xref: /openbmc/linux/drivers/scsi/sun_esp.c (revision b737eecd)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* sun_esp.c: ESP front-end for Sparc SBUS systems.
3  *
4  * Copyright (C) 2007, 2008 David S. Miller (davem@davemloft.net)
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/types.h>
9 #include <linux/delay.h>
10 #include <linux/module.h>
11 #include <linux/mm.h>
12 #include <linux/init.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/of.h>
15 #include <linux/of_device.h>
16 #include <linux/gfp.h>
17 
18 #include <asm/irq.h>
19 #include <asm/io.h>
20 #include <asm/dma.h>
21 
22 #include <scsi/scsi_host.h>
23 
24 #include "esp_scsi.h"
25 
26 #define DRV_MODULE_NAME		"sun_esp"
27 #define PFX DRV_MODULE_NAME	": "
28 #define DRV_VERSION		"1.100"
29 #define DRV_MODULE_RELDATE	"August 27, 2008"
30 
31 #define dma_read32(REG) \
32 	sbus_readl(esp->dma_regs + (REG))
33 #define dma_write32(VAL, REG) \
34 	sbus_writel((VAL), esp->dma_regs + (REG))
35 
36 /* DVMA chip revisions */
37 enum dvma_rev {
38 	dvmarev0,
39 	dvmaesc1,
40 	dvmarev1,
41 	dvmarev2,
42 	dvmarev3,
43 	dvmarevplus,
44 	dvmahme
45 };
46 
47 static int esp_sbus_setup_dma(struct esp *esp, struct platform_device *dma_of)
48 {
49 	esp->dma = dma_of;
50 
51 	esp->dma_regs = of_ioremap(&dma_of->resource[0], 0,
52 				   resource_size(&dma_of->resource[0]),
53 				   "espdma");
54 	if (!esp->dma_regs)
55 		return -ENOMEM;
56 
57 	switch (dma_read32(DMA_CSR) & DMA_DEVICE_ID) {
58 	case DMA_VERS0:
59 		esp->dmarev = dvmarev0;
60 		break;
61 	case DMA_ESCV1:
62 		esp->dmarev = dvmaesc1;
63 		break;
64 	case DMA_VERS1:
65 		esp->dmarev = dvmarev1;
66 		break;
67 	case DMA_VERS2:
68 		esp->dmarev = dvmarev2;
69 		break;
70 	case DMA_VERHME:
71 		esp->dmarev = dvmahme;
72 		break;
73 	case DMA_VERSPLUS:
74 		esp->dmarev = dvmarevplus;
75 		break;
76 	}
77 
78 	return 0;
79 
80 }
81 
82 static int esp_sbus_map_regs(struct esp *esp, int hme)
83 {
84 	struct platform_device *op = to_platform_device(esp->dev);
85 	struct resource *res;
86 
87 	/* On HME, two reg sets exist, first is DVMA,
88 	 * second is ESP registers.
89 	 */
90 	if (hme)
91 		res = &op->resource[1];
92 	else
93 		res = &op->resource[0];
94 
95 	esp->regs = of_ioremap(res, 0, SBUS_ESP_REG_SIZE, "ESP");
96 	if (!esp->regs)
97 		return -ENOMEM;
98 
99 	return 0;
100 }
101 
102 static int esp_sbus_map_command_block(struct esp *esp)
103 {
104 	esp->command_block = dma_alloc_coherent(esp->dev, 16,
105 						&esp->command_block_dma,
106 						GFP_KERNEL);
107 	if (!esp->command_block)
108 		return -ENOMEM;
109 	return 0;
110 }
111 
112 static int esp_sbus_register_irq(struct esp *esp)
113 {
114 	struct Scsi_Host *host = esp->host;
115 	struct platform_device *op = to_platform_device(esp->dev);
116 
117 	host->irq = op->archdata.irqs[0];
118 	return request_irq(host->irq, scsi_esp_intr, IRQF_SHARED, "ESP", esp);
119 }
120 
121 static void esp_get_scsi_id(struct esp *esp, struct platform_device *espdma)
122 {
123 	struct platform_device *op = to_platform_device(esp->dev);
124 	struct device_node *dp;
125 
126 	dp = op->dev.of_node;
127 	esp->scsi_id = of_getintprop_default(dp, "initiator-id", 0xff);
128 	if (esp->scsi_id != 0xff)
129 		goto done;
130 
131 	esp->scsi_id = of_getintprop_default(dp, "scsi-initiator-id", 0xff);
132 	if (esp->scsi_id != 0xff)
133 		goto done;
134 
135 	esp->scsi_id = of_getintprop_default(espdma->dev.of_node,
136 					     "scsi-initiator-id", 7);
137 
138 done:
139 	esp->host->this_id = esp->scsi_id;
140 	esp->scsi_id_mask = (1 << esp->scsi_id);
141 }
142 
143 static void esp_get_differential(struct esp *esp)
144 {
145 	struct platform_device *op = to_platform_device(esp->dev);
146 	struct device_node *dp;
147 
148 	dp = op->dev.of_node;
149 	if (of_find_property(dp, "differential", NULL))
150 		esp->flags |= ESP_FLAG_DIFFERENTIAL;
151 	else
152 		esp->flags &= ~ESP_FLAG_DIFFERENTIAL;
153 }
154 
155 static void esp_get_clock_params(struct esp *esp)
156 {
157 	struct platform_device *op = to_platform_device(esp->dev);
158 	struct device_node *bus_dp, *dp;
159 	int fmhz;
160 
161 	dp = op->dev.of_node;
162 	bus_dp = dp->parent;
163 
164 	fmhz = of_getintprop_default(dp, "clock-frequency", 0);
165 	if (fmhz == 0)
166 		fmhz = of_getintprop_default(bus_dp, "clock-frequency", 0);
167 
168 	esp->cfreq = fmhz;
169 }
170 
171 static void esp_get_bursts(struct esp *esp, struct platform_device *dma_of)
172 {
173 	struct device_node *dma_dp = dma_of->dev.of_node;
174 	struct platform_device *op = to_platform_device(esp->dev);
175 	struct device_node *dp;
176 	u8 bursts, val;
177 
178 	dp = op->dev.of_node;
179 	bursts = of_getintprop_default(dp, "burst-sizes", 0xff);
180 	val = of_getintprop_default(dma_dp, "burst-sizes", 0xff);
181 	if (val != 0xff)
182 		bursts &= val;
183 
184 	val = of_getintprop_default(dma_dp->parent, "burst-sizes", 0xff);
185 	if (val != 0xff)
186 		bursts &= val;
187 
188 	if (bursts == 0xff ||
189 	    (bursts & DMA_BURST16) == 0 ||
190 	    (bursts & DMA_BURST32) == 0)
191 		bursts = (DMA_BURST32 - 1);
192 
193 	esp->bursts = bursts;
194 }
195 
196 static void esp_sbus_get_props(struct esp *esp, struct platform_device *espdma)
197 {
198 	esp_get_scsi_id(esp, espdma);
199 	esp_get_differential(esp);
200 	esp_get_clock_params(esp);
201 	esp_get_bursts(esp, espdma);
202 }
203 
204 static void sbus_esp_write8(struct esp *esp, u8 val, unsigned long reg)
205 {
206 	sbus_writeb(val, esp->regs + (reg * 4UL));
207 }
208 
209 static u8 sbus_esp_read8(struct esp *esp, unsigned long reg)
210 {
211 	return sbus_readb(esp->regs + (reg * 4UL));
212 }
213 
214 static int sbus_esp_irq_pending(struct esp *esp)
215 {
216 	if (dma_read32(DMA_CSR) & (DMA_HNDL_INTR | DMA_HNDL_ERROR))
217 		return 1;
218 	return 0;
219 }
220 
221 static void sbus_esp_reset_dma(struct esp *esp)
222 {
223 	int can_do_burst16, can_do_burst32, can_do_burst64;
224 	int can_do_sbus64, lim;
225 	struct platform_device *op = to_platform_device(esp->dev);
226 	u32 val;
227 
228 	can_do_burst16 = (esp->bursts & DMA_BURST16) != 0;
229 	can_do_burst32 = (esp->bursts & DMA_BURST32) != 0;
230 	can_do_burst64 = 0;
231 	can_do_sbus64 = 0;
232 	if (sbus_can_dma_64bit())
233 		can_do_sbus64 = 1;
234 	if (sbus_can_burst64())
235 		can_do_burst64 = (esp->bursts & DMA_BURST64) != 0;
236 
237 	/* Put the DVMA into a known state. */
238 	if (esp->dmarev != dvmahme) {
239 		val = dma_read32(DMA_CSR);
240 		dma_write32(val | DMA_RST_SCSI, DMA_CSR);
241 		dma_write32(val & ~DMA_RST_SCSI, DMA_CSR);
242 	}
243 	switch (esp->dmarev) {
244 	case dvmahme:
245 		dma_write32(DMA_RESET_FAS366, DMA_CSR);
246 		dma_write32(DMA_RST_SCSI, DMA_CSR);
247 
248 		esp->prev_hme_dmacsr = (DMA_PARITY_OFF | DMA_2CLKS |
249 					DMA_SCSI_DISAB | DMA_INT_ENAB);
250 
251 		esp->prev_hme_dmacsr &= ~(DMA_ENABLE | DMA_ST_WRITE |
252 					  DMA_BRST_SZ);
253 
254 		if (can_do_burst64)
255 			esp->prev_hme_dmacsr |= DMA_BRST64;
256 		else if (can_do_burst32)
257 			esp->prev_hme_dmacsr |= DMA_BRST32;
258 
259 		if (can_do_sbus64) {
260 			esp->prev_hme_dmacsr |= DMA_SCSI_SBUS64;
261 			sbus_set_sbus64(&op->dev, esp->bursts);
262 		}
263 
264 		lim = 1000;
265 		while (dma_read32(DMA_CSR) & DMA_PEND_READ) {
266 			if (--lim == 0) {
267 				printk(KERN_ALERT PFX "esp%d: DMA_PEND_READ "
268 				       "will not clear!\n",
269 				       esp->host->unique_id);
270 				break;
271 			}
272 			udelay(1);
273 		}
274 
275 		dma_write32(0, DMA_CSR);
276 		dma_write32(esp->prev_hme_dmacsr, DMA_CSR);
277 
278 		dma_write32(0, DMA_ADDR);
279 		break;
280 
281 	case dvmarev2:
282 		if (esp->rev != ESP100) {
283 			val = dma_read32(DMA_CSR);
284 			dma_write32(val | DMA_3CLKS, DMA_CSR);
285 		}
286 		break;
287 
288 	case dvmarev3:
289 		val = dma_read32(DMA_CSR);
290 		val &= ~DMA_3CLKS;
291 		val |= DMA_2CLKS;
292 		if (can_do_burst32) {
293 			val &= ~DMA_BRST_SZ;
294 			val |= DMA_BRST32;
295 		}
296 		dma_write32(val, DMA_CSR);
297 		break;
298 
299 	case dvmaesc1:
300 		val = dma_read32(DMA_CSR);
301 		val |= DMA_ADD_ENABLE;
302 		val &= ~DMA_BCNT_ENAB;
303 		if (!can_do_burst32 && can_do_burst16) {
304 			val |= DMA_ESC_BURST;
305 		} else {
306 			val &= ~(DMA_ESC_BURST);
307 		}
308 		dma_write32(val, DMA_CSR);
309 		break;
310 
311 	default:
312 		break;
313 	}
314 
315 	/* Enable interrupts.  */
316 	val = dma_read32(DMA_CSR);
317 	dma_write32(val | DMA_INT_ENAB, DMA_CSR);
318 }
319 
320 static void sbus_esp_dma_drain(struct esp *esp)
321 {
322 	u32 csr;
323 	int lim;
324 
325 	if (esp->dmarev == dvmahme)
326 		return;
327 
328 	csr = dma_read32(DMA_CSR);
329 	if (!(csr & DMA_FIFO_ISDRAIN))
330 		return;
331 
332 	if (esp->dmarev != dvmarev3 && esp->dmarev != dvmaesc1)
333 		dma_write32(csr | DMA_FIFO_STDRAIN, DMA_CSR);
334 
335 	lim = 1000;
336 	while (dma_read32(DMA_CSR) & DMA_FIFO_ISDRAIN) {
337 		if (--lim == 0) {
338 			printk(KERN_ALERT PFX "esp%d: DMA will not drain!\n",
339 			       esp->host->unique_id);
340 			break;
341 		}
342 		udelay(1);
343 	}
344 }
345 
346 static void sbus_esp_dma_invalidate(struct esp *esp)
347 {
348 	if (esp->dmarev == dvmahme) {
349 		dma_write32(DMA_RST_SCSI, DMA_CSR);
350 
351 		esp->prev_hme_dmacsr = ((esp->prev_hme_dmacsr |
352 					 (DMA_PARITY_OFF | DMA_2CLKS |
353 					  DMA_SCSI_DISAB | DMA_INT_ENAB)) &
354 					~(DMA_ST_WRITE | DMA_ENABLE));
355 
356 		dma_write32(0, DMA_CSR);
357 		dma_write32(esp->prev_hme_dmacsr, DMA_CSR);
358 
359 		/* This is necessary to avoid having the SCSI channel
360 		 * engine lock up on us.
361 		 */
362 		dma_write32(0, DMA_ADDR);
363 	} else {
364 		u32 val;
365 		int lim;
366 
367 		lim = 1000;
368 		while ((val = dma_read32(DMA_CSR)) & DMA_PEND_READ) {
369 			if (--lim == 0) {
370 				printk(KERN_ALERT PFX "esp%d: DMA will not "
371 				       "invalidate!\n", esp->host->unique_id);
372 				break;
373 			}
374 			udelay(1);
375 		}
376 
377 		val &= ~(DMA_ENABLE | DMA_ST_WRITE | DMA_BCNT_ENAB);
378 		val |= DMA_FIFO_INV;
379 		dma_write32(val, DMA_CSR);
380 		val &= ~DMA_FIFO_INV;
381 		dma_write32(val, DMA_CSR);
382 	}
383 }
384 
385 static void sbus_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
386 				  u32 dma_count, int write, u8 cmd)
387 {
388 	u32 csr;
389 
390 	BUG_ON(!(cmd & ESP_CMD_DMA));
391 
392 	sbus_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
393 	sbus_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
394 	if (esp->rev == FASHME) {
395 		sbus_esp_write8(esp, (esp_count >> 16) & 0xff, FAS_RLO);
396 		sbus_esp_write8(esp, 0, FAS_RHI);
397 
398 		scsi_esp_cmd(esp, cmd);
399 
400 		csr = esp->prev_hme_dmacsr;
401 		csr |= DMA_SCSI_DISAB | DMA_ENABLE;
402 		if (write)
403 			csr |= DMA_ST_WRITE;
404 		else
405 			csr &= ~DMA_ST_WRITE;
406 		esp->prev_hme_dmacsr = csr;
407 
408 		dma_write32(dma_count, DMA_COUNT);
409 		dma_write32(addr, DMA_ADDR);
410 		dma_write32(csr, DMA_CSR);
411 	} else {
412 		csr = dma_read32(DMA_CSR);
413 		csr |= DMA_ENABLE;
414 		if (write)
415 			csr |= DMA_ST_WRITE;
416 		else
417 			csr &= ~DMA_ST_WRITE;
418 		dma_write32(csr, DMA_CSR);
419 		if (esp->dmarev == dvmaesc1) {
420 			u32 end = PAGE_ALIGN(addr + dma_count + 16U);
421 			dma_write32(end - addr, DMA_COUNT);
422 		}
423 		dma_write32(addr, DMA_ADDR);
424 
425 		scsi_esp_cmd(esp, cmd);
426 	}
427 
428 }
429 
430 static int sbus_esp_dma_error(struct esp *esp)
431 {
432 	u32 csr = dma_read32(DMA_CSR);
433 
434 	if (csr & DMA_HNDL_ERROR)
435 		return 1;
436 
437 	return 0;
438 }
439 
440 static const struct esp_driver_ops sbus_esp_ops = {
441 	.esp_write8	=	sbus_esp_write8,
442 	.esp_read8	=	sbus_esp_read8,
443 	.irq_pending	=	sbus_esp_irq_pending,
444 	.reset_dma	=	sbus_esp_reset_dma,
445 	.dma_drain	=	sbus_esp_dma_drain,
446 	.dma_invalidate	=	sbus_esp_dma_invalidate,
447 	.send_dma_cmd	=	sbus_esp_send_dma_cmd,
448 	.dma_error	=	sbus_esp_dma_error,
449 };
450 
451 static int esp_sbus_probe_one(struct platform_device *op,
452 			      struct platform_device *espdma, int hme)
453 {
454 	struct scsi_host_template *tpnt = &scsi_esp_template;
455 	struct Scsi_Host *host;
456 	struct esp *esp;
457 	int err;
458 
459 	host = scsi_host_alloc(tpnt, sizeof(struct esp));
460 
461 	err = -ENOMEM;
462 	if (!host)
463 		goto fail;
464 
465 	host->max_id = (hme ? 16 : 8);
466 	esp = shost_priv(host);
467 
468 	esp->host = host;
469 	esp->dev = &op->dev;
470 	esp->ops = &sbus_esp_ops;
471 
472 	if (hme)
473 		esp->flags |= ESP_FLAG_WIDE_CAPABLE;
474 
475 	err = esp_sbus_setup_dma(esp, espdma);
476 	if (err < 0)
477 		goto fail_unlink;
478 
479 	err = esp_sbus_map_regs(esp, hme);
480 	if (err < 0)
481 		goto fail_unlink;
482 
483 	err = esp_sbus_map_command_block(esp);
484 	if (err < 0)
485 		goto fail_unmap_regs;
486 
487 	err = esp_sbus_register_irq(esp);
488 	if (err < 0)
489 		goto fail_unmap_command_block;
490 
491 	esp_sbus_get_props(esp, espdma);
492 
493 	/* Before we try to touch the ESP chip, ESC1 dma can
494 	 * come up with the reset bit set, so make sure that
495 	 * is clear first.
496 	 */
497 	if (esp->dmarev == dvmaesc1) {
498 		u32 val = dma_read32(DMA_CSR);
499 
500 		dma_write32(val & ~DMA_RST_SCSI, DMA_CSR);
501 	}
502 
503 	dev_set_drvdata(&op->dev, esp);
504 
505 	err = scsi_esp_register(esp);
506 	if (err)
507 		goto fail_free_irq;
508 
509 	return 0;
510 
511 fail_free_irq:
512 	free_irq(host->irq, esp);
513 fail_unmap_command_block:
514 	dma_free_coherent(&op->dev, 16,
515 			  esp->command_block,
516 			  esp->command_block_dma);
517 fail_unmap_regs:
518 	of_iounmap(&op->resource[(hme ? 1 : 0)], esp->regs, SBUS_ESP_REG_SIZE);
519 fail_unlink:
520 	scsi_host_put(host);
521 fail:
522 	return err;
523 }
524 
525 static int esp_sbus_probe(struct platform_device *op)
526 {
527 	struct device_node *dma_node = NULL;
528 	struct device_node *dp = op->dev.of_node;
529 	struct platform_device *dma_of = NULL;
530 	int hme = 0;
531 	int ret;
532 
533 	if (of_node_name_eq(dp->parent, "espdma") ||
534 	    of_node_name_eq(dp->parent, "dma"))
535 		dma_node = dp->parent;
536 	else if (of_node_name_eq(dp, "SUNW,fas")) {
537 		dma_node = op->dev.of_node;
538 		hme = 1;
539 	}
540 	if (dma_node)
541 		dma_of = of_find_device_by_node(dma_node);
542 	if (!dma_of)
543 		return -ENODEV;
544 
545 	ret = esp_sbus_probe_one(op, dma_of, hme);
546 	if (ret)
547 		put_device(&dma_of->dev);
548 
549 	return ret;
550 }
551 
552 static int esp_sbus_remove(struct platform_device *op)
553 {
554 	struct esp *esp = dev_get_drvdata(&op->dev);
555 	struct platform_device *dma_of = esp->dma;
556 	unsigned int irq = esp->host->irq;
557 	bool is_hme;
558 	u32 val;
559 
560 	scsi_esp_unregister(esp);
561 
562 	/* Disable interrupts.  */
563 	val = dma_read32(DMA_CSR);
564 	dma_write32(val & ~DMA_INT_ENAB, DMA_CSR);
565 
566 	free_irq(irq, esp);
567 
568 	is_hme = (esp->dmarev == dvmahme);
569 
570 	dma_free_coherent(&op->dev, 16,
571 			  esp->command_block,
572 			  esp->command_block_dma);
573 	of_iounmap(&op->resource[(is_hme ? 1 : 0)], esp->regs,
574 		   SBUS_ESP_REG_SIZE);
575 	of_iounmap(&dma_of->resource[0], esp->dma_regs,
576 		   resource_size(&dma_of->resource[0]));
577 
578 	scsi_host_put(esp->host);
579 
580 	dev_set_drvdata(&op->dev, NULL);
581 
582 	put_device(&dma_of->dev);
583 
584 	return 0;
585 }
586 
587 static const struct of_device_id esp_match[] = {
588 	{
589 		.name = "SUNW,esp",
590 	},
591 	{
592 		.name = "SUNW,fas",
593 	},
594 	{
595 		.name = "esp",
596 	},
597 	{},
598 };
599 MODULE_DEVICE_TABLE(of, esp_match);
600 
601 static struct platform_driver esp_sbus_driver = {
602 	.driver = {
603 		.name = "esp",
604 		.of_match_table = esp_match,
605 	},
606 	.probe		= esp_sbus_probe,
607 	.remove		= esp_sbus_remove,
608 };
609 module_platform_driver(esp_sbus_driver);
610 
611 MODULE_DESCRIPTION("Sun ESP SCSI driver");
612 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
613 MODULE_LICENSE("GPL");
614 MODULE_VERSION(DRV_VERSION);
615