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  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
 24struct 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
 33struct 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
 56static 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
 85static 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
 92static 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
100static 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
109static 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
116static 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
126static 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
133static 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
143struct 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
161static 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
166static 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
192static 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
203static 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
217static 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
228static 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
242static 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
273static 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
304static void pci_epf_mhi_dma_callback(void *param)
305{
306	complete(param);
307}
308
309static 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
372err_unmap:
373	dma_unmap_single(dma_dev, dst_addr, buf_info->size, DMA_FROM_DEVICE);
374err_unlock:
375	mutex_unlock(&epf_mhi->lock);
376
377	return ret;
378}
379
380static 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
443err_unmap:
444	dma_unmap_single(dma_dev, src_addr, buf_info->size, DMA_TO_DEVICE);
445err_unlock:
446	mutex_unlock(&epf_mhi->lock);
447
448	return ret;
449}
450
451static 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
473static 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
485static 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
554err_free_transfer:
555	kfree(transfer);
556err_unmap:
557	dma_unmap_single(dma_dev, dst_addr, buf_info->size, DMA_FROM_DEVICE);
558err_unlock:
559	mutex_unlock(&epf_mhi->lock);
560
561	return ret;
562}
563
564static 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
633err_free_transfer:
634	kfree(transfer);
635err_unmap:
636	dma_unmap_single(dma_dev, src_addr, buf_info->size, DMA_TO_DEVICE);
637err_unlock:
638	mutex_unlock(&epf_mhi->lock);
639
640	return ret;
641}
642
643struct epf_dma_filter {
644	struct device *dev;
645	u32 dma_mask;
646};
647
648static 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
660static 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
701err_release_rx:
702	dma_release_channel(epf_mhi->dma_chan_rx);
703	epf_mhi->dma_chan_rx = NULL;
704err_release_tx:
705	dma_release_channel(epf_mhi->dma_chan_tx);
706	epf_mhi->dma_chan_tx = NULL;
707
708	return ret;
709}
710
711static 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
720static 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
768static 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
786static 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
825static 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
841static 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
866static 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 device *dev = &epf->dev;
871	struct platform_device *pdev = to_platform_device(epc->dev.parent);
872	struct resource *res;
873	int ret;
874
875	/* Get MMIO base address from Endpoint controller */
876	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mmio");
877	if (!res) {
878		dev_err(dev, "Failed to get \"mmio\" resource\n");
879		return -ENODEV;
880	}
881
882	epf_mhi->mmio_phys = res->start;
883	epf_mhi->mmio_size = resource_size(res);
884
885	epf_mhi->mmio = ioremap(epf_mhi->mmio_phys, epf_mhi->mmio_size);
886	if (!epf_mhi->mmio)
887		return -ENOMEM;
888
889	ret = platform_get_irq_byname(pdev, "doorbell");
890	if (ret < 0) {
891		iounmap(epf_mhi->mmio);
892		return ret;
893	}
894
895	epf_mhi->irq = ret;
896
897	return 0;
898}
899
900static void pci_epf_mhi_unbind(struct pci_epf *epf)
901{
902	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
903	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
904	struct pci_epf_bar *epf_bar = &epf->bar[info->bar_num];
905	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
906	struct pci_epc *epc = epf->epc;
907
908	/*
909	 * Forcefully power down the MHI EP stack. Only way to bring the MHI EP
910	 * stack back to working state after successive bind is by getting Bus
911	 * Master Enable event from host.
912	 */
913	if (mhi_cntrl->mhi_dev) {
914		mhi_ep_power_down(mhi_cntrl);
915		if (info->flags & MHI_EPF_USE_DMA)
916			pci_epf_mhi_dma_deinit(epf_mhi);
917		mhi_ep_unregister_controller(mhi_cntrl);
918	}
919
920	iounmap(epf_mhi->mmio);
921	pci_epc_clear_bar(epc, epf->func_no, epf->vfunc_no, epf_bar);
922}
923
924static const struct pci_epc_event_ops pci_epf_mhi_event_ops = {
925	.epc_init = pci_epf_mhi_epc_init,
926	.epc_deinit = pci_epf_mhi_epc_deinit,
927	.link_up = pci_epf_mhi_link_up,
928	.link_down = pci_epf_mhi_link_down,
929	.bus_master_enable = pci_epf_mhi_bus_master_enable,
930};
931
932static int pci_epf_mhi_probe(struct pci_epf *epf,
933			     const struct pci_epf_device_id *id)
934{
935	struct pci_epf_mhi_ep_info *info =
936			(struct pci_epf_mhi_ep_info *)id->driver_data;
937	struct pci_epf_mhi *epf_mhi;
938	struct device *dev = &epf->dev;
939
940	epf_mhi = devm_kzalloc(dev, sizeof(*epf_mhi), GFP_KERNEL);
941	if (!epf_mhi)
942		return -ENOMEM;
943
944	epf->header = info->epf_header;
945	epf_mhi->info = info;
946	epf_mhi->epf = epf;
947
948	epf->event_ops = &pci_epf_mhi_event_ops;
949
950	mutex_init(&epf_mhi->lock);
951
952	epf_set_drvdata(epf, epf_mhi);
953
954	return 0;
955}
956
957static const struct pci_epf_device_id pci_epf_mhi_ids[] = {
958	{ .name = "pci_epf_mhi_sa8775p", .driver_data = (kernel_ulong_t)&sa8775p_info },
959	{ .name = "pci_epf_mhi_sdx55", .driver_data = (kernel_ulong_t)&sdx55_info },
960	{ .name = "pci_epf_mhi_sm8450", .driver_data = (kernel_ulong_t)&sm8450_info },
961	{},
962};
963
964static const struct pci_epf_ops pci_epf_mhi_ops = {
965	.unbind	= pci_epf_mhi_unbind,
966	.bind	= pci_epf_mhi_bind,
967};
968
969static struct pci_epf_driver pci_epf_mhi_driver = {
970	.driver.name	= "pci_epf_mhi",
971	.probe		= pci_epf_mhi_probe,
972	.id_table	= pci_epf_mhi_ids,
973	.ops		= &pci_epf_mhi_ops,
974	.owner		= THIS_MODULE,
975};
976
977static int __init pci_epf_mhi_init(void)
978{
979	return pci_epf_register_driver(&pci_epf_mhi_driver);
980}
981module_init(pci_epf_mhi_init);
982
983static void __exit pci_epf_mhi_exit(void)
984{
985	pci_epf_unregister_driver(&pci_epf_mhi_driver);
986}
987module_exit(pci_epf_mhi_exit);
988
989MODULE_DESCRIPTION("PCI EPF driver for MHI Endpoint devices");
990MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
991MODULE_LICENSE("GPL");