xref: /openbmc/linux/drivers/iommu/mtk_iommu_v1.c (revision 3d37ef41)
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/module.h>
24 #include <linux/of_address.h>
25 #include <linux/of_iommu.h>
26 #include <linux/of_irq.h>
27 #include <linux/of_platform.h>
28 #include <linux/platform_device.h>
29 #include <linux/slab.h>
30 #include <linux/spinlock.h>
31 #include <asm/barrier.h>
32 #include <asm/dma-iommu.h>
33 #include <linux/init.h>
34 #include <dt-bindings/memory/mt2701-larb-port.h>
35 #include <soc/mediatek/smi.h>
36 #include "mtk_iommu.h"
37 
38 #define REG_MMU_PT_BASE_ADDR			0x000
39 
40 #define F_ALL_INVLD				0x2
41 #define F_MMU_INV_RANGE				0x1
42 #define F_INVLD_EN0				BIT(0)
43 #define F_INVLD_EN1				BIT(1)
44 
45 #define F_MMU_FAULT_VA_MSK			0xfffff000
46 #define MTK_PROTECT_PA_ALIGN			128
47 
48 #define REG_MMU_CTRL_REG			0x210
49 #define F_MMU_CTRL_COHERENT_EN			BIT(8)
50 #define REG_MMU_IVRP_PADDR			0x214
51 #define REG_MMU_INT_CONTROL			0x220
52 #define F_INT_TRANSLATION_FAULT			BIT(0)
53 #define F_INT_MAIN_MULTI_HIT_FAULT		BIT(1)
54 #define F_INT_INVALID_PA_FAULT			BIT(2)
55 #define F_INT_ENTRY_REPLACEMENT_FAULT		BIT(3)
56 #define F_INT_TABLE_WALK_FAULT			BIT(4)
57 #define F_INT_TLB_MISS_FAULT			BIT(5)
58 #define F_INT_PFH_DMA_FIFO_OVERFLOW		BIT(6)
59 #define F_INT_MISS_DMA_FIFO_OVERFLOW		BIT(7)
60 
61 #define F_MMU_TF_PROTECT_SEL(prot)		(((prot) & 0x3) << 5)
62 #define F_INT_CLR_BIT				BIT(12)
63 
64 #define REG_MMU_FAULT_ST			0x224
65 #define REG_MMU_FAULT_VA			0x228
66 #define REG_MMU_INVLD_PA			0x22C
67 #define REG_MMU_INT_ID				0x388
68 #define REG_MMU_INVALIDATE			0x5c0
69 #define REG_MMU_INVLD_START_A			0x5c4
70 #define REG_MMU_INVLD_END_A			0x5c8
71 
72 #define REG_MMU_INV_SEL				0x5d8
73 #define REG_MMU_STANDARD_AXI_MODE		0x5e8
74 
75 #define REG_MMU_DCM				0x5f0
76 #define F_MMU_DCM_ON				BIT(1)
77 #define REG_MMU_CPE_DONE			0x60c
78 #define F_DESC_VALID				0x2
79 #define F_DESC_NONSEC				BIT(3)
80 #define MT2701_M4U_TF_LARB(TF)			(6 - (((TF) >> 13) & 0x7))
81 #define MT2701_M4U_TF_PORT(TF)			(((TF) >> 8) & 0xF)
82 /* MTK generation one iommu HW only support 4K size mapping */
83 #define MT2701_IOMMU_PAGE_SHIFT			12
84 #define MT2701_IOMMU_PAGE_SIZE			(1UL << MT2701_IOMMU_PAGE_SHIFT)
85 
86 /*
87  * MTK m4u support 4GB iova address space, and only support 4K page
88  * mapping. So the pagetable size should be exactly as 4M.
89  */
90 #define M2701_IOMMU_PGT_SIZE			SZ_4M
91 
92 struct mtk_iommu_domain {
93 	spinlock_t			pgtlock; /* lock for page table */
94 	struct iommu_domain		domain;
95 	u32				*pgt_va;
96 	dma_addr_t			pgt_pa;
97 	struct mtk_iommu_data		*data;
98 };
99 
100 static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
101 {
102 	return container_of(dom, struct mtk_iommu_domain, domain);
103 }
104 
105 static const int mt2701_m4u_in_larb[] = {
106 	LARB0_PORT_OFFSET, LARB1_PORT_OFFSET,
107 	LARB2_PORT_OFFSET, LARB3_PORT_OFFSET
108 };
109 
110 static inline int mt2701_m4u_to_larb(int id)
111 {
112 	int i;
113 
114 	for (i = ARRAY_SIZE(mt2701_m4u_in_larb) - 1; i >= 0; i--)
115 		if ((id) >= mt2701_m4u_in_larb[i])
116 			return i;
117 
118 	return 0;
119 }
120 
121 static inline int mt2701_m4u_to_port(int id)
122 {
123 	int larb = mt2701_m4u_to_larb(id);
124 
125 	return id - mt2701_m4u_in_larb[larb];
126 }
127 
128 static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data)
129 {
130 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
131 			data->base + REG_MMU_INV_SEL);
132 	writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE);
133 	wmb(); /* Make sure the tlb flush all done */
134 }
135 
136 static void mtk_iommu_tlb_flush_range(struct mtk_iommu_data *data,
137 				unsigned long iova, size_t size)
138 {
139 	int ret;
140 	u32 tmp;
141 
142 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
143 		data->base + REG_MMU_INV_SEL);
144 	writel_relaxed(iova & F_MMU_FAULT_VA_MSK,
145 		data->base + REG_MMU_INVLD_START_A);
146 	writel_relaxed((iova + size - 1) & F_MMU_FAULT_VA_MSK,
147 		data->base + REG_MMU_INVLD_END_A);
148 	writel_relaxed(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
149 
150 	ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
151 				tmp, tmp != 0, 10, 100000);
152 	if (ret) {
153 		dev_warn(data->dev,
154 			 "Partial TLB flush timed out, falling back to full flush\n");
155 		mtk_iommu_tlb_flush_all(data);
156 	}
157 	/* Clear the CPE status */
158 	writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
159 }
160 
161 static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
162 {
163 	struct mtk_iommu_data *data = dev_id;
164 	struct mtk_iommu_domain *dom = data->m4u_dom;
165 	u32 int_state, regval, fault_iova, fault_pa;
166 	unsigned int fault_larb, fault_port;
167 
168 	/* Read error information from registers */
169 	int_state = readl_relaxed(data->base + REG_MMU_FAULT_ST);
170 	fault_iova = readl_relaxed(data->base + REG_MMU_FAULT_VA);
171 
172 	fault_iova &= F_MMU_FAULT_VA_MSK;
173 	fault_pa = readl_relaxed(data->base + REG_MMU_INVLD_PA);
174 	regval = readl_relaxed(data->base + REG_MMU_INT_ID);
175 	fault_larb = MT2701_M4U_TF_LARB(regval);
176 	fault_port = MT2701_M4U_TF_PORT(regval);
177 
178 	/*
179 	 * MTK v1 iommu HW could not determine whether the fault is read or
180 	 * write fault, report as read fault.
181 	 */
182 	if (report_iommu_fault(&dom->domain, data->dev, fault_iova,
183 			IOMMU_FAULT_READ))
184 		dev_err_ratelimited(data->dev,
185 			"fault type=0x%x iova=0x%x pa=0x%x larb=%d port=%d\n",
186 			int_state, fault_iova, fault_pa,
187 			fault_larb, fault_port);
188 
189 	/* Interrupt clear */
190 	regval = readl_relaxed(data->base + REG_MMU_INT_CONTROL);
191 	regval |= F_INT_CLR_BIT;
192 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
193 
194 	mtk_iommu_tlb_flush_all(data);
195 
196 	return IRQ_HANDLED;
197 }
198 
199 static void mtk_iommu_config(struct mtk_iommu_data *data,
200 			     struct device *dev, bool enable)
201 {
202 	struct mtk_smi_larb_iommu    *larb_mmu;
203 	unsigned int                 larbid, portid;
204 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
205 	int i;
206 
207 	for (i = 0; i < fwspec->num_ids; ++i) {
208 		larbid = mt2701_m4u_to_larb(fwspec->ids[i]);
209 		portid = mt2701_m4u_to_port(fwspec->ids[i]);
210 		larb_mmu = &data->larb_imu[larbid];
211 
212 		dev_dbg(dev, "%s iommu port: %d\n",
213 			enable ? "enable" : "disable", portid);
214 
215 		if (enable)
216 			larb_mmu->mmu |= MTK_SMI_MMU_EN(portid);
217 		else
218 			larb_mmu->mmu &= ~MTK_SMI_MMU_EN(portid);
219 	}
220 }
221 
222 static int mtk_iommu_domain_finalise(struct mtk_iommu_data *data)
223 {
224 	struct mtk_iommu_domain *dom = data->m4u_dom;
225 
226 	spin_lock_init(&dom->pgtlock);
227 
228 	dom->pgt_va = dma_alloc_coherent(data->dev, M2701_IOMMU_PGT_SIZE,
229 					 &dom->pgt_pa, GFP_KERNEL);
230 	if (!dom->pgt_va)
231 		return -ENOMEM;
232 
233 	writel(dom->pgt_pa, data->base + REG_MMU_PT_BASE_ADDR);
234 
235 	dom->data = data;
236 
237 	return 0;
238 }
239 
240 static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
241 {
242 	struct mtk_iommu_domain *dom;
243 
244 	if (type != IOMMU_DOMAIN_UNMANAGED)
245 		return NULL;
246 
247 	dom = kzalloc(sizeof(*dom), GFP_KERNEL);
248 	if (!dom)
249 		return NULL;
250 
251 	return &dom->domain;
252 }
253 
254 static void mtk_iommu_domain_free(struct iommu_domain *domain)
255 {
256 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
257 	struct mtk_iommu_data *data = dom->data;
258 
259 	dma_free_coherent(data->dev, M2701_IOMMU_PGT_SIZE,
260 			dom->pgt_va, dom->pgt_pa);
261 	kfree(to_mtk_domain(domain));
262 }
263 
264 static int mtk_iommu_attach_device(struct iommu_domain *domain,
265 				   struct device *dev)
266 {
267 	struct mtk_iommu_data *data = dev_iommu_priv_get(dev);
268 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
269 	struct dma_iommu_mapping *mtk_mapping;
270 	int ret;
271 
272 	/* Only allow the domain created internally. */
273 	mtk_mapping = data->mapping;
274 	if (mtk_mapping->domain != domain)
275 		return 0;
276 
277 	if (!data->m4u_dom) {
278 		data->m4u_dom = dom;
279 		ret = mtk_iommu_domain_finalise(data);
280 		if (ret) {
281 			data->m4u_dom = NULL;
282 			return ret;
283 		}
284 	}
285 
286 	mtk_iommu_config(data, dev, true);
287 	return 0;
288 }
289 
290 static void mtk_iommu_detach_device(struct iommu_domain *domain,
291 				    struct device *dev)
292 {
293 	struct mtk_iommu_data *data = dev_iommu_priv_get(dev);
294 
295 	mtk_iommu_config(data, dev, false);
296 }
297 
298 static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
299 			 phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
300 {
301 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
302 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
303 	unsigned long flags;
304 	unsigned int i;
305 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
306 	u32 pabase = (u32)paddr;
307 	int map_size = 0;
308 
309 	spin_lock_irqsave(&dom->pgtlock, flags);
310 	for (i = 0; i < page_num; i++) {
311 		if (pgt_base_iova[i]) {
312 			memset(pgt_base_iova, 0, i * sizeof(u32));
313 			break;
314 		}
315 		pgt_base_iova[i] = pabase | F_DESC_VALID | F_DESC_NONSEC;
316 		pabase += MT2701_IOMMU_PAGE_SIZE;
317 		map_size += MT2701_IOMMU_PAGE_SIZE;
318 	}
319 
320 	spin_unlock_irqrestore(&dom->pgtlock, flags);
321 
322 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
323 
324 	return map_size == size ? 0 : -EEXIST;
325 }
326 
327 static size_t mtk_iommu_unmap(struct iommu_domain *domain,
328 			      unsigned long iova, size_t size,
329 			      struct iommu_iotlb_gather *gather)
330 {
331 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
332 	unsigned long flags;
333 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
334 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
335 
336 	spin_lock_irqsave(&dom->pgtlock, flags);
337 	memset(pgt_base_iova, 0, page_num * sizeof(u32));
338 	spin_unlock_irqrestore(&dom->pgtlock, flags);
339 
340 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
341 
342 	return size;
343 }
344 
345 static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
346 					  dma_addr_t iova)
347 {
348 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
349 	unsigned long flags;
350 	phys_addr_t pa;
351 
352 	spin_lock_irqsave(&dom->pgtlock, flags);
353 	pa = *(dom->pgt_va + (iova >> MT2701_IOMMU_PAGE_SHIFT));
354 	pa = pa & (~(MT2701_IOMMU_PAGE_SIZE - 1));
355 	spin_unlock_irqrestore(&dom->pgtlock, flags);
356 
357 	return pa;
358 }
359 
360 static const struct iommu_ops mtk_iommu_ops;
361 
362 /*
363  * MTK generation one iommu HW only support one iommu domain, and all the client
364  * sharing the same iova address space.
365  */
366 static int mtk_iommu_create_mapping(struct device *dev,
367 				    struct of_phandle_args *args)
368 {
369 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
370 	struct mtk_iommu_data *data;
371 	struct platform_device *m4updev;
372 	struct dma_iommu_mapping *mtk_mapping;
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 	mtk_mapping = data->mapping;
405 	if (!mtk_mapping) {
406 		/* MTK iommu support 4GB iova address space. */
407 		mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,
408 						0, 1ULL << 32);
409 		if (IS_ERR(mtk_mapping))
410 			return PTR_ERR(mtk_mapping);
411 
412 		data->mapping = mtk_mapping;
413 	}
414 
415 	return 0;
416 }
417 
418 static int mtk_iommu_def_domain_type(struct device *dev)
419 {
420 	return IOMMU_DOMAIN_UNMANAGED;
421 }
422 
423 static struct iommu_device *mtk_iommu_probe_device(struct device *dev)
424 {
425 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
426 	struct of_phandle_args iommu_spec;
427 	struct mtk_iommu_data *data;
428 	int err, idx = 0;
429 
430 	while (!of_parse_phandle_with_args(dev->of_node, "iommus",
431 					   "#iommu-cells",
432 					   idx, &iommu_spec)) {
433 
434 		err = mtk_iommu_create_mapping(dev, &iommu_spec);
435 		of_node_put(iommu_spec.np);
436 		if (err)
437 			return ERR_PTR(err);
438 
439 		/* dev->iommu_fwspec might have changed */
440 		fwspec = dev_iommu_fwspec_get(dev);
441 		idx++;
442 	}
443 
444 	if (!fwspec || fwspec->ops != &mtk_iommu_ops)
445 		return ERR_PTR(-ENODEV); /* Not a iommu client device */
446 
447 	data = dev_iommu_priv_get(dev);
448 
449 	return &data->iommu;
450 }
451 
452 static void mtk_iommu_probe_finalize(struct device *dev)
453 {
454 	struct dma_iommu_mapping *mtk_mapping;
455 	struct mtk_iommu_data *data;
456 	int err;
457 
458 	data        = dev_iommu_priv_get(dev);
459 	mtk_mapping = data->mapping;
460 
461 	err = arm_iommu_attach_device(dev, mtk_mapping);
462 	if (err)
463 		dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");
464 }
465 
466 static void mtk_iommu_release_device(struct device *dev)
467 {
468 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
469 
470 	if (!fwspec || fwspec->ops != &mtk_iommu_ops)
471 		return;
472 
473 	iommu_fwspec_free(dev);
474 }
475 
476 static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
477 {
478 	u32 regval;
479 	int ret;
480 
481 	ret = clk_prepare_enable(data->bclk);
482 	if (ret) {
483 		dev_err(data->dev, "Failed to enable iommu bclk(%d)\n", ret);
484 		return ret;
485 	}
486 
487 	regval = F_MMU_CTRL_COHERENT_EN | F_MMU_TF_PROTECT_SEL(2);
488 	writel_relaxed(regval, data->base + REG_MMU_CTRL_REG);
489 
490 	regval = F_INT_TRANSLATION_FAULT |
491 		F_INT_MAIN_MULTI_HIT_FAULT |
492 		F_INT_INVALID_PA_FAULT |
493 		F_INT_ENTRY_REPLACEMENT_FAULT |
494 		F_INT_TABLE_WALK_FAULT |
495 		F_INT_TLB_MISS_FAULT |
496 		F_INT_PFH_DMA_FIFO_OVERFLOW |
497 		F_INT_MISS_DMA_FIFO_OVERFLOW;
498 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
499 
500 	/* protect memory,hw will write here while translation fault */
501 	writel_relaxed(data->protect_base,
502 			data->base + REG_MMU_IVRP_PADDR);
503 
504 	writel_relaxed(F_MMU_DCM_ON, data->base + REG_MMU_DCM);
505 
506 	if (devm_request_irq(data->dev, data->irq, mtk_iommu_isr, 0,
507 			     dev_name(data->dev), (void *)data)) {
508 		writel_relaxed(0, data->base + REG_MMU_PT_BASE_ADDR);
509 		clk_disable_unprepare(data->bclk);
510 		dev_err(data->dev, "Failed @ IRQ-%d Request\n", data->irq);
511 		return -ENODEV;
512 	}
513 
514 	return 0;
515 }
516 
517 static const struct iommu_ops mtk_iommu_ops = {
518 	.domain_alloc	= mtk_iommu_domain_alloc,
519 	.domain_free	= mtk_iommu_domain_free,
520 	.attach_dev	= mtk_iommu_attach_device,
521 	.detach_dev	= mtk_iommu_detach_device,
522 	.map		= mtk_iommu_map,
523 	.unmap		= mtk_iommu_unmap,
524 	.iova_to_phys	= mtk_iommu_iova_to_phys,
525 	.probe_device	= mtk_iommu_probe_device,
526 	.probe_finalize = mtk_iommu_probe_finalize,
527 	.release_device	= mtk_iommu_release_device,
528 	.def_domain_type = mtk_iommu_def_domain_type,
529 	.device_group	= generic_device_group,
530 	.pgsize_bitmap	= ~0UL << MT2701_IOMMU_PAGE_SHIFT,
531 	.owner          = THIS_MODULE,
532 };
533 
534 static const struct of_device_id mtk_iommu_of_ids[] = {
535 	{ .compatible = "mediatek,mt2701-m4u", },
536 	{}
537 };
538 
539 static const struct component_master_ops mtk_iommu_com_ops = {
540 	.bind		= mtk_iommu_bind,
541 	.unbind		= mtk_iommu_unbind,
542 };
543 
544 static int mtk_iommu_probe(struct platform_device *pdev)
545 {
546 	struct mtk_iommu_data		*data;
547 	struct device			*dev = &pdev->dev;
548 	struct resource			*res;
549 	struct component_match		*match = NULL;
550 	void				*protect;
551 	int				larb_nr, ret, i;
552 
553 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
554 	if (!data)
555 		return -ENOMEM;
556 
557 	data->dev = dev;
558 
559 	/* Protect memory. HW will access here while translation fault.*/
560 	protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2,
561 			GFP_KERNEL | GFP_DMA);
562 	if (!protect)
563 		return -ENOMEM;
564 	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
565 
566 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
567 	data->base = devm_ioremap_resource(dev, res);
568 	if (IS_ERR(data->base))
569 		return PTR_ERR(data->base);
570 
571 	data->irq = platform_get_irq(pdev, 0);
572 	if (data->irq < 0)
573 		return data->irq;
574 
575 	data->bclk = devm_clk_get(dev, "bclk");
576 	if (IS_ERR(data->bclk))
577 		return PTR_ERR(data->bclk);
578 
579 	larb_nr = of_count_phandle_with_args(dev->of_node,
580 					     "mediatek,larbs", NULL);
581 	if (larb_nr < 0)
582 		return larb_nr;
583 
584 	for (i = 0; i < larb_nr; i++) {
585 		struct device_node *larbnode;
586 		struct platform_device *plarbdev;
587 
588 		larbnode = of_parse_phandle(dev->of_node, "mediatek,larbs", i);
589 		if (!larbnode)
590 			return -EINVAL;
591 
592 		if (!of_device_is_available(larbnode)) {
593 			of_node_put(larbnode);
594 			continue;
595 		}
596 
597 		plarbdev = of_find_device_by_node(larbnode);
598 		if (!plarbdev) {
599 			of_node_put(larbnode);
600 			return -EPROBE_DEFER;
601 		}
602 		data->larb_imu[i].dev = &plarbdev->dev;
603 
604 		component_match_add_release(dev, &match, release_of,
605 					    compare_of, larbnode);
606 	}
607 
608 	platform_set_drvdata(pdev, data);
609 
610 	ret = mtk_iommu_hw_init(data);
611 	if (ret)
612 		return ret;
613 
614 	ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
615 				     dev_name(&pdev->dev));
616 	if (ret)
617 		return ret;
618 
619 	ret = iommu_device_register(&data->iommu, &mtk_iommu_ops, dev);
620 	if (ret)
621 		goto out_sysfs_remove;
622 
623 	if (!iommu_present(&platform_bus_type)) {
624 		ret = bus_set_iommu(&platform_bus_type,  &mtk_iommu_ops);
625 		if (ret)
626 			goto out_dev_unreg;
627 	}
628 
629 	ret = component_master_add_with_match(dev, &mtk_iommu_com_ops, match);
630 	if (ret)
631 		goto out_bus_set_null;
632 	return ret;
633 
634 out_bus_set_null:
635 	bus_set_iommu(&platform_bus_type, NULL);
636 out_dev_unreg:
637 	iommu_device_unregister(&data->iommu);
638 out_sysfs_remove:
639 	iommu_device_sysfs_remove(&data->iommu);
640 	return ret;
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 module_platform_driver(mtk_iommu_driver);
703 
704 MODULE_DESCRIPTION("IOMMU API for MediaTek M4U v1 implementations");
705 MODULE_LICENSE("GPL v2");
706