xref: /openbmc/linux/drivers/dma/mmp_tdma.c (revision 39b6f3aa)
1 /*
2  * Driver For Marvell Two-channel DMA Engine
3  *
4  * Copyright: Marvell International Ltd.
5  *
6  * The code contained herein is licensed under the GNU General Public
7  * License. You may obtain a copy of the GNU General Public License
8  * Version 2 or later at the following locations:
9  *
10  */
11 
12 #include <linux/err.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/interrupt.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/slab.h>
19 #include <linux/dmaengine.h>
20 #include <linux/platform_device.h>
21 #include <linux/device.h>
22 #include <mach/regs-icu.h>
23 #include <linux/platform_data/dma-mmp_tdma.h>
24 #include <linux/of_device.h>
25 
26 #include "dmaengine.h"
27 
28 /*
29  * Two-Channel DMA registers
30  */
31 #define TDBCR		0x00	/* Byte Count */
32 #define TDSAR		0x10	/* Src Addr */
33 #define TDDAR		0x20	/* Dst Addr */
34 #define TDNDPR		0x30	/* Next Desc */
35 #define TDCR		0x40	/* Control */
36 #define TDCP		0x60	/* Priority*/
37 #define TDCDPR		0x70	/* Current Desc */
38 #define TDIMR		0x80	/* Int Mask */
39 #define TDISR		0xa0	/* Int Status */
40 
41 /* Two-Channel DMA Control Register */
42 #define TDCR_SSZ_8_BITS		(0x0 << 22)	/* Sample Size */
43 #define TDCR_SSZ_12_BITS	(0x1 << 22)
44 #define TDCR_SSZ_16_BITS	(0x2 << 22)
45 #define TDCR_SSZ_20_BITS	(0x3 << 22)
46 #define TDCR_SSZ_24_BITS	(0x4 << 22)
47 #define TDCR_SSZ_32_BITS	(0x5 << 22)
48 #define TDCR_SSZ_SHIFT		(0x1 << 22)
49 #define TDCR_SSZ_MASK		(0x7 << 22)
50 #define TDCR_SSPMOD		(0x1 << 21)	/* SSP MOD */
51 #define TDCR_ABR		(0x1 << 20)	/* Channel Abort */
52 #define TDCR_CDE		(0x1 << 17)	/* Close Desc Enable */
53 #define TDCR_PACKMOD		(0x1 << 16)	/* Pack Mode (ADMA Only) */
54 #define TDCR_CHANACT		(0x1 << 14)	/* Channel Active */
55 #define TDCR_FETCHND		(0x1 << 13)	/* Fetch Next Desc */
56 #define TDCR_CHANEN		(0x1 << 12)	/* Channel Enable */
57 #define TDCR_INTMODE		(0x1 << 10)	/* Interrupt Mode */
58 #define TDCR_CHAINMOD		(0x1 << 9)	/* Chain Mode */
59 #define TDCR_BURSTSZ_MSK	(0x7 << 6)	/* Burst Size */
60 #define TDCR_BURSTSZ_4B		(0x0 << 6)
61 #define TDCR_BURSTSZ_8B		(0x1 << 6)
62 #define TDCR_BURSTSZ_16B	(0x3 << 6)
63 #define TDCR_BURSTSZ_32B	(0x6 << 6)
64 #define TDCR_BURSTSZ_64B	(0x7 << 6)
65 #define TDCR_BURSTSZ_SQU_32B	(0x7 << 6)
66 #define TDCR_BURSTSZ_128B	(0x5 << 6)
67 #define TDCR_DSTDIR_MSK		(0x3 << 4)	/* Dst Direction */
68 #define TDCR_DSTDIR_ADDR_HOLD	(0x2 << 4)	/* Dst Addr Hold */
69 #define TDCR_DSTDIR_ADDR_INC	(0x0 << 4)	/* Dst Addr Increment */
70 #define TDCR_SRCDIR_MSK		(0x3 << 2)	/* Src Direction */
71 #define TDCR_SRCDIR_ADDR_HOLD	(0x2 << 2)	/* Src Addr Hold */
72 #define TDCR_SRCDIR_ADDR_INC	(0x0 << 2)	/* Src Addr Increment */
73 #define TDCR_DSTDESCCONT	(0x1 << 1)
74 #define TDCR_SRCDESTCONT	(0x1 << 0)
75 
76 /* Two-Channel DMA Int Mask Register */
77 #define TDIMR_COMP		(0x1 << 0)
78 
79 /* Two-Channel DMA Int Status Register */
80 #define TDISR_COMP		(0x1 << 0)
81 
82 /*
83  * Two-Channel DMA Descriptor Struct
84  * NOTE: desc's buf must be aligned to 16 bytes.
85  */
86 struct mmp_tdma_desc {
87 	u32 byte_cnt;
88 	u32 src_addr;
89 	u32 dst_addr;
90 	u32 nxt_desc;
91 };
92 
93 enum mmp_tdma_type {
94 	MMP_AUD_TDMA = 0,
95 	PXA910_SQU,
96 };
97 
98 #define TDMA_ALIGNMENT		3
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 	phys_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 
116 	int				idx;
117 	enum mmp_tdma_type		type;
118 	int				irq;
119 	unsigned long			reg_base;
120 
121 	size_t				buf_len;
122 	size_t				period_len;
123 	size_t				pos;
124 };
125 
126 #define TDMA_CHANNEL_NUM 2
127 struct mmp_tdma_device {
128 	struct device			*dev;
129 	void __iomem			*base;
130 	struct dma_device		device;
131 	struct mmp_tdma_chan		*tdmac[TDMA_CHANNEL_NUM];
132 };
133 
134 #define to_mmp_tdma_chan(dchan) container_of(dchan, struct mmp_tdma_chan, chan)
135 
136 static void mmp_tdma_chan_set_desc(struct mmp_tdma_chan *tdmac, dma_addr_t phys)
137 {
138 	writel(phys, tdmac->reg_base + TDNDPR);
139 	writel(readl(tdmac->reg_base + TDCR) | TDCR_FETCHND,
140 					tdmac->reg_base + TDCR);
141 }
142 
143 static void mmp_tdma_enable_chan(struct mmp_tdma_chan *tdmac)
144 {
145 	/* enable irq */
146 	writel(TDIMR_COMP, tdmac->reg_base + TDIMR);
147 	/* enable dma chan */
148 	writel(readl(tdmac->reg_base + TDCR) | TDCR_CHANEN,
149 					tdmac->reg_base + TDCR);
150 	tdmac->status = DMA_IN_PROGRESS;
151 }
152 
153 static void mmp_tdma_disable_chan(struct mmp_tdma_chan *tdmac)
154 {
155 	writel(readl(tdmac->reg_base + TDCR) & ~TDCR_CHANEN,
156 					tdmac->reg_base + TDCR);
157 	tdmac->status = DMA_SUCCESS;
158 }
159 
160 static void mmp_tdma_resume_chan(struct mmp_tdma_chan *tdmac)
161 {
162 	writel(readl(tdmac->reg_base + TDCR) | TDCR_CHANEN,
163 					tdmac->reg_base + TDCR);
164 	tdmac->status = DMA_IN_PROGRESS;
165 }
166 
167 static void mmp_tdma_pause_chan(struct mmp_tdma_chan *tdmac)
168 {
169 	writel(readl(tdmac->reg_base + TDCR) & ~TDCR_CHANEN,
170 					tdmac->reg_base + TDCR);
171 	tdmac->status = DMA_PAUSED;
172 }
173 
174 static int mmp_tdma_config_chan(struct mmp_tdma_chan *tdmac)
175 {
176 	unsigned int tdcr;
177 
178 	mmp_tdma_disable_chan(tdmac);
179 
180 	if (tdmac->dir == DMA_MEM_TO_DEV)
181 		tdcr = TDCR_DSTDIR_ADDR_HOLD | TDCR_SRCDIR_ADDR_INC;
182 	else if (tdmac->dir == DMA_DEV_TO_MEM)
183 		tdcr = TDCR_SRCDIR_ADDR_HOLD | TDCR_DSTDIR_ADDR_INC;
184 
185 	if (tdmac->type == MMP_AUD_TDMA) {
186 		tdcr |= TDCR_PACKMOD;
187 
188 		switch (tdmac->burst_sz) {
189 		case 4:
190 			tdcr |= TDCR_BURSTSZ_4B;
191 			break;
192 		case 8:
193 			tdcr |= TDCR_BURSTSZ_8B;
194 			break;
195 		case 16:
196 			tdcr |= TDCR_BURSTSZ_16B;
197 			break;
198 		case 32:
199 			tdcr |= TDCR_BURSTSZ_32B;
200 			break;
201 		case 64:
202 			tdcr |= TDCR_BURSTSZ_64B;
203 			break;
204 		case 128:
205 			tdcr |= TDCR_BURSTSZ_128B;
206 			break;
207 		default:
208 			dev_err(tdmac->dev, "mmp_tdma: unknown burst size.\n");
209 			return -EINVAL;
210 		}
211 
212 		switch (tdmac->buswidth) {
213 		case DMA_SLAVE_BUSWIDTH_1_BYTE:
214 			tdcr |= TDCR_SSZ_8_BITS;
215 			break;
216 		case DMA_SLAVE_BUSWIDTH_2_BYTES:
217 			tdcr |= TDCR_SSZ_16_BITS;
218 			break;
219 		case DMA_SLAVE_BUSWIDTH_4_BYTES:
220 			tdcr |= TDCR_SSZ_32_BITS;
221 			break;
222 		default:
223 			dev_err(tdmac->dev, "mmp_tdma: unknown bus size.\n");
224 			return -EINVAL;
225 		}
226 	} else if (tdmac->type == PXA910_SQU) {
227 		tdcr |= TDCR_BURSTSZ_SQU_32B;
228 		tdcr |= TDCR_SSPMOD;
229 	}
230 
231 	writel(tdcr, tdmac->reg_base + TDCR);
232 	return 0;
233 }
234 
235 static int mmp_tdma_clear_chan_irq(struct mmp_tdma_chan *tdmac)
236 {
237 	u32 reg = readl(tdmac->reg_base + TDISR);
238 
239 	if (reg & TDISR_COMP) {
240 		/* clear irq */
241 		reg &= ~TDISR_COMP;
242 		writel(reg, tdmac->reg_base + TDISR);
243 
244 		return 0;
245 	}
246 	return -EAGAIN;
247 }
248 
249 static irqreturn_t mmp_tdma_chan_handler(int irq, void *dev_id)
250 {
251 	struct mmp_tdma_chan *tdmac = dev_id;
252 
253 	if (mmp_tdma_clear_chan_irq(tdmac) == 0) {
254 		tdmac->pos = (tdmac->pos + tdmac->period_len) % tdmac->buf_len;
255 		tasklet_schedule(&tdmac->tasklet);
256 		return IRQ_HANDLED;
257 	} else
258 		return IRQ_NONE;
259 }
260 
261 static irqreturn_t mmp_tdma_int_handler(int irq, void *dev_id)
262 {
263 	struct mmp_tdma_device *tdev = dev_id;
264 	int i, ret;
265 	int irq_num = 0;
266 
267 	for (i = 0; i < TDMA_CHANNEL_NUM; i++) {
268 		struct mmp_tdma_chan *tdmac = tdev->tdmac[i];
269 
270 		ret = mmp_tdma_chan_handler(irq, tdmac);
271 		if (ret == IRQ_HANDLED)
272 			irq_num++;
273 	}
274 
275 	if (irq_num)
276 		return IRQ_HANDLED;
277 	else
278 		return IRQ_NONE;
279 }
280 
281 static void dma_do_tasklet(unsigned long data)
282 {
283 	struct mmp_tdma_chan *tdmac = (struct mmp_tdma_chan *)data;
284 
285 	if (tdmac->desc.callback)
286 		tdmac->desc.callback(tdmac->desc.callback_param);
287 
288 }
289 
290 static void mmp_tdma_free_descriptor(struct mmp_tdma_chan *tdmac)
291 {
292 	struct gen_pool *gpool;
293 	int size = tdmac->desc_num * sizeof(struct mmp_tdma_desc);
294 
295 	gpool = sram_get_gpool("asram");
296 	if (tdmac->desc_arr)
297 		gen_pool_free(gpool, (unsigned long)tdmac->desc_arr,
298 				size);
299 	tdmac->desc_arr = NULL;
300 
301 	return;
302 }
303 
304 static dma_cookie_t mmp_tdma_tx_submit(struct dma_async_tx_descriptor *tx)
305 {
306 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(tx->chan);
307 
308 	mmp_tdma_chan_set_desc(tdmac, tdmac->desc_arr_phys);
309 
310 	return 0;
311 }
312 
313 static int mmp_tdma_alloc_chan_resources(struct dma_chan *chan)
314 {
315 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
316 	int ret;
317 
318 	dma_async_tx_descriptor_init(&tdmac->desc, chan);
319 	tdmac->desc.tx_submit = mmp_tdma_tx_submit;
320 
321 	if (tdmac->irq) {
322 		ret = devm_request_irq(tdmac->dev, tdmac->irq,
323 			mmp_tdma_chan_handler, IRQF_DISABLED, "tdma", tdmac);
324 		if (ret)
325 			return ret;
326 	}
327 	return 1;
328 }
329 
330 static void mmp_tdma_free_chan_resources(struct dma_chan *chan)
331 {
332 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
333 
334 	if (tdmac->irq)
335 		devm_free_irq(tdmac->dev, tdmac->irq, tdmac);
336 	mmp_tdma_free_descriptor(tdmac);
337 	return;
338 }
339 
340 struct mmp_tdma_desc *mmp_tdma_alloc_descriptor(struct mmp_tdma_chan *tdmac)
341 {
342 	struct gen_pool *gpool;
343 	int size = tdmac->desc_num * sizeof(struct mmp_tdma_desc);
344 
345 	gpool = sram_get_gpool("asram");
346 	if (!gpool)
347 		return NULL;
348 
349 	tdmac->desc_arr = (void *)gen_pool_alloc(gpool, size);
350 	if (!tdmac->desc_arr)
351 		return NULL;
352 
353 	tdmac->desc_arr_phys = gen_pool_virt_to_phys(gpool,
354 			(unsigned long)tdmac->desc_arr);
355 
356 	return tdmac->desc_arr;
357 }
358 
359 static struct dma_async_tx_descriptor *mmp_tdma_prep_dma_cyclic(
360 		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
361 		size_t period_len, enum dma_transfer_direction direction,
362 		unsigned long flags, void *context)
363 {
364 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
365 	struct mmp_tdma_desc *desc;
366 	int num_periods = buf_len / period_len;
367 	int i = 0, buf = 0;
368 
369 	if (tdmac->status != DMA_SUCCESS)
370 		return NULL;
371 
372 	if (period_len > TDMA_MAX_XFER_BYTES) {
373 		dev_err(tdmac->dev,
374 				"maximum period size exceeded: %d > %d\n",
375 				period_len, TDMA_MAX_XFER_BYTES);
376 		goto err_out;
377 	}
378 
379 	tdmac->status = DMA_IN_PROGRESS;
380 	tdmac->desc_num = num_periods;
381 	desc = mmp_tdma_alloc_descriptor(tdmac);
382 	if (!desc)
383 		goto err_out;
384 
385 	while (buf < buf_len) {
386 		desc = &tdmac->desc_arr[i];
387 
388 		if (i + 1 == num_periods)
389 			desc->nxt_desc = tdmac->desc_arr_phys;
390 		else
391 			desc->nxt_desc = tdmac->desc_arr_phys +
392 				sizeof(*desc) * (i + 1);
393 
394 		if (direction == DMA_MEM_TO_DEV) {
395 			desc->src_addr = dma_addr;
396 			desc->dst_addr = tdmac->dev_addr;
397 		} else {
398 			desc->src_addr = tdmac->dev_addr;
399 			desc->dst_addr = dma_addr;
400 		}
401 		desc->byte_cnt = period_len;
402 		dma_addr += period_len;
403 		buf += period_len;
404 		i++;
405 	}
406 
407 	tdmac->buf_len = buf_len;
408 	tdmac->period_len = period_len;
409 	tdmac->pos = 0;
410 
411 	return &tdmac->desc;
412 
413 err_out:
414 	tdmac->status = DMA_ERROR;
415 	return NULL;
416 }
417 
418 static int mmp_tdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
419 		unsigned long arg)
420 {
421 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
422 	struct dma_slave_config *dmaengine_cfg = (void *)arg;
423 	int ret = 0;
424 
425 	switch (cmd) {
426 	case DMA_TERMINATE_ALL:
427 		mmp_tdma_disable_chan(tdmac);
428 		break;
429 	case DMA_PAUSE:
430 		mmp_tdma_pause_chan(tdmac);
431 		break;
432 	case DMA_RESUME:
433 		mmp_tdma_resume_chan(tdmac);
434 		break;
435 	case DMA_SLAVE_CONFIG:
436 		if (dmaengine_cfg->direction == DMA_DEV_TO_MEM) {
437 			tdmac->dev_addr = dmaengine_cfg->src_addr;
438 			tdmac->burst_sz = dmaengine_cfg->src_maxburst;
439 			tdmac->buswidth = dmaengine_cfg->src_addr_width;
440 		} else {
441 			tdmac->dev_addr = dmaengine_cfg->dst_addr;
442 			tdmac->burst_sz = dmaengine_cfg->dst_maxburst;
443 			tdmac->buswidth = dmaengine_cfg->dst_addr_width;
444 		}
445 		tdmac->dir = dmaengine_cfg->direction;
446 		return mmp_tdma_config_chan(tdmac);
447 	default:
448 		ret = -ENOSYS;
449 	}
450 
451 	return ret;
452 }
453 
454 static enum dma_status mmp_tdma_tx_status(struct dma_chan *chan,
455 			dma_cookie_t cookie, struct dma_tx_state *txstate)
456 {
457 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
458 
459 	dma_set_residue(txstate, tdmac->buf_len - tdmac->pos);
460 
461 	return tdmac->status;
462 }
463 
464 static void mmp_tdma_issue_pending(struct dma_chan *chan)
465 {
466 	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
467 
468 	mmp_tdma_enable_chan(tdmac);
469 }
470 
471 static int mmp_tdma_remove(struct platform_device *pdev)
472 {
473 	struct mmp_tdma_device *tdev = platform_get_drvdata(pdev);
474 
475 	dma_async_device_unregister(&tdev->device);
476 	return 0;
477 }
478 
479 static int mmp_tdma_chan_init(struct mmp_tdma_device *tdev,
480 						int idx, int irq, int type)
481 {
482 	struct mmp_tdma_chan *tdmac;
483 
484 	if (idx >= TDMA_CHANNEL_NUM) {
485 		dev_err(tdev->dev, "too many channels for device!\n");
486 		return -EINVAL;
487 	}
488 
489 	/* alloc channel */
490 	tdmac = devm_kzalloc(tdev->dev, sizeof(*tdmac), GFP_KERNEL);
491 	if (!tdmac) {
492 		dev_err(tdev->dev, "no free memory for DMA channels!\n");
493 		return -ENOMEM;
494 	}
495 	if (irq)
496 		tdmac->irq = irq;
497 	tdmac->dev	   = tdev->dev;
498 	tdmac->chan.device = &tdev->device;
499 	tdmac->idx	   = idx;
500 	tdmac->type	   = type;
501 	tdmac->reg_base	   = (unsigned long)tdev->base + idx * 4;
502 	tdmac->status = DMA_SUCCESS;
503 	tdev->tdmac[tdmac->idx] = tdmac;
504 	tasklet_init(&tdmac->tasklet, dma_do_tasklet, (unsigned long)tdmac);
505 
506 	/* add the channel to tdma_chan list */
507 	list_add_tail(&tdmac->chan.device_node,
508 			&tdev->device.channels);
509 	return 0;
510 }
511 
512 static struct of_device_id mmp_tdma_dt_ids[] = {
513 	{ .compatible = "marvell,adma-1.0", .data = (void *)MMP_AUD_TDMA},
514 	{ .compatible = "marvell,pxa910-squ", .data = (void *)PXA910_SQU},
515 	{}
516 };
517 MODULE_DEVICE_TABLE(of, mmp_tdma_dt_ids);
518 
519 static int mmp_tdma_probe(struct platform_device *pdev)
520 {
521 	enum mmp_tdma_type type;
522 	const struct of_device_id *of_id;
523 	struct mmp_tdma_device *tdev;
524 	struct resource *iores;
525 	int i, ret;
526 	int irq = 0, irq_num = 0;
527 	int chan_num = TDMA_CHANNEL_NUM;
528 
529 	of_id = of_match_device(mmp_tdma_dt_ids, &pdev->dev);
530 	if (of_id)
531 		type = (enum mmp_tdma_type) of_id->data;
532 	else
533 		type = platform_get_device_id(pdev)->driver_data;
534 
535 	/* always have couple channels */
536 	tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
537 	if (!tdev)
538 		return -ENOMEM;
539 
540 	tdev->dev = &pdev->dev;
541 
542 	for (i = 0; i < chan_num; i++) {
543 		if (platform_get_irq(pdev, i) > 0)
544 			irq_num++;
545 	}
546 
547 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
548 	if (!iores)
549 		return -EINVAL;
550 
551 	tdev->base = devm_ioremap_resource(&pdev->dev, iores);
552 	if (IS_ERR(tdev->base))
553 		return PTR_ERR(tdev->base);
554 
555 	INIT_LIST_HEAD(&tdev->device.channels);
556 
557 	if (irq_num != chan_num) {
558 		irq = platform_get_irq(pdev, 0);
559 		ret = devm_request_irq(&pdev->dev, irq,
560 			mmp_tdma_int_handler, IRQF_DISABLED, "tdma", tdev);
561 		if (ret)
562 			return ret;
563 	}
564 
565 	/* initialize channel parameters */
566 	for (i = 0; i < chan_num; i++) {
567 		irq = (irq_num != chan_num) ? 0 : platform_get_irq(pdev, i);
568 		ret = mmp_tdma_chan_init(tdev, i, irq, type);
569 		if (ret)
570 			return ret;
571 	}
572 
573 	dma_cap_set(DMA_SLAVE, tdev->device.cap_mask);
574 	dma_cap_set(DMA_CYCLIC, tdev->device.cap_mask);
575 	tdev->device.dev = &pdev->dev;
576 	tdev->device.device_alloc_chan_resources =
577 					mmp_tdma_alloc_chan_resources;
578 	tdev->device.device_free_chan_resources =
579 					mmp_tdma_free_chan_resources;
580 	tdev->device.device_prep_dma_cyclic = mmp_tdma_prep_dma_cyclic;
581 	tdev->device.device_tx_status = mmp_tdma_tx_status;
582 	tdev->device.device_issue_pending = mmp_tdma_issue_pending;
583 	tdev->device.device_control = mmp_tdma_control;
584 	tdev->device.copy_align = TDMA_ALIGNMENT;
585 
586 	dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
587 	platform_set_drvdata(pdev, tdev);
588 
589 	ret = dma_async_device_register(&tdev->device);
590 	if (ret) {
591 		dev_err(tdev->device.dev, "unable to register\n");
592 		return ret;
593 	}
594 
595 	dev_info(tdev->device.dev, "initialized\n");
596 	return 0;
597 }
598 
599 static const struct platform_device_id mmp_tdma_id_table[] = {
600 	{ "mmp-adma",	MMP_AUD_TDMA },
601 	{ "pxa910-squ",	PXA910_SQU },
602 	{ },
603 };
604 
605 static struct platform_driver mmp_tdma_driver = {
606 	.driver		= {
607 		.name	= "mmp-tdma",
608 		.owner  = THIS_MODULE,
609 		.of_match_table = mmp_tdma_dt_ids,
610 	},
611 	.id_table	= mmp_tdma_id_table,
612 	.probe		= mmp_tdma_probe,
613 	.remove		= mmp_tdma_remove,
614 };
615 
616 module_platform_driver(mmp_tdma_driver);
617 
618 MODULE_LICENSE("GPL");
619 MODULE_DESCRIPTION("MMP Two-Channel DMA Driver");
620 MODULE_ALIAS("platform:mmp-tdma");
621 MODULE_AUTHOR("Leo Yan <leoy@marvell.com>");
622 MODULE_AUTHOR("Zhangfei Gao <zhangfei.gao@marvell.com>");
623