b12ad7c7c6736908419987896a2402898ba2620e
[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 *);
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(" %.2x", cmd->cmnd[i]);
79                 printk("\n" KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",
80                        scsi_sg_count(cmd), scsi_bufflen(cmd), scsi_sglist(cmd));
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         set_dma_cmds(state, cmd);
177 }
178
179 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id)
180 {
181         unsigned long flags;
182         struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
183         
184         spin_lock_irqsave(dev->host_lock, flags);
185         mac53c94_interrupt(irq, dev_id);
186         spin_unlock_irqrestore(dev->host_lock, flags);
187         return IRQ_HANDLED;
188 }
189
190 static void mac53c94_interrupt(int irq, void *dev_id)
191 {
192         struct fsc_state *state = (struct fsc_state *) dev_id;
193         struct mac53c94_regs __iomem *regs = state->regs;
194         struct dbdma_regs __iomem *dma = state->dma;
195         struct scsi_cmnd *cmd = state->current_req;
196         int nb, stat, seq, intr;
197         static int mac53c94_errors;
198
199         /*
200          * Apparently, reading the interrupt register unlatches
201          * the status and sequence step registers.
202          */
203         seq = readb(&regs->seqstep);
204         stat = readb(&regs->status);
205         intr = readb(&regs->interrupt);
206
207 #if 0
208         printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
209                intr, stat, seq, state->phase);
210 #endif
211
212         if (intr & INTR_RESET) {
213                 /* SCSI bus was reset */
214                 printk(KERN_INFO "external SCSI bus reset detected\n");
215                 writeb(CMD_NOP, &regs->command);
216                 writel(RUN << 16, &dma->control);       /* stop dma */
217                 cmd_done(state, DID_RESET << 16);
218                 return;
219         }
220         if (intr & INTR_ILL_CMD) {
221                 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
222                        intr, stat, seq, state->phase);
223                 cmd_done(state, DID_ERROR << 16);
224                 return;
225         }
226         if (stat & STAT_ERROR) {
227 #if 0
228                 /* XXX these seem to be harmless? */
229                 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
230                        intr, stat, seq, state->phase);
231 #endif
232                 ++mac53c94_errors;
233                 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
234         }
235         if (cmd == 0) {
236                 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
237                 return;
238         }
239         if (stat & STAT_PARITY) {
240                 printk(KERN_ERR "mac53c94: parity error\n");
241                 cmd_done(state, DID_PARITY << 16);
242                 return;
243         }
244         switch (state->phase) {
245         case selecting:
246                 if (intr & INTR_DISCONNECT) {
247                         /* selection timed out */
248                         cmd_done(state, DID_BAD_TARGET << 16);
249                         return;
250                 }
251                 if (intr != INTR_BUS_SERV + INTR_DONE) {
252                         printk(KERN_DEBUG "got intr %x during selection\n", intr);
253                         cmd_done(state, DID_ERROR << 16);
254                         return;
255                 }
256                 if ((seq & SS_MASK) != SS_DONE) {
257                         printk(KERN_DEBUG "seq step %x after command\n", seq);
258                         cmd_done(state, DID_ERROR << 16);
259                         return;
260                 }
261                 writeb(CMD_NOP, &regs->command);
262                 /* set DMA controller going if any data to transfer */
263                 if ((stat & (STAT_MSG|STAT_CD)) == 0
264                     && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {
265                         nb = cmd->SCp.this_residual;
266                         if (nb > 0xfff0)
267                                 nb = 0xfff0;
268                         cmd->SCp.this_residual -= nb;
269                         writeb(nb, &regs->count_lo);
270                         writeb(nb >> 8, &regs->count_mid);
271                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
272                         writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
273                         writel((RUN << 16) | RUN, &dma->control);
274                         writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
275                         state->phase = dataing;
276                         break;
277                 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
278                         /* up to status phase already */
279                         writeb(CMD_I_COMPLETE, &regs->command);
280                         state->phase = completing;
281                 } else {
282                         printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
283                                stat & STAT_PHASE);
284                         cmd_done(state, DID_ERROR << 16);
285                         return;
286                 }
287                 break;
288
289         case dataing:
290                 if (intr != INTR_BUS_SERV) {
291                         printk(KERN_DEBUG "got intr %x before status\n", intr);
292                         cmd_done(state, DID_ERROR << 16);
293                         return;
294                 }
295                 if (cmd->SCp.this_residual != 0
296                     && (stat & (STAT_MSG|STAT_CD)) == 0) {
297                         /* Set up the count regs to transfer more */
298                         nb = cmd->SCp.this_residual;
299                         if (nb > 0xfff0)
300                                 nb = 0xfff0;
301                         cmd->SCp.this_residual -= nb;
302                         writeb(nb, &regs->count_lo);
303                         writeb(nb >> 8, &regs->count_mid);
304                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
305                         writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
306                         break;
307                 }
308                 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
309                         printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
310                 }
311                 writel(RUN << 16, &dma->control);       /* stop dma */
312                 scsi_dma_unmap(cmd);
313                 /* should check dma status */
314                 writeb(CMD_I_COMPLETE, &regs->command);
315                 state->phase = completing;
316                 break;
317         case completing:
318                 if (intr != INTR_DONE) {
319                         printk(KERN_DEBUG "got intr %x on completion\n", intr);
320                         cmd_done(state, DID_ERROR << 16);
321                         return;
322                 }
323                 cmd->SCp.Status = readb(&regs->fifo);
324                 cmd->SCp.Message = readb(&regs->fifo);
325                 cmd->result = CMD_ACCEPT_MSG;
326                 writeb(CMD_ACCEPT_MSG, &regs->command);
327                 state->phase = busfreeing;
328                 break;
329         case busfreeing:
330                 if (intr != INTR_DISCONNECT) {
331                         printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
332                 }
333                 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
334                          + cmd->SCp.Status);
335                 break;
336         default:
337                 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
338         }
339 }
340
341 static void cmd_done(struct fsc_state *state, int result)
342 {
343         struct scsi_cmnd *cmd;
344
345         cmd = state->current_req;
346         if (cmd != 0) {
347                 cmd->result = result;
348                 (*cmd->scsi_done)(cmd);
349                 state->current_req = NULL;
350         }
351         state->phase = idle;
352         mac53c94_start(state);
353 }
354
355 /*
356  * Set up DMA commands for transferring data.
357  */
358 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
359 {
360         int i, dma_cmd, total, nseg;
361         struct scatterlist *scl;
362         struct dbdma_cmd *dcmds;
363         dma_addr_t dma_addr;
364         u32 dma_len;
365
366         nseg = scsi_dma_map(cmd);
367         BUG_ON(nseg < 0);
368         if (!nseg)
369                 return;
370
371         dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
372                         OUTPUT_MORE : INPUT_MORE;
373         dcmds = state->dma_cmds;
374         total = 0;
375
376         scsi_for_each_sg(cmd, scl, nseg, i) {
377                 dma_addr = sg_dma_address(scl);
378                 dma_len = sg_dma_len(scl);
379                 if (dma_len > 0xffff)
380                         panic("mac53c94: scatterlist element >= 64k");
381                 total += dma_len;
382                 st_le16(&dcmds->req_count, dma_len);
383                 st_le16(&dcmds->command, dma_cmd);
384                 st_le32(&dcmds->phy_addr, dma_addr);
385                 dcmds->xfer_status = 0;
386                 ++dcmds;
387         }
388
389         dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
390         st_le16(&dcmds[-1].command, dma_cmd);
391         st_le16(&dcmds->command, DBDMA_STOP);
392         cmd->SCp.this_residual = total;
393 }
394
395 static struct scsi_host_template mac53c94_template = {
396         .proc_name      = "53c94",
397         .name           = "53C94",
398         .queuecommand   = mac53c94_queue,
399         .eh_host_reset_handler = mac53c94_host_reset,
400         .can_queue      = 1,
401         .this_id        = 7,
402         .sg_tablesize   = SG_ALL,
403         .cmd_per_lun    = 1,
404         .use_clustering = DISABLE_CLUSTERING,
405 };
406
407 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
408 {
409         struct device_node *node = macio_get_of_node(mdev);
410         struct pci_dev *pdev = macio_get_pci_dev(mdev);
411         struct fsc_state *state;
412         struct Scsi_Host *host;
413         void *dma_cmd_space;
414         const unsigned char *clkprop;
415         int proplen, rc = -ENODEV;
416
417         if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
418                 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs"
419                        " (got %d/%d)\n",
420                        macio_resource_count(mdev), macio_irq_count(mdev));
421                 return -ENODEV;
422         }
423
424         if (macio_request_resources(mdev, "mac53c94") != 0) {
425                 printk(KERN_ERR "mac53c94: unable to request memory resources");
426                 return -EBUSY;
427         }
428
429         host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
430         if (host == NULL) {
431                 printk(KERN_ERR "mac53c94: couldn't register host");
432                 rc = -ENOMEM;
433                 goto out_release;
434         }
435
436         state = (struct fsc_state *) host->hostdata;
437         macio_set_drvdata(mdev, state);
438         state->host = host;
439         state->pdev = pdev;
440         state->mdev = mdev;
441
442         state->regs = (struct mac53c94_regs __iomem *)
443                 ioremap(macio_resource_start(mdev, 0), 0x1000);
444         state->intr = macio_irq(mdev, 0);
445         state->dma = (struct dbdma_regs __iomem *)
446                 ioremap(macio_resource_start(mdev, 1), 0x1000);
447         state->dmaintr = macio_irq(mdev, 1);
448         if (state->regs == NULL || state->dma == NULL) {
449                 printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
450                        node->full_name);
451                 goto out_free;
452         }
453
454         clkprop = of_get_property(node, "clock-frequency", &proplen);
455         if (clkprop == NULL || proplen != sizeof(int)) {
456                 printk(KERN_ERR "%s: can't get clock frequency, "
457                        "assuming 25MHz\n", node->full_name);
458                 state->clk_freq = 25000000;
459         } else
460                 state->clk_freq = *(int *)clkprop;
461
462         /* Space for dma command list: +1 for stop command,
463          * +1 to allow for aligning.
464          * XXX FIXME: Use DMA consistent routines
465          */
466         dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
467                                 sizeof(struct dbdma_cmd), GFP_KERNEL);
468         if (dma_cmd_space == 0) {
469                 printk(KERN_ERR "mac53c94: couldn't allocate dma "
470                        "command space for %s\n", node->full_name);
471                 rc = -ENOMEM;
472                 goto out_free;
473         }
474         state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);
475         memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
476                * sizeof(struct dbdma_cmd));
477         state->dma_cmd_space = dma_cmd_space;
478
479         mac53c94_init(state);
480
481         if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) {
482                 printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
483                        state->intr, node->full_name);
484                 goto out_free_dma;
485         }
486
487         rc = scsi_add_host(host, &mdev->ofdev.dev);
488         if (rc != 0)
489                 goto out_release_irq;
490
491         scsi_scan_host(host);
492         return 0;
493
494  out_release_irq:
495         free_irq(state->intr, state);
496  out_free_dma:
497         kfree(state->dma_cmd_space);
498  out_free:
499         if (state->dma != NULL)
500                 iounmap(state->dma);
501         if (state->regs != NULL)
502                 iounmap(state->regs);
503         scsi_host_put(host);
504  out_release:
505         macio_release_resources(mdev);
506
507         return rc;
508 }
509
510 static int mac53c94_remove(struct macio_dev *mdev)
511 {
512         struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
513         struct Scsi_Host *host = fp->host;
514
515         scsi_remove_host(host);
516
517         free_irq(fp->intr, fp);
518
519         if (fp->regs)
520                 iounmap(fp->regs);
521         if (fp->dma)
522                 iounmap(fp->dma);
523         kfree(fp->dma_cmd_space);
524
525         scsi_host_put(host);
526
527         macio_release_resources(mdev);
528
529         return 0;
530 }
531
532
533 static struct of_device_id mac53c94_match[] = 
534 {
535         {
536         .name           = "53c94",
537         },
538         {},
539 };
540 MODULE_DEVICE_TABLE (of, mac53c94_match);
541
542 static struct macio_driver mac53c94_driver = 
543 {
544         .name           = "mac53c94",
545         .match_table    = mac53c94_match,
546         .probe          = mac53c94_probe,
547         .remove         = mac53c94_remove,
548 };
549
550
551 static int __init init_mac53c94(void)
552 {
553         return macio_register_driver(&mac53c94_driver);
554 }
555
556 static void __exit exit_mac53c94(void)
557 {
558         return macio_unregister_driver(&mac53c94_driver);
559 }
560
561 module_init(init_mac53c94);
562 module_exit(exit_mac53c94);
563
564 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
565 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
566 MODULE_LICENSE("GPL");