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net: Refactor full duplex flow control resolution
[linux-2.6/mini2440.git] / drivers / scsi / mac53c94.c
blobb12ad7c7c6736908419987896a2402898ba2620e
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");
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