xref: /openbmc/linux/drivers/memory/tegra/mc.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014 NVIDIA CORPORATION.  All rights reserved.
4  */
5 
6 #include <linux/clk.h>
7 #include <linux/delay.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/interrupt.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/of_device.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/sort.h>
17 
18 #include <soc/tegra/fuse.h>
19 
20 #include "mc.h"
21 
22 static const struct of_device_id tegra_mc_of_match[] = {
23 #ifdef CONFIG_ARCH_TEGRA_2x_SOC
24 	{ .compatible = "nvidia,tegra20-mc-gart", .data = &tegra20_mc_soc },
25 #endif
26 #ifdef CONFIG_ARCH_TEGRA_3x_SOC
27 	{ .compatible = "nvidia,tegra30-mc", .data = &tegra30_mc_soc },
28 #endif
29 #ifdef CONFIG_ARCH_TEGRA_114_SOC
30 	{ .compatible = "nvidia,tegra114-mc", .data = &tegra114_mc_soc },
31 #endif
32 #ifdef CONFIG_ARCH_TEGRA_124_SOC
33 	{ .compatible = "nvidia,tegra124-mc", .data = &tegra124_mc_soc },
34 #endif
35 #ifdef CONFIG_ARCH_TEGRA_132_SOC
36 	{ .compatible = "nvidia,tegra132-mc", .data = &tegra132_mc_soc },
37 #endif
38 #ifdef CONFIG_ARCH_TEGRA_210_SOC
39 	{ .compatible = "nvidia,tegra210-mc", .data = &tegra210_mc_soc },
40 #endif
41 	{ }
42 };
43 MODULE_DEVICE_TABLE(of, tegra_mc_of_match);
44 
45 static int tegra_mc_block_dma_common(struct tegra_mc *mc,
46 				     const struct tegra_mc_reset *rst)
47 {
48 	unsigned long flags;
49 	u32 value;
50 
51 	spin_lock_irqsave(&mc->lock, flags);
52 
53 	value = mc_readl(mc, rst->control) | BIT(rst->bit);
54 	mc_writel(mc, value, rst->control);
55 
56 	spin_unlock_irqrestore(&mc->lock, flags);
57 
58 	return 0;
59 }
60 
61 static bool tegra_mc_dma_idling_common(struct tegra_mc *mc,
62 				       const struct tegra_mc_reset *rst)
63 {
64 	return (mc_readl(mc, rst->status) & BIT(rst->bit)) != 0;
65 }
66 
67 static int tegra_mc_unblock_dma_common(struct tegra_mc *mc,
68 				       const struct tegra_mc_reset *rst)
69 {
70 	unsigned long flags;
71 	u32 value;
72 
73 	spin_lock_irqsave(&mc->lock, flags);
74 
75 	value = mc_readl(mc, rst->control) & ~BIT(rst->bit);
76 	mc_writel(mc, value, rst->control);
77 
78 	spin_unlock_irqrestore(&mc->lock, flags);
79 
80 	return 0;
81 }
82 
83 static int tegra_mc_reset_status_common(struct tegra_mc *mc,
84 					const struct tegra_mc_reset *rst)
85 {
86 	return (mc_readl(mc, rst->control) & BIT(rst->bit)) != 0;
87 }
88 
89 const struct tegra_mc_reset_ops tegra_mc_reset_ops_common = {
90 	.block_dma = tegra_mc_block_dma_common,
91 	.dma_idling = tegra_mc_dma_idling_common,
92 	.unblock_dma = tegra_mc_unblock_dma_common,
93 	.reset_status = tegra_mc_reset_status_common,
94 };
95 
96 static inline struct tegra_mc *reset_to_mc(struct reset_controller_dev *rcdev)
97 {
98 	return container_of(rcdev, struct tegra_mc, reset);
99 }
100 
101 static const struct tegra_mc_reset *tegra_mc_reset_find(struct tegra_mc *mc,
102 							unsigned long id)
103 {
104 	unsigned int i;
105 
106 	for (i = 0; i < mc->soc->num_resets; i++)
107 		if (mc->soc->resets[i].id == id)
108 			return &mc->soc->resets[i];
109 
110 	return NULL;
111 }
112 
113 static int tegra_mc_hotreset_assert(struct reset_controller_dev *rcdev,
114 				    unsigned long id)
115 {
116 	struct tegra_mc *mc = reset_to_mc(rcdev);
117 	const struct tegra_mc_reset_ops *rst_ops;
118 	const struct tegra_mc_reset *rst;
119 	int retries = 500;
120 	int err;
121 
122 	rst = tegra_mc_reset_find(mc, id);
123 	if (!rst)
124 		return -ENODEV;
125 
126 	rst_ops = mc->soc->reset_ops;
127 	if (!rst_ops)
128 		return -ENODEV;
129 
130 	if (rst_ops->block_dma) {
131 		/* block clients DMA requests */
132 		err = rst_ops->block_dma(mc, rst);
133 		if (err) {
134 			dev_err(mc->dev, "failed to block %s DMA: %d\n",
135 				rst->name, err);
136 			return err;
137 		}
138 	}
139 
140 	if (rst_ops->dma_idling) {
141 		/* wait for completion of the outstanding DMA requests */
142 		while (!rst_ops->dma_idling(mc, rst)) {
143 			if (!retries--) {
144 				dev_err(mc->dev, "failed to flush %s DMA\n",
145 					rst->name);
146 				return -EBUSY;
147 			}
148 
149 			usleep_range(10, 100);
150 		}
151 	}
152 
153 	if (rst_ops->hotreset_assert) {
154 		/* clear clients DMA requests sitting before arbitration */
155 		err = rst_ops->hotreset_assert(mc, rst);
156 		if (err) {
157 			dev_err(mc->dev, "failed to hot reset %s: %d\n",
158 				rst->name, err);
159 			return err;
160 		}
161 	}
162 
163 	return 0;
164 }
165 
166 static int tegra_mc_hotreset_deassert(struct reset_controller_dev *rcdev,
167 				      unsigned long id)
168 {
169 	struct tegra_mc *mc = reset_to_mc(rcdev);
170 	const struct tegra_mc_reset_ops *rst_ops;
171 	const struct tegra_mc_reset *rst;
172 	int err;
173 
174 	rst = tegra_mc_reset_find(mc, id);
175 	if (!rst)
176 		return -ENODEV;
177 
178 	rst_ops = mc->soc->reset_ops;
179 	if (!rst_ops)
180 		return -ENODEV;
181 
182 	if (rst_ops->hotreset_deassert) {
183 		/* take out client from hot reset */
184 		err = rst_ops->hotreset_deassert(mc, rst);
185 		if (err) {
186 			dev_err(mc->dev, "failed to deassert hot reset %s: %d\n",
187 				rst->name, err);
188 			return err;
189 		}
190 	}
191 
192 	if (rst_ops->unblock_dma) {
193 		/* allow new DMA requests to proceed to arbitration */
194 		err = rst_ops->unblock_dma(mc, rst);
195 		if (err) {
196 			dev_err(mc->dev, "failed to unblock %s DMA : %d\n",
197 				rst->name, err);
198 			return err;
199 		}
200 	}
201 
202 	return 0;
203 }
204 
205 static int tegra_mc_hotreset_status(struct reset_controller_dev *rcdev,
206 				    unsigned long id)
207 {
208 	struct tegra_mc *mc = reset_to_mc(rcdev);
209 	const struct tegra_mc_reset_ops *rst_ops;
210 	const struct tegra_mc_reset *rst;
211 
212 	rst = tegra_mc_reset_find(mc, id);
213 	if (!rst)
214 		return -ENODEV;
215 
216 	rst_ops = mc->soc->reset_ops;
217 	if (!rst_ops)
218 		return -ENODEV;
219 
220 	return rst_ops->reset_status(mc, rst);
221 }
222 
223 static const struct reset_control_ops tegra_mc_reset_ops = {
224 	.assert = tegra_mc_hotreset_assert,
225 	.deassert = tegra_mc_hotreset_deassert,
226 	.status = tegra_mc_hotreset_status,
227 };
228 
229 static int tegra_mc_reset_setup(struct tegra_mc *mc)
230 {
231 	int err;
232 
233 	mc->reset.ops = &tegra_mc_reset_ops;
234 	mc->reset.owner = THIS_MODULE;
235 	mc->reset.of_node = mc->dev->of_node;
236 	mc->reset.of_reset_n_cells = 1;
237 	mc->reset.nr_resets = mc->soc->num_resets;
238 
239 	err = reset_controller_register(&mc->reset);
240 	if (err < 0)
241 		return err;
242 
243 	return 0;
244 }
245 
246 static int tegra_mc_setup_latency_allowance(struct tegra_mc *mc)
247 {
248 	unsigned long long tick;
249 	unsigned int i;
250 	u32 value;
251 
252 	/* compute the number of MC clock cycles per tick */
253 	tick = (unsigned long long)mc->tick * clk_get_rate(mc->clk);
254 	do_div(tick, NSEC_PER_SEC);
255 
256 	value = mc_readl(mc, MC_EMEM_ARB_CFG);
257 	value &= ~MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE_MASK;
258 	value |= MC_EMEM_ARB_CFG_CYCLES_PER_UPDATE(tick);
259 	mc_writel(mc, value, MC_EMEM_ARB_CFG);
260 
261 	/* write latency allowance defaults */
262 	for (i = 0; i < mc->soc->num_clients; i++) {
263 		const struct tegra_mc_la *la = &mc->soc->clients[i].la;
264 		u32 value;
265 
266 		value = mc_readl(mc, la->reg);
267 		value &= ~(la->mask << la->shift);
268 		value |= (la->def & la->mask) << la->shift;
269 		mc_writel(mc, value, la->reg);
270 	}
271 
272 	/* latch new values */
273 	mc_writel(mc, MC_TIMING_UPDATE, MC_TIMING_CONTROL);
274 
275 	return 0;
276 }
277 
278 int tegra_mc_write_emem_configuration(struct tegra_mc *mc, unsigned long rate)
279 {
280 	unsigned int i;
281 	struct tegra_mc_timing *timing = NULL;
282 
283 	for (i = 0; i < mc->num_timings; i++) {
284 		if (mc->timings[i].rate == rate) {
285 			timing = &mc->timings[i];
286 			break;
287 		}
288 	}
289 
290 	if (!timing) {
291 		dev_err(mc->dev, "no memory timing registered for rate %lu\n",
292 			rate);
293 		return -EINVAL;
294 	}
295 
296 	for (i = 0; i < mc->soc->num_emem_regs; ++i)
297 		mc_writel(mc, timing->emem_data[i], mc->soc->emem_regs[i]);
298 
299 	return 0;
300 }
301 
302 unsigned int tegra_mc_get_emem_device_count(struct tegra_mc *mc)
303 {
304 	u8 dram_count;
305 
306 	dram_count = mc_readl(mc, MC_EMEM_ADR_CFG);
307 	dram_count &= MC_EMEM_ADR_CFG_EMEM_NUMDEV;
308 	dram_count++;
309 
310 	return dram_count;
311 }
312 
313 static int load_one_timing(struct tegra_mc *mc,
314 			   struct tegra_mc_timing *timing,
315 			   struct device_node *node)
316 {
317 	int err;
318 	u32 tmp;
319 
320 	err = of_property_read_u32(node, "clock-frequency", &tmp);
321 	if (err) {
322 		dev_err(mc->dev,
323 			"timing %pOFn: failed to read rate\n", node);
324 		return err;
325 	}
326 
327 	timing->rate = tmp;
328 	timing->emem_data = devm_kcalloc(mc->dev, mc->soc->num_emem_regs,
329 					 sizeof(u32), GFP_KERNEL);
330 	if (!timing->emem_data)
331 		return -ENOMEM;
332 
333 	err = of_property_read_u32_array(node, "nvidia,emem-configuration",
334 					 timing->emem_data,
335 					 mc->soc->num_emem_regs);
336 	if (err) {
337 		dev_err(mc->dev,
338 			"timing %pOFn: failed to read EMEM configuration\n",
339 			node);
340 		return err;
341 	}
342 
343 	return 0;
344 }
345 
346 static int load_timings(struct tegra_mc *mc, struct device_node *node)
347 {
348 	struct device_node *child;
349 	struct tegra_mc_timing *timing;
350 	int child_count = of_get_child_count(node);
351 	int i = 0, err;
352 
353 	mc->timings = devm_kcalloc(mc->dev, child_count, sizeof(*timing),
354 				   GFP_KERNEL);
355 	if (!mc->timings)
356 		return -ENOMEM;
357 
358 	mc->num_timings = child_count;
359 
360 	for_each_child_of_node(node, child) {
361 		timing = &mc->timings[i++];
362 
363 		err = load_one_timing(mc, timing, child);
364 		if (err) {
365 			of_node_put(child);
366 			return err;
367 		}
368 	}
369 
370 	return 0;
371 }
372 
373 static int tegra_mc_setup_timings(struct tegra_mc *mc)
374 {
375 	struct device_node *node;
376 	u32 ram_code, node_ram_code;
377 	int err;
378 
379 	ram_code = tegra_read_ram_code();
380 
381 	mc->num_timings = 0;
382 
383 	for_each_child_of_node(mc->dev->of_node, node) {
384 		err = of_property_read_u32(node, "nvidia,ram-code",
385 					   &node_ram_code);
386 		if (err || (node_ram_code != ram_code))
387 			continue;
388 
389 		err = load_timings(mc, node);
390 		of_node_put(node);
391 		if (err)
392 			return err;
393 		break;
394 	}
395 
396 	if (mc->num_timings == 0)
397 		dev_warn(mc->dev,
398 			 "no memory timings for RAM code %u registered\n",
399 			 ram_code);
400 
401 	return 0;
402 }
403 
404 static const char *const status_names[32] = {
405 	[ 1] = "External interrupt",
406 	[ 6] = "EMEM address decode error",
407 	[ 7] = "GART page fault",
408 	[ 8] = "Security violation",
409 	[ 9] = "EMEM arbitration error",
410 	[10] = "Page fault",
411 	[11] = "Invalid APB ASID update",
412 	[12] = "VPR violation",
413 	[13] = "Secure carveout violation",
414 	[16] = "MTS carveout violation",
415 };
416 
417 static const char *const error_names[8] = {
418 	[2] = "EMEM decode error",
419 	[3] = "TrustZone violation",
420 	[4] = "Carveout violation",
421 	[6] = "SMMU translation error",
422 };
423 
424 static irqreturn_t tegra_mc_irq(int irq, void *data)
425 {
426 	struct tegra_mc *mc = data;
427 	unsigned long status;
428 	unsigned int bit;
429 
430 	/* mask all interrupts to avoid flooding */
431 	status = mc_readl(mc, MC_INTSTATUS) & mc->soc->intmask;
432 	if (!status)
433 		return IRQ_NONE;
434 
435 	for_each_set_bit(bit, &status, 32) {
436 		const char *error = status_names[bit] ?: "unknown";
437 		const char *client = "unknown", *desc;
438 		const char *direction, *secure;
439 		phys_addr_t addr = 0;
440 		unsigned int i;
441 		char perm[7];
442 		u8 id, type;
443 		u32 value;
444 
445 		value = mc_readl(mc, MC_ERR_STATUS);
446 
447 #ifdef CONFIG_PHYS_ADDR_T_64BIT
448 		if (mc->soc->num_address_bits > 32) {
449 			addr = ((value >> MC_ERR_STATUS_ADR_HI_SHIFT) &
450 				MC_ERR_STATUS_ADR_HI_MASK);
451 			addr <<= 32;
452 		}
453 #endif
454 
455 		if (value & MC_ERR_STATUS_RW)
456 			direction = "write";
457 		else
458 			direction = "read";
459 
460 		if (value & MC_ERR_STATUS_SECURITY)
461 			secure = "secure ";
462 		else
463 			secure = "";
464 
465 		id = value & mc->soc->client_id_mask;
466 
467 		for (i = 0; i < mc->soc->num_clients; i++) {
468 			if (mc->soc->clients[i].id == id) {
469 				client = mc->soc->clients[i].name;
470 				break;
471 			}
472 		}
473 
474 		type = (value & MC_ERR_STATUS_TYPE_MASK) >>
475 		       MC_ERR_STATUS_TYPE_SHIFT;
476 		desc = error_names[type];
477 
478 		switch (value & MC_ERR_STATUS_TYPE_MASK) {
479 		case MC_ERR_STATUS_TYPE_INVALID_SMMU_PAGE:
480 			perm[0] = ' ';
481 			perm[1] = '[';
482 
483 			if (value & MC_ERR_STATUS_READABLE)
484 				perm[2] = 'R';
485 			else
486 				perm[2] = '-';
487 
488 			if (value & MC_ERR_STATUS_WRITABLE)
489 				perm[3] = 'W';
490 			else
491 				perm[3] = '-';
492 
493 			if (value & MC_ERR_STATUS_NONSECURE)
494 				perm[4] = '-';
495 			else
496 				perm[4] = 'S';
497 
498 			perm[5] = ']';
499 			perm[6] = '\0';
500 			break;
501 
502 		default:
503 			perm[0] = '\0';
504 			break;
505 		}
506 
507 		value = mc_readl(mc, MC_ERR_ADR);
508 		addr |= value;
509 
510 		dev_err_ratelimited(mc->dev, "%s: %s%s @%pa: %s (%s%s)\n",
511 				    client, secure, direction, &addr, error,
512 				    desc, perm);
513 	}
514 
515 	/* clear interrupts */
516 	mc_writel(mc, status, MC_INTSTATUS);
517 
518 	return IRQ_HANDLED;
519 }
520 
521 static __maybe_unused irqreturn_t tegra20_mc_irq(int irq, void *data)
522 {
523 	struct tegra_mc *mc = data;
524 	unsigned long status;
525 	unsigned int bit;
526 
527 	/* mask all interrupts to avoid flooding */
528 	status = mc_readl(mc, MC_INTSTATUS) & mc->soc->intmask;
529 	if (!status)
530 		return IRQ_NONE;
531 
532 	for_each_set_bit(bit, &status, 32) {
533 		const char *direction = "read", *secure = "";
534 		const char *error = status_names[bit];
535 		const char *client, *desc;
536 		phys_addr_t addr;
537 		u32 value, reg;
538 		u8 id, type;
539 
540 		switch (BIT(bit)) {
541 		case MC_INT_DECERR_EMEM:
542 			reg = MC_DECERR_EMEM_OTHERS_STATUS;
543 			value = mc_readl(mc, reg);
544 
545 			id = value & mc->soc->client_id_mask;
546 			desc = error_names[2];
547 
548 			if (value & BIT(31))
549 				direction = "write";
550 			break;
551 
552 		case MC_INT_INVALID_GART_PAGE:
553 			reg = MC_GART_ERROR_REQ;
554 			value = mc_readl(mc, reg);
555 
556 			id = (value >> 1) & mc->soc->client_id_mask;
557 			desc = error_names[2];
558 
559 			if (value & BIT(0))
560 				direction = "write";
561 			break;
562 
563 		case MC_INT_SECURITY_VIOLATION:
564 			reg = MC_SECURITY_VIOLATION_STATUS;
565 			value = mc_readl(mc, reg);
566 
567 			id = value & mc->soc->client_id_mask;
568 			type = (value & BIT(30)) ? 4 : 3;
569 			desc = error_names[type];
570 			secure = "secure ";
571 
572 			if (value & BIT(31))
573 				direction = "write";
574 			break;
575 
576 		default:
577 			continue;
578 		}
579 
580 		client = mc->soc->clients[id].name;
581 		addr = mc_readl(mc, reg + sizeof(u32));
582 
583 		dev_err_ratelimited(mc->dev, "%s: %s%s @%pa: %s (%s)\n",
584 				    client, secure, direction, &addr, error,
585 				    desc);
586 	}
587 
588 	/* clear interrupts */
589 	mc_writel(mc, status, MC_INTSTATUS);
590 
591 	return IRQ_HANDLED;
592 }
593 
594 static int tegra_mc_probe(struct platform_device *pdev)
595 {
596 	struct resource *res;
597 	struct tegra_mc *mc;
598 	void *isr;
599 	u64 mask;
600 	int err;
601 
602 	mc = devm_kzalloc(&pdev->dev, sizeof(*mc), GFP_KERNEL);
603 	if (!mc)
604 		return -ENOMEM;
605 
606 	platform_set_drvdata(pdev, mc);
607 	spin_lock_init(&mc->lock);
608 	mc->soc = of_device_get_match_data(&pdev->dev);
609 	mc->dev = &pdev->dev;
610 
611 	mask = DMA_BIT_MASK(mc->soc->num_address_bits);
612 
613 	err = dma_coerce_mask_and_coherent(&pdev->dev, mask);
614 	if (err < 0) {
615 		dev_err(&pdev->dev, "failed to set DMA mask: %d\n", err);
616 		return err;
617 	}
618 
619 	/* length of MC tick in nanoseconds */
620 	mc->tick = 30;
621 
622 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
623 	mc->regs = devm_ioremap_resource(&pdev->dev, res);
624 	if (IS_ERR(mc->regs))
625 		return PTR_ERR(mc->regs);
626 
627 	mc->clk = devm_clk_get(&pdev->dev, "mc");
628 	if (IS_ERR(mc->clk)) {
629 		dev_err(&pdev->dev, "failed to get MC clock: %ld\n",
630 			PTR_ERR(mc->clk));
631 		return PTR_ERR(mc->clk);
632 	}
633 
634 #ifdef CONFIG_ARCH_TEGRA_2x_SOC
635 	if (mc->soc == &tegra20_mc_soc) {
636 		isr = tegra20_mc_irq;
637 	} else
638 #endif
639 	{
640 		/* ensure that debug features are disabled */
641 		mc_writel(mc, 0x00000000, MC_TIMING_CONTROL_DBG);
642 
643 		err = tegra_mc_setup_latency_allowance(mc);
644 		if (err < 0) {
645 			dev_err(&pdev->dev,
646 				"failed to setup latency allowance: %d\n",
647 				err);
648 			return err;
649 		}
650 
651 		isr = tegra_mc_irq;
652 
653 		err = tegra_mc_setup_timings(mc);
654 		if (err < 0) {
655 			dev_err(&pdev->dev, "failed to setup timings: %d\n",
656 				err);
657 			return err;
658 		}
659 	}
660 
661 	mc->irq = platform_get_irq(pdev, 0);
662 	if (mc->irq < 0) {
663 		dev_err(&pdev->dev, "interrupt not specified\n");
664 		return mc->irq;
665 	}
666 
667 	WARN(!mc->soc->client_id_mask, "missing client ID mask for this SoC\n");
668 
669 	mc_writel(mc, mc->soc->intmask, MC_INTMASK);
670 
671 	err = devm_request_irq(&pdev->dev, mc->irq, isr, 0,
672 			       dev_name(&pdev->dev), mc);
673 	if (err < 0) {
674 		dev_err(&pdev->dev, "failed to request IRQ#%u: %d\n", mc->irq,
675 			err);
676 		return err;
677 	}
678 
679 	err = tegra_mc_reset_setup(mc);
680 	if (err < 0)
681 		dev_err(&pdev->dev, "failed to register reset controller: %d\n",
682 			err);
683 
684 	if (IS_ENABLED(CONFIG_TEGRA_IOMMU_SMMU) && mc->soc->smmu) {
685 		mc->smmu = tegra_smmu_probe(&pdev->dev, mc->soc->smmu, mc);
686 		if (IS_ERR(mc->smmu)) {
687 			dev_err(&pdev->dev, "failed to probe SMMU: %ld\n",
688 				PTR_ERR(mc->smmu));
689 			mc->smmu = NULL;
690 		}
691 	}
692 
693 	if (IS_ENABLED(CONFIG_TEGRA_IOMMU_GART) && !mc->soc->smmu) {
694 		mc->gart = tegra_gart_probe(&pdev->dev, mc);
695 		if (IS_ERR(mc->gart)) {
696 			dev_err(&pdev->dev, "failed to probe GART: %ld\n",
697 				PTR_ERR(mc->gart));
698 			mc->gart = NULL;
699 		}
700 	}
701 
702 	return 0;
703 }
704 
705 static int tegra_mc_suspend(struct device *dev)
706 {
707 	struct tegra_mc *mc = dev_get_drvdata(dev);
708 	int err;
709 
710 	if (IS_ENABLED(CONFIG_TEGRA_IOMMU_GART) && mc->gart) {
711 		err = tegra_gart_suspend(mc->gart);
712 		if (err)
713 			return err;
714 	}
715 
716 	return 0;
717 }
718 
719 static int tegra_mc_resume(struct device *dev)
720 {
721 	struct tegra_mc *mc = dev_get_drvdata(dev);
722 	int err;
723 
724 	if (IS_ENABLED(CONFIG_TEGRA_IOMMU_GART) && mc->gart) {
725 		err = tegra_gart_resume(mc->gart);
726 		if (err)
727 			return err;
728 	}
729 
730 	return 0;
731 }
732 
733 static const struct dev_pm_ops tegra_mc_pm_ops = {
734 	.suspend = tegra_mc_suspend,
735 	.resume = tegra_mc_resume,
736 };
737 
738 static struct platform_driver tegra_mc_driver = {
739 	.driver = {
740 		.name = "tegra-mc",
741 		.of_match_table = tegra_mc_of_match,
742 		.pm = &tegra_mc_pm_ops,
743 		.suppress_bind_attrs = true,
744 	},
745 	.prevent_deferred_probe = true,
746 	.probe = tegra_mc_probe,
747 };
748 
749 static int tegra_mc_init(void)
750 {
751 	return platform_driver_register(&tegra_mc_driver);
752 }
753 arch_initcall(tegra_mc_init);
754 
755 MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
756 MODULE_DESCRIPTION("NVIDIA Tegra Memory Controller driver");
757 MODULE_LICENSE("GPL v2");
758