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[mirror_ubuntu-artful-kernel.git] / drivers / dma / dma-axi-dmac.c
1 /*
2 * Driver for the Analog Devices AXI-DMAC core
3 *
4 * Copyright 2013-2015 Analog Devices Inc.
5 * Author: Lars-Peter Clausen <lars@metafoo.de>
6 *
7 * Licensed under the GPL-2.
8 */
9
10 #include <linux/clk.h>
11 #include <linux/device.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/dmaengine.h>
14 #include <linux/err.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_dma.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
23
24 #include <dt-bindings/dma/axi-dmac.h>
25
26 #include "dmaengine.h"
27 #include "virt-dma.h"
28
29 /*
30 * The AXI-DMAC is a soft IP core that is used in FPGA designs. The core has
31 * various instantiation parameters which decided the exact feature set support
32 * by the core.
33 *
34 * Each channel of the core has a source interface and a destination interface.
35 * The number of channels and the type of the channel interfaces is selected at
36 * configuration time. A interface can either be a connected to a central memory
37 * interconnect, which allows access to system memory, or it can be connected to
38 * a dedicated bus which is directly connected to a data port on a peripheral.
39 * Given that those are configuration options of the core that are selected when
40 * it is instantiated this means that they can not be changed by software at
41 * runtime. By extension this means that each channel is uni-directional. It can
42 * either be device to memory or memory to device, but not both. Also since the
43 * device side is a dedicated data bus only connected to a single peripheral
44 * there is no address than can or needs to be configured for the device side.
45 */
46
47 #define AXI_DMAC_REG_IRQ_MASK 0x80
48 #define AXI_DMAC_REG_IRQ_PENDING 0x84
49 #define AXI_DMAC_REG_IRQ_SOURCE 0x88
50
51 #define AXI_DMAC_REG_CTRL 0x400
52 #define AXI_DMAC_REG_TRANSFER_ID 0x404
53 #define AXI_DMAC_REG_START_TRANSFER 0x408
54 #define AXI_DMAC_REG_FLAGS 0x40c
55 #define AXI_DMAC_REG_DEST_ADDRESS 0x410
56 #define AXI_DMAC_REG_SRC_ADDRESS 0x414
57 #define AXI_DMAC_REG_X_LENGTH 0x418
58 #define AXI_DMAC_REG_Y_LENGTH 0x41c
59 #define AXI_DMAC_REG_DEST_STRIDE 0x420
60 #define AXI_DMAC_REG_SRC_STRIDE 0x424
61 #define AXI_DMAC_REG_TRANSFER_DONE 0x428
62 #define AXI_DMAC_REG_ACTIVE_TRANSFER_ID 0x42c
63 #define AXI_DMAC_REG_STATUS 0x430
64 #define AXI_DMAC_REG_CURRENT_SRC_ADDR 0x434
65 #define AXI_DMAC_REG_CURRENT_DEST_ADDR 0x438
66
67 #define AXI_DMAC_CTRL_ENABLE BIT(0)
68 #define AXI_DMAC_CTRL_PAUSE BIT(1)
69
70 #define AXI_DMAC_IRQ_SOT BIT(0)
71 #define AXI_DMAC_IRQ_EOT BIT(1)
72
73 #define AXI_DMAC_FLAG_CYCLIC BIT(0)
74
75 struct axi_dmac_sg {
76 dma_addr_t src_addr;
77 dma_addr_t dest_addr;
78 unsigned int x_len;
79 unsigned int y_len;
80 unsigned int dest_stride;
81 unsigned int src_stride;
82 unsigned int id;
83 };
84
85 struct axi_dmac_desc {
86 struct virt_dma_desc vdesc;
87 bool cyclic;
88
89 unsigned int num_submitted;
90 unsigned int num_completed;
91 unsigned int num_sgs;
92 struct axi_dmac_sg sg[];
93 };
94
95 struct axi_dmac_chan {
96 struct virt_dma_chan vchan;
97
98 struct axi_dmac_desc *next_desc;
99 struct list_head active_descs;
100 enum dma_transfer_direction direction;
101
102 unsigned int src_width;
103 unsigned int dest_width;
104 unsigned int src_type;
105 unsigned int dest_type;
106
107 unsigned int max_length;
108 unsigned int align_mask;
109
110 bool hw_cyclic;
111 bool hw_2d;
112 };
113
114 struct axi_dmac {
115 void __iomem *base;
116 int irq;
117
118 struct clk *clk;
119
120 struct dma_device dma_dev;
121 struct axi_dmac_chan chan;
122
123 struct device_dma_parameters dma_parms;
124 };
125
126 static struct axi_dmac *chan_to_axi_dmac(struct axi_dmac_chan *chan)
127 {
128 return container_of(chan->vchan.chan.device, struct axi_dmac,
129 dma_dev);
130 }
131
132 static struct axi_dmac_chan *to_axi_dmac_chan(struct dma_chan *c)
133 {
134 return container_of(c, struct axi_dmac_chan, vchan.chan);
135 }
136
137 static struct axi_dmac_desc *to_axi_dmac_desc(struct virt_dma_desc *vdesc)
138 {
139 return container_of(vdesc, struct axi_dmac_desc, vdesc);
140 }
141
142 static void axi_dmac_write(struct axi_dmac *axi_dmac, unsigned int reg,
143 unsigned int val)
144 {
145 writel(val, axi_dmac->base + reg);
146 }
147
148 static int axi_dmac_read(struct axi_dmac *axi_dmac, unsigned int reg)
149 {
150 return readl(axi_dmac->base + reg);
151 }
152
153 static int axi_dmac_src_is_mem(struct axi_dmac_chan *chan)
154 {
155 return chan->src_type == AXI_DMAC_BUS_TYPE_AXI_MM;
156 }
157
158 static int axi_dmac_dest_is_mem(struct axi_dmac_chan *chan)
159 {
160 return chan->dest_type == AXI_DMAC_BUS_TYPE_AXI_MM;
161 }
162
163 static bool axi_dmac_check_len(struct axi_dmac_chan *chan, unsigned int len)
164 {
165 if (len == 0 || len > chan->max_length)
166 return false;
167 if ((len & chan->align_mask) != 0) /* Not aligned */
168 return false;
169 return true;
170 }
171
172 static bool axi_dmac_check_addr(struct axi_dmac_chan *chan, dma_addr_t addr)
173 {
174 if ((addr & chan->align_mask) != 0) /* Not aligned */
175 return false;
176 return true;
177 }
178
179 static void axi_dmac_start_transfer(struct axi_dmac_chan *chan)
180 {
181 struct axi_dmac *dmac = chan_to_axi_dmac(chan);
182 struct virt_dma_desc *vdesc;
183 struct axi_dmac_desc *desc;
184 struct axi_dmac_sg *sg;
185 unsigned int flags = 0;
186 unsigned int val;
187
188 val = axi_dmac_read(dmac, AXI_DMAC_REG_START_TRANSFER);
189 if (val) /* Queue is full, wait for the next SOT IRQ */
190 return;
191
192 desc = chan->next_desc;
193
194 if (!desc) {
195 vdesc = vchan_next_desc(&chan->vchan);
196 if (!vdesc)
197 return;
198 list_move_tail(&vdesc->node, &chan->active_descs);
199 desc = to_axi_dmac_desc(vdesc);
200 }
201 sg = &desc->sg[desc->num_submitted];
202
203 desc->num_submitted++;
204 if (desc->num_submitted == desc->num_sgs)
205 chan->next_desc = NULL;
206 else
207 chan->next_desc = desc;
208
209 sg->id = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_ID);
210
211 if (axi_dmac_dest_is_mem(chan)) {
212 axi_dmac_write(dmac, AXI_DMAC_REG_DEST_ADDRESS, sg->dest_addr);
213 axi_dmac_write(dmac, AXI_DMAC_REG_DEST_STRIDE, sg->dest_stride);
214 }
215
216 if (axi_dmac_src_is_mem(chan)) {
217 axi_dmac_write(dmac, AXI_DMAC_REG_SRC_ADDRESS, sg->src_addr);
218 axi_dmac_write(dmac, AXI_DMAC_REG_SRC_STRIDE, sg->src_stride);
219 }
220
221 /*
222 * If the hardware supports cyclic transfers and there is no callback to
223 * call, enable hw cyclic mode to avoid unnecessary interrupts.
224 */
225 if (chan->hw_cyclic && desc->cyclic && !desc->vdesc.tx.callback)
226 flags |= AXI_DMAC_FLAG_CYCLIC;
227
228 axi_dmac_write(dmac, AXI_DMAC_REG_X_LENGTH, sg->x_len - 1);
229 axi_dmac_write(dmac, AXI_DMAC_REG_Y_LENGTH, sg->y_len - 1);
230 axi_dmac_write(dmac, AXI_DMAC_REG_FLAGS, flags);
231 axi_dmac_write(dmac, AXI_DMAC_REG_START_TRANSFER, 1);
232 }
233
234 static struct axi_dmac_desc *axi_dmac_active_desc(struct axi_dmac_chan *chan)
235 {
236 return list_first_entry_or_null(&chan->active_descs,
237 struct axi_dmac_desc, vdesc.node);
238 }
239
240 static void axi_dmac_transfer_done(struct axi_dmac_chan *chan,
241 unsigned int completed_transfers)
242 {
243 struct axi_dmac_desc *active;
244 struct axi_dmac_sg *sg;
245
246 active = axi_dmac_active_desc(chan);
247 if (!active)
248 return;
249
250 if (active->cyclic) {
251 vchan_cyclic_callback(&active->vdesc);
252 } else {
253 do {
254 sg = &active->sg[active->num_completed];
255 if (!(BIT(sg->id) & completed_transfers))
256 break;
257 active->num_completed++;
258 if (active->num_completed == active->num_sgs) {
259 list_del(&active->vdesc.node);
260 vchan_cookie_complete(&active->vdesc);
261 active = axi_dmac_active_desc(chan);
262 }
263 } while (active);
264 }
265 }
266
267 static irqreturn_t axi_dmac_interrupt_handler(int irq, void *devid)
268 {
269 struct axi_dmac *dmac = devid;
270 unsigned int pending;
271
272 pending = axi_dmac_read(dmac, AXI_DMAC_REG_IRQ_PENDING);
273 if (!pending)
274 return IRQ_NONE;
275
276 axi_dmac_write(dmac, AXI_DMAC_REG_IRQ_PENDING, pending);
277
278 spin_lock(&dmac->chan.vchan.lock);
279 /* One or more transfers have finished */
280 if (pending & AXI_DMAC_IRQ_EOT) {
281 unsigned int completed;
282
283 completed = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_DONE);
284 axi_dmac_transfer_done(&dmac->chan, completed);
285 }
286 /* Space has become available in the descriptor queue */
287 if (pending & AXI_DMAC_IRQ_SOT)
288 axi_dmac_start_transfer(&dmac->chan);
289 spin_unlock(&dmac->chan.vchan.lock);
290
291 return IRQ_HANDLED;
292 }
293
294 static int axi_dmac_terminate_all(struct dma_chan *c)
295 {
296 struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
297 struct axi_dmac *dmac = chan_to_axi_dmac(chan);
298 unsigned long flags;
299 LIST_HEAD(head);
300
301 spin_lock_irqsave(&chan->vchan.lock, flags);
302 axi_dmac_write(dmac, AXI_DMAC_REG_CTRL, 0);
303 chan->next_desc = NULL;
304 vchan_get_all_descriptors(&chan->vchan, &head);
305 list_splice_tail_init(&chan->active_descs, &head);
306 spin_unlock_irqrestore(&chan->vchan.lock, flags);
307
308 vchan_dma_desc_free_list(&chan->vchan, &head);
309
310 return 0;
311 }
312
313 static void axi_dmac_synchronize(struct dma_chan *c)
314 {
315 struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
316
317 vchan_synchronize(&chan->vchan);
318 }
319
320 static void axi_dmac_issue_pending(struct dma_chan *c)
321 {
322 struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
323 struct axi_dmac *dmac = chan_to_axi_dmac(chan);
324 unsigned long flags;
325
326 axi_dmac_write(dmac, AXI_DMAC_REG_CTRL, AXI_DMAC_CTRL_ENABLE);
327
328 spin_lock_irqsave(&chan->vchan.lock, flags);
329 if (vchan_issue_pending(&chan->vchan))
330 axi_dmac_start_transfer(chan);
331 spin_unlock_irqrestore(&chan->vchan.lock, flags);
332 }
333
334 static struct axi_dmac_desc *axi_dmac_alloc_desc(unsigned int num_sgs)
335 {
336 struct axi_dmac_desc *desc;
337
338 desc = kzalloc(sizeof(struct axi_dmac_desc) +
339 sizeof(struct axi_dmac_sg) * num_sgs, GFP_NOWAIT);
340 if (!desc)
341 return NULL;
342
343 desc->num_sgs = num_sgs;
344
345 return desc;
346 }
347
348 static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg(
349 struct dma_chan *c, struct scatterlist *sgl,
350 unsigned int sg_len, enum dma_transfer_direction direction,
351 unsigned long flags, void *context)
352 {
353 struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
354 struct axi_dmac_desc *desc;
355 struct scatterlist *sg;
356 unsigned int i;
357
358 if (direction != chan->direction)
359 return NULL;
360
361 desc = axi_dmac_alloc_desc(sg_len);
362 if (!desc)
363 return NULL;
364
365 for_each_sg(sgl, sg, sg_len, i) {
366 if (!axi_dmac_check_addr(chan, sg_dma_address(sg)) ||
367 !axi_dmac_check_len(chan, sg_dma_len(sg))) {
368 kfree(desc);
369 return NULL;
370 }
371
372 if (direction == DMA_DEV_TO_MEM)
373 desc->sg[i].dest_addr = sg_dma_address(sg);
374 else
375 desc->sg[i].src_addr = sg_dma_address(sg);
376 desc->sg[i].x_len = sg_dma_len(sg);
377 desc->sg[i].y_len = 1;
378 }
379
380 desc->cyclic = false;
381
382 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
383 }
384
385 static struct dma_async_tx_descriptor *axi_dmac_prep_dma_cyclic(
386 struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
387 size_t period_len, enum dma_transfer_direction direction,
388 unsigned long flags)
389 {
390 struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
391 struct axi_dmac_desc *desc;
392 unsigned int num_periods, i;
393
394 if (direction != chan->direction)
395 return NULL;
396
397 if (!axi_dmac_check_len(chan, buf_len) ||
398 !axi_dmac_check_addr(chan, buf_addr))
399 return NULL;
400
401 if (period_len == 0 || buf_len % period_len)
402 return NULL;
403
404 num_periods = buf_len / period_len;
405
406 desc = axi_dmac_alloc_desc(num_periods);
407 if (!desc)
408 return NULL;
409
410 for (i = 0; i < num_periods; i++) {
411 if (direction == DMA_DEV_TO_MEM)
412 desc->sg[i].dest_addr = buf_addr;
413 else
414 desc->sg[i].src_addr = buf_addr;
415 desc->sg[i].x_len = period_len;
416 desc->sg[i].y_len = 1;
417 buf_addr += period_len;
418 }
419
420 desc->cyclic = true;
421
422 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
423 }
424
425 static struct dma_async_tx_descriptor *axi_dmac_prep_interleaved(
426 struct dma_chan *c, struct dma_interleaved_template *xt,
427 unsigned long flags)
428 {
429 struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
430 struct axi_dmac_desc *desc;
431 size_t dst_icg, src_icg;
432
433 if (xt->frame_size != 1)
434 return NULL;
435
436 if (xt->dir != chan->direction)
437 return NULL;
438
439 if (axi_dmac_src_is_mem(chan)) {
440 if (!xt->src_inc || !axi_dmac_check_addr(chan, xt->src_start))
441 return NULL;
442 }
443
444 if (axi_dmac_dest_is_mem(chan)) {
445 if (!xt->dst_inc || !axi_dmac_check_addr(chan, xt->dst_start))
446 return NULL;
447 }
448
449 dst_icg = dmaengine_get_dst_icg(xt, &xt->sgl[0]);
450 src_icg = dmaengine_get_src_icg(xt, &xt->sgl[0]);
451
452 if (chan->hw_2d) {
453 if (!axi_dmac_check_len(chan, xt->sgl[0].size) ||
454 !axi_dmac_check_len(chan, xt->numf))
455 return NULL;
456 if (xt->sgl[0].size + dst_icg > chan->max_length ||
457 xt->sgl[0].size + src_icg > chan->max_length)
458 return NULL;
459 } else {
460 if (dst_icg != 0 || src_icg != 0)
461 return NULL;
462 if (chan->max_length / xt->sgl[0].size < xt->numf)
463 return NULL;
464 if (!axi_dmac_check_len(chan, xt->sgl[0].size * xt->numf))
465 return NULL;
466 }
467
468 desc = axi_dmac_alloc_desc(1);
469 if (!desc)
470 return NULL;
471
472 if (axi_dmac_src_is_mem(chan)) {
473 desc->sg[0].src_addr = xt->src_start;
474 desc->sg[0].src_stride = xt->sgl[0].size + src_icg;
475 }
476
477 if (axi_dmac_dest_is_mem(chan)) {
478 desc->sg[0].dest_addr = xt->dst_start;
479 desc->sg[0].dest_stride = xt->sgl[0].size + dst_icg;
480 }
481
482 if (chan->hw_2d) {
483 desc->sg[0].x_len = xt->sgl[0].size;
484 desc->sg[0].y_len = xt->numf;
485 } else {
486 desc->sg[0].x_len = xt->sgl[0].size * xt->numf;
487 desc->sg[0].y_len = 1;
488 }
489
490 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
491 }
492
493 static void axi_dmac_free_chan_resources(struct dma_chan *c)
494 {
495 vchan_free_chan_resources(to_virt_chan(c));
496 }
497
498 static void axi_dmac_desc_free(struct virt_dma_desc *vdesc)
499 {
500 kfree(container_of(vdesc, struct axi_dmac_desc, vdesc));
501 }
502
503 /*
504 * The configuration stored in the devicetree matches the configuration
505 * parameters of the peripheral instance and allows the driver to know which
506 * features are implemented and how it should behave.
507 */
508 static int axi_dmac_parse_chan_dt(struct device_node *of_chan,
509 struct axi_dmac_chan *chan)
510 {
511 u32 val;
512 int ret;
513
514 ret = of_property_read_u32(of_chan, "reg", &val);
515 if (ret)
516 return ret;
517
518 /* We only support 1 channel for now */
519 if (val != 0)
520 return -EINVAL;
521
522 ret = of_property_read_u32(of_chan, "adi,source-bus-type", &val);
523 if (ret)
524 return ret;
525 if (val > AXI_DMAC_BUS_TYPE_FIFO)
526 return -EINVAL;
527 chan->src_type = val;
528
529 ret = of_property_read_u32(of_chan, "adi,destination-bus-type", &val);
530 if (ret)
531 return ret;
532 if (val > AXI_DMAC_BUS_TYPE_FIFO)
533 return -EINVAL;
534 chan->dest_type = val;
535
536 ret = of_property_read_u32(of_chan, "adi,source-bus-width", &val);
537 if (ret)
538 return ret;
539 chan->src_width = val / 8;
540
541 ret = of_property_read_u32(of_chan, "adi,destination-bus-width", &val);
542 if (ret)
543 return ret;
544 chan->dest_width = val / 8;
545
546 ret = of_property_read_u32(of_chan, "adi,length-width", &val);
547 if (ret)
548 return ret;
549
550 if (val >= 32)
551 chan->max_length = UINT_MAX;
552 else
553 chan->max_length = (1ULL << val) - 1;
554
555 chan->align_mask = max(chan->dest_width, chan->src_width) - 1;
556
557 if (axi_dmac_dest_is_mem(chan) && axi_dmac_src_is_mem(chan))
558 chan->direction = DMA_MEM_TO_MEM;
559 else if (!axi_dmac_dest_is_mem(chan) && axi_dmac_src_is_mem(chan))
560 chan->direction = DMA_MEM_TO_DEV;
561 else if (axi_dmac_dest_is_mem(chan) && !axi_dmac_src_is_mem(chan))
562 chan->direction = DMA_DEV_TO_MEM;
563 else
564 chan->direction = DMA_DEV_TO_DEV;
565
566 chan->hw_cyclic = of_property_read_bool(of_chan, "adi,cyclic");
567 chan->hw_2d = of_property_read_bool(of_chan, "adi,2d");
568
569 return 0;
570 }
571
572 static int axi_dmac_probe(struct platform_device *pdev)
573 {
574 struct device_node *of_channels, *of_chan;
575 struct dma_device *dma_dev;
576 struct axi_dmac *dmac;
577 struct resource *res;
578 int ret;
579
580 dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
581 if (!dmac)
582 return -ENOMEM;
583
584 dmac->irq = platform_get_irq(pdev, 0);
585 if (dmac->irq < 0)
586 return dmac->irq;
587 if (dmac->irq == 0)
588 return -EINVAL;
589
590 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
591 dmac->base = devm_ioremap_resource(&pdev->dev, res);
592 if (IS_ERR(dmac->base))
593 return PTR_ERR(dmac->base);
594
595 dmac->clk = devm_clk_get(&pdev->dev, NULL);
596 if (IS_ERR(dmac->clk))
597 return PTR_ERR(dmac->clk);
598
599 INIT_LIST_HEAD(&dmac->chan.active_descs);
600
601 of_channels = of_get_child_by_name(pdev->dev.of_node, "adi,channels");
602 if (of_channels == NULL)
603 return -ENODEV;
604
605 for_each_child_of_node(of_channels, of_chan) {
606 ret = axi_dmac_parse_chan_dt(of_chan, &dmac->chan);
607 if (ret) {
608 of_node_put(of_chan);
609 of_node_put(of_channels);
610 return -EINVAL;
611 }
612 }
613 of_node_put(of_channels);
614
615 pdev->dev.dma_parms = &dmac->dma_parms;
616 dma_set_max_seg_size(&pdev->dev, dmac->chan.max_length);
617
618 dma_dev = &dmac->dma_dev;
619 dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
620 dma_cap_set(DMA_CYCLIC, dma_dev->cap_mask);
621 dma_dev->device_free_chan_resources = axi_dmac_free_chan_resources;
622 dma_dev->device_tx_status = dma_cookie_status;
623 dma_dev->device_issue_pending = axi_dmac_issue_pending;
624 dma_dev->device_prep_slave_sg = axi_dmac_prep_slave_sg;
625 dma_dev->device_prep_dma_cyclic = axi_dmac_prep_dma_cyclic;
626 dma_dev->device_prep_interleaved_dma = axi_dmac_prep_interleaved;
627 dma_dev->device_terminate_all = axi_dmac_terminate_all;
628 dma_dev->device_synchronize = axi_dmac_synchronize;
629 dma_dev->dev = &pdev->dev;
630 dma_dev->chancnt = 1;
631 dma_dev->src_addr_widths = BIT(dmac->chan.src_width);
632 dma_dev->dst_addr_widths = BIT(dmac->chan.dest_width);
633 dma_dev->directions = BIT(dmac->chan.direction);
634 dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
635 INIT_LIST_HEAD(&dma_dev->channels);
636
637 dmac->chan.vchan.desc_free = axi_dmac_desc_free;
638 vchan_init(&dmac->chan.vchan, dma_dev);
639
640 ret = clk_prepare_enable(dmac->clk);
641 if (ret < 0)
642 return ret;
643
644 axi_dmac_write(dmac, AXI_DMAC_REG_IRQ_MASK, 0x00);
645
646 ret = dma_async_device_register(dma_dev);
647 if (ret)
648 goto err_clk_disable;
649
650 ret = of_dma_controller_register(pdev->dev.of_node,
651 of_dma_xlate_by_chan_id, dma_dev);
652 if (ret)
653 goto err_unregister_device;
654
655 ret = request_irq(dmac->irq, axi_dmac_interrupt_handler, 0,
656 dev_name(&pdev->dev), dmac);
657 if (ret)
658 goto err_unregister_of;
659
660 platform_set_drvdata(pdev, dmac);
661
662 return 0;
663
664 err_unregister_of:
665 of_dma_controller_free(pdev->dev.of_node);
666 err_unregister_device:
667 dma_async_device_unregister(&dmac->dma_dev);
668 err_clk_disable:
669 clk_disable_unprepare(dmac->clk);
670
671 return ret;
672 }
673
674 static int axi_dmac_remove(struct platform_device *pdev)
675 {
676 struct axi_dmac *dmac = platform_get_drvdata(pdev);
677
678 of_dma_controller_free(pdev->dev.of_node);
679 free_irq(dmac->irq, dmac);
680 tasklet_kill(&dmac->chan.vchan.task);
681 dma_async_device_unregister(&dmac->dma_dev);
682 clk_disable_unprepare(dmac->clk);
683
684 return 0;
685 }
686
687 static const struct of_device_id axi_dmac_of_match_table[] = {
688 { .compatible = "adi,axi-dmac-1.00.a" },
689 { },
690 };
691 MODULE_DEVICE_TABLE(of, axi_dmac_of_match_table);
692
693 static struct platform_driver axi_dmac_driver = {
694 .driver = {
695 .name = "dma-axi-dmac",
696 .of_match_table = axi_dmac_of_match_table,
697 },
698 .probe = axi_dmac_probe,
699 .remove = axi_dmac_remove,
700 };
701 module_platform_driver(axi_dmac_driver);
702
703 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
704 MODULE_DESCRIPTION("DMA controller driver for the AXI-DMAC controller");
705 MODULE_LICENSE("GPL v2");