Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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. */ |
Marko Kohtala | b44d3bd | 2006-01-06 00:19:47 -0800 | [diff] [blame] | 147 | deviceid = kmalloc (1024, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | if (deviceid) { |
Marko Kohtala | b44d3bd | 2006-01-06 00:19:47 -0800 | [diff] [blame] | 149 | if (parport_device_id (numdevs - 1, deviceid, 1024) > 2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 *, struct pt_regs *), |
| 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 | |
Marko Kohtala | c29a75e | 2006-01-06 00:19:46 -0800 | [diff] [blame] | 255 | if (selected != daisy) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | /** |
| 279 | * parport_device_num - convert device coordinates |
| 280 | * @parport: parallel port number |
| 281 | * @mux: multiplexor port number (-1 for no multiplexor) |
| 282 | * @daisy: daisy chain address (-1 for no daisy chain address) |
| 283 | * |
| 284 | * This tries to locate a device on the given parallel port, |
| 285 | * multiplexor port and daisy chain address, and returns its |
Randy Dunlap | 7d46972 | 2006-06-25 05:49:29 -0700 | [diff] [blame^] | 286 | * device number or %-ENXIO if no device with those coordinates |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | * exists. |
| 288 | **/ |
| 289 | |
| 290 | int parport_device_num (int parport, int mux, int daisy) |
| 291 | { |
| 292 | int res = -ENXIO; |
| 293 | struct daisydev *dev; |
| 294 | |
| 295 | spin_lock(&topology_lock); |
| 296 | dev = topology; |
| 297 | while (dev && dev->port->portnum != parport && |
| 298 | dev->port->muxport != mux && dev->daisy != daisy) |
| 299 | dev = dev->next; |
| 300 | if (dev) |
| 301 | res = dev->devnum; |
| 302 | spin_unlock(&topology_lock); |
| 303 | |
| 304 | return res; |
| 305 | } |
| 306 | |
| 307 | /* Send a daisy-chain-style CPP command packet. */ |
| 308 | static int cpp_daisy (struct parport *port, int cmd) |
| 309 | { |
| 310 | unsigned char s; |
| 311 | |
| 312 | parport_data_forward (port); |
| 313 | parport_write_data (port, 0xaa); udelay (2); |
| 314 | parport_write_data (port, 0x55); udelay (2); |
| 315 | parport_write_data (port, 0x00); udelay (2); |
| 316 | parport_write_data (port, 0xff); udelay (2); |
| 317 | s = parport_read_status (port) & (PARPORT_STATUS_BUSY |
| 318 | | PARPORT_STATUS_PAPEROUT |
| 319 | | PARPORT_STATUS_SELECT |
| 320 | | PARPORT_STATUS_ERROR); |
| 321 | if (s != (PARPORT_STATUS_BUSY |
| 322 | | PARPORT_STATUS_PAPEROUT |
| 323 | | PARPORT_STATUS_SELECT |
| 324 | | PARPORT_STATUS_ERROR)) { |
| 325 | DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n", |
| 326 | port->name, s); |
| 327 | return -ENXIO; |
| 328 | } |
| 329 | |
| 330 | parport_write_data (port, 0x87); udelay (2); |
| 331 | s = parport_read_status (port) & (PARPORT_STATUS_BUSY |
| 332 | | PARPORT_STATUS_PAPEROUT |
| 333 | | PARPORT_STATUS_SELECT |
| 334 | | PARPORT_STATUS_ERROR); |
| 335 | if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { |
| 336 | DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n", |
| 337 | port->name, s); |
| 338 | return -ENXIO; |
| 339 | } |
| 340 | |
| 341 | parport_write_data (port, 0x78); udelay (2); |
| 342 | parport_write_data (port, cmd); udelay (2); |
| 343 | parport_frob_control (port, |
| 344 | PARPORT_CONTROL_STROBE, |
| 345 | PARPORT_CONTROL_STROBE); |
| 346 | udelay (1); |
Marko Kohtala | 7c9cc3b | 2006-01-06 00:19:46 -0800 | [diff] [blame] | 347 | s = parport_read_status (port); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | parport_frob_control (port, PARPORT_CONTROL_STROBE, 0); |
| 349 | udelay (1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | parport_write_data (port, 0xff); udelay (2); |
| 351 | |
| 352 | return s; |
| 353 | } |
| 354 | |
| 355 | /* Send a mux-style CPP command packet. */ |
| 356 | static int cpp_mux (struct parport *port, int cmd) |
| 357 | { |
| 358 | unsigned char s; |
| 359 | int rc; |
| 360 | |
| 361 | parport_data_forward (port); |
| 362 | parport_write_data (port, 0xaa); udelay (2); |
| 363 | parport_write_data (port, 0x55); udelay (2); |
| 364 | parport_write_data (port, 0xf0); udelay (2); |
| 365 | parport_write_data (port, 0x0f); udelay (2); |
| 366 | parport_write_data (port, 0x52); udelay (2); |
| 367 | parport_write_data (port, 0xad); udelay (2); |
| 368 | parport_write_data (port, cmd); udelay (2); |
| 369 | |
| 370 | s = parport_read_status (port); |
| 371 | if (!(s & PARPORT_STATUS_ACK)) { |
| 372 | DPRINTK (KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n", |
| 373 | port->name, cmd, s); |
| 374 | return -EIO; |
| 375 | } |
| 376 | |
| 377 | rc = (((s & PARPORT_STATUS_SELECT ? 1 : 0) << 0) | |
| 378 | ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) | |
| 379 | ((s & PARPORT_STATUS_BUSY ? 0 : 1) << 2) | |
| 380 | ((s & PARPORT_STATUS_ERROR ? 0 : 1) << 3)); |
| 381 | |
| 382 | return rc; |
| 383 | } |
| 384 | |
| 385 | void parport_daisy_deselect_all (struct parport *port) |
| 386 | { |
| 387 | cpp_daisy (port, 0x30); |
| 388 | } |
| 389 | |
| 390 | int parport_daisy_select (struct parport *port, int daisy, int mode) |
| 391 | { |
| 392 | switch (mode) |
| 393 | { |
| 394 | // For these modes we should switch to EPP mode: |
| 395 | case IEEE1284_MODE_EPP: |
| 396 | case IEEE1284_MODE_EPPSL: |
| 397 | case IEEE1284_MODE_EPPSWE: |
Marko Kohtala | 7c9cc3b | 2006-01-06 00:19:46 -0800 | [diff] [blame] | 398 | return !(cpp_daisy (port, 0x20 + daisy) & |
| 399 | PARPORT_STATUS_ERROR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | |
| 401 | // For these modes we should switch to ECP mode: |
| 402 | case IEEE1284_MODE_ECP: |
| 403 | case IEEE1284_MODE_ECPRLE: |
| 404 | case IEEE1284_MODE_ECPSWE: |
Marko Kohtala | 7c9cc3b | 2006-01-06 00:19:46 -0800 | [diff] [blame] | 405 | return !(cpp_daisy (port, 0xd0 + daisy) & |
| 406 | PARPORT_STATUS_ERROR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 407 | |
| 408 | // Nothing was told for BECP in Daisy chain specification. |
| 409 | // May be it's wise to use ECP? |
| 410 | case IEEE1284_MODE_BECP: |
| 411 | // Others use compat mode |
| 412 | case IEEE1284_MODE_NIBBLE: |
| 413 | case IEEE1284_MODE_BYTE: |
| 414 | case IEEE1284_MODE_COMPAT: |
| 415 | default: |
Marko Kohtala | 7c9cc3b | 2006-01-06 00:19:46 -0800 | [diff] [blame] | 416 | return !(cpp_daisy (port, 0xe0 + daisy) & |
| 417 | PARPORT_STATUS_ERROR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | } |
| 419 | } |
| 420 | |
| 421 | static int mux_present (struct parport *port) |
| 422 | { |
| 423 | return cpp_mux (port, 0x51) == 3; |
| 424 | } |
| 425 | |
| 426 | static int num_mux_ports (struct parport *port) |
| 427 | { |
| 428 | return cpp_mux (port, 0x58); |
| 429 | } |
| 430 | |
| 431 | static int select_port (struct parport *port) |
| 432 | { |
| 433 | int muxport = port->muxport; |
| 434 | return cpp_mux (port, 0x60 + muxport) == muxport; |
| 435 | } |
| 436 | |
| 437 | static int assign_addrs (struct parport *port) |
| 438 | { |
Marko Kohtala | 310c8c3 | 2006-01-06 00:19:45 -0800 | [diff] [blame] | 439 | unsigned char s; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | unsigned char daisy; |
| 441 | int thisdev = numdevs; |
| 442 | int detected; |
| 443 | char *deviceid; |
| 444 | |
| 445 | parport_data_forward (port); |
| 446 | parport_write_data (port, 0xaa); udelay (2); |
| 447 | parport_write_data (port, 0x55); udelay (2); |
| 448 | parport_write_data (port, 0x00); udelay (2); |
| 449 | parport_write_data (port, 0xff); udelay (2); |
| 450 | s = parport_read_status (port) & (PARPORT_STATUS_BUSY |
| 451 | | PARPORT_STATUS_PAPEROUT |
| 452 | | PARPORT_STATUS_SELECT |
| 453 | | PARPORT_STATUS_ERROR); |
| 454 | if (s != (PARPORT_STATUS_BUSY |
| 455 | | PARPORT_STATUS_PAPEROUT |
| 456 | | PARPORT_STATUS_SELECT |
| 457 | | PARPORT_STATUS_ERROR)) { |
| 458 | DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n", |
| 459 | port->name, s); |
| 460 | return 0; |
| 461 | } |
| 462 | |
| 463 | parport_write_data (port, 0x87); udelay (2); |
| 464 | s = parport_read_status (port) & (PARPORT_STATUS_BUSY |
| 465 | | PARPORT_STATUS_PAPEROUT |
| 466 | | PARPORT_STATUS_SELECT |
| 467 | | PARPORT_STATUS_ERROR); |
| 468 | if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { |
| 469 | DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n", |
| 470 | port->name, s); |
| 471 | return 0; |
| 472 | } |
| 473 | |
| 474 | parport_write_data (port, 0x78); udelay (2); |
Marko Kohtala | 310c8c3 | 2006-01-06 00:19:45 -0800 | [diff] [blame] | 475 | s = parport_read_status (port); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | |
Marko Kohtala | 310c8c3 | 2006-01-06 00:19:45 -0800 | [diff] [blame] | 477 | for (daisy = 0; |
| 478 | (s & (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT)) |
| 479 | == (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT) |
| 480 | && daisy < 4; |
| 481 | ++daisy) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | parport_write_data (port, daisy); |
| 483 | udelay (2); |
| 484 | parport_frob_control (port, |
| 485 | PARPORT_CONTROL_STROBE, |
| 486 | PARPORT_CONTROL_STROBE); |
| 487 | udelay (1); |
| 488 | parport_frob_control (port, PARPORT_CONTROL_STROBE, 0); |
| 489 | udelay (1); |
| 490 | |
Marko Kohtala | 310c8c3 | 2006-01-06 00:19:45 -0800 | [diff] [blame] | 491 | add_dev (numdevs++, port, daisy); |
| 492 | |
| 493 | /* See if this device thought it was the last in the |
| 494 | * chain. */ |
| 495 | if (!(s & PARPORT_STATUS_BUSY)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | break; |
| 497 | |
Marko Kohtala | 310c8c3 | 2006-01-06 00:19:45 -0800 | [diff] [blame] | 498 | /* We are seeing pass through status now. We see |
| 499 | last_dev from next device or if last_dev does not |
| 500 | work status lines from some non-daisy chain |
| 501 | device. */ |
| 502 | s = parport_read_status (port); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | } |
| 504 | |
| 505 | parport_write_data (port, 0xff); udelay (2); |
| 506 | detected = numdevs - thisdev; |
| 507 | DPRINTK (KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name, |
| 508 | detected); |
| 509 | |
| 510 | /* Ask the new devices to introduce themselves. */ |
Marko Kohtala | b44d3bd | 2006-01-06 00:19:47 -0800 | [diff] [blame] | 511 | deviceid = kmalloc (1024, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | if (!deviceid) return 0; |
| 513 | |
| 514 | for (daisy = 0; thisdev < numdevs; thisdev++, daisy++) |
Marko Kohtala | b44d3bd | 2006-01-06 00:19:47 -0800 | [diff] [blame] | 515 | parport_device_id (thisdev, deviceid, 1024); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | |
| 517 | kfree (deviceid); |
| 518 | return detected; |
| 519 | } |