1 /*
2 pg.c (c) 1998 Grant R. Guenther <grant@torque.net>
3 Under the terms of the GNU General Public License.
4
5 The pg driver provides a simple character device interface for
6 sending ATAPI commands to a device. With the exception of the
7 ATAPI reset operation, all operations are performed by a pair
8 of read and write operations to the appropriate /dev/pgN device.
9 A write operation delivers a command and any outbound data in
10 a single buffer. Normally, the write will succeed unless the
11 device is offline or malfunctioning, or there is already another
12 command pending. If the write succeeds, it should be followed
13 immediately by a read operation, to obtain any returned data and
14 status information. A read will fail if there is no operation
15 in progress.
16
17 As a special case, the device can be reset with a write operation,
18 and in this case, no following read is expected, or permitted.
19
20 There are no ioctl() operations. Any single operation
21 may transfer at most PG_MAX_DATA bytes. Note that the driver must
22 copy the data through an internal buffer. In keeping with all
23 current ATAPI devices, command packets are assumed to be exactly
24 12 bytes in length.
25
26 To permit future changes to this interface, the headers in the
27 read and write buffers contain a single character "magic" flag.
28 Currently this flag must be the character "P".
29
30 By default, the driver will autoprobe for a single parallel
31 port ATAPI device, but if their individual parameters are
32 specified, the driver can handle up to 4 devices.
33
34 To use this device, you must have the following device
35 special files defined:
36
37 /dev/pg0 c 97 0
38 /dev/pg1 c 97 1
39 /dev/pg2 c 97 2
40 /dev/pg3 c 97 3
41
42 (You'll need to change the 97 to something else if you use
43 the 'major' parameter to install the driver on a different
44 major number.)
45
46 The behaviour of the pg driver can be altered by setting
47 some parameters from the insmod command line. The following
48 parameters are adjustable:
49
50 drive0 These four arguments can be arrays of
51 drive1 1-6 integers as follows:
52 drive2
53 drive3 <prt>,<pro>,<uni>,<mod>,<slv>,<dly>
54
55 Where,
56
57 <prt> is the base of the parallel port address for
58 the corresponding drive. (required)
59
60 <pro> is the protocol number for the adapter that
61 supports this drive. These numbers are
62 logged by 'paride' when the protocol modules
63 are initialised. (0 if not given)
64
65 <uni> for those adapters that support chained
66 devices, this is the unit selector for the
67 chain of devices on the given port. It should
68 be zero for devices that don't support chaining.
69 (0 if not given)
70
71 <mod> this can be -1 to choose the best mode, or one
72 of the mode numbers supported by the adapter.
73 (-1 if not given)
74
75 <slv> ATAPI devices can be jumpered to master or slave.
76 Set this to 0 to choose the master drive, 1 to
77 choose the slave, -1 (the default) to choose the
78 first drive found.
79
80 <dly> some parallel ports require the driver to
81 go more slowly. -1 sets a default value that
82 should work with the chosen protocol. Otherwise,
83 set this to a small integer, the larger it is
84 the slower the port i/o. In some cases, setting
85 this to zero will speed up the device. (default -1)
86
87 major You may use this parameter to overide the
88 default major number (97) that this driver
89 will use. Be sure to change the device
90 name as well.
91
92 name This parameter is a character string that
93 contains the name the kernel will use for this
94 device (in /proc output, for instance).
95 (default "pg").
96
97 verbose This parameter controls the amount of logging
98 that is done by the driver. Set it to 0 for
99 quiet operation, to 1 to enable progress
100 messages while the driver probes for devices,
101 or to 2 for full debug logging. (default 0)
102
103 If this driver is built into the kernel, you can use
104 the following command line parameters, with the same values
105 as the corresponding module parameters listed above:
106
107 pg.drive0
108 pg.drive1
109 pg.drive2
110 pg.drive3
111
112 In addition, you can use the parameter pg.disable to disable
113 the driver entirely.
114
115 */
116
117 /* Changes:
118
119 1.01 GRG 1998.06.16 Bug fixes
120 1.02 GRG 1998.09.24 Added jumbo support
121
122 */
123
124 #define PG_VERSION "1.02"
125 #define PG_MAJOR 97
126 #define PG_NAME "pg"
127 #define PG_UNITS 4
128
129 #ifndef PI_PG
130 #define PI_PG 4
131 #endif
132
133 #include <linux/types.h>
134 /* Here are things one can override from the insmod command.
135 Most are autoprobed by paride unless set here. Verbose is 0
136 by default.
137
138 */
139
140 static int verbose;
141 static int major = PG_MAJOR;
142 static char *name = PG_NAME;
143 static int disable = 0;
144
145 static int drive0[6] = { 0, 0, 0, -1, -1, -1 };
146 static int drive1[6] = { 0, 0, 0, -1, -1, -1 };
147 static int drive2[6] = { 0, 0, 0, -1, -1, -1 };
148 static int drive3[6] = { 0, 0, 0, -1, -1, -1 };
149
150 static int (*drives[4])[6] = {&drive0, &drive1, &drive2, &drive3};
151 static int pg_drive_count;
152
153 enum {D_PRT, D_PRO, D_UNI, D_MOD, D_SLV, D_DLY};
154
155 /* end of parameters */
156
157 #include <linux/module.h>
158 #include <linux/init.h>
159 #include <linux/fs.h>
160 #include <linux/delay.h>
161 #include <linux/slab.h>
162 #include <linux/mtio.h>
163 #include <linux/pg.h>
164 #include <linux/device.h>
165 #include <linux/sched.h> /* current, TASK_* */
166 #include <linux/mutex.h>
167 #include <linux/jiffies.h>
168
169 #include <asm/uaccess.h>
170
171 module_param(verbose, int, 0644);
172 module_param(major, int, 0);
173 module_param(name, charp, 0);
174 module_param_array(drive0, int, NULL, 0);
175 module_param_array(drive1, int, NULL, 0);
176 module_param_array(drive2, int, NULL, 0);
177 module_param_array(drive3, int, NULL, 0);
178
179 #include "paride.h"
180
181 #define PG_SPIN_DEL 50 /* spin delay in micro-seconds */
182 #define PG_SPIN 200
183 #define PG_TMO HZ
184 #define PG_RESET_TMO 10*HZ
185
186 #define STAT_ERR 0x01
187 #define STAT_INDEX 0x02
188 #define STAT_ECC 0x04
189 #define STAT_DRQ 0x08
190 #define STAT_SEEK 0x10
191 #define STAT_WRERR 0x20
192 #define STAT_READY 0x40
193 #define STAT_BUSY 0x80
194
195 #define ATAPI_IDENTIFY 0x12
196
197 static DEFINE_MUTEX(pg_mutex);
198 static int pg_open(struct inode *inode, struct file *file);
199 static int pg_release(struct inode *inode, struct file *file);
200 static ssize_t pg_read(struct file *filp, char __user *buf,
201 size_t count, loff_t * ppos);
202 static ssize_t pg_write(struct file *filp, const char __user *buf,
203 size_t count, loff_t * ppos);
204 static int pg_detect(void);
205
206 #define PG_NAMELEN 8
207
208 struct pg {
209 struct pi_adapter pia; /* interface to paride layer */
210 struct pi_adapter *pi;
211 int busy; /* write done, read expected */
212 int start; /* jiffies at command start */
213 int dlen; /* transfer size requested */
214 unsigned long timeout; /* timeout requested */
215 int status; /* last sense key */
216 int drive; /* drive */
217 unsigned long access; /* count of active opens ... */
218 int present; /* device present ? */
219 char *bufptr;
220 char name[PG_NAMELEN]; /* pg0, pg1, ... */
221 };
222
223 static struct pg devices[PG_UNITS];
224
225 static int pg_identify(struct pg *dev, int log);
226
227 static char pg_scratch[512]; /* scratch block buffer */
228
229 static struct class *pg_class;
230
231 /* kernel glue structures */
232
233 static const struct file_operations pg_fops = {
234 .owner = THIS_MODULE,
235 .read = pg_read,
236 .write = pg_write,
237 .open = pg_open,
238 .release = pg_release,
239 .llseek = noop_llseek,
240 };
241
pg_init_units(void)242 static void pg_init_units(void)
243 {
244 int unit;
245
246 pg_drive_count = 0;
247 for (unit = 0; unit < PG_UNITS; unit++) {
248 int *parm = *drives[unit];
249 struct pg *dev = &devices[unit];
250 dev->pi = &dev->pia;
251 clear_bit(0, &dev->access);
252 dev->busy = 0;
253 dev->present = 0;
254 dev->bufptr = NULL;
255 dev->drive = parm[D_SLV];
256 snprintf(dev->name, PG_NAMELEN, "%s%c", name, 'a'+unit);
257 if (parm[D_PRT])
258 pg_drive_count++;
259 }
260 }
261
status_reg(struct pg * dev)262 static inline int status_reg(struct pg *dev)
263 {
264 return pi_read_regr(dev->pi, 1, 6);
265 }
266
read_reg(struct pg * dev,int reg)267 static inline int read_reg(struct pg *dev, int reg)
268 {
269 return pi_read_regr(dev->pi, 0, reg);
270 }
271
write_reg(struct pg * dev,int reg,int val)272 static inline void write_reg(struct pg *dev, int reg, int val)
273 {
274 pi_write_regr(dev->pi, 0, reg, val);
275 }
276
DRIVE(struct pg * dev)277 static inline u8 DRIVE(struct pg *dev)
278 {
279 return 0xa0+0x10*dev->drive;
280 }
281
pg_sleep(int cs)282 static void pg_sleep(int cs)
283 {
284 schedule_timeout_interruptible(cs);
285 }
286
pg_wait(struct pg * dev,int go,int stop,unsigned long tmo,char * msg)287 static int pg_wait(struct pg *dev, int go, int stop, unsigned long tmo, char *msg)
288 {
289 int j, r, e, s, p, to;
290
291 dev->status = 0;
292
293 j = 0;
294 while ((((r = status_reg(dev)) & go) || (stop && (!(r & stop))))
295 && time_before(jiffies, tmo)) {
296 if (j++ < PG_SPIN)
297 udelay(PG_SPIN_DEL);
298 else
299 pg_sleep(1);
300 }
301
302 to = time_after_eq(jiffies, tmo);
303
304 if ((r & (STAT_ERR & stop)) || to) {
305 s = read_reg(dev, 7);
306 e = read_reg(dev, 1);
307 p = read_reg(dev, 2);
308 if (verbose > 1)
309 printk("%s: %s: stat=0x%x err=0x%x phase=%d%s\n",
310 dev->name, msg, s, e, p, to ? " timeout" : "");
311 if (to)
312 e |= 0x100;
313 dev->status = (e >> 4) & 0xff;
314 return -1;
315 }
316 return 0;
317 }
318
pg_command(struct pg * dev,char * cmd,int dlen,unsigned long tmo)319 static int pg_command(struct pg *dev, char *cmd, int dlen, unsigned long tmo)
320 {
321 int k;
322
323 pi_connect(dev->pi);
324
325 write_reg(dev, 6, DRIVE(dev));
326
327 if (pg_wait(dev, STAT_BUSY | STAT_DRQ, 0, tmo, "before command"))
328 goto fail;
329
330 write_reg(dev, 4, dlen % 256);
331 write_reg(dev, 5, dlen / 256);
332 write_reg(dev, 7, 0xa0); /* ATAPI packet command */
333
334 if (pg_wait(dev, STAT_BUSY, STAT_DRQ, tmo, "command DRQ"))
335 goto fail;
336
337 if (read_reg(dev, 2) != 1) {
338 printk("%s: command phase error\n", dev->name);
339 goto fail;
340 }
341
342 pi_write_block(dev->pi, cmd, 12);
343
344 if (verbose > 1) {
345 printk("%s: Command sent, dlen=%d packet= ", dev->name, dlen);
346 for (k = 0; k < 12; k++)
347 printk("%02x ", cmd[k] & 0xff);
348 printk("\n");
349 }
350 return 0;
351 fail:
352 pi_disconnect(dev->pi);
353 return -1;
354 }
355
pg_completion(struct pg * dev,char * buf,unsigned long tmo)356 static int pg_completion(struct pg *dev, char *buf, unsigned long tmo)
357 {
358 int r, d, n, p;
359
360 r = pg_wait(dev, STAT_BUSY, STAT_DRQ | STAT_READY | STAT_ERR,
361 tmo, "completion");
362
363 dev->dlen = 0;
364
365 while (read_reg(dev, 7) & STAT_DRQ) {
366 d = (read_reg(dev, 4) + 256 * read_reg(dev, 5));
367 n = ((d + 3) & 0xfffc);
368 p = read_reg(dev, 2) & 3;
369 if (p == 0)
370 pi_write_block(dev->pi, buf, n);
371 if (p == 2)
372 pi_read_block(dev->pi, buf, n);
373 if (verbose > 1)
374 printk("%s: %s %d bytes\n", dev->name,
375 p ? "Read" : "Write", n);
376 dev->dlen += (1 - p) * d;
377 buf += d;
378 r = pg_wait(dev, STAT_BUSY, STAT_DRQ | STAT_READY | STAT_ERR,
379 tmo, "completion");
380 }
381
382 pi_disconnect(dev->pi);
383
384 return r;
385 }
386
pg_reset(struct pg * dev)387 static int pg_reset(struct pg *dev)
388 {
389 int i, k, err;
390 int expect[5] = { 1, 1, 1, 0x14, 0xeb };
391 int got[5];
392
393 pi_connect(dev->pi);
394 write_reg(dev, 6, DRIVE(dev));
395 write_reg(dev, 7, 8);
396
397 pg_sleep(20 * HZ / 1000);
398
399 k = 0;
400 while ((k++ < PG_RESET_TMO) && (status_reg(dev) & STAT_BUSY))
401 pg_sleep(1);
402
403 for (i = 0; i < 5; i++)
404 got[i] = read_reg(dev, i + 1);
405
406 err = memcmp(expect, got, sizeof(got)) ? -1 : 0;
407
408 if (verbose) {
409 printk("%s: Reset (%d) signature = ", dev->name, k);
410 for (i = 0; i < 5; i++)
411 printk("%3x", got[i]);
412 if (err)
413 printk(" (incorrect)");
414 printk("\n");
415 }
416
417 pi_disconnect(dev->pi);
418 return err;
419 }
420
xs(char * buf,char * targ,int len)421 static void xs(char *buf, char *targ, int len)
422 {
423 char l = '\0';
424 int k;
425
426 for (k = 0; k < len; k++) {
427 char c = *buf++;
428 if (c != ' ' && c != l)
429 l = *targ++ = c;
430 }
431 if (l == ' ')
432 targ--;
433 *targ = '\0';
434 }
435
pg_identify(struct pg * dev,int log)436 static int pg_identify(struct pg *dev, int log)
437 {
438 int s;
439 char *ms[2] = { "master", "slave" };
440 char mf[10], id[18];
441 char id_cmd[12] = { ATAPI_IDENTIFY, 0, 0, 0, 36, 0, 0, 0, 0, 0, 0, 0 };
442 char buf[36];
443
444 s = pg_command(dev, id_cmd, 36, jiffies + PG_TMO);
445 if (s)
446 return -1;
447 s = pg_completion(dev, buf, jiffies + PG_TMO);
448 if (s)
449 return -1;
450
451 if (log) {
452 xs(buf + 8, mf, 8);
453 xs(buf + 16, id, 16);
454 printk("%s: %s %s, %s\n", dev->name, mf, id, ms[dev->drive]);
455 }
456
457 return 0;
458 }
459
460 /*
461 * returns 0, with id set if drive is detected
462 * -1, if drive detection failed
463 */
pg_probe(struct pg * dev)464 static int pg_probe(struct pg *dev)
465 {
466 if (dev->drive == -1) {
467 for (dev->drive = 0; dev->drive <= 1; dev->drive++)
468 if (!pg_reset(dev))
469 return pg_identify(dev, 1);
470 } else {
471 if (!pg_reset(dev))
472 return pg_identify(dev, 1);
473 }
474 return -1;
475 }
476
pg_detect(void)477 static int pg_detect(void)
478 {
479 struct pg *dev = &devices[0];
480 int k, unit;
481
482 printk("%s: %s version %s, major %d\n", name, name, PG_VERSION, major);
483
484 k = 0;
485 if (pg_drive_count == 0) {
486 if (pi_init(dev->pi, 1, -1, -1, -1, -1, -1, pg_scratch,
487 PI_PG, verbose, dev->name)) {
488 if (!pg_probe(dev)) {
489 dev->present = 1;
490 k++;
491 } else
492 pi_release(dev->pi);
493 }
494
495 } else
496 for (unit = 0; unit < PG_UNITS; unit++, dev++) {
497 int *parm = *drives[unit];
498 if (!parm[D_PRT])
499 continue;
500 if (pi_init(dev->pi, 0, parm[D_PRT], parm[D_MOD],
501 parm[D_UNI], parm[D_PRO], parm[D_DLY],
502 pg_scratch, PI_PG, verbose, dev->name)) {
503 if (!pg_probe(dev)) {
504 dev->present = 1;
505 k++;
506 } else
507 pi_release(dev->pi);
508 }
509 }
510
511 if (k)
512 return 0;
513
514 printk("%s: No ATAPI device detected\n", name);
515 return -1;
516 }
517
pg_open(struct inode * inode,struct file * file)518 static int pg_open(struct inode *inode, struct file *file)
519 {
520 int unit = iminor(inode) & 0x7f;
521 struct pg *dev = &devices[unit];
522 int ret = 0;
523
524 mutex_lock(&pg_mutex);
525 if ((unit >= PG_UNITS) || (!dev->present)) {
526 ret = -ENODEV;
527 goto out;
528 }
529
530 if (test_and_set_bit(0, &dev->access)) {
531 ret = -EBUSY;
532 goto out;
533 }
534
535 if (dev->busy) {
536 pg_reset(dev);
537 dev->busy = 0;
538 }
539
540 pg_identify(dev, (verbose > 1));
541
542 dev->bufptr = kmalloc(PG_MAX_DATA, GFP_KERNEL);
543 if (dev->bufptr == NULL) {
544 clear_bit(0, &dev->access);
545 printk("%s: buffer allocation failed\n", dev->name);
546 ret = -ENOMEM;
547 goto out;
548 }
549
550 file->private_data = dev;
551
552 out:
553 mutex_unlock(&pg_mutex);
554 return ret;
555 }
556
pg_release(struct inode * inode,struct file * file)557 static int pg_release(struct inode *inode, struct file *file)
558 {
559 struct pg *dev = file->private_data;
560
561 kfree(dev->bufptr);
562 dev->bufptr = NULL;
563 clear_bit(0, &dev->access);
564
565 return 0;
566 }
567
pg_write(struct file * filp,const char __user * buf,size_t count,loff_t * ppos)568 static ssize_t pg_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos)
569 {
570 struct pg *dev = filp->private_data;
571 struct pg_write_hdr hdr;
572 int hs = sizeof (hdr);
573
574 if (dev->busy)
575 return -EBUSY;
576 if (count < hs)
577 return -EINVAL;
578
579 if (copy_from_user(&hdr, buf, hs))
580 return -EFAULT;
581
582 if (hdr.magic != PG_MAGIC)
583 return -EINVAL;
584 if (hdr.dlen < 0 || hdr.dlen > PG_MAX_DATA)
585 return -EINVAL;
586 if ((count - hs) > PG_MAX_DATA)
587 return -EINVAL;
588
589 if (hdr.func == PG_RESET) {
590 if (count != hs)
591 return -EINVAL;
592 if (pg_reset(dev))
593 return -EIO;
594 return count;
595 }
596
597 if (hdr.func != PG_COMMAND)
598 return -EINVAL;
599
600 dev->start = jiffies;
601 dev->timeout = hdr.timeout * HZ + HZ / 2 + jiffies;
602
603 if (pg_command(dev, hdr.packet, hdr.dlen, jiffies + PG_TMO)) {
604 if (dev->status & 0x10)
605 return -ETIME;
606 return -EIO;
607 }
608
609 dev->busy = 1;
610
611 if (copy_from_user(dev->bufptr, buf + hs, count - hs))
612 return -EFAULT;
613 return count;
614 }
615
pg_read(struct file * filp,char __user * buf,size_t count,loff_t * ppos)616 static ssize_t pg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
617 {
618 struct pg *dev = filp->private_data;
619 struct pg_read_hdr hdr;
620 int hs = sizeof (hdr);
621 int copy;
622
623 if (!dev->busy)
624 return -EINVAL;
625 if (count < hs)
626 return -EINVAL;
627
628 dev->busy = 0;
629
630 if (pg_completion(dev, dev->bufptr, dev->timeout))
631 if (dev->status & 0x10)
632 return -ETIME;
633
634 memset(&hdr, 0, sizeof(hdr));
635 hdr.magic = PG_MAGIC;
636 hdr.dlen = dev->dlen;
637 copy = 0;
638
639 if (hdr.dlen < 0) {
640 hdr.dlen = -1 * hdr.dlen;
641 copy = hdr.dlen;
642 if (copy > (count - hs))
643 copy = count - hs;
644 }
645
646 hdr.duration = (jiffies - dev->start + HZ / 2) / HZ;
647 hdr.scsi = dev->status & 0x0f;
648
649 if (copy_to_user(buf, &hdr, hs))
650 return -EFAULT;
651 if (copy > 0)
652 if (copy_to_user(buf + hs, dev->bufptr, copy))
653 return -EFAULT;
654 return copy + hs;
655 }
656
pg_init(void)657 static int __init pg_init(void)
658 {
659 int unit;
660 int err;
661
662 if (disable){
663 err = -EINVAL;
664 goto out;
665 }
666
667 pg_init_units();
668
669 if (pg_detect()) {
670 err = -ENODEV;
671 goto out;
672 }
673
674 err = register_chrdev(major, name, &pg_fops);
675 if (err < 0) {
676 printk("pg_init: unable to get major number %d\n", major);
677 for (unit = 0; unit < PG_UNITS; unit++) {
678 struct pg *dev = &devices[unit];
679 if (dev->present)
680 pi_release(dev->pi);
681 }
682 goto out;
683 }
684 major = err; /* In case the user specified `major=0' (dynamic) */
685 pg_class = class_create(THIS_MODULE, "pg");
686 if (IS_ERR(pg_class)) {
687 err = PTR_ERR(pg_class);
688 goto out_chrdev;
689 }
690 for (unit = 0; unit < PG_UNITS; unit++) {
691 struct pg *dev = &devices[unit];
692 if (dev->present)
693 device_create(pg_class, NULL, MKDEV(major, unit), NULL,
694 "pg%u", unit);
695 }
696 err = 0;
697 goto out;
698
699 out_chrdev:
700 unregister_chrdev(major, "pg");
701 out:
702 return err;
703 }
704
pg_exit(void)705 static void __exit pg_exit(void)
706 {
707 int unit;
708
709 for (unit = 0; unit < PG_UNITS; unit++) {
710 struct pg *dev = &devices[unit];
711 if (dev->present)
712 device_destroy(pg_class, MKDEV(major, unit));
713 }
714 class_destroy(pg_class);
715 unregister_chrdev(major, name);
716
717 for (unit = 0; unit < PG_UNITS; unit++) {
718 struct pg *dev = &devices[unit];
719 if (dev->present)
720 pi_release(dev->pi);
721 }
722 }
723
724 MODULE_LICENSE("GPL");
725 module_init(pg_init)
726 module_exit(pg_exit)
727