xref: /linux/drivers/iommu/mtk_iommu_v1.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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-iommu.h>
22 #include <linux/err.h>
23 #include <linux/interrupt.h>
24 #include <linux/io.h>
25 #include <linux/iommu.h>
26 #include <linux/iopoll.h>
27 #include <linux/kmemleak.h>
28 #include <linux/list.h>
29 #include <linux/of_address.h>
30 #include <linux/of_iommu.h>
31 #include <linux/of_irq.h>
32 #include <linux/of_platform.h>
33 #include <linux/platform_device.h>
34 #include <linux/slab.h>
35 #include <linux/spinlock.h>
36 #include <asm/barrier.h>
37 #include <asm/dma-iommu.h>
38 #include <linux/module.h>
39 #include <dt-bindings/memory/mt2701-larb-port.h>
40 #include <soc/mediatek/smi.h>
41 #include "mtk_iommu.h"
42 
43 #define REG_MMU_PT_BASE_ADDR			0x000
44 
45 #define F_ALL_INVLD				0x2
46 #define F_MMU_INV_RANGE				0x1
47 #define F_INVLD_EN0				BIT(0)
48 #define F_INVLD_EN1				BIT(1)
49 
50 #define F_MMU_FAULT_VA_MSK			0xfffff000
51 #define MTK_PROTECT_PA_ALIGN			128
52 
53 #define REG_MMU_CTRL_REG			0x210
54 #define F_MMU_CTRL_COHERENT_EN			BIT(8)
55 #define REG_MMU_IVRP_PADDR			0x214
56 #define REG_MMU_INT_CONTROL			0x220
57 #define F_INT_TRANSLATION_FAULT			BIT(0)
58 #define F_INT_MAIN_MULTI_HIT_FAULT		BIT(1)
59 #define F_INT_INVALID_PA_FAULT			BIT(2)
60 #define F_INT_ENTRY_REPLACEMENT_FAULT		BIT(3)
61 #define F_INT_TABLE_WALK_FAULT			BIT(4)
62 #define F_INT_TLB_MISS_FAULT			BIT(5)
63 #define F_INT_PFH_DMA_FIFO_OVERFLOW		BIT(6)
64 #define F_INT_MISS_DMA_FIFO_OVERFLOW		BIT(7)
65 
66 #define F_MMU_TF_PROTECT_SEL(prot)		(((prot) & 0x3) << 5)
67 #define F_INT_CLR_BIT				BIT(12)
68 
69 #define REG_MMU_FAULT_ST			0x224
70 #define REG_MMU_FAULT_VA			0x228
71 #define REG_MMU_INVLD_PA			0x22C
72 #define REG_MMU_INT_ID				0x388
73 #define REG_MMU_INVALIDATE			0x5c0
74 #define REG_MMU_INVLD_START_A			0x5c4
75 #define REG_MMU_INVLD_END_A			0x5c8
76 
77 #define REG_MMU_INV_SEL				0x5d8
78 #define REG_MMU_STANDARD_AXI_MODE		0x5e8
79 
80 #define REG_MMU_DCM				0x5f0
81 #define F_MMU_DCM_ON				BIT(1)
82 #define REG_MMU_CPE_DONE			0x60c
83 #define F_DESC_VALID				0x2
84 #define F_DESC_NONSEC				BIT(3)
85 #define MT2701_M4U_TF_LARB(TF)			(6 - (((TF) >> 13) & 0x7))
86 #define MT2701_M4U_TF_PORT(TF)			(((TF) >> 8) & 0xF)
87 /* MTK generation one iommu HW only support 4K size mapping */
88 #define MT2701_IOMMU_PAGE_SHIFT			12
89 #define MT2701_IOMMU_PAGE_SIZE			(1UL << MT2701_IOMMU_PAGE_SHIFT)
90 
91 /*
92  * MTK m4u support 4GB iova address space, and only support 4K page
93  * mapping. So the pagetable size should be exactly as 4M.
94  */
95 #define M2701_IOMMU_PGT_SIZE			SZ_4M
96 
97 struct mtk_iommu_domain {
98 	spinlock_t			pgtlock; /* lock for page table */
99 	struct iommu_domain		domain;
100 	u32				*pgt_va;
101 	dma_addr_t			pgt_pa;
102 	struct mtk_iommu_data		*data;
103 };
104 
105 static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
106 {
107 	return container_of(dom, struct mtk_iommu_domain, domain);
108 }
109 
110 static const int mt2701_m4u_in_larb[] = {
111 	LARB0_PORT_OFFSET, LARB1_PORT_OFFSET,
112 	LARB2_PORT_OFFSET, LARB3_PORT_OFFSET
113 };
114 
115 static inline int mt2701_m4u_to_larb(int id)
116 {
117 	int i;
118 
119 	for (i = ARRAY_SIZE(mt2701_m4u_in_larb) - 1; i >= 0; i--)
120 		if ((id) >= mt2701_m4u_in_larb[i])
121 			return i;
122 
123 	return 0;
124 }
125 
126 static inline int mt2701_m4u_to_port(int id)
127 {
128 	int larb = mt2701_m4u_to_larb(id);
129 
130 	return id - mt2701_m4u_in_larb[larb];
131 }
132 
133 static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data)
134 {
135 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
136 			data->base + REG_MMU_INV_SEL);
137 	writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE);
138 	wmb(); /* Make sure the tlb flush all done */
139 }
140 
141 static void mtk_iommu_tlb_flush_range(struct mtk_iommu_data *data,
142 				unsigned long iova, size_t size)
143 {
144 	int ret;
145 	u32 tmp;
146 
147 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
148 		data->base + REG_MMU_INV_SEL);
149 	writel_relaxed(iova & F_MMU_FAULT_VA_MSK,
150 		data->base + REG_MMU_INVLD_START_A);
151 	writel_relaxed((iova + size - 1) & F_MMU_FAULT_VA_MSK,
152 		data->base + REG_MMU_INVLD_END_A);
153 	writel_relaxed(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
154 
155 	ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
156 				tmp, tmp != 0, 10, 100000);
157 	if (ret) {
158 		dev_warn(data->dev,
159 			 "Partial TLB flush timed out, falling back to full flush\n");
160 		mtk_iommu_tlb_flush_all(data);
161 	}
162 	/* Clear the CPE status */
163 	writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
164 }
165 
166 static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
167 {
168 	struct mtk_iommu_data *data = dev_id;
169 	struct mtk_iommu_domain *dom = data->m4u_dom;
170 	u32 int_state, regval, fault_iova, fault_pa;
171 	unsigned int fault_larb, fault_port;
172 
173 	/* Read error information from registers */
174 	int_state = readl_relaxed(data->base + REG_MMU_FAULT_ST);
175 	fault_iova = readl_relaxed(data->base + REG_MMU_FAULT_VA);
176 
177 	fault_iova &= F_MMU_FAULT_VA_MSK;
178 	fault_pa = readl_relaxed(data->base + REG_MMU_INVLD_PA);
179 	regval = readl_relaxed(data->base + REG_MMU_INT_ID);
180 	fault_larb = MT2701_M4U_TF_LARB(regval);
181 	fault_port = MT2701_M4U_TF_PORT(regval);
182 
183 	/*
184 	 * MTK v1 iommu HW could not determine whether the fault is read or
185 	 * write fault, report as read fault.
186 	 */
187 	if (report_iommu_fault(&dom->domain, data->dev, fault_iova,
188 			IOMMU_FAULT_READ))
189 		dev_err_ratelimited(data->dev,
190 			"fault type=0x%x iova=0x%x pa=0x%x larb=%d port=%d\n",
191 			int_state, fault_iova, fault_pa,
192 			fault_larb, fault_port);
193 
194 	/* Interrupt clear */
195 	regval = readl_relaxed(data->base + REG_MMU_INT_CONTROL);
196 	regval |= F_INT_CLR_BIT;
197 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
198 
199 	mtk_iommu_tlb_flush_all(data);
200 
201 	return IRQ_HANDLED;
202 }
203 
204 static void mtk_iommu_config(struct mtk_iommu_data *data,
205 			     struct device *dev, bool enable)
206 {
207 	struct mtk_smi_larb_iommu    *larb_mmu;
208 	unsigned int                 larbid, portid;
209 	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
210 	int i;
211 
212 	for (i = 0; i < fwspec->num_ids; ++i) {
213 		larbid = mt2701_m4u_to_larb(fwspec->ids[i]);
214 		portid = mt2701_m4u_to_port(fwspec->ids[i]);
215 		larb_mmu = &data->smi_imu.larb_imu[larbid];
216 
217 		dev_dbg(dev, "%s iommu port: %d\n",
218 			enable ? "enable" : "disable", portid);
219 
220 		if (enable)
221 			larb_mmu->mmu |= MTK_SMI_MMU_EN(portid);
222 		else
223 			larb_mmu->mmu &= ~MTK_SMI_MMU_EN(portid);
224 	}
225 }
226 
227 static int mtk_iommu_domain_finalise(struct mtk_iommu_data *data)
228 {
229 	struct mtk_iommu_domain *dom = data->m4u_dom;
230 
231 	spin_lock_init(&dom->pgtlock);
232 
233 	dom->pgt_va = dma_zalloc_coherent(data->dev,
234 				M2701_IOMMU_PGT_SIZE,
235 				&dom->pgt_pa, GFP_KERNEL);
236 	if (!dom->pgt_va)
237 		return -ENOMEM;
238 
239 	writel(dom->pgt_pa, data->base + REG_MMU_PT_BASE_ADDR);
240 
241 	dom->data = data;
242 
243 	return 0;
244 }
245 
246 static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
247 {
248 	struct mtk_iommu_domain *dom;
249 
250 	if (type != IOMMU_DOMAIN_UNMANAGED)
251 		return NULL;
252 
253 	dom = kzalloc(sizeof(*dom), GFP_KERNEL);
254 	if (!dom)
255 		return NULL;
256 
257 	return &dom->domain;
258 }
259 
260 static void mtk_iommu_domain_free(struct iommu_domain *domain)
261 {
262 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
263 	struct mtk_iommu_data *data = dom->data;
264 
265 	dma_free_coherent(data->dev, M2701_IOMMU_PGT_SIZE,
266 			dom->pgt_va, dom->pgt_pa);
267 	kfree(to_mtk_domain(domain));
268 }
269 
270 static int mtk_iommu_attach_device(struct iommu_domain *domain,
271 				   struct device *dev)
272 {
273 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
274 	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
275 	int ret;
276 
277 	if (!data)
278 		return -ENODEV;
279 
280 	if (!data->m4u_dom) {
281 		data->m4u_dom = dom;
282 		ret = mtk_iommu_domain_finalise(data);
283 		if (ret) {
284 			data->m4u_dom = NULL;
285 			return ret;
286 		}
287 	}
288 
289 	mtk_iommu_config(data, dev, true);
290 	return 0;
291 }
292 
293 static void mtk_iommu_detach_device(struct iommu_domain *domain,
294 				    struct device *dev)
295 {
296 	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
297 
298 	if (!data)
299 		return;
300 
301 	mtk_iommu_config(data, dev, false);
302 }
303 
304 static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
305 			 phys_addr_t paddr, size_t size, int prot)
306 {
307 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
308 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
309 	unsigned long flags;
310 	unsigned int i;
311 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
312 	u32 pabase = (u32)paddr;
313 	int map_size = 0;
314 
315 	spin_lock_irqsave(&dom->pgtlock, flags);
316 	for (i = 0; i < page_num; i++) {
317 		if (pgt_base_iova[i]) {
318 			memset(pgt_base_iova, 0, i * sizeof(u32));
319 			break;
320 		}
321 		pgt_base_iova[i] = pabase | F_DESC_VALID | F_DESC_NONSEC;
322 		pabase += MT2701_IOMMU_PAGE_SIZE;
323 		map_size += MT2701_IOMMU_PAGE_SIZE;
324 	}
325 
326 	spin_unlock_irqrestore(&dom->pgtlock, flags);
327 
328 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
329 
330 	return map_size == size ? 0 : -EEXIST;
331 }
332 
333 static size_t mtk_iommu_unmap(struct iommu_domain *domain,
334 			      unsigned long iova, size_t size)
335 {
336 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
337 	unsigned long flags;
338 	u32 *pgt_base_iova = dom->pgt_va + (iova  >> MT2701_IOMMU_PAGE_SHIFT);
339 	unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
340 
341 	spin_lock_irqsave(&dom->pgtlock, flags);
342 	memset(pgt_base_iova, 0, page_num * sizeof(u32));
343 	spin_unlock_irqrestore(&dom->pgtlock, flags);
344 
345 	mtk_iommu_tlb_flush_range(dom->data, iova, size);
346 
347 	return size;
348 }
349 
350 static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
351 					  dma_addr_t iova)
352 {
353 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
354 	unsigned long flags;
355 	phys_addr_t pa;
356 
357 	spin_lock_irqsave(&dom->pgtlock, flags);
358 	pa = *(dom->pgt_va + (iova >> MT2701_IOMMU_PAGE_SHIFT));
359 	pa = pa & (~(MT2701_IOMMU_PAGE_SIZE - 1));
360 	spin_unlock_irqrestore(&dom->pgtlock, flags);
361 
362 	return pa;
363 }
364 
365 static struct iommu_ops mtk_iommu_ops;
366 
367 /*
368  * MTK generation one iommu HW only support one iommu domain, and all the client
369  * sharing the same iova address space.
370  */
371 static int mtk_iommu_create_mapping(struct device *dev,
372 				    struct of_phandle_args *args)
373 {
374 	struct mtk_iommu_data *data;
375 	struct platform_device *m4updev;
376 	struct dma_iommu_mapping *mtk_mapping;
377 	struct device *m4udev;
378 	int ret;
379 
380 	if (args->args_count != 1) {
381 		dev_err(dev, "invalid #iommu-cells(%d) property for IOMMU\n",
382 			args->args_count);
383 		return -EINVAL;
384 	}
385 
386 	if (!dev->iommu_fwspec) {
387 		ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_ops);
388 		if (ret)
389 			return ret;
390 	} else if (dev->iommu_fwspec->ops != &mtk_iommu_ops) {
391 		return -EINVAL;
392 	}
393 
394 	if (!dev->iommu_fwspec->iommu_priv) {
395 		/* Get the m4u device */
396 		m4updev = of_find_device_by_node(args->np);
397 		if (WARN_ON(!m4updev))
398 			return -EINVAL;
399 
400 		dev->iommu_fwspec->iommu_priv = platform_get_drvdata(m4updev);
401 	}
402 
403 	ret = iommu_fwspec_add_ids(dev, args->args, 1);
404 	if (ret)
405 		return ret;
406 
407 	data = dev->iommu_fwspec->iommu_priv;
408 	m4udev = data->dev;
409 	mtk_mapping = m4udev->archdata.iommu;
410 	if (!mtk_mapping) {
411 		/* MTK iommu support 4GB iova address space. */
412 		mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,
413 						0, 1ULL << 32);
414 		if (IS_ERR(mtk_mapping))
415 			return PTR_ERR(mtk_mapping);
416 
417 		m4udev->archdata.iommu = mtk_mapping;
418 	}
419 
420 	ret = arm_iommu_attach_device(dev, mtk_mapping);
421 	if (ret)
422 		goto err_release_mapping;
423 
424 	return 0;
425 
426 err_release_mapping:
427 	arm_iommu_release_mapping(mtk_mapping);
428 	m4udev->archdata.iommu = NULL;
429 	return ret;
430 }
431 
432 static int mtk_iommu_add_device(struct device *dev)
433 {
434 	struct iommu_group *group;
435 	struct of_phandle_args iommu_spec;
436 	struct of_phandle_iterator it;
437 	int err;
438 
439 	of_for_each_phandle(&it, err, dev->of_node, "iommus",
440 			"#iommu-cells", 0) {
441 		int count = of_phandle_iterator_args(&it, iommu_spec.args,
442 					MAX_PHANDLE_ARGS);
443 		iommu_spec.np = of_node_get(it.node);
444 		iommu_spec.args_count = count;
445 
446 		mtk_iommu_create_mapping(dev, &iommu_spec);
447 		of_node_put(iommu_spec.np);
448 	}
449 
450 	if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &mtk_iommu_ops)
451 		return -ENODEV; /* Not a iommu client device */
452 
453 	group = iommu_group_get_for_dev(dev);
454 	if (IS_ERR(group))
455 		return PTR_ERR(group);
456 
457 	iommu_group_put(group);
458 	return 0;
459 }
460 
461 static void mtk_iommu_remove_device(struct device *dev)
462 {
463 	if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &mtk_iommu_ops)
464 		return;
465 
466 	iommu_group_remove_device(dev);
467 	iommu_fwspec_free(dev);
468 }
469 
470 static struct iommu_group *mtk_iommu_device_group(struct device *dev)
471 {
472 	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
473 
474 	if (!data)
475 		return ERR_PTR(-ENODEV);
476 
477 	/* All the client devices are in the same m4u iommu-group */
478 	if (!data->m4u_group) {
479 		data->m4u_group = iommu_group_alloc();
480 		if (IS_ERR(data->m4u_group))
481 			dev_err(dev, "Failed to allocate M4U IOMMU group\n");
482 	} else {
483 		iommu_group_ref_get(data->m4u_group);
484 	}
485 	return data->m4u_group;
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 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 	.map_sg		= default_iommu_map_sg,
537 	.iova_to_phys	= mtk_iommu_iova_to_phys,
538 	.add_device	= mtk_iommu_add_device,
539 	.remove_device	= mtk_iommu_remove_device,
540 	.device_group	= mtk_iommu_device_group,
541 	.pgsize_bitmap	= ~0UL << MT2701_IOMMU_PAGE_SHIFT,
542 };
543 
544 static const struct of_device_id mtk_iommu_of_ids[] = {
545 	{ .compatible = "mediatek,mt2701-m4u", },
546 	{}
547 };
548 
549 static const struct component_master_ops mtk_iommu_com_ops = {
550 	.bind		= mtk_iommu_bind,
551 	.unbind		= mtk_iommu_unbind,
552 };
553 
554 static int mtk_iommu_probe(struct platform_device *pdev)
555 {
556 	struct mtk_iommu_data		*data;
557 	struct device			*dev = &pdev->dev;
558 	struct resource			*res;
559 	struct component_match		*match = NULL;
560 	struct of_phandle_args		larb_spec;
561 	struct of_phandle_iterator	it;
562 	void				*protect;
563 	int				larb_nr, ret, err;
564 
565 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
566 	if (!data)
567 		return -ENOMEM;
568 
569 	data->dev = dev;
570 
571 	/* Protect memory. HW will access here while translation fault.*/
572 	protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2,
573 			GFP_KERNEL | GFP_DMA);
574 	if (!protect)
575 		return -ENOMEM;
576 	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
577 
578 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
579 	data->base = devm_ioremap_resource(dev, res);
580 	if (IS_ERR(data->base))
581 		return PTR_ERR(data->base);
582 
583 	data->irq = platform_get_irq(pdev, 0);
584 	if (data->irq < 0)
585 		return data->irq;
586 
587 	data->bclk = devm_clk_get(dev, "bclk");
588 	if (IS_ERR(data->bclk))
589 		return PTR_ERR(data->bclk);
590 
591 	larb_nr = 0;
592 	of_for_each_phandle(&it, err, dev->of_node,
593 			"mediatek,larbs", NULL, 0) {
594 		struct platform_device *plarbdev;
595 		int count = of_phandle_iterator_args(&it, larb_spec.args,
596 					MAX_PHANDLE_ARGS);
597 
598 		if (count)
599 			continue;
600 
601 		larb_spec.np = of_node_get(it.node);
602 		if (!of_device_is_available(larb_spec.np))
603 			continue;
604 
605 		plarbdev = of_find_device_by_node(larb_spec.np);
606 		if (!plarbdev) {
607 			plarbdev = of_platform_device_create(
608 						larb_spec.np, NULL,
609 						platform_bus_type.dev_root);
610 			if (!plarbdev) {
611 				of_node_put(larb_spec.np);
612 				return -EPROBE_DEFER;
613 			}
614 		}
615 
616 		data->smi_imu.larb_imu[larb_nr].dev = &plarbdev->dev;
617 		component_match_add_release(dev, &match, release_of,
618 					    compare_of, larb_spec.np);
619 		larb_nr++;
620 	}
621 
622 	data->smi_imu.larb_nr = larb_nr;
623 
624 	platform_set_drvdata(pdev, data);
625 
626 	ret = mtk_iommu_hw_init(data);
627 	if (ret)
628 		return ret;
629 
630 	if (!iommu_present(&platform_bus_type))
631 		bus_set_iommu(&platform_bus_type,  &mtk_iommu_ops);
632 
633 	return component_master_add_with_match(dev, &mtk_iommu_com_ops, match);
634 }
635 
636 static int mtk_iommu_remove(struct platform_device *pdev)
637 {
638 	struct mtk_iommu_data *data = platform_get_drvdata(pdev);
639 
640 	if (iommu_present(&platform_bus_type))
641 		bus_set_iommu(&platform_bus_type, NULL);
642 
643 	clk_disable_unprepare(data->bclk);
644 	devm_free_irq(&pdev->dev, data->irq, data);
645 	component_master_del(&pdev->dev, &mtk_iommu_com_ops);
646 	return 0;
647 }
648 
649 static int __maybe_unused mtk_iommu_suspend(struct device *dev)
650 {
651 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
652 	struct mtk_iommu_suspend_reg *reg = &data->reg;
653 	void __iomem *base = data->base;
654 
655 	reg->standard_axi_mode = readl_relaxed(base +
656 					       REG_MMU_STANDARD_AXI_MODE);
657 	reg->dcm_dis = readl_relaxed(base + REG_MMU_DCM);
658 	reg->ctrl_reg = readl_relaxed(base + REG_MMU_CTRL_REG);
659 	reg->int_control0 = readl_relaxed(base + REG_MMU_INT_CONTROL);
660 	return 0;
661 }
662 
663 static int __maybe_unused mtk_iommu_resume(struct device *dev)
664 {
665 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
666 	struct mtk_iommu_suspend_reg *reg = &data->reg;
667 	void __iomem *base = data->base;
668 
669 	writel_relaxed(data->m4u_dom->pgt_pa, base + REG_MMU_PT_BASE_ADDR);
670 	writel_relaxed(reg->standard_axi_mode,
671 		       base + REG_MMU_STANDARD_AXI_MODE);
672 	writel_relaxed(reg->dcm_dis, base + REG_MMU_DCM);
673 	writel_relaxed(reg->ctrl_reg, base + REG_MMU_CTRL_REG);
674 	writel_relaxed(reg->int_control0, base + REG_MMU_INT_CONTROL);
675 	writel_relaxed(data->protect_base, base + REG_MMU_IVRP_PADDR);
676 	return 0;
677 }
678 
679 static const struct dev_pm_ops mtk_iommu_pm_ops = {
680 	SET_SYSTEM_SLEEP_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume)
681 };
682 
683 static struct platform_driver mtk_iommu_driver = {
684 	.probe	= mtk_iommu_probe,
685 	.remove	= mtk_iommu_remove,
686 	.driver	= {
687 		.name = "mtk-iommu",
688 		.of_match_table = mtk_iommu_of_ids,
689 		.pm = &mtk_iommu_pm_ops,
690 	}
691 };
692 
693 static int __init m4u_init(void)
694 {
695 	return platform_driver_register(&mtk_iommu_driver);
696 }
697 
698 static void __exit m4u_exit(void)
699 {
700 	return platform_driver_unregister(&mtk_iommu_driver);
701 }
702 
703 subsys_initcall(m4u_init);
704 module_exit(m4u_exit);
705 
706 MODULE_DESCRIPTION("IOMMU API for MTK architected m4u v1 implementations");
707 MODULE_AUTHOR("Honghui Zhang <honghui.zhang@mediatek.com>");
708 MODULE_LICENSE("GPL v2");
709