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1 /*
2  *  Copyright (C) 2013, Lars-Peter Clausen <lars@metafoo.de>
3  *  JZ4740 DMAC support
4  *
5  *  This program is free software; you can redistribute it and/or modify it
6  *  under  the terms of the GNU General	 Public License as published by the
7  *  Free Software Foundation;  either version 2 of the License, or (at your
8  *  option) any later version.
9  *
10  */
11 
12 #include <linux/dmaengine.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/err.h>
15 #include <linux/init.h>
16 #include <linux/list.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20 #include <linux/spinlock.h>
21 #include <linux/irq.h>
22 #include <linux/clk.h>
23 
24 #include "virt-dma.h"
25 
26 #define JZ_DMA_NR_CHANS 6
27 
28 #define JZ_REG_DMA_SRC_ADDR(x)		(0x00 + (x) * 0x20)
29 #define JZ_REG_DMA_DST_ADDR(x)		(0x04 + (x) * 0x20)
30 #define JZ_REG_DMA_TRANSFER_COUNT(x)	(0x08 + (x) * 0x20)
31 #define JZ_REG_DMA_REQ_TYPE(x)		(0x0C + (x) * 0x20)
32 #define JZ_REG_DMA_STATUS_CTRL(x)	(0x10 + (x) * 0x20)
33 #define JZ_REG_DMA_CMD(x)		(0x14 + (x) * 0x20)
34 #define JZ_REG_DMA_DESC_ADDR(x)		(0x18 + (x) * 0x20)
35 
36 #define JZ_REG_DMA_CTRL			0x300
37 #define JZ_REG_DMA_IRQ			0x304
38 #define JZ_REG_DMA_DOORBELL		0x308
39 #define JZ_REG_DMA_DOORBELL_SET		0x30C
40 
41 #define JZ_DMA_STATUS_CTRL_NO_DESC		BIT(31)
42 #define JZ_DMA_STATUS_CTRL_DESC_INV		BIT(6)
43 #define JZ_DMA_STATUS_CTRL_ADDR_ERR		BIT(4)
44 #define JZ_DMA_STATUS_CTRL_TRANSFER_DONE	BIT(3)
45 #define JZ_DMA_STATUS_CTRL_HALT			BIT(2)
46 #define JZ_DMA_STATUS_CTRL_COUNT_TERMINATE	BIT(1)
47 #define JZ_DMA_STATUS_CTRL_ENABLE		BIT(0)
48 
49 #define JZ_DMA_CMD_SRC_INC			BIT(23)
50 #define JZ_DMA_CMD_DST_INC			BIT(22)
51 #define JZ_DMA_CMD_RDIL_MASK			(0xf << 16)
52 #define JZ_DMA_CMD_SRC_WIDTH_MASK		(0x3 << 14)
53 #define JZ_DMA_CMD_DST_WIDTH_MASK		(0x3 << 12)
54 #define JZ_DMA_CMD_INTERVAL_LENGTH_MASK		(0x7 << 8)
55 #define JZ_DMA_CMD_BLOCK_MODE			BIT(7)
56 #define JZ_DMA_CMD_DESC_VALID			BIT(4)
57 #define JZ_DMA_CMD_DESC_VALID_MODE		BIT(3)
58 #define JZ_DMA_CMD_VALID_IRQ_ENABLE		BIT(2)
59 #define JZ_DMA_CMD_TRANSFER_IRQ_ENABLE		BIT(1)
60 #define JZ_DMA_CMD_LINK_ENABLE			BIT(0)
61 
62 #define JZ_DMA_CMD_FLAGS_OFFSET 22
63 #define JZ_DMA_CMD_RDIL_OFFSET 16
64 #define JZ_DMA_CMD_SRC_WIDTH_OFFSET 14
65 #define JZ_DMA_CMD_DST_WIDTH_OFFSET 12
66 #define JZ_DMA_CMD_TRANSFER_SIZE_OFFSET 8
67 #define JZ_DMA_CMD_MODE_OFFSET 7
68 
69 #define JZ_DMA_CTRL_PRIORITY_MASK		(0x3 << 8)
70 #define JZ_DMA_CTRL_HALT			BIT(3)
71 #define JZ_DMA_CTRL_ADDRESS_ERROR		BIT(2)
72 #define JZ_DMA_CTRL_ENABLE			BIT(0)
73 
74 enum jz4740_dma_width {
75 	JZ4740_DMA_WIDTH_32BIT	= 0,
76 	JZ4740_DMA_WIDTH_8BIT	= 1,
77 	JZ4740_DMA_WIDTH_16BIT	= 2,
78 };
79 
80 enum jz4740_dma_transfer_size {
81 	JZ4740_DMA_TRANSFER_SIZE_4BYTE	= 0,
82 	JZ4740_DMA_TRANSFER_SIZE_1BYTE	= 1,
83 	JZ4740_DMA_TRANSFER_SIZE_2BYTE	= 2,
84 	JZ4740_DMA_TRANSFER_SIZE_16BYTE = 3,
85 	JZ4740_DMA_TRANSFER_SIZE_32BYTE = 4,
86 };
87 
88 enum jz4740_dma_flags {
89 	JZ4740_DMA_SRC_AUTOINC = 0x2,
90 	JZ4740_DMA_DST_AUTOINC = 0x1,
91 };
92 
93 enum jz4740_dma_mode {
94 	JZ4740_DMA_MODE_SINGLE	= 0,
95 	JZ4740_DMA_MODE_BLOCK	= 1,
96 };
97 
98 struct jz4740_dma_sg {
99 	dma_addr_t addr;
100 	unsigned int len;
101 };
102 
103 struct jz4740_dma_desc {
104 	struct virt_dma_desc vdesc;
105 
106 	enum dma_transfer_direction direction;
107 	bool cyclic;
108 
109 	unsigned int num_sgs;
110 	struct jz4740_dma_sg sg[];
111 };
112 
113 struct jz4740_dmaengine_chan {
114 	struct virt_dma_chan vchan;
115 	unsigned int id;
116 
117 	dma_addr_t fifo_addr;
118 	unsigned int transfer_shift;
119 
120 	struct jz4740_dma_desc *desc;
121 	unsigned int next_sg;
122 };
123 
124 struct jz4740_dma_dev {
125 	struct dma_device ddev;
126 	void __iomem *base;
127 	struct clk *clk;
128 
129 	struct jz4740_dmaengine_chan chan[JZ_DMA_NR_CHANS];
130 };
131 
jz4740_dma_chan_get_dev(struct jz4740_dmaengine_chan * chan)132 static struct jz4740_dma_dev *jz4740_dma_chan_get_dev(
133 	struct jz4740_dmaengine_chan *chan)
134 {
135 	return container_of(chan->vchan.chan.device, struct jz4740_dma_dev,
136 		ddev);
137 }
138 
to_jz4740_dma_chan(struct dma_chan * c)139 static struct jz4740_dmaengine_chan *to_jz4740_dma_chan(struct dma_chan *c)
140 {
141 	return container_of(c, struct jz4740_dmaengine_chan, vchan.chan);
142 }
143 
to_jz4740_dma_desc(struct virt_dma_desc * vdesc)144 static struct jz4740_dma_desc *to_jz4740_dma_desc(struct virt_dma_desc *vdesc)
145 {
146 	return container_of(vdesc, struct jz4740_dma_desc, vdesc);
147 }
148 
jz4740_dma_read(struct jz4740_dma_dev * dmadev,unsigned int reg)149 static inline uint32_t jz4740_dma_read(struct jz4740_dma_dev *dmadev,
150 	unsigned int reg)
151 {
152 	return readl(dmadev->base + reg);
153 }
154 
jz4740_dma_write(struct jz4740_dma_dev * dmadev,unsigned reg,uint32_t val)155 static inline void jz4740_dma_write(struct jz4740_dma_dev *dmadev,
156 	unsigned reg, uint32_t val)
157 {
158 	writel(val, dmadev->base + reg);
159 }
160 
jz4740_dma_write_mask(struct jz4740_dma_dev * dmadev,unsigned int reg,uint32_t val,uint32_t mask)161 static inline void jz4740_dma_write_mask(struct jz4740_dma_dev *dmadev,
162 	unsigned int reg, uint32_t val, uint32_t mask)
163 {
164 	uint32_t tmp;
165 
166 	tmp = jz4740_dma_read(dmadev, reg);
167 	tmp &= ~mask;
168 	tmp |= val;
169 	jz4740_dma_write(dmadev, reg, tmp);
170 }
171 
jz4740_dma_alloc_desc(unsigned int num_sgs)172 static struct jz4740_dma_desc *jz4740_dma_alloc_desc(unsigned int num_sgs)
173 {
174 	return kzalloc(sizeof(struct jz4740_dma_desc) +
175 		sizeof(struct jz4740_dma_sg) * num_sgs, GFP_ATOMIC);
176 }
177 
jz4740_dma_width(enum dma_slave_buswidth width)178 static enum jz4740_dma_width jz4740_dma_width(enum dma_slave_buswidth width)
179 {
180 	switch (width) {
181 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
182 		return JZ4740_DMA_WIDTH_8BIT;
183 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
184 		return JZ4740_DMA_WIDTH_16BIT;
185 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
186 		return JZ4740_DMA_WIDTH_32BIT;
187 	default:
188 		return JZ4740_DMA_WIDTH_32BIT;
189 	}
190 }
191 
jz4740_dma_maxburst(u32 maxburst)192 static enum jz4740_dma_transfer_size jz4740_dma_maxburst(u32 maxburst)
193 {
194 	if (maxburst <= 1)
195 		return JZ4740_DMA_TRANSFER_SIZE_1BYTE;
196 	else if (maxburst <= 3)
197 		return JZ4740_DMA_TRANSFER_SIZE_2BYTE;
198 	else if (maxburst <= 15)
199 		return JZ4740_DMA_TRANSFER_SIZE_4BYTE;
200 	else if (maxburst <= 31)
201 		return JZ4740_DMA_TRANSFER_SIZE_16BYTE;
202 
203 	return JZ4740_DMA_TRANSFER_SIZE_32BYTE;
204 }
205 
jz4740_dma_slave_config(struct dma_chan * c,struct dma_slave_config * config)206 static int jz4740_dma_slave_config(struct dma_chan *c,
207 				   struct dma_slave_config *config)
208 {
209 	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
210 	struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
211 	enum jz4740_dma_width src_width;
212 	enum jz4740_dma_width dst_width;
213 	enum jz4740_dma_transfer_size transfer_size;
214 	enum jz4740_dma_flags flags;
215 	uint32_t cmd;
216 
217 	switch (config->direction) {
218 	case DMA_MEM_TO_DEV:
219 		flags = JZ4740_DMA_SRC_AUTOINC;
220 		transfer_size = jz4740_dma_maxburst(config->dst_maxburst);
221 		chan->fifo_addr = config->dst_addr;
222 		break;
223 	case DMA_DEV_TO_MEM:
224 		flags = JZ4740_DMA_DST_AUTOINC;
225 		transfer_size = jz4740_dma_maxburst(config->src_maxburst);
226 		chan->fifo_addr = config->src_addr;
227 		break;
228 	default:
229 		return -EINVAL;
230 	}
231 
232 	src_width = jz4740_dma_width(config->src_addr_width);
233 	dst_width = jz4740_dma_width(config->dst_addr_width);
234 
235 	switch (transfer_size) {
236 	case JZ4740_DMA_TRANSFER_SIZE_2BYTE:
237 		chan->transfer_shift = 1;
238 		break;
239 	case JZ4740_DMA_TRANSFER_SIZE_4BYTE:
240 		chan->transfer_shift = 2;
241 		break;
242 	case JZ4740_DMA_TRANSFER_SIZE_16BYTE:
243 		chan->transfer_shift = 4;
244 		break;
245 	case JZ4740_DMA_TRANSFER_SIZE_32BYTE:
246 		chan->transfer_shift = 5;
247 		break;
248 	default:
249 		chan->transfer_shift = 0;
250 		break;
251 	}
252 
253 	cmd = flags << JZ_DMA_CMD_FLAGS_OFFSET;
254 	cmd |= src_width << JZ_DMA_CMD_SRC_WIDTH_OFFSET;
255 	cmd |= dst_width << JZ_DMA_CMD_DST_WIDTH_OFFSET;
256 	cmd |= transfer_size << JZ_DMA_CMD_TRANSFER_SIZE_OFFSET;
257 	cmd |= JZ4740_DMA_MODE_SINGLE << JZ_DMA_CMD_MODE_OFFSET;
258 	cmd |= JZ_DMA_CMD_TRANSFER_IRQ_ENABLE;
259 
260 	jz4740_dma_write(dmadev, JZ_REG_DMA_CMD(chan->id), cmd);
261 	jz4740_dma_write(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0);
262 	jz4740_dma_write(dmadev, JZ_REG_DMA_REQ_TYPE(chan->id),
263 		config->slave_id);
264 
265 	return 0;
266 }
267 
jz4740_dma_terminate_all(struct dma_chan * c)268 static int jz4740_dma_terminate_all(struct dma_chan *c)
269 {
270 	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
271 	struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
272 	unsigned long flags;
273 	LIST_HEAD(head);
274 
275 	spin_lock_irqsave(&chan->vchan.lock, flags);
276 	jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0,
277 			JZ_DMA_STATUS_CTRL_ENABLE);
278 	chan->desc = NULL;
279 	vchan_get_all_descriptors(&chan->vchan, &head);
280 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
281 
282 	vchan_dma_desc_free_list(&chan->vchan, &head);
283 
284 	return 0;
285 }
286 
jz4740_dma_start_transfer(struct jz4740_dmaengine_chan * chan)287 static int jz4740_dma_start_transfer(struct jz4740_dmaengine_chan *chan)
288 {
289 	struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
290 	dma_addr_t src_addr, dst_addr;
291 	struct virt_dma_desc *vdesc;
292 	struct jz4740_dma_sg *sg;
293 
294 	jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0,
295 			JZ_DMA_STATUS_CTRL_ENABLE);
296 
297 	if (!chan->desc) {
298 		vdesc = vchan_next_desc(&chan->vchan);
299 		if (!vdesc)
300 			return 0;
301 		chan->desc = to_jz4740_dma_desc(vdesc);
302 		chan->next_sg = 0;
303 	}
304 
305 	if (chan->next_sg == chan->desc->num_sgs)
306 		chan->next_sg = 0;
307 
308 	sg = &chan->desc->sg[chan->next_sg];
309 
310 	if (chan->desc->direction == DMA_MEM_TO_DEV) {
311 		src_addr = sg->addr;
312 		dst_addr = chan->fifo_addr;
313 	} else {
314 		src_addr = chan->fifo_addr;
315 		dst_addr = sg->addr;
316 	}
317 	jz4740_dma_write(dmadev, JZ_REG_DMA_SRC_ADDR(chan->id), src_addr);
318 	jz4740_dma_write(dmadev, JZ_REG_DMA_DST_ADDR(chan->id), dst_addr);
319 	jz4740_dma_write(dmadev, JZ_REG_DMA_TRANSFER_COUNT(chan->id),
320 			sg->len >> chan->transfer_shift);
321 
322 	chan->next_sg++;
323 
324 	jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id),
325 			JZ_DMA_STATUS_CTRL_NO_DESC | JZ_DMA_STATUS_CTRL_ENABLE,
326 			JZ_DMA_STATUS_CTRL_HALT | JZ_DMA_STATUS_CTRL_NO_DESC |
327 			JZ_DMA_STATUS_CTRL_ENABLE);
328 
329 	jz4740_dma_write_mask(dmadev, JZ_REG_DMA_CTRL,
330 			JZ_DMA_CTRL_ENABLE,
331 			JZ_DMA_CTRL_HALT | JZ_DMA_CTRL_ENABLE);
332 
333 	return 0;
334 }
335 
jz4740_dma_chan_irq(struct jz4740_dmaengine_chan * chan)336 static void jz4740_dma_chan_irq(struct jz4740_dmaengine_chan *chan)
337 {
338 	spin_lock(&chan->vchan.lock);
339 	if (chan->desc) {
340 		if (chan->desc->cyclic) {
341 			vchan_cyclic_callback(&chan->desc->vdesc);
342 		} else {
343 			if (chan->next_sg == chan->desc->num_sgs) {
344 				list_del(&chan->desc->vdesc.node);
345 				vchan_cookie_complete(&chan->desc->vdesc);
346 				chan->desc = NULL;
347 			}
348 		}
349 	}
350 	jz4740_dma_start_transfer(chan);
351 	spin_unlock(&chan->vchan.lock);
352 }
353 
jz4740_dma_irq(int irq,void * devid)354 static irqreturn_t jz4740_dma_irq(int irq, void *devid)
355 {
356 	struct jz4740_dma_dev *dmadev = devid;
357 	uint32_t irq_status;
358 	unsigned int i;
359 
360 	irq_status = readl(dmadev->base + JZ_REG_DMA_IRQ);
361 
362 	for (i = 0; i < 6; ++i) {
363 		if (irq_status & (1 << i)) {
364 			jz4740_dma_write_mask(dmadev,
365 				JZ_REG_DMA_STATUS_CTRL(i), 0,
366 				JZ_DMA_STATUS_CTRL_ENABLE |
367 				JZ_DMA_STATUS_CTRL_TRANSFER_DONE);
368 
369 			jz4740_dma_chan_irq(&dmadev->chan[i]);
370 		}
371 	}
372 
373 	return IRQ_HANDLED;
374 }
375 
jz4740_dma_issue_pending(struct dma_chan * c)376 static void jz4740_dma_issue_pending(struct dma_chan *c)
377 {
378 	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
379 	unsigned long flags;
380 
381 	spin_lock_irqsave(&chan->vchan.lock, flags);
382 	if (vchan_issue_pending(&chan->vchan) && !chan->desc)
383 		jz4740_dma_start_transfer(chan);
384 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
385 }
386 
jz4740_dma_prep_slave_sg(struct dma_chan * c,struct scatterlist * sgl,unsigned int sg_len,enum dma_transfer_direction direction,unsigned long flags,void * context)387 static struct dma_async_tx_descriptor *jz4740_dma_prep_slave_sg(
388 	struct dma_chan *c, struct scatterlist *sgl,
389 	unsigned int sg_len, enum dma_transfer_direction direction,
390 	unsigned long flags, void *context)
391 {
392 	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
393 	struct jz4740_dma_desc *desc;
394 	struct scatterlist *sg;
395 	unsigned int i;
396 
397 	desc = jz4740_dma_alloc_desc(sg_len);
398 	if (!desc)
399 		return NULL;
400 
401 	for_each_sg(sgl, sg, sg_len, i) {
402 		desc->sg[i].addr = sg_dma_address(sg);
403 		desc->sg[i].len = sg_dma_len(sg);
404 	}
405 
406 	desc->num_sgs = sg_len;
407 	desc->direction = direction;
408 	desc->cyclic = false;
409 
410 	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
411 }
412 
jz4740_dma_prep_dma_cyclic(struct dma_chan * c,dma_addr_t buf_addr,size_t buf_len,size_t period_len,enum dma_transfer_direction direction,unsigned long flags)413 static struct dma_async_tx_descriptor *jz4740_dma_prep_dma_cyclic(
414 	struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
415 	size_t period_len, enum dma_transfer_direction direction,
416 	unsigned long flags)
417 {
418 	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
419 	struct jz4740_dma_desc *desc;
420 	unsigned int num_periods, i;
421 
422 	if (buf_len % period_len)
423 		return NULL;
424 
425 	num_periods = buf_len / period_len;
426 
427 	desc = jz4740_dma_alloc_desc(num_periods);
428 	if (!desc)
429 		return NULL;
430 
431 	for (i = 0; i < num_periods; i++) {
432 		desc->sg[i].addr = buf_addr;
433 		desc->sg[i].len = period_len;
434 		buf_addr += period_len;
435 	}
436 
437 	desc->num_sgs = num_periods;
438 	desc->direction = direction;
439 	desc->cyclic = true;
440 
441 	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
442 }
443 
jz4740_dma_desc_residue(struct jz4740_dmaengine_chan * chan,struct jz4740_dma_desc * desc,unsigned int next_sg)444 static size_t jz4740_dma_desc_residue(struct jz4740_dmaengine_chan *chan,
445 	struct jz4740_dma_desc *desc, unsigned int next_sg)
446 {
447 	struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan);
448 	unsigned int residue, count;
449 	unsigned int i;
450 
451 	residue = 0;
452 
453 	for (i = next_sg; i < desc->num_sgs; i++)
454 		residue += desc->sg[i].len;
455 
456 	if (next_sg != 0) {
457 		count = jz4740_dma_read(dmadev,
458 			JZ_REG_DMA_TRANSFER_COUNT(chan->id));
459 		residue += count << chan->transfer_shift;
460 	}
461 
462 	return residue;
463 }
464 
jz4740_dma_tx_status(struct dma_chan * c,dma_cookie_t cookie,struct dma_tx_state * state)465 static enum dma_status jz4740_dma_tx_status(struct dma_chan *c,
466 	dma_cookie_t cookie, struct dma_tx_state *state)
467 {
468 	struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c);
469 	struct virt_dma_desc *vdesc;
470 	enum dma_status status;
471 	unsigned long flags;
472 
473 	status = dma_cookie_status(c, cookie, state);
474 	if (status == DMA_COMPLETE || !state)
475 		return status;
476 
477 	spin_lock_irqsave(&chan->vchan.lock, flags);
478 	vdesc = vchan_find_desc(&chan->vchan, cookie);
479 	if (cookie == chan->desc->vdesc.tx.cookie) {
480 		state->residue = jz4740_dma_desc_residue(chan, chan->desc,
481 				chan->next_sg);
482 	} else if (vdesc) {
483 		state->residue = jz4740_dma_desc_residue(chan,
484 				to_jz4740_dma_desc(vdesc), 0);
485 	} else {
486 		state->residue = 0;
487 	}
488 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
489 
490 	return status;
491 }
492 
jz4740_dma_free_chan_resources(struct dma_chan * c)493 static void jz4740_dma_free_chan_resources(struct dma_chan *c)
494 {
495 	vchan_free_chan_resources(to_virt_chan(c));
496 }
497 
jz4740_dma_desc_free(struct virt_dma_desc * vdesc)498 static void jz4740_dma_desc_free(struct virt_dma_desc *vdesc)
499 {
500 	kfree(container_of(vdesc, struct jz4740_dma_desc, vdesc));
501 }
502 
503 #define JZ4740_DMA_BUSWIDTHS (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
504 	BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
505 
jz4740_dma_probe(struct platform_device * pdev)506 static int jz4740_dma_probe(struct platform_device *pdev)
507 {
508 	struct jz4740_dmaengine_chan *chan;
509 	struct jz4740_dma_dev *dmadev;
510 	struct dma_device *dd;
511 	unsigned int i;
512 	struct resource *res;
513 	int ret;
514 	int irq;
515 
516 	dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
517 	if (!dmadev)
518 		return -EINVAL;
519 
520 	dd = &dmadev->ddev;
521 
522 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
523 	dmadev->base = devm_ioremap_resource(&pdev->dev, res);
524 	if (IS_ERR(dmadev->base))
525 		return PTR_ERR(dmadev->base);
526 
527 	dmadev->clk = clk_get(&pdev->dev, "dma");
528 	if (IS_ERR(dmadev->clk))
529 		return PTR_ERR(dmadev->clk);
530 
531 	clk_prepare_enable(dmadev->clk);
532 
533 	dma_cap_set(DMA_SLAVE, dd->cap_mask);
534 	dma_cap_set(DMA_CYCLIC, dd->cap_mask);
535 	dd->device_free_chan_resources = jz4740_dma_free_chan_resources;
536 	dd->device_tx_status = jz4740_dma_tx_status;
537 	dd->device_issue_pending = jz4740_dma_issue_pending;
538 	dd->device_prep_slave_sg = jz4740_dma_prep_slave_sg;
539 	dd->device_prep_dma_cyclic = jz4740_dma_prep_dma_cyclic;
540 	dd->device_config = jz4740_dma_slave_config;
541 	dd->device_terminate_all = jz4740_dma_terminate_all;
542 	dd->src_addr_widths = JZ4740_DMA_BUSWIDTHS;
543 	dd->dst_addr_widths = JZ4740_DMA_BUSWIDTHS;
544 	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
545 	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
546 	dd->dev = &pdev->dev;
547 	INIT_LIST_HEAD(&dd->channels);
548 
549 	for (i = 0; i < JZ_DMA_NR_CHANS; i++) {
550 		chan = &dmadev->chan[i];
551 		chan->id = i;
552 		chan->vchan.desc_free = jz4740_dma_desc_free;
553 		vchan_init(&chan->vchan, dd);
554 	}
555 
556 	ret = dma_async_device_register(dd);
557 	if (ret)
558 		goto err_clk;
559 
560 	irq = platform_get_irq(pdev, 0);
561 	ret = request_irq(irq, jz4740_dma_irq, 0, dev_name(&pdev->dev), dmadev);
562 	if (ret)
563 		goto err_unregister;
564 
565 	platform_set_drvdata(pdev, dmadev);
566 
567 	return 0;
568 
569 err_unregister:
570 	dma_async_device_unregister(dd);
571 err_clk:
572 	clk_disable_unprepare(dmadev->clk);
573 	return ret;
574 }
575 
jz4740_cleanup_vchan(struct dma_device * dmadev)576 static void jz4740_cleanup_vchan(struct dma_device *dmadev)
577 {
578 	struct jz4740_dmaengine_chan *chan, *_chan;
579 
580 	list_for_each_entry_safe(chan, _chan,
581 				&dmadev->channels, vchan.chan.device_node) {
582 		list_del(&chan->vchan.chan.device_node);
583 		tasklet_kill(&chan->vchan.task);
584 	}
585 }
586 
587 
jz4740_dma_remove(struct platform_device * pdev)588 static int jz4740_dma_remove(struct platform_device *pdev)
589 {
590 	struct jz4740_dma_dev *dmadev = platform_get_drvdata(pdev);
591 	int irq = platform_get_irq(pdev, 0);
592 
593 	free_irq(irq, dmadev);
594 
595 	jz4740_cleanup_vchan(&dmadev->ddev);
596 	dma_async_device_unregister(&dmadev->ddev);
597 	clk_disable_unprepare(dmadev->clk);
598 
599 	return 0;
600 }
601 
602 static struct platform_driver jz4740_dma_driver = {
603 	.probe = jz4740_dma_probe,
604 	.remove = jz4740_dma_remove,
605 	.driver = {
606 		.name = "jz4740-dma",
607 	},
608 };
609 module_platform_driver(jz4740_dma_driver);
610 
611 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
612 MODULE_DESCRIPTION("JZ4740 DMA driver");
613 MODULE_LICENSE("GPL v2");
614