1/* 2 * IEEE 1284.3 Parallel port daisy chain and multiplexor code 3 * 4 * Copyright (C) 1999, 2000 Tim Waugh <tim@cyberelk.demon.co.uk> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 * ??-12-1998: Initial implementation. 12 * 31-01-1999: Make port-cloning transparent. 13 * 13-02-1999: Move DeviceID technique from parport_probe. 14 * 13-03-1999: Get DeviceID from non-IEEE 1284.3 devices too. 15 * 22-02-2000: Count devices that are actually detected. 16 * 17 * Any part of this program may be used in documents licensed under 18 * the GNU Free Documentation License, Version 1.1 or any later version 19 * published by the Free Software Foundation. 20 */ 21 22#include <linux/module.h> 23#include <linux/parport.h> 24#include <linux/delay.h> 25#include <linux/slab.h> 26#include <linux/sched.h> 27 28#include <asm/current.h> 29#include <asm/uaccess.h> 30 31#undef DEBUG 32 33#ifdef DEBUG 34#define DPRINTK(stuff...) printk(stuff) 35#else 36#define DPRINTK(stuff...) 37#endif 38 39static struct daisydev { 40 struct daisydev *next; 41 struct parport *port; 42 int daisy; 43 int devnum; 44} *topology = NULL; 45static DEFINE_SPINLOCK(topology_lock); 46 47static int numdevs = 0; 48 49/* Forward-declaration of lower-level functions. */ 50static int mux_present(struct parport *port); 51static int num_mux_ports(struct parport *port); 52static int select_port(struct parport *port); 53static int assign_addrs(struct parport *port); 54 55/* Add a device to the discovered topology. */ 56static void add_dev(int devnum, struct parport *port, int daisy) 57{ 58 struct daisydev *newdev, **p; 59 newdev = kmalloc(sizeof(struct daisydev), GFP_KERNEL); 60 if (newdev) { 61 newdev->port = port; 62 newdev->daisy = daisy; 63 newdev->devnum = devnum; 64 spin_lock(&topology_lock); 65 for (p = &topology; *p && (*p)->devnum<devnum; p = &(*p)->next) 66 ; 67 newdev->next = *p; 68 *p = newdev; 69 spin_unlock(&topology_lock); 70 } 71} 72 73/* Clone a parport (actually, make an alias). */ 74static struct parport *clone_parport(struct parport *real, int muxport) 75{ 76 struct parport *extra = parport_register_port(real->base, 77 real->irq, 78 real->dma, 79 real->ops); 80 if (extra) { 81 extra->portnum = real->portnum; 82 extra->physport = real; 83 extra->muxport = muxport; 84 real->slaves[muxport-1] = extra; 85 } 86 87 return extra; 88} 89 90/* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains. 91 * Return value is number of devices actually detected. */ 92int parport_daisy_init(struct parport *port) 93{ 94 int detected = 0; 95 char *deviceid; 96 static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" }; 97 int num_ports; 98 int i; 99 int last_try = 0; 100 101again: 102 /* Because this is called before any other devices exist, 103 * we don't have to claim exclusive access. */ 104 105 /* If mux present on normal port, need to create new 106 * parports for each extra port. */ 107 if (port->muxport < 0 && mux_present(port) && 108 /* don't be fooled: a mux must have 2 or 4 ports. */ 109 ((num_ports = num_mux_ports(port)) == 2 || num_ports == 4)) { 110 /* Leave original as port zero. */ 111 port->muxport = 0; 112 printk(KERN_INFO 113 "%s: 1st (default) port of %d-way multiplexor\n", 114 port->name, num_ports); 115 for (i = 1; i < num_ports; i++) { 116 /* Clone the port. */ 117 struct parport *extra = clone_parport(port, i); 118 if (!extra) { 119 if (signal_pending(current)) 120 break; 121 122 schedule(); 123 continue; 124 } 125 126 printk(KERN_INFO 127 "%s: %d%s port of %d-way multiplexor on %s\n", 128 extra->name, i + 1, th[i + 1], num_ports, 129 port->name); 130 131 /* Analyse that port too. We won't recurse 132 forever because of the 'port->muxport < 0' 133 test above. */ 134 parport_daisy_init(extra); 135 } 136 } 137 138 if (port->muxport >= 0) 139 select_port(port); 140 141 parport_daisy_deselect_all(port); 142 detected += assign_addrs(port); 143 144 /* Count the potential legacy device at the end. */ 145 add_dev(numdevs++, port, -1); 146 147 /* Find out the legacy device's IEEE 1284 device ID. */ 148 deviceid = kmalloc(1024, GFP_KERNEL); 149 if (deviceid) { 150 if (parport_device_id(numdevs - 1, deviceid, 1024) > 2) 151 detected++; 152 153 kfree(deviceid); 154 } 155 156 if (!detected && !last_try) { 157 /* No devices were detected. Perhaps they are in some 158 funny state; let's try to reset them and see if 159 they wake up. */ 160 parport_daisy_fini(port); 161 parport_write_control(port, PARPORT_CONTROL_SELECT); 162 udelay(50); 163 parport_write_control(port, 164 PARPORT_CONTROL_SELECT | 165 PARPORT_CONTROL_INIT); 166 udelay(50); 167 last_try = 1; 168 goto again; 169 } 170 171 return detected; 172} 173 174/* Forget about devices on a physical port. */ 175void parport_daisy_fini(struct parport *port) 176{ 177 struct daisydev **p; 178 179 spin_lock(&topology_lock); 180 p = &topology; 181 while (*p) { 182 struct daisydev *dev = *p; 183 if (dev->port != port) { 184 p = &dev->next; 185 continue; 186 } 187 *p = dev->next; 188 kfree(dev); 189 } 190 191 /* Gaps in the numbering could be handled better. How should 192 someone enumerate through all IEEE1284.3 devices in the 193 topology?. */ 194 if (!topology) numdevs = 0; 195 spin_unlock(&topology_lock); 196 return; 197} 198 199/** 200 * parport_open - find a device by canonical device number 201 * @devnum: canonical device number 202 * @name: name to associate with the device 203 * 204 * This function is similar to parport_register_device(), except 205 * that it locates a device by its number rather than by the port 206 * it is attached to. 207 * 208 * All parameters except for @devnum are the same as for 209 * parport_register_device(). The return value is the same as 210 * for parport_register_device(). 211 **/ 212 213struct pardevice *parport_open(int devnum, const char *name) 214{ 215 struct daisydev *p = topology; 216 struct parport *port; 217 struct pardevice *dev; 218 int daisy; 219 220 spin_lock(&topology_lock); 221 while (p && p->devnum != devnum) 222 p = p->next; 223 224 if (!p) { 225 spin_unlock(&topology_lock); 226 return NULL; 227 } 228 229 daisy = p->daisy; 230 port = parport_get_port(p->port); 231 spin_unlock(&topology_lock); 232 233 dev = parport_register_device(port, name, NULL, NULL, NULL, 0, NULL); 234 parport_put_port(port); 235 if (!dev) 236 return NULL; 237 238 dev->daisy = daisy; 239 240 /* Check that there really is a device to select. */ 241 if (daisy >= 0) { 242 int selected; 243 parport_claim_or_block(dev); 244 selected = port->daisy; 245 parport_release(dev); 246 247 if (selected != daisy) { 248 /* No corresponding device. */ 249 parport_unregister_device(dev); 250 return NULL; 251 } 252 } 253 254 return dev; 255} 256 257/** 258 * parport_close - close a device opened with parport_open() 259 * @dev: device to close 260 * 261 * This is to parport_open() as parport_unregister_device() is to 262 * parport_register_device(). 263 **/ 264 265void parport_close(struct pardevice *dev) 266{ 267 parport_unregister_device(dev); 268} 269 270/* Send a daisy-chain-style CPP command packet. */ 271static int cpp_daisy(struct parport *port, int cmd) 272{ 273 unsigned char s; 274 275 parport_data_forward(port); 276 parport_write_data(port, 0xaa); udelay(2); 277 parport_write_data(port, 0x55); udelay(2); 278 parport_write_data(port, 0x00); udelay(2); 279 parport_write_data(port, 0xff); udelay(2); 280 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 281 | PARPORT_STATUS_PAPEROUT 282 | PARPORT_STATUS_SELECT 283 | PARPORT_STATUS_ERROR); 284 if (s != (PARPORT_STATUS_BUSY 285 | PARPORT_STATUS_PAPEROUT 286 | PARPORT_STATUS_SELECT 287 | PARPORT_STATUS_ERROR)) { 288 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n", 289 port->name, s); 290 return -ENXIO; 291 } 292 293 parport_write_data(port, 0x87); udelay(2); 294 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 295 | PARPORT_STATUS_PAPEROUT 296 | PARPORT_STATUS_SELECT 297 | PARPORT_STATUS_ERROR); 298 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { 299 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n", 300 port->name, s); 301 return -ENXIO; 302 } 303 304 parport_write_data(port, 0x78); udelay(2); 305 parport_write_data(port, cmd); udelay(2); 306 parport_frob_control(port, 307 PARPORT_CONTROL_STROBE, 308 PARPORT_CONTROL_STROBE); 309 udelay(1); 310 s = parport_read_status(port); 311 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0); 312 udelay(1); 313 parport_write_data(port, 0xff); udelay(2); 314 315 return s; 316} 317 318/* Send a mux-style CPP command packet. */ 319static int cpp_mux(struct parport *port, int cmd) 320{ 321 unsigned char s; 322 int rc; 323 324 parport_data_forward(port); 325 parport_write_data(port, 0xaa); udelay(2); 326 parport_write_data(port, 0x55); udelay(2); 327 parport_write_data(port, 0xf0); udelay(2); 328 parport_write_data(port, 0x0f); udelay(2); 329 parport_write_data(port, 0x52); udelay(2); 330 parport_write_data(port, 0xad); udelay(2); 331 parport_write_data(port, cmd); udelay(2); 332 333 s = parport_read_status(port); 334 if (!(s & PARPORT_STATUS_ACK)) { 335 DPRINTK(KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n", 336 port->name, cmd, s); 337 return -EIO; 338 } 339 340 rc = (((s & PARPORT_STATUS_SELECT ? 1 : 0) << 0) | 341 ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) | 342 ((s & PARPORT_STATUS_BUSY ? 0 : 1) << 2) | 343 ((s & PARPORT_STATUS_ERROR ? 0 : 1) << 3)); 344 345 return rc; 346} 347 348void parport_daisy_deselect_all(struct parport *port) 349{ 350 cpp_daisy(port, 0x30); 351} 352 353int parport_daisy_select(struct parport *port, int daisy, int mode) 354{ 355 switch (mode) 356 { 357 // For these modes we should switch to EPP mode: 358 case IEEE1284_MODE_EPP: 359 case IEEE1284_MODE_EPPSL: 360 case IEEE1284_MODE_EPPSWE: 361 return !(cpp_daisy(port, 0x20 + daisy) & 362 PARPORT_STATUS_ERROR); 363 364 // For these modes we should switch to ECP mode: 365 case IEEE1284_MODE_ECP: 366 case IEEE1284_MODE_ECPRLE: 367 case IEEE1284_MODE_ECPSWE: 368 return !(cpp_daisy(port, 0xd0 + daisy) & 369 PARPORT_STATUS_ERROR); 370 371 // Nothing was told for BECP in Daisy chain specification. 372 // May be it's wise to use ECP? 373 case IEEE1284_MODE_BECP: 374 // Others use compat mode 375 case IEEE1284_MODE_NIBBLE: 376 case IEEE1284_MODE_BYTE: 377 case IEEE1284_MODE_COMPAT: 378 default: 379 return !(cpp_daisy(port, 0xe0 + daisy) & 380 PARPORT_STATUS_ERROR); 381 } 382} 383 384static int mux_present(struct parport *port) 385{ 386 return cpp_mux(port, 0x51) == 3; 387} 388 389static int num_mux_ports(struct parport *port) 390{ 391 return cpp_mux(port, 0x58); 392} 393 394static int select_port(struct parport *port) 395{ 396 int muxport = port->muxport; 397 return cpp_mux(port, 0x60 + muxport) == muxport; 398} 399 400static int assign_addrs(struct parport *port) 401{ 402 unsigned char s; 403 unsigned char daisy; 404 int thisdev = numdevs; 405 int detected; 406 char *deviceid; 407 408 parport_data_forward(port); 409 parport_write_data(port, 0xaa); udelay(2); 410 parport_write_data(port, 0x55); udelay(2); 411 parport_write_data(port, 0x00); udelay(2); 412 parport_write_data(port, 0xff); udelay(2); 413 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 414 | PARPORT_STATUS_PAPEROUT 415 | PARPORT_STATUS_SELECT 416 | PARPORT_STATUS_ERROR); 417 if (s != (PARPORT_STATUS_BUSY 418 | PARPORT_STATUS_PAPEROUT 419 | PARPORT_STATUS_SELECT 420 | PARPORT_STATUS_ERROR)) { 421 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n", 422 port->name, s); 423 return 0; 424 } 425 426 parport_write_data(port, 0x87); udelay(2); 427 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 428 | PARPORT_STATUS_PAPEROUT 429 | PARPORT_STATUS_SELECT 430 | PARPORT_STATUS_ERROR); 431 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { 432 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n", 433 port->name, s); 434 return 0; 435 } 436 437 parport_write_data(port, 0x78); udelay(2); 438 s = parport_read_status(port); 439 440 for (daisy = 0; 441 (s & (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT)) 442 == (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT) 443 && daisy < 4; 444 ++daisy) { 445 parport_write_data(port, daisy); 446 udelay(2); 447 parport_frob_control(port, 448 PARPORT_CONTROL_STROBE, 449 PARPORT_CONTROL_STROBE); 450 udelay(1); 451 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0); 452 udelay(1); 453 454 add_dev(numdevs++, port, daisy); 455 456 /* See if this device thought it was the last in the 457 * chain. */ 458 if (!(s & PARPORT_STATUS_BUSY)) 459 break; 460 461 /* We are seeing pass through status now. We see 462 last_dev from next device or if last_dev does not 463 work status lines from some non-daisy chain 464 device. */ 465 s = parport_read_status(port); 466 } 467 468 parport_write_data(port, 0xff); udelay(2); 469 detected = numdevs - thisdev; 470 DPRINTK(KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name, 471 detected); 472 473 /* Ask the new devices to introduce themselves. */ 474 deviceid = kmalloc(1024, GFP_KERNEL); 475 if (!deviceid) return 0; 476 477 for (daisy = 0; thisdev < numdevs; thisdev++, daisy++) 478 parport_device_id(thisdev, deviceid, 1024); 479 480 kfree(deviceid); 481 return detected; 482} 483