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/sched.h> 26 27 #include <asm/current.h> 28 #include <asm/uaccess.h> 29 30 #undef DEBUG 31 32 #ifdef DEBUG 33 #define DPRINTK(stuff...) printk(stuff) 34 #else 35 #define DPRINTK(stuff...) 36 #endif 37 38 static struct daisydev { 39 struct daisydev *next; 40 struct parport *port; 41 int daisy; 42 int devnum; 43 } *topology = NULL; 44 static DEFINE_SPINLOCK(topology_lock); 45 46 static int numdevs = 0; 47 48 /* Forward-declaration of lower-level functions. */ 49 static int mux_present(struct parport *port); 50 static int num_mux_ports(struct parport *port); 51 static int select_port(struct parport *port); 52 static int assign_addrs(struct parport *port); 53 54 /* Add a device to the discovered topology. */ 55 static void add_dev(int devnum, struct parport *port, int daisy) 56 { 57 struct daisydev *newdev, **p; 58 newdev = kmalloc(sizeof(struct daisydev), GFP_KERNEL); 59 if (newdev) { 60 newdev->port = port; 61 newdev->daisy = daisy; 62 newdev->devnum = devnum; 63 spin_lock(&topology_lock); 64 for (p = &topology; *p && (*p)->devnum<devnum; p = &(*p)->next) 65 ; 66 newdev->next = *p; 67 *p = newdev; 68 spin_unlock(&topology_lock); 69 } 70 } 71 72 /* Clone a parport (actually, make an alias). */ 73 static struct parport *clone_parport(struct parport *real, int muxport) 74 { 75 struct parport *extra = parport_register_port(real->base, 76 real->irq, 77 real->dma, 78 real->ops); 79 if (extra) { 80 extra->portnum = real->portnum; 81 extra->physport = real; 82 extra->muxport = muxport; 83 real->slaves[muxport-1] = extra; 84 } 85 86 return extra; 87 } 88 89 /* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains. 90 * Return value is number of devices actually detected. */ 91 int parport_daisy_init(struct parport *port) 92 { 93 int detected = 0; 94 char *deviceid; 95 static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" }; 96 int num_ports; 97 int i; 98 int last_try = 0; 99 100 again: 101 /* Because this is called before any other devices exist, 102 * we don't have to claim exclusive access. */ 103 104 /* If mux present on normal port, need to create new 105 * parports for each extra port. */ 106 if (port->muxport < 0 && mux_present(port) && 107 /* don't be fooled: a mux must have 2 or 4 ports. */ 108 ((num_ports = num_mux_ports(port)) == 2 || num_ports == 4)) { 109 /* Leave original as port zero. */ 110 port->muxport = 0; 111 printk(KERN_INFO 112 "%s: 1st (default) port of %d-way multiplexor\n", 113 port->name, num_ports); 114 for (i = 1; i < num_ports; i++) { 115 /* Clone the port. */ 116 struct parport *extra = clone_parport(port, i); 117 if (!extra) { 118 if (signal_pending(current)) 119 break; 120 121 schedule(); 122 continue; 123 } 124 125 printk(KERN_INFO 126 "%s: %d%s port of %d-way multiplexor on %s\n", 127 extra->name, i + 1, th[i + 1], num_ports, 128 port->name); 129 130 /* Analyse that port too. We won't recurse 131 forever because of the 'port->muxport < 0' 132 test above. */ 133 parport_daisy_init(extra); 134 } 135 } 136 137 if (port->muxport >= 0) 138 select_port(port); 139 140 parport_daisy_deselect_all(port); 141 detected += assign_addrs(port); 142 143 /* Count the potential legacy device at the end. */ 144 add_dev(numdevs++, port, -1); 145 146 /* Find out the legacy device's IEEE 1284 device ID. */ 147 deviceid = kmalloc(1024, GFP_KERNEL); 148 if (deviceid) { 149 if (parport_device_id(numdevs - 1, deviceid, 1024) > 2) 150 detected++; 151 152 kfree(deviceid); 153 } 154 155 if (!detected && !last_try) { 156 /* No devices were detected. Perhaps they are in some 157 funny state; let's try to reset them and see if 158 they wake up. */ 159 parport_daisy_fini(port); 160 parport_write_control(port, PARPORT_CONTROL_SELECT); 161 udelay(50); 162 parport_write_control(port, 163 PARPORT_CONTROL_SELECT | 164 PARPORT_CONTROL_INIT); 165 udelay(50); 166 last_try = 1; 167 goto again; 168 } 169 170 return detected; 171 } 172 173 /* Forget about devices on a physical port. */ 174 void parport_daisy_fini(struct parport *port) 175 { 176 struct daisydev **p; 177 178 spin_lock(&topology_lock); 179 p = &topology; 180 while (*p) { 181 struct daisydev *dev = *p; 182 if (dev->port != port) { 183 p = &dev->next; 184 continue; 185 } 186 *p = dev->next; 187 kfree(dev); 188 } 189 190 /* Gaps in the numbering could be handled better. How should 191 someone enumerate through all IEEE1284.3 devices in the 192 topology?. */ 193 if (!topology) numdevs = 0; 194 spin_unlock(&topology_lock); 195 return; 196 } 197 198 /** 199 * parport_open - find a device by canonical device number 200 * @devnum: canonical device number 201 * @name: name to associate with the device 202 * @pf: preemption callback 203 * @kf: kick callback 204 * @irqf: interrupt handler 205 * @flags: registration flags 206 * @handle: driver data 207 * 208 * This function is similar to parport_register_device(), except 209 * that it locates a device by its number rather than by the port 210 * it is attached to. 211 * 212 * All parameters except for @devnum are the same as for 213 * parport_register_device(). The return value is the same as 214 * for parport_register_device(). 215 **/ 216 217 struct pardevice *parport_open(int devnum, const char *name, 218 int (*pf) (void *), void (*kf) (void *), 219 void (*irqf) (int, void *), 220 int flags, void *handle) 221 { 222 struct daisydev *p = topology; 223 struct parport *port; 224 struct pardevice *dev; 225 int daisy; 226 227 spin_lock(&topology_lock); 228 while (p && p->devnum != devnum) 229 p = p->next; 230 231 if (!p) { 232 spin_unlock(&topology_lock); 233 return NULL; 234 } 235 236 daisy = p->daisy; 237 port = parport_get_port(p->port); 238 spin_unlock(&topology_lock); 239 240 dev = parport_register_device(port, name, pf, kf, 241 irqf, flags, handle); 242 parport_put_port(port); 243 if (!dev) 244 return NULL; 245 246 dev->daisy = daisy; 247 248 /* Check that there really is a device to select. */ 249 if (daisy >= 0) { 250 int selected; 251 parport_claim_or_block(dev); 252 selected = port->daisy; 253 parport_release(dev); 254 255 if (selected != daisy) { 256 /* No corresponding device. */ 257 parport_unregister_device(dev); 258 return NULL; 259 } 260 } 261 262 return dev; 263 } 264 265 /** 266 * parport_close - close a device opened with parport_open() 267 * @dev: device to close 268 * 269 * This is to parport_open() as parport_unregister_device() is to 270 * parport_register_device(). 271 **/ 272 273 void parport_close(struct pardevice *dev) 274 { 275 parport_unregister_device(dev); 276 } 277 278 /* Send a daisy-chain-style CPP command packet. */ 279 static int cpp_daisy(struct parport *port, int cmd) 280 { 281 unsigned char s; 282 283 parport_data_forward(port); 284 parport_write_data(port, 0xaa); udelay(2); 285 parport_write_data(port, 0x55); udelay(2); 286 parport_write_data(port, 0x00); udelay(2); 287 parport_write_data(port, 0xff); udelay(2); 288 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 289 | PARPORT_STATUS_PAPEROUT 290 | PARPORT_STATUS_SELECT 291 | PARPORT_STATUS_ERROR); 292 if (s != (PARPORT_STATUS_BUSY 293 | PARPORT_STATUS_PAPEROUT 294 | PARPORT_STATUS_SELECT 295 | PARPORT_STATUS_ERROR)) { 296 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n", 297 port->name, s); 298 return -ENXIO; 299 } 300 301 parport_write_data(port, 0x87); udelay(2); 302 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 303 | PARPORT_STATUS_PAPEROUT 304 | PARPORT_STATUS_SELECT 305 | PARPORT_STATUS_ERROR); 306 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { 307 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n", 308 port->name, s); 309 return -ENXIO; 310 } 311 312 parport_write_data(port, 0x78); udelay(2); 313 parport_write_data(port, cmd); udelay(2); 314 parport_frob_control(port, 315 PARPORT_CONTROL_STROBE, 316 PARPORT_CONTROL_STROBE); 317 udelay(1); 318 s = parport_read_status(port); 319 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0); 320 udelay(1); 321 parport_write_data(port, 0xff); udelay(2); 322 323 return s; 324 } 325 326 /* Send a mux-style CPP command packet. */ 327 static int cpp_mux(struct parport *port, int cmd) 328 { 329 unsigned char s; 330 int rc; 331 332 parport_data_forward(port); 333 parport_write_data(port, 0xaa); udelay(2); 334 parport_write_data(port, 0x55); udelay(2); 335 parport_write_data(port, 0xf0); udelay(2); 336 parport_write_data(port, 0x0f); udelay(2); 337 parport_write_data(port, 0x52); udelay(2); 338 parport_write_data(port, 0xad); udelay(2); 339 parport_write_data(port, cmd); udelay(2); 340 341 s = parport_read_status(port); 342 if (!(s & PARPORT_STATUS_ACK)) { 343 DPRINTK(KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n", 344 port->name, cmd, s); 345 return -EIO; 346 } 347 348 rc = (((s & PARPORT_STATUS_SELECT ? 1 : 0) << 0) | 349 ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) | 350 ((s & PARPORT_STATUS_BUSY ? 0 : 1) << 2) | 351 ((s & PARPORT_STATUS_ERROR ? 0 : 1) << 3)); 352 353 return rc; 354 } 355 356 void parport_daisy_deselect_all(struct parport *port) 357 { 358 cpp_daisy(port, 0x30); 359 } 360 361 int parport_daisy_select(struct parport *port, int daisy, int mode) 362 { 363 switch (mode) 364 { 365 // For these modes we should switch to EPP mode: 366 case IEEE1284_MODE_EPP: 367 case IEEE1284_MODE_EPPSL: 368 case IEEE1284_MODE_EPPSWE: 369 return !(cpp_daisy(port, 0x20 + daisy) & 370 PARPORT_STATUS_ERROR); 371 372 // For these modes we should switch to ECP mode: 373 case IEEE1284_MODE_ECP: 374 case IEEE1284_MODE_ECPRLE: 375 case IEEE1284_MODE_ECPSWE: 376 return !(cpp_daisy(port, 0xd0 + daisy) & 377 PARPORT_STATUS_ERROR); 378 379 // Nothing was told for BECP in Daisy chain specification. 380 // May be it's wise to use ECP? 381 case IEEE1284_MODE_BECP: 382 // Others use compat mode 383 case IEEE1284_MODE_NIBBLE: 384 case IEEE1284_MODE_BYTE: 385 case IEEE1284_MODE_COMPAT: 386 default: 387 return !(cpp_daisy(port, 0xe0 + daisy) & 388 PARPORT_STATUS_ERROR); 389 } 390 } 391 392 static int mux_present(struct parport *port) 393 { 394 return cpp_mux(port, 0x51) == 3; 395 } 396 397 static int num_mux_ports(struct parport *port) 398 { 399 return cpp_mux(port, 0x58); 400 } 401 402 static int select_port(struct parport *port) 403 { 404 int muxport = port->muxport; 405 return cpp_mux(port, 0x60 + muxport) == muxport; 406 } 407 408 static int assign_addrs(struct parport *port) 409 { 410 unsigned char s; 411 unsigned char daisy; 412 int thisdev = numdevs; 413 int detected; 414 char *deviceid; 415 416 parport_data_forward(port); 417 parport_write_data(port, 0xaa); udelay(2); 418 parport_write_data(port, 0x55); udelay(2); 419 parport_write_data(port, 0x00); udelay(2); 420 parport_write_data(port, 0xff); udelay(2); 421 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 422 | PARPORT_STATUS_PAPEROUT 423 | PARPORT_STATUS_SELECT 424 | PARPORT_STATUS_ERROR); 425 if (s != (PARPORT_STATUS_BUSY 426 | PARPORT_STATUS_PAPEROUT 427 | PARPORT_STATUS_SELECT 428 | PARPORT_STATUS_ERROR)) { 429 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n", 430 port->name, s); 431 return 0; 432 } 433 434 parport_write_data(port, 0x87); udelay(2); 435 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 436 | PARPORT_STATUS_PAPEROUT 437 | PARPORT_STATUS_SELECT 438 | PARPORT_STATUS_ERROR); 439 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { 440 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n", 441 port->name, s); 442 return 0; 443 } 444 445 parport_write_data(port, 0x78); udelay(2); 446 s = parport_read_status(port); 447 448 for (daisy = 0; 449 (s & (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT)) 450 == (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT) 451 && daisy < 4; 452 ++daisy) { 453 parport_write_data(port, daisy); 454 udelay(2); 455 parport_frob_control(port, 456 PARPORT_CONTROL_STROBE, 457 PARPORT_CONTROL_STROBE); 458 udelay(1); 459 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0); 460 udelay(1); 461 462 add_dev(numdevs++, port, daisy); 463 464 /* See if this device thought it was the last in the 465 * chain. */ 466 if (!(s & PARPORT_STATUS_BUSY)) 467 break; 468 469 /* We are seeing pass through status now. We see 470 last_dev from next device or if last_dev does not 471 work status lines from some non-daisy chain 472 device. */ 473 s = parport_read_status(port); 474 } 475 476 parport_write_data(port, 0xff); udelay(2); 477 detected = numdevs - thisdev; 478 DPRINTK(KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name, 479 detected); 480 481 /* Ask the new devices to introduce themselves. */ 482 deviceid = kmalloc(1024, GFP_KERNEL); 483 if (!deviceid) return 0; 484 485 for (daisy = 0; thisdev < numdevs; thisdev++, daisy++) 486 parport_device_id(thisdev, deviceid, 1024); 487 488 kfree(deviceid); 489 return detected; 490 } 491