xref: /openbmc/linux/drivers/iommu/mtk_iommu_v1.c (revision d87c25e8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * IOMMU API for MTK architected m4u v1 implementations
4  *
5  * Copyright (c) 2015-2016 MediaTek Inc.
6  * Author: Honghui Zhang <honghui.zhang@mediatek.com>
7  *
8  * Based on driver/iommu/mtk_iommu.c
9  */
10 #include <linux/memblock.h>
11 #include <linux/bug.h>
12 #include <linux/clk.h>
13 #include <linux/component.h>
14 #include <linux/device.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/err.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/iommu.h>
20 #include <linux/iopoll.h>
21 #include <linux/list.h>
22 #include <linux/module.h>
23 #include <linux/of_address.h>
24 #include <linux/of_irq.h>
25 #include <linux/of_platform.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <asm/barrier.h>
30 #include <asm/dma-iommu.h>
31 #include <linux/init.h>
32 #include <dt-bindings/memory/mt2701-larb-port.h>
33 #include <soc/mediatek/smi.h>
34 #include "mtk_iommu.h"
35 
36 #define REG_MMU_PT_BASE_ADDR			0x000
37 
38 #define F_ALL_INVLD				0x2
39 #define F_MMU_INV_RANGE				0x1
40 #define F_INVLD_EN0				BIT(0)
41 #define F_INVLD_EN1				BIT(1)
42 
43 #define F_MMU_FAULT_VA_MSK			0xfffff000
44 #define MTK_PROTECT_PA_ALIGN			128
45 
46 #define REG_MMU_CTRL_REG			0x210
47 #define F_MMU_CTRL_COHERENT_EN			BIT(8)
48 #define REG_MMU_IVRP_PADDR			0x214
49 #define REG_MMU_INT_CONTROL			0x220
50 #define F_INT_TRANSLATION_FAULT			BIT(0)
51 #define F_INT_MAIN_MULTI_HIT_FAULT		BIT(1)
52 #define F_INT_INVALID_PA_FAULT			BIT(2)
53 #define F_INT_ENTRY_REPLACEMENT_FAULT		BIT(3)
54 #define F_INT_TABLE_WALK_FAULT			BIT(4)
55 #define F_INT_TLB_MISS_FAULT			BIT(5)
56 #define F_INT_PFH_DMA_FIFO_OVERFLOW		BIT(6)
57 #define F_INT_MISS_DMA_FIFO_OVERFLOW		BIT(7)
58 
59 #define F_MMU_TF_PROTECT_SEL(prot)		(((prot) & 0x3) << 5)
60 #define F_INT_CLR_BIT				BIT(12)
61 
62 #define REG_MMU_FAULT_ST			0x224
63 #define REG_MMU_FAULT_VA			0x228
64 #define REG_MMU_INVLD_PA			0x22C
65 #define REG_MMU_INT_ID				0x388
66 #define REG_MMU_INVALIDATE			0x5c0
67 #define REG_MMU_INVLD_START_A			0x5c4
68 #define REG_MMU_INVLD_END_A			0x5c8
69 
70 #define REG_MMU_INV_SEL				0x5d8
71 #define REG_MMU_STANDARD_AXI_MODE		0x5e8
72 
73 #define REG_MMU_DCM				0x5f0
74 #define F_MMU_DCM_ON				BIT(1)
75 #define REG_MMU_CPE_DONE			0x60c
76 #define F_DESC_VALID				0x2
77 #define F_DESC_NONSEC				BIT(3)
78 #define MT2701_M4U_TF_LARB(TF)			(6 - (((TF) >> 13) & 0x7))
79 #define MT2701_M4U_TF_PORT(TF)			(((TF) >> 8) & 0xF)
80 /* MTK generation one iommu HW only support 4K size mapping */
81 #define MT2701_IOMMU_PAGE_SHIFT			12
82 #define MT2701_IOMMU_PAGE_SIZE			(1UL << MT2701_IOMMU_PAGE_SHIFT)
83 
84 /*
85  * MTK m4u support 4GB iova address space, and only support 4K page
86  * mapping. So the pagetable size should be exactly as 4M.
87  */
88 #define M2701_IOMMU_PGT_SIZE			SZ_4M
89 
90 struct mtk_iommu_domain {
91 	spinlock_t			pgtlock; /* lock for page table */
92 	struct iommu_domain		domain;
93 	u32				*pgt_va;
94 	dma_addr_t			pgt_pa;
95 	struct mtk_iommu_data		*data;
96 };
97 
98 static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
99 {
100 	return container_of(dom, struct mtk_iommu_domain, domain);
101 }
102 
103 static const int mt2701_m4u_in_larb[] = {
104 	LARB0_PORT_OFFSET, LARB1_PORT_OFFSET,
105 	LARB2_PORT_OFFSET, LARB3_PORT_OFFSET
106 };
107 
108 static inline int mt2701_m4u_to_larb(int id)
109 {
110 	int i;
111 
112 	for (i = ARRAY_SIZE(mt2701_m4u_in_larb) - 1; i >= 0; i--)
113 		if ((id) >= mt2701_m4u_in_larb[i])
114 			return i;
115 
116 	return 0;
117 }
118 
119 static inline int mt2701_m4u_to_port(int id)
120 {
121 	int larb = mt2701_m4u_to_larb(id);
122 
123 	return id - mt2701_m4u_in_larb[larb];
124 }
125 
126 static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data)
127 {
128 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
129 			data->base + REG_MMU_INV_SEL);
130 	writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE);
131 	wmb(); /* Make sure the tlb flush all done */
132 }
133 
134 static void mtk_iommu_tlb_flush_range(struct mtk_iommu_data *data,
135 				unsigned long iova, size_t size)
136 {
137 	int ret;
138 	u32 tmp;
139 
140 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
141 		data->base + REG_MMU_INV_SEL);
142 	writel_relaxed(iova & F_MMU_FAULT_VA_MSK,
143 		data->base + REG_MMU_INVLD_START_A);
144 	writel_relaxed((iova + size - 1) & F_MMU_FAULT_VA_MSK,
145 		data->base + REG_MMU_INVLD_END_A);
146 	writel_relaxed(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
147 
148 	ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
149 				tmp, tmp != 0, 10, 100000);
150 	if (ret) {
151 		dev_warn(data->dev,
152 			 "Partial TLB flush timed out, falling back to full flush\n");
153 		mtk_iommu_tlb_flush_all(data);
154 	}
155 	/* Clear the CPE status */
156 	writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
157 }
158 
159 static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
160 {
161 	struct mtk_iommu_data *data = dev_id;
162 	struct mtk_iommu_domain *dom = data->m4u_dom;
163 	u32 int_state, regval, fault_iova, fault_pa;
164 	unsigned int fault_larb, fault_port;
165 
166 	/* Read error information from registers */
167 	int_state = readl_relaxed(data->base + REG_MMU_FAULT_ST);
168 	fault_iova = readl_relaxed(data->base + REG_MMU_FAULT_VA);
169 
170 	fault_iova &= F_MMU_FAULT_VA_MSK;
171 	fault_pa = readl_relaxed(data->base + REG_MMU_INVLD_PA);
172 	regval = readl_relaxed(data->base + REG_MMU_INT_ID);
173 	fault_larb = MT2701_M4U_TF_LARB(regval);
174 	fault_port = MT2701_M4U_TF_PORT(regval);
175 
176 	/*
177 	 * MTK v1 iommu HW could not determine whether the fault is read or
178 	 * write fault, report as read fault.
179 	 */
180 	if (report_iommu_fault(&dom->domain, data->dev, fault_iova,
181 			IOMMU_FAULT_READ))
182 		dev_err_ratelimited(data->dev,
183 			"fault type=0x%x iova=0x%x pa=0x%x larb=%d port=%d\n",
184 			int_state, fault_iova, fault_pa,
185 			fault_larb, fault_port);
186 
187 	/* Interrupt clear */
188 	regval = readl_relaxed(data->base + REG_MMU_INT_CONTROL);
189 	regval |= F_INT_CLR_BIT;
190 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
191 
192 	mtk_iommu_tlb_flush_all(data);
193 
194 	return IRQ_HANDLED;
195 }
196 
197 static void mtk_iommu_config(struct mtk_iommu_data *data,
198 			     struct device *dev, bool enable)
199 {
200 	struct mtk_smi_larb_iommu    *larb_mmu;
201 	unsigned int                 larbid, portid;
202 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
203 	int i;
204 
205 	for (i = 0; i < fwspec->num_ids; ++i) {
206 		larbid = mt2701_m4u_to_larb(fwspec->ids[i]);
207 		portid = mt2701_m4u_to_port(fwspec->ids[i]);
208 		larb_mmu = &data->larb_imu[larbid];
209 
210 		dev_dbg(dev, "%s iommu port: %d\n",
211 			enable ? "enable" : "disable", portid);
212 
213 		if (enable)
214 			larb_mmu->mmu |= MTK_SMI_MMU_EN(portid);
215 		else
216 			larb_mmu->mmu &= ~MTK_SMI_MMU_EN(portid);
217 	}
218 }
219 
220 static int mtk_iommu_domain_finalise(struct mtk_iommu_data *data)
221 {
222 	struct mtk_iommu_domain *dom = data->m4u_dom;
223 
224 	spin_lock_init(&dom->pgtlock);
225 
226 	dom->pgt_va = dma_alloc_coherent(data->dev, M2701_IOMMU_PGT_SIZE,
227 					 &dom->pgt_pa, GFP_KERNEL);
228 	if (!dom->pgt_va)
229 		return -ENOMEM;
230 
231 	writel(dom->pgt_pa, data->base + REG_MMU_PT_BASE_ADDR);
232 
233 	dom->data = data;
234 
235 	return 0;
236 }
237 
238 static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
239 {
240 	struct mtk_iommu_domain *dom;
241 
242 	if (type != IOMMU_DOMAIN_UNMANAGED)
243 		return NULL;
244 
245 	dom = kzalloc(sizeof(*dom), GFP_KERNEL);
246 	if (!dom)
247 		return NULL;
248 
249 	return &dom->domain;
250 }
251 
252 static void mtk_iommu_domain_free(struct iommu_domain *domain)
253 {
254 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
255 	struct mtk_iommu_data *data = dom->data;
256 
257 	dma_free_coherent(data->dev, M2701_IOMMU_PGT_SIZE,
258 			dom->pgt_va, dom->pgt_pa);
259 	kfree(to_mtk_domain(domain));
260 }
261 
262 static int mtk_iommu_attach_device(struct iommu_domain *domain,
263 				   struct device *dev)
264 {
265 	struct mtk_iommu_data *data = dev_iommu_priv_get(dev);
266 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
267 	struct dma_iommu_mapping *mtk_mapping;
268 	int ret;
269 
270 	/* Only allow the domain created internally. */
271 	mtk_mapping = data->mapping;
272 	if (mtk_mapping->domain != domain)
273 		return 0;
274 
275 	if (!data->m4u_dom) {
276 		data->m4u_dom = dom;
277 		ret = mtk_iommu_domain_finalise(data);
278 		if (ret) {
279 			data->m4u_dom = NULL;
280 			return ret;
281 		}
282 	}
283 
284 	mtk_iommu_config(data, dev, true);
285 	return 0;
286 }
287 
288 static void mtk_iommu_detach_device(struct iommu_domain *domain,
289 				    struct device *dev)
290 {
291 	struct mtk_iommu_data *data = dev_iommu_priv_get(dev);
292 
293 	mtk_iommu_config(data, dev, false);
294 }
295 
296 static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
297 			 phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
298 {
299 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
300 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
301 	unsigned long flags;
302 	unsigned int i;
303 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
304 	u32 pabase = (u32)paddr;
305 	int map_size = 0;
306 
307 	spin_lock_irqsave(&dom->pgtlock, flags);
308 	for (i = 0; i < page_num; i++) {
309 		if (pgt_base_iova[i]) {
310 			memset(pgt_base_iova, 0, i * sizeof(u32));
311 			break;
312 		}
313 		pgt_base_iova[i] = pabase | F_DESC_VALID | F_DESC_NONSEC;
314 		pabase += MT2701_IOMMU_PAGE_SIZE;
315 		map_size += MT2701_IOMMU_PAGE_SIZE;
316 	}
317 
318 	spin_unlock_irqrestore(&dom->pgtlock, flags);
319 
320 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
321 
322 	return map_size == size ? 0 : -EEXIST;
323 }
324 
325 static size_t mtk_iommu_unmap(struct iommu_domain *domain,
326 			      unsigned long iova, size_t size,
327 			      struct iommu_iotlb_gather *gather)
328 {
329 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
330 	unsigned long flags;
331 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
332 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
333 
334 	spin_lock_irqsave(&dom->pgtlock, flags);
335 	memset(pgt_base_iova, 0, page_num * sizeof(u32));
336 	spin_unlock_irqrestore(&dom->pgtlock, flags);
337 
338 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
339 
340 	return size;
341 }
342 
343 static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
344 					  dma_addr_t iova)
345 {
346 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
347 	unsigned long flags;
348 	phys_addr_t pa;
349 
350 	spin_lock_irqsave(&dom->pgtlock, flags);
351 	pa = *(dom->pgt_va + (iova >> MT2701_IOMMU_PAGE_SHIFT));
352 	pa = pa & (~(MT2701_IOMMU_PAGE_SIZE - 1));
353 	spin_unlock_irqrestore(&dom->pgtlock, flags);
354 
355 	return pa;
356 }
357 
358 static const struct iommu_ops mtk_iommu_ops;
359 
360 /*
361  * MTK generation one iommu HW only support one iommu domain, and all the client
362  * sharing the same iova address space.
363  */
364 static int mtk_iommu_create_mapping(struct device *dev,
365 				    struct of_phandle_args *args)
366 {
367 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
368 	struct mtk_iommu_data *data;
369 	struct platform_device *m4updev;
370 	struct dma_iommu_mapping *mtk_mapping;
371 	int ret;
372 
373 	if (args->args_count != 1) {
374 		dev_err(dev, "invalid #iommu-cells(%d) property for IOMMU\n",
375 			args->args_count);
376 		return -EINVAL;
377 	}
378 
379 	if (!fwspec) {
380 		ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_ops);
381 		if (ret)
382 			return ret;
383 		fwspec = dev_iommu_fwspec_get(dev);
384 	} else if (dev_iommu_fwspec_get(dev)->ops != &mtk_iommu_ops) {
385 		return -EINVAL;
386 	}
387 
388 	if (!dev_iommu_priv_get(dev)) {
389 		/* Get the m4u device */
390 		m4updev = of_find_device_by_node(args->np);
391 		if (WARN_ON(!m4updev))
392 			return -EINVAL;
393 
394 		dev_iommu_priv_set(dev, platform_get_drvdata(m4updev));
395 	}
396 
397 	ret = iommu_fwspec_add_ids(dev, args->args, 1);
398 	if (ret)
399 		return ret;
400 
401 	data = dev_iommu_priv_get(dev);
402 	mtk_mapping = data->mapping;
403 	if (!mtk_mapping) {
404 		/* MTK iommu support 4GB iova address space. */
405 		mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,
406 						0, 1ULL << 32);
407 		if (IS_ERR(mtk_mapping))
408 			return PTR_ERR(mtk_mapping);
409 
410 		data->mapping = mtk_mapping;
411 	}
412 
413 	return 0;
414 }
415 
416 static int mtk_iommu_def_domain_type(struct device *dev)
417 {
418 	return IOMMU_DOMAIN_UNMANAGED;
419 }
420 
421 static struct iommu_device *mtk_iommu_probe_device(struct device *dev)
422 {
423 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
424 	struct of_phandle_args iommu_spec;
425 	struct mtk_iommu_data *data;
426 	int err, idx = 0;
427 
428 	while (!of_parse_phandle_with_args(dev->of_node, "iommus",
429 					   "#iommu-cells",
430 					   idx, &iommu_spec)) {
431 
432 		err = mtk_iommu_create_mapping(dev, &iommu_spec);
433 		of_node_put(iommu_spec.np);
434 		if (err)
435 			return ERR_PTR(err);
436 
437 		/* dev->iommu_fwspec might have changed */
438 		fwspec = dev_iommu_fwspec_get(dev);
439 		idx++;
440 	}
441 
442 	if (!fwspec || fwspec->ops != &mtk_iommu_ops)
443 		return ERR_PTR(-ENODEV); /* Not a iommu client device */
444 
445 	data = dev_iommu_priv_get(dev);
446 
447 	return &data->iommu;
448 }
449 
450 static void mtk_iommu_probe_finalize(struct device *dev)
451 {
452 	struct dma_iommu_mapping *mtk_mapping;
453 	struct mtk_iommu_data *data;
454 	int err;
455 
456 	data        = dev_iommu_priv_get(dev);
457 	mtk_mapping = data->mapping;
458 
459 	err = arm_iommu_attach_device(dev, mtk_mapping);
460 	if (err)
461 		dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");
462 }
463 
464 static void mtk_iommu_release_device(struct device *dev)
465 {
466 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
467 
468 	if (!fwspec || fwspec->ops != &mtk_iommu_ops)
469 		return;
470 
471 	iommu_fwspec_free(dev);
472 }
473 
474 static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
475 {
476 	u32 regval;
477 	int ret;
478 
479 	ret = clk_prepare_enable(data->bclk);
480 	if (ret) {
481 		dev_err(data->dev, "Failed to enable iommu bclk(%d)\n", ret);
482 		return ret;
483 	}
484 
485 	regval = F_MMU_CTRL_COHERENT_EN | F_MMU_TF_PROTECT_SEL(2);
486 	writel_relaxed(regval, data->base + REG_MMU_CTRL_REG);
487 
488 	regval = F_INT_TRANSLATION_FAULT |
489 		F_INT_MAIN_MULTI_HIT_FAULT |
490 		F_INT_INVALID_PA_FAULT |
491 		F_INT_ENTRY_REPLACEMENT_FAULT |
492 		F_INT_TABLE_WALK_FAULT |
493 		F_INT_TLB_MISS_FAULT |
494 		F_INT_PFH_DMA_FIFO_OVERFLOW |
495 		F_INT_MISS_DMA_FIFO_OVERFLOW;
496 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
497 
498 	/* protect memory,hw will write here while translation fault */
499 	writel_relaxed(data->protect_base,
500 			data->base + REG_MMU_IVRP_PADDR);
501 
502 	writel_relaxed(F_MMU_DCM_ON, data->base + REG_MMU_DCM);
503 
504 	if (devm_request_irq(data->dev, data->irq, mtk_iommu_isr, 0,
505 			     dev_name(data->dev), (void *)data)) {
506 		writel_relaxed(0, data->base + REG_MMU_PT_BASE_ADDR);
507 		clk_disable_unprepare(data->bclk);
508 		dev_err(data->dev, "Failed @ IRQ-%d Request\n", data->irq);
509 		return -ENODEV;
510 	}
511 
512 	return 0;
513 }
514 
515 static const struct iommu_ops mtk_iommu_ops = {
516 	.domain_alloc	= mtk_iommu_domain_alloc,
517 	.domain_free	= mtk_iommu_domain_free,
518 	.attach_dev	= mtk_iommu_attach_device,
519 	.detach_dev	= mtk_iommu_detach_device,
520 	.map		= mtk_iommu_map,
521 	.unmap		= mtk_iommu_unmap,
522 	.iova_to_phys	= mtk_iommu_iova_to_phys,
523 	.probe_device	= mtk_iommu_probe_device,
524 	.probe_finalize = mtk_iommu_probe_finalize,
525 	.release_device	= mtk_iommu_release_device,
526 	.def_domain_type = mtk_iommu_def_domain_type,
527 	.device_group	= generic_device_group,
528 	.pgsize_bitmap	= ~0UL << MT2701_IOMMU_PAGE_SHIFT,
529 	.owner          = THIS_MODULE,
530 };
531 
532 static const struct of_device_id mtk_iommu_of_ids[] = {
533 	{ .compatible = "mediatek,mt2701-m4u", },
534 	{}
535 };
536 
537 static const struct component_master_ops mtk_iommu_com_ops = {
538 	.bind		= mtk_iommu_bind,
539 	.unbind		= mtk_iommu_unbind,
540 };
541 
542 static int mtk_iommu_probe(struct platform_device *pdev)
543 {
544 	struct mtk_iommu_data		*data;
545 	struct device			*dev = &pdev->dev;
546 	struct resource			*res;
547 	struct component_match		*match = NULL;
548 	void				*protect;
549 	int				larb_nr, ret, i;
550 
551 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
552 	if (!data)
553 		return -ENOMEM;
554 
555 	data->dev = dev;
556 
557 	/* Protect memory. HW will access here while translation fault.*/
558 	protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2,
559 			GFP_KERNEL | GFP_DMA);
560 	if (!protect)
561 		return -ENOMEM;
562 	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
563 
564 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
565 	data->base = devm_ioremap_resource(dev, res);
566 	if (IS_ERR(data->base))
567 		return PTR_ERR(data->base);
568 
569 	data->irq = platform_get_irq(pdev, 0);
570 	if (data->irq < 0)
571 		return data->irq;
572 
573 	data->bclk = devm_clk_get(dev, "bclk");
574 	if (IS_ERR(data->bclk))
575 		return PTR_ERR(data->bclk);
576 
577 	larb_nr = of_count_phandle_with_args(dev->of_node,
578 					     "mediatek,larbs", NULL);
579 	if (larb_nr < 0)
580 		return larb_nr;
581 
582 	for (i = 0; i < larb_nr; i++) {
583 		struct device_node *larbnode;
584 		struct platform_device *plarbdev;
585 
586 		larbnode = of_parse_phandle(dev->of_node, "mediatek,larbs", i);
587 		if (!larbnode)
588 			return -EINVAL;
589 
590 		if (!of_device_is_available(larbnode)) {
591 			of_node_put(larbnode);
592 			continue;
593 		}
594 
595 		plarbdev = of_find_device_by_node(larbnode);
596 		if (!plarbdev) {
597 			of_node_put(larbnode);
598 			return -EPROBE_DEFER;
599 		}
600 		data->larb_imu[i].dev = &plarbdev->dev;
601 
602 		component_match_add_release(dev, &match, release_of,
603 					    compare_of, larbnode);
604 	}
605 
606 	platform_set_drvdata(pdev, data);
607 
608 	ret = mtk_iommu_hw_init(data);
609 	if (ret)
610 		return ret;
611 
612 	ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
613 				     dev_name(&pdev->dev));
614 	if (ret)
615 		return ret;
616 
617 	ret = iommu_device_register(&data->iommu, &mtk_iommu_ops, dev);
618 	if (ret)
619 		goto out_sysfs_remove;
620 
621 	if (!iommu_present(&platform_bus_type)) {
622 		ret = bus_set_iommu(&platform_bus_type,  &mtk_iommu_ops);
623 		if (ret)
624 			goto out_dev_unreg;
625 	}
626 
627 	ret = component_master_add_with_match(dev, &mtk_iommu_com_ops, match);
628 	if (ret)
629 		goto out_bus_set_null;
630 	return ret;
631 
632 out_bus_set_null:
633 	bus_set_iommu(&platform_bus_type, NULL);
634 out_dev_unreg:
635 	iommu_device_unregister(&data->iommu);
636 out_sysfs_remove:
637 	iommu_device_sysfs_remove(&data->iommu);
638 	return ret;
639 }
640 
641 static int mtk_iommu_remove(struct platform_device *pdev)
642 {
643 	struct mtk_iommu_data *data = platform_get_drvdata(pdev);
644 
645 	iommu_device_sysfs_remove(&data->iommu);
646 	iommu_device_unregister(&data->iommu);
647 
648 	if (iommu_present(&platform_bus_type))
649 		bus_set_iommu(&platform_bus_type, NULL);
650 
651 	clk_disable_unprepare(data->bclk);
652 	devm_free_irq(&pdev->dev, data->irq, data);
653 	component_master_del(&pdev->dev, &mtk_iommu_com_ops);
654 	return 0;
655 }
656 
657 static int __maybe_unused mtk_iommu_suspend(struct device *dev)
658 {
659 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
660 	struct mtk_iommu_suspend_reg *reg = &data->reg;
661 	void __iomem *base = data->base;
662 
663 	reg->standard_axi_mode = readl_relaxed(base +
664 					       REG_MMU_STANDARD_AXI_MODE);
665 	reg->dcm_dis = readl_relaxed(base + REG_MMU_DCM);
666 	reg->ctrl_reg = readl_relaxed(base + REG_MMU_CTRL_REG);
667 	reg->int_control0 = readl_relaxed(base + REG_MMU_INT_CONTROL);
668 	return 0;
669 }
670 
671 static int __maybe_unused mtk_iommu_resume(struct device *dev)
672 {
673 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
674 	struct mtk_iommu_suspend_reg *reg = &data->reg;
675 	void __iomem *base = data->base;
676 
677 	writel_relaxed(data->m4u_dom->pgt_pa, base + REG_MMU_PT_BASE_ADDR);
678 	writel_relaxed(reg->standard_axi_mode,
679 		       base + REG_MMU_STANDARD_AXI_MODE);
680 	writel_relaxed(reg->dcm_dis, base + REG_MMU_DCM);
681 	writel_relaxed(reg->ctrl_reg, base + REG_MMU_CTRL_REG);
682 	writel_relaxed(reg->int_control0, base + REG_MMU_INT_CONTROL);
683 	writel_relaxed(data->protect_base, base + REG_MMU_IVRP_PADDR);
684 	return 0;
685 }
686 
687 static const struct dev_pm_ops mtk_iommu_pm_ops = {
688 	SET_SYSTEM_SLEEP_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume)
689 };
690 
691 static struct platform_driver mtk_iommu_driver = {
692 	.probe	= mtk_iommu_probe,
693 	.remove	= mtk_iommu_remove,
694 	.driver	= {
695 		.name = "mtk-iommu-v1",
696 		.of_match_table = mtk_iommu_of_ids,
697 		.pm = &mtk_iommu_pm_ops,
698 	}
699 };
700 module_platform_driver(mtk_iommu_driver);
701 
702 MODULE_DESCRIPTION("IOMMU API for MediaTek M4U v1 implementations");
703 MODULE_LICENSE("GPL v2");
704