| 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 | } |