mac_esp.c revision 02507a80b35edd720480540d917e9f92cc371009 
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#include <asm/macints.h>
26#include <asm/macintosh.h>
27
28#include <scsi/scsi_host.h>
29
30#include "esp_scsi.h"
31
32#define DRV_MODULE_NAME     "mac_esp"
33#define PFX                 DRV_MODULE_NAME ": "
34#define DRV_VERSION         "1.000"
35#define DRV_MODULE_RELDATE  "Sept 15, 2007"
36
37#define MAC_ESP_IO_BASE          0x50F00000
38#define MAC_ESP_REGS_QUADRA      (MAC_ESP_IO_BASE + 0x10000)
39#define MAC_ESP_REGS_QUADRA2     (MAC_ESP_IO_BASE + 0xF000)
40#define MAC_ESP_REGS_QUADRA3     (MAC_ESP_IO_BASE + 0x18000)
41#define MAC_ESP_REGS_SPACING     0x402
42#define MAC_ESP_PDMA_REG         0xF9800024
43#define MAC_ESP_PDMA_REG_SPACING 0x4
44#define MAC_ESP_PDMA_IO_OFFSET   0x100
45
46#define esp_read8(REG)		mac_esp_read8(esp, REG)
47#define esp_write8(VAL, REG)	mac_esp_write8(esp, VAL, REG)
48
49struct mac_esp_priv {
50	struct esp *esp;
51	void __iomem *pdma_regs;
52	void __iomem *pdma_io;
53	int error;
54};
55static struct platform_device *internal_pdev, *external_pdev;
56static struct esp *esp_chips[2];
57
58#define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \
59			       platform_get_drvdata((struct platform_device *) \
60						    (esp->dev)))
61
62static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg)
63{
64	nubus_writeb(val, esp->regs + reg * 16);
65}
66
67static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg)
68{
69	return nubus_readb(esp->regs + reg * 16);
70}
71
72/* For pseudo DMA and PIO we need the virtual address
73 * so this address mapping is the identity mapping.
74 */
75
76static dma_addr_t mac_esp_map_single(struct esp *esp, void *buf,
77				     size_t sz, int dir)
78{
79	return (dma_addr_t)buf;
80}
81
82static int mac_esp_map_sg(struct esp *esp, struct scatterlist *sg,
83			  int num_sg, int dir)
84{
85	int i;
86
87	for (i = 0; i < num_sg; i++)
88		sg[i].dma_address = (u32)sg_virt(&sg[i]);
89	return num_sg;
90}
91
92static void mac_esp_unmap_single(struct esp *esp, dma_addr_t addr,
93				 size_t sz, int dir)
94{
95	/* Nothing to do. */
96}
97
98static void mac_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
99			     int num_sg, int dir)
100{
101	/* Nothing to do. */
102}
103
104static void mac_esp_reset_dma(struct esp *esp)
105{
106	/* Nothing to do. */
107}
108
109static void mac_esp_dma_drain(struct esp *esp)
110{
111	/* Nothing to do. */
112}
113
114static void mac_esp_dma_invalidate(struct esp *esp)
115{
116	/* Nothing to do. */
117}
118
119static int mac_esp_dma_error(struct esp *esp)
120{
121	return MAC_ESP_GET_PRIV(esp)->error;
122}
123
124static inline int mac_esp_wait_for_empty_fifo(struct esp *esp)
125{
126	struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
127	int i = 500000;
128
129	do {
130		if (!(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES))
131			return 0;
132
133		if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
134			return 1;
135
136		udelay(2);
137	} while (--i);
138
139	printk(KERN_ERR PFX "FIFO is not empty (sreg %02x)\n",
140	       esp_read8(ESP_STATUS));
141	mep->error = 1;
142	return 1;
143}
144
145static inline int mac_esp_wait_for_dreq(struct esp *esp)
146{
147	struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
148	int i = 500000;
149
150	do {
151		if (mep->pdma_regs == NULL) {
152			if (mac_irq_pending(IRQ_MAC_SCSIDRQ))
153				return 0;
154		} else {
155			if (nubus_readl(mep->pdma_regs) & 0x200)
156				return 0;
157		}
158
159		if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
160			return 1;
161
162		udelay(2);
163	} while (--i);
164
165	printk(KERN_ERR PFX "PDMA timeout (sreg %02x)\n",
166	       esp_read8(ESP_STATUS));
167	mep->error = 1;
168	return 1;
169}
170
171#define MAC_ESP_PDMA_LOOP(operands) \
172	asm volatile ( \
173	     "       tstw %1                   \n" \
174	     "       jbeq 20f                  \n" \
175	     "1:     movew " operands "        \n" \
176	     "2:     movew " operands "        \n" \
177	     "3:     movew " operands "        \n" \
178	     "4:     movew " operands "        \n" \
179	     "5:     movew " operands "        \n" \
180	     "6:     movew " operands "        \n" \
181	     "7:     movew " operands "        \n" \
182	     "8:     movew " operands "        \n" \
183	     "9:     movew " operands "        \n" \
184	     "10:    movew " operands "        \n" \
185	     "11:    movew " operands "        \n" \
186	     "12:    movew " operands "        \n" \
187	     "13:    movew " operands "        \n" \
188	     "14:    movew " operands "        \n" \
189	     "15:    movew " operands "        \n" \
190	     "16:    movew " operands "        \n" \
191	     "       subqw #1,%1               \n" \
192	     "       jbne 1b                   \n" \
193	     "20:    tstw %2                   \n" \
194	     "       jbeq 30f                  \n" \
195	     "21:    movew " operands "        \n" \
196	     "       subqw #1,%2               \n" \
197	     "       jbne 21b                  \n" \
198	     "30:    tstw %3                   \n" \
199	     "       jbeq 40f                  \n" \
200	     "31:    moveb " operands "        \n" \
201	     "32:    nop                       \n" \
202	     "40:                              \n" \
203	     "                                 \n" \
204	     "       .section __ex_table,\"a\" \n" \
205	     "       .align  4                 \n" \
206	     "       .long   1b,40b            \n" \
207	     "       .long   2b,40b            \n" \
208	     "       .long   3b,40b            \n" \
209	     "       .long   4b,40b            \n" \
210	     "       .long   5b,40b            \n" \
211	     "       .long   6b,40b            \n" \
212	     "       .long   7b,40b            \n" \
213	     "       .long   8b,40b            \n" \
214	     "       .long   9b,40b            \n" \
215	     "       .long  10b,40b            \n" \
216	     "       .long  11b,40b            \n" \
217	     "       .long  12b,40b            \n" \
218	     "       .long  13b,40b            \n" \
219	     "       .long  14b,40b            \n" \
220	     "       .long  15b,40b            \n" \
221	     "       .long  16b,40b            \n" \
222	     "       .long  21b,40b            \n" \
223	     "       .long  31b,40b            \n" \
224	     "       .long  32b,40b            \n" \
225	     "       .previous                 \n" \
226	     : "+a" (addr), "+r" (count32), "+r" (count2) \
227	     : "g" (count1), "a" (mep->pdma_io))
228
229static void mac_esp_send_pdma_cmd(struct esp *esp, u32 addr, u32 esp_count,
230				  u32 dma_count, int write, u8 cmd)
231{
232	struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
233	unsigned long flags;
234
235	local_irq_save(flags);
236
237	mep->error = 0;
238
239	if (!write)
240		scsi_esp_cmd(esp, ESP_CMD_FLUSH);
241
242	esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW);
243	esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED);
244
245	scsi_esp_cmd(esp, cmd);
246
247	do {
248		unsigned int count32 = esp_count >> 5;
249		unsigned int count2 = (esp_count & 0x1F) >> 1;
250		unsigned int count1 = esp_count & 1;
251		unsigned int start_addr = addr;
252
253		if (mac_esp_wait_for_dreq(esp))
254			break;
255
256		if (write) {
257			MAC_ESP_PDMA_LOOP("%4@,%0@+");
258
259			esp_count -= addr - start_addr;
260		} else {
261			unsigned int n;
262
263			MAC_ESP_PDMA_LOOP("%0@+,%4@");
264
265			if (mac_esp_wait_for_empty_fifo(esp))
266				break;
267
268			n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW);
269			addr = start_addr + esp_count - n;
270			esp_count = n;
271		}
272	} while (esp_count);
273
274	local_irq_restore(flags);
275}
276
277/*
278 * Programmed IO routines follow.
279 */
280
281static inline unsigned int mac_esp_wait_for_fifo(struct esp *esp)
282{
283	int i = 500000;
284
285	do {
286		unsigned int fbytes = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
287
288		if (fbytes)
289			return fbytes;
290
291		udelay(2);
292	} while (--i);
293
294	printk(KERN_ERR PFX "FIFO is empty (sreg %02x)\n",
295	       esp_read8(ESP_STATUS));
296	return 0;
297}
298
299static inline int mac_esp_wait_for_intr(struct esp *esp)
300{
301	struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
302	int i = 500000;
303
304	do {
305		esp->sreg = esp_read8(ESP_STATUS);
306		if (esp->sreg & ESP_STAT_INTR)
307			return 0;
308
309		udelay(2);
310	} while (--i);
311
312	printk(KERN_ERR PFX "IRQ timeout (sreg %02x)\n", esp->sreg);
313	mep->error = 1;
314	return 1;
315}
316
317#define MAC_ESP_PIO_LOOP(operands, reg1) \
318	asm volatile ( \
319	     "1:     moveb " operands " \n" \
320	     "       subqw #1,%1        \n" \
321	     "       jbne 1b            \n" \
322	     : "+a" (addr), "+r" (reg1) \
323	     : "a" (fifo))
324
325#define MAC_ESP_PIO_FILL(operands, reg1) \
326	asm volatile ( \
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	     "       moveb " operands " \n" \
341	     "       moveb " operands " \n" \
342	     "       moveb " operands " \n" \
343	     "       subqw #8,%1        \n" \
344	     "       subqw #8,%1        \n" \
345	     : "+a" (addr), "+r" (reg1) \
346	     : "a" (fifo))
347
348#define MAC_ESP_FIFO_SIZE 16
349
350static void mac_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count,
351				 u32 dma_count, int write, u8 cmd)
352{
353	struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
354	u8 *fifo = esp->regs + ESP_FDATA * 16;
355
356	disable_irq(esp->host->irq);
357
358	cmd &= ~ESP_CMD_DMA;
359	mep->error = 0;
360
361	if (write) {
362		scsi_esp_cmd(esp, cmd);
363
364		while (1) {
365			unsigned int n;
366
367			n = mac_esp_wait_for_fifo(esp);
368			if (!n)
369				break;
370
371			if (n > esp_count)
372				n = esp_count;
373			esp_count -= n;
374
375			MAC_ESP_PIO_LOOP("%2@,%0@+", n);
376
377			if (!esp_count)
378				break;
379
380			if (mac_esp_wait_for_intr(esp))
381				break;
382
383			if (((esp->sreg & ESP_STAT_PMASK) != ESP_DIP) &&
384			    ((esp->sreg & ESP_STAT_PMASK) != ESP_MIP))
385				break;
386
387			esp->ireg = esp_read8(ESP_INTRPT);
388			if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
389			    ESP_INTR_BSERV)
390				break;
391
392			scsi_esp_cmd(esp, ESP_CMD_TI);
393		}
394	} else {
395		scsi_esp_cmd(esp, ESP_CMD_FLUSH);
396
397		if (esp_count >= MAC_ESP_FIFO_SIZE)
398			MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
399		else
400			MAC_ESP_PIO_LOOP("%0@+,%2@", esp_count);
401
402		scsi_esp_cmd(esp, cmd);
403
404		while (esp_count) {
405			unsigned int n;
406
407			if (mac_esp_wait_for_intr(esp))
408				break;
409
410			if (((esp->sreg & ESP_STAT_PMASK) != ESP_DOP) &&
411			    ((esp->sreg & ESP_STAT_PMASK) != ESP_MOP))
412				break;
413
414			esp->ireg = esp_read8(ESP_INTRPT);
415			if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
416			    ESP_INTR_BSERV)
417				break;
418
419			n = MAC_ESP_FIFO_SIZE -
420			    (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES);
421			if (n > esp_count)
422				n = esp_count;
423
424			if (n == MAC_ESP_FIFO_SIZE) {
425				MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
426			} else {
427				esp_count -= n;
428				MAC_ESP_PIO_LOOP("%0@+,%2@", n);
429			}
430
431			scsi_esp_cmd(esp, ESP_CMD_TI);
432		}
433	}
434
435	enable_irq(esp->host->irq);
436}
437
438static int mac_esp_irq_pending(struct esp *esp)
439{
440	if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
441		return 1;
442	return 0;
443}
444
445static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
446{
447	return dma_len > 0xFFFF ? 0xFFFF : dma_len;
448}
449
450static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id)
451{
452	int got_intr;
453
454	/*
455	 * This is an edge triggered IRQ, so we have to be careful to
456	 * avoid missing a transition when it is shared by two ESP devices.
457	 */
458
459	do {
460		got_intr = 0;
461		if (esp_chips[0] &&
462		    (mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) {
463			(void)scsi_esp_intr(irq, esp_chips[0]);
464			got_intr = 1;
465		}
466		if (esp_chips[1] &&
467		    (mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) {
468			(void)scsi_esp_intr(irq, esp_chips[1]);
469			got_intr = 1;
470		}
471	} while (got_intr);
472
473	return IRQ_HANDLED;
474}
475
476static struct esp_driver_ops mac_esp_ops = {
477	.esp_write8       = mac_esp_write8,
478	.esp_read8        = mac_esp_read8,
479	.map_single       = mac_esp_map_single,
480	.map_sg           = mac_esp_map_sg,
481	.unmap_single     = mac_esp_unmap_single,
482	.unmap_sg         = mac_esp_unmap_sg,
483	.irq_pending      = mac_esp_irq_pending,
484	.dma_length_limit = mac_esp_dma_length_limit,
485	.reset_dma        = mac_esp_reset_dma,
486	.dma_drain        = mac_esp_dma_drain,
487	.dma_invalidate   = mac_esp_dma_invalidate,
488	.send_dma_cmd     = mac_esp_send_pdma_cmd,
489	.dma_error        = mac_esp_dma_error,
490};
491
492static int __devinit esp_mac_probe(struct platform_device *dev)
493{
494	struct scsi_host_template *tpnt = &scsi_esp_template;
495	struct Scsi_Host *host;
496	struct esp *esp;
497	int err;
498	int chips_present;
499	struct mac_esp_priv *mep;
500
501	if (!MACH_IS_MAC)
502		return -ENODEV;
503
504	switch (macintosh_config->scsi_type) {
505	case MAC_SCSI_QUADRA:
506	case MAC_SCSI_QUADRA3:
507		chips_present = 1;
508		break;
509	case MAC_SCSI_QUADRA2:
510		if ((macintosh_config->ident == MAC_MODEL_Q900) ||
511		    (macintosh_config->ident == MAC_MODEL_Q950))
512			chips_present = 2;
513		else
514			chips_present = 1;
515		break;
516	default:
517		chips_present = 0;
518	}
519
520	if (dev->id + 1 > chips_present)
521		return -ENODEV;
522
523	host = scsi_host_alloc(tpnt, sizeof(struct esp));
524
525	err = -ENOMEM;
526	if (!host)
527		goto fail;
528
529	host->max_id = 8;
530	host->use_clustering = DISABLE_CLUSTERING;
531	esp = shost_priv(host);
532
533	esp->host = host;
534	esp->dev = dev;
535
536	esp->command_block = kzalloc(16, GFP_KERNEL);
537	if (!esp->command_block)
538		goto fail_unlink;
539	esp->command_block_dma = (dma_addr_t)esp->command_block;
540
541	esp->scsi_id = 7;
542	host->this_id = esp->scsi_id;
543	esp->scsi_id_mask = 1 << esp->scsi_id;
544
545	mep = kzalloc(sizeof(struct mac_esp_priv), GFP_KERNEL);
546	if (!mep)
547		goto fail_free_command_block;
548	mep->esp = esp;
549	platform_set_drvdata(dev, mep);
550
551	switch (macintosh_config->scsi_type) {
552	case MAC_SCSI_QUADRA:
553		esp->cfreq     = 16500000;
554		esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA;
555		mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
556		mep->pdma_regs = NULL;
557		break;
558	case MAC_SCSI_QUADRA2:
559		esp->cfreq     = 25000000;
560		esp->regs      = (void __iomem *)(MAC_ESP_REGS_QUADRA2 +
561				 dev->id * MAC_ESP_REGS_SPACING);
562		mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
563		mep->pdma_regs = (void __iomem *)(MAC_ESP_PDMA_REG +
564				 dev->id * MAC_ESP_PDMA_REG_SPACING);
565		nubus_writel(0x1d1, mep->pdma_regs);
566		break;
567	case MAC_SCSI_QUADRA3:
568		/* These quadras have a real DMA controller (the PSC) but we
569		 * don't know how to drive it so we must use PIO instead.
570		 */
571		esp->cfreq     = 25000000;
572		esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA3;
573		mep->pdma_io   = NULL;
574		mep->pdma_regs = NULL;
575		break;
576	}
577
578	esp->ops = &mac_esp_ops;
579	if (mep->pdma_io == NULL) {
580		printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id);
581		esp_write8(0, ESP_TCLOW);
582		esp_write8(0, ESP_TCMED);
583		esp->flags = ESP_FLAG_DISABLE_SYNC;
584		mac_esp_ops.send_dma_cmd = mac_esp_send_pio_cmd;
585	} else {
586		printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);
587	}
588
589	host->irq = IRQ_MAC_SCSI;
590	esp_chips[dev->id] = esp;
591	mb();
592	if (esp_chips[!dev->id] == NULL) {
593		err = request_irq(host->irq, mac_scsi_esp_intr, 0,
594		                  "Mac ESP", NULL);
595		if (err < 0) {
596			esp_chips[dev->id] = NULL;
597			goto fail_free_priv;
598		}
599	}
600
601	err = scsi_esp_register(esp, &dev->dev);
602	if (err)
603		goto fail_free_irq;
604
605	return 0;
606
607fail_free_irq:
608	if (esp_chips[!dev->id] == NULL)
609		free_irq(host->irq, esp);
610fail_free_priv:
611	kfree(mep);
612fail_free_command_block:
613	kfree(esp->command_block);
614fail_unlink:
615	scsi_host_put(host);
616fail:
617	return err;
618}
619
620static int __devexit esp_mac_remove(struct platform_device *dev)
621{
622	struct mac_esp_priv *mep = platform_get_drvdata(dev);
623	struct esp *esp = mep->esp;
624	unsigned int irq = esp->host->irq;
625
626	scsi_esp_unregister(esp);
627
628	esp_chips[dev->id] = NULL;
629	if (!(esp_chips[0] || esp_chips[1]))
630		free_irq(irq, NULL);
631
632	kfree(mep);
633
634	kfree(esp->command_block);
635
636	scsi_host_put(esp->host);
637
638	return 0;
639}
640
641static struct platform_driver esp_mac_driver = {
642	.probe    = esp_mac_probe,
643	.remove   = __devexit_p(esp_mac_remove),
644	.driver   = {
645		.name     = DRV_MODULE_NAME,
646	},
647};
648
649static int __init mac_esp_init(void)
650{
651	int err;
652
653	err = platform_driver_register(&esp_mac_driver);
654	if (err)
655		return err;
656
657	internal_pdev = platform_device_alloc(DRV_MODULE_NAME, 0);
658	if (internal_pdev && platform_device_add(internal_pdev)) {
659		platform_device_put(internal_pdev);
660		internal_pdev = NULL;
661	}
662	external_pdev = platform_device_alloc(DRV_MODULE_NAME, 1);
663	if (external_pdev && platform_device_add(external_pdev)) {
664		platform_device_put(external_pdev);
665		external_pdev = NULL;
666	}
667
668	if (internal_pdev || external_pdev) {
669		return 0;
670	} else {
671		platform_driver_unregister(&esp_mac_driver);
672		return -ENOMEM;
673	}
674}
675
676static void __exit mac_esp_exit(void)
677{
678	platform_driver_unregister(&esp_mac_driver);
679
680	if (internal_pdev) {
681		platform_device_unregister(internal_pdev);
682		internal_pdev = NULL;
683	}
684	if (external_pdev) {
685		platform_device_unregister(external_pdev);
686		external_pdev = NULL;
687	}
688}
689
690MODULE_DESCRIPTION("Mac ESP SCSI driver");
691MODULE_AUTHOR("Finn Thain <fthain@telegraphics.com.au>");
692MODULE_LICENSE("GPL v2");
693MODULE_VERSION(DRV_VERSION);
694
695module_init(mac_esp_init);
696module_exit(mac_esp_exit);
697