[PATCH] openfirmware: generate device table for userspace
[linux-2.6.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 *, struct pt_regs *);
64 static irqreturn_t do_mac53c94_interrupt(int, void *, struct pt_regs *);
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(" %.2x", cmd->cmnd[i]);
79                 printk("\n" KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",
80                        cmd->use_sg, cmd->request_bufflen, cmd->request_buffer);
81         }
82 #endif
83
84         cmd->scsi_done = done;
85         cmd->host_scribble = NULL;
86
87         state = (struct fsc_state *) cmd->device->host->hostdata;
88
89         if (state->request_q == NULL)
90                 state->request_q = cmd;
91         else
92                 state->request_qtail->host_scribble = (void *) cmd;
93         state->request_qtail = cmd;
94
95         if (state->phase == idle)
96                 mac53c94_start(state);
97
98         return 0;
99 }
100
101 static int mac53c94_host_reset(struct scsi_cmnd *cmd)
102 {
103         struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;
104         struct mac53c94_regs __iomem *regs = state->regs;
105         struct dbdma_regs __iomem *dma = state->dma;
106         unsigned long flags;
107
108         spin_lock_irqsave(cmd->device->host->host_lock, flags);
109
110         writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
111         writeb(CMD_SCSI_RESET, &regs->command); /* assert RST */
112         udelay(100);                    /* leave it on for a while (>= 25us) */
113         writeb(CMD_RESET, &regs->command);
114         udelay(20);
115         mac53c94_init(state);
116         writeb(CMD_NOP, &regs->command);
117
118         spin_unlock_irqrestore(cmd->device->host->host_lock, flags);
119         return SUCCESS;
120 }
121
122 static void mac53c94_init(struct fsc_state *state)
123 {
124         struct mac53c94_regs __iomem *regs = state->regs;
125         struct dbdma_regs __iomem *dma = state->dma;
126         int x;
127
128         writeb(state->host->this_id | CF1_PAR_ENABLE, &regs->config1);
129         writeb(TIMO_VAL(250), &regs->sel_timeout);      /* 250ms */
130         writeb(CLKF_VAL(state->clk_freq), &regs->clk_factor);
131         writeb(CF2_FEATURE_EN, &regs->config2);
132         writeb(0, &regs->config3);
133         writeb(0, &regs->sync_period);
134         writeb(0, &regs->sync_offset);
135         x = readb(&regs->interrupt);
136         writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
137 }
138
139 /*
140  * Start the next command for a 53C94.
141  * Should be called with interrupts disabled.
142  */
143 static void mac53c94_start(struct fsc_state *state)
144 {
145         struct scsi_cmnd *cmd;
146         struct mac53c94_regs __iomem *regs = state->regs;
147         int i;
148
149         if (state->phase != idle || state->current_req != NULL)
150                 panic("inappropriate mac53c94_start (state=%p)", state);
151         if (state->request_q == NULL)
152                 return;
153         state->current_req = cmd = state->request_q;
154         state->request_q = (struct scsi_cmnd *) cmd->host_scribble;
155
156         /* Off we go */
157         writeb(0, &regs->count_lo);
158         writeb(0, &regs->count_mid);
159         writeb(0, &regs->count_hi);
160         writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
161         udelay(1);
162         writeb(CMD_FLUSH, &regs->command);
163         udelay(1);
164         writeb(cmd->device->id, &regs->dest_id);
165         writeb(0, &regs->sync_period);
166         writeb(0, &regs->sync_offset);
167
168         /* load the command into the FIFO */
169         for (i = 0; i < cmd->cmd_len; ++i)
170                 writeb(cmd->cmnd[i], &regs->fifo);
171
172         /* do select without ATN XXX */
173         writeb(CMD_SELECT, &regs->command);
174         state->phase = selecting;
175
176         if (cmd->use_sg > 0 || cmd->request_bufflen != 0)
177                 set_dma_cmds(state, cmd);
178 }
179
180 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
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, ptregs);
187         spin_unlock_irqrestore(dev->host_lock, flags);
188         return IRQ_HANDLED;
189 }
190
191 static void mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
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                     && (cmd->use_sg > 0 || cmd->request_bufflen != 0)) {
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                 if (cmd->use_sg != 0) {
314                         pci_unmap_sg(state->pdev,
315                                 (struct scatterlist *)cmd->request_buffer,
316                                 cmd->use_sg, cmd->sc_data_direction);
317                 } else {
318                         pci_unmap_single(state->pdev, state->dma_addr,
319                                 cmd->request_bufflen, cmd->sc_data_direction);
320                 }
321                 /* should check dma status */
322                 writeb(CMD_I_COMPLETE, &regs->command);
323                 state->phase = completing;
324                 break;
325         case completing:
326                 if (intr != INTR_DONE) {
327                         printk(KERN_DEBUG "got intr %x on completion\n", intr);
328                         cmd_done(state, DID_ERROR << 16);
329                         return;
330                 }
331                 cmd->SCp.Status = readb(&regs->fifo);
332                 cmd->SCp.Message = readb(&regs->fifo);
333                 cmd->result = CMD_ACCEPT_MSG;
334                 writeb(CMD_ACCEPT_MSG, &regs->command);
335                 state->phase = busfreeing;
336                 break;
337         case busfreeing:
338                 if (intr != INTR_DISCONNECT) {
339                         printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
340                 }
341                 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
342                          + cmd->SCp.Status);
343                 break;
344         default:
345                 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
346         }
347 }
348
349 static void cmd_done(struct fsc_state *state, int result)
350 {
351         struct scsi_cmnd *cmd;
352
353         cmd = state->current_req;
354         if (cmd != 0) {
355                 cmd->result = result;
356                 (*cmd->scsi_done)(cmd);
357                 state->current_req = NULL;
358         }
359         state->phase = idle;
360         mac53c94_start(state);
361 }
362
363 /*
364  * Set up DMA commands for transferring data.
365  */
366 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
367 {
368         int i, dma_cmd, total;
369         struct scatterlist *scl;
370         struct dbdma_cmd *dcmds;
371         dma_addr_t dma_addr;
372         u32 dma_len;
373
374         dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
375                         OUTPUT_MORE : INPUT_MORE;
376         dcmds = state->dma_cmds;
377         if (cmd->use_sg > 0) {
378                 int nseg;
379
380                 total = 0;
381                 scl = (struct scatterlist *) cmd->buffer;
382                 nseg = pci_map_sg(state->pdev, scl, cmd->use_sg,
383                                 cmd->sc_data_direction);
384                 for (i = 0; i < nseg; ++i) {
385                         dma_addr = sg_dma_address(scl);
386                         dma_len = sg_dma_len(scl);
387                         if (dma_len > 0xffff)
388                                 panic("mac53c94: scatterlist element >= 64k");
389                         total += dma_len;
390                         st_le16(&dcmds->req_count, dma_len);
391                         st_le16(&dcmds->command, dma_cmd);
392                         st_le32(&dcmds->phy_addr, dma_addr);
393                         dcmds->xfer_status = 0;
394                         ++scl;
395                         ++dcmds;
396                 }
397         } else {
398                 total = cmd->request_bufflen;
399                 if (total > 0xffff)
400                         panic("mac53c94: transfer size >= 64k");
401                 dma_addr = pci_map_single(state->pdev, cmd->request_buffer,
402                                           total, cmd->sc_data_direction);
403                 state->dma_addr = dma_addr;
404                 st_le16(&dcmds->req_count, total);
405                 st_le32(&dcmds->phy_addr, dma_addr);
406                 dcmds->xfer_status = 0;
407                 ++dcmds;
408         }
409         dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
410         st_le16(&dcmds[-1].command, dma_cmd);
411         st_le16(&dcmds->command, DBDMA_STOP);
412         cmd->SCp.this_residual = total;
413 }
414
415 static struct scsi_host_template mac53c94_template = {
416         .proc_name      = "53c94",
417         .name           = "53C94",
418         .queuecommand   = mac53c94_queue,
419         .eh_host_reset_handler = mac53c94_host_reset,
420         .can_queue      = 1,
421         .this_id        = 7,
422         .sg_tablesize   = SG_ALL,
423         .cmd_per_lun    = 1,
424         .use_clustering = DISABLE_CLUSTERING,
425 };
426
427 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
428 {
429         struct device_node *node = macio_get_of_node(mdev);
430         struct pci_dev *pdev = macio_get_pci_dev(mdev);
431         struct fsc_state *state;
432         struct Scsi_Host *host;
433         void *dma_cmd_space;
434         unsigned char *clkprop;
435         int proplen;
436
437         if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
438                 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs (got %d/%d)\n",
439                        node->n_addrs, node->n_intrs);
440                 return -ENODEV;
441         }
442
443         if (macio_request_resources(mdev, "mac53c94") != 0) {
444                 printk(KERN_ERR "mac53c94: unable to request memory resources");
445                 return -EBUSY;
446         }
447
448         host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
449         if (host == NULL) {
450                 printk(KERN_ERR "mac53c94: couldn't register host");
451                 goto out_release;
452         }
453
454         state = (struct fsc_state *) host->hostdata;
455         macio_set_drvdata(mdev, state);
456         state->host = host;
457         state->pdev = pdev;
458         state->mdev = mdev;
459
460         state->regs = (struct mac53c94_regs __iomem *)
461                 ioremap(macio_resource_start(mdev, 0), 0x1000);
462         state->intr = macio_irq(mdev, 0);
463         state->dma = (struct dbdma_regs __iomem *)
464                 ioremap(macio_resource_start(mdev, 1), 0x1000);
465         state->dmaintr = macio_irq(mdev, 1);
466         if (state->regs == NULL || state->dma == NULL) {
467                 printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
468                        node->full_name);
469                 goto out_free;
470         }
471
472         clkprop = get_property(node, "clock-frequency", &proplen);
473         if (clkprop == NULL || proplen != sizeof(int)) {
474                 printk(KERN_ERR "%s: can't get clock frequency, "
475                        "assuming 25MHz\n", node->full_name);
476                 state->clk_freq = 25000000;
477         } else
478                 state->clk_freq = *(int *)clkprop;
479
480         /* Space for dma command list: +1 for stop command,
481          * +1 to allow for aligning.
482          * XXX FIXME: Use DMA consistent routines
483          */
484         dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
485                                 sizeof(struct dbdma_cmd), GFP_KERNEL);
486         if (dma_cmd_space == 0) {
487                 printk(KERN_ERR "mac53c94: couldn't allocate dma "
488                        "command space for %s\n", node->full_name);
489                 goto out_free;
490         }
491         state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);
492         memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
493                * sizeof(struct dbdma_cmd));
494         state->dma_cmd_space = dma_cmd_space;
495
496         mac53c94_init(state);
497
498         if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94", state)) {
499                 printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
500                        state->intr, node->full_name);
501                 goto out_free_dma;
502         }
503
504         /* XXX FIXME: handle failure */
505         scsi_add_host(host, &mdev->ofdev.dev);
506         scsi_scan_host(host);
507
508         return 0;
509
510  out_free_dma:
511         kfree(state->dma_cmd_space);
512  out_free:
513         if (state->dma != NULL)
514                 iounmap(state->dma);
515         if (state->regs != NULL)
516                 iounmap(state->regs);
517         scsi_host_put(host);
518  out_release:
519         macio_release_resources(mdev);
520
521         return  -ENODEV;
522 }
523
524 static int mac53c94_remove(struct macio_dev *mdev)
525 {
526         struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
527         struct Scsi_Host *host = fp->host;
528
529         scsi_remove_host(host);
530
531         free_irq(fp->intr, fp);
532
533         if (fp->regs)
534                 iounmap((void *) fp->regs);
535         if (fp->dma)
536                 iounmap((void *) fp->dma);
537         kfree(fp->dma_cmd_space);
538
539         scsi_host_put(host);
540
541         macio_release_resources(mdev);
542
543         return 0;
544 }
545
546
547 static struct of_device_id mac53c94_match[] = 
548 {
549         {
550         .name           = "53c94",
551         },
552         {},
553 };
554 MODULE_DEVICE_TABLE (of, mac53c94_match);
555
556 static struct macio_driver mac53c94_driver = 
557 {
558         .name           = "mac53c94",
559         .match_table    = mac53c94_match,
560         .probe          = mac53c94_probe,
561         .remove         = mac53c94_remove,
562 };
563
564
565 static int __init init_mac53c94(void)
566 {
567         return macio_register_driver(&mac53c94_driver);
568 }
569
570 static void __exit exit_mac53c94(void)
571 {
572         return macio_unregister_driver(&mac53c94_driver);
573 }
574
575 module_init(init_mac53c94);
576 module_exit(exit_mac53c94);
577
578 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
579 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
580 MODULE_LICENSE("GPL");