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Fix gcc 4.5.1 miscompiling drivers/char/i8k.c (again)
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / scsi / mac_esp.c
blobc24e86f07804fe5e77d01d6d4c828a72ca0bf7d1
1 /* mac_esp.c: ESP front-end for Macintosh Quadra systems.
2 *
3 * Adapted from jazz_esp.c and the old mac_esp.c.
4 *
5 * The pseudo DMA algorithm is based on the one used in NetBSD.
6 * See sys/arch/mac68k/obio/esp.c for some background information.
7 *
8 * Copyright (C) 2007-2008 Finn Thain
9 */
10
11 #include <linux/kernel.h>
12 #include <linux/types.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/platform_device.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/scatterlist.h>
19 #include <linux/delay.h>
20 #include <linux/io.h>
21 #include <linux/nubus.h>
22
23 #include <asm/irq.h>
24 #include <asm/dma.h>
25
26 #include <asm/macints.h>
27 #include <asm/macintosh.h>
28
29 #include <scsi/scsi_host.h>
30
31 #include "esp_scsi.h"
32
33 #define DRV_MODULE_NAME "mac_esp"
34 #define PFX DRV_MODULE_NAME ": "
35 #define DRV_VERSION "1.000"
36 #define DRV_MODULE_RELDATE "Sept 15, 2007"
37
38 #define MAC_ESP_IO_BASE 0x50F00000
39 #define MAC_ESP_REGS_QUADRA (MAC_ESP_IO_BASE + 0x10000)
40 #define MAC_ESP_REGS_QUADRA2 (MAC_ESP_IO_BASE + 0xF000)
41 #define MAC_ESP_REGS_QUADRA3 (MAC_ESP_IO_BASE + 0x18000)
42 #define MAC_ESP_REGS_SPACING 0x402
43 #define MAC_ESP_PDMA_REG 0xF9800024
44 #define MAC_ESP_PDMA_REG_SPACING 0x4
45 #define MAC_ESP_PDMA_IO_OFFSET 0x100
46
47 #define esp_read8(REG) mac_esp_read8(esp, REG)
48 #define esp_write8(VAL, REG) mac_esp_write8(esp, VAL, REG)
49
50 struct mac_esp_priv {
51 struct esp *esp;
52 void __iomem *pdma_regs;
53 void __iomem *pdma_io;
54 int error;
55 };
56 static struct platform_device *internal_pdev, *external_pdev;
57 static struct esp *esp_chips[2];
58
59 #define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \
60 platform_get_drvdata((struct platform_device *) \
61 (esp->dev)))
62
63 static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg)
64 {
65 nubus_writeb(val, esp->regs + reg * 16);
66 }
67
68 static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg)
69 {
70 return nubus_readb(esp->regs + reg * 16);
71 }
72
73 /* For pseudo DMA and PIO we need the virtual address
74 * so this address mapping is the identity mapping.
75 */
76
77 static dma_addr_t mac_esp_map_single(struct esp *esp, void *buf,
78 size_t sz, int dir)
79 {
80 return (dma_addr_t)buf;
81 }
82
83 static int mac_esp_map_sg(struct esp *esp, struct scatterlist *sg,
84 int num_sg, int dir)
85 {
86 int i;
87
88 for (i = 0; i < num_sg; i++)
89 sg[i].dma_address = (u32)sg_virt(&sg[i]);
90 return num_sg;
91 }
92
93 static void mac_esp_unmap_single(struct esp *esp, dma_addr_t addr,
94 size_t sz, int dir)
95 {
96 /* Nothing to do. */
97 }
98
99 static void mac_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
100 int num_sg, int dir)
101 {
102 /* Nothing to do. */
103 }
104
105 static void mac_esp_reset_dma(struct esp *esp)
106 {
107 /* Nothing to do. */
108 }
109
110 static void mac_esp_dma_drain(struct esp *esp)
111 {
112 /* Nothing to do. */
113 }
114
115 static void mac_esp_dma_invalidate(struct esp *esp)
116 {
117 /* Nothing to do. */
118 }
119
120 static int mac_esp_dma_error(struct esp *esp)
121 {
122 return MAC_ESP_GET_PRIV(esp)->error;
123 }
124
125 static inline int mac_esp_wait_for_empty_fifo(struct esp *esp)
126 {
127 struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
128 int i = 500000;
129
130 do {
131 if (!(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES))
132 return 0;
133
134 if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
135 return 1;
136
137 udelay(2);
138 } while (--i);
139
140 printk(KERN_ERR PFX "FIFO is not empty (sreg %02x)\n",
141 esp_read8(ESP_STATUS));
142 mep->error = 1;
143 return 1;
144 }
145
146 static inline int mac_esp_wait_for_dreq(struct esp *esp)
147 {
148 struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
149 int i = 500000;
150
151 do {
152 if (mep->pdma_regs == NULL) {
153 if (mac_irq_pending(IRQ_MAC_SCSIDRQ))
154 return 0;
155 } else {
156 if (nubus_readl(mep->pdma_regs) & 0x200)
157 return 0;
158 }
159
160 if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
161 return 1;
162
163 udelay(2);
164 } while (--i);
165
166 printk(KERN_ERR PFX "PDMA timeout (sreg %02x)\n",
167 esp_read8(ESP_STATUS));
168 mep->error = 1;
169 return 1;
170 }
171
172 #define MAC_ESP_PDMA_LOOP(operands) \
173 asm volatile ( \
174 " tstw %1 \n" \
175 " jbeq 20f \n" \
176 "1: movew " operands " \n" \
177 "2: movew " operands " \n" \
178 "3: movew " operands " \n" \
179 "4: movew " operands " \n" \
180 "5: movew " operands " \n" \
181 "6: movew " operands " \n" \
182 "7: movew " operands " \n" \
183 "8: movew " operands " \n" \
184 "9: movew " operands " \n" \
185 "10: movew " operands " \n" \
186 "11: movew " operands " \n" \
187 "12: movew " operands " \n" \
188 "13: movew " operands " \n" \
189 "14: movew " operands " \n" \
190 "15: movew " operands " \n" \
191 "16: movew " operands " \n" \
192 " subqw #1,%1 \n" \
193 " jbne 1b \n" \
194 "20: tstw %2 \n" \
195 " jbeq 30f \n" \
196 "21: movew " operands " \n" \
197 " subqw #1,%2 \n" \
198 " jbne 21b \n" \
199 "30: tstw %3 \n" \
200 " jbeq 40f \n" \
201 "31: moveb " operands " \n" \
202 "32: nop \n" \
203 "40: \n" \
204 " \n" \
205 " .section __ex_table,\"a\" \n" \
206 " .align 4 \n" \
207 " .long 1b,40b \n" \
208 " .long 2b,40b \n" \
209 " .long 3b,40b \n" \
210 " .long 4b,40b \n" \
211 " .long 5b,40b \n" \
212 " .long 6b,40b \n" \
213 " .long 7b,40b \n" \
214 " .long 8b,40b \n" \
215 " .long 9b,40b \n" \
216 " .long 10b,40b \n" \
217 " .long 11b,40b \n" \
218 " .long 12b,40b \n" \
219 " .long 13b,40b \n" \
220 " .long 14b,40b \n" \
221 " .long 15b,40b \n" \
222 " .long 16b,40b \n" \
223 " .long 21b,40b \n" \
224 " .long 31b,40b \n" \
225 " .long 32b,40b \n" \
226 " .previous \n" \
227 : "+a" (addr), "+r" (count32), "+r" (count2) \
228 : "g" (count1), "a" (mep->pdma_io))
229
230 static void mac_esp_send_pdma_cmd(struct esp *esp, u32 addr, u32 esp_count,
231 u32 dma_count, int write, u8 cmd)
232 {
233 struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
234 unsigned long flags;
235
236 local_irq_save(flags);
237
238 mep->error = 0;
239
240 if (!write)
241 scsi_esp_cmd(esp, ESP_CMD_FLUSH);
242
243 esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW);
244 esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED);
245
246 scsi_esp_cmd(esp, cmd);
247
248 do {
249 unsigned int count32 = esp_count >> 5;
250 unsigned int count2 = (esp_count & 0x1F) >> 1;
251 unsigned int count1 = esp_count & 1;
252 unsigned int start_addr = addr;
253
254 if (mac_esp_wait_for_dreq(esp))
255 break;
256
257 if (write) {
258 MAC_ESP_PDMA_LOOP("%4@,%0@+");
259
260 esp_count -= addr - start_addr;
261 } else {
262 unsigned int n;
263
264 MAC_ESP_PDMA_LOOP("%0@+,%4@");
265
266 if (mac_esp_wait_for_empty_fifo(esp))
267 break;
268
269 n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW);
270 addr = start_addr + esp_count - n;
271 esp_count = n;
272 }
273 } while (esp_count);
274
275 local_irq_restore(flags);
276 }
277
278 /*
279 * Programmed IO routines follow.
280 */
281
282 static inline int mac_esp_wait_for_fifo(struct esp *esp)
283 {
284 int i = 500000;
285
286 do {
287 if (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES)
288 return 0;
289
290 udelay(2);
291 } while (--i);
292
293 printk(KERN_ERR PFX "FIFO is empty (sreg %02x)\n",
294 esp_read8(ESP_STATUS));
295 return 1;
296 }
297
298 static inline int mac_esp_wait_for_intr(struct esp *esp)
299 {
300 int i = 500000;
301
302 do {
303 esp->sreg = esp_read8(ESP_STATUS);
304 if (esp->sreg & ESP_STAT_INTR)
305 return 0;
306
307 udelay(2);
308 } while (--i);
309
310 printk(KERN_ERR PFX "IRQ timeout (sreg %02x)\n", esp->sreg);
311 return 1;
312 }
313
314 #define MAC_ESP_PIO_LOOP(operands, reg1) \
315 asm volatile ( \
316 "1: moveb " operands " \n" \
317 " subqw #1,%1 \n" \
318 " jbne 1b \n" \
319 : "+a" (addr), "+r" (reg1) \
320 : "a" (fifo))
321
322 #define MAC_ESP_PIO_FILL(operands, reg1) \
323 asm volatile ( \
324 " moveb " operands " \n" \
325 " moveb " operands " \n" \
326 " moveb " operands " \n" \
327 " moveb " operands " \n" \
328 " moveb " operands " \n" \
329 " moveb " operands " \n" \
330 " moveb " operands " \n" \
331 " moveb " operands " \n" \
332 " moveb " operands " \n" \
333 " moveb " operands " \n" \
334 " moveb " operands " \n" \
335 " moveb " operands " \n" \
336 " moveb " operands " \n" \
337 " moveb " operands " \n" \
338 " moveb " operands " \n" \
339 " moveb " operands " \n" \
340 " subqw #8,%1 \n" \
341 " subqw #8,%1 \n" \
342 : "+a" (addr), "+r" (reg1) \
343 : "a" (fifo))
344
345 #define MAC_ESP_FIFO_SIZE 16
346
347 static void mac_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count,
348 u32 dma_count, int write, u8 cmd)
349 {
350 unsigned long flags;
351 struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
352 u8 *fifo = esp->regs + ESP_FDATA * 16;
353
354 local_irq_save(flags);
355
356 cmd &= ~ESP_CMD_DMA;
357 mep->error = 0;
358
359 if (write) {
360 scsi_esp_cmd(esp, cmd);
361
362 if (!mac_esp_wait_for_intr(esp)) {
363 if (mac_esp_wait_for_fifo(esp))
364 esp_count = 0;
365 } else {
366 esp_count = 0;
367 }
368 } else {
369 scsi_esp_cmd(esp, ESP_CMD_FLUSH);
370
371 if (esp_count >= MAC_ESP_FIFO_SIZE)
372 MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
373 else
374 MAC_ESP_PIO_LOOP("%0@+,%2@", esp_count);
375
376 scsi_esp_cmd(esp, cmd);
377 }
378
379 while (esp_count) {
380 unsigned int n;
381
382 if (mac_esp_wait_for_intr(esp)) {
383 mep->error = 1;
384 break;
385 }
386
387 if (esp->sreg & ESP_STAT_SPAM) {
388 printk(KERN_ERR PFX "gross error\n");
389 mep->error = 1;
390 break;
391 }
392
393 n = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
394
395 if (write) {
396 if (n > esp_count)
397 n = esp_count;
398 esp_count -= n;
399
400 MAC_ESP_PIO_LOOP("%2@,%0@+", n);
401
402 if ((esp->sreg & ESP_STAT_PMASK) == ESP_STATP)
403 break;
404
405 if (esp_count) {
406 esp->ireg = esp_read8(ESP_INTRPT);
407 if (esp->ireg & ESP_INTR_DC)
408 break;
409
410 scsi_esp_cmd(esp, ESP_CMD_TI);
411 }
412 } else {
413 esp->ireg = esp_read8(ESP_INTRPT);
414 if (esp->ireg & ESP_INTR_DC)
415 break;
416
417 n = MAC_ESP_FIFO_SIZE - n;
418 if (n > esp_count)
419 n = esp_count;
420
421 if (n == MAC_ESP_FIFO_SIZE) {
422 MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
423 } else {
424 esp_count -= n;
425 MAC_ESP_PIO_LOOP("%0@+,%2@", n);
426 }
427
428 scsi_esp_cmd(esp, ESP_CMD_TI);
429 }
430 }
431
432 local_irq_restore(flags);
433 }
434
435 static int mac_esp_irq_pending(struct esp *esp)
436 {
437 if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
438 return 1;
439 return 0;
440 }
441
442 static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
443 {
444 return dma_len > 0xFFFF ? 0xFFFF : dma_len;
445 }
446
447 static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id)
448 {
449 int got_intr;
450
451 /*
452 * This is an edge triggered IRQ, so we have to be careful to
453 * avoid missing a transition when it is shared by two ESP devices.
454 */
455
456 do {
457 got_intr = 0;
458 if (esp_chips[0] &&
459 (mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) {
460 (void)scsi_esp_intr(irq, esp_chips[0]);
461 got_intr = 1;
462 }
463 if (esp_chips[1] &&
464 (mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) {
465 (void)scsi_esp_intr(irq, esp_chips[1]);
466 got_intr = 1;
467 }
468 } while (got_intr);
469
470 return IRQ_HANDLED;
471 }
472
473 static struct esp_driver_ops mac_esp_ops = {
474 .esp_write8 = mac_esp_write8,
475 .esp_read8 = mac_esp_read8,
476 .map_single = mac_esp_map_single,
477 .map_sg = mac_esp_map_sg,
478 .unmap_single = mac_esp_unmap_single,
479 .unmap_sg = mac_esp_unmap_sg,
480 .irq_pending = mac_esp_irq_pending,
481 .dma_length_limit = mac_esp_dma_length_limit,
482 .reset_dma = mac_esp_reset_dma,
483 .dma_drain = mac_esp_dma_drain,
484 .dma_invalidate = mac_esp_dma_invalidate,
485 .send_dma_cmd = mac_esp_send_pdma_cmd,
486 .dma_error = mac_esp_dma_error,
487 };
488
489 static int __devinit esp_mac_probe(struct platform_device *dev)
490 {
491 struct scsi_host_template *tpnt = &scsi_esp_template;
492 struct Scsi_Host *host;
493 struct esp *esp;
494 int err;
495 int chips_present;
496 struct mac_esp_priv *mep;
497
498 if (!MACH_IS_MAC)
499 return -ENODEV;
500
501 switch (macintosh_config->scsi_type) {
502 case MAC_SCSI_QUADRA:
503 case MAC_SCSI_QUADRA3:
504 chips_present = 1;
505 break;
506 case MAC_SCSI_QUADRA2:
507 if ((macintosh_config->ident == MAC_MODEL_Q900) ||
508 (macintosh_config->ident == MAC_MODEL_Q950))
509 chips_present = 2;
510 else
511 chips_present = 1;
512 break;
513 default:
514 chips_present = 0;
515 }
516
517 if (dev->id + 1 > chips_present)
518 return -ENODEV;
519
520 host = scsi_host_alloc(tpnt, sizeof(struct esp));
521
522 err = -ENOMEM;
523 if (!host)
524 goto fail;
525
526 host->max_id = 8;
527 host->use_clustering = DISABLE_CLUSTERING;
528 esp = shost_priv(host);
529
530 esp->host = host;
531 esp->dev = dev;
532
533 esp->command_block = kzalloc(16, GFP_KERNEL);
534 if (!esp->command_block)
535 goto fail_unlink;
536 esp->command_block_dma = (dma_addr_t)esp->command_block;
537
538 esp->scsi_id = 7;
539 host->this_id = esp->scsi_id;
540 esp->scsi_id_mask = 1 << esp->scsi_id;
541
542 mep = kzalloc(sizeof(struct mac_esp_priv), GFP_KERNEL);
543 if (!mep)
544 goto fail_free_command_block;
545 mep->esp = esp;
546 platform_set_drvdata(dev, mep);
547
548 switch (macintosh_config->scsi_type) {
549 case MAC_SCSI_QUADRA:
550 esp->cfreq = 16500000;
551 esp->regs = (void __iomem *)MAC_ESP_REGS_QUADRA;
552 mep->pdma_io = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
553 mep->pdma_regs = NULL;
554 break;
555 case MAC_SCSI_QUADRA2:
556 esp->cfreq = 25000000;
557 esp->regs = (void __iomem *)(MAC_ESP_REGS_QUADRA2 +
558 dev->id * MAC_ESP_REGS_SPACING);
559 mep->pdma_io = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
560 mep->pdma_regs = (void __iomem *)(MAC_ESP_PDMA_REG +
561 dev->id * MAC_ESP_PDMA_REG_SPACING);
562 nubus_writel(0x1d1, mep->pdma_regs);
563 break;
564 case MAC_SCSI_QUADRA3:
565 /* These quadras have a real DMA controller (the PSC) but we
566 * don't know how to drive it so we must use PIO instead.
567 */
568 esp->cfreq = 25000000;
569 esp->regs = (void __iomem *)MAC_ESP_REGS_QUADRA3;
570 mep->pdma_io = NULL;
571 mep->pdma_regs = NULL;
572 break;
573 }
574
575 esp->ops = &mac_esp_ops;
576 if (mep->pdma_io == NULL) {
577 printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id);
578 esp_write8(0, ESP_TCLOW);
579 esp_write8(0, ESP_TCMED);
580 esp->flags = ESP_FLAG_DISABLE_SYNC;
581 mac_esp_ops.send_dma_cmd = mac_esp_send_pio_cmd;
582 } else {
583 printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);
584 }
585
586 host->irq = IRQ_MAC_SCSI;
587 esp_chips[dev->id] = esp;
588 mb();
589 if (esp_chips[!dev->id] == NULL) {
590 err = request_irq(host->irq, mac_scsi_esp_intr, 0,
591 "Mac ESP", NULL);
592 if (err < 0) {
593 esp_chips[dev->id] = NULL;
594 goto fail_free_priv;
595 }
596 }
597
598 err = scsi_esp_register(esp, &dev->dev);
599 if (err)
600 goto fail_free_irq;
601
602 return 0;
603
604 fail_free_irq:
605 if (esp_chips[!dev->id] == NULL)
606 free_irq(host->irq, esp);
607 fail_free_priv:
608 kfree(mep);
609 fail_free_command_block:
610 kfree(esp->command_block);
611 fail_unlink:
612 scsi_host_put(host);
613 fail:
614 return err;
615 }
616
617 static int __devexit esp_mac_remove(struct platform_device *dev)
618 {
619 struct mac_esp_priv *mep = platform_get_drvdata(dev);
620 struct esp *esp = mep->esp;
621 unsigned int irq = esp->host->irq;
622
623 scsi_esp_unregister(esp);
624
625 esp_chips[dev->id] = NULL;
626 if (!(esp_chips[0] || esp_chips[1]))
627 free_irq(irq, NULL);
628
629 kfree(mep);
630
631 kfree(esp->command_block);
632
633 scsi_host_put(esp->host);
634
635 return 0;
636 }
637
638 static struct platform_driver esp_mac_driver = {
639 .probe = esp_mac_probe,
640 .remove = __devexit_p(esp_mac_remove),
641 .driver = {
642 .name = DRV_MODULE_NAME,
643 },
644 };
645
646 static int __init mac_esp_init(void)
647 {
648 int err;
649
650 err = platform_driver_register(&esp_mac_driver);
651 if (err)
652 return err;
653
654 internal_pdev = platform_device_alloc(DRV_MODULE_NAME, 0);
655 if (internal_pdev && platform_device_add(internal_pdev)) {
656 platform_device_put(internal_pdev);
657 internal_pdev = NULL;
658 }
659 external_pdev = platform_device_alloc(DRV_MODULE_NAME, 1);
660 if (external_pdev && platform_device_add(external_pdev)) {
661 platform_device_put(external_pdev);
662 external_pdev = NULL;
663 }
664
665 if (internal_pdev || external_pdev) {
666 return 0;
667 } else {
668 platform_driver_unregister(&esp_mac_driver);
669 return -ENOMEM;
670 }
671 }
672
673 static void __exit mac_esp_exit(void)
674 {
675 platform_driver_unregister(&esp_mac_driver);
676
677 if (internal_pdev) {
678 platform_device_unregister(internal_pdev);
679 internal_pdev = NULL;
680 }
681 if (external_pdev) {
682 platform_device_unregister(external_pdev);
683 external_pdev = NULL;
684 }
685 }
686
687 MODULE_DESCRIPTION("Mac ESP SCSI driver");
688 MODULE_AUTHOR("Finn Thain <fthain@telegraphics.com.au>");
689 MODULE_LICENSE("GPL v2");
690 MODULE_VERSION(DRV_VERSION);
691
692 module_init(mac_esp_init);
693 module_exit(mac_esp_exit);
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