[go: nahoru, domu]
1/* ppa.c   --  low level driver for the IOMEGA PPA3
2 * parallel port SCSI host adapter.
3 *
4 * (The PPA3 is the embedded controller in the ZIP drive.)
5 *
6 * (c) 1995,1996 Grant R. Guenther, grant@torque.net,
7 * under the terms of the GNU General Public License.
8 *
9 */
10
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/module.h>
15#include <linux/blkdev.h>
16#include <linux/parport.h>
17#include <linux/workqueue.h>
18#include <linux/delay.h>
19#include <linux/jiffies.h>
20#include <asm/io.h>
21
22#include <scsi/scsi.h>
23#include <scsi/scsi_cmnd.h>
24#include <scsi/scsi_device.h>
25#include <scsi/scsi_host.h>
26
27
28static void ppa_reset_pulse(unsigned int base);
29
30typedef struct {
31	struct pardevice *dev;	/* Parport device entry         */
32	int base;		/* Actual port address          */
33	int mode;		/* Transfer mode                */
34	struct scsi_cmnd *cur_cmd;	/* Current queued command       */
35	struct delayed_work ppa_tq;	/* Polling interrupt stuff       */
36	unsigned long jstart;	/* Jiffies at start             */
37	unsigned long recon_tmo;	/* How many usecs to wait for reconnection (6th bit) */
38	unsigned int failed:1;	/* Failure flag                 */
39	unsigned wanted:1;	/* Parport sharing busy flag    */
40	wait_queue_head_t *waiting;
41	struct Scsi_Host *host;
42	struct list_head list;
43} ppa_struct;
44
45#include  "ppa.h"
46
47static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
48{
49	return *(ppa_struct **)&host->hostdata;
50}
51
52static DEFINE_SPINLOCK(arbitration_lock);
53
54static void got_it(ppa_struct *dev)
55{
56	dev->base = dev->dev->port->base;
57	if (dev->cur_cmd)
58		dev->cur_cmd->SCp.phase = 1;
59	else
60		wake_up(dev->waiting);
61}
62
63static void ppa_wakeup(void *ref)
64{
65	ppa_struct *dev = (ppa_struct *) ref;
66	unsigned long flags;
67
68	spin_lock_irqsave(&arbitration_lock, flags);
69	if (dev->wanted) {
70		parport_claim(dev->dev);
71		got_it(dev);
72		dev->wanted = 0;
73	}
74	spin_unlock_irqrestore(&arbitration_lock, flags);
75	return;
76}
77
78static int ppa_pb_claim(ppa_struct *dev)
79{
80	unsigned long flags;
81	int res = 1;
82	spin_lock_irqsave(&arbitration_lock, flags);
83	if (parport_claim(dev->dev) == 0) {
84		got_it(dev);
85		res = 0;
86	}
87	dev->wanted = res;
88	spin_unlock_irqrestore(&arbitration_lock, flags);
89	return res;
90}
91
92static void ppa_pb_dismiss(ppa_struct *dev)
93{
94	unsigned long flags;
95	int wanted;
96	spin_lock_irqsave(&arbitration_lock, flags);
97	wanted = dev->wanted;
98	dev->wanted = 0;
99	spin_unlock_irqrestore(&arbitration_lock, flags);
100	if (!wanted)
101		parport_release(dev->dev);
102}
103
104static inline void ppa_pb_release(ppa_struct *dev)
105{
106	parport_release(dev->dev);
107}
108
109/*
110 * Start of Chipset kludges
111 */
112
113/* This is to give the ppa driver a way to modify the timings (and other
114 * parameters) by writing to the /proc/scsi/ppa/0 file.
115 * Very simple method really... (To simple, no error checking :( )
116 * Reason: Kernel hackers HATE having to unload and reload modules for
117 * testing...
118 * Also gives a method to use a script to obtain optimum timings (TODO)
119 */
120
121static inline int ppa_write_info(struct Scsi_Host *host, char *buffer, int length)
122{
123	ppa_struct *dev = ppa_dev(host);
124	unsigned long x;
125
126	if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
127		x = simple_strtoul(buffer + 5, NULL, 0);
128		dev->mode = x;
129		return length;
130	}
131	if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
132		x = simple_strtoul(buffer + 10, NULL, 0);
133		dev->recon_tmo = x;
134		printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
135		return length;
136	}
137	printk(KERN_WARNING "ppa /proc: invalid variable\n");
138	return -EINVAL;
139}
140
141static int ppa_show_info(struct seq_file *m, struct Scsi_Host *host)
142{
143	ppa_struct *dev = ppa_dev(host);
144
145	seq_printf(m, "Version : %s\n", PPA_VERSION);
146	seq_printf(m, "Parport : %s\n", dev->dev->port->name);
147	seq_printf(m, "Mode    : %s\n", PPA_MODE_STRING[dev->mode]);
148#if PPA_DEBUG > 0
149	seq_printf(m, "recon_tmo : %lu\n", dev->recon_tmo);
150#endif
151	return 0;
152}
153
154static int device_check(ppa_struct *dev);
155
156#if PPA_DEBUG > 0
157#define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
158	   y, __func__, __LINE__); ppa_fail_func(x,y);
159static inline void ppa_fail_func(ppa_struct *dev, int error_code)
160#else
161static inline void ppa_fail(ppa_struct *dev, int error_code)
162#endif
163{
164	/* If we fail a device then we trash status / message bytes */
165	if (dev->cur_cmd) {
166		dev->cur_cmd->result = error_code << 16;
167		dev->failed = 1;
168	}
169}
170
171/*
172 * Wait for the high bit to be set.
173 *
174 * In principle, this could be tied to an interrupt, but the adapter
175 * doesn't appear to be designed to support interrupts.  We spin on
176 * the 0x80 ready bit.
177 */
178static unsigned char ppa_wait(ppa_struct *dev)
179{
180	int k;
181	unsigned short ppb = dev->base;
182	unsigned char r;
183
184	k = PPA_SPIN_TMO;
185	/* Wait for bit 6 and 7 - PJC */
186	for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
187		udelay(1);
188		r = r_str(ppb);
189	}
190
191	/*
192	 * return some status information.
193	 * Semantics: 0xc0 = ZIP wants more data
194	 *            0xd0 = ZIP wants to send more data
195	 *            0xe0 = ZIP is expecting SCSI command data
196	 *            0xf0 = end of transfer, ZIP is sending status
197	 */
198	if (k)
199		return (r & 0xf0);
200
201	/* Counter expired - Time out occurred */
202	ppa_fail(dev, DID_TIME_OUT);
203	printk(KERN_WARNING "ppa timeout in ppa_wait\n");
204	return 0;		/* command timed out */
205}
206
207/*
208 * Clear EPP Timeout Bit
209 */
210static inline void epp_reset(unsigned short ppb)
211{
212	int i;
213
214	i = r_str(ppb);
215	w_str(ppb, i);
216	w_str(ppb, i & 0xfe);
217}
218
219/*
220 * Wait for empty ECP fifo (if we are in ECP fifo mode only)
221 */
222static inline void ecp_sync(ppa_struct *dev)
223{
224	int i, ppb_hi = dev->dev->port->base_hi;
225
226	if (ppb_hi == 0)
227		return;
228
229	if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {	/* mode 011 == ECP fifo mode */
230		for (i = 0; i < 100; i++) {
231			if (r_ecr(ppb_hi) & 0x01)
232				return;
233			udelay(5);
234		}
235		printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
236	}
237}
238
239static int ppa_byte_out(unsigned short base, const char *buffer, int len)
240{
241	int i;
242
243	for (i = len; i; i--) {
244		w_dtr(base, *buffer++);
245		w_ctr(base, 0xe);
246		w_ctr(base, 0xc);
247	}
248	return 1;		/* All went well - we hope! */
249}
250
251static int ppa_byte_in(unsigned short base, char *buffer, int len)
252{
253	int i;
254
255	for (i = len; i; i--) {
256		*buffer++ = r_dtr(base);
257		w_ctr(base, 0x27);
258		w_ctr(base, 0x25);
259	}
260	return 1;		/* All went well - we hope! */
261}
262
263static int ppa_nibble_in(unsigned short base, char *buffer, int len)
264{
265	for (; len; len--) {
266		unsigned char h;
267
268		w_ctr(base, 0x4);
269		h = r_str(base) & 0xf0;
270		w_ctr(base, 0x6);
271		*buffer++ = h | ((r_str(base) & 0xf0) >> 4);
272	}
273	return 1;		/* All went well - we hope! */
274}
275
276static int ppa_out(ppa_struct *dev, char *buffer, int len)
277{
278	int r;
279	unsigned short ppb = dev->base;
280
281	r = ppa_wait(dev);
282
283	if ((r & 0x50) != 0x40) {
284		ppa_fail(dev, DID_ERROR);
285		return 0;
286	}
287	switch (dev->mode) {
288	case PPA_NIBBLE:
289	case PPA_PS2:
290		/* 8 bit output, with a loop */
291		r = ppa_byte_out(ppb, buffer, len);
292		break;
293
294	case PPA_EPP_32:
295	case PPA_EPP_16:
296	case PPA_EPP_8:
297		epp_reset(ppb);
298		w_ctr(ppb, 0x4);
299#ifdef CONFIG_SCSI_IZIP_EPP16
300		if (!(((long) buffer | len) & 0x01))
301			outsw(ppb + 4, buffer, len >> 1);
302#else
303		if (!(((long) buffer | len) & 0x03))
304			outsl(ppb + 4, buffer, len >> 2);
305#endif
306		else
307			outsb(ppb + 4, buffer, len);
308		w_ctr(ppb, 0xc);
309		r = !(r_str(ppb) & 0x01);
310		w_ctr(ppb, 0xc);
311		ecp_sync(dev);
312		break;
313
314	default:
315		printk(KERN_ERR "PPA: bug in ppa_out()\n");
316		r = 0;
317	}
318	return r;
319}
320
321static int ppa_in(ppa_struct *dev, char *buffer, int len)
322{
323	int r;
324	unsigned short ppb = dev->base;
325
326	r = ppa_wait(dev);
327
328	if ((r & 0x50) != 0x50) {
329		ppa_fail(dev, DID_ERROR);
330		return 0;
331	}
332	switch (dev->mode) {
333	case PPA_NIBBLE:
334		/* 4 bit input, with a loop */
335		r = ppa_nibble_in(ppb, buffer, len);
336		w_ctr(ppb, 0xc);
337		break;
338
339	case PPA_PS2:
340		/* 8 bit input, with a loop */
341		w_ctr(ppb, 0x25);
342		r = ppa_byte_in(ppb, buffer, len);
343		w_ctr(ppb, 0x4);
344		w_ctr(ppb, 0xc);
345		break;
346
347	case PPA_EPP_32:
348	case PPA_EPP_16:
349	case PPA_EPP_8:
350		epp_reset(ppb);
351		w_ctr(ppb, 0x24);
352#ifdef CONFIG_SCSI_IZIP_EPP16
353		if (!(((long) buffer | len) & 0x01))
354			insw(ppb + 4, buffer, len >> 1);
355#else
356		if (!(((long) buffer | len) & 0x03))
357			insl(ppb + 4, buffer, len >> 2);
358#endif
359		else
360			insb(ppb + 4, buffer, len);
361		w_ctr(ppb, 0x2c);
362		r = !(r_str(ppb) & 0x01);
363		w_ctr(ppb, 0x2c);
364		ecp_sync(dev);
365		break;
366
367	default:
368		printk(KERN_ERR "PPA: bug in ppa_ins()\n");
369		r = 0;
370		break;
371	}
372	return r;
373}
374
375/* end of ppa_io.h */
376static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
377{
378	w_dtr(ppb, b);
379	w_ctr(ppb, 0xc);
380	w_ctr(ppb, 0xe);
381	w_ctr(ppb, 0xc);
382	w_ctr(ppb, 0x4);
383	w_ctr(ppb, 0xc);
384}
385
386static void ppa_disconnect(ppa_struct *dev)
387{
388	unsigned short ppb = dev->base;
389
390	ppa_d_pulse(ppb, 0);
391	ppa_d_pulse(ppb, 0x3c);
392	ppa_d_pulse(ppb, 0x20);
393	ppa_d_pulse(ppb, 0xf);
394}
395
396static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
397{
398	w_dtr(ppb, b);
399	w_ctr(ppb, 0x4);
400	w_ctr(ppb, 0x6);
401	w_ctr(ppb, 0x4);
402	w_ctr(ppb, 0xc);
403}
404
405static inline void ppa_connect(ppa_struct *dev, int flag)
406{
407	unsigned short ppb = dev->base;
408
409	ppa_c_pulse(ppb, 0);
410	ppa_c_pulse(ppb, 0x3c);
411	ppa_c_pulse(ppb, 0x20);
412	if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
413		ppa_c_pulse(ppb, 0xcf);
414	else
415		ppa_c_pulse(ppb, 0x8f);
416}
417
418static int ppa_select(ppa_struct *dev, int target)
419{
420	int k;
421	unsigned short ppb = dev->base;
422
423	/*
424	 * Bit 6 (0x40) is the device selected bit.
425	 * First we must wait till the current device goes off line...
426	 */
427	k = PPA_SELECT_TMO;
428	do {
429		k--;
430		udelay(1);
431	} while ((r_str(ppb) & 0x40) && (k));
432	if (!k)
433		return 0;
434
435	w_dtr(ppb, (1 << target));
436	w_ctr(ppb, 0xe);
437	w_ctr(ppb, 0xc);
438	w_dtr(ppb, 0x80);	/* This is NOT the initator */
439	w_ctr(ppb, 0x8);
440
441	k = PPA_SELECT_TMO;
442	do {
443		k--;
444		udelay(1);
445	}
446	while (!(r_str(ppb) & 0x40) && (k));
447	if (!k)
448		return 0;
449
450	return 1;
451}
452
453/*
454 * This is based on a trace of what the Iomega DOS 'guest' driver does.
455 * I've tried several different kinds of parallel ports with guest and
456 * coded this to react in the same ways that it does.
457 *
458 * The return value from this function is just a hint about where the
459 * handshaking failed.
460 *
461 */
462static int ppa_init(ppa_struct *dev)
463{
464	int retv;
465	unsigned short ppb = dev->base;
466
467	ppa_disconnect(dev);
468	ppa_connect(dev, CONNECT_NORMAL);
469
470	retv = 2;		/* Failed */
471
472	w_ctr(ppb, 0xe);
473	if ((r_str(ppb) & 0x08) == 0x08)
474		retv--;
475
476	w_ctr(ppb, 0xc);
477	if ((r_str(ppb) & 0x08) == 0x00)
478		retv--;
479
480	if (!retv)
481		ppa_reset_pulse(ppb);
482	udelay(1000);		/* Allow devices to settle down */
483	ppa_disconnect(dev);
484	udelay(1000);		/* Another delay to allow devices to settle */
485
486	if (retv)
487		return -EIO;
488
489	return device_check(dev);
490}
491
492static inline int ppa_send_command(struct scsi_cmnd *cmd)
493{
494	ppa_struct *dev = ppa_dev(cmd->device->host);
495	int k;
496
497	w_ctr(dev->base, 0x0c);
498
499	for (k = 0; k < cmd->cmd_len; k++)
500		if (!ppa_out(dev, &cmd->cmnd[k], 1))
501			return 0;
502	return 1;
503}
504
505/*
506 * The bulk flag enables some optimisations in the data transfer loops,
507 * it should be true for any command that transfers data in integral
508 * numbers of sectors.
509 *
510 * The driver appears to remain stable if we speed up the parallel port
511 * i/o in this function, but not elsewhere.
512 */
513static int ppa_completion(struct scsi_cmnd *cmd)
514{
515	/* Return codes:
516	 * -1     Error
517	 *  0     Told to schedule
518	 *  1     Finished data transfer
519	 */
520	ppa_struct *dev = ppa_dev(cmd->device->host);
521	unsigned short ppb = dev->base;
522	unsigned long start_jiffies = jiffies;
523
524	unsigned char r, v;
525	int fast, bulk, status;
526
527	v = cmd->cmnd[0];
528	bulk = ((v == READ_6) ||
529		(v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
530
531	/*
532	 * We only get here if the drive is ready to comunicate,
533	 * hence no need for a full ppa_wait.
534	 */
535	r = (r_str(ppb) & 0xf0);
536
537	while (r != (unsigned char) 0xf0) {
538		/*
539		 * If we have been running for more than a full timer tick
540		 * then take a rest.
541		 */
542		if (time_after(jiffies, start_jiffies + 1))
543			return 0;
544
545		if ((cmd->SCp.this_residual <= 0)) {
546			ppa_fail(dev, DID_ERROR);
547			return -1;	/* ERROR_RETURN */
548		}
549
550		/* On some hardware we have SCSI disconnected (6th bit low)
551		 * for about 100usecs. It is too expensive to wait a
552		 * tick on every loop so we busy wait for no more than
553		 * 500usecs to give the drive a chance first. We do not
554		 * change things for "normal" hardware since generally
555		 * the 6th bit is always high.
556		 * This makes the CPU load higher on some hardware
557		 * but otherwise we can not get more than 50K/secs
558		 * on this problem hardware.
559		 */
560		if ((r & 0xc0) != 0xc0) {
561			/* Wait for reconnection should be no more than
562			 * jiffy/2 = 5ms = 5000 loops
563			 */
564			unsigned long k = dev->recon_tmo;
565			for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
566			     k--)
567				udelay(1);
568
569			if (!k)
570				return 0;
571		}
572
573		/* determine if we should use burst I/O */
574		fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
575		    ? PPA_BURST_SIZE : 1;
576
577		if (r == (unsigned char) 0xc0)
578			status = ppa_out(dev, cmd->SCp.ptr, fast);
579		else
580			status = ppa_in(dev, cmd->SCp.ptr, fast);
581
582		cmd->SCp.ptr += fast;
583		cmd->SCp.this_residual -= fast;
584
585		if (!status) {
586			ppa_fail(dev, DID_BUS_BUSY);
587			return -1;	/* ERROR_RETURN */
588		}
589		if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
590			/* if scatter/gather, advance to the next segment */
591			if (cmd->SCp.buffers_residual--) {
592				cmd->SCp.buffer++;
593				cmd->SCp.this_residual =
594				    cmd->SCp.buffer->length;
595				cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
596			}
597		}
598		/* Now check to see if the drive is ready to comunicate */
599		r = (r_str(ppb) & 0xf0);
600		/* If not, drop back down to the scheduler and wait a timer tick */
601		if (!(r & 0x80))
602			return 0;
603	}
604	return 1;		/* FINISH_RETURN */
605}
606
607/*
608 * Since the PPA itself doesn't generate interrupts, we use
609 * the scheduler's task queue to generate a stream of call-backs and
610 * complete the request when the drive is ready.
611 */
612static void ppa_interrupt(struct work_struct *work)
613{
614	ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
615	struct scsi_cmnd *cmd = dev->cur_cmd;
616
617	if (!cmd) {
618		printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
619		return;
620	}
621	if (ppa_engine(dev, cmd)) {
622		schedule_delayed_work(&dev->ppa_tq, 1);
623		return;
624	}
625	/* Command must of completed hence it is safe to let go... */
626#if PPA_DEBUG > 0
627	switch ((cmd->result >> 16) & 0xff) {
628	case DID_OK:
629		break;
630	case DID_NO_CONNECT:
631		printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
632		break;
633	case DID_BUS_BUSY:
634		printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
635		break;
636	case DID_TIME_OUT:
637		printk(KERN_DEBUG "ppa: unknown timeout\n");
638		break;
639	case DID_ABORT:
640		printk(KERN_DEBUG "ppa: told to abort\n");
641		break;
642	case DID_PARITY:
643		printk(KERN_DEBUG "ppa: parity error (???)\n");
644		break;
645	case DID_ERROR:
646		printk(KERN_DEBUG "ppa: internal driver error\n");
647		break;
648	case DID_RESET:
649		printk(KERN_DEBUG "ppa: told to reset device\n");
650		break;
651	case DID_BAD_INTR:
652		printk(KERN_WARNING "ppa: bad interrupt (???)\n");
653		break;
654	default:
655		printk(KERN_WARNING "ppa: bad return code (%02x)\n",
656		       (cmd->result >> 16) & 0xff);
657	}
658#endif
659
660	if (cmd->SCp.phase > 1)
661		ppa_disconnect(dev);
662
663	ppa_pb_dismiss(dev);
664
665	dev->cur_cmd = NULL;
666
667	cmd->scsi_done(cmd);
668}
669
670static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
671{
672	unsigned short ppb = dev->base;
673	unsigned char l = 0, h = 0;
674	int retv;
675
676	/* First check for any errors that may of occurred
677	 * Here we check for internal errors
678	 */
679	if (dev->failed)
680		return 0;
681
682	switch (cmd->SCp.phase) {
683	case 0:		/* Phase 0 - Waiting for parport */
684		if (time_after(jiffies, dev->jstart + HZ)) {
685			/*
686			 * We waited more than a second
687			 * for parport to call us
688			 */
689			ppa_fail(dev, DID_BUS_BUSY);
690			return 0;
691		}
692		return 1;	/* wait until ppa_wakeup claims parport */
693	case 1:		/* Phase 1 - Connected */
694		{		/* Perform a sanity check for cable unplugged */
695			int retv = 2;	/* Failed */
696
697			ppa_connect(dev, CONNECT_EPP_MAYBE);
698
699			w_ctr(ppb, 0xe);
700			if ((r_str(ppb) & 0x08) == 0x08)
701				retv--;
702
703			w_ctr(ppb, 0xc);
704			if ((r_str(ppb) & 0x08) == 0x00)
705				retv--;
706
707			if (retv) {
708				if (time_after(jiffies, dev->jstart + (1 * HZ))) {
709					printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
710					ppa_fail(dev, DID_BUS_BUSY);
711					return 0;
712				} else {
713					ppa_disconnect(dev);
714					return 1;	/* Try again in a jiffy */
715				}
716			}
717			cmd->SCp.phase++;
718		}
719
720	case 2:		/* Phase 2 - We are now talking to the scsi bus */
721		if (!ppa_select(dev, scmd_id(cmd))) {
722			ppa_fail(dev, DID_NO_CONNECT);
723			return 0;
724		}
725		cmd->SCp.phase++;
726
727	case 3:		/* Phase 3 - Ready to accept a command */
728		w_ctr(ppb, 0x0c);
729		if (!(r_str(ppb) & 0x80))
730			return 1;
731
732		if (!ppa_send_command(cmd))
733			return 0;
734		cmd->SCp.phase++;
735
736	case 4:		/* Phase 4 - Setup scatter/gather buffers */
737		if (scsi_bufflen(cmd)) {
738			cmd->SCp.buffer = scsi_sglist(cmd);
739			cmd->SCp.this_residual = cmd->SCp.buffer->length;
740			cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
741		} else {
742			cmd->SCp.buffer = NULL;
743			cmd->SCp.this_residual = 0;
744			cmd->SCp.ptr = NULL;
745		}
746		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
747		cmd->SCp.phase++;
748
749	case 5:		/* Phase 5 - Data transfer stage */
750		w_ctr(ppb, 0x0c);
751		if (!(r_str(ppb) & 0x80))
752			return 1;
753
754		retv = ppa_completion(cmd);
755		if (retv == -1)
756			return 0;
757		if (retv == 0)
758			return 1;
759		cmd->SCp.phase++;
760
761	case 6:		/* Phase 6 - Read status/message */
762		cmd->result = DID_OK << 16;
763		/* Check for data overrun */
764		if (ppa_wait(dev) != (unsigned char) 0xf0) {
765			ppa_fail(dev, DID_ERROR);
766			return 0;
767		}
768		if (ppa_in(dev, &l, 1)) {	/* read status byte */
769			/* Check for optional message byte */
770			if (ppa_wait(dev) == (unsigned char) 0xf0)
771				ppa_in(dev, &h, 1);
772			cmd->result =
773			    (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
774		}
775		return 0;	/* Finished */
776		break;
777
778	default:
779		printk(KERN_ERR "ppa: Invalid scsi phase\n");
780	}
781	return 0;
782}
783
784static int ppa_queuecommand_lck(struct scsi_cmnd *cmd,
785		void (*done) (struct scsi_cmnd *))
786{
787	ppa_struct *dev = ppa_dev(cmd->device->host);
788
789	if (dev->cur_cmd) {
790		printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
791		return 0;
792	}
793	dev->failed = 0;
794	dev->jstart = jiffies;
795	dev->cur_cmd = cmd;
796	cmd->scsi_done = done;
797	cmd->result = DID_ERROR << 16;	/* default return code */
798	cmd->SCp.phase = 0;	/* bus free */
799
800	schedule_delayed_work(&dev->ppa_tq, 0);
801
802	ppa_pb_claim(dev);
803
804	return 0;
805}
806
807static DEF_SCSI_QCMD(ppa_queuecommand)
808
809/*
810 * Apparently the disk->capacity attribute is off by 1 sector
811 * for all disk drives.  We add the one here, but it should really
812 * be done in sd.c.  Even if it gets fixed there, this will still
813 * work.
814 */
815static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
816	      sector_t capacity, int ip[])
817{
818	ip[0] = 0x40;
819	ip[1] = 0x20;
820	ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
821	if (ip[2] > 1024) {
822		ip[0] = 0xff;
823		ip[1] = 0x3f;
824		ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
825		if (ip[2] > 1023)
826			ip[2] = 1023;
827	}
828	return 0;
829}
830
831static int ppa_abort(struct scsi_cmnd *cmd)
832{
833	ppa_struct *dev = ppa_dev(cmd->device->host);
834	/*
835	 * There is no method for aborting commands since Iomega
836	 * have tied the SCSI_MESSAGE line high in the interface
837	 */
838
839	switch (cmd->SCp.phase) {
840	case 0:		/* Do not have access to parport */
841	case 1:		/* Have not connected to interface */
842		dev->cur_cmd = NULL;	/* Forget the problem */
843		return SUCCESS;
844		break;
845	default:		/* SCSI command sent, can not abort */
846		return FAILED;
847		break;
848	}
849}
850
851static void ppa_reset_pulse(unsigned int base)
852{
853	w_dtr(base, 0x40);
854	w_ctr(base, 0x8);
855	udelay(30);
856	w_ctr(base, 0xc);
857}
858
859static int ppa_reset(struct scsi_cmnd *cmd)
860{
861	ppa_struct *dev = ppa_dev(cmd->device->host);
862
863	if (cmd->SCp.phase)
864		ppa_disconnect(dev);
865	dev->cur_cmd = NULL;	/* Forget the problem */
866
867	ppa_connect(dev, CONNECT_NORMAL);
868	ppa_reset_pulse(dev->base);
869	mdelay(1);		/* device settle delay */
870	ppa_disconnect(dev);
871	mdelay(1);		/* device settle delay */
872	return SUCCESS;
873}
874
875static int device_check(ppa_struct *dev)
876{
877	/* This routine looks for a device and then attempts to use EPP
878	   to send a command. If all goes as planned then EPP is available. */
879
880	static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
881	int loop, old_mode, status, k, ppb = dev->base;
882	unsigned char l;
883
884	old_mode = dev->mode;
885	for (loop = 0; loop < 8; loop++) {
886		/* Attempt to use EPP for Test Unit Ready */
887		if ((ppb & 0x0007) == 0x0000)
888			dev->mode = PPA_EPP_32;
889
890second_pass:
891		ppa_connect(dev, CONNECT_EPP_MAYBE);
892		/* Select SCSI device */
893		if (!ppa_select(dev, loop)) {
894			ppa_disconnect(dev);
895			continue;
896		}
897		printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
898		       loop, PPA_MODE_STRING[dev->mode]);
899
900		/* Send SCSI command */
901		status = 1;
902		w_ctr(ppb, 0x0c);
903		for (l = 0; (l < 6) && (status); l++)
904			status = ppa_out(dev, cmd, 1);
905
906		if (!status) {
907			ppa_disconnect(dev);
908			ppa_connect(dev, CONNECT_EPP_MAYBE);
909			w_dtr(ppb, 0x40);
910			w_ctr(ppb, 0x08);
911			udelay(30);
912			w_ctr(ppb, 0x0c);
913			udelay(1000);
914			ppa_disconnect(dev);
915			udelay(1000);
916			if (dev->mode == PPA_EPP_32) {
917				dev->mode = old_mode;
918				goto second_pass;
919			}
920			return -EIO;
921		}
922		w_ctr(ppb, 0x0c);
923		k = 1000000;	/* 1 Second */
924		do {
925			l = r_str(ppb);
926			k--;
927			udelay(1);
928		} while (!(l & 0x80) && (k));
929
930		l &= 0xf0;
931
932		if (l != 0xf0) {
933			ppa_disconnect(dev);
934			ppa_connect(dev, CONNECT_EPP_MAYBE);
935			ppa_reset_pulse(ppb);
936			udelay(1000);
937			ppa_disconnect(dev);
938			udelay(1000);
939			if (dev->mode == PPA_EPP_32) {
940				dev->mode = old_mode;
941				goto second_pass;
942			}
943			return -EIO;
944		}
945		ppa_disconnect(dev);
946		printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
947		       loop, PPA_MODE_STRING[dev->mode]);
948		ppa_connect(dev, CONNECT_EPP_MAYBE);
949		ppa_reset_pulse(ppb);
950		udelay(1000);
951		ppa_disconnect(dev);
952		udelay(1000);
953		return 0;
954	}
955	return -ENODEV;
956}
957
958static int ppa_adjust_queue(struct scsi_device *device)
959{
960	blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
961	return 0;
962}
963
964static struct scsi_host_template ppa_template = {
965	.module			= THIS_MODULE,
966	.proc_name		= "ppa",
967	.show_info		= ppa_show_info,
968	.write_info		= ppa_write_info,
969	.name			= "Iomega VPI0 (ppa) interface",
970	.queuecommand		= ppa_queuecommand,
971	.eh_abort_handler	= ppa_abort,
972	.eh_bus_reset_handler	= ppa_reset,
973	.eh_host_reset_handler	= ppa_reset,
974	.bios_param		= ppa_biosparam,
975	.this_id		= -1,
976	.sg_tablesize		= SG_ALL,
977	.cmd_per_lun		= 1,
978	.use_clustering		= ENABLE_CLUSTERING,
979	.can_queue		= 1,
980	.slave_alloc		= ppa_adjust_queue,
981};
982
983/***************************************************************************
984 *                   Parallel port probing routines                        *
985 ***************************************************************************/
986
987static LIST_HEAD(ppa_hosts);
988
989static int __ppa_attach(struct parport *pb)
990{
991	struct Scsi_Host *host;
992	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
993	DEFINE_WAIT(wait);
994	ppa_struct *dev;
995	int ports;
996	int modes, ppb, ppb_hi;
997	int err = -ENOMEM;
998
999	dev = kzalloc(sizeof(ppa_struct), GFP_KERNEL);
1000	if (!dev)
1001		return -ENOMEM;
1002	dev->base = -1;
1003	dev->mode = PPA_AUTODETECT;
1004	dev->recon_tmo = PPA_RECON_TMO;
1005	init_waitqueue_head(&waiting);
1006	dev->dev = parport_register_device(pb, "ppa", NULL, ppa_wakeup,
1007					    NULL, 0, dev);
1008
1009	if (!dev->dev)
1010		goto out;
1011
1012	/* Claim the bus so it remembers what we do to the control
1013	 * registers. [ CTR and ECP ]
1014	 */
1015	err = -EBUSY;
1016	dev->waiting = &waiting;
1017	prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1018	if (ppa_pb_claim(dev))
1019		schedule_timeout(3 * HZ);
1020	if (dev->wanted) {
1021		printk(KERN_ERR "ppa%d: failed to claim parport because "
1022				"a pardevice is owning the port for too long "
1023				"time!\n", pb->number);
1024		ppa_pb_dismiss(dev);
1025		dev->waiting = NULL;
1026		finish_wait(&waiting, &wait);
1027		goto out1;
1028	}
1029	dev->waiting = NULL;
1030	finish_wait(&waiting, &wait);
1031	ppb = dev->base = dev->dev->port->base;
1032	ppb_hi = dev->dev->port->base_hi;
1033	w_ctr(ppb, 0x0c);
1034	modes = dev->dev->port->modes;
1035
1036	/* Mode detection works up the chain of speed
1037	 * This avoids a nasty if-then-else-if-... tree
1038	 */
1039	dev->mode = PPA_NIBBLE;
1040
1041	if (modes & PARPORT_MODE_TRISTATE)
1042		dev->mode = PPA_PS2;
1043
1044	if (modes & PARPORT_MODE_ECP) {
1045		w_ecr(ppb_hi, 0x20);
1046		dev->mode = PPA_PS2;
1047	}
1048	if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
1049		w_ecr(ppb_hi, 0x80);
1050
1051	/* Done configuration */
1052
1053	err = ppa_init(dev);
1054	ppa_pb_release(dev);
1055
1056	if (err)
1057		goto out1;
1058
1059	/* now the glue ... */
1060	if (dev->mode == PPA_NIBBLE || dev->mode == PPA_PS2)
1061		ports = 3;
1062	else
1063		ports = 8;
1064
1065	INIT_DELAYED_WORK(&dev->ppa_tq, ppa_interrupt);
1066
1067	err = -ENOMEM;
1068	host = scsi_host_alloc(&ppa_template, sizeof(ppa_struct *));
1069	if (!host)
1070		goto out1;
1071	host->io_port = pb->base;
1072	host->n_io_port = ports;
1073	host->dma_channel = -1;
1074	host->unique_id = pb->number;
1075	*(ppa_struct **)&host->hostdata = dev;
1076	dev->host = host;
1077	list_add_tail(&dev->list, &ppa_hosts);
1078	err = scsi_add_host(host, NULL);
1079	if (err)
1080		goto out2;
1081	scsi_scan_host(host);
1082	return 0;
1083out2:
1084	list_del_init(&dev->list);
1085	scsi_host_put(host);
1086out1:
1087	parport_unregister_device(dev->dev);
1088out:
1089	kfree(dev);
1090	return err;
1091}
1092
1093static void ppa_attach(struct parport *pb)
1094{
1095	__ppa_attach(pb);
1096}
1097
1098static void ppa_detach(struct parport *pb)
1099{
1100	ppa_struct *dev;
1101	list_for_each_entry(dev, &ppa_hosts, list) {
1102		if (dev->dev->port == pb) {
1103			list_del_init(&dev->list);
1104			scsi_remove_host(dev->host);
1105			scsi_host_put(dev->host);
1106			parport_unregister_device(dev->dev);
1107			kfree(dev);
1108			break;
1109		}
1110	}
1111}
1112
1113static struct parport_driver ppa_driver = {
1114	.name	= "ppa",
1115	.attach	= ppa_attach,
1116	.detach	= ppa_detach,
1117};
1118
1119static int __init ppa_driver_init(void)
1120{
1121	printk(KERN_INFO "ppa: Version %s\n", PPA_VERSION);
1122	return parport_register_driver(&ppa_driver);
1123}
1124
1125static void __exit ppa_driver_exit(void)
1126{
1127	parport_unregister_driver(&ppa_driver);
1128}
1129
1130module_init(ppa_driver_init);
1131module_exit(ppa_driver_exit);
1132MODULE_LICENSE("GPL");
1133