Commit | Line | Data |
---|---|---|
96286b57 FM |
1 | /* |
2 | * BCM2835 DMA engine support | |
3 | * | |
4 | * This driver only supports cyclic DMA transfers | |
5 | * as needed for the I2S module. | |
6 | * | |
7 | * Author: Florian Meier <florian.meier@koalo.de> | |
8 | * Copyright 2013 | |
9 | * | |
10 | * Based on | |
11 | * OMAP DMAengine support by Russell King | |
12 | * | |
13 | * BCM2708 DMA Driver | |
14 | * Copyright (C) 2010 Broadcom | |
15 | * | |
16 | * Raspberry Pi PCM I2S ALSA Driver | |
17 | * Copyright (c) by Phil Poole 2013 | |
18 | * | |
19 | * MARVELL MMP Peripheral DMA Driver | |
20 | * Copyright 2012 Marvell International Ltd. | |
21 | * | |
22 | * This program is free software; you can redistribute it and/or modify | |
23 | * it under the terms of the GNU General Public License as published by | |
24 | * the Free Software Foundation; either version 2 of the License, or | |
25 | * (at your option) any later version. | |
26 | * | |
27 | * This program is distributed in the hope that it will be useful, | |
28 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
29 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
30 | * GNU General Public License for more details. | |
31 | */ | |
32 | #include <linux/dmaengine.h> | |
33 | #include <linux/dma-mapping.h> | |
27bc944c | 34 | #include <linux/dmapool.h> |
96286b57 FM |
35 | #include <linux/err.h> |
36 | #include <linux/init.h> | |
37 | #include <linux/interrupt.h> | |
38 | #include <linux/list.h> | |
39 | #include <linux/module.h> | |
40 | #include <linux/platform_device.h> | |
41 | #include <linux/slab.h> | |
42 | #include <linux/io.h> | |
43 | #include <linux/spinlock.h> | |
44 | #include <linux/of.h> | |
45 | #include <linux/of_dma.h> | |
46 | ||
47 | #include "virt-dma.h" | |
48 | ||
49 | struct bcm2835_dmadev { | |
50 | struct dma_device ddev; | |
51 | spinlock_t lock; | |
52 | void __iomem *base; | |
53 | struct device_dma_parameters dma_parms; | |
54 | }; | |
55 | ||
56 | struct bcm2835_dma_cb { | |
57 | uint32_t info; | |
58 | uint32_t src; | |
59 | uint32_t dst; | |
60 | uint32_t length; | |
61 | uint32_t stride; | |
62 | uint32_t next; | |
63 | uint32_t pad[2]; | |
64 | }; | |
65 | ||
27bc944c PU |
66 | struct bcm2835_cb_entry { |
67 | struct bcm2835_dma_cb *cb; | |
68 | dma_addr_t paddr; | |
69 | }; | |
70 | ||
96286b57 FM |
71 | struct bcm2835_chan { |
72 | struct virt_dma_chan vc; | |
73 | struct list_head node; | |
74 | ||
75 | struct dma_slave_config cfg; | |
76 | bool cyclic; | |
77 | unsigned int dreq; | |
78 | ||
79 | int ch; | |
80 | struct bcm2835_desc *desc; | |
27bc944c | 81 | struct dma_pool *cb_pool; |
96286b57 FM |
82 | |
83 | void __iomem *chan_base; | |
84 | int irq_number; | |
85 | }; | |
86 | ||
87 | struct bcm2835_desc { | |
27bc944c | 88 | struct bcm2835_chan *c; |
96286b57 FM |
89 | struct virt_dma_desc vd; |
90 | enum dma_transfer_direction dir; | |
91 | ||
27bc944c | 92 | struct bcm2835_cb_entry *cb_list; |
96286b57 FM |
93 | |
94 | unsigned int frames; | |
95 | size_t size; | |
96 | }; | |
97 | ||
98 | #define BCM2835_DMA_CS 0x00 | |
99 | #define BCM2835_DMA_ADDR 0x04 | |
100 | #define BCM2835_DMA_SOURCE_AD 0x0c | |
101 | #define BCM2835_DMA_DEST_AD 0x10 | |
102 | #define BCM2835_DMA_NEXTCB 0x1C | |
103 | ||
104 | /* DMA CS Control and Status bits */ | |
105 | #define BCM2835_DMA_ACTIVE BIT(0) | |
106 | #define BCM2835_DMA_INT BIT(2) | |
107 | #define BCM2835_DMA_ISPAUSED BIT(4) /* Pause requested or not active */ | |
108 | #define BCM2835_DMA_ISHELD BIT(5) /* Is held by DREQ flow control */ | |
109 | #define BCM2835_DMA_ERR BIT(8) | |
110 | #define BCM2835_DMA_ABORT BIT(30) /* Stop current CB, go to next, WO */ | |
111 | #define BCM2835_DMA_RESET BIT(31) /* WO, self clearing */ | |
112 | ||
113 | #define BCM2835_DMA_INT_EN BIT(0) | |
114 | #define BCM2835_DMA_D_INC BIT(4) | |
115 | #define BCM2835_DMA_D_DREQ BIT(6) | |
116 | #define BCM2835_DMA_S_INC BIT(8) | |
117 | #define BCM2835_DMA_S_DREQ BIT(10) | |
118 | ||
119 | #define BCM2835_DMA_PER_MAP(x) ((x) << 16) | |
120 | ||
121 | #define BCM2835_DMA_DATA_TYPE_S8 1 | |
122 | #define BCM2835_DMA_DATA_TYPE_S16 2 | |
123 | #define BCM2835_DMA_DATA_TYPE_S32 4 | |
124 | #define BCM2835_DMA_DATA_TYPE_S128 16 | |
125 | ||
126 | #define BCM2835_DMA_BULK_MASK BIT(0) | |
127 | #define BCM2835_DMA_FIQ_MASK (BIT(2) | BIT(3)) | |
128 | ||
129 | /* Valid only for channels 0 - 14, 15 has its own base address */ | |
130 | #define BCM2835_DMA_CHAN(n) ((n) << 8) /* Base address */ | |
131 | #define BCM2835_DMA_CHANIO(base, n) ((base) + BCM2835_DMA_CHAN(n)) | |
132 | ||
133 | static inline struct bcm2835_dmadev *to_bcm2835_dma_dev(struct dma_device *d) | |
134 | { | |
135 | return container_of(d, struct bcm2835_dmadev, ddev); | |
136 | } | |
137 | ||
138 | static inline struct bcm2835_chan *to_bcm2835_dma_chan(struct dma_chan *c) | |
139 | { | |
140 | return container_of(c, struct bcm2835_chan, vc.chan); | |
141 | } | |
142 | ||
143 | static inline struct bcm2835_desc *to_bcm2835_dma_desc( | |
144 | struct dma_async_tx_descriptor *t) | |
145 | { | |
146 | return container_of(t, struct bcm2835_desc, vd.tx); | |
147 | } | |
148 | ||
149 | static void bcm2835_dma_desc_free(struct virt_dma_desc *vd) | |
150 | { | |
151 | struct bcm2835_desc *desc = container_of(vd, struct bcm2835_desc, vd); | |
27bc944c PU |
152 | int i; |
153 | ||
154 | for (i = 0; i < desc->frames; i++) | |
155 | dma_pool_free(desc->c->cb_pool, desc->cb_list[i].cb, | |
156 | desc->cb_list[i].paddr); | |
157 | ||
158 | kfree(desc->cb_list); | |
96286b57 FM |
159 | kfree(desc); |
160 | } | |
161 | ||
162 | static int bcm2835_dma_abort(void __iomem *chan_base) | |
163 | { | |
164 | unsigned long cs; | |
165 | long int timeout = 10000; | |
166 | ||
167 | cs = readl(chan_base + BCM2835_DMA_CS); | |
168 | if (!(cs & BCM2835_DMA_ACTIVE)) | |
169 | return 0; | |
170 | ||
171 | /* Write 0 to the active bit - Pause the DMA */ | |
172 | writel(0, chan_base + BCM2835_DMA_CS); | |
173 | ||
174 | /* Wait for any current AXI transfer to complete */ | |
175 | while ((cs & BCM2835_DMA_ISPAUSED) && --timeout) { | |
176 | cpu_relax(); | |
177 | cs = readl(chan_base + BCM2835_DMA_CS); | |
178 | } | |
179 | ||
180 | /* We'll un-pause when we set of our next DMA */ | |
181 | if (!timeout) | |
182 | return -ETIMEDOUT; | |
183 | ||
184 | if (!(cs & BCM2835_DMA_ACTIVE)) | |
185 | return 0; | |
186 | ||
187 | /* Terminate the control block chain */ | |
188 | writel(0, chan_base + BCM2835_DMA_NEXTCB); | |
189 | ||
190 | /* Abort the whole DMA */ | |
191 | writel(BCM2835_DMA_ABORT | BCM2835_DMA_ACTIVE, | |
192 | chan_base + BCM2835_DMA_CS); | |
193 | ||
194 | return 0; | |
195 | } | |
196 | ||
197 | static void bcm2835_dma_start_desc(struct bcm2835_chan *c) | |
198 | { | |
199 | struct virt_dma_desc *vd = vchan_next_desc(&c->vc); | |
200 | struct bcm2835_desc *d; | |
201 | ||
202 | if (!vd) { | |
203 | c->desc = NULL; | |
204 | return; | |
205 | } | |
206 | ||
207 | list_del(&vd->node); | |
208 | ||
209 | c->desc = d = to_bcm2835_dma_desc(&vd->tx); | |
210 | ||
27bc944c | 211 | writel(d->cb_list[0].paddr, c->chan_base + BCM2835_DMA_ADDR); |
96286b57 FM |
212 | writel(BCM2835_DMA_ACTIVE, c->chan_base + BCM2835_DMA_CS); |
213 | } | |
214 | ||
215 | static irqreturn_t bcm2835_dma_callback(int irq, void *data) | |
216 | { | |
217 | struct bcm2835_chan *c = data; | |
218 | struct bcm2835_desc *d; | |
219 | unsigned long flags; | |
220 | ||
221 | spin_lock_irqsave(&c->vc.lock, flags); | |
222 | ||
223 | /* Acknowledge interrupt */ | |
224 | writel(BCM2835_DMA_INT, c->chan_base + BCM2835_DMA_CS); | |
225 | ||
226 | d = c->desc; | |
227 | ||
228 | if (d) { | |
229 | /* TODO Only works for cyclic DMA */ | |
230 | vchan_cyclic_callback(&d->vd); | |
231 | } | |
232 | ||
233 | /* Keep the DMA engine running */ | |
234 | writel(BCM2835_DMA_ACTIVE, c->chan_base + BCM2835_DMA_CS); | |
235 | ||
236 | spin_unlock_irqrestore(&c->vc.lock, flags); | |
237 | ||
238 | return IRQ_HANDLED; | |
239 | } | |
240 | ||
241 | static int bcm2835_dma_alloc_chan_resources(struct dma_chan *chan) | |
242 | { | |
243 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
27bc944c | 244 | struct device *dev = c->vc.chan.device->dev; |
96286b57 | 245 | |
27bc944c PU |
246 | dev_dbg(dev, "Allocating DMA channel %d\n", c->ch); |
247 | ||
248 | c->cb_pool = dma_pool_create(dev_name(dev), dev, | |
249 | sizeof(struct bcm2835_dma_cb), 0, 0); | |
250 | if (!c->cb_pool) { | |
251 | dev_err(dev, "unable to allocate descriptor pool\n"); | |
252 | return -ENOMEM; | |
253 | } | |
96286b57 FM |
254 | |
255 | return request_irq(c->irq_number, | |
256 | bcm2835_dma_callback, 0, "DMA IRQ", c); | |
257 | } | |
258 | ||
259 | static void bcm2835_dma_free_chan_resources(struct dma_chan *chan) | |
260 | { | |
261 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
262 | ||
263 | vchan_free_chan_resources(&c->vc); | |
264 | free_irq(c->irq_number, c); | |
27bc944c | 265 | dma_pool_destroy(c->cb_pool); |
96286b57 FM |
266 | |
267 | dev_dbg(c->vc.chan.device->dev, "Freeing DMA channel %u\n", c->ch); | |
268 | } | |
269 | ||
270 | static size_t bcm2835_dma_desc_size(struct bcm2835_desc *d) | |
271 | { | |
272 | return d->size; | |
273 | } | |
274 | ||
275 | static size_t bcm2835_dma_desc_size_pos(struct bcm2835_desc *d, dma_addr_t addr) | |
276 | { | |
277 | unsigned int i; | |
278 | size_t size; | |
279 | ||
280 | for (size = i = 0; i < d->frames; i++) { | |
27bc944c | 281 | struct bcm2835_dma_cb *control_block = d->cb_list[i].cb; |
96286b57 FM |
282 | size_t this_size = control_block->length; |
283 | dma_addr_t dma; | |
284 | ||
285 | if (d->dir == DMA_DEV_TO_MEM) | |
286 | dma = control_block->dst; | |
287 | else | |
288 | dma = control_block->src; | |
289 | ||
290 | if (size) | |
291 | size += this_size; | |
292 | else if (addr >= dma && addr < dma + this_size) | |
293 | size += dma + this_size - addr; | |
294 | } | |
295 | ||
296 | return size; | |
297 | } | |
298 | ||
299 | static enum dma_status bcm2835_dma_tx_status(struct dma_chan *chan, | |
300 | dma_cookie_t cookie, struct dma_tx_state *txstate) | |
301 | { | |
302 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
303 | struct virt_dma_desc *vd; | |
304 | enum dma_status ret; | |
305 | unsigned long flags; | |
306 | ||
307 | ret = dma_cookie_status(chan, cookie, txstate); | |
308 | if (ret == DMA_COMPLETE || !txstate) | |
309 | return ret; | |
310 | ||
311 | spin_lock_irqsave(&c->vc.lock, flags); | |
312 | vd = vchan_find_desc(&c->vc, cookie); | |
313 | if (vd) { | |
314 | txstate->residue = | |
315 | bcm2835_dma_desc_size(to_bcm2835_dma_desc(&vd->tx)); | |
316 | } else if (c->desc && c->desc->vd.tx.cookie == cookie) { | |
317 | struct bcm2835_desc *d = c->desc; | |
318 | dma_addr_t pos; | |
319 | ||
320 | if (d->dir == DMA_MEM_TO_DEV) | |
321 | pos = readl(c->chan_base + BCM2835_DMA_SOURCE_AD); | |
322 | else if (d->dir == DMA_DEV_TO_MEM) | |
323 | pos = readl(c->chan_base + BCM2835_DMA_DEST_AD); | |
324 | else | |
325 | pos = 0; | |
326 | ||
327 | txstate->residue = bcm2835_dma_desc_size_pos(d, pos); | |
328 | } else { | |
329 | txstate->residue = 0; | |
330 | } | |
331 | ||
332 | spin_unlock_irqrestore(&c->vc.lock, flags); | |
333 | ||
334 | return ret; | |
335 | } | |
336 | ||
337 | static void bcm2835_dma_issue_pending(struct dma_chan *chan) | |
338 | { | |
339 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
340 | unsigned long flags; | |
341 | ||
342 | c->cyclic = true; /* Nothing else is implemented */ | |
343 | ||
344 | spin_lock_irqsave(&c->vc.lock, flags); | |
345 | if (vchan_issue_pending(&c->vc) && !c->desc) | |
346 | bcm2835_dma_start_desc(c); | |
347 | ||
348 | spin_unlock_irqrestore(&c->vc.lock, flags); | |
349 | } | |
350 | ||
351 | static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic( | |
352 | struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, | |
353 | size_t period_len, enum dma_transfer_direction direction, | |
31c1e5a1 | 354 | unsigned long flags) |
96286b57 FM |
355 | { |
356 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
357 | enum dma_slave_buswidth dev_width; | |
358 | struct bcm2835_desc *d; | |
359 | dma_addr_t dev_addr; | |
360 | unsigned int es, sync_type; | |
361 | unsigned int frame; | |
27bc944c | 362 | int i; |
96286b57 FM |
363 | |
364 | /* Grab configuration */ | |
365 | if (!is_slave_direction(direction)) { | |
366 | dev_err(chan->device->dev, "%s: bad direction?\n", __func__); | |
367 | return NULL; | |
368 | } | |
369 | ||
370 | if (direction == DMA_DEV_TO_MEM) { | |
371 | dev_addr = c->cfg.src_addr; | |
372 | dev_width = c->cfg.src_addr_width; | |
373 | sync_type = BCM2835_DMA_S_DREQ; | |
374 | } else { | |
375 | dev_addr = c->cfg.dst_addr; | |
376 | dev_width = c->cfg.dst_addr_width; | |
377 | sync_type = BCM2835_DMA_D_DREQ; | |
378 | } | |
379 | ||
380 | /* Bus width translates to the element size (ES) */ | |
381 | switch (dev_width) { | |
382 | case DMA_SLAVE_BUSWIDTH_4_BYTES: | |
383 | es = BCM2835_DMA_DATA_TYPE_S32; | |
384 | break; | |
385 | default: | |
386 | return NULL; | |
387 | } | |
388 | ||
389 | /* Now allocate and setup the descriptor. */ | |
390 | d = kzalloc(sizeof(*d), GFP_NOWAIT); | |
391 | if (!d) | |
392 | return NULL; | |
393 | ||
27bc944c | 394 | d->c = c; |
96286b57 FM |
395 | d->dir = direction; |
396 | d->frames = buf_len / period_len; | |
397 | ||
27bc944c PU |
398 | d->cb_list = kcalloc(d->frames, sizeof(*d->cb_list), GFP_KERNEL); |
399 | if (!d->cb_list) { | |
96286b57 FM |
400 | kfree(d); |
401 | return NULL; | |
402 | } | |
27bc944c PU |
403 | /* Allocate memory for control blocks */ |
404 | for (i = 0; i < d->frames; i++) { | |
405 | struct bcm2835_cb_entry *cb_entry = &d->cb_list[i]; | |
406 | ||
407 | cb_entry->cb = dma_pool_zalloc(c->cb_pool, GFP_ATOMIC, | |
408 | &cb_entry->paddr); | |
409 | if (!cb_entry->cb) | |
410 | goto error_cb; | |
411 | } | |
96286b57 FM |
412 | |
413 | /* | |
414 | * Iterate over all frames, create a control block | |
415 | * for each frame and link them together. | |
416 | */ | |
417 | for (frame = 0; frame < d->frames; frame++) { | |
27bc944c | 418 | struct bcm2835_dma_cb *control_block = d->cb_list[frame].cb; |
96286b57 FM |
419 | |
420 | /* Setup adresses */ | |
421 | if (d->dir == DMA_DEV_TO_MEM) { | |
422 | control_block->info = BCM2835_DMA_D_INC; | |
423 | control_block->src = dev_addr; | |
424 | control_block->dst = buf_addr + frame * period_len; | |
425 | } else { | |
426 | control_block->info = BCM2835_DMA_S_INC; | |
427 | control_block->src = buf_addr + frame * period_len; | |
428 | control_block->dst = dev_addr; | |
429 | } | |
430 | ||
431 | /* Enable interrupt */ | |
432 | control_block->info |= BCM2835_DMA_INT_EN; | |
433 | ||
434 | /* Setup synchronization */ | |
435 | if (sync_type != 0) | |
436 | control_block->info |= sync_type; | |
437 | ||
438 | /* Setup DREQ channel */ | |
439 | if (c->dreq != 0) | |
440 | control_block->info |= | |
441 | BCM2835_DMA_PER_MAP(c->dreq); | |
442 | ||
443 | /* Length of a frame */ | |
444 | control_block->length = period_len; | |
445 | d->size += control_block->length; | |
446 | ||
447 | /* | |
448 | * Next block is the next frame. | |
449 | * This DMA engine driver currently only supports cyclic DMA. | |
450 | * Therefore, wrap around at number of frames. | |
451 | */ | |
27bc944c | 452 | control_block->next = d->cb_list[((frame + 1) % d->frames)].paddr; |
96286b57 FM |
453 | } |
454 | ||
455 | return vchan_tx_prep(&c->vc, &d->vd, flags); | |
27bc944c PU |
456 | error_cb: |
457 | i--; | |
458 | for (; i >= 0; i--) { | |
459 | struct bcm2835_cb_entry *cb_entry = &d->cb_list[i]; | |
460 | ||
461 | dma_pool_free(c->cb_pool, cb_entry->cb, cb_entry->paddr); | |
462 | } | |
463 | ||
464 | kfree(d->cb_list); | |
465 | kfree(d); | |
466 | return NULL; | |
96286b57 FM |
467 | } |
468 | ||
39159bea MR |
469 | static int bcm2835_dma_slave_config(struct dma_chan *chan, |
470 | struct dma_slave_config *cfg) | |
96286b57 | 471 | { |
39159bea MR |
472 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); |
473 | ||
96286b57 FM |
474 | if ((cfg->direction == DMA_DEV_TO_MEM && |
475 | cfg->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) || | |
476 | (cfg->direction == DMA_MEM_TO_DEV && | |
477 | cfg->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) || | |
478 | !is_slave_direction(cfg->direction)) { | |
479 | return -EINVAL; | |
480 | } | |
481 | ||
482 | c->cfg = *cfg; | |
483 | ||
484 | return 0; | |
485 | } | |
486 | ||
39159bea | 487 | static int bcm2835_dma_terminate_all(struct dma_chan *chan) |
96286b57 | 488 | { |
39159bea | 489 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); |
96286b57 FM |
490 | struct bcm2835_dmadev *d = to_bcm2835_dma_dev(c->vc.chan.device); |
491 | unsigned long flags; | |
492 | int timeout = 10000; | |
493 | LIST_HEAD(head); | |
494 | ||
495 | spin_lock_irqsave(&c->vc.lock, flags); | |
496 | ||
497 | /* Prevent this channel being scheduled */ | |
498 | spin_lock(&d->lock); | |
499 | list_del_init(&c->node); | |
500 | spin_unlock(&d->lock); | |
501 | ||
502 | /* | |
503 | * Stop DMA activity: we assume the callback will not be called | |
504 | * after bcm_dma_abort() returns (even if it does, it will see | |
505 | * c->desc is NULL and exit.) | |
506 | */ | |
507 | if (c->desc) { | |
f9317829 | 508 | bcm2835_dma_desc_free(&c->desc->vd); |
96286b57 FM |
509 | c->desc = NULL; |
510 | bcm2835_dma_abort(c->chan_base); | |
511 | ||
512 | /* Wait for stopping */ | |
513 | while (--timeout) { | |
514 | if (!(readl(c->chan_base + BCM2835_DMA_CS) & | |
515 | BCM2835_DMA_ACTIVE)) | |
516 | break; | |
517 | ||
518 | cpu_relax(); | |
519 | } | |
520 | ||
521 | if (!timeout) | |
522 | dev_err(d->ddev.dev, "DMA transfer could not be terminated\n"); | |
523 | } | |
524 | ||
525 | vchan_get_all_descriptors(&c->vc, &head); | |
526 | spin_unlock_irqrestore(&c->vc.lock, flags); | |
527 | vchan_dma_desc_free_list(&c->vc, &head); | |
528 | ||
529 | return 0; | |
530 | } | |
531 | ||
96286b57 FM |
532 | static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id, int irq) |
533 | { | |
534 | struct bcm2835_chan *c; | |
535 | ||
536 | c = devm_kzalloc(d->ddev.dev, sizeof(*c), GFP_KERNEL); | |
537 | if (!c) | |
538 | return -ENOMEM; | |
539 | ||
540 | c->vc.desc_free = bcm2835_dma_desc_free; | |
541 | vchan_init(&c->vc, &d->ddev); | |
542 | INIT_LIST_HEAD(&c->node); | |
543 | ||
96286b57 FM |
544 | c->chan_base = BCM2835_DMA_CHANIO(d->base, chan_id); |
545 | c->ch = chan_id; | |
546 | c->irq_number = irq; | |
547 | ||
548 | return 0; | |
549 | } | |
550 | ||
551 | static void bcm2835_dma_free(struct bcm2835_dmadev *od) | |
552 | { | |
553 | struct bcm2835_chan *c, *next; | |
554 | ||
555 | list_for_each_entry_safe(c, next, &od->ddev.channels, | |
556 | vc.chan.device_node) { | |
557 | list_del(&c->vc.chan.device_node); | |
558 | tasklet_kill(&c->vc.task); | |
559 | } | |
560 | } | |
561 | ||
562 | static const struct of_device_id bcm2835_dma_of_match[] = { | |
563 | { .compatible = "brcm,bcm2835-dma", }, | |
564 | {}, | |
565 | }; | |
566 | MODULE_DEVICE_TABLE(of, bcm2835_dma_of_match); | |
567 | ||
568 | static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec, | |
569 | struct of_dma *ofdma) | |
570 | { | |
571 | struct bcm2835_dmadev *d = ofdma->of_dma_data; | |
572 | struct dma_chan *chan; | |
573 | ||
574 | chan = dma_get_any_slave_channel(&d->ddev); | |
575 | if (!chan) | |
576 | return NULL; | |
577 | ||
578 | /* Set DREQ from param */ | |
579 | to_bcm2835_dma_chan(chan)->dreq = spec->args[0]; | |
580 | ||
581 | return chan; | |
582 | } | |
583 | ||
96286b57 FM |
584 | static int bcm2835_dma_probe(struct platform_device *pdev) |
585 | { | |
586 | struct bcm2835_dmadev *od; | |
587 | struct resource *res; | |
588 | void __iomem *base; | |
589 | int rc; | |
590 | int i; | |
591 | int irq; | |
592 | uint32_t chans_available; | |
593 | ||
594 | if (!pdev->dev.dma_mask) | |
595 | pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; | |
596 | ||
597 | rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); | |
598 | if (rc) | |
599 | return rc; | |
600 | ||
601 | od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL); | |
602 | if (!od) | |
603 | return -ENOMEM; | |
604 | ||
605 | pdev->dev.dma_parms = &od->dma_parms; | |
606 | dma_set_max_seg_size(&pdev->dev, 0x3FFFFFFF); | |
607 | ||
608 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
609 | base = devm_ioremap_resource(&pdev->dev, res); | |
610 | if (IS_ERR(base)) | |
611 | return PTR_ERR(base); | |
612 | ||
613 | od->base = base; | |
614 | ||
615 | dma_cap_set(DMA_SLAVE, od->ddev.cap_mask); | |
7f5ae355 | 616 | dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask); |
96286b57 FM |
617 | dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask); |
618 | od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources; | |
619 | od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources; | |
620 | od->ddev.device_tx_status = bcm2835_dma_tx_status; | |
621 | od->ddev.device_issue_pending = bcm2835_dma_issue_pending; | |
96286b57 | 622 | od->ddev.device_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic; |
39159bea MR |
623 | od->ddev.device_config = bcm2835_dma_slave_config; |
624 | od->ddev.device_terminate_all = bcm2835_dma_terminate_all; | |
b5743680 MR |
625 | od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); |
626 | od->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); | |
627 | od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); | |
96286b57 FM |
628 | od->ddev.dev = &pdev->dev; |
629 | INIT_LIST_HEAD(&od->ddev.channels); | |
630 | spin_lock_init(&od->lock); | |
631 | ||
632 | platform_set_drvdata(pdev, od); | |
633 | ||
634 | /* Request DMA channel mask from device tree */ | |
635 | if (of_property_read_u32(pdev->dev.of_node, | |
636 | "brcm,dma-channel-mask", | |
637 | &chans_available)) { | |
638 | dev_err(&pdev->dev, "Failed to get channel mask\n"); | |
639 | rc = -EINVAL; | |
640 | goto err_no_dma; | |
641 | } | |
642 | ||
643 | /* | |
644 | * Do not use the FIQ and BULK channels, | |
645 | * because they are used by the GPU. | |
646 | */ | |
647 | chans_available &= ~(BCM2835_DMA_FIQ_MASK | BCM2835_DMA_BULK_MASK); | |
648 | ||
649 | for (i = 0; i < pdev->num_resources; i++) { | |
650 | irq = platform_get_irq(pdev, i); | |
651 | if (irq < 0) | |
652 | break; | |
653 | ||
654 | if (chans_available & (1 << i)) { | |
655 | rc = bcm2835_dma_chan_init(od, i, irq); | |
656 | if (rc) | |
657 | goto err_no_dma; | |
658 | } | |
659 | } | |
660 | ||
661 | dev_dbg(&pdev->dev, "Initialized %i DMA channels\n", i); | |
662 | ||
663 | /* Device-tree DMA controller registration */ | |
664 | rc = of_dma_controller_register(pdev->dev.of_node, | |
665 | bcm2835_dma_xlate, od); | |
666 | if (rc) { | |
667 | dev_err(&pdev->dev, "Failed to register DMA controller\n"); | |
668 | goto err_no_dma; | |
669 | } | |
670 | ||
671 | rc = dma_async_device_register(&od->ddev); | |
672 | if (rc) { | |
673 | dev_err(&pdev->dev, | |
674 | "Failed to register slave DMA engine device: %d\n", rc); | |
675 | goto err_no_dma; | |
676 | } | |
677 | ||
678 | dev_dbg(&pdev->dev, "Load BCM2835 DMA engine driver\n"); | |
679 | ||
680 | return 0; | |
681 | ||
682 | err_no_dma: | |
683 | bcm2835_dma_free(od); | |
684 | return rc; | |
685 | } | |
686 | ||
687 | static int bcm2835_dma_remove(struct platform_device *pdev) | |
688 | { | |
689 | struct bcm2835_dmadev *od = platform_get_drvdata(pdev); | |
690 | ||
691 | dma_async_device_unregister(&od->ddev); | |
692 | bcm2835_dma_free(od); | |
693 | ||
694 | return 0; | |
695 | } | |
696 | ||
697 | static struct platform_driver bcm2835_dma_driver = { | |
698 | .probe = bcm2835_dma_probe, | |
699 | .remove = bcm2835_dma_remove, | |
700 | .driver = { | |
701 | .name = "bcm2835-dma", | |
96286b57 FM |
702 | .of_match_table = of_match_ptr(bcm2835_dma_of_match), |
703 | }, | |
704 | }; | |
705 | ||
706 | module_platform_driver(bcm2835_dma_driver); | |
707 | ||
708 | MODULE_ALIAS("platform:bcm2835-dma"); | |
709 | MODULE_DESCRIPTION("BCM2835 DMA engine driver"); | |
710 | MODULE_AUTHOR("Florian Meier <florian.meier@koalo.de>"); | |
711 | MODULE_LICENSE("GPL v2"); |