xref: /openbmc/linux/drivers/iommu/mtk_iommu_v1.c (revision e3b9f1e8)
1 /*
2  * Copyright (c) 2015-2016 MediaTek Inc.
3  * Author: Honghui Zhang <honghui.zhang@mediatek.com>
4  *
5  * Based on driver/iommu/mtk_iommu.c
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  */
16 #include <linux/bootmem.h>
17 #include <linux/bug.h>
18 #include <linux/clk.h>
19 #include <linux/component.h>
20 #include <linux/device.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/dma-iommu.h>
23 #include <linux/err.h>
24 #include <linux/interrupt.h>
25 #include <linux/io.h>
26 #include <linux/iommu.h>
27 #include <linux/iopoll.h>
28 #include <linux/kmemleak.h>
29 #include <linux/list.h>
30 #include <linux/of_address.h>
31 #include <linux/of_iommu.h>
32 #include <linux/of_irq.h>
33 #include <linux/of_platform.h>
34 #include <linux/platform_device.h>
35 #include <linux/slab.h>
36 #include <linux/spinlock.h>
37 #include <asm/barrier.h>
38 #include <asm/dma-iommu.h>
39 #include <linux/module.h>
40 #include <dt-bindings/memory/mt2701-larb-port.h>
41 #include <soc/mediatek/smi.h>
42 #include "mtk_iommu.h"
43 
44 #define REG_MMU_PT_BASE_ADDR			0x000
45 
46 #define F_ALL_INVLD				0x2
47 #define F_MMU_INV_RANGE				0x1
48 #define F_INVLD_EN0				BIT(0)
49 #define F_INVLD_EN1				BIT(1)
50 
51 #define F_MMU_FAULT_VA_MSK			0xfffff000
52 #define MTK_PROTECT_PA_ALIGN			128
53 
54 #define REG_MMU_CTRL_REG			0x210
55 #define F_MMU_CTRL_COHERENT_EN			BIT(8)
56 #define REG_MMU_IVRP_PADDR			0x214
57 #define REG_MMU_INT_CONTROL			0x220
58 #define F_INT_TRANSLATION_FAULT			BIT(0)
59 #define F_INT_MAIN_MULTI_HIT_FAULT		BIT(1)
60 #define F_INT_INVALID_PA_FAULT			BIT(2)
61 #define F_INT_ENTRY_REPLACEMENT_FAULT		BIT(3)
62 #define F_INT_TABLE_WALK_FAULT			BIT(4)
63 #define F_INT_TLB_MISS_FAULT			BIT(5)
64 #define F_INT_PFH_DMA_FIFO_OVERFLOW		BIT(6)
65 #define F_INT_MISS_DMA_FIFO_OVERFLOW		BIT(7)
66 
67 #define F_MMU_TF_PROTECT_SEL(prot)		(((prot) & 0x3) << 5)
68 #define F_INT_CLR_BIT				BIT(12)
69 
70 #define REG_MMU_FAULT_ST			0x224
71 #define REG_MMU_FAULT_VA			0x228
72 #define REG_MMU_INVLD_PA			0x22C
73 #define REG_MMU_INT_ID				0x388
74 #define REG_MMU_INVALIDATE			0x5c0
75 #define REG_MMU_INVLD_START_A			0x5c4
76 #define REG_MMU_INVLD_END_A			0x5c8
77 
78 #define REG_MMU_INV_SEL				0x5d8
79 #define REG_MMU_STANDARD_AXI_MODE		0x5e8
80 
81 #define REG_MMU_DCM				0x5f0
82 #define F_MMU_DCM_ON				BIT(1)
83 #define REG_MMU_CPE_DONE			0x60c
84 #define F_DESC_VALID				0x2
85 #define F_DESC_NONSEC				BIT(3)
86 #define MT2701_M4U_TF_LARB(TF)			(6 - (((TF) >> 13) & 0x7))
87 #define MT2701_M4U_TF_PORT(TF)			(((TF) >> 8) & 0xF)
88 /* MTK generation one iommu HW only support 4K size mapping */
89 #define MT2701_IOMMU_PAGE_SHIFT			12
90 #define MT2701_IOMMU_PAGE_SIZE			(1UL << MT2701_IOMMU_PAGE_SHIFT)
91 
92 /*
93  * MTK m4u support 4GB iova address space, and only support 4K page
94  * mapping. So the pagetable size should be exactly as 4M.
95  */
96 #define M2701_IOMMU_PGT_SIZE			SZ_4M
97 
98 struct mtk_iommu_domain {
99 	spinlock_t			pgtlock; /* lock for page table */
100 	struct iommu_domain		domain;
101 	u32				*pgt_va;
102 	dma_addr_t			pgt_pa;
103 	struct mtk_iommu_data		*data;
104 };
105 
106 static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
107 {
108 	return container_of(dom, struct mtk_iommu_domain, domain);
109 }
110 
111 static const int mt2701_m4u_in_larb[] = {
112 	LARB0_PORT_OFFSET, LARB1_PORT_OFFSET,
113 	LARB2_PORT_OFFSET, LARB3_PORT_OFFSET
114 };
115 
116 static inline int mt2701_m4u_to_larb(int id)
117 {
118 	int i;
119 
120 	for (i = ARRAY_SIZE(mt2701_m4u_in_larb) - 1; i >= 0; i--)
121 		if ((id) >= mt2701_m4u_in_larb[i])
122 			return i;
123 
124 	return 0;
125 }
126 
127 static inline int mt2701_m4u_to_port(int id)
128 {
129 	int larb = mt2701_m4u_to_larb(id);
130 
131 	return id - mt2701_m4u_in_larb[larb];
132 }
133 
134 static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data)
135 {
136 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
137 			data->base + REG_MMU_INV_SEL);
138 	writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE);
139 	wmb(); /* Make sure the tlb flush all done */
140 }
141 
142 static void mtk_iommu_tlb_flush_range(struct mtk_iommu_data *data,
143 				unsigned long iova, size_t size)
144 {
145 	int ret;
146 	u32 tmp;
147 
148 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
149 		data->base + REG_MMU_INV_SEL);
150 	writel_relaxed(iova & F_MMU_FAULT_VA_MSK,
151 		data->base + REG_MMU_INVLD_START_A);
152 	writel_relaxed((iova + size - 1) & F_MMU_FAULT_VA_MSK,
153 		data->base + REG_MMU_INVLD_END_A);
154 	writel_relaxed(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
155 
156 	ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
157 				tmp, tmp != 0, 10, 100000);
158 	if (ret) {
159 		dev_warn(data->dev,
160 			 "Partial TLB flush timed out, falling back to full flush\n");
161 		mtk_iommu_tlb_flush_all(data);
162 	}
163 	/* Clear the CPE status */
164 	writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
165 }
166 
167 static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
168 {
169 	struct mtk_iommu_data *data = dev_id;
170 	struct mtk_iommu_domain *dom = data->m4u_dom;
171 	u32 int_state, regval, fault_iova, fault_pa;
172 	unsigned int fault_larb, fault_port;
173 
174 	/* Read error information from registers */
175 	int_state = readl_relaxed(data->base + REG_MMU_FAULT_ST);
176 	fault_iova = readl_relaxed(data->base + REG_MMU_FAULT_VA);
177 
178 	fault_iova &= F_MMU_FAULT_VA_MSK;
179 	fault_pa = readl_relaxed(data->base + REG_MMU_INVLD_PA);
180 	regval = readl_relaxed(data->base + REG_MMU_INT_ID);
181 	fault_larb = MT2701_M4U_TF_LARB(regval);
182 	fault_port = MT2701_M4U_TF_PORT(regval);
183 
184 	/*
185 	 * MTK v1 iommu HW could not determine whether the fault is read or
186 	 * write fault, report as read fault.
187 	 */
188 	if (report_iommu_fault(&dom->domain, data->dev, fault_iova,
189 			IOMMU_FAULT_READ))
190 		dev_err_ratelimited(data->dev,
191 			"fault type=0x%x iova=0x%x pa=0x%x larb=%d port=%d\n",
192 			int_state, fault_iova, fault_pa,
193 			fault_larb, fault_port);
194 
195 	/* Interrupt clear */
196 	regval = readl_relaxed(data->base + REG_MMU_INT_CONTROL);
197 	regval |= F_INT_CLR_BIT;
198 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
199 
200 	mtk_iommu_tlb_flush_all(data);
201 
202 	return IRQ_HANDLED;
203 }
204 
205 static void mtk_iommu_config(struct mtk_iommu_data *data,
206 			     struct device *dev, bool enable)
207 {
208 	struct mtk_smi_larb_iommu    *larb_mmu;
209 	unsigned int                 larbid, portid;
210 	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
211 	int i;
212 
213 	for (i = 0; i < fwspec->num_ids; ++i) {
214 		larbid = mt2701_m4u_to_larb(fwspec->ids[i]);
215 		portid = mt2701_m4u_to_port(fwspec->ids[i]);
216 		larb_mmu = &data->smi_imu.larb_imu[larbid];
217 
218 		dev_dbg(dev, "%s iommu port: %d\n",
219 			enable ? "enable" : "disable", portid);
220 
221 		if (enable)
222 			larb_mmu->mmu |= MTK_SMI_MMU_EN(portid);
223 		else
224 			larb_mmu->mmu &= ~MTK_SMI_MMU_EN(portid);
225 	}
226 }
227 
228 static int mtk_iommu_domain_finalise(struct mtk_iommu_data *data)
229 {
230 	struct mtk_iommu_domain *dom = data->m4u_dom;
231 
232 	spin_lock_init(&dom->pgtlock);
233 
234 	dom->pgt_va = dma_zalloc_coherent(data->dev,
235 				M2701_IOMMU_PGT_SIZE,
236 				&dom->pgt_pa, GFP_KERNEL);
237 	if (!dom->pgt_va)
238 		return -ENOMEM;
239 
240 	writel(dom->pgt_pa, data->base + REG_MMU_PT_BASE_ADDR);
241 
242 	dom->data = data;
243 
244 	return 0;
245 }
246 
247 static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
248 {
249 	struct mtk_iommu_domain *dom;
250 
251 	if (type != IOMMU_DOMAIN_UNMANAGED)
252 		return NULL;
253 
254 	dom = kzalloc(sizeof(*dom), GFP_KERNEL);
255 	if (!dom)
256 		return NULL;
257 
258 	return &dom->domain;
259 }
260 
261 static void mtk_iommu_domain_free(struct iommu_domain *domain)
262 {
263 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
264 	struct mtk_iommu_data *data = dom->data;
265 
266 	dma_free_coherent(data->dev, M2701_IOMMU_PGT_SIZE,
267 			dom->pgt_va, dom->pgt_pa);
268 	kfree(to_mtk_domain(domain));
269 }
270 
271 static int mtk_iommu_attach_device(struct iommu_domain *domain,
272 				   struct device *dev)
273 {
274 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
275 	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
276 	int ret;
277 
278 	if (!data)
279 		return -ENODEV;
280 
281 	if (!data->m4u_dom) {
282 		data->m4u_dom = dom;
283 		ret = mtk_iommu_domain_finalise(data);
284 		if (ret) {
285 			data->m4u_dom = NULL;
286 			return ret;
287 		}
288 	}
289 
290 	mtk_iommu_config(data, dev, true);
291 	return 0;
292 }
293 
294 static void mtk_iommu_detach_device(struct iommu_domain *domain,
295 				    struct device *dev)
296 {
297 	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
298 
299 	if (!data)
300 		return;
301 
302 	mtk_iommu_config(data, dev, false);
303 }
304 
305 static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
306 			 phys_addr_t paddr, size_t size, int prot)
307 {
308 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
309 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
310 	unsigned long flags;
311 	unsigned int i;
312 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
313 	u32 pabase = (u32)paddr;
314 	int map_size = 0;
315 
316 	spin_lock_irqsave(&dom->pgtlock, flags);
317 	for (i = 0; i < page_num; i++) {
318 		if (pgt_base_iova[i]) {
319 			memset(pgt_base_iova, 0, i * sizeof(u32));
320 			break;
321 		}
322 		pgt_base_iova[i] = pabase | F_DESC_VALID | F_DESC_NONSEC;
323 		pabase += MT2701_IOMMU_PAGE_SIZE;
324 		map_size += MT2701_IOMMU_PAGE_SIZE;
325 	}
326 
327 	spin_unlock_irqrestore(&dom->pgtlock, flags);
328 
329 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
330 
331 	return map_size == size ? 0 : -EEXIST;
332 }
333 
334 static size_t mtk_iommu_unmap(struct iommu_domain *domain,
335 			      unsigned long iova, size_t size)
336 {
337 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
338 	unsigned long flags;
339 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
340 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
341 
342 	spin_lock_irqsave(&dom->pgtlock, flags);
343 	memset(pgt_base_iova, 0, page_num * sizeof(u32));
344 	spin_unlock_irqrestore(&dom->pgtlock, flags);
345 
346 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
347 
348 	return size;
349 }
350 
351 static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
352 					  dma_addr_t iova)
353 {
354 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
355 	unsigned long flags;
356 	phys_addr_t pa;
357 
358 	spin_lock_irqsave(&dom->pgtlock, flags);
359 	pa = *(dom->pgt_va + (iova >> MT2701_IOMMU_PAGE_SHIFT));
360 	pa = pa & (~(MT2701_IOMMU_PAGE_SIZE - 1));
361 	spin_unlock_irqrestore(&dom->pgtlock, flags);
362 
363 	return pa;
364 }
365 
366 static struct iommu_ops mtk_iommu_ops;
367 
368 /*
369  * MTK generation one iommu HW only support one iommu domain, and all the client
370  * sharing the same iova address space.
371  */
372 static int mtk_iommu_create_mapping(struct device *dev,
373 				    struct of_phandle_args *args)
374 {
375 	struct mtk_iommu_data *data;
376 	struct platform_device *m4updev;
377 	struct dma_iommu_mapping *mtk_mapping;
378 	struct device *m4udev;
379 	int ret;
380 
381 	if (args->args_count != 1) {
382 		dev_err(dev, "invalid #iommu-cells(%d) property for IOMMU\n",
383 			args->args_count);
384 		return -EINVAL;
385 	}
386 
387 	if (!dev->iommu_fwspec) {
388 		ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_ops);
389 		if (ret)
390 			return ret;
391 	} else if (dev->iommu_fwspec->ops != &mtk_iommu_ops) {
392 		return -EINVAL;
393 	}
394 
395 	if (!dev->iommu_fwspec->iommu_priv) {
396 		/* Get the m4u device */
397 		m4updev = of_find_device_by_node(args->np);
398 		if (WARN_ON(!m4updev))
399 			return -EINVAL;
400 
401 		dev->iommu_fwspec->iommu_priv = platform_get_drvdata(m4updev);
402 	}
403 
404 	ret = iommu_fwspec_add_ids(dev, args->args, 1);
405 	if (ret)
406 		return ret;
407 
408 	data = dev->iommu_fwspec->iommu_priv;
409 	m4udev = data->dev;
410 	mtk_mapping = m4udev->archdata.iommu;
411 	if (!mtk_mapping) {
412 		/* MTK iommu support 4GB iova address space. */
413 		mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,
414 						0, 1ULL << 32);
415 		if (IS_ERR(mtk_mapping))
416 			return PTR_ERR(mtk_mapping);
417 
418 		m4udev->archdata.iommu = mtk_mapping;
419 	}
420 
421 	ret = arm_iommu_attach_device(dev, mtk_mapping);
422 	if (ret)
423 		goto err_release_mapping;
424 
425 	return 0;
426 
427 err_release_mapping:
428 	arm_iommu_release_mapping(mtk_mapping);
429 	m4udev->archdata.iommu = NULL;
430 	return ret;
431 }
432 
433 static int mtk_iommu_add_device(struct device *dev)
434 {
435 	struct of_phandle_args iommu_spec;
436 	struct of_phandle_iterator it;
437 	struct mtk_iommu_data *data;
438 	struct iommu_group *group;
439 	int err;
440 
441 	of_for_each_phandle(&it, err, dev->of_node, "iommus",
442 			"#iommu-cells", 0) {
443 		int count = of_phandle_iterator_args(&it, iommu_spec.args,
444 					MAX_PHANDLE_ARGS);
445 		iommu_spec.np = of_node_get(it.node);
446 		iommu_spec.args_count = count;
447 
448 		mtk_iommu_create_mapping(dev, &iommu_spec);
449 		of_node_put(iommu_spec.np);
450 	}
451 
452 	if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &mtk_iommu_ops)
453 		return -ENODEV; /* Not a iommu client device */
454 
455 	data = dev->iommu_fwspec->iommu_priv;
456 	iommu_device_link(&data->iommu, dev);
457 
458 	group = iommu_group_get_for_dev(dev);
459 	if (IS_ERR(group))
460 		return PTR_ERR(group);
461 
462 	iommu_group_put(group);
463 	return 0;
464 }
465 
466 static void mtk_iommu_remove_device(struct device *dev)
467 {
468 	struct mtk_iommu_data *data;
469 
470 	if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &mtk_iommu_ops)
471 		return;
472 
473 	data = dev->iommu_fwspec->iommu_priv;
474 	iommu_device_unlink(&data->iommu, dev);
475 
476 	iommu_group_remove_device(dev);
477 	iommu_fwspec_free(dev);
478 }
479 
480 static struct iommu_group *mtk_iommu_device_group(struct device *dev)
481 {
482 	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
483 
484 	if (!data)
485 		return ERR_PTR(-ENODEV);
486 
487 	/* All the client devices are in the same m4u iommu-group */
488 	if (!data->m4u_group) {
489 		data->m4u_group = iommu_group_alloc();
490 		if (IS_ERR(data->m4u_group))
491 			dev_err(dev, "Failed to allocate M4U IOMMU group\n");
492 	} else {
493 		iommu_group_ref_get(data->m4u_group);
494 	}
495 	return data->m4u_group;
496 }
497 
498 static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
499 {
500 	u32 regval;
501 	int ret;
502 
503 	ret = clk_prepare_enable(data->bclk);
504 	if (ret) {
505 		dev_err(data->dev, "Failed to enable iommu bclk(%d)\n", ret);
506 		return ret;
507 	}
508 
509 	regval = F_MMU_CTRL_COHERENT_EN | F_MMU_TF_PROTECT_SEL(2);
510 	writel_relaxed(regval, data->base + REG_MMU_CTRL_REG);
511 
512 	regval = F_INT_TRANSLATION_FAULT |
513 		F_INT_MAIN_MULTI_HIT_FAULT |
514 		F_INT_INVALID_PA_FAULT |
515 		F_INT_ENTRY_REPLACEMENT_FAULT |
516 		F_INT_TABLE_WALK_FAULT |
517 		F_INT_TLB_MISS_FAULT |
518 		F_INT_PFH_DMA_FIFO_OVERFLOW |
519 		F_INT_MISS_DMA_FIFO_OVERFLOW;
520 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
521 
522 	/* protect memory,hw will write here while translation fault */
523 	writel_relaxed(data->protect_base,
524 			data->base + REG_MMU_IVRP_PADDR);
525 
526 	writel_relaxed(F_MMU_DCM_ON, data->base + REG_MMU_DCM);
527 
528 	if (devm_request_irq(data->dev, data->irq, mtk_iommu_isr, 0,
529 			     dev_name(data->dev), (void *)data)) {
530 		writel_relaxed(0, data->base + REG_MMU_PT_BASE_ADDR);
531 		clk_disable_unprepare(data->bclk);
532 		dev_err(data->dev, "Failed @ IRQ-%d Request\n", data->irq);
533 		return -ENODEV;
534 	}
535 
536 	return 0;
537 }
538 
539 static struct iommu_ops mtk_iommu_ops = {
540 	.domain_alloc	= mtk_iommu_domain_alloc,
541 	.domain_free	= mtk_iommu_domain_free,
542 	.attach_dev	= mtk_iommu_attach_device,
543 	.detach_dev	= mtk_iommu_detach_device,
544 	.map		= mtk_iommu_map,
545 	.unmap		= mtk_iommu_unmap,
546 	.map_sg		= default_iommu_map_sg,
547 	.iova_to_phys	= mtk_iommu_iova_to_phys,
548 	.add_device	= mtk_iommu_add_device,
549 	.remove_device	= mtk_iommu_remove_device,
550 	.device_group	= mtk_iommu_device_group,
551 	.pgsize_bitmap	= ~0UL << MT2701_IOMMU_PAGE_SHIFT,
552 };
553 
554 static const struct of_device_id mtk_iommu_of_ids[] = {
555 	{ .compatible = "mediatek,mt2701-m4u", },
556 	{}
557 };
558 
559 static const struct component_master_ops mtk_iommu_com_ops = {
560 	.bind		= mtk_iommu_bind,
561 	.unbind		= mtk_iommu_unbind,
562 };
563 
564 static int mtk_iommu_probe(struct platform_device *pdev)
565 {
566 	struct mtk_iommu_data		*data;
567 	struct device			*dev = &pdev->dev;
568 	struct resource			*res;
569 	struct component_match		*match = NULL;
570 	struct of_phandle_args		larb_spec;
571 	struct of_phandle_iterator	it;
572 	void				*protect;
573 	int				larb_nr, ret, err;
574 
575 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
576 	if (!data)
577 		return -ENOMEM;
578 
579 	data->dev = dev;
580 
581 	/* Protect memory. HW will access here while translation fault.*/
582 	protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2,
583 			GFP_KERNEL | GFP_DMA);
584 	if (!protect)
585 		return -ENOMEM;
586 	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
587 
588 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
589 	data->base = devm_ioremap_resource(dev, res);
590 	if (IS_ERR(data->base))
591 		return PTR_ERR(data->base);
592 
593 	data->irq = platform_get_irq(pdev, 0);
594 	if (data->irq < 0)
595 		return data->irq;
596 
597 	data->bclk = devm_clk_get(dev, "bclk");
598 	if (IS_ERR(data->bclk))
599 		return PTR_ERR(data->bclk);
600 
601 	larb_nr = 0;
602 	of_for_each_phandle(&it, err, dev->of_node,
603 			"mediatek,larbs", NULL, 0) {
604 		struct platform_device *plarbdev;
605 		int count = of_phandle_iterator_args(&it, larb_spec.args,
606 					MAX_PHANDLE_ARGS);
607 
608 		if (count)
609 			continue;
610 
611 		larb_spec.np = of_node_get(it.node);
612 		if (!of_device_is_available(larb_spec.np))
613 			continue;
614 
615 		plarbdev = of_find_device_by_node(larb_spec.np);
616 		if (!plarbdev) {
617 			plarbdev = of_platform_device_create(
618 						larb_spec.np, NULL,
619 						platform_bus_type.dev_root);
620 			if (!plarbdev) {
621 				of_node_put(larb_spec.np);
622 				return -EPROBE_DEFER;
623 			}
624 		}
625 
626 		data->smi_imu.larb_imu[larb_nr].dev = &plarbdev->dev;
627 		component_match_add_release(dev, &match, release_of,
628 					    compare_of, larb_spec.np);
629 		larb_nr++;
630 	}
631 
632 	data->smi_imu.larb_nr = larb_nr;
633 
634 	platform_set_drvdata(pdev, data);
635 
636 	ret = mtk_iommu_hw_init(data);
637 	if (ret)
638 		return ret;
639 
640 	ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
641 				     dev_name(&pdev->dev));
642 	if (ret)
643 		return ret;
644 
645 	iommu_device_set_ops(&data->iommu, &mtk_iommu_ops);
646 
647 	ret = iommu_device_register(&data->iommu);
648 	if (ret)
649 		return ret;
650 
651 	if (!iommu_present(&platform_bus_type))
652 		bus_set_iommu(&platform_bus_type,  &mtk_iommu_ops);
653 
654 	return component_master_add_with_match(dev, &mtk_iommu_com_ops, match);
655 }
656 
657 static int mtk_iommu_remove(struct platform_device *pdev)
658 {
659 	struct mtk_iommu_data *data = platform_get_drvdata(pdev);
660 
661 	iommu_device_sysfs_remove(&data->iommu);
662 	iommu_device_unregister(&data->iommu);
663 
664 	if (iommu_present(&platform_bus_type))
665 		bus_set_iommu(&platform_bus_type, NULL);
666 
667 	clk_disable_unprepare(data->bclk);
668 	devm_free_irq(&pdev->dev, data->irq, data);
669 	component_master_del(&pdev->dev, &mtk_iommu_com_ops);
670 	return 0;
671 }
672 
673 static int __maybe_unused mtk_iommu_suspend(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 	reg->standard_axi_mode = readl_relaxed(base +
680 					       REG_MMU_STANDARD_AXI_MODE);
681 	reg->dcm_dis = readl_relaxed(base + REG_MMU_DCM);
682 	reg->ctrl_reg = readl_relaxed(base + REG_MMU_CTRL_REG);
683 	reg->int_control0 = readl_relaxed(base + REG_MMU_INT_CONTROL);
684 	return 0;
685 }
686 
687 static int __maybe_unused mtk_iommu_resume(struct device *dev)
688 {
689 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
690 	struct mtk_iommu_suspend_reg *reg = &data->reg;
691 	void __iomem *base = data->base;
692 
693 	writel_relaxed(data->m4u_dom->pgt_pa, base + REG_MMU_PT_BASE_ADDR);
694 	writel_relaxed(reg->standard_axi_mode,
695 		       base + REG_MMU_STANDARD_AXI_MODE);
696 	writel_relaxed(reg->dcm_dis, base + REG_MMU_DCM);
697 	writel_relaxed(reg->ctrl_reg, base + REG_MMU_CTRL_REG);
698 	writel_relaxed(reg->int_control0, base + REG_MMU_INT_CONTROL);
699 	writel_relaxed(data->protect_base, base + REG_MMU_IVRP_PADDR);
700 	return 0;
701 }
702 
703 static const struct dev_pm_ops mtk_iommu_pm_ops = {
704 	SET_SYSTEM_SLEEP_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume)
705 };
706 
707 static struct platform_driver mtk_iommu_driver = {
708 	.probe	= mtk_iommu_probe,
709 	.remove	= mtk_iommu_remove,
710 	.driver	= {
711 		.name = "mtk-iommu-v1",
712 		.of_match_table = mtk_iommu_of_ids,
713 		.pm = &mtk_iommu_pm_ops,
714 	}
715 };
716 
717 static int __init m4u_init(void)
718 {
719 	return platform_driver_register(&mtk_iommu_driver);
720 }
721 
722 static void __exit m4u_exit(void)
723 {
724 	return platform_driver_unregister(&mtk_iommu_driver);
725 }
726 
727 subsys_initcall(m4u_init);
728 module_exit(m4u_exit);
729 
730 MODULE_DESCRIPTION("IOMMU API for MTK architected m4u v1 implementations");
731 MODULE_AUTHOR("Honghui Zhang <honghui.zhang@mediatek.com>");
732 MODULE_LICENSE("GPL v2");
733