xref: /openbmc/linux/drivers/scsi/sun_esp.c (revision e3b9f1e8)
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 */
36 enum dvma_rev {
37 	dvmarev0,
38 	dvmaesc1,
39 	dvmarev1,
40 	dvmarev2,
41 	dvmarev3,
42 	dvmarevplus,
43 	dvmahme
44 };
45 
46 static 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 
81 static 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 
101 static 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 
113 static 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 
122 static 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 
139 done:
140 	esp->host->this_id = esp->scsi_id;
141 	esp->scsi_id_mask = (1 << esp->scsi_id);
142 }
143 
144 static 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 
156 static 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 
172 static 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 
197 static 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 
205 static void sbus_esp_write8(struct esp *esp, u8 val, unsigned long reg)
206 {
207 	sbus_writeb(val, esp->regs + (reg * 4UL));
208 }
209 
210 static u8 sbus_esp_read8(struct esp *esp, unsigned long reg)
211 {
212 	return sbus_readb(esp->regs + (reg * 4UL));
213 }
214 
215 static 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 
223 static 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 
231 static 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 
239 static 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 
247 static 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 
254 static 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 
354 static 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 
380 static 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 
419 static 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 
464 static 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 
474 static 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 
489 static 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 
549 fail_free_irq:
550 	free_irq(host->irq, esp);
551 fail_unmap_command_block:
552 	dma_free_coherent(&op->dev, 16,
553 			  esp->command_block,
554 			  esp->command_block_dma);
555 fail_unmap_regs:
556 	of_iounmap(&op->resource[(hme ? 1 : 0)], esp->regs, SBUS_ESP_REG_SIZE);
557 fail_unlink:
558 	scsi_host_put(host);
559 fail:
560 	return err;
561 }
562 
563 static 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 	int ret;
570 
571 	if (dp->parent &&
572 	    (!strcmp(dp->parent->name, "espdma") ||
573 	     !strcmp(dp->parent->name, "dma")))
574 		dma_node = dp->parent;
575 	else if (!strcmp(dp->name, "SUNW,fas")) {
576 		dma_node = op->dev.of_node;
577 		hme = 1;
578 	}
579 	if (dma_node)
580 		dma_of = of_find_device_by_node(dma_node);
581 	if (!dma_of)
582 		return -ENODEV;
583 
584 	ret = esp_sbus_probe_one(op, dma_of, hme);
585 	if (ret)
586 		put_device(&dma_of->dev);
587 
588 	return ret;
589 }
590 
591 static int esp_sbus_remove(struct platform_device *op)
592 {
593 	struct esp *esp = dev_get_drvdata(&op->dev);
594 	struct platform_device *dma_of = esp->dma;
595 	unsigned int irq = esp->host->irq;
596 	bool is_hme;
597 	u32 val;
598 
599 	scsi_esp_unregister(esp);
600 
601 	/* Disable interrupts.  */
602 	val = dma_read32(DMA_CSR);
603 	dma_write32(val & ~DMA_INT_ENAB, DMA_CSR);
604 
605 	free_irq(irq, esp);
606 
607 	is_hme = (esp->dmarev == dvmahme);
608 
609 	dma_free_coherent(&op->dev, 16,
610 			  esp->command_block,
611 			  esp->command_block_dma);
612 	of_iounmap(&op->resource[(is_hme ? 1 : 0)], esp->regs,
613 		   SBUS_ESP_REG_SIZE);
614 	of_iounmap(&dma_of->resource[0], esp->dma_regs,
615 		   resource_size(&dma_of->resource[0]));
616 
617 	scsi_host_put(esp->host);
618 
619 	dev_set_drvdata(&op->dev, NULL);
620 
621 	put_device(&dma_of->dev);
622 
623 	return 0;
624 }
625 
626 static const struct of_device_id esp_match[] = {
627 	{
628 		.name = "SUNW,esp",
629 	},
630 	{
631 		.name = "SUNW,fas",
632 	},
633 	{
634 		.name = "esp",
635 	},
636 	{},
637 };
638 MODULE_DEVICE_TABLE(of, esp_match);
639 
640 static struct platform_driver esp_sbus_driver = {
641 	.driver = {
642 		.name = "esp",
643 		.of_match_table = esp_match,
644 	},
645 	.probe		= esp_sbus_probe,
646 	.remove		= esp_sbus_remove,
647 };
648 
649 static int __init sunesp_init(void)
650 {
651 	return platform_driver_register(&esp_sbus_driver);
652 }
653 
654 static void __exit sunesp_exit(void)
655 {
656 	platform_driver_unregister(&esp_sbus_driver);
657 }
658 
659 MODULE_DESCRIPTION("Sun ESP SCSI driver");
660 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
661 MODULE_LICENSE("GPL");
662 MODULE_VERSION(DRV_VERSION);
663 
664 module_init(sunesp_init);
665 module_exit(sunesp_exit);
666