xref: /openbmc/linux/drivers/iommu/mtk_iommu_v1.c (revision 9ab0cb30)
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/dma-iommu.h>
17 #include <linux/err.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/iommu.h>
21 #include <linux/iopoll.h>
22 #include <linux/list.h>
23 #include <linux/of_address.h>
24 #include <linux/of_iommu.h>
25 #include <linux/of_irq.h>
26 #include <linux/of_platform.h>
27 #include <linux/platform_device.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <asm/barrier.h>
31 #include <asm/dma-iommu.h>
32 #include <linux/init.h>
33 #include <dt-bindings/memory/mt2701-larb-port.h>
34 #include <soc/mediatek/smi.h>
35 #include "mtk_iommu.h"
36 
37 #define REG_MMU_PT_BASE_ADDR			0x000
38 
39 #define F_ALL_INVLD				0x2
40 #define F_MMU_INV_RANGE				0x1
41 #define F_INVLD_EN0				BIT(0)
42 #define F_INVLD_EN1				BIT(1)
43 
44 #define F_MMU_FAULT_VA_MSK			0xfffff000
45 #define MTK_PROTECT_PA_ALIGN			128
46 
47 #define REG_MMU_CTRL_REG			0x210
48 #define F_MMU_CTRL_COHERENT_EN			BIT(8)
49 #define REG_MMU_IVRP_PADDR			0x214
50 #define REG_MMU_INT_CONTROL			0x220
51 #define F_INT_TRANSLATION_FAULT			BIT(0)
52 #define F_INT_MAIN_MULTI_HIT_FAULT		BIT(1)
53 #define F_INT_INVALID_PA_FAULT			BIT(2)
54 #define F_INT_ENTRY_REPLACEMENT_FAULT		BIT(3)
55 #define F_INT_TABLE_WALK_FAULT			BIT(4)
56 #define F_INT_TLB_MISS_FAULT			BIT(5)
57 #define F_INT_PFH_DMA_FIFO_OVERFLOW		BIT(6)
58 #define F_INT_MISS_DMA_FIFO_OVERFLOW		BIT(7)
59 
60 #define F_MMU_TF_PROTECT_SEL(prot)		(((prot) & 0x3) << 5)
61 #define F_INT_CLR_BIT				BIT(12)
62 
63 #define REG_MMU_FAULT_ST			0x224
64 #define REG_MMU_FAULT_VA			0x228
65 #define REG_MMU_INVLD_PA			0x22C
66 #define REG_MMU_INT_ID				0x388
67 #define REG_MMU_INVALIDATE			0x5c0
68 #define REG_MMU_INVLD_START_A			0x5c4
69 #define REG_MMU_INVLD_END_A			0x5c8
70 
71 #define REG_MMU_INV_SEL				0x5d8
72 #define REG_MMU_STANDARD_AXI_MODE		0x5e8
73 
74 #define REG_MMU_DCM				0x5f0
75 #define F_MMU_DCM_ON				BIT(1)
76 #define REG_MMU_CPE_DONE			0x60c
77 #define F_DESC_VALID				0x2
78 #define F_DESC_NONSEC				BIT(3)
79 #define MT2701_M4U_TF_LARB(TF)			(6 - (((TF) >> 13) & 0x7))
80 #define MT2701_M4U_TF_PORT(TF)			(((TF) >> 8) & 0xF)
81 /* MTK generation one iommu HW only support 4K size mapping */
82 #define MT2701_IOMMU_PAGE_SHIFT			12
83 #define MT2701_IOMMU_PAGE_SIZE			(1UL << MT2701_IOMMU_PAGE_SHIFT)
84 
85 /*
86  * MTK m4u support 4GB iova address space, and only support 4K page
87  * mapping. So the pagetable size should be exactly as 4M.
88  */
89 #define M2701_IOMMU_PGT_SIZE			SZ_4M
90 
91 struct mtk_iommu_domain {
92 	spinlock_t			pgtlock; /* lock for page table */
93 	struct iommu_domain		domain;
94 	u32				*pgt_va;
95 	dma_addr_t			pgt_pa;
96 	struct mtk_iommu_data		*data;
97 };
98 
99 static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
100 {
101 	return container_of(dom, struct mtk_iommu_domain, domain);
102 }
103 
104 static const int mt2701_m4u_in_larb[] = {
105 	LARB0_PORT_OFFSET, LARB1_PORT_OFFSET,
106 	LARB2_PORT_OFFSET, LARB3_PORT_OFFSET
107 };
108 
109 static inline int mt2701_m4u_to_larb(int id)
110 {
111 	int i;
112 
113 	for (i = ARRAY_SIZE(mt2701_m4u_in_larb) - 1; i >= 0; i--)
114 		if ((id) >= mt2701_m4u_in_larb[i])
115 			return i;
116 
117 	return 0;
118 }
119 
120 static inline int mt2701_m4u_to_port(int id)
121 {
122 	int larb = mt2701_m4u_to_larb(id);
123 
124 	return id - mt2701_m4u_in_larb[larb];
125 }
126 
127 static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data)
128 {
129 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
130 			data->base + REG_MMU_INV_SEL);
131 	writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE);
132 	wmb(); /* Make sure the tlb flush all done */
133 }
134 
135 static void mtk_iommu_tlb_flush_range(struct mtk_iommu_data *data,
136 				unsigned long iova, size_t size)
137 {
138 	int ret;
139 	u32 tmp;
140 
141 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
142 		data->base + REG_MMU_INV_SEL);
143 	writel_relaxed(iova & F_MMU_FAULT_VA_MSK,
144 		data->base + REG_MMU_INVLD_START_A);
145 	writel_relaxed((iova + size - 1) & F_MMU_FAULT_VA_MSK,
146 		data->base + REG_MMU_INVLD_END_A);
147 	writel_relaxed(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
148 
149 	ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
150 				tmp, tmp != 0, 10, 100000);
151 	if (ret) {
152 		dev_warn(data->dev,
153 			 "Partial TLB flush timed out, falling back to full flush\n");
154 		mtk_iommu_tlb_flush_all(data);
155 	}
156 	/* Clear the CPE status */
157 	writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
158 }
159 
160 static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
161 {
162 	struct mtk_iommu_data *data = dev_id;
163 	struct mtk_iommu_domain *dom = data->m4u_dom;
164 	u32 int_state, regval, fault_iova, fault_pa;
165 	unsigned int fault_larb, fault_port;
166 
167 	/* Read error information from registers */
168 	int_state = readl_relaxed(data->base + REG_MMU_FAULT_ST);
169 	fault_iova = readl_relaxed(data->base + REG_MMU_FAULT_VA);
170 
171 	fault_iova &= F_MMU_FAULT_VA_MSK;
172 	fault_pa = readl_relaxed(data->base + REG_MMU_INVLD_PA);
173 	regval = readl_relaxed(data->base + REG_MMU_INT_ID);
174 	fault_larb = MT2701_M4U_TF_LARB(regval);
175 	fault_port = MT2701_M4U_TF_PORT(regval);
176 
177 	/*
178 	 * MTK v1 iommu HW could not determine whether the fault is read or
179 	 * write fault, report as read fault.
180 	 */
181 	if (report_iommu_fault(&dom->domain, data->dev, fault_iova,
182 			IOMMU_FAULT_READ))
183 		dev_err_ratelimited(data->dev,
184 			"fault type=0x%x iova=0x%x pa=0x%x larb=%d port=%d\n",
185 			int_state, fault_iova, fault_pa,
186 			fault_larb, fault_port);
187 
188 	/* Interrupt clear */
189 	regval = readl_relaxed(data->base + REG_MMU_INT_CONTROL);
190 	regval |= F_INT_CLR_BIT;
191 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
192 
193 	mtk_iommu_tlb_flush_all(data);
194 
195 	return IRQ_HANDLED;
196 }
197 
198 static void mtk_iommu_config(struct mtk_iommu_data *data,
199 			     struct device *dev, bool enable)
200 {
201 	struct mtk_smi_larb_iommu    *larb_mmu;
202 	unsigned int                 larbid, portid;
203 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
204 	int i;
205 
206 	for (i = 0; i < fwspec->num_ids; ++i) {
207 		larbid = mt2701_m4u_to_larb(fwspec->ids[i]);
208 		portid = mt2701_m4u_to_port(fwspec->ids[i]);
209 		larb_mmu = &data->larb_imu[larbid];
210 
211 		dev_dbg(dev, "%s iommu port: %d\n",
212 			enable ? "enable" : "disable", portid);
213 
214 		if (enable)
215 			larb_mmu->mmu |= MTK_SMI_MMU_EN(portid);
216 		else
217 			larb_mmu->mmu &= ~MTK_SMI_MMU_EN(portid);
218 	}
219 }
220 
221 static int mtk_iommu_domain_finalise(struct mtk_iommu_data *data)
222 {
223 	struct mtk_iommu_domain *dom = data->m4u_dom;
224 
225 	spin_lock_init(&dom->pgtlock);
226 
227 	dom->pgt_va = dma_alloc_coherent(data->dev, M2701_IOMMU_PGT_SIZE,
228 					 &dom->pgt_pa, GFP_KERNEL);
229 	if (!dom->pgt_va)
230 		return -ENOMEM;
231 
232 	writel(dom->pgt_pa, data->base + REG_MMU_PT_BASE_ADDR);
233 
234 	dom->data = data;
235 
236 	return 0;
237 }
238 
239 static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
240 {
241 	struct mtk_iommu_domain *dom;
242 
243 	if (type != IOMMU_DOMAIN_UNMANAGED)
244 		return NULL;
245 
246 	dom = kzalloc(sizeof(*dom), GFP_KERNEL);
247 	if (!dom)
248 		return NULL;
249 
250 	return &dom->domain;
251 }
252 
253 static void mtk_iommu_domain_free(struct iommu_domain *domain)
254 {
255 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
256 	struct mtk_iommu_data *data = dom->data;
257 
258 	dma_free_coherent(data->dev, M2701_IOMMU_PGT_SIZE,
259 			dom->pgt_va, dom->pgt_pa);
260 	kfree(to_mtk_domain(domain));
261 }
262 
263 static int mtk_iommu_attach_device(struct iommu_domain *domain,
264 				   struct device *dev)
265 {
266 	struct mtk_iommu_data *data = dev_iommu_priv_get(dev);
267 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
268 	struct dma_iommu_mapping *mtk_mapping;
269 	int ret;
270 
271 	/* Only allow the domain created internally. */
272 	mtk_mapping = data->dev->archdata.iommu;
273 	if (mtk_mapping->domain != domain)
274 		return 0;
275 
276 	if (!data->m4u_dom) {
277 		data->m4u_dom = dom;
278 		ret = mtk_iommu_domain_finalise(data);
279 		if (ret) {
280 			data->m4u_dom = NULL;
281 			return ret;
282 		}
283 	}
284 
285 	mtk_iommu_config(data, dev, true);
286 	return 0;
287 }
288 
289 static void mtk_iommu_detach_device(struct iommu_domain *domain,
290 				    struct device *dev)
291 {
292 	struct mtk_iommu_data *data = dev_iommu_priv_get(dev);
293 
294 	mtk_iommu_config(data, dev, false);
295 }
296 
297 static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
298 			 phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
299 {
300 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
301 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
302 	unsigned long flags;
303 	unsigned int i;
304 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
305 	u32 pabase = (u32)paddr;
306 	int map_size = 0;
307 
308 	spin_lock_irqsave(&dom->pgtlock, flags);
309 	for (i = 0; i < page_num; i++) {
310 		if (pgt_base_iova[i]) {
311 			memset(pgt_base_iova, 0, i * sizeof(u32));
312 			break;
313 		}
314 		pgt_base_iova[i] = pabase | F_DESC_VALID | F_DESC_NONSEC;
315 		pabase += MT2701_IOMMU_PAGE_SIZE;
316 		map_size += MT2701_IOMMU_PAGE_SIZE;
317 	}
318 
319 	spin_unlock_irqrestore(&dom->pgtlock, flags);
320 
321 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
322 
323 	return map_size == size ? 0 : -EEXIST;
324 }
325 
326 static size_t mtk_iommu_unmap(struct iommu_domain *domain,
327 			      unsigned long iova, size_t size,
328 			      struct iommu_iotlb_gather *gather)
329 {
330 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
331 	unsigned long flags;
332 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
333 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
334 
335 	spin_lock_irqsave(&dom->pgtlock, flags);
336 	memset(pgt_base_iova, 0, page_num * sizeof(u32));
337 	spin_unlock_irqrestore(&dom->pgtlock, flags);
338 
339 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
340 
341 	return size;
342 }
343 
344 static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
345 					  dma_addr_t iova)
346 {
347 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
348 	unsigned long flags;
349 	phys_addr_t pa;
350 
351 	spin_lock_irqsave(&dom->pgtlock, flags);
352 	pa = *(dom->pgt_va + (iova >> MT2701_IOMMU_PAGE_SHIFT));
353 	pa = pa & (~(MT2701_IOMMU_PAGE_SIZE - 1));
354 	spin_unlock_irqrestore(&dom->pgtlock, flags);
355 
356 	return pa;
357 }
358 
359 static const struct iommu_ops mtk_iommu_ops;
360 
361 /*
362  * MTK generation one iommu HW only support one iommu domain, and all the client
363  * sharing the same iova address space.
364  */
365 static int mtk_iommu_create_mapping(struct device *dev,
366 				    struct of_phandle_args *args)
367 {
368 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
369 	struct mtk_iommu_data *data;
370 	struct platform_device *m4updev;
371 	struct dma_iommu_mapping *mtk_mapping;
372 	struct device *m4udev;
373 	int ret;
374 
375 	if (args->args_count != 1) {
376 		dev_err(dev, "invalid #iommu-cells(%d) property for IOMMU\n",
377 			args->args_count);
378 		return -EINVAL;
379 	}
380 
381 	if (!fwspec) {
382 		ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_ops);
383 		if (ret)
384 			return ret;
385 		fwspec = dev_iommu_fwspec_get(dev);
386 	} else if (dev_iommu_fwspec_get(dev)->ops != &mtk_iommu_ops) {
387 		return -EINVAL;
388 	}
389 
390 	if (!dev_iommu_priv_get(dev)) {
391 		/* Get the m4u device */
392 		m4updev = of_find_device_by_node(args->np);
393 		if (WARN_ON(!m4updev))
394 			return -EINVAL;
395 
396 		dev_iommu_priv_set(dev, platform_get_drvdata(m4updev));
397 	}
398 
399 	ret = iommu_fwspec_add_ids(dev, args->args, 1);
400 	if (ret)
401 		return ret;
402 
403 	data = dev_iommu_priv_get(dev);
404 	m4udev = data->dev;
405 	mtk_mapping = m4udev->archdata.iommu;
406 	if (!mtk_mapping) {
407 		/* MTK iommu support 4GB iova address space. */
408 		mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,
409 						0, 1ULL << 32);
410 		if (IS_ERR(mtk_mapping))
411 			return PTR_ERR(mtk_mapping);
412 
413 		m4udev->archdata.iommu = mtk_mapping;
414 	}
415 
416 	return 0;
417 }
418 
419 static int mtk_iommu_def_domain_type(struct device *dev)
420 {
421 	return IOMMU_DOMAIN_UNMANAGED;
422 }
423 
424 static struct iommu_device *mtk_iommu_probe_device(struct device *dev)
425 {
426 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
427 	struct of_phandle_args iommu_spec;
428 	struct of_phandle_iterator it;
429 	struct mtk_iommu_data *data;
430 	int err;
431 
432 	of_for_each_phandle(&it, err, dev->of_node, "iommus",
433 			"#iommu-cells", -1) {
434 		int count = of_phandle_iterator_args(&it, iommu_spec.args,
435 					MAX_PHANDLE_ARGS);
436 		iommu_spec.np = of_node_get(it.node);
437 		iommu_spec.args_count = count;
438 
439 		mtk_iommu_create_mapping(dev, &iommu_spec);
440 
441 		/* dev->iommu_fwspec might have changed */
442 		fwspec = dev_iommu_fwspec_get(dev);
443 
444 		of_node_put(iommu_spec.np);
445 	}
446 
447 	if (!fwspec || fwspec->ops != &mtk_iommu_ops)
448 		return ERR_PTR(-ENODEV); /* Not a iommu client device */
449 
450 	data = dev_iommu_priv_get(dev);
451 
452 	return &data->iommu;
453 }
454 
455 static void mtk_iommu_probe_finalize(struct device *dev)
456 {
457 	struct dma_iommu_mapping *mtk_mapping;
458 	struct mtk_iommu_data *data;
459 	int err;
460 
461 	data        = dev_iommu_priv_get(dev);
462 	mtk_mapping = data->dev->archdata.iommu;
463 
464 	err = arm_iommu_attach_device(dev, mtk_mapping);
465 	if (err)
466 		dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");
467 }
468 
469 static void mtk_iommu_release_device(struct device *dev)
470 {
471 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
472 
473 	if (!fwspec || fwspec->ops != &mtk_iommu_ops)
474 		return;
475 
476 	iommu_fwspec_free(dev);
477 }
478 
479 static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
480 {
481 	u32 regval;
482 	int ret;
483 
484 	ret = clk_prepare_enable(data->bclk);
485 	if (ret) {
486 		dev_err(data->dev, "Failed to enable iommu bclk(%d)\n", ret);
487 		return ret;
488 	}
489 
490 	regval = F_MMU_CTRL_COHERENT_EN | F_MMU_TF_PROTECT_SEL(2);
491 	writel_relaxed(regval, data->base + REG_MMU_CTRL_REG);
492 
493 	regval = F_INT_TRANSLATION_FAULT |
494 		F_INT_MAIN_MULTI_HIT_FAULT |
495 		F_INT_INVALID_PA_FAULT |
496 		F_INT_ENTRY_REPLACEMENT_FAULT |
497 		F_INT_TABLE_WALK_FAULT |
498 		F_INT_TLB_MISS_FAULT |
499 		F_INT_PFH_DMA_FIFO_OVERFLOW |
500 		F_INT_MISS_DMA_FIFO_OVERFLOW;
501 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
502 
503 	/* protect memory,hw will write here while translation fault */
504 	writel_relaxed(data->protect_base,
505 			data->base + REG_MMU_IVRP_PADDR);
506 
507 	writel_relaxed(F_MMU_DCM_ON, data->base + REG_MMU_DCM);
508 
509 	if (devm_request_irq(data->dev, data->irq, mtk_iommu_isr, 0,
510 			     dev_name(data->dev), (void *)data)) {
511 		writel_relaxed(0, data->base + REG_MMU_PT_BASE_ADDR);
512 		clk_disable_unprepare(data->bclk);
513 		dev_err(data->dev, "Failed @ IRQ-%d Request\n", data->irq);
514 		return -ENODEV;
515 	}
516 
517 	return 0;
518 }
519 
520 static const struct iommu_ops mtk_iommu_ops = {
521 	.domain_alloc	= mtk_iommu_domain_alloc,
522 	.domain_free	= mtk_iommu_domain_free,
523 	.attach_dev	= mtk_iommu_attach_device,
524 	.detach_dev	= mtk_iommu_detach_device,
525 	.map		= mtk_iommu_map,
526 	.unmap		= mtk_iommu_unmap,
527 	.iova_to_phys	= mtk_iommu_iova_to_phys,
528 	.probe_device	= mtk_iommu_probe_device,
529 	.probe_finalize = mtk_iommu_probe_finalize,
530 	.release_device	= mtk_iommu_release_device,
531 	.def_domain_type = mtk_iommu_def_domain_type,
532 	.device_group	= generic_device_group,
533 	.pgsize_bitmap	= ~0UL << MT2701_IOMMU_PAGE_SHIFT,
534 };
535 
536 static const struct of_device_id mtk_iommu_of_ids[] = {
537 	{ .compatible = "mediatek,mt2701-m4u", },
538 	{}
539 };
540 
541 static const struct component_master_ops mtk_iommu_com_ops = {
542 	.bind		= mtk_iommu_bind,
543 	.unbind		= mtk_iommu_unbind,
544 };
545 
546 static int mtk_iommu_probe(struct platform_device *pdev)
547 {
548 	struct mtk_iommu_data		*data;
549 	struct device			*dev = &pdev->dev;
550 	struct resource			*res;
551 	struct component_match		*match = NULL;
552 	struct of_phandle_args		larb_spec;
553 	struct of_phandle_iterator	it;
554 	void				*protect;
555 	int				larb_nr, ret, err;
556 
557 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
558 	if (!data)
559 		return -ENOMEM;
560 
561 	data->dev = dev;
562 
563 	/* Protect memory. HW will access here while translation fault.*/
564 	protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2,
565 			GFP_KERNEL | GFP_DMA);
566 	if (!protect)
567 		return -ENOMEM;
568 	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
569 
570 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
571 	data->base = devm_ioremap_resource(dev, res);
572 	if (IS_ERR(data->base))
573 		return PTR_ERR(data->base);
574 
575 	data->irq = platform_get_irq(pdev, 0);
576 	if (data->irq < 0)
577 		return data->irq;
578 
579 	data->bclk = devm_clk_get(dev, "bclk");
580 	if (IS_ERR(data->bclk))
581 		return PTR_ERR(data->bclk);
582 
583 	larb_nr = 0;
584 	of_for_each_phandle(&it, err, dev->of_node,
585 			"mediatek,larbs", NULL, 0) {
586 		struct platform_device *plarbdev;
587 		int count = of_phandle_iterator_args(&it, larb_spec.args,
588 					MAX_PHANDLE_ARGS);
589 
590 		if (count)
591 			continue;
592 
593 		larb_spec.np = of_node_get(it.node);
594 		if (!of_device_is_available(larb_spec.np))
595 			continue;
596 
597 		plarbdev = of_find_device_by_node(larb_spec.np);
598 		if (!plarbdev) {
599 			plarbdev = of_platform_device_create(
600 						larb_spec.np, NULL,
601 						platform_bus_type.dev_root);
602 			if (!plarbdev) {
603 				of_node_put(larb_spec.np);
604 				return -EPROBE_DEFER;
605 			}
606 		}
607 
608 		data->larb_imu[larb_nr].dev = &plarbdev->dev;
609 		component_match_add_release(dev, &match, release_of,
610 					    compare_of, larb_spec.np);
611 		larb_nr++;
612 	}
613 
614 	platform_set_drvdata(pdev, data);
615 
616 	ret = mtk_iommu_hw_init(data);
617 	if (ret)
618 		return ret;
619 
620 	ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
621 				     dev_name(&pdev->dev));
622 	if (ret)
623 		return ret;
624 
625 	iommu_device_set_ops(&data->iommu, &mtk_iommu_ops);
626 
627 	ret = iommu_device_register(&data->iommu);
628 	if (ret)
629 		return ret;
630 
631 	if (!iommu_present(&platform_bus_type))
632 		bus_set_iommu(&platform_bus_type,  &mtk_iommu_ops);
633 
634 	return component_master_add_with_match(dev, &mtk_iommu_com_ops, match);
635 }
636 
637 static int mtk_iommu_remove(struct platform_device *pdev)
638 {
639 	struct mtk_iommu_data *data = platform_get_drvdata(pdev);
640 
641 	iommu_device_sysfs_remove(&data->iommu);
642 	iommu_device_unregister(&data->iommu);
643 
644 	if (iommu_present(&platform_bus_type))
645 		bus_set_iommu(&platform_bus_type, NULL);
646 
647 	clk_disable_unprepare(data->bclk);
648 	devm_free_irq(&pdev->dev, data->irq, data);
649 	component_master_del(&pdev->dev, &mtk_iommu_com_ops);
650 	return 0;
651 }
652 
653 static int __maybe_unused mtk_iommu_suspend(struct device *dev)
654 {
655 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
656 	struct mtk_iommu_suspend_reg *reg = &data->reg;
657 	void __iomem *base = data->base;
658 
659 	reg->standard_axi_mode = readl_relaxed(base +
660 					       REG_MMU_STANDARD_AXI_MODE);
661 	reg->dcm_dis = readl_relaxed(base + REG_MMU_DCM);
662 	reg->ctrl_reg = readl_relaxed(base + REG_MMU_CTRL_REG);
663 	reg->int_control0 = readl_relaxed(base + REG_MMU_INT_CONTROL);
664 	return 0;
665 }
666 
667 static int __maybe_unused mtk_iommu_resume(struct device *dev)
668 {
669 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
670 	struct mtk_iommu_suspend_reg *reg = &data->reg;
671 	void __iomem *base = data->base;
672 
673 	writel_relaxed(data->m4u_dom->pgt_pa, base + REG_MMU_PT_BASE_ADDR);
674 	writel_relaxed(reg->standard_axi_mode,
675 		       base + REG_MMU_STANDARD_AXI_MODE);
676 	writel_relaxed(reg->dcm_dis, base + REG_MMU_DCM);
677 	writel_relaxed(reg->ctrl_reg, base + REG_MMU_CTRL_REG);
678 	writel_relaxed(reg->int_control0, base + REG_MMU_INT_CONTROL);
679 	writel_relaxed(data->protect_base, base + REG_MMU_IVRP_PADDR);
680 	return 0;
681 }
682 
683 static const struct dev_pm_ops mtk_iommu_pm_ops = {
684 	SET_SYSTEM_SLEEP_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume)
685 };
686 
687 static struct platform_driver mtk_iommu_driver = {
688 	.probe	= mtk_iommu_probe,
689 	.remove	= mtk_iommu_remove,
690 	.driver	= {
691 		.name = "mtk-iommu-v1",
692 		.of_match_table = mtk_iommu_of_ids,
693 		.pm = &mtk_iommu_pm_ops,
694 	}
695 };
696 
697 static int __init m4u_init(void)
698 {
699 	return platform_driver_register(&mtk_iommu_driver);
700 }
701 subsys_initcall(m4u_init);
702