1/*
2 * Intel MIC Platform Software Stack (MPSS)
3 *
4 * Copyright(c) 2014 Intel Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2, as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * The full GNU General Public License is included in this distribution in
16 * the file called "COPYING".
17 *
18 * Intel MIC X100 DMA Driver.
19 *
20 * Adapted from IOAT dma driver.
21 */
22#include <linux/module.h>
23#include <linux/io.h>
24#include <linux/seq_file.h>
25
26#include "mic_x100_dma.h"
27
28#define MIC_DMA_MAX_XFER_SIZE_CARD  (1 * 1024 * 1024 -\
29				       MIC_DMA_ALIGN_BYTES)
30#define MIC_DMA_MAX_XFER_SIZE_HOST  (1 * 1024 * 1024 >> 1)
31#define MIC_DMA_DESC_TYPE_SHIFT	60
32#define MIC_DMA_MEMCPY_LEN_SHIFT 46
33#define MIC_DMA_STAT_INTR_SHIFT 59
34
35/* high-water mark for pushing dma descriptors */
36static int mic_dma_pending_level = 4;
37
38/* Status descriptor is used to write a 64 bit value to a memory location */
39enum mic_dma_desc_format_type {
40	MIC_DMA_MEMCPY = 1,
41	MIC_DMA_STATUS,
42};
43
44static inline u32 mic_dma_hw_ring_inc(u32 val)
45{
46	return (val + 1) % MIC_DMA_DESC_RX_SIZE;
47}
48
49static inline u32 mic_dma_hw_ring_dec(u32 val)
50{
51	return val ? val - 1 : MIC_DMA_DESC_RX_SIZE - 1;
52}
53
54static inline void mic_dma_hw_ring_inc_head(struct mic_dma_chan *ch)
55{
56	ch->head = mic_dma_hw_ring_inc(ch->head);
57}
58
59/* Prepare a memcpy desc */
60static inline void mic_dma_memcpy_desc(struct mic_dma_desc *desc,
61	dma_addr_t src_phys, dma_addr_t dst_phys, u64 size)
62{
63	u64 qw0, qw1;
64
65	qw0 = src_phys;
66	qw0 |= (size >> MIC_DMA_ALIGN_SHIFT) << MIC_DMA_MEMCPY_LEN_SHIFT;
67	qw1 = MIC_DMA_MEMCPY;
68	qw1 <<= MIC_DMA_DESC_TYPE_SHIFT;
69	qw1 |= dst_phys;
70	desc->qw0 = qw0;
71	desc->qw1 = qw1;
72}
73
74/* Prepare a status desc. with @data to be written at @dst_phys */
75static inline void mic_dma_prep_status_desc(struct mic_dma_desc *desc, u64 data,
76	dma_addr_t dst_phys, bool generate_intr)
77{
78	u64 qw0, qw1;
79
80	qw0 = data;
81	qw1 = (u64) MIC_DMA_STATUS << MIC_DMA_DESC_TYPE_SHIFT | dst_phys;
82	if (generate_intr)
83		qw1 |= (1ULL << MIC_DMA_STAT_INTR_SHIFT);
84	desc->qw0 = qw0;
85	desc->qw1 = qw1;
86}
87
88static void mic_dma_cleanup(struct mic_dma_chan *ch)
89{
90	struct dma_async_tx_descriptor *tx;
91	u32 tail;
92	u32 last_tail;
93
94	spin_lock(&ch->cleanup_lock);
95	tail = mic_dma_read_cmp_cnt(ch);
96	/*
97	 * This is the barrier pair for smp_wmb() in fn.
98	 * mic_dma_tx_submit_unlock. It's required so that we read the
99	 * updated cookie value from tx->cookie.
100	 */
101	smp_rmb();
102	for (last_tail = ch->last_tail; tail != last_tail;) {
103		tx = &ch->tx_array[last_tail];
104		if (tx->cookie) {
105			dma_cookie_complete(tx);
106			if (tx->callback) {
107				tx->callback(tx->callback_param);
108				tx->callback = NULL;
109			}
110		}
111		last_tail = mic_dma_hw_ring_inc(last_tail);
112	}
113	/* finish all completion callbacks before incrementing tail */
114	smp_mb();
115	ch->last_tail = last_tail;
116	spin_unlock(&ch->cleanup_lock);
117}
118
119static u32 mic_dma_ring_count(u32 head, u32 tail)
120{
121	u32 count;
122
123	if (head >= tail)
124		count = (tail - 0) + (MIC_DMA_DESC_RX_SIZE - head);
125	else
126		count = tail - head;
127	return count - 1;
128}
129
130/* Returns the num. of free descriptors on success, -ENOMEM on failure */
131static int mic_dma_avail_desc_ring_space(struct mic_dma_chan *ch, int required)
132{
133	struct device *dev = mic_dma_ch_to_device(ch);
134	u32 count;
135
136	count = mic_dma_ring_count(ch->head, ch->last_tail);
137	if (count < required) {
138		mic_dma_cleanup(ch);
139		count = mic_dma_ring_count(ch->head, ch->last_tail);
140	}
141
142	if (count < required) {
143		dev_dbg(dev, "Not enough desc space");
144		dev_dbg(dev, "%s %d required=%u, avail=%u\n",
145			__func__, __LINE__, required, count);
146		return -ENOMEM;
147	} else {
148		return count;
149	}
150}
151
152/* Program memcpy descriptors into the descriptor ring and update s/w head ptr*/
153static int mic_dma_prog_memcpy_desc(struct mic_dma_chan *ch, dma_addr_t src,
154				    dma_addr_t dst, size_t len)
155{
156	size_t current_transfer_len;
157	size_t max_xfer_size = to_mic_dma_dev(ch)->max_xfer_size;
158	/* 3 is added to make sure we have enough space for status desc */
159	int num_desc = len / max_xfer_size + 3;
160	int ret;
161
162	if (len % max_xfer_size)
163		num_desc++;
164
165	ret = mic_dma_avail_desc_ring_space(ch, num_desc);
166	if (ret < 0)
167		return ret;
168	do {
169		current_transfer_len = min(len, max_xfer_size);
170		mic_dma_memcpy_desc(&ch->desc_ring[ch->head],
171				    src, dst, current_transfer_len);
172		mic_dma_hw_ring_inc_head(ch);
173		len -= current_transfer_len;
174		dst = dst + current_transfer_len;
175		src = src + current_transfer_len;
176	} while (len > 0);
177	return 0;
178}
179
180/* It's a h/w quirk and h/w needs 2 status descriptors for every status desc */
181static void mic_dma_prog_intr(struct mic_dma_chan *ch)
182{
183	mic_dma_prep_status_desc(&ch->desc_ring[ch->head], 0,
184				 ch->status_dest_micpa, false);
185	mic_dma_hw_ring_inc_head(ch);
186	mic_dma_prep_status_desc(&ch->desc_ring[ch->head], 0,
187				 ch->status_dest_micpa, true);
188	mic_dma_hw_ring_inc_head(ch);
189}
190
191/* Wrapper function to program memcpy descriptors/status descriptors */
192static int mic_dma_do_dma(struct mic_dma_chan *ch, int flags, dma_addr_t src,
193			  dma_addr_t dst, size_t len)
194{
195	if (-ENOMEM == mic_dma_prog_memcpy_desc(ch, src, dst, len))
196		return -ENOMEM;
197	/* Above mic_dma_prog_memcpy_desc() makes sure we have enough space */
198	if (flags & DMA_PREP_FENCE) {
199		mic_dma_prep_status_desc(&ch->desc_ring[ch->head], 0,
200					 ch->status_dest_micpa, false);
201		mic_dma_hw_ring_inc_head(ch);
202	}
203
204	if (flags & DMA_PREP_INTERRUPT)
205		mic_dma_prog_intr(ch);
206
207	return 0;
208}
209
210static inline void mic_dma_issue_pending(struct dma_chan *ch)
211{
212	struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
213
214	spin_lock(&mic_ch->issue_lock);
215	/*
216	 * Write to head triggers h/w to act on the descriptors.
217	 * On MIC, writing the same head value twice causes
218	 * a h/w error. On second write, h/w assumes we filled
219	 * the entire ring & overwrote some of the descriptors.
220	 */
221	if (mic_ch->issued == mic_ch->submitted)
222		goto out;
223	mic_ch->issued = mic_ch->submitted;
224	/*
225	 * make descriptor updates visible before advancing head,
226	 * this is purposefully not smp_wmb() since we are also
227	 * publishing the descriptor updates to a dma device
228	 */
229	wmb();
230	mic_dma_write_reg(mic_ch, MIC_DMA_REG_DHPR, mic_ch->issued);
231out:
232	spin_unlock(&mic_ch->issue_lock);
233}
234
235static inline void mic_dma_update_pending(struct mic_dma_chan *ch)
236{
237	if (mic_dma_ring_count(ch->issued, ch->submitted)
238			> mic_dma_pending_level)
239		mic_dma_issue_pending(&ch->api_ch);
240}
241
242static dma_cookie_t mic_dma_tx_submit_unlock(struct dma_async_tx_descriptor *tx)
243{
244	struct mic_dma_chan *mic_ch = to_mic_dma_chan(tx->chan);
245	dma_cookie_t cookie;
246
247	dma_cookie_assign(tx);
248	cookie = tx->cookie;
249	/*
250	 * We need an smp write barrier here because another CPU might see
251	 * an update to submitted and update h/w head even before we
252	 * assigned a cookie to this tx.
253	 */
254	smp_wmb();
255	mic_ch->submitted = mic_ch->head;
256	spin_unlock(&mic_ch->prep_lock);
257	mic_dma_update_pending(mic_ch);
258	return cookie;
259}
260
261static inline struct dma_async_tx_descriptor *
262allocate_tx(struct mic_dma_chan *ch)
263{
264	u32 idx = mic_dma_hw_ring_dec(ch->head);
265	struct dma_async_tx_descriptor *tx = &ch->tx_array[idx];
266
267	dma_async_tx_descriptor_init(tx, &ch->api_ch);
268	tx->tx_submit = mic_dma_tx_submit_unlock;
269	return tx;
270}
271
272/*
273 * Prepare a memcpy descriptor to be added to the ring.
274 * Note that the temporary descriptor adds an extra overhead of copying the
275 * descriptor to ring. So, we copy directly to the descriptor ring
276 */
277static struct dma_async_tx_descriptor *
278mic_dma_prep_memcpy_lock(struct dma_chan *ch, dma_addr_t dma_dest,
279			 dma_addr_t dma_src, size_t len, unsigned long flags)
280{
281	struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
282	struct device *dev = mic_dma_ch_to_device(mic_ch);
283	int result;
284
285	if (!len && !flags)
286		return NULL;
287
288	spin_lock(&mic_ch->prep_lock);
289	result = mic_dma_do_dma(mic_ch, flags, dma_src, dma_dest, len);
290	if (result >= 0)
291		return allocate_tx(mic_ch);
292	dev_err(dev, "Error enqueueing dma, error=%d\n", result);
293	spin_unlock(&mic_ch->prep_lock);
294	return NULL;
295}
296
297static struct dma_async_tx_descriptor *
298mic_dma_prep_interrupt_lock(struct dma_chan *ch, unsigned long flags)
299{
300	struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
301	int ret;
302
303	spin_lock(&mic_ch->prep_lock);
304	ret = mic_dma_do_dma(mic_ch, flags, 0, 0, 0);
305	if (!ret)
306		return allocate_tx(mic_ch);
307	spin_unlock(&mic_ch->prep_lock);
308	return NULL;
309}
310
311/* Return the status of the transaction */
312static enum dma_status
313mic_dma_tx_status(struct dma_chan *ch, dma_cookie_t cookie,
314		  struct dma_tx_state *txstate)
315{
316	struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
317
318	if (DMA_COMPLETE != dma_cookie_status(ch, cookie, txstate))
319		mic_dma_cleanup(mic_ch);
320
321	return dma_cookie_status(ch, cookie, txstate);
322}
323
324static irqreturn_t mic_dma_thread_fn(int irq, void *data)
325{
326	mic_dma_cleanup((struct mic_dma_chan *)data);
327	return IRQ_HANDLED;
328}
329
330static irqreturn_t mic_dma_intr_handler(int irq, void *data)
331{
332	struct mic_dma_chan *ch = ((struct mic_dma_chan *)data);
333
334	mic_dma_ack_interrupt(ch);
335	return IRQ_WAKE_THREAD;
336}
337
338static int mic_dma_alloc_desc_ring(struct mic_dma_chan *ch)
339{
340	u64 desc_ring_size = MIC_DMA_DESC_RX_SIZE * sizeof(*ch->desc_ring);
341	struct device *dev = &to_mbus_device(ch)->dev;
342
343	desc_ring_size = ALIGN(desc_ring_size, MIC_DMA_ALIGN_BYTES);
344	ch->desc_ring = kzalloc(desc_ring_size, GFP_KERNEL);
345
346	if (!ch->desc_ring)
347		return -ENOMEM;
348
349	ch->desc_ring_micpa = dma_map_single(dev, ch->desc_ring,
350					     desc_ring_size, DMA_BIDIRECTIONAL);
351	if (dma_mapping_error(dev, ch->desc_ring_micpa))
352		goto map_error;
353
354	ch->tx_array = vzalloc(MIC_DMA_DESC_RX_SIZE * sizeof(*ch->tx_array));
355	if (!ch->tx_array)
356		goto tx_error;
357	return 0;
358tx_error:
359	dma_unmap_single(dev, ch->desc_ring_micpa, desc_ring_size,
360			 DMA_BIDIRECTIONAL);
361map_error:
362	kfree(ch->desc_ring);
363	return -ENOMEM;
364}
365
366static void mic_dma_free_desc_ring(struct mic_dma_chan *ch)
367{
368	u64 desc_ring_size = MIC_DMA_DESC_RX_SIZE * sizeof(*ch->desc_ring);
369
370	vfree(ch->tx_array);
371	desc_ring_size = ALIGN(desc_ring_size, MIC_DMA_ALIGN_BYTES);
372	dma_unmap_single(&to_mbus_device(ch)->dev, ch->desc_ring_micpa,
373			 desc_ring_size, DMA_BIDIRECTIONAL);
374	kfree(ch->desc_ring);
375	ch->desc_ring = NULL;
376}
377
378static void mic_dma_free_status_dest(struct mic_dma_chan *ch)
379{
380	dma_unmap_single(&to_mbus_device(ch)->dev, ch->status_dest_micpa,
381			 L1_CACHE_BYTES, DMA_BIDIRECTIONAL);
382	kfree(ch->status_dest);
383}
384
385static int mic_dma_alloc_status_dest(struct mic_dma_chan *ch)
386{
387	struct device *dev = &to_mbus_device(ch)->dev;
388
389	ch->status_dest = kzalloc(L1_CACHE_BYTES, GFP_KERNEL);
390	if (!ch->status_dest)
391		return -ENOMEM;
392	ch->status_dest_micpa = dma_map_single(dev, ch->status_dest,
393					L1_CACHE_BYTES, DMA_BIDIRECTIONAL);
394	if (dma_mapping_error(dev, ch->status_dest_micpa)) {
395		kfree(ch->status_dest);
396		ch->status_dest = NULL;
397		return -ENOMEM;
398	}
399	return 0;
400}
401
402static int mic_dma_check_chan(struct mic_dma_chan *ch)
403{
404	if (mic_dma_read_reg(ch, MIC_DMA_REG_DCHERR) ||
405	    mic_dma_read_reg(ch, MIC_DMA_REG_DSTAT) & MIC_DMA_CHAN_QUIESCE) {
406		mic_dma_disable_chan(ch);
407		mic_dma_chan_mask_intr(ch);
408		dev_err(mic_dma_ch_to_device(ch),
409			"%s %d error setting up mic dma chan %d\n",
410			__func__, __LINE__, ch->ch_num);
411		return -EBUSY;
412	}
413	return 0;
414}
415
416static int mic_dma_chan_setup(struct mic_dma_chan *ch)
417{
418	if (MIC_DMA_CHAN_MIC == ch->owner)
419		mic_dma_chan_set_owner(ch);
420	mic_dma_disable_chan(ch);
421	mic_dma_chan_mask_intr(ch);
422	mic_dma_write_reg(ch, MIC_DMA_REG_DCHERRMSK, 0);
423	mic_dma_chan_set_desc_ring(ch);
424	ch->last_tail = mic_dma_read_reg(ch, MIC_DMA_REG_DTPR);
425	ch->head = ch->last_tail;
426	ch->issued = 0;
427	mic_dma_chan_unmask_intr(ch);
428	mic_dma_enable_chan(ch);
429	return mic_dma_check_chan(ch);
430}
431
432static void mic_dma_chan_destroy(struct mic_dma_chan *ch)
433{
434	mic_dma_disable_chan(ch);
435	mic_dma_chan_mask_intr(ch);
436}
437
438static void mic_dma_unregister_dma_device(struct mic_dma_device *mic_dma_dev)
439{
440	dma_async_device_unregister(&mic_dma_dev->dma_dev);
441}
442
443static int mic_dma_setup_irq(struct mic_dma_chan *ch)
444{
445	ch->cookie =
446		to_mbus_hw_ops(ch)->request_threaded_irq(to_mbus_device(ch),
447			mic_dma_intr_handler, mic_dma_thread_fn,
448			"mic dma_channel", ch, ch->ch_num);
449	if (IS_ERR(ch->cookie))
450		return IS_ERR(ch->cookie);
451	return 0;
452}
453
454static inline void mic_dma_free_irq(struct mic_dma_chan *ch)
455{
456	to_mbus_hw_ops(ch)->free_irq(to_mbus_device(ch), ch->cookie, ch);
457}
458
459static int mic_dma_chan_init(struct mic_dma_chan *ch)
460{
461	int ret = mic_dma_alloc_desc_ring(ch);
462
463	if (ret)
464		goto ring_error;
465	ret = mic_dma_alloc_status_dest(ch);
466	if (ret)
467		goto status_error;
468	ret = mic_dma_chan_setup(ch);
469	if (ret)
470		goto chan_error;
471	return ret;
472chan_error:
473	mic_dma_free_status_dest(ch);
474status_error:
475	mic_dma_free_desc_ring(ch);
476ring_error:
477	return ret;
478}
479
480static int mic_dma_drain_chan(struct mic_dma_chan *ch)
481{
482	struct dma_async_tx_descriptor *tx;
483	int err = 0;
484	dma_cookie_t cookie;
485
486	tx = mic_dma_prep_memcpy_lock(&ch->api_ch, 0, 0, 0, DMA_PREP_FENCE);
487	if (!tx) {
488		err = -ENOMEM;
489		goto error;
490	}
491
492	cookie = tx->tx_submit(tx);
493	if (dma_submit_error(cookie))
494		err = -ENOMEM;
495	else
496		err = dma_sync_wait(&ch->api_ch, cookie);
497	if (err) {
498		dev_err(mic_dma_ch_to_device(ch), "%s %d TO chan 0x%x\n",
499			__func__, __LINE__, ch->ch_num);
500		err = -EIO;
501	}
502error:
503	mic_dma_cleanup(ch);
504	return err;
505}
506
507static inline void mic_dma_chan_uninit(struct mic_dma_chan *ch)
508{
509	mic_dma_chan_destroy(ch);
510	mic_dma_cleanup(ch);
511	mic_dma_free_status_dest(ch);
512	mic_dma_free_desc_ring(ch);
513}
514
515static int mic_dma_init(struct mic_dma_device *mic_dma_dev,
516			enum mic_dma_chan_owner owner)
517{
518	int i, first_chan = mic_dma_dev->start_ch;
519	struct mic_dma_chan *ch;
520	int ret;
521
522	for (i = first_chan; i < first_chan + MIC_DMA_NUM_CHAN; i++) {
523		unsigned long data;
524		ch = &mic_dma_dev->mic_ch[i];
525		data = (unsigned long)ch;
526		ch->ch_num = i;
527		ch->owner = owner;
528		spin_lock_init(&ch->cleanup_lock);
529		spin_lock_init(&ch->prep_lock);
530		spin_lock_init(&ch->issue_lock);
531		ret = mic_dma_setup_irq(ch);
532		if (ret)
533			goto error;
534	}
535	return 0;
536error:
537	for (i = i - 1; i >= first_chan; i--)
538		mic_dma_free_irq(ch);
539	return ret;
540}
541
542static void mic_dma_uninit(struct mic_dma_device *mic_dma_dev)
543{
544	int i, first_chan = mic_dma_dev->start_ch;
545	struct mic_dma_chan *ch;
546
547	for (i = first_chan; i < first_chan + MIC_DMA_NUM_CHAN; i++) {
548		ch = &mic_dma_dev->mic_ch[i];
549		mic_dma_free_irq(ch);
550	}
551}
552
553static int mic_dma_alloc_chan_resources(struct dma_chan *ch)
554{
555	int ret = mic_dma_chan_init(to_mic_dma_chan(ch));
556	if (ret)
557		return ret;
558	return MIC_DMA_DESC_RX_SIZE;
559}
560
561static void mic_dma_free_chan_resources(struct dma_chan *ch)
562{
563	struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
564	mic_dma_drain_chan(mic_ch);
565	mic_dma_chan_uninit(mic_ch);
566}
567
568/* Set the fn. handlers and register the dma device with dma api */
569static int mic_dma_register_dma_device(struct mic_dma_device *mic_dma_dev,
570				       enum mic_dma_chan_owner owner)
571{
572	int i, first_chan = mic_dma_dev->start_ch;
573
574	dma_cap_zero(mic_dma_dev->dma_dev.cap_mask);
575	/*
576	 * This dma engine is not capable of host memory to host memory
577	 * transfers
578	 */
579	dma_cap_set(DMA_MEMCPY, mic_dma_dev->dma_dev.cap_mask);
580
581	if (MIC_DMA_CHAN_HOST == owner)
582		dma_cap_set(DMA_PRIVATE, mic_dma_dev->dma_dev.cap_mask);
583	mic_dma_dev->dma_dev.device_alloc_chan_resources =
584		mic_dma_alloc_chan_resources;
585	mic_dma_dev->dma_dev.device_free_chan_resources =
586		mic_dma_free_chan_resources;
587	mic_dma_dev->dma_dev.device_tx_status = mic_dma_tx_status;
588	mic_dma_dev->dma_dev.device_prep_dma_memcpy = mic_dma_prep_memcpy_lock;
589	mic_dma_dev->dma_dev.device_prep_dma_interrupt =
590		mic_dma_prep_interrupt_lock;
591	mic_dma_dev->dma_dev.device_issue_pending = mic_dma_issue_pending;
592	mic_dma_dev->dma_dev.copy_align = MIC_DMA_ALIGN_SHIFT;
593	INIT_LIST_HEAD(&mic_dma_dev->dma_dev.channels);
594	for (i = first_chan; i < first_chan + MIC_DMA_NUM_CHAN; i++) {
595		mic_dma_dev->mic_ch[i].api_ch.device = &mic_dma_dev->dma_dev;
596		dma_cookie_init(&mic_dma_dev->mic_ch[i].api_ch);
597		list_add_tail(&mic_dma_dev->mic_ch[i].api_ch.device_node,
598			      &mic_dma_dev->dma_dev.channels);
599	}
600	return dma_async_device_register(&mic_dma_dev->dma_dev);
601}
602
603/*
604 * Initializes dma channels and registers the dma device with the
605 * dma engine api.
606 */
607static struct mic_dma_device *mic_dma_dev_reg(struct mbus_device *mbdev,
608					      enum mic_dma_chan_owner owner)
609{
610	struct mic_dma_device *mic_dma_dev;
611	int ret;
612	struct device *dev = &mbdev->dev;
613
614	mic_dma_dev = kzalloc(sizeof(*mic_dma_dev), GFP_KERNEL);
615	if (!mic_dma_dev) {
616		ret = -ENOMEM;
617		goto alloc_error;
618	}
619	mic_dma_dev->mbdev = mbdev;
620	mic_dma_dev->dma_dev.dev = dev;
621	mic_dma_dev->mmio = mbdev->mmio_va;
622	if (MIC_DMA_CHAN_HOST == owner) {
623		mic_dma_dev->start_ch = 0;
624		mic_dma_dev->max_xfer_size = MIC_DMA_MAX_XFER_SIZE_HOST;
625	} else {
626		mic_dma_dev->start_ch = 4;
627		mic_dma_dev->max_xfer_size = MIC_DMA_MAX_XFER_SIZE_CARD;
628	}
629	ret = mic_dma_init(mic_dma_dev, owner);
630	if (ret)
631		goto init_error;
632	ret = mic_dma_register_dma_device(mic_dma_dev, owner);
633	if (ret)
634		goto reg_error;
635	return mic_dma_dev;
636reg_error:
637	mic_dma_uninit(mic_dma_dev);
638init_error:
639	kfree(mic_dma_dev);
640	mic_dma_dev = NULL;
641alloc_error:
642	dev_err(dev, "Error at %s %d ret=%d\n", __func__, __LINE__, ret);
643	return mic_dma_dev;
644}
645
646static void mic_dma_dev_unreg(struct mic_dma_device *mic_dma_dev)
647{
648	mic_dma_unregister_dma_device(mic_dma_dev);
649	mic_dma_uninit(mic_dma_dev);
650	kfree(mic_dma_dev);
651}
652
653/* DEBUGFS CODE */
654static int mic_dma_reg_seq_show(struct seq_file *s, void *pos)
655{
656	struct mic_dma_device *mic_dma_dev = s->private;
657	int i, chan_num, first_chan = mic_dma_dev->start_ch;
658	struct mic_dma_chan *ch;
659
660	seq_printf(s, "SBOX_DCR: %#x\n",
661		   mic_dma_mmio_read(&mic_dma_dev->mic_ch[first_chan],
662				     MIC_DMA_SBOX_BASE + MIC_DMA_SBOX_DCR));
663	seq_puts(s, "DMA Channel Registers\n");
664	seq_printf(s, "%-10s| %-10s %-10s %-10s %-10s %-10s",
665		   "Channel", "DCAR", "DTPR", "DHPR", "DRAR_HI", "DRAR_LO");
666	seq_printf(s, " %-11s %-14s %-10s\n", "DCHERR", "DCHERRMSK", "DSTAT");
667	for (i = first_chan; i < first_chan + MIC_DMA_NUM_CHAN; i++) {
668		ch = &mic_dma_dev->mic_ch[i];
669		chan_num = ch->ch_num;
670		seq_printf(s, "%-10i| %-#10x %-#10x %-#10x %-#10x",
671			   chan_num,
672			   mic_dma_read_reg(ch, MIC_DMA_REG_DCAR),
673			   mic_dma_read_reg(ch, MIC_DMA_REG_DTPR),
674			   mic_dma_read_reg(ch, MIC_DMA_REG_DHPR),
675			   mic_dma_read_reg(ch, MIC_DMA_REG_DRAR_HI));
676		seq_printf(s, " %-#10x %-#10x %-#14x %-#10x\n",
677			   mic_dma_read_reg(ch, MIC_DMA_REG_DRAR_LO),
678			   mic_dma_read_reg(ch, MIC_DMA_REG_DCHERR),
679			   mic_dma_read_reg(ch, MIC_DMA_REG_DCHERRMSK),
680			   mic_dma_read_reg(ch, MIC_DMA_REG_DSTAT));
681	}
682	return 0;
683}
684
685static int mic_dma_reg_debug_open(struct inode *inode, struct file *file)
686{
687	return single_open(file, mic_dma_reg_seq_show, inode->i_private);
688}
689
690static int mic_dma_reg_debug_release(struct inode *inode, struct file *file)
691{
692	return single_release(inode, file);
693}
694
695static const struct file_operations mic_dma_reg_ops = {
696	.owner   = THIS_MODULE,
697	.open    = mic_dma_reg_debug_open,
698	.read    = seq_read,
699	.llseek  = seq_lseek,
700	.release = mic_dma_reg_debug_release
701};
702
703/* Debugfs parent dir */
704static struct dentry *mic_dma_dbg;
705
706static int mic_dma_driver_probe(struct mbus_device *mbdev)
707{
708	struct mic_dma_device *mic_dma_dev;
709	enum mic_dma_chan_owner owner;
710
711	if (MBUS_DEV_DMA_MIC == mbdev->id.device)
712		owner = MIC_DMA_CHAN_MIC;
713	else
714		owner = MIC_DMA_CHAN_HOST;
715
716	mic_dma_dev = mic_dma_dev_reg(mbdev, owner);
717	dev_set_drvdata(&mbdev->dev, mic_dma_dev);
718
719	if (mic_dma_dbg) {
720		mic_dma_dev->dbg_dir = debugfs_create_dir(dev_name(&mbdev->dev),
721							  mic_dma_dbg);
722		if (mic_dma_dev->dbg_dir)
723			debugfs_create_file("mic_dma_reg", 0444,
724					    mic_dma_dev->dbg_dir, mic_dma_dev,
725					    &mic_dma_reg_ops);
726	}
727	return 0;
728}
729
730static void mic_dma_driver_remove(struct mbus_device *mbdev)
731{
732	struct mic_dma_device *mic_dma_dev;
733
734	mic_dma_dev = dev_get_drvdata(&mbdev->dev);
735	debugfs_remove_recursive(mic_dma_dev->dbg_dir);
736	mic_dma_dev_unreg(mic_dma_dev);
737}
738
739static struct mbus_device_id id_table[] = {
740	{MBUS_DEV_DMA_MIC, MBUS_DEV_ANY_ID},
741	{MBUS_DEV_DMA_HOST, MBUS_DEV_ANY_ID},
742	{0},
743};
744
745static struct mbus_driver mic_dma_driver = {
746	.driver.name =	KBUILD_MODNAME,
747	.driver.owner =	THIS_MODULE,
748	.id_table = id_table,
749	.probe = mic_dma_driver_probe,
750	.remove = mic_dma_driver_remove,
751};
752
753static int __init mic_x100_dma_init(void)
754{
755	int rc = mbus_register_driver(&mic_dma_driver);
756	if (rc)
757		return rc;
758	mic_dma_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
759	return 0;
760}
761
762static void __exit mic_x100_dma_exit(void)
763{
764	debugfs_remove_recursive(mic_dma_dbg);
765	mbus_unregister_driver(&mic_dma_driver);
766}
767
768module_init(mic_x100_dma_init);
769module_exit(mic_x100_dma_exit);
770
771MODULE_DEVICE_TABLE(mbus, id_table);
772MODULE_AUTHOR("Intel Corporation");
773MODULE_DESCRIPTION("Intel(R) MIC X100 DMA Driver");
774MODULE_LICENSE("GPL v2");
775