1 /* $Id: parport_ieee1284.c,v 1.4 1997/10/19 21:37:21 philip Exp $ 2 * IEEE-1284 implementation for parport. 3 * 4 * Authors: Phil Blundell <philb@gnu.org> 5 * Carsten Gross <carsten@sol.wohnheim.uni-ulm.de> 6 * Jose Renau <renau@acm.org> 7 * Tim Waugh <tim@cyberelk.demon.co.uk> (largely rewritten) 8 * 9 * This file is responsible for IEEE 1284 negotiation, and for handing 10 * read/write requests to low-level drivers. 11 * 12 * Any part of this program may be used in documents licensed under 13 * the GNU Free Documentation License, Version 1.1 or any later version 14 * published by the Free Software Foundation. 15 * 16 * Various hacks, Fred Barnes <frmb2@ukc.ac.uk>, 04/2000 17 */ 18 19 #include <linux/config.h> 20 #include <linux/module.h> 21 #include <linux/threads.h> 22 #include <linux/parport.h> 23 #include <linux/delay.h> 24 #include <linux/kernel.h> 25 #include <linux/interrupt.h> 26 #include <linux/timer.h> 27 #include <linux/sched.h> 28 29 #undef DEBUG /* undef me for production */ 30 31 #ifdef CONFIG_LP_CONSOLE 32 #undef DEBUG /* Don't want a garbled console */ 33 #endif 34 35 #ifdef DEBUG 36 #define DPRINTK(stuff...) printk (stuff) 37 #else 38 #define DPRINTK(stuff...) 39 #endif 40 41 /* Make parport_wait_peripheral wake up. 42 * It will be useful to call this from an interrupt handler. */ 43 static void parport_ieee1284_wakeup (struct parport *port) 44 { 45 up (&port->physport->ieee1284.irq); 46 } 47 48 static struct parport *port_from_cookie[PARPORT_MAX]; 49 static void timeout_waiting_on_port (unsigned long cookie) 50 { 51 parport_ieee1284_wakeup (port_from_cookie[cookie % PARPORT_MAX]); 52 } 53 54 /** 55 * parport_wait_event - wait for an event on a parallel port 56 * @port: port to wait on 57 * @timeout: time to wait (in jiffies) 58 * 59 * This function waits for up to @timeout jiffies for an 60 * interrupt to occur on a parallel port. If the port timeout is 61 * set to zero, it returns immediately. 62 * 63 * If an interrupt occurs before the timeout period elapses, this 64 * function returns one immediately. If it times out, it returns 65 * a value greater than zero. An error code less than zero 66 * indicates an error (most likely a pending signal), and the 67 * calling code should finish what it's doing as soon as it can. 68 */ 69 70 int parport_wait_event (struct parport *port, signed long timeout) 71 { 72 int ret; 73 struct timer_list timer; 74 75 if (!port->physport->cad->timeout) 76 /* Zero timeout is special, and we can't down() the 77 semaphore. */ 78 return 1; 79 80 init_timer (&timer); 81 timer.expires = jiffies + timeout; 82 timer.function = timeout_waiting_on_port; 83 port_from_cookie[port->number % PARPORT_MAX] = port; 84 timer.data = port->number; 85 86 add_timer (&timer); 87 ret = down_interruptible (&port->physport->ieee1284.irq); 88 if (!del_timer (&timer) && !ret) 89 /* Timed out. */ 90 ret = 1; 91 92 return ret; 93 } 94 95 /** 96 * parport_poll_peripheral - poll status lines 97 * @port: port to watch 98 * @mask: status lines to watch 99 * @result: desired values of chosen status lines 100 * @usec: timeout 101 * 102 * This function busy-waits until the masked status lines have 103 * the desired values, or until the timeout period elapses. The 104 * @mask and @result parameters are bitmasks, with the bits 105 * defined by the constants in parport.h: %PARPORT_STATUS_BUSY, 106 * and so on. 107 * 108 * This function does not call schedule(); instead it busy-waits 109 * using udelay(). It currently has a resolution of 5usec. 110 * 111 * If the status lines take on the desired values before the 112 * timeout period elapses, parport_poll_peripheral() returns zero 113 * immediately. A zero return value greater than zero indicates 114 * a timeout. An error code (less than zero) indicates an error, 115 * most likely a signal that arrived, and the caller should 116 * finish what it is doing as soon as possible. 117 */ 118 119 int parport_poll_peripheral(struct parport *port, 120 unsigned char mask, 121 unsigned char result, 122 int usec) 123 { 124 /* Zero return code is success, >0 is timeout. */ 125 int count = usec / 5 + 2; 126 int i; 127 unsigned char status; 128 for (i = 0; i < count; i++) { 129 status = parport_read_status (port); 130 if ((status & mask) == result) 131 return 0; 132 if (signal_pending (current)) 133 return -EINTR; 134 if (need_resched()) 135 break; 136 if (i >= 2) 137 udelay (5); 138 } 139 140 return 1; 141 } 142 143 /** 144 * parport_wait_peripheral - wait for status lines to change in 35ms 145 * @port: port to watch 146 * @mask: status lines to watch 147 * @result: desired values of chosen status lines 148 * 149 * This function waits until the masked status lines have the 150 * desired values, or until 35ms have elapsed (see IEEE 1284-1994 151 * page 24 to 25 for why this value in particular is hardcoded). 152 * The @mask and @result parameters are bitmasks, with the bits 153 * defined by the constants in parport.h: %PARPORT_STATUS_BUSY, 154 * and so on. 155 * 156 * The port is polled quickly to start off with, in anticipation 157 * of a fast response from the peripheral. This fast polling 158 * time is configurable (using /proc), and defaults to 500usec. 159 * If the timeout for this port (see parport_set_timeout()) is 160 * zero, the fast polling time is 35ms, and this function does 161 * not call schedule(). 162 * 163 * If the timeout for this port is non-zero, after the fast 164 * polling fails it uses parport_wait_event() to wait for up to 165 * 10ms, waking up if an interrupt occurs. 166 */ 167 168 int parport_wait_peripheral(struct parport *port, 169 unsigned char mask, 170 unsigned char result) 171 { 172 int ret; 173 int usec; 174 unsigned long deadline; 175 unsigned char status; 176 177 usec = port->physport->spintime; /* usecs of fast polling */ 178 if (!port->physport->cad->timeout) 179 /* A zero timeout is "special": busy wait for the 180 entire 35ms. */ 181 usec = 35000; 182 183 /* Fast polling. 184 * 185 * This should be adjustable. 186 * How about making a note (in the device structure) of how long 187 * it takes, so we know for next time? 188 */ 189 ret = parport_poll_peripheral (port, mask, result, usec); 190 if (ret != 1) 191 return ret; 192 193 if (!port->physport->cad->timeout) 194 /* We may be in an interrupt handler, so we can't poll 195 * slowly anyway. */ 196 return 1; 197 198 /* 40ms of slow polling. */ 199 deadline = jiffies + msecs_to_jiffies(40); 200 while (time_before (jiffies, deadline)) { 201 int ret; 202 203 if (signal_pending (current)) 204 return -EINTR; 205 206 /* Wait for 10ms (or until an interrupt occurs if 207 * the handler is set) */ 208 if ((ret = parport_wait_event (port, msecs_to_jiffies(10))) < 0) 209 return ret; 210 211 status = parport_read_status (port); 212 if ((status & mask) == result) 213 return 0; 214 215 if (!ret) { 216 /* parport_wait_event didn't time out, but the 217 * peripheral wasn't actually ready either. 218 * Wait for another 10ms. */ 219 schedule_timeout_interruptible(msecs_to_jiffies(10)); 220 } 221 } 222 223 return 1; 224 } 225 226 #ifdef CONFIG_PARPORT_1284 227 /* Terminate a negotiated mode. */ 228 static void parport_ieee1284_terminate (struct parport *port) 229 { 230 int r; 231 port = port->physport; 232 233 /* EPP terminates differently. */ 234 switch (port->ieee1284.mode) { 235 case IEEE1284_MODE_EPP: 236 case IEEE1284_MODE_EPPSL: 237 case IEEE1284_MODE_EPPSWE: 238 /* Terminate from EPP mode. */ 239 240 /* Event 68: Set nInit low */ 241 parport_frob_control (port, PARPORT_CONTROL_INIT, 0); 242 udelay (50); 243 244 /* Event 69: Set nInit high, nSelectIn low */ 245 parport_frob_control (port, 246 PARPORT_CONTROL_SELECT 247 | PARPORT_CONTROL_INIT, 248 PARPORT_CONTROL_SELECT 249 | PARPORT_CONTROL_INIT); 250 break; 251 252 case IEEE1284_MODE_ECP: 253 case IEEE1284_MODE_ECPRLE: 254 case IEEE1284_MODE_ECPSWE: 255 /* In ECP we can only terminate from fwd idle phase. */ 256 if (port->ieee1284.phase != IEEE1284_PH_FWD_IDLE) { 257 /* Event 47: Set nInit high */ 258 parport_frob_control (port, 259 PARPORT_CONTROL_INIT 260 | PARPORT_CONTROL_AUTOFD, 261 PARPORT_CONTROL_INIT 262 | PARPORT_CONTROL_AUTOFD); 263 264 /* Event 49: PError goes high */ 265 r = parport_wait_peripheral (port, 266 PARPORT_STATUS_PAPEROUT, 267 PARPORT_STATUS_PAPEROUT); 268 if (r) 269 DPRINTK (KERN_INFO "%s: Timeout at event 49\n", 270 port->name); 271 272 parport_data_forward (port); 273 DPRINTK (KERN_DEBUG "%s: ECP direction: forward\n", 274 port->name); 275 port->ieee1284.phase = IEEE1284_PH_FWD_IDLE; 276 } 277 278 /* fall-though.. */ 279 280 default: 281 /* Terminate from all other modes. */ 282 283 /* Event 22: Set nSelectIn low, nAutoFd high */ 284 parport_frob_control (port, 285 PARPORT_CONTROL_SELECT 286 | PARPORT_CONTROL_AUTOFD, 287 PARPORT_CONTROL_SELECT); 288 289 /* Event 24: nAck goes low */ 290 r = parport_wait_peripheral (port, PARPORT_STATUS_ACK, 0); 291 if (r) 292 DPRINTK (KERN_INFO "%s: Timeout at event 24\n", 293 port->name); 294 295 /* Event 25: Set nAutoFd low */ 296 parport_frob_control (port, 297 PARPORT_CONTROL_AUTOFD, 298 PARPORT_CONTROL_AUTOFD); 299 300 /* Event 27: nAck goes high */ 301 r = parport_wait_peripheral (port, 302 PARPORT_STATUS_ACK, 303 PARPORT_STATUS_ACK); 304 if (r) 305 DPRINTK (KERN_INFO "%s: Timeout at event 27\n", 306 port->name); 307 308 /* Event 29: Set nAutoFd high */ 309 parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0); 310 } 311 312 port->ieee1284.mode = IEEE1284_MODE_COMPAT; 313 port->ieee1284.phase = IEEE1284_PH_FWD_IDLE; 314 315 DPRINTK (KERN_DEBUG "%s: In compatibility (forward idle) mode\n", 316 port->name); 317 } 318 #endif /* IEEE1284 support */ 319 320 /** 321 * parport_negotiate - negotiate an IEEE 1284 mode 322 * @port: port to use 323 * @mode: mode to negotiate to 324 * 325 * Use this to negotiate to a particular IEEE 1284 transfer mode. 326 * The @mode parameter should be one of the constants in 327 * parport.h starting %IEEE1284_MODE_xxx. 328 * 329 * The return value is 0 if the peripheral has accepted the 330 * negotiation to the mode specified, -1 if the peripheral is not 331 * IEEE 1284 compliant (or not present), or 1 if the peripheral 332 * has rejected the negotiation. 333 */ 334 335 int parport_negotiate (struct parport *port, int mode) 336 { 337 #ifndef CONFIG_PARPORT_1284 338 if (mode == IEEE1284_MODE_COMPAT) 339 return 0; 340 printk (KERN_ERR "parport: IEEE1284 not supported in this kernel\n"); 341 return -1; 342 #else 343 int m = mode & ~IEEE1284_ADDR; 344 int r; 345 unsigned char xflag; 346 347 port = port->physport; 348 349 /* Is there anything to do? */ 350 if (port->ieee1284.mode == mode) 351 return 0; 352 353 /* Is the difference just an address-or-not bit? */ 354 if ((port->ieee1284.mode & ~IEEE1284_ADDR) == (mode & ~IEEE1284_ADDR)){ 355 port->ieee1284.mode = mode; 356 return 0; 357 } 358 359 /* Go to compability forward idle mode */ 360 if (port->ieee1284.mode != IEEE1284_MODE_COMPAT) 361 parport_ieee1284_terminate (port); 362 363 if (mode == IEEE1284_MODE_COMPAT) 364 /* Compatibility mode: no negotiation. */ 365 return 0; 366 367 switch (mode) { 368 case IEEE1284_MODE_ECPSWE: 369 m = IEEE1284_MODE_ECP; 370 break; 371 case IEEE1284_MODE_EPPSL: 372 case IEEE1284_MODE_EPPSWE: 373 m = IEEE1284_MODE_EPP; 374 break; 375 case IEEE1284_MODE_BECP: 376 return -ENOSYS; /* FIXME (implement BECP) */ 377 } 378 379 if (mode & IEEE1284_EXT_LINK) 380 m = 1<<7; /* request extensibility link */ 381 382 port->ieee1284.phase = IEEE1284_PH_NEGOTIATION; 383 384 /* Start off with nStrobe and nAutoFd high, and nSelectIn low */ 385 parport_frob_control (port, 386 PARPORT_CONTROL_STROBE 387 | PARPORT_CONTROL_AUTOFD 388 | PARPORT_CONTROL_SELECT, 389 PARPORT_CONTROL_SELECT); 390 udelay(1); 391 392 /* Event 0: Set data */ 393 parport_data_forward (port); 394 parport_write_data (port, m); 395 udelay (400); /* Shouldn't need to wait this long. */ 396 397 /* Event 1: Set nSelectIn high, nAutoFd low */ 398 parport_frob_control (port, 399 PARPORT_CONTROL_SELECT 400 | PARPORT_CONTROL_AUTOFD, 401 PARPORT_CONTROL_AUTOFD); 402 403 /* Event 2: PError, Select, nFault go high, nAck goes low */ 404 if (parport_wait_peripheral (port, 405 PARPORT_STATUS_ERROR 406 | PARPORT_STATUS_SELECT 407 | PARPORT_STATUS_PAPEROUT 408 | PARPORT_STATUS_ACK, 409 PARPORT_STATUS_ERROR 410 | PARPORT_STATUS_SELECT 411 | PARPORT_STATUS_PAPEROUT)) { 412 /* Timeout */ 413 parport_frob_control (port, 414 PARPORT_CONTROL_SELECT 415 | PARPORT_CONTROL_AUTOFD, 416 PARPORT_CONTROL_SELECT); 417 DPRINTK (KERN_DEBUG 418 "%s: Peripheral not IEEE1284 compliant (0x%02X)\n", 419 port->name, parport_read_status (port)); 420 port->ieee1284.phase = IEEE1284_PH_FWD_IDLE; 421 return -1; /* Not IEEE1284 compliant */ 422 } 423 424 /* Event 3: Set nStrobe low */ 425 parport_frob_control (port, 426 PARPORT_CONTROL_STROBE, 427 PARPORT_CONTROL_STROBE); 428 429 /* Event 4: Set nStrobe and nAutoFd high */ 430 udelay (5); 431 parport_frob_control (port, 432 PARPORT_CONTROL_STROBE 433 | PARPORT_CONTROL_AUTOFD, 434 0); 435 436 /* Event 6: nAck goes high */ 437 if (parport_wait_peripheral (port, 438 PARPORT_STATUS_ACK, 439 PARPORT_STATUS_ACK)) { 440 /* This shouldn't really happen with a compliant device. */ 441 DPRINTK (KERN_DEBUG 442 "%s: Mode 0x%02x not supported? (0x%02x)\n", 443 port->name, mode, port->ops->read_status (port)); 444 parport_ieee1284_terminate (port); 445 return 1; 446 } 447 448 xflag = parport_read_status (port) & PARPORT_STATUS_SELECT; 449 450 /* xflag should be high for all modes other than nibble (0). */ 451 if (mode && !xflag) { 452 /* Mode not supported. */ 453 DPRINTK (KERN_DEBUG "%s: Mode 0x%02x rejected by peripheral\n", 454 port->name, mode); 455 parport_ieee1284_terminate (port); 456 return 1; 457 } 458 459 /* More to do if we've requested extensibility link. */ 460 if (mode & IEEE1284_EXT_LINK) { 461 m = mode & 0x7f; 462 udelay (1); 463 parport_write_data (port, m); 464 udelay (1); 465 466 /* Event 51: Set nStrobe low */ 467 parport_frob_control (port, 468 PARPORT_CONTROL_STROBE, 469 PARPORT_CONTROL_STROBE); 470 471 /* Event 52: nAck goes low */ 472 if (parport_wait_peripheral (port, PARPORT_STATUS_ACK, 0)) { 473 /* This peripheral is _very_ slow. */ 474 DPRINTK (KERN_DEBUG 475 "%s: Event 52 didn't happen\n", 476 port->name); 477 parport_ieee1284_terminate (port); 478 return 1; 479 } 480 481 /* Event 53: Set nStrobe high */ 482 parport_frob_control (port, 483 PARPORT_CONTROL_STROBE, 484 0); 485 486 /* Event 55: nAck goes high */ 487 if (parport_wait_peripheral (port, 488 PARPORT_STATUS_ACK, 489 PARPORT_STATUS_ACK)) { 490 /* This shouldn't really happen with a compliant 491 * device. */ 492 DPRINTK (KERN_DEBUG 493 "%s: Mode 0x%02x not supported? (0x%02x)\n", 494 port->name, mode, 495 port->ops->read_status (port)); 496 parport_ieee1284_terminate (port); 497 return 1; 498 } 499 500 /* Event 54: Peripheral sets XFlag to reflect support */ 501 xflag = parport_read_status (port) & PARPORT_STATUS_SELECT; 502 503 /* xflag should be high. */ 504 if (!xflag) { 505 /* Extended mode not supported. */ 506 DPRINTK (KERN_DEBUG "%s: Extended mode 0x%02x not " 507 "supported\n", port->name, mode); 508 parport_ieee1284_terminate (port); 509 return 1; 510 } 511 512 /* Any further setup is left to the caller. */ 513 } 514 515 /* Mode is supported */ 516 DPRINTK (KERN_DEBUG "%s: In mode 0x%02x\n", port->name, mode); 517 port->ieee1284.mode = mode; 518 519 /* But ECP is special */ 520 if (!(mode & IEEE1284_EXT_LINK) && (m & IEEE1284_MODE_ECP)) { 521 port->ieee1284.phase = IEEE1284_PH_ECP_SETUP; 522 523 /* Event 30: Set nAutoFd low */ 524 parport_frob_control (port, 525 PARPORT_CONTROL_AUTOFD, 526 PARPORT_CONTROL_AUTOFD); 527 528 /* Event 31: PError goes high. */ 529 r = parport_wait_peripheral (port, 530 PARPORT_STATUS_PAPEROUT, 531 PARPORT_STATUS_PAPEROUT); 532 if (r) { 533 DPRINTK (KERN_INFO "%s: Timeout at event 31\n", 534 port->name); 535 } 536 537 port->ieee1284.phase = IEEE1284_PH_FWD_IDLE; 538 DPRINTK (KERN_DEBUG "%s: ECP direction: forward\n", 539 port->name); 540 } else switch (mode) { 541 case IEEE1284_MODE_NIBBLE: 542 case IEEE1284_MODE_BYTE: 543 port->ieee1284.phase = IEEE1284_PH_REV_IDLE; 544 break; 545 default: 546 port->ieee1284.phase = IEEE1284_PH_FWD_IDLE; 547 } 548 549 550 return 0; 551 #endif /* IEEE1284 support */ 552 } 553 554 /* Acknowledge that the peripheral has data available. 555 * Events 18-20, in order to get from Reverse Idle phase 556 * to Host Busy Data Available. 557 * This will most likely be called from an interrupt. 558 * Returns zero if data was available. 559 */ 560 #ifdef CONFIG_PARPORT_1284 561 static int parport_ieee1284_ack_data_avail (struct parport *port) 562 { 563 if (parport_read_status (port) & PARPORT_STATUS_ERROR) 564 /* Event 18 didn't happen. */ 565 return -1; 566 567 /* Event 20: nAutoFd goes high. */ 568 port->ops->frob_control (port, PARPORT_CONTROL_AUTOFD, 0); 569 port->ieee1284.phase = IEEE1284_PH_HBUSY_DAVAIL; 570 return 0; 571 } 572 #endif /* IEEE1284 support */ 573 574 /* Handle an interrupt. */ 575 void parport_ieee1284_interrupt (int which, void *handle, struct pt_regs *regs) 576 { 577 struct parport *port = handle; 578 parport_ieee1284_wakeup (port); 579 580 #ifdef CONFIG_PARPORT_1284 581 if (port->ieee1284.phase == IEEE1284_PH_REV_IDLE) { 582 /* An interrupt in this phase means that data 583 * is now available. */ 584 DPRINTK (KERN_DEBUG "%s: Data available\n", port->name); 585 parport_ieee1284_ack_data_avail (port); 586 } 587 #endif /* IEEE1284 support */ 588 } 589 590 /** 591 * parport_write - write a block of data to a parallel port 592 * @port: port to write to 593 * @buffer: data buffer (in kernel space) 594 * @len: number of bytes of data to transfer 595 * 596 * This will write up to @len bytes of @buffer to the port 597 * specified, using the IEEE 1284 transfer mode most recently 598 * negotiated to (using parport_negotiate()), as long as that 599 * mode supports forward transfers (host to peripheral). 600 * 601 * It is the caller's responsibility to ensure that the first 602 * @len bytes of @buffer are valid. 603 * 604 * This function returns the number of bytes transferred (if zero 605 * or positive), or else an error code. 606 */ 607 608 ssize_t parport_write (struct parport *port, const void *buffer, size_t len) 609 { 610 #ifndef CONFIG_PARPORT_1284 611 return port->ops->compat_write_data (port, buffer, len, 0); 612 #else 613 ssize_t retval; 614 int mode = port->ieee1284.mode; 615 int addr = mode & IEEE1284_ADDR; 616 size_t (*fn) (struct parport *, const void *, size_t, int); 617 618 /* Ignore the device-ID-request bit and the address bit. */ 619 mode &= ~(IEEE1284_DEVICEID | IEEE1284_ADDR); 620 621 /* Use the mode we're in. */ 622 switch (mode) { 623 case IEEE1284_MODE_NIBBLE: 624 case IEEE1284_MODE_BYTE: 625 parport_negotiate (port, IEEE1284_MODE_COMPAT); 626 case IEEE1284_MODE_COMPAT: 627 DPRINTK (KERN_DEBUG "%s: Using compatibility mode\n", 628 port->name); 629 fn = port->ops->compat_write_data; 630 break; 631 632 case IEEE1284_MODE_EPP: 633 DPRINTK (KERN_DEBUG "%s: Using EPP mode\n", port->name); 634 if (addr) { 635 fn = port->ops->epp_write_addr; 636 } else { 637 fn = port->ops->epp_write_data; 638 } 639 break; 640 case IEEE1284_MODE_EPPSWE: 641 DPRINTK (KERN_DEBUG "%s: Using software-emulated EPP mode\n", 642 port->name); 643 if (addr) { 644 fn = parport_ieee1284_epp_write_addr; 645 } else { 646 fn = parport_ieee1284_epp_write_data; 647 } 648 break; 649 case IEEE1284_MODE_ECP: 650 case IEEE1284_MODE_ECPRLE: 651 DPRINTK (KERN_DEBUG "%s: Using ECP mode\n", port->name); 652 if (addr) { 653 fn = port->ops->ecp_write_addr; 654 } else { 655 fn = port->ops->ecp_write_data; 656 } 657 break; 658 659 case IEEE1284_MODE_ECPSWE: 660 DPRINTK (KERN_DEBUG "%s: Using software-emulated ECP mode\n", 661 port->name); 662 /* The caller has specified that it must be emulated, 663 * even if we have ECP hardware! */ 664 if (addr) { 665 fn = parport_ieee1284_ecp_write_addr; 666 } else { 667 fn = parport_ieee1284_ecp_write_data; 668 } 669 break; 670 671 default: 672 DPRINTK (KERN_DEBUG "%s: Unknown mode 0x%02x\n", port->name, 673 port->ieee1284.mode); 674 return -ENOSYS; 675 } 676 677 retval = (*fn) (port, buffer, len, 0); 678 DPRINTK (KERN_DEBUG "%s: wrote %d/%d bytes\n", port->name, retval, len); 679 return retval; 680 #endif /* IEEE1284 support */ 681 } 682 683 /** 684 * parport_read - read a block of data from a parallel port 685 * @port: port to read from 686 * @buffer: data buffer (in kernel space) 687 * @len: number of bytes of data to transfer 688 * 689 * This will read up to @len bytes of @buffer to the port 690 * specified, using the IEEE 1284 transfer mode most recently 691 * negotiated to (using parport_negotiate()), as long as that 692 * mode supports reverse transfers (peripheral to host). 693 * 694 * It is the caller's responsibility to ensure that the first 695 * @len bytes of @buffer are available to write to. 696 * 697 * This function returns the number of bytes transferred (if zero 698 * or positive), or else an error code. 699 */ 700 701 ssize_t parport_read (struct parport *port, void *buffer, size_t len) 702 { 703 #ifndef CONFIG_PARPORT_1284 704 printk (KERN_ERR "parport: IEEE1284 not supported in this kernel\n"); 705 return -ENODEV; 706 #else 707 int mode = port->physport->ieee1284.mode; 708 int addr = mode & IEEE1284_ADDR; 709 size_t (*fn) (struct parport *, void *, size_t, int); 710 711 /* Ignore the device-ID-request bit and the address bit. */ 712 mode &= ~(IEEE1284_DEVICEID | IEEE1284_ADDR); 713 714 /* Use the mode we're in. */ 715 switch (mode) { 716 case IEEE1284_MODE_COMPAT: 717 /* if we can tri-state use BYTE mode instead of NIBBLE mode, 718 * if that fails, revert to NIBBLE mode -- ought to store somewhere 719 * the device's ability to do BYTE mode reverse transfers, so we don't 720 * end up needlessly calling negotiate(BYTE) repeately.. (fb) 721 */ 722 if ((port->physport->modes & PARPORT_MODE_TRISTATE) && 723 !parport_negotiate (port, IEEE1284_MODE_BYTE)) { 724 /* got into BYTE mode OK */ 725 DPRINTK (KERN_DEBUG "%s: Using byte mode\n", port->name); 726 fn = port->ops->byte_read_data; 727 break; 728 } 729 if (parport_negotiate (port, IEEE1284_MODE_NIBBLE)) { 730 return -EIO; 731 } 732 /* fall through to NIBBLE */ 733 case IEEE1284_MODE_NIBBLE: 734 DPRINTK (KERN_DEBUG "%s: Using nibble mode\n", port->name); 735 fn = port->ops->nibble_read_data; 736 break; 737 738 case IEEE1284_MODE_BYTE: 739 DPRINTK (KERN_DEBUG "%s: Using byte mode\n", port->name); 740 fn = port->ops->byte_read_data; 741 break; 742 743 case IEEE1284_MODE_EPP: 744 DPRINTK (KERN_DEBUG "%s: Using EPP mode\n", port->name); 745 if (addr) { 746 fn = port->ops->epp_read_addr; 747 } else { 748 fn = port->ops->epp_read_data; 749 } 750 break; 751 case IEEE1284_MODE_EPPSWE: 752 DPRINTK (KERN_DEBUG "%s: Using software-emulated EPP mode\n", 753 port->name); 754 if (addr) { 755 fn = parport_ieee1284_epp_read_addr; 756 } else { 757 fn = parport_ieee1284_epp_read_data; 758 } 759 break; 760 case IEEE1284_MODE_ECP: 761 case IEEE1284_MODE_ECPRLE: 762 DPRINTK (KERN_DEBUG "%s: Using ECP mode\n", port->name); 763 fn = port->ops->ecp_read_data; 764 break; 765 766 case IEEE1284_MODE_ECPSWE: 767 DPRINTK (KERN_DEBUG "%s: Using software-emulated ECP mode\n", 768 port->name); 769 fn = parport_ieee1284_ecp_read_data; 770 break; 771 772 default: 773 DPRINTK (KERN_DEBUG "%s: Unknown mode 0x%02x\n", port->name, 774 port->physport->ieee1284.mode); 775 return -ENOSYS; 776 } 777 778 return (*fn) (port, buffer, len, 0); 779 #endif /* IEEE1284 support */ 780 } 781 782 /** 783 * parport_set_timeout - set the inactivity timeout for a device 784 * @dev: device on a port 785 * @inactivity: inactivity timeout (in jiffies) 786 * 787 * This sets the inactivity timeout for a particular device on a 788 * port. This affects functions like parport_wait_peripheral(). 789 * The special value 0 means not to call schedule() while dealing 790 * with this device. 791 * 792 * The return value is the previous inactivity timeout. 793 * 794 * Any callers of parport_wait_event() for this device are woken 795 * up. 796 */ 797 798 long parport_set_timeout (struct pardevice *dev, long inactivity) 799 { 800 long int old = dev->timeout; 801 802 dev->timeout = inactivity; 803 804 if (dev->port->physport->cad == dev) 805 parport_ieee1284_wakeup (dev->port); 806 807 return old; 808 } 809 810 /* Exported symbols for modules. */ 811 812 EXPORT_SYMBOL(parport_negotiate); 813 EXPORT_SYMBOL(parport_write); 814 EXPORT_SYMBOL(parport_read); 815 EXPORT_SYMBOL(parport_wait_peripheral); 816 EXPORT_SYMBOL(parport_wait_event); 817 EXPORT_SYMBOL(parport_set_timeout); 818 EXPORT_SYMBOL(parport_ieee1284_interrupt); 819