xref: /linux/drivers/iommu/mtk_iommu_v1.c (revision d6e4b3e326d8b44675b9e19534347d97073826aa)
1 /*
2  * IOMMU API for MTK architected m4u v1 implementations
3  *
4  * Copyright (c) 2015-2016 MediaTek Inc.
5  * Author: Honghui Zhang <honghui.zhang@mediatek.com>
6  *
7  * Based on driver/iommu/mtk_iommu.c
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  */
18 #include <linux/memblock.h>
19 #include <linux/bug.h>
20 #include <linux/clk.h>
21 #include <linux/component.h>
22 #include <linux/device.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/dma-iommu.h>
25 #include <linux/err.h>
26 #include <linux/interrupt.h>
27 #include <linux/io.h>
28 #include <linux/iommu.h>
29 #include <linux/iopoll.h>
30 #include <linux/list.h>
31 #include <linux/of_address.h>
32 #include <linux/of_iommu.h>
33 #include <linux/of_irq.h>
34 #include <linux/of_platform.h>
35 #include <linux/platform_device.h>
36 #include <linux/slab.h>
37 #include <linux/spinlock.h>
38 #include <asm/barrier.h>
39 #include <asm/dma-iommu.h>
40 #include <linux/init.h>
41 #include <dt-bindings/memory/mt2701-larb-port.h>
42 #include <soc/mediatek/smi.h>
43 #include "mtk_iommu.h"
44 
45 #define REG_MMU_PT_BASE_ADDR			0x000
46 
47 #define F_ALL_INVLD				0x2
48 #define F_MMU_INV_RANGE				0x1
49 #define F_INVLD_EN0				BIT(0)
50 #define F_INVLD_EN1				BIT(1)
51 
52 #define F_MMU_FAULT_VA_MSK			0xfffff000
53 #define MTK_PROTECT_PA_ALIGN			128
54 
55 #define REG_MMU_CTRL_REG			0x210
56 #define F_MMU_CTRL_COHERENT_EN			BIT(8)
57 #define REG_MMU_IVRP_PADDR			0x214
58 #define REG_MMU_INT_CONTROL			0x220
59 #define F_INT_TRANSLATION_FAULT			BIT(0)
60 #define F_INT_MAIN_MULTI_HIT_FAULT		BIT(1)
61 #define F_INT_INVALID_PA_FAULT			BIT(2)
62 #define F_INT_ENTRY_REPLACEMENT_FAULT		BIT(3)
63 #define F_INT_TABLE_WALK_FAULT			BIT(4)
64 #define F_INT_TLB_MISS_FAULT			BIT(5)
65 #define F_INT_PFH_DMA_FIFO_OVERFLOW		BIT(6)
66 #define F_INT_MISS_DMA_FIFO_OVERFLOW		BIT(7)
67 
68 #define F_MMU_TF_PROTECT_SEL(prot)		(((prot) & 0x3) << 5)
69 #define F_INT_CLR_BIT				BIT(12)
70 
71 #define REG_MMU_FAULT_ST			0x224
72 #define REG_MMU_FAULT_VA			0x228
73 #define REG_MMU_INVLD_PA			0x22C
74 #define REG_MMU_INT_ID				0x388
75 #define REG_MMU_INVALIDATE			0x5c0
76 #define REG_MMU_INVLD_START_A			0x5c4
77 #define REG_MMU_INVLD_END_A			0x5c8
78 
79 #define REG_MMU_INV_SEL				0x5d8
80 #define REG_MMU_STANDARD_AXI_MODE		0x5e8
81 
82 #define REG_MMU_DCM				0x5f0
83 #define F_MMU_DCM_ON				BIT(1)
84 #define REG_MMU_CPE_DONE			0x60c
85 #define F_DESC_VALID				0x2
86 #define F_DESC_NONSEC				BIT(3)
87 #define MT2701_M4U_TF_LARB(TF)			(6 - (((TF) >> 13) & 0x7))
88 #define MT2701_M4U_TF_PORT(TF)			(((TF) >> 8) & 0xF)
89 /* MTK generation one iommu HW only support 4K size mapping */
90 #define MT2701_IOMMU_PAGE_SHIFT			12
91 #define MT2701_IOMMU_PAGE_SIZE			(1UL << MT2701_IOMMU_PAGE_SHIFT)
92 
93 /*
94  * MTK m4u support 4GB iova address space, and only support 4K page
95  * mapping. So the pagetable size should be exactly as 4M.
96  */
97 #define M2701_IOMMU_PGT_SIZE			SZ_4M
98 
99 struct mtk_iommu_domain {
100 	spinlock_t			pgtlock; /* lock for page table */
101 	struct iommu_domain		domain;
102 	u32				*pgt_va;
103 	dma_addr_t			pgt_pa;
104 	struct mtk_iommu_data		*data;
105 };
106 
107 static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
108 {
109 	return container_of(dom, struct mtk_iommu_domain, domain);
110 }
111 
112 static const int mt2701_m4u_in_larb[] = {
113 	LARB0_PORT_OFFSET, LARB1_PORT_OFFSET,
114 	LARB2_PORT_OFFSET, LARB3_PORT_OFFSET
115 };
116 
117 static inline int mt2701_m4u_to_larb(int id)
118 {
119 	int i;
120 
121 	for (i = ARRAY_SIZE(mt2701_m4u_in_larb) - 1; i >= 0; i--)
122 		if ((id) >= mt2701_m4u_in_larb[i])
123 			return i;
124 
125 	return 0;
126 }
127 
128 static inline int mt2701_m4u_to_port(int id)
129 {
130 	int larb = mt2701_m4u_to_larb(id);
131 
132 	return id - mt2701_m4u_in_larb[larb];
133 }
134 
135 static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data)
136 {
137 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
138 			data->base + REG_MMU_INV_SEL);
139 	writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE);
140 	wmb(); /* Make sure the tlb flush all done */
141 }
142 
143 static void mtk_iommu_tlb_flush_range(struct mtk_iommu_data *data,
144 				unsigned long iova, size_t size)
145 {
146 	int ret;
147 	u32 tmp;
148 
149 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
150 		data->base + REG_MMU_INV_SEL);
151 	writel_relaxed(iova & F_MMU_FAULT_VA_MSK,
152 		data->base + REG_MMU_INVLD_START_A);
153 	writel_relaxed((iova + size - 1) & F_MMU_FAULT_VA_MSK,
154 		data->base + REG_MMU_INVLD_END_A);
155 	writel_relaxed(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
156 
157 	ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
158 				tmp, tmp != 0, 10, 100000);
159 	if (ret) {
160 		dev_warn(data->dev,
161 			 "Partial TLB flush timed out, falling back to full flush\n");
162 		mtk_iommu_tlb_flush_all(data);
163 	}
164 	/* Clear the CPE status */
165 	writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
166 }
167 
168 static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
169 {
170 	struct mtk_iommu_data *data = dev_id;
171 	struct mtk_iommu_domain *dom = data->m4u_dom;
172 	u32 int_state, regval, fault_iova, fault_pa;
173 	unsigned int fault_larb, fault_port;
174 
175 	/* Read error information from registers */
176 	int_state = readl_relaxed(data->base + REG_MMU_FAULT_ST);
177 	fault_iova = readl_relaxed(data->base + REG_MMU_FAULT_VA);
178 
179 	fault_iova &= F_MMU_FAULT_VA_MSK;
180 	fault_pa = readl_relaxed(data->base + REG_MMU_INVLD_PA);
181 	regval = readl_relaxed(data->base + REG_MMU_INT_ID);
182 	fault_larb = MT2701_M4U_TF_LARB(regval);
183 	fault_port = MT2701_M4U_TF_PORT(regval);
184 
185 	/*
186 	 * MTK v1 iommu HW could not determine whether the fault is read or
187 	 * write fault, report as read fault.
188 	 */
189 	if (report_iommu_fault(&dom->domain, data->dev, fault_iova,
190 			IOMMU_FAULT_READ))
191 		dev_err_ratelimited(data->dev,
192 			"fault type=0x%x iova=0x%x pa=0x%x larb=%d port=%d\n",
193 			int_state, fault_iova, fault_pa,
194 			fault_larb, fault_port);
195 
196 	/* Interrupt clear */
197 	regval = readl_relaxed(data->base + REG_MMU_INT_CONTROL);
198 	regval |= F_INT_CLR_BIT;
199 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
200 
201 	mtk_iommu_tlb_flush_all(data);
202 
203 	return IRQ_HANDLED;
204 }
205 
206 static void mtk_iommu_config(struct mtk_iommu_data *data,
207 			     struct device *dev, bool enable)
208 {
209 	struct mtk_smi_larb_iommu    *larb_mmu;
210 	unsigned int                 larbid, portid;
211 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
212 	int i;
213 
214 	for (i = 0; i < fwspec->num_ids; ++i) {
215 		larbid = mt2701_m4u_to_larb(fwspec->ids[i]);
216 		portid = mt2701_m4u_to_port(fwspec->ids[i]);
217 		larb_mmu = &data->smi_imu.larb_imu[larbid];
218 
219 		dev_dbg(dev, "%s iommu port: %d\n",
220 			enable ? "enable" : "disable", portid);
221 
222 		if (enable)
223 			larb_mmu->mmu |= MTK_SMI_MMU_EN(portid);
224 		else
225 			larb_mmu->mmu &= ~MTK_SMI_MMU_EN(portid);
226 	}
227 }
228 
229 static int mtk_iommu_domain_finalise(struct mtk_iommu_data *data)
230 {
231 	struct mtk_iommu_domain *dom = data->m4u_dom;
232 
233 	spin_lock_init(&dom->pgtlock);
234 
235 	dom->pgt_va = dma_zalloc_coherent(data->dev,
236 				M2701_IOMMU_PGT_SIZE,
237 				&dom->pgt_pa, GFP_KERNEL);
238 	if (!dom->pgt_va)
239 		return -ENOMEM;
240 
241 	writel(dom->pgt_pa, data->base + REG_MMU_PT_BASE_ADDR);
242 
243 	dom->data = data;
244 
245 	return 0;
246 }
247 
248 static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
249 {
250 	struct mtk_iommu_domain *dom;
251 
252 	if (type != IOMMU_DOMAIN_UNMANAGED)
253 		return NULL;
254 
255 	dom = kzalloc(sizeof(*dom), GFP_KERNEL);
256 	if (!dom)
257 		return NULL;
258 
259 	return &dom->domain;
260 }
261 
262 static void mtk_iommu_domain_free(struct iommu_domain *domain)
263 {
264 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
265 	struct mtk_iommu_data *data = dom->data;
266 
267 	dma_free_coherent(data->dev, M2701_IOMMU_PGT_SIZE,
268 			dom->pgt_va, dom->pgt_pa);
269 	kfree(to_mtk_domain(domain));
270 }
271 
272 static int mtk_iommu_attach_device(struct iommu_domain *domain,
273 				   struct device *dev)
274 {
275 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
276 	struct mtk_iommu_data *data = dev_iommu_fwspec_get(dev)->iommu_priv;
277 	int ret;
278 
279 	if (!data)
280 		return -ENODEV;
281 
282 	if (!data->m4u_dom) {
283 		data->m4u_dom = dom;
284 		ret = mtk_iommu_domain_finalise(data);
285 		if (ret) {
286 			data->m4u_dom = NULL;
287 			return ret;
288 		}
289 	}
290 
291 	mtk_iommu_config(data, dev, true);
292 	return 0;
293 }
294 
295 static void mtk_iommu_detach_device(struct iommu_domain *domain,
296 				    struct device *dev)
297 {
298 	struct mtk_iommu_data *data = dev_iommu_fwspec_get(dev)->iommu_priv;
299 
300 	if (!data)
301 		return;
302 
303 	mtk_iommu_config(data, dev, false);
304 }
305 
306 static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
307 			 phys_addr_t paddr, size_t size, int prot)
308 {
309 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
310 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
311 	unsigned long flags;
312 	unsigned int i;
313 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
314 	u32 pabase = (u32)paddr;
315 	int map_size = 0;
316 
317 	spin_lock_irqsave(&dom->pgtlock, flags);
318 	for (i = 0; i < page_num; i++) {
319 		if (pgt_base_iova[i]) {
320 			memset(pgt_base_iova, 0, i * sizeof(u32));
321 			break;
322 		}
323 		pgt_base_iova[i] = pabase | F_DESC_VALID | F_DESC_NONSEC;
324 		pabase += MT2701_IOMMU_PAGE_SIZE;
325 		map_size += MT2701_IOMMU_PAGE_SIZE;
326 	}
327 
328 	spin_unlock_irqrestore(&dom->pgtlock, flags);
329 
330 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
331 
332 	return map_size == size ? 0 : -EEXIST;
333 }
334 
335 static size_t mtk_iommu_unmap(struct iommu_domain *domain,
336 			      unsigned long iova, size_t size)
337 {
338 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
339 	unsigned long flags;
340 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
341 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
342 
343 	spin_lock_irqsave(&dom->pgtlock, flags);
344 	memset(pgt_base_iova, 0, page_num * sizeof(u32));
345 	spin_unlock_irqrestore(&dom->pgtlock, flags);
346 
347 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
348 
349 	return size;
350 }
351 
352 static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
353 					  dma_addr_t iova)
354 {
355 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
356 	unsigned long flags;
357 	phys_addr_t pa;
358 
359 	spin_lock_irqsave(&dom->pgtlock, flags);
360 	pa = *(dom->pgt_va + (iova >> MT2701_IOMMU_PAGE_SHIFT));
361 	pa = pa & (~(MT2701_IOMMU_PAGE_SIZE - 1));
362 	spin_unlock_irqrestore(&dom->pgtlock, flags);
363 
364 	return pa;
365 }
366 
367 static const struct iommu_ops mtk_iommu_ops;
368 
369 /*
370  * MTK generation one iommu HW only support one iommu domain, and all the client
371  * sharing the same iova address space.
372  */
373 static int mtk_iommu_create_mapping(struct device *dev,
374 				    struct of_phandle_args *args)
375 {
376 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
377 	struct mtk_iommu_data *data;
378 	struct platform_device *m4updev;
379 	struct dma_iommu_mapping *mtk_mapping;
380 	struct device *m4udev;
381 	int ret;
382 
383 	if (args->args_count != 1) {
384 		dev_err(dev, "invalid #iommu-cells(%d) property for IOMMU\n",
385 			args->args_count);
386 		return -EINVAL;
387 	}
388 
389 	if (!fwspec) {
390 		ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_ops);
391 		if (ret)
392 			return ret;
393 		fwspec = dev_iommu_fwspec_get(dev);
394 	} else if (dev_iommu_fwspec_get(dev)->ops != &mtk_iommu_ops) {
395 		return -EINVAL;
396 	}
397 
398 	if (!fwspec->iommu_priv) {
399 		/* Get the m4u device */
400 		m4updev = of_find_device_by_node(args->np);
401 		if (WARN_ON(!m4updev))
402 			return -EINVAL;
403 
404 		fwspec->iommu_priv = platform_get_drvdata(m4updev);
405 	}
406 
407 	ret = iommu_fwspec_add_ids(dev, args->args, 1);
408 	if (ret)
409 		return ret;
410 
411 	data = fwspec->iommu_priv;
412 	m4udev = data->dev;
413 	mtk_mapping = m4udev->archdata.iommu;
414 	if (!mtk_mapping) {
415 		/* MTK iommu support 4GB iova address space. */
416 		mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,
417 						0, 1ULL << 32);
418 		if (IS_ERR(mtk_mapping))
419 			return PTR_ERR(mtk_mapping);
420 
421 		m4udev->archdata.iommu = mtk_mapping;
422 	}
423 
424 	return 0;
425 }
426 
427 static int mtk_iommu_add_device(struct device *dev)
428 {
429 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
430 	struct dma_iommu_mapping *mtk_mapping;
431 	struct of_phandle_args iommu_spec;
432 	struct of_phandle_iterator it;
433 	struct mtk_iommu_data *data;
434 	struct iommu_group *group;
435 	int err;
436 
437 	of_for_each_phandle(&it, err, dev->of_node, "iommus",
438 			"#iommu-cells", 0) {
439 		int count = of_phandle_iterator_args(&it, iommu_spec.args,
440 					MAX_PHANDLE_ARGS);
441 		iommu_spec.np = of_node_get(it.node);
442 		iommu_spec.args_count = count;
443 
444 		mtk_iommu_create_mapping(dev, &iommu_spec);
445 		of_node_put(iommu_spec.np);
446 	}
447 
448 	if (!fwspec || fwspec->ops != &mtk_iommu_ops)
449 		return -ENODEV; /* Not a iommu client device */
450 
451 	/*
452 	 * This is a short-term bodge because the ARM DMA code doesn't
453 	 * understand multi-device groups, but we have to call into it
454 	 * successfully (and not just rely on a normal IOMMU API attach
455 	 * here) in order to set the correct DMA API ops on @dev.
456 	 */
457 	group = iommu_group_alloc();
458 	if (IS_ERR(group))
459 		return PTR_ERR(group);
460 
461 	err = iommu_group_add_device(group, dev);
462 	iommu_group_put(group);
463 	if (err)
464 		return err;
465 
466 	data = fwspec->iommu_priv;
467 	mtk_mapping = data->dev->archdata.iommu;
468 	err = arm_iommu_attach_device(dev, mtk_mapping);
469 	if (err) {
470 		iommu_group_remove_device(dev);
471 		return err;
472 	}
473 
474 	return iommu_device_link(&data->iommu, dev);;
475 }
476 
477 static void mtk_iommu_remove_device(struct device *dev)
478 {
479 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
480 	struct mtk_iommu_data *data;
481 
482 	if (!fwspec || fwspec->ops != &mtk_iommu_ops)
483 		return;
484 
485 	data = fwspec->iommu_priv;
486 	iommu_device_unlink(&data->iommu, dev);
487 
488 	iommu_group_remove_device(dev);
489 	iommu_fwspec_free(dev);
490 }
491 
492 static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
493 {
494 	u32 regval;
495 	int ret;
496 
497 	ret = clk_prepare_enable(data->bclk);
498 	if (ret) {
499 		dev_err(data->dev, "Failed to enable iommu bclk(%d)\n", ret);
500 		return ret;
501 	}
502 
503 	regval = F_MMU_CTRL_COHERENT_EN | F_MMU_TF_PROTECT_SEL(2);
504 	writel_relaxed(regval, data->base + REG_MMU_CTRL_REG);
505 
506 	regval = F_INT_TRANSLATION_FAULT |
507 		F_INT_MAIN_MULTI_HIT_FAULT |
508 		F_INT_INVALID_PA_FAULT |
509 		F_INT_ENTRY_REPLACEMENT_FAULT |
510 		F_INT_TABLE_WALK_FAULT |
511 		F_INT_TLB_MISS_FAULT |
512 		F_INT_PFH_DMA_FIFO_OVERFLOW |
513 		F_INT_MISS_DMA_FIFO_OVERFLOW;
514 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
515 
516 	/* protect memory,hw will write here while translation fault */
517 	writel_relaxed(data->protect_base,
518 			data->base + REG_MMU_IVRP_PADDR);
519 
520 	writel_relaxed(F_MMU_DCM_ON, data->base + REG_MMU_DCM);
521 
522 	if (devm_request_irq(data->dev, data->irq, mtk_iommu_isr, 0,
523 			     dev_name(data->dev), (void *)data)) {
524 		writel_relaxed(0, data->base + REG_MMU_PT_BASE_ADDR);
525 		clk_disable_unprepare(data->bclk);
526 		dev_err(data->dev, "Failed @ IRQ-%d Request\n", data->irq);
527 		return -ENODEV;
528 	}
529 
530 	return 0;
531 }
532 
533 static const struct iommu_ops mtk_iommu_ops = {
534 	.domain_alloc	= mtk_iommu_domain_alloc,
535 	.domain_free	= mtk_iommu_domain_free,
536 	.attach_dev	= mtk_iommu_attach_device,
537 	.detach_dev	= mtk_iommu_detach_device,
538 	.map		= mtk_iommu_map,
539 	.unmap		= mtk_iommu_unmap,
540 	.iova_to_phys	= mtk_iommu_iova_to_phys,
541 	.add_device	= mtk_iommu_add_device,
542 	.remove_device	= mtk_iommu_remove_device,
543 	.pgsize_bitmap	= ~0UL << MT2701_IOMMU_PAGE_SHIFT,
544 };
545 
546 static const struct of_device_id mtk_iommu_of_ids[] = {
547 	{ .compatible = "mediatek,mt2701-m4u", },
548 	{}
549 };
550 
551 static const struct component_master_ops mtk_iommu_com_ops = {
552 	.bind		= mtk_iommu_bind,
553 	.unbind		= mtk_iommu_unbind,
554 };
555 
556 static int mtk_iommu_probe(struct platform_device *pdev)
557 {
558 	struct mtk_iommu_data		*data;
559 	struct device			*dev = &pdev->dev;
560 	struct resource			*res;
561 	struct component_match		*match = NULL;
562 	struct of_phandle_args		larb_spec;
563 	struct of_phandle_iterator	it;
564 	void				*protect;
565 	int				larb_nr, ret, err;
566 
567 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
568 	if (!data)
569 		return -ENOMEM;
570 
571 	data->dev = dev;
572 
573 	/* Protect memory. HW will access here while translation fault.*/
574 	protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2,
575 			GFP_KERNEL | GFP_DMA);
576 	if (!protect)
577 		return -ENOMEM;
578 	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
579 
580 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
581 	data->base = devm_ioremap_resource(dev, res);
582 	if (IS_ERR(data->base))
583 		return PTR_ERR(data->base);
584 
585 	data->irq = platform_get_irq(pdev, 0);
586 	if (data->irq < 0)
587 		return data->irq;
588 
589 	data->bclk = devm_clk_get(dev, "bclk");
590 	if (IS_ERR(data->bclk))
591 		return PTR_ERR(data->bclk);
592 
593 	larb_nr = 0;
594 	of_for_each_phandle(&it, err, dev->of_node,
595 			"mediatek,larbs", NULL, 0) {
596 		struct platform_device *plarbdev;
597 		int count = of_phandle_iterator_args(&it, larb_spec.args,
598 					MAX_PHANDLE_ARGS);
599 
600 		if (count)
601 			continue;
602 
603 		larb_spec.np = of_node_get(it.node);
604 		if (!of_device_is_available(larb_spec.np))
605 			continue;
606 
607 		plarbdev = of_find_device_by_node(larb_spec.np);
608 		if (!plarbdev) {
609 			plarbdev = of_platform_device_create(
610 						larb_spec.np, NULL,
611 						platform_bus_type.dev_root);
612 			if (!plarbdev) {
613 				of_node_put(larb_spec.np);
614 				return -EPROBE_DEFER;
615 			}
616 		}
617 
618 		data->smi_imu.larb_imu[larb_nr].dev = &plarbdev->dev;
619 		component_match_add_release(dev, &match, release_of,
620 					    compare_of, larb_spec.np);
621 		larb_nr++;
622 	}
623 
624 	data->smi_imu.larb_nr = larb_nr;
625 
626 	platform_set_drvdata(pdev, data);
627 
628 	ret = mtk_iommu_hw_init(data);
629 	if (ret)
630 		return ret;
631 
632 	ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
633 				     dev_name(&pdev->dev));
634 	if (ret)
635 		return ret;
636 
637 	iommu_device_set_ops(&data->iommu, &mtk_iommu_ops);
638 
639 	ret = iommu_device_register(&data->iommu);
640 	if (ret)
641 		return ret;
642 
643 	if (!iommu_present(&platform_bus_type))
644 		bus_set_iommu(&platform_bus_type,  &mtk_iommu_ops);
645 
646 	return component_master_add_with_match(dev, &mtk_iommu_com_ops, match);
647 }
648 
649 static int mtk_iommu_remove(struct platform_device *pdev)
650 {
651 	struct mtk_iommu_data *data = platform_get_drvdata(pdev);
652 
653 	iommu_device_sysfs_remove(&data->iommu);
654 	iommu_device_unregister(&data->iommu);
655 
656 	if (iommu_present(&platform_bus_type))
657 		bus_set_iommu(&platform_bus_type, NULL);
658 
659 	clk_disable_unprepare(data->bclk);
660 	devm_free_irq(&pdev->dev, data->irq, data);
661 	component_master_del(&pdev->dev, &mtk_iommu_com_ops);
662 	return 0;
663 }
664 
665 static int __maybe_unused mtk_iommu_suspend(struct device *dev)
666 {
667 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
668 	struct mtk_iommu_suspend_reg *reg = &data->reg;
669 	void __iomem *base = data->base;
670 
671 	reg->standard_axi_mode = readl_relaxed(base +
672 					       REG_MMU_STANDARD_AXI_MODE);
673 	reg->dcm_dis = readl_relaxed(base + REG_MMU_DCM);
674 	reg->ctrl_reg = readl_relaxed(base + REG_MMU_CTRL_REG);
675 	reg->int_control0 = readl_relaxed(base + REG_MMU_INT_CONTROL);
676 	return 0;
677 }
678 
679 static int __maybe_unused mtk_iommu_resume(struct device *dev)
680 {
681 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
682 	struct mtk_iommu_suspend_reg *reg = &data->reg;
683 	void __iomem *base = data->base;
684 
685 	writel_relaxed(data->m4u_dom->pgt_pa, base + REG_MMU_PT_BASE_ADDR);
686 	writel_relaxed(reg->standard_axi_mode,
687 		       base + REG_MMU_STANDARD_AXI_MODE);
688 	writel_relaxed(reg->dcm_dis, base + REG_MMU_DCM);
689 	writel_relaxed(reg->ctrl_reg, base + REG_MMU_CTRL_REG);
690 	writel_relaxed(reg->int_control0, base + REG_MMU_INT_CONTROL);
691 	writel_relaxed(data->protect_base, base + REG_MMU_IVRP_PADDR);
692 	return 0;
693 }
694 
695 static const struct dev_pm_ops mtk_iommu_pm_ops = {
696 	SET_SYSTEM_SLEEP_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume)
697 };
698 
699 static struct platform_driver mtk_iommu_driver = {
700 	.probe	= mtk_iommu_probe,
701 	.remove	= mtk_iommu_remove,
702 	.driver	= {
703 		.name = "mtk-iommu-v1",
704 		.of_match_table = mtk_iommu_of_ids,
705 		.pm = &mtk_iommu_pm_ops,
706 	}
707 };
708 
709 static int __init m4u_init(void)
710 {
711 	return platform_driver_register(&mtk_iommu_driver);
712 }
713 subsys_initcall(m4u_init);
714