2 * Copyright (c) 2013 Daisuke Aoyama <aoyama@peach.ne.jp>
3 * Copyright (c) 2013 Oleksandr Tymoshenko <gonzo@bluezbox.com>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
31 #include <sys/param.h>
32 #include <sys/systm.h>
34 #include <sys/kernel.h>
36 #include <sys/malloc.h>
37 #include <sys/module.h>
38 #include <sys/mutex.h>
39 #include <sys/queue.h>
40 #include <sys/resource.h>
43 #include <dev/fdt/fdt_common.h>
44 #include <dev/ofw/openfirm.h>
45 #include <dev/ofw/ofw_bus.h>
46 #include <dev/ofw/ofw_bus_subr.h>
50 #include <machine/bus.h>
51 #include <machine/cpu.h>
52 #include <machine/cpufunc.h>
54 #include "bcm2835_dma.h"
55 #include "bcm2835_vcbus.h"
60 #define BCM_DMA_CH_USED 0x00000001
61 #define BCM_DMA_CH_FREE 0x40000000
62 #define BCM_DMA_CH_UNMAP 0x80000000
64 /* Register Map (4.2.1.2) */
65 #define BCM_DMA_CS(n) (0x100*(n) + 0x00)
66 #define CS_ACTIVE (1 << 0)
67 #define CS_END (1 << 1)
68 #define CS_INT (1 << 2)
69 #define CS_DREQ (1 << 3)
70 #define CS_ISPAUSED (1 << 4)
71 #define CS_ISHELD (1 << 5)
72 #define CS_ISWAIT (1 << 6)
73 #define CS_ERR (1 << 8)
74 #define CS_WAITWRT (1 << 28)
75 #define CS_DISDBG (1 << 29)
76 #define CS_ABORT (1 << 30)
77 #define CS_RESET (1U << 31)
78 #define BCM_DMA_CBADDR(n) (0x100*(n) + 0x04)
79 #define BCM_DMA_INFO(n) (0x100*(n) + 0x08)
80 #define INFO_INT_EN (1 << 0)
81 #define INFO_TDMODE (1 << 1)
82 #define INFO_WAIT_RESP (1 << 3)
83 #define INFO_D_INC (1 << 4)
84 #define INFO_D_WIDTH (1 << 5)
85 #define INFO_D_DREQ (1 << 6)
86 #define INFO_S_INC (1 << 8)
87 #define INFO_S_WIDTH (1 << 9)
88 #define INFO_S_DREQ (1 << 10)
89 #define INFO_WAITS_SHIFT (21)
90 #define INFO_PERMAP_SHIFT (16)
91 #define INFO_PERMAP_MASK (0x1f << INFO_PERMAP_SHIFT)
93 #define BCM_DMA_SRC(n) (0x100*(n) + 0x0C)
94 #define BCM_DMA_DST(n) (0x100*(n) + 0x10)
95 #define BCM_DMA_LEN(n) (0x100*(n) + 0x14)
96 #define BCM_DMA_STRIDE(n) (0x100*(n) + 0x18)
97 #define BCM_DMA_CBNEXT(n) (0x100*(n) + 0x1C)
98 #define BCM_DMA_DEBUG(n) (0x100*(n) + 0x20)
99 #define DEBUG_ERROR_MASK (7)
101 #define BCM_DMA_INT_STATUS 0xfe0
102 #define BCM_DMA_ENABLE 0xff0
104 /* relative offset from BCM_VC_DMA0_BASE (p.39) */
105 #define BCM_DMA_CH(n) (0x100*(n))
107 /* channels used by GPU */
108 #define BCM_DMA_CH_BULK 0
109 #define BCM_DMA_CH_FAST1 2
110 #define BCM_DMA_CH_FAST2 3
112 #define BCM_DMA_CH_GPU_MASK ((1 << BCM_DMA_CH_BULK) | \
113 (1 << BCM_DMA_CH_FAST1) | \
114 (1 << BCM_DMA_CH_FAST2))
116 /* DMA Control Block - 256bit aligned (p.40) */
118 uint32_t info; /* Transfer Information */
119 uint32_t src; /* Source Address */
120 uint32_t dst; /* Destination Address */
121 uint32_t len; /* Transfer Length */
122 uint32_t stride; /* 2D Mode Stride */
123 uint32_t next; /* Next Control Block Address */
124 uint32_t rsvd1; /* Reserved */
125 uint32_t rsvd2; /* Reserved */
129 static void bcm_dma_cb_dump(struct bcm_dma_cb *cb);
130 static void bcm_dma_reg_dump(int ch);
133 /* DMA channel private info */
137 struct bcm_dma_cb * cb;
139 bus_dmamap_t dma_map;
140 void (*intr_func)(int, void *);
144 struct bcm_dma_softc {
147 struct resource * sc_mem;
148 struct resource * sc_irq[BCM_DMA_CH_MAX];
149 void * sc_intrhand[BCM_DMA_CH_MAX];
150 struct bcm_dma_ch sc_dma_ch[BCM_DMA_CH_MAX];
151 bus_dma_tag_t sc_dma_tag;
154 static struct bcm_dma_softc *bcm_dma_sc = NULL;
155 static uint32_t bcm_dma_channel_mask;
157 static struct ofw_compat_data compat_data[] = {
158 {"broadcom,bcm2835-dma", 1},
159 {"brcm,bcm2835-dma", 1},
164 bcm_dmamap_cb(void *arg, bus_dma_segment_t *segs,
172 addr = (bus_addr_t*)arg;
173 *addr = PHYS_TO_VCBUS(segs[0].ds_addr);
177 bcm_dma_reset(device_t dev, int ch)
179 struct bcm_dma_softc *sc = device_get_softc(dev);
180 struct bcm_dma_cb *cb;
184 if (ch < 0 || ch >= BCM_DMA_CH_MAX)
187 cs = bus_read_4(sc->sc_mem, BCM_DMA_CS(ch));
189 if (cs & CS_ACTIVE) {
190 /* pause current task */
191 bus_write_4(sc->sc_mem, BCM_DMA_CS(ch), 0);
195 cs = bus_read_4(sc->sc_mem, BCM_DMA_CS(ch));
196 } while (!(cs & CS_ISPAUSED) && (count-- > 0));
198 if (!(cs & CS_ISPAUSED)) {
200 "Can't abort DMA transfer at channel %d\n", ch);
203 bus_write_4(sc->sc_mem, BCM_DMA_CBNEXT(ch), 0);
205 /* Complete everything, clear interrupt */
206 bus_write_4(sc->sc_mem, BCM_DMA_CS(ch),
207 CS_ABORT | CS_INT | CS_END| CS_ACTIVE);
210 /* clear control blocks */
211 bus_write_4(sc->sc_mem, BCM_DMA_CBADDR(ch), 0);
212 bus_write_4(sc->sc_mem, BCM_DMA_CBNEXT(ch), 0);
214 /* Reset control block */
215 cb = sc->sc_dma_ch[ch].cb;
216 bzero(cb, sizeof(*cb));
217 cb->info = INFO_WAIT_RESP;
221 bcm_dma_init(device_t dev)
223 struct bcm_dma_softc *sc = device_get_softc(dev);
225 struct bcm_dma_ch *ch;
232 * Only channels set in bcm_dma_channel_mask can be controlled by us.
233 * The others are out of our control as well as the corresponding bits
234 * in both BCM_DMA_ENABLE and BCM_DMA_INT_STATUS global registers. As
235 * these registers are RW ones, there is no safe way how to write only
236 * the bits which can be controlled by us.
238 * Fortunately, after reset, all channels are enabled in BCM_DMA_ENABLE
239 * register and all statuses are cleared in BCM_DMA_INT_STATUS one.
240 * Not touching these registers is a trade off between correct
241 * initialization which does not count on anything and not messing up
242 * something we have no control over.
244 reg = bus_read_4(sc->sc_mem, BCM_DMA_ENABLE);
245 if ((reg & bcm_dma_channel_mask) != bcm_dma_channel_mask)
246 device_printf(dev, "channels are not enabled\n");
247 reg = bus_read_4(sc->sc_mem, BCM_DMA_INT_STATUS);
248 if ((reg & bcm_dma_channel_mask) != 0)
249 device_printf(dev, "statuses are not cleared\n");
251 /* Allocate DMA chunks control blocks */
252 /* p.40 of spec - control block should be 32-bit aligned */
253 err = bus_dma_tag_create(bus_get_dma_tag(dev),
254 1, 0, BUS_SPACE_MAXADDR_32BIT,
255 BUS_SPACE_MAXADDR, NULL, NULL,
256 sizeof(struct bcm_dma_cb), 1,
257 sizeof(struct bcm_dma_cb),
258 BUS_DMA_ALLOCNOW, NULL, NULL,
262 device_printf(dev, "failed allocate DMA tag\n");
266 /* setup initial settings */
267 for (i = 0; i < BCM_DMA_CH_MAX; i++) {
268 ch = &sc->sc_dma_ch[i];
270 bzero(ch, sizeof(struct bcm_dma_ch));
272 ch->flags = BCM_DMA_CH_UNMAP;
274 if ((bcm_dma_channel_mask & (1 << i)) == 0)
277 err = bus_dmamem_alloc(sc->sc_dma_tag, &cb_virt,
278 BUS_DMA_WAITOK | BUS_DMA_COHERENT | BUS_DMA_ZERO,
281 device_printf(dev, "cannot allocate DMA memory\n");
286 * Least alignment for busdma-allocated stuff is cache
287 * line size, so just make sure nothing stupid happend
288 * and we got properly aligned address
290 if ((uintptr_t)cb_virt & 0x1f) {
292 "DMA address is not 32-bytes aligned: %p\n",
297 err = bus_dmamap_load(sc->sc_dma_tag, ch->dma_map, cb_virt,
298 sizeof(struct bcm_dma_cb), bcm_dmamap_cb, &cb_phys,
301 device_printf(dev, "cannot load DMA memory\n");
307 ch->flags = BCM_DMA_CH_FREE;
308 ch->cb->info = INFO_WAIT_RESP;
310 /* reset DMA engine */
311 bus_write_4(sc->sc_mem, BCM_DMA_CS(i), CS_RESET);
318 * Allocate DMA channel for further use, returns channel # or
322 bcm_dma_allocate(int req_ch)
324 struct bcm_dma_softc *sc = bcm_dma_sc;
325 int ch = BCM_DMA_CH_INVALID;
328 if (req_ch >= BCM_DMA_CH_MAX)
329 return (BCM_DMA_CH_INVALID);
331 /* Auto(req_ch < 0) or CH specified */
332 mtx_lock(&sc->sc_mtx);
335 for (i = 0; i < BCM_DMA_CH_MAX; i++) {
336 if (sc->sc_dma_ch[i].flags & BCM_DMA_CH_FREE) {
338 sc->sc_dma_ch[ch].flags &= ~BCM_DMA_CH_FREE;
339 sc->sc_dma_ch[ch].flags |= BCM_DMA_CH_USED;
345 if (sc->sc_dma_ch[req_ch].flags & BCM_DMA_CH_FREE) {
347 sc->sc_dma_ch[ch].flags &= ~BCM_DMA_CH_FREE;
348 sc->sc_dma_ch[ch].flags |= BCM_DMA_CH_USED;
352 mtx_unlock(&sc->sc_mtx);
357 * Frees allocated channel. Returns 0 on success, -1 otherwise
362 struct bcm_dma_softc *sc = bcm_dma_sc;
364 if (ch < 0 || ch >= BCM_DMA_CH_MAX)
367 mtx_lock(&sc->sc_mtx);
368 if (sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED) {
369 sc->sc_dma_ch[ch].flags |= BCM_DMA_CH_FREE;
370 sc->sc_dma_ch[ch].flags &= ~BCM_DMA_CH_USED;
371 sc->sc_dma_ch[ch].intr_func = NULL;
372 sc->sc_dma_ch[ch].intr_arg = NULL;
374 /* reset DMA engine */
375 bcm_dma_reset(sc->sc_dev, ch);
378 mtx_unlock(&sc->sc_mtx);
383 * Assign handler function for channel interrupt
384 * Returns 0 on success, -1 otherwise
387 bcm_dma_setup_intr(int ch, void (*func)(int, void *), void *arg)
389 struct bcm_dma_softc *sc = bcm_dma_sc;
390 struct bcm_dma_cb *cb;
392 if (ch < 0 || ch >= BCM_DMA_CH_MAX)
395 if (!(sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED))
398 sc->sc_dma_ch[ch].intr_func = func;
399 sc->sc_dma_ch[ch].intr_arg = arg;
400 cb = sc->sc_dma_ch[ch].cb;
401 cb->info |= INFO_INT_EN;
407 * Setup DMA source parameters
408 * ch - channel number
409 * dreq - hardware DREQ # or BCM_DMA_DREQ_NONE if
410 * source is physical memory
411 * inc_addr - BCM_DMA_INC_ADDR if source address
412 * should be increased after each access or
413 * BCM_DMA_SAME_ADDR if address should remain
415 * width - size of read operation, BCM_DMA_32BIT
416 * for 32bit bursts, BCM_DMA_128BIT for 128 bits
418 * Returns 0 on success, -1 otherwise
421 bcm_dma_setup_src(int ch, int dreq, int inc_addr, int width)
423 struct bcm_dma_softc *sc = bcm_dma_sc;
426 if (ch < 0 || ch >= BCM_DMA_CH_MAX)
429 if (!(sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED))
432 info = sc->sc_dma_ch[ch].cb->info;
433 info &= ~INFO_PERMAP_MASK;
434 info |= (dreq << INFO_PERMAP_SHIFT) & INFO_PERMAP_MASK;
439 info &= ~INFO_S_DREQ;
441 if (width == BCM_DMA_128BIT)
442 info |= INFO_S_WIDTH;
444 info &= ~INFO_S_WIDTH;
446 if (inc_addr == BCM_DMA_INC_ADDR)
451 sc->sc_dma_ch[ch].cb->info = info;
457 * Setup DMA destination parameters
458 * ch - channel number
459 * dreq - hardware DREQ # or BCM_DMA_DREQ_NONE if
460 * destination is physical memory
461 * inc_addr - BCM_DMA_INC_ADDR if source address
462 * should be increased after each access or
463 * BCM_DMA_SAME_ADDR if address should remain
465 * width - size of write operation, BCM_DMA_32BIT
466 * for 32bit bursts, BCM_DMA_128BIT for 128 bits
468 * Returns 0 on success, -1 otherwise
471 bcm_dma_setup_dst(int ch, int dreq, int inc_addr, int width)
473 struct bcm_dma_softc *sc = bcm_dma_sc;
476 if (ch < 0 || ch >= BCM_DMA_CH_MAX)
479 if (!(sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED))
482 info = sc->sc_dma_ch[ch].cb->info;
483 info &= ~INFO_PERMAP_MASK;
484 info |= (dreq << INFO_PERMAP_SHIFT) & INFO_PERMAP_MASK;
489 info &= ~INFO_D_DREQ;
491 if (width == BCM_DMA_128BIT)
492 info |= INFO_D_WIDTH;
494 info &= ~INFO_D_WIDTH;
496 if (inc_addr == BCM_DMA_INC_ADDR)
501 sc->sc_dma_ch[ch].cb->info = info;
508 bcm_dma_cb_dump(struct bcm_dma_cb *cb)
512 printf("INFO: %8.8x ", cb->info);
513 printf("SRC: %8.8x ", cb->src);
514 printf("DST: %8.8x ", cb->dst);
515 printf("LEN: %8.8x ", cb->len);
517 printf("STRIDE: %8.8x ", cb->stride);
518 printf("NEXT: %8.8x ", cb->next);
519 printf("RSVD1: %8.8x ", cb->rsvd1);
520 printf("RSVD2: %8.8x ", cb->rsvd2);
525 bcm_dma_reg_dump(int ch)
527 struct bcm_dma_softc *sc = bcm_dma_sc;
531 if (ch < 0 || ch >= BCM_DMA_CH_MAX)
534 printf("DMA%d: ", ch);
535 for (i = 0; i < MAX_REG; i++) {
536 reg = bus_read_4(sc->sc_mem, BCM_DMA_CH(ch) + i*4);
537 printf("%8.8x ", reg);
544 * Start DMA transaction
545 * ch - channel number
546 * src, dst - source and destination address in
547 * ARM physical memory address space.
548 * len - amount of bytes to be transfered
550 * Returns 0 on success, -1 otherwise
553 bcm_dma_start(int ch, vm_paddr_t src, vm_paddr_t dst, int len)
555 struct bcm_dma_softc *sc = bcm_dma_sc;
556 struct bcm_dma_cb *cb;
558 if (ch < 0 || ch >= BCM_DMA_CH_MAX)
561 if (!(sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED))
564 cb = sc->sc_dma_ch[ch].cb;
565 if (BCM2835_ARM_IS_IO(src))
566 cb->src = IO_TO_VCBUS(src);
568 cb->src = PHYS_TO_VCBUS(src);
569 if (BCM2835_ARM_IS_IO(dst))
570 cb->dst = IO_TO_VCBUS(dst);
572 cb->dst = PHYS_TO_VCBUS(dst);
575 bus_dmamap_sync(sc->sc_dma_tag,
576 sc->sc_dma_ch[ch].dma_map, BUS_DMASYNC_PREWRITE);
578 bus_write_4(sc->sc_mem, BCM_DMA_CBADDR(ch),
579 sc->sc_dma_ch[ch].vc_cb);
580 bus_write_4(sc->sc_mem, BCM_DMA_CS(ch), CS_ACTIVE);
583 bcm_dma_cb_dump(sc->sc_dma_ch[ch].cb);
584 bcm_dma_reg_dump(ch);
591 * Get length requested for DMA transaction
592 * ch - channel number
594 * Returns size of transaction, 0 if channel is invalid
597 bcm_dma_length(int ch)
599 struct bcm_dma_softc *sc = bcm_dma_sc;
600 struct bcm_dma_cb *cb;
602 if (ch < 0 || ch >= BCM_DMA_CH_MAX)
605 if (!(sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED))
608 cb = sc->sc_dma_ch[ch].cb;
614 bcm_dma_intr(void *arg)
616 struct bcm_dma_softc *sc = bcm_dma_sc;
617 struct bcm_dma_ch *ch = (struct bcm_dma_ch *)arg;
621 cs = bus_read_4(sc->sc_mem, BCM_DMA_CS(ch->ch));
623 if (!(cs & (CS_INT | CS_ERR))) {
624 device_printf(sc->sc_dev,
625 "unexpected DMA intr CH=%d, CS=%x\n", ch->ch, cs);
630 if (!(ch->flags & BCM_DMA_CH_USED)) {
631 device_printf(sc->sc_dev,
632 "unused DMA intr CH=%d, CS=%x\n", ch->ch, cs);
637 debug = bus_read_4(sc->sc_mem, BCM_DMA_DEBUG(ch->ch));
638 device_printf(sc->sc_dev, "DMA error %d on CH%d\n",
639 debug & DEBUG_ERROR_MASK, ch->ch);
640 bus_write_4(sc->sc_mem, BCM_DMA_DEBUG(ch->ch),
641 debug & DEBUG_ERROR_MASK);
642 bcm_dma_reset(sc->sc_dev, ch->ch);
646 /* acknowledge interrupt */
647 bus_write_4(sc->sc_mem, BCM_DMA_CS(ch->ch),
650 /* Prepare for possible access to len field */
651 bus_dmamap_sync(sc->sc_dma_tag, ch->dma_map,
652 BUS_DMASYNC_POSTWRITE);
654 /* save callback function and argument */
656 ch->intr_func(ch->ch, ch->intr_arg);
661 bcm_dma_probe(device_t dev)
664 if (!ofw_bus_status_okay(dev))
667 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
670 device_set_desc(dev, "BCM2835 DMA Controller");
671 return (BUS_PROBE_DEFAULT);
675 bcm_dma_attach(device_t dev)
677 struct bcm_dma_softc *sc = device_get_softc(dev);
687 for (i = 0; i < BCM_DMA_CH_MAX; i++) {
688 sc->sc_irq[i] = NULL;
689 sc->sc_intrhand[i] = NULL;
692 /* Get DMA channel mask. */
693 node = ofw_bus_get_node(sc->sc_dev);
694 if (OF_getencprop(node, "brcm,dma-channel-mask", &bcm_dma_channel_mask,
695 sizeof(bcm_dma_channel_mask)) == -1 &&
696 OF_getencprop(node, "broadcom,channels", &bcm_dma_channel_mask,
697 sizeof(bcm_dma_channel_mask)) == -1) {
698 device_printf(dev, "could not get channel mask property\n");
702 /* Mask out channels used by GPU. */
703 bcm_dma_channel_mask &= ~BCM_DMA_CH_GPU_MASK;
707 sc->sc_mem = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
708 if (sc->sc_mem == NULL) {
709 device_printf(dev, "could not allocate memory resource\n");
713 /* IRQ DMA0 - DMA11 XXX NOT USE DMA12(spurious?) */
714 for (rid = 0; rid < BCM_DMA_CH_MAX; rid++) {
715 if ((bcm_dma_channel_mask & (1 << rid)) == 0)
718 sc->sc_irq[rid] = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
720 if (sc->sc_irq[rid] == NULL) {
721 device_printf(dev, "cannot allocate interrupt\n");
725 if (bus_setup_intr(dev, sc->sc_irq[rid], INTR_TYPE_MISC | INTR_MPSAFE,
726 NULL, bcm_dma_intr, &sc->sc_dma_ch[rid],
727 &sc->sc_intrhand[rid])) {
728 device_printf(dev, "cannot setup interrupt handler\n");
734 mtx_init(&sc->sc_mtx, "bcmdma", "bcmdma", MTX_DEF);
737 err = bcm_dma_init(dev);
745 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem);
747 for (i = 0; i < BCM_DMA_CH_MAX; i++) {
748 if (sc->sc_intrhand[i])
749 bus_teardown_intr(dev, sc->sc_irq[i], sc->sc_intrhand[i]);
751 bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq[i]);
757 static device_method_t bcm_dma_methods[] = {
758 DEVMETHOD(device_probe, bcm_dma_probe),
759 DEVMETHOD(device_attach, bcm_dma_attach),
763 static driver_t bcm_dma_driver = {
766 sizeof(struct bcm_dma_softc),
769 static devclass_t bcm_dma_devclass;
771 DRIVER_MODULE(bcm_dma, simplebus, bcm_dma_driver, bcm_dma_devclass, 0, 0);
772 MODULE_VERSION(bcm_dma, 1);