xref: /openbmc/linux/drivers/dma/mmp_tdma.c (revision adb57164)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver For Marvell Two-channel DMA Engine
4  *
5  * Copyright: Marvell International Ltd.
6  */
7 
8 #include <linux/err.h>
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/types.h>
12 #include <linux/interrupt.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/slab.h>
15 #include <linux/dmaengine.h>
16 #include <linux/platform_device.h>
17 #include <linux/device.h>
18 #include <linux/platform_data/dma-mmp_tdma.h>
19 #include <linux/of_device.h>
20 #include <linux/of_dma.h>
21 
22 #include "dmaengine.h"
23 
24 /*
25  * Two-Channel DMA registers
26  */
27 #define TDBCR		0x00	/* Byte Count */
28 #define TDSAR		0x10	/* Src Addr */
29 #define TDDAR		0x20	/* Dst Addr */
30 #define TDNDPR		0x30	/* Next Desc */
31 #define TDCR		0x40	/* Control */
32 #define TDCP		0x60	/* Priority*/
33 #define TDCDPR		0x70	/* Current Desc */
34 #define TDIMR		0x80	/* Int Mask */
35 #define TDISR		0xa0	/* Int Status */
36 
37 /* Two-Channel DMA Control Register */
38 #define TDCR_SSZ_8_BITS		(0x0 << 22)	/* Sample Size */
39 #define TDCR_SSZ_12_BITS	(0x1 << 22)
40 #define TDCR_SSZ_16_BITS	(0x2 << 22)
41 #define TDCR_SSZ_20_BITS	(0x3 << 22)
42 #define TDCR_SSZ_24_BITS	(0x4 << 22)
43 #define TDCR_SSZ_32_BITS	(0x5 << 22)
44 #define TDCR_SSZ_SHIFT		(0x1 << 22)
45 #define TDCR_SSZ_MASK		(0x7 << 22)
46 #define TDCR_SSPMOD		(0x1 << 21)	/* SSP MOD */
47 #define TDCR_ABR		(0x1 << 20)	/* Channel Abort */
48 #define TDCR_CDE		(0x1 << 17)	/* Close Desc Enable */
49 #define TDCR_PACKMOD		(0x1 << 16)	/* Pack Mode (ADMA Only) */
50 #define TDCR_CHANACT		(0x1 << 14)	/* Channel Active */
51 #define TDCR_FETCHND		(0x1 << 13)	/* Fetch Next Desc */
52 #define TDCR_CHANEN		(0x1 << 12)	/* Channel Enable */
53 #define TDCR_INTMODE		(0x1 << 10)	/* Interrupt Mode */
54 #define TDCR_CHAINMOD		(0x1 << 9)	/* Chain Mode */
55 #define TDCR_BURSTSZ_MSK	(0x7 << 6)	/* Burst Size */
56 #define TDCR_BURSTSZ_4B		(0x0 << 6)
57 #define TDCR_BURSTSZ_8B		(0x1 << 6)
58 #define TDCR_BURSTSZ_16B	(0x3 << 6)
59 #define TDCR_BURSTSZ_32B	(0x6 << 6)
60 #define TDCR_BURSTSZ_64B	(0x7 << 6)
61 #define TDCR_BURSTSZ_SQU_1B		(0x5 << 6)
62 #define TDCR_BURSTSZ_SQU_2B		(0x6 << 6)
63 #define TDCR_BURSTSZ_SQU_4B		(0x0 << 6)
64 #define TDCR_BURSTSZ_SQU_8B		(0x1 << 6)
65 #define TDCR_BURSTSZ_SQU_16B	(0x3 << 6)
66 #define TDCR_BURSTSZ_SQU_32B	(0x7 << 6)
67 #define TDCR_BURSTSZ_128B	(0x5 << 6)
68 #define TDCR_DSTDIR_MSK		(0x3 << 4)	/* Dst Direction */
69 #define TDCR_DSTDIR_ADDR_HOLD	(0x2 << 4)	/* Dst Addr Hold */
70 #define TDCR_DSTDIR_ADDR_INC	(0x0 << 4)	/* Dst Addr Increment */
71 #define TDCR_SRCDIR_MSK		(0x3 << 2)	/* Src Direction */
72 #define TDCR_SRCDIR_ADDR_HOLD	(0x2 << 2)	/* Src Addr Hold */
73 #define TDCR_SRCDIR_ADDR_INC	(0x0 << 2)	/* Src Addr Increment */
74 #define TDCR_DSTDESCCONT	(0x1 << 1)
75 #define TDCR_SRCDESTCONT	(0x1 << 0)
76 
77 /* Two-Channel DMA Int Mask Register */
78 #define TDIMR_COMP		(0x1 << 0)
79 
80 /* Two-Channel DMA Int Status Register */
81 #define TDISR_COMP		(0x1 << 0)
82 
83 /*
84  * Two-Channel DMA Descriptor Struct
85  * NOTE: desc's buf must be aligned to 16 bytes.
86  */
87 struct mmp_tdma_desc {
88 	u32 byte_cnt;
89 	u32 src_addr;
90 	u32 dst_addr;
91 	u32 nxt_desc;
92 };
93 
94 enum mmp_tdma_type {
95 	MMP_AUD_TDMA = 0,
96 	PXA910_SQU,
97 };
98 
99 #define TDMA_MAX_XFER_BYTES    SZ_64K
100 
101 struct mmp_tdma_chan {
102 	struct device			*dev;
103 	struct dma_chan			chan;
104 	struct dma_async_tx_descriptor	desc;
105 	struct tasklet_struct		tasklet;
106 
107 	struct mmp_tdma_desc		*desc_arr;
108 	dma_addr_t			desc_arr_phys;
109 	int				desc_num;
110 	enum dma_transfer_direction	dir;
111 	dma_addr_t			dev_addr;
112 	u32				burst_sz;
113 	enum dma_slave_buswidth		buswidth;
114 	enum dma_status			status;
115 	struct dma_slave_config		slave_config;
116 
117 	int				idx;
118 	enum mmp_tdma_type		type;
119 	int				irq;
120 	void __iomem			*reg_base;
121 
122 	size_t				buf_len;
123 	size_t				period_len;
124 	size_t				pos;
125 
126 	struct gen_pool			*pool;
127 };
128 
129 #define TDMA_CHANNEL_NUM 2
130 struct mmp_tdma_device {
131 	struct device			*dev;
132 	void __iomem			*base;
133 	struct dma_device		device;
134 	struct mmp_tdma_chan		*tdmac[TDMA_CHANNEL_NUM];
135 };
136 
137 #define to_mmp_tdma_chan(dchan) container_of(dchan, struct mmp_tdma_chan, chan)
138 
139 static int mmp_tdma_config_write(struct dma_chan *chan,
140 				 enum dma_transfer_direction dir,
141 				 struct dma_slave_config *dmaengine_cfg);
142 
143 static void mmp_tdma_chan_set_desc(struct mmp_tdma_chan *tdmac, dma_addr_t phys)
144 {
145 	writel(phys, tdmac->reg_base + TDNDPR);
146 	writel(readl(tdmac->reg_base + TDCR) | TDCR_FETCHND,
147 					tdmac->reg_base + TDCR);
148 }
149 
150 static void mmp_tdma_enable_irq(struct mmp_tdma_chan *tdmac, bool enable)
151 {
152 	if (enable)
153 		writel(TDIMR_COMP, tdmac->reg_base + TDIMR);
154 	else
155 		writel(0, tdmac->reg_base + TDIMR);
156 }
157 
158 static void mmp_tdma_enable_chan(struct mmp_tdma_chan *tdmac)
159 {
160 	/* enable dma chan */
161 	writel(readl(tdmac->reg_base + TDCR) | TDCR_CHANEN,
162 					tdmac->reg_base + TDCR);
163 	tdmac->status = DMA_IN_PROGRESS;
164 }
165 
166 static int mmp_tdma_disable_chan(struct dma_chan *chan)
167 {
168 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
169 	u32 tdcr;
170 
171 	tdcr = readl(tdmac->reg_base + TDCR);
172 	tdcr |= TDCR_ABR;
173 	tdcr &= ~TDCR_CHANEN;
174 	writel(tdcr, tdmac->reg_base + TDCR);
175 
176 	tdmac->status = DMA_COMPLETE;
177 
178 	return 0;
179 }
180 
181 static int mmp_tdma_resume_chan(struct dma_chan *chan)
182 {
183 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
184 
185 	writel(readl(tdmac->reg_base + TDCR) | TDCR_CHANEN,
186 					tdmac->reg_base + TDCR);
187 	tdmac->status = DMA_IN_PROGRESS;
188 
189 	return 0;
190 }
191 
192 static int mmp_tdma_pause_chan(struct dma_chan *chan)
193 {
194 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
195 
196 	writel(readl(tdmac->reg_base + TDCR) & ~TDCR_CHANEN,
197 					tdmac->reg_base + TDCR);
198 	tdmac->status = DMA_PAUSED;
199 
200 	return 0;
201 }
202 
203 static int mmp_tdma_config_chan(struct dma_chan *chan)
204 {
205 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
206 	unsigned int tdcr = 0;
207 
208 	mmp_tdma_disable_chan(chan);
209 
210 	if (tdmac->dir == DMA_MEM_TO_DEV)
211 		tdcr = TDCR_DSTDIR_ADDR_HOLD | TDCR_SRCDIR_ADDR_INC;
212 	else if (tdmac->dir == DMA_DEV_TO_MEM)
213 		tdcr = TDCR_SRCDIR_ADDR_HOLD | TDCR_DSTDIR_ADDR_INC;
214 
215 	if (tdmac->type == MMP_AUD_TDMA) {
216 		tdcr |= TDCR_PACKMOD;
217 
218 		switch (tdmac->burst_sz) {
219 		case 4:
220 			tdcr |= TDCR_BURSTSZ_4B;
221 			break;
222 		case 8:
223 			tdcr |= TDCR_BURSTSZ_8B;
224 			break;
225 		case 16:
226 			tdcr |= TDCR_BURSTSZ_16B;
227 			break;
228 		case 32:
229 			tdcr |= TDCR_BURSTSZ_32B;
230 			break;
231 		case 64:
232 			tdcr |= TDCR_BURSTSZ_64B;
233 			break;
234 		case 128:
235 			tdcr |= TDCR_BURSTSZ_128B;
236 			break;
237 		default:
238 			dev_err(tdmac->dev, "mmp_tdma: unknown burst size.\n");
239 			return -EINVAL;
240 		}
241 
242 		switch (tdmac->buswidth) {
243 		case DMA_SLAVE_BUSWIDTH_1_BYTE:
244 			tdcr |= TDCR_SSZ_8_BITS;
245 			break;
246 		case DMA_SLAVE_BUSWIDTH_2_BYTES:
247 			tdcr |= TDCR_SSZ_16_BITS;
248 			break;
249 		case DMA_SLAVE_BUSWIDTH_4_BYTES:
250 			tdcr |= TDCR_SSZ_32_BITS;
251 			break;
252 		default:
253 			dev_err(tdmac->dev, "mmp_tdma: unknown bus size.\n");
254 			return -EINVAL;
255 		}
256 	} else if (tdmac->type == PXA910_SQU) {
257 		tdcr |= TDCR_SSPMOD;
258 
259 		switch (tdmac->burst_sz) {
260 		case 1:
261 			tdcr |= TDCR_BURSTSZ_SQU_1B;
262 			break;
263 		case 2:
264 			tdcr |= TDCR_BURSTSZ_SQU_2B;
265 			break;
266 		case 4:
267 			tdcr |= TDCR_BURSTSZ_SQU_4B;
268 			break;
269 		case 8:
270 			tdcr |= TDCR_BURSTSZ_SQU_8B;
271 			break;
272 		case 16:
273 			tdcr |= TDCR_BURSTSZ_SQU_16B;
274 			break;
275 		case 32:
276 			tdcr |= TDCR_BURSTSZ_SQU_32B;
277 			break;
278 		default:
279 			dev_err(tdmac->dev, "mmp_tdma: unknown burst size.\n");
280 			return -EINVAL;
281 		}
282 	}
283 
284 	writel(tdcr, tdmac->reg_base + TDCR);
285 	return 0;
286 }
287 
288 static int mmp_tdma_clear_chan_irq(struct mmp_tdma_chan *tdmac)
289 {
290 	u32 reg = readl(tdmac->reg_base + TDISR);
291 
292 	if (reg & TDISR_COMP) {
293 		/* clear irq */
294 		reg &= ~TDISR_COMP;
295 		writel(reg, tdmac->reg_base + TDISR);
296 
297 		return 0;
298 	}
299 	return -EAGAIN;
300 }
301 
302 static size_t mmp_tdma_get_pos(struct mmp_tdma_chan *tdmac)
303 {
304 	size_t reg;
305 
306 	if (tdmac->idx == 0) {
307 		reg = __raw_readl(tdmac->reg_base + TDSAR);
308 		reg -= tdmac->desc_arr[0].src_addr;
309 	} else if (tdmac->idx == 1) {
310 		reg = __raw_readl(tdmac->reg_base + TDDAR);
311 		reg -= tdmac->desc_arr[0].dst_addr;
312 	} else
313 		return -EINVAL;
314 
315 	return reg;
316 }
317 
318 static irqreturn_t mmp_tdma_chan_handler(int irq, void *dev_id)
319 {
320 	struct mmp_tdma_chan *tdmac = dev_id;
321 
322 	if (mmp_tdma_clear_chan_irq(tdmac) == 0) {
323 		tasklet_schedule(&tdmac->tasklet);
324 		return IRQ_HANDLED;
325 	} else
326 		return IRQ_NONE;
327 }
328 
329 static irqreturn_t mmp_tdma_int_handler(int irq, void *dev_id)
330 {
331 	struct mmp_tdma_device *tdev = dev_id;
332 	int i, ret;
333 	int irq_num = 0;
334 
335 	for (i = 0; i < TDMA_CHANNEL_NUM; i++) {
336 		struct mmp_tdma_chan *tdmac = tdev->tdmac[i];
337 
338 		ret = mmp_tdma_chan_handler(irq, tdmac);
339 		if (ret == IRQ_HANDLED)
340 			irq_num++;
341 	}
342 
343 	if (irq_num)
344 		return IRQ_HANDLED;
345 	else
346 		return IRQ_NONE;
347 }
348 
349 static void dma_do_tasklet(unsigned long data)
350 {
351 	struct mmp_tdma_chan *tdmac = (struct mmp_tdma_chan *)data;
352 
353 	dmaengine_desc_get_callback_invoke(&tdmac->desc, NULL);
354 }
355 
356 static void mmp_tdma_free_descriptor(struct mmp_tdma_chan *tdmac)
357 {
358 	struct gen_pool *gpool;
359 	int size = tdmac->desc_num * sizeof(struct mmp_tdma_desc);
360 
361 	gpool = tdmac->pool;
362 	if (gpool && tdmac->desc_arr)
363 		gen_pool_free(gpool, (unsigned long)tdmac->desc_arr,
364 				size);
365 	tdmac->desc_arr = NULL;
366 	if (tdmac->status == DMA_ERROR)
367 		tdmac->status = DMA_COMPLETE;
368 
369 	return;
370 }
371 
372 static dma_cookie_t mmp_tdma_tx_submit(struct dma_async_tx_descriptor *tx)
373 {
374 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(tx->chan);
375 
376 	mmp_tdma_chan_set_desc(tdmac, tdmac->desc_arr_phys);
377 
378 	return 0;
379 }
380 
381 static int mmp_tdma_alloc_chan_resources(struct dma_chan *chan)
382 {
383 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
384 	int ret;
385 
386 	dma_async_tx_descriptor_init(&tdmac->desc, chan);
387 	tdmac->desc.tx_submit = mmp_tdma_tx_submit;
388 
389 	if (tdmac->irq) {
390 		ret = devm_request_irq(tdmac->dev, tdmac->irq,
391 			mmp_tdma_chan_handler, 0, "tdma", tdmac);
392 		if (ret)
393 			return ret;
394 	}
395 	return 1;
396 }
397 
398 static void mmp_tdma_free_chan_resources(struct dma_chan *chan)
399 {
400 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
401 
402 	if (tdmac->irq)
403 		devm_free_irq(tdmac->dev, tdmac->irq, tdmac);
404 	mmp_tdma_free_descriptor(tdmac);
405 	return;
406 }
407 
408 static struct mmp_tdma_desc *mmp_tdma_alloc_descriptor(struct mmp_tdma_chan *tdmac)
409 {
410 	struct gen_pool *gpool;
411 	int size = tdmac->desc_num * sizeof(struct mmp_tdma_desc);
412 
413 	gpool = tdmac->pool;
414 	if (!gpool)
415 		return NULL;
416 
417 	tdmac->desc_arr = gen_pool_dma_alloc(gpool, size, &tdmac->desc_arr_phys);
418 
419 	return tdmac->desc_arr;
420 }
421 
422 static struct dma_async_tx_descriptor *mmp_tdma_prep_dma_cyclic(
423 		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
424 		size_t period_len, enum dma_transfer_direction direction,
425 		unsigned long flags)
426 {
427 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
428 	struct mmp_tdma_desc *desc;
429 	int num_periods = buf_len / period_len;
430 	int i = 0, buf = 0;
431 
432 	if (tdmac->status != DMA_COMPLETE)
433 		return NULL;
434 
435 	if (period_len > TDMA_MAX_XFER_BYTES) {
436 		dev_err(tdmac->dev,
437 				"maximum period size exceeded: %zu > %d\n",
438 				period_len, TDMA_MAX_XFER_BYTES);
439 		goto err_out;
440 	}
441 
442 	tdmac->status = DMA_IN_PROGRESS;
443 	tdmac->desc_num = num_periods;
444 	desc = mmp_tdma_alloc_descriptor(tdmac);
445 	if (!desc)
446 		goto err_out;
447 
448 	if (mmp_tdma_config_write(chan, direction, &tdmac->slave_config))
449 		goto err_out;
450 
451 	while (buf < buf_len) {
452 		desc = &tdmac->desc_arr[i];
453 
454 		if (i + 1 == num_periods)
455 			desc->nxt_desc = tdmac->desc_arr_phys;
456 		else
457 			desc->nxt_desc = tdmac->desc_arr_phys +
458 				sizeof(*desc) * (i + 1);
459 
460 		if (direction == DMA_MEM_TO_DEV) {
461 			desc->src_addr = dma_addr;
462 			desc->dst_addr = tdmac->dev_addr;
463 		} else {
464 			desc->src_addr = tdmac->dev_addr;
465 			desc->dst_addr = dma_addr;
466 		}
467 		desc->byte_cnt = period_len;
468 		dma_addr += period_len;
469 		buf += period_len;
470 		i++;
471 	}
472 
473 	/* enable interrupt */
474 	if (flags & DMA_PREP_INTERRUPT)
475 		mmp_tdma_enable_irq(tdmac, true);
476 
477 	tdmac->buf_len = buf_len;
478 	tdmac->period_len = period_len;
479 	tdmac->pos = 0;
480 
481 	return &tdmac->desc;
482 
483 err_out:
484 	tdmac->status = DMA_ERROR;
485 	return NULL;
486 }
487 
488 static int mmp_tdma_terminate_all(struct dma_chan *chan)
489 {
490 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
491 
492 	mmp_tdma_disable_chan(chan);
493 	/* disable interrupt */
494 	mmp_tdma_enable_irq(tdmac, false);
495 
496 	return 0;
497 }
498 
499 static int mmp_tdma_config(struct dma_chan *chan,
500 			   struct dma_slave_config *dmaengine_cfg)
501 {
502 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
503 
504 	memcpy(&tdmac->slave_config, dmaengine_cfg, sizeof(*dmaengine_cfg));
505 
506 	return 0;
507 }
508 
509 static int mmp_tdma_config_write(struct dma_chan *chan,
510 				 enum dma_transfer_direction dir,
511 				 struct dma_slave_config *dmaengine_cfg)
512 {
513 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
514 
515 	if (dir == DMA_DEV_TO_MEM) {
516 		tdmac->dev_addr = dmaengine_cfg->src_addr;
517 		tdmac->burst_sz = dmaengine_cfg->src_maxburst;
518 		tdmac->buswidth = dmaengine_cfg->src_addr_width;
519 	} else {
520 		tdmac->dev_addr = dmaengine_cfg->dst_addr;
521 		tdmac->burst_sz = dmaengine_cfg->dst_maxburst;
522 		tdmac->buswidth = dmaengine_cfg->dst_addr_width;
523 	}
524 	tdmac->dir = dir;
525 
526 	return mmp_tdma_config_chan(chan);
527 }
528 
529 static enum dma_status mmp_tdma_tx_status(struct dma_chan *chan,
530 			dma_cookie_t cookie, struct dma_tx_state *txstate)
531 {
532 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
533 
534 	tdmac->pos = mmp_tdma_get_pos(tdmac);
535 	dma_set_tx_state(txstate, chan->completed_cookie, chan->cookie,
536 			 tdmac->buf_len - tdmac->pos);
537 
538 	return tdmac->status;
539 }
540 
541 static void mmp_tdma_issue_pending(struct dma_chan *chan)
542 {
543 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
544 
545 	mmp_tdma_enable_chan(tdmac);
546 }
547 
548 static int mmp_tdma_remove(struct platform_device *pdev)
549 {
550 	if (pdev->dev.of_node)
551 		of_dma_controller_free(pdev->dev.of_node);
552 
553 	return 0;
554 }
555 
556 static int mmp_tdma_chan_init(struct mmp_tdma_device *tdev,
557 					int idx, int irq,
558 					int type, struct gen_pool *pool)
559 {
560 	struct mmp_tdma_chan *tdmac;
561 
562 	if (idx >= TDMA_CHANNEL_NUM) {
563 		dev_err(tdev->dev, "too many channels for device!\n");
564 		return -EINVAL;
565 	}
566 
567 	/* alloc channel */
568 	tdmac = devm_kzalloc(tdev->dev, sizeof(*tdmac), GFP_KERNEL);
569 	if (!tdmac)
570 		return -ENOMEM;
571 
572 	if (irq)
573 		tdmac->irq = irq;
574 	tdmac->dev	   = tdev->dev;
575 	tdmac->chan.device = &tdev->device;
576 	tdmac->idx	   = idx;
577 	tdmac->type	   = type;
578 	tdmac->reg_base	   = tdev->base + idx * 4;
579 	tdmac->pool	   = pool;
580 	tdmac->status = DMA_COMPLETE;
581 	tdev->tdmac[tdmac->idx] = tdmac;
582 	tasklet_init(&tdmac->tasklet, dma_do_tasklet, (unsigned long)tdmac);
583 
584 	/* add the channel to tdma_chan list */
585 	list_add_tail(&tdmac->chan.device_node,
586 			&tdev->device.channels);
587 	return 0;
588 }
589 
590 struct mmp_tdma_filter_param {
591 	unsigned int chan_id;
592 };
593 
594 static bool mmp_tdma_filter_fn(struct dma_chan *chan, void *fn_param)
595 {
596 	struct mmp_tdma_filter_param *param = fn_param;
597 
598 	if (chan->chan_id != param->chan_id)
599 		return false;
600 
601 	return true;
602 }
603 
604 static struct dma_chan *mmp_tdma_xlate(struct of_phandle_args *dma_spec,
605 			       struct of_dma *ofdma)
606 {
607 	struct mmp_tdma_device *tdev = ofdma->of_dma_data;
608 	dma_cap_mask_t mask = tdev->device.cap_mask;
609 	struct mmp_tdma_filter_param param;
610 
611 	if (dma_spec->args_count != 1)
612 		return NULL;
613 
614 	param.chan_id = dma_spec->args[0];
615 
616 	if (param.chan_id >= TDMA_CHANNEL_NUM)
617 		return NULL;
618 
619 	return __dma_request_channel(&mask, mmp_tdma_filter_fn, &param,
620 				     ofdma->of_node);
621 }
622 
623 static const struct of_device_id mmp_tdma_dt_ids[] = {
624 	{ .compatible = "marvell,adma-1.0", .data = (void *)MMP_AUD_TDMA},
625 	{ .compatible = "marvell,pxa910-squ", .data = (void *)PXA910_SQU},
626 	{}
627 };
628 MODULE_DEVICE_TABLE(of, mmp_tdma_dt_ids);
629 
630 static int mmp_tdma_probe(struct platform_device *pdev)
631 {
632 	enum mmp_tdma_type type;
633 	const struct of_device_id *of_id;
634 	struct mmp_tdma_device *tdev;
635 	struct resource *iores;
636 	int i, ret;
637 	int irq = 0, irq_num = 0;
638 	int chan_num = TDMA_CHANNEL_NUM;
639 	struct gen_pool *pool = NULL;
640 
641 	of_id = of_match_device(mmp_tdma_dt_ids, &pdev->dev);
642 	if (of_id)
643 		type = (enum mmp_tdma_type) of_id->data;
644 	else
645 		type = platform_get_device_id(pdev)->driver_data;
646 
647 	/* always have couple channels */
648 	tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
649 	if (!tdev)
650 		return -ENOMEM;
651 
652 	tdev->dev = &pdev->dev;
653 
654 	for (i = 0; i < chan_num; i++) {
655 		if (platform_get_irq(pdev, i) > 0)
656 			irq_num++;
657 	}
658 
659 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
660 	tdev->base = devm_ioremap_resource(&pdev->dev, iores);
661 	if (IS_ERR(tdev->base))
662 		return PTR_ERR(tdev->base);
663 
664 	INIT_LIST_HEAD(&tdev->device.channels);
665 
666 	if (pdev->dev.of_node)
667 		pool = of_gen_pool_get(pdev->dev.of_node, "asram", 0);
668 	else
669 		pool = sram_get_gpool("asram");
670 	if (!pool) {
671 		dev_err(&pdev->dev, "asram pool not available\n");
672 		return -ENOMEM;
673 	}
674 
675 	if (irq_num != chan_num) {
676 		irq = platform_get_irq(pdev, 0);
677 		ret = devm_request_irq(&pdev->dev, irq,
678 			mmp_tdma_int_handler, 0, "tdma", tdev);
679 		if (ret)
680 			return ret;
681 	}
682 
683 	/* initialize channel parameters */
684 	for (i = 0; i < chan_num; i++) {
685 		irq = (irq_num != chan_num) ? 0 : platform_get_irq(pdev, i);
686 		ret = mmp_tdma_chan_init(tdev, i, irq, type, pool);
687 		if (ret)
688 			return ret;
689 	}
690 
691 	dma_cap_set(DMA_SLAVE, tdev->device.cap_mask);
692 	dma_cap_set(DMA_CYCLIC, tdev->device.cap_mask);
693 	tdev->device.dev = &pdev->dev;
694 	tdev->device.device_alloc_chan_resources =
695 					mmp_tdma_alloc_chan_resources;
696 	tdev->device.device_free_chan_resources =
697 					mmp_tdma_free_chan_resources;
698 	tdev->device.device_prep_dma_cyclic = mmp_tdma_prep_dma_cyclic;
699 	tdev->device.device_tx_status = mmp_tdma_tx_status;
700 	tdev->device.device_issue_pending = mmp_tdma_issue_pending;
701 	tdev->device.device_config = mmp_tdma_config;
702 	tdev->device.device_pause = mmp_tdma_pause_chan;
703 	tdev->device.device_resume = mmp_tdma_resume_chan;
704 	tdev->device.device_terminate_all = mmp_tdma_terminate_all;
705 	tdev->device.copy_align = DMAENGINE_ALIGN_8_BYTES;
706 
707 	dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
708 	platform_set_drvdata(pdev, tdev);
709 
710 	ret = dmaenginem_async_device_register(&tdev->device);
711 	if (ret) {
712 		dev_err(tdev->device.dev, "unable to register\n");
713 		return ret;
714 	}
715 
716 	if (pdev->dev.of_node) {
717 		ret = of_dma_controller_register(pdev->dev.of_node,
718 							mmp_tdma_xlate, tdev);
719 		if (ret) {
720 			dev_err(tdev->device.dev,
721 				"failed to register controller\n");
722 			return ret;
723 		}
724 	}
725 
726 	dev_info(tdev->device.dev, "initialized\n");
727 	return 0;
728 }
729 
730 static const struct platform_device_id mmp_tdma_id_table[] = {
731 	{ "mmp-adma",	MMP_AUD_TDMA },
732 	{ "pxa910-squ",	PXA910_SQU },
733 	{ },
734 };
735 
736 static struct platform_driver mmp_tdma_driver = {
737 	.driver		= {
738 		.name	= "mmp-tdma",
739 		.of_match_table = mmp_tdma_dt_ids,
740 	},
741 	.id_table	= mmp_tdma_id_table,
742 	.probe		= mmp_tdma_probe,
743 	.remove		= mmp_tdma_remove,
744 };
745 
746 module_platform_driver(mmp_tdma_driver);
747 
748 MODULE_LICENSE("GPL");
749 MODULE_DESCRIPTION("MMP Two-Channel DMA Driver");
750 MODULE_ALIAS("platform:mmp-tdma");
751 MODULE_AUTHOR("Leo Yan <leoy@marvell.com>");
752 MODULE_AUTHOR("Zhangfei Gao <zhangfei.gao@marvell.com>");
753