xref: /linux/drivers/dma/dma-jz4780.c (revision 320fefa9e2edc67011e235ea1d50f0d00ddfe004)
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/dma-mapping.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_device.h>
17 #include <linux/of_dma.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20 
21 #include "dmaengine.h"
22 #include "virt-dma.h"
23 
24 /* Global registers. */
25 #define JZ_DMA_REG_DMAC		0x00
26 #define JZ_DMA_REG_DIRQP	0x04
27 #define JZ_DMA_REG_DDR		0x08
28 #define JZ_DMA_REG_DDRS		0x0c
29 #define JZ_DMA_REG_DCKE		0x10
30 #define JZ_DMA_REG_DCKES	0x14
31 #define JZ_DMA_REG_DCKEC	0x18
32 #define JZ_DMA_REG_DMACP	0x1c
33 #define JZ_DMA_REG_DSIRQP	0x20
34 #define JZ_DMA_REG_DSIRQM	0x24
35 #define JZ_DMA_REG_DCIRQP	0x28
36 #define JZ_DMA_REG_DCIRQM	0x2c
37 
38 /* Per-channel registers. */
39 #define JZ_DMA_REG_CHAN(n)	(n * 0x20)
40 #define JZ_DMA_REG_DSA		0x00
41 #define JZ_DMA_REG_DTA		0x04
42 #define JZ_DMA_REG_DTC		0x08
43 #define JZ_DMA_REG_DRT		0x0c
44 #define JZ_DMA_REG_DCS		0x10
45 #define JZ_DMA_REG_DCM		0x14
46 #define JZ_DMA_REG_DDA		0x18
47 #define JZ_DMA_REG_DSD		0x1c
48 
49 #define JZ_DMA_DMAC_DMAE	BIT(0)
50 #define JZ_DMA_DMAC_AR		BIT(2)
51 #define JZ_DMA_DMAC_HLT		BIT(3)
52 #define JZ_DMA_DMAC_FAIC	BIT(27)
53 #define JZ_DMA_DMAC_FMSC	BIT(31)
54 
55 #define JZ_DMA_DRT_AUTO		0x8
56 
57 #define JZ_DMA_DCS_CTE		BIT(0)
58 #define JZ_DMA_DCS_HLT		BIT(2)
59 #define JZ_DMA_DCS_TT		BIT(3)
60 #define JZ_DMA_DCS_AR		BIT(4)
61 #define JZ_DMA_DCS_DES8		BIT(30)
62 
63 #define JZ_DMA_DCM_LINK		BIT(0)
64 #define JZ_DMA_DCM_TIE		BIT(1)
65 #define JZ_DMA_DCM_STDE		BIT(2)
66 #define JZ_DMA_DCM_TSZ_SHIFT	8
67 #define JZ_DMA_DCM_TSZ_MASK	(0x7 << JZ_DMA_DCM_TSZ_SHIFT)
68 #define JZ_DMA_DCM_DP_SHIFT	12
69 #define JZ_DMA_DCM_SP_SHIFT	14
70 #define JZ_DMA_DCM_DAI		BIT(22)
71 #define JZ_DMA_DCM_SAI		BIT(23)
72 
73 #define JZ_DMA_SIZE_4_BYTE	0x0
74 #define JZ_DMA_SIZE_1_BYTE	0x1
75 #define JZ_DMA_SIZE_2_BYTE	0x2
76 #define JZ_DMA_SIZE_16_BYTE	0x3
77 #define JZ_DMA_SIZE_32_BYTE	0x4
78 #define JZ_DMA_SIZE_64_BYTE	0x5
79 #define JZ_DMA_SIZE_128_BYTE	0x6
80 
81 #define JZ_DMA_WIDTH_32_BIT	0x0
82 #define JZ_DMA_WIDTH_8_BIT	0x1
83 #define JZ_DMA_WIDTH_16_BIT	0x2
84 
85 #define JZ_DMA_BUSWIDTHS	(BIT(DMA_SLAVE_BUSWIDTH_1_BYTE)	 | \
86 				 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
87 				 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
88 
89 #define JZ4780_DMA_CTRL_OFFSET	0x1000
90 
91 /* macros for use with jz4780_dma_soc_data.flags */
92 #define JZ_SOC_DATA_ALLOW_LEGACY_DT	BIT(0)
93 #define JZ_SOC_DATA_PROGRAMMABLE_DMA	BIT(1)
94 #define JZ_SOC_DATA_PER_CHAN_PM		BIT(2)
95 #define JZ_SOC_DATA_NO_DCKES_DCKEC	BIT(3)
96 #define JZ_SOC_DATA_BREAK_LINKS		BIT(4)
97 
98 /**
99  * struct jz4780_dma_hwdesc - descriptor structure read by the DMA controller.
100  * @dcm: value for the DCM (channel command) register
101  * @dsa: source address
102  * @dta: target address
103  * @dtc: transfer count (number of blocks of the transfer size specified in DCM
104  * to transfer) in the low 24 bits, offset of the next descriptor from the
105  * descriptor base address in the upper 8 bits.
106  */
107 struct jz4780_dma_hwdesc {
108 	u32 dcm;
109 	u32 dsa;
110 	u32 dta;
111 	u32 dtc;
112 };
113 
114 /* Size of allocations for hardware descriptor blocks. */
115 #define JZ_DMA_DESC_BLOCK_SIZE	PAGE_SIZE
116 #define JZ_DMA_MAX_DESC		\
117 	(JZ_DMA_DESC_BLOCK_SIZE / sizeof(struct jz4780_dma_hwdesc))
118 
119 struct jz4780_dma_desc {
120 	struct virt_dma_desc vdesc;
121 
122 	struct jz4780_dma_hwdesc *desc;
123 	dma_addr_t desc_phys;
124 	unsigned int count;
125 	enum dma_transaction_type type;
126 	u32 transfer_type;
127 	u32 status;
128 };
129 
130 struct jz4780_dma_chan {
131 	struct virt_dma_chan vchan;
132 	unsigned int id;
133 	struct dma_pool *desc_pool;
134 
135 	u32 transfer_type_tx, transfer_type_rx;
136 	u32 transfer_shift;
137 	struct dma_slave_config	config;
138 
139 	struct jz4780_dma_desc *desc;
140 	unsigned int curr_hwdesc;
141 };
142 
143 struct jz4780_dma_soc_data {
144 	unsigned int nb_channels;
145 	unsigned int transfer_ord_max;
146 	unsigned long flags;
147 };
148 
149 struct jz4780_dma_dev {
150 	struct dma_device dma_device;
151 	void __iomem *chn_base;
152 	void __iomem *ctrl_base;
153 	struct clk *clk;
154 	unsigned int irq;
155 	const struct jz4780_dma_soc_data *soc_data;
156 
157 	u32 chan_reserved;
158 	struct jz4780_dma_chan chan[];
159 };
160 
161 struct jz4780_dma_filter_data {
162 	u32 transfer_type_tx, transfer_type_rx;
163 	int channel;
164 };
165 
166 static inline struct jz4780_dma_chan *to_jz4780_dma_chan(struct dma_chan *chan)
167 {
168 	return container_of(chan, struct jz4780_dma_chan, vchan.chan);
169 }
170 
171 static inline struct jz4780_dma_desc *to_jz4780_dma_desc(
172 	struct virt_dma_desc *vdesc)
173 {
174 	return container_of(vdesc, struct jz4780_dma_desc, vdesc);
175 }
176 
177 static inline struct jz4780_dma_dev *jz4780_dma_chan_parent(
178 	struct jz4780_dma_chan *jzchan)
179 {
180 	return container_of(jzchan->vchan.chan.device, struct jz4780_dma_dev,
181 			    dma_device);
182 }
183 
184 static inline u32 jz4780_dma_chn_readl(struct jz4780_dma_dev *jzdma,
185 	unsigned int chn, unsigned int reg)
186 {
187 	return readl(jzdma->chn_base + reg + JZ_DMA_REG_CHAN(chn));
188 }
189 
190 static inline void jz4780_dma_chn_writel(struct jz4780_dma_dev *jzdma,
191 	unsigned int chn, unsigned int reg, u32 val)
192 {
193 	writel(val, jzdma->chn_base + reg + JZ_DMA_REG_CHAN(chn));
194 }
195 
196 static inline u32 jz4780_dma_ctrl_readl(struct jz4780_dma_dev *jzdma,
197 	unsigned int reg)
198 {
199 	return readl(jzdma->ctrl_base + reg);
200 }
201 
202 static inline void jz4780_dma_ctrl_writel(struct jz4780_dma_dev *jzdma,
203 	unsigned int reg, u32 val)
204 {
205 	writel(val, jzdma->ctrl_base + reg);
206 }
207 
208 static inline void jz4780_dma_chan_enable(struct jz4780_dma_dev *jzdma,
209 	unsigned int chn)
210 {
211 	if (jzdma->soc_data->flags & JZ_SOC_DATA_PER_CHAN_PM) {
212 		unsigned int reg;
213 
214 		if (jzdma->soc_data->flags & JZ_SOC_DATA_NO_DCKES_DCKEC)
215 			reg = JZ_DMA_REG_DCKE;
216 		else
217 			reg = JZ_DMA_REG_DCKES;
218 
219 		jz4780_dma_ctrl_writel(jzdma, reg, BIT(chn));
220 	}
221 }
222 
223 static inline void jz4780_dma_chan_disable(struct jz4780_dma_dev *jzdma,
224 	unsigned int chn)
225 {
226 	if ((jzdma->soc_data->flags & JZ_SOC_DATA_PER_CHAN_PM) &&
227 			!(jzdma->soc_data->flags & JZ_SOC_DATA_NO_DCKES_DCKEC))
228 		jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DCKEC, BIT(chn));
229 }
230 
231 static struct jz4780_dma_desc *
232 jz4780_dma_desc_alloc(struct jz4780_dma_chan *jzchan, unsigned int count,
233 		      enum dma_transaction_type type,
234 		      enum dma_transfer_direction direction)
235 {
236 	struct jz4780_dma_desc *desc;
237 
238 	if (count > JZ_DMA_MAX_DESC)
239 		return NULL;
240 
241 	desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
242 	if (!desc)
243 		return NULL;
244 
245 	desc->desc = dma_pool_alloc(jzchan->desc_pool, GFP_NOWAIT,
246 				    &desc->desc_phys);
247 	if (!desc->desc) {
248 		kfree(desc);
249 		return NULL;
250 	}
251 
252 	desc->count = count;
253 	desc->type = type;
254 
255 	if (direction == DMA_DEV_TO_MEM)
256 		desc->transfer_type = jzchan->transfer_type_rx;
257 	else
258 		desc->transfer_type = jzchan->transfer_type_tx;
259 
260 	return desc;
261 }
262 
263 static void jz4780_dma_desc_free(struct virt_dma_desc *vdesc)
264 {
265 	struct jz4780_dma_desc *desc = to_jz4780_dma_desc(vdesc);
266 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(vdesc->tx.chan);
267 
268 	dma_pool_free(jzchan->desc_pool, desc->desc, desc->desc_phys);
269 	kfree(desc);
270 }
271 
272 static u32 jz4780_dma_transfer_size(struct jz4780_dma_chan *jzchan,
273 	unsigned long val, u32 *shift)
274 {
275 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
276 	int ord = ffs(val) - 1;
277 
278 	/*
279 	 * 8 byte transfer sizes unsupported so fall back on 4. If it's larger
280 	 * than the maximum, just limit it. It is perfectly safe to fall back
281 	 * in this way since we won't exceed the maximum burst size supported
282 	 * by the device, the only effect is reduced efficiency. This is better
283 	 * than refusing to perform the request at all.
284 	 */
285 	if (ord == 3)
286 		ord = 2;
287 	else if (ord > jzdma->soc_data->transfer_ord_max)
288 		ord = jzdma->soc_data->transfer_ord_max;
289 
290 	*shift = ord;
291 
292 	switch (ord) {
293 	case 0:
294 		return JZ_DMA_SIZE_1_BYTE;
295 	case 1:
296 		return JZ_DMA_SIZE_2_BYTE;
297 	case 2:
298 		return JZ_DMA_SIZE_4_BYTE;
299 	case 4:
300 		return JZ_DMA_SIZE_16_BYTE;
301 	case 5:
302 		return JZ_DMA_SIZE_32_BYTE;
303 	case 6:
304 		return JZ_DMA_SIZE_64_BYTE;
305 	default:
306 		return JZ_DMA_SIZE_128_BYTE;
307 	}
308 }
309 
310 static int jz4780_dma_setup_hwdesc(struct jz4780_dma_chan *jzchan,
311 	struct jz4780_dma_hwdesc *desc, dma_addr_t addr, size_t len,
312 	enum dma_transfer_direction direction)
313 {
314 	struct dma_slave_config *config = &jzchan->config;
315 	u32 width, maxburst, tsz;
316 
317 	if (direction == DMA_MEM_TO_DEV) {
318 		desc->dcm = JZ_DMA_DCM_SAI;
319 		desc->dsa = addr;
320 		desc->dta = config->dst_addr;
321 
322 		width = config->dst_addr_width;
323 		maxburst = config->dst_maxburst;
324 	} else {
325 		desc->dcm = JZ_DMA_DCM_DAI;
326 		desc->dsa = config->src_addr;
327 		desc->dta = addr;
328 
329 		width = config->src_addr_width;
330 		maxburst = config->src_maxburst;
331 	}
332 
333 	/*
334 	 * This calculates the maximum transfer size that can be used with the
335 	 * given address, length, width and maximum burst size. The address
336 	 * must be aligned to the transfer size, the total length must be
337 	 * divisible by the transfer size, and we must not use more than the
338 	 * maximum burst specified by the user.
339 	 */
340 	tsz = jz4780_dma_transfer_size(jzchan, addr | len | (width * maxburst),
341 				       &jzchan->transfer_shift);
342 
343 	switch (width) {
344 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
345 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
346 		break;
347 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
348 		width = JZ_DMA_WIDTH_32_BIT;
349 		break;
350 	default:
351 		return -EINVAL;
352 	}
353 
354 	desc->dcm |= tsz << JZ_DMA_DCM_TSZ_SHIFT;
355 	desc->dcm |= width << JZ_DMA_DCM_SP_SHIFT;
356 	desc->dcm |= width << JZ_DMA_DCM_DP_SHIFT;
357 
358 	desc->dtc = len >> jzchan->transfer_shift;
359 	return 0;
360 }
361 
362 static struct dma_async_tx_descriptor *jz4780_dma_prep_slave_sg(
363 	struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
364 	enum dma_transfer_direction direction, unsigned long flags,
365 	void *context)
366 {
367 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
368 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
369 	struct jz4780_dma_desc *desc;
370 	unsigned int i;
371 	int err;
372 
373 	desc = jz4780_dma_desc_alloc(jzchan, sg_len, DMA_SLAVE, direction);
374 	if (!desc)
375 		return NULL;
376 
377 	for (i = 0; i < sg_len; i++) {
378 		err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i],
379 					      sg_dma_address(&sgl[i]),
380 					      sg_dma_len(&sgl[i]),
381 					      direction);
382 		if (err < 0) {
383 			jz4780_dma_desc_free(&jzchan->desc->vdesc);
384 			return NULL;
385 		}
386 
387 		desc->desc[i].dcm |= JZ_DMA_DCM_TIE;
388 
389 		if (i != (sg_len - 1) &&
390 		    !(jzdma->soc_data->flags & JZ_SOC_DATA_BREAK_LINKS)) {
391 			/* Automatically proceed to the next descriptor. */
392 			desc->desc[i].dcm |= JZ_DMA_DCM_LINK;
393 
394 			/*
395 			 * The upper 8 bits of the DTC field in the descriptor
396 			 * must be set to (offset from descriptor base of next
397 			 * descriptor >> 4).
398 			 */
399 			desc->desc[i].dtc |=
400 				(((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
401 		}
402 	}
403 
404 	return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
405 }
406 
407 static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_cyclic(
408 	struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
409 	size_t period_len, enum dma_transfer_direction direction,
410 	unsigned long flags)
411 {
412 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
413 	struct jz4780_dma_desc *desc;
414 	unsigned int periods, i;
415 	int err;
416 
417 	if (buf_len % period_len)
418 		return NULL;
419 
420 	periods = buf_len / period_len;
421 
422 	desc = jz4780_dma_desc_alloc(jzchan, periods, DMA_CYCLIC, direction);
423 	if (!desc)
424 		return NULL;
425 
426 	for (i = 0; i < periods; i++) {
427 		err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i], buf_addr,
428 					      period_len, direction);
429 		if (err < 0) {
430 			jz4780_dma_desc_free(&jzchan->desc->vdesc);
431 			return NULL;
432 		}
433 
434 		buf_addr += period_len;
435 
436 		/*
437 		 * Set the link bit to indicate that the controller should
438 		 * automatically proceed to the next descriptor. In
439 		 * jz4780_dma_begin(), this will be cleared if we need to issue
440 		 * an interrupt after each period.
441 		 */
442 		desc->desc[i].dcm |= JZ_DMA_DCM_TIE | JZ_DMA_DCM_LINK;
443 
444 		/*
445 		 * The upper 8 bits of the DTC field in the descriptor must be
446 		 * set to (offset from descriptor base of next descriptor >> 4).
447 		 * If this is the last descriptor, link it back to the first,
448 		 * i.e. leave offset set to 0, otherwise point to the next one.
449 		 */
450 		if (i != (periods - 1)) {
451 			desc->desc[i].dtc |=
452 				(((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
453 		}
454 	}
455 
456 	return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
457 }
458 
459 static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_memcpy(
460 	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
461 	size_t len, unsigned long flags)
462 {
463 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
464 	struct jz4780_dma_desc *desc;
465 	u32 tsz;
466 
467 	desc = jz4780_dma_desc_alloc(jzchan, 1, DMA_MEMCPY, 0);
468 	if (!desc)
469 		return NULL;
470 
471 	tsz = jz4780_dma_transfer_size(jzchan, dest | src | len,
472 				       &jzchan->transfer_shift);
473 
474 	desc->transfer_type = JZ_DMA_DRT_AUTO;
475 
476 	desc->desc[0].dsa = src;
477 	desc->desc[0].dta = dest;
478 	desc->desc[0].dcm = JZ_DMA_DCM_TIE | JZ_DMA_DCM_SAI | JZ_DMA_DCM_DAI |
479 			    tsz << JZ_DMA_DCM_TSZ_SHIFT |
480 			    JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_SP_SHIFT |
481 			    JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_DP_SHIFT;
482 	desc->desc[0].dtc = len >> jzchan->transfer_shift;
483 
484 	return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
485 }
486 
487 static void jz4780_dma_begin(struct jz4780_dma_chan *jzchan)
488 {
489 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
490 	struct virt_dma_desc *vdesc;
491 	unsigned int i;
492 	dma_addr_t desc_phys;
493 
494 	if (!jzchan->desc) {
495 		vdesc = vchan_next_desc(&jzchan->vchan);
496 		if (!vdesc)
497 			return;
498 
499 		list_del(&vdesc->node);
500 
501 		jzchan->desc = to_jz4780_dma_desc(vdesc);
502 		jzchan->curr_hwdesc = 0;
503 
504 		if (jzchan->desc->type == DMA_CYCLIC && vdesc->tx.callback) {
505 			/*
506 			 * The DMA controller doesn't support triggering an
507 			 * interrupt after processing each descriptor, only
508 			 * after processing an entire terminated list of
509 			 * descriptors. For a cyclic DMA setup the list of
510 			 * descriptors is not terminated so we can never get an
511 			 * interrupt.
512 			 *
513 			 * If the user requested a callback for a cyclic DMA
514 			 * setup then we workaround this hardware limitation
515 			 * here by degrading to a set of unlinked descriptors
516 			 * which we will submit in sequence in response to the
517 			 * completion of processing the previous descriptor.
518 			 */
519 			for (i = 0; i < jzchan->desc->count; i++)
520 				jzchan->desc->desc[i].dcm &= ~JZ_DMA_DCM_LINK;
521 		}
522 	} else {
523 		/*
524 		 * There is an existing transfer, therefore this must be one
525 		 * for which we unlinked the descriptors above. Advance to the
526 		 * next one in the list.
527 		 */
528 		jzchan->curr_hwdesc =
529 			(jzchan->curr_hwdesc + 1) % jzchan->desc->count;
530 	}
531 
532 	/* Enable the channel's clock. */
533 	jz4780_dma_chan_enable(jzdma, jzchan->id);
534 
535 	/* Use 4-word descriptors. */
536 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
537 
538 	/* Set transfer type. */
539 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DRT,
540 			      jzchan->desc->transfer_type);
541 
542 	/*
543 	 * Set the transfer count. This is redundant for a descriptor-driven
544 	 * transfer. However, there can be a delay between the transfer start
545 	 * time and when DTCn reg contains the new transfer count. Setting
546 	 * it explicitly ensures residue is computed correctly at all times.
547 	 */
548 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DTC,
549 				jzchan->desc->desc[jzchan->curr_hwdesc].dtc);
550 
551 	/* Write descriptor address and initiate descriptor fetch. */
552 	desc_phys = jzchan->desc->desc_phys +
553 		    (jzchan->curr_hwdesc * sizeof(*jzchan->desc->desc));
554 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DDA, desc_phys);
555 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DDRS, BIT(jzchan->id));
556 
557 	/* Enable the channel. */
558 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS,
559 			      JZ_DMA_DCS_CTE);
560 }
561 
562 static void jz4780_dma_issue_pending(struct dma_chan *chan)
563 {
564 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
565 	unsigned long flags;
566 
567 	spin_lock_irqsave(&jzchan->vchan.lock, flags);
568 
569 	if (vchan_issue_pending(&jzchan->vchan) && !jzchan->desc)
570 		jz4780_dma_begin(jzchan);
571 
572 	spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
573 }
574 
575 static int jz4780_dma_terminate_all(struct dma_chan *chan)
576 {
577 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
578 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
579 	unsigned long flags;
580 	LIST_HEAD(head);
581 
582 	spin_lock_irqsave(&jzchan->vchan.lock, flags);
583 
584 	/* Clear the DMA status and stop the transfer. */
585 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
586 	if (jzchan->desc) {
587 		vchan_terminate_vdesc(&jzchan->desc->vdesc);
588 		jzchan->desc = NULL;
589 	}
590 
591 	jz4780_dma_chan_disable(jzdma, jzchan->id);
592 
593 	vchan_get_all_descriptors(&jzchan->vchan, &head);
594 
595 	spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
596 
597 	vchan_dma_desc_free_list(&jzchan->vchan, &head);
598 	return 0;
599 }
600 
601 static void jz4780_dma_synchronize(struct dma_chan *chan)
602 {
603 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
604 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
605 
606 	vchan_synchronize(&jzchan->vchan);
607 	jz4780_dma_chan_disable(jzdma, jzchan->id);
608 }
609 
610 static int jz4780_dma_config(struct dma_chan *chan,
611 	struct dma_slave_config *config)
612 {
613 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
614 
615 	if ((config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
616 	   || (config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES))
617 		return -EINVAL;
618 
619 	/* Copy the reset of the slave configuration, it is used later. */
620 	memcpy(&jzchan->config, config, sizeof(jzchan->config));
621 
622 	return 0;
623 }
624 
625 static size_t jz4780_dma_desc_residue(struct jz4780_dma_chan *jzchan,
626 	struct jz4780_dma_desc *desc, unsigned int next_sg)
627 {
628 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
629 	unsigned int count = 0;
630 	unsigned int i;
631 
632 	for (i = next_sg; i < desc->count; i++)
633 		count += desc->desc[i].dtc & GENMASK(23, 0);
634 
635 	if (next_sg != 0)
636 		count += jz4780_dma_chn_readl(jzdma, jzchan->id,
637 					 JZ_DMA_REG_DTC);
638 
639 	return count << jzchan->transfer_shift;
640 }
641 
642 static enum dma_status jz4780_dma_tx_status(struct dma_chan *chan,
643 	dma_cookie_t cookie, struct dma_tx_state *txstate)
644 {
645 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
646 	struct virt_dma_desc *vdesc;
647 	enum dma_status status;
648 	unsigned long flags;
649 	unsigned long residue = 0;
650 
651 	spin_lock_irqsave(&jzchan->vchan.lock, flags);
652 
653 	status = dma_cookie_status(chan, cookie, txstate);
654 	if ((status == DMA_COMPLETE) || (txstate == NULL))
655 		goto out_unlock_irqrestore;
656 
657 	vdesc = vchan_find_desc(&jzchan->vchan, cookie);
658 	if (vdesc) {
659 		/* On the issued list, so hasn't been processed yet */
660 		residue = jz4780_dma_desc_residue(jzchan,
661 					to_jz4780_dma_desc(vdesc), 0);
662 	} else if (cookie == jzchan->desc->vdesc.tx.cookie) {
663 		residue = jz4780_dma_desc_residue(jzchan, jzchan->desc,
664 					jzchan->curr_hwdesc + 1);
665 	}
666 	dma_set_residue(txstate, residue);
667 
668 	if (vdesc && jzchan->desc && vdesc == &jzchan->desc->vdesc
669 	    && jzchan->desc->status & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT))
670 		status = DMA_ERROR;
671 
672 out_unlock_irqrestore:
673 	spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
674 	return status;
675 }
676 
677 static bool jz4780_dma_chan_irq(struct jz4780_dma_dev *jzdma,
678 				struct jz4780_dma_chan *jzchan)
679 {
680 	const unsigned int soc_flags = jzdma->soc_data->flags;
681 	struct jz4780_dma_desc *desc = jzchan->desc;
682 	u32 dcs;
683 	bool ack = true;
684 
685 	spin_lock(&jzchan->vchan.lock);
686 
687 	dcs = jz4780_dma_chn_readl(jzdma, jzchan->id, JZ_DMA_REG_DCS);
688 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
689 
690 	if (dcs & JZ_DMA_DCS_AR) {
691 		dev_warn(&jzchan->vchan.chan.dev->device,
692 			 "address error (DCS=0x%x)\n", dcs);
693 	}
694 
695 	if (dcs & JZ_DMA_DCS_HLT) {
696 		dev_warn(&jzchan->vchan.chan.dev->device,
697 			 "channel halt (DCS=0x%x)\n", dcs);
698 	}
699 
700 	if (jzchan->desc) {
701 		jzchan->desc->status = dcs;
702 
703 		if ((dcs & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT)) == 0) {
704 			if (jzchan->desc->type == DMA_CYCLIC) {
705 				vchan_cyclic_callback(&jzchan->desc->vdesc);
706 
707 				jz4780_dma_begin(jzchan);
708 			} else if (dcs & JZ_DMA_DCS_TT) {
709 				if (!(soc_flags & JZ_SOC_DATA_BREAK_LINKS) ||
710 				    (jzchan->curr_hwdesc + 1 == desc->count)) {
711 					vchan_cookie_complete(&desc->vdesc);
712 					jzchan->desc = NULL;
713 				}
714 
715 				jz4780_dma_begin(jzchan);
716 			} else {
717 				/* False positive - continue the transfer */
718 				ack = false;
719 				jz4780_dma_chn_writel(jzdma, jzchan->id,
720 						      JZ_DMA_REG_DCS,
721 						      JZ_DMA_DCS_CTE);
722 			}
723 		}
724 	} else {
725 		dev_err(&jzchan->vchan.chan.dev->device,
726 			"channel IRQ with no active transfer\n");
727 	}
728 
729 	spin_unlock(&jzchan->vchan.lock);
730 
731 	return ack;
732 }
733 
734 static irqreturn_t jz4780_dma_irq_handler(int irq, void *data)
735 {
736 	struct jz4780_dma_dev *jzdma = data;
737 	unsigned int nb_channels = jzdma->soc_data->nb_channels;
738 	unsigned long pending;
739 	u32 dmac;
740 	int i;
741 
742 	pending = jz4780_dma_ctrl_readl(jzdma, JZ_DMA_REG_DIRQP);
743 
744 	for_each_set_bit(i, &pending, nb_channels) {
745 		if (jz4780_dma_chan_irq(jzdma, &jzdma->chan[i]))
746 			pending &= ~BIT(i);
747 	}
748 
749 	/* Clear halt and address error status of all channels. */
750 	dmac = jz4780_dma_ctrl_readl(jzdma, JZ_DMA_REG_DMAC);
751 	dmac &= ~(JZ_DMA_DMAC_HLT | JZ_DMA_DMAC_AR);
752 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMAC, dmac);
753 
754 	/* Clear interrupt pending status. */
755 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DIRQP, pending);
756 
757 	return IRQ_HANDLED;
758 }
759 
760 static int jz4780_dma_alloc_chan_resources(struct dma_chan *chan)
761 {
762 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
763 
764 	jzchan->desc_pool = dma_pool_create(dev_name(&chan->dev->device),
765 					    chan->device->dev,
766 					    JZ_DMA_DESC_BLOCK_SIZE,
767 					    PAGE_SIZE, 0);
768 	if (!jzchan->desc_pool) {
769 		dev_err(&chan->dev->device,
770 			"failed to allocate descriptor pool\n");
771 		return -ENOMEM;
772 	}
773 
774 	return 0;
775 }
776 
777 static void jz4780_dma_free_chan_resources(struct dma_chan *chan)
778 {
779 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
780 
781 	vchan_free_chan_resources(&jzchan->vchan);
782 	dma_pool_destroy(jzchan->desc_pool);
783 	jzchan->desc_pool = NULL;
784 }
785 
786 static bool jz4780_dma_filter_fn(struct dma_chan *chan, void *param)
787 {
788 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
789 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
790 	struct jz4780_dma_filter_data *data = param;
791 
792 
793 	if (data->channel > -1) {
794 		if (data->channel != jzchan->id)
795 			return false;
796 	} else if (jzdma->chan_reserved & BIT(jzchan->id)) {
797 		return false;
798 	}
799 
800 	jzchan->transfer_type_tx = data->transfer_type_tx;
801 	jzchan->transfer_type_rx = data->transfer_type_rx;
802 
803 	return true;
804 }
805 
806 static struct dma_chan *jz4780_of_dma_xlate(struct of_phandle_args *dma_spec,
807 	struct of_dma *ofdma)
808 {
809 	struct jz4780_dma_dev *jzdma = ofdma->of_dma_data;
810 	dma_cap_mask_t mask = jzdma->dma_device.cap_mask;
811 	struct jz4780_dma_filter_data data;
812 
813 	if (dma_spec->args_count == 2) {
814 		data.transfer_type_tx = dma_spec->args[0];
815 		data.transfer_type_rx = dma_spec->args[0];
816 		data.channel = dma_spec->args[1];
817 	} else if (dma_spec->args_count == 3) {
818 		data.transfer_type_tx = dma_spec->args[0];
819 		data.transfer_type_rx = dma_spec->args[1];
820 		data.channel = dma_spec->args[2];
821 	} else {
822 		return NULL;
823 	}
824 
825 	if (data.channel > -1) {
826 		if (data.channel >= jzdma->soc_data->nb_channels) {
827 			dev_err(jzdma->dma_device.dev,
828 				"device requested non-existent channel %u\n",
829 				data.channel);
830 			return NULL;
831 		}
832 
833 		/* Can only select a channel marked as reserved. */
834 		if (!(jzdma->chan_reserved & BIT(data.channel))) {
835 			dev_err(jzdma->dma_device.dev,
836 				"device requested unreserved channel %u\n",
837 				data.channel);
838 			return NULL;
839 		}
840 
841 		jzdma->chan[data.channel].transfer_type_tx = data.transfer_type_tx;
842 		jzdma->chan[data.channel].transfer_type_rx = data.transfer_type_rx;
843 
844 		return dma_get_slave_channel(
845 			&jzdma->chan[data.channel].vchan.chan);
846 	} else {
847 		return __dma_request_channel(&mask, jz4780_dma_filter_fn, &data,
848 					     ofdma->of_node);
849 	}
850 }
851 
852 static int jz4780_dma_probe(struct platform_device *pdev)
853 {
854 	struct device *dev = &pdev->dev;
855 	const struct jz4780_dma_soc_data *soc_data;
856 	struct jz4780_dma_dev *jzdma;
857 	struct jz4780_dma_chan *jzchan;
858 	struct dma_device *dd;
859 	struct resource *res;
860 	int i, ret;
861 
862 	if (!dev->of_node) {
863 		dev_err(dev, "This driver must be probed from devicetree\n");
864 		return -EINVAL;
865 	}
866 
867 	soc_data = device_get_match_data(dev);
868 	if (!soc_data)
869 		return -EINVAL;
870 
871 	jzdma = devm_kzalloc(dev, struct_size(jzdma, chan,
872 			     soc_data->nb_channels), GFP_KERNEL);
873 	if (!jzdma)
874 		return -ENOMEM;
875 
876 	jzdma->soc_data = soc_data;
877 	platform_set_drvdata(pdev, jzdma);
878 
879 	jzdma->chn_base = devm_platform_ioremap_resource(pdev, 0);
880 	if (IS_ERR(jzdma->chn_base))
881 		return PTR_ERR(jzdma->chn_base);
882 
883 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
884 	if (res) {
885 		jzdma->ctrl_base = devm_ioremap_resource(dev, res);
886 		if (IS_ERR(jzdma->ctrl_base))
887 			return PTR_ERR(jzdma->ctrl_base);
888 	} else if (soc_data->flags & JZ_SOC_DATA_ALLOW_LEGACY_DT) {
889 		/*
890 		 * On JZ4780, if the second memory resource was not supplied,
891 		 * assume we're using an old devicetree, and calculate the
892 		 * offset to the control registers.
893 		 */
894 		jzdma->ctrl_base = jzdma->chn_base + JZ4780_DMA_CTRL_OFFSET;
895 	} else {
896 		dev_err(dev, "failed to get I/O memory\n");
897 		return -EINVAL;
898 	}
899 
900 	jzdma->clk = devm_clk_get(dev, NULL);
901 	if (IS_ERR(jzdma->clk)) {
902 		dev_err(dev, "failed to get clock\n");
903 		ret = PTR_ERR(jzdma->clk);
904 		return ret;
905 	}
906 
907 	clk_prepare_enable(jzdma->clk);
908 
909 	/* Property is optional, if it doesn't exist the value will remain 0. */
910 	of_property_read_u32_index(dev->of_node, "ingenic,reserved-channels",
911 				   0, &jzdma->chan_reserved);
912 
913 	dd = &jzdma->dma_device;
914 
915 	/*
916 	 * The real segment size limit is dependent on the size unit selected
917 	 * for the transfer. Because the size unit is selected automatically
918 	 * and may be as small as 1 byte, use a safe limit of 2^24-1 bytes to
919 	 * ensure the 24-bit transfer count in the descriptor cannot overflow.
920 	 */
921 	dma_set_max_seg_size(dev, 0xffffff);
922 
923 	dma_cap_set(DMA_MEMCPY, dd->cap_mask);
924 	dma_cap_set(DMA_SLAVE, dd->cap_mask);
925 	dma_cap_set(DMA_CYCLIC, dd->cap_mask);
926 
927 	dd->dev = dev;
928 	dd->copy_align = DMAENGINE_ALIGN_4_BYTES;
929 	dd->device_alloc_chan_resources = jz4780_dma_alloc_chan_resources;
930 	dd->device_free_chan_resources = jz4780_dma_free_chan_resources;
931 	dd->device_prep_slave_sg = jz4780_dma_prep_slave_sg;
932 	dd->device_prep_dma_cyclic = jz4780_dma_prep_dma_cyclic;
933 	dd->device_prep_dma_memcpy = jz4780_dma_prep_dma_memcpy;
934 	dd->device_config = jz4780_dma_config;
935 	dd->device_terminate_all = jz4780_dma_terminate_all;
936 	dd->device_synchronize = jz4780_dma_synchronize;
937 	dd->device_tx_status = jz4780_dma_tx_status;
938 	dd->device_issue_pending = jz4780_dma_issue_pending;
939 	dd->src_addr_widths = JZ_DMA_BUSWIDTHS;
940 	dd->dst_addr_widths = JZ_DMA_BUSWIDTHS;
941 	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
942 	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
943 	dd->max_sg_burst = JZ_DMA_MAX_DESC;
944 
945 	/*
946 	 * Enable DMA controller, mark all channels as not programmable.
947 	 * Also set the FMSC bit - it increases MSC performance, so it makes
948 	 * little sense not to enable it.
949 	 */
950 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMAC, JZ_DMA_DMAC_DMAE |
951 			       JZ_DMA_DMAC_FAIC | JZ_DMA_DMAC_FMSC);
952 
953 	if (soc_data->flags & JZ_SOC_DATA_PROGRAMMABLE_DMA)
954 		jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMACP, 0);
955 
956 	INIT_LIST_HEAD(&dd->channels);
957 
958 	for (i = 0; i < soc_data->nb_channels; i++) {
959 		jzchan = &jzdma->chan[i];
960 		jzchan->id = i;
961 
962 		vchan_init(&jzchan->vchan, dd);
963 		jzchan->vchan.desc_free = jz4780_dma_desc_free;
964 	}
965 
966 	/*
967 	 * On JZ4760, chan0 won't enable properly the first time.
968 	 * Enabling then disabling chan1 will magically make chan0 work
969 	 * correctly.
970 	 */
971 	jz4780_dma_chan_enable(jzdma, 1);
972 	jz4780_dma_chan_disable(jzdma, 1);
973 
974 	ret = platform_get_irq(pdev, 0);
975 	if (ret < 0)
976 		goto err_disable_clk;
977 
978 	jzdma->irq = ret;
979 
980 	ret = request_irq(jzdma->irq, jz4780_dma_irq_handler, 0, dev_name(dev),
981 			  jzdma);
982 	if (ret) {
983 		dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq);
984 		goto err_disable_clk;
985 	}
986 
987 	ret = dmaenginem_async_device_register(dd);
988 	if (ret) {
989 		dev_err(dev, "failed to register device\n");
990 		goto err_free_irq;
991 	}
992 
993 	/* Register with OF DMA helpers. */
994 	ret = of_dma_controller_register(dev->of_node, jz4780_of_dma_xlate,
995 					 jzdma);
996 	if (ret) {
997 		dev_err(dev, "failed to register OF DMA controller\n");
998 		goto err_free_irq;
999 	}
1000 
1001 	dev_info(dev, "JZ4780 DMA controller initialised\n");
1002 	return 0;
1003 
1004 err_free_irq:
1005 	free_irq(jzdma->irq, jzdma);
1006 
1007 err_disable_clk:
1008 	clk_disable_unprepare(jzdma->clk);
1009 	return ret;
1010 }
1011 
1012 static int jz4780_dma_remove(struct platform_device *pdev)
1013 {
1014 	struct jz4780_dma_dev *jzdma = platform_get_drvdata(pdev);
1015 	int i;
1016 
1017 	of_dma_controller_free(pdev->dev.of_node);
1018 
1019 	clk_disable_unprepare(jzdma->clk);
1020 	free_irq(jzdma->irq, jzdma);
1021 
1022 	for (i = 0; i < jzdma->soc_data->nb_channels; i++)
1023 		tasklet_kill(&jzdma->chan[i].vchan.task);
1024 
1025 	return 0;
1026 }
1027 
1028 static const struct jz4780_dma_soc_data jz4740_dma_soc_data = {
1029 	.nb_channels = 6,
1030 	.transfer_ord_max = 5,
1031 	.flags = JZ_SOC_DATA_BREAK_LINKS,
1032 };
1033 
1034 static const struct jz4780_dma_soc_data jz4725b_dma_soc_data = {
1035 	.nb_channels = 6,
1036 	.transfer_ord_max = 5,
1037 	.flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC |
1038 		 JZ_SOC_DATA_BREAK_LINKS,
1039 };
1040 
1041 static const struct jz4780_dma_soc_data jz4760_dma_soc_data = {
1042 	.nb_channels = 5,
1043 	.transfer_ord_max = 6,
1044 	.flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC,
1045 };
1046 
1047 static const struct jz4780_dma_soc_data jz4760_mdma_soc_data = {
1048 	.nb_channels = 2,
1049 	.transfer_ord_max = 6,
1050 	.flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC,
1051 };
1052 
1053 static const struct jz4780_dma_soc_data jz4760_bdma_soc_data = {
1054 	.nb_channels = 3,
1055 	.transfer_ord_max = 6,
1056 	.flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC,
1057 };
1058 
1059 static const struct jz4780_dma_soc_data jz4760b_dma_soc_data = {
1060 	.nb_channels = 5,
1061 	.transfer_ord_max = 6,
1062 	.flags = JZ_SOC_DATA_PER_CHAN_PM,
1063 };
1064 
1065 static const struct jz4780_dma_soc_data jz4760b_mdma_soc_data = {
1066 	.nb_channels = 2,
1067 	.transfer_ord_max = 6,
1068 	.flags = JZ_SOC_DATA_PER_CHAN_PM,
1069 };
1070 
1071 static const struct jz4780_dma_soc_data jz4760b_bdma_soc_data = {
1072 	.nb_channels = 3,
1073 	.transfer_ord_max = 6,
1074 	.flags = JZ_SOC_DATA_PER_CHAN_PM,
1075 };
1076 
1077 static const struct jz4780_dma_soc_data jz4770_dma_soc_data = {
1078 	.nb_channels = 6,
1079 	.transfer_ord_max = 6,
1080 	.flags = JZ_SOC_DATA_PER_CHAN_PM,
1081 };
1082 
1083 static const struct jz4780_dma_soc_data jz4780_dma_soc_data = {
1084 	.nb_channels = 32,
1085 	.transfer_ord_max = 7,
1086 	.flags = JZ_SOC_DATA_ALLOW_LEGACY_DT | JZ_SOC_DATA_PROGRAMMABLE_DMA,
1087 };
1088 
1089 static const struct jz4780_dma_soc_data x1000_dma_soc_data = {
1090 	.nb_channels = 8,
1091 	.transfer_ord_max = 7,
1092 	.flags = JZ_SOC_DATA_PROGRAMMABLE_DMA,
1093 };
1094 
1095 static const struct jz4780_dma_soc_data x1830_dma_soc_data = {
1096 	.nb_channels = 32,
1097 	.transfer_ord_max = 7,
1098 	.flags = JZ_SOC_DATA_PROGRAMMABLE_DMA,
1099 };
1100 
1101 static const struct of_device_id jz4780_dma_dt_match[] = {
1102 	{ .compatible = "ingenic,jz4740-dma", .data = &jz4740_dma_soc_data },
1103 	{ .compatible = "ingenic,jz4725b-dma", .data = &jz4725b_dma_soc_data },
1104 	{ .compatible = "ingenic,jz4760-dma", .data = &jz4760_dma_soc_data },
1105 	{ .compatible = "ingenic,jz4760-mdma", .data = &jz4760_mdma_soc_data },
1106 	{ .compatible = "ingenic,jz4760-bdma", .data = &jz4760_bdma_soc_data },
1107 	{ .compatible = "ingenic,jz4760b-dma", .data = &jz4760b_dma_soc_data },
1108 	{ .compatible = "ingenic,jz4760b-mdma", .data = &jz4760b_mdma_soc_data },
1109 	{ .compatible = "ingenic,jz4760b-bdma", .data = &jz4760b_bdma_soc_data },
1110 	{ .compatible = "ingenic,jz4770-dma", .data = &jz4770_dma_soc_data },
1111 	{ .compatible = "ingenic,jz4780-dma", .data = &jz4780_dma_soc_data },
1112 	{ .compatible = "ingenic,x1000-dma", .data = &x1000_dma_soc_data },
1113 	{ .compatible = "ingenic,x1830-dma", .data = &x1830_dma_soc_data },
1114 	{},
1115 };
1116 MODULE_DEVICE_TABLE(of, jz4780_dma_dt_match);
1117 
1118 static struct platform_driver jz4780_dma_driver = {
1119 	.probe		= jz4780_dma_probe,
1120 	.remove		= jz4780_dma_remove,
1121 	.driver	= {
1122 		.name	= "jz4780-dma",
1123 		.of_match_table = jz4780_dma_dt_match,
1124 	},
1125 };
1126 
1127 static int __init jz4780_dma_init(void)
1128 {
1129 	return platform_driver_register(&jz4780_dma_driver);
1130 }
1131 subsys_initcall(jz4780_dma_init);
1132 
1133 static void __exit jz4780_dma_exit(void)
1134 {
1135 	platform_driver_unregister(&jz4780_dma_driver);
1136 }
1137 module_exit(jz4780_dma_exit);
1138 
1139 MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
1140 MODULE_DESCRIPTION("Ingenic JZ4780 DMA controller driver");
1141 MODULE_LICENSE("GPL");
1142