xref: /openbmc/linux/drivers/iommu/mtk_iommu_v1.c (revision 50df3be7)
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_domain *dom = to_mtk_domain(domain);
267 	struct mtk_iommu_data *data = dev_iommu_fwspec_get(dev)->iommu_priv;
268 	int ret;
269 
270 	if (!data)
271 		return -ENODEV;
272 
273 	if (!data->m4u_dom) {
274 		data->m4u_dom = dom;
275 		ret = mtk_iommu_domain_finalise(data);
276 		if (ret) {
277 			data->m4u_dom = NULL;
278 			return ret;
279 		}
280 	}
281 
282 	mtk_iommu_config(data, dev, true);
283 	return 0;
284 }
285 
286 static void mtk_iommu_detach_device(struct iommu_domain *domain,
287 				    struct device *dev)
288 {
289 	struct mtk_iommu_data *data = dev_iommu_fwspec_get(dev)->iommu_priv;
290 
291 	if (!data)
292 		return;
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)
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 (!fwspec->iommu_priv) {
391 		/* Get the m4u device */
392 		m4updev = of_find_device_by_node(args->np);
393 		if (WARN_ON(!m4updev))
394 			return -EINVAL;
395 
396 		fwspec->iommu_priv = 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 = fwspec->iommu_priv;
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_add_device(struct device *dev)
420 {
421 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
422 	struct dma_iommu_mapping *mtk_mapping;
423 	struct of_phandle_args iommu_spec;
424 	struct of_phandle_iterator it;
425 	struct mtk_iommu_data *data;
426 	struct iommu_group *group;
427 	int err;
428 
429 	of_for_each_phandle(&it, err, dev->of_node, "iommus",
430 			"#iommu-cells", -1) {
431 		int count = of_phandle_iterator_args(&it, iommu_spec.args,
432 					MAX_PHANDLE_ARGS);
433 		iommu_spec.np = of_node_get(it.node);
434 		iommu_spec.args_count = count;
435 
436 		mtk_iommu_create_mapping(dev, &iommu_spec);
437 
438 		/* dev->iommu_fwspec might have changed */
439 		fwspec = dev_iommu_fwspec_get(dev);
440 
441 		of_node_put(iommu_spec.np);
442 	}
443 
444 	if (!fwspec || fwspec->ops != &mtk_iommu_ops)
445 		return -ENODEV; /* Not a iommu client device */
446 
447 	/*
448 	 * This is a short-term bodge because the ARM DMA code doesn't
449 	 * understand multi-device groups, but we have to call into it
450 	 * successfully (and not just rely on a normal IOMMU API attach
451 	 * here) in order to set the correct DMA API ops on @dev.
452 	 */
453 	group = iommu_group_alloc();
454 	if (IS_ERR(group))
455 		return PTR_ERR(group);
456 
457 	err = iommu_group_add_device(group, dev);
458 	iommu_group_put(group);
459 	if (err)
460 		return err;
461 
462 	data = fwspec->iommu_priv;
463 	mtk_mapping = data->dev->archdata.iommu;
464 	err = arm_iommu_attach_device(dev, mtk_mapping);
465 	if (err) {
466 		iommu_group_remove_device(dev);
467 		return err;
468 	}
469 
470 	return iommu_device_link(&data->iommu, dev);
471 }
472 
473 static void mtk_iommu_remove_device(struct device *dev)
474 {
475 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
476 	struct mtk_iommu_data *data;
477 
478 	if (!fwspec || fwspec->ops != &mtk_iommu_ops)
479 		return;
480 
481 	data = fwspec->iommu_priv;
482 	iommu_device_unlink(&data->iommu, dev);
483 
484 	iommu_group_remove_device(dev);
485 	iommu_fwspec_free(dev);
486 }
487 
488 static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
489 {
490 	u32 regval;
491 	int ret;
492 
493 	ret = clk_prepare_enable(data->bclk);
494 	if (ret) {
495 		dev_err(data->dev, "Failed to enable iommu bclk(%d)\n", ret);
496 		return ret;
497 	}
498 
499 	regval = F_MMU_CTRL_COHERENT_EN | F_MMU_TF_PROTECT_SEL(2);
500 	writel_relaxed(regval, data->base + REG_MMU_CTRL_REG);
501 
502 	regval = F_INT_TRANSLATION_FAULT |
503 		F_INT_MAIN_MULTI_HIT_FAULT |
504 		F_INT_INVALID_PA_FAULT |
505 		F_INT_ENTRY_REPLACEMENT_FAULT |
506 		F_INT_TABLE_WALK_FAULT |
507 		F_INT_TLB_MISS_FAULT |
508 		F_INT_PFH_DMA_FIFO_OVERFLOW |
509 		F_INT_MISS_DMA_FIFO_OVERFLOW;
510 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
511 
512 	/* protect memory,hw will write here while translation fault */
513 	writel_relaxed(data->protect_base,
514 			data->base + REG_MMU_IVRP_PADDR);
515 
516 	writel_relaxed(F_MMU_DCM_ON, data->base + REG_MMU_DCM);
517 
518 	if (devm_request_irq(data->dev, data->irq, mtk_iommu_isr, 0,
519 			     dev_name(data->dev), (void *)data)) {
520 		writel_relaxed(0, data->base + REG_MMU_PT_BASE_ADDR);
521 		clk_disable_unprepare(data->bclk);
522 		dev_err(data->dev, "Failed @ IRQ-%d Request\n", data->irq);
523 		return -ENODEV;
524 	}
525 
526 	return 0;
527 }
528 
529 static const struct iommu_ops mtk_iommu_ops = {
530 	.domain_alloc	= mtk_iommu_domain_alloc,
531 	.domain_free	= mtk_iommu_domain_free,
532 	.attach_dev	= mtk_iommu_attach_device,
533 	.detach_dev	= mtk_iommu_detach_device,
534 	.map		= mtk_iommu_map,
535 	.unmap		= mtk_iommu_unmap,
536 	.iova_to_phys	= mtk_iommu_iova_to_phys,
537 	.add_device	= mtk_iommu_add_device,
538 	.remove_device	= mtk_iommu_remove_device,
539 	.pgsize_bitmap	= ~0UL << MT2701_IOMMU_PAGE_SHIFT,
540 };
541 
542 static const struct of_device_id mtk_iommu_of_ids[] = {
543 	{ .compatible = "mediatek,mt2701-m4u", },
544 	{}
545 };
546 
547 static const struct component_master_ops mtk_iommu_com_ops = {
548 	.bind		= mtk_iommu_bind,
549 	.unbind		= mtk_iommu_unbind,
550 };
551 
552 static int mtk_iommu_probe(struct platform_device *pdev)
553 {
554 	struct mtk_iommu_data		*data;
555 	struct device			*dev = &pdev->dev;
556 	struct resource			*res;
557 	struct component_match		*match = NULL;
558 	struct of_phandle_args		larb_spec;
559 	struct of_phandle_iterator	it;
560 	void				*protect;
561 	int				larb_nr, ret, err;
562 
563 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
564 	if (!data)
565 		return -ENOMEM;
566 
567 	data->dev = dev;
568 
569 	/* Protect memory. HW will access here while translation fault.*/
570 	protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2,
571 			GFP_KERNEL | GFP_DMA);
572 	if (!protect)
573 		return -ENOMEM;
574 	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
575 
576 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
577 	data->base = devm_ioremap_resource(dev, res);
578 	if (IS_ERR(data->base))
579 		return PTR_ERR(data->base);
580 
581 	data->irq = platform_get_irq(pdev, 0);
582 	if (data->irq < 0)
583 		return data->irq;
584 
585 	data->bclk = devm_clk_get(dev, "bclk");
586 	if (IS_ERR(data->bclk))
587 		return PTR_ERR(data->bclk);
588 
589 	larb_nr = 0;
590 	of_for_each_phandle(&it, err, dev->of_node,
591 			"mediatek,larbs", NULL, 0) {
592 		struct platform_device *plarbdev;
593 		int count = of_phandle_iterator_args(&it, larb_spec.args,
594 					MAX_PHANDLE_ARGS);
595 
596 		if (count)
597 			continue;
598 
599 		larb_spec.np = of_node_get(it.node);
600 		if (!of_device_is_available(larb_spec.np))
601 			continue;
602 
603 		plarbdev = of_find_device_by_node(larb_spec.np);
604 		if (!plarbdev) {
605 			plarbdev = of_platform_device_create(
606 						larb_spec.np, NULL,
607 						platform_bus_type.dev_root);
608 			if (!plarbdev) {
609 				of_node_put(larb_spec.np);
610 				return -EPROBE_DEFER;
611 			}
612 		}
613 
614 		data->larb_imu[larb_nr].dev = &plarbdev->dev;
615 		component_match_add_release(dev, &match, release_of,
616 					    compare_of, larb_spec.np);
617 		larb_nr++;
618 	}
619 
620 	platform_set_drvdata(pdev, data);
621 
622 	ret = mtk_iommu_hw_init(data);
623 	if (ret)
624 		return ret;
625 
626 	ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
627 				     dev_name(&pdev->dev));
628 	if (ret)
629 		return ret;
630 
631 	iommu_device_set_ops(&data->iommu, &mtk_iommu_ops);
632 
633 	ret = iommu_device_register(&data->iommu);
634 	if (ret)
635 		return ret;
636 
637 	if (!iommu_present(&platform_bus_type))
638 		bus_set_iommu(&platform_bus_type,  &mtk_iommu_ops);
639 
640 	return component_master_add_with_match(dev, &mtk_iommu_com_ops, match);
641 }
642 
643 static int mtk_iommu_remove(struct platform_device *pdev)
644 {
645 	struct mtk_iommu_data *data = platform_get_drvdata(pdev);
646 
647 	iommu_device_sysfs_remove(&data->iommu);
648 	iommu_device_unregister(&data->iommu);
649 
650 	if (iommu_present(&platform_bus_type))
651 		bus_set_iommu(&platform_bus_type, NULL);
652 
653 	clk_disable_unprepare(data->bclk);
654 	devm_free_irq(&pdev->dev, data->irq, data);
655 	component_master_del(&pdev->dev, &mtk_iommu_com_ops);
656 	return 0;
657 }
658 
659 static int __maybe_unused mtk_iommu_suspend(struct device *dev)
660 {
661 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
662 	struct mtk_iommu_suspend_reg *reg = &data->reg;
663 	void __iomem *base = data->base;
664 
665 	reg->standard_axi_mode = readl_relaxed(base +
666 					       REG_MMU_STANDARD_AXI_MODE);
667 	reg->dcm_dis = readl_relaxed(base + REG_MMU_DCM);
668 	reg->ctrl_reg = readl_relaxed(base + REG_MMU_CTRL_REG);
669 	reg->int_control0 = readl_relaxed(base + REG_MMU_INT_CONTROL);
670 	return 0;
671 }
672 
673 static int __maybe_unused mtk_iommu_resume(struct device *dev)
674 {
675 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
676 	struct mtk_iommu_suspend_reg *reg = &data->reg;
677 	void __iomem *base = data->base;
678 
679 	writel_relaxed(data->m4u_dom->pgt_pa, base + REG_MMU_PT_BASE_ADDR);
680 	writel_relaxed(reg->standard_axi_mode,
681 		       base + REG_MMU_STANDARD_AXI_MODE);
682 	writel_relaxed(reg->dcm_dis, base + REG_MMU_DCM);
683 	writel_relaxed(reg->ctrl_reg, base + REG_MMU_CTRL_REG);
684 	writel_relaxed(reg->int_control0, base + REG_MMU_INT_CONTROL);
685 	writel_relaxed(data->protect_base, base + REG_MMU_IVRP_PADDR);
686 	return 0;
687 }
688 
689 static const struct dev_pm_ops mtk_iommu_pm_ops = {
690 	SET_SYSTEM_SLEEP_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume)
691 };
692 
693 static struct platform_driver mtk_iommu_driver = {
694 	.probe	= mtk_iommu_probe,
695 	.remove	= mtk_iommu_remove,
696 	.driver	= {
697 		.name = "mtk-iommu-v1",
698 		.of_match_table = mtk_iommu_of_ids,
699 		.pm = &mtk_iommu_pm_ops,
700 	}
701 };
702 
703 static int __init m4u_init(void)
704 {
705 	return platform_driver_register(&mtk_iommu_driver);
706 }
707 subsys_initcall(m4u_init);
708