xref: /openbmc/linux/drivers/iommu/mtk_iommu.c (revision 8730046c)
1 /*
2  * Copyright (c) 2015-2016 MediaTek Inc.
3  * Author: Yong Wu <yong.wu@mediatek.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 #include <linux/bootmem.h>
15 #include <linux/bug.h>
16 #include <linux/clk.h>
17 #include <linux/component.h>
18 #include <linux/device.h>
19 #include <linux/dma-iommu.h>
20 #include <linux/err.h>
21 #include <linux/interrupt.h>
22 #include <linux/io.h>
23 #include <linux/iommu.h>
24 #include <linux/iopoll.h>
25 #include <linux/list.h>
26 #include <linux/of_address.h>
27 #include <linux/of_iommu.h>
28 #include <linux/of_irq.h>
29 #include <linux/of_platform.h>
30 #include <linux/platform_device.h>
31 #include <linux/slab.h>
32 #include <linux/spinlock.h>
33 #include <asm/barrier.h>
34 #include <dt-bindings/memory/mt8173-larb-port.h>
35 #include <soc/mediatek/smi.h>
36 
37 #include "mtk_iommu.h"
38 
39 #define REG_MMU_PT_BASE_ADDR			0x000
40 
41 #define REG_MMU_INVALIDATE			0x020
42 #define F_ALL_INVLD				0x2
43 #define F_MMU_INV_RANGE				0x1
44 
45 #define REG_MMU_INVLD_START_A			0x024
46 #define REG_MMU_INVLD_END_A			0x028
47 
48 #define REG_MMU_INV_SEL				0x038
49 #define F_INVLD_EN0				BIT(0)
50 #define F_INVLD_EN1				BIT(1)
51 
52 #define REG_MMU_STANDARD_AXI_MODE		0x048
53 #define REG_MMU_DCM_DIS				0x050
54 
55 #define REG_MMU_CTRL_REG			0x110
56 #define F_MMU_PREFETCH_RT_REPLACE_MOD		BIT(4)
57 #define F_MMU_TF_PROTECT_SEL(prot)		(((prot) & 0x3) << 5)
58 
59 #define REG_MMU_IVRP_PADDR			0x114
60 #define F_MMU_IVRP_PA_SET(pa, ext)		(((pa) >> 1) | ((!!(ext)) << 31))
61 
62 #define REG_MMU_INT_CONTROL0			0x120
63 #define F_L2_MULIT_HIT_EN			BIT(0)
64 #define F_TABLE_WALK_FAULT_INT_EN		BIT(1)
65 #define F_PREETCH_FIFO_OVERFLOW_INT_EN		BIT(2)
66 #define F_MISS_FIFO_OVERFLOW_INT_EN		BIT(3)
67 #define F_PREFETCH_FIFO_ERR_INT_EN		BIT(5)
68 #define F_MISS_FIFO_ERR_INT_EN			BIT(6)
69 #define F_INT_CLR_BIT				BIT(12)
70 
71 #define REG_MMU_INT_MAIN_CONTROL		0x124
72 #define F_INT_TRANSLATION_FAULT			BIT(0)
73 #define F_INT_MAIN_MULTI_HIT_FAULT		BIT(1)
74 #define F_INT_INVALID_PA_FAULT			BIT(2)
75 #define F_INT_ENTRY_REPLACEMENT_FAULT		BIT(3)
76 #define F_INT_TLB_MISS_FAULT			BIT(4)
77 #define F_INT_MISS_TRANSACTION_FIFO_FAULT	BIT(5)
78 #define F_INT_PRETETCH_TRANSATION_FIFO_FAULT	BIT(6)
79 
80 #define REG_MMU_CPE_DONE			0x12C
81 
82 #define REG_MMU_FAULT_ST1			0x134
83 
84 #define REG_MMU_FAULT_VA			0x13c
85 #define F_MMU_FAULT_VA_MSK			0xfffff000
86 #define F_MMU_FAULT_VA_WRITE_BIT		BIT(1)
87 #define F_MMU_FAULT_VA_LAYER_BIT		BIT(0)
88 
89 #define REG_MMU_INVLD_PA			0x140
90 #define REG_MMU_INT_ID				0x150
91 #define F_MMU0_INT_ID_LARB_ID(a)		(((a) >> 7) & 0x7)
92 #define F_MMU0_INT_ID_PORT_ID(a)		(((a) >> 2) & 0x1f)
93 
94 #define MTK_PROTECT_PA_ALIGN			128
95 
96 struct mtk_iommu_domain {
97 	spinlock_t			pgtlock; /* lock for page table */
98 
99 	struct io_pgtable_cfg		cfg;
100 	struct io_pgtable_ops		*iop;
101 
102 	struct iommu_domain		domain;
103 };
104 
105 static struct iommu_ops mtk_iommu_ops;
106 
107 static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
108 {
109 	return container_of(dom, struct mtk_iommu_domain, domain);
110 }
111 
112 static void mtk_iommu_tlb_flush_all(void *cookie)
113 {
114 	struct mtk_iommu_data *data = cookie;
115 
116 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, data->base + REG_MMU_INV_SEL);
117 	writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE);
118 	wmb(); /* Make sure the tlb flush all done */
119 }
120 
121 static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size,
122 					   size_t granule, bool leaf,
123 					   void *cookie)
124 {
125 	struct mtk_iommu_data *data = cookie;
126 
127 	writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, data->base + REG_MMU_INV_SEL);
128 
129 	writel_relaxed(iova, data->base + REG_MMU_INVLD_START_A);
130 	writel_relaxed(iova + size - 1, data->base + REG_MMU_INVLD_END_A);
131 	writel_relaxed(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
132 }
133 
134 static void mtk_iommu_tlb_sync(void *cookie)
135 {
136 	struct mtk_iommu_data *data = cookie;
137 	int ret;
138 	u32 tmp;
139 
140 	ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE, tmp,
141 					tmp != 0, 10, 100000);
142 	if (ret) {
143 		dev_warn(data->dev,
144 			 "Partial TLB flush timed out, falling back to full flush\n");
145 		mtk_iommu_tlb_flush_all(cookie);
146 	}
147 	/* Clear the CPE status */
148 	writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
149 }
150 
151 static const struct iommu_gather_ops mtk_iommu_gather_ops = {
152 	.tlb_flush_all = mtk_iommu_tlb_flush_all,
153 	.tlb_add_flush = mtk_iommu_tlb_add_flush_nosync,
154 	.tlb_sync = mtk_iommu_tlb_sync,
155 };
156 
157 static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
158 {
159 	struct mtk_iommu_data *data = dev_id;
160 	struct mtk_iommu_domain *dom = data->m4u_dom;
161 	u32 int_state, regval, fault_iova, fault_pa;
162 	unsigned int fault_larb, fault_port;
163 	bool layer, write;
164 
165 	/* Read error info from registers */
166 	int_state = readl_relaxed(data->base + REG_MMU_FAULT_ST1);
167 	fault_iova = readl_relaxed(data->base + REG_MMU_FAULT_VA);
168 	layer = fault_iova & F_MMU_FAULT_VA_LAYER_BIT;
169 	write = fault_iova & F_MMU_FAULT_VA_WRITE_BIT;
170 	fault_iova &= F_MMU_FAULT_VA_MSK;
171 	fault_pa = readl_relaxed(data->base + REG_MMU_INVLD_PA);
172 	regval = readl_relaxed(data->base + REG_MMU_INT_ID);
173 	fault_larb = F_MMU0_INT_ID_LARB_ID(regval);
174 	fault_port = F_MMU0_INT_ID_PORT_ID(regval);
175 
176 	if (report_iommu_fault(&dom->domain, data->dev, fault_iova,
177 			       write ? IOMMU_FAULT_WRITE : IOMMU_FAULT_READ)) {
178 		dev_err_ratelimited(
179 			data->dev,
180 			"fault type=0x%x iova=0x%x pa=0x%x larb=%d port=%d layer=%d %s\n",
181 			int_state, fault_iova, fault_pa, fault_larb, fault_port,
182 			layer, write ? "write" : "read");
183 	}
184 
185 	/* Interrupt clear */
186 	regval = readl_relaxed(data->base + REG_MMU_INT_CONTROL0);
187 	regval |= F_INT_CLR_BIT;
188 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL0);
189 
190 	mtk_iommu_tlb_flush_all(data);
191 
192 	return IRQ_HANDLED;
193 }
194 
195 static void mtk_iommu_config(struct mtk_iommu_data *data,
196 			     struct device *dev, bool enable)
197 {
198 	struct mtk_smi_larb_iommu    *larb_mmu;
199 	unsigned int                 larbid, portid;
200 	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
201 	int i;
202 
203 	for (i = 0; i < fwspec->num_ids; ++i) {
204 		larbid = MTK_M4U_TO_LARB(fwspec->ids[i]);
205 		portid = MTK_M4U_TO_PORT(fwspec->ids[i]);
206 		larb_mmu = &data->smi_imu.larb_imu[larbid];
207 
208 		dev_dbg(dev, "%s iommu port: %d\n",
209 			enable ? "enable" : "disable", portid);
210 
211 		if (enable)
212 			larb_mmu->mmu |= MTK_SMI_MMU_EN(portid);
213 		else
214 			larb_mmu->mmu &= ~MTK_SMI_MMU_EN(portid);
215 	}
216 }
217 
218 static int mtk_iommu_domain_finalise(struct mtk_iommu_data *data)
219 {
220 	struct mtk_iommu_domain *dom = data->m4u_dom;
221 
222 	spin_lock_init(&dom->pgtlock);
223 
224 	dom->cfg = (struct io_pgtable_cfg) {
225 		.quirks = IO_PGTABLE_QUIRK_ARM_NS |
226 			IO_PGTABLE_QUIRK_NO_PERMS |
227 			IO_PGTABLE_QUIRK_TLBI_ON_MAP,
228 		.pgsize_bitmap = mtk_iommu_ops.pgsize_bitmap,
229 		.ias = 32,
230 		.oas = 32,
231 		.tlb = &mtk_iommu_gather_ops,
232 		.iommu_dev = data->dev,
233 	};
234 
235 	if (data->enable_4GB)
236 		dom->cfg.quirks |= IO_PGTABLE_QUIRK_ARM_MTK_4GB;
237 
238 	dom->iop = alloc_io_pgtable_ops(ARM_V7S, &dom->cfg, data);
239 	if (!dom->iop) {
240 		dev_err(data->dev, "Failed to alloc io pgtable\n");
241 		return -EINVAL;
242 	}
243 
244 	/* Update our support page sizes bitmap */
245 	dom->domain.pgsize_bitmap = dom->cfg.pgsize_bitmap;
246 
247 	writel(data->m4u_dom->cfg.arm_v7s_cfg.ttbr[0],
248 	       data->base + REG_MMU_PT_BASE_ADDR);
249 	return 0;
250 }
251 
252 static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
253 {
254 	struct mtk_iommu_domain *dom;
255 
256 	if (type != IOMMU_DOMAIN_DMA)
257 		return NULL;
258 
259 	dom = kzalloc(sizeof(*dom), GFP_KERNEL);
260 	if (!dom)
261 		return NULL;
262 
263 	if (iommu_get_dma_cookie(&dom->domain)) {
264 		kfree(dom);
265 		return NULL;
266 	}
267 
268 	dom->domain.geometry.aperture_start = 0;
269 	dom->domain.geometry.aperture_end = DMA_BIT_MASK(32);
270 	dom->domain.geometry.force_aperture = true;
271 
272 	return &dom->domain;
273 }
274 
275 static void mtk_iommu_domain_free(struct iommu_domain *domain)
276 {
277 	iommu_put_dma_cookie(domain);
278 	kfree(to_mtk_domain(domain));
279 }
280 
281 static int mtk_iommu_attach_device(struct iommu_domain *domain,
282 				   struct device *dev)
283 {
284 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
285 	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
286 	int ret;
287 
288 	if (!data)
289 		return -ENODEV;
290 
291 	if (!data->m4u_dom) {
292 		data->m4u_dom = dom;
293 		ret = mtk_iommu_domain_finalise(data);
294 		if (ret) {
295 			data->m4u_dom = NULL;
296 			return ret;
297 		}
298 	} else if (data->m4u_dom != dom) {
299 		/* All the client devices should be in the same m4u domain */
300 		dev_err(dev, "try to attach into the error iommu domain\n");
301 		return -EPERM;
302 	}
303 
304 	mtk_iommu_config(data, dev, true);
305 	return 0;
306 }
307 
308 static void mtk_iommu_detach_device(struct iommu_domain *domain,
309 				    struct device *dev)
310 {
311 	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
312 
313 	if (!data)
314 		return;
315 
316 	mtk_iommu_config(data, dev, false);
317 }
318 
319 static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
320 			 phys_addr_t paddr, size_t size, int prot)
321 {
322 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
323 	unsigned long flags;
324 	int ret;
325 
326 	spin_lock_irqsave(&dom->pgtlock, flags);
327 	ret = dom->iop->map(dom->iop, iova, paddr, size, prot);
328 	spin_unlock_irqrestore(&dom->pgtlock, flags);
329 
330 	return ret;
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 	size_t unmapsz;
339 
340 	spin_lock_irqsave(&dom->pgtlock, flags);
341 	unmapsz = dom->iop->unmap(dom->iop, iova, size);
342 	spin_unlock_irqrestore(&dom->pgtlock, flags);
343 
344 	return unmapsz;
345 }
346 
347 static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
348 					  dma_addr_t iova)
349 {
350 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
351 	unsigned long flags;
352 	phys_addr_t pa;
353 
354 	spin_lock_irqsave(&dom->pgtlock, flags);
355 	pa = dom->iop->iova_to_phys(dom->iop, iova);
356 	spin_unlock_irqrestore(&dom->pgtlock, flags);
357 
358 	return pa;
359 }
360 
361 static int mtk_iommu_add_device(struct device *dev)
362 {
363 	struct iommu_group *group;
364 
365 	if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &mtk_iommu_ops)
366 		return -ENODEV; /* Not a iommu client device */
367 
368 	group = iommu_group_get_for_dev(dev);
369 	if (IS_ERR(group))
370 		return PTR_ERR(group);
371 
372 	iommu_group_put(group);
373 	return 0;
374 }
375 
376 static void mtk_iommu_remove_device(struct device *dev)
377 {
378 	if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &mtk_iommu_ops)
379 		return;
380 
381 	iommu_group_remove_device(dev);
382 	iommu_fwspec_free(dev);
383 }
384 
385 static struct iommu_group *mtk_iommu_device_group(struct device *dev)
386 {
387 	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
388 
389 	if (!data)
390 		return ERR_PTR(-ENODEV);
391 
392 	/* All the client devices are in the same m4u iommu-group */
393 	if (!data->m4u_group) {
394 		data->m4u_group = iommu_group_alloc();
395 		if (IS_ERR(data->m4u_group))
396 			dev_err(dev, "Failed to allocate M4U IOMMU group\n");
397 	} else {
398 		iommu_group_ref_get(data->m4u_group);
399 	}
400 	return data->m4u_group;
401 }
402 
403 static int mtk_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
404 {
405 	struct platform_device *m4updev;
406 
407 	if (args->args_count != 1) {
408 		dev_err(dev, "invalid #iommu-cells(%d) property for IOMMU\n",
409 			args->args_count);
410 		return -EINVAL;
411 	}
412 
413 	if (!dev->iommu_fwspec->iommu_priv) {
414 		/* Get the m4u device */
415 		m4updev = of_find_device_by_node(args->np);
416 		if (WARN_ON(!m4updev))
417 			return -EINVAL;
418 
419 		dev->iommu_fwspec->iommu_priv = platform_get_drvdata(m4updev);
420 	}
421 
422 	return iommu_fwspec_add_ids(dev, args->args, 1);
423 }
424 
425 static struct iommu_ops mtk_iommu_ops = {
426 	.domain_alloc	= mtk_iommu_domain_alloc,
427 	.domain_free	= mtk_iommu_domain_free,
428 	.attach_dev	= mtk_iommu_attach_device,
429 	.detach_dev	= mtk_iommu_detach_device,
430 	.map		= mtk_iommu_map,
431 	.unmap		= mtk_iommu_unmap,
432 	.map_sg		= default_iommu_map_sg,
433 	.iova_to_phys	= mtk_iommu_iova_to_phys,
434 	.add_device	= mtk_iommu_add_device,
435 	.remove_device	= mtk_iommu_remove_device,
436 	.device_group	= mtk_iommu_device_group,
437 	.of_xlate	= mtk_iommu_of_xlate,
438 	.pgsize_bitmap	= SZ_4K | SZ_64K | SZ_1M | SZ_16M,
439 };
440 
441 static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
442 {
443 	u32 regval;
444 	int ret;
445 
446 	ret = clk_prepare_enable(data->bclk);
447 	if (ret) {
448 		dev_err(data->dev, "Failed to enable iommu bclk(%d)\n", ret);
449 		return ret;
450 	}
451 
452 	regval = F_MMU_PREFETCH_RT_REPLACE_MOD |
453 		F_MMU_TF_PROTECT_SEL(2);
454 	writel_relaxed(regval, data->base + REG_MMU_CTRL_REG);
455 
456 	regval = F_L2_MULIT_HIT_EN |
457 		F_TABLE_WALK_FAULT_INT_EN |
458 		F_PREETCH_FIFO_OVERFLOW_INT_EN |
459 		F_MISS_FIFO_OVERFLOW_INT_EN |
460 		F_PREFETCH_FIFO_ERR_INT_EN |
461 		F_MISS_FIFO_ERR_INT_EN;
462 	writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL0);
463 
464 	regval = F_INT_TRANSLATION_FAULT |
465 		F_INT_MAIN_MULTI_HIT_FAULT |
466 		F_INT_INVALID_PA_FAULT |
467 		F_INT_ENTRY_REPLACEMENT_FAULT |
468 		F_INT_TLB_MISS_FAULT |
469 		F_INT_MISS_TRANSACTION_FIFO_FAULT |
470 		F_INT_PRETETCH_TRANSATION_FIFO_FAULT;
471 	writel_relaxed(regval, data->base + REG_MMU_INT_MAIN_CONTROL);
472 
473 	writel_relaxed(F_MMU_IVRP_PA_SET(data->protect_base, data->enable_4GB),
474 		       data->base + REG_MMU_IVRP_PADDR);
475 
476 	writel_relaxed(0, data->base + REG_MMU_DCM_DIS);
477 	writel_relaxed(0, data->base + REG_MMU_STANDARD_AXI_MODE);
478 
479 	if (devm_request_irq(data->dev, data->irq, mtk_iommu_isr, 0,
480 			     dev_name(data->dev), (void *)data)) {
481 		writel_relaxed(0, data->base + REG_MMU_PT_BASE_ADDR);
482 		clk_disable_unprepare(data->bclk);
483 		dev_err(data->dev, "Failed @ IRQ-%d Request\n", data->irq);
484 		return -ENODEV;
485 	}
486 
487 	return 0;
488 }
489 
490 static const struct component_master_ops mtk_iommu_com_ops = {
491 	.bind		= mtk_iommu_bind,
492 	.unbind		= mtk_iommu_unbind,
493 };
494 
495 static int mtk_iommu_probe(struct platform_device *pdev)
496 {
497 	struct mtk_iommu_data   *data;
498 	struct device           *dev = &pdev->dev;
499 	struct resource         *res;
500 	struct component_match  *match = NULL;
501 	void                    *protect;
502 	int                     i, larb_nr, ret;
503 
504 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
505 	if (!data)
506 		return -ENOMEM;
507 	data->dev = dev;
508 
509 	/* Protect memory. HW will access here while translation fault.*/
510 	protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2, GFP_KERNEL);
511 	if (!protect)
512 		return -ENOMEM;
513 	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
514 
515 	/* Whether the current dram is over 4GB */
516 	data->enable_4GB = !!(max_pfn > (0xffffffffUL >> PAGE_SHIFT));
517 
518 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
519 	data->base = devm_ioremap_resource(dev, res);
520 	if (IS_ERR(data->base))
521 		return PTR_ERR(data->base);
522 
523 	data->irq = platform_get_irq(pdev, 0);
524 	if (data->irq < 0)
525 		return data->irq;
526 
527 	data->bclk = devm_clk_get(dev, "bclk");
528 	if (IS_ERR(data->bclk))
529 		return PTR_ERR(data->bclk);
530 
531 	larb_nr = of_count_phandle_with_args(dev->of_node,
532 					     "mediatek,larbs", NULL);
533 	if (larb_nr < 0)
534 		return larb_nr;
535 	data->smi_imu.larb_nr = larb_nr;
536 
537 	for (i = 0; i < larb_nr; i++) {
538 		struct device_node *larbnode;
539 		struct platform_device *plarbdev;
540 
541 		larbnode = of_parse_phandle(dev->of_node, "mediatek,larbs", i);
542 		if (!larbnode)
543 			return -EINVAL;
544 
545 		if (!of_device_is_available(larbnode))
546 			continue;
547 
548 		plarbdev = of_find_device_by_node(larbnode);
549 		if (!plarbdev) {
550 			plarbdev = of_platform_device_create(
551 						larbnode, NULL,
552 						platform_bus_type.dev_root);
553 			if (!plarbdev) {
554 				of_node_put(larbnode);
555 				return -EPROBE_DEFER;
556 			}
557 		}
558 		data->smi_imu.larb_imu[i].dev = &plarbdev->dev;
559 
560 		component_match_add_release(dev, &match, release_of,
561 					    compare_of, larbnode);
562 	}
563 
564 	platform_set_drvdata(pdev, data);
565 
566 	ret = mtk_iommu_hw_init(data);
567 	if (ret)
568 		return ret;
569 
570 	if (!iommu_present(&platform_bus_type))
571 		bus_set_iommu(&platform_bus_type, &mtk_iommu_ops);
572 
573 	return component_master_add_with_match(dev, &mtk_iommu_com_ops, match);
574 }
575 
576 static int mtk_iommu_remove(struct platform_device *pdev)
577 {
578 	struct mtk_iommu_data *data = platform_get_drvdata(pdev);
579 
580 	if (iommu_present(&platform_bus_type))
581 		bus_set_iommu(&platform_bus_type, NULL);
582 
583 	free_io_pgtable_ops(data->m4u_dom->iop);
584 	clk_disable_unprepare(data->bclk);
585 	devm_free_irq(&pdev->dev, data->irq, data);
586 	component_master_del(&pdev->dev, &mtk_iommu_com_ops);
587 	return 0;
588 }
589 
590 static int __maybe_unused mtk_iommu_suspend(struct device *dev)
591 {
592 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
593 	struct mtk_iommu_suspend_reg *reg = &data->reg;
594 	void __iomem *base = data->base;
595 
596 	reg->standard_axi_mode = readl_relaxed(base +
597 					       REG_MMU_STANDARD_AXI_MODE);
598 	reg->dcm_dis = readl_relaxed(base + REG_MMU_DCM_DIS);
599 	reg->ctrl_reg = readl_relaxed(base + REG_MMU_CTRL_REG);
600 	reg->int_control0 = readl_relaxed(base + REG_MMU_INT_CONTROL0);
601 	reg->int_main_control = readl_relaxed(base + REG_MMU_INT_MAIN_CONTROL);
602 	return 0;
603 }
604 
605 static int __maybe_unused mtk_iommu_resume(struct device *dev)
606 {
607 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
608 	struct mtk_iommu_suspend_reg *reg = &data->reg;
609 	void __iomem *base = data->base;
610 
611 	writel_relaxed(data->m4u_dom->cfg.arm_v7s_cfg.ttbr[0],
612 		       base + REG_MMU_PT_BASE_ADDR);
613 	writel_relaxed(reg->standard_axi_mode,
614 		       base + REG_MMU_STANDARD_AXI_MODE);
615 	writel_relaxed(reg->dcm_dis, base + REG_MMU_DCM_DIS);
616 	writel_relaxed(reg->ctrl_reg, base + REG_MMU_CTRL_REG);
617 	writel_relaxed(reg->int_control0, base + REG_MMU_INT_CONTROL0);
618 	writel_relaxed(reg->int_main_control, base + REG_MMU_INT_MAIN_CONTROL);
619 	writel_relaxed(F_MMU_IVRP_PA_SET(data->protect_base, data->enable_4GB),
620 		       base + REG_MMU_IVRP_PADDR);
621 	return 0;
622 }
623 
624 const struct dev_pm_ops mtk_iommu_pm_ops = {
625 	SET_SYSTEM_SLEEP_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume)
626 };
627 
628 static const struct of_device_id mtk_iommu_of_ids[] = {
629 	{ .compatible = "mediatek,mt8173-m4u", },
630 	{}
631 };
632 
633 static struct platform_driver mtk_iommu_driver = {
634 	.probe	= mtk_iommu_probe,
635 	.remove	= mtk_iommu_remove,
636 	.driver	= {
637 		.name = "mtk-iommu",
638 		.of_match_table = mtk_iommu_of_ids,
639 		.pm = &mtk_iommu_pm_ops,
640 	}
641 };
642 
643 static int mtk_iommu_init_fn(struct device_node *np)
644 {
645 	int ret;
646 	struct platform_device *pdev;
647 
648 	pdev = of_platform_device_create(np, NULL, platform_bus_type.dev_root);
649 	if (!pdev)
650 		return -ENOMEM;
651 
652 	ret = platform_driver_register(&mtk_iommu_driver);
653 	if (ret) {
654 		pr_err("%s: Failed to register driver\n", __func__);
655 		return ret;
656 	}
657 
658 	of_iommu_set_ops(np, &mtk_iommu_ops);
659 	return 0;
660 }
661 
662 IOMMU_OF_DECLARE(mtkm4u, "mediatek,mt8173-m4u", mtk_iommu_init_fn);
663