet sent */ 84 static struct sclp_vt220_request *sclp_vt220_current_request; 85 86 /* Number of characters in current request buffer */ 87 static int sclp_vt220_buffered_chars; 88 89 /* Flag indicating whether this driver has already been initialized */ 90 static int sclp_vt220_initialized = 0; 91 92 /* Flag indicating that sclp_vt220_current_request should really 93 * have been already queued but wasn't because the SCLP was processing 94 * another buffer */ 95 static int sclp_vt220_flush_later; 96 97 static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf); 98 static int __sclp_vt220_emit(struct sclp_vt220_request *request); 99 static void sclp_vt220_emit_current(void); 100 101 /* Registration structure for our interest in SCLP event buffers */ 102 static struct sclp_register sclp_vt220_register = { 103 .send_mask = EvTyp_VT220Msg_Mask, 104 .receive_mask = EvTyp_VT220Msg_Mask, 105 .state_change_fn = NULL, 106 .receiver_fn = sclp_vt220_receiver_fn 107 }; 108 109 110 /* 111 * Put provided request buffer back into queue and check emit pending 112 * buffers if necessary. 113 */ 114 static void 115 sclp_vt220_process_queue(struct sclp_vt220_request *request) 116 { 117 unsigned long flags; 118 void *page; 119 120 do { 121 /* Put buffer back to list of empty buffers */ 122 page = request->sclp_req.sccb; 123 spin_lock_irqsave(&sclp_vt220_lock, flags); 124 /* Move request from outqueue to empty queue */ 125 list_del(&request->list); 126 sclp_vt220_outqueue_count--; 127 list_add_tail((struct list_head *) page, &sclp_vt220_empty); 128 /* Check if there is a pending buffer on the out queue. */ 129 request = NULL; 130 if (!list_empty(&sclp_vt220_outqueue)) 131 request = list_entry(sclp_vt220_outqueue.next, 132 struct sclp_vt220_request, list); 133 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 134 } while (request && __sclp_vt220_emit(request)); 135 if (request == NULL && sclp_vt220_flush_later) 136 sclp_vt220_emit_current(); 137 wake_up(&sclp_vt220_waitq); 138 /* Check if the tty needs a wake up call */ 139 if (sclp_vt220_tty != NULL) { 140 tty_wakeup(sclp_vt220_tty); 141 } 142 } 143 144 #define SCLP_BUFFER_MAX_RETRY 1 145 146 /* 147 * Callback through which the result of a write request is reported by the 148 * SCLP. 149 */ 150 static void 151 sclp_vt220_callback(struct sclp_req *request, void *data) 152 { 153 struct sclp_vt220_request *vt220_request; 154 struct sclp_vt220_sccb *sccb; 155 156 vt220_request = (struct sclp_vt220_request *) data; 157 if (request->status == SCLP_REQ_FAILED) { 158 sclp_vt220_process_queue(vt220_request); 159 return; 160 } 161 sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb; 162 163 /* Check SCLP response code and choose suitable action */ 164 switch (sccb->header.response_code) { 165 case 0x0020 : 166 break; 167 168 case 0x05f0: /* Target resource in improper state */ 169 break; 170 171 case 0x0340: /* Contained SCLP equipment check */ 172 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) 173 break; 174 /* Remove processed buffers and requeue rest */ 175 if (sclp_remove_processed((struct sccb_header *) sccb) > 0) { 176 /* Not all buffers were processed */ 177 sccb->header.response_code = 0x0000; 178 vt220_request->sclp_req.status = SCLP_REQ_FILLED; 179 if (sclp_add_request(request) == 0) 180 return; 181 } 182 break; 183 184 case 0x0040: /* SCLP equipment check */ 185 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) 186 break; 187 sccb->header.response_code = 0x0000; 188 vt220_request->sclp_req.status = SCLP_REQ_FILLED; 189 if (sclp_add_request(request) == 0) 190 return; 191 break; 192 193 default: 194 break; 195 } 196 sclp_vt220_process_queue(vt220_request); 197 } 198 199 /* 200 * Emit vt220 request buffer to SCLP. Return zero on success, non-zero 201 * otherwise. 202 */ 203 static int 204 __sclp_vt220_emit(struct sclp_vt220_request *request) 205 { 206 if (!(sclp_vt220_register.sclp_send_mask & EvTyp_VT220Msg_Mask)) { 207 request->sclp_req.status = SCLP_REQ_FAILED; 208 return -EIO; 209 } 210 request->sclp_req.command = SCLP_CMDW_WRITEDATA; 211 request->sclp_req.status = SCLP_REQ_FILLED; 212 request->sclp_req.callback = sclp_vt220_callback; 213 request->sclp_req.callback_data = (void *) request; 214 215 return sclp_add_request(&request->sclp_req); 216 } 217 218 /* 219 * Queue and emit given request. 220 */ 221 static void 222 sclp_vt220_emit(struct sclp_vt220_request *request) 223 { 224 unsigned long flags; 225 int count; 226 227 spin_lock_irqsave(&sclp_vt220_lock, flags); 228 list_add_tail(&request->list, &sclp_vt220_outqueue); 229 count = sclp_vt220_outqueue_count++; 230 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 231 /* Emit only the first buffer immediately - callback takes care of 232 * the rest */ 233 if (count == 0 && __sclp_vt220_emit(request)) 234 sclp_vt220_process_queue(request); 235 } 236 237 /* 238 * Queue and emit current request. Return zero on success, non-zero otherwise. 239 */ 240 static void 241 sclp_vt220_emit_current(void) 242 { 243 unsigned long flags; 244 struct sclp_vt220_request *request; 245 struct sclp_vt220_sccb *sccb; 246 247 spin_lock_irqsave(&sclp_vt220_lock, flags); 248 request = NULL; 249 if (sclp_vt220_current_request != NULL) { 250 sccb = (struct sclp_vt220_sccb *) 251 sclp_vt220_current_request->sclp_req.sccb; 252 /* Only emit buffers with content */ 253 if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) { 254 request = sclp_vt220_current_request; 255 sclp_vt220_current_request = NULL; 256 if (timer_pending(&sclp_vt220_timer)) 257 del_timer(&sclp_vt220_timer); 258 } 259 sclp_vt220_flush_later = 0; 260 } 261 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 262 if (request != NULL) 263 sclp_vt220_emit(request); 264 } 265 266 #define SCLP_NORMAL_WRITE 0x00 267 268 /* 269 * Helper function to initialize a page with the sclp request structure. 270 */ 271 static struct sclp_vt220_request * 272 sclp_vt220_initialize_page(void *page) 273 { 274 struct sclp_vt220_request *request; 275 struct sclp_vt220_sccb *sccb; 276 277 /* Place request structure at end of page */ 278 request = ((struct sclp_vt220_request *) 279 ((addr_t) page + PAGE_SIZE)) - 1; 280 request->retry_count = 0; 281 request->sclp_req.sccb = page; 282 /* SCCB goes at start of page */ 283 sccb = (struct sclp_vt220_sccb *) page; 284 memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb)); 285 sccb->header.length = sizeof(struct sclp_vt220_sccb); 286 sccb->header.function_code = SCLP_NORMAL_WRITE; 287 sccb->header.response_code = 0x0000; 288 sccb->evbuf.type = EvTyp_VT220Msg; 289 sccb->evbuf.length = sizeof(struct evbuf_header); 290 291 return request; 292 } 293 294 static inline unsigned int 295 sclp_vt220_space_left(struct sclp_vt220_request *request) 296 { 297 struct sclp_vt220_sccb *sccb; 298 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; 299 return PAGE_SIZE - sizeof(struct sclp_vt220_request) - 300 sccb->header.length; 301 } 302 303 static inline unsigned int 304 sclp_vt220_chars_stored(struct sclp_vt220_request *request) 305 { 306 struct sclp_vt220_sccb *sccb; 307 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; 308 return sccb->evbuf.length - sizeof(struct evbuf_header); 309 } 310 311 /* 312 * Add msg to buffer associated with request. Return the number of characters 313 * added. 314 */ 315 static int 316 sclp_vt220_add_msg(struct sclp_vt220_request *request, 317 const unsigned char *msg, int count, int convertlf) 318 { 319 struct sclp_vt220_sccb *sccb; 320 void *buffer; 321 unsigned char c; 322 int from; 323 int to; 324 325 if (count > sclp_vt220_space_left(request)) 326 count = sclp_vt220_space_left(request); 327 if (count <= 0) 328 return 0; 329 330 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; 331 buffer = (void *) ((addr_t) sccb + sccb->header.length); 332 333 if (convertlf) { 334 /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/ 335 for (from=0, to=0; 336 (from < count) && (to < sclp_vt220_space_left(request)); 337 from++) { 338 /* Retrieve character */ 339 c = msg[from]; 340 /* Perform conversion */ 341 if (c == 0x0a) { 342 if (to + 1 < sclp_vt220_space_left(request)) { 343 ((unsigned char *) buffer)[to++] = c; 344 ((unsigned char *) buffer)[to++] = 0x0d; 345 } else 346 break; 347 348 } else 349 ((unsigned char *) buffer)[to++] = c; 350 } 351 sccb->header.length += to; 352 sccb->evbuf.length += to; 353 return from; 354 } else { 355 memcpy(buffer, (const void *) msg, count); 356 sccb->header.length += count; 357 sccb->evbuf.length += count; 358 return count; 359 } 360 } 361 362 /* 363 * Emit buffer after having waited long enough for more data to arrive. 364 */ 365 static void 366 sclp_vt220_timeout(unsigned long data) 367 { 368 sclp_vt220_emit_current(); 369 } 370 371 #define BUFFER_MAX_DELAY HZ/2 372 373 /* 374 * Internal implementation of the write function. Write COUNT bytes of data 375 * from memory at BUF 376 * to the SCLP interface. In case that the data does not fit into the current 377 * write buffer, emit the current one and allocate a new one. If there are no 378 * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE 379 * is non-zero, the buffer will be scheduled for emitting after a timeout - 380 * otherwise the user has to explicitly call the flush function. 381 * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message 382 * buffer should be converted to 0x0a 0x0d. After completion, return the number 383 * of bytes written. 384 */ 385 static int 386 __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, 387 int convertlf) 388 { 389 unsigned long flags; 390 void *page; 391 int written; 392 int overall_written; 393 394 if (count <= 0) 395 return 0; 396 overall_written = 0; 397 spin_lock_irqsave(&sclp_vt220_lock, flags); 398 do { 399 /* Create a sclp output buffer if none exists yet */ 400 if (sclp_vt220_current_request == NULL) { 401 while (list_empty(&sclp_vt220_empty)) { 402 spin_unlock_irqrestore(&sclp_vt220_lock, 403 flags); 404 if (in_interrupt()) 405 sclp_sync_wait(); 406 else 407 wait_event(sclp_vt220_waitq, 408 !list_empty(&sclp_vt220_empty)); 409 spin_lock_irqsave(&sclp_vt220_lock, flags); 410 } 411 page = (void *) sclp_vt220_empty.next; 412 list_del((struct list_head *) page); 413 sclp_vt220_current_request = 414 sclp_vt220_initialize_page(page); 415 } 416 /* Try to write the string to the current request buffer */ 417 written = sclp_vt220_add_msg(sclp_vt220_current_request, 418 buf, count, convertlf); 419 overall_written += written; 420 if (written == count) 421 break; 422 /* 423 * Not all characters could be written to the current 424 * output buffer. Emit the buffer, create a new buffer 425 * and then output the rest of the string. 426 */ 427 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 428 sclp_vt220_emit_current(); 429 spin_lock_irqsave(&sclp_vt220_lock, flags); 430 buf += written; 431 count -= written; 432 } while (count > 0); 433 /* Setup timer to output current console buffer after some time */ 434 if (sclp_vt220_current_request != NULL && 435 !timer_pending(&sclp_vt220_timer) && do_schedule) { 436 sclp_vt220_timer.function = sclp_vt220_timeout; 437 sclp_vt220_timer.data = 0UL; 438 sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY; 439 add_timer(&sclp_vt220_timer); 440 } 441 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 442 return overall_written; 443 } 444 445 /* 446 * This routine is called by the kernel to write a series of 447 * characters to the tty device. The characters may come from 448 * user space or kernel space. This routine will return the 449 * number of characters actually accepted for writing. 450 */ 451 static int 452 sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count) 453 { 454 return __sclp_vt220_write(buf, count, 1, 0); 455 } 456 457 #define SCLP_VT220_SESSION_ENDED 0x01 458 #define SCLP_VT220_SESSION_STARTED 0x80 459 #define SCLP_VT220_SESSION_DATA 0x00 460 461 /* 462 * Called by the SCLP to report incoming event buffers. 463 */ 464 static void 465 sclp_vt220_receiver_fn(struct evbuf_header *evbuf) 466 { 467 char *buffer; 468 unsigned int count; 469 470 /* Ignore input if device is not open */ 471 if (sclp_vt220_tty == NULL) 472 return; 473 474 buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header)); 475 count = evbuf->length - sizeof(struct evbuf_header); 476 477 switch (*buffer) { 478 case SCLP_VT220_SESSION_ENDED: 479 case SCLP_VT220_SESSION_STARTED: 480 break; 481 case SCLP_VT220_SESSION_DATA: 482 /* Send input to line discipline */ 483 buffer++; 484 count--; 485 /* Prevent buffer overrun by discarding input. Note that 486 * because buffer_push works asynchronously, we cannot wait 487 * for the buffer to be emptied. */ 488 if (count + sclp_vt220_tty->flip.count > TTY_FLIPBUF_SIZE) 489 count = TTY_FLIPBUF_SIZE - sclp_vt220_tty->flip.count; 490 memcpy(sclp_vt220_tty->flip.char_buf_ptr, buffer, count); 491 memset(sclp_vt220_tty->flip.flag_buf_ptr, TTY_NORMAL, count); 492 sclp_vt220_tty->flip.char_buf_ptr += count; 493 sclp_vt220_tty->flip.flag_buf_ptr += count; 494 sclp_vt220_tty->flip.count += count; 495 tty_flip_buffer_push(sclp_vt220_tty); 496 break; 497 } 498 } 499 500 /* 501 * This routine is called when a particular tty device is opened. 502 */ 503 static int 504 sclp_vt220_open(struct tty_struct *tty, struct file *filp) 505 { 506 if (tty->count == 1) { 507 sclp_vt220_tty = tty; 508 tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL); 509 if (tty->driver_data == NULL) 510 return -ENOMEM; 511 tty->low_latency = 0; 512 } 513 return 0; 514 } 515 516 /* 517 * This routine is called when a particular tty device is closed. 518 */ 519 static void 520 sclp_vt220_close(struct tty_struct *tty, struct file *filp) 521 { 522 if (tty->count == 1) { 523 sclp_vt220_tty = NULL; 524 kfree(tty->driver_data); 525 tty->driver_data = NULL; 526 } 527 } 528 529 /* 530 * This routine is called by the kernel to write a single 531 * character to the tty device. If the kernel uses this routine, 532 * it must call the flush_chars() routine (if defined) when it is 533 * done stuffing characters into the driver. 534 * 535 * NOTE: include/linux/tty_driver.h specifies that a character should be 536 * ignored if there is no room in the queue. This driver implements a different 537 * semantic in that it will block when there is no more room left. 538 */ 539 static void 540 sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch) 541 { 542 __sclp_vt220_write(&ch, 1, 0, 0); 543 } 544 545 /* 546 * This routine is called by the kernel after it has written a 547 * series of characters to the tty device using put_char(). 548 */ 549 static void 550 sclp_vt220_flush_chars(struct tty_struct *tty) 551 { 552 if (sclp_vt220_outqueue_count == 0) 553 sclp_vt220_emit_current(); 554 else 555 sclp_vt220_flush_later = 1; 556 } 557 558 /* 559 * This routine returns the numbers of characters the tty driver 560 * will accept for queuing to be written. This number is subject 561 * to change as output buffers get emptied, or if the output flow 562 * control is acted. 563 */ 564 static int 565 sclp_vt220_write_room(struct tty_struct *tty) 566 { 567 unsigned long flags; 568 struct list_head *l; 569 int count; 570 571 spin_lock_irqsave(&sclp_vt220_lock, flags); 572 count = 0; 573 if (sclp_vt220_current_request != NULL) 574 count = sclp_vt220_space_left(sclp_vt220_current_request); 575 list_for_each(l, &sclp_vt220_empty) 576 count += SCLP_VT220_MAX_CHARS_PER_BUFFER; 577 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 578 return count; 579 } 580 581 /* 582 * Return number of buffered chars. 583 */ 584 static int 585 sclp_vt220_chars_in_buffer(struct tty_struct *tty) 586 { 587 unsigned long flags; 588 struct list_head *l; 589 struct sclp_vt220_request *r; 590 int count; 591 592 spin_lock_irqsave(&sclp_vt220_lock, flags); 593 count = 0; 594 if (sclp_vt220_current_request != NULL) 595 count = sclp_vt220_chars_stored(sclp_vt220_current_request); 596 list_for_each(l, &sclp_vt220_outqueue) { 597 r = list_entry(l, struct sclp_vt220_request, list); 598 count += sclp_vt220_chars_stored(r); 599 } 600 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 601 return count; 602 } 603 604 static void 605 __sclp_vt220_flush_buffer(void) 606 { 607 unsigned long flags; 608 609 sclp_vt220_emit_current(); 610 spin_lock_irqsave(&sclp_vt220_lock, flags); 611 if (timer_pending(&sclp_vt220_timer)) 612 del_timer(&sclp_vt220_timer); 613 while (sclp_vt220_outqueue_count > 0) { 614 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 615 sclp_sync_wait(); 616 spin_lock_irqsave(&sclp_vt220_lock, flags); 617 } 618 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 619 } 620 621 /* 622 * Pass on all buffers to the hardware. Return only when there are no more 623 * buffers pending. 624 */ 625 static void 626 sclp_vt220_flush_buffer(struct tty_struct *tty) 627 { 628 sclp_vt220_emit_current(); 629 } 630 631 /* 632 * Initialize all relevant components and register driver with system. 633 */ 634 static int 635 __sclp_vt220_init(int early) 636 { 637 void *page; 638 int i; 639 640 if (sclp_vt220_initialized) 641 return 0; 642 sclp_vt220_initialized = 1; 643 spin_lock_init(&sclp_vt220_lock); 644 INIT_LIST_HEAD(&sclp_vt220_empty); 645 INIT_LIST_HEAD(&sclp_vt220_outqueue); 646 init_waitqueue_head(&sclp_vt220_waitq); 647 init_timer(&sclp_vt220_timer); 648 sclp_vt220_current_request = NULL; 649 sclp_vt220_buffered_chars = 0; 650 sclp_vt220_outqueue_count = 0; 651 sclp_vt220_tty = NULL; 652 sclp_vt220_flush_later = 0; 653 654 /* Allocate pages for output buffering */ 655 for (i = 0; i < (early ? MAX_CONSOLE_PAGES : MAX_KMEM_PAGES); i++) { 656 if (early) 657 page = alloc_bootmem_low_pages(PAGE_SIZE); 658 else 659 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); 660 if (!page) 661 return -ENOMEM; 662 list_add_tail((struct list_head *) page, &sclp_vt220_empty); 663 } 664 return 0; 665 } 666 667 static struct tty_operations sclp_vt220_ops = { 668 .open = sclp_vt220_open, 669 .close = sclp_vt220_close, 670 .write = sclp_vt220_write, 671 .put_char = sclp_vt220_put_char, 672 .flush_chars = sclp_vt220_flush_chars, 673 .write_room = sclp_vt220_write_room, 674 .chars_in_buffer = sclp_vt220_chars_in_buffer, 675 .flush_buffer = sclp_vt220_flush_buffer 676 }; 677 678 /* 679 * Register driver with SCLP and Linux and initialize internal tty structures. 680 */ 681 int __init 682 sclp_vt220_tty_init(void) 683 { 684 struct tty_driver *driver; 685 int rc; 686 687 /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve 688 * symmetry between VM and LPAR systems regarding ttyS1. */ 689 driver = alloc_tty_driver(1); 690 if (!driver) 691 return -ENOMEM; 692 rc = __sclp_vt220_init(0); 693 if (rc) { 694 put_tty_driver(driver); 695 return rc; 696 } 697 rc = sclp_register(&sclp_vt220_register); 698 if (rc) { 699 printk(KERN_ERR SCLP_VT220_PRINT_HEADER 700 "could not register tty - " 701 "sclp_register returned %d\n", rc); 702 put_tty_driver(driver); 703 return rc; 704 } 705 706 driver->owner = THIS_MODULE; 707 driver->driver_name = SCLP_VT220_DRIVER_NAME; 708 driver->name = SCLP_VT220_DEVICE_NAME; 709 driver->major = SCLP_VT220_MAJOR; 710 driver->minor_start = SCLP_VT220_MINOR; 711 driver->type = TTY_DRIVER_TYPE_SYSTEM; 712 driver->subtype = SYSTEM_TYPE_TTY; 713 driver->init_termios = tty_std_termios; 714 driver->flags = TTY_DRIVER_REAL_RAW; 715 tty_set_operations(driver, &sclp_vt220_ops); 716 717 rc = tty_register_driver(driver); 718 if (rc) { 719 printk(KERN_ERR SCLP_VT220_PRINT_HEADER 720 "could not register tty - " 721 "tty_register_driver returned %d\n", rc); 722 put_tty_driver(driver); 723 return rc; 724 } 725 sclp_vt220_driver = driver; 726 return 0; 727 } 728 729 module_init(sclp_vt220_tty_init); 730 731 #ifdef CONFIG_SCLP_VT220_CONSOLE 732 733 static void 734 sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count) 735 { 736 __sclp_vt220_write((const unsigned char *) buf, count, 1, 1); 737 } 738 739 static struct tty_driver * 740 sclp_vt220_con_device(struct console *c, int *index) 741 { 742 *index = 0; 743 return sclp_vt220_driver; 744 } 745 746 /* 747 * This routine is called from panic when the kernel is going to give up. 748 * We have to make sure that all buffers will be flushed to the SCLP. 749 * Note that this function may be called from within an interrupt context. 750 */ 751 static void 752 sclp_vt220_con_unblank(void) 753 { 754 __sclp_vt220_flush_buffer(); 755 } 756 757 /* Structure needed to register with printk */ 758 static struct console sclp_vt220_console = 759 { 760 .name = SCLP_VT220_CONSOLE_NAME, 761 .write = sclp_vt220_con_write, 762 .device = sclp_vt220_con_device, 763 .unblank = sclp_vt220_con_unblank, 764 .flags = CON_PRINTBUFFER, 765 .index = SCLP_VT220_CONSOLE_INDEX 766 }; 767 768 static int __init 769 sclp_vt220_con_init(void) 770 { 771 int rc; 772 773 if (!CONSOLE_IS_SCLP) 774 return 0; 775 rc = __sclp_vt220_init(1); 776 if (rc) 777 return rc; 778 /* Attach linux console */ 779 register_console(&sclp_vt220_console); 780 return 0; 781 } 782 783 console_initcall(sclp_vt220_con_init); 784 #endif /* CONFIG_SCLP_VT220_CONSOLE */ 785 786