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 * 203 * This function is similar to parport_register_device(), except 204 * that it locates a device by its number rather than by the port 205 * it is attached to. 206 * 207 * All parameters except for @devnum are the same as for 208 * parport_register_device(). The return value is the same as 209 * for parport_register_device(). 210 **/ 211 212 struct pardevice *parport_open(int devnum, const char *name) 213 { 214 struct daisydev *p = topology; 215 struct parport *port; 216 struct pardevice *dev; 217 int daisy; 218 219 spin_lock(&topology_lock); 220 while (p && p->devnum != devnum) 221 p = p->next; 222 223 if (!p) { 224 spin_unlock(&topology_lock); 225 return NULL; 226 } 227 228 daisy = p->daisy; 229 port = parport_get_port(p->port); 230 spin_unlock(&topology_lock); 231 232 dev = parport_register_device(port, name, NULL, NULL, NULL, 0, NULL); 233 parport_put_port(port); 234 if (!dev) 235 return NULL; 236 237 dev->daisy = daisy; 238 239 /* Check that there really is a device to select. */ 240 if (daisy >= 0) { 241 int selected; 242 parport_claim_or_block(dev); 243 selected = port->daisy; 244 parport_release(dev); 245 246 if (selected != daisy) { 247 /* No corresponding device. */ 248 parport_unregister_device(dev); 249 return NULL; 250 } 251 } 252 253 return dev; 254 } 255 256 /** 257 * parport_close - close a device opened with parport_open() 258 * @dev: device to close 259 * 260 * This is to parport_open() as parport_unregister_device() is to 261 * parport_register_device(). 262 **/ 263 264 void parport_close(struct pardevice *dev) 265 { 266 parport_unregister_device(dev); 267 } 268 269 /* Send a daisy-chain-style CPP command packet. */ 270 static int cpp_daisy(struct parport *port, int cmd) 271 { 272 unsigned char s; 273 274 parport_data_forward(port); 275 parport_write_data(port, 0xaa); udelay(2); 276 parport_write_data(port, 0x55); udelay(2); 277 parport_write_data(port, 0x00); udelay(2); 278 parport_write_data(port, 0xff); udelay(2); 279 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 280 | PARPORT_STATUS_PAPEROUT 281 | PARPORT_STATUS_SELECT 282 | PARPORT_STATUS_ERROR); 283 if (s != (PARPORT_STATUS_BUSY 284 | PARPORT_STATUS_PAPEROUT 285 | PARPORT_STATUS_SELECT 286 | PARPORT_STATUS_ERROR)) { 287 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n", 288 port->name, s); 289 return -ENXIO; 290 } 291 292 parport_write_data(port, 0x87); udelay(2); 293 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 294 | PARPORT_STATUS_PAPEROUT 295 | PARPORT_STATUS_SELECT 296 | PARPORT_STATUS_ERROR); 297 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { 298 DPRINTK(KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n", 299 port->name, s); 300 return -ENXIO; 301 } 302 303 parport_write_data(port, 0x78); udelay(2); 304 parport_write_data(port, cmd); udelay(2); 305 parport_frob_control(port, 306 PARPORT_CONTROL_STROBE, 307 PARPORT_CONTROL_STROBE); 308 udelay(1); 309 s = parport_read_status(port); 310 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0); 311 udelay(1); 312 parport_write_data(port, 0xff); udelay(2); 313 314 return s; 315 } 316 317 /* Send a mux-style CPP command packet. */ 318 static int cpp_mux(struct parport *port, int cmd) 319 { 320 unsigned char s; 321 int rc; 322 323 parport_data_forward(port); 324 parport_write_data(port, 0xaa); udelay(2); 325 parport_write_data(port, 0x55); udelay(2); 326 parport_write_data(port, 0xf0); udelay(2); 327 parport_write_data(port, 0x0f); udelay(2); 328 parport_write_data(port, 0x52); udelay(2); 329 parport_write_data(port, 0xad); udelay(2); 330 parport_write_data(port, cmd); udelay(2); 331 332 s = parport_read_status(port); 333 if (!(s & PARPORT_STATUS_ACK)) { 334 DPRINTK(KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n", 335 port->name, cmd, s); 336 return -EIO; 337 } 338 339 rc = (((s & PARPORT_STATUS_SELECT ? 1 : 0) << 0) | 340 ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) | 341 ((s & PARPORT_STATUS_BUSY ? 0 : 1) << 2) | 342 ((s & PARPORT_STATUS_ERROR ? 0 : 1) << 3)); 343 344 return rc; 345 } 346 347 void parport_daisy_deselect_all(struct parport *port) 348 { 349 cpp_daisy(port, 0x30); 350 } 351 352 int parport_daisy_select(struct parport *port, int daisy, int mode) 353 { 354 switch (mode) 355 { 356 // For these modes we should switch to EPP mode: 357 case IEEE1284_MODE_EPP: 358 case IEEE1284_MODE_EPPSL: 359 case IEEE1284_MODE_EPPSWE: 360 return !(cpp_daisy(port, 0x20 + daisy) & 361 PARPORT_STATUS_ERROR); 362 363 // For these modes we should switch to ECP mode: 364 case IEEE1284_MODE_ECP: 365 case IEEE1284_MODE_ECPRLE: 366 case IEEE1284_MODE_ECPSWE: 367 return !(cpp_daisy(port, 0xd0 + daisy) & 368 PARPORT_STATUS_ERROR); 369 370 // Nothing was told for BECP in Daisy chain specification. 371 // May be it's wise to use ECP? 372 case IEEE1284_MODE_BECP: 373 // Others use compat mode 374 case IEEE1284_MODE_NIBBLE: 375 case IEEE1284_MODE_BYTE: 376 case IEEE1284_MODE_COMPAT: 377 default: 378 return !(cpp_daisy(port, 0xe0 + daisy) & 379 PARPORT_STATUS_ERROR); 380 } 381 } 382 383 static int mux_present(struct parport *port) 384 { 385 return cpp_mux(port, 0x51) == 3; 386 } 387 388 static int num_mux_ports(struct parport *port) 389 { 390 return cpp_mux(port, 0x58); 391 } 392 393 static int select_port(struct parport *port) 394 { 395 int muxport = port->muxport; 396 return cpp_mux(port, 0x60 + muxport) == muxport; 397 } 398 399 static int assign_addrs(struct parport *port) 400 { 401 unsigned char s; 402 unsigned char daisy; 403 int thisdev = numdevs; 404 int detected; 405 char *deviceid; 406 407 parport_data_forward(port); 408 parport_write_data(port, 0xaa); udelay(2); 409 parport_write_data(port, 0x55); udelay(2); 410 parport_write_data(port, 0x00); udelay(2); 411 parport_write_data(port, 0xff); udelay(2); 412 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 413 | PARPORT_STATUS_PAPEROUT 414 | PARPORT_STATUS_SELECT 415 | PARPORT_STATUS_ERROR); 416 if (s != (PARPORT_STATUS_BUSY 417 | PARPORT_STATUS_PAPEROUT 418 | PARPORT_STATUS_SELECT 419 | PARPORT_STATUS_ERROR)) { 420 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n", 421 port->name, s); 422 return 0; 423 } 424 425 parport_write_data(port, 0x87); udelay(2); 426 s = parport_read_status(port) & (PARPORT_STATUS_BUSY 427 | PARPORT_STATUS_PAPEROUT 428 | PARPORT_STATUS_SELECT 429 | PARPORT_STATUS_ERROR); 430 if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { 431 DPRINTK(KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n", 432 port->name, s); 433 return 0; 434 } 435 436 parport_write_data(port, 0x78); udelay(2); 437 s = parport_read_status(port); 438 439 for (daisy = 0; 440 (s & (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT)) 441 == (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT) 442 && daisy < 4; 443 ++daisy) { 444 parport_write_data(port, daisy); 445 udelay(2); 446 parport_frob_control(port, 447 PARPORT_CONTROL_STROBE, 448 PARPORT_CONTROL_STROBE); 449 udelay(1); 450 parport_frob_control(port, PARPORT_CONTROL_STROBE, 0); 451 udelay(1); 452 453 add_dev(numdevs++, port, daisy); 454 455 /* See if this device thought it was the last in the 456 * chain. */ 457 if (!(s & PARPORT_STATUS_BUSY)) 458 break; 459 460 /* We are seeing pass through status now. We see 461 last_dev from next device or if last_dev does not 462 work status lines from some non-daisy chain 463 device. */ 464 s = parport_read_status(port); 465 } 466 467 parport_write_data(port, 0xff); udelay(2); 468 detected = numdevs - thisdev; 469 DPRINTK(KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name, 470 detected); 471 472 /* Ask the new devices to introduce themselves. */ 473 deviceid = kmalloc(1024, GFP_KERNEL); 474 if (!deviceid) return 0; 475 476 for (daisy = 0; thisdev < numdevs; thisdev++, daisy++) 477 parport_device_id(thisdev, deviceid, 1024); 478 479 kfree(deviceid); 480 return detected; 481 } 482