xref: /openbmc/linux/drivers/memory/tegra/mc.c (revision be709d48)
1 /*
2  * Copyright (C) 2014 NVIDIA CORPORATION.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/delay.h>
11 #include <linux/interrupt.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/of_device.h>
16 #include <linux/platform_device.h>
17 #include <linux/slab.h>
18 #include <linux/sort.h>
19 
20 #include <soc/tegra/fuse.h>
21 
22 #include "mc.h"
23 
24 #define MC_INTSTATUS 0x000
25 
26 #define MC_INTMASK 0x004
27 
28 #define MC_ERR_STATUS 0x08
29 #define  MC_ERR_STATUS_TYPE_SHIFT 28
30 #define  MC_ERR_STATUS_TYPE_INVALID_SMMU_PAGE (6 << MC_ERR_STATUS_TYPE_SHIFT)
31 #define  MC_ERR_STATUS_TYPE_MASK (0x7 << MC_ERR_STATUS_TYPE_SHIFT)
32 #define  MC_ERR_STATUS_READABLE (1 << 27)
33 #define  MC_ERR_STATUS_WRITABLE (1 << 26)
34 #define  MC_ERR_STATUS_NONSECURE (1 << 25)
35 #define  MC_ERR_STATUS_ADR_HI_SHIFT 20
36 #define  MC_ERR_STATUS_ADR_HI_MASK 0x3
37 #define  MC_ERR_STATUS_SECURITY (1 << 17)
38 #define  MC_ERR_STATUS_RW (1 << 16)
39 
40 #define MC_ERR_ADR 0x0c
41 
42 #define MC_GART_ERROR_REQ		0x30
43 #define MC_DECERR_EMEM_OTHERS_STATUS	0x58
44 #define MC_SECURITY_VIOLATION_STATUS	0x74
45 
46 #define MC_EMEM_ARB_CFG 0x90
47 #define  MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE(x)	(((x) & 0x1ff) << 0)
48 #define  MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE_MASK	0x1ff
49 #define MC_EMEM_ARB_MISC0 0xd8
50 
51 #define MC_EMEM_ADR_CFG 0x54
52 #define MC_EMEM_ADR_CFG_EMEM_NUMDEV BIT(0)
53 
54 static const struct of_device_id tegra_mc_of_match[] = {
55 #ifdef CONFIG_ARCH_TEGRA_2x_SOC
56 	{ .compatible = "nvidia,tegra20-mc-gart", .data = &tegra20_mc_soc },
57 #endif
58 #ifdef CONFIG_ARCH_TEGRA_3x_SOC
59 	{ .compatible = "nvidia,tegra30-mc", .data = &tegra30_mc_soc },
60 #endif
61 #ifdef CONFIG_ARCH_TEGRA_114_SOC
62 	{ .compatible = "nvidia,tegra114-mc", .data = &tegra114_mc_soc },
63 #endif
64 #ifdef CONFIG_ARCH_TEGRA_124_SOC
65 	{ .compatible = "nvidia,tegra124-mc", .data = &tegra124_mc_soc },
66 #endif
67 #ifdef CONFIG_ARCH_TEGRA_132_SOC
68 	{ .compatible = "nvidia,tegra132-mc", .data = &tegra132_mc_soc },
69 #endif
70 #ifdef CONFIG_ARCH_TEGRA_210_SOC
71 	{ .compatible = "nvidia,tegra210-mc", .data = &tegra210_mc_soc },
72 #endif
73 	{ }
74 };
75 MODULE_DEVICE_TABLE(of, tegra_mc_of_match);
76 
77 static int terga_mc_block_dma_common(struct tegra_mc *mc,
78 				     const struct tegra_mc_reset *rst)
79 {
80 	unsigned long flags;
81 	u32 value;
82 
83 	spin_lock_irqsave(&mc->lock, flags);
84 
85 	value = mc_readl(mc, rst->control) | BIT(rst->bit);
86 	mc_writel(mc, value, rst->control);
87 
88 	spin_unlock_irqrestore(&mc->lock, flags);
89 
90 	return 0;
91 }
92 
93 static bool terga_mc_dma_idling_common(struct tegra_mc *mc,
94 				       const struct tegra_mc_reset *rst)
95 {
96 	return (mc_readl(mc, rst->status) & BIT(rst->bit)) != 0;
97 }
98 
99 static int terga_mc_unblock_dma_common(struct tegra_mc *mc,
100 				       const struct tegra_mc_reset *rst)
101 {
102 	unsigned long flags;
103 	u32 value;
104 
105 	spin_lock_irqsave(&mc->lock, flags);
106 
107 	value = mc_readl(mc, rst->control) & ~BIT(rst->bit);
108 	mc_writel(mc, value, rst->control);
109 
110 	spin_unlock_irqrestore(&mc->lock, flags);
111 
112 	return 0;
113 }
114 
115 static int terga_mc_reset_status_common(struct tegra_mc *mc,
116 					const struct tegra_mc_reset *rst)
117 {
118 	return (mc_readl(mc, rst->control) & BIT(rst->bit)) != 0;
119 }
120 
121 const struct tegra_mc_reset_ops terga_mc_reset_ops_common = {
122 	.block_dma = terga_mc_block_dma_common,
123 	.dma_idling = terga_mc_dma_idling_common,
124 	.unblock_dma = terga_mc_unblock_dma_common,
125 	.reset_status = terga_mc_reset_status_common,
126 };
127 
128 static inline struct tegra_mc *reset_to_mc(struct reset_controller_dev *rcdev)
129 {
130 	return container_of(rcdev, struct tegra_mc, reset);
131 }
132 
133 static const struct tegra_mc_reset *tegra_mc_reset_find(struct tegra_mc *mc,
134 							unsigned long id)
135 {
136 	unsigned int i;
137 
138 	for (i = 0; i < mc->soc->num_resets; i++)
139 		if (mc->soc->resets[i].id == id)
140 			return &mc->soc->resets[i];
141 
142 	return NULL;
143 }
144 
145 static int tegra_mc_hotreset_assert(struct reset_controller_dev *rcdev,
146 				    unsigned long id)
147 {
148 	struct tegra_mc *mc = reset_to_mc(rcdev);
149 	const struct tegra_mc_reset_ops *rst_ops;
150 	const struct tegra_mc_reset *rst;
151 	int retries = 500;
152 	int err;
153 
154 	rst = tegra_mc_reset_find(mc, id);
155 	if (!rst)
156 		return -ENODEV;
157 
158 	rst_ops = mc->soc->reset_ops;
159 	if (!rst_ops)
160 		return -ENODEV;
161 
162 	if (rst_ops->block_dma) {
163 		/* block clients DMA requests */
164 		err = rst_ops->block_dma(mc, rst);
165 		if (err) {
166 			dev_err(mc->dev, "failed to block %s DMA: %d\n",
167 				rst->name, err);
168 			return err;
169 		}
170 	}
171 
172 	if (rst_ops->dma_idling) {
173 		/* wait for completion of the outstanding DMA requests */
174 		while (!rst_ops->dma_idling(mc, rst)) {
175 			if (!retries--) {
176 				dev_err(mc->dev, "failed to flush %s DMA\n",
177 					rst->name);
178 				return -EBUSY;
179 			}
180 
181 			usleep_range(10, 100);
182 		}
183 	}
184 
185 	if (rst_ops->hotreset_assert) {
186 		/* clear clients DMA requests sitting before arbitration */
187 		err = rst_ops->hotreset_assert(mc, rst);
188 		if (err) {
189 			dev_err(mc->dev, "failed to hot reset %s: %d\n",
190 				rst->name, err);
191 			return err;
192 		}
193 	}
194 
195 	return 0;
196 }
197 
198 static int tegra_mc_hotreset_deassert(struct reset_controller_dev *rcdev,
199 				      unsigned long id)
200 {
201 	struct tegra_mc *mc = reset_to_mc(rcdev);
202 	const struct tegra_mc_reset_ops *rst_ops;
203 	const struct tegra_mc_reset *rst;
204 	int err;
205 
206 	rst = tegra_mc_reset_find(mc, id);
207 	if (!rst)
208 		return -ENODEV;
209 
210 	rst_ops = mc->soc->reset_ops;
211 	if (!rst_ops)
212 		return -ENODEV;
213 
214 	if (rst_ops->hotreset_deassert) {
215 		/* take out client from hot reset */
216 		err = rst_ops->hotreset_deassert(mc, rst);
217 		if (err) {
218 			dev_err(mc->dev, "failed to deassert hot reset %s: %d\n",
219 				rst->name, err);
220 			return err;
221 		}
222 	}
223 
224 	if (rst_ops->unblock_dma) {
225 		/* allow new DMA requests to proceed to arbitration */
226 		err = rst_ops->unblock_dma(mc, rst);
227 		if (err) {
228 			dev_err(mc->dev, "failed to unblock %s DMA : %d\n",
229 				rst->name, err);
230 			return err;
231 		}
232 	}
233 
234 	return 0;
235 }
236 
237 static int tegra_mc_hotreset_status(struct reset_controller_dev *rcdev,
238 				    unsigned long id)
239 {
240 	struct tegra_mc *mc = reset_to_mc(rcdev);
241 	const struct tegra_mc_reset_ops *rst_ops;
242 	const struct tegra_mc_reset *rst;
243 
244 	rst = tegra_mc_reset_find(mc, id);
245 	if (!rst)
246 		return -ENODEV;
247 
248 	rst_ops = mc->soc->reset_ops;
249 	if (!rst_ops)
250 		return -ENODEV;
251 
252 	return rst_ops->reset_status(mc, rst);
253 }
254 
255 static const struct reset_control_ops tegra_mc_reset_ops = {
256 	.assert = tegra_mc_hotreset_assert,
257 	.deassert = tegra_mc_hotreset_deassert,
258 	.status = tegra_mc_hotreset_status,
259 };
260 
261 static int tegra_mc_reset_setup(struct tegra_mc *mc)
262 {
263 	int err;
264 
265 	mc->reset.ops = &tegra_mc_reset_ops;
266 	mc->reset.owner = THIS_MODULE;
267 	mc->reset.of_node = mc->dev->of_node;
268 	mc->reset.of_reset_n_cells = 1;
269 	mc->reset.nr_resets = mc->soc->num_resets;
270 
271 	err = reset_controller_register(&mc->reset);
272 	if (err < 0)
273 		return err;
274 
275 	return 0;
276 }
277 
278 static int tegra_mc_setup_latency_allowance(struct tegra_mc *mc)
279 {
280 	unsigned long long tick;
281 	unsigned int i;
282 	u32 value;
283 
284 	/* compute the number of MC clock cycles per tick */
285 	tick = mc->tick * clk_get_rate(mc->clk);
286 	do_div(tick, NSEC_PER_SEC);
287 
288 	value = readl(mc->regs + MC_EMEM_ARB_CFG);
289 	value &= ~MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE_MASK;
290 	value |= MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE(tick);
291 	writel(value, mc->regs + MC_EMEM_ARB_CFG);
292 
293 	/* write latency allowance defaults */
294 	for (i = 0; i < mc->soc->num_clients; i++) {
295 		const struct tegra_mc_la *la = &mc->soc->clients[i].la;
296 		u32 value;
297 
298 		value = readl(mc->regs + la->reg);
299 		value &= ~(la->mask << la->shift);
300 		value |= (la->def & la->mask) << la->shift;
301 		writel(value, mc->regs + la->reg);
302 	}
303 
304 	return 0;
305 }
306 
307 void tegra_mc_write_emem_configuration(struct tegra_mc *mc, unsigned long rate)
308 {
309 	unsigned int i;
310 	struct tegra_mc_timing *timing = NULL;
311 
312 	for (i = 0; i < mc->num_timings; i++) {
313 		if (mc->timings[i].rate == rate) {
314 			timing = &mc->timings[i];
315 			break;
316 		}
317 	}
318 
319 	if (!timing) {
320 		dev_err(mc->dev, "no memory timing registered for rate %lu\n",
321 			rate);
322 		return;
323 	}
324 
325 	for (i = 0; i < mc->soc->num_emem_regs; ++i)
326 		mc_writel(mc, timing->emem_data[i], mc->soc->emem_regs[i]);
327 }
328 
329 unsigned int tegra_mc_get_emem_device_count(struct tegra_mc *mc)
330 {
331 	u8 dram_count;
332 
333 	dram_count = mc_readl(mc, MC_EMEM_ADR_CFG);
334 	dram_count &= MC_EMEM_ADR_CFG_EMEM_NUMDEV;
335 	dram_count++;
336 
337 	return dram_count;
338 }
339 
340 static int load_one_timing(struct tegra_mc *mc,
341 			   struct tegra_mc_timing *timing,
342 			   struct device_node *node)
343 {
344 	int err;
345 	u32 tmp;
346 
347 	err = of_property_read_u32(node, "clock-frequency", &tmp);
348 	if (err) {
349 		dev_err(mc->dev,
350 			"timing %pOFn: failed to read rate\n", node);
351 		return err;
352 	}
353 
354 	timing->rate = tmp;
355 	timing->emem_data = devm_kcalloc(mc->dev, mc->soc->num_emem_regs,
356 					 sizeof(u32), GFP_KERNEL);
357 	if (!timing->emem_data)
358 		return -ENOMEM;
359 
360 	err = of_property_read_u32_array(node, "nvidia,emem-configuration",
361 					 timing->emem_data,
362 					 mc->soc->num_emem_regs);
363 	if (err) {
364 		dev_err(mc->dev,
365 			"timing %pOFn: failed to read EMEM configuration\n",
366 			node);
367 		return err;
368 	}
369 
370 	return 0;
371 }
372 
373 static int load_timings(struct tegra_mc *mc, struct device_node *node)
374 {
375 	struct device_node *child;
376 	struct tegra_mc_timing *timing;
377 	int child_count = of_get_child_count(node);
378 	int i = 0, err;
379 
380 	mc->timings = devm_kcalloc(mc->dev, child_count, sizeof(*timing),
381 				   GFP_KERNEL);
382 	if (!mc->timings)
383 		return -ENOMEM;
384 
385 	mc->num_timings = child_count;
386 
387 	for_each_child_of_node(node, child) {
388 		timing = &mc->timings[i++];
389 
390 		err = load_one_timing(mc, timing, child);
391 		if (err) {
392 			of_node_put(child);
393 			return err;
394 		}
395 	}
396 
397 	return 0;
398 }
399 
400 static int tegra_mc_setup_timings(struct tegra_mc *mc)
401 {
402 	struct device_node *node;
403 	u32 ram_code, node_ram_code;
404 	int err;
405 
406 	ram_code = tegra_read_ram_code();
407 
408 	mc->num_timings = 0;
409 
410 	for_each_child_of_node(mc->dev->of_node, node) {
411 		err = of_property_read_u32(node, "nvidia,ram-code",
412 					   &node_ram_code);
413 		if (err || (node_ram_code != ram_code))
414 			continue;
415 
416 		err = load_timings(mc, node);
417 		of_node_put(node);
418 		if (err)
419 			return err;
420 		break;
421 	}
422 
423 	if (mc->num_timings == 0)
424 		dev_warn(mc->dev,
425 			 "no memory timings for RAM code %u registered\n",
426 			 ram_code);
427 
428 	return 0;
429 }
430 
431 static const char *const status_names[32] = {
432 	[ 1] = "External interrupt",
433 	[ 6] = "EMEM address decode error",
434 	[ 7] = "GART page fault",
435 	[ 8] = "Security violation",
436 	[ 9] = "EMEM arbitration error",
437 	[10] = "Page fault",
438 	[11] = "Invalid APB ASID update",
439 	[12] = "VPR violation",
440 	[13] = "Secure carveout violation",
441 	[16] = "MTS carveout violation",
442 };
443 
444 static const char *const error_names[8] = {
445 	[2] = "EMEM decode error",
446 	[3] = "TrustZone violation",
447 	[4] = "Carveout violation",
448 	[6] = "SMMU translation error",
449 };
450 
451 static irqreturn_t tegra_mc_irq(int irq, void *data)
452 {
453 	struct tegra_mc *mc = data;
454 	unsigned long status;
455 	unsigned int bit;
456 
457 	/* mask all interrupts to avoid flooding */
458 	status = mc_readl(mc, MC_INTSTATUS) & mc->soc->intmask;
459 	if (!status)
460 		return IRQ_NONE;
461 
462 	for_each_set_bit(bit, &status, 32) {
463 		const char *error = status_names[bit] ?: "unknown";
464 		const char *client = "unknown", *desc;
465 		const char *direction, *secure;
466 		phys_addr_t addr = 0;
467 		unsigned int i;
468 		char perm[7];
469 		u8 id, type;
470 		u32 value;
471 
472 		value = mc_readl(mc, MC_ERR_STATUS);
473 
474 #ifdef CONFIG_PHYS_ADDR_T_64BIT
475 		if (mc->soc->num_address_bits > 32) {
476 			addr = ((value >> MC_ERR_STATUS_ADR_HI_SHIFT) &
477 				MC_ERR_STATUS_ADR_HI_MASK);
478 			addr <<= 32;
479 		}
480 #endif
481 
482 		if (value & MC_ERR_STATUS_RW)
483 			direction = "write";
484 		else
485 			direction = "read";
486 
487 		if (value & MC_ERR_STATUS_SECURITY)
488 			secure = "secure ";
489 		else
490 			secure = "";
491 
492 		id = value & mc->soc->client_id_mask;
493 
494 		for (i = 0; i < mc->soc->num_clients; i++) {
495 			if (mc->soc->clients[i].id == id) {
496 				client = mc->soc->clients[i].name;
497 				break;
498 			}
499 		}
500 
501 		type = (value & MC_ERR_STATUS_TYPE_MASK) >>
502 		       MC_ERR_STATUS_TYPE_SHIFT;
503 		desc = error_names[type];
504 
505 		switch (value & MC_ERR_STATUS_TYPE_MASK) {
506 		case MC_ERR_STATUS_TYPE_INVALID_SMMU_PAGE:
507 			perm[0] = ' ';
508 			perm[1] = '[';
509 
510 			if (value & MC_ERR_STATUS_READABLE)
511 				perm[2] = 'R';
512 			else
513 				perm[2] = '-';
514 
515 			if (value & MC_ERR_STATUS_WRITABLE)
516 				perm[3] = 'W';
517 			else
518 				perm[3] = '-';
519 
520 			if (value & MC_ERR_STATUS_NONSECURE)
521 				perm[4] = '-';
522 			else
523 				perm[4] = 'S';
524 
525 			perm[5] = ']';
526 			perm[6] = '\0';
527 			break;
528 
529 		default:
530 			perm[0] = '\0';
531 			break;
532 		}
533 
534 		value = mc_readl(mc, MC_ERR_ADR);
535 		addr |= value;
536 
537 		dev_err_ratelimited(mc->dev, "%s: %s%s @%pa: %s (%s%s)\n",
538 				    client, secure, direction, &addr, error,
539 				    desc, perm);
540 	}
541 
542 	/* clear interrupts */
543 	mc_writel(mc, status, MC_INTSTATUS);
544 
545 	return IRQ_HANDLED;
546 }
547 
548 static __maybe_unused irqreturn_t tegra20_mc_irq(int irq, void *data)
549 {
550 	struct tegra_mc *mc = data;
551 	unsigned long status;
552 	unsigned int bit;
553 
554 	/* mask all interrupts to avoid flooding */
555 	status = mc_readl(mc, MC_INTSTATUS) & mc->soc->intmask;
556 	if (!status)
557 		return IRQ_NONE;
558 
559 	for_each_set_bit(bit, &status, 32) {
560 		const char *direction = "read", *secure = "";
561 		const char *error = status_names[bit];
562 		const char *client, *desc;
563 		phys_addr_t addr;
564 		u32 value, reg;
565 		u8 id, type;
566 
567 		switch (BIT(bit)) {
568 		case MC_INT_DECERR_EMEM:
569 			reg = MC_DECERR_EMEM_OTHERS_STATUS;
570 			value = mc_readl(mc, reg);
571 
572 			id = value & mc->soc->client_id_mask;
573 			desc = error_names[2];
574 
575 			if (value & BIT(31))
576 				direction = "write";
577 			break;
578 
579 		case MC_INT_INVALID_GART_PAGE:
580 			reg = MC_GART_ERROR_REQ;
581 			value = mc_readl(mc, reg);
582 
583 			id = (value >> 1) & mc->soc->client_id_mask;
584 			desc = error_names[2];
585 
586 			if (value & BIT(0))
587 				direction = "write";
588 			break;
589 
590 		case MC_INT_SECURITY_VIOLATION:
591 			reg = MC_SECURITY_VIOLATION_STATUS;
592 			value = mc_readl(mc, reg);
593 
594 			id = value & mc->soc->client_id_mask;
595 			type = (value & BIT(30)) ? 4 : 3;
596 			desc = error_names[type];
597 			secure = "secure ";
598 
599 			if (value & BIT(31))
600 				direction = "write";
601 			break;
602 
603 		default:
604 			continue;
605 		}
606 
607 		client = mc->soc->clients[id].name;
608 		addr = mc_readl(mc, reg + sizeof(u32));
609 
610 		dev_err_ratelimited(mc->dev, "%s: %s%s @%pa: %s (%s)\n",
611 				    client, secure, direction, &addr, error,
612 				    desc);
613 	}
614 
615 	/* clear interrupts */
616 	mc_writel(mc, status, MC_INTSTATUS);
617 
618 	return IRQ_HANDLED;
619 }
620 
621 static int tegra_mc_probe(struct platform_device *pdev)
622 {
623 	struct resource *res;
624 	struct tegra_mc *mc;
625 	void *isr;
626 	int err;
627 
628 	mc = devm_kzalloc(&pdev->dev, sizeof(*mc), GFP_KERNEL);
629 	if (!mc)
630 		return -ENOMEM;
631 
632 	platform_set_drvdata(pdev, mc);
633 	spin_lock_init(&mc->lock);
634 	mc->soc = of_device_get_match_data(&pdev->dev);
635 	mc->dev = &pdev->dev;
636 
637 	/* length of MC tick in nanoseconds */
638 	mc->tick = 30;
639 
640 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
641 	mc->regs = devm_ioremap_resource(&pdev->dev, res);
642 	if (IS_ERR(mc->regs))
643 		return PTR_ERR(mc->regs);
644 
645 	mc->clk = devm_clk_get(&pdev->dev, "mc");
646 	if (IS_ERR(mc->clk)) {
647 		dev_err(&pdev->dev, "failed to get MC clock: %ld\n",
648 			PTR_ERR(mc->clk));
649 		return PTR_ERR(mc->clk);
650 	}
651 
652 #ifdef CONFIG_ARCH_TEGRA_2x_SOC
653 	if (mc->soc == &tegra20_mc_soc) {
654 		isr = tegra20_mc_irq;
655 	} else
656 #endif
657 	{
658 		err = tegra_mc_setup_latency_allowance(mc);
659 		if (err < 0) {
660 			dev_err(&pdev->dev,
661 				"failed to setup latency allowance: %d\n",
662 				err);
663 			return err;
664 		}
665 
666 		isr = tegra_mc_irq;
667 
668 		err = tegra_mc_setup_timings(mc);
669 		if (err < 0) {
670 			dev_err(&pdev->dev, "failed to setup timings: %d\n",
671 				err);
672 			return err;
673 		}
674 	}
675 
676 	mc->irq = platform_get_irq(pdev, 0);
677 	if (mc->irq < 0) {
678 		dev_err(&pdev->dev, "interrupt not specified\n");
679 		return mc->irq;
680 	}
681 
682 	WARN(!mc->soc->client_id_mask, "missing client ID mask for this SoC\n");
683 
684 	mc_writel(mc, mc->soc->intmask, MC_INTMASK);
685 
686 	err = devm_request_irq(&pdev->dev, mc->irq, isr, 0,
687 			       dev_name(&pdev->dev), mc);
688 	if (err < 0) {
689 		dev_err(&pdev->dev, "failed to request IRQ#%u: %d\n", mc->irq,
690 			err);
691 		return err;
692 	}
693 
694 	err = tegra_mc_reset_setup(mc);
695 	if (err < 0)
696 		dev_err(&pdev->dev, "failed to register reset controller: %d\n",
697 			err);
698 
699 	if (IS_ENABLED(CONFIG_TEGRA_IOMMU_SMMU) && mc->soc->smmu) {
700 		mc->smmu = tegra_smmu_probe(&pdev->dev, mc->soc->smmu, mc);
701 		if (IS_ERR(mc->smmu)) {
702 			dev_err(&pdev->dev, "failed to probe SMMU: %ld\n",
703 				PTR_ERR(mc->smmu));
704 			mc->smmu = NULL;
705 		}
706 	}
707 
708 	if (IS_ENABLED(CONFIG_TEGRA_IOMMU_GART) && !mc->soc->smmu) {
709 		mc->gart = tegra_gart_probe(&pdev->dev, mc);
710 		if (IS_ERR(mc->gart)) {
711 			dev_err(&pdev->dev, "failed to probe GART: %ld\n",
712 				PTR_ERR(mc->gart));
713 			mc->gart = NULL;
714 		}
715 	}
716 
717 	return 0;
718 }
719 
720 static int tegra_mc_suspend(struct device *dev)
721 {
722 	struct tegra_mc *mc = dev_get_drvdata(dev);
723 	int err;
724 
725 	if (IS_ENABLED(CONFIG_TEGRA_IOMMU_GART) && mc->gart) {
726 		err = tegra_gart_suspend(mc->gart);
727 		if (err)
728 			return err;
729 	}
730 
731 	return 0;
732 }
733 
734 static int tegra_mc_resume(struct device *dev)
735 {
736 	struct tegra_mc *mc = dev_get_drvdata(dev);
737 	int err;
738 
739 	if (IS_ENABLED(CONFIG_TEGRA_IOMMU_GART) && mc->gart) {
740 		err = tegra_gart_resume(mc->gart);
741 		if (err)
742 			return err;
743 	}
744 
745 	return 0;
746 }
747 
748 static const struct dev_pm_ops tegra_mc_pm_ops = {
749 	.suspend = tegra_mc_suspend,
750 	.resume = tegra_mc_resume,
751 };
752 
753 static struct platform_driver tegra_mc_driver = {
754 	.driver = {
755 		.name = "tegra-mc",
756 		.of_match_table = tegra_mc_of_match,
757 		.pm = &tegra_mc_pm_ops,
758 		.suppress_bind_attrs = true,
759 	},
760 	.prevent_deferred_probe = true,
761 	.probe = tegra_mc_probe,
762 };
763 
764 static int tegra_mc_init(void)
765 {
766 	return platform_driver_register(&tegra_mc_driver);
767 }
768 arch_initcall(tegra_mc_init);
769 
770 MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
771 MODULE_DESCRIPTION("NVIDIA Tegra Memory Controller driver");
772 MODULE_LICENSE("GPL v2");
773