summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/mac53c94.c
blob: a035001f44386a36e49abcd3d292fb31239cf85e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
/*
 * SCSI low-level driver for the 53c94 SCSI bus adaptor found
 * on Power Macintosh computers, controlling the external SCSI chain.
 * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA)
 * controller.
 *
 * Paul Mackerras, August 1996.
 * Copyright (C) 1996 Paul Mackerras.
 */
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <asm/dbdma.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/prom.h>
#include <asm/system.h>
#include <asm/pci-bridge.h>
#include <asm/macio.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>

#include "mac53c94.h"

enum fsc_phase {
	idle,
	selecting,
	dataing,
	completing,
	busfreeing,
};

struct fsc_state {
	struct	mac53c94_regs __iomem *regs;
	int	intr;
	struct	dbdma_regs __iomem *dma;
	int	dmaintr;
	int	clk_freq;
	struct	Scsi_Host *host;
	struct scsi_cmnd *request_q;
	struct scsi_cmnd *request_qtail;
	struct scsi_cmnd *current_req;		/* req we're currently working on */
	enum fsc_phase phase;		/* what we're currently trying to do */
	struct dbdma_cmd *dma_cmds;	/* space for dbdma commands, aligned */
	void	*dma_cmd_space;
	struct	pci_dev *pdev;
	dma_addr_t dma_addr;
	struct macio_dev *mdev;
};

static void mac53c94_init(struct fsc_state *);
static void mac53c94_start(struct fsc_state *);
static void mac53c94_interrupt(int, void *);
static irqreturn_t do_mac53c94_interrupt(int, void *);
static void cmd_done(struct fsc_state *, int result);
static void set_dma_cmds(struct fsc_state *, struct scsi_cmnd *);


static int mac53c94_queue(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
{
	struct fsc_state *state;

#if 0
	if (cmd->sc_data_direction == DMA_TO_DEVICE) {
		int i;
		printk(KERN_DEBUG "mac53c94_queue %p: command is", cmd);
		for (i = 0; i < cmd->cmd_len; ++i)
			printk(" %.2x", cmd->cmnd[i]);
		printk("\n" KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",
		       scsi_sg_count(cmd), scsi_bufflen(cmd), scsi_sglist(cmd));
	}
#endif

	cmd->scsi_done = done;
	cmd->host_scribble = NULL;

	state = (struct fsc_state *) cmd->device->host->hostdata;

	if (state->request_q == NULL)
		state->request_q = cmd;
	else
		state->request_qtail->host_scribble = (void *) cmd;
	state->request_qtail = cmd;

	if (state->phase == idle)
		mac53c94_start(state);

	return 0;
}

static int mac53c94_host_reset(struct scsi_cmnd *cmd)
{
	struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;
	struct mac53c94_regs __iomem *regs = state->regs;
	struct dbdma_regs __iomem *dma = state->dma;
	unsigned long flags;

	spin_lock_irqsave(cmd->device->host->host_lock, flags);

	writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
	writeb(CMD_SCSI_RESET, &regs->command);	/* assert RST */
	udelay(100);			/* leave it on for a while (>= 25us) */
	writeb(CMD_RESET, &regs->command);
	udelay(20);
	mac53c94_init(state);
	writeb(CMD_NOP, &regs->command);

	spin_unlock_irqrestore(cmd->device->host->host_lock, flags);
	return SUCCESS;
}

static void mac53c94_init(struct fsc_state *state)
{
	struct mac53c94_regs __iomem *regs = state->regs;
	struct dbdma_regs __iomem *dma = state->dma;
	int x;

	writeb(state->host->this_id | CF1_PAR_ENABLE, &regs->config1);
	writeb(TIMO_VAL(250), &regs->sel_timeout);	/* 250ms */
	writeb(CLKF_VAL(state->clk_freq), &regs->clk_factor);
	writeb(CF2_FEATURE_EN, &regs->config2);
	writeb(0, &regs->config3);
	writeb(0, &regs->sync_period);
	writeb(0, &regs->sync_offset);
	x = readb(&regs->interrupt);
	writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
}

/*
 * Start the next command for a 53C94.
 * Should be called with interrupts disabled.
 */
static void mac53c94_start(struct fsc_state *state)
{
	struct scsi_cmnd *cmd;
	struct mac53c94_regs __iomem *regs = state->regs;
	int i;

	if (state->phase != idle || state->current_req != NULL)
		panic("inappropriate mac53c94_start (state=%p)", state);
	if (state->request_q == NULL)
		return;
	state->current_req = cmd = state->request_q;
	state->request_q = (struct scsi_cmnd *) cmd->host_scribble;

	/* Off we go */
	writeb(0, &regs->count_lo);
	writeb(0, &regs->count_mid);
	writeb(0, &regs->count_hi);
	writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
	udelay(1);
	writeb(CMD_FLUSH, &regs->command);
	udelay(1);
	writeb(cmd->device->id, &regs->dest_id);
	writeb(0, &regs->sync_period);
	writeb(0, &regs->sync_offset);

	/* load the command into the FIFO */
	for (i = 0; i < cmd->cmd_len; ++i)
		writeb(cmd->cmnd[i], &regs->fifo);

	/* do select without ATN XXX */
	writeb(CMD_SELECT, &regs->command);
	state->phase = selecting;

	set_dma_cmds(state, cmd);
}

static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id)
{
	unsigned long flags;
	struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
	
	spin_lock_irqsave(dev->host_lock, flags);
	mac53c94_interrupt(irq, dev_id);
	spin_unlock_irqrestore(dev->host_lock, flags);
	return IRQ_HANDLED;
}

static void mac53c94_interrupt(int irq, void *dev_id)
{
	struct fsc_state *state = (struct fsc_state *) dev_id;
	struct mac53c94_regs __iomem *regs = state->regs;
	struct dbdma_regs __iomem *dma = state->dma;
	struct scsi_cmnd *cmd = state->current_req;
	int nb, stat, seq, intr;
	static int mac53c94_errors;

	/*
	 * Apparently, reading the interrupt register unlatches
	 * the status and sequence step registers.
	 */
	seq = readb(&regs->seqstep);
	stat = readb(&regs->status);
	intr = readb(&regs->interrupt);

#if 0
	printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
	       intr, stat, seq, state->phase);
#endif

	if (intr & INTR_RESET) {
		/* SCSI bus was reset */
		printk(KERN_INFO "external SCSI bus reset detected\n");
		writeb(CMD_NOP, &regs->command);
		writel(RUN << 16, &dma->control);	/* stop dma */
		cmd_done(state, DID_RESET << 16);
		return;
	}
	if (intr & INTR_ILL_CMD) {
		printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
		       intr, stat, seq, state->phase);
		cmd_done(state, DID_ERROR << 16);
		return;
	}
	if (stat & STAT_ERROR) {
#if 0
		/* XXX these seem to be harmless? */
		printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
		       intr, stat, seq, state->phase);
#endif
		++mac53c94_errors;
		writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
	}
	if (cmd == 0) {
		printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
		return;
	}
	if (stat & STAT_PARITY) {
		printk(KERN_ERR "mac53c94: parity error\n");
		cmd_done(state, DID_PARITY << 16);
		return;
	}
	switch (state->phase) {
	case selecting:
		if (intr & INTR_DISCONNECT) {
			/* selection timed out */
			cmd_done(state, DID_BAD_TARGET << 16);
			return;
		}
		if (intr != INTR_BUS_SERV + INTR_DONE) {
			printk(KERN_DEBUG "got intr %x during selection\n", intr);
			cmd_done(state, DID_ERROR << 16);
			return;
		}
		if ((seq & SS_MASK) != SS_DONE) {
			printk(KERN_DEBUG "seq step %x after command\n", seq);
			cmd_done(state, DID_ERROR << 16);
			return;
		}
		writeb(CMD_NOP, &regs->command);
		/* set DMA controller going if any data to transfer */
		if ((stat & (STAT_MSG|STAT_CD)) == 0
		    && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {
			nb = cmd->SCp.this_residual;
			if (nb > 0xfff0)
				nb = 0xfff0;
			cmd->SCp.this_residual -= nb;
			writeb(nb, &regs->count_lo);
			writeb(nb >> 8, &regs->count_mid);
			writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
			writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
			writel((RUN << 16) | RUN, &dma->control);
			writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
			state->phase = dataing;
			break;
		} else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
			/* up to status phase already */
			writeb(CMD_I_COMPLETE, &regs->command);
			state->phase = completing;
		} else {
			printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
			       stat & STAT_PHASE);
			cmd_done(state, DID_ERROR << 16);
			return;
		}
		break;

	case dataing:
		if (intr != INTR_BUS_SERV) {
			printk(KERN_DEBUG "got intr %x before status\n", intr);
			cmd_done(state, DID_ERROR << 16);
			return;
		}
		if (cmd->SCp.this_residual != 0
		    && (stat & (STAT_MSG|STAT_CD)) == 0) {
			/* Set up the count regs to transfer more */
			nb = cmd->SCp.this_residual;
			if (nb > 0xfff0)
				nb = 0xfff0;
			cmd->SCp.this_residual -= nb;
			writeb(nb, &regs->count_lo);
			writeb(nb >> 8, &regs->count_mid);
			writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
			writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
			break;
		}
		if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
			printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
		}
		writel(RUN << 16, &dma->control);	/* stop dma */
		scsi_dma_unmap(cmd);
		/* should check dma status */
		writeb(CMD_I_COMPLETE, &regs->command);
		state->phase = completing;
		break;
	case completing:
		if (intr != INTR_DONE) {
			printk(KERN_DEBUG "got intr %x on completion\n", intr);
			cmd_done(state, DID_ERROR << 16);
			return;
		}
		cmd->SCp.Status = readb(&regs->fifo);
		cmd->SCp.Message = readb(&regs->fifo);
		cmd->result = CMD_ACCEPT_MSG;
		writeb(CMD_ACCEPT_MSG, &regs->command);
		state->phase = busfreeing;
		break;
	case busfreeing:
		if (intr != INTR_DISCONNECT) {
			printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
		}
		cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
			 + cmd->SCp.Status);
		break;
	default:
		printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
	}
}

static void cmd_done(struct fsc_state *state, int result)
{
	struct scsi_cmnd *cmd;

	cmd = state->current_req;
	if (cmd != 0) {
		cmd->result = result;
		(*cmd->scsi_done)(cmd);
		state->current_req = NULL;
	}
	state->phase = idle;
	mac53c94_start(state);
}

/*
 * Set up DMA commands for transferring data.
 */
static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
{
	int i, dma_cmd, total, nseg;
	struct scatterlist *scl;
	struct dbdma_cmd *dcmds;
	dma_addr_t dma_addr;
	u32 dma_len;

	nseg = scsi_dma_map(cmd);
	BUG_ON(nseg < 0);
	if (!nseg)
		return;

	dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
			OUTPUT_MORE : INPUT_MORE;
	dcmds = state->dma_cmds;
	total = 0;

	scsi_for_each_sg(cmd, scl, nseg, i) {
		dma_addr = sg_dma_address(scl);
		dma_len = sg_dma_len(scl);
		if (dma_len > 0xffff)
			panic("mac53c94: scatterlist element >= 64k");
		total += dma_len;
		st_le16(&dcmds->req_count, dma_len);
		st_le16(&dcmds->command, dma_cmd);
		st_le32(&dcmds->phy_addr, dma_addr);
		dcmds->xfer_status = 0;
		++dcmds;
	}

	dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
	st_le16(&dcmds[-1].command, dma_cmd);
	st_le16(&dcmds->command, DBDMA_STOP);
	cmd->SCp.this_residual = total;
}

static struct scsi_host_template mac53c94_template = {
	.proc_name	= "53c94",
	.name		= "53C94",
	.queuecommand	= mac53c94_queue,
	.eh_host_reset_handler = mac53c94_host_reset,
	.can_queue	= 1,
	.this_id	= 7,
	.sg_tablesize	= SG_ALL,
	.cmd_per_lun	= 1,
	.use_clustering	= DISABLE_CLUSTERING,
	.use_sg_chaining = ENABLE_SG_CHAINING,
};

static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
{
	struct device_node *node = macio_get_of_node(mdev);
	struct pci_dev *pdev = macio_get_pci_dev(mdev);
	struct fsc_state *state;
	struct Scsi_Host *host;
	void *dma_cmd_space;
	const unsigned char *clkprop;
	int proplen, rc = -ENODEV;

	if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
		printk(KERN_ERR "mac53c94: expected 2 addrs and intrs"
		       " (got %d/%d)\n",
		       macio_resource_count(mdev), macio_irq_count(mdev));
		return -ENODEV;
	}

	if (macio_request_resources(mdev, "mac53c94") != 0) {
       		printk(KERN_ERR "mac53c94: unable to request memory resources");
		return -EBUSY;
	}

       	host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
	if (host == NULL) {
		printk(KERN_ERR "mac53c94: couldn't register host");
		rc = -ENOMEM;
		goto out_release;
	}

	state = (struct fsc_state *) host->hostdata;
	macio_set_drvdata(mdev, state);
	state->host = host;
	state->pdev = pdev;
	state->mdev = mdev;

	state->regs = (struct mac53c94_regs __iomem *)
		ioremap(macio_resource_start(mdev, 0), 0x1000);
	state->intr = macio_irq(mdev, 0);
	state->dma = (struct dbdma_regs __iomem *)
		ioremap(macio_resource_start(mdev, 1), 0x1000);
	state->dmaintr = macio_irq(mdev, 1);
	if (state->regs == NULL || state->dma == NULL) {
		printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
		       node->full_name);
		goto out_free;
	}

	clkprop = of_get_property(node, "clock-frequency", &proplen);
       	if (clkprop == NULL || proplen != sizeof(int)) {
       		printk(KERN_ERR "%s: can't get clock frequency, "
       		       "assuming 25MHz\n", node->full_name);
       		state->clk_freq = 25000000;
       	} else
       		state->clk_freq = *(int *)clkprop;

       	/* Space for dma command list: +1 for stop command,
       	 * +1 to allow for aligning.
	 * XXX FIXME: Use DMA consistent routines
	 */
       	dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
       				sizeof(struct dbdma_cmd), GFP_KERNEL);
       	if (dma_cmd_space == 0) {
       		printk(KERN_ERR "mac53c94: couldn't allocate dma "
       		       "command space for %s\n", node->full_name);
		rc = -ENOMEM;
       		goto out_free;
       	}
	state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);
	memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
	       * sizeof(struct dbdma_cmd));
	state->dma_cmd_space = dma_cmd_space;

	mac53c94_init(state);

	if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) {
		printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
		       state->intr, node->full_name);
		goto out_free_dma;
	}

	rc = scsi_add_host(host, &mdev->ofdev.dev);
	if (rc != 0)
		goto out_release_irq;

	scsi_scan_host(host);
	return 0;

 out_release_irq:
	free_irq(state->intr, state);
 out_free_dma:
	kfree(state->dma_cmd_space);
 out_free:
	if (state->dma != NULL)
		iounmap(state->dma);
	if (state->regs != NULL)
		iounmap(state->regs);
	scsi_host_put(host);
 out_release:
	macio_release_resources(mdev);

	return rc;
}

static int mac53c94_remove(struct macio_dev *mdev)
{
	struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
	struct Scsi_Host *host = fp->host;

	scsi_remove_host(host);

	free_irq(fp->intr, fp);

	if (fp->regs)
		iounmap(fp->regs);
	if (fp->dma)
		iounmap(fp->dma);
	kfree(fp->dma_cmd_space);

	scsi_host_put(host);

	macio_release_resources(mdev);

	return 0;
}


static struct of_device_id mac53c94_match[] = 
{
	{
	.name 		= "53c94",
	},
	{},
};
MODULE_DEVICE_TABLE (of, mac53c94_match);

static struct macio_driver mac53c94_driver = 
{
	.name 		= "mac53c94",
	.match_table	= mac53c94_match,
	.probe		= mac53c94_probe,
	.remove		= mac53c94_remove,
};


static int __init init_mac53c94(void)
{
	return macio_register_driver(&mac53c94_driver);
}

static void __exit exit_mac53c94(void)
{
	return macio_unregister_driver(&mac53c94_driver);
}

module_init(init_mac53c94);
module_exit(exit_mac53c94);

MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud