xref: /linux/drivers/dma/dma-jz4780.c (revision f68f2ff91512c199ec24883001245912afc17873)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Ingenic JZ4780 DMA controller
4  *
5  * Copyright (c) 2015 Imagination Technologies
6  * Author: Alex Smith <alex@alex-smith.me.uk>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/dmapool.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/of_device.h>
16 #include <linux/of_dma.h>
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19 
20 #include "dmaengine.h"
21 #include "virt-dma.h"
22 
23 /* Global registers. */
24 #define JZ_DMA_REG_DMAC		0x00
25 #define JZ_DMA_REG_DIRQP	0x04
26 #define JZ_DMA_REG_DDR		0x08
27 #define JZ_DMA_REG_DDRS		0x0c
28 #define JZ_DMA_REG_DCKE		0x10
29 #define JZ_DMA_REG_DCKES	0x14
30 #define JZ_DMA_REG_DCKEC	0x18
31 #define JZ_DMA_REG_DMACP	0x1c
32 #define JZ_DMA_REG_DSIRQP	0x20
33 #define JZ_DMA_REG_DSIRQM	0x24
34 #define JZ_DMA_REG_DCIRQP	0x28
35 #define JZ_DMA_REG_DCIRQM	0x2c
36 
37 /* Per-channel registers. */
38 #define JZ_DMA_REG_CHAN(n)	(n * 0x20)
39 #define JZ_DMA_REG_DSA		0x00
40 #define JZ_DMA_REG_DTA		0x04
41 #define JZ_DMA_REG_DTC		0x08
42 #define JZ_DMA_REG_DRT		0x0c
43 #define JZ_DMA_REG_DCS		0x10
44 #define JZ_DMA_REG_DCM		0x14
45 #define JZ_DMA_REG_DDA		0x18
46 #define JZ_DMA_REG_DSD		0x1c
47 
48 #define JZ_DMA_DMAC_DMAE	BIT(0)
49 #define JZ_DMA_DMAC_AR		BIT(2)
50 #define JZ_DMA_DMAC_HLT		BIT(3)
51 #define JZ_DMA_DMAC_FAIC	BIT(27)
52 #define JZ_DMA_DMAC_FMSC	BIT(31)
53 
54 #define JZ_DMA_DRT_AUTO		0x8
55 
56 #define JZ_DMA_DCS_CTE		BIT(0)
57 #define JZ_DMA_DCS_HLT		BIT(2)
58 #define JZ_DMA_DCS_TT		BIT(3)
59 #define JZ_DMA_DCS_AR		BIT(4)
60 #define JZ_DMA_DCS_DES8		BIT(30)
61 
62 #define JZ_DMA_DCM_LINK		BIT(0)
63 #define JZ_DMA_DCM_TIE		BIT(1)
64 #define JZ_DMA_DCM_STDE		BIT(2)
65 #define JZ_DMA_DCM_TSZ_SHIFT	8
66 #define JZ_DMA_DCM_TSZ_MASK	(0x7 << JZ_DMA_DCM_TSZ_SHIFT)
67 #define JZ_DMA_DCM_DP_SHIFT	12
68 #define JZ_DMA_DCM_SP_SHIFT	14
69 #define JZ_DMA_DCM_DAI		BIT(22)
70 #define JZ_DMA_DCM_SAI		BIT(23)
71 
72 #define JZ_DMA_SIZE_4_BYTE	0x0
73 #define JZ_DMA_SIZE_1_BYTE	0x1
74 #define JZ_DMA_SIZE_2_BYTE	0x2
75 #define JZ_DMA_SIZE_16_BYTE	0x3
76 #define JZ_DMA_SIZE_32_BYTE	0x4
77 #define JZ_DMA_SIZE_64_BYTE	0x5
78 #define JZ_DMA_SIZE_128_BYTE	0x6
79 
80 #define JZ_DMA_WIDTH_32_BIT	0x0
81 #define JZ_DMA_WIDTH_8_BIT	0x1
82 #define JZ_DMA_WIDTH_16_BIT	0x2
83 
84 #define JZ_DMA_BUSWIDTHS	(BIT(DMA_SLAVE_BUSWIDTH_1_BYTE)	 | \
85 				 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
86 				 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
87 
88 #define JZ4780_DMA_CTRL_OFFSET	0x1000
89 
90 /* macros for use with jz4780_dma_soc_data.flags */
91 #define JZ_SOC_DATA_ALLOW_LEGACY_DT	BIT(0)
92 #define JZ_SOC_DATA_PROGRAMMABLE_DMA	BIT(1)
93 #define JZ_SOC_DATA_PER_CHAN_PM		BIT(2)
94 #define JZ_SOC_DATA_NO_DCKES_DCKEC	BIT(3)
95 #define JZ_SOC_DATA_BREAK_LINKS		BIT(4)
96 
97 /**
98  * struct jz4780_dma_hwdesc - descriptor structure read by the DMA controller.
99  * @dcm: value for the DCM (channel command) register
100  * @dsa: source address
101  * @dta: target address
102  * @dtc: transfer count (number of blocks of the transfer size specified in DCM
103  * to transfer) in the low 24 bits, offset of the next descriptor from the
104  * descriptor base address in the upper 8 bits.
105  */
106 struct jz4780_dma_hwdesc {
107 	u32 dcm;
108 	u32 dsa;
109 	u32 dta;
110 	u32 dtc;
111 };
112 
113 /* Size of allocations for hardware descriptor blocks. */
114 #define JZ_DMA_DESC_BLOCK_SIZE	PAGE_SIZE
115 #define JZ_DMA_MAX_DESC		\
116 	(JZ_DMA_DESC_BLOCK_SIZE / sizeof(struct jz4780_dma_hwdesc))
117 
118 struct jz4780_dma_desc {
119 	struct virt_dma_desc vdesc;
120 
121 	struct jz4780_dma_hwdesc *desc;
122 	dma_addr_t desc_phys;
123 	unsigned int count;
124 	enum dma_transaction_type type;
125 	u32 transfer_type;
126 	u32 status;
127 };
128 
129 struct jz4780_dma_chan {
130 	struct virt_dma_chan vchan;
131 	unsigned int id;
132 	struct dma_pool *desc_pool;
133 
134 	u32 transfer_type_tx, transfer_type_rx;
135 	u32 transfer_shift;
136 	struct dma_slave_config	config;
137 
138 	struct jz4780_dma_desc *desc;
139 	unsigned int curr_hwdesc;
140 };
141 
142 struct jz4780_dma_soc_data {
143 	unsigned int nb_channels;
144 	unsigned int transfer_ord_max;
145 	unsigned long flags;
146 };
147 
148 struct jz4780_dma_dev {
149 	struct dma_device dma_device;
150 	void __iomem *chn_base;
151 	void __iomem *ctrl_base;
152 	struct clk *clk;
153 	unsigned int irq;
154 	const struct jz4780_dma_soc_data *soc_data;
155 
156 	u32 chan_reserved;
157 	struct jz4780_dma_chan chan[];
158 };
159 
160 struct jz4780_dma_filter_data {
161 	u32 transfer_type_tx, transfer_type_rx;
162 	int channel;
163 };
164 
165 static inline struct jz4780_dma_chan *to_jz4780_dma_chan(struct dma_chan *chan)
166 {
167 	return container_of(chan, struct jz4780_dma_chan, vchan.chan);
168 }
169 
170 static inline struct jz4780_dma_desc *to_jz4780_dma_desc(
171 	struct virt_dma_desc *vdesc)
172 {
173 	return container_of(vdesc, struct jz4780_dma_desc, vdesc);
174 }
175 
176 static inline struct jz4780_dma_dev *jz4780_dma_chan_parent(
177 	struct jz4780_dma_chan *jzchan)
178 {
179 	return container_of(jzchan->vchan.chan.device, struct jz4780_dma_dev,
180 			    dma_device);
181 }
182 
183 static inline u32 jz4780_dma_chn_readl(struct jz4780_dma_dev *jzdma,
184 	unsigned int chn, unsigned int reg)
185 {
186 	return readl(jzdma->chn_base + reg + JZ_DMA_REG_CHAN(chn));
187 }
188 
189 static inline void jz4780_dma_chn_writel(struct jz4780_dma_dev *jzdma,
190 	unsigned int chn, unsigned int reg, u32 val)
191 {
192 	writel(val, jzdma->chn_base + reg + JZ_DMA_REG_CHAN(chn));
193 }
194 
195 static inline u32 jz4780_dma_ctrl_readl(struct jz4780_dma_dev *jzdma,
196 	unsigned int reg)
197 {
198 	return readl(jzdma->ctrl_base + reg);
199 }
200 
201 static inline void jz4780_dma_ctrl_writel(struct jz4780_dma_dev *jzdma,
202 	unsigned int reg, u32 val)
203 {
204 	writel(val, jzdma->ctrl_base + reg);
205 }
206 
207 static inline void jz4780_dma_chan_enable(struct jz4780_dma_dev *jzdma,
208 	unsigned int chn)
209 {
210 	if (jzdma->soc_data->flags & JZ_SOC_DATA_PER_CHAN_PM) {
211 		unsigned int reg;
212 
213 		if (jzdma->soc_data->flags & JZ_SOC_DATA_NO_DCKES_DCKEC)
214 			reg = JZ_DMA_REG_DCKE;
215 		else
216 			reg = JZ_DMA_REG_DCKES;
217 
218 		jz4780_dma_ctrl_writel(jzdma, reg, BIT(chn));
219 	}
220 }
221 
222 static inline void jz4780_dma_chan_disable(struct jz4780_dma_dev *jzdma,
223 	unsigned int chn)
224 {
225 	if ((jzdma->soc_data->flags & JZ_SOC_DATA_PER_CHAN_PM) &&
226 			!(jzdma->soc_data->flags & JZ_SOC_DATA_NO_DCKES_DCKEC))
227 		jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DCKEC, BIT(chn));
228 }
229 
230 static struct jz4780_dma_desc *
231 jz4780_dma_desc_alloc(struct jz4780_dma_chan *jzchan, unsigned int count,
232 		      enum dma_transaction_type type,
233 		      enum dma_transfer_direction direction)
234 {
235 	struct jz4780_dma_desc *desc;
236 
237 	if (count > JZ_DMA_MAX_DESC)
238 		return NULL;
239 
240 	desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
241 	if (!desc)
242 		return NULL;
243 
244 	desc->desc = dma_pool_alloc(jzchan->desc_pool, GFP_NOWAIT,
245 				    &desc->desc_phys);
246 	if (!desc->desc) {
247 		kfree(desc);
248 		return NULL;
249 	}
250 
251 	desc->count = count;
252 	desc->type = type;
253 
254 	if (direction == DMA_DEV_TO_MEM)
255 		desc->transfer_type = jzchan->transfer_type_rx;
256 	else
257 		desc->transfer_type = jzchan->transfer_type_tx;
258 
259 	return desc;
260 }
261 
262 static void jz4780_dma_desc_free(struct virt_dma_desc *vdesc)
263 {
264 	struct jz4780_dma_desc *desc = to_jz4780_dma_desc(vdesc);
265 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(vdesc->tx.chan);
266 
267 	dma_pool_free(jzchan->desc_pool, desc->desc, desc->desc_phys);
268 	kfree(desc);
269 }
270 
271 static u32 jz4780_dma_transfer_size(struct jz4780_dma_chan *jzchan,
272 	unsigned long val, u32 *shift)
273 {
274 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
275 	int ord = ffs(val) - 1;
276 
277 	/*
278 	 * 8 byte transfer sizes unsupported so fall back on 4. If it's larger
279 	 * than the maximum, just limit it. It is perfectly safe to fall back
280 	 * in this way since we won't exceed the maximum burst size supported
281 	 * by the device, the only effect is reduced efficiency. This is better
282 	 * than refusing to perform the request at all.
283 	 */
284 	if (ord == 3)
285 		ord = 2;
286 	else if (ord > jzdma->soc_data->transfer_ord_max)
287 		ord = jzdma->soc_data->transfer_ord_max;
288 
289 	*shift = ord;
290 
291 	switch (ord) {
292 	case 0:
293 		return JZ_DMA_SIZE_1_BYTE;
294 	case 1:
295 		return JZ_DMA_SIZE_2_BYTE;
296 	case 2:
297 		return JZ_DMA_SIZE_4_BYTE;
298 	case 4:
299 		return JZ_DMA_SIZE_16_BYTE;
300 	case 5:
301 		return JZ_DMA_SIZE_32_BYTE;
302 	case 6:
303 		return JZ_DMA_SIZE_64_BYTE;
304 	default:
305 		return JZ_DMA_SIZE_128_BYTE;
306 	}
307 }
308 
309 static int jz4780_dma_setup_hwdesc(struct jz4780_dma_chan *jzchan,
310 	struct jz4780_dma_hwdesc *desc, dma_addr_t addr, size_t len,
311 	enum dma_transfer_direction direction)
312 {
313 	struct dma_slave_config *config = &jzchan->config;
314 	u32 width, maxburst, tsz;
315 
316 	if (direction == DMA_MEM_TO_DEV) {
317 		desc->dcm = JZ_DMA_DCM_SAI;
318 		desc->dsa = addr;
319 		desc->dta = config->dst_addr;
320 
321 		width = config->dst_addr_width;
322 		maxburst = config->dst_maxburst;
323 	} else {
324 		desc->dcm = JZ_DMA_DCM_DAI;
325 		desc->dsa = config->src_addr;
326 		desc->dta = addr;
327 
328 		width = config->src_addr_width;
329 		maxburst = config->src_maxburst;
330 	}
331 
332 	/*
333 	 * This calculates the maximum transfer size that can be used with the
334 	 * given address, length, width and maximum burst size. The address
335 	 * must be aligned to the transfer size, the total length must be
336 	 * divisible by the transfer size, and we must not use more than the
337 	 * maximum burst specified by the user.
338 	 */
339 	tsz = jz4780_dma_transfer_size(jzchan, addr | len | (width * maxburst),
340 				       &jzchan->transfer_shift);
341 
342 	switch (width) {
343 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
344 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
345 		break;
346 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
347 		width = JZ_DMA_WIDTH_32_BIT;
348 		break;
349 	default:
350 		return -EINVAL;
351 	}
352 
353 	desc->dcm |= tsz << JZ_DMA_DCM_TSZ_SHIFT;
354 	desc->dcm |= width << JZ_DMA_DCM_SP_SHIFT;
355 	desc->dcm |= width << JZ_DMA_DCM_DP_SHIFT;
356 
357 	desc->dtc = len >> jzchan->transfer_shift;
358 	return 0;
359 }
360 
361 static struct dma_async_tx_descriptor *jz4780_dma_prep_slave_sg(
362 	struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
363 	enum dma_transfer_direction direction, unsigned long flags,
364 	void *context)
365 {
366 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
367 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
368 	struct jz4780_dma_desc *desc;
369 	unsigned int i;
370 	int err;
371 
372 	desc = jz4780_dma_desc_alloc(jzchan, sg_len, DMA_SLAVE, direction);
373 	if (!desc)
374 		return NULL;
375 
376 	for (i = 0; i < sg_len; i++) {
377 		err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i],
378 					      sg_dma_address(&sgl[i]),
379 					      sg_dma_len(&sgl[i]),
380 					      direction);
381 		if (err < 0) {
382 			jz4780_dma_desc_free(&jzchan->desc->vdesc);
383 			return NULL;
384 		}
385 
386 		desc->desc[i].dcm |= JZ_DMA_DCM_TIE;
387 
388 		if (i != (sg_len - 1) &&
389 		    !(jzdma->soc_data->flags & JZ_SOC_DATA_BREAK_LINKS)) {
390 			/* Automatically proceeed to the next descriptor. */
391 			desc->desc[i].dcm |= JZ_DMA_DCM_LINK;
392 
393 			/*
394 			 * The upper 8 bits of the DTC field in the descriptor
395 			 * must be set to (offset from descriptor base of next
396 			 * descriptor >> 4).
397 			 */
398 			desc->desc[i].dtc |=
399 				(((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
400 		}
401 	}
402 
403 	return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
404 }
405 
406 static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_cyclic(
407 	struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
408 	size_t period_len, enum dma_transfer_direction direction,
409 	unsigned long flags)
410 {
411 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
412 	struct jz4780_dma_desc *desc;
413 	unsigned int periods, i;
414 	int err;
415 
416 	if (buf_len % period_len)
417 		return NULL;
418 
419 	periods = buf_len / period_len;
420 
421 	desc = jz4780_dma_desc_alloc(jzchan, periods, DMA_CYCLIC, direction);
422 	if (!desc)
423 		return NULL;
424 
425 	for (i = 0; i < periods; i++) {
426 		err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i], buf_addr,
427 					      period_len, direction);
428 		if (err < 0) {
429 			jz4780_dma_desc_free(&jzchan->desc->vdesc);
430 			return NULL;
431 		}
432 
433 		buf_addr += period_len;
434 
435 		/*
436 		 * Set the link bit to indicate that the controller should
437 		 * automatically proceed to the next descriptor. In
438 		 * jz4780_dma_begin(), this will be cleared if we need to issue
439 		 * an interrupt after each period.
440 		 */
441 		desc->desc[i].dcm |= JZ_DMA_DCM_TIE | JZ_DMA_DCM_LINK;
442 
443 		/*
444 		 * The upper 8 bits of the DTC field in the descriptor must be
445 		 * set to (offset from descriptor base of next descriptor >> 4).
446 		 * If this is the last descriptor, link it back to the first,
447 		 * i.e. leave offset set to 0, otherwise point to the next one.
448 		 */
449 		if (i != (periods - 1)) {
450 			desc->desc[i].dtc |=
451 				(((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
452 		}
453 	}
454 
455 	return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
456 }
457 
458 static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_memcpy(
459 	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
460 	size_t len, unsigned long flags)
461 {
462 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
463 	struct jz4780_dma_desc *desc;
464 	u32 tsz;
465 
466 	desc = jz4780_dma_desc_alloc(jzchan, 1, DMA_MEMCPY, 0);
467 	if (!desc)
468 		return NULL;
469 
470 	tsz = jz4780_dma_transfer_size(jzchan, dest | src | len,
471 				       &jzchan->transfer_shift);
472 
473 	desc->transfer_type = JZ_DMA_DRT_AUTO;
474 
475 	desc->desc[0].dsa = src;
476 	desc->desc[0].dta = dest;
477 	desc->desc[0].dcm = JZ_DMA_DCM_TIE | JZ_DMA_DCM_SAI | JZ_DMA_DCM_DAI |
478 			    tsz << JZ_DMA_DCM_TSZ_SHIFT |
479 			    JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_SP_SHIFT |
480 			    JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_DP_SHIFT;
481 	desc->desc[0].dtc = len >> jzchan->transfer_shift;
482 
483 	return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
484 }
485 
486 static void jz4780_dma_begin(struct jz4780_dma_chan *jzchan)
487 {
488 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
489 	struct virt_dma_desc *vdesc;
490 	unsigned int i;
491 	dma_addr_t desc_phys;
492 
493 	if (!jzchan->desc) {
494 		vdesc = vchan_next_desc(&jzchan->vchan);
495 		if (!vdesc)
496 			return;
497 
498 		list_del(&vdesc->node);
499 
500 		jzchan->desc = to_jz4780_dma_desc(vdesc);
501 		jzchan->curr_hwdesc = 0;
502 
503 		if (jzchan->desc->type == DMA_CYCLIC && vdesc->tx.callback) {
504 			/*
505 			 * The DMA controller doesn't support triggering an
506 			 * interrupt after processing each descriptor, only
507 			 * after processing an entire terminated list of
508 			 * descriptors. For a cyclic DMA setup the list of
509 			 * descriptors is not terminated so we can never get an
510 			 * interrupt.
511 			 *
512 			 * If the user requested a callback for a cyclic DMA
513 			 * setup then we workaround this hardware limitation
514 			 * here by degrading to a set of unlinked descriptors
515 			 * which we will submit in sequence in response to the
516 			 * completion of processing the previous descriptor.
517 			 */
518 			for (i = 0; i < jzchan->desc->count; i++)
519 				jzchan->desc->desc[i].dcm &= ~JZ_DMA_DCM_LINK;
520 		}
521 	} else {
522 		/*
523 		 * There is an existing transfer, therefore this must be one
524 		 * for which we unlinked the descriptors above. Advance to the
525 		 * next one in the list.
526 		 */
527 		jzchan->curr_hwdesc =
528 			(jzchan->curr_hwdesc + 1) % jzchan->desc->count;
529 	}
530 
531 	/* Enable the channel's clock. */
532 	jz4780_dma_chan_enable(jzdma, jzchan->id);
533 
534 	/* Use 4-word descriptors. */
535 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
536 
537 	/* Set transfer type. */
538 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DRT,
539 			      jzchan->desc->transfer_type);
540 
541 	/*
542 	 * Set the transfer count. This is redundant for a descriptor-driven
543 	 * transfer. However, there can be a delay between the transfer start
544 	 * time and when DTCn reg contains the new transfer count. Setting
545 	 * it explicitly ensures residue is computed correctly at all times.
546 	 */
547 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DTC,
548 				jzchan->desc->desc[jzchan->curr_hwdesc].dtc);
549 
550 	/* Write descriptor address and initiate descriptor fetch. */
551 	desc_phys = jzchan->desc->desc_phys +
552 		    (jzchan->curr_hwdesc * sizeof(*jzchan->desc->desc));
553 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DDA, desc_phys);
554 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DDRS, BIT(jzchan->id));
555 
556 	/* Enable the channel. */
557 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS,
558 			      JZ_DMA_DCS_CTE);
559 }
560 
561 static void jz4780_dma_issue_pending(struct dma_chan *chan)
562 {
563 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
564 	unsigned long flags;
565 
566 	spin_lock_irqsave(&jzchan->vchan.lock, flags);
567 
568 	if (vchan_issue_pending(&jzchan->vchan) && !jzchan->desc)
569 		jz4780_dma_begin(jzchan);
570 
571 	spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
572 }
573 
574 static int jz4780_dma_terminate_all(struct dma_chan *chan)
575 {
576 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
577 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
578 	unsigned long flags;
579 	LIST_HEAD(head);
580 
581 	spin_lock_irqsave(&jzchan->vchan.lock, flags);
582 
583 	/* Clear the DMA status and stop the transfer. */
584 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
585 	if (jzchan->desc) {
586 		vchan_terminate_vdesc(&jzchan->desc->vdesc);
587 		jzchan->desc = NULL;
588 	}
589 
590 	jz4780_dma_chan_disable(jzdma, jzchan->id);
591 
592 	vchan_get_all_descriptors(&jzchan->vchan, &head);
593 
594 	spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
595 
596 	vchan_dma_desc_free_list(&jzchan->vchan, &head);
597 	return 0;
598 }
599 
600 static void jz4780_dma_synchronize(struct dma_chan *chan)
601 {
602 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
603 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
604 
605 	vchan_synchronize(&jzchan->vchan);
606 	jz4780_dma_chan_disable(jzdma, jzchan->id);
607 }
608 
609 static int jz4780_dma_config(struct dma_chan *chan,
610 	struct dma_slave_config *config)
611 {
612 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
613 
614 	if ((config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
615 	   || (config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES))
616 		return -EINVAL;
617 
618 	/* Copy the reset of the slave configuration, it is used later. */
619 	memcpy(&jzchan->config, config, sizeof(jzchan->config));
620 
621 	return 0;
622 }
623 
624 static size_t jz4780_dma_desc_residue(struct jz4780_dma_chan *jzchan,
625 	struct jz4780_dma_desc *desc, unsigned int next_sg)
626 {
627 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
628 	unsigned int count = 0;
629 	unsigned int i;
630 
631 	for (i = next_sg; i < desc->count; i++)
632 		count += desc->desc[i].dtc & GENMASK(23, 0);
633 
634 	if (next_sg != 0)
635 		count += jz4780_dma_chn_readl(jzdma, jzchan->id,
636 					 JZ_DMA_REG_DTC);
637 
638 	return count << jzchan->transfer_shift;
639 }
640 
641 static enum dma_status jz4780_dma_tx_status(struct dma_chan *chan,
642 	dma_cookie_t cookie, struct dma_tx_state *txstate)
643 {
644 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
645 	struct virt_dma_desc *vdesc;
646 	enum dma_status status;
647 	unsigned long flags;
648 	unsigned long residue = 0;
649 
650 	spin_lock_irqsave(&jzchan->vchan.lock, flags);
651 
652 	status = dma_cookie_status(chan, cookie, txstate);
653 	if ((status == DMA_COMPLETE) || (txstate == NULL))
654 		goto out_unlock_irqrestore;
655 
656 	vdesc = vchan_find_desc(&jzchan->vchan, cookie);
657 	if (vdesc) {
658 		/* On the issued list, so hasn't been processed yet */
659 		residue = jz4780_dma_desc_residue(jzchan,
660 					to_jz4780_dma_desc(vdesc), 0);
661 	} else if (cookie == jzchan->desc->vdesc.tx.cookie) {
662 		residue = jz4780_dma_desc_residue(jzchan, jzchan->desc,
663 					jzchan->curr_hwdesc + 1);
664 	}
665 	dma_set_residue(txstate, residue);
666 
667 	if (vdesc && jzchan->desc && vdesc == &jzchan->desc->vdesc
668 	    && jzchan->desc->status & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT))
669 		status = DMA_ERROR;
670 
671 out_unlock_irqrestore:
672 	spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
673 	return status;
674 }
675 
676 static bool jz4780_dma_chan_irq(struct jz4780_dma_dev *jzdma,
677 				struct jz4780_dma_chan *jzchan)
678 {
679 	const unsigned int soc_flags = jzdma->soc_data->flags;
680 	struct jz4780_dma_desc *desc = jzchan->desc;
681 	u32 dcs;
682 	bool ack = true;
683 
684 	spin_lock(&jzchan->vchan.lock);
685 
686 	dcs = jz4780_dma_chn_readl(jzdma, jzchan->id, JZ_DMA_REG_DCS);
687 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
688 
689 	if (dcs & JZ_DMA_DCS_AR) {
690 		dev_warn(&jzchan->vchan.chan.dev->device,
691 			 "address error (DCS=0x%x)\n", dcs);
692 	}
693 
694 	if (dcs & JZ_DMA_DCS_HLT) {
695 		dev_warn(&jzchan->vchan.chan.dev->device,
696 			 "channel halt (DCS=0x%x)\n", dcs);
697 	}
698 
699 	if (jzchan->desc) {
700 		jzchan->desc->status = dcs;
701 
702 		if ((dcs & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT)) == 0) {
703 			if (jzchan->desc->type == DMA_CYCLIC) {
704 				vchan_cyclic_callback(&jzchan->desc->vdesc);
705 
706 				jz4780_dma_begin(jzchan);
707 			} else if (dcs & JZ_DMA_DCS_TT) {
708 				if (!(soc_flags & JZ_SOC_DATA_BREAK_LINKS) ||
709 				    (jzchan->curr_hwdesc + 1 == desc->count)) {
710 					vchan_cookie_complete(&desc->vdesc);
711 					jzchan->desc = NULL;
712 				}
713 
714 				jz4780_dma_begin(jzchan);
715 			} else {
716 				/* False positive - continue the transfer */
717 				ack = false;
718 				jz4780_dma_chn_writel(jzdma, jzchan->id,
719 						      JZ_DMA_REG_DCS,
720 						      JZ_DMA_DCS_CTE);
721 			}
722 		}
723 	} else {
724 		dev_err(&jzchan->vchan.chan.dev->device,
725 			"channel IRQ with no active transfer\n");
726 	}
727 
728 	spin_unlock(&jzchan->vchan.lock);
729 
730 	return ack;
731 }
732 
733 static irqreturn_t jz4780_dma_irq_handler(int irq, void *data)
734 {
735 	struct jz4780_dma_dev *jzdma = data;
736 	unsigned int nb_channels = jzdma->soc_data->nb_channels;
737 	unsigned long pending;
738 	u32 dmac;
739 	int i;
740 
741 	pending = jz4780_dma_ctrl_readl(jzdma, JZ_DMA_REG_DIRQP);
742 
743 	for_each_set_bit(i, &pending, nb_channels) {
744 		if (jz4780_dma_chan_irq(jzdma, &jzdma->chan[i]))
745 			pending &= ~BIT(i);
746 	}
747 
748 	/* Clear halt and address error status of all channels. */
749 	dmac = jz4780_dma_ctrl_readl(jzdma, JZ_DMA_REG_DMAC);
750 	dmac &= ~(JZ_DMA_DMAC_HLT | JZ_DMA_DMAC_AR);
751 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMAC, dmac);
752 
753 	/* Clear interrupt pending status. */
754 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DIRQP, pending);
755 
756 	return IRQ_HANDLED;
757 }
758 
759 static int jz4780_dma_alloc_chan_resources(struct dma_chan *chan)
760 {
761 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
762 
763 	jzchan->desc_pool = dma_pool_create(dev_name(&chan->dev->device),
764 					    chan->device->dev,
765 					    JZ_DMA_DESC_BLOCK_SIZE,
766 					    PAGE_SIZE, 0);
767 	if (!jzchan->desc_pool) {
768 		dev_err(&chan->dev->device,
769 			"failed to allocate descriptor pool\n");
770 		return -ENOMEM;
771 	}
772 
773 	return 0;
774 }
775 
776 static void jz4780_dma_free_chan_resources(struct dma_chan *chan)
777 {
778 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
779 
780 	vchan_free_chan_resources(&jzchan->vchan);
781 	dma_pool_destroy(jzchan->desc_pool);
782 	jzchan->desc_pool = NULL;
783 }
784 
785 static bool jz4780_dma_filter_fn(struct dma_chan *chan, void *param)
786 {
787 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
788 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
789 	struct jz4780_dma_filter_data *data = param;
790 
791 
792 	if (data->channel > -1) {
793 		if (data->channel != jzchan->id)
794 			return false;
795 	} else if (jzdma->chan_reserved & BIT(jzchan->id)) {
796 		return false;
797 	}
798 
799 	jzchan->transfer_type_tx = data->transfer_type_tx;
800 	jzchan->transfer_type_rx = data->transfer_type_rx;
801 
802 	return true;
803 }
804 
805 static struct dma_chan *jz4780_of_dma_xlate(struct of_phandle_args *dma_spec,
806 	struct of_dma *ofdma)
807 {
808 	struct jz4780_dma_dev *jzdma = ofdma->of_dma_data;
809 	dma_cap_mask_t mask = jzdma->dma_device.cap_mask;
810 	struct jz4780_dma_filter_data data;
811 
812 	if (dma_spec->args_count == 2) {
813 		data.transfer_type_tx = dma_spec->args[0];
814 		data.transfer_type_rx = dma_spec->args[0];
815 		data.channel = dma_spec->args[1];
816 	} else if (dma_spec->args_count == 3) {
817 		data.transfer_type_tx = dma_spec->args[0];
818 		data.transfer_type_rx = dma_spec->args[1];
819 		data.channel = dma_spec->args[2];
820 	} else {
821 		return NULL;
822 	}
823 
824 	if (data.channel > -1) {
825 		if (data.channel >= jzdma->soc_data->nb_channels) {
826 			dev_err(jzdma->dma_device.dev,
827 				"device requested non-existent channel %u\n",
828 				data.channel);
829 			return NULL;
830 		}
831 
832 		/* Can only select a channel marked as reserved. */
833 		if (!(jzdma->chan_reserved & BIT(data.channel))) {
834 			dev_err(jzdma->dma_device.dev,
835 				"device requested unreserved channel %u\n",
836 				data.channel);
837 			return NULL;
838 		}
839 
840 		jzdma->chan[data.channel].transfer_type_tx = data.transfer_type_tx;
841 		jzdma->chan[data.channel].transfer_type_rx = data.transfer_type_rx;
842 
843 		return dma_get_slave_channel(
844 			&jzdma->chan[data.channel].vchan.chan);
845 	} else {
846 		return __dma_request_channel(&mask, jz4780_dma_filter_fn, &data,
847 					     ofdma->of_node);
848 	}
849 }
850 
851 static int jz4780_dma_probe(struct platform_device *pdev)
852 {
853 	struct device *dev = &pdev->dev;
854 	const struct jz4780_dma_soc_data *soc_data;
855 	struct jz4780_dma_dev *jzdma;
856 	struct jz4780_dma_chan *jzchan;
857 	struct dma_device *dd;
858 	struct resource *res;
859 	int i, ret;
860 
861 	if (!dev->of_node) {
862 		dev_err(dev, "This driver must be probed from devicetree\n");
863 		return -EINVAL;
864 	}
865 
866 	soc_data = device_get_match_data(dev);
867 	if (!soc_data)
868 		return -EINVAL;
869 
870 	jzdma = devm_kzalloc(dev, struct_size(jzdma, chan,
871 			     soc_data->nb_channels), GFP_KERNEL);
872 	if (!jzdma)
873 		return -ENOMEM;
874 
875 	jzdma->soc_data = soc_data;
876 	platform_set_drvdata(pdev, jzdma);
877 
878 	jzdma->chn_base = devm_platform_ioremap_resource(pdev, 0);
879 	if (IS_ERR(jzdma->chn_base))
880 		return PTR_ERR(jzdma->chn_base);
881 
882 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
883 	if (res) {
884 		jzdma->ctrl_base = devm_ioremap_resource(dev, res);
885 		if (IS_ERR(jzdma->ctrl_base))
886 			return PTR_ERR(jzdma->ctrl_base);
887 	} else if (soc_data->flags & JZ_SOC_DATA_ALLOW_LEGACY_DT) {
888 		/*
889 		 * On JZ4780, if the second memory resource was not supplied,
890 		 * assume we're using an old devicetree, and calculate the
891 		 * offset to the control registers.
892 		 */
893 		jzdma->ctrl_base = jzdma->chn_base + JZ4780_DMA_CTRL_OFFSET;
894 	} else {
895 		dev_err(dev, "failed to get I/O memory\n");
896 		return -EINVAL;
897 	}
898 
899 	jzdma->clk = devm_clk_get(dev, NULL);
900 	if (IS_ERR(jzdma->clk)) {
901 		dev_err(dev, "failed to get clock\n");
902 		ret = PTR_ERR(jzdma->clk);
903 		return ret;
904 	}
905 
906 	clk_prepare_enable(jzdma->clk);
907 
908 	/* Property is optional, if it doesn't exist the value will remain 0. */
909 	of_property_read_u32_index(dev->of_node, "ingenic,reserved-channels",
910 				   0, &jzdma->chan_reserved);
911 
912 	dd = &jzdma->dma_device;
913 
914 	dma_cap_set(DMA_MEMCPY, dd->cap_mask);
915 	dma_cap_set(DMA_SLAVE, dd->cap_mask);
916 	dma_cap_set(DMA_CYCLIC, dd->cap_mask);
917 
918 	dd->dev = dev;
919 	dd->copy_align = DMAENGINE_ALIGN_4_BYTES;
920 	dd->device_alloc_chan_resources = jz4780_dma_alloc_chan_resources;
921 	dd->device_free_chan_resources = jz4780_dma_free_chan_resources;
922 	dd->device_prep_slave_sg = jz4780_dma_prep_slave_sg;
923 	dd->device_prep_dma_cyclic = jz4780_dma_prep_dma_cyclic;
924 	dd->device_prep_dma_memcpy = jz4780_dma_prep_dma_memcpy;
925 	dd->device_config = jz4780_dma_config;
926 	dd->device_terminate_all = jz4780_dma_terminate_all;
927 	dd->device_synchronize = jz4780_dma_synchronize;
928 	dd->device_tx_status = jz4780_dma_tx_status;
929 	dd->device_issue_pending = jz4780_dma_issue_pending;
930 	dd->src_addr_widths = JZ_DMA_BUSWIDTHS;
931 	dd->dst_addr_widths = JZ_DMA_BUSWIDTHS;
932 	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
933 	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
934 	dd->max_sg_burst = JZ_DMA_MAX_DESC;
935 
936 	/*
937 	 * Enable DMA controller, mark all channels as not programmable.
938 	 * Also set the FMSC bit - it increases MSC performance, so it makes
939 	 * little sense not to enable it.
940 	 */
941 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMAC, JZ_DMA_DMAC_DMAE |
942 			       JZ_DMA_DMAC_FAIC | JZ_DMA_DMAC_FMSC);
943 
944 	if (soc_data->flags & JZ_SOC_DATA_PROGRAMMABLE_DMA)
945 		jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMACP, 0);
946 
947 	INIT_LIST_HEAD(&dd->channels);
948 
949 	for (i = 0; i < soc_data->nb_channels; i++) {
950 		jzchan = &jzdma->chan[i];
951 		jzchan->id = i;
952 
953 		vchan_init(&jzchan->vchan, dd);
954 		jzchan->vchan.desc_free = jz4780_dma_desc_free;
955 	}
956 
957 	/*
958 	 * On JZ4760, chan0 won't enable properly the first time.
959 	 * Enabling then disabling chan1 will magically make chan0 work
960 	 * correctly.
961 	 */
962 	jz4780_dma_chan_enable(jzdma, 1);
963 	jz4780_dma_chan_disable(jzdma, 1);
964 
965 	ret = platform_get_irq(pdev, 0);
966 	if (ret < 0)
967 		goto err_disable_clk;
968 
969 	jzdma->irq = ret;
970 
971 	ret = request_irq(jzdma->irq, jz4780_dma_irq_handler, 0, dev_name(dev),
972 			  jzdma);
973 	if (ret) {
974 		dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq);
975 		goto err_disable_clk;
976 	}
977 
978 	ret = dmaenginem_async_device_register(dd);
979 	if (ret) {
980 		dev_err(dev, "failed to register device\n");
981 		goto err_free_irq;
982 	}
983 
984 	/* Register with OF DMA helpers. */
985 	ret = of_dma_controller_register(dev->of_node, jz4780_of_dma_xlate,
986 					 jzdma);
987 	if (ret) {
988 		dev_err(dev, "failed to register OF DMA controller\n");
989 		goto err_free_irq;
990 	}
991 
992 	dev_info(dev, "JZ4780 DMA controller initialised\n");
993 	return 0;
994 
995 err_free_irq:
996 	free_irq(jzdma->irq, jzdma);
997 
998 err_disable_clk:
999 	clk_disable_unprepare(jzdma->clk);
1000 	return ret;
1001 }
1002 
1003 static int jz4780_dma_remove(struct platform_device *pdev)
1004 {
1005 	struct jz4780_dma_dev *jzdma = platform_get_drvdata(pdev);
1006 	int i;
1007 
1008 	of_dma_controller_free(pdev->dev.of_node);
1009 
1010 	clk_disable_unprepare(jzdma->clk);
1011 	free_irq(jzdma->irq, jzdma);
1012 
1013 	for (i = 0; i < jzdma->soc_data->nb_channels; i++)
1014 		tasklet_kill(&jzdma->chan[i].vchan.task);
1015 
1016 	return 0;
1017 }
1018 
1019 static const struct jz4780_dma_soc_data jz4740_dma_soc_data = {
1020 	.nb_channels = 6,
1021 	.transfer_ord_max = 5,
1022 	.flags = JZ_SOC_DATA_BREAK_LINKS,
1023 };
1024 
1025 static const struct jz4780_dma_soc_data jz4725b_dma_soc_data = {
1026 	.nb_channels = 6,
1027 	.transfer_ord_max = 5,
1028 	.flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC |
1029 		 JZ_SOC_DATA_BREAK_LINKS,
1030 };
1031 
1032 static const struct jz4780_dma_soc_data jz4760_dma_soc_data = {
1033 	.nb_channels = 5,
1034 	.transfer_ord_max = 6,
1035 	.flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC,
1036 };
1037 
1038 static const struct jz4780_dma_soc_data jz4760_mdma_soc_data = {
1039 	.nb_channels = 2,
1040 	.transfer_ord_max = 6,
1041 	.flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC,
1042 };
1043 
1044 static const struct jz4780_dma_soc_data jz4760_bdma_soc_data = {
1045 	.nb_channels = 3,
1046 	.transfer_ord_max = 6,
1047 	.flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC,
1048 };
1049 
1050 static const struct jz4780_dma_soc_data jz4760b_dma_soc_data = {
1051 	.nb_channels = 5,
1052 	.transfer_ord_max = 6,
1053 	.flags = JZ_SOC_DATA_PER_CHAN_PM,
1054 };
1055 
1056 static const struct jz4780_dma_soc_data jz4760b_mdma_soc_data = {
1057 	.nb_channels = 2,
1058 	.transfer_ord_max = 6,
1059 	.flags = JZ_SOC_DATA_PER_CHAN_PM,
1060 };
1061 
1062 static const struct jz4780_dma_soc_data jz4760b_bdma_soc_data = {
1063 	.nb_channels = 3,
1064 	.transfer_ord_max = 6,
1065 	.flags = JZ_SOC_DATA_PER_CHAN_PM,
1066 };
1067 
1068 static const struct jz4780_dma_soc_data jz4770_dma_soc_data = {
1069 	.nb_channels = 6,
1070 	.transfer_ord_max = 6,
1071 	.flags = JZ_SOC_DATA_PER_CHAN_PM,
1072 };
1073 
1074 static const struct jz4780_dma_soc_data jz4780_dma_soc_data = {
1075 	.nb_channels = 32,
1076 	.transfer_ord_max = 7,
1077 	.flags = JZ_SOC_DATA_ALLOW_LEGACY_DT | JZ_SOC_DATA_PROGRAMMABLE_DMA,
1078 };
1079 
1080 static const struct jz4780_dma_soc_data x1000_dma_soc_data = {
1081 	.nb_channels = 8,
1082 	.transfer_ord_max = 7,
1083 	.flags = JZ_SOC_DATA_PROGRAMMABLE_DMA,
1084 };
1085 
1086 static const struct jz4780_dma_soc_data x1830_dma_soc_data = {
1087 	.nb_channels = 32,
1088 	.transfer_ord_max = 7,
1089 	.flags = JZ_SOC_DATA_PROGRAMMABLE_DMA,
1090 };
1091 
1092 static const struct of_device_id jz4780_dma_dt_match[] = {
1093 	{ .compatible = "ingenic,jz4740-dma", .data = &jz4740_dma_soc_data },
1094 	{ .compatible = "ingenic,jz4725b-dma", .data = &jz4725b_dma_soc_data },
1095 	{ .compatible = "ingenic,jz4760-dma", .data = &jz4760_dma_soc_data },
1096 	{ .compatible = "ingenic,jz4760-mdma", .data = &jz4760_mdma_soc_data },
1097 	{ .compatible = "ingenic,jz4760-bdma", .data = &jz4760_bdma_soc_data },
1098 	{ .compatible = "ingenic,jz4760b-dma", .data = &jz4760b_dma_soc_data },
1099 	{ .compatible = "ingenic,jz4760b-mdma", .data = &jz4760b_mdma_soc_data },
1100 	{ .compatible = "ingenic,jz4760b-bdma", .data = &jz4760b_bdma_soc_data },
1101 	{ .compatible = "ingenic,jz4770-dma", .data = &jz4770_dma_soc_data },
1102 	{ .compatible = "ingenic,jz4780-dma", .data = &jz4780_dma_soc_data },
1103 	{ .compatible = "ingenic,x1000-dma", .data = &x1000_dma_soc_data },
1104 	{ .compatible = "ingenic,x1830-dma", .data = &x1830_dma_soc_data },
1105 	{},
1106 };
1107 MODULE_DEVICE_TABLE(of, jz4780_dma_dt_match);
1108 
1109 static struct platform_driver jz4780_dma_driver = {
1110 	.probe		= jz4780_dma_probe,
1111 	.remove		= jz4780_dma_remove,
1112 	.driver	= {
1113 		.name	= "jz4780-dma",
1114 		.of_match_table = jz4780_dma_dt_match,
1115 	},
1116 };
1117 
1118 static int __init jz4780_dma_init(void)
1119 {
1120 	return platform_driver_register(&jz4780_dma_driver);
1121 }
1122 subsys_initcall(jz4780_dma_init);
1123 
1124 static void __exit jz4780_dma_exit(void)
1125 {
1126 	platform_driver_unregister(&jz4780_dma_driver);
1127 }
1128 module_exit(jz4780_dma_exit);
1129 
1130 MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
1131 MODULE_DESCRIPTION("Ingenic JZ4780 DMA controller driver");
1132 MODULE_LICENSE("GPL");
1133