xref: /openbmc/linux/drivers/scsi/ch.c (revision 867a0e05)
1 /*
2  * SCSI Media Changer device driver for Linux 2.6
3  *
4  *     (c) 1996-2003 Gerd Knorr <kraxel@bytesex.org>
5  *
6  */
7 
8 #define VERSION "0.25"
9 
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/fs.h>
13 #include <linux/kernel.h>
14 #include <linux/mm.h>
15 #include <linux/major.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
18 #include <linux/interrupt.h>
19 #include <linux/blkdev.h>
20 #include <linux/completion.h>
21 #include <linux/compat.h>
22 #include <linux/chio.h>			/* here are all the ioctls */
23 #include <linux/mutex.h>
24 #include <linux/idr.h>
25 #include <linux/slab.h>
26 
27 #include <scsi/scsi.h>
28 #include <scsi/scsi_cmnd.h>
29 #include <scsi/scsi_driver.h>
30 #include <scsi/scsi_ioctl.h>
31 #include <scsi/scsi_host.h>
32 #include <scsi/scsi_device.h>
33 #include <scsi/scsi_eh.h>
34 #include <scsi/scsi_dbg.h>
35 
36 #define CH_DT_MAX       16
37 #define CH_TYPES        8
38 #define CH_MAX_DEVS     128
39 
40 MODULE_DESCRIPTION("device driver for scsi media changer devices");
41 MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org>");
42 MODULE_LICENSE("GPL");
43 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_CHANGER_MAJOR);
44 MODULE_ALIAS_SCSI_DEVICE(TYPE_MEDIUM_CHANGER);
45 
46 static DEFINE_MUTEX(ch_mutex);
47 static int init = 1;
48 module_param(init, int, 0444);
49 MODULE_PARM_DESC(init, \
50     "initialize element status on driver load (default: on)");
51 
52 static int timeout_move = 300;
53 module_param(timeout_move, int, 0644);
54 MODULE_PARM_DESC(timeout_move,"timeout for move commands "
55 		 "(default: 300 seconds)");
56 
57 static int timeout_init = 3600;
58 module_param(timeout_init, int, 0644);
59 MODULE_PARM_DESC(timeout_init,"timeout for INITIALIZE ELEMENT STATUS "
60 		 "(default: 3600 seconds)");
61 
62 static int verbose = 1;
63 module_param(verbose, int, 0644);
64 MODULE_PARM_DESC(verbose,"be verbose (default: on)");
65 
66 static int debug = 0;
67 module_param(debug, int, 0644);
68 MODULE_PARM_DESC(debug,"enable/disable debug messages, also prints more "
69 		 "detailed sense codes on scsi errors (default: off)");
70 
71 static int dt_id[CH_DT_MAX] = { [ 0 ... (CH_DT_MAX-1) ] = -1 };
72 static int dt_lun[CH_DT_MAX];
73 module_param_array(dt_id,  int, NULL, 0444);
74 module_param_array(dt_lun, int, NULL, 0444);
75 
76 /* tell the driver about vendor-specific slots */
77 static int vendor_firsts[CH_TYPES-4];
78 static int vendor_counts[CH_TYPES-4];
79 module_param_array(vendor_firsts, int, NULL, 0444);
80 module_param_array(vendor_counts, int, NULL, 0444);
81 
82 static const char * vendor_labels[CH_TYPES-4] = {
83 	"v0", "v1", "v2", "v3"
84 };
85 // module_param_string_array(vendor_labels, NULL, 0444);
86 
87 #define ch_printk(prefix, ch, fmt, a...) \
88 	sdev_prefix_printk(prefix, (ch)->device, (ch)->name, fmt, ##a)
89 
90 #define DPRINTK(fmt, arg...)						\
91 do {									\
92 	if (debug)							\
93 		ch_printk(KERN_DEBUG, ch, fmt, ##arg);			\
94 } while (0)
95 #define VPRINTK(level, fmt, arg...)					\
96 do {									\
97 	if (verbose)							\
98 		ch_printk(level, ch, fmt, ##arg);			\
99 } while (0)
100 
101 /* ------------------------------------------------------------------- */
102 
103 #define MAX_RETRIES   1
104 
105 static struct class * ch_sysfs_class;
106 
107 typedef struct {
108 	struct list_head    list;
109 	int                 minor;
110 	char                name[8];
111 	struct scsi_device  *device;
112 	struct scsi_device  **dt;        /* ptrs to data transfer elements */
113 	u_int               firsts[CH_TYPES];
114 	u_int               counts[CH_TYPES];
115 	u_int               unit_attention;
116 	u_int		    voltags;
117 	struct mutex	    lock;
118 } scsi_changer;
119 
120 static DEFINE_IDR(ch_index_idr);
121 static DEFINE_SPINLOCK(ch_index_lock);
122 
123 static const struct {
124 	unsigned char  sense;
125 	unsigned char  asc;
126 	unsigned char  ascq;
127 	int	       errno;
128 } ch_err[] = {
129 /* Just filled in what looks right. Hav'nt checked any standard paper for
130    these errno assignments, so they may be wrong... */
131 	{
132 		.sense  = ILLEGAL_REQUEST,
133 		.asc    = 0x21,
134 		.ascq   = 0x01,
135 		.errno  = EBADSLT, /* Invalid element address */
136 	},{
137 		.sense  = ILLEGAL_REQUEST,
138 		.asc    = 0x28,
139 		.ascq   = 0x01,
140 		.errno  = EBADE,   /* Import or export element accessed */
141 	},{
142 		.sense  = ILLEGAL_REQUEST,
143 		.asc    = 0x3B,
144 		.ascq   = 0x0D,
145 		.errno  = EXFULL,  /* Medium destination element full */
146 	},{
147 		.sense  = ILLEGAL_REQUEST,
148 		.asc    = 0x3B,
149 		.ascq   = 0x0E,
150 		.errno  = EBADE,   /* Medium source element empty */
151 	},{
152 		.sense  = ILLEGAL_REQUEST,
153 		.asc    = 0x20,
154 		.ascq   = 0x00,
155 		.errno  = EBADRQC, /* Invalid command operation code */
156 	},{
157 	        /* end of list */
158 	}
159 };
160 
161 /* ------------------------------------------------------------------- */
162 
163 static int ch_find_errno(struct scsi_sense_hdr *sshdr)
164 {
165 	int i,errno = 0;
166 
167 	/* Check to see if additional sense information is available */
168 	if (scsi_sense_valid(sshdr) &&
169 	    sshdr->asc != 0) {
170 		for (i = 0; ch_err[i].errno != 0; i++) {
171 			if (ch_err[i].sense == sshdr->sense_key &&
172 			    ch_err[i].asc   == sshdr->asc &&
173 			    ch_err[i].ascq  == sshdr->ascq) {
174 				errno = -ch_err[i].errno;
175 				break;
176 			}
177 		}
178 	}
179 	if (errno == 0)
180 		errno = -EIO;
181 	return errno;
182 }
183 
184 static int
185 ch_do_scsi(scsi_changer *ch, unsigned char *cmd, int cmd_len,
186 	   void *buffer, unsigned buflength,
187 	   enum dma_data_direction direction)
188 {
189 	int errno, retries = 0, timeout, result;
190 	struct scsi_sense_hdr sshdr;
191 
192 	timeout = (cmd[0] == INITIALIZE_ELEMENT_STATUS)
193 		? timeout_init : timeout_move;
194 
195  retry:
196 	errno = 0;
197 	if (debug) {
198 		DPRINTK("command: ");
199 		__scsi_print_command(cmd, cmd_len);
200 	}
201 
202 	result = scsi_execute_req(ch->device, cmd, direction, buffer,
203 				  buflength, &sshdr, timeout * HZ,
204 				  MAX_RETRIES, NULL);
205 
206 	DPRINTK("result: 0x%x\n",result);
207 	if (driver_byte(result) & DRIVER_SENSE) {
208 		if (debug)
209 			scsi_print_sense_hdr(ch->device, ch->name, &sshdr);
210 		errno = ch_find_errno(&sshdr);
211 
212 		switch(sshdr.sense_key) {
213 		case UNIT_ATTENTION:
214 			ch->unit_attention = 1;
215 			if (retries++ < 3)
216 				goto retry;
217 			break;
218 		}
219 	}
220 	return errno;
221 }
222 
223 /* ------------------------------------------------------------------------ */
224 
225 static int
226 ch_elem_to_typecode(scsi_changer *ch, u_int elem)
227 {
228 	int i;
229 
230 	for (i = 0; i < CH_TYPES; i++) {
231 		if (elem >= ch->firsts[i]  &&
232 		    elem <  ch->firsts[i] +
233 	            ch->counts[i])
234 			return i+1;
235 	}
236 	return 0;
237 }
238 
239 static int
240 ch_read_element_status(scsi_changer *ch, u_int elem, char *data)
241 {
242 	u_char  cmd[12];
243 	u_char  *buffer;
244 	int     result;
245 
246 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
247 	if(!buffer)
248 		return -ENOMEM;
249 
250  retry:
251 	memset(cmd,0,sizeof(cmd));
252 	cmd[0] = READ_ELEMENT_STATUS;
253 	cmd[1] = ((ch->device->lun & 0x7) << 5) |
254 		(ch->voltags ? 0x10 : 0) |
255 		ch_elem_to_typecode(ch,elem);
256 	cmd[2] = (elem >> 8) & 0xff;
257 	cmd[3] = elem        & 0xff;
258 	cmd[5] = 1;
259 	cmd[9] = 255;
260 	if (0 == (result = ch_do_scsi(ch, cmd, 12,
261 				      buffer, 256, DMA_FROM_DEVICE))) {
262 		if (((buffer[16] << 8) | buffer[17]) != elem) {
263 			DPRINTK("asked for element 0x%02x, got 0x%02x\n",
264 				elem,(buffer[16] << 8) | buffer[17]);
265 			kfree(buffer);
266 			return -EIO;
267 		}
268 		memcpy(data,buffer+16,16);
269 	} else {
270 		if (ch->voltags) {
271 			ch->voltags = 0;
272 			VPRINTK(KERN_INFO, "device has no volume tag support\n");
273 			goto retry;
274 		}
275 		DPRINTK("READ ELEMENT STATUS for element 0x%x failed\n",elem);
276 	}
277 	kfree(buffer);
278 	return result;
279 }
280 
281 static int
282 ch_init_elem(scsi_changer *ch)
283 {
284 	int err;
285 	u_char cmd[6];
286 
287 	VPRINTK(KERN_INFO, "INITIALIZE ELEMENT STATUS, may take some time ...\n");
288 	memset(cmd,0,sizeof(cmd));
289 	cmd[0] = INITIALIZE_ELEMENT_STATUS;
290 	cmd[1] = (ch->device->lun & 0x7) << 5;
291 	err = ch_do_scsi(ch, cmd, 6, NULL, 0, DMA_NONE);
292 	VPRINTK(KERN_INFO, "... finished\n");
293 	return err;
294 }
295 
296 static int
297 ch_readconfig(scsi_changer *ch)
298 {
299 	u_char  cmd[10], data[16];
300 	u_char  *buffer;
301 	int     result,id,lun,i;
302 	u_int   elem;
303 
304 	buffer = kzalloc(512, GFP_KERNEL | GFP_DMA);
305 	if (!buffer)
306 		return -ENOMEM;
307 
308 	memset(cmd,0,sizeof(cmd));
309 	cmd[0] = MODE_SENSE;
310 	cmd[1] = (ch->device->lun & 0x7) << 5;
311 	cmd[2] = 0x1d;
312 	cmd[4] = 255;
313 	result = ch_do_scsi(ch, cmd, 10, buffer, 255, DMA_FROM_DEVICE);
314 	if (0 != result) {
315 		cmd[1] |= (1<<3);
316 		result  = ch_do_scsi(ch, cmd, 10, buffer, 255, DMA_FROM_DEVICE);
317 	}
318 	if (0 == result) {
319 		ch->firsts[CHET_MT] =
320 			(buffer[buffer[3]+ 6] << 8) | buffer[buffer[3]+ 7];
321 		ch->counts[CHET_MT] =
322 			(buffer[buffer[3]+ 8] << 8) | buffer[buffer[3]+ 9];
323 		ch->firsts[CHET_ST] =
324 			(buffer[buffer[3]+10] << 8) | buffer[buffer[3]+11];
325 		ch->counts[CHET_ST] =
326 			(buffer[buffer[3]+12] << 8) | buffer[buffer[3]+13];
327 		ch->firsts[CHET_IE] =
328 			(buffer[buffer[3]+14] << 8) | buffer[buffer[3]+15];
329 		ch->counts[CHET_IE] =
330 			(buffer[buffer[3]+16] << 8) | buffer[buffer[3]+17];
331 		ch->firsts[CHET_DT] =
332 			(buffer[buffer[3]+18] << 8) | buffer[buffer[3]+19];
333 		ch->counts[CHET_DT] =
334 			(buffer[buffer[3]+20] << 8) | buffer[buffer[3]+21];
335 		VPRINTK(KERN_INFO, "type #1 (mt): 0x%x+%d [medium transport]\n",
336 			ch->firsts[CHET_MT],
337 			ch->counts[CHET_MT]);
338 		VPRINTK(KERN_INFO, "type #2 (st): 0x%x+%d [storage]\n",
339 			ch->firsts[CHET_ST],
340 			ch->counts[CHET_ST]);
341 		VPRINTK(KERN_INFO, "type #3 (ie): 0x%x+%d [import/export]\n",
342 			ch->firsts[CHET_IE],
343 			ch->counts[CHET_IE]);
344 		VPRINTK(KERN_INFO, "type #4 (dt): 0x%x+%d [data transfer]\n",
345 			ch->firsts[CHET_DT],
346 			ch->counts[CHET_DT]);
347 	} else {
348 		VPRINTK(KERN_INFO, "reading element address assigment page failed!\n");
349 	}
350 
351 	/* vendor specific element types */
352 	for (i = 0; i < 4; i++) {
353 		if (0 == vendor_counts[i])
354 			continue;
355 		if (NULL == vendor_labels[i])
356 			continue;
357 		ch->firsts[CHET_V1+i] = vendor_firsts[i];
358 		ch->counts[CHET_V1+i] = vendor_counts[i];
359 		VPRINTK(KERN_INFO, "type #%d (v%d): 0x%x+%d [%s, vendor specific]\n",
360 			i+5,i+1,vendor_firsts[i],vendor_counts[i],
361 			vendor_labels[i]);
362 	}
363 
364 	/* look up the devices of the data transfer elements */
365 	ch->dt = kcalloc(ch->counts[CHET_DT], sizeof(*ch->dt),
366 			 GFP_KERNEL);
367 
368 	if (!ch->dt) {
369 		kfree(buffer);
370 		return -ENOMEM;
371 	}
372 
373 	for (elem = 0; elem < ch->counts[CHET_DT]; elem++) {
374 		id  = -1;
375 		lun = 0;
376 		if (elem < CH_DT_MAX  &&  -1 != dt_id[elem]) {
377 			id  = dt_id[elem];
378 			lun = dt_lun[elem];
379 			VPRINTK(KERN_INFO, "dt 0x%x: [insmod option] ",
380 				elem+ch->firsts[CHET_DT]);
381 		} else if (0 != ch_read_element_status
382 			   (ch,elem+ch->firsts[CHET_DT],data)) {
383 			VPRINTK(KERN_INFO, "dt 0x%x: READ ELEMENT STATUS failed\n",
384 				elem+ch->firsts[CHET_DT]);
385 		} else {
386 			VPRINTK(KERN_INFO, "dt 0x%x: ",elem+ch->firsts[CHET_DT]);
387 			if (data[6] & 0x80) {
388 				VPRINTK(KERN_CONT, "not this SCSI bus\n");
389 				ch->dt[elem] = NULL;
390 			} else if (0 == (data[6] & 0x30)) {
391 				VPRINTK(KERN_CONT, "ID/LUN unknown\n");
392 				ch->dt[elem] = NULL;
393 			} else {
394 				id  = ch->device->id;
395 				lun = 0;
396 				if (data[6] & 0x20) id  = data[7];
397 				if (data[6] & 0x10) lun = data[6] & 7;
398 			}
399 		}
400 		if (-1 != id) {
401 			VPRINTK(KERN_CONT, "ID %i, LUN %i, ",id,lun);
402 			ch->dt[elem] =
403 				scsi_device_lookup(ch->device->host,
404 						   ch->device->channel,
405 						   id,lun);
406 			if (!ch->dt[elem]) {
407 				/* should not happen */
408 				VPRINTK(KERN_CONT, "Huh? device not found!\n");
409 			} else {
410 				VPRINTK(KERN_CONT, "name: %8.8s %16.16s %4.4s\n",
411 					ch->dt[elem]->vendor,
412 					ch->dt[elem]->model,
413 					ch->dt[elem]->rev);
414 			}
415 		}
416 	}
417 	ch->voltags = 1;
418 	kfree(buffer);
419 
420 	return 0;
421 }
422 
423 /* ------------------------------------------------------------------------ */
424 
425 static int
426 ch_position(scsi_changer *ch, u_int trans, u_int elem, int rotate)
427 {
428 	u_char  cmd[10];
429 
430 	DPRINTK("position: 0x%x\n",elem);
431 	if (0 == trans)
432 		trans = ch->firsts[CHET_MT];
433 	memset(cmd,0,sizeof(cmd));
434 	cmd[0]  = POSITION_TO_ELEMENT;
435 	cmd[1]  = (ch->device->lun & 0x7) << 5;
436 	cmd[2]  = (trans >> 8) & 0xff;
437 	cmd[3]  =  trans       & 0xff;
438 	cmd[4]  = (elem  >> 8) & 0xff;
439 	cmd[5]  =  elem        & 0xff;
440 	cmd[8]  = rotate ? 1 : 0;
441 	return ch_do_scsi(ch, cmd, 10, NULL, 0, DMA_NONE);
442 }
443 
444 static int
445 ch_move(scsi_changer *ch, u_int trans, u_int src, u_int dest, int rotate)
446 {
447 	u_char  cmd[12];
448 
449 	DPRINTK("move: 0x%x => 0x%x\n",src,dest);
450 	if (0 == trans)
451 		trans = ch->firsts[CHET_MT];
452 	memset(cmd,0,sizeof(cmd));
453 	cmd[0]  = MOVE_MEDIUM;
454 	cmd[1]  = (ch->device->lun & 0x7) << 5;
455 	cmd[2]  = (trans >> 8) & 0xff;
456 	cmd[3]  =  trans       & 0xff;
457 	cmd[4]  = (src   >> 8) & 0xff;
458 	cmd[5]  =  src         & 0xff;
459 	cmd[6]  = (dest  >> 8) & 0xff;
460 	cmd[7]  =  dest        & 0xff;
461 	cmd[10] = rotate ? 1 : 0;
462 	return ch_do_scsi(ch, cmd, 12, NULL,0, DMA_NONE);
463 }
464 
465 static int
466 ch_exchange(scsi_changer *ch, u_int trans, u_int src,
467 	    u_int dest1, u_int dest2, int rotate1, int rotate2)
468 {
469 	u_char  cmd[12];
470 
471 	DPRINTK("exchange: 0x%x => 0x%x => 0x%x\n",
472 		src,dest1,dest2);
473 	if (0 == trans)
474 		trans = ch->firsts[CHET_MT];
475 	memset(cmd,0,sizeof(cmd));
476 	cmd[0]  = EXCHANGE_MEDIUM;
477 	cmd[1]  = (ch->device->lun & 0x7) << 5;
478 	cmd[2]  = (trans >> 8) & 0xff;
479 	cmd[3]  =  trans       & 0xff;
480 	cmd[4]  = (src   >> 8) & 0xff;
481 	cmd[5]  =  src         & 0xff;
482 	cmd[6]  = (dest1 >> 8) & 0xff;
483 	cmd[7]  =  dest1       & 0xff;
484 	cmd[8]  = (dest2 >> 8) & 0xff;
485 	cmd[9]  =  dest2       & 0xff;
486 	cmd[10] = (rotate1 ? 1 : 0) | (rotate2 ? 2 : 0);
487 
488 	return ch_do_scsi(ch, cmd, 12, NULL, 0, DMA_NONE);
489 }
490 
491 static void
492 ch_check_voltag(char *tag)
493 {
494 	int i;
495 
496 	for (i = 0; i < 32; i++) {
497 		/* restrict to ascii */
498 		if (tag[i] >= 0x7f || tag[i] < 0x20)
499 			tag[i] = ' ';
500 		/* don't allow search wildcards */
501 		if (tag[i] == '?' ||
502 		    tag[i] == '*')
503 			tag[i] = ' ';
504 	}
505 }
506 
507 static int
508 ch_set_voltag(scsi_changer *ch, u_int elem,
509 	      int alternate, int clear, u_char *tag)
510 {
511 	u_char  cmd[12];
512 	u_char  *buffer;
513 	int result;
514 
515 	buffer = kzalloc(512, GFP_KERNEL);
516 	if (!buffer)
517 		return -ENOMEM;
518 
519 	DPRINTK("%s %s voltag: 0x%x => \"%s\"\n",
520 		clear     ? "clear"     : "set",
521 		alternate ? "alternate" : "primary",
522 		elem, tag);
523 	memset(cmd,0,sizeof(cmd));
524 	cmd[0]  = SEND_VOLUME_TAG;
525 	cmd[1] = ((ch->device->lun & 0x7) << 5) |
526 		ch_elem_to_typecode(ch,elem);
527 	cmd[2] = (elem >> 8) & 0xff;
528 	cmd[3] = elem        & 0xff;
529 	cmd[5] = clear
530 		? (alternate ? 0x0d : 0x0c)
531 		: (alternate ? 0x0b : 0x0a);
532 
533 	cmd[9] = 255;
534 
535 	memcpy(buffer,tag,32);
536 	ch_check_voltag(buffer);
537 
538 	result = ch_do_scsi(ch, cmd, 12, buffer, 256, DMA_TO_DEVICE);
539 	kfree(buffer);
540 	return result;
541 }
542 
543 static int ch_gstatus(scsi_changer *ch, int type, unsigned char __user *dest)
544 {
545 	int retval = 0;
546 	u_char data[16];
547 	unsigned int i;
548 
549 	mutex_lock(&ch->lock);
550 	for (i = 0; i < ch->counts[type]; i++) {
551 		if (0 != ch_read_element_status
552 		    (ch, ch->firsts[type]+i,data)) {
553 			retval = -EIO;
554 			break;
555 		}
556 		put_user(data[2], dest+i);
557 		if (data[2] & CESTATUS_EXCEPT)
558 			VPRINTK(KERN_INFO, "element 0x%x: asc=0x%x, ascq=0x%x\n",
559 				ch->firsts[type]+i,
560 				(int)data[4],(int)data[5]);
561 		retval = ch_read_element_status
562 			(ch, ch->firsts[type]+i,data);
563 		if (0 != retval)
564 			break;
565 	}
566 	mutex_unlock(&ch->lock);
567 	return retval;
568 }
569 
570 /* ------------------------------------------------------------------------ */
571 
572 static int
573 ch_release(struct inode *inode, struct file *file)
574 {
575 	scsi_changer *ch = file->private_data;
576 
577 	scsi_device_put(ch->device);
578 	file->private_data = NULL;
579 	return 0;
580 }
581 
582 static int
583 ch_open(struct inode *inode, struct file *file)
584 {
585 	scsi_changer *ch;
586 	int minor = iminor(inode);
587 
588 	mutex_lock(&ch_mutex);
589 	spin_lock(&ch_index_lock);
590 	ch = idr_find(&ch_index_idr, minor);
591 
592 	if (NULL == ch || scsi_device_get(ch->device)) {
593 		spin_unlock(&ch_index_lock);
594 		mutex_unlock(&ch_mutex);
595 		return -ENXIO;
596 	}
597 	spin_unlock(&ch_index_lock);
598 
599 	file->private_data = ch;
600 	mutex_unlock(&ch_mutex);
601 	return 0;
602 }
603 
604 static int
605 ch_checkrange(scsi_changer *ch, unsigned int type, unsigned int unit)
606 {
607 	if (type >= CH_TYPES  ||  unit >= ch->counts[type])
608 		return -1;
609 	return 0;
610 }
611 
612 static long ch_ioctl(struct file *file,
613 		    unsigned int cmd, unsigned long arg)
614 {
615 	scsi_changer *ch = file->private_data;
616 	int retval;
617 	void __user *argp = (void __user *)arg;
618 
619 	retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
620 			file->f_flags & O_NDELAY);
621 	if (retval)
622 		return retval;
623 
624 	switch (cmd) {
625 	case CHIOGPARAMS:
626 	{
627 		struct changer_params params;
628 
629 		params.cp_curpicker = 0;
630 		params.cp_npickers  = ch->counts[CHET_MT];
631 		params.cp_nslots    = ch->counts[CHET_ST];
632 		params.cp_nportals  = ch->counts[CHET_IE];
633 		params.cp_ndrives   = ch->counts[CHET_DT];
634 
635 		if (copy_to_user(argp, &params, sizeof(params)))
636 			return -EFAULT;
637 		return 0;
638 	}
639 	case CHIOGVPARAMS:
640 	{
641 		struct changer_vendor_params vparams;
642 
643 		memset(&vparams,0,sizeof(vparams));
644 		if (ch->counts[CHET_V1]) {
645 			vparams.cvp_n1  = ch->counts[CHET_V1];
646 			strncpy(vparams.cvp_label1,vendor_labels[0],16);
647 		}
648 		if (ch->counts[CHET_V2]) {
649 			vparams.cvp_n2  = ch->counts[CHET_V2];
650 			strncpy(vparams.cvp_label2,vendor_labels[1],16);
651 		}
652 		if (ch->counts[CHET_V3]) {
653 			vparams.cvp_n3  = ch->counts[CHET_V3];
654 			strncpy(vparams.cvp_label3,vendor_labels[2],16);
655 		}
656 		if (ch->counts[CHET_V4]) {
657 			vparams.cvp_n4  = ch->counts[CHET_V4];
658 			strncpy(vparams.cvp_label4,vendor_labels[3],16);
659 		}
660 		if (copy_to_user(argp, &vparams, sizeof(vparams)))
661 			return -EFAULT;
662 		return 0;
663 	}
664 
665 	case CHIOPOSITION:
666 	{
667 		struct changer_position pos;
668 
669 		if (copy_from_user(&pos, argp, sizeof (pos)))
670 			return -EFAULT;
671 
672 		if (0 != ch_checkrange(ch, pos.cp_type, pos.cp_unit)) {
673 			DPRINTK("CHIOPOSITION: invalid parameter\n");
674 			return -EBADSLT;
675 		}
676 		mutex_lock(&ch->lock);
677 		retval = ch_position(ch,0,
678 				     ch->firsts[pos.cp_type] + pos.cp_unit,
679 				     pos.cp_flags & CP_INVERT);
680 		mutex_unlock(&ch->lock);
681 		return retval;
682 	}
683 
684 	case CHIOMOVE:
685 	{
686 		struct changer_move mv;
687 
688 		if (copy_from_user(&mv, argp, sizeof (mv)))
689 			return -EFAULT;
690 
691 		if (0 != ch_checkrange(ch, mv.cm_fromtype, mv.cm_fromunit) ||
692 		    0 != ch_checkrange(ch, mv.cm_totype,   mv.cm_tounit  )) {
693 			DPRINTK("CHIOMOVE: invalid parameter\n");
694 			return -EBADSLT;
695 		}
696 
697 		mutex_lock(&ch->lock);
698 		retval = ch_move(ch,0,
699 				 ch->firsts[mv.cm_fromtype] + mv.cm_fromunit,
700 				 ch->firsts[mv.cm_totype]   + mv.cm_tounit,
701 				 mv.cm_flags & CM_INVERT);
702 		mutex_unlock(&ch->lock);
703 		return retval;
704 	}
705 
706 	case CHIOEXCHANGE:
707 	{
708 		struct changer_exchange mv;
709 
710 		if (copy_from_user(&mv, argp, sizeof (mv)))
711 			return -EFAULT;
712 
713 		if (0 != ch_checkrange(ch, mv.ce_srctype,  mv.ce_srcunit ) ||
714 		    0 != ch_checkrange(ch, mv.ce_fdsttype, mv.ce_fdstunit) ||
715 		    0 != ch_checkrange(ch, mv.ce_sdsttype, mv.ce_sdstunit)) {
716 			DPRINTK("CHIOEXCHANGE: invalid parameter\n");
717 			return -EBADSLT;
718 		}
719 
720 		mutex_lock(&ch->lock);
721 		retval = ch_exchange
722 			(ch,0,
723 			 ch->firsts[mv.ce_srctype]  + mv.ce_srcunit,
724 			 ch->firsts[mv.ce_fdsttype] + mv.ce_fdstunit,
725 			 ch->firsts[mv.ce_sdsttype] + mv.ce_sdstunit,
726 			 mv.ce_flags & CE_INVERT1, mv.ce_flags & CE_INVERT2);
727 		mutex_unlock(&ch->lock);
728 		return retval;
729 	}
730 
731 	case CHIOGSTATUS:
732 	{
733 		struct changer_element_status ces;
734 
735 		if (copy_from_user(&ces, argp, sizeof (ces)))
736 			return -EFAULT;
737 		if (ces.ces_type < 0 || ces.ces_type >= CH_TYPES)
738 			return -EINVAL;
739 
740 		return ch_gstatus(ch, ces.ces_type, ces.ces_data);
741 	}
742 
743 	case CHIOGELEM:
744 	{
745 		struct changer_get_element cge;
746 		u_char ch_cmd[12];
747 		u_char *buffer;
748 		unsigned int elem;
749 		int     result,i;
750 
751 		if (copy_from_user(&cge, argp, sizeof (cge)))
752 			return -EFAULT;
753 
754 		if (0 != ch_checkrange(ch, cge.cge_type, cge.cge_unit))
755 			return -EINVAL;
756 		elem = ch->firsts[cge.cge_type] + cge.cge_unit;
757 
758 		buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
759 		if (!buffer)
760 			return -ENOMEM;
761 		mutex_lock(&ch->lock);
762 
763 	voltag_retry:
764 		memset(ch_cmd, 0, sizeof(ch_cmd));
765 		ch_cmd[0] = READ_ELEMENT_STATUS;
766 		ch_cmd[1] = ((ch->device->lun & 0x7) << 5) |
767 			(ch->voltags ? 0x10 : 0) |
768 			ch_elem_to_typecode(ch,elem);
769 		ch_cmd[2] = (elem >> 8) & 0xff;
770 		ch_cmd[3] = elem        & 0xff;
771 		ch_cmd[5] = 1;
772 		ch_cmd[9] = 255;
773 
774 		result = ch_do_scsi(ch, ch_cmd, 12,
775 				    buffer, 256, DMA_FROM_DEVICE);
776 		if (!result) {
777 			cge.cge_status = buffer[18];
778 			cge.cge_flags = 0;
779 			if (buffer[18] & CESTATUS_EXCEPT) {
780 				cge.cge_errno = EIO;
781 			}
782 			if (buffer[25] & 0x80) {
783 				cge.cge_flags |= CGE_SRC;
784 				if (buffer[25] & 0x40)
785 					cge.cge_flags |= CGE_INVERT;
786 				elem = (buffer[26]<<8) | buffer[27];
787 				for (i = 0; i < 4; i++) {
788 					if (elem >= ch->firsts[i] &&
789 					    elem <  ch->firsts[i] + ch->counts[i]) {
790 						cge.cge_srctype = i;
791 						cge.cge_srcunit = elem-ch->firsts[i];
792 					}
793 				}
794 			}
795 			if ((buffer[22] & 0x30) == 0x30) {
796 				cge.cge_flags |= CGE_IDLUN;
797 				cge.cge_id  = buffer[23];
798 				cge.cge_lun = buffer[22] & 7;
799 			}
800 			if (buffer[9] & 0x80) {
801 				cge.cge_flags |= CGE_PVOLTAG;
802 				memcpy(cge.cge_pvoltag,buffer+28,36);
803 			}
804 			if (buffer[9] & 0x40) {
805 				cge.cge_flags |= CGE_AVOLTAG;
806 				memcpy(cge.cge_avoltag,buffer+64,36);
807 			}
808 		} else if (ch->voltags) {
809 			ch->voltags = 0;
810 			VPRINTK(KERN_INFO, "device has no volume tag support\n");
811 			goto voltag_retry;
812 		}
813 		kfree(buffer);
814 		mutex_unlock(&ch->lock);
815 
816 		if (copy_to_user(argp, &cge, sizeof (cge)))
817 			return -EFAULT;
818 		return result;
819 	}
820 
821 	case CHIOINITELEM:
822 	{
823 		mutex_lock(&ch->lock);
824 		retval = ch_init_elem(ch);
825 		mutex_unlock(&ch->lock);
826 		return retval;
827 	}
828 
829 	case CHIOSVOLTAG:
830 	{
831 		struct changer_set_voltag csv;
832 		int elem;
833 
834 		if (copy_from_user(&csv, argp, sizeof(csv)))
835 			return -EFAULT;
836 
837 		if (0 != ch_checkrange(ch, csv.csv_type, csv.csv_unit)) {
838 			DPRINTK("CHIOSVOLTAG: invalid parameter\n");
839 			return -EBADSLT;
840 		}
841 		elem = ch->firsts[csv.csv_type] + csv.csv_unit;
842 		mutex_lock(&ch->lock);
843 		retval = ch_set_voltag(ch, elem,
844 				       csv.csv_flags & CSV_AVOLTAG,
845 				       csv.csv_flags & CSV_CLEARTAG,
846 				       csv.csv_voltag);
847 		mutex_unlock(&ch->lock);
848 		return retval;
849 	}
850 
851 	default:
852 		return scsi_ioctl(ch->device, cmd, argp);
853 
854 	}
855 }
856 
857 #ifdef CONFIG_COMPAT
858 
859 struct changer_element_status32 {
860 	int		ces_type;
861 	compat_uptr_t	ces_data;
862 };
863 #define CHIOGSTATUS32  _IOW('c', 8,struct changer_element_status32)
864 
865 static long ch_ioctl_compat(struct file * file,
866 			    unsigned int cmd, unsigned long arg)
867 {
868 	scsi_changer *ch = file->private_data;
869 
870 	switch (cmd) {
871 	case CHIOGPARAMS:
872 	case CHIOGVPARAMS:
873 	case CHIOPOSITION:
874 	case CHIOMOVE:
875 	case CHIOEXCHANGE:
876 	case CHIOGELEM:
877 	case CHIOINITELEM:
878 	case CHIOSVOLTAG:
879 		/* compatible */
880 		return ch_ioctl(file, cmd, arg);
881 	case CHIOGSTATUS32:
882 	{
883 		struct changer_element_status32 ces32;
884 		unsigned char __user *data;
885 
886 		if (copy_from_user(&ces32, (void __user *)arg, sizeof (ces32)))
887 			return -EFAULT;
888 		if (ces32.ces_type < 0 || ces32.ces_type >= CH_TYPES)
889 			return -EINVAL;
890 
891 		data = compat_ptr(ces32.ces_data);
892 		return ch_gstatus(ch, ces32.ces_type, data);
893 	}
894 	default:
895 		// return scsi_ioctl_compat(ch->device, cmd, (void*)arg);
896 		return -ENOIOCTLCMD;
897 
898 	}
899 }
900 #endif
901 
902 /* ------------------------------------------------------------------------ */
903 
904 static int ch_probe(struct device *dev)
905 {
906 	struct scsi_device *sd = to_scsi_device(dev);
907 	struct device *class_dev;
908 	int ret;
909 	scsi_changer *ch;
910 
911 	if (sd->type != TYPE_MEDIUM_CHANGER)
912 		return -ENODEV;
913 
914 	ch = kzalloc(sizeof(*ch), GFP_KERNEL);
915 	if (NULL == ch)
916 		return -ENOMEM;
917 
918 	idr_preload(GFP_KERNEL);
919 	spin_lock(&ch_index_lock);
920 	ret = idr_alloc(&ch_index_idr, ch, 0, CH_MAX_DEVS + 1, GFP_NOWAIT);
921 	spin_unlock(&ch_index_lock);
922 	idr_preload_end();
923 
924 	if (ret < 0) {
925 		if (ret == -ENOSPC)
926 			ret = -ENODEV;
927 		goto free_ch;
928 	}
929 
930 	ch->minor = ret;
931 	sprintf(ch->name,"ch%d",ch->minor);
932 
933 	class_dev = device_create(ch_sysfs_class, dev,
934 				  MKDEV(SCSI_CHANGER_MAJOR, ch->minor), ch,
935 				  "s%s", ch->name);
936 	if (IS_ERR(class_dev)) {
937 		sdev_printk(KERN_WARNING, sd, "ch%d: device_create failed\n",
938 			    ch->minor);
939 		ret = PTR_ERR(class_dev);
940 		goto remove_idr;
941 	}
942 
943 	mutex_init(&ch->lock);
944 	ch->device = sd;
945 	ch_readconfig(ch);
946 	if (init)
947 		ch_init_elem(ch);
948 
949 	dev_set_drvdata(dev, ch);
950 	sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name);
951 
952 	return 0;
953 remove_idr:
954 	idr_remove(&ch_index_idr, ch->minor);
955 free_ch:
956 	kfree(ch);
957 	return ret;
958 }
959 
960 static int ch_remove(struct device *dev)
961 {
962 	scsi_changer *ch = dev_get_drvdata(dev);
963 
964 	spin_lock(&ch_index_lock);
965 	idr_remove(&ch_index_idr, ch->minor);
966 	spin_unlock(&ch_index_lock);
967 
968 	device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR,ch->minor));
969 	kfree(ch->dt);
970 	kfree(ch);
971 	return 0;
972 }
973 
974 static struct scsi_driver ch_template = {
975 	.gendrv     	= {
976 		.name	= "ch",
977 		.owner	= THIS_MODULE,
978 		.probe  = ch_probe,
979 		.remove = ch_remove,
980 	},
981 };
982 
983 static const struct file_operations changer_fops = {
984 	.owner		= THIS_MODULE,
985 	.open		= ch_open,
986 	.release	= ch_release,
987 	.unlocked_ioctl	= ch_ioctl,
988 #ifdef CONFIG_COMPAT
989 	.compat_ioctl	= ch_ioctl_compat,
990 #endif
991 	.llseek		= noop_llseek,
992 };
993 
994 static int __init init_ch_module(void)
995 {
996 	int rc;
997 
998 	printk(KERN_INFO "SCSI Media Changer driver v" VERSION " \n");
999         ch_sysfs_class = class_create(THIS_MODULE, "scsi_changer");
1000         if (IS_ERR(ch_sysfs_class)) {
1001 		rc = PTR_ERR(ch_sysfs_class);
1002 		return rc;
1003         }
1004 	rc = register_chrdev(SCSI_CHANGER_MAJOR,"ch",&changer_fops);
1005 	if (rc < 0) {
1006 		printk("Unable to get major %d for SCSI-Changer\n",
1007 		       SCSI_CHANGER_MAJOR);
1008 		goto fail1;
1009 	}
1010 	rc = scsi_register_driver(&ch_template.gendrv);
1011 	if (rc < 0)
1012 		goto fail2;
1013 	return 0;
1014 
1015  fail2:
1016 	unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1017  fail1:
1018 	class_destroy(ch_sysfs_class);
1019 	return rc;
1020 }
1021 
1022 static void __exit exit_ch_module(void)
1023 {
1024 	scsi_unregister_driver(&ch_template.gendrv);
1025 	unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1026 	class_destroy(ch_sysfs_class);
1027 	idr_destroy(&ch_index_idr);
1028 }
1029 
1030 module_init(init_ch_module);
1031 module_exit(exit_ch_module);
1032 
1033 /*
1034  * Local variables:
1035  * c-basic-offset: 8
1036  * End:
1037  */
1038