1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * OMAP DMAengine support
4 */
5#include <linux/cpu_pm.h>
6#include <linux/delay.h>
7#include <linux/dmaengine.h>
8#include <linux/dma-mapping.h>
9#include <linux/dmapool.h>
10#include <linux/err.h>
11#include <linux/init.h>
12#include <linux/interrupt.h>
13#include <linux/list.h>
14#include <linux/module.h>
15#include <linux/omap-dma.h>
16#include <linux/platform_device.h>
17#include <linux/slab.h>
18#include <linux/spinlock.h>
19#include <linux/of_dma.h>
20#include <linux/of_device.h>
21
22#include "../virt-dma.h"
23
24#define OMAP_SDMA_REQUESTS	127
25#define OMAP_SDMA_CHANNELS	32
26
27struct omap_dma_config {
28	int lch_end;
29	unsigned int rw_priority:1;
30	unsigned int needs_busy_check:1;
31	unsigned int may_lose_context:1;
32	unsigned int needs_lch_clear:1;
33};
34
35struct omap_dma_context {
36	u32 irqenable_l0;
37	u32 irqenable_l1;
38	u32 ocp_sysconfig;
39	u32 gcr;
40};
41
42struct omap_dmadev {
43	struct dma_device ddev;
44	spinlock_t lock;
45	void __iomem *base;
46	const struct omap_dma_reg *reg_map;
47	struct omap_system_dma_plat_info *plat;
48	const struct omap_dma_config *cfg;
49	struct notifier_block nb;
50	struct omap_dma_context context;
51	int lch_count;
52	DECLARE_BITMAP(lch_bitmap, OMAP_SDMA_CHANNELS);
53	struct mutex lch_lock;		/* for assigning logical channels */
54	bool legacy;
55	bool ll123_supported;
56	struct dma_pool *desc_pool;
57	unsigned dma_requests;
58	spinlock_t irq_lock;
59	uint32_t irq_enable_mask;
60	struct omap_chan **lch_map;
61};
62
63struct omap_chan {
64	struct virt_dma_chan vc;
65	void __iomem *channel_base;
66	const struct omap_dma_reg *reg_map;
67	uint32_t ccr;
68
69	struct dma_slave_config	cfg;
70	unsigned dma_sig;
71	bool cyclic;
72	bool paused;
73	bool running;
74
75	int dma_ch;
76	struct omap_desc *desc;
77	unsigned sgidx;
78};
79
80#define DESC_NXT_SV_REFRESH	(0x1 << 24)
81#define DESC_NXT_SV_REUSE	(0x2 << 24)
82#define DESC_NXT_DV_REFRESH	(0x1 << 26)
83#define DESC_NXT_DV_REUSE	(0x2 << 26)
84#define DESC_NTYPE_TYPE2	(0x2 << 29)
85
86/* Type 2 descriptor with Source or Destination address update */
87struct omap_type2_desc {
88	uint32_t next_desc;
89	uint32_t en;
90	uint32_t addr; /* src or dst */
91	uint16_t fn;
92	uint16_t cicr;
93	int16_t cdei;
94	int16_t csei;
95	int32_t cdfi;
96	int32_t csfi;
97} __packed;
98
99struct omap_sg {
100	dma_addr_t addr;
101	uint32_t en;		/* number of elements (24-bit) */
102	uint32_t fn;		/* number of frames (16-bit) */
103	int32_t fi;		/* for double indexing */
104	int16_t ei;		/* for double indexing */
105
106	/* Linked list */
107	struct omap_type2_desc *t2_desc;
108	dma_addr_t t2_desc_paddr;
109};
110
111struct omap_desc {
112	struct virt_dma_desc vd;
113	bool using_ll;
114	enum dma_transfer_direction dir;
115	dma_addr_t dev_addr;
116	bool polled;
117
118	int32_t fi;		/* for OMAP_DMA_SYNC_PACKET / double indexing */
119	int16_t ei;		/* for double indexing */
120	uint8_t es;		/* CSDP_DATA_TYPE_xxx */
121	uint32_t ccr;		/* CCR value */
122	uint16_t clnk_ctrl;	/* CLNK_CTRL value */
123	uint16_t cicr;		/* CICR value */
124	uint32_t csdp;		/* CSDP value */
125
126	unsigned sglen;
127	struct omap_sg sg[];
128};
129
130enum {
131	CAPS_0_SUPPORT_LL123	= BIT(20),	/* Linked List type1/2/3 */
132	CAPS_0_SUPPORT_LL4	= BIT(21),	/* Linked List type4 */
133
134	CCR_FS			= BIT(5),
135	CCR_READ_PRIORITY	= BIT(6),
136	CCR_ENABLE		= BIT(7),
137	CCR_AUTO_INIT		= BIT(8),	/* OMAP1 only */
138	CCR_REPEAT		= BIT(9),	/* OMAP1 only */
139	CCR_OMAP31_DISABLE	= BIT(10),	/* OMAP1 only */
140	CCR_SUSPEND_SENSITIVE	= BIT(8),	/* OMAP2+ only */
141	CCR_RD_ACTIVE		= BIT(9),	/* OMAP2+ only */
142	CCR_WR_ACTIVE		= BIT(10),	/* OMAP2+ only */
143	CCR_SRC_AMODE_CONSTANT	= 0 << 12,
144	CCR_SRC_AMODE_POSTINC	= 1 << 12,
145	CCR_SRC_AMODE_SGLIDX	= 2 << 12,
146	CCR_SRC_AMODE_DBLIDX	= 3 << 12,
147	CCR_DST_AMODE_CONSTANT	= 0 << 14,
148	CCR_DST_AMODE_POSTINC	= 1 << 14,
149	CCR_DST_AMODE_SGLIDX	= 2 << 14,
150	CCR_DST_AMODE_DBLIDX	= 3 << 14,
151	CCR_CONSTANT_FILL	= BIT(16),
152	CCR_TRANSPARENT_COPY	= BIT(17),
153	CCR_BS			= BIT(18),
154	CCR_SUPERVISOR		= BIT(22),
155	CCR_PREFETCH		= BIT(23),
156	CCR_TRIGGER_SRC		= BIT(24),
157	CCR_BUFFERING_DISABLE	= BIT(25),
158	CCR_WRITE_PRIORITY	= BIT(26),
159	CCR_SYNC_ELEMENT	= 0,
160	CCR_SYNC_FRAME		= CCR_FS,
161	CCR_SYNC_BLOCK		= CCR_BS,
162	CCR_SYNC_PACKET		= CCR_BS | CCR_FS,
163
164	CSDP_DATA_TYPE_8	= 0,
165	CSDP_DATA_TYPE_16	= 1,
166	CSDP_DATA_TYPE_32	= 2,
167	CSDP_SRC_PORT_EMIFF	= 0 << 2, /* OMAP1 only */
168	CSDP_SRC_PORT_EMIFS	= 1 << 2, /* OMAP1 only */
169	CSDP_SRC_PORT_OCP_T1	= 2 << 2, /* OMAP1 only */
170	CSDP_SRC_PORT_TIPB	= 3 << 2, /* OMAP1 only */
171	CSDP_SRC_PORT_OCP_T2	= 4 << 2, /* OMAP1 only */
172	CSDP_SRC_PORT_MPUI	= 5 << 2, /* OMAP1 only */
173	CSDP_SRC_PACKED		= BIT(6),
174	CSDP_SRC_BURST_1	= 0 << 7,
175	CSDP_SRC_BURST_16	= 1 << 7,
176	CSDP_SRC_BURST_32	= 2 << 7,
177	CSDP_SRC_BURST_64	= 3 << 7,
178	CSDP_DST_PORT_EMIFF	= 0 << 9, /* OMAP1 only */
179	CSDP_DST_PORT_EMIFS	= 1 << 9, /* OMAP1 only */
180	CSDP_DST_PORT_OCP_T1	= 2 << 9, /* OMAP1 only */
181	CSDP_DST_PORT_TIPB	= 3 << 9, /* OMAP1 only */
182	CSDP_DST_PORT_OCP_T2	= 4 << 9, /* OMAP1 only */
183	CSDP_DST_PORT_MPUI	= 5 << 9, /* OMAP1 only */
184	CSDP_DST_PACKED		= BIT(13),
185	CSDP_DST_BURST_1	= 0 << 14,
186	CSDP_DST_BURST_16	= 1 << 14,
187	CSDP_DST_BURST_32	= 2 << 14,
188	CSDP_DST_BURST_64	= 3 << 14,
189	CSDP_WRITE_NON_POSTED	= 0 << 16,
190	CSDP_WRITE_POSTED	= 1 << 16,
191	CSDP_WRITE_LAST_NON_POSTED = 2 << 16,
192
193	CICR_TOUT_IE		= BIT(0),	/* OMAP1 only */
194	CICR_DROP_IE		= BIT(1),
195	CICR_HALF_IE		= BIT(2),
196	CICR_FRAME_IE		= BIT(3),
197	CICR_LAST_IE		= BIT(4),
198	CICR_BLOCK_IE		= BIT(5),
199	CICR_PKT_IE		= BIT(7),	/* OMAP2+ only */
200	CICR_TRANS_ERR_IE	= BIT(8),	/* OMAP2+ only */
201	CICR_SUPERVISOR_ERR_IE	= BIT(10),	/* OMAP2+ only */
202	CICR_MISALIGNED_ERR_IE	= BIT(11),	/* OMAP2+ only */
203	CICR_DRAIN_IE		= BIT(12),	/* OMAP2+ only */
204	CICR_SUPER_BLOCK_IE	= BIT(14),	/* OMAP2+ only */
205
206	CLNK_CTRL_ENABLE_LNK	= BIT(15),
207
208	CDP_DST_VALID_INC	= 0 << 0,
209	CDP_DST_VALID_RELOAD	= 1 << 0,
210	CDP_DST_VALID_REUSE	= 2 << 0,
211	CDP_SRC_VALID_INC	= 0 << 2,
212	CDP_SRC_VALID_RELOAD	= 1 << 2,
213	CDP_SRC_VALID_REUSE	= 2 << 2,
214	CDP_NTYPE_TYPE1		= 1 << 4,
215	CDP_NTYPE_TYPE2		= 2 << 4,
216	CDP_NTYPE_TYPE3		= 3 << 4,
217	CDP_TMODE_NORMAL	= 0 << 8,
218	CDP_TMODE_LLIST		= 1 << 8,
219	CDP_FAST		= BIT(10),
220};
221
222static const unsigned es_bytes[] = {
223	[CSDP_DATA_TYPE_8] = 1,
224	[CSDP_DATA_TYPE_16] = 2,
225	[CSDP_DATA_TYPE_32] = 4,
226};
227
228static bool omap_dma_filter_fn(struct dma_chan *chan, void *param);
229static struct of_dma_filter_info omap_dma_info = {
230	.filter_fn = omap_dma_filter_fn,
231};
232
233static inline struct omap_dmadev *to_omap_dma_dev(struct dma_device *d)
234{
235	return container_of(d, struct omap_dmadev, ddev);
236}
237
238static inline struct omap_chan *to_omap_dma_chan(struct dma_chan *c)
239{
240	return container_of(c, struct omap_chan, vc.chan);
241}
242
243static inline struct omap_desc *to_omap_dma_desc(struct dma_async_tx_descriptor *t)
244{
245	return container_of(t, struct omap_desc, vd.tx);
246}
247
248static void omap_dma_desc_free(struct virt_dma_desc *vd)
249{
250	struct omap_desc *d = to_omap_dma_desc(&vd->tx);
251
252	if (d->using_ll) {
253		struct omap_dmadev *od = to_omap_dma_dev(vd->tx.chan->device);
254		int i;
255
256		for (i = 0; i < d->sglen; i++) {
257			if (d->sg[i].t2_desc)
258				dma_pool_free(od->desc_pool, d->sg[i].t2_desc,
259					      d->sg[i].t2_desc_paddr);
260		}
261	}
262
263	kfree(d);
264}
265
266static void omap_dma_fill_type2_desc(struct omap_desc *d, int idx,
267				     enum dma_transfer_direction dir, bool last)
268{
269	struct omap_sg *sg = &d->sg[idx];
270	struct omap_type2_desc *t2_desc = sg->t2_desc;
271
272	if (idx)
273		d->sg[idx - 1].t2_desc->next_desc = sg->t2_desc_paddr;
274	if (last)
275		t2_desc->next_desc = 0xfffffffc;
276
277	t2_desc->en = sg->en;
278	t2_desc->addr = sg->addr;
279	t2_desc->fn = sg->fn & 0xffff;
280	t2_desc->cicr = d->cicr;
281	if (!last)
282		t2_desc->cicr &= ~CICR_BLOCK_IE;
283
284	switch (dir) {
285	case DMA_DEV_TO_MEM:
286		t2_desc->cdei = sg->ei;
287		t2_desc->csei = d->ei;
288		t2_desc->cdfi = sg->fi;
289		t2_desc->csfi = d->fi;
290
291		t2_desc->en |= DESC_NXT_DV_REFRESH;
292		t2_desc->en |= DESC_NXT_SV_REUSE;
293		break;
294	case DMA_MEM_TO_DEV:
295		t2_desc->cdei = d->ei;
296		t2_desc->csei = sg->ei;
297		t2_desc->cdfi = d->fi;
298		t2_desc->csfi = sg->fi;
299
300		t2_desc->en |= DESC_NXT_SV_REFRESH;
301		t2_desc->en |= DESC_NXT_DV_REUSE;
302		break;
303	default:
304		return;
305	}
306
307	t2_desc->en |= DESC_NTYPE_TYPE2;
308}
309
310static void omap_dma_write(uint32_t val, unsigned type, void __iomem *addr)
311{
312	switch (type) {
313	case OMAP_DMA_REG_16BIT:
314		writew_relaxed(val, addr);
315		break;
316	case OMAP_DMA_REG_2X16BIT:
317		writew_relaxed(val, addr);
318		writew_relaxed(val >> 16, addr + 2);
319		break;
320	case OMAP_DMA_REG_32BIT:
321		writel_relaxed(val, addr);
322		break;
323	default:
324		WARN_ON(1);
325	}
326}
327
328static unsigned omap_dma_read(unsigned type, void __iomem *addr)
329{
330	unsigned val;
331
332	switch (type) {
333	case OMAP_DMA_REG_16BIT:
334		val = readw_relaxed(addr);
335		break;
336	case OMAP_DMA_REG_2X16BIT:
337		val = readw_relaxed(addr);
338		val |= readw_relaxed(addr + 2) << 16;
339		break;
340	case OMAP_DMA_REG_32BIT:
341		val = readl_relaxed(addr);
342		break;
343	default:
344		WARN_ON(1);
345		val = 0;
346	}
347
348	return val;
349}
350
351static void omap_dma_glbl_write(struct omap_dmadev *od, unsigned reg, unsigned val)
352{
353	const struct omap_dma_reg *r = od->reg_map + reg;
354
355	WARN_ON(r->stride);
356
357	omap_dma_write(val, r->type, od->base + r->offset);
358}
359
360static unsigned omap_dma_glbl_read(struct omap_dmadev *od, unsigned reg)
361{
362	const struct omap_dma_reg *r = od->reg_map + reg;
363
364	WARN_ON(r->stride);
365
366	return omap_dma_read(r->type, od->base + r->offset);
367}
368
369static void omap_dma_chan_write(struct omap_chan *c, unsigned reg, unsigned val)
370{
371	const struct omap_dma_reg *r = c->reg_map + reg;
372
373	omap_dma_write(val, r->type, c->channel_base + r->offset);
374}
375
376static unsigned omap_dma_chan_read(struct omap_chan *c, unsigned reg)
377{
378	const struct omap_dma_reg *r = c->reg_map + reg;
379
380	return omap_dma_read(r->type, c->channel_base + r->offset);
381}
382
383static void omap_dma_clear_csr(struct omap_chan *c)
384{
385	if (dma_omap1())
386		omap_dma_chan_read(c, CSR);
387	else
388		omap_dma_chan_write(c, CSR, ~0);
389}
390
391static unsigned omap_dma_get_csr(struct omap_chan *c)
392{
393	unsigned val = omap_dma_chan_read(c, CSR);
394
395	if (!dma_omap1())
396		omap_dma_chan_write(c, CSR, val);
397
398	return val;
399}
400
401static void omap_dma_clear_lch(struct omap_dmadev *od, int lch)
402{
403	struct omap_chan *c;
404	int i;
405
406	c = od->lch_map[lch];
407	if (!c)
408		return;
409
410	for (i = CSDP; i <= od->cfg->lch_end; i++)
411		omap_dma_chan_write(c, i, 0);
412}
413
414static void omap_dma_assign(struct omap_dmadev *od, struct omap_chan *c,
415	unsigned lch)
416{
417	c->channel_base = od->base + od->plat->channel_stride * lch;
418
419	od->lch_map[lch] = c;
420}
421
422static void omap_dma_start(struct omap_chan *c, struct omap_desc *d)
423{
424	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
425	uint16_t cicr = d->cicr;
426
427	if (__dma_omap15xx(od->plat->dma_attr))
428		omap_dma_chan_write(c, CPC, 0);
429	else
430		omap_dma_chan_write(c, CDAC, 0);
431
432	omap_dma_clear_csr(c);
433
434	if (d->using_ll) {
435		uint32_t cdp = CDP_TMODE_LLIST | CDP_NTYPE_TYPE2 | CDP_FAST;
436
437		if (d->dir == DMA_DEV_TO_MEM)
438			cdp |= (CDP_DST_VALID_RELOAD | CDP_SRC_VALID_REUSE);
439		else
440			cdp |= (CDP_DST_VALID_REUSE | CDP_SRC_VALID_RELOAD);
441		omap_dma_chan_write(c, CDP, cdp);
442
443		omap_dma_chan_write(c, CNDP, d->sg[0].t2_desc_paddr);
444		omap_dma_chan_write(c, CCDN, 0);
445		omap_dma_chan_write(c, CCFN, 0xffff);
446		omap_dma_chan_write(c, CCEN, 0xffffff);
447
448		cicr &= ~CICR_BLOCK_IE;
449	} else if (od->ll123_supported) {
450		omap_dma_chan_write(c, CDP, 0);
451	}
452
453	/* Enable interrupts */
454	omap_dma_chan_write(c, CICR, cicr);
455
456	/* Enable channel */
457	omap_dma_chan_write(c, CCR, d->ccr | CCR_ENABLE);
458
459	c->running = true;
460}
461
462static void omap_dma_drain_chan(struct omap_chan *c)
463{
464	int i;
465	u32 val;
466
467	/* Wait for sDMA FIFO to drain */
468	for (i = 0; ; i++) {
469		val = omap_dma_chan_read(c, CCR);
470		if (!(val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE)))
471			break;
472
473		if (i > 100)
474			break;
475
476		udelay(5);
477	}
478
479	if (val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE))
480		dev_err(c->vc.chan.device->dev,
481			"DMA drain did not complete on lch %d\n",
482			c->dma_ch);
483}
484
485static int omap_dma_stop(struct omap_chan *c)
486{
487	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
488	uint32_t val;
489
490	/* disable irq */
491	omap_dma_chan_write(c, CICR, 0);
492
493	omap_dma_clear_csr(c);
494
495	val = omap_dma_chan_read(c, CCR);
496	if (od->plat->errata & DMA_ERRATA_i541 && val & CCR_TRIGGER_SRC) {
497		uint32_t sysconfig;
498
499		sysconfig = omap_dma_glbl_read(od, OCP_SYSCONFIG);
500		val = sysconfig & ~DMA_SYSCONFIG_MIDLEMODE_MASK;
501		val |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
502		omap_dma_glbl_write(od, OCP_SYSCONFIG, val);
503
504		val = omap_dma_chan_read(c, CCR);
505		val &= ~CCR_ENABLE;
506		omap_dma_chan_write(c, CCR, val);
507
508		if (!(c->ccr & CCR_BUFFERING_DISABLE))
509			omap_dma_drain_chan(c);
510
511		omap_dma_glbl_write(od, OCP_SYSCONFIG, sysconfig);
512	} else {
513		if (!(val & CCR_ENABLE))
514			return -EINVAL;
515
516		val &= ~CCR_ENABLE;
517		omap_dma_chan_write(c, CCR, val);
518
519		if (!(c->ccr & CCR_BUFFERING_DISABLE))
520			omap_dma_drain_chan(c);
521	}
522
523	mb();
524
525	if (!__dma_omap15xx(od->plat->dma_attr) && c->cyclic) {
526		val = omap_dma_chan_read(c, CLNK_CTRL);
527
528		if (dma_omap1())
529			val |= 1 << 14; /* set the STOP_LNK bit */
530		else
531			val &= ~CLNK_CTRL_ENABLE_LNK;
532
533		omap_dma_chan_write(c, CLNK_CTRL, val);
534	}
535	c->running = false;
536	return 0;
537}
538
539static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d)
540{
541	struct omap_sg *sg = d->sg + c->sgidx;
542	unsigned cxsa, cxei, cxfi;
543
544	if (d->dir == DMA_DEV_TO_MEM || d->dir == DMA_MEM_TO_MEM) {
545		cxsa = CDSA;
546		cxei = CDEI;
547		cxfi = CDFI;
548	} else {
549		cxsa = CSSA;
550		cxei = CSEI;
551		cxfi = CSFI;
552	}
553
554	omap_dma_chan_write(c, cxsa, sg->addr);
555	omap_dma_chan_write(c, cxei, sg->ei);
556	omap_dma_chan_write(c, cxfi, sg->fi);
557	omap_dma_chan_write(c, CEN, sg->en);
558	omap_dma_chan_write(c, CFN, sg->fn);
559
560	omap_dma_start(c, d);
561	c->sgidx++;
562}
563
564static void omap_dma_start_desc(struct omap_chan *c)
565{
566	struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
567	struct omap_desc *d;
568	unsigned cxsa, cxei, cxfi;
569
570	if (!vd) {
571		c->desc = NULL;
572		return;
573	}
574
575	list_del(&vd->node);
576
577	c->desc = d = to_omap_dma_desc(&vd->tx);
578	c->sgidx = 0;
579
580	/*
581	 * This provides the necessary barrier to ensure data held in
582	 * DMA coherent memory is visible to the DMA engine prior to
583	 * the transfer starting.
584	 */
585	mb();
586
587	omap_dma_chan_write(c, CCR, d->ccr);
588	if (dma_omap1())
589		omap_dma_chan_write(c, CCR2, d->ccr >> 16);
590
591	if (d->dir == DMA_DEV_TO_MEM || d->dir == DMA_MEM_TO_MEM) {
592		cxsa = CSSA;
593		cxei = CSEI;
594		cxfi = CSFI;
595	} else {
596		cxsa = CDSA;
597		cxei = CDEI;
598		cxfi = CDFI;
599	}
600
601	omap_dma_chan_write(c, cxsa, d->dev_addr);
602	omap_dma_chan_write(c, cxei, d->ei);
603	omap_dma_chan_write(c, cxfi, d->fi);
604	omap_dma_chan_write(c, CSDP, d->csdp);
605	omap_dma_chan_write(c, CLNK_CTRL, d->clnk_ctrl);
606
607	omap_dma_start_sg(c, d);
608}
609
610static void omap_dma_callback(int ch, u16 status, void *data)
611{
612	struct omap_chan *c = data;
613	struct omap_desc *d;
614	unsigned long flags;
615
616	spin_lock_irqsave(&c->vc.lock, flags);
617	d = c->desc;
618	if (d) {
619		if (c->cyclic) {
620			vchan_cyclic_callback(&d->vd);
621		} else if (d->using_ll || c->sgidx == d->sglen) {
622			omap_dma_start_desc(c);
623			vchan_cookie_complete(&d->vd);
624		} else {
625			omap_dma_start_sg(c, d);
626		}
627	}
628	spin_unlock_irqrestore(&c->vc.lock, flags);
629}
630
631static irqreturn_t omap_dma_irq(int irq, void *devid)
632{
633	struct omap_dmadev *od = devid;
634	unsigned status, channel;
635
636	spin_lock(&od->irq_lock);
637
638	status = omap_dma_glbl_read(od, IRQSTATUS_L1);
639	status &= od->irq_enable_mask;
640	if (status == 0) {
641		spin_unlock(&od->irq_lock);
642		return IRQ_NONE;
643	}
644
645	while ((channel = ffs(status)) != 0) {
646		unsigned mask, csr;
647		struct omap_chan *c;
648
649		channel -= 1;
650		mask = BIT(channel);
651		status &= ~mask;
652
653		c = od->lch_map[channel];
654		if (c == NULL) {
655			/* This should never happen */
656			dev_err(od->ddev.dev, "invalid channel %u\n", channel);
657			continue;
658		}
659
660		csr = omap_dma_get_csr(c);
661		omap_dma_glbl_write(od, IRQSTATUS_L1, mask);
662
663		omap_dma_callback(channel, csr, c);
664	}
665
666	spin_unlock(&od->irq_lock);
667
668	return IRQ_HANDLED;
669}
670
671static int omap_dma_get_lch(struct omap_dmadev *od, int *lch)
672{
673	int channel;
674
675	mutex_lock(&od->lch_lock);
676	channel = find_first_zero_bit(od->lch_bitmap, od->lch_count);
677	if (channel >= od->lch_count)
678		goto out_busy;
679	set_bit(channel, od->lch_bitmap);
680	mutex_unlock(&od->lch_lock);
681
682	omap_dma_clear_lch(od, channel);
683	*lch = channel;
684
685	return 0;
686
687out_busy:
688	mutex_unlock(&od->lch_lock);
689	*lch = -EINVAL;
690
691	return -EBUSY;
692}
693
694static void omap_dma_put_lch(struct omap_dmadev *od, int lch)
695{
696	omap_dma_clear_lch(od, lch);
697	mutex_lock(&od->lch_lock);
698	clear_bit(lch, od->lch_bitmap);
699	mutex_unlock(&od->lch_lock);
700}
701
702static int omap_dma_alloc_chan_resources(struct dma_chan *chan)
703{
704	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
705	struct omap_chan *c = to_omap_dma_chan(chan);
706	struct device *dev = od->ddev.dev;
707	int ret;
708
709	if (od->legacy) {
710		ret = omap_request_dma(c->dma_sig, "DMA engine",
711				       omap_dma_callback, c, &c->dma_ch);
712	} else {
713		ret = omap_dma_get_lch(od, &c->dma_ch);
714	}
715
716	dev_dbg(dev, "allocating channel %u for %u\n", c->dma_ch, c->dma_sig);
717
718	if (ret >= 0) {
719		omap_dma_assign(od, c, c->dma_ch);
720
721		if (!od->legacy) {
722			unsigned val;
723
724			spin_lock_irq(&od->irq_lock);
725			val = BIT(c->dma_ch);
726			omap_dma_glbl_write(od, IRQSTATUS_L1, val);
727			od->irq_enable_mask |= val;
728			omap_dma_glbl_write(od, IRQENABLE_L1, od->irq_enable_mask);
729
730			val = omap_dma_glbl_read(od, IRQENABLE_L0);
731			val &= ~BIT(c->dma_ch);
732			omap_dma_glbl_write(od, IRQENABLE_L0, val);
733			spin_unlock_irq(&od->irq_lock);
734		}
735	}
736
737	if (dma_omap1()) {
738		if (__dma_omap16xx(od->plat->dma_attr)) {
739			c->ccr = CCR_OMAP31_DISABLE;
740			/* Duplicate what plat-omap/dma.c does */
741			c->ccr |= c->dma_ch + 1;
742		} else {
743			c->ccr = c->dma_sig & 0x1f;
744		}
745	} else {
746		c->ccr = c->dma_sig & 0x1f;
747		c->ccr |= (c->dma_sig & ~0x1f) << 14;
748	}
749	if (od->plat->errata & DMA_ERRATA_IFRAME_BUFFERING)
750		c->ccr |= CCR_BUFFERING_DISABLE;
751
752	return ret;
753}
754
755static void omap_dma_free_chan_resources(struct dma_chan *chan)
756{
757	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
758	struct omap_chan *c = to_omap_dma_chan(chan);
759
760	if (!od->legacy) {
761		spin_lock_irq(&od->irq_lock);
762		od->irq_enable_mask &= ~BIT(c->dma_ch);
763		omap_dma_glbl_write(od, IRQENABLE_L1, od->irq_enable_mask);
764		spin_unlock_irq(&od->irq_lock);
765	}
766
767	c->channel_base = NULL;
768	od->lch_map[c->dma_ch] = NULL;
769	vchan_free_chan_resources(&c->vc);
770
771	if (od->legacy)
772		omap_free_dma(c->dma_ch);
773	else
774		omap_dma_put_lch(od, c->dma_ch);
775
776	dev_dbg(od->ddev.dev, "freeing channel %u used for %u\n", c->dma_ch,
777		c->dma_sig);
778	c->dma_sig = 0;
779}
780
781static size_t omap_dma_sg_size(struct omap_sg *sg)
782{
783	return sg->en * sg->fn;
784}
785
786static size_t omap_dma_desc_size(struct omap_desc *d)
787{
788	unsigned i;
789	size_t size;
790
791	for (size = i = 0; i < d->sglen; i++)
792		size += omap_dma_sg_size(&d->sg[i]);
793
794	return size * es_bytes[d->es];
795}
796
797static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr)
798{
799	unsigned i;
800	size_t size, es_size = es_bytes[d->es];
801
802	for (size = i = 0; i < d->sglen; i++) {
803		size_t this_size = omap_dma_sg_size(&d->sg[i]) * es_size;
804
805		if (size)
806			size += this_size;
807		else if (addr >= d->sg[i].addr &&
808			 addr < d->sg[i].addr + this_size)
809			size += d->sg[i].addr + this_size - addr;
810	}
811	return size;
812}
813
814/*
815 * OMAP 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is
816 * read before the DMA controller finished disabling the channel.
817 */
818static uint32_t omap_dma_chan_read_3_3(struct omap_chan *c, unsigned reg)
819{
820	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
821	uint32_t val;
822
823	val = omap_dma_chan_read(c, reg);
824	if (val == 0 && od->plat->errata & DMA_ERRATA_3_3)
825		val = omap_dma_chan_read(c, reg);
826
827	return val;
828}
829
830static dma_addr_t omap_dma_get_src_pos(struct omap_chan *c)
831{
832	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
833	dma_addr_t addr, cdac;
834
835	if (__dma_omap15xx(od->plat->dma_attr)) {
836		addr = omap_dma_chan_read(c, CPC);
837	} else {
838		addr = omap_dma_chan_read_3_3(c, CSAC);
839		cdac = omap_dma_chan_read_3_3(c, CDAC);
840
841		/*
842		 * CDAC == 0 indicates that the DMA transfer on the channel has
843		 * not been started (no data has been transferred so far).
844		 * Return the programmed source start address in this case.
845		 */
846		if (cdac == 0)
847			addr = omap_dma_chan_read(c, CSSA);
848	}
849
850	if (dma_omap1())
851		addr |= omap_dma_chan_read(c, CSSA) & 0xffff0000;
852
853	return addr;
854}
855
856static dma_addr_t omap_dma_get_dst_pos(struct omap_chan *c)
857{
858	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
859	dma_addr_t addr;
860
861	if (__dma_omap15xx(od->plat->dma_attr)) {
862		addr = omap_dma_chan_read(c, CPC);
863	} else {
864		addr = omap_dma_chan_read_3_3(c, CDAC);
865
866		/*
867		 * CDAC == 0 indicates that the DMA transfer on the channel
868		 * has not been started (no data has been transferred so
869		 * far).  Return the programmed destination start address in
870		 * this case.
871		 */
872		if (addr == 0)
873			addr = omap_dma_chan_read(c, CDSA);
874	}
875
876	if (dma_omap1())
877		addr |= omap_dma_chan_read(c, CDSA) & 0xffff0000;
878
879	return addr;
880}
881
882static enum dma_status omap_dma_tx_status(struct dma_chan *chan,
883	dma_cookie_t cookie, struct dma_tx_state *txstate)
884{
885	struct omap_chan *c = to_omap_dma_chan(chan);
886	enum dma_status ret;
887	unsigned long flags;
888	struct omap_desc *d = NULL;
889
890	ret = dma_cookie_status(chan, cookie, txstate);
891	if (ret == DMA_COMPLETE)
892		return ret;
893
894	spin_lock_irqsave(&c->vc.lock, flags);
895	if (c->desc && c->desc->vd.tx.cookie == cookie)
896		d = c->desc;
897
898	if (!txstate)
899		goto out;
900
901	if (d) {
902		dma_addr_t pos;
903
904		if (d->dir == DMA_MEM_TO_DEV)
905			pos = omap_dma_get_src_pos(c);
906		else if (d->dir == DMA_DEV_TO_MEM  || d->dir == DMA_MEM_TO_MEM)
907			pos = omap_dma_get_dst_pos(c);
908		else
909			pos = 0;
910
911		txstate->residue = omap_dma_desc_size_pos(d, pos);
912	} else {
913		struct virt_dma_desc *vd = vchan_find_desc(&c->vc, cookie);
914
915		if (vd)
916			txstate->residue = omap_dma_desc_size(
917						to_omap_dma_desc(&vd->tx));
918		else
919			txstate->residue = 0;
920	}
921
922out:
923	if (ret == DMA_IN_PROGRESS && c->paused) {
924		ret = DMA_PAUSED;
925	} else if (d && d->polled && c->running) {
926		uint32_t ccr = omap_dma_chan_read(c, CCR);
927		/*
928		 * The channel is no longer active, set the return value
929		 * accordingly and mark it as completed
930		 */
931		if (!(ccr & CCR_ENABLE)) {
932			ret = DMA_COMPLETE;
933			omap_dma_start_desc(c);
934			vchan_cookie_complete(&d->vd);
935		}
936	}
937
938	spin_unlock_irqrestore(&c->vc.lock, flags);
939
940	return ret;
941}
942
943static void omap_dma_issue_pending(struct dma_chan *chan)
944{
945	struct omap_chan *c = to_omap_dma_chan(chan);
946	unsigned long flags;
947
948	spin_lock_irqsave(&c->vc.lock, flags);
949	if (vchan_issue_pending(&c->vc) && !c->desc)
950		omap_dma_start_desc(c);
951	spin_unlock_irqrestore(&c->vc.lock, flags);
952}
953
954static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
955	struct dma_chan *chan, struct scatterlist *sgl, unsigned sglen,
956	enum dma_transfer_direction dir, unsigned long tx_flags, void *context)
957{
958	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
959	struct omap_chan *c = to_omap_dma_chan(chan);
960	enum dma_slave_buswidth dev_width;
961	struct scatterlist *sgent;
962	struct omap_desc *d;
963	dma_addr_t dev_addr;
964	unsigned i, es, en, frame_bytes;
965	bool ll_failed = false;
966	u32 burst;
967	u32 port_window, port_window_bytes;
968
969	if (dir == DMA_DEV_TO_MEM) {
970		dev_addr = c->cfg.src_addr;
971		dev_width = c->cfg.src_addr_width;
972		burst = c->cfg.src_maxburst;
973		port_window = c->cfg.src_port_window_size;
974	} else if (dir == DMA_MEM_TO_DEV) {
975		dev_addr = c->cfg.dst_addr;
976		dev_width = c->cfg.dst_addr_width;
977		burst = c->cfg.dst_maxburst;
978		port_window = c->cfg.dst_port_window_size;
979	} else {
980		dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
981		return NULL;
982	}
983
984	/* Bus width translates to the element size (ES) */
985	switch (dev_width) {
986	case DMA_SLAVE_BUSWIDTH_1_BYTE:
987		es = CSDP_DATA_TYPE_8;
988		break;
989	case DMA_SLAVE_BUSWIDTH_2_BYTES:
990		es = CSDP_DATA_TYPE_16;
991		break;
992	case DMA_SLAVE_BUSWIDTH_4_BYTES:
993		es = CSDP_DATA_TYPE_32;
994		break;
995	default: /* not reached */
996		return NULL;
997	}
998
999	/* Now allocate and setup the descriptor. */
1000	d = kzalloc(struct_size(d, sg, sglen), GFP_ATOMIC);
1001	if (!d)
1002		return NULL;
1003
1004	d->dir = dir;
1005	d->dev_addr = dev_addr;
1006	d->es = es;
1007
1008	/* When the port_window is used, one frame must cover the window */
1009	if (port_window) {
1010		burst = port_window;
1011		port_window_bytes = port_window * es_bytes[es];
1012
1013		d->ei = 1;
1014		/*
1015		 * One frame covers the port_window and by  configure
1016		 * the source frame index to be -1 * (port_window - 1)
1017		 * we instruct the sDMA that after a frame is processed
1018		 * it should move back to the start of the window.
1019		 */
1020		d->fi = -(port_window_bytes - 1);
1021	}
1022
1023	d->ccr = c->ccr | CCR_SYNC_FRAME;
1024	if (dir == DMA_DEV_TO_MEM) {
1025		d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
1026
1027		d->ccr |= CCR_DST_AMODE_POSTINC;
1028		if (port_window) {
1029			d->ccr |= CCR_SRC_AMODE_DBLIDX;
1030
1031			if (port_window_bytes >= 64)
1032				d->csdp |= CSDP_SRC_BURST_64;
1033			else if (port_window_bytes >= 32)
1034				d->csdp |= CSDP_SRC_BURST_32;
1035			else if (port_window_bytes >= 16)
1036				d->csdp |= CSDP_SRC_BURST_16;
1037
1038		} else {
1039			d->ccr |= CCR_SRC_AMODE_CONSTANT;
1040		}
1041	} else {
1042		d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
1043
1044		d->ccr |= CCR_SRC_AMODE_POSTINC;
1045		if (port_window) {
1046			d->ccr |= CCR_DST_AMODE_DBLIDX;
1047
1048			if (port_window_bytes >= 64)
1049				d->csdp |= CSDP_DST_BURST_64;
1050			else if (port_window_bytes >= 32)
1051				d->csdp |= CSDP_DST_BURST_32;
1052			else if (port_window_bytes >= 16)
1053				d->csdp |= CSDP_DST_BURST_16;
1054		} else {
1055			d->ccr |= CCR_DST_AMODE_CONSTANT;
1056		}
1057	}
1058
1059	d->cicr = CICR_DROP_IE | CICR_BLOCK_IE;
1060	d->csdp |= es;
1061
1062	if (dma_omap1()) {
1063		d->cicr |= CICR_TOUT_IE;
1064
1065		if (dir == DMA_DEV_TO_MEM)
1066			d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_TIPB;
1067		else
1068			d->csdp |= CSDP_DST_PORT_TIPB | CSDP_SRC_PORT_EMIFF;
1069	} else {
1070		if (dir == DMA_DEV_TO_MEM)
1071			d->ccr |= CCR_TRIGGER_SRC;
1072
1073		d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
1074
1075		if (port_window)
1076			d->csdp |= CSDP_WRITE_LAST_NON_POSTED;
1077	}
1078	if (od->plat->errata & DMA_ERRATA_PARALLEL_CHANNELS)
1079		d->clnk_ctrl = c->dma_ch;
1080
1081	/*
1082	 * Build our scatterlist entries: each contains the address,
1083	 * the number of elements (EN) in each frame, and the number of
1084	 * frames (FN).  Number of bytes for this entry = ES * EN * FN.
1085	 *
1086	 * Burst size translates to number of elements with frame sync.
1087	 * Note: DMA engine defines burst to be the number of dev-width
1088	 * transfers.
1089	 */
1090	en = burst;
1091	frame_bytes = es_bytes[es] * en;
1092
1093	if (sglen >= 2)
1094		d->using_ll = od->ll123_supported;
1095
1096	for_each_sg(sgl, sgent, sglen, i) {
1097		struct omap_sg *osg = &d->sg[i];
1098
1099		osg->addr = sg_dma_address(sgent);
1100		osg->en = en;
1101		osg->fn = sg_dma_len(sgent) / frame_bytes;
1102
1103		if (d->using_ll) {
1104			osg->t2_desc = dma_pool_alloc(od->desc_pool, GFP_ATOMIC,
1105						      &osg->t2_desc_paddr);
1106			if (!osg->t2_desc) {
1107				dev_err(chan->device->dev,
1108					"t2_desc[%d] allocation failed\n", i);
1109				ll_failed = true;
1110				d->using_ll = false;
1111				continue;
1112			}
1113
1114			omap_dma_fill_type2_desc(d, i, dir, (i == sglen - 1));
1115		}
1116	}
1117
1118	d->sglen = sglen;
1119
1120	/* Release the dma_pool entries if one allocation failed */
1121	if (ll_failed) {
1122		for (i = 0; i < d->sglen; i++) {
1123			struct omap_sg *osg = &d->sg[i];
1124
1125			if (osg->t2_desc) {
1126				dma_pool_free(od->desc_pool, osg->t2_desc,
1127					      osg->t2_desc_paddr);
1128				osg->t2_desc = NULL;
1129			}
1130		}
1131	}
1132
1133	return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
1134}
1135
1136static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic(
1137	struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
1138	size_t period_len, enum dma_transfer_direction dir, unsigned long flags)
1139{
1140	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1141	struct omap_chan *c = to_omap_dma_chan(chan);
1142	enum dma_slave_buswidth dev_width;
1143	struct omap_desc *d;
1144	dma_addr_t dev_addr;
1145	unsigned es;
1146	u32 burst;
1147
1148	if (dir == DMA_DEV_TO_MEM) {
1149		dev_addr = c->cfg.src_addr;
1150		dev_width = c->cfg.src_addr_width;
1151		burst = c->cfg.src_maxburst;
1152	} else if (dir == DMA_MEM_TO_DEV) {
1153		dev_addr = c->cfg.dst_addr;
1154		dev_width = c->cfg.dst_addr_width;
1155		burst = c->cfg.dst_maxburst;
1156	} else {
1157		dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
1158		return NULL;
1159	}
1160
1161	/* Bus width translates to the element size (ES) */
1162	switch (dev_width) {
1163	case DMA_SLAVE_BUSWIDTH_1_BYTE:
1164		es = CSDP_DATA_TYPE_8;
1165		break;
1166	case DMA_SLAVE_BUSWIDTH_2_BYTES:
1167		es = CSDP_DATA_TYPE_16;
1168		break;
1169	case DMA_SLAVE_BUSWIDTH_4_BYTES:
1170		es = CSDP_DATA_TYPE_32;
1171		break;
1172	default: /* not reached */
1173		return NULL;
1174	}
1175
1176	/* Now allocate and setup the descriptor. */
1177	d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
1178	if (!d)
1179		return NULL;
1180
1181	d->dir = dir;
1182	d->dev_addr = dev_addr;
1183	d->fi = burst;
1184	d->es = es;
1185	d->sg[0].addr = buf_addr;
1186	d->sg[0].en = period_len / es_bytes[es];
1187	d->sg[0].fn = buf_len / period_len;
1188	d->sglen = 1;
1189
1190	d->ccr = c->ccr;
1191	if (dir == DMA_DEV_TO_MEM)
1192		d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
1193	else
1194		d->ccr |= CCR_DST_AMODE_CONSTANT | CCR_SRC_AMODE_POSTINC;
1195
1196	d->cicr = CICR_DROP_IE;
1197	if (flags & DMA_PREP_INTERRUPT)
1198		d->cicr |= CICR_FRAME_IE;
1199
1200	d->csdp = es;
1201
1202	if (dma_omap1()) {
1203		d->cicr |= CICR_TOUT_IE;
1204
1205		if (dir == DMA_DEV_TO_MEM)
1206			d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_MPUI;
1207		else
1208			d->csdp |= CSDP_DST_PORT_MPUI | CSDP_SRC_PORT_EMIFF;
1209	} else {
1210		if (burst)
1211			d->ccr |= CCR_SYNC_PACKET;
1212		else
1213			d->ccr |= CCR_SYNC_ELEMENT;
1214
1215		if (dir == DMA_DEV_TO_MEM) {
1216			d->ccr |= CCR_TRIGGER_SRC;
1217			d->csdp |= CSDP_DST_PACKED;
1218		} else {
1219			d->csdp |= CSDP_SRC_PACKED;
1220		}
1221
1222		d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
1223
1224		d->csdp |= CSDP_DST_BURST_64 | CSDP_SRC_BURST_64;
1225	}
1226
1227	if (__dma_omap15xx(od->plat->dma_attr))
1228		d->ccr |= CCR_AUTO_INIT | CCR_REPEAT;
1229	else
1230		d->clnk_ctrl = c->dma_ch | CLNK_CTRL_ENABLE_LNK;
1231
1232	c->cyclic = true;
1233
1234	return vchan_tx_prep(&c->vc, &d->vd, flags);
1235}
1236
1237static struct dma_async_tx_descriptor *omap_dma_prep_dma_memcpy(
1238	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
1239	size_t len, unsigned long tx_flags)
1240{
1241	struct omap_chan *c = to_omap_dma_chan(chan);
1242	struct omap_desc *d;
1243	uint8_t data_type;
1244
1245	d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
1246	if (!d)
1247		return NULL;
1248
1249	data_type = __ffs((src | dest | len));
1250	if (data_type > CSDP_DATA_TYPE_32)
1251		data_type = CSDP_DATA_TYPE_32;
1252
1253	d->dir = DMA_MEM_TO_MEM;
1254	d->dev_addr = src;
1255	d->fi = 0;
1256	d->es = data_type;
1257	d->sg[0].en = len / BIT(data_type);
1258	d->sg[0].fn = 1;
1259	d->sg[0].addr = dest;
1260	d->sglen = 1;
1261	d->ccr = c->ccr;
1262	d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_POSTINC;
1263
1264	if (tx_flags & DMA_PREP_INTERRUPT)
1265		d->cicr |= CICR_FRAME_IE;
1266	else
1267		d->polled = true;
1268
1269	d->csdp = data_type;
1270
1271	if (dma_omap1()) {
1272		d->cicr |= CICR_TOUT_IE;
1273		d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_EMIFF;
1274	} else {
1275		d->csdp |= CSDP_DST_PACKED | CSDP_SRC_PACKED;
1276		d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
1277		d->csdp |= CSDP_DST_BURST_64 | CSDP_SRC_BURST_64;
1278	}
1279
1280	return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
1281}
1282
1283static struct dma_async_tx_descriptor *omap_dma_prep_dma_interleaved(
1284	struct dma_chan *chan, struct dma_interleaved_template *xt,
1285	unsigned long flags)
1286{
1287	struct omap_chan *c = to_omap_dma_chan(chan);
1288	struct omap_desc *d;
1289	struct omap_sg *sg;
1290	uint8_t data_type;
1291	size_t src_icg, dst_icg;
1292
1293	/* Slave mode is not supported */
1294	if (is_slave_direction(xt->dir))
1295		return NULL;
1296
1297	if (xt->frame_size != 1 || xt->numf == 0)
1298		return NULL;
1299
1300	d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
1301	if (!d)
1302		return NULL;
1303
1304	data_type = __ffs((xt->src_start | xt->dst_start | xt->sgl[0].size));
1305	if (data_type > CSDP_DATA_TYPE_32)
1306		data_type = CSDP_DATA_TYPE_32;
1307
1308	sg = &d->sg[0];
1309	d->dir = DMA_MEM_TO_MEM;
1310	d->dev_addr = xt->src_start;
1311	d->es = data_type;
1312	sg->en = xt->sgl[0].size / BIT(data_type);
1313	sg->fn = xt->numf;
1314	sg->addr = xt->dst_start;
1315	d->sglen = 1;
1316	d->ccr = c->ccr;
1317
1318	src_icg = dmaengine_get_src_icg(xt, &xt->sgl[0]);
1319	dst_icg = dmaengine_get_dst_icg(xt, &xt->sgl[0]);
1320	if (src_icg) {
1321		d->ccr |= CCR_SRC_AMODE_DBLIDX;
1322		d->ei = 1;
1323		d->fi = src_icg + 1;
1324	} else if (xt->src_inc) {
1325		d->ccr |= CCR_SRC_AMODE_POSTINC;
1326		d->fi = 0;
1327	} else {
1328		dev_err(chan->device->dev,
1329			"%s: SRC constant addressing is not supported\n",
1330			__func__);
1331		kfree(d);
1332		return NULL;
1333	}
1334
1335	if (dst_icg) {
1336		d->ccr |= CCR_DST_AMODE_DBLIDX;
1337		sg->ei = 1;
1338		sg->fi = dst_icg + 1;
1339	} else if (xt->dst_inc) {
1340		d->ccr |= CCR_DST_AMODE_POSTINC;
1341		sg->fi = 0;
1342	} else {
1343		dev_err(chan->device->dev,
1344			"%s: DST constant addressing is not supported\n",
1345			__func__);
1346		kfree(d);
1347		return NULL;
1348	}
1349
1350	d->cicr = CICR_DROP_IE | CICR_FRAME_IE;
1351
1352	d->csdp = data_type;
1353
1354	if (dma_omap1()) {
1355		d->cicr |= CICR_TOUT_IE;
1356		d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_EMIFF;
1357	} else {
1358		d->csdp |= CSDP_DST_PACKED | CSDP_SRC_PACKED;
1359		d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
1360		d->csdp |= CSDP_DST_BURST_64 | CSDP_SRC_BURST_64;
1361	}
1362
1363	return vchan_tx_prep(&c->vc, &d->vd, flags);
1364}
1365
1366static int omap_dma_slave_config(struct dma_chan *chan, struct dma_slave_config *cfg)
1367{
1368	struct omap_chan *c = to_omap_dma_chan(chan);
1369
1370	if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
1371	    cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
1372		return -EINVAL;
1373
1374	if (cfg->src_maxburst > chan->device->max_burst ||
1375	    cfg->dst_maxburst > chan->device->max_burst)
1376		return -EINVAL;
1377
1378	memcpy(&c->cfg, cfg, sizeof(c->cfg));
1379
1380	return 0;
1381}
1382
1383static int omap_dma_terminate_all(struct dma_chan *chan)
1384{
1385	struct omap_chan *c = to_omap_dma_chan(chan);
1386	unsigned long flags;
1387	LIST_HEAD(head);
1388
1389	spin_lock_irqsave(&c->vc.lock, flags);
1390
1391	/*
1392	 * Stop DMA activity: we assume the callback will not be called
1393	 * after omap_dma_stop() returns (even if it does, it will see
1394	 * c->desc is NULL and exit.)
1395	 */
1396	if (c->desc) {
1397		vchan_terminate_vdesc(&c->desc->vd);
1398		c->desc = NULL;
1399		/* Avoid stopping the dma twice */
1400		if (!c->paused)
1401			omap_dma_stop(c);
1402	}
1403
1404	c->cyclic = false;
1405	c->paused = false;
1406
1407	vchan_get_all_descriptors(&c->vc, &head);
1408	spin_unlock_irqrestore(&c->vc.lock, flags);
1409	vchan_dma_desc_free_list(&c->vc, &head);
1410
1411	return 0;
1412}
1413
1414static void omap_dma_synchronize(struct dma_chan *chan)
1415{
1416	struct omap_chan *c = to_omap_dma_chan(chan);
1417
1418	vchan_synchronize(&c->vc);
1419}
1420
1421static int omap_dma_pause(struct dma_chan *chan)
1422{
1423	struct omap_chan *c = to_omap_dma_chan(chan);
1424	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1425	unsigned long flags;
1426	int ret = -EINVAL;
1427	bool can_pause = false;
1428
1429	spin_lock_irqsave(&od->irq_lock, flags);
1430
1431	if (!c->desc)
1432		goto out;
1433
1434	if (c->cyclic)
1435		can_pause = true;
1436
1437	/*
1438	 * We do not allow DMA_MEM_TO_DEV transfers to be paused.
1439	 * From the AM572x TRM, 16.1.4.18 Disabling a Channel During Transfer:
1440	 * "When a channel is disabled during a transfer, the channel undergoes
1441	 * an abort, unless it is hardware-source-synchronized …".
1442	 * A source-synchronised channel is one where the fetching of data is
1443	 * under control of the device. In other words, a device-to-memory
1444	 * transfer. So, a destination-synchronised channel (which would be a
1445	 * memory-to-device transfer) undergoes an abort if the the CCR_ENABLE
1446	 * bit is cleared.
1447	 * From 16.1.4.20.4.6.2 Abort: "If an abort trigger occurs, the channel
1448	 * aborts immediately after completion of current read/write
1449	 * transactions and then the FIFO is cleaned up." The term "cleaned up"
1450	 * is not defined. TI recommends to check that RD_ACTIVE and WR_ACTIVE
1451	 * are both clear _before_ disabling the channel, otherwise data loss
1452	 * will occur.
1453	 * The problem is that if the channel is active, then device activity
1454	 * can result in DMA activity starting between reading those as both
1455	 * clear and the write to DMA_CCR to clear the enable bit hitting the
1456	 * hardware. If the DMA hardware can't drain the data in its FIFO to the
1457	 * destination, then data loss "might" occur (say if we write to an UART
1458	 * and the UART is not accepting any further data).
1459	 */
1460	else if (c->desc->dir == DMA_DEV_TO_MEM)
1461		can_pause = true;
1462
1463	if (can_pause && !c->paused) {
1464		ret = omap_dma_stop(c);
1465		if (!ret)
1466			c->paused = true;
1467	}
1468out:
1469	spin_unlock_irqrestore(&od->irq_lock, flags);
1470
1471	return ret;
1472}
1473
1474static int omap_dma_resume(struct dma_chan *chan)
1475{
1476	struct omap_chan *c = to_omap_dma_chan(chan);
1477	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1478	unsigned long flags;
1479	int ret = -EINVAL;
1480
1481	spin_lock_irqsave(&od->irq_lock, flags);
1482
1483	if (c->paused && c->desc) {
1484		mb();
1485
1486		/* Restore channel link register */
1487		omap_dma_chan_write(c, CLNK_CTRL, c->desc->clnk_ctrl);
1488
1489		omap_dma_start(c, c->desc);
1490		c->paused = false;
1491		ret = 0;
1492	}
1493	spin_unlock_irqrestore(&od->irq_lock, flags);
1494
1495	return ret;
1496}
1497
1498static int omap_dma_chan_init(struct omap_dmadev *od)
1499{
1500	struct omap_chan *c;
1501
1502	c = kzalloc(sizeof(*c), GFP_KERNEL);
1503	if (!c)
1504		return -ENOMEM;
1505
1506	c->reg_map = od->reg_map;
1507	c->vc.desc_free = omap_dma_desc_free;
1508	vchan_init(&c->vc, &od->ddev);
1509
1510	return 0;
1511}
1512
1513static void omap_dma_free(struct omap_dmadev *od)
1514{
1515	while (!list_empty(&od->ddev.channels)) {
1516		struct omap_chan *c = list_first_entry(&od->ddev.channels,
1517			struct omap_chan, vc.chan.device_node);
1518
1519		list_del(&c->vc.chan.device_node);
1520		tasklet_kill(&c->vc.task);
1521		kfree(c);
1522	}
1523}
1524
1525/* Currently used by omap2 & 3 to block deeper SoC idle states */
1526static bool omap_dma_busy(struct omap_dmadev *od)
1527{
1528	struct omap_chan *c;
1529	int lch = -1;
1530
1531	while (1) {
1532		lch = find_next_bit(od->lch_bitmap, od->lch_count, lch + 1);
1533		if (lch >= od->lch_count)
1534			break;
1535		c = od->lch_map[lch];
1536		if (!c)
1537			continue;
1538		if (omap_dma_chan_read(c, CCR) & CCR_ENABLE)
1539			return true;
1540	}
1541
1542	return false;
1543}
1544
1545/* Currently only used for omap2. For omap1, also a check for lcd_dma is needed */
1546static int omap_dma_busy_notifier(struct notifier_block *nb,
1547				  unsigned long cmd, void *v)
1548{
1549	struct omap_dmadev *od;
1550
1551	od = container_of(nb, struct omap_dmadev, nb);
1552
1553	switch (cmd) {
1554	case CPU_CLUSTER_PM_ENTER:
1555		if (omap_dma_busy(od))
1556			return NOTIFY_BAD;
1557		break;
1558	case CPU_CLUSTER_PM_ENTER_FAILED:
1559	case CPU_CLUSTER_PM_EXIT:
1560		break;
1561	}
1562
1563	return NOTIFY_OK;
1564}
1565
1566/*
1567 * We are using IRQENABLE_L1, and legacy DMA code was using IRQENABLE_L0.
1568 * As the DSP may be using IRQENABLE_L2 and L3, let's not touch those for
1569 * now. Context save seems to be only currently needed on omap3.
1570 */
1571static void omap_dma_context_save(struct omap_dmadev *od)
1572{
1573	od->context.irqenable_l0 = omap_dma_glbl_read(od, IRQENABLE_L0);
1574	od->context.irqenable_l1 = omap_dma_glbl_read(od, IRQENABLE_L1);
1575	od->context.ocp_sysconfig = omap_dma_glbl_read(od, OCP_SYSCONFIG);
1576	od->context.gcr = omap_dma_glbl_read(od, GCR);
1577}
1578
1579static void omap_dma_context_restore(struct omap_dmadev *od)
1580{
1581	int i;
1582
1583	omap_dma_glbl_write(od, GCR, od->context.gcr);
1584	omap_dma_glbl_write(od, OCP_SYSCONFIG, od->context.ocp_sysconfig);
1585	omap_dma_glbl_write(od, IRQENABLE_L0, od->context.irqenable_l0);
1586	omap_dma_glbl_write(od, IRQENABLE_L1, od->context.irqenable_l1);
1587
1588	/* Clear IRQSTATUS_L0 as legacy DMA code is no longer doing it */
1589	if (od->plat->errata & DMA_ROMCODE_BUG)
1590		omap_dma_glbl_write(od, IRQSTATUS_L0, 0);
1591
1592	/* Clear dma channels */
1593	for (i = 0; i < od->lch_count; i++)
1594		omap_dma_clear_lch(od, i);
1595}
1596
1597/* Currently only used for omap3 */
1598static int omap_dma_context_notifier(struct notifier_block *nb,
1599				     unsigned long cmd, void *v)
1600{
1601	struct omap_dmadev *od;
1602
1603	od = container_of(nb, struct omap_dmadev, nb);
1604
1605	switch (cmd) {
1606	case CPU_CLUSTER_PM_ENTER:
1607		if (omap_dma_busy(od))
1608			return NOTIFY_BAD;
1609		omap_dma_context_save(od);
1610		break;
1611	case CPU_CLUSTER_PM_ENTER_FAILED:
1612	case CPU_CLUSTER_PM_EXIT:
1613		omap_dma_context_restore(od);
1614		break;
1615	}
1616
1617	return NOTIFY_OK;
1618}
1619
1620static void omap_dma_init_gcr(struct omap_dmadev *od, int arb_rate,
1621			      int max_fifo_depth, int tparams)
1622{
1623	u32 val;
1624
1625	/* Set only for omap2430 and later */
1626	if (!od->cfg->rw_priority)
1627		return;
1628
1629	if (max_fifo_depth == 0)
1630		max_fifo_depth = 1;
1631	if (arb_rate == 0)
1632		arb_rate = 1;
1633
1634	val = 0xff & max_fifo_depth;
1635	val |= (0x3 & tparams) << 12;
1636	val |= (arb_rate & 0xff) << 16;
1637
1638	omap_dma_glbl_write(od, GCR, val);
1639}
1640
1641#define OMAP_DMA_BUSWIDTHS	(BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
1642				 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
1643				 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
1644
1645/*
1646 * No flags currently set for default configuration as omap1 is still
1647 * using platform data.
1648 */
1649static const struct omap_dma_config default_cfg;
1650
1651static int omap_dma_probe(struct platform_device *pdev)
1652{
1653	const struct omap_dma_config *conf;
1654	struct omap_dmadev *od;
1655	struct resource *res;
1656	int rc, i, irq;
1657	u32 val;
1658
1659	od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
1660	if (!od)
1661		return -ENOMEM;
1662
1663	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1664	od->base = devm_ioremap_resource(&pdev->dev, res);
1665	if (IS_ERR(od->base))
1666		return PTR_ERR(od->base);
1667
1668	conf = of_device_get_match_data(&pdev->dev);
1669	if (conf) {
1670		od->cfg = conf;
1671		od->plat = dev_get_platdata(&pdev->dev);
1672		if (!od->plat) {
1673			dev_err(&pdev->dev, "omap_system_dma_plat_info is missing");
1674			return -ENODEV;
1675		}
1676	} else {
1677		od->cfg = &default_cfg;
1678
1679		od->plat = omap_get_plat_info();
1680		if (!od->plat)
1681			return -EPROBE_DEFER;
1682	}
1683
1684	od->reg_map = od->plat->reg_map;
1685
1686	dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
1687	dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
1688	dma_cap_set(DMA_MEMCPY, od->ddev.cap_mask);
1689	dma_cap_set(DMA_INTERLEAVE, od->ddev.cap_mask);
1690	od->ddev.device_alloc_chan_resources = omap_dma_alloc_chan_resources;
1691	od->ddev.device_free_chan_resources = omap_dma_free_chan_resources;
1692	od->ddev.device_tx_status = omap_dma_tx_status;
1693	od->ddev.device_issue_pending = omap_dma_issue_pending;
1694	od->ddev.device_prep_slave_sg = omap_dma_prep_slave_sg;
1695	od->ddev.device_prep_dma_cyclic = omap_dma_prep_dma_cyclic;
1696	od->ddev.device_prep_dma_memcpy = omap_dma_prep_dma_memcpy;
1697	od->ddev.device_prep_interleaved_dma = omap_dma_prep_dma_interleaved;
1698	od->ddev.device_config = omap_dma_slave_config;
1699	od->ddev.device_pause = omap_dma_pause;
1700	od->ddev.device_resume = omap_dma_resume;
1701	od->ddev.device_terminate_all = omap_dma_terminate_all;
1702	od->ddev.device_synchronize = omap_dma_synchronize;
1703	od->ddev.src_addr_widths = OMAP_DMA_BUSWIDTHS;
1704	od->ddev.dst_addr_widths = OMAP_DMA_BUSWIDTHS;
1705	od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1706	if (__dma_omap15xx(od->plat->dma_attr))
1707		od->ddev.residue_granularity =
1708				DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1709	else
1710		od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1711	od->ddev.max_burst = SZ_16M - 1; /* CCEN: 24bit unsigned */
1712	od->ddev.dev = &pdev->dev;
1713	INIT_LIST_HEAD(&od->ddev.channels);
1714	mutex_init(&od->lch_lock);
1715	spin_lock_init(&od->lock);
1716	spin_lock_init(&od->irq_lock);
1717
1718	/* Number of DMA requests */
1719	od->dma_requests = OMAP_SDMA_REQUESTS;
1720	if (pdev->dev.of_node && of_property_read_u32(pdev->dev.of_node,
1721						      "dma-requests",
1722						      &od->dma_requests)) {
1723		dev_info(&pdev->dev,
1724			 "Missing dma-requests property, using %u.\n",
1725			 OMAP_SDMA_REQUESTS);
1726	}
1727
1728	/* Number of available logical channels */
1729	if (!pdev->dev.of_node) {
1730		od->lch_count = od->plat->dma_attr->lch_count;
1731		if (unlikely(!od->lch_count))
1732			od->lch_count = OMAP_SDMA_CHANNELS;
1733	} else if (of_property_read_u32(pdev->dev.of_node, "dma-channels",
1734					&od->lch_count)) {
1735		dev_info(&pdev->dev,
1736			 "Missing dma-channels property, using %u.\n",
1737			 OMAP_SDMA_CHANNELS);
1738		od->lch_count = OMAP_SDMA_CHANNELS;
1739	}
1740
1741	/* Mask of allowed logical channels */
1742	if (pdev->dev.of_node && !of_property_read_u32(pdev->dev.of_node,
1743						       "dma-channel-mask",
1744						       &val)) {
1745		/* Tag channels not in mask as reserved */
1746		val = ~val;
1747		bitmap_from_arr32(od->lch_bitmap, &val, od->lch_count);
1748	}
1749	if (od->plat->dma_attr->dev_caps & HS_CHANNELS_RESERVED)
1750		bitmap_set(od->lch_bitmap, 0, 2);
1751
1752	od->lch_map = devm_kcalloc(&pdev->dev, od->lch_count,
1753				   sizeof(*od->lch_map),
1754				   GFP_KERNEL);
1755	if (!od->lch_map)
1756		return -ENOMEM;
1757
1758	for (i = 0; i < od->dma_requests; i++) {
1759		rc = omap_dma_chan_init(od);
1760		if (rc) {
1761			omap_dma_free(od);
1762			return rc;
1763		}
1764	}
1765
1766	irq = platform_get_irq(pdev, 1);
1767	if (irq <= 0) {
1768		dev_info(&pdev->dev, "failed to get L1 IRQ: %d\n", irq);
1769		od->legacy = true;
1770	} else {
1771		/* Disable all interrupts */
1772		od->irq_enable_mask = 0;
1773		omap_dma_glbl_write(od, IRQENABLE_L1, 0);
1774
1775		rc = devm_request_irq(&pdev->dev, irq, omap_dma_irq,
1776				      IRQF_SHARED, "omap-dma-engine", od);
1777		if (rc) {
1778			omap_dma_free(od);
1779			return rc;
1780		}
1781	}
1782
1783	if (omap_dma_glbl_read(od, CAPS_0) & CAPS_0_SUPPORT_LL123)
1784		od->ll123_supported = true;
1785
1786	od->ddev.filter.map = od->plat->slave_map;
1787	od->ddev.filter.mapcnt = od->plat->slavecnt;
1788	od->ddev.filter.fn = omap_dma_filter_fn;
1789
1790	if (od->ll123_supported) {
1791		od->desc_pool = dma_pool_create(dev_name(&pdev->dev),
1792						&pdev->dev,
1793						sizeof(struct omap_type2_desc),
1794						4, 0);
1795		if (!od->desc_pool) {
1796			dev_err(&pdev->dev,
1797				"unable to allocate descriptor pool\n");
1798			od->ll123_supported = false;
1799		}
1800	}
1801
1802	rc = dma_async_device_register(&od->ddev);
1803	if (rc) {
1804		pr_warn("OMAP-DMA: failed to register slave DMA engine device: %d\n",
1805			rc);
1806		omap_dma_free(od);
1807		return rc;
1808	}
1809
1810	platform_set_drvdata(pdev, od);
1811
1812	if (pdev->dev.of_node) {
1813		omap_dma_info.dma_cap = od->ddev.cap_mask;
1814
1815		/* Device-tree DMA controller registration */
1816		rc = of_dma_controller_register(pdev->dev.of_node,
1817				of_dma_simple_xlate, &omap_dma_info);
1818		if (rc) {
1819			pr_warn("OMAP-DMA: failed to register DMA controller\n");
1820			dma_async_device_unregister(&od->ddev);
1821			omap_dma_free(od);
1822		}
1823	}
1824
1825	omap_dma_init_gcr(od, DMA_DEFAULT_ARB_RATE, DMA_DEFAULT_FIFO_DEPTH, 0);
1826
1827	if (od->cfg->needs_busy_check) {
1828		od->nb.notifier_call = omap_dma_busy_notifier;
1829		cpu_pm_register_notifier(&od->nb);
1830	} else if (od->cfg->may_lose_context) {
1831		od->nb.notifier_call = omap_dma_context_notifier;
1832		cpu_pm_register_notifier(&od->nb);
1833	}
1834
1835	dev_info(&pdev->dev, "OMAP DMA engine driver%s\n",
1836		 od->ll123_supported ? " (LinkedList1/2/3 supported)" : "");
1837
1838	return rc;
1839}
1840
1841static int omap_dma_remove(struct platform_device *pdev)
1842{
1843	struct omap_dmadev *od = platform_get_drvdata(pdev);
1844	int irq;
1845
1846	if (od->cfg->may_lose_context)
1847		cpu_pm_unregister_notifier(&od->nb);
1848
1849	if (pdev->dev.of_node)
1850		of_dma_controller_free(pdev->dev.of_node);
1851
1852	irq = platform_get_irq(pdev, 1);
1853	devm_free_irq(&pdev->dev, irq, od);
1854
1855	dma_async_device_unregister(&od->ddev);
1856
1857	if (!od->legacy) {
1858		/* Disable all interrupts */
1859		omap_dma_glbl_write(od, IRQENABLE_L0, 0);
1860	}
1861
1862	if (od->ll123_supported)
1863		dma_pool_destroy(od->desc_pool);
1864
1865	omap_dma_free(od);
1866
1867	return 0;
1868}
1869
1870static const struct omap_dma_config omap2420_data = {
1871	.lch_end = CCFN,
1872	.rw_priority = true,
1873	.needs_lch_clear = true,
1874	.needs_busy_check = true,
1875};
1876
1877static const struct omap_dma_config omap2430_data = {
1878	.lch_end = CCFN,
1879	.rw_priority = true,
1880	.needs_lch_clear = true,
1881};
1882
1883static const struct omap_dma_config omap3430_data = {
1884	.lch_end = CCFN,
1885	.rw_priority = true,
1886	.needs_lch_clear = true,
1887	.may_lose_context = true,
1888};
1889
1890static const struct omap_dma_config omap3630_data = {
1891	.lch_end = CCDN,
1892	.rw_priority = true,
1893	.needs_lch_clear = true,
1894	.may_lose_context = true,
1895};
1896
1897static const struct omap_dma_config omap4_data = {
1898	.lch_end = CCDN,
1899	.rw_priority = true,
1900	.needs_lch_clear = true,
1901};
1902
1903static const struct of_device_id omap_dma_match[] = {
1904	{ .compatible = "ti,omap2420-sdma", .data = &omap2420_data, },
1905	{ .compatible = "ti,omap2430-sdma", .data = &omap2430_data, },
1906	{ .compatible = "ti,omap3430-sdma", .data = &omap3430_data, },
1907	{ .compatible = "ti,omap3630-sdma", .data = &omap3630_data, },
1908	{ .compatible = "ti,omap4430-sdma", .data = &omap4_data, },
1909	{},
1910};
1911MODULE_DEVICE_TABLE(of, omap_dma_match);
1912
1913static struct platform_driver omap_dma_driver = {
1914	.probe	= omap_dma_probe,
1915	.remove	= omap_dma_remove,
1916	.driver = {
1917		.name = "omap-dma-engine",
1918		.of_match_table = omap_dma_match,
1919	},
1920};
1921
1922static bool omap_dma_filter_fn(struct dma_chan *chan, void *param)
1923{
1924	if (chan->device->dev->driver == &omap_dma_driver.driver) {
1925		struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1926		struct omap_chan *c = to_omap_dma_chan(chan);
1927		unsigned req = *(unsigned *)param;
1928
1929		if (req <= od->dma_requests) {
1930			c->dma_sig = req;
1931			return true;
1932		}
1933	}
1934	return false;
1935}
1936
1937static int omap_dma_init(void)
1938{
1939	return platform_driver_register(&omap_dma_driver);
1940}
1941subsys_initcall(omap_dma_init);
1942
1943static void __exit omap_dma_exit(void)
1944{
1945	platform_driver_unregister(&omap_dma_driver);
1946}
1947module_exit(omap_dma_exit);
1948
1949MODULE_AUTHOR("Russell King");
1950MODULE_LICENSE("GPL");
1951