1/*
2 * Topcliff PCH DMA controller driver
3 * Copyright (c) 2010 Intel Corporation
4 * Copyright (C) 2011 LAPIS Semiconductor Co., Ltd.
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,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19
20#include <linux/dmaengine.h>
21#include <linux/dma-mapping.h>
22#include <linux/init.h>
23#include <linux/pci.h>
24#include <linux/slab.h>
25#include <linux/interrupt.h>
26#include <linux/module.h>
27#include <linux/pch_dma.h>
28
29#include "dmaengine.h"
30
31#define DRV_NAME "pch-dma"
32
33#define DMA_CTL0_DISABLE		0x0
34#define DMA_CTL0_SG			0x1
35#define DMA_CTL0_ONESHOT		0x2
36#define DMA_CTL0_MODE_MASK_BITS		0x3
37#define DMA_CTL0_DIR_SHIFT_BITS		2
38#define DMA_CTL0_BITS_PER_CH		4
39
40#define DMA_CTL2_START_SHIFT_BITS	8
41#define DMA_CTL2_IRQ_ENABLE_MASK	((1UL << DMA_CTL2_START_SHIFT_BITS) - 1)
42
43#define DMA_STATUS_IDLE			0x0
44#define DMA_STATUS_DESC_READ		0x1
45#define DMA_STATUS_WAIT			0x2
46#define DMA_STATUS_ACCESS		0x3
47#define DMA_STATUS_BITS_PER_CH		2
48#define DMA_STATUS_MASK_BITS		0x3
49#define DMA_STATUS_SHIFT_BITS		16
50#define DMA_STATUS_IRQ(x)		(0x1 << (x))
51#define DMA_STATUS0_ERR(x)		(0x1 << ((x) + 8))
52#define DMA_STATUS2_ERR(x)		(0x1 << (x))
53
54#define DMA_DESC_WIDTH_SHIFT_BITS	12
55#define DMA_DESC_WIDTH_1_BYTE		(0x3 << DMA_DESC_WIDTH_SHIFT_BITS)
56#define DMA_DESC_WIDTH_2_BYTES		(0x2 << DMA_DESC_WIDTH_SHIFT_BITS)
57#define DMA_DESC_WIDTH_4_BYTES		(0x0 << DMA_DESC_WIDTH_SHIFT_BITS)
58#define DMA_DESC_MAX_COUNT_1_BYTE	0x3FF
59#define DMA_DESC_MAX_COUNT_2_BYTES	0x3FF
60#define DMA_DESC_MAX_COUNT_4_BYTES	0x7FF
61#define DMA_DESC_END_WITHOUT_IRQ	0x0
62#define DMA_DESC_END_WITH_IRQ		0x1
63#define DMA_DESC_FOLLOW_WITHOUT_IRQ	0x2
64#define DMA_DESC_FOLLOW_WITH_IRQ	0x3
65
66#define MAX_CHAN_NR			12
67
68#define DMA_MASK_CTL0_MODE	0x33333333
69#define DMA_MASK_CTL2_MODE	0x00003333
70
71static unsigned int init_nr_desc_per_channel = 64;
72module_param(init_nr_desc_per_channel, uint, 0644);
73MODULE_PARM_DESC(init_nr_desc_per_channel,
74		 "initial descriptors per channel (default: 64)");
75
76struct pch_dma_desc_regs {
77	u32	dev_addr;
78	u32	mem_addr;
79	u32	size;
80	u32	next;
81};
82
83struct pch_dma_regs {
84	u32	dma_ctl0;
85	u32	dma_ctl1;
86	u32	dma_ctl2;
87	u32	dma_ctl3;
88	u32	dma_sts0;
89	u32	dma_sts1;
90	u32	dma_sts2;
91	u32	reserved3;
92	struct pch_dma_desc_regs desc[MAX_CHAN_NR];
93};
94
95struct pch_dma_desc {
96	struct pch_dma_desc_regs regs;
97	struct dma_async_tx_descriptor txd;
98	struct list_head	desc_node;
99	struct list_head	tx_list;
100};
101
102struct pch_dma_chan {
103	struct dma_chan		chan;
104	void __iomem *membase;
105	enum dma_transfer_direction dir;
106	struct tasklet_struct	tasklet;
107	unsigned long		err_status;
108
109	spinlock_t		lock;
110
111	struct list_head	active_list;
112	struct list_head	queue;
113	struct list_head	free_list;
114	unsigned int		descs_allocated;
115};
116
117#define PDC_DEV_ADDR	0x00
118#define PDC_MEM_ADDR	0x04
119#define PDC_SIZE	0x08
120#define PDC_NEXT	0x0C
121
122#define channel_readl(pdc, name) \
123	readl((pdc)->membase + PDC_##name)
124#define channel_writel(pdc, name, val) \
125	writel((val), (pdc)->membase + PDC_##name)
126
127struct pch_dma {
128	struct dma_device	dma;
129	void __iomem *membase;
130	struct pci_pool		*pool;
131	struct pch_dma_regs	regs;
132	struct pch_dma_desc_regs ch_regs[MAX_CHAN_NR];
133	struct pch_dma_chan	channels[MAX_CHAN_NR];
134};
135
136#define PCH_DMA_CTL0	0x00
137#define PCH_DMA_CTL1	0x04
138#define PCH_DMA_CTL2	0x08
139#define PCH_DMA_CTL3	0x0C
140#define PCH_DMA_STS0	0x10
141#define PCH_DMA_STS1	0x14
142#define PCH_DMA_STS2	0x18
143
144#define dma_readl(pd, name) \
145	readl((pd)->membase + PCH_DMA_##name)
146#define dma_writel(pd, name, val) \
147	writel((val), (pd)->membase + PCH_DMA_##name)
148
149static inline
150struct pch_dma_desc *to_pd_desc(struct dma_async_tx_descriptor *txd)
151{
152	return container_of(txd, struct pch_dma_desc, txd);
153}
154
155static inline struct pch_dma_chan *to_pd_chan(struct dma_chan *chan)
156{
157	return container_of(chan, struct pch_dma_chan, chan);
158}
159
160static inline struct pch_dma *to_pd(struct dma_device *ddev)
161{
162	return container_of(ddev, struct pch_dma, dma);
163}
164
165static inline struct device *chan2dev(struct dma_chan *chan)
166{
167	return &chan->dev->device;
168}
169
170static inline struct device *chan2parent(struct dma_chan *chan)
171{
172	return chan->dev->device.parent;
173}
174
175static inline
176struct pch_dma_desc *pdc_first_active(struct pch_dma_chan *pd_chan)
177{
178	return list_first_entry(&pd_chan->active_list,
179				struct pch_dma_desc, desc_node);
180}
181
182static inline
183struct pch_dma_desc *pdc_first_queued(struct pch_dma_chan *pd_chan)
184{
185	return list_first_entry(&pd_chan->queue,
186				struct pch_dma_desc, desc_node);
187}
188
189static void pdc_enable_irq(struct dma_chan *chan, int enable)
190{
191	struct pch_dma *pd = to_pd(chan->device);
192	u32 val;
193	int pos;
194
195	if (chan->chan_id < 8)
196		pos = chan->chan_id;
197	else
198		pos = chan->chan_id + 8;
199
200	val = dma_readl(pd, CTL2);
201
202	if (enable)
203		val |= 0x1 << pos;
204	else
205		val &= ~(0x1 << pos);
206
207	dma_writel(pd, CTL2, val);
208
209	dev_dbg(chan2dev(chan), "pdc_enable_irq: chan %d -> %x\n",
210		chan->chan_id, val);
211}
212
213static void pdc_set_dir(struct dma_chan *chan)
214{
215	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
216	struct pch_dma *pd = to_pd(chan->device);
217	u32 val;
218	u32 mask_mode;
219	u32 mask_ctl;
220
221	if (chan->chan_id < 8) {
222		val = dma_readl(pd, CTL0);
223
224		mask_mode = DMA_CTL0_MODE_MASK_BITS <<
225					(DMA_CTL0_BITS_PER_CH * chan->chan_id);
226		mask_ctl = DMA_MASK_CTL0_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
227				       (DMA_CTL0_BITS_PER_CH * chan->chan_id));
228		val &= mask_mode;
229		if (pd_chan->dir == DMA_MEM_TO_DEV)
230			val |= 0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
231				       DMA_CTL0_DIR_SHIFT_BITS);
232		else
233			val &= ~(0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
234					 DMA_CTL0_DIR_SHIFT_BITS));
235
236		val |= mask_ctl;
237		dma_writel(pd, CTL0, val);
238	} else {
239		int ch = chan->chan_id - 8; /* ch8-->0 ch9-->1 ... ch11->3 */
240		val = dma_readl(pd, CTL3);
241
242		mask_mode = DMA_CTL0_MODE_MASK_BITS <<
243						(DMA_CTL0_BITS_PER_CH * ch);
244		mask_ctl = DMA_MASK_CTL2_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
245						 (DMA_CTL0_BITS_PER_CH * ch));
246		val &= mask_mode;
247		if (pd_chan->dir == DMA_MEM_TO_DEV)
248			val |= 0x1 << (DMA_CTL0_BITS_PER_CH * ch +
249				       DMA_CTL0_DIR_SHIFT_BITS);
250		else
251			val &= ~(0x1 << (DMA_CTL0_BITS_PER_CH * ch +
252					 DMA_CTL0_DIR_SHIFT_BITS));
253		val |= mask_ctl;
254		dma_writel(pd, CTL3, val);
255	}
256
257	dev_dbg(chan2dev(chan), "pdc_set_dir: chan %d -> %x\n",
258		chan->chan_id, val);
259}
260
261static void pdc_set_mode(struct dma_chan *chan, u32 mode)
262{
263	struct pch_dma *pd = to_pd(chan->device);
264	u32 val;
265	u32 mask_ctl;
266	u32 mask_dir;
267
268	if (chan->chan_id < 8) {
269		mask_ctl = DMA_MASK_CTL0_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
270			   (DMA_CTL0_BITS_PER_CH * chan->chan_id));
271		mask_dir = 1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +\
272				 DMA_CTL0_DIR_SHIFT_BITS);
273		val = dma_readl(pd, CTL0);
274		val &= mask_dir;
275		val |= mode << (DMA_CTL0_BITS_PER_CH * chan->chan_id);
276		val |= mask_ctl;
277		dma_writel(pd, CTL0, val);
278	} else {
279		int ch = chan->chan_id - 8; /* ch8-->0 ch9-->1 ... ch11->3 */
280		mask_ctl = DMA_MASK_CTL2_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
281						 (DMA_CTL0_BITS_PER_CH * ch));
282		mask_dir = 1 << (DMA_CTL0_BITS_PER_CH * ch +\
283				 DMA_CTL0_DIR_SHIFT_BITS);
284		val = dma_readl(pd, CTL3);
285		val &= mask_dir;
286		val |= mode << (DMA_CTL0_BITS_PER_CH * ch);
287		val |= mask_ctl;
288		dma_writel(pd, CTL3, val);
289	}
290
291	dev_dbg(chan2dev(chan), "pdc_set_mode: chan %d -> %x\n",
292		chan->chan_id, val);
293}
294
295static u32 pdc_get_status0(struct pch_dma_chan *pd_chan)
296{
297	struct pch_dma *pd = to_pd(pd_chan->chan.device);
298	u32 val;
299
300	val = dma_readl(pd, STS0);
301	return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
302			DMA_STATUS_BITS_PER_CH * pd_chan->chan.chan_id));
303}
304
305static u32 pdc_get_status2(struct pch_dma_chan *pd_chan)
306{
307	struct pch_dma *pd = to_pd(pd_chan->chan.device);
308	u32 val;
309
310	val = dma_readl(pd, STS2);
311	return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
312			DMA_STATUS_BITS_PER_CH * (pd_chan->chan.chan_id - 8)));
313}
314
315static bool pdc_is_idle(struct pch_dma_chan *pd_chan)
316{
317	u32 sts;
318
319	if (pd_chan->chan.chan_id < 8)
320		sts = pdc_get_status0(pd_chan);
321	else
322		sts = pdc_get_status2(pd_chan);
323
324
325	if (sts == DMA_STATUS_IDLE)
326		return true;
327	else
328		return false;
329}
330
331static void pdc_dostart(struct pch_dma_chan *pd_chan, struct pch_dma_desc* desc)
332{
333	if (!pdc_is_idle(pd_chan)) {
334		dev_err(chan2dev(&pd_chan->chan),
335			"BUG: Attempt to start non-idle channel\n");
336		return;
337	}
338
339	dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> dev_addr: %x\n",
340		pd_chan->chan.chan_id, desc->regs.dev_addr);
341	dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> mem_addr: %x\n",
342		pd_chan->chan.chan_id, desc->regs.mem_addr);
343	dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> size: %x\n",
344		pd_chan->chan.chan_id, desc->regs.size);
345	dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> next: %x\n",
346		pd_chan->chan.chan_id, desc->regs.next);
347
348	if (list_empty(&desc->tx_list)) {
349		channel_writel(pd_chan, DEV_ADDR, desc->regs.dev_addr);
350		channel_writel(pd_chan, MEM_ADDR, desc->regs.mem_addr);
351		channel_writel(pd_chan, SIZE, desc->regs.size);
352		channel_writel(pd_chan, NEXT, desc->regs.next);
353		pdc_set_mode(&pd_chan->chan, DMA_CTL0_ONESHOT);
354	} else {
355		channel_writel(pd_chan, NEXT, desc->txd.phys);
356		pdc_set_mode(&pd_chan->chan, DMA_CTL0_SG);
357	}
358}
359
360static void pdc_chain_complete(struct pch_dma_chan *pd_chan,
361			       struct pch_dma_desc *desc)
362{
363	struct dma_async_tx_descriptor *txd = &desc->txd;
364	dma_async_tx_callback callback = txd->callback;
365	void *param = txd->callback_param;
366
367	list_splice_init(&desc->tx_list, &pd_chan->free_list);
368	list_move(&desc->desc_node, &pd_chan->free_list);
369
370	if (callback)
371		callback(param);
372}
373
374static void pdc_complete_all(struct pch_dma_chan *pd_chan)
375{
376	struct pch_dma_desc *desc, *_d;
377	LIST_HEAD(list);
378
379	BUG_ON(!pdc_is_idle(pd_chan));
380
381	if (!list_empty(&pd_chan->queue))
382		pdc_dostart(pd_chan, pdc_first_queued(pd_chan));
383
384	list_splice_init(&pd_chan->active_list, &list);
385	list_splice_init(&pd_chan->queue, &pd_chan->active_list);
386
387	list_for_each_entry_safe(desc, _d, &list, desc_node)
388		pdc_chain_complete(pd_chan, desc);
389}
390
391static void pdc_handle_error(struct pch_dma_chan *pd_chan)
392{
393	struct pch_dma_desc *bad_desc;
394
395	bad_desc = pdc_first_active(pd_chan);
396	list_del(&bad_desc->desc_node);
397
398	list_splice_init(&pd_chan->queue, pd_chan->active_list.prev);
399
400	if (!list_empty(&pd_chan->active_list))
401		pdc_dostart(pd_chan, pdc_first_active(pd_chan));
402
403	dev_crit(chan2dev(&pd_chan->chan), "Bad descriptor submitted\n");
404	dev_crit(chan2dev(&pd_chan->chan), "descriptor cookie: %d\n",
405		 bad_desc->txd.cookie);
406
407	pdc_chain_complete(pd_chan, bad_desc);
408}
409
410static void pdc_advance_work(struct pch_dma_chan *pd_chan)
411{
412	if (list_empty(&pd_chan->active_list) ||
413		list_is_singular(&pd_chan->active_list)) {
414		pdc_complete_all(pd_chan);
415	} else {
416		pdc_chain_complete(pd_chan, pdc_first_active(pd_chan));
417		pdc_dostart(pd_chan, pdc_first_active(pd_chan));
418	}
419}
420
421static dma_cookie_t pd_tx_submit(struct dma_async_tx_descriptor *txd)
422{
423	struct pch_dma_desc *desc = to_pd_desc(txd);
424	struct pch_dma_chan *pd_chan = to_pd_chan(txd->chan);
425	dma_cookie_t cookie;
426
427	spin_lock(&pd_chan->lock);
428	cookie = dma_cookie_assign(txd);
429
430	if (list_empty(&pd_chan->active_list)) {
431		list_add_tail(&desc->desc_node, &pd_chan->active_list);
432		pdc_dostart(pd_chan, desc);
433	} else {
434		list_add_tail(&desc->desc_node, &pd_chan->queue);
435	}
436
437	spin_unlock(&pd_chan->lock);
438	return 0;
439}
440
441static struct pch_dma_desc *pdc_alloc_desc(struct dma_chan *chan, gfp_t flags)
442{
443	struct pch_dma_desc *desc = NULL;
444	struct pch_dma *pd = to_pd(chan->device);
445	dma_addr_t addr;
446
447	desc = pci_pool_alloc(pd->pool, flags, &addr);
448	if (desc) {
449		memset(desc, 0, sizeof(struct pch_dma_desc));
450		INIT_LIST_HEAD(&desc->tx_list);
451		dma_async_tx_descriptor_init(&desc->txd, chan);
452		desc->txd.tx_submit = pd_tx_submit;
453		desc->txd.flags = DMA_CTRL_ACK;
454		desc->txd.phys = addr;
455	}
456
457	return desc;
458}
459
460static struct pch_dma_desc *pdc_desc_get(struct pch_dma_chan *pd_chan)
461{
462	struct pch_dma_desc *desc, *_d;
463	struct pch_dma_desc *ret = NULL;
464	int i = 0;
465
466	spin_lock(&pd_chan->lock);
467	list_for_each_entry_safe(desc, _d, &pd_chan->free_list, desc_node) {
468		i++;
469		if (async_tx_test_ack(&desc->txd)) {
470			list_del(&desc->desc_node);
471			ret = desc;
472			break;
473		}
474		dev_dbg(chan2dev(&pd_chan->chan), "desc %p not ACKed\n", desc);
475	}
476	spin_unlock(&pd_chan->lock);
477	dev_dbg(chan2dev(&pd_chan->chan), "scanned %d descriptors\n", i);
478
479	if (!ret) {
480		ret = pdc_alloc_desc(&pd_chan->chan, GFP_ATOMIC);
481		if (ret) {
482			spin_lock(&pd_chan->lock);
483			pd_chan->descs_allocated++;
484			spin_unlock(&pd_chan->lock);
485		} else {
486			dev_err(chan2dev(&pd_chan->chan),
487				"failed to alloc desc\n");
488		}
489	}
490
491	return ret;
492}
493
494static void pdc_desc_put(struct pch_dma_chan *pd_chan,
495			 struct pch_dma_desc *desc)
496{
497	if (desc) {
498		spin_lock(&pd_chan->lock);
499		list_splice_init(&desc->tx_list, &pd_chan->free_list);
500		list_add(&desc->desc_node, &pd_chan->free_list);
501		spin_unlock(&pd_chan->lock);
502	}
503}
504
505static int pd_alloc_chan_resources(struct dma_chan *chan)
506{
507	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
508	struct pch_dma_desc *desc;
509	LIST_HEAD(tmp_list);
510	int i;
511
512	if (!pdc_is_idle(pd_chan)) {
513		dev_dbg(chan2dev(chan), "DMA channel not idle ?\n");
514		return -EIO;
515	}
516
517	if (!list_empty(&pd_chan->free_list))
518		return pd_chan->descs_allocated;
519
520	for (i = 0; i < init_nr_desc_per_channel; i++) {
521		desc = pdc_alloc_desc(chan, GFP_KERNEL);
522
523		if (!desc) {
524			dev_warn(chan2dev(chan),
525				"Only allocated %d initial descriptors\n", i);
526			break;
527		}
528
529		list_add_tail(&desc->desc_node, &tmp_list);
530	}
531
532	spin_lock_irq(&pd_chan->lock);
533	list_splice(&tmp_list, &pd_chan->free_list);
534	pd_chan->descs_allocated = i;
535	dma_cookie_init(chan);
536	spin_unlock_irq(&pd_chan->lock);
537
538	pdc_enable_irq(chan, 1);
539
540	return pd_chan->descs_allocated;
541}
542
543static void pd_free_chan_resources(struct dma_chan *chan)
544{
545	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
546	struct pch_dma *pd = to_pd(chan->device);
547	struct pch_dma_desc *desc, *_d;
548	LIST_HEAD(tmp_list);
549
550	BUG_ON(!pdc_is_idle(pd_chan));
551	BUG_ON(!list_empty(&pd_chan->active_list));
552	BUG_ON(!list_empty(&pd_chan->queue));
553
554	spin_lock_irq(&pd_chan->lock);
555	list_splice_init(&pd_chan->free_list, &tmp_list);
556	pd_chan->descs_allocated = 0;
557	spin_unlock_irq(&pd_chan->lock);
558
559	list_for_each_entry_safe(desc, _d, &tmp_list, desc_node)
560		pci_pool_free(pd->pool, desc, desc->txd.phys);
561
562	pdc_enable_irq(chan, 0);
563}
564
565static enum dma_status pd_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
566				    struct dma_tx_state *txstate)
567{
568	return dma_cookie_status(chan, cookie, txstate);
569}
570
571static void pd_issue_pending(struct dma_chan *chan)
572{
573	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
574
575	if (pdc_is_idle(pd_chan)) {
576		spin_lock(&pd_chan->lock);
577		pdc_advance_work(pd_chan);
578		spin_unlock(&pd_chan->lock);
579	}
580}
581
582static struct dma_async_tx_descriptor *pd_prep_slave_sg(struct dma_chan *chan,
583			struct scatterlist *sgl, unsigned int sg_len,
584			enum dma_transfer_direction direction, unsigned long flags,
585			void *context)
586{
587	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
588	struct pch_dma_slave *pd_slave = chan->private;
589	struct pch_dma_desc *first = NULL;
590	struct pch_dma_desc *prev = NULL;
591	struct pch_dma_desc *desc = NULL;
592	struct scatterlist *sg;
593	dma_addr_t reg;
594	int i;
595
596	if (unlikely(!sg_len)) {
597		dev_info(chan2dev(chan), "prep_slave_sg: length is zero!\n");
598		return NULL;
599	}
600
601	if (direction == DMA_DEV_TO_MEM)
602		reg = pd_slave->rx_reg;
603	else if (direction == DMA_MEM_TO_DEV)
604		reg = pd_slave->tx_reg;
605	else
606		return NULL;
607
608	pd_chan->dir = direction;
609	pdc_set_dir(chan);
610
611	for_each_sg(sgl, sg, sg_len, i) {
612		desc = pdc_desc_get(pd_chan);
613
614		if (!desc)
615			goto err_desc_get;
616
617		desc->regs.dev_addr = reg;
618		desc->regs.mem_addr = sg_dma_address(sg);
619		desc->regs.size = sg_dma_len(sg);
620		desc->regs.next = DMA_DESC_FOLLOW_WITHOUT_IRQ;
621
622		switch (pd_slave->width) {
623		case PCH_DMA_WIDTH_1_BYTE:
624			if (desc->regs.size > DMA_DESC_MAX_COUNT_1_BYTE)
625				goto err_desc_get;
626			desc->regs.size |= DMA_DESC_WIDTH_1_BYTE;
627			break;
628		case PCH_DMA_WIDTH_2_BYTES:
629			if (desc->regs.size > DMA_DESC_MAX_COUNT_2_BYTES)
630				goto err_desc_get;
631			desc->regs.size |= DMA_DESC_WIDTH_2_BYTES;
632			break;
633		case PCH_DMA_WIDTH_4_BYTES:
634			if (desc->regs.size > DMA_DESC_MAX_COUNT_4_BYTES)
635				goto err_desc_get;
636			desc->regs.size |= DMA_DESC_WIDTH_4_BYTES;
637			break;
638		default:
639			goto err_desc_get;
640		}
641
642		if (!first) {
643			first = desc;
644		} else {
645			prev->regs.next |= desc->txd.phys;
646			list_add_tail(&desc->desc_node, &first->tx_list);
647		}
648
649		prev = desc;
650	}
651
652	if (flags & DMA_PREP_INTERRUPT)
653		desc->regs.next = DMA_DESC_END_WITH_IRQ;
654	else
655		desc->regs.next = DMA_DESC_END_WITHOUT_IRQ;
656
657	first->txd.cookie = -EBUSY;
658	desc->txd.flags = flags;
659
660	return &first->txd;
661
662err_desc_get:
663	dev_err(chan2dev(chan), "failed to get desc or wrong parameters\n");
664	pdc_desc_put(pd_chan, first);
665	return NULL;
666}
667
668static int pd_device_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
669			     unsigned long arg)
670{
671	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
672	struct pch_dma_desc *desc, *_d;
673	LIST_HEAD(list);
674
675	if (cmd != DMA_TERMINATE_ALL)
676		return -ENXIO;
677
678	spin_lock_irq(&pd_chan->lock);
679
680	pdc_set_mode(&pd_chan->chan, DMA_CTL0_DISABLE);
681
682	list_splice_init(&pd_chan->active_list, &list);
683	list_splice_init(&pd_chan->queue, &list);
684
685	list_for_each_entry_safe(desc, _d, &list, desc_node)
686		pdc_chain_complete(pd_chan, desc);
687
688	spin_unlock_irq(&pd_chan->lock);
689
690	return 0;
691}
692
693static void pdc_tasklet(unsigned long data)
694{
695	struct pch_dma_chan *pd_chan = (struct pch_dma_chan *)data;
696	unsigned long flags;
697
698	if (!pdc_is_idle(pd_chan)) {
699		dev_err(chan2dev(&pd_chan->chan),
700			"BUG: handle non-idle channel in tasklet\n");
701		return;
702	}
703
704	spin_lock_irqsave(&pd_chan->lock, flags);
705	if (test_and_clear_bit(0, &pd_chan->err_status))
706		pdc_handle_error(pd_chan);
707	else
708		pdc_advance_work(pd_chan);
709	spin_unlock_irqrestore(&pd_chan->lock, flags);
710}
711
712static irqreturn_t pd_irq(int irq, void *devid)
713{
714	struct pch_dma *pd = (struct pch_dma *)devid;
715	struct pch_dma_chan *pd_chan;
716	u32 sts0;
717	u32 sts2;
718	int i;
719	int ret0 = IRQ_NONE;
720	int ret2 = IRQ_NONE;
721
722	sts0 = dma_readl(pd, STS0);
723	sts2 = dma_readl(pd, STS2);
724
725	dev_dbg(pd->dma.dev, "pd_irq sts0: %x\n", sts0);
726
727	for (i = 0; i < pd->dma.chancnt; i++) {
728		pd_chan = &pd->channels[i];
729
730		if (i < 8) {
731			if (sts0 & DMA_STATUS_IRQ(i)) {
732				if (sts0 & DMA_STATUS0_ERR(i))
733					set_bit(0, &pd_chan->err_status);
734
735				tasklet_schedule(&pd_chan->tasklet);
736				ret0 = IRQ_HANDLED;
737			}
738		} else {
739			if (sts2 & DMA_STATUS_IRQ(i - 8)) {
740				if (sts2 & DMA_STATUS2_ERR(i))
741					set_bit(0, &pd_chan->err_status);
742
743				tasklet_schedule(&pd_chan->tasklet);
744				ret2 = IRQ_HANDLED;
745			}
746		}
747	}
748
749	/* clear interrupt bits in status register */
750	if (ret0)
751		dma_writel(pd, STS0, sts0);
752	if (ret2)
753		dma_writel(pd, STS2, sts2);
754
755	return ret0 | ret2;
756}
757
758#ifdef	CONFIG_PM
759static void pch_dma_save_regs(struct pch_dma *pd)
760{
761	struct pch_dma_chan *pd_chan;
762	struct dma_chan *chan, *_c;
763	int i = 0;
764
765	pd->regs.dma_ctl0 = dma_readl(pd, CTL0);
766	pd->regs.dma_ctl1 = dma_readl(pd, CTL1);
767	pd->regs.dma_ctl2 = dma_readl(pd, CTL2);
768	pd->regs.dma_ctl3 = dma_readl(pd, CTL3);
769
770	list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
771		pd_chan = to_pd_chan(chan);
772
773		pd->ch_regs[i].dev_addr = channel_readl(pd_chan, DEV_ADDR);
774		pd->ch_regs[i].mem_addr = channel_readl(pd_chan, MEM_ADDR);
775		pd->ch_regs[i].size = channel_readl(pd_chan, SIZE);
776		pd->ch_regs[i].next = channel_readl(pd_chan, NEXT);
777
778		i++;
779	}
780}
781
782static void pch_dma_restore_regs(struct pch_dma *pd)
783{
784	struct pch_dma_chan *pd_chan;
785	struct dma_chan *chan, *_c;
786	int i = 0;
787
788	dma_writel(pd, CTL0, pd->regs.dma_ctl0);
789	dma_writel(pd, CTL1, pd->regs.dma_ctl1);
790	dma_writel(pd, CTL2, pd->regs.dma_ctl2);
791	dma_writel(pd, CTL3, pd->regs.dma_ctl3);
792
793	list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
794		pd_chan = to_pd_chan(chan);
795
796		channel_writel(pd_chan, DEV_ADDR, pd->ch_regs[i].dev_addr);
797		channel_writel(pd_chan, MEM_ADDR, pd->ch_regs[i].mem_addr);
798		channel_writel(pd_chan, SIZE, pd->ch_regs[i].size);
799		channel_writel(pd_chan, NEXT, pd->ch_regs[i].next);
800
801		i++;
802	}
803}
804
805static int pch_dma_suspend(struct pci_dev *pdev, pm_message_t state)
806{
807	struct pch_dma *pd = pci_get_drvdata(pdev);
808
809	if (pd)
810		pch_dma_save_regs(pd);
811
812	pci_save_state(pdev);
813	pci_disable_device(pdev);
814	pci_set_power_state(pdev, pci_choose_state(pdev, state));
815
816	return 0;
817}
818
819static int pch_dma_resume(struct pci_dev *pdev)
820{
821	struct pch_dma *pd = pci_get_drvdata(pdev);
822	int err;
823
824	pci_set_power_state(pdev, PCI_D0);
825	pci_restore_state(pdev);
826
827	err = pci_enable_device(pdev);
828	if (err) {
829		dev_dbg(&pdev->dev, "failed to enable device\n");
830		return err;
831	}
832
833	if (pd)
834		pch_dma_restore_regs(pd);
835
836	return 0;
837}
838#endif
839
840static int pch_dma_probe(struct pci_dev *pdev,
841				   const struct pci_device_id *id)
842{
843	struct pch_dma *pd;
844	struct pch_dma_regs *regs;
845	unsigned int nr_channels;
846	int err;
847	int i;
848
849	nr_channels = id->driver_data;
850	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
851	if (!pd)
852		return -ENOMEM;
853
854	pci_set_drvdata(pdev, pd);
855
856	err = pci_enable_device(pdev);
857	if (err) {
858		dev_err(&pdev->dev, "Cannot enable PCI device\n");
859		goto err_free_mem;
860	}
861
862	if (!(pci_resource_flags(pdev, 1) & IORESOURCE_MEM)) {
863		dev_err(&pdev->dev, "Cannot find proper base address\n");
864		err = -ENODEV;
865		goto err_disable_pdev;
866	}
867
868	err = pci_request_regions(pdev, DRV_NAME);
869	if (err) {
870		dev_err(&pdev->dev, "Cannot obtain PCI resources\n");
871		goto err_disable_pdev;
872	}
873
874	err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
875	if (err) {
876		dev_err(&pdev->dev, "Cannot set proper DMA config\n");
877		goto err_free_res;
878	}
879
880	regs = pd->membase = pci_iomap(pdev, 1, 0);
881	if (!pd->membase) {
882		dev_err(&pdev->dev, "Cannot map MMIO registers\n");
883		err = -ENOMEM;
884		goto err_free_res;
885	}
886
887	pci_set_master(pdev);
888
889	err = request_irq(pdev->irq, pd_irq, IRQF_SHARED, DRV_NAME, pd);
890	if (err) {
891		dev_err(&pdev->dev, "Failed to request IRQ\n");
892		goto err_iounmap;
893	}
894
895	pd->pool = pci_pool_create("pch_dma_desc_pool", pdev,
896				   sizeof(struct pch_dma_desc), 4, 0);
897	if (!pd->pool) {
898		dev_err(&pdev->dev, "Failed to alloc DMA descriptors\n");
899		err = -ENOMEM;
900		goto err_free_irq;
901	}
902
903	pd->dma.dev = &pdev->dev;
904
905	INIT_LIST_HEAD(&pd->dma.channels);
906
907	for (i = 0; i < nr_channels; i++) {
908		struct pch_dma_chan *pd_chan = &pd->channels[i];
909
910		pd_chan->chan.device = &pd->dma;
911		dma_cookie_init(&pd_chan->chan);
912
913		pd_chan->membase = &regs->desc[i];
914
915		spin_lock_init(&pd_chan->lock);
916
917		INIT_LIST_HEAD(&pd_chan->active_list);
918		INIT_LIST_HEAD(&pd_chan->queue);
919		INIT_LIST_HEAD(&pd_chan->free_list);
920
921		tasklet_init(&pd_chan->tasklet, pdc_tasklet,
922			     (unsigned long)pd_chan);
923		list_add_tail(&pd_chan->chan.device_node, &pd->dma.channels);
924	}
925
926	dma_cap_zero(pd->dma.cap_mask);
927	dma_cap_set(DMA_PRIVATE, pd->dma.cap_mask);
928	dma_cap_set(DMA_SLAVE, pd->dma.cap_mask);
929
930	pd->dma.device_alloc_chan_resources = pd_alloc_chan_resources;
931	pd->dma.device_free_chan_resources = pd_free_chan_resources;
932	pd->dma.device_tx_status = pd_tx_status;
933	pd->dma.device_issue_pending = pd_issue_pending;
934	pd->dma.device_prep_slave_sg = pd_prep_slave_sg;
935	pd->dma.device_control = pd_device_control;
936
937	err = dma_async_device_register(&pd->dma);
938	if (err) {
939		dev_err(&pdev->dev, "Failed to register DMA device\n");
940		goto err_free_pool;
941	}
942
943	return 0;
944
945err_free_pool:
946	pci_pool_destroy(pd->pool);
947err_free_irq:
948	free_irq(pdev->irq, pd);
949err_iounmap:
950	pci_iounmap(pdev, pd->membase);
951err_free_res:
952	pci_release_regions(pdev);
953err_disable_pdev:
954	pci_disable_device(pdev);
955err_free_mem:
956	return err;
957}
958
959static void pch_dma_remove(struct pci_dev *pdev)
960{
961	struct pch_dma *pd = pci_get_drvdata(pdev);
962	struct pch_dma_chan *pd_chan;
963	struct dma_chan *chan, *_c;
964
965	if (pd) {
966		dma_async_device_unregister(&pd->dma);
967
968		free_irq(pdev->irq, pd);
969
970		list_for_each_entry_safe(chan, _c, &pd->dma.channels,
971					 device_node) {
972			pd_chan = to_pd_chan(chan);
973
974			tasklet_kill(&pd_chan->tasklet);
975		}
976
977		pci_pool_destroy(pd->pool);
978		pci_iounmap(pdev, pd->membase);
979		pci_release_regions(pdev);
980		pci_disable_device(pdev);
981		kfree(pd);
982	}
983}
984
985/* PCI Device ID of DMA device */
986#define PCI_VENDOR_ID_ROHM             0x10DB
987#define PCI_DEVICE_ID_EG20T_PCH_DMA_8CH        0x8810
988#define PCI_DEVICE_ID_EG20T_PCH_DMA_4CH        0x8815
989#define PCI_DEVICE_ID_ML7213_DMA1_8CH	0x8026
990#define PCI_DEVICE_ID_ML7213_DMA2_8CH	0x802B
991#define PCI_DEVICE_ID_ML7213_DMA3_4CH	0x8034
992#define PCI_DEVICE_ID_ML7213_DMA4_12CH	0x8032
993#define PCI_DEVICE_ID_ML7223_DMA1_4CH	0x800B
994#define PCI_DEVICE_ID_ML7223_DMA2_4CH	0x800E
995#define PCI_DEVICE_ID_ML7223_DMA3_4CH	0x8017
996#define PCI_DEVICE_ID_ML7223_DMA4_4CH	0x803B
997#define PCI_DEVICE_ID_ML7831_DMA1_8CH	0x8810
998#define PCI_DEVICE_ID_ML7831_DMA2_4CH	0x8815
999
1000const struct pci_device_id pch_dma_id_table[] = {
1001	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_8CH), 8 },
1002	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_4CH), 4 },
1003	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA1_8CH), 8}, /* UART Video */
1004	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA2_8CH), 8}, /* PCMIF SPI */
1005	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA3_4CH), 4}, /* FPGA */
1006	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA4_12CH), 12}, /* I2S */
1007	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA1_4CH), 4}, /* UART */
1008	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA2_4CH), 4}, /* Video SPI */
1009	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA3_4CH), 4}, /* Security */
1010	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA4_4CH), 4}, /* FPGA */
1011	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_DMA1_8CH), 8}, /* UART */
1012	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_DMA2_4CH), 4}, /* SPI */
1013	{ 0, },
1014};
1015
1016static struct pci_driver pch_dma_driver = {
1017	.name		= DRV_NAME,
1018	.id_table	= pch_dma_id_table,
1019	.probe		= pch_dma_probe,
1020	.remove		= pch_dma_remove,
1021#ifdef CONFIG_PM
1022	.suspend	= pch_dma_suspend,
1023	.resume		= pch_dma_resume,
1024#endif
1025};
1026
1027module_pci_driver(pch_dma_driver);
1028
1029MODULE_DESCRIPTION("Intel EG20T PCH / LAPIS Semicon ML7213/ML7223/ML7831 IOH "
1030		   "DMA controller driver");
1031MODULE_AUTHOR("Yong Wang <yong.y.wang@intel.com>");
1032MODULE_LICENSE("GPL v2");
1033MODULE_DEVICE_TABLE(pci, pch_dma_id_table);
1034