xref: /openbmc/linux/drivers/dma/ti/omap-dma.c (revision be709d48)
1 /*
2  * OMAP DMAengine support
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 #include <linux/delay.h>
9 #include <linux/dmaengine.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/dmapool.h>
12 #include <linux/err.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/omap-dma.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20 #include <linux/spinlock.h>
21 #include <linux/of_dma.h>
22 #include <linux/of_device.h>
23 
24 #include "../virt-dma.h"
25 
26 #define OMAP_SDMA_REQUESTS	127
27 #define OMAP_SDMA_CHANNELS	32
28 
29 struct omap_dmadev {
30 	struct dma_device ddev;
31 	spinlock_t lock;
32 	void __iomem *base;
33 	const struct omap_dma_reg *reg_map;
34 	struct omap_system_dma_plat_info *plat;
35 	bool legacy;
36 	bool ll123_supported;
37 	struct dma_pool *desc_pool;
38 	unsigned dma_requests;
39 	spinlock_t irq_lock;
40 	uint32_t irq_enable_mask;
41 	struct omap_chan **lch_map;
42 };
43 
44 struct omap_chan {
45 	struct virt_dma_chan vc;
46 	void __iomem *channel_base;
47 	const struct omap_dma_reg *reg_map;
48 	uint32_t ccr;
49 
50 	struct dma_slave_config	cfg;
51 	unsigned dma_sig;
52 	bool cyclic;
53 	bool paused;
54 	bool running;
55 
56 	int dma_ch;
57 	struct omap_desc *desc;
58 	unsigned sgidx;
59 };
60 
61 #define DESC_NXT_SV_REFRESH	(0x1 << 24)
62 #define DESC_NXT_SV_REUSE	(0x2 << 24)
63 #define DESC_NXT_DV_REFRESH	(0x1 << 26)
64 #define DESC_NXT_DV_REUSE	(0x2 << 26)
65 #define DESC_NTYPE_TYPE2	(0x2 << 29)
66 
67 /* Type 2 descriptor with Source or Destination address update */
68 struct omap_type2_desc {
69 	uint32_t next_desc;
70 	uint32_t en;
71 	uint32_t addr; /* src or dst */
72 	uint16_t fn;
73 	uint16_t cicr;
74 	int16_t cdei;
75 	int16_t csei;
76 	int32_t cdfi;
77 	int32_t csfi;
78 } __packed;
79 
80 struct omap_sg {
81 	dma_addr_t addr;
82 	uint32_t en;		/* number of elements (24-bit) */
83 	uint32_t fn;		/* number of frames (16-bit) */
84 	int32_t fi;		/* for double indexing */
85 	int16_t ei;		/* for double indexing */
86 
87 	/* Linked list */
88 	struct omap_type2_desc *t2_desc;
89 	dma_addr_t t2_desc_paddr;
90 };
91 
92 struct omap_desc {
93 	struct virt_dma_desc vd;
94 	bool using_ll;
95 	enum dma_transfer_direction dir;
96 	dma_addr_t dev_addr;
97 
98 	int32_t fi;		/* for OMAP_DMA_SYNC_PACKET / double indexing */
99 	int16_t ei;		/* for double indexing */
100 	uint8_t es;		/* CSDP_DATA_TYPE_xxx */
101 	uint32_t ccr;		/* CCR value */
102 	uint16_t clnk_ctrl;	/* CLNK_CTRL value */
103 	uint16_t cicr;		/* CICR value */
104 	uint32_t csdp;		/* CSDP value */
105 
106 	unsigned sglen;
107 	struct omap_sg sg[0];
108 };
109 
110 enum {
111 	CAPS_0_SUPPORT_LL123	= BIT(20),	/* Linked List type1/2/3 */
112 	CAPS_0_SUPPORT_LL4	= BIT(21),	/* Linked List type4 */
113 
114 	CCR_FS			= BIT(5),
115 	CCR_READ_PRIORITY	= BIT(6),
116 	CCR_ENABLE		= BIT(7),
117 	CCR_AUTO_INIT		= BIT(8),	/* OMAP1 only */
118 	CCR_REPEAT		= BIT(9),	/* OMAP1 only */
119 	CCR_OMAP31_DISABLE	= BIT(10),	/* OMAP1 only */
120 	CCR_SUSPEND_SENSITIVE	= BIT(8),	/* OMAP2+ only */
121 	CCR_RD_ACTIVE		= BIT(9),	/* OMAP2+ only */
122 	CCR_WR_ACTIVE		= BIT(10),	/* OMAP2+ only */
123 	CCR_SRC_AMODE_CONSTANT	= 0 << 12,
124 	CCR_SRC_AMODE_POSTINC	= 1 << 12,
125 	CCR_SRC_AMODE_SGLIDX	= 2 << 12,
126 	CCR_SRC_AMODE_DBLIDX	= 3 << 12,
127 	CCR_DST_AMODE_CONSTANT	= 0 << 14,
128 	CCR_DST_AMODE_POSTINC	= 1 << 14,
129 	CCR_DST_AMODE_SGLIDX	= 2 << 14,
130 	CCR_DST_AMODE_DBLIDX	= 3 << 14,
131 	CCR_CONSTANT_FILL	= BIT(16),
132 	CCR_TRANSPARENT_COPY	= BIT(17),
133 	CCR_BS			= BIT(18),
134 	CCR_SUPERVISOR		= BIT(22),
135 	CCR_PREFETCH		= BIT(23),
136 	CCR_TRIGGER_SRC		= BIT(24),
137 	CCR_BUFFERING_DISABLE	= BIT(25),
138 	CCR_WRITE_PRIORITY	= BIT(26),
139 	CCR_SYNC_ELEMENT	= 0,
140 	CCR_SYNC_FRAME		= CCR_FS,
141 	CCR_SYNC_BLOCK		= CCR_BS,
142 	CCR_SYNC_PACKET		= CCR_BS | CCR_FS,
143 
144 	CSDP_DATA_TYPE_8	= 0,
145 	CSDP_DATA_TYPE_16	= 1,
146 	CSDP_DATA_TYPE_32	= 2,
147 	CSDP_SRC_PORT_EMIFF	= 0 << 2, /* OMAP1 only */
148 	CSDP_SRC_PORT_EMIFS	= 1 << 2, /* OMAP1 only */
149 	CSDP_SRC_PORT_OCP_T1	= 2 << 2, /* OMAP1 only */
150 	CSDP_SRC_PORT_TIPB	= 3 << 2, /* OMAP1 only */
151 	CSDP_SRC_PORT_OCP_T2	= 4 << 2, /* OMAP1 only */
152 	CSDP_SRC_PORT_MPUI	= 5 << 2, /* OMAP1 only */
153 	CSDP_SRC_PACKED		= BIT(6),
154 	CSDP_SRC_BURST_1	= 0 << 7,
155 	CSDP_SRC_BURST_16	= 1 << 7,
156 	CSDP_SRC_BURST_32	= 2 << 7,
157 	CSDP_SRC_BURST_64	= 3 << 7,
158 	CSDP_DST_PORT_EMIFF	= 0 << 9, /* OMAP1 only */
159 	CSDP_DST_PORT_EMIFS	= 1 << 9, /* OMAP1 only */
160 	CSDP_DST_PORT_OCP_T1	= 2 << 9, /* OMAP1 only */
161 	CSDP_DST_PORT_TIPB	= 3 << 9, /* OMAP1 only */
162 	CSDP_DST_PORT_OCP_T2	= 4 << 9, /* OMAP1 only */
163 	CSDP_DST_PORT_MPUI	= 5 << 9, /* OMAP1 only */
164 	CSDP_DST_PACKED		= BIT(13),
165 	CSDP_DST_BURST_1	= 0 << 14,
166 	CSDP_DST_BURST_16	= 1 << 14,
167 	CSDP_DST_BURST_32	= 2 << 14,
168 	CSDP_DST_BURST_64	= 3 << 14,
169 	CSDP_WRITE_NON_POSTED	= 0 << 16,
170 	CSDP_WRITE_POSTED	= 1 << 16,
171 	CSDP_WRITE_LAST_NON_POSTED = 2 << 16,
172 
173 	CICR_TOUT_IE		= BIT(0),	/* OMAP1 only */
174 	CICR_DROP_IE		= BIT(1),
175 	CICR_HALF_IE		= BIT(2),
176 	CICR_FRAME_IE		= BIT(3),
177 	CICR_LAST_IE		= BIT(4),
178 	CICR_BLOCK_IE		= BIT(5),
179 	CICR_PKT_IE		= BIT(7),	/* OMAP2+ only */
180 	CICR_TRANS_ERR_IE	= BIT(8),	/* OMAP2+ only */
181 	CICR_SUPERVISOR_ERR_IE	= BIT(10),	/* OMAP2+ only */
182 	CICR_MISALIGNED_ERR_IE	= BIT(11),	/* OMAP2+ only */
183 	CICR_DRAIN_IE		= BIT(12),	/* OMAP2+ only */
184 	CICR_SUPER_BLOCK_IE	= BIT(14),	/* OMAP2+ only */
185 
186 	CLNK_CTRL_ENABLE_LNK	= BIT(15),
187 
188 	CDP_DST_VALID_INC	= 0 << 0,
189 	CDP_DST_VALID_RELOAD	= 1 << 0,
190 	CDP_DST_VALID_REUSE	= 2 << 0,
191 	CDP_SRC_VALID_INC	= 0 << 2,
192 	CDP_SRC_VALID_RELOAD	= 1 << 2,
193 	CDP_SRC_VALID_REUSE	= 2 << 2,
194 	CDP_NTYPE_TYPE1		= 1 << 4,
195 	CDP_NTYPE_TYPE2		= 2 << 4,
196 	CDP_NTYPE_TYPE3		= 3 << 4,
197 	CDP_TMODE_NORMAL	= 0 << 8,
198 	CDP_TMODE_LLIST		= 1 << 8,
199 	CDP_FAST		= BIT(10),
200 };
201 
202 static const unsigned es_bytes[] = {
203 	[CSDP_DATA_TYPE_8] = 1,
204 	[CSDP_DATA_TYPE_16] = 2,
205 	[CSDP_DATA_TYPE_32] = 4,
206 };
207 
208 static struct of_dma_filter_info omap_dma_info = {
209 	.filter_fn = omap_dma_filter_fn,
210 };
211 
212 static inline struct omap_dmadev *to_omap_dma_dev(struct dma_device *d)
213 {
214 	return container_of(d, struct omap_dmadev, ddev);
215 }
216 
217 static inline struct omap_chan *to_omap_dma_chan(struct dma_chan *c)
218 {
219 	return container_of(c, struct omap_chan, vc.chan);
220 }
221 
222 static inline struct omap_desc *to_omap_dma_desc(struct dma_async_tx_descriptor *t)
223 {
224 	return container_of(t, struct omap_desc, vd.tx);
225 }
226 
227 static void omap_dma_desc_free(struct virt_dma_desc *vd)
228 {
229 	struct omap_desc *d = to_omap_dma_desc(&vd->tx);
230 
231 	if (d->using_ll) {
232 		struct omap_dmadev *od = to_omap_dma_dev(vd->tx.chan->device);
233 		int i;
234 
235 		for (i = 0; i < d->sglen; i++) {
236 			if (d->sg[i].t2_desc)
237 				dma_pool_free(od->desc_pool, d->sg[i].t2_desc,
238 					      d->sg[i].t2_desc_paddr);
239 		}
240 	}
241 
242 	kfree(d);
243 }
244 
245 static void omap_dma_fill_type2_desc(struct omap_desc *d, int idx,
246 				     enum dma_transfer_direction dir, bool last)
247 {
248 	struct omap_sg *sg = &d->sg[idx];
249 	struct omap_type2_desc *t2_desc = sg->t2_desc;
250 
251 	if (idx)
252 		d->sg[idx - 1].t2_desc->next_desc = sg->t2_desc_paddr;
253 	if (last)
254 		t2_desc->next_desc = 0xfffffffc;
255 
256 	t2_desc->en = sg->en;
257 	t2_desc->addr = sg->addr;
258 	t2_desc->fn = sg->fn & 0xffff;
259 	t2_desc->cicr = d->cicr;
260 	if (!last)
261 		t2_desc->cicr &= ~CICR_BLOCK_IE;
262 
263 	switch (dir) {
264 	case DMA_DEV_TO_MEM:
265 		t2_desc->cdei = sg->ei;
266 		t2_desc->csei = d->ei;
267 		t2_desc->cdfi = sg->fi;
268 		t2_desc->csfi = d->fi;
269 
270 		t2_desc->en |= DESC_NXT_DV_REFRESH;
271 		t2_desc->en |= DESC_NXT_SV_REUSE;
272 		break;
273 	case DMA_MEM_TO_DEV:
274 		t2_desc->cdei = d->ei;
275 		t2_desc->csei = sg->ei;
276 		t2_desc->cdfi = d->fi;
277 		t2_desc->csfi = sg->fi;
278 
279 		t2_desc->en |= DESC_NXT_SV_REFRESH;
280 		t2_desc->en |= DESC_NXT_DV_REUSE;
281 		break;
282 	default:
283 		return;
284 	}
285 
286 	t2_desc->en |= DESC_NTYPE_TYPE2;
287 }
288 
289 static void omap_dma_write(uint32_t val, unsigned type, void __iomem *addr)
290 {
291 	switch (type) {
292 	case OMAP_DMA_REG_16BIT:
293 		writew_relaxed(val, addr);
294 		break;
295 	case OMAP_DMA_REG_2X16BIT:
296 		writew_relaxed(val, addr);
297 		writew_relaxed(val >> 16, addr + 2);
298 		break;
299 	case OMAP_DMA_REG_32BIT:
300 		writel_relaxed(val, addr);
301 		break;
302 	default:
303 		WARN_ON(1);
304 	}
305 }
306 
307 static unsigned omap_dma_read(unsigned type, void __iomem *addr)
308 {
309 	unsigned val;
310 
311 	switch (type) {
312 	case OMAP_DMA_REG_16BIT:
313 		val = readw_relaxed(addr);
314 		break;
315 	case OMAP_DMA_REG_2X16BIT:
316 		val = readw_relaxed(addr);
317 		val |= readw_relaxed(addr + 2) << 16;
318 		break;
319 	case OMAP_DMA_REG_32BIT:
320 		val = readl_relaxed(addr);
321 		break;
322 	default:
323 		WARN_ON(1);
324 		val = 0;
325 	}
326 
327 	return val;
328 }
329 
330 static void omap_dma_glbl_write(struct omap_dmadev *od, unsigned reg, unsigned val)
331 {
332 	const struct omap_dma_reg *r = od->reg_map + reg;
333 
334 	WARN_ON(r->stride);
335 
336 	omap_dma_write(val, r->type, od->base + r->offset);
337 }
338 
339 static unsigned omap_dma_glbl_read(struct omap_dmadev *od, unsigned reg)
340 {
341 	const struct omap_dma_reg *r = od->reg_map + reg;
342 
343 	WARN_ON(r->stride);
344 
345 	return omap_dma_read(r->type, od->base + r->offset);
346 }
347 
348 static void omap_dma_chan_write(struct omap_chan *c, unsigned reg, unsigned val)
349 {
350 	const struct omap_dma_reg *r = c->reg_map + reg;
351 
352 	omap_dma_write(val, r->type, c->channel_base + r->offset);
353 }
354 
355 static unsigned omap_dma_chan_read(struct omap_chan *c, unsigned reg)
356 {
357 	const struct omap_dma_reg *r = c->reg_map + reg;
358 
359 	return omap_dma_read(r->type, c->channel_base + r->offset);
360 }
361 
362 static void omap_dma_clear_csr(struct omap_chan *c)
363 {
364 	if (dma_omap1())
365 		omap_dma_chan_read(c, CSR);
366 	else
367 		omap_dma_chan_write(c, CSR, ~0);
368 }
369 
370 static unsigned omap_dma_get_csr(struct omap_chan *c)
371 {
372 	unsigned val = omap_dma_chan_read(c, CSR);
373 
374 	if (!dma_omap1())
375 		omap_dma_chan_write(c, CSR, val);
376 
377 	return val;
378 }
379 
380 static void omap_dma_assign(struct omap_dmadev *od, struct omap_chan *c,
381 	unsigned lch)
382 {
383 	c->channel_base = od->base + od->plat->channel_stride * lch;
384 
385 	od->lch_map[lch] = c;
386 }
387 
388 static void omap_dma_start(struct omap_chan *c, struct omap_desc *d)
389 {
390 	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
391 	uint16_t cicr = d->cicr;
392 
393 	if (__dma_omap15xx(od->plat->dma_attr))
394 		omap_dma_chan_write(c, CPC, 0);
395 	else
396 		omap_dma_chan_write(c, CDAC, 0);
397 
398 	omap_dma_clear_csr(c);
399 
400 	if (d->using_ll) {
401 		uint32_t cdp = CDP_TMODE_LLIST | CDP_NTYPE_TYPE2 | CDP_FAST;
402 
403 		if (d->dir == DMA_DEV_TO_MEM)
404 			cdp |= (CDP_DST_VALID_RELOAD | CDP_SRC_VALID_REUSE);
405 		else
406 			cdp |= (CDP_DST_VALID_REUSE | CDP_SRC_VALID_RELOAD);
407 		omap_dma_chan_write(c, CDP, cdp);
408 
409 		omap_dma_chan_write(c, CNDP, d->sg[0].t2_desc_paddr);
410 		omap_dma_chan_write(c, CCDN, 0);
411 		omap_dma_chan_write(c, CCFN, 0xffff);
412 		omap_dma_chan_write(c, CCEN, 0xffffff);
413 
414 		cicr &= ~CICR_BLOCK_IE;
415 	} else if (od->ll123_supported) {
416 		omap_dma_chan_write(c, CDP, 0);
417 	}
418 
419 	/* Enable interrupts */
420 	omap_dma_chan_write(c, CICR, cicr);
421 
422 	/* Enable channel */
423 	omap_dma_chan_write(c, CCR, d->ccr | CCR_ENABLE);
424 
425 	c->running = true;
426 }
427 
428 static void omap_dma_drain_chan(struct omap_chan *c)
429 {
430 	int i;
431 	u32 val;
432 
433 	/* Wait for sDMA FIFO to drain */
434 	for (i = 0; ; i++) {
435 		val = omap_dma_chan_read(c, CCR);
436 		if (!(val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE)))
437 			break;
438 
439 		if (i > 100)
440 			break;
441 
442 		udelay(5);
443 	}
444 
445 	if (val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE))
446 		dev_err(c->vc.chan.device->dev,
447 			"DMA drain did not complete on lch %d\n",
448 			c->dma_ch);
449 }
450 
451 static int omap_dma_stop(struct omap_chan *c)
452 {
453 	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
454 	uint32_t val;
455 
456 	/* disable irq */
457 	omap_dma_chan_write(c, CICR, 0);
458 
459 	omap_dma_clear_csr(c);
460 
461 	val = omap_dma_chan_read(c, CCR);
462 	if (od->plat->errata & DMA_ERRATA_i541 && val & CCR_TRIGGER_SRC) {
463 		uint32_t sysconfig;
464 
465 		sysconfig = omap_dma_glbl_read(od, OCP_SYSCONFIG);
466 		val = sysconfig & ~DMA_SYSCONFIG_MIDLEMODE_MASK;
467 		val |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
468 		omap_dma_glbl_write(od, OCP_SYSCONFIG, val);
469 
470 		val = omap_dma_chan_read(c, CCR);
471 		val &= ~CCR_ENABLE;
472 		omap_dma_chan_write(c, CCR, val);
473 
474 		if (!(c->ccr & CCR_BUFFERING_DISABLE))
475 			omap_dma_drain_chan(c);
476 
477 		omap_dma_glbl_write(od, OCP_SYSCONFIG, sysconfig);
478 	} else {
479 		if (!(val & CCR_ENABLE))
480 			return -EINVAL;
481 
482 		val &= ~CCR_ENABLE;
483 		omap_dma_chan_write(c, CCR, val);
484 
485 		if (!(c->ccr & CCR_BUFFERING_DISABLE))
486 			omap_dma_drain_chan(c);
487 	}
488 
489 	mb();
490 
491 	if (!__dma_omap15xx(od->plat->dma_attr) && c->cyclic) {
492 		val = omap_dma_chan_read(c, CLNK_CTRL);
493 
494 		if (dma_omap1())
495 			val |= 1 << 14; /* set the STOP_LNK bit */
496 		else
497 			val &= ~CLNK_CTRL_ENABLE_LNK;
498 
499 		omap_dma_chan_write(c, CLNK_CTRL, val);
500 	}
501 	c->running = false;
502 	return 0;
503 }
504 
505 static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d)
506 {
507 	struct omap_sg *sg = d->sg + c->sgidx;
508 	unsigned cxsa, cxei, cxfi;
509 
510 	if (d->dir == DMA_DEV_TO_MEM || d->dir == DMA_MEM_TO_MEM) {
511 		cxsa = CDSA;
512 		cxei = CDEI;
513 		cxfi = CDFI;
514 	} else {
515 		cxsa = CSSA;
516 		cxei = CSEI;
517 		cxfi = CSFI;
518 	}
519 
520 	omap_dma_chan_write(c, cxsa, sg->addr);
521 	omap_dma_chan_write(c, cxei, sg->ei);
522 	omap_dma_chan_write(c, cxfi, sg->fi);
523 	omap_dma_chan_write(c, CEN, sg->en);
524 	omap_dma_chan_write(c, CFN, sg->fn);
525 
526 	omap_dma_start(c, d);
527 	c->sgidx++;
528 }
529 
530 static void omap_dma_start_desc(struct omap_chan *c)
531 {
532 	struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
533 	struct omap_desc *d;
534 	unsigned cxsa, cxei, cxfi;
535 
536 	if (!vd) {
537 		c->desc = NULL;
538 		return;
539 	}
540 
541 	list_del(&vd->node);
542 
543 	c->desc = d = to_omap_dma_desc(&vd->tx);
544 	c->sgidx = 0;
545 
546 	/*
547 	 * This provides the necessary barrier to ensure data held in
548 	 * DMA coherent memory is visible to the DMA engine prior to
549 	 * the transfer starting.
550 	 */
551 	mb();
552 
553 	omap_dma_chan_write(c, CCR, d->ccr);
554 	if (dma_omap1())
555 		omap_dma_chan_write(c, CCR2, d->ccr >> 16);
556 
557 	if (d->dir == DMA_DEV_TO_MEM || d->dir == DMA_MEM_TO_MEM) {
558 		cxsa = CSSA;
559 		cxei = CSEI;
560 		cxfi = CSFI;
561 	} else {
562 		cxsa = CDSA;
563 		cxei = CDEI;
564 		cxfi = CDFI;
565 	}
566 
567 	omap_dma_chan_write(c, cxsa, d->dev_addr);
568 	omap_dma_chan_write(c, cxei, d->ei);
569 	omap_dma_chan_write(c, cxfi, d->fi);
570 	omap_dma_chan_write(c, CSDP, d->csdp);
571 	omap_dma_chan_write(c, CLNK_CTRL, d->clnk_ctrl);
572 
573 	omap_dma_start_sg(c, d);
574 }
575 
576 static void omap_dma_callback(int ch, u16 status, void *data)
577 {
578 	struct omap_chan *c = data;
579 	struct omap_desc *d;
580 	unsigned long flags;
581 
582 	spin_lock_irqsave(&c->vc.lock, flags);
583 	d = c->desc;
584 	if (d) {
585 		if (c->cyclic) {
586 			vchan_cyclic_callback(&d->vd);
587 		} else if (d->using_ll || c->sgidx == d->sglen) {
588 			omap_dma_start_desc(c);
589 			vchan_cookie_complete(&d->vd);
590 		} else {
591 			omap_dma_start_sg(c, d);
592 		}
593 	}
594 	spin_unlock_irqrestore(&c->vc.lock, flags);
595 }
596 
597 static irqreturn_t omap_dma_irq(int irq, void *devid)
598 {
599 	struct omap_dmadev *od = devid;
600 	unsigned status, channel;
601 
602 	spin_lock(&od->irq_lock);
603 
604 	status = omap_dma_glbl_read(od, IRQSTATUS_L1);
605 	status &= od->irq_enable_mask;
606 	if (status == 0) {
607 		spin_unlock(&od->irq_lock);
608 		return IRQ_NONE;
609 	}
610 
611 	while ((channel = ffs(status)) != 0) {
612 		unsigned mask, csr;
613 		struct omap_chan *c;
614 
615 		channel -= 1;
616 		mask = BIT(channel);
617 		status &= ~mask;
618 
619 		c = od->lch_map[channel];
620 		if (c == NULL) {
621 			/* This should never happen */
622 			dev_err(od->ddev.dev, "invalid channel %u\n", channel);
623 			continue;
624 		}
625 
626 		csr = omap_dma_get_csr(c);
627 		omap_dma_glbl_write(od, IRQSTATUS_L1, mask);
628 
629 		omap_dma_callback(channel, csr, c);
630 	}
631 
632 	spin_unlock(&od->irq_lock);
633 
634 	return IRQ_HANDLED;
635 }
636 
637 static int omap_dma_alloc_chan_resources(struct dma_chan *chan)
638 {
639 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
640 	struct omap_chan *c = to_omap_dma_chan(chan);
641 	struct device *dev = od->ddev.dev;
642 	int ret;
643 
644 	if (od->legacy) {
645 		ret = omap_request_dma(c->dma_sig, "DMA engine",
646 				       omap_dma_callback, c, &c->dma_ch);
647 	} else {
648 		ret = omap_request_dma(c->dma_sig, "DMA engine", NULL, NULL,
649 				       &c->dma_ch);
650 	}
651 
652 	dev_dbg(dev, "allocating channel %u for %u\n", c->dma_ch, c->dma_sig);
653 
654 	if (ret >= 0) {
655 		omap_dma_assign(od, c, c->dma_ch);
656 
657 		if (!od->legacy) {
658 			unsigned val;
659 
660 			spin_lock_irq(&od->irq_lock);
661 			val = BIT(c->dma_ch);
662 			omap_dma_glbl_write(od, IRQSTATUS_L1, val);
663 			od->irq_enable_mask |= val;
664 			omap_dma_glbl_write(od, IRQENABLE_L1, od->irq_enable_mask);
665 
666 			val = omap_dma_glbl_read(od, IRQENABLE_L0);
667 			val &= ~BIT(c->dma_ch);
668 			omap_dma_glbl_write(od, IRQENABLE_L0, val);
669 			spin_unlock_irq(&od->irq_lock);
670 		}
671 	}
672 
673 	if (dma_omap1()) {
674 		if (__dma_omap16xx(od->plat->dma_attr)) {
675 			c->ccr = CCR_OMAP31_DISABLE;
676 			/* Duplicate what plat-omap/dma.c does */
677 			c->ccr |= c->dma_ch + 1;
678 		} else {
679 			c->ccr = c->dma_sig & 0x1f;
680 		}
681 	} else {
682 		c->ccr = c->dma_sig & 0x1f;
683 		c->ccr |= (c->dma_sig & ~0x1f) << 14;
684 	}
685 	if (od->plat->errata & DMA_ERRATA_IFRAME_BUFFERING)
686 		c->ccr |= CCR_BUFFERING_DISABLE;
687 
688 	return ret;
689 }
690 
691 static void omap_dma_free_chan_resources(struct dma_chan *chan)
692 {
693 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
694 	struct omap_chan *c = to_omap_dma_chan(chan);
695 
696 	if (!od->legacy) {
697 		spin_lock_irq(&od->irq_lock);
698 		od->irq_enable_mask &= ~BIT(c->dma_ch);
699 		omap_dma_glbl_write(od, IRQENABLE_L1, od->irq_enable_mask);
700 		spin_unlock_irq(&od->irq_lock);
701 	}
702 
703 	c->channel_base = NULL;
704 	od->lch_map[c->dma_ch] = NULL;
705 	vchan_free_chan_resources(&c->vc);
706 	omap_free_dma(c->dma_ch);
707 
708 	dev_dbg(od->ddev.dev, "freeing channel %u used for %u\n", c->dma_ch,
709 		c->dma_sig);
710 	c->dma_sig = 0;
711 }
712 
713 static size_t omap_dma_sg_size(struct omap_sg *sg)
714 {
715 	return sg->en * sg->fn;
716 }
717 
718 static size_t omap_dma_desc_size(struct omap_desc *d)
719 {
720 	unsigned i;
721 	size_t size;
722 
723 	for (size = i = 0; i < d->sglen; i++)
724 		size += omap_dma_sg_size(&d->sg[i]);
725 
726 	return size * es_bytes[d->es];
727 }
728 
729 static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr)
730 {
731 	unsigned i;
732 	size_t size, es_size = es_bytes[d->es];
733 
734 	for (size = i = 0; i < d->sglen; i++) {
735 		size_t this_size = omap_dma_sg_size(&d->sg[i]) * es_size;
736 
737 		if (size)
738 			size += this_size;
739 		else if (addr >= d->sg[i].addr &&
740 			 addr < d->sg[i].addr + this_size)
741 			size += d->sg[i].addr + this_size - addr;
742 	}
743 	return size;
744 }
745 
746 /*
747  * OMAP 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is
748  * read before the DMA controller finished disabling the channel.
749  */
750 static uint32_t omap_dma_chan_read_3_3(struct omap_chan *c, unsigned reg)
751 {
752 	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
753 	uint32_t val;
754 
755 	val = omap_dma_chan_read(c, reg);
756 	if (val == 0 && od->plat->errata & DMA_ERRATA_3_3)
757 		val = omap_dma_chan_read(c, reg);
758 
759 	return val;
760 }
761 
762 static dma_addr_t omap_dma_get_src_pos(struct omap_chan *c)
763 {
764 	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
765 	dma_addr_t addr, cdac;
766 
767 	if (__dma_omap15xx(od->plat->dma_attr)) {
768 		addr = omap_dma_chan_read(c, CPC);
769 	} else {
770 		addr = omap_dma_chan_read_3_3(c, CSAC);
771 		cdac = omap_dma_chan_read_3_3(c, CDAC);
772 
773 		/*
774 		 * CDAC == 0 indicates that the DMA transfer on the channel has
775 		 * not been started (no data has been transferred so far).
776 		 * Return the programmed source start address in this case.
777 		 */
778 		if (cdac == 0)
779 			addr = omap_dma_chan_read(c, CSSA);
780 	}
781 
782 	if (dma_omap1())
783 		addr |= omap_dma_chan_read(c, CSSA) & 0xffff0000;
784 
785 	return addr;
786 }
787 
788 static dma_addr_t omap_dma_get_dst_pos(struct omap_chan *c)
789 {
790 	struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
791 	dma_addr_t addr;
792 
793 	if (__dma_omap15xx(od->plat->dma_attr)) {
794 		addr = omap_dma_chan_read(c, CPC);
795 	} else {
796 		addr = omap_dma_chan_read_3_3(c, CDAC);
797 
798 		/*
799 		 * CDAC == 0 indicates that the DMA transfer on the channel
800 		 * has not been started (no data has been transferred so
801 		 * far).  Return the programmed destination start address in
802 		 * this case.
803 		 */
804 		if (addr == 0)
805 			addr = omap_dma_chan_read(c, CDSA);
806 	}
807 
808 	if (dma_omap1())
809 		addr |= omap_dma_chan_read(c, CDSA) & 0xffff0000;
810 
811 	return addr;
812 }
813 
814 static enum dma_status omap_dma_tx_status(struct dma_chan *chan,
815 	dma_cookie_t cookie, struct dma_tx_state *txstate)
816 {
817 	struct omap_chan *c = to_omap_dma_chan(chan);
818 	struct virt_dma_desc *vd;
819 	enum dma_status ret;
820 	unsigned long flags;
821 
822 	ret = dma_cookie_status(chan, cookie, txstate);
823 
824 	if (!c->paused && c->running) {
825 		uint32_t ccr = omap_dma_chan_read(c, CCR);
826 		/*
827 		 * The channel is no longer active, set the return value
828 		 * accordingly
829 		 */
830 		if (!(ccr & CCR_ENABLE))
831 			ret = DMA_COMPLETE;
832 	}
833 
834 	if (ret == DMA_COMPLETE || !txstate)
835 		return ret;
836 
837 	spin_lock_irqsave(&c->vc.lock, flags);
838 	vd = vchan_find_desc(&c->vc, cookie);
839 	if (vd) {
840 		txstate->residue = omap_dma_desc_size(to_omap_dma_desc(&vd->tx));
841 	} else if (c->desc && c->desc->vd.tx.cookie == cookie) {
842 		struct omap_desc *d = c->desc;
843 		dma_addr_t pos;
844 
845 		if (d->dir == DMA_MEM_TO_DEV)
846 			pos = omap_dma_get_src_pos(c);
847 		else if (d->dir == DMA_DEV_TO_MEM  || d->dir == DMA_MEM_TO_MEM)
848 			pos = omap_dma_get_dst_pos(c);
849 		else
850 			pos = 0;
851 
852 		txstate->residue = omap_dma_desc_size_pos(d, pos);
853 	} else {
854 		txstate->residue = 0;
855 	}
856 	if (ret == DMA_IN_PROGRESS && c->paused)
857 		ret = DMA_PAUSED;
858 	spin_unlock_irqrestore(&c->vc.lock, flags);
859 
860 	return ret;
861 }
862 
863 static void omap_dma_issue_pending(struct dma_chan *chan)
864 {
865 	struct omap_chan *c = to_omap_dma_chan(chan);
866 	unsigned long flags;
867 
868 	spin_lock_irqsave(&c->vc.lock, flags);
869 	if (vchan_issue_pending(&c->vc) && !c->desc)
870 		omap_dma_start_desc(c);
871 	spin_unlock_irqrestore(&c->vc.lock, flags);
872 }
873 
874 static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
875 	struct dma_chan *chan, struct scatterlist *sgl, unsigned sglen,
876 	enum dma_transfer_direction dir, unsigned long tx_flags, void *context)
877 {
878 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
879 	struct omap_chan *c = to_omap_dma_chan(chan);
880 	enum dma_slave_buswidth dev_width;
881 	struct scatterlist *sgent;
882 	struct omap_desc *d;
883 	dma_addr_t dev_addr;
884 	unsigned i, es, en, frame_bytes;
885 	bool ll_failed = false;
886 	u32 burst;
887 	u32 port_window, port_window_bytes;
888 
889 	if (dir == DMA_DEV_TO_MEM) {
890 		dev_addr = c->cfg.src_addr;
891 		dev_width = c->cfg.src_addr_width;
892 		burst = c->cfg.src_maxburst;
893 		port_window = c->cfg.src_port_window_size;
894 	} else if (dir == DMA_MEM_TO_DEV) {
895 		dev_addr = c->cfg.dst_addr;
896 		dev_width = c->cfg.dst_addr_width;
897 		burst = c->cfg.dst_maxburst;
898 		port_window = c->cfg.dst_port_window_size;
899 	} else {
900 		dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
901 		return NULL;
902 	}
903 
904 	/* Bus width translates to the element size (ES) */
905 	switch (dev_width) {
906 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
907 		es = CSDP_DATA_TYPE_8;
908 		break;
909 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
910 		es = CSDP_DATA_TYPE_16;
911 		break;
912 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
913 		es = CSDP_DATA_TYPE_32;
914 		break;
915 	default: /* not reached */
916 		return NULL;
917 	}
918 
919 	/* Now allocate and setup the descriptor. */
920 	d = kzalloc(struct_size(d, sg, sglen), GFP_ATOMIC);
921 	if (!d)
922 		return NULL;
923 
924 	d->dir = dir;
925 	d->dev_addr = dev_addr;
926 	d->es = es;
927 
928 	/* When the port_window is used, one frame must cover the window */
929 	if (port_window) {
930 		burst = port_window;
931 		port_window_bytes = port_window * es_bytes[es];
932 
933 		d->ei = 1;
934 		/*
935 		 * One frame covers the port_window and by  configure
936 		 * the source frame index to be -1 * (port_window - 1)
937 		 * we instruct the sDMA that after a frame is processed
938 		 * it should move back to the start of the window.
939 		 */
940 		d->fi = -(port_window_bytes - 1);
941 	}
942 
943 	d->ccr = c->ccr | CCR_SYNC_FRAME;
944 	if (dir == DMA_DEV_TO_MEM) {
945 		d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
946 
947 		d->ccr |= CCR_DST_AMODE_POSTINC;
948 		if (port_window) {
949 			d->ccr |= CCR_SRC_AMODE_DBLIDX;
950 
951 			if (port_window_bytes >= 64)
952 				d->csdp |= CSDP_SRC_BURST_64;
953 			else if (port_window_bytes >= 32)
954 				d->csdp |= CSDP_SRC_BURST_32;
955 			else if (port_window_bytes >= 16)
956 				d->csdp |= CSDP_SRC_BURST_16;
957 
958 		} else {
959 			d->ccr |= CCR_SRC_AMODE_CONSTANT;
960 		}
961 	} else {
962 		d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
963 
964 		d->ccr |= CCR_SRC_AMODE_POSTINC;
965 		if (port_window) {
966 			d->ccr |= CCR_DST_AMODE_DBLIDX;
967 
968 			if (port_window_bytes >= 64)
969 				d->csdp |= CSDP_DST_BURST_64;
970 			else if (port_window_bytes >= 32)
971 				d->csdp |= CSDP_DST_BURST_32;
972 			else if (port_window_bytes >= 16)
973 				d->csdp |= CSDP_DST_BURST_16;
974 		} else {
975 			d->ccr |= CCR_DST_AMODE_CONSTANT;
976 		}
977 	}
978 
979 	d->cicr = CICR_DROP_IE | CICR_BLOCK_IE;
980 	d->csdp |= es;
981 
982 	if (dma_omap1()) {
983 		d->cicr |= CICR_TOUT_IE;
984 
985 		if (dir == DMA_DEV_TO_MEM)
986 			d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_TIPB;
987 		else
988 			d->csdp |= CSDP_DST_PORT_TIPB | CSDP_SRC_PORT_EMIFF;
989 	} else {
990 		if (dir == DMA_DEV_TO_MEM)
991 			d->ccr |= CCR_TRIGGER_SRC;
992 
993 		d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
994 
995 		if (port_window)
996 			d->csdp |= CSDP_WRITE_LAST_NON_POSTED;
997 	}
998 	if (od->plat->errata & DMA_ERRATA_PARALLEL_CHANNELS)
999 		d->clnk_ctrl = c->dma_ch;
1000 
1001 	/*
1002 	 * Build our scatterlist entries: each contains the address,
1003 	 * the number of elements (EN) in each frame, and the number of
1004 	 * frames (FN).  Number of bytes for this entry = ES * EN * FN.
1005 	 *
1006 	 * Burst size translates to number of elements with frame sync.
1007 	 * Note: DMA engine defines burst to be the number of dev-width
1008 	 * transfers.
1009 	 */
1010 	en = burst;
1011 	frame_bytes = es_bytes[es] * en;
1012 
1013 	if (sglen >= 2)
1014 		d->using_ll = od->ll123_supported;
1015 
1016 	for_each_sg(sgl, sgent, sglen, i) {
1017 		struct omap_sg *osg = &d->sg[i];
1018 
1019 		osg->addr = sg_dma_address(sgent);
1020 		osg->en = en;
1021 		osg->fn = sg_dma_len(sgent) / frame_bytes;
1022 
1023 		if (d->using_ll) {
1024 			osg->t2_desc = dma_pool_alloc(od->desc_pool, GFP_ATOMIC,
1025 						      &osg->t2_desc_paddr);
1026 			if (!osg->t2_desc) {
1027 				dev_err(chan->device->dev,
1028 					"t2_desc[%d] allocation failed\n", i);
1029 				ll_failed = true;
1030 				d->using_ll = false;
1031 				continue;
1032 			}
1033 
1034 			omap_dma_fill_type2_desc(d, i, dir, (i == sglen - 1));
1035 		}
1036 	}
1037 
1038 	d->sglen = sglen;
1039 
1040 	/* Release the dma_pool entries if one allocation failed */
1041 	if (ll_failed) {
1042 		for (i = 0; i < d->sglen; i++) {
1043 			struct omap_sg *osg = &d->sg[i];
1044 
1045 			if (osg->t2_desc) {
1046 				dma_pool_free(od->desc_pool, osg->t2_desc,
1047 					      osg->t2_desc_paddr);
1048 				osg->t2_desc = NULL;
1049 			}
1050 		}
1051 	}
1052 
1053 	return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
1054 }
1055 
1056 static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic(
1057 	struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
1058 	size_t period_len, enum dma_transfer_direction dir, unsigned long flags)
1059 {
1060 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1061 	struct omap_chan *c = to_omap_dma_chan(chan);
1062 	enum dma_slave_buswidth dev_width;
1063 	struct omap_desc *d;
1064 	dma_addr_t dev_addr;
1065 	unsigned es;
1066 	u32 burst;
1067 
1068 	if (dir == DMA_DEV_TO_MEM) {
1069 		dev_addr = c->cfg.src_addr;
1070 		dev_width = c->cfg.src_addr_width;
1071 		burst = c->cfg.src_maxburst;
1072 	} else if (dir == DMA_MEM_TO_DEV) {
1073 		dev_addr = c->cfg.dst_addr;
1074 		dev_width = c->cfg.dst_addr_width;
1075 		burst = c->cfg.dst_maxburst;
1076 	} else {
1077 		dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
1078 		return NULL;
1079 	}
1080 
1081 	/* Bus width translates to the element size (ES) */
1082 	switch (dev_width) {
1083 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
1084 		es = CSDP_DATA_TYPE_8;
1085 		break;
1086 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
1087 		es = CSDP_DATA_TYPE_16;
1088 		break;
1089 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
1090 		es = CSDP_DATA_TYPE_32;
1091 		break;
1092 	default: /* not reached */
1093 		return NULL;
1094 	}
1095 
1096 	/* Now allocate and setup the descriptor. */
1097 	d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
1098 	if (!d)
1099 		return NULL;
1100 
1101 	d->dir = dir;
1102 	d->dev_addr = dev_addr;
1103 	d->fi = burst;
1104 	d->es = es;
1105 	d->sg[0].addr = buf_addr;
1106 	d->sg[0].en = period_len / es_bytes[es];
1107 	d->sg[0].fn = buf_len / period_len;
1108 	d->sglen = 1;
1109 
1110 	d->ccr = c->ccr;
1111 	if (dir == DMA_DEV_TO_MEM)
1112 		d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
1113 	else
1114 		d->ccr |= CCR_DST_AMODE_CONSTANT | CCR_SRC_AMODE_POSTINC;
1115 
1116 	d->cicr = CICR_DROP_IE;
1117 	if (flags & DMA_PREP_INTERRUPT)
1118 		d->cicr |= CICR_FRAME_IE;
1119 
1120 	d->csdp = es;
1121 
1122 	if (dma_omap1()) {
1123 		d->cicr |= CICR_TOUT_IE;
1124 
1125 		if (dir == DMA_DEV_TO_MEM)
1126 			d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_MPUI;
1127 		else
1128 			d->csdp |= CSDP_DST_PORT_MPUI | CSDP_SRC_PORT_EMIFF;
1129 	} else {
1130 		if (burst)
1131 			d->ccr |= CCR_SYNC_PACKET;
1132 		else
1133 			d->ccr |= CCR_SYNC_ELEMENT;
1134 
1135 		if (dir == DMA_DEV_TO_MEM) {
1136 			d->ccr |= CCR_TRIGGER_SRC;
1137 			d->csdp |= CSDP_DST_PACKED;
1138 		} else {
1139 			d->csdp |= CSDP_SRC_PACKED;
1140 		}
1141 
1142 		d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
1143 
1144 		d->csdp |= CSDP_DST_BURST_64 | CSDP_SRC_BURST_64;
1145 	}
1146 
1147 	if (__dma_omap15xx(od->plat->dma_attr))
1148 		d->ccr |= CCR_AUTO_INIT | CCR_REPEAT;
1149 	else
1150 		d->clnk_ctrl = c->dma_ch | CLNK_CTRL_ENABLE_LNK;
1151 
1152 	c->cyclic = true;
1153 
1154 	return vchan_tx_prep(&c->vc, &d->vd, flags);
1155 }
1156 
1157 static struct dma_async_tx_descriptor *omap_dma_prep_dma_memcpy(
1158 	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
1159 	size_t len, unsigned long tx_flags)
1160 {
1161 	struct omap_chan *c = to_omap_dma_chan(chan);
1162 	struct omap_desc *d;
1163 	uint8_t data_type;
1164 
1165 	d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
1166 	if (!d)
1167 		return NULL;
1168 
1169 	data_type = __ffs((src | dest | len));
1170 	if (data_type > CSDP_DATA_TYPE_32)
1171 		data_type = CSDP_DATA_TYPE_32;
1172 
1173 	d->dir = DMA_MEM_TO_MEM;
1174 	d->dev_addr = src;
1175 	d->fi = 0;
1176 	d->es = data_type;
1177 	d->sg[0].en = len / BIT(data_type);
1178 	d->sg[0].fn = 1;
1179 	d->sg[0].addr = dest;
1180 	d->sglen = 1;
1181 	d->ccr = c->ccr;
1182 	d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_POSTINC;
1183 
1184 	d->cicr = CICR_DROP_IE | CICR_FRAME_IE;
1185 
1186 	d->csdp = data_type;
1187 
1188 	if (dma_omap1()) {
1189 		d->cicr |= CICR_TOUT_IE;
1190 		d->csdp |= CSDP_DST_PORT_EMIFF | CSDP_SRC_PORT_EMIFF;
1191 	} else {
1192 		d->csdp |= CSDP_DST_PACKED | CSDP_SRC_PACKED;
1193 		d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
1194 		d->csdp |= CSDP_DST_BURST_64 | CSDP_SRC_BURST_64;
1195 	}
1196 
1197 	return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
1198 }
1199 
1200 static struct dma_async_tx_descriptor *omap_dma_prep_dma_interleaved(
1201 	struct dma_chan *chan, struct dma_interleaved_template *xt,
1202 	unsigned long flags)
1203 {
1204 	struct omap_chan *c = to_omap_dma_chan(chan);
1205 	struct omap_desc *d;
1206 	struct omap_sg *sg;
1207 	uint8_t data_type;
1208 	size_t src_icg, dst_icg;
1209 
1210 	/* Slave mode is not supported */
1211 	if (is_slave_direction(xt->dir))
1212 		return NULL;
1213 
1214 	if (xt->frame_size != 1 || xt->numf == 0)
1215 		return NULL;
1216 
1217 	d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
1218 	if (!d)
1219 		return NULL;
1220 
1221 	data_type = __ffs((xt->src_start | xt->dst_start | xt->sgl[0].size));
1222 	if (data_type > CSDP_DATA_TYPE_32)
1223 		data_type = CSDP_DATA_TYPE_32;
1224 
1225 	sg = &d->sg[0];
1226 	d->dir = DMA_MEM_TO_MEM;
1227 	d->dev_addr = xt->src_start;
1228 	d->es = data_type;
1229 	sg->en = xt->sgl[0].size / BIT(data_type);
1230 	sg->fn = xt->numf;
1231 	sg->addr = xt->dst_start;
1232 	d->sglen = 1;
1233 	d->ccr = c->ccr;
1234 
1235 	src_icg = dmaengine_get_src_icg(xt, &xt->sgl[0]);
1236 	dst_icg = dmaengine_get_dst_icg(xt, &xt->sgl[0]);
1237 	if (src_icg) {
1238 		d->ccr |= CCR_SRC_AMODE_DBLIDX;
1239 		d->ei = 1;
1240 		d->fi = src_icg;
1241 	} else if (xt->src_inc) {
1242 		d->ccr |= CCR_SRC_AMODE_POSTINC;
1243 		d->fi = 0;
1244 	} else {
1245 		dev_err(chan->device->dev,
1246 			"%s: SRC constant addressing is not supported\n",
1247 			__func__);
1248 		kfree(d);
1249 		return NULL;
1250 	}
1251 
1252 	if (dst_icg) {
1253 		d->ccr |= CCR_DST_AMODE_DBLIDX;
1254 		sg->ei = 1;
1255 		sg->fi = dst_icg;
1256 	} else if (xt->dst_inc) {
1257 		d->ccr |= CCR_DST_AMODE_POSTINC;
1258 		sg->fi = 0;
1259 	} else {
1260 		dev_err(chan->device->dev,
1261 			"%s: DST constant addressing is not supported\n",
1262 			__func__);
1263 		kfree(d);
1264 		return NULL;
1265 	}
1266 
1267 	d->cicr = CICR_DROP_IE | CICR_FRAME_IE;
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, flags);
1281 }
1282 
1283 static int omap_dma_slave_config(struct dma_chan *chan, struct dma_slave_config *cfg)
1284 {
1285 	struct omap_chan *c = to_omap_dma_chan(chan);
1286 
1287 	if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
1288 	    cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
1289 		return -EINVAL;
1290 
1291 	if (cfg->src_maxburst > chan->device->max_burst ||
1292 	    cfg->dst_maxburst > chan->device->max_burst)
1293 		return -EINVAL;
1294 
1295 	memcpy(&c->cfg, cfg, sizeof(c->cfg));
1296 
1297 	return 0;
1298 }
1299 
1300 static int omap_dma_terminate_all(struct dma_chan *chan)
1301 {
1302 	struct omap_chan *c = to_omap_dma_chan(chan);
1303 	unsigned long flags;
1304 	LIST_HEAD(head);
1305 
1306 	spin_lock_irqsave(&c->vc.lock, flags);
1307 
1308 	/*
1309 	 * Stop DMA activity: we assume the callback will not be called
1310 	 * after omap_dma_stop() returns (even if it does, it will see
1311 	 * c->desc is NULL and exit.)
1312 	 */
1313 	if (c->desc) {
1314 		vchan_terminate_vdesc(&c->desc->vd);
1315 		c->desc = NULL;
1316 		/* Avoid stopping the dma twice */
1317 		if (!c->paused)
1318 			omap_dma_stop(c);
1319 	}
1320 
1321 	c->cyclic = false;
1322 	c->paused = false;
1323 
1324 	vchan_get_all_descriptors(&c->vc, &head);
1325 	spin_unlock_irqrestore(&c->vc.lock, flags);
1326 	vchan_dma_desc_free_list(&c->vc, &head);
1327 
1328 	return 0;
1329 }
1330 
1331 static void omap_dma_synchronize(struct dma_chan *chan)
1332 {
1333 	struct omap_chan *c = to_omap_dma_chan(chan);
1334 
1335 	vchan_synchronize(&c->vc);
1336 }
1337 
1338 static int omap_dma_pause(struct dma_chan *chan)
1339 {
1340 	struct omap_chan *c = to_omap_dma_chan(chan);
1341 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1342 	unsigned long flags;
1343 	int ret = -EINVAL;
1344 	bool can_pause = false;
1345 
1346 	spin_lock_irqsave(&od->irq_lock, flags);
1347 
1348 	if (!c->desc)
1349 		goto out;
1350 
1351 	if (c->cyclic)
1352 		can_pause = true;
1353 
1354 	/*
1355 	 * We do not allow DMA_MEM_TO_DEV transfers to be paused.
1356 	 * From the AM572x TRM, 16.1.4.18 Disabling a Channel During Transfer:
1357 	 * "When a channel is disabled during a transfer, the channel undergoes
1358 	 * an abort, unless it is hardware-source-synchronized …".
1359 	 * A source-synchronised channel is one where the fetching of data is
1360 	 * under control of the device. In other words, a device-to-memory
1361 	 * transfer. So, a destination-synchronised channel (which would be a
1362 	 * memory-to-device transfer) undergoes an abort if the the CCR_ENABLE
1363 	 * bit is cleared.
1364 	 * From 16.1.4.20.4.6.2 Abort: "If an abort trigger occurs, the channel
1365 	 * aborts immediately after completion of current read/write
1366 	 * transactions and then the FIFO is cleaned up." The term "cleaned up"
1367 	 * is not defined. TI recommends to check that RD_ACTIVE and WR_ACTIVE
1368 	 * are both clear _before_ disabling the channel, otherwise data loss
1369 	 * will occur.
1370 	 * The problem is that if the channel is active, then device activity
1371 	 * can result in DMA activity starting between reading those as both
1372 	 * clear and the write to DMA_CCR to clear the enable bit hitting the
1373 	 * hardware. If the DMA hardware can't drain the data in its FIFO to the
1374 	 * destination, then data loss "might" occur (say if we write to an UART
1375 	 * and the UART is not accepting any further data).
1376 	 */
1377 	else if (c->desc->dir == DMA_DEV_TO_MEM)
1378 		can_pause = true;
1379 
1380 	if (can_pause && !c->paused) {
1381 		ret = omap_dma_stop(c);
1382 		if (!ret)
1383 			c->paused = true;
1384 	}
1385 out:
1386 	spin_unlock_irqrestore(&od->irq_lock, flags);
1387 
1388 	return ret;
1389 }
1390 
1391 static int omap_dma_resume(struct dma_chan *chan)
1392 {
1393 	struct omap_chan *c = to_omap_dma_chan(chan);
1394 	struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1395 	unsigned long flags;
1396 	int ret = -EINVAL;
1397 
1398 	spin_lock_irqsave(&od->irq_lock, flags);
1399 
1400 	if (c->paused && c->desc) {
1401 		mb();
1402 
1403 		/* Restore channel link register */
1404 		omap_dma_chan_write(c, CLNK_CTRL, c->desc->clnk_ctrl);
1405 
1406 		omap_dma_start(c, c->desc);
1407 		c->paused = false;
1408 		ret = 0;
1409 	}
1410 	spin_unlock_irqrestore(&od->irq_lock, flags);
1411 
1412 	return ret;
1413 }
1414 
1415 static int omap_dma_chan_init(struct omap_dmadev *od)
1416 {
1417 	struct omap_chan *c;
1418 
1419 	c = kzalloc(sizeof(*c), GFP_KERNEL);
1420 	if (!c)
1421 		return -ENOMEM;
1422 
1423 	c->reg_map = od->reg_map;
1424 	c->vc.desc_free = omap_dma_desc_free;
1425 	vchan_init(&c->vc, &od->ddev);
1426 
1427 	return 0;
1428 }
1429 
1430 static void omap_dma_free(struct omap_dmadev *od)
1431 {
1432 	while (!list_empty(&od->ddev.channels)) {
1433 		struct omap_chan *c = list_first_entry(&od->ddev.channels,
1434 			struct omap_chan, vc.chan.device_node);
1435 
1436 		list_del(&c->vc.chan.device_node);
1437 		tasklet_kill(&c->vc.task);
1438 		kfree(c);
1439 	}
1440 }
1441 
1442 #define OMAP_DMA_BUSWIDTHS	(BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
1443 				 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
1444 				 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
1445 
1446 static int omap_dma_probe(struct platform_device *pdev)
1447 {
1448 	struct omap_dmadev *od;
1449 	struct resource *res;
1450 	int rc, i, irq;
1451 	u32 lch_count;
1452 
1453 	od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL);
1454 	if (!od)
1455 		return -ENOMEM;
1456 
1457 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1458 	od->base = devm_ioremap_resource(&pdev->dev, res);
1459 	if (IS_ERR(od->base))
1460 		return PTR_ERR(od->base);
1461 
1462 	od->plat = omap_get_plat_info();
1463 	if (!od->plat)
1464 		return -EPROBE_DEFER;
1465 
1466 	od->reg_map = od->plat->reg_map;
1467 
1468 	dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
1469 	dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
1470 	dma_cap_set(DMA_MEMCPY, od->ddev.cap_mask);
1471 	dma_cap_set(DMA_INTERLEAVE, od->ddev.cap_mask);
1472 	od->ddev.device_alloc_chan_resources = omap_dma_alloc_chan_resources;
1473 	od->ddev.device_free_chan_resources = omap_dma_free_chan_resources;
1474 	od->ddev.device_tx_status = omap_dma_tx_status;
1475 	od->ddev.device_issue_pending = omap_dma_issue_pending;
1476 	od->ddev.device_prep_slave_sg = omap_dma_prep_slave_sg;
1477 	od->ddev.device_prep_dma_cyclic = omap_dma_prep_dma_cyclic;
1478 	od->ddev.device_prep_dma_memcpy = omap_dma_prep_dma_memcpy;
1479 	od->ddev.device_prep_interleaved_dma = omap_dma_prep_dma_interleaved;
1480 	od->ddev.device_config = omap_dma_slave_config;
1481 	od->ddev.device_pause = omap_dma_pause;
1482 	od->ddev.device_resume = omap_dma_resume;
1483 	od->ddev.device_terminate_all = omap_dma_terminate_all;
1484 	od->ddev.device_synchronize = omap_dma_synchronize;
1485 	od->ddev.src_addr_widths = OMAP_DMA_BUSWIDTHS;
1486 	od->ddev.dst_addr_widths = OMAP_DMA_BUSWIDTHS;
1487 	od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1488 	if (__dma_omap15xx(od->plat->dma_attr))
1489 		od->ddev.residue_granularity =
1490 				DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1491 	else
1492 		od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1493 	od->ddev.max_burst = SZ_16M - 1; /* CCEN: 24bit unsigned */
1494 	od->ddev.dev = &pdev->dev;
1495 	INIT_LIST_HEAD(&od->ddev.channels);
1496 	spin_lock_init(&od->lock);
1497 	spin_lock_init(&od->irq_lock);
1498 
1499 	/* Number of DMA requests */
1500 	od->dma_requests = OMAP_SDMA_REQUESTS;
1501 	if (pdev->dev.of_node && of_property_read_u32(pdev->dev.of_node,
1502 						      "dma-requests",
1503 						      &od->dma_requests)) {
1504 		dev_info(&pdev->dev,
1505 			 "Missing dma-requests property, using %u.\n",
1506 			 OMAP_SDMA_REQUESTS);
1507 	}
1508 
1509 	/* Number of available logical channels */
1510 	if (!pdev->dev.of_node) {
1511 		lch_count = od->plat->dma_attr->lch_count;
1512 		if (unlikely(!lch_count))
1513 			lch_count = OMAP_SDMA_CHANNELS;
1514 	} else if (of_property_read_u32(pdev->dev.of_node, "dma-channels",
1515 					&lch_count)) {
1516 		dev_info(&pdev->dev,
1517 			 "Missing dma-channels property, using %u.\n",
1518 			 OMAP_SDMA_CHANNELS);
1519 		lch_count = OMAP_SDMA_CHANNELS;
1520 	}
1521 
1522 	od->lch_map = devm_kcalloc(&pdev->dev, lch_count, sizeof(*od->lch_map),
1523 				   GFP_KERNEL);
1524 	if (!od->lch_map)
1525 		return -ENOMEM;
1526 
1527 	for (i = 0; i < od->dma_requests; i++) {
1528 		rc = omap_dma_chan_init(od);
1529 		if (rc) {
1530 			omap_dma_free(od);
1531 			return rc;
1532 		}
1533 	}
1534 
1535 	irq = platform_get_irq(pdev, 1);
1536 	if (irq <= 0) {
1537 		dev_info(&pdev->dev, "failed to get L1 IRQ: %d\n", irq);
1538 		od->legacy = true;
1539 	} else {
1540 		/* Disable all interrupts */
1541 		od->irq_enable_mask = 0;
1542 		omap_dma_glbl_write(od, IRQENABLE_L1, 0);
1543 
1544 		rc = devm_request_irq(&pdev->dev, irq, omap_dma_irq,
1545 				      IRQF_SHARED, "omap-dma-engine", od);
1546 		if (rc)
1547 			return rc;
1548 	}
1549 
1550 	if (omap_dma_glbl_read(od, CAPS_0) & CAPS_0_SUPPORT_LL123)
1551 		od->ll123_supported = true;
1552 
1553 	od->ddev.filter.map = od->plat->slave_map;
1554 	od->ddev.filter.mapcnt = od->plat->slavecnt;
1555 	od->ddev.filter.fn = omap_dma_filter_fn;
1556 
1557 	if (od->ll123_supported) {
1558 		od->desc_pool = dma_pool_create(dev_name(&pdev->dev),
1559 						&pdev->dev,
1560 						sizeof(struct omap_type2_desc),
1561 						4, 0);
1562 		if (!od->desc_pool) {
1563 			dev_err(&pdev->dev,
1564 				"unable to allocate descriptor pool\n");
1565 			od->ll123_supported = false;
1566 		}
1567 	}
1568 
1569 	rc = dma_async_device_register(&od->ddev);
1570 	if (rc) {
1571 		pr_warn("OMAP-DMA: failed to register slave DMA engine device: %d\n",
1572 			rc);
1573 		omap_dma_free(od);
1574 		return rc;
1575 	}
1576 
1577 	platform_set_drvdata(pdev, od);
1578 
1579 	if (pdev->dev.of_node) {
1580 		omap_dma_info.dma_cap = od->ddev.cap_mask;
1581 
1582 		/* Device-tree DMA controller registration */
1583 		rc = of_dma_controller_register(pdev->dev.of_node,
1584 				of_dma_simple_xlate, &omap_dma_info);
1585 		if (rc) {
1586 			pr_warn("OMAP-DMA: failed to register DMA controller\n");
1587 			dma_async_device_unregister(&od->ddev);
1588 			omap_dma_free(od);
1589 		}
1590 	}
1591 
1592 	dev_info(&pdev->dev, "OMAP DMA engine driver%s\n",
1593 		 od->ll123_supported ? " (LinkedList1/2/3 supported)" : "");
1594 
1595 	return rc;
1596 }
1597 
1598 static int omap_dma_remove(struct platform_device *pdev)
1599 {
1600 	struct omap_dmadev *od = platform_get_drvdata(pdev);
1601 	int irq;
1602 
1603 	if (pdev->dev.of_node)
1604 		of_dma_controller_free(pdev->dev.of_node);
1605 
1606 	irq = platform_get_irq(pdev, 1);
1607 	devm_free_irq(&pdev->dev, irq, od);
1608 
1609 	dma_async_device_unregister(&od->ddev);
1610 
1611 	if (!od->legacy) {
1612 		/* Disable all interrupts */
1613 		omap_dma_glbl_write(od, IRQENABLE_L0, 0);
1614 	}
1615 
1616 	if (od->ll123_supported)
1617 		dma_pool_destroy(od->desc_pool);
1618 
1619 	omap_dma_free(od);
1620 
1621 	return 0;
1622 }
1623 
1624 static const struct of_device_id omap_dma_match[] = {
1625 	{ .compatible = "ti,omap2420-sdma", },
1626 	{ .compatible = "ti,omap2430-sdma", },
1627 	{ .compatible = "ti,omap3430-sdma", },
1628 	{ .compatible = "ti,omap3630-sdma", },
1629 	{ .compatible = "ti,omap4430-sdma", },
1630 	{},
1631 };
1632 MODULE_DEVICE_TABLE(of, omap_dma_match);
1633 
1634 static struct platform_driver omap_dma_driver = {
1635 	.probe	= omap_dma_probe,
1636 	.remove	= omap_dma_remove,
1637 	.driver = {
1638 		.name = "omap-dma-engine",
1639 		.of_match_table = of_match_ptr(omap_dma_match),
1640 	},
1641 };
1642 
1643 bool omap_dma_filter_fn(struct dma_chan *chan, void *param)
1644 {
1645 	if (chan->device->dev->driver == &omap_dma_driver.driver) {
1646 		struct omap_dmadev *od = to_omap_dma_dev(chan->device);
1647 		struct omap_chan *c = to_omap_dma_chan(chan);
1648 		unsigned req = *(unsigned *)param;
1649 
1650 		if (req <= od->dma_requests) {
1651 			c->dma_sig = req;
1652 			return true;
1653 		}
1654 	}
1655 	return false;
1656 }
1657 EXPORT_SYMBOL_GPL(omap_dma_filter_fn);
1658 
1659 static int omap_dma_init(void)
1660 {
1661 	return platform_driver_register(&omap_dma_driver);
1662 }
1663 subsys_initcall(omap_dma_init);
1664 
1665 static void __exit omap_dma_exit(void)
1666 {
1667 	platform_driver_unregister(&omap_dma_driver);
1668 }
1669 module_exit(omap_dma_exit);
1670 
1671 MODULE_AUTHOR("Russell King");
1672 MODULE_LICENSE("GPL");
1673