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/signal.h> 27 28 #include <asm/current.h> 29 #include <linux/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 39 static struct daisydev { 40 struct daisydev *next; 41 struct parport *port; 42 int daisy; 43 int devnum; 44 } *topology = NULL; 45 static DEFINE_SPINLOCK(topology_lock); 46 47 static int numdevs; 48 49 /* Forward-declaration of lower-level functions. */ 50 static int mux_present(struct parport *port); 51 static int num_mux_ports(struct parport *port); 52 static int select_port(struct parport *port); 53 static int assign_addrs(struct parport *port); 54 55 /* Add a device to the discovered topology. */ 56 static 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). */ 74 static 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. */ 92 int 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; 100 101 again: 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. */ 175 void 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 **/ 212 213 struct pardevice *parport_open(int devnum, const char *name) 214 { 215 struct daisydev *p = topology; 216 struct pardev_cb par_cb; 217 struct parport *port; 218 struct pardevice *dev; 219 int daisy; 220 221 memset(&par_cb, 0, sizeof(par_cb)); 222 spin_lock(&topology_lock); 223 while (p && p->devnum != devnum) 224 p = p->next; 225 226 if (!p) { 227 spin_unlock(&topology_lock); 228 return NULL; 229 } 230 231 daisy = p->daisy; 232 port = parport_get_port(p->port); 233 spin_unlock(&topology_lock); 234 235 dev = parport_register_dev_model(port, name, &par_cb, devnum); 236 parport_put_port(port); 237 if (!dev) 238 return NULL; 239 240 dev->daisy = daisy; 241 242 /* Check that there really is a device to select. */ 243 if (daisy >= 0) { 244 int selected; 245 parport_claim_or_block(dev); 246 selected = port->daisy; 247 parport_release(dev); 248 249 if (selected != daisy) { 250 /* No corresponding device. */ 251 parport_unregister_device(dev); 252 return NULL; 253 } 254 } 255 256 return dev; 257 } 258 259 /** 260 * parport_close - close a device opened with parport_open() 261 * @dev: device to close 262 * 263 * This is to parport_open() as parport_unregister_device() is to 264 * parport_register_device(). 265 **/ 266 267 void parport_close(struct pardevice *dev) 268 { 269 parport_unregister_device(dev); 270 } 271 272 /* Send a daisy-chain-style CPP command packet. */ 273 static int cpp_daisy(struct parport *port, int cmd) 274 { 275 unsigned char s; 276 277 parport_data_forward(port); 278 parport_write_data(port, 0xaa); udelay(2); 279 parport_write_data(port, 0x55); udelay(2); 280 parport_write_data(port, 0x00); udelay(2); 281 parport_write_data(port, 0xff); udelay(2); 282 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 283 | PARPORT_STATUS_PAPEROUT 284 | PARPORT_STATUS_SELECT 285 | PARPORT_STATUS_ERROR); 286 if (s != (PARPORT_STATUS_BUSY 287 | PARPORT_STATUS_PAPEROUT 288 | PARPORT_STATUS_SELECT 289 | PARPORT_STATUS_ERROR)) { 290 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n", 291 port->name, s); 292 return -ENXIO; 293 } 294 295 parport_write_data(port, 0x87); udelay(2); 296 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 297 | PARPORT_STATUS_PAPEROUT 298 | PARPORT_STATUS_SELECT 299 | PARPORT_STATUS_ERROR); 300 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { 301 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n", 302 port->name, s); 303 return -ENXIO; 304 } 305 306 parport_write_data(port, 0x78); udelay(2); 307 parport_write_data(port, cmd); udelay(2); 308 parport_frob_control(port, 309 PARPORT_CONTROL_STROBE, 310 PARPORT_CONTROL_STROBE); 311 udelay(1); 312 s = parport_read_status(port); 313 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0); 314 udelay(1); 315 parport_write_data(port, 0xff); udelay(2); 316 317 return s; 318 } 319 320 /* Send a mux-style CPP command packet. */ 321 static int cpp_mux(struct parport *port, int cmd) 322 { 323 unsigned char s; 324 int rc; 325 326 parport_data_forward(port); 327 parport_write_data(port, 0xaa); udelay(2); 328 parport_write_data(port, 0x55); udelay(2); 329 parport_write_data(port, 0xf0); udelay(2); 330 parport_write_data(port, 0x0f); udelay(2); 331 parport_write_data(port, 0x52); udelay(2); 332 parport_write_data(port, 0xad); udelay(2); 333 parport_write_data(port, cmd); udelay(2); 334 335 s = parport_read_status(port); 336 if (!(s & PARPORT_STATUS_ACK)) { 337 DPRINTK(KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n", 338 port->name, cmd, s); 339 return -EIO; 340 } 341 342 rc = (((s & PARPORT_STATUS_SELECT ? 1 : 0) << 0) | 343 ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) | 344 ((s & PARPORT_STATUS_BUSY ? 0 : 1) << 2) | 345 ((s & PARPORT_STATUS_ERROR ? 0 : 1) << 3)); 346 347 return rc; 348 } 349 350 void parport_daisy_deselect_all(struct parport *port) 351 { 352 cpp_daisy(port, 0x30); 353 } 354 355 int parport_daisy_select(struct parport *port, int daisy, int mode) 356 { 357 switch (mode) 358 { 359 // For these modes we should switch to EPP mode: 360 case IEEE1284_MODE_EPP: 361 case IEEE1284_MODE_EPPSL: 362 case IEEE1284_MODE_EPPSWE: 363 return !(cpp_daisy(port, 0x20 + daisy) & 364 PARPORT_STATUS_ERROR); 365 366 // For these modes we should switch to ECP mode: 367 case IEEE1284_MODE_ECP: 368 case IEEE1284_MODE_ECPRLE: 369 case IEEE1284_MODE_ECPSWE: 370 return !(cpp_daisy(port, 0xd0 + daisy) & 371 PARPORT_STATUS_ERROR); 372 373 // Nothing was told for BECP in Daisy chain specification. 374 // May be it's wise to use ECP? 375 case IEEE1284_MODE_BECP: 376 // Others use compat mode 377 case IEEE1284_MODE_NIBBLE: 378 case IEEE1284_MODE_BYTE: 379 case IEEE1284_MODE_COMPAT: 380 default: 381 return !(cpp_daisy(port, 0xe0 + daisy) & 382 PARPORT_STATUS_ERROR); 383 } 384 } 385 386 static int mux_present(struct parport *port) 387 { 388 return cpp_mux(port, 0x51) == 3; 389 } 390 391 static int num_mux_ports(struct parport *port) 392 { 393 return cpp_mux(port, 0x58); 394 } 395 396 static int select_port(struct parport *port) 397 { 398 int muxport = port->muxport; 399 return cpp_mux(port, 0x60 + muxport) == muxport; 400 } 401 402 static int assign_addrs(struct parport *port) 403 { 404 unsigned char s; 405 unsigned char daisy; 406 int thisdev = numdevs; 407 int detected; 408 char *deviceid; 409 410 parport_data_forward(port); 411 parport_write_data(port, 0xaa); udelay(2); 412 parport_write_data(port, 0x55); udelay(2); 413 parport_write_data(port, 0x00); udelay(2); 414 parport_write_data(port, 0xff); udelay(2); 415 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 416 | PARPORT_STATUS_PAPEROUT 417 | PARPORT_STATUS_SELECT 418 | PARPORT_STATUS_ERROR); 419 if (s != (PARPORT_STATUS_BUSY 420 | PARPORT_STATUS_PAPEROUT 421 | PARPORT_STATUS_SELECT 422 | PARPORT_STATUS_ERROR)) { 423 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n", 424 port->name, s); 425 return 0; 426 } 427 428 parport_write_data(port, 0x87); udelay(2); 429 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 430 | PARPORT_STATUS_PAPEROUT 431 | PARPORT_STATUS_SELECT 432 | PARPORT_STATUS_ERROR); 433 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { 434 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n", 435 port->name, s); 436 return 0; 437 } 438 439 parport_write_data(port, 0x78); udelay(2); 440 s = parport_read_status(port); 441 442 for (daisy = 0; 443 (s & (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT)) 444 == (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT) 445 && daisy < 4; 446 ++daisy) { 447 parport_write_data(port, daisy); 448 udelay(2); 449 parport_frob_control(port, 450 PARPORT_CONTROL_STROBE, 451 PARPORT_CONTROL_STROBE); 452 udelay(1); 453 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0); 454 udelay(1); 455 456 add_dev(numdevs++, port, daisy); 457 458 /* See if this device thought it was the last in the 459 * chain. */ 460 if (!(s & PARPORT_STATUS_BUSY)) 461 break; 462 463 /* We are seeing pass through status now. We see 464 last_dev from next device or if last_dev does not 465 work status lines from some non-daisy chain 466 device. */ 467 s = parport_read_status(port); 468 } 469 470 parport_write_data(port, 0xff); udelay(2); 471 detected = numdevs - thisdev; 472 DPRINTK(KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name, 473 detected); 474 475 /* Ask the new devices to introduce themselves. */ 476 deviceid = kmalloc(1024, GFP_KERNEL); 477 if (!deviceid) return 0; 478 479 for (daisy = 0; thisdev < numdevs; thisdev++, daisy++) 480 parport_device_id(thisdev, deviceid, 1024); 481 482 kfree(deviceid); 483 return detected; 484 } 485 486 static int daisy_drv_probe(struct pardevice *par_dev) 487 { 488 struct device_driver *drv = par_dev->dev.driver; 489 490 if (strcmp(drv->name, "daisy_drv")) 491 return -ENODEV; 492 if (strcmp(par_dev->name, daisy_dev_name)) 493 return -ENODEV; 494 495 return 0; 496 } 497 498 static struct parport_driver daisy_driver = { 499 .name = "daisy_drv", 500 .probe = daisy_drv_probe, 501 .devmodel = true, 502 }; 503 504 int daisy_drv_init(void) 505 { 506 return parport_register_driver(&daisy_driver); 507 } 508 509 void daisy_drv_exit(void) 510 { 511 parport_unregister_driver(&daisy_driver); 512 } 513