Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
[pandora-kernel.git] / drivers / scsi / mac53c94.c
1 /*
2  * SCSI low-level driver for the 53c94 SCSI bus adaptor found
3  * on Power Macintosh computers, controlling the external SCSI chain.
4  * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA)
5  * controller.
6  *
7  * Paul Mackerras, August 1996.
8  * Copyright (C) 1996 Paul Mackerras.
9  */
10 #include <linux/kernel.h>
11 #include <linux/delay.h>
12 #include <linux/types.h>
13 #include <linux/string.h>
14 #include <linux/slab.h>
15 #include <linux/blkdev.h>
16 #include <linux/proc_fs.h>
17 #include <linux/stat.h>
18 #include <linux/spinlock.h>
19 #include <linux/interrupt.h>
20 #include <asm/dbdma.h>
21 #include <asm/io.h>
22 #include <asm/pgtable.h>
23 #include <asm/prom.h>
24 #include <asm/system.h>
25 #include <asm/pci-bridge.h>
26 #include <asm/macio.h>
27
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_cmnd.h>
30 #include <scsi/scsi_device.h>
31 #include <scsi/scsi_host.h>
32
33 #include "mac53c94.h"
34
35 enum fsc_phase {
36         idle,
37         selecting,
38         dataing,
39         completing,
40         busfreeing,
41 };
42
43 struct fsc_state {
44         struct  mac53c94_regs __iomem *regs;
45         int     intr;
46         struct  dbdma_regs __iomem *dma;
47         int     dmaintr;
48         int     clk_freq;
49         struct  Scsi_Host *host;
50         struct scsi_cmnd *request_q;
51         struct scsi_cmnd *request_qtail;
52         struct scsi_cmnd *current_req;          /* req we're currently working on */
53         enum fsc_phase phase;           /* what we're currently trying to do */
54         struct dbdma_cmd *dma_cmds;     /* space for dbdma commands, aligned */
55         void    *dma_cmd_space;
56         struct  pci_dev *pdev;
57         dma_addr_t dma_addr;
58         struct macio_dev *mdev;
59 };
60
61 static void mac53c94_init(struct fsc_state *);
62 static void mac53c94_start(struct fsc_state *);
63 static void mac53c94_interrupt(int, void *);
64 static irqreturn_t do_mac53c94_interrupt(int, void *);
65 static void cmd_done(struct fsc_state *, int result);
66 static void set_dma_cmds(struct fsc_state *, struct scsi_cmnd *);
67
68
69 static int mac53c94_queue(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
70 {
71         struct fsc_state *state;
72
73 #if 0
74         if (cmd->sc_data_direction == DMA_TO_DEVICE) {
75                 int i;
76                 printk(KERN_DEBUG "mac53c94_queue %p: command is", cmd);
77                 for (i = 0; i < cmd->cmd_len; ++i)
78                         printk(KERN_CONT " %.2x", cmd->cmnd[i]);
79                 printk(KERN_CONT "\n");
80                 printk(KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",
81                        scsi_sg_count(cmd), scsi_bufflen(cmd), scsi_sglist(cmd));
82         }
83 #endif
84
85         cmd->scsi_done = done;
86         cmd->host_scribble = NULL;
87
88         state = (struct fsc_state *) cmd->device->host->hostdata;
89
90         if (state->request_q == NULL)
91                 state->request_q = cmd;
92         else
93                 state->request_qtail->host_scribble = (void *) cmd;
94         state->request_qtail = cmd;
95
96         if (state->phase == idle)
97                 mac53c94_start(state);
98
99         return 0;
100 }
101
102 static int mac53c94_host_reset(struct scsi_cmnd *cmd)
103 {
104         struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;
105         struct mac53c94_regs __iomem *regs = state->regs;
106         struct dbdma_regs __iomem *dma = state->dma;
107         unsigned long flags;
108
109         spin_lock_irqsave(cmd->device->host->host_lock, flags);
110
111         writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
112         writeb(CMD_SCSI_RESET, &regs->command); /* assert RST */
113         udelay(100);                    /* leave it on for a while (>= 25us) */
114         writeb(CMD_RESET, &regs->command);
115         udelay(20);
116         mac53c94_init(state);
117         writeb(CMD_NOP, &regs->command);
118
119         spin_unlock_irqrestore(cmd->device->host->host_lock, flags);
120         return SUCCESS;
121 }
122
123 static void mac53c94_init(struct fsc_state *state)
124 {
125         struct mac53c94_regs __iomem *regs = state->regs;
126         struct dbdma_regs __iomem *dma = state->dma;
127         int x;
128
129         writeb(state->host->this_id | CF1_PAR_ENABLE, &regs->config1);
130         writeb(TIMO_VAL(250), &regs->sel_timeout);      /* 250ms */
131         writeb(CLKF_VAL(state->clk_freq), &regs->clk_factor);
132         writeb(CF2_FEATURE_EN, &regs->config2);
133         writeb(0, &regs->config3);
134         writeb(0, &regs->sync_period);
135         writeb(0, &regs->sync_offset);
136         x = readb(&regs->interrupt);
137         writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
138 }
139
140 /*
141  * Start the next command for a 53C94.
142  * Should be called with interrupts disabled.
143  */
144 static void mac53c94_start(struct fsc_state *state)
145 {
146         struct scsi_cmnd *cmd;
147         struct mac53c94_regs __iomem *regs = state->regs;
148         int i;
149
150         if (state->phase != idle || state->current_req != NULL)
151                 panic("inappropriate mac53c94_start (state=%p)", state);
152         if (state->request_q == NULL)
153                 return;
154         state->current_req = cmd = state->request_q;
155         state->request_q = (struct scsi_cmnd *) cmd->host_scribble;
156
157         /* Off we go */
158         writeb(0, &regs->count_lo);
159         writeb(0, &regs->count_mid);
160         writeb(0, &regs->count_hi);
161         writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
162         udelay(1);
163         writeb(CMD_FLUSH, &regs->command);
164         udelay(1);
165         writeb(cmd->device->id, &regs->dest_id);
166         writeb(0, &regs->sync_period);
167         writeb(0, &regs->sync_offset);
168
169         /* load the command into the FIFO */
170         for (i = 0; i < cmd->cmd_len; ++i)
171                 writeb(cmd->cmnd[i], &regs->fifo);
172
173         /* do select without ATN XXX */
174         writeb(CMD_SELECT, &regs->command);
175         state->phase = selecting;
176
177         set_dma_cmds(state, cmd);
178 }
179
180 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id)
181 {
182         unsigned long flags;
183         struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
184         
185         spin_lock_irqsave(dev->host_lock, flags);
186         mac53c94_interrupt(irq, dev_id);
187         spin_unlock_irqrestore(dev->host_lock, flags);
188         return IRQ_HANDLED;
189 }
190
191 static void mac53c94_interrupt(int irq, void *dev_id)
192 {
193         struct fsc_state *state = (struct fsc_state *) dev_id;
194         struct mac53c94_regs __iomem *regs = state->regs;
195         struct dbdma_regs __iomem *dma = state->dma;
196         struct scsi_cmnd *cmd = state->current_req;
197         int nb, stat, seq, intr;
198         static int mac53c94_errors;
199
200         /*
201          * Apparently, reading the interrupt register unlatches
202          * the status and sequence step registers.
203          */
204         seq = readb(&regs->seqstep);
205         stat = readb(&regs->status);
206         intr = readb(&regs->interrupt);
207
208 #if 0
209         printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
210                intr, stat, seq, state->phase);
211 #endif
212
213         if (intr & INTR_RESET) {
214                 /* SCSI bus was reset */
215                 printk(KERN_INFO "external SCSI bus reset detected\n");
216                 writeb(CMD_NOP, &regs->command);
217                 writel(RUN << 16, &dma->control);       /* stop dma */
218                 cmd_done(state, DID_RESET << 16);
219                 return;
220         }
221         if (intr & INTR_ILL_CMD) {
222                 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
223                        intr, stat, seq, state->phase);
224                 cmd_done(state, DID_ERROR << 16);
225                 return;
226         }
227         if (stat & STAT_ERROR) {
228 #if 0
229                 /* XXX these seem to be harmless? */
230                 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
231                        intr, stat, seq, state->phase);
232 #endif
233                 ++mac53c94_errors;
234                 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
235         }
236         if (cmd == 0) {
237                 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
238                 return;
239         }
240         if (stat & STAT_PARITY) {
241                 printk(KERN_ERR "mac53c94: parity error\n");
242                 cmd_done(state, DID_PARITY << 16);
243                 return;
244         }
245         switch (state->phase) {
246         case selecting:
247                 if (intr & INTR_DISCONNECT) {
248                         /* selection timed out */
249                         cmd_done(state, DID_BAD_TARGET << 16);
250                         return;
251                 }
252                 if (intr != INTR_BUS_SERV + INTR_DONE) {
253                         printk(KERN_DEBUG "got intr %x during selection\n", intr);
254                         cmd_done(state, DID_ERROR << 16);
255                         return;
256                 }
257                 if ((seq & SS_MASK) != SS_DONE) {
258                         printk(KERN_DEBUG "seq step %x after command\n", seq);
259                         cmd_done(state, DID_ERROR << 16);
260                         return;
261                 }
262                 writeb(CMD_NOP, &regs->command);
263                 /* set DMA controller going if any data to transfer */
264                 if ((stat & (STAT_MSG|STAT_CD)) == 0
265                     && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {
266                         nb = cmd->SCp.this_residual;
267                         if (nb > 0xfff0)
268                                 nb = 0xfff0;
269                         cmd->SCp.this_residual -= nb;
270                         writeb(nb, &regs->count_lo);
271                         writeb(nb >> 8, &regs->count_mid);
272                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
273                         writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
274                         writel((RUN << 16) | RUN, &dma->control);
275                         writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
276                         state->phase = dataing;
277                         break;
278                 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
279                         /* up to status phase already */
280                         writeb(CMD_I_COMPLETE, &regs->command);
281                         state->phase = completing;
282                 } else {
283                         printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
284                                stat & STAT_PHASE);
285                         cmd_done(state, DID_ERROR << 16);
286                         return;
287                 }
288                 break;
289
290         case dataing:
291                 if (intr != INTR_BUS_SERV) {
292                         printk(KERN_DEBUG "got intr %x before status\n", intr);
293                         cmd_done(state, DID_ERROR << 16);
294                         return;
295                 }
296                 if (cmd->SCp.this_residual != 0
297                     && (stat & (STAT_MSG|STAT_CD)) == 0) {
298                         /* Set up the count regs to transfer more */
299                         nb = cmd->SCp.this_residual;
300                         if (nb > 0xfff0)
301                                 nb = 0xfff0;
302                         cmd->SCp.this_residual -= nb;
303                         writeb(nb, &regs->count_lo);
304                         writeb(nb >> 8, &regs->count_mid);
305                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
306                         writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
307                         break;
308                 }
309                 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
310                         printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
311                 }
312                 writel(RUN << 16, &dma->control);       /* stop dma */
313                 scsi_dma_unmap(cmd);
314                 /* should check dma status */
315                 writeb(CMD_I_COMPLETE, &regs->command);
316                 state->phase = completing;
317                 break;
318         case completing:
319                 if (intr != INTR_DONE) {
320                         printk(KERN_DEBUG "got intr %x on completion\n", intr);
321                         cmd_done(state, DID_ERROR << 16);
322                         return;
323                 }
324                 cmd->SCp.Status = readb(&regs->fifo);
325                 cmd->SCp.Message = readb(&regs->fifo);
326                 cmd->result = CMD_ACCEPT_MSG;
327                 writeb(CMD_ACCEPT_MSG, &regs->command);
328                 state->phase = busfreeing;
329                 break;
330         case busfreeing:
331                 if (intr != INTR_DISCONNECT) {
332                         printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
333                 }
334                 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
335                          + cmd->SCp.Status);
336                 break;
337         default:
338                 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
339         }
340 }
341
342 static void cmd_done(struct fsc_state *state, int result)
343 {
344         struct scsi_cmnd *cmd;
345
346         cmd = state->current_req;
347         if (cmd != 0) {
348                 cmd->result = result;
349                 (*cmd->scsi_done)(cmd);
350                 state->current_req = NULL;
351         }
352         state->phase = idle;
353         mac53c94_start(state);
354 }
355
356 /*
357  * Set up DMA commands for transferring data.
358  */
359 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
360 {
361         int i, dma_cmd, total, nseg;
362         struct scatterlist *scl;
363         struct dbdma_cmd *dcmds;
364         dma_addr_t dma_addr;
365         u32 dma_len;
366
367         nseg = scsi_dma_map(cmd);
368         BUG_ON(nseg < 0);
369         if (!nseg)
370                 return;
371
372         dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
373                         OUTPUT_MORE : INPUT_MORE;
374         dcmds = state->dma_cmds;
375         total = 0;
376
377         scsi_for_each_sg(cmd, scl, nseg, i) {
378                 dma_addr = sg_dma_address(scl);
379                 dma_len = sg_dma_len(scl);
380                 if (dma_len > 0xffff)
381                         panic("mac53c94: scatterlist element >= 64k");
382                 total += dma_len;
383                 st_le16(&dcmds->req_count, dma_len);
384                 st_le16(&dcmds->command, dma_cmd);
385                 st_le32(&dcmds->phy_addr, dma_addr);
386                 dcmds->xfer_status = 0;
387                 ++dcmds;
388         }
389
390         dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
391         st_le16(&dcmds[-1].command, dma_cmd);
392         st_le16(&dcmds->command, DBDMA_STOP);
393         cmd->SCp.this_residual = total;
394 }
395
396 static struct scsi_host_template mac53c94_template = {
397         .proc_name      = "53c94",
398         .name           = "53C94",
399         .queuecommand   = mac53c94_queue,
400         .eh_host_reset_handler = mac53c94_host_reset,
401         .can_queue      = 1,
402         .this_id        = 7,
403         .sg_tablesize   = SG_ALL,
404         .cmd_per_lun    = 1,
405         .use_clustering = DISABLE_CLUSTERING,
406 };
407
408 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
409 {
410         struct device_node *node = macio_get_of_node(mdev);
411         struct pci_dev *pdev = macio_get_pci_dev(mdev);
412         struct fsc_state *state;
413         struct Scsi_Host *host;
414         void *dma_cmd_space;
415         const unsigned char *clkprop;
416         int proplen, rc = -ENODEV;
417
418         if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
419                 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs"
420                        " (got %d/%d)\n",
421                        macio_resource_count(mdev), macio_irq_count(mdev));
422                 return -ENODEV;
423         }
424
425         if (macio_request_resources(mdev, "mac53c94") != 0) {
426                 printk(KERN_ERR "mac53c94: unable to request memory resources");
427                 return -EBUSY;
428         }
429
430         host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
431         if (host == NULL) {
432                 printk(KERN_ERR "mac53c94: couldn't register host");
433                 rc = -ENOMEM;
434                 goto out_release;
435         }
436
437         state = (struct fsc_state *) host->hostdata;
438         macio_set_drvdata(mdev, state);
439         state->host = host;
440         state->pdev = pdev;
441         state->mdev = mdev;
442
443         state->regs = (struct mac53c94_regs __iomem *)
444                 ioremap(macio_resource_start(mdev, 0), 0x1000);
445         state->intr = macio_irq(mdev, 0);
446         state->dma = (struct dbdma_regs __iomem *)
447                 ioremap(macio_resource_start(mdev, 1), 0x1000);
448         state->dmaintr = macio_irq(mdev, 1);
449         if (state->regs == NULL || state->dma == NULL) {
450                 printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
451                        node->full_name);
452                 goto out_free;
453         }
454
455         clkprop = of_get_property(node, "clock-frequency", &proplen);
456         if (clkprop == NULL || proplen != sizeof(int)) {
457                 printk(KERN_ERR "%s: can't get clock frequency, "
458                        "assuming 25MHz\n", node->full_name);
459                 state->clk_freq = 25000000;
460         } else
461                 state->clk_freq = *(int *)clkprop;
462
463         /* Space for dma command list: +1 for stop command,
464          * +1 to allow for aligning.
465          * XXX FIXME: Use DMA consistent routines
466          */
467         dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
468                                 sizeof(struct dbdma_cmd), GFP_KERNEL);
469         if (dma_cmd_space == 0) {
470                 printk(KERN_ERR "mac53c94: couldn't allocate dma "
471                        "command space for %s\n", node->full_name);
472                 rc = -ENOMEM;
473                 goto out_free;
474         }
475         state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);
476         memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
477                * sizeof(struct dbdma_cmd));
478         state->dma_cmd_space = dma_cmd_space;
479
480         mac53c94_init(state);
481
482         if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) {
483                 printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
484                        state->intr, node->full_name);
485                 goto out_free_dma;
486         }
487
488         rc = scsi_add_host(host, &mdev->ofdev.dev);
489         if (rc != 0)
490                 goto out_release_irq;
491
492         scsi_scan_host(host);
493         return 0;
494
495  out_release_irq:
496         free_irq(state->intr, state);
497  out_free_dma:
498         kfree(state->dma_cmd_space);
499  out_free:
500         if (state->dma != NULL)
501                 iounmap(state->dma);
502         if (state->regs != NULL)
503                 iounmap(state->regs);
504         scsi_host_put(host);
505  out_release:
506         macio_release_resources(mdev);
507
508         return rc;
509 }
510
511 static int mac53c94_remove(struct macio_dev *mdev)
512 {
513         struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
514         struct Scsi_Host *host = fp->host;
515
516         scsi_remove_host(host);
517
518         free_irq(fp->intr, fp);
519
520         if (fp->regs)
521                 iounmap(fp->regs);
522         if (fp->dma)
523                 iounmap(fp->dma);
524         kfree(fp->dma_cmd_space);
525
526         scsi_host_put(host);
527
528         macio_release_resources(mdev);
529
530         return 0;
531 }
532
533
534 static struct of_device_id mac53c94_match[] = 
535 {
536         {
537         .name           = "53c94",
538         },
539         {},
540 };
541 MODULE_DEVICE_TABLE (of, mac53c94_match);
542
543 static struct macio_driver mac53c94_driver = 
544 {
545         .name           = "mac53c94",
546         .match_table    = mac53c94_match,
547         .probe          = mac53c94_probe,
548         .remove         = mac53c94_remove,
549 };
550
551
552 static int __init init_mac53c94(void)
553 {
554         return macio_register_driver(&mac53c94_driver);
555 }
556
557 static void __exit exit_mac53c94(void)
558 {
559         return macio_unregister_driver(&mac53c94_driver);
560 }
561
562 module_init(init_mac53c94);
563 module_exit(exit_mac53c94);
564
565 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
566 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
567 MODULE_LICENSE("GPL");