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treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / scsi / mac53c94.c
blob35d3e322d6d5137fa4625be901d5eec9ae4a2e33
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * SCSI low-level driver for the 53c94 SCSI bus adaptor found
4 * on Power Macintosh computers, controlling the external SCSI chain.
5 * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA)
6 * controller.
7 *
8 * Paul Mackerras, August 1996.
9 * Copyright (C) 1996 Paul Mackerras.
10 */
11 #include <linux/kernel.h>
12 #include <linux/delay.h>
13 #include <linux/types.h>
14 #include <linux/string.h>
15 #include <linux/slab.h>
16 #include <linux/blkdev.h>
17 #include <linux/proc_fs.h>
18 #include <linux/stat.h>
19 #include <linux/spinlock.h>
20 #include <linux/interrupt.h>
21 #include <linux/module.h>
22 #include <linux/pci.h>
23 #include <asm/dbdma.h>
24 #include <asm/io.h>
25 #include <asm/pgtable.h>
26 #include <asm/prom.h>
27 #include <asm/macio.h>
28
29 #include <scsi/scsi.h>
30 #include <scsi/scsi_cmnd.h>
31 #include <scsi/scsi_device.h>
32 #include <scsi/scsi_host.h>
33
34 #include "mac53c94.h"
35
36 enum fsc_phase {
37 idle,
38 selecting,
39 dataing,
40 completing,
41 busfreeing,
42 };
43
44 struct fsc_state {
45 struct mac53c94_regs __iomem *regs;
46 int intr;
47 struct dbdma_regs __iomem *dma;
48 int dmaintr;
49 int clk_freq;
50 struct Scsi_Host *host;
51 struct scsi_cmnd *request_q;
52 struct scsi_cmnd *request_qtail;
53 struct scsi_cmnd *current_req; /* req we're currently working on */
54 enum fsc_phase phase; /* what we're currently trying to do */
55 struct dbdma_cmd *dma_cmds; /* space for dbdma commands, aligned */
56 void *dma_cmd_space;
57 struct pci_dev *pdev;
58 dma_addr_t dma_addr;
59 struct macio_dev *mdev;
60 };
61
62 static void mac53c94_init(struct fsc_state *);
63 static void mac53c94_start(struct fsc_state *);
64 static void mac53c94_interrupt(int, void *);
65 static irqreturn_t do_mac53c94_interrupt(int, void *);
66 static void cmd_done(struct fsc_state *, int result);
67 static void set_dma_cmds(struct fsc_state *, struct scsi_cmnd *);
68
69
70 static int mac53c94_queue_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
71 {
72 struct fsc_state *state;
73
74 #if 0
75 if (cmd->sc_data_direction == DMA_TO_DEVICE) {
76 int i;
77 printk(KERN_DEBUG "mac53c94_queue %p: command is", cmd);
78 for (i = 0; i < cmd->cmd_len; ++i)
79 printk(KERN_CONT " %.2x", cmd->cmnd[i]);
80 printk(KERN_CONT "\n");
81 printk(KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",
82 scsi_sg_count(cmd), scsi_bufflen(cmd), scsi_sglist(cmd));
83 }
84 #endif
85
86 cmd->scsi_done = done;
87 cmd->host_scribble = NULL;
88
89 state = (struct fsc_state *) cmd->device->host->hostdata;
90
91 if (state->request_q == NULL)
92 state->request_q = cmd;
93 else
94 state->request_qtail->host_scribble = (void *) cmd;
95 state->request_qtail = cmd;
96
97 if (state->phase == idle)
98 mac53c94_start(state);
99
100 return 0;
101 }
102
103 static DEF_SCSI_QCMD(mac53c94_queue)
104
105 static int mac53c94_host_reset(struct scsi_cmnd *cmd)
106 {
107 struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;
108 struct mac53c94_regs __iomem *regs = state->regs;
109 struct dbdma_regs __iomem *dma = state->dma;
110 unsigned long flags;
111
112 spin_lock_irqsave(cmd->device->host->host_lock, flags);
113
114 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
115 writeb(CMD_SCSI_RESET, &regs->command); /* assert RST */
116 udelay(100); /* leave it on for a while (>= 25us) */
117 writeb(CMD_RESET, &regs->command);
118 udelay(20);
119 mac53c94_init(state);
120 writeb(CMD_NOP, &regs->command);
121
122 spin_unlock_irqrestore(cmd->device->host->host_lock, flags);
123 return SUCCESS;
124 }
125
126 static void mac53c94_init(struct fsc_state *state)
127 {
128 struct mac53c94_regs __iomem *regs = state->regs;
129 struct dbdma_regs __iomem *dma = state->dma;
130 int x;
131
132 writeb(state->host->this_id | CF1_PAR_ENABLE, &regs->config1);
133 writeb(TIMO_VAL(250), &regs->sel_timeout); /* 250ms */
134 writeb(CLKF_VAL(state->clk_freq), &regs->clk_factor);
135 writeb(CF2_FEATURE_EN, &regs->config2);
136 writeb(0, &regs->config3);
137 writeb(0, &regs->sync_period);
138 writeb(0, &regs->sync_offset);
139 x = readb(&regs->interrupt);
140 writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
141 }
142
143 /*
144 * Start the next command for a 53C94.
145 * Should be called with interrupts disabled.
146 */
147 static void mac53c94_start(struct fsc_state *state)
148 {
149 struct scsi_cmnd *cmd;
150 struct mac53c94_regs __iomem *regs = state->regs;
151 int i;
152
153 if (state->phase != idle || state->current_req != NULL)
154 panic("inappropriate mac53c94_start (state=%p)", state);
155 if (state->request_q == NULL)
156 return;
157 state->current_req = cmd = state->request_q;
158 state->request_q = (struct scsi_cmnd *) cmd->host_scribble;
159
160 /* Off we go */
161 writeb(0, &regs->count_lo);
162 writeb(0, &regs->count_mid);
163 writeb(0, &regs->count_hi);
164 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
165 udelay(1);
166 writeb(CMD_FLUSH, &regs->command);
167 udelay(1);
168 writeb(cmd->device->id, &regs->dest_id);
169 writeb(0, &regs->sync_period);
170 writeb(0, &regs->sync_offset);
171
172 /* load the command into the FIFO */
173 for (i = 0; i < cmd->cmd_len; ++i)
174 writeb(cmd->cmnd[i], &regs->fifo);
175
176 /* do select without ATN XXX */
177 writeb(CMD_SELECT, &regs->command);
178 state->phase = selecting;
179
180 set_dma_cmds(state, cmd);
181 }
182
183 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id)
184 {
185 unsigned long flags;
186 struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
187
188 spin_lock_irqsave(dev->host_lock, flags);
189 mac53c94_interrupt(irq, dev_id);
190 spin_unlock_irqrestore(dev->host_lock, flags);
191 return IRQ_HANDLED;
192 }
193
194 static void mac53c94_interrupt(int irq, void *dev_id)
195 {
196 struct fsc_state *state = (struct fsc_state *) dev_id;
197 struct mac53c94_regs __iomem *regs = state->regs;
198 struct dbdma_regs __iomem *dma = state->dma;
199 struct scsi_cmnd *cmd = state->current_req;
200 int nb, stat, seq, intr;
201 static int mac53c94_errors;
202
203 /*
204 * Apparently, reading the interrupt register unlatches
205 * the status and sequence step registers.
206 */
207 seq = readb(&regs->seqstep);
208 stat = readb(&regs->status);
209 intr = readb(&regs->interrupt);
210
211 #if 0
212 printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
213 intr, stat, seq, state->phase);
214 #endif
215
216 if (intr & INTR_RESET) {
217 /* SCSI bus was reset */
218 printk(KERN_INFO "external SCSI bus reset detected\n");
219 writeb(CMD_NOP, &regs->command);
220 writel(RUN << 16, &dma->control); /* stop dma */
221 cmd_done(state, DID_RESET << 16);
222 return;
223 }
224 if (intr & INTR_ILL_CMD) {
225 printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
226 intr, stat, seq, state->phase);
227 cmd_done(state, DID_ERROR << 16);
228 return;
229 }
230 if (stat & STAT_ERROR) {
231 #if 0
232 /* XXX these seem to be harmless? */
233 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
234 intr, stat, seq, state->phase);
235 #endif
236 ++mac53c94_errors;
237 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
238 }
239 if (cmd == 0) {
240 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
241 return;
242 }
243 if (stat & STAT_PARITY) {
244 printk(KERN_ERR "mac53c94: parity error\n");
245 cmd_done(state, DID_PARITY << 16);
246 return;
247 }
248 switch (state->phase) {
249 case selecting:
250 if (intr & INTR_DISCONNECT) {
251 /* selection timed out */
252 cmd_done(state, DID_BAD_TARGET << 16);
253 return;
254 }
255 if (intr != INTR_BUS_SERV + INTR_DONE) {
256 printk(KERN_DEBUG "got intr %x during selection\n", intr);
257 cmd_done(state, DID_ERROR << 16);
258 return;
259 }
260 if ((seq & SS_MASK) != SS_DONE) {
261 printk(KERN_DEBUG "seq step %x after command\n", seq);
262 cmd_done(state, DID_ERROR << 16);
263 return;
264 }
265 writeb(CMD_NOP, &regs->command);
266 /* set DMA controller going if any data to transfer */
267 if ((stat & (STAT_MSG|STAT_CD)) == 0
268 && (scsi_sg_count(cmd) > 0 || scsi_bufflen(cmd))) {
269 nb = cmd->SCp.this_residual;
270 if (nb > 0xfff0)
271 nb = 0xfff0;
272 cmd->SCp.this_residual -= nb;
273 writeb(nb, &regs->count_lo);
274 writeb(nb >> 8, &regs->count_mid);
275 writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
276 writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
277 writel((RUN << 16) | RUN, &dma->control);
278 writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
279 state->phase = dataing;
280 break;
281 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
282 /* up to status phase already */
283 writeb(CMD_I_COMPLETE, &regs->command);
284 state->phase = completing;
285 } else {
286 printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
287 stat & STAT_PHASE);
288 cmd_done(state, DID_ERROR << 16);
289 return;
290 }
291 break;
292
293 case dataing:
294 if (intr != INTR_BUS_SERV) {
295 printk(KERN_DEBUG "got intr %x before status\n", intr);
296 cmd_done(state, DID_ERROR << 16);
297 return;
298 }
299 if (cmd->SCp.this_residual != 0
300 && (stat & (STAT_MSG|STAT_CD)) == 0) {
301 /* Set up the count regs to transfer more */
302 nb = cmd->SCp.this_residual;
303 if (nb > 0xfff0)
304 nb = 0xfff0;
305 cmd->SCp.this_residual -= nb;
306 writeb(nb, &regs->count_lo);
307 writeb(nb >> 8, &regs->count_mid);
308 writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
309 writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
310 break;
311 }
312 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
313 printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
314 }
315 writel(RUN << 16, &dma->control); /* stop dma */
316 scsi_dma_unmap(cmd);
317 /* should check dma status */
318 writeb(CMD_I_COMPLETE, &regs->command);
319 state->phase = completing;
320 break;
321 case completing:
322 if (intr != INTR_DONE) {
323 printk(KERN_DEBUG "got intr %x on completion\n", intr);
324 cmd_done(state, DID_ERROR << 16);
325 return;
326 }
327 cmd->SCp.Status = readb(&regs->fifo);
328 cmd->SCp.Message = readb(&regs->fifo);
329 cmd->result = CMD_ACCEPT_MSG;
330 writeb(CMD_ACCEPT_MSG, &regs->command);
331 state->phase = busfreeing;
332 break;
333 case busfreeing:
334 if (intr != INTR_DISCONNECT) {
335 printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
336 }
337 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
338 + cmd->SCp.Status);
339 break;
340 default:
341 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
342 }
343 }
344
345 static void cmd_done(struct fsc_state *state, int result)
346 {
347 struct scsi_cmnd *cmd;
348
349 cmd = state->current_req;
350 if (cmd != 0) {
351 cmd->result = result;
352 (*cmd->scsi_done)(cmd);
353 state->current_req = NULL;
354 }
355 state->phase = idle;
356 mac53c94_start(state);
357 }
358
359 /*
360 * Set up DMA commands for transferring data.
361 */
362 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
363 {
364 int i, dma_cmd, total, nseg;
365 struct scatterlist *scl;
366 struct dbdma_cmd *dcmds;
367 dma_addr_t dma_addr;
368 u32 dma_len;
369
370 nseg = scsi_dma_map(cmd);
371 BUG_ON(nseg < 0);
372 if (!nseg)
373 return;
374
375 dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
376 OUTPUT_MORE : INPUT_MORE;
377 dcmds = state->dma_cmds;
378 total = 0;
379
380 scsi_for_each_sg(cmd, scl, nseg, i) {
381 dma_addr = sg_dma_address(scl);
382 dma_len = sg_dma_len(scl);
383 if (dma_len > 0xffff)
384 panic("mac53c94: scatterlist element >= 64k");
385 total += dma_len;
386 dcmds->req_count = cpu_to_le16(dma_len);
387 dcmds->command = cpu_to_le16(dma_cmd);
388 dcmds->phy_addr = cpu_to_le32(dma_addr);
389 dcmds->xfer_status = 0;
390 ++dcmds;
391 }
392
393 dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
394 dcmds[-1].command = cpu_to_le16(dma_cmd);
395 dcmds->command = cpu_to_le16(DBDMA_STOP);
396 cmd->SCp.this_residual = total;
397 }
398
399 static struct scsi_host_template mac53c94_template = {
400 .proc_name = "53c94",
401 .name = "53C94",
402 .queuecommand = mac53c94_queue,
403 .eh_host_reset_handler = mac53c94_host_reset,
404 .can_queue = 1,
405 .this_id = 7,
406 .sg_tablesize = SG_ALL,
407 .max_segment_size = 65535,
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 %pOF\n", node);
453 goto out_free;
454 }
455
456 clkprop = of_get_property(node, "clock-frequency", &proplen);
457 if (clkprop == NULL || proplen != sizeof(int)) {
458 printk(KERN_ERR "%pOF: can't get clock frequency, "
459 "assuming 25MHz\n", node);
460 state->clk_freq = 25000000;
461 } else
462 state->clk_freq = *(int *)clkprop;
463
464 /* Space for dma command list: +1 for stop command,
465 * +1 to allow for aligning.
466 * XXX FIXME: Use DMA consistent routines
467 */
468 dma_cmd_space = kmalloc_array(host->sg_tablesize + 2,
469 sizeof(struct dbdma_cmd),
470 GFP_KERNEL);
471 if (dma_cmd_space == 0) {
472 printk(KERN_ERR "mac53c94: couldn't allocate dma "
473 "command space for %pOF\n", node);
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 %pOF\n",
486 state->intr, node);
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");
Linux with added FPC-III support