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1/* sun_esp.c: ESP front-end for Sparc SBUS systems.
2 *
3 * Copyright (C) 2007, 2008 David S. Miller (davem@davemloft.net)
4 */
5
6#include <linux/kernel.h>
7#include <linux/types.h>
8#include <linux/delay.h>
9#include <linux/module.h>
10#include <linux/mm.h>
11#include <linux/init.h>
12#include <linux/dma-mapping.h>
13#include <linux/of.h>
14#include <linux/of_device.h>
15#include <linux/gfp.h>
16
17#include <asm/irq.h>
18#include <asm/io.h>
19#include <asm/dma.h>
20
21#include <scsi/scsi_host.h>
22
23#include "esp_scsi.h"
24
25#define DRV_MODULE_NAME		"sun_esp"
26#define PFX DRV_MODULE_NAME	": "
27#define DRV_VERSION		"1.100"
28#define DRV_MODULE_RELDATE	"August 27, 2008"
29
30#define dma_read32(REG) \
31	sbus_readl(esp->dma_regs + (REG))
32#define dma_write32(VAL, REG) \
33	sbus_writel((VAL), esp->dma_regs + (REG))
34
35/* DVMA chip revisions */
36enum dvma_rev {
37	dvmarev0,
38	dvmaesc1,
39	dvmarev1,
40	dvmarev2,
41	dvmarev3,
42	dvmarevplus,
43	dvmahme
44};
45
46static int esp_sbus_setup_dma(struct esp *esp, struct platform_device *dma_of)
47{
48	esp->dma = dma_of;
49
50	esp->dma_regs = of_ioremap(&dma_of->resource[0], 0,
51				   resource_size(&dma_of->resource[0]),
52				   "espdma");
53	if (!esp->dma_regs)
54		return -ENOMEM;
55
56	switch (dma_read32(DMA_CSR) & DMA_DEVICE_ID) {
57	case DMA_VERS0:
58		esp->dmarev = dvmarev0;
59		break;
60	case DMA_ESCV1:
61		esp->dmarev = dvmaesc1;
62		break;
63	case DMA_VERS1:
64		esp->dmarev = dvmarev1;
65		break;
66	case DMA_VERS2:
67		esp->dmarev = dvmarev2;
68		break;
69	case DMA_VERHME:
70		esp->dmarev = dvmahme;
71		break;
72	case DMA_VERSPLUS:
73		esp->dmarev = dvmarevplus;
74		break;
75	}
76
77	return 0;
78
79}
80
81static int esp_sbus_map_regs(struct esp *esp, int hme)
82{
83	struct platform_device *op = esp->dev;
84	struct resource *res;
85
86	/* On HME, two reg sets exist, first is DVMA,
87	 * second is ESP registers.
88	 */
89	if (hme)
90		res = &op->resource[1];
91	else
92		res = &op->resource[0];
93
94	esp->regs = of_ioremap(res, 0, SBUS_ESP_REG_SIZE, "ESP");
95	if (!esp->regs)
96		return -ENOMEM;
97
98	return 0;
99}
100
101static int esp_sbus_map_command_block(struct esp *esp)
102{
103	struct platform_device *op = esp->dev;
104
105	esp->command_block = dma_alloc_coherent(&op->dev, 16,
106						&esp->command_block_dma,
107						GFP_ATOMIC);
108	if (!esp->command_block)
109		return -ENOMEM;
110	return 0;
111}
112
113static int esp_sbus_register_irq(struct esp *esp)
114{
115	struct Scsi_Host *host = esp->host;
116	struct platform_device *op = esp->dev;
117
118	host->irq = op->archdata.irqs[0];
119	return request_irq(host->irq, scsi_esp_intr, IRQF_SHARED, "ESP", esp);
120}
121
122static void esp_get_scsi_id(struct esp *esp, struct platform_device *espdma)
123{
124	struct platform_device *op = esp->dev;
125	struct device_node *dp;
126
127	dp = op->dev.of_node;
128	esp->scsi_id = of_getintprop_default(dp, "initiator-id", 0xff);
129	if (esp->scsi_id != 0xff)
130		goto done;
131
132	esp->scsi_id = of_getintprop_default(dp, "scsi-initiator-id", 0xff);
133	if (esp->scsi_id != 0xff)
134		goto done;
135
136	esp->scsi_id = of_getintprop_default(espdma->dev.of_node,
137					     "scsi-initiator-id", 7);
138
139done:
140	esp->host->this_id = esp->scsi_id;
141	esp->scsi_id_mask = (1 << esp->scsi_id);
142}
143
144static void esp_get_differential(struct esp *esp)
145{
146	struct platform_device *op = esp->dev;
147	struct device_node *dp;
148
149	dp = op->dev.of_node;
150	if (of_find_property(dp, "differential", NULL))
151		esp->flags |= ESP_FLAG_DIFFERENTIAL;
152	else
153		esp->flags &= ~ESP_FLAG_DIFFERENTIAL;
154}
155
156static void esp_get_clock_params(struct esp *esp)
157{
158	struct platform_device *op = esp->dev;
159	struct device_node *bus_dp, *dp;
160	int fmhz;
161
162	dp = op->dev.of_node;
163	bus_dp = dp->parent;
164
165	fmhz = of_getintprop_default(dp, "clock-frequency", 0);
166	if (fmhz == 0)
167		fmhz = of_getintprop_default(bus_dp, "clock-frequency", 0);
168
169	esp->cfreq = fmhz;
170}
171
172static void esp_get_bursts(struct esp *esp, struct platform_device *dma_of)
173{
174	struct device_node *dma_dp = dma_of->dev.of_node;
175	struct platform_device *op = esp->dev;
176	struct device_node *dp;
177	u8 bursts, val;
178
179	dp = op->dev.of_node;
180	bursts = of_getintprop_default(dp, "burst-sizes", 0xff);
181	val = of_getintprop_default(dma_dp, "burst-sizes", 0xff);
182	if (val != 0xff)
183		bursts &= val;
184
185	val = of_getintprop_default(dma_dp->parent, "burst-sizes", 0xff);
186	if (val != 0xff)
187		bursts &= val;
188
189	if (bursts == 0xff ||
190	    (bursts & DMA_BURST16) == 0 ||
191	    (bursts & DMA_BURST32) == 0)
192		bursts = (DMA_BURST32 - 1);
193
194	esp->bursts = bursts;
195}
196
197static void esp_sbus_get_props(struct esp *esp, struct platform_device *espdma)
198{
199	esp_get_scsi_id(esp, espdma);
200	esp_get_differential(esp);
201	esp_get_clock_params(esp);
202	esp_get_bursts(esp, espdma);
203}
204
205static void sbus_esp_write8(struct esp *esp, u8 val, unsigned long reg)
206{
207	sbus_writeb(val, esp->regs + (reg * 4UL));
208}
209
210static u8 sbus_esp_read8(struct esp *esp, unsigned long reg)
211{
212	return sbus_readb(esp->regs + (reg * 4UL));
213}
214
215static dma_addr_t sbus_esp_map_single(struct esp *esp, void *buf,
216				      size_t sz, int dir)
217{
218	struct platform_device *op = esp->dev;
219
220	return dma_map_single(&op->dev, buf, sz, dir);
221}
222
223static int sbus_esp_map_sg(struct esp *esp, struct scatterlist *sg,
224				  int num_sg, int dir)
225{
226	struct platform_device *op = esp->dev;
227
228	return dma_map_sg(&op->dev, sg, num_sg, dir);
229}
230
231static void sbus_esp_unmap_single(struct esp *esp, dma_addr_t addr,
232				  size_t sz, int dir)
233{
234	struct platform_device *op = esp->dev;
235
236	dma_unmap_single(&op->dev, addr, sz, dir);
237}
238
239static void sbus_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
240			      int num_sg, int dir)
241{
242	struct platform_device *op = esp->dev;
243
244	dma_unmap_sg(&op->dev, sg, num_sg, dir);
245}
246
247static int sbus_esp_irq_pending(struct esp *esp)
248{
249	if (dma_read32(DMA_CSR) & (DMA_HNDL_INTR | DMA_HNDL_ERROR))
250		return 1;
251	return 0;
252}
253
254static void sbus_esp_reset_dma(struct esp *esp)
255{
256	int can_do_burst16, can_do_burst32, can_do_burst64;
257	int can_do_sbus64, lim;
258	struct platform_device *op;
259	u32 val;
260
261	can_do_burst16 = (esp->bursts & DMA_BURST16) != 0;
262	can_do_burst32 = (esp->bursts & DMA_BURST32) != 0;
263	can_do_burst64 = 0;
264	can_do_sbus64 = 0;
265	op = esp->dev;
266	if (sbus_can_dma_64bit())
267		can_do_sbus64 = 1;
268	if (sbus_can_burst64())
269		can_do_burst64 = (esp->bursts & DMA_BURST64) != 0;
270
271	/* Put the DVMA into a known state. */
272	if (esp->dmarev != dvmahme) {
273		val = dma_read32(DMA_CSR);
274		dma_write32(val | DMA_RST_SCSI, DMA_CSR);
275		dma_write32(val & ~DMA_RST_SCSI, DMA_CSR);
276	}
277	switch (esp->dmarev) {
278	case dvmahme:
279		dma_write32(DMA_RESET_FAS366, DMA_CSR);
280		dma_write32(DMA_RST_SCSI, DMA_CSR);
281
282		esp->prev_hme_dmacsr = (DMA_PARITY_OFF | DMA_2CLKS |
283					DMA_SCSI_DISAB | DMA_INT_ENAB);
284
285		esp->prev_hme_dmacsr &= ~(DMA_ENABLE | DMA_ST_WRITE |
286					  DMA_BRST_SZ);
287
288		if (can_do_burst64)
289			esp->prev_hme_dmacsr |= DMA_BRST64;
290		else if (can_do_burst32)
291			esp->prev_hme_dmacsr |= DMA_BRST32;
292
293		if (can_do_sbus64) {
294			esp->prev_hme_dmacsr |= DMA_SCSI_SBUS64;
295			sbus_set_sbus64(&op->dev, esp->bursts);
296		}
297
298		lim = 1000;
299		while (dma_read32(DMA_CSR) & DMA_PEND_READ) {
300			if (--lim == 0) {
301				printk(KERN_ALERT PFX "esp%d: DMA_PEND_READ "
302				       "will not clear!\n",
303				       esp->host->unique_id);
304				break;
305			}
306			udelay(1);
307		}
308
309		dma_write32(0, DMA_CSR);
310		dma_write32(esp->prev_hme_dmacsr, DMA_CSR);
311
312		dma_write32(0, DMA_ADDR);
313		break;
314
315	case dvmarev2:
316		if (esp->rev != ESP100) {
317			val = dma_read32(DMA_CSR);
318			dma_write32(val | DMA_3CLKS, DMA_CSR);
319		}
320		break;
321
322	case dvmarev3:
323		val = dma_read32(DMA_CSR);
324		val &= ~DMA_3CLKS;
325		val |= DMA_2CLKS;
326		if (can_do_burst32) {
327			val &= ~DMA_BRST_SZ;
328			val |= DMA_BRST32;
329		}
330		dma_write32(val, DMA_CSR);
331		break;
332
333	case dvmaesc1:
334		val = dma_read32(DMA_CSR);
335		val |= DMA_ADD_ENABLE;
336		val &= ~DMA_BCNT_ENAB;
337		if (!can_do_burst32 && can_do_burst16) {
338			val |= DMA_ESC_BURST;
339		} else {
340			val &= ~(DMA_ESC_BURST);
341		}
342		dma_write32(val, DMA_CSR);
343		break;
344
345	default:
346		break;
347	}
348
349	/* Enable interrupts.  */
350	val = dma_read32(DMA_CSR);
351	dma_write32(val | DMA_INT_ENAB, DMA_CSR);
352}
353
354static void sbus_esp_dma_drain(struct esp *esp)
355{
356	u32 csr;
357	int lim;
358
359	if (esp->dmarev == dvmahme)
360		return;
361
362	csr = dma_read32(DMA_CSR);
363	if (!(csr & DMA_FIFO_ISDRAIN))
364		return;
365
366	if (esp->dmarev != dvmarev3 && esp->dmarev != dvmaesc1)
367		dma_write32(csr | DMA_FIFO_STDRAIN, DMA_CSR);
368
369	lim = 1000;
370	while (dma_read32(DMA_CSR) & DMA_FIFO_ISDRAIN) {
371		if (--lim == 0) {
372			printk(KERN_ALERT PFX "esp%d: DMA will not drain!\n",
373			       esp->host->unique_id);
374			break;
375		}
376		udelay(1);
377	}
378}
379
380static void sbus_esp_dma_invalidate(struct esp *esp)
381{
382	if (esp->dmarev == dvmahme) {
383		dma_write32(DMA_RST_SCSI, DMA_CSR);
384
385		esp->prev_hme_dmacsr = ((esp->prev_hme_dmacsr |
386					 (DMA_PARITY_OFF | DMA_2CLKS |
387					  DMA_SCSI_DISAB | DMA_INT_ENAB)) &
388					~(DMA_ST_WRITE | DMA_ENABLE));
389
390		dma_write32(0, DMA_CSR);
391		dma_write32(esp->prev_hme_dmacsr, DMA_CSR);
392
393		/* This is necessary to avoid having the SCSI channel
394		 * engine lock up on us.
395		 */
396		dma_write32(0, DMA_ADDR);
397	} else {
398		u32 val;
399		int lim;
400
401		lim = 1000;
402		while ((val = dma_read32(DMA_CSR)) & DMA_PEND_READ) {
403			if (--lim == 0) {
404				printk(KERN_ALERT PFX "esp%d: DMA will not "
405				       "invalidate!\n", esp->host->unique_id);
406				break;
407			}
408			udelay(1);
409		}
410
411		val &= ~(DMA_ENABLE | DMA_ST_WRITE | DMA_BCNT_ENAB);
412		val |= DMA_FIFO_INV;
413		dma_write32(val, DMA_CSR);
414		val &= ~DMA_FIFO_INV;
415		dma_write32(val, DMA_CSR);
416	}
417}
418
419static void sbus_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
420				  u32 dma_count, int write, u8 cmd)
421{
422	u32 csr;
423
424	BUG_ON(!(cmd & ESP_CMD_DMA));
425
426	sbus_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
427	sbus_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
428	if (esp->rev == FASHME) {
429		sbus_esp_write8(esp, (esp_count >> 16) & 0xff, FAS_RLO);
430		sbus_esp_write8(esp, 0, FAS_RHI);
431
432		scsi_esp_cmd(esp, cmd);
433
434		csr = esp->prev_hme_dmacsr;
435		csr |= DMA_SCSI_DISAB | DMA_ENABLE;
436		if (write)
437			csr |= DMA_ST_WRITE;
438		else
439			csr &= ~DMA_ST_WRITE;
440		esp->prev_hme_dmacsr = csr;
441
442		dma_write32(dma_count, DMA_COUNT);
443		dma_write32(addr, DMA_ADDR);
444		dma_write32(csr, DMA_CSR);
445	} else {
446		csr = dma_read32(DMA_CSR);
447		csr |= DMA_ENABLE;
448		if (write)
449			csr |= DMA_ST_WRITE;
450		else
451			csr &= ~DMA_ST_WRITE;
452		dma_write32(csr, DMA_CSR);
453		if (esp->dmarev == dvmaesc1) {
454			u32 end = PAGE_ALIGN(addr + dma_count + 16U);
455			dma_write32(end - addr, DMA_COUNT);
456		}
457		dma_write32(addr, DMA_ADDR);
458
459		scsi_esp_cmd(esp, cmd);
460	}
461
462}
463
464static int sbus_esp_dma_error(struct esp *esp)
465{
466	u32 csr = dma_read32(DMA_CSR);
467
468	if (csr & DMA_HNDL_ERROR)
469		return 1;
470
471	return 0;
472}
473
474static const struct esp_driver_ops sbus_esp_ops = {
475	.esp_write8	=	sbus_esp_write8,
476	.esp_read8	=	sbus_esp_read8,
477	.map_single	=	sbus_esp_map_single,
478	.map_sg		=	sbus_esp_map_sg,
479	.unmap_single	=	sbus_esp_unmap_single,
480	.unmap_sg	=	sbus_esp_unmap_sg,
481	.irq_pending	=	sbus_esp_irq_pending,
482	.reset_dma	=	sbus_esp_reset_dma,
483	.dma_drain	=	sbus_esp_dma_drain,
484	.dma_invalidate	=	sbus_esp_dma_invalidate,
485	.send_dma_cmd	=	sbus_esp_send_dma_cmd,
486	.dma_error	=	sbus_esp_dma_error,
487};
488
489static int esp_sbus_probe_one(struct platform_device *op,
490			      struct platform_device *espdma, int hme)
491{
492	struct scsi_host_template *tpnt = &scsi_esp_template;
493	struct Scsi_Host *host;
494	struct esp *esp;
495	int err;
496
497	host = scsi_host_alloc(tpnt, sizeof(struct esp));
498
499	err = -ENOMEM;
500	if (!host)
501		goto fail;
502
503	host->max_id = (hme ? 16 : 8);
504	esp = shost_priv(host);
505
506	esp->host = host;
507	esp->dev = op;
508	esp->ops = &sbus_esp_ops;
509
510	if (hme)
511		esp->flags |= ESP_FLAG_WIDE_CAPABLE;
512
513	err = esp_sbus_setup_dma(esp, espdma);
514	if (err < 0)
515		goto fail_unlink;
516
517	err = esp_sbus_map_regs(esp, hme);
518	if (err < 0)
519		goto fail_unlink;
520
521	err = esp_sbus_map_command_block(esp);
522	if (err < 0)
523		goto fail_unmap_regs;
524
525	err = esp_sbus_register_irq(esp);
526	if (err < 0)
527		goto fail_unmap_command_block;
528
529	esp_sbus_get_props(esp, espdma);
530
531	/* Before we try to touch the ESP chip, ESC1 dma can
532	 * come up with the reset bit set, so make sure that
533	 * is clear first.
534	 */
535	if (esp->dmarev == dvmaesc1) {
536		u32 val = dma_read32(DMA_CSR);
537
538		dma_write32(val & ~DMA_RST_SCSI, DMA_CSR);
539	}
540
541	dev_set_drvdata(&op->dev, esp);
542
543	err = scsi_esp_register(esp, &op->dev);
544	if (err)
545		goto fail_free_irq;
546
547	return 0;
548
549fail_free_irq:
550	free_irq(host->irq, esp);
551fail_unmap_command_block:
552	dma_free_coherent(&op->dev, 16,
553			  esp->command_block,
554			  esp->command_block_dma);
555fail_unmap_regs:
556	of_iounmap(&op->resource[(hme ? 1 : 0)], esp->regs, SBUS_ESP_REG_SIZE);
557fail_unlink:
558	scsi_host_put(host);
559fail:
560	return err;
561}
562
563static int esp_sbus_probe(struct platform_device *op)
564{
565	struct device_node *dma_node = NULL;
566	struct device_node *dp = op->dev.of_node;
567	struct platform_device *dma_of = NULL;
568	int hme = 0;
569
570	if (dp->parent &&
571	    (!strcmp(dp->parent->name, "espdma") ||
572	     !strcmp(dp->parent->name, "dma")))
573		dma_node = dp->parent;
574	else if (!strcmp(dp->name, "SUNW,fas")) {
575		dma_node = op->dev.of_node;
576		hme = 1;
577	}
578	if (dma_node)
579		dma_of = of_find_device_by_node(dma_node);
580	if (!dma_of)
581		return -ENODEV;
582
583	return esp_sbus_probe_one(op, dma_of, hme);
584}
585
586static int esp_sbus_remove(struct platform_device *op)
587{
588	struct esp *esp = dev_get_drvdata(&op->dev);
589	struct platform_device *dma_of = esp->dma;
590	unsigned int irq = esp->host->irq;
591	bool is_hme;
592	u32 val;
593
594	scsi_esp_unregister(esp);
595
596	/* Disable interrupts.  */
597	val = dma_read32(DMA_CSR);
598	dma_write32(val & ~DMA_INT_ENAB, DMA_CSR);
599
600	free_irq(irq, esp);
601
602	is_hme = (esp->dmarev == dvmahme);
603
604	dma_free_coherent(&op->dev, 16,
605			  esp->command_block,
606			  esp->command_block_dma);
607	of_iounmap(&op->resource[(is_hme ? 1 : 0)], esp->regs,
608		   SBUS_ESP_REG_SIZE);
609	of_iounmap(&dma_of->resource[0], esp->dma_regs,
610		   resource_size(&dma_of->resource[0]));
611
612	scsi_host_put(esp->host);
613
614	dev_set_drvdata(&op->dev, NULL);
615
616	return 0;
617}
618
619static const struct of_device_id esp_match[] = {
620	{
621		.name = "SUNW,esp",
622	},
623	{
624		.name = "SUNW,fas",
625	},
626	{
627		.name = "esp",
628	},
629	{},
630};
631MODULE_DEVICE_TABLE(of, esp_match);
632
633static struct platform_driver esp_sbus_driver = {
634	.driver = {
635		.name = "esp",
636		.owner = THIS_MODULE,
637		.of_match_table = esp_match,
638	},
639	.probe		= esp_sbus_probe,
640	.remove		= esp_sbus_remove,
641};
642
643static int __init sunesp_init(void)
644{
645	return platform_driver_register(&esp_sbus_driver);
646}
647
648static void __exit sunesp_exit(void)
649{
650	platform_driver_unregister(&esp_sbus_driver);
651}
652
653MODULE_DESCRIPTION("Sun ESP SCSI driver");
654MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
655MODULE_LICENSE("GPL");
656MODULE_VERSION(DRV_VERSION);
657
658module_init(sunesp_init);
659module_exit(sunesp_exit);
660