xref: /linux/drivers/pci/endpoint/functions/pci-epf-mhi.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * PCI EPF driver for MHI Endpoint devices
4  *
5  * Copyright (C) 2023 Linaro Ltd.
6  * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
7  */
8 
9 #include <linux/dmaengine.h>
10 #include <linux/mhi_ep.h>
11 #include <linux/module.h>
12 #include <linux/of_dma.h>
13 #include <linux/platform_device.h>
14 #include <linux/pci-epc.h>
15 #include <linux/pci-epf.h>
16 
17 #define MHI_VERSION_1_0 0x01000000
18 
19 #define to_epf_mhi(cntrl) container_of(cntrl, struct pci_epf_mhi, cntrl)
20 
21 /* Platform specific flags */
22 #define MHI_EPF_USE_DMA BIT(0)
23 
24 struct pci_epf_mhi_dma_transfer {
25 	struct pci_epf_mhi *epf_mhi;
26 	struct mhi_ep_buf_info buf_info;
27 	struct list_head node;
28 	dma_addr_t paddr;
29 	enum dma_data_direction dir;
30 	size_t size;
31 };
32 
33 struct pci_epf_mhi_ep_info {
34 	const struct mhi_ep_cntrl_config *config;
35 	struct pci_epf_header *epf_header;
36 	enum pci_barno bar_num;
37 	u32 epf_flags;
38 	u32 msi_count;
39 	u32 mru;
40 	u32 flags;
41 };
42 
43 #define MHI_EP_CHANNEL_CONFIG(ch_num, ch_name, direction)	\
44 	{							\
45 		.num = ch_num,					\
46 		.name = ch_name,				\
47 		.dir = direction,				\
48 	}
49 
50 #define MHI_EP_CHANNEL_CONFIG_UL(ch_num, ch_name)		\
51 	MHI_EP_CHANNEL_CONFIG(ch_num, ch_name, DMA_TO_DEVICE)
52 
53 #define MHI_EP_CHANNEL_CONFIG_DL(ch_num, ch_name)		\
54 	MHI_EP_CHANNEL_CONFIG(ch_num, ch_name, DMA_FROM_DEVICE)
55 
56 static const struct mhi_ep_channel_config mhi_v1_channels[] = {
57 	MHI_EP_CHANNEL_CONFIG_UL(0, "LOOPBACK"),
58 	MHI_EP_CHANNEL_CONFIG_DL(1, "LOOPBACK"),
59 	MHI_EP_CHANNEL_CONFIG_UL(2, "SAHARA"),
60 	MHI_EP_CHANNEL_CONFIG_DL(3, "SAHARA"),
61 	MHI_EP_CHANNEL_CONFIG_UL(4, "DIAG"),
62 	MHI_EP_CHANNEL_CONFIG_DL(5, "DIAG"),
63 	MHI_EP_CHANNEL_CONFIG_UL(6, "SSR"),
64 	MHI_EP_CHANNEL_CONFIG_DL(7, "SSR"),
65 	MHI_EP_CHANNEL_CONFIG_UL(8, "QDSS"),
66 	MHI_EP_CHANNEL_CONFIG_DL(9, "QDSS"),
67 	MHI_EP_CHANNEL_CONFIG_UL(10, "EFS"),
68 	MHI_EP_CHANNEL_CONFIG_DL(11, "EFS"),
69 	MHI_EP_CHANNEL_CONFIG_UL(12, "MBIM"),
70 	MHI_EP_CHANNEL_CONFIG_DL(13, "MBIM"),
71 	MHI_EP_CHANNEL_CONFIG_UL(14, "QMI"),
72 	MHI_EP_CHANNEL_CONFIG_DL(15, "QMI"),
73 	MHI_EP_CHANNEL_CONFIG_UL(16, "QMI"),
74 	MHI_EP_CHANNEL_CONFIG_DL(17, "QMI"),
75 	MHI_EP_CHANNEL_CONFIG_UL(18, "IP-CTRL-1"),
76 	MHI_EP_CHANNEL_CONFIG_DL(19, "IP-CTRL-1"),
77 	MHI_EP_CHANNEL_CONFIG_UL(20, "IPCR"),
78 	MHI_EP_CHANNEL_CONFIG_DL(21, "IPCR"),
79 	MHI_EP_CHANNEL_CONFIG_UL(32, "DUN"),
80 	MHI_EP_CHANNEL_CONFIG_DL(33, "DUN"),
81 	MHI_EP_CHANNEL_CONFIG_UL(46, "IP_SW0"),
82 	MHI_EP_CHANNEL_CONFIG_DL(47, "IP_SW0"),
83 };
84 
85 static const struct mhi_ep_cntrl_config mhi_v1_config = {
86 	.max_channels = 128,
87 	.num_channels = ARRAY_SIZE(mhi_v1_channels),
88 	.ch_cfg = mhi_v1_channels,
89 	.mhi_version = MHI_VERSION_1_0,
90 };
91 
92 static struct pci_epf_header sdx55_header = {
93 	.vendorid = PCI_VENDOR_ID_QCOM,
94 	.deviceid = 0x0306,
95 	.baseclass_code = PCI_BASE_CLASS_COMMUNICATION,
96 	.subclass_code = PCI_CLASS_COMMUNICATION_MODEM & 0xff,
97 	.interrupt_pin	= PCI_INTERRUPT_INTA,
98 };
99 
100 static const struct pci_epf_mhi_ep_info sdx55_info = {
101 	.config = &mhi_v1_config,
102 	.epf_header = &sdx55_header,
103 	.bar_num = BAR_0,
104 	.epf_flags = PCI_BASE_ADDRESS_MEM_TYPE_32,
105 	.msi_count = 32,
106 	.mru = 0x8000,
107 };
108 
109 static struct pci_epf_header sm8450_header = {
110 	.vendorid = PCI_VENDOR_ID_QCOM,
111 	.deviceid = 0x0306,
112 	.baseclass_code = PCI_CLASS_OTHERS,
113 	.interrupt_pin = PCI_INTERRUPT_INTA,
114 };
115 
116 static const struct pci_epf_mhi_ep_info sm8450_info = {
117 	.config = &mhi_v1_config,
118 	.epf_header = &sm8450_header,
119 	.bar_num = BAR_0,
120 	.epf_flags = PCI_BASE_ADDRESS_MEM_TYPE_32,
121 	.msi_count = 32,
122 	.mru = 0x8000,
123 	.flags = MHI_EPF_USE_DMA,
124 };
125 
126 static struct pci_epf_header sa8775p_header = {
127 	.vendorid = PCI_VENDOR_ID_QCOM,
128 	.deviceid = 0x0306,               /* FIXME: Update deviceid for sa8775p EP */
129 	.baseclass_code = PCI_CLASS_OTHERS,
130 	.interrupt_pin = PCI_INTERRUPT_INTA,
131 };
132 
133 static const struct pci_epf_mhi_ep_info sa8775p_info = {
134 	.config = &mhi_v1_config,
135 	.epf_header = &sa8775p_header,
136 	.bar_num = BAR_0,
137 	.epf_flags = PCI_BASE_ADDRESS_MEM_TYPE_32,
138 	.msi_count = 32,
139 	.mru = 0x8000,
140 	.flags = MHI_EPF_USE_DMA,
141 };
142 
143 struct pci_epf_mhi {
144 	const struct pci_epc_features *epc_features;
145 	const struct pci_epf_mhi_ep_info *info;
146 	struct mhi_ep_cntrl mhi_cntrl;
147 	struct pci_epf *epf;
148 	struct mutex lock;
149 	void __iomem *mmio;
150 	resource_size_t mmio_phys;
151 	struct dma_chan *dma_chan_tx;
152 	struct dma_chan *dma_chan_rx;
153 	struct workqueue_struct *dma_wq;
154 	struct work_struct dma_work;
155 	struct list_head dma_list;
156 	spinlock_t list_lock;
157 	u32 mmio_size;
158 	int irq;
159 };
160 
161 static size_t get_align_offset(struct pci_epf_mhi *epf_mhi, u64 addr)
162 {
163 	return addr & (epf_mhi->epc_features->align -1);
164 }
165 
166 static int __pci_epf_mhi_alloc_map(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr,
167 				 phys_addr_t *paddr, void __iomem **vaddr,
168 				 size_t offset, size_t size)
169 {
170 	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
171 	struct pci_epf *epf = epf_mhi->epf;
172 	struct pci_epc *epc = epf->epc;
173 	int ret;
174 
175 	*vaddr = pci_epc_mem_alloc_addr(epc, paddr, size + offset);
176 	if (!*vaddr)
177 		return -ENOMEM;
178 
179 	ret = pci_epc_map_addr(epc, epf->func_no, epf->vfunc_no, *paddr,
180 			       pci_addr - offset, size + offset);
181 	if (ret) {
182 		pci_epc_mem_free_addr(epc, *paddr, *vaddr, size + offset);
183 		return ret;
184 	}
185 
186 	*paddr = *paddr + offset;
187 	*vaddr = *vaddr + offset;
188 
189 	return 0;
190 }
191 
192 static int pci_epf_mhi_alloc_map(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr,
193 				 phys_addr_t *paddr, void __iomem **vaddr,
194 				 size_t size)
195 {
196 	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
197 	size_t offset = get_align_offset(epf_mhi, pci_addr);
198 
199 	return __pci_epf_mhi_alloc_map(mhi_cntrl, pci_addr, paddr, vaddr,
200 				      offset, size);
201 }
202 
203 static void __pci_epf_mhi_unmap_free(struct mhi_ep_cntrl *mhi_cntrl,
204 				     u64 pci_addr, phys_addr_t paddr,
205 				     void __iomem *vaddr, size_t offset,
206 				     size_t size)
207 {
208 	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
209 	struct pci_epf *epf = epf_mhi->epf;
210 	struct pci_epc *epc = epf->epc;
211 
212 	pci_epc_unmap_addr(epc, epf->func_no, epf->vfunc_no, paddr - offset);
213 	pci_epc_mem_free_addr(epc, paddr - offset, vaddr - offset,
214 			      size + offset);
215 }
216 
217 static void pci_epf_mhi_unmap_free(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr,
218 				   phys_addr_t paddr, void __iomem *vaddr,
219 				   size_t size)
220 {
221 	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
222 	size_t offset = get_align_offset(epf_mhi, pci_addr);
223 
224 	__pci_epf_mhi_unmap_free(mhi_cntrl, pci_addr, paddr, vaddr, offset,
225 				 size);
226 }
227 
228 static void pci_epf_mhi_raise_irq(struct mhi_ep_cntrl *mhi_cntrl, u32 vector)
229 {
230 	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
231 	struct pci_epf *epf = epf_mhi->epf;
232 	struct pci_epc *epc = epf->epc;
233 
234 	/*
235 	 * MHI supplies 0 based MSI vectors but the API expects the vector
236 	 * number to start from 1, so we need to increment the vector by 1.
237 	 */
238 	pci_epc_raise_irq(epc, epf->func_no, epf->vfunc_no, PCI_IRQ_MSI,
239 			  vector + 1);
240 }
241 
242 static int pci_epf_mhi_iatu_read(struct mhi_ep_cntrl *mhi_cntrl,
243 				 struct mhi_ep_buf_info *buf_info)
244 {
245 	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
246 	size_t offset = get_align_offset(epf_mhi, buf_info->host_addr);
247 	void __iomem *tre_buf;
248 	phys_addr_t tre_phys;
249 	int ret;
250 
251 	mutex_lock(&epf_mhi->lock);
252 
253 	ret = __pci_epf_mhi_alloc_map(mhi_cntrl, buf_info->host_addr, &tre_phys,
254 				      &tre_buf, offset, buf_info->size);
255 	if (ret) {
256 		mutex_unlock(&epf_mhi->lock);
257 		return ret;
258 	}
259 
260 	memcpy_fromio(buf_info->dev_addr, tre_buf, buf_info->size);
261 
262 	__pci_epf_mhi_unmap_free(mhi_cntrl, buf_info->host_addr, tre_phys,
263 				 tre_buf, offset, buf_info->size);
264 
265 	mutex_unlock(&epf_mhi->lock);
266 
267 	if (buf_info->cb)
268 		buf_info->cb(buf_info);
269 
270 	return 0;
271 }
272 
273 static int pci_epf_mhi_iatu_write(struct mhi_ep_cntrl *mhi_cntrl,
274 				  struct mhi_ep_buf_info *buf_info)
275 {
276 	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
277 	size_t offset = get_align_offset(epf_mhi, buf_info->host_addr);
278 	void __iomem *tre_buf;
279 	phys_addr_t tre_phys;
280 	int ret;
281 
282 	mutex_lock(&epf_mhi->lock);
283 
284 	ret = __pci_epf_mhi_alloc_map(mhi_cntrl, buf_info->host_addr, &tre_phys,
285 				      &tre_buf, offset, buf_info->size);
286 	if (ret) {
287 		mutex_unlock(&epf_mhi->lock);
288 		return ret;
289 	}
290 
291 	memcpy_toio(tre_buf, buf_info->dev_addr, buf_info->size);
292 
293 	__pci_epf_mhi_unmap_free(mhi_cntrl, buf_info->host_addr, tre_phys,
294 				 tre_buf, offset, buf_info->size);
295 
296 	mutex_unlock(&epf_mhi->lock);
297 
298 	if (buf_info->cb)
299 		buf_info->cb(buf_info);
300 
301 	return 0;
302 }
303 
304 static void pci_epf_mhi_dma_callback(void *param)
305 {
306 	complete(param);
307 }
308 
309 static int pci_epf_mhi_edma_read(struct mhi_ep_cntrl *mhi_cntrl,
310 				 struct mhi_ep_buf_info *buf_info)
311 {
312 	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
313 	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
314 	struct dma_chan *chan = epf_mhi->dma_chan_rx;
315 	struct device *dev = &epf_mhi->epf->dev;
316 	DECLARE_COMPLETION_ONSTACK(complete);
317 	struct dma_async_tx_descriptor *desc;
318 	struct dma_slave_config config = {};
319 	dma_cookie_t cookie;
320 	dma_addr_t dst_addr;
321 	int ret;
322 
323 	if (buf_info->size < SZ_4K)
324 		return pci_epf_mhi_iatu_read(mhi_cntrl, buf_info);
325 
326 	mutex_lock(&epf_mhi->lock);
327 
328 	config.direction = DMA_DEV_TO_MEM;
329 	config.src_addr = buf_info->host_addr;
330 
331 	ret = dmaengine_slave_config(chan, &config);
332 	if (ret) {
333 		dev_err(dev, "Failed to configure DMA channel\n");
334 		goto err_unlock;
335 	}
336 
337 	dst_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
338 				  DMA_FROM_DEVICE);
339 	ret = dma_mapping_error(dma_dev, dst_addr);
340 	if (ret) {
341 		dev_err(dev, "Failed to map remote memory\n");
342 		goto err_unlock;
343 	}
344 
345 	desc = dmaengine_prep_slave_single(chan, dst_addr, buf_info->size,
346 					   DMA_DEV_TO_MEM,
347 					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
348 	if (!desc) {
349 		dev_err(dev, "Failed to prepare DMA\n");
350 		ret = -EIO;
351 		goto err_unmap;
352 	}
353 
354 	desc->callback = pci_epf_mhi_dma_callback;
355 	desc->callback_param = &complete;
356 
357 	cookie = dmaengine_submit(desc);
358 	ret = dma_submit_error(cookie);
359 	if (ret) {
360 		dev_err(dev, "Failed to do DMA submit\n");
361 		goto err_unmap;
362 	}
363 
364 	dma_async_issue_pending(chan);
365 	ret = wait_for_completion_timeout(&complete, msecs_to_jiffies(1000));
366 	if (!ret) {
367 		dev_err(dev, "DMA transfer timeout\n");
368 		dmaengine_terminate_sync(chan);
369 		ret = -ETIMEDOUT;
370 	}
371 
372 err_unmap:
373 	dma_unmap_single(dma_dev, dst_addr, buf_info->size, DMA_FROM_DEVICE);
374 err_unlock:
375 	mutex_unlock(&epf_mhi->lock);
376 
377 	return ret;
378 }
379 
380 static int pci_epf_mhi_edma_write(struct mhi_ep_cntrl *mhi_cntrl,
381 				  struct mhi_ep_buf_info *buf_info)
382 {
383 	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
384 	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
385 	struct dma_chan *chan = epf_mhi->dma_chan_tx;
386 	struct device *dev = &epf_mhi->epf->dev;
387 	DECLARE_COMPLETION_ONSTACK(complete);
388 	struct dma_async_tx_descriptor *desc;
389 	struct dma_slave_config config = {};
390 	dma_cookie_t cookie;
391 	dma_addr_t src_addr;
392 	int ret;
393 
394 	if (buf_info->size < SZ_4K)
395 		return pci_epf_mhi_iatu_write(mhi_cntrl, buf_info);
396 
397 	mutex_lock(&epf_mhi->lock);
398 
399 	config.direction = DMA_MEM_TO_DEV;
400 	config.dst_addr = buf_info->host_addr;
401 
402 	ret = dmaengine_slave_config(chan, &config);
403 	if (ret) {
404 		dev_err(dev, "Failed to configure DMA channel\n");
405 		goto err_unlock;
406 	}
407 
408 	src_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
409 				  DMA_TO_DEVICE);
410 	ret = dma_mapping_error(dma_dev, src_addr);
411 	if (ret) {
412 		dev_err(dev, "Failed to map remote memory\n");
413 		goto err_unlock;
414 	}
415 
416 	desc = dmaengine_prep_slave_single(chan, src_addr, buf_info->size,
417 					   DMA_MEM_TO_DEV,
418 					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
419 	if (!desc) {
420 		dev_err(dev, "Failed to prepare DMA\n");
421 		ret = -EIO;
422 		goto err_unmap;
423 	}
424 
425 	desc->callback = pci_epf_mhi_dma_callback;
426 	desc->callback_param = &complete;
427 
428 	cookie = dmaengine_submit(desc);
429 	ret = dma_submit_error(cookie);
430 	if (ret) {
431 		dev_err(dev, "Failed to do DMA submit\n");
432 		goto err_unmap;
433 	}
434 
435 	dma_async_issue_pending(chan);
436 	ret = wait_for_completion_timeout(&complete, msecs_to_jiffies(1000));
437 	if (!ret) {
438 		dev_err(dev, "DMA transfer timeout\n");
439 		dmaengine_terminate_sync(chan);
440 		ret = -ETIMEDOUT;
441 	}
442 
443 err_unmap:
444 	dma_unmap_single(dma_dev, src_addr, buf_info->size, DMA_TO_DEVICE);
445 err_unlock:
446 	mutex_unlock(&epf_mhi->lock);
447 
448 	return ret;
449 }
450 
451 static void pci_epf_mhi_dma_worker(struct work_struct *work)
452 {
453 	struct pci_epf_mhi *epf_mhi = container_of(work, struct pci_epf_mhi, dma_work);
454 	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
455 	struct pci_epf_mhi_dma_transfer *itr, *tmp;
456 	struct mhi_ep_buf_info *buf_info;
457 	unsigned long flags;
458 	LIST_HEAD(head);
459 
460 	spin_lock_irqsave(&epf_mhi->list_lock, flags);
461 	list_splice_tail_init(&epf_mhi->dma_list, &head);
462 	spin_unlock_irqrestore(&epf_mhi->list_lock, flags);
463 
464 	list_for_each_entry_safe(itr, tmp, &head, node) {
465 		list_del(&itr->node);
466 		dma_unmap_single(dma_dev, itr->paddr, itr->size, itr->dir);
467 		buf_info = &itr->buf_info;
468 		buf_info->cb(buf_info);
469 		kfree(itr);
470 	}
471 }
472 
473 static void pci_epf_mhi_dma_async_callback(void *param)
474 {
475 	struct pci_epf_mhi_dma_transfer *transfer = param;
476 	struct pci_epf_mhi *epf_mhi = transfer->epf_mhi;
477 
478 	spin_lock(&epf_mhi->list_lock);
479 	list_add_tail(&transfer->node, &epf_mhi->dma_list);
480 	spin_unlock(&epf_mhi->list_lock);
481 
482 	queue_work(epf_mhi->dma_wq, &epf_mhi->dma_work);
483 }
484 
485 static int pci_epf_mhi_edma_read_async(struct mhi_ep_cntrl *mhi_cntrl,
486 				       struct mhi_ep_buf_info *buf_info)
487 {
488 	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
489 	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
490 	struct pci_epf_mhi_dma_transfer *transfer = NULL;
491 	struct dma_chan *chan = epf_mhi->dma_chan_rx;
492 	struct device *dev = &epf_mhi->epf->dev;
493 	DECLARE_COMPLETION_ONSTACK(complete);
494 	struct dma_async_tx_descriptor *desc;
495 	struct dma_slave_config config = {};
496 	dma_cookie_t cookie;
497 	dma_addr_t dst_addr;
498 	int ret;
499 
500 	mutex_lock(&epf_mhi->lock);
501 
502 	config.direction = DMA_DEV_TO_MEM;
503 	config.src_addr = buf_info->host_addr;
504 
505 	ret = dmaengine_slave_config(chan, &config);
506 	if (ret) {
507 		dev_err(dev, "Failed to configure DMA channel\n");
508 		goto err_unlock;
509 	}
510 
511 	dst_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
512 				  DMA_FROM_DEVICE);
513 	ret = dma_mapping_error(dma_dev, dst_addr);
514 	if (ret) {
515 		dev_err(dev, "Failed to map remote memory\n");
516 		goto err_unlock;
517 	}
518 
519 	desc = dmaengine_prep_slave_single(chan, dst_addr, buf_info->size,
520 					   DMA_DEV_TO_MEM,
521 					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
522 	if (!desc) {
523 		dev_err(dev, "Failed to prepare DMA\n");
524 		ret = -EIO;
525 		goto err_unmap;
526 	}
527 
528 	transfer = kzalloc(sizeof(*transfer), GFP_KERNEL);
529 	if (!transfer) {
530 		ret = -ENOMEM;
531 		goto err_unmap;
532 	}
533 
534 	transfer->epf_mhi = epf_mhi;
535 	transfer->paddr = dst_addr;
536 	transfer->size = buf_info->size;
537 	transfer->dir = DMA_FROM_DEVICE;
538 	memcpy(&transfer->buf_info, buf_info, sizeof(*buf_info));
539 
540 	desc->callback = pci_epf_mhi_dma_async_callback;
541 	desc->callback_param = transfer;
542 
543 	cookie = dmaengine_submit(desc);
544 	ret = dma_submit_error(cookie);
545 	if (ret) {
546 		dev_err(dev, "Failed to do DMA submit\n");
547 		goto err_free_transfer;
548 	}
549 
550 	dma_async_issue_pending(chan);
551 
552 	goto err_unlock;
553 
554 err_free_transfer:
555 	kfree(transfer);
556 err_unmap:
557 	dma_unmap_single(dma_dev, dst_addr, buf_info->size, DMA_FROM_DEVICE);
558 err_unlock:
559 	mutex_unlock(&epf_mhi->lock);
560 
561 	return ret;
562 }
563 
564 static int pci_epf_mhi_edma_write_async(struct mhi_ep_cntrl *mhi_cntrl,
565 					struct mhi_ep_buf_info *buf_info)
566 {
567 	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
568 	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
569 	struct pci_epf_mhi_dma_transfer *transfer = NULL;
570 	struct dma_chan *chan = epf_mhi->dma_chan_tx;
571 	struct device *dev = &epf_mhi->epf->dev;
572 	DECLARE_COMPLETION_ONSTACK(complete);
573 	struct dma_async_tx_descriptor *desc;
574 	struct dma_slave_config config = {};
575 	dma_cookie_t cookie;
576 	dma_addr_t src_addr;
577 	int ret;
578 
579 	mutex_lock(&epf_mhi->lock);
580 
581 	config.direction = DMA_MEM_TO_DEV;
582 	config.dst_addr = buf_info->host_addr;
583 
584 	ret = dmaengine_slave_config(chan, &config);
585 	if (ret) {
586 		dev_err(dev, "Failed to configure DMA channel\n");
587 		goto err_unlock;
588 	}
589 
590 	src_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
591 				  DMA_TO_DEVICE);
592 	ret = dma_mapping_error(dma_dev, src_addr);
593 	if (ret) {
594 		dev_err(dev, "Failed to map remote memory\n");
595 		goto err_unlock;
596 	}
597 
598 	desc = dmaengine_prep_slave_single(chan, src_addr, buf_info->size,
599 					   DMA_MEM_TO_DEV,
600 					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
601 	if (!desc) {
602 		dev_err(dev, "Failed to prepare DMA\n");
603 		ret = -EIO;
604 		goto err_unmap;
605 	}
606 
607 	transfer = kzalloc(sizeof(*transfer), GFP_KERNEL);
608 	if (!transfer) {
609 		ret = -ENOMEM;
610 		goto err_unmap;
611 	}
612 
613 	transfer->epf_mhi = epf_mhi;
614 	transfer->paddr = src_addr;
615 	transfer->size = buf_info->size;
616 	transfer->dir = DMA_TO_DEVICE;
617 	memcpy(&transfer->buf_info, buf_info, sizeof(*buf_info));
618 
619 	desc->callback = pci_epf_mhi_dma_async_callback;
620 	desc->callback_param = transfer;
621 
622 	cookie = dmaengine_submit(desc);
623 	ret = dma_submit_error(cookie);
624 	if (ret) {
625 		dev_err(dev, "Failed to do DMA submit\n");
626 		goto err_free_transfer;
627 	}
628 
629 	dma_async_issue_pending(chan);
630 
631 	goto err_unlock;
632 
633 err_free_transfer:
634 	kfree(transfer);
635 err_unmap:
636 	dma_unmap_single(dma_dev, src_addr, buf_info->size, DMA_TO_DEVICE);
637 err_unlock:
638 	mutex_unlock(&epf_mhi->lock);
639 
640 	return ret;
641 }
642 
643 struct epf_dma_filter {
644 	struct device *dev;
645 	u32 dma_mask;
646 };
647 
648 static bool pci_epf_mhi_filter(struct dma_chan *chan, void *node)
649 {
650 	struct epf_dma_filter *filter = node;
651 	struct dma_slave_caps caps;
652 
653 	memset(&caps, 0, sizeof(caps));
654 	dma_get_slave_caps(chan, &caps);
655 
656 	return chan->device->dev == filter->dev && filter->dma_mask &
657 					caps.directions;
658 }
659 
660 static int pci_epf_mhi_dma_init(struct pci_epf_mhi *epf_mhi)
661 {
662 	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
663 	struct device *dev = &epf_mhi->epf->dev;
664 	struct epf_dma_filter filter;
665 	dma_cap_mask_t mask;
666 	int ret;
667 
668 	dma_cap_zero(mask);
669 	dma_cap_set(DMA_SLAVE, mask);
670 
671 	filter.dev = dma_dev;
672 	filter.dma_mask = BIT(DMA_MEM_TO_DEV);
673 	epf_mhi->dma_chan_tx = dma_request_channel(mask, pci_epf_mhi_filter,
674 						   &filter);
675 	if (IS_ERR_OR_NULL(epf_mhi->dma_chan_tx)) {
676 		dev_err(dev, "Failed to request tx channel\n");
677 		return -ENODEV;
678 	}
679 
680 	filter.dma_mask = BIT(DMA_DEV_TO_MEM);
681 	epf_mhi->dma_chan_rx = dma_request_channel(mask, pci_epf_mhi_filter,
682 						   &filter);
683 	if (IS_ERR_OR_NULL(epf_mhi->dma_chan_rx)) {
684 		dev_err(dev, "Failed to request rx channel\n");
685 		ret = -ENODEV;
686 		goto err_release_tx;
687 	}
688 
689 	epf_mhi->dma_wq = alloc_workqueue("pci_epf_mhi_dma_wq", 0, 0);
690 	if (!epf_mhi->dma_wq) {
691 		ret = -ENOMEM;
692 		goto err_release_rx;
693 	}
694 
695 	INIT_LIST_HEAD(&epf_mhi->dma_list);
696 	INIT_WORK(&epf_mhi->dma_work, pci_epf_mhi_dma_worker);
697 	spin_lock_init(&epf_mhi->list_lock);
698 
699 	return 0;
700 
701 err_release_rx:
702 	dma_release_channel(epf_mhi->dma_chan_rx);
703 	epf_mhi->dma_chan_rx = NULL;
704 err_release_tx:
705 	dma_release_channel(epf_mhi->dma_chan_tx);
706 	epf_mhi->dma_chan_tx = NULL;
707 
708 	return ret;
709 }
710 
711 static void pci_epf_mhi_dma_deinit(struct pci_epf_mhi *epf_mhi)
712 {
713 	destroy_workqueue(epf_mhi->dma_wq);
714 	dma_release_channel(epf_mhi->dma_chan_tx);
715 	dma_release_channel(epf_mhi->dma_chan_rx);
716 	epf_mhi->dma_chan_tx = NULL;
717 	epf_mhi->dma_chan_rx = NULL;
718 }
719 
720 static int pci_epf_mhi_epc_init(struct pci_epf *epf)
721 {
722 	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
723 	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
724 	struct pci_epf_bar *epf_bar = &epf->bar[info->bar_num];
725 	struct pci_epc *epc = epf->epc;
726 	struct device *dev = &epf->dev;
727 	int ret;
728 
729 	epf_bar->phys_addr = epf_mhi->mmio_phys;
730 	epf_bar->size = epf_mhi->mmio_size;
731 	epf_bar->barno = info->bar_num;
732 	epf_bar->flags = info->epf_flags;
733 	ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no, epf_bar);
734 	if (ret) {
735 		dev_err(dev, "Failed to set BAR: %d\n", ret);
736 		return ret;
737 	}
738 
739 	ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no,
740 			      order_base_2(info->msi_count));
741 	if (ret) {
742 		dev_err(dev, "Failed to set MSI configuration: %d\n", ret);
743 		return ret;
744 	}
745 
746 	ret = pci_epc_write_header(epc, epf->func_no, epf->vfunc_no,
747 				   epf->header);
748 	if (ret) {
749 		dev_err(dev, "Failed to set Configuration header: %d\n", ret);
750 		return ret;
751 	}
752 
753 	epf_mhi->epc_features = pci_epc_get_features(epc, epf->func_no, epf->vfunc_no);
754 	if (!epf_mhi->epc_features)
755 		return -ENODATA;
756 
757 	if (info->flags & MHI_EPF_USE_DMA) {
758 		ret = pci_epf_mhi_dma_init(epf_mhi);
759 		if (ret) {
760 			dev_err(dev, "Failed to initialize DMA: %d\n", ret);
761 			return ret;
762 		}
763 	}
764 
765 	return 0;
766 }
767 
768 static void pci_epf_mhi_epc_deinit(struct pci_epf *epf)
769 {
770 	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
771 	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
772 	struct pci_epf_bar *epf_bar = &epf->bar[info->bar_num];
773 	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
774 	struct pci_epc *epc = epf->epc;
775 
776 	if (mhi_cntrl->mhi_dev) {
777 		mhi_ep_power_down(mhi_cntrl);
778 		if (info->flags & MHI_EPF_USE_DMA)
779 			pci_epf_mhi_dma_deinit(epf_mhi);
780 		mhi_ep_unregister_controller(mhi_cntrl);
781 	}
782 
783 	pci_epc_clear_bar(epc, epf->func_no, epf->vfunc_no, epf_bar);
784 }
785 
786 static int pci_epf_mhi_link_up(struct pci_epf *epf)
787 {
788 	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
789 	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
790 	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
791 	struct pci_epc *epc = epf->epc;
792 	struct device *dev = &epf->dev;
793 	int ret;
794 
795 	mhi_cntrl->mmio = epf_mhi->mmio;
796 	mhi_cntrl->irq = epf_mhi->irq;
797 	mhi_cntrl->mru = info->mru;
798 
799 	/* Assign the struct dev of PCI EP as MHI controller device */
800 	mhi_cntrl->cntrl_dev = epc->dev.parent;
801 	mhi_cntrl->raise_irq = pci_epf_mhi_raise_irq;
802 	mhi_cntrl->alloc_map = pci_epf_mhi_alloc_map;
803 	mhi_cntrl->unmap_free = pci_epf_mhi_unmap_free;
804 	mhi_cntrl->read_sync = mhi_cntrl->read_async = pci_epf_mhi_iatu_read;
805 	mhi_cntrl->write_sync = mhi_cntrl->write_async = pci_epf_mhi_iatu_write;
806 	if (info->flags & MHI_EPF_USE_DMA) {
807 		mhi_cntrl->read_sync = pci_epf_mhi_edma_read;
808 		mhi_cntrl->write_sync = pci_epf_mhi_edma_write;
809 		mhi_cntrl->read_async = pci_epf_mhi_edma_read_async;
810 		mhi_cntrl->write_async = pci_epf_mhi_edma_write_async;
811 	}
812 
813 	/* Register the MHI EP controller */
814 	ret = mhi_ep_register_controller(mhi_cntrl, info->config);
815 	if (ret) {
816 		dev_err(dev, "Failed to register MHI EP controller: %d\n", ret);
817 		if (info->flags & MHI_EPF_USE_DMA)
818 			pci_epf_mhi_dma_deinit(epf_mhi);
819 		return ret;
820 	}
821 
822 	return 0;
823 }
824 
825 static int pci_epf_mhi_link_down(struct pci_epf *epf)
826 {
827 	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
828 	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
829 	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
830 
831 	if (mhi_cntrl->mhi_dev) {
832 		mhi_ep_power_down(mhi_cntrl);
833 		if (info->flags & MHI_EPF_USE_DMA)
834 			pci_epf_mhi_dma_deinit(epf_mhi);
835 		mhi_ep_unregister_controller(mhi_cntrl);
836 	}
837 
838 	return 0;
839 }
840 
841 static int pci_epf_mhi_bus_master_enable(struct pci_epf *epf)
842 {
843 	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
844 	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
845 	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
846 	struct device *dev = &epf->dev;
847 	int ret;
848 
849 	/*
850 	 * Power up the MHI EP stack if link is up and stack is in power down
851 	 * state.
852 	 */
853 	if (!mhi_cntrl->enabled && mhi_cntrl->mhi_dev) {
854 		ret = mhi_ep_power_up(mhi_cntrl);
855 		if (ret) {
856 			dev_err(dev, "Failed to power up MHI EP: %d\n", ret);
857 			if (info->flags & MHI_EPF_USE_DMA)
858 				pci_epf_mhi_dma_deinit(epf_mhi);
859 			mhi_ep_unregister_controller(mhi_cntrl);
860 		}
861 	}
862 
863 	return 0;
864 }
865 
866 static int pci_epf_mhi_bind(struct pci_epf *epf)
867 {
868 	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
869 	struct pci_epc *epc = epf->epc;
870 	struct platform_device *pdev = to_platform_device(epc->dev.parent);
871 	struct resource *res;
872 	int ret;
873 
874 	/* Get MMIO base address from Endpoint controller */
875 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mmio");
876 	epf_mhi->mmio_phys = res->start;
877 	epf_mhi->mmio_size = resource_size(res);
878 
879 	epf_mhi->mmio = ioremap(epf_mhi->mmio_phys, epf_mhi->mmio_size);
880 	if (!epf_mhi->mmio)
881 		return -ENOMEM;
882 
883 	ret = platform_get_irq_byname(pdev, "doorbell");
884 	if (ret < 0) {
885 		iounmap(epf_mhi->mmio);
886 		return ret;
887 	}
888 
889 	epf_mhi->irq = ret;
890 
891 	return 0;
892 }
893 
894 static void pci_epf_mhi_unbind(struct pci_epf *epf)
895 {
896 	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
897 	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
898 	struct pci_epf_bar *epf_bar = &epf->bar[info->bar_num];
899 	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
900 	struct pci_epc *epc = epf->epc;
901 
902 	/*
903 	 * Forcefully power down the MHI EP stack. Only way to bring the MHI EP
904 	 * stack back to working state after successive bind is by getting Bus
905 	 * Master Enable event from host.
906 	 */
907 	if (mhi_cntrl->mhi_dev) {
908 		mhi_ep_power_down(mhi_cntrl);
909 		if (info->flags & MHI_EPF_USE_DMA)
910 			pci_epf_mhi_dma_deinit(epf_mhi);
911 		mhi_ep_unregister_controller(mhi_cntrl);
912 	}
913 
914 	iounmap(epf_mhi->mmio);
915 	pci_epc_clear_bar(epc, epf->func_no, epf->vfunc_no, epf_bar);
916 }
917 
918 static const struct pci_epc_event_ops pci_epf_mhi_event_ops = {
919 	.epc_init = pci_epf_mhi_epc_init,
920 	.epc_deinit = pci_epf_mhi_epc_deinit,
921 	.link_up = pci_epf_mhi_link_up,
922 	.link_down = pci_epf_mhi_link_down,
923 	.bus_master_enable = pci_epf_mhi_bus_master_enable,
924 };
925 
926 static int pci_epf_mhi_probe(struct pci_epf *epf,
927 			     const struct pci_epf_device_id *id)
928 {
929 	struct pci_epf_mhi_ep_info *info =
930 			(struct pci_epf_mhi_ep_info *)id->driver_data;
931 	struct pci_epf_mhi *epf_mhi;
932 	struct device *dev = &epf->dev;
933 
934 	epf_mhi = devm_kzalloc(dev, sizeof(*epf_mhi), GFP_KERNEL);
935 	if (!epf_mhi)
936 		return -ENOMEM;
937 
938 	epf->header = info->epf_header;
939 	epf_mhi->info = info;
940 	epf_mhi->epf = epf;
941 
942 	epf->event_ops = &pci_epf_mhi_event_ops;
943 
944 	mutex_init(&epf_mhi->lock);
945 
946 	epf_set_drvdata(epf, epf_mhi);
947 
948 	return 0;
949 }
950 
951 static const struct pci_epf_device_id pci_epf_mhi_ids[] = {
952 	{ .name = "pci_epf_mhi_sa8775p", .driver_data = (kernel_ulong_t)&sa8775p_info },
953 	{ .name = "pci_epf_mhi_sdx55", .driver_data = (kernel_ulong_t)&sdx55_info },
954 	{ .name = "pci_epf_mhi_sm8450", .driver_data = (kernel_ulong_t)&sm8450_info },
955 	{},
956 };
957 
958 static const struct pci_epf_ops pci_epf_mhi_ops = {
959 	.unbind	= pci_epf_mhi_unbind,
960 	.bind	= pci_epf_mhi_bind,
961 };
962 
963 static struct pci_epf_driver pci_epf_mhi_driver = {
964 	.driver.name	= "pci_epf_mhi",
965 	.probe		= pci_epf_mhi_probe,
966 	.id_table	= pci_epf_mhi_ids,
967 	.ops		= &pci_epf_mhi_ops,
968 	.owner		= THIS_MODULE,
969 };
970 
971 static int __init pci_epf_mhi_init(void)
972 {
973 	return pci_epf_register_driver(&pci_epf_mhi_driver);
974 }
975 module_init(pci_epf_mhi_init);
976 
977 static void __exit pci_epf_mhi_exit(void)
978 {
979 	pci_epf_unregister_driver(&pci_epf_mhi_driver);
980 }
981 module_exit(pci_epf_mhi_exit);
982 
983 MODULE_DESCRIPTION("PCI EPF driver for MHI Endpoint devices");
984 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
985 MODULE_LICENSE("GPL");
986