Commit | Line | Data |
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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 | ||
e2eca638 MS |
49 | #define BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED 14 |
50 | #define BCM2835_DMA_CHAN_NAME_SIZE 8 | |
51 | ||
96286b57 FM |
52 | struct bcm2835_dmadev { |
53 | struct dma_device ddev; | |
54 | spinlock_t lock; | |
55 | void __iomem *base; | |
56 | struct device_dma_parameters dma_parms; | |
57 | }; | |
58 | ||
59 | struct bcm2835_dma_cb { | |
60 | uint32_t info; | |
61 | uint32_t src; | |
62 | uint32_t dst; | |
63 | uint32_t length; | |
64 | uint32_t stride; | |
65 | uint32_t next; | |
66 | uint32_t pad[2]; | |
67 | }; | |
68 | ||
27bc944c PU |
69 | struct bcm2835_cb_entry { |
70 | struct bcm2835_dma_cb *cb; | |
71 | dma_addr_t paddr; | |
72 | }; | |
73 | ||
96286b57 FM |
74 | struct bcm2835_chan { |
75 | struct virt_dma_chan vc; | |
76 | struct list_head node; | |
77 | ||
78 | struct dma_slave_config cfg; | |
96286b57 FM |
79 | unsigned int dreq; |
80 | ||
81 | int ch; | |
82 | struct bcm2835_desc *desc; | |
27bc944c | 83 | struct dma_pool *cb_pool; |
96286b57 FM |
84 | |
85 | void __iomem *chan_base; | |
86 | int irq_number; | |
e2eca638 | 87 | unsigned int irq_flags; |
40874122 MS |
88 | |
89 | bool is_lite_channel; | |
96286b57 FM |
90 | }; |
91 | ||
92 | struct bcm2835_desc { | |
27bc944c | 93 | struct bcm2835_chan *c; |
96286b57 FM |
94 | struct virt_dma_desc vd; |
95 | enum dma_transfer_direction dir; | |
96 | ||
96286b57 FM |
97 | unsigned int frames; |
98 | size_t size; | |
a4dcdd84 MS |
99 | |
100 | bool cyclic; | |
92153bb5 MS |
101 | |
102 | struct bcm2835_cb_entry cb_list[]; | |
96286b57 FM |
103 | }; |
104 | ||
105 | #define BCM2835_DMA_CS 0x00 | |
106 | #define BCM2835_DMA_ADDR 0x04 | |
e42685d7 | 107 | #define BCM2835_DMA_TI 0x08 |
96286b57 FM |
108 | #define BCM2835_DMA_SOURCE_AD 0x0c |
109 | #define BCM2835_DMA_DEST_AD 0x10 | |
e42685d7 MS |
110 | #define BCM2835_DMA_LEN 0x14 |
111 | #define BCM2835_DMA_STRIDE 0x18 | |
112 | #define BCM2835_DMA_NEXTCB 0x1c | |
113 | #define BCM2835_DMA_DEBUG 0x20 | |
96286b57 FM |
114 | |
115 | /* DMA CS Control and Status bits */ | |
e42685d7 MS |
116 | #define BCM2835_DMA_ACTIVE BIT(0) /* activate the DMA */ |
117 | #define BCM2835_DMA_END BIT(1) /* current CB has ended */ | |
118 | #define BCM2835_DMA_INT BIT(2) /* interrupt status */ | |
119 | #define BCM2835_DMA_DREQ BIT(3) /* DREQ state */ | |
96286b57 FM |
120 | #define BCM2835_DMA_ISPAUSED BIT(4) /* Pause requested or not active */ |
121 | #define BCM2835_DMA_ISHELD BIT(5) /* Is held by DREQ flow control */ | |
e42685d7 MS |
122 | #define BCM2835_DMA_WAITING_FOR_WRITES BIT(6) /* waiting for last |
123 | * AXI-write to ack | |
124 | */ | |
125 | #define BCM2835_DMA_ERR BIT(8) | |
126 | #define BCM2835_DMA_PRIORITY(x) ((x & 15) << 16) /* AXI priority */ | |
127 | #define BCM2835_DMA_PANIC_PRIORITY(x) ((x & 15) << 20) /* panic priority */ | |
128 | /* current value of TI.BCM2835_DMA_WAIT_RESP */ | |
129 | #define BCM2835_DMA_WAIT_FOR_WRITES BIT(28) | |
130 | #define BCM2835_DMA_DIS_DEBUG BIT(29) /* disable debug pause signal */ | |
96286b57 FM |
131 | #define BCM2835_DMA_ABORT BIT(30) /* Stop current CB, go to next, WO */ |
132 | #define BCM2835_DMA_RESET BIT(31) /* WO, self clearing */ | |
133 | ||
e42685d7 | 134 | /* Transfer information bits - also bcm2835_cb.info field */ |
96286b57 | 135 | #define BCM2835_DMA_INT_EN BIT(0) |
e42685d7 MS |
136 | #define BCM2835_DMA_TDMODE BIT(1) /* 2D-Mode */ |
137 | #define BCM2835_DMA_WAIT_RESP BIT(3) /* wait for AXI-write to be acked */ | |
96286b57 | 138 | #define BCM2835_DMA_D_INC BIT(4) |
e42685d7 MS |
139 | #define BCM2835_DMA_D_WIDTH BIT(5) /* 128bit writes if set */ |
140 | #define BCM2835_DMA_D_DREQ BIT(6) /* enable DREQ for destination */ | |
141 | #define BCM2835_DMA_D_IGNORE BIT(7) /* ignore destination writes */ | |
96286b57 | 142 | #define BCM2835_DMA_S_INC BIT(8) |
e42685d7 MS |
143 | #define BCM2835_DMA_S_WIDTH BIT(9) /* 128bit writes if set */ |
144 | #define BCM2835_DMA_S_DREQ BIT(10) /* enable SREQ for source */ | |
145 | #define BCM2835_DMA_S_IGNORE BIT(11) /* ignore source reads - read 0 */ | |
146 | #define BCM2835_DMA_BURST_LENGTH(x) ((x & 15) << 12) | |
147 | #define BCM2835_DMA_PER_MAP(x) ((x & 31) << 16) /* REQ source */ | |
148 | #define BCM2835_DMA_WAIT(x) ((x & 31) << 21) /* add DMA-wait cycles */ | |
149 | #define BCM2835_DMA_NO_WIDE_BURSTS BIT(26) /* no 2 beat write bursts */ | |
150 | ||
151 | /* debug register bits */ | |
152 | #define BCM2835_DMA_DEBUG_LAST_NOT_SET_ERR BIT(0) | |
153 | #define BCM2835_DMA_DEBUG_FIFO_ERR BIT(1) | |
154 | #define BCM2835_DMA_DEBUG_READ_ERR BIT(2) | |
155 | #define BCM2835_DMA_DEBUG_OUTSTANDING_WRITES_SHIFT 4 | |
156 | #define BCM2835_DMA_DEBUG_OUTSTANDING_WRITES_BITS 4 | |
157 | #define BCM2835_DMA_DEBUG_ID_SHIFT 16 | |
158 | #define BCM2835_DMA_DEBUG_ID_BITS 9 | |
159 | #define BCM2835_DMA_DEBUG_STATE_SHIFT 16 | |
160 | #define BCM2835_DMA_DEBUG_STATE_BITS 9 | |
161 | #define BCM2835_DMA_DEBUG_VERSION_SHIFT 25 | |
162 | #define BCM2835_DMA_DEBUG_VERSION_BITS 3 | |
163 | #define BCM2835_DMA_DEBUG_LITE BIT(28) | |
164 | ||
165 | /* shared registers for all dma channels */ | |
166 | #define BCM2835_DMA_INT_STATUS 0xfe0 | |
167 | #define BCM2835_DMA_ENABLE 0xff0 | |
96286b57 FM |
168 | |
169 | #define BCM2835_DMA_DATA_TYPE_S8 1 | |
170 | #define BCM2835_DMA_DATA_TYPE_S16 2 | |
171 | #define BCM2835_DMA_DATA_TYPE_S32 4 | |
172 | #define BCM2835_DMA_DATA_TYPE_S128 16 | |
173 | ||
96286b57 FM |
174 | /* Valid only for channels 0 - 14, 15 has its own base address */ |
175 | #define BCM2835_DMA_CHAN(n) ((n) << 8) /* Base address */ | |
176 | #define BCM2835_DMA_CHANIO(base, n) ((base) + BCM2835_DMA_CHAN(n)) | |
177 | ||
40874122 MS |
178 | /* the max dma length for different channels */ |
179 | #define MAX_DMA_LEN SZ_1G | |
180 | #define MAX_LITE_DMA_LEN (SZ_64K - 4) | |
181 | ||
182 | static inline size_t bcm2835_dma_max_frame_length(struct bcm2835_chan *c) | |
183 | { | |
184 | /* lite and normal channels have different max frame length */ | |
185 | return c->is_lite_channel ? MAX_LITE_DMA_LEN : MAX_DMA_LEN; | |
186 | } | |
187 | ||
92153bb5 MS |
188 | /* how many frames of max_len size do we need to transfer len bytes */ |
189 | static inline size_t bcm2835_dma_frames_for_length(size_t len, | |
190 | size_t max_len) | |
191 | { | |
192 | return DIV_ROUND_UP(len, max_len); | |
193 | } | |
194 | ||
96286b57 FM |
195 | static inline struct bcm2835_dmadev *to_bcm2835_dma_dev(struct dma_device *d) |
196 | { | |
197 | return container_of(d, struct bcm2835_dmadev, ddev); | |
198 | } | |
199 | ||
200 | static inline struct bcm2835_chan *to_bcm2835_dma_chan(struct dma_chan *c) | |
201 | { | |
202 | return container_of(c, struct bcm2835_chan, vc.chan); | |
203 | } | |
204 | ||
205 | static inline struct bcm2835_desc *to_bcm2835_dma_desc( | |
206 | struct dma_async_tx_descriptor *t) | |
207 | { | |
208 | return container_of(t, struct bcm2835_desc, vd.tx); | |
209 | } | |
210 | ||
92153bb5 | 211 | static void bcm2835_dma_free_cb_chain(struct bcm2835_desc *desc) |
96286b57 | 212 | { |
92153bb5 | 213 | size_t i; |
27bc944c PU |
214 | |
215 | for (i = 0; i < desc->frames; i++) | |
216 | dma_pool_free(desc->c->cb_pool, desc->cb_list[i].cb, | |
217 | desc->cb_list[i].paddr); | |
218 | ||
96286b57 FM |
219 | kfree(desc); |
220 | } | |
221 | ||
92153bb5 MS |
222 | static void bcm2835_dma_desc_free(struct virt_dma_desc *vd) |
223 | { | |
224 | bcm2835_dma_free_cb_chain( | |
225 | container_of(vd, struct bcm2835_desc, vd)); | |
226 | } | |
227 | ||
228 | static void bcm2835_dma_create_cb_set_length( | |
229 | struct bcm2835_chan *chan, | |
230 | struct bcm2835_dma_cb *control_block, | |
231 | size_t len, | |
232 | size_t period_len, | |
233 | size_t *total_len, | |
234 | u32 finalextrainfo) | |
235 | { | |
40874122 MS |
236 | size_t max_len = bcm2835_dma_max_frame_length(chan); |
237 | ||
238 | /* set the length taking lite-channel limitations into account */ | |
239 | control_block->length = min_t(u32, len, max_len); | |
92153bb5 MS |
240 | |
241 | /* finished if we have no period_length */ | |
242 | if (!period_len) | |
243 | return; | |
244 | ||
245 | /* | |
246 | * period_len means: that we need to generate | |
247 | * transfers that are terminating at every | |
248 | * multiple of period_len - this is typically | |
249 | * used to set the interrupt flag in info | |
250 | * which is required during cyclic transfers | |
251 | */ | |
252 | ||
253 | /* have we filled in period_length yet? */ | |
2201ac61 MR |
254 | if (*total_len + control_block->length < period_len) { |
255 | /* update number of bytes in this period so far */ | |
256 | *total_len += control_block->length; | |
92153bb5 | 257 | return; |
2201ac61 | 258 | } |
92153bb5 MS |
259 | |
260 | /* calculate the length that remains to reach period_length */ | |
261 | control_block->length = period_len - *total_len; | |
262 | ||
263 | /* reset total_length for next period */ | |
264 | *total_len = 0; | |
265 | ||
266 | /* add extrainfo bits in info */ | |
267 | control_block->info |= finalextrainfo; | |
268 | } | |
269 | ||
388cc7a2 MS |
270 | static inline size_t bcm2835_dma_count_frames_for_sg( |
271 | struct bcm2835_chan *c, | |
272 | struct scatterlist *sgl, | |
273 | unsigned int sg_len) | |
274 | { | |
275 | size_t frames = 0; | |
276 | struct scatterlist *sgent; | |
277 | unsigned int i; | |
278 | size_t plength = bcm2835_dma_max_frame_length(c); | |
279 | ||
280 | for_each_sg(sgl, sgent, sg_len, i) | |
281 | frames += bcm2835_dma_frames_for_length( | |
282 | sg_dma_len(sgent), plength); | |
283 | ||
284 | return frames; | |
285 | } | |
286 | ||
92153bb5 MS |
287 | /** |
288 | * bcm2835_dma_create_cb_chain - create a control block and fills data in | |
289 | * | |
290 | * @chan: the @dma_chan for which we run this | |
291 | * @direction: the direction in which we transfer | |
292 | * @cyclic: it is a cyclic transfer | |
293 | * @info: the default info bits to apply per controlblock | |
294 | * @frames: number of controlblocks to allocate | |
295 | * @src: the src address to assign (if the S_INC bit is set | |
296 | * in @info, then it gets incremented) | |
297 | * @dst: the dst address to assign (if the D_INC bit is set | |
298 | * in @info, then it gets incremented) | |
299 | * @buf_len: the full buffer length (may also be 0) | |
300 | * @period_len: the period length when to apply @finalextrainfo | |
301 | * in addition to the last transfer | |
302 | * this will also break some control-blocks early | |
303 | * @finalextrainfo: additional bits in last controlblock | |
304 | * (or when period_len is reached in case of cyclic) | |
305 | * @gfp: the GFP flag to use for allocation | |
306 | */ | |
307 | static struct bcm2835_desc *bcm2835_dma_create_cb_chain( | |
308 | struct dma_chan *chan, enum dma_transfer_direction direction, | |
309 | bool cyclic, u32 info, u32 finalextrainfo, size_t frames, | |
310 | dma_addr_t src, dma_addr_t dst, size_t buf_len, | |
311 | size_t period_len, gfp_t gfp) | |
312 | { | |
313 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
314 | size_t len = buf_len, total_len; | |
315 | size_t frame; | |
316 | struct bcm2835_desc *d; | |
317 | struct bcm2835_cb_entry *cb_entry; | |
318 | struct bcm2835_dma_cb *control_block; | |
319 | ||
d9f094a0 MS |
320 | if (!frames) |
321 | return NULL; | |
322 | ||
92153bb5 MS |
323 | /* allocate and setup the descriptor. */ |
324 | d = kzalloc(sizeof(*d) + frames * sizeof(struct bcm2835_cb_entry), | |
325 | gfp); | |
326 | if (!d) | |
327 | return NULL; | |
328 | ||
329 | d->c = c; | |
330 | d->dir = direction; | |
331 | d->cyclic = cyclic; | |
332 | ||
333 | /* | |
334 | * Iterate over all frames, create a control block | |
335 | * for each frame and link them together. | |
336 | */ | |
337 | for (frame = 0, total_len = 0; frame < frames; d->frames++, frame++) { | |
338 | cb_entry = &d->cb_list[frame]; | |
339 | cb_entry->cb = dma_pool_alloc(c->cb_pool, gfp, | |
340 | &cb_entry->paddr); | |
341 | if (!cb_entry->cb) | |
342 | goto error_cb; | |
343 | ||
344 | /* fill in the control block */ | |
345 | control_block = cb_entry->cb; | |
346 | control_block->info = info; | |
347 | control_block->src = src; | |
348 | control_block->dst = dst; | |
349 | control_block->stride = 0; | |
350 | control_block->next = 0; | |
351 | /* set up length in control_block if requested */ | |
352 | if (buf_len) { | |
353 | /* calculate length honoring period_length */ | |
354 | bcm2835_dma_create_cb_set_length( | |
355 | c, control_block, | |
356 | len, period_len, &total_len, | |
357 | cyclic ? finalextrainfo : 0); | |
358 | ||
359 | /* calculate new remaining length */ | |
360 | len -= control_block->length; | |
361 | } | |
362 | ||
363 | /* link this the last controlblock */ | |
364 | if (frame) | |
365 | d->cb_list[frame - 1].cb->next = cb_entry->paddr; | |
366 | ||
367 | /* update src and dst and length */ | |
368 | if (src && (info & BCM2835_DMA_S_INC)) | |
369 | src += control_block->length; | |
370 | if (dst && (info & BCM2835_DMA_D_INC)) | |
371 | dst += control_block->length; | |
372 | ||
373 | /* Length of total transfer */ | |
374 | d->size += control_block->length; | |
375 | } | |
376 | ||
377 | /* the last frame requires extra flags */ | |
378 | d->cb_list[d->frames - 1].cb->info |= finalextrainfo; | |
379 | ||
380 | /* detect a size missmatch */ | |
381 | if (buf_len && (d->size != buf_len)) | |
382 | goto error_cb; | |
383 | ||
384 | return d; | |
385 | error_cb: | |
386 | bcm2835_dma_free_cb_chain(d); | |
387 | ||
388 | return NULL; | |
389 | } | |
390 | ||
388cc7a2 MS |
391 | static void bcm2835_dma_fill_cb_chain_with_sg( |
392 | struct dma_chan *chan, | |
393 | enum dma_transfer_direction direction, | |
394 | struct bcm2835_cb_entry *cb, | |
395 | struct scatterlist *sgl, | |
396 | unsigned int sg_len) | |
397 | { | |
398 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
4aa819c7 AB |
399 | size_t len, max_len; |
400 | unsigned int i; | |
388cc7a2 MS |
401 | dma_addr_t addr; |
402 | struct scatterlist *sgent; | |
403 | ||
4aa819c7 | 404 | max_len = bcm2835_dma_max_frame_length(c); |
388cc7a2 MS |
405 | for_each_sg(sgl, sgent, sg_len, i) { |
406 | for (addr = sg_dma_address(sgent), len = sg_dma_len(sgent); | |
407 | len > 0; | |
408 | addr += cb->cb->length, len -= cb->cb->length, cb++) { | |
409 | if (direction == DMA_DEV_TO_MEM) | |
410 | cb->cb->dst = addr; | |
411 | else | |
412 | cb->cb->src = addr; | |
413 | cb->cb->length = min(len, max_len); | |
414 | } | |
415 | } | |
416 | } | |
417 | ||
96286b57 FM |
418 | static int bcm2835_dma_abort(void __iomem *chan_base) |
419 | { | |
420 | unsigned long cs; | |
421 | long int timeout = 10000; | |
422 | ||
423 | cs = readl(chan_base + BCM2835_DMA_CS); | |
424 | if (!(cs & BCM2835_DMA_ACTIVE)) | |
425 | return 0; | |
426 | ||
427 | /* Write 0 to the active bit - Pause the DMA */ | |
428 | writel(0, chan_base + BCM2835_DMA_CS); | |
429 | ||
430 | /* Wait for any current AXI transfer to complete */ | |
431 | while ((cs & BCM2835_DMA_ISPAUSED) && --timeout) { | |
432 | cpu_relax(); | |
433 | cs = readl(chan_base + BCM2835_DMA_CS); | |
434 | } | |
435 | ||
436 | /* We'll un-pause when we set of our next DMA */ | |
437 | if (!timeout) | |
438 | return -ETIMEDOUT; | |
439 | ||
440 | if (!(cs & BCM2835_DMA_ACTIVE)) | |
441 | return 0; | |
442 | ||
443 | /* Terminate the control block chain */ | |
444 | writel(0, chan_base + BCM2835_DMA_NEXTCB); | |
445 | ||
446 | /* Abort the whole DMA */ | |
447 | writel(BCM2835_DMA_ABORT | BCM2835_DMA_ACTIVE, | |
448 | chan_base + BCM2835_DMA_CS); | |
449 | ||
450 | return 0; | |
451 | } | |
452 | ||
453 | static void bcm2835_dma_start_desc(struct bcm2835_chan *c) | |
454 | { | |
455 | struct virt_dma_desc *vd = vchan_next_desc(&c->vc); | |
456 | struct bcm2835_desc *d; | |
457 | ||
458 | if (!vd) { | |
459 | c->desc = NULL; | |
460 | return; | |
461 | } | |
462 | ||
463 | list_del(&vd->node); | |
464 | ||
465 | c->desc = d = to_bcm2835_dma_desc(&vd->tx); | |
466 | ||
27bc944c | 467 | writel(d->cb_list[0].paddr, c->chan_base + BCM2835_DMA_ADDR); |
96286b57 FM |
468 | writel(BCM2835_DMA_ACTIVE, c->chan_base + BCM2835_DMA_CS); |
469 | } | |
470 | ||
471 | static irqreturn_t bcm2835_dma_callback(int irq, void *data) | |
472 | { | |
473 | struct bcm2835_chan *c = data; | |
474 | struct bcm2835_desc *d; | |
475 | unsigned long flags; | |
476 | ||
e2eca638 MS |
477 | /* check the shared interrupt */ |
478 | if (c->irq_flags & IRQF_SHARED) { | |
479 | /* check if the interrupt is enabled */ | |
480 | flags = readl(c->chan_base + BCM2835_DMA_CS); | |
481 | /* if not set then we are not the reason for the irq */ | |
482 | if (!(flags & BCM2835_DMA_INT)) | |
483 | return IRQ_NONE; | |
484 | } | |
485 | ||
96286b57 FM |
486 | spin_lock_irqsave(&c->vc.lock, flags); |
487 | ||
488 | /* Acknowledge interrupt */ | |
489 | writel(BCM2835_DMA_INT, c->chan_base + BCM2835_DMA_CS); | |
490 | ||
491 | d = c->desc; | |
492 | ||
493 | if (d) { | |
388cc7a2 MS |
494 | if (d->cyclic) { |
495 | /* call the cyclic callback */ | |
496 | vchan_cyclic_callback(&d->vd); | |
497 | ||
498 | /* Keep the DMA engine running */ | |
499 | writel(BCM2835_DMA_ACTIVE, | |
500 | c->chan_base + BCM2835_DMA_CS); | |
501 | } else { | |
502 | vchan_cookie_complete(&c->desc->vd); | |
503 | bcm2835_dma_start_desc(c); | |
504 | } | |
96286b57 FM |
505 | } |
506 | ||
96286b57 FM |
507 | spin_unlock_irqrestore(&c->vc.lock, flags); |
508 | ||
509 | return IRQ_HANDLED; | |
510 | } | |
511 | ||
512 | static int bcm2835_dma_alloc_chan_resources(struct dma_chan *chan) | |
513 | { | |
514 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
27bc944c | 515 | struct device *dev = c->vc.chan.device->dev; |
96286b57 | 516 | |
27bc944c PU |
517 | dev_dbg(dev, "Allocating DMA channel %d\n", c->ch); |
518 | ||
519 | c->cb_pool = dma_pool_create(dev_name(dev), dev, | |
520 | sizeof(struct bcm2835_dma_cb), 0, 0); | |
521 | if (!c->cb_pool) { | |
522 | dev_err(dev, "unable to allocate descriptor pool\n"); | |
523 | return -ENOMEM; | |
524 | } | |
96286b57 | 525 | |
e2eca638 MS |
526 | return request_irq(c->irq_number, bcm2835_dma_callback, |
527 | c->irq_flags, "DMA IRQ", c); | |
96286b57 FM |
528 | } |
529 | ||
530 | static void bcm2835_dma_free_chan_resources(struct dma_chan *chan) | |
531 | { | |
532 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
533 | ||
534 | vchan_free_chan_resources(&c->vc); | |
535 | free_irq(c->irq_number, c); | |
27bc944c | 536 | dma_pool_destroy(c->cb_pool); |
96286b57 FM |
537 | |
538 | dev_dbg(c->vc.chan.device->dev, "Freeing DMA channel %u\n", c->ch); | |
539 | } | |
540 | ||
541 | static size_t bcm2835_dma_desc_size(struct bcm2835_desc *d) | |
542 | { | |
543 | return d->size; | |
544 | } | |
545 | ||
546 | static size_t bcm2835_dma_desc_size_pos(struct bcm2835_desc *d, dma_addr_t addr) | |
547 | { | |
548 | unsigned int i; | |
549 | size_t size; | |
550 | ||
551 | for (size = i = 0; i < d->frames; i++) { | |
27bc944c | 552 | struct bcm2835_dma_cb *control_block = d->cb_list[i].cb; |
96286b57 FM |
553 | size_t this_size = control_block->length; |
554 | dma_addr_t dma; | |
555 | ||
556 | if (d->dir == DMA_DEV_TO_MEM) | |
557 | dma = control_block->dst; | |
558 | else | |
559 | dma = control_block->src; | |
560 | ||
561 | if (size) | |
562 | size += this_size; | |
563 | else if (addr >= dma && addr < dma + this_size) | |
564 | size += dma + this_size - addr; | |
565 | } | |
566 | ||
567 | return size; | |
568 | } | |
569 | ||
570 | static enum dma_status bcm2835_dma_tx_status(struct dma_chan *chan, | |
571 | dma_cookie_t cookie, struct dma_tx_state *txstate) | |
572 | { | |
573 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
574 | struct virt_dma_desc *vd; | |
575 | enum dma_status ret; | |
576 | unsigned long flags; | |
577 | ||
578 | ret = dma_cookie_status(chan, cookie, txstate); | |
579 | if (ret == DMA_COMPLETE || !txstate) | |
580 | return ret; | |
581 | ||
582 | spin_lock_irqsave(&c->vc.lock, flags); | |
583 | vd = vchan_find_desc(&c->vc, cookie); | |
584 | if (vd) { | |
585 | txstate->residue = | |
586 | bcm2835_dma_desc_size(to_bcm2835_dma_desc(&vd->tx)); | |
587 | } else if (c->desc && c->desc->vd.tx.cookie == cookie) { | |
588 | struct bcm2835_desc *d = c->desc; | |
589 | dma_addr_t pos; | |
590 | ||
591 | if (d->dir == DMA_MEM_TO_DEV) | |
592 | pos = readl(c->chan_base + BCM2835_DMA_SOURCE_AD); | |
593 | else if (d->dir == DMA_DEV_TO_MEM) | |
594 | pos = readl(c->chan_base + BCM2835_DMA_DEST_AD); | |
595 | else | |
596 | pos = 0; | |
597 | ||
598 | txstate->residue = bcm2835_dma_desc_size_pos(d, pos); | |
599 | } else { | |
600 | txstate->residue = 0; | |
601 | } | |
602 | ||
603 | spin_unlock_irqrestore(&c->vc.lock, flags); | |
604 | ||
605 | return ret; | |
606 | } | |
607 | ||
608 | static void bcm2835_dma_issue_pending(struct dma_chan *chan) | |
609 | { | |
610 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
611 | unsigned long flags; | |
612 | ||
96286b57 FM |
613 | spin_lock_irqsave(&c->vc.lock, flags); |
614 | if (vchan_issue_pending(&c->vc) && !c->desc) | |
615 | bcm2835_dma_start_desc(c); | |
616 | ||
617 | spin_unlock_irqrestore(&c->vc.lock, flags); | |
618 | } | |
619 | ||
63637228 | 620 | static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_memcpy( |
d9f094a0 MS |
621 | struct dma_chan *chan, dma_addr_t dst, dma_addr_t src, |
622 | size_t len, unsigned long flags) | |
623 | { | |
624 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
625 | struct bcm2835_desc *d; | |
626 | u32 info = BCM2835_DMA_D_INC | BCM2835_DMA_S_INC; | |
627 | u32 extra = BCM2835_DMA_INT_EN | BCM2835_DMA_WAIT_RESP; | |
628 | size_t max_len = bcm2835_dma_max_frame_length(c); | |
629 | size_t frames; | |
630 | ||
631 | /* if src, dst or len is not given return with an error */ | |
632 | if (!src || !dst || !len) | |
633 | return NULL; | |
634 | ||
635 | /* calculate number of frames */ | |
636 | frames = bcm2835_dma_frames_for_length(len, max_len); | |
637 | ||
638 | /* allocate the CB chain - this also fills in the pointers */ | |
639 | d = bcm2835_dma_create_cb_chain(chan, DMA_MEM_TO_MEM, false, | |
640 | info, extra, frames, | |
641 | src, dst, len, 0, GFP_KERNEL); | |
642 | if (!d) | |
643 | return NULL; | |
644 | ||
645 | return vchan_tx_prep(&c->vc, &d->vd, flags); | |
646 | } | |
647 | ||
388cc7a2 MS |
648 | static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg( |
649 | struct dma_chan *chan, | |
650 | struct scatterlist *sgl, unsigned int sg_len, | |
651 | enum dma_transfer_direction direction, | |
652 | unsigned long flags, void *context) | |
653 | { | |
654 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
655 | struct bcm2835_desc *d; | |
656 | dma_addr_t src = 0, dst = 0; | |
657 | u32 info = BCM2835_DMA_WAIT_RESP; | |
658 | u32 extra = BCM2835_DMA_INT_EN; | |
659 | size_t frames; | |
660 | ||
661 | if (!is_slave_direction(direction)) { | |
662 | dev_err(chan->device->dev, | |
663 | "%s: bad direction?\n", __func__); | |
664 | return NULL; | |
665 | } | |
666 | ||
667 | if (c->dreq != 0) | |
668 | info |= BCM2835_DMA_PER_MAP(c->dreq); | |
669 | ||
670 | if (direction == DMA_DEV_TO_MEM) { | |
671 | if (c->cfg.src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) | |
672 | return NULL; | |
673 | src = c->cfg.src_addr; | |
674 | info |= BCM2835_DMA_S_DREQ | BCM2835_DMA_D_INC; | |
675 | } else { | |
676 | if (c->cfg.dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) | |
677 | return NULL; | |
678 | dst = c->cfg.dst_addr; | |
679 | info |= BCM2835_DMA_D_DREQ | BCM2835_DMA_S_INC; | |
680 | } | |
681 | ||
682 | /* count frames in sg list */ | |
683 | frames = bcm2835_dma_count_frames_for_sg(c, sgl, sg_len); | |
684 | ||
685 | /* allocate the CB chain */ | |
686 | d = bcm2835_dma_create_cb_chain(chan, direction, false, | |
687 | info, extra, | |
688 | frames, src, dst, 0, 0, | |
689 | GFP_KERNEL); | |
690 | if (!d) | |
691 | return NULL; | |
692 | ||
693 | /* fill in frames with scatterlist pointers */ | |
694 | bcm2835_dma_fill_cb_chain_with_sg(chan, direction, d->cb_list, | |
695 | sgl, sg_len); | |
696 | ||
697 | return vchan_tx_prep(&c->vc, &d->vd, flags); | |
698 | } | |
699 | ||
96286b57 FM |
700 | static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic( |
701 | struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, | |
702 | size_t period_len, enum dma_transfer_direction direction, | |
31c1e5a1 | 703 | unsigned long flags) |
96286b57 FM |
704 | { |
705 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
96286b57 | 706 | struct bcm2835_desc *d; |
92153bb5 MS |
707 | dma_addr_t src, dst; |
708 | u32 info = BCM2835_DMA_WAIT_RESP; | |
709 | u32 extra = BCM2835_DMA_INT_EN; | |
40874122 | 710 | size_t max_len = bcm2835_dma_max_frame_length(c); |
92153bb5 | 711 | size_t frames; |
96286b57 FM |
712 | |
713 | /* Grab configuration */ | |
714 | if (!is_slave_direction(direction)) { | |
715 | dev_err(chan->device->dev, "%s: bad direction?\n", __func__); | |
716 | return NULL; | |
717 | } | |
718 | ||
92153bb5 MS |
719 | if (!buf_len) { |
720 | dev_err(chan->device->dev, | |
721 | "%s: bad buffer length (= 0)\n", __func__); | |
96286b57 FM |
722 | return NULL; |
723 | } | |
724 | ||
92153bb5 MS |
725 | /* |
726 | * warn if buf_len is not a multiple of period_len - this may leed | |
727 | * to unexpected latencies for interrupts and thus audiable clicks | |
728 | */ | |
729 | if (buf_len % period_len) | |
730 | dev_warn_once(chan->device->dev, | |
731 | "%s: buffer_length (%zd) is not a multiple of period_len (%zd)\n", | |
732 | __func__, buf_len, period_len); | |
96286b57 | 733 | |
92153bb5 MS |
734 | /* Setup DREQ channel */ |
735 | if (c->dreq != 0) | |
736 | info |= BCM2835_DMA_PER_MAP(c->dreq); | |
96286b57 | 737 | |
92153bb5 MS |
738 | if (direction == DMA_DEV_TO_MEM) { |
739 | if (c->cfg.src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) | |
740 | return NULL; | |
741 | src = c->cfg.src_addr; | |
742 | dst = buf_addr; | |
743 | info |= BCM2835_DMA_S_DREQ | BCM2835_DMA_D_INC; | |
744 | } else { | |
745 | if (c->cfg.dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) | |
746 | return NULL; | |
747 | dst = c->cfg.dst_addr; | |
748 | src = buf_addr; | |
749 | info |= BCM2835_DMA_D_DREQ | BCM2835_DMA_S_INC; | |
96286b57 | 750 | } |
27bc944c | 751 | |
92153bb5 | 752 | /* calculate number of frames */ |
40874122 MS |
753 | frames = /* number of periods */ |
754 | DIV_ROUND_UP(buf_len, period_len) * | |
755 | /* number of frames per period */ | |
756 | bcm2835_dma_frames_for_length(period_len, max_len); | |
96286b57 FM |
757 | |
758 | /* | |
92153bb5 MS |
759 | * allocate the CB chain |
760 | * note that we need to use GFP_NOWAIT, as the ALSA i2s dmaengine | |
761 | * implementation calls prep_dma_cyclic with interrupts disabled. | |
96286b57 | 762 | */ |
92153bb5 MS |
763 | d = bcm2835_dma_create_cb_chain(chan, direction, true, |
764 | info, extra, | |
765 | frames, src, dst, buf_len, | |
766 | period_len, GFP_NOWAIT); | |
767 | if (!d) | |
768 | return NULL; | |
96286b57 | 769 | |
92153bb5 MS |
770 | /* wrap around into a loop */ |
771 | d->cb_list[d->frames - 1].cb->next = d->cb_list[0].paddr; | |
96286b57 FM |
772 | |
773 | return vchan_tx_prep(&c->vc, &d->vd, flags); | |
774 | } | |
775 | ||
39159bea MR |
776 | static int bcm2835_dma_slave_config(struct dma_chan *chan, |
777 | struct dma_slave_config *cfg) | |
96286b57 | 778 | { |
39159bea MR |
779 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); |
780 | ||
96286b57 FM |
781 | if ((cfg->direction == DMA_DEV_TO_MEM && |
782 | cfg->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) || | |
783 | (cfg->direction == DMA_MEM_TO_DEV && | |
784 | cfg->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) || | |
785 | !is_slave_direction(cfg->direction)) { | |
786 | return -EINVAL; | |
787 | } | |
788 | ||
789 | c->cfg = *cfg; | |
790 | ||
791 | return 0; | |
792 | } | |
793 | ||
39159bea | 794 | static int bcm2835_dma_terminate_all(struct dma_chan *chan) |
96286b57 | 795 | { |
39159bea | 796 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); |
96286b57 FM |
797 | struct bcm2835_dmadev *d = to_bcm2835_dma_dev(c->vc.chan.device); |
798 | unsigned long flags; | |
799 | int timeout = 10000; | |
800 | LIST_HEAD(head); | |
801 | ||
802 | spin_lock_irqsave(&c->vc.lock, flags); | |
803 | ||
804 | /* Prevent this channel being scheduled */ | |
805 | spin_lock(&d->lock); | |
806 | list_del_init(&c->node); | |
807 | spin_unlock(&d->lock); | |
808 | ||
809 | /* | |
810 | * Stop DMA activity: we assume the callback will not be called | |
811 | * after bcm_dma_abort() returns (even if it does, it will see | |
812 | * c->desc is NULL and exit.) | |
813 | */ | |
814 | if (c->desc) { | |
de92436a | 815 | vchan_terminate_vdesc(&c->desc->vd); |
96286b57 FM |
816 | c->desc = NULL; |
817 | bcm2835_dma_abort(c->chan_base); | |
818 | ||
819 | /* Wait for stopping */ | |
820 | while (--timeout) { | |
821 | if (!(readl(c->chan_base + BCM2835_DMA_CS) & | |
822 | BCM2835_DMA_ACTIVE)) | |
823 | break; | |
824 | ||
825 | cpu_relax(); | |
826 | } | |
827 | ||
828 | if (!timeout) | |
829 | dev_err(d->ddev.dev, "DMA transfer could not be terminated\n"); | |
830 | } | |
831 | ||
832 | vchan_get_all_descriptors(&c->vc, &head); | |
833 | spin_unlock_irqrestore(&c->vc.lock, flags); | |
834 | vchan_dma_desc_free_list(&c->vc, &head); | |
835 | ||
836 | return 0; | |
837 | } | |
838 | ||
de92436a PU |
839 | static void bcm2835_dma_synchronize(struct dma_chan *chan) |
840 | { | |
841 | struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); | |
842 | ||
843 | vchan_synchronize(&c->vc); | |
844 | } | |
845 | ||
e2eca638 MS |
846 | static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id, |
847 | int irq, unsigned int irq_flags) | |
96286b57 FM |
848 | { |
849 | struct bcm2835_chan *c; | |
850 | ||
851 | c = devm_kzalloc(d->ddev.dev, sizeof(*c), GFP_KERNEL); | |
852 | if (!c) | |
853 | return -ENOMEM; | |
854 | ||
855 | c->vc.desc_free = bcm2835_dma_desc_free; | |
856 | vchan_init(&c->vc, &d->ddev); | |
857 | INIT_LIST_HEAD(&c->node); | |
858 | ||
96286b57 FM |
859 | c->chan_base = BCM2835_DMA_CHANIO(d->base, chan_id); |
860 | c->ch = chan_id; | |
861 | c->irq_number = irq; | |
e2eca638 | 862 | c->irq_flags = irq_flags; |
96286b57 | 863 | |
40874122 MS |
864 | /* check in DEBUG register if this is a LITE channel */ |
865 | if (readl(c->chan_base + BCM2835_DMA_DEBUG) & | |
866 | BCM2835_DMA_DEBUG_LITE) | |
867 | c->is_lite_channel = true; | |
868 | ||
96286b57 FM |
869 | return 0; |
870 | } | |
871 | ||
872 | static void bcm2835_dma_free(struct bcm2835_dmadev *od) | |
873 | { | |
874 | struct bcm2835_chan *c, *next; | |
875 | ||
876 | list_for_each_entry_safe(c, next, &od->ddev.channels, | |
877 | vc.chan.device_node) { | |
878 | list_del(&c->vc.chan.device_node); | |
879 | tasklet_kill(&c->vc.task); | |
880 | } | |
881 | } | |
882 | ||
883 | static const struct of_device_id bcm2835_dma_of_match[] = { | |
884 | { .compatible = "brcm,bcm2835-dma", }, | |
885 | {}, | |
886 | }; | |
887 | MODULE_DEVICE_TABLE(of, bcm2835_dma_of_match); | |
888 | ||
889 | static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec, | |
890 | struct of_dma *ofdma) | |
891 | { | |
892 | struct bcm2835_dmadev *d = ofdma->of_dma_data; | |
893 | struct dma_chan *chan; | |
894 | ||
895 | chan = dma_get_any_slave_channel(&d->ddev); | |
896 | if (!chan) | |
897 | return NULL; | |
898 | ||
899 | /* Set DREQ from param */ | |
900 | to_bcm2835_dma_chan(chan)->dreq = spec->args[0]; | |
901 | ||
902 | return chan; | |
903 | } | |
904 | ||
96286b57 FM |
905 | static int bcm2835_dma_probe(struct platform_device *pdev) |
906 | { | |
907 | struct bcm2835_dmadev *od; | |
908 | struct resource *res; | |
909 | void __iomem *base; | |
910 | int rc; | |
e2eca638 MS |
911 | int i, j; |
912 | int irq[BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED + 1]; | |
913 | int irq_flags; | |
96286b57 | 914 | uint32_t chans_available; |
e2eca638 | 915 | char chan_name[BCM2835_DMA_CHAN_NAME_SIZE]; |
96286b57 FM |
916 | |
917 | if (!pdev->dev.dma_mask) | |
918 | pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; | |
919 | ||
920 | rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); | |
921 | if (rc) | |
922 | return rc; | |
923 | ||
924 | od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL); | |
925 | if (!od) | |
926 | return -ENOMEM; | |
927 | ||
928 | pdev->dev.dma_parms = &od->dma_parms; | |
929 | dma_set_max_seg_size(&pdev->dev, 0x3FFFFFFF); | |
930 | ||
931 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
932 | base = devm_ioremap_resource(&pdev->dev, res); | |
933 | if (IS_ERR(base)) | |
934 | return PTR_ERR(base); | |
935 | ||
936 | od->base = base; | |
937 | ||
938 | dma_cap_set(DMA_SLAVE, od->ddev.cap_mask); | |
7f5ae355 | 939 | dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask); |
96286b57 | 940 | dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask); |
388cc7a2 | 941 | dma_cap_set(DMA_SLAVE, od->ddev.cap_mask); |
d9f094a0 | 942 | dma_cap_set(DMA_MEMCPY, od->ddev.cap_mask); |
96286b57 FM |
943 | od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources; |
944 | od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources; | |
945 | od->ddev.device_tx_status = bcm2835_dma_tx_status; | |
946 | od->ddev.device_issue_pending = bcm2835_dma_issue_pending; | |
96286b57 | 947 | od->ddev.device_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic; |
388cc7a2 | 948 | od->ddev.device_prep_slave_sg = bcm2835_dma_prep_slave_sg; |
d9f094a0 | 949 | od->ddev.device_prep_dma_memcpy = bcm2835_dma_prep_dma_memcpy; |
39159bea MR |
950 | od->ddev.device_config = bcm2835_dma_slave_config; |
951 | od->ddev.device_terminate_all = bcm2835_dma_terminate_all; | |
de92436a | 952 | od->ddev.device_synchronize = bcm2835_dma_synchronize; |
b5743680 MR |
953 | od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); |
954 | od->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); | |
d9f094a0 MS |
955 | od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) | |
956 | BIT(DMA_MEM_TO_MEM); | |
0fa5867e | 957 | od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; |
96286b57 FM |
958 | od->ddev.dev = &pdev->dev; |
959 | INIT_LIST_HEAD(&od->ddev.channels); | |
960 | spin_lock_init(&od->lock); | |
961 | ||
962 | platform_set_drvdata(pdev, od); | |
963 | ||
964 | /* Request DMA channel mask from device tree */ | |
965 | if (of_property_read_u32(pdev->dev.of_node, | |
966 | "brcm,dma-channel-mask", | |
967 | &chans_available)) { | |
968 | dev_err(&pdev->dev, "Failed to get channel mask\n"); | |
969 | rc = -EINVAL; | |
970 | goto err_no_dma; | |
971 | } | |
972 | ||
e2eca638 MS |
973 | /* get irqs for each channel that we support */ |
974 | for (i = 0; i <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; i++) { | |
975 | /* skip masked out channels */ | |
976 | if (!(chans_available & (1 << i))) { | |
977 | irq[i] = -1; | |
978 | continue; | |
96286b57 | 979 | } |
e2eca638 MS |
980 | |
981 | /* get the named irq */ | |
982 | snprintf(chan_name, sizeof(chan_name), "dma%i", i); | |
983 | irq[i] = platform_get_irq_byname(pdev, chan_name); | |
984 | if (irq[i] >= 0) | |
985 | continue; | |
986 | ||
987 | /* legacy device tree case handling */ | |
988 | dev_warn_once(&pdev->dev, | |
0eef727a | 989 | "missing interrupt-names property in device tree - legacy interpretation is used\n"); |
e2eca638 MS |
990 | /* |
991 | * in case of channel >= 11 | |
992 | * use the 11th interrupt and that is shared | |
993 | */ | |
994 | irq[i] = platform_get_irq(pdev, i < 11 ? i : 11); | |
995 | } | |
996 | ||
997 | /* get irqs for each channel */ | |
998 | for (i = 0; i <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; i++) { | |
999 | /* skip channels without irq */ | |
1000 | if (irq[i] < 0) | |
1001 | continue; | |
1002 | ||
1003 | /* check if there are other channels that also use this irq */ | |
1004 | irq_flags = 0; | |
1005 | for (j = 0; j <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; j++) | |
1006 | if ((i != j) && (irq[j] == irq[i])) { | |
1007 | irq_flags = IRQF_SHARED; | |
1008 | break; | |
1009 | } | |
1010 | ||
1011 | /* initialize the channel */ | |
1012 | rc = bcm2835_dma_chan_init(od, i, irq[i], irq_flags); | |
1013 | if (rc) | |
1014 | goto err_no_dma; | |
96286b57 FM |
1015 | } |
1016 | ||
1017 | dev_dbg(&pdev->dev, "Initialized %i DMA channels\n", i); | |
1018 | ||
1019 | /* Device-tree DMA controller registration */ | |
1020 | rc = of_dma_controller_register(pdev->dev.of_node, | |
1021 | bcm2835_dma_xlate, od); | |
1022 | if (rc) { | |
1023 | dev_err(&pdev->dev, "Failed to register DMA controller\n"); | |
1024 | goto err_no_dma; | |
1025 | } | |
1026 | ||
1027 | rc = dma_async_device_register(&od->ddev); | |
1028 | if (rc) { | |
1029 | dev_err(&pdev->dev, | |
1030 | "Failed to register slave DMA engine device: %d\n", rc); | |
1031 | goto err_no_dma; | |
1032 | } | |
1033 | ||
1034 | dev_dbg(&pdev->dev, "Load BCM2835 DMA engine driver\n"); | |
1035 | ||
1036 | return 0; | |
1037 | ||
1038 | err_no_dma: | |
1039 | bcm2835_dma_free(od); | |
1040 | return rc; | |
1041 | } | |
1042 | ||
1043 | static int bcm2835_dma_remove(struct platform_device *pdev) | |
1044 | { | |
1045 | struct bcm2835_dmadev *od = platform_get_drvdata(pdev); | |
1046 | ||
1047 | dma_async_device_unregister(&od->ddev); | |
1048 | bcm2835_dma_free(od); | |
1049 | ||
1050 | return 0; | |
1051 | } | |
1052 | ||
1053 | static struct platform_driver bcm2835_dma_driver = { | |
1054 | .probe = bcm2835_dma_probe, | |
1055 | .remove = bcm2835_dma_remove, | |
1056 | .driver = { | |
1057 | .name = "bcm2835-dma", | |
96286b57 FM |
1058 | .of_match_table = of_match_ptr(bcm2835_dma_of_match), |
1059 | }, | |
1060 | }; | |
1061 | ||
1062 | module_platform_driver(bcm2835_dma_driver); | |
1063 | ||
1064 | MODULE_ALIAS("platform:bcm2835-dma"); | |
1065 | MODULE_DESCRIPTION("BCM2835 DMA engine driver"); | |
1066 | MODULE_AUTHOR("Florian Meier <florian.meier@koalo.de>"); | |
1067 | MODULE_LICENSE("GPL v2"); |