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Linux/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 <linux/module.h>
 21 #include <asm/dbdma.h>
 22 #include <asm/io.h>
 23 #include <asm/pgtable.h>
 24 #include <asm/prom.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_lck(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 DEF_SCSI_QCMD(mac53c94_queue)
103 
104 static int mac53c94_host_reset(struct scsi_cmnd *cmd)
105 {
106         struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;
107         struct mac53c94_regs __iomem *regs = state->regs;
108         struct dbdma_regs __iomem *dma = state->dma;
109         unsigned long flags;
110 
111         spin_lock_irqsave(cmd->device->host->host_lock, flags);
112 
113         writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
114         writeb(CMD_SCSI_RESET, &regs->command); /* assert RST */
115         udelay(100);                    /* leave it on for a while (>= 25us) */
116         writeb(CMD_RESET, &regs->command);
117         udelay(20);
118         mac53c94_init(state);
119         writeb(CMD_NOP, &regs->command);
120 
121         spin_unlock_irqrestore(cmd->device->host->host_lock, flags);
122         return SUCCESS;
123 }
124 
125 static void mac53c94_init(struct fsc_state *state)
126 {
127         struct mac53c94_regs __iomem *regs = state->regs;
128         struct dbdma_regs __iomem *dma = state->dma;
129         int x;
130 
131         writeb(state->host->this_id | CF1_PAR_ENABLE, &regs->config1);
132         writeb(TIMO_VAL(250), &regs->sel_timeout);      /* 250ms */
133         writeb(CLKF_VAL(state->clk_freq), &regs->clk_factor);
134         writeb(CF2_FEATURE_EN, &regs->config2);
135         writeb(0, &regs->config3);
136         writeb(0, &regs->sync_period);
137         writeb(0, &regs->sync_offset);
138         x = readb(&regs->interrupt);
139         writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
140 }
141 
142 /*
143  * Start the next command for a 53C94.
144  * Should be called with interrupts disabled.
145  */
146 static void mac53c94_start(struct fsc_state *state)
147 {
148         struct scsi_cmnd *cmd;
149         struct mac53c94_regs __iomem *regs = state->regs;
150         int i;
151 
152         if (state->phase != idle || state->current_req != NULL)
153                 panic("inappropriate mac53c94_start (state=%p)", state);
154         if (state->request_q == NULL)
155                 return;
156         state->current_req = cmd = state->request_q;
157         state->request_q = (struct scsi_cmnd *) cmd->host_scribble;
158 
159         /* Off we go */
160         writeb(0, &regs->count_lo);
161         writeb(0, &regs->count_mid);
162         writeb(0, &regs->count_hi);
163         writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
164         udelay(1);
165         writeb(CMD_FLUSH, &regs->command);
166         udelay(1);
167         writeb(cmd->device->id, &regs->dest_id);
168         writeb(0, &regs->sync_period);
169         writeb(0, &regs->sync_offset);
170 
171         /* load the command into the FIFO */
172         for (i = 0; i < cmd->cmd_len; ++i)
173                 writeb(cmd->cmnd[i], &regs->fifo);
174 
175         /* do select without ATN XXX */
176         writeb(CMD_SELECT, &regs->command);
177         state->phase = selecting;
178 
179         set_dma_cmds(state, cmd);
180 }
181 
182 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id)
183 {
184         unsigned long flags;
185         struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
186         
187         spin_lock_irqsave(dev->host_lock, flags);
188         mac53c94_interrupt(irq, dev_id);
189         spin_unlock_irqrestore(dev->host_lock, flags);
190         return IRQ_HANDLED;
191 }
192 
193 static void mac53c94_interrupt(int irq, void *dev_id)
194 {
195         struct fsc_state *state = (struct fsc_state *) dev_id;
196         struct mac53c94_regs __iomem *regs = state->regs;
197         struct dbdma_regs __iomem *dma = state->dma;
198         struct scsi_cmnd *cmd = state->current_req;
199         int nb, stat, seq, intr;
200         static int mac53c94_errors;
201 
202         /*
203          * Apparently, reading the interrupt register unlatches
204          * the status and sequence step registers.
205          */
206         seq = readb(&regs->seqstep);
207         stat = readb(&regs->status);
208         intr = readb(&regs->interrupt);
209 
210 #if 0
211         printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
212                intr, stat, seq, state->phase);
213 #endif
214 
215         if (intr & INTR_RESET) {
216                 /* SCSI bus was reset */
217                 printk(KERN_INFO "external SCSI bus reset detected\n");
218                 writeb(CMD_NOP, &regs->command);
219                 writel(RUN << 16, &dma->control);       /* stop dma */
220                 cmd_done(state, DID_RESET << 16);
221                 return;
222         }
223         if (intr & INTR_ILL_CMD) {
224                 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
225                        intr, stat, seq, state->phase);
226                 cmd_done(state, DID_ERROR << 16);
227                 return;
228         }
229         if (stat & STAT_ERROR) {
230 #if 0
231                 /* XXX these seem to be harmless? */
232                 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
233                        intr, stat, seq, state->phase);
234 #endif
235                 ++mac53c94_errors;
236                 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
237         }
238         if (cmd == 0) {
239                 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
240                 return;
241         }
242         if (stat & STAT_PARITY) {
243                 printk(KERN_ERR "mac53c94: parity error\n");
244                 cmd_done(state, DID_PARITY << 16);
245                 return;
246         }
247         switch (state->phase) {
248         case selecting:
249                 if (intr & INTR_DISCONNECT) {
250                         /* selection timed out */
251                         cmd_done(state, DID_BAD_TARGET << 16);
252                         return;
253                 }
254                 if (intr != INTR_BUS_SERV + INTR_DONE) {
255                         printk(KERN_DEBUG "got intr %x during selection\n", intr);
256                         cmd_done(state, DID_ERROR << 16);
257                         return;
258                 }
259                 if ((seq & SS_MASK) != SS_DONE) {
260                         printk(KERN_DEBUG "seq step %x after command\n", seq);
261                         cmd_done(state, DID_ERROR << 16);
262                         return;
263                 }
264                 writeb(CMD_NOP, &regs->command);
265                 /* set DMA controller going if any data to transfer */
266                 if ((stat & (STAT_MSG|STAT_CD)) == 0
267                     && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {
268                         nb = cmd->SCp.this_residual;
269                         if (nb > 0xfff0)
270                                 nb = 0xfff0;
271                         cmd->SCp.this_residual -= nb;
272                         writeb(nb, &regs->count_lo);
273                         writeb(nb >> 8, &regs->count_mid);
274                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
275                         writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
276                         writel((RUN << 16) | RUN, &dma->control);
277                         writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
278                         state->phase = dataing;
279                         break;
280                 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
281                         /* up to status phase already */
282                         writeb(CMD_I_COMPLETE, &regs->command);
283                         state->phase = completing;
284                 } else {
285                         printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
286                                stat & STAT_PHASE);
287                         cmd_done(state, DID_ERROR << 16);
288                         return;
289                 }
290                 break;
291 
292         case dataing:
293                 if (intr != INTR_BUS_SERV) {
294                         printk(KERN_DEBUG "got intr %x before status\n", intr);
295                         cmd_done(state, DID_ERROR << 16);
296                         return;
297                 }
298                 if (cmd->SCp.this_residual != 0
299                     && (stat & (STAT_MSG|STAT_CD)) == 0) {
300                         /* Set up the count regs to transfer more */
301                         nb = cmd->SCp.this_residual;
302                         if (nb > 0xfff0)
303                                 nb = 0xfff0;
304                         cmd->SCp.this_residual -= nb;
305                         writeb(nb, &regs->count_lo);
306                         writeb(nb >> 8, &regs->count_mid);
307                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
308                         writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
309                         break;
310                 }
311                 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
312                         printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
313                 }
314                 writel(RUN << 16, &dma->control);       /* stop dma */
315                 scsi_dma_unmap(cmd);
316                 /* should check dma status */
317                 writeb(CMD_I_COMPLETE, &regs->command);
318                 state->phase = completing;
319                 break;
320         case completing:
321                 if (intr != INTR_DONE) {
322                         printk(KERN_DEBUG "got intr %x on completion\n", intr);
323                         cmd_done(state, DID_ERROR << 16);
324                         return;
325                 }
326                 cmd->SCp.Status = readb(&regs->fifo);
327                 cmd->SCp.Message = readb(&regs->fifo);
328                 cmd->result = CMD_ACCEPT_MSG;
329                 writeb(CMD_ACCEPT_MSG, &regs->command);
330                 state->phase = busfreeing;
331                 break;
332         case busfreeing:
333                 if (intr != INTR_DISCONNECT) {
334                         printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
335                 }
336                 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
337                          + cmd->SCp.Status);
338                 break;
339         default:
340                 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
341         }
342 }
343 
344 static void cmd_done(struct fsc_state *state, int result)
345 {
346         struct scsi_cmnd *cmd;
347 
348         cmd = state->current_req;
349         if (cmd != 0) {
350                 cmd->result = result;
351                 (*cmd->scsi_done)(cmd);
352                 state->current_req = NULL;
353         }
354         state->phase = idle;
355         mac53c94_start(state);
356 }
357 
358 /*
359  * Set up DMA commands for transferring data.
360  */
361 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
362 {
363         int i, dma_cmd, total, nseg;
364         struct scatterlist *scl;
365         struct dbdma_cmd *dcmds;
366         dma_addr_t dma_addr;
367         u32 dma_len;
368 
369         nseg = scsi_dma_map(cmd);
370         BUG_ON(nseg < 0);
371         if (!nseg)
372                 return;
373 
374         dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
375                         OUTPUT_MORE : INPUT_MORE;
376         dcmds = state->dma_cmds;
377         total = 0;
378 
379         scsi_for_each_sg(cmd, scl, nseg, i) {
380                 dma_addr = sg_dma_address(scl);
381                 dma_len = sg_dma_len(scl);
382                 if (dma_len > 0xffff)
383                         panic("mac53c94: scatterlist element >= 64k");
384                 total += dma_len;
385                 st_le16(&dcmds->req_count, dma_len);
386                 st_le16(&dcmds->command, dma_cmd);
387                 st_le32(&dcmds->phy_addr, dma_addr);
388                 dcmds->xfer_status = 0;
389                 ++dcmds;
390         }
391 
392         dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
393         st_le16(&dcmds[-1].command, dma_cmd);
394         st_le16(&dcmds->command, DBDMA_STOP);
395         cmd->SCp.this_residual = total;
396 }
397 
398 static struct scsi_host_template mac53c94_template = {
399         .proc_name      = "53c94",
400         .name           = "53C94",
401         .queuecommand   = mac53c94_queue,
402         .eh_host_reset_handler = mac53c94_host_reset,
403         .can_queue      = 1,
404         .this_id        = 7,
405         .sg_tablesize   = SG_ALL,
406         .cmd_per_lun    = 1,
407         .use_clustering = DISABLE_CLUSTERING,
408 };
409 
410 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
411 {
412         struct device_node *node = macio_get_of_node(mdev);
413         struct pci_dev *pdev = macio_get_pci_dev(mdev);
414         struct fsc_state *state;
415         struct Scsi_Host *host;
416         void *dma_cmd_space;
417         const unsigned char *clkprop;
418         int proplen, rc = -ENODEV;
419 
420         if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
421                 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs"
422                        " (got %d/%d)\n",
423                        macio_resource_count(mdev), macio_irq_count(mdev));
424                 return -ENODEV;
425         }
426 
427         if (macio_request_resources(mdev, "mac53c94") != 0) {
428                 printk(KERN_ERR "mac53c94: unable to request memory resources");
429                 return -EBUSY;
430         }
431 
432         host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
433         if (host == NULL) {
434                 printk(KERN_ERR "mac53c94: couldn't register host");
435                 rc = -ENOMEM;
436                 goto out_release;
437         }
438 
439         state = (struct fsc_state *) host->hostdata;
440         macio_set_drvdata(mdev, state);
441         state->host = host;
442         state->pdev = pdev;
443         state->mdev = mdev;
444 
445         state->regs = (struct mac53c94_regs __iomem *)
446                 ioremap(macio_resource_start(mdev, 0), 0x1000);
447         state->intr = macio_irq(mdev, 0);
448         state->dma = (struct dbdma_regs __iomem *)
449                 ioremap(macio_resource_start(mdev, 1), 0x1000);
450         state->dmaintr = macio_irq(mdev, 1);
451         if (state->regs == NULL || state->dma == NULL) {
452                 printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
453                        node->full_name);
454                 goto out_free;
455         }
456 
457         clkprop = of_get_property(node, "clock-frequency", &proplen);
458         if (clkprop == NULL || proplen != sizeof(int)) {
459                 printk(KERN_ERR "%s: can't get clock frequency, "
460                        "assuming 25MHz\n", node->full_name);
461                 state->clk_freq = 25000000;
462         } else
463                 state->clk_freq = *(int *)clkprop;
464 
465         /* Space for dma command list: +1 for stop command,
466          * +1 to allow for aligning.
467          * XXX FIXME: Use DMA consistent routines
468          */
469         dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
470                                 sizeof(struct dbdma_cmd), GFP_KERNEL);
471         if (dma_cmd_space == 0) {
472                 printk(KERN_ERR "mac53c94: couldn't allocate dma "
473                        "command space for %s\n", node->full_name);
474                 rc = -ENOMEM;
475                 goto out_free;
476         }
477         state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);
478         memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
479                * sizeof(struct dbdma_cmd));
480         state->dma_cmd_space = dma_cmd_space;
481 
482         mac53c94_init(state);
483 
484         if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94",state)) {
485                 printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
486                        state->intr, node->full_name);
487                 goto out_free_dma;
488         }
489 
490         rc = scsi_add_host(host, &mdev->ofdev.dev);
491         if (rc != 0)
492                 goto out_release_irq;
493 
494         scsi_scan_host(host);
495         return 0;
496 
497  out_release_irq:
498         free_irq(state->intr, state);
499  out_free_dma:
500         kfree(state->dma_cmd_space);
501  out_free:
502         if (state->dma != NULL)
503                 iounmap(state->dma);
504         if (state->regs != NULL)
505                 iounmap(state->regs);
506         scsi_host_put(host);
507  out_release:
508         macio_release_resources(mdev);
509 
510         return rc;
511 }
512 
513 static int mac53c94_remove(struct macio_dev *mdev)
514 {
515         struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
516         struct Scsi_Host *host = fp->host;
517 
518         scsi_remove_host(host);
519 
520         free_irq(fp->intr, fp);
521 
522         if (fp->regs)
523                 iounmap(fp->regs);
524         if (fp->dma)
525                 iounmap(fp->dma);
526         kfree(fp->dma_cmd_space);
527 
528         scsi_host_put(host);
529 
530         macio_release_resources(mdev);
531 
532         return 0;
533 }
534 
535 
536 static struct of_device_id mac53c94_match[] = 
537 {
538         {
539         .name           = "53c94",
540         },
541         {},
542 };
543 MODULE_DEVICE_TABLE (of, mac53c94_match);
544 
545 static struct macio_driver mac53c94_driver = 
546 {
547         .driver = {
548                 .name           = "mac53c94",
549                 .owner          = THIS_MODULE,
550                 .of_match_table = mac53c94_match,
551         },
552         .probe          = mac53c94_probe,
553         .remove         = mac53c94_remove,
554 };
555 
556 
557 static int __init init_mac53c94(void)
558 {
559         return macio_register_driver(&mac53c94_driver);
560 }
561 
562 static void __exit exit_mac53c94(void)
563 {
564         return macio_unregister_driver(&mac53c94_driver);
565 }
566 
567 module_init(init_mac53c94);
568 module_exit(exit_mac53c94);
569 
570 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
571 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
572 MODULE_LICENSE("GPL");
573 

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