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mac_esp.c
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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 #include <linux/slab.h>
23 
24 #include <asm/irq.h>
25 #include <asm/dma.h>
26 #include <asm/macints.h>
27 #include <asm/macintosh.h>
28 #include <asm/mac_via.h>
29 
30 #include <scsi/scsi_host.h>
31 
32 #include "esp_scsi.h"
33 
34 #define DRV_MODULE_NAME "mac_esp"
35 #define PFX DRV_MODULE_NAME ": "
36 #define DRV_VERSION "1.000"
37 #define DRV_MODULE_RELDATE "Sept 15, 2007"
38 
39 #define MAC_ESP_IO_BASE 0x50F00000
40 #define MAC_ESP_REGS_QUADRA (MAC_ESP_IO_BASE + 0x10000)
41 #define MAC_ESP_REGS_QUADRA2 (MAC_ESP_IO_BASE + 0xF000)
42 #define MAC_ESP_REGS_QUADRA3 (MAC_ESP_IO_BASE + 0x18000)
43 #define MAC_ESP_REGS_SPACING 0x402
44 #define MAC_ESP_PDMA_REG 0xF9800024
45 #define MAC_ESP_PDMA_REG_SPACING 0x4
46 #define MAC_ESP_PDMA_IO_OFFSET 0x100
47 
48 #define esp_read8(REG) mac_esp_read8(esp, REG)
49 #define esp_write8(VAL, REG) mac_esp_write8(esp, VAL, REG)
50 
51 struct mac_esp_priv {
52  struct esp *esp;
53  void __iomem *pdma_regs;
54  void __iomem *pdma_io;
55  int error;
56 };
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 (via2_scsi_drq_pending())
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 
235  mep->error = 0;
236 
237  if (!write)
238  scsi_esp_cmd(esp, ESP_CMD_FLUSH);
239 
240  esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW);
241  esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED);
242 
243  scsi_esp_cmd(esp, cmd);
244 
245  do {
246  unsigned int count32 = esp_count >> 5;
247  unsigned int count2 = (esp_count & 0x1F) >> 1;
248  unsigned int count1 = esp_count & 1;
249  unsigned int start_addr = addr;
250 
251  if (mac_esp_wait_for_dreq(esp))
252  break;
253 
254  if (write) {
255  MAC_ESP_PDMA_LOOP("%4@,%0@+");
256 
257  esp_count -= addr - start_addr;
258  } else {
259  unsigned int n;
260 
261  MAC_ESP_PDMA_LOOP("%0@+,%4@");
262 
263  if (mac_esp_wait_for_empty_fifo(esp))
264  break;
265 
266  n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW);
267  addr = start_addr + esp_count - n;
268  esp_count = n;
269  }
270  } while (esp_count);
271 }
272 
273 /*
274  * Programmed IO routines follow.
275  */
276 
277 static inline unsigned int mac_esp_wait_for_fifo(struct esp *esp)
278 {
279  int i = 500000;
280 
281  do {
282  unsigned int fbytes = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
283 
284  if (fbytes)
285  return fbytes;
286 
287  udelay(2);
288  } while (--i);
289 
290  printk(KERN_ERR PFX "FIFO is empty (sreg %02x)\n",
291  esp_read8(ESP_STATUS));
292  return 0;
293 }
294 
295 static inline int mac_esp_wait_for_intr(struct esp *esp)
296 {
297  struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
298  int i = 500000;
299 
300  do {
301  esp->sreg = esp_read8(ESP_STATUS);
302  if (esp->sreg & ESP_STAT_INTR)
303  return 0;
304 
305  udelay(2);
306  } while (--i);
307 
308  printk(KERN_ERR PFX "IRQ timeout (sreg %02x)\n", esp->sreg);
309  mep->error = 1;
310  return 1;
311 }
312 
313 #define MAC_ESP_PIO_LOOP(operands, reg1) \
314  asm volatile ( \
315  "1: moveb " operands " \n" \
316  " subqw #1,%1 \n" \
317  " jbne 1b \n" \
318  : "+a" (addr), "+r" (reg1) \
319  : "a" (fifo))
320 
321 #define MAC_ESP_PIO_FILL(operands, reg1) \
322  asm volatile ( \
323  " moveb " operands " \n" \
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  " subqw #8,%1 \n" \
340  " subqw #8,%1 \n" \
341  : "+a" (addr), "+r" (reg1) \
342  : "a" (fifo))
343 
344 #define MAC_ESP_FIFO_SIZE 16
345 
346 static void mac_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count,
347  u32 dma_count, int write, u8 cmd)
348 {
349  struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
350  u8 *fifo = esp->regs + ESP_FDATA * 16;
351 
352  cmd &= ~ESP_CMD_DMA;
353  mep->error = 0;
354 
355  if (write) {
356  scsi_esp_cmd(esp, cmd);
357 
358  while (1) {
359  unsigned int n;
360 
361  n = mac_esp_wait_for_fifo(esp);
362  if (!n)
363  break;
364 
365  if (n > esp_count)
366  n = esp_count;
367  esp_count -= n;
368 
369  MAC_ESP_PIO_LOOP("%2@,%0@+", n);
370 
371  if (!esp_count)
372  break;
373 
374  if (mac_esp_wait_for_intr(esp))
375  break;
376 
377  if (((esp->sreg & ESP_STAT_PMASK) != ESP_DIP) &&
378  ((esp->sreg & ESP_STAT_PMASK) != ESP_MIP))
379  break;
380 
381  esp->ireg = esp_read8(ESP_INTRPT);
382  if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
383  ESP_INTR_BSERV)
384  break;
385 
386  scsi_esp_cmd(esp, ESP_CMD_TI);
387  }
388  } else {
389  scsi_esp_cmd(esp, ESP_CMD_FLUSH);
390 
391  if (esp_count >= MAC_ESP_FIFO_SIZE)
392  MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
393  else
394  MAC_ESP_PIO_LOOP("%0@+,%2@", esp_count);
395 
396  scsi_esp_cmd(esp, cmd);
397 
398  while (esp_count) {
399  unsigned int n;
400 
401  if (mac_esp_wait_for_intr(esp))
402  break;
403 
404  if (((esp->sreg & ESP_STAT_PMASK) != ESP_DOP) &&
405  ((esp->sreg & ESP_STAT_PMASK) != ESP_MOP))
406  break;
407 
408  esp->ireg = esp_read8(ESP_INTRPT);
409  if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
410  ESP_INTR_BSERV)
411  break;
412 
413  n = MAC_ESP_FIFO_SIZE -
414  (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES);
415  if (n > esp_count)
416  n = esp_count;
417 
418  if (n == MAC_ESP_FIFO_SIZE) {
419  MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
420  } else {
421  esp_count -= n;
422  MAC_ESP_PIO_LOOP("%0@+,%2@", n);
423  }
424 
425  scsi_esp_cmd(esp, ESP_CMD_TI);
426  }
427  }
428 }
429 
430 static int mac_esp_irq_pending(struct esp *esp)
431 {
432  if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
433  return 1;
434  return 0;
435 }
436 
437 static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
438 {
439  return dma_len > 0xFFFF ? 0xFFFF : dma_len;
440 }
441 
442 static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id)
443 {
444  int got_intr;
445 
446  /*
447  * This is an edge triggered IRQ, so we have to be careful to
448  * avoid missing a transition when it is shared by two ESP devices.
449  */
450 
451  do {
452  got_intr = 0;
453  if (esp_chips[0] &&
454  (mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) {
455  (void)scsi_esp_intr(irq, esp_chips[0]);
456  got_intr = 1;
457  }
458  if (esp_chips[1] &&
459  (mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) {
460  (void)scsi_esp_intr(irq, esp_chips[1]);
461  got_intr = 1;
462  }
463  } while (got_intr);
464 
465  return IRQ_HANDLED;
466 }
467 
468 static struct esp_driver_ops mac_esp_ops = {
469  .esp_write8 = mac_esp_write8,
470  .esp_read8 = mac_esp_read8,
471  .map_single = mac_esp_map_single,
472  .map_sg = mac_esp_map_sg,
473  .unmap_single = mac_esp_unmap_single,
474  .unmap_sg = mac_esp_unmap_sg,
475  .irq_pending = mac_esp_irq_pending,
476  .dma_length_limit = mac_esp_dma_length_limit,
477  .reset_dma = mac_esp_reset_dma,
478  .dma_drain = mac_esp_dma_drain,
479  .dma_invalidate = mac_esp_dma_invalidate,
480  .send_dma_cmd = mac_esp_send_pdma_cmd,
481  .dma_error = mac_esp_dma_error,
482 };
483 
484 static int __devinit esp_mac_probe(struct platform_device *dev)
485 {
486  struct scsi_host_template *tpnt = &scsi_esp_template;
487  struct Scsi_Host *host;
488  struct esp *esp;
489  int err;
490  struct mac_esp_priv *mep;
491 
492  if (!MACH_IS_MAC)
493  return -ENODEV;
494 
495  if (dev->id > 1)
496  return -ENODEV;
497 
498  host = scsi_host_alloc(tpnt, sizeof(struct esp));
499 
500  err = -ENOMEM;
501  if (!host)
502  goto fail;
503 
504  host->max_id = 8;
505  host->use_clustering = DISABLE_CLUSTERING;
506  esp = shost_priv(host);
507 
508  esp->host = host;
509  esp->dev = dev;
510 
511  esp->command_block = kzalloc(16, GFP_KERNEL);
512  if (!esp->command_block)
513  goto fail_unlink;
514  esp->command_block_dma = (dma_addr_t)esp->command_block;
515 
516  esp->scsi_id = 7;
517  host->this_id = esp->scsi_id;
518  esp->scsi_id_mask = 1 << esp->scsi_id;
519 
520  mep = kzalloc(sizeof(struct mac_esp_priv), GFP_KERNEL);
521  if (!mep)
522  goto fail_free_command_block;
523  mep->esp = esp;
524  platform_set_drvdata(dev, mep);
525 
526  switch (macintosh_config->scsi_type) {
527  case MAC_SCSI_QUADRA:
528  esp->cfreq = 16500000;
529  esp->regs = (void __iomem *)MAC_ESP_REGS_QUADRA;
530  mep->pdma_io = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
531  mep->pdma_regs = NULL;
532  break;
533  case MAC_SCSI_QUADRA2:
534  esp->cfreq = 25000000;
535  esp->regs = (void __iomem *)(MAC_ESP_REGS_QUADRA2 +
536  dev->id * MAC_ESP_REGS_SPACING);
537  mep->pdma_io = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
538  mep->pdma_regs = (void __iomem *)(MAC_ESP_PDMA_REG +
539  dev->id * MAC_ESP_PDMA_REG_SPACING);
540  nubus_writel(0x1d1, mep->pdma_regs);
541  break;
542  case MAC_SCSI_QUADRA3:
543  /* These quadras have a real DMA controller (the PSC) but we
544  * don't know how to drive it so we must use PIO instead.
545  */
546  esp->cfreq = 25000000;
547  esp->regs = (void __iomem *)MAC_ESP_REGS_QUADRA3;
548  mep->pdma_io = NULL;
549  mep->pdma_regs = NULL;
550  break;
551  }
552 
553  esp->ops = &mac_esp_ops;
554  if (mep->pdma_io == NULL) {
555  printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id);
556  esp_write8(0, ESP_TCLOW);
557  esp_write8(0, ESP_TCMED);
558  esp->flags = ESP_FLAG_DISABLE_SYNC;
559  mac_esp_ops.send_dma_cmd = mac_esp_send_pio_cmd;
560  } else {
561  printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);
562  }
563 
564  host->irq = IRQ_MAC_SCSI;
565  esp_chips[dev->id] = esp;
566  mb();
567  if (esp_chips[!dev->id] == NULL) {
568  err = request_irq(host->irq, mac_scsi_esp_intr, 0, "ESP", NULL);
569  if (err < 0) {
570  esp_chips[dev->id] = NULL;
571  goto fail_free_priv;
572  }
573  }
574 
575  err = scsi_esp_register(esp, &dev->dev);
576  if (err)
577  goto fail_free_irq;
578 
579  return 0;
580 
581 fail_free_irq:
582  if (esp_chips[!dev->id] == NULL)
583  free_irq(host->irq, esp);
584 fail_free_priv:
585  kfree(mep);
586 fail_free_command_block:
587  kfree(esp->command_block);
588 fail_unlink:
589  scsi_host_put(host);
590 fail:
591  return err;
592 }
593 
594 static int __devexit esp_mac_remove(struct platform_device *dev)
595 {
596  struct mac_esp_priv *mep = platform_get_drvdata(dev);
597  struct esp *esp = mep->esp;
598  unsigned int irq = esp->host->irq;
599 
600  scsi_esp_unregister(esp);
601 
602  esp_chips[dev->id] = NULL;
603  if (!(esp_chips[0] || esp_chips[1]))
604  free_irq(irq, NULL);
605 
606  kfree(mep);
607 
608  kfree(esp->command_block);
609 
610  scsi_host_put(esp->host);
611 
612  return 0;
613 }
614 
615 static struct platform_driver esp_mac_driver = {
616  .probe = esp_mac_probe,
617  .remove = __devexit_p(esp_mac_remove),
618  .driver = {
619  .name = DRV_MODULE_NAME,
620  .owner = THIS_MODULE,
621  },
622 };
623 
624 static int __init mac_esp_init(void)
625 {
626  return platform_driver_register(&esp_mac_driver);
627 }
628 
629 static void __exit mac_esp_exit(void)
630 {
631  platform_driver_unregister(&esp_mac_driver);
632 }
633 
634 MODULE_DESCRIPTION("Mac ESP SCSI driver");
635 MODULE_AUTHOR("Finn Thain <[email protected]>");
636 MODULE_LICENSE("GPL v2");
637 MODULE_VERSION(DRV_VERSION);
638 MODULE_ALIAS("platform:" DRV_MODULE_NAME);
639 
640 module_init(mac_esp_init);
641 module_exit(mac_esp_exit);
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