xref: /linux/drivers/dma/ti/omap-dma.c (revision e6f2a617ac53bc0753b885ffb94379ff48b2e2df)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP DMAengine support
4  */
5 #include <linux/delay.h>
6 #include <linux/dmaengine.h>
7 #include <linux/dma-mapping.h>
8 #include <linux/dmapool.h>
9 #include <linux/err.h>
10 #include <linux/init.h>
11 #include <linux/interrupt.h>
12 #include <linux/list.h>
13 #include <linux/module.h>
14 #include <linux/omap-dma.h>
15 #include <linux/platform_device.h>
16 #include <linux/slab.h>
17 #include <linux/spinlock.h>
18 #include <linux/of_dma.h>
19 #include <linux/of_device.h>
20 
21 #include "../virt-dma.h"
22 
23 #define OMAP_SDMA_REQUESTS	127
24 #define OMAP_SDMA_CHANNELS	32
25 
26 struct omap_dmadev {
27 	struct dma_device ddev;
28 	spinlock_t lock;
29 	void __iomem *base;
30 	const struct omap_dma_reg *reg_map;
31 	struct omap_system_dma_plat_info *plat;
32 	bool legacy;
33 	bool ll123_supported;
34 	struct dma_pool *desc_pool;
35 	unsigned dma_requests;
36 	spinlock_t irq_lock;
37 	uint32_t irq_enable_mask;
38 	struct omap_chan **lch_map;
39 };
40 
41 struct omap_chan {
42 	struct virt_dma_chan vc;
43 	void __iomem *channel_base;
44 	const struct omap_dma_reg *reg_map;
45 	uint32_t ccr;
46 
47 	struct dma_slave_config	cfg;
48 	unsigned dma_sig;
49 	bool cyclic;
50 	bool paused;
51 	bool running;
52 
53 	int dma_ch;
54 	struct omap_desc *desc;
55 	unsigned sgidx;
56 };
57 
58 #define DESC_NXT_SV_REFRESH	(0x1 << 24)
59 #define DESC_NXT_SV_REUSE	(0x2 << 24)
60 #define DESC_NXT_DV_REFRESH	(0x1 << 26)
61 #define DESC_NXT_DV_REUSE	(0x2 << 26)
62 #define DESC_NTYPE_TYPE2	(0x2 << 29)
63 
64 /* Type 2 descriptor with Source or Destination address update */
65 struct omap_type2_desc {
66 	uint32_t next_desc;
67 	uint32_t en;
68 	uint32_t addr; /* src or dst */
69 	uint16_t fn;
70 	uint16_t cicr;
71 	int16_t cdei;
72 	int16_t csei;
73 	int32_t cdfi;
74 	int32_t csfi;
75 } __packed;
76 
77 struct omap_sg {
78 	dma_addr_t addr;
79 	uint32_t en;		/* number of elements (24-bit) */
80 	uint32_t fn;		/* number of frames (16-bit) */
81 	int32_t fi;		/* for double indexing */
82 	int16_t ei;		/* for double indexing */
83 
84 	/* Linked list */
85 	struct omap_type2_desc *t2_desc;
86 	dma_addr_t t2_desc_paddr;
87 };
88 
89 struct omap_desc {
90 	struct virt_dma_desc vd;
91 	bool using_ll;
92 	enum dma_transfer_direction dir;
93 	dma_addr_t dev_addr;
94 	bool polled;
95 
96 	int32_t fi;		/* for OMAP_DMA_SYNC_PACKET / double indexing */
97 	int16_t ei;		/* for double indexing */
98 	uint8_t es;		/* CSDP_DATA_TYPE_xxx */
99 	uint32_t ccr;		/* CCR value */
100 	uint16_t clnk_ctrl;	/* CLNK_CTRL value */
101 	uint16_t cicr;		/* CICR value */
102 	uint32_t csdp;		/* CSDP value */
103 
104 	unsigned sglen;
105 	struct omap_sg sg[0];
106 };
107 
108 enum {
109 	CAPS_0_SUPPORT_LL123	= BIT(20),	/* Linked List type1/2/3 */
110 	CAPS_0_SUPPORT_LL4	= BIT(21),	/* Linked List type4 */
111 
112 	CCR_FS			= BIT(5),
113 	CCR_READ_PRIORITY	= BIT(6),
114 	CCR_ENABLE		= BIT(7),
115 	CCR_AUTO_INIT		= BIT(8),	/* OMAP1 only */
116 	CCR_REPEAT		= BIT(9),	/* OMAP1 only */
117 	CCR_OMAP31_DISABLE	= BIT(10),	/* OMAP1 only */
118 	CCR_SUSPEND_SENSITIVE	= BIT(8),	/* OMAP2+ only */
119 	CCR_RD_ACTIVE		= BIT(9),	/* OMAP2+ only */
120 	CCR_WR_ACTIVE		= BIT(10),	/* OMAP2+ only */
121 	CCR_SRC_AMODE_CONSTANT	= 0 << 12,
122 	CCR_SRC_AMODE_POSTINC	= 1 << 12,
123 	CCR_SRC_AMODE_SGLIDX	= 2 << 12,
124 	CCR_SRC_AMODE_DBLIDX	= 3 << 12,
125 	CCR_DST_AMODE_CONSTANT	= 0 << 14,
126 	CCR_DST_AMODE_POSTINC	= 1 << 14,
127 	CCR_DST_AMODE_SGLIDX	= 2 << 14,
128 	CCR_DST_AMODE_DBLIDX	= 3 << 14,
129 	CCR_CONSTANT_FILL	= BIT(16),
130 	CCR_TRANSPARENT_COPY	= BIT(17),
131 	CCR_BS			= BIT(18),
132 	CCR_SUPERVISOR		= BIT(22),
133 	CCR_PREFETCH		= BIT(23),
134 	CCR_TRIGGER_SRC		= BIT(24),
135 	CCR_BUFFERING_DISABLE	= BIT(25),
136 	CCR_WRITE_PRIORITY	= BIT(26),
137 	CCR_SYNC_ELEMENT	= 0,
138 	CCR_SYNC_FRAME		= CCR_FS,
139 	CCR_SYNC_BLOCK		= CCR_BS,
140 	CCR_SYNC_PACKET		= CCR_BS | CCR_FS,
141 
142 	CSDP_DATA_TYPE_8	= 0,
143 	CSDP_DATA_TYPE_16	= 1,
144 	CSDP_DATA_TYPE_32	= 2,
145 	CSDP_SRC_PORT_EMIFF	= 0 << 2, /* OMAP1 only */
146 	CSDP_SRC_PORT_EMIFS	= 1 << 2, /* OMAP1 only */
147 	CSDP_SRC_PORT_OCP_T1	= 2 << 2, /* OMAP1 only */
148 	CSDP_SRC_PORT_TIPB	= 3 << 2, /* OMAP1 only */
149 	CSDP_SRC_PORT_OCP_T2	= 4 << 2, /* OMAP1 only */
150 	CSDP_SRC_PORT_MPUI	= 5 << 2, /* OMAP1 only */
151 	CSDP_SRC_PACKED		= BIT(6),
152 	CSDP_SRC_BURST_1	= 0 << 7,
153 	CSDP_SRC_BURST_16	= 1 << 7,
154 	CSDP_SRC_BURST_32	= 2 << 7,
155 	CSDP_SRC_BURST_64	= 3 << 7,
156 	CSDP_DST_PORT_EMIFF	= 0 << 9, /* OMAP1 only */
157 	CSDP_DST_PORT_EMIFS	= 1 << 9, /* OMAP1 only */
158 	CSDP_DST_PORT_OCP_T1	= 2 << 9, /* OMAP1 only */
159 	CSDP_DST_PORT_TIPB	= 3 << 9, /* OMAP1 only */
160 	CSDP_DST_PORT_OCP_T2	= 4 << 9, /* OMAP1 only */
161 	CSDP_DST_PORT_MPUI	= 5 << 9, /* OMAP1 only */
162 	CSDP_DST_PACKED		= BIT(13),
163 	CSDP_DST_BURST_1	= 0 << 14,
164 	CSDP_DST_BURST_16	= 1 << 14,
165 	CSDP_DST_BURST_32	= 2 << 14,
166 	CSDP_DST_BURST_64	= 3 << 14,
167 	CSDP_WRITE_NON_POSTED	= 0 << 16,
168 	CSDP_WRITE_POSTED	= 1 << 16,
169 	CSDP_WRITE_LAST_NON_POSTED = 2 << 16,
170 
171 	CICR_TOUT_IE		= BIT(0),	/* OMAP1 only */
172 	CICR_DROP_IE		= BIT(1),
173 	CICR_HALF_IE		= BIT(2),
174 	CICR_FRAME_IE		= BIT(3),
175 	CICR_LAST_IE		= BIT(4),
176 	CICR_BLOCK_IE		= BIT(5),
177 	CICR_PKT_IE		= BIT(7),	/* OMAP2+ only */
178 	CICR_TRANS_ERR_IE	= BIT(8),	/* OMAP2+ only */
179 	CICR_SUPERVISOR_ERR_IE	= BIT(10),	/* OMAP2+ only */
180 	CICR_MISALIGNED_ERR_IE	= BIT(11),	/* OMAP2+ only */
181 	CICR_DRAIN_IE		= BIT(12),	/* OMAP2+ only */
182 	CICR_SUPER_BLOCK_IE	= BIT(14),	/* OMAP2+ only */
183 
184 	CLNK_CTRL_ENABLE_LNK	= BIT(15),
185 
186 	CDP_DST_VALID_INC	= 0 << 0,
187 	CDP_DST_VALID_RELOAD	= 1 << 0,
188 	CDP_DST_VALID_REUSE	= 2 << 0,
189 	CDP_SRC_VALID_INC	= 0 << 2,
190 	CDP_SRC_VALID_RELOAD	= 1 << 2,
191 	CDP_SRC_VALID_REUSE	= 2 << 2,
192 	CDP_NTYPE_TYPE1		= 1 << 4,
193 	CDP_NTYPE_TYPE2		= 2 << 4,
194 	CDP_NTYPE_TYPE3		= 3 << 4,
195 	CDP_TMODE_NORMAL	= 0 << 8,
196 	CDP_TMODE_LLIST		= 1 << 8,
197 	CDP_FAST		= BIT(10),
198 };
199 
200 static const unsigned es_bytes[] = {
201 	[CSDP_DATA_TYPE_8] = 1,
202 	[CSDP_DATA_TYPE_16] = 2,
203 	[CSDP_DATA_TYPE_32] = 4,
204 };
205 
206 static bool omap_dma_filter_fn(struct dma_chan *chan, void *param);
207 static struct of_dma_filter_info omap_dma_info = {
208 	.filter_fn = omap_dma_filter_fn,
209 };
210 
211 static inline struct omap_dmadev *to_omap_dma_dev(struct dma_device *d)
212 {
213 	return container_of(d, struct omap_dmadev, ddev);
214 }
215 
216 static inline struct omap_chan *to_omap_dma_chan(struct dma_chan *c)
217 {
218 	return container_of(c, struct omap_chan, vc.chan);
219 }
220 
221 static inline struct omap_desc *to_omap_dma_desc(struct dma_async_tx_descriptor *t)
222 {
223 	return container_of(t, struct omap_desc, vd.tx);
224 }
225 
226 static void omap_dma_desc_free(struct virt_dma_desc *vd)
227 {
228 	struct omap_desc *d = to_omap_dma_desc(&vd->tx);
229 
230 	if (d->using_ll) {
231 		struct omap_dmadev *od = to_omap_dma_dev(vd->tx.chan->device);
232 		int i;
233 
234 		for (i = 0; i < d->sglen; i++) {
235 			if (d->sg[i].t2_desc)
236 				dma_pool_free(od->desc_pool, d->sg[i].t2_desc,
237 					      d->sg[i].t2_desc_paddr);
238 		}
239 	}
240 
241 	kfree(d);
242 }
243 
244 static void omap_dma_fill_type2_desc(struct omap_desc *d, int idx,
245 				     enum dma_transfer_direction dir, bool last)
246 {
247 	struct omap_sg *sg = &d->sg[idx];
248 	struct omap_type2_desc *t2_desc = sg->t2_desc;
249 
250 	if (idx)
251 		d->sg[idx - 1].t2_desc->next_desc = sg->t2_desc_paddr;
252 	if (last)
253 		t2_desc->next_desc = 0xfffffffc;
254 
255 	t2_desc->en = sg->en;
256 	t2_desc->addr = sg->addr;
257 	t2_desc->fn = sg->fn & 0xffff;
258 	t2_desc->cicr = d->cicr;
259 	if (!last)
260 		t2_desc->cicr &= ~CICR_BLOCK_IE;
261 
262 	switch (dir) {
263 	case DMA_DEV_TO_MEM:
264 		t2_desc->cdei = sg->ei;
265 		t2_desc->csei = d->ei;
266 		t2_desc->cdfi = sg->fi;
267 		t2_desc->csfi = d->fi;
268 
269 		t2_desc->en |= DESC_NXT_DV_REFRESH;
270 		t2_desc->en |= DESC_NXT_SV_REUSE;
271 		break;
272 	case DMA_MEM_TO_DEV:
273 		t2_desc->cdei = d->ei;
274 		t2_desc->csei = sg->ei;
275 		t2_desc->cdfi = d->fi;
276 		t2_desc->csfi = sg->fi;
277 
278 		t2_desc->en |= DESC_NXT_SV_REFRESH;
279 		t2_desc->en |= DESC_NXT_DV_REUSE;
280 		break;
281 	default:
282 		return;
283 	}
284 
285 	t2_desc->en |= DESC_NTYPE_TYPE2;
286 }
287 
288 static void omap_dma_write(uint32_t val, unsigned type, void __iomem *addr)
289 {
290 	switch (type) {
291 	case OMAP_DMA_REG_16BIT:
292 		writew_relaxed(val, addr);
293 		break;
294 	case OMAP_DMA_REG_2X16BIT:
295 		writew_relaxed(val, addr);
296 		writew_relaxed(val >> 16, addr + 2);
297 		break;
298 	case OMAP_DMA_REG_32BIT:
299 		writel_relaxed(val, addr);
300 		break;
301 	default:
302 		WARN_ON(1);
303 	}
304 }
305 
306 static unsigned omap_dma_read(unsigned type, void __iomem *addr)
307 {
308 	unsigned val;
309 
310 	switch (type) {
311 	case OMAP_DMA_REG_16BIT:
312 		val = readw_relaxed(addr);
313 		break;
314 	case OMAP_DMA_REG_2X16BIT:
315 		val = readw_relaxed(addr);
316 		val |= readw_relaxed(addr + 2) << 16;
317 		break;
318 	case OMAP_DMA_REG_32BIT:
319 		val = readl_relaxed(addr);
320 		break;
321 	default:
322 		WARN_ON(1);
323 		val = 0;
324 	}
325 
326 	return val;
327 }
328 
329 static void omap_dma_glbl_write(struct omap_dmadev *od, unsigned reg, unsigned val)
330 {
331 	const struct omap_dma_reg *r = od->reg_map + reg;
332 
333 	WARN_ON(r->stride);
334 
335 	omap_dma_write(val, r->type, od->base + r->offset);
336 }
337 
338 static unsigned omap_dma_glbl_read(struct omap_dmadev *od, unsigned reg)
339 {
340 	const struct omap_dma_reg *r = od->reg_map + reg;
341 
342 	WARN_ON(r->stride);
343 
344 	return omap_dma_read(r->type, od->base + r->offset);
345 }
346 
347 static void omap_dma_chan_write(struct omap_chan *c, unsigned reg, unsigned val)
348 {
349 	const struct omap_dma_reg *r = c->reg_map + reg;
350 
351 	omap_dma_write(val, r->type, c->channel_base + r->offset);
352 }
353 
354 static unsigned omap_dma_chan_read(struct omap_chan *c, unsigned reg)
355 {
356 	const struct omap_dma_reg *r = c->reg_map + reg;
357 
358 	return omap_dma_read(r->type, c->channel_base + r->offset);
359 }
360 
361 static void omap_dma_clear_csr(struct omap_chan *c)
362 {
363 	if (dma_omap1())
364 		omap_dma_chan_read(c, CSR);
365 	else
366 		omap_dma_chan_write(c, CSR, ~0);
367 }
368 
369 static unsigned omap_dma_get_csr(struct omap_chan *c)
370 {
371 	unsigned val = omap_dma_chan_read(c, CSR);
372 
373 	if (!dma_omap1())
374 		omap_dma_chan_write(c, CSR, val);
375 
376 	return val;
377 }
378 
379 static void omap_dma_assign(struct omap_dmadev *od, struct omap_chan *c,
380 	unsigned lch)
381 {
382 	c->channel_base = od->base + od->plat->channel_stride * lch;
383 
384 	od->lch_map[lch] = c;
385 }
386 
387 static void omap_dma_start(struct omap_chan *c, struct omap_desc *d)
388 {
389 	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
390 	uint16_t cicr = d->cicr;
391 
392 	if (__dma_omap15xx(od->plat->dma_attr))
393 		omap_dma_chan_write(c, CPC, 0);
394 	else
395 		omap_dma_chan_write(c, CDAC, 0);
396 
397 	omap_dma_clear_csr(c);
398 
399 	if (d->using_ll) {
400 		uint32_t cdp = CDP_TMODE_LLIST | CDP_NTYPE_TYPE2 | CDP_FAST;
401 
402 		if (d->dir == DMA_DEV_TO_MEM)
403 			cdp |= (CDP_DST_VALID_RELOAD | CDP_SRC_VALID_REUSE);
404 		else
405 			cdp |= (CDP_DST_VALID_REUSE | CDP_SRC_VALID_RELOAD);
406 		omap_dma_chan_write(c, CDP, cdp);
407 
408 		omap_dma_chan_write(c, CNDP, d->sg[0].t2_desc_paddr);
409 		omap_dma_chan_write(c, CCDN, 0);
410 		omap_dma_chan_write(c, CCFN, 0xffff);
411 		omap_dma_chan_write(c, CCEN, 0xffffff);
412 
413 		cicr &= ~CICR_BLOCK_IE;
414 	} else if (od->ll123_supported) {
415 		omap_dma_chan_write(c, CDP, 0);
416 	}
417 
418 	/* Enable interrupts */
419 	omap_dma_chan_write(c, CICR, cicr);
420 
421 	/* Enable channel */
422 	omap_dma_chan_write(c, CCR, d->ccr | CCR_ENABLE);
423 
424 	c->running = true;
425 }
426 
427 static void omap_dma_drain_chan(struct omap_chan *c)
428 {
429 	int i;
430 	u32 val;
431 
432 	/* Wait for sDMA FIFO to drain */
433 	for (i = 0; ; i++) {
434 		val = omap_dma_chan_read(c, CCR);
435 		if (!(val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE)))
436 			break;
437 
438 		if (i > 100)
439 			break;
440 
441 		udelay(5);
442 	}
443 
444 	if (val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE))
445 		dev_err(c->vc.chan.device->dev,
446 			"DMA drain did not complete on lch %d\n",
447 			c->dma_ch);
448 }
449 
450 static int omap_dma_stop(struct omap_chan *c)
451 {
452 	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
453 	uint32_t val;
454 
455 	/* disable irq */
456 	omap_dma_chan_write(c, CICR, 0);
457 
458 	omap_dma_clear_csr(c);
459 
460 	val = omap_dma_chan_read(c, CCR);
461 	if (od->plat->errata & DMA_ERRATA_i541 && val & CCR_TRIGGER_SRC) {
462 		uint32_t sysconfig;
463 
464 		sysconfig = omap_dma_glbl_read(od, OCP_SYSCONFIG);
465 		val = sysconfig & ~DMA_SYSCONFIG_MIDLEMODE_MASK;
466 		val |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
467 		omap_dma_glbl_write(od, OCP_SYSCONFIG, val);
468 
469 		val = omap_dma_chan_read(c, CCR);
470 		val &= ~CCR_ENABLE;
471 		omap_dma_chan_write(c, CCR, val);
472 
473 		if (!(c->ccr & CCR_BUFFERING_DISABLE))
474 			omap_dma_drain_chan(c);
475 
476 		omap_dma_glbl_write(od, OCP_SYSCONFIG, sysconfig);
477 	} else {
478 		if (!(val & CCR_ENABLE))
479 			return -EINVAL;
480 
481 		val &= ~CCR_ENABLE;
482 		omap_dma_chan_write(c, CCR, val);
483 
484 		if (!(c->ccr & CCR_BUFFERING_DISABLE))
485 			omap_dma_drain_chan(c);
486 	}
487 
488 	mb();
489 
490 	if (!__dma_omap15xx(od->plat->dma_attr) && c->cyclic) {
491 		val = omap_dma_chan_read(c, CLNK_CTRL);
492 
493 		if (dma_omap1())
494 			val |= 1 << 14; /* set the STOP_LNK bit */
495 		else
496 			val &= ~CLNK_CTRL_ENABLE_LNK;
497 
498 		omap_dma_chan_write(c, CLNK_CTRL, val);
499 	}
500 	c->running = false;
501 	return 0;
502 }
503 
504 static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d)
505 {
506 	struct omap_sg *sg = d->sg + c->sgidx;
507 	unsigned cxsa, cxei, cxfi;
508 
509 	if (d->dir == DMA_DEV_TO_MEM || d->dir == DMA_MEM_TO_MEM) {
510 		cxsa = CDSA;
511 		cxei = CDEI;
512 		cxfi = CDFI;
513 	} else {
514 		cxsa = CSSA;
515 		cxei = CSEI;
516 		cxfi = CSFI;
517 	}
518 
519 	omap_dma_chan_write(c, cxsa, sg->addr);
520 	omap_dma_chan_write(c, cxei, sg->ei);
521 	omap_dma_chan_write(c, cxfi, sg->fi);
522 	omap_dma_chan_write(c, CEN, sg->en);
523 	omap_dma_chan_write(c, CFN, sg->fn);
524 
525 	omap_dma_start(c, d);
526 	c->sgidx++;
527 }
528 
529 static void omap_dma_start_desc(struct omap_chan *c)
530 {
531 	struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
532 	struct omap_desc *d;
533 	unsigned cxsa, cxei, cxfi;
534 
535 	if (!vd) {
536 		c->desc = NULL;
537 		return;
538 	}
539 
540 	list_del(&vd->node);
541 
542 	c->desc = d = to_omap_dma_desc(&vd->tx);
543 	c->sgidx = 0;
544 
545 	/*
546 	 * This provides the necessary barrier to ensure data held in
547 	 * DMA coherent memory is visible to the DMA engine prior to
548 	 * the transfer starting.
549 	 */
550 	mb();
551 
552 	omap_dma_chan_write(c, CCR, d->ccr);
553 	if (dma_omap1())
554 		omap_dma_chan_write(c, CCR2, d->ccr >> 16);
555 
556 	if (d->dir == DMA_DEV_TO_MEM || d->dir == DMA_MEM_TO_MEM) {
557 		cxsa = CSSA;
558 		cxei = CSEI;
559 		cxfi = CSFI;
560 	} else {
561 		cxsa = CDSA;
562 		cxei = CDEI;
563 		cxfi = CDFI;
564 	}
565 
566 	omap_dma_chan_write(c, cxsa, d->dev_addr);
567 	omap_dma_chan_write(c, cxei, d->ei);
568 	omap_dma_chan_write(c, cxfi, d->fi);
569 	omap_dma_chan_write(c, CSDP, d->csdp);
570 	omap_dma_chan_write(c, CLNK_CTRL, d->clnk_ctrl);
571 
572 	omap_dma_start_sg(c, d);
573 }
574 
575 static void omap_dma_callback(int ch, u16 status, void *data)
576 {
577 	struct omap_chan *c = data;
578 	struct omap_desc *d;
579 	unsigned long flags;
580 
581 	spin_lock_irqsave(&c->vc.lock, flags);
582 	d = c->desc;
583 	if (d) {
584 		if (c->cyclic) {
585 			vchan_cyclic_callback(&d->vd);
586 		} else if (d->using_ll || c->sgidx == d->sglen) {
587 			omap_dma_start_desc(c);
588 			vchan_cookie_complete(&d->vd);
589 		} else {
590 			omap_dma_start_sg(c, d);
591 		}
592 	}
593 	spin_unlock_irqrestore(&c->vc.lock, flags);
594 }
595 
596 static irqreturn_t omap_dma_irq(int irq, void *devid)
597 {
598 	struct omap_dmadev *od = devid;
599 	unsigned status, channel;
600 
601 	spin_lock(&od->irq_lock);
602 
603 	status = omap_dma_glbl_read(od, IRQSTATUS_L1);
604 	status &= od->irq_enable_mask;
605 	if (status == 0) {
606 		spin_unlock(&od->irq_lock);
607 		return IRQ_NONE;
608 	}
609 
610 	while ((channel = ffs(status)) != 0) {
611 		unsigned mask, csr;
612 		struct omap_chan *c;
613 
614 		channel -= 1;
615 		mask = BIT(channel);
616 		status &= ~mask;
617 
618 		c = od->lch_map[channel];
619 		if (c == NULL) {
620 			/* This should never happen */
621 			dev_err(od->ddev.dev, "invalid channel %u\n", channel);
622 			continue;
623 		}
624 
625 		csr = omap_dma_get_csr(c);
626 		omap_dma_glbl_write(od, IRQSTATUS_L1, mask);
627 
628 		omap_dma_callback(channel, csr, c);
629 	}
630 
631 	spin_unlock(&od->irq_lock);
632 
633 	return IRQ_HANDLED;
634 }
635 
636 static int omap_dma_alloc_chan_resources(struct dma_chan *chan)
637 {
638 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
639 	struct omap_chan *c = to_omap_dma_chan(chan);
640 	struct device *dev = od->ddev.dev;
641 	int ret;
642 
643 	if (od->legacy) {
644 		ret = omap_request_dma(c->dma_sig, "DMA engine",
645 				       omap_dma_callback, c, &c->dma_ch);
646 	} else {
647 		ret = omap_request_dma(c->dma_sig, "DMA engine", NULL, NULL,
648 				       &c->dma_ch);
649 	}
650 
651 	dev_dbg(dev, "allocating channel %u for %u\n", c->dma_ch, c->dma_sig);
652 
653 	if (ret >= 0) {
654 		omap_dma_assign(od, c, c->dma_ch);
655 
656 		if (!od->legacy) {
657 			unsigned val;
658 
659 			spin_lock_irq(&od->irq_lock);
660 			val = BIT(c->dma_ch);
661 			omap_dma_glbl_write(od, IRQSTATUS_L1, val);
662 			od->irq_enable_mask |= val;
663 			omap_dma_glbl_write(od, IRQENABLE_L1, od->irq_enable_mask);
664 
665 			val = omap_dma_glbl_read(od, IRQENABLE_L0);
666 			val &= ~BIT(c->dma_ch);
667 			omap_dma_glbl_write(od, IRQENABLE_L0, val);
668 			spin_unlock_irq(&od->irq_lock);
669 		}
670 	}
671 
672 	if (dma_omap1()) {
673 		if (__dma_omap16xx(od->plat->dma_attr)) {
674 			c->ccr = CCR_OMAP31_DISABLE;
675 			/* Duplicate what plat-omap/dma.c does */
676 			c->ccr |= c->dma_ch + 1;
677 		} else {
678 			c->ccr = c->dma_sig & 0x1f;
679 		}
680 	} else {
681 		c->ccr = c->dma_sig & 0x1f;
682 		c->ccr |= (c->dma_sig & ~0x1f) << 14;
683 	}
684 	if (od->plat->errata & DMA_ERRATA_IFRAME_BUFFERING)
685 		c->ccr |= CCR_BUFFERING_DISABLE;
686 
687 	return ret;
688 }
689 
690 static void omap_dma_free_chan_resources(struct dma_chan *chan)
691 {
692 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
693 	struct omap_chan *c = to_omap_dma_chan(chan);
694 
695 	if (!od->legacy) {
696 		spin_lock_irq(&od->irq_lock);
697 		od->irq_enable_mask &= ~BIT(c->dma_ch);
698 		omap_dma_glbl_write(od, IRQENABLE_L1, od->irq_enable_mask);
699 		spin_unlock_irq(&od->irq_lock);
700 	}
701 
702 	c->channel_base = NULL;
703 	od->lch_map[c->dma_ch] = NULL;
704 	vchan_free_chan_resources(&c->vc);
705 	omap_free_dma(c->dma_ch);
706 
707 	dev_dbg(od->ddev.dev, "freeing channel %u used for %u\n", c->dma_ch,
708 		c->dma_sig);
709 	c->dma_sig = 0;
710 }
711 
712 static size_t omap_dma_sg_size(struct omap_sg *sg)
713 {
714 	return sg->en * sg->fn;
715 }
716 
717 static size_t omap_dma_desc_size(struct omap_desc *d)
718 {
719 	unsigned i;
720 	size_t size;
721 
722 	for (size = i = 0; i < d->sglen; i++)
723 		size += omap_dma_sg_size(&d->sg[i]);
724 
725 	return size * es_bytes[d->es];
726 }
727 
728 static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr)
729 {
730 	unsigned i;
731 	size_t size, es_size = es_bytes[d->es];
732 
733 	for (size = i = 0; i < d->sglen; i++) {
734 		size_t this_size = omap_dma_sg_size(&d->sg[i]) * es_size;
735 
736 		if (size)
737 			size += this_size;
738 		else if (addr >= d->sg[i].addr &&
739 			 addr < d->sg[i].addr + this_size)
740 			size += d->sg[i].addr + this_size - addr;
741 	}
742 	return size;
743 }
744 
745 /*
746  * OMAP 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is
747  * read before the DMA controller finished disabling the channel.
748  */
749 static uint32_t omap_dma_chan_read_3_3(struct omap_chan *c, unsigned reg)
750 {
751 	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
752 	uint32_t val;
753 
754 	val = omap_dma_chan_read(c, reg);
755 	if (val == 0 && od->plat->errata & DMA_ERRATA_3_3)
756 		val = omap_dma_chan_read(c, reg);
757 
758 	return val;
759 }
760 
761 static dma_addr_t omap_dma_get_src_pos(struct omap_chan *c)
762 {
763 	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
764 	dma_addr_t addr, cdac;
765 
766 	if (__dma_omap15xx(od->plat->dma_attr)) {
767 		addr = omap_dma_chan_read(c, CPC);
768 	} else {
769 		addr = omap_dma_chan_read_3_3(c, CSAC);
770 		cdac = omap_dma_chan_read_3_3(c, CDAC);
771 
772 		/*
773 		 * CDAC == 0 indicates that the DMA transfer on the channel has
774 		 * not been started (no data has been transferred so far).
775 		 * Return the programmed source start address in this case.
776 		 */
777 		if (cdac == 0)
778 			addr = omap_dma_chan_read(c, CSSA);
779 	}
780 
781 	if (dma_omap1())
782 		addr |= omap_dma_chan_read(c, CSSA) & 0xffff0000;
783 
784 	return addr;
785 }
786 
787 static dma_addr_t omap_dma_get_dst_pos(struct omap_chan *c)
788 {
789 	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
790 	dma_addr_t addr;
791 
792 	if (__dma_omap15xx(od->plat->dma_attr)) {
793 		addr = omap_dma_chan_read(c, CPC);
794 	} else {
795 		addr = omap_dma_chan_read_3_3(c, CDAC);
796 
797 		/*
798 		 * CDAC == 0 indicates that the DMA transfer on the channel
799 		 * has not been started (no data has been transferred so
800 		 * far).  Return the programmed destination start address in
801 		 * this case.
802 		 */
803 		if (addr == 0)
804 			addr = omap_dma_chan_read(c, CDSA);
805 	}
806 
807 	if (dma_omap1())
808 		addr |= omap_dma_chan_read(c, CDSA) & 0xffff0000;
809 
810 	return addr;
811 }
812 
813 static enum dma_status omap_dma_tx_status(struct dma_chan *chan,
814 	dma_cookie_t cookie, struct dma_tx_state *txstate)
815 {
816 	struct omap_chan *c = to_omap_dma_chan(chan);
817 	enum dma_status ret;
818 	unsigned long flags;
819 	struct omap_desc *d = NULL;
820 
821 	ret = dma_cookie_status(chan, cookie, txstate);
822 	if (ret == DMA_COMPLETE)
823 		return ret;
824 
825 	spin_lock_irqsave(&c->vc.lock, flags);
826 	if (c->desc && c->desc->vd.tx.cookie == cookie)
827 		d = c->desc;
828 
829 	if (!txstate)
830 		goto out;
831 
832 	if (d) {
833 		dma_addr_t pos;
834 
835 		if (d->dir == DMA_MEM_TO_DEV)
836 			pos = omap_dma_get_src_pos(c);
837 		else if (d->dir == DMA_DEV_TO_MEM  || d->dir == DMA_MEM_TO_MEM)
838 			pos = omap_dma_get_dst_pos(c);
839 		else
840 			pos = 0;
841 
842 		txstate->residue = omap_dma_desc_size_pos(d, pos);
843 	} else {
844 		struct virt_dma_desc *vd = vchan_find_desc(&c->vc, cookie);
845 
846 		if (vd)
847 			txstate->residue = omap_dma_desc_size(
848 						to_omap_dma_desc(&vd->tx));
849 		else
850 			txstate->residue = 0;
851 	}
852 
853 out:
854 	if (ret == DMA_IN_PROGRESS && c->paused) {
855 		ret = DMA_PAUSED;
856 	} else if (d && d->polled && c->running) {
857 		uint32_t ccr = omap_dma_chan_read(c, CCR);
858 		/*
859 		 * The channel is no longer active, set the return value
860 		 * accordingly and mark it as completed
861 		 */
862 		if (!(ccr & CCR_ENABLE)) {
863 			ret = DMA_COMPLETE;
864 			omap_dma_start_desc(c);
865 			vchan_cookie_complete(&d->vd);
866 		}
867 	}
868 
869 	spin_unlock_irqrestore(&c->vc.lock, flags);
870 
871 	return ret;
872 }
873 
874 static void omap_dma_issue_pending(struct dma_chan *chan)
875 {
876 	struct omap_chan *c = to_omap_dma_chan(chan);
877 	unsigned long flags;
878 
879 	spin_lock_irqsave(&c->vc.lock, flags);
880 	if (vchan_issue_pending(&c->vc) && !c->desc)
881 		omap_dma_start_desc(c);
882 	spin_unlock_irqrestore(&c->vc.lock, flags);
883 }
884 
885 static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
886 	struct dma_chan *chan, struct scatterlist *sgl, unsigned sglen,
887 	enum dma_transfer_direction dir, unsigned long tx_flags, void *context)
888 {
889 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
890 	struct omap_chan *c = to_omap_dma_chan(chan);
891 	enum dma_slave_buswidth dev_width;
892 	struct scatterlist *sgent;
893 	struct omap_desc *d;
894 	dma_addr_t dev_addr;
895 	unsigned i, es, en, frame_bytes;
896 	bool ll_failed = false;
897 	u32 burst;
898 	u32 port_window, port_window_bytes;
899 
900 	if (dir == DMA_DEV_TO_MEM) {
901 		dev_addr = c->cfg.src_addr;
902 		dev_width = c->cfg.src_addr_width;
903 		burst = c->cfg.src_maxburst;
904 		port_window = c->cfg.src_port_window_size;
905 	} else if (dir == DMA_MEM_TO_DEV) {
906 		dev_addr = c->cfg.dst_addr;
907 		dev_width = c->cfg.dst_addr_width;
908 		burst = c->cfg.dst_maxburst;
909 		port_window = c->cfg.dst_port_window_size;
910 	} else {
911 		dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
912 		return NULL;
913 	}
914 
915 	/* Bus width translates to the element size (ES) */
916 	switch (dev_width) {
917 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
918 		es = CSDP_DATA_TYPE_8;
919 		break;
920 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
921 		es = CSDP_DATA_TYPE_16;
922 		break;
923 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
924 		es = CSDP_DATA_TYPE_32;
925 		break;
926 	default: /* not reached */
927 		return NULL;
928 	}
929 
930 	/* Now allocate and setup the descriptor. */
931 	d = kzalloc(struct_size(d, sg, sglen), GFP_ATOMIC);
932 	if (!d)
933 		return NULL;
934 
935 	d->dir = dir;
936 	d->dev_addr = dev_addr;
937 	d->es = es;
938 
939 	/* When the port_window is used, one frame must cover the window */
940 	if (port_window) {
941 		burst = port_window;
942 		port_window_bytes = port_window * es_bytes[es];
943 
944 		d->ei = 1;
945 		/*
946 		 * One frame covers the port_window and by  configure
947 		 * the source frame index to be -1 * (port_window - 1)
948 		 * we instruct the sDMA that after a frame is processed
949 		 * it should move back to the start of the window.
950 		 */
951 		d->fi = -(port_window_bytes - 1);
952 	}
953 
954 	d->ccr = c->ccr | CCR_SYNC_FRAME;
955 	if (dir == DMA_DEV_TO_MEM) {
956 		d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
957 
958 		d->ccr |= CCR_DST_AMODE_POSTINC;
959 		if (port_window) {
960 			d->ccr |= CCR_SRC_AMODE_DBLIDX;
961 
962 			if (port_window_bytes >= 64)
963 				d->csdp |= CSDP_SRC_BURST_64;
964 			else if (port_window_bytes >= 32)
965 				d->csdp |= CSDP_SRC_BURST_32;
966 			else if (port_window_bytes >= 16)
967 				d->csdp |= CSDP_SRC_BURST_16;
968 
969 		} else {
970 			d->ccr |= CCR_SRC_AMODE_CONSTANT;
971 		}
972 	} else {
973 		d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
974 
975 		d->ccr |= CCR_SRC_AMODE_POSTINC;
976 		if (port_window) {
977 			d->ccr |= CCR_DST_AMODE_DBLIDX;
978 
979 			if (port_window_bytes >= 64)
980 				d->csdp |= CSDP_DST_BURST_64;
981 			else if (port_window_bytes >= 32)
982 				d->csdp |= CSDP_DST_BURST_32;
983 			else if (port_window_bytes >= 16)
984 				d->csdp |= CSDP_DST_BURST_16;
985 		} else {
986 			d->ccr |= CCR_DST_AMODE_CONSTANT;
987 		}
988 	}
989 
990 	d->cicr = CICR_DROP_IE | CICR_BLOCK_IE;
991 	d->csdp |= es;
992 
993 	if (dma_omap1()) {
994 		d->cicr |= CICR_TOUT_IE;
995 
996 		if (dir == DMA_DEV_TO_MEM)
997 			d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_TIPB;
998 		else
999 			d->csdp |= CSDP_DST_PORT_TIPB | CSDP_SRC_PORT_EMIFF;
1000 	} else {
1001 		if (dir == DMA_DEV_TO_MEM)
1002 			d->ccr |= CCR_TRIGGER_SRC;
1003 
1004 		d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
1005 
1006 		if (port_window)
1007 			d->csdp |= CSDP_WRITE_LAST_NON_POSTED;
1008 	}
1009 	if (od->plat->errata & DMA_ERRATA_PARALLEL_CHANNELS)
1010 		d->clnk_ctrl = c->dma_ch;
1011 
1012 	/*
1013 	 * Build our scatterlist entries: each contains the address,
1014 	 * the number of elements (EN) in each frame, and the number of
1015 	 * frames (FN).  Number of bytes for this entry = ES * EN * FN.
1016 	 *
1017 	 * Burst size translates to number of elements with frame sync.
1018 	 * Note: DMA engine defines burst to be the number of dev-width
1019 	 * transfers.
1020 	 */
1021 	en = burst;
1022 	frame_bytes = es_bytes[es] * en;
1023 
1024 	if (sglen >= 2)
1025 		d->using_ll = od->ll123_supported;
1026 
1027 	for_each_sg(sgl, sgent, sglen, i) {
1028 		struct omap_sg *osg = &d->sg[i];
1029 
1030 		osg->addr = sg_dma_address(sgent);
1031 		osg->en = en;
1032 		osg->fn = sg_dma_len(sgent) / frame_bytes;
1033 
1034 		if (d->using_ll) {
1035 			osg->t2_desc = dma_pool_alloc(od->desc_pool, GFP_ATOMIC,
1036 						      &osg->t2_desc_paddr);
1037 			if (!osg->t2_desc) {
1038 				dev_err(chan->device->dev,
1039 					"t2_desc[%d] allocation failed\n", i);
1040 				ll_failed = true;
1041 				d->using_ll = false;
1042 				continue;
1043 			}
1044 
1045 			omap_dma_fill_type2_desc(d, i, dir, (i == sglen - 1));
1046 		}
1047 	}
1048 
1049 	d->sglen = sglen;
1050 
1051 	/* Release the dma_pool entries if one allocation failed */
1052 	if (ll_failed) {
1053 		for (i = 0; i < d->sglen; i++) {
1054 			struct omap_sg *osg = &d->sg[i];
1055 
1056 			if (osg->t2_desc) {
1057 				dma_pool_free(od->desc_pool, osg->t2_desc,
1058 					      osg->t2_desc_paddr);
1059 				osg->t2_desc = NULL;
1060 			}
1061 		}
1062 	}
1063 
1064 	return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
1065 }
1066 
1067 static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic(
1068 	struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
1069 	size_t period_len, enum dma_transfer_direction dir, unsigned long flags)
1070 {
1071 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1072 	struct omap_chan *c = to_omap_dma_chan(chan);
1073 	enum dma_slave_buswidth dev_width;
1074 	struct omap_desc *d;
1075 	dma_addr_t dev_addr;
1076 	unsigned es;
1077 	u32 burst;
1078 
1079 	if (dir == DMA_DEV_TO_MEM) {
1080 		dev_addr = c->cfg.src_addr;
1081 		dev_width = c->cfg.src_addr_width;
1082 		burst = c->cfg.src_maxburst;
1083 	} else if (dir == DMA_MEM_TO_DEV) {
1084 		dev_addr = c->cfg.dst_addr;
1085 		dev_width = c->cfg.dst_addr_width;
1086 		burst = c->cfg.dst_maxburst;
1087 	} else {
1088 		dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
1089 		return NULL;
1090 	}
1091 
1092 	/* Bus width translates to the element size (ES) */
1093 	switch (dev_width) {
1094 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
1095 		es = CSDP_DATA_TYPE_8;
1096 		break;
1097 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
1098 		es = CSDP_DATA_TYPE_16;
1099 		break;
1100 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
1101 		es = CSDP_DATA_TYPE_32;
1102 		break;
1103 	default: /* not reached */
1104 		return NULL;
1105 	}
1106 
1107 	/* Now allocate and setup the descriptor. */
1108 	d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
1109 	if (!d)
1110 		return NULL;
1111 
1112 	d->dir = dir;
1113 	d->dev_addr = dev_addr;
1114 	d->fi = burst;
1115 	d->es = es;
1116 	d->sg[0].addr = buf_addr;
1117 	d->sg[0].en = period_len / es_bytes[es];
1118 	d->sg[0].fn = buf_len / period_len;
1119 	d->sglen = 1;
1120 
1121 	d->ccr = c->ccr;
1122 	if (dir == DMA_DEV_TO_MEM)
1123 		d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
1124 	else
1125 		d->ccr |= CCR_DST_AMODE_CONSTANT | CCR_SRC_AMODE_POSTINC;
1126 
1127 	d->cicr = CICR_DROP_IE;
1128 	if (flags & DMA_PREP_INTERRUPT)
1129 		d->cicr |= CICR_FRAME_IE;
1130 
1131 	d->csdp = es;
1132 
1133 	if (dma_omap1()) {
1134 		d->cicr |= CICR_TOUT_IE;
1135 
1136 		if (dir == DMA_DEV_TO_MEM)
1137 			d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_MPUI;
1138 		else
1139 			d->csdp |= CSDP_DST_PORT_MPUI | CSDP_SRC_PORT_EMIFF;
1140 	} else {
1141 		if (burst)
1142 			d->ccr |= CCR_SYNC_PACKET;
1143 		else
1144 			d->ccr |= CCR_SYNC_ELEMENT;
1145 
1146 		if (dir == DMA_DEV_TO_MEM) {
1147 			d->ccr |= CCR_TRIGGER_SRC;
1148 			d->csdp |= CSDP_DST_PACKED;
1149 		} else {
1150 			d->csdp |= CSDP_SRC_PACKED;
1151 		}
1152 
1153 		d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
1154 
1155 		d->csdp |= CSDP_DST_BURST_64 | CSDP_SRC_BURST_64;
1156 	}
1157 
1158 	if (__dma_omap15xx(od->plat->dma_attr))
1159 		d->ccr |= CCR_AUTO_INIT | CCR_REPEAT;
1160 	else
1161 		d->clnk_ctrl = c->dma_ch | CLNK_CTRL_ENABLE_LNK;
1162 
1163 	c->cyclic = true;
1164 
1165 	return vchan_tx_prep(&c->vc, &d->vd, flags);
1166 }
1167 
1168 static struct dma_async_tx_descriptor *omap_dma_prep_dma_memcpy(
1169 	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
1170 	size_t len, unsigned long tx_flags)
1171 {
1172 	struct omap_chan *c = to_omap_dma_chan(chan);
1173 	struct omap_desc *d;
1174 	uint8_t data_type;
1175 
1176 	d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
1177 	if (!d)
1178 		return NULL;
1179 
1180 	data_type = __ffs((src | dest | len));
1181 	if (data_type > CSDP_DATA_TYPE_32)
1182 		data_type = CSDP_DATA_TYPE_32;
1183 
1184 	d->dir = DMA_MEM_TO_MEM;
1185 	d->dev_addr = src;
1186 	d->fi = 0;
1187 	d->es = data_type;
1188 	d->sg[0].en = len / BIT(data_type);
1189 	d->sg[0].fn = 1;
1190 	d->sg[0].addr = dest;
1191 	d->sglen = 1;
1192 	d->ccr = c->ccr;
1193 	d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_POSTINC;
1194 
1195 	if (tx_flags & DMA_PREP_INTERRUPT)
1196 		d->cicr |= CICR_FRAME_IE;
1197 	else
1198 		d->polled = true;
1199 
1200 	d->csdp = data_type;
1201 
1202 	if (dma_omap1()) {
1203 		d->cicr |= CICR_TOUT_IE;
1204 		d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_EMIFF;
1205 	} else {
1206 		d->csdp |= CSDP_DST_PACKED | CSDP_SRC_PACKED;
1207 		d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
1208 		d->csdp |= CSDP_DST_BURST_64 | CSDP_SRC_BURST_64;
1209 	}
1210 
1211 	return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
1212 }
1213 
1214 static struct dma_async_tx_descriptor *omap_dma_prep_dma_interleaved(
1215 	struct dma_chan *chan, struct dma_interleaved_template *xt,
1216 	unsigned long flags)
1217 {
1218 	struct omap_chan *c = to_omap_dma_chan(chan);
1219 	struct omap_desc *d;
1220 	struct omap_sg *sg;
1221 	uint8_t data_type;
1222 	size_t src_icg, dst_icg;
1223 
1224 	/* Slave mode is not supported */
1225 	if (is_slave_direction(xt->dir))
1226 		return NULL;
1227 
1228 	if (xt->frame_size != 1 || xt->numf == 0)
1229 		return NULL;
1230 
1231 	d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
1232 	if (!d)
1233 		return NULL;
1234 
1235 	data_type = __ffs((xt->src_start | xt->dst_start | xt->sgl[0].size));
1236 	if (data_type > CSDP_DATA_TYPE_32)
1237 		data_type = CSDP_DATA_TYPE_32;
1238 
1239 	sg = &d->sg[0];
1240 	d->dir = DMA_MEM_TO_MEM;
1241 	d->dev_addr = xt->src_start;
1242 	d->es = data_type;
1243 	sg->en = xt->sgl[0].size / BIT(data_type);
1244 	sg->fn = xt->numf;
1245 	sg->addr = xt->dst_start;
1246 	d->sglen = 1;
1247 	d->ccr = c->ccr;
1248 
1249 	src_icg = dmaengine_get_src_icg(xt, &xt->sgl[0]);
1250 	dst_icg = dmaengine_get_dst_icg(xt, &xt->sgl[0]);
1251 	if (src_icg) {
1252 		d->ccr |= CCR_SRC_AMODE_DBLIDX;
1253 		d->ei = 1;
1254 		d->fi = src_icg + 1;
1255 	} else if (xt->src_inc) {
1256 		d->ccr |= CCR_SRC_AMODE_POSTINC;
1257 		d->fi = 0;
1258 	} else {
1259 		dev_err(chan->device->dev,
1260 			"%s: SRC constant addressing is not supported\n",
1261 			__func__);
1262 		kfree(d);
1263 		return NULL;
1264 	}
1265 
1266 	if (dst_icg) {
1267 		d->ccr |= CCR_DST_AMODE_DBLIDX;
1268 		sg->ei = 1;
1269 		sg->fi = dst_icg + 1;
1270 	} else if (xt->dst_inc) {
1271 		d->ccr |= CCR_DST_AMODE_POSTINC;
1272 		sg->fi = 0;
1273 	} else {
1274 		dev_err(chan->device->dev,
1275 			"%s: DST constant addressing is not supported\n",
1276 			__func__);
1277 		kfree(d);
1278 		return NULL;
1279 	}
1280 
1281 	d->cicr = CICR_DROP_IE | CICR_FRAME_IE;
1282 
1283 	d->csdp = data_type;
1284 
1285 	if (dma_omap1()) {
1286 		d->cicr |= CICR_TOUT_IE;
1287 		d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_EMIFF;
1288 	} else {
1289 		d->csdp |= CSDP_DST_PACKED | CSDP_SRC_PACKED;
1290 		d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
1291 		d->csdp |= CSDP_DST_BURST_64 | CSDP_SRC_BURST_64;
1292 	}
1293 
1294 	return vchan_tx_prep(&c->vc, &d->vd, flags);
1295 }
1296 
1297 static int omap_dma_slave_config(struct dma_chan *chan, struct dma_slave_config *cfg)
1298 {
1299 	struct omap_chan *c = to_omap_dma_chan(chan);
1300 
1301 	if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
1302 	    cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
1303 		return -EINVAL;
1304 
1305 	if (cfg->src_maxburst > chan->device->max_burst ||
1306 	    cfg->dst_maxburst > chan->device->max_burst)
1307 		return -EINVAL;
1308 
1309 	memcpy(&c->cfg, cfg, sizeof(c->cfg));
1310 
1311 	return 0;
1312 }
1313 
1314 static int omap_dma_terminate_all(struct dma_chan *chan)
1315 {
1316 	struct omap_chan *c = to_omap_dma_chan(chan);
1317 	unsigned long flags;
1318 	LIST_HEAD(head);
1319 
1320 	spin_lock_irqsave(&c->vc.lock, flags);
1321 
1322 	/*
1323 	 * Stop DMA activity: we assume the callback will not be called
1324 	 * after omap_dma_stop() returns (even if it does, it will see
1325 	 * c->desc is NULL and exit.)
1326 	 */
1327 	if (c->desc) {
1328 		vchan_terminate_vdesc(&c->desc->vd);
1329 		c->desc = NULL;
1330 		/* Avoid stopping the dma twice */
1331 		if (!c->paused)
1332 			omap_dma_stop(c);
1333 	}
1334 
1335 	c->cyclic = false;
1336 	c->paused = false;
1337 
1338 	vchan_get_all_descriptors(&c->vc, &head);
1339 	spin_unlock_irqrestore(&c->vc.lock, flags);
1340 	vchan_dma_desc_free_list(&c->vc, &head);
1341 
1342 	return 0;
1343 }
1344 
1345 static void omap_dma_synchronize(struct dma_chan *chan)
1346 {
1347 	struct omap_chan *c = to_omap_dma_chan(chan);
1348 
1349 	vchan_synchronize(&c->vc);
1350 }
1351 
1352 static int omap_dma_pause(struct dma_chan *chan)
1353 {
1354 	struct omap_chan *c = to_omap_dma_chan(chan);
1355 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1356 	unsigned long flags;
1357 	int ret = -EINVAL;
1358 	bool can_pause = false;
1359 
1360 	spin_lock_irqsave(&od->irq_lock, flags);
1361 
1362 	if (!c->desc)
1363 		goto out;
1364 
1365 	if (c->cyclic)
1366 		can_pause = true;
1367 
1368 	/*
1369 	 * We do not allow DMA_MEM_TO_DEV transfers to be paused.
1370 	 * From the AM572x TRM, 16.1.4.18 Disabling a Channel During Transfer:
1371 	 * "When a channel is disabled during a transfer, the channel undergoes
1372 	 * an abort, unless it is hardware-source-synchronized …".
1373 	 * A source-synchronised channel is one where the fetching of data is
1374 	 * under control of the device. In other words, a device-to-memory
1375 	 * transfer. So, a destination-synchronised channel (which would be a
1376 	 * memory-to-device transfer) undergoes an abort if the the CCR_ENABLE
1377 	 * bit is cleared.
1378 	 * From 16.1.4.20.4.6.2 Abort: "If an abort trigger occurs, the channel
1379 	 * aborts immediately after completion of current read/write
1380 	 * transactions and then the FIFO is cleaned up." The term "cleaned up"
1381 	 * is not defined. TI recommends to check that RD_ACTIVE and WR_ACTIVE
1382 	 * are both clear _before_ disabling the channel, otherwise data loss
1383 	 * will occur.
1384 	 * The problem is that if the channel is active, then device activity
1385 	 * can result in DMA activity starting between reading those as both
1386 	 * clear and the write to DMA_CCR to clear the enable bit hitting the
1387 	 * hardware. If the DMA hardware can't drain the data in its FIFO to the
1388 	 * destination, then data loss "might" occur (say if we write to an UART
1389 	 * and the UART is not accepting any further data).
1390 	 */
1391 	else if (c->desc->dir == DMA_DEV_TO_MEM)
1392 		can_pause = true;
1393 
1394 	if (can_pause && !c->paused) {
1395 		ret = omap_dma_stop(c);
1396 		if (!ret)
1397 			c->paused = true;
1398 	}
1399 out:
1400 	spin_unlock_irqrestore(&od->irq_lock, flags);
1401 
1402 	return ret;
1403 }
1404 
1405 static int omap_dma_resume(struct dma_chan *chan)
1406 {
1407 	struct omap_chan *c = to_omap_dma_chan(chan);
1408 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1409 	unsigned long flags;
1410 	int ret = -EINVAL;
1411 
1412 	spin_lock_irqsave(&od->irq_lock, flags);
1413 
1414 	if (c->paused && c->desc) {
1415 		mb();
1416 
1417 		/* Restore channel link register */
1418 		omap_dma_chan_write(c, CLNK_CTRL, c->desc->clnk_ctrl);
1419 
1420 		omap_dma_start(c, c->desc);
1421 		c->paused = false;
1422 		ret = 0;
1423 	}
1424 	spin_unlock_irqrestore(&od->irq_lock, flags);
1425 
1426 	return ret;
1427 }
1428 
1429 static int omap_dma_chan_init(struct omap_dmadev *od)
1430 {
1431 	struct omap_chan *c;
1432 
1433 	c = kzalloc(sizeof(*c), GFP_KERNEL);
1434 	if (!c)
1435 		return -ENOMEM;
1436 
1437 	c->reg_map = od->reg_map;
1438 	c->vc.desc_free = omap_dma_desc_free;
1439 	vchan_init(&c->vc, &od->ddev);
1440 
1441 	return 0;
1442 }
1443 
1444 static void omap_dma_free(struct omap_dmadev *od)
1445 {
1446 	while (!list_empty(&od->ddev.channels)) {
1447 		struct omap_chan *c = list_first_entry(&od->ddev.channels,
1448 			struct omap_chan, vc.chan.device_node);
1449 
1450 		list_del(&c->vc.chan.device_node);
1451 		tasklet_kill(&c->vc.task);
1452 		kfree(c);
1453 	}
1454 }
1455 
1456 #define OMAP_DMA_BUSWIDTHS	(BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
1457 				 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
1458 				 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
1459 
1460 static int omap_dma_probe(struct platform_device *pdev)
1461 {
1462 	struct omap_dmadev *od;
1463 	struct resource *res;
1464 	int rc, i, irq;
1465 	u32 lch_count;
1466 
1467 	od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
1468 	if (!od)
1469 		return -ENOMEM;
1470 
1471 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1472 	od->base = devm_ioremap_resource(&pdev->dev, res);
1473 	if (IS_ERR(od->base))
1474 		return PTR_ERR(od->base);
1475 
1476 	od->plat = omap_get_plat_info();
1477 	if (!od->plat)
1478 		return -EPROBE_DEFER;
1479 
1480 	od->reg_map = od->plat->reg_map;
1481 
1482 	dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
1483 	dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
1484 	dma_cap_set(DMA_MEMCPY, od->ddev.cap_mask);
1485 	dma_cap_set(DMA_INTERLEAVE, od->ddev.cap_mask);
1486 	od->ddev.device_alloc_chan_resources = omap_dma_alloc_chan_resources;
1487 	od->ddev.device_free_chan_resources = omap_dma_free_chan_resources;
1488 	od->ddev.device_tx_status = omap_dma_tx_status;
1489 	od->ddev.device_issue_pending = omap_dma_issue_pending;
1490 	od->ddev.device_prep_slave_sg = omap_dma_prep_slave_sg;
1491 	od->ddev.device_prep_dma_cyclic = omap_dma_prep_dma_cyclic;
1492 	od->ddev.device_prep_dma_memcpy = omap_dma_prep_dma_memcpy;
1493 	od->ddev.device_prep_interleaved_dma = omap_dma_prep_dma_interleaved;
1494 	od->ddev.device_config = omap_dma_slave_config;
1495 	od->ddev.device_pause = omap_dma_pause;
1496 	od->ddev.device_resume = omap_dma_resume;
1497 	od->ddev.device_terminate_all = omap_dma_terminate_all;
1498 	od->ddev.device_synchronize = omap_dma_synchronize;
1499 	od->ddev.src_addr_widths = OMAP_DMA_BUSWIDTHS;
1500 	od->ddev.dst_addr_widths = OMAP_DMA_BUSWIDTHS;
1501 	od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1502 	if (__dma_omap15xx(od->plat->dma_attr))
1503 		od->ddev.residue_granularity =
1504 				DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1505 	else
1506 		od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1507 	od->ddev.max_burst = SZ_16M - 1; /* CCEN: 24bit unsigned */
1508 	od->ddev.dev = &pdev->dev;
1509 	INIT_LIST_HEAD(&od->ddev.channels);
1510 	spin_lock_init(&od->lock);
1511 	spin_lock_init(&od->irq_lock);
1512 
1513 	/* Number of DMA requests */
1514 	od->dma_requests = OMAP_SDMA_REQUESTS;
1515 	if (pdev->dev.of_node && of_property_read_u32(pdev->dev.of_node,
1516 						      "dma-requests",
1517 						      &od->dma_requests)) {
1518 		dev_info(&pdev->dev,
1519 			 "Missing dma-requests property, using %u.\n",
1520 			 OMAP_SDMA_REQUESTS);
1521 	}
1522 
1523 	/* Number of available logical channels */
1524 	if (!pdev->dev.of_node) {
1525 		lch_count = od->plat->dma_attr->lch_count;
1526 		if (unlikely(!lch_count))
1527 			lch_count = OMAP_SDMA_CHANNELS;
1528 	} else if (of_property_read_u32(pdev->dev.of_node, "dma-channels",
1529 					&lch_count)) {
1530 		dev_info(&pdev->dev,
1531 			 "Missing dma-channels property, using %u.\n",
1532 			 OMAP_SDMA_CHANNELS);
1533 		lch_count = OMAP_SDMA_CHANNELS;
1534 	}
1535 
1536 	od->lch_map = devm_kcalloc(&pdev->dev, lch_count, sizeof(*od->lch_map),
1537 				   GFP_KERNEL);
1538 	if (!od->lch_map)
1539 		return -ENOMEM;
1540 
1541 	for (i = 0; i < od->dma_requests; i++) {
1542 		rc = omap_dma_chan_init(od);
1543 		if (rc) {
1544 			omap_dma_free(od);
1545 			return rc;
1546 		}
1547 	}
1548 
1549 	irq = platform_get_irq(pdev, 1);
1550 	if (irq <= 0) {
1551 		dev_info(&pdev->dev, "failed to get L1 IRQ: %d\n", irq);
1552 		od->legacy = true;
1553 	} else {
1554 		/* Disable all interrupts */
1555 		od->irq_enable_mask = 0;
1556 		omap_dma_glbl_write(od, IRQENABLE_L1, 0);
1557 
1558 		rc = devm_request_irq(&pdev->dev, irq, omap_dma_irq,
1559 				      IRQF_SHARED, "omap-dma-engine", od);
1560 		if (rc) {
1561 			omap_dma_free(od);
1562 			return rc;
1563 		}
1564 	}
1565 
1566 	if (omap_dma_glbl_read(od, CAPS_0) & CAPS_0_SUPPORT_LL123)
1567 		od->ll123_supported = true;
1568 
1569 	od->ddev.filter.map = od->plat->slave_map;
1570 	od->ddev.filter.mapcnt = od->plat->slavecnt;
1571 	od->ddev.filter.fn = omap_dma_filter_fn;
1572 
1573 	if (od->ll123_supported) {
1574 		od->desc_pool = dma_pool_create(dev_name(&pdev->dev),
1575 						&pdev->dev,
1576 						sizeof(struct omap_type2_desc),
1577 						4, 0);
1578 		if (!od->desc_pool) {
1579 			dev_err(&pdev->dev,
1580 				"unable to allocate descriptor pool\n");
1581 			od->ll123_supported = false;
1582 		}
1583 	}
1584 
1585 	rc = dma_async_device_register(&od->ddev);
1586 	if (rc) {
1587 		pr_warn("OMAP-DMA: failed to register slave DMA engine device: %d\n",
1588 			rc);
1589 		omap_dma_free(od);
1590 		return rc;
1591 	}
1592 
1593 	platform_set_drvdata(pdev, od);
1594 
1595 	if (pdev->dev.of_node) {
1596 		omap_dma_info.dma_cap = od->ddev.cap_mask;
1597 
1598 		/* Device-tree DMA controller registration */
1599 		rc = of_dma_controller_register(pdev->dev.of_node,
1600 				of_dma_simple_xlate, &omap_dma_info);
1601 		if (rc) {
1602 			pr_warn("OMAP-DMA: failed to register DMA controller\n");
1603 			dma_async_device_unregister(&od->ddev);
1604 			omap_dma_free(od);
1605 		}
1606 	}
1607 
1608 	dev_info(&pdev->dev, "OMAP DMA engine driver%s\n",
1609 		 od->ll123_supported ? " (LinkedList1/2/3 supported)" : "");
1610 
1611 	return rc;
1612 }
1613 
1614 static int omap_dma_remove(struct platform_device *pdev)
1615 {
1616 	struct omap_dmadev *od = platform_get_drvdata(pdev);
1617 	int irq;
1618 
1619 	if (pdev->dev.of_node)
1620 		of_dma_controller_free(pdev->dev.of_node);
1621 
1622 	irq = platform_get_irq(pdev, 1);
1623 	devm_free_irq(&pdev->dev, irq, od);
1624 
1625 	dma_async_device_unregister(&od->ddev);
1626 
1627 	if (!od->legacy) {
1628 		/* Disable all interrupts */
1629 		omap_dma_glbl_write(od, IRQENABLE_L0, 0);
1630 	}
1631 
1632 	if (od->ll123_supported)
1633 		dma_pool_destroy(od->desc_pool);
1634 
1635 	omap_dma_free(od);
1636 
1637 	return 0;
1638 }
1639 
1640 static const struct of_device_id omap_dma_match[] = {
1641 	{ .compatible = "ti,omap2420-sdma", },
1642 	{ .compatible = "ti,omap2430-sdma", },
1643 	{ .compatible = "ti,omap3430-sdma", },
1644 	{ .compatible = "ti,omap3630-sdma", },
1645 	{ .compatible = "ti,omap4430-sdma", },
1646 	{},
1647 };
1648 MODULE_DEVICE_TABLE(of, omap_dma_match);
1649 
1650 static struct platform_driver omap_dma_driver = {
1651 	.probe	= omap_dma_probe,
1652 	.remove	= omap_dma_remove,
1653 	.driver = {
1654 		.name = "omap-dma-engine",
1655 		.of_match_table = of_match_ptr(omap_dma_match),
1656 	},
1657 };
1658 
1659 static bool omap_dma_filter_fn(struct dma_chan *chan, void *param)
1660 {
1661 	if (chan->device->dev->driver == &omap_dma_driver.driver) {
1662 		struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1663 		struct omap_chan *c = to_omap_dma_chan(chan);
1664 		unsigned req = *(unsigned *)param;
1665 
1666 		if (req <= od->dma_requests) {
1667 			c->dma_sig = req;
1668 			return true;
1669 		}
1670 	}
1671 	return false;
1672 }
1673 
1674 static int omap_dma_init(void)
1675 {
1676 	return platform_driver_register(&omap_dma_driver);
1677 }
1678 subsys_initcall(omap_dma_init);
1679 
1680 static void __exit omap_dma_exit(void)
1681 {
1682 	platform_driver_unregister(&omap_dma_driver);
1683 }
1684 module_exit(omap_dma_exit);
1685 
1686 MODULE_AUTHOR("Russell King");
1687 MODULE_LICENSE("GPL");
1688