bcm2835_dma.c revision 331722
1/*
2 * Copyright (c) 2013 Daisuke Aoyama <aoyama@peach.ne.jp>
3 * Copyright (c) 2013 Oleksandr Tymoshenko <gonzo@bluezbox.com>
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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
24 * SUCH DAMAGE.
25 *
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: stable/11/sys/arm/broadcom/bcm2835/bcm2835_dma.c 331722 2018-03-29 02:50:57Z eadler $");
30
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/bus.h>
34#include <sys/kernel.h>
35#include <sys/lock.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>
41#include <sys/rman.h>
42
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>
47
48#include <vm/vm.h>
49#include <vm/pmap.h>
50#include <machine/bus.h>
51
52#include "bcm2835_dma.h"
53#include "bcm2835_vcbus.h"
54
55#define	MAX_REG			9
56
57/* private flags */
58#define	BCM_DMA_CH_USED		0x00000001
59#define	BCM_DMA_CH_FREE		0x40000000
60#define	BCM_DMA_CH_UNMAP	0x80000000
61
62/* Register Map (4.2.1.2) */
63#define	BCM_DMA_CS(n)		(0x100*(n) + 0x00)
64#define		CS_ACTIVE		(1 <<  0)
65#define		CS_END			(1 <<  1)
66#define		CS_INT			(1 <<  2)
67#define		CS_DREQ			(1 <<  3)
68#define		CS_ISPAUSED		(1 <<  4)
69#define		CS_ISHELD		(1 <<  5)
70#define		CS_ISWAIT		(1 <<  6)
71#define		CS_ERR			(1 <<  8)
72#define		CS_WAITWRT		(1 << 28)
73#define		CS_DISDBG		(1 << 29)
74#define		CS_ABORT		(1 << 30)
75#define		CS_RESET		(1U << 31)
76#define	BCM_DMA_CBADDR(n)	(0x100*(n) + 0x04)
77#define	BCM_DMA_INFO(n)		(0x100*(n) + 0x08)
78#define		INFO_INT_EN		(1 << 0)
79#define		INFO_TDMODE		(1 << 1)
80#define		INFO_WAIT_RESP		(1 << 3)
81#define		INFO_D_INC		(1 << 4)
82#define		INFO_D_WIDTH		(1 << 5)
83#define		INFO_D_DREQ		(1 << 6)
84#define		INFO_S_INC		(1 << 8)
85#define		INFO_S_WIDTH		(1 << 9)
86#define		INFO_S_DREQ		(1 << 10)
87#define		INFO_WAITS_SHIFT	(21)
88#define		INFO_PERMAP_SHIFT	(16)
89#define		INFO_PERMAP_MASK	(0x1f << INFO_PERMAP_SHIFT)
90
91#define	BCM_DMA_SRC(n)		(0x100*(n) + 0x0C)
92#define	BCM_DMA_DST(n)		(0x100*(n) + 0x10)
93#define	BCM_DMA_LEN(n)		(0x100*(n) + 0x14)
94#define	BCM_DMA_STRIDE(n)	(0x100*(n) + 0x18)
95#define	BCM_DMA_CBNEXT(n)	(0x100*(n) + 0x1C)
96#define	BCM_DMA_DEBUG(n)	(0x100*(n) + 0x20)
97#define		DEBUG_ERROR_MASK	(7)
98
99#define	BCM_DMA_INT_STATUS	0xfe0
100#define	BCM_DMA_ENABLE		0xff0
101
102/* relative offset from BCM_VC_DMA0_BASE (p.39) */
103#define	BCM_DMA_CH(n)		(0x100*(n))
104
105/* channels used by GPU */
106#define	BCM_DMA_CH_BULK		0
107#define	BCM_DMA_CH_FAST1	2
108#define	BCM_DMA_CH_FAST2	3
109
110#define	BCM_DMA_CH_GPU_MASK	((1 << BCM_DMA_CH_BULK) |	\
111				 (1 << BCM_DMA_CH_FAST1) |	\
112				 (1 << BCM_DMA_CH_FAST2))
113
114/* DMA Control Block - 256bit aligned (p.40) */
115struct bcm_dma_cb {
116	uint32_t info;		/* Transfer Information */
117	uint32_t src;		/* Source Address */
118	uint32_t dst;		/* Destination Address */
119	uint32_t len;		/* Transfer Length */
120	uint32_t stride;	/* 2D Mode Stride */
121	uint32_t next;		/* Next Control Block Address */
122	uint32_t rsvd1;		/* Reserved */
123	uint32_t rsvd2;		/* Reserved */
124};
125
126#ifdef DEBUG
127static void bcm_dma_cb_dump(struct bcm_dma_cb *cb);
128static void bcm_dma_reg_dump(int ch);
129#endif
130
131/* DMA channel private info */
132struct bcm_dma_ch {
133	int			ch;
134	uint32_t		flags;
135	struct bcm_dma_cb *	cb;
136	uint32_t		vc_cb;
137	bus_dmamap_t		dma_map;
138	void 			(*intr_func)(int, void *);
139	void *			intr_arg;
140};
141
142struct bcm_dma_softc {
143	device_t		sc_dev;
144	struct mtx		sc_mtx;
145	struct resource *	sc_mem;
146	struct resource *	sc_irq[BCM_DMA_CH_MAX];
147	void *			sc_intrhand[BCM_DMA_CH_MAX];
148	struct bcm_dma_ch	sc_dma_ch[BCM_DMA_CH_MAX];
149	bus_dma_tag_t		sc_dma_tag;
150};
151
152static struct bcm_dma_softc *bcm_dma_sc = NULL;
153static uint32_t bcm_dma_channel_mask;
154
155static struct ofw_compat_data compat_data[] = {
156	{"broadcom,bcm2835-dma",	1},
157	{"brcm,bcm2835-dma",		1},
158	{NULL,				0}
159};
160
161static void
162bcm_dmamap_cb(void *arg, bus_dma_segment_t *segs,
163	int nseg, int err)
164{
165        bus_addr_t *addr;
166
167        if (err)
168                return;
169
170        addr = (bus_addr_t*)arg;
171        *addr = PHYS_TO_VCBUS(segs[0].ds_addr);
172}
173
174static void
175bcm_dma_reset(device_t dev, int ch)
176{
177	struct bcm_dma_softc *sc = device_get_softc(dev);
178	struct bcm_dma_cb *cb;
179	uint32_t cs;
180	int count;
181
182	if (ch < 0 || ch >= BCM_DMA_CH_MAX)
183		return;
184
185	cs = bus_read_4(sc->sc_mem, BCM_DMA_CS(ch));
186
187	if (cs & CS_ACTIVE) {
188		/* pause current task */
189		bus_write_4(sc->sc_mem, BCM_DMA_CS(ch), 0);
190
191		count = 1000;
192		do {
193			cs = bus_read_4(sc->sc_mem, BCM_DMA_CS(ch));
194		} while (!(cs & CS_ISPAUSED) && (count-- > 0));
195
196		if (!(cs & CS_ISPAUSED)) {
197			device_printf(dev,
198			    "Can't abort DMA transfer at channel %d\n", ch);
199		}
200
201		bus_write_4(sc->sc_mem, BCM_DMA_CBNEXT(ch), 0);
202
203		/* Complete everything, clear interrupt */
204		bus_write_4(sc->sc_mem, BCM_DMA_CS(ch),
205		    CS_ABORT | CS_INT | CS_END| CS_ACTIVE);
206	}
207
208	/* clear control blocks */
209	bus_write_4(sc->sc_mem, BCM_DMA_CBADDR(ch), 0);
210	bus_write_4(sc->sc_mem, BCM_DMA_CBNEXT(ch), 0);
211
212	/* Reset control block */
213	cb = sc->sc_dma_ch[ch].cb;
214	bzero(cb, sizeof(*cb));
215	cb->info = INFO_WAIT_RESP;
216}
217
218static int
219bcm_dma_init(device_t dev)
220{
221	struct bcm_dma_softc *sc = device_get_softc(dev);
222	uint32_t reg;
223	struct bcm_dma_ch *ch;
224	void *cb_virt;
225	vm_paddr_t cb_phys;
226	int err;
227	int i;
228
229	/*
230	 * Only channels set in bcm_dma_channel_mask can be controlled by us.
231	 * The others are out of our control as well as the corresponding bits
232	 * in both BCM_DMA_ENABLE and BCM_DMA_INT_STATUS global registers. As
233	 * these registers are RW ones, there is no safe way how to write only
234	 * the bits which can be controlled by us.
235	 *
236	 * Fortunately, after reset, all channels are enabled in BCM_DMA_ENABLE
237	 * register and all statuses are cleared in BCM_DMA_INT_STATUS one.
238	 * Not touching these registers is a trade off between correct
239	 * initialization which does not count on anything and not messing up
240	 * something we have no control over.
241	 */
242	reg = bus_read_4(sc->sc_mem, BCM_DMA_ENABLE);
243	if ((reg & bcm_dma_channel_mask) != bcm_dma_channel_mask)
244		device_printf(dev, "channels are not enabled\n");
245	reg = bus_read_4(sc->sc_mem, BCM_DMA_INT_STATUS);
246	if ((reg & bcm_dma_channel_mask) != 0)
247		device_printf(dev, "statuses are not cleared\n");
248
249	/* Allocate DMA chunks control blocks */
250	/* p.40 of spec - control block should be 32-bit aligned */
251	err = bus_dma_tag_create(bus_get_dma_tag(dev),
252	    1, 0, BUS_SPACE_MAXADDR_32BIT,
253	    BUS_SPACE_MAXADDR, NULL, NULL,
254	    sizeof(struct bcm_dma_cb), 1,
255	    sizeof(struct bcm_dma_cb),
256	    BUS_DMA_ALLOCNOW, NULL, NULL,
257	    &sc->sc_dma_tag);
258
259	if (err) {
260		device_printf(dev, "failed allocate DMA tag\n");
261		return (err);
262	}
263
264	/* setup initial settings */
265	for (i = 0; i < BCM_DMA_CH_MAX; i++) {
266		ch = &sc->sc_dma_ch[i];
267
268		bzero(ch, sizeof(struct bcm_dma_ch));
269		ch->ch = i;
270		ch->flags = BCM_DMA_CH_UNMAP;
271
272		if ((bcm_dma_channel_mask & (1 << i)) == 0)
273			continue;
274
275		err = bus_dmamem_alloc(sc->sc_dma_tag, &cb_virt,
276		    BUS_DMA_WAITOK | BUS_DMA_COHERENT | BUS_DMA_ZERO,
277		    &ch->dma_map);
278		if (err) {
279			device_printf(dev, "cannot allocate DMA memory\n");
280			break;
281		}
282
283		/*
284		 * Least alignment for busdma-allocated stuff is cache
285		 * line size, so just make sure nothing stupid happened
286		 * and we got properly aligned address
287		 */
288		if ((uintptr_t)cb_virt & 0x1f) {
289			device_printf(dev,
290			    "DMA address is not 32-bytes aligned: %p\n",
291			    (void*)cb_virt);
292			break;
293		}
294
295		err = bus_dmamap_load(sc->sc_dma_tag, ch->dma_map, cb_virt,
296		    sizeof(struct bcm_dma_cb), bcm_dmamap_cb, &cb_phys,
297		    BUS_DMA_WAITOK);
298		if (err) {
299			device_printf(dev, "cannot load DMA memory\n");
300			break;
301		}
302
303		ch->cb = cb_virt;
304		ch->vc_cb = cb_phys;
305		ch->flags = BCM_DMA_CH_FREE;
306		ch->cb->info = INFO_WAIT_RESP;
307
308		/* reset DMA engine */
309		bus_write_4(sc->sc_mem, BCM_DMA_CS(i), CS_RESET);
310	}
311
312	return (0);
313}
314
315/*
316 * Allocate DMA channel for further use, returns channel # or
317 *     BCM_DMA_CH_INVALID
318 */
319int
320bcm_dma_allocate(int req_ch)
321{
322	struct bcm_dma_softc *sc = bcm_dma_sc;
323	int ch = BCM_DMA_CH_INVALID;
324	int i;
325
326	if (req_ch >= BCM_DMA_CH_MAX)
327		return (BCM_DMA_CH_INVALID);
328
329	/* Auto(req_ch < 0) or CH specified */
330	mtx_lock(&sc->sc_mtx);
331
332	if (req_ch < 0) {
333		for (i = 0; i < BCM_DMA_CH_MAX; i++) {
334			if (sc->sc_dma_ch[i].flags & BCM_DMA_CH_FREE) {
335				ch = i;
336				sc->sc_dma_ch[ch].flags &= ~BCM_DMA_CH_FREE;
337				sc->sc_dma_ch[ch].flags |= BCM_DMA_CH_USED;
338				break;
339			}
340		}
341	}
342	else {
343		if (sc->sc_dma_ch[req_ch].flags & BCM_DMA_CH_FREE) {
344			ch = req_ch;
345			sc->sc_dma_ch[ch].flags &= ~BCM_DMA_CH_FREE;
346			sc->sc_dma_ch[ch].flags |= BCM_DMA_CH_USED;
347		}
348	}
349
350	mtx_unlock(&sc->sc_mtx);
351	return (ch);
352}
353
354/*
355 * Frees allocated channel. Returns 0 on success, -1 otherwise
356 */
357int
358bcm_dma_free(int ch)
359{
360	struct bcm_dma_softc *sc = bcm_dma_sc;
361
362	if (ch < 0 || ch >= BCM_DMA_CH_MAX)
363		return (-1);
364
365	mtx_lock(&sc->sc_mtx);
366	if (sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED) {
367		sc->sc_dma_ch[ch].flags |= BCM_DMA_CH_FREE;
368		sc->sc_dma_ch[ch].flags &= ~BCM_DMA_CH_USED;
369		sc->sc_dma_ch[ch].intr_func = NULL;
370		sc->sc_dma_ch[ch].intr_arg = NULL;
371
372		/* reset DMA engine */
373		bcm_dma_reset(sc->sc_dev, ch);
374	}
375
376	mtx_unlock(&sc->sc_mtx);
377	return (0);
378}
379
380/*
381 * Assign handler function for channel interrupt
382 * Returns 0 on success, -1 otherwise
383 */
384int
385bcm_dma_setup_intr(int ch, void (*func)(int, void *), void *arg)
386{
387	struct bcm_dma_softc *sc = bcm_dma_sc;
388	struct bcm_dma_cb *cb;
389
390	if (ch < 0 || ch >= BCM_DMA_CH_MAX)
391		return (-1);
392
393	if (!(sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED))
394		return (-1);
395
396	sc->sc_dma_ch[ch].intr_func = func;
397	sc->sc_dma_ch[ch].intr_arg = arg;
398	cb = sc->sc_dma_ch[ch].cb;
399	cb->info |= INFO_INT_EN;
400
401	return (0);
402}
403
404/*
405 * Setup DMA source parameters
406 *     ch - channel number
407 *     dreq - hardware DREQ # or BCM_DMA_DREQ_NONE if
408 *         source is physical memory
409 *     inc_addr - BCM_DMA_INC_ADDR if source address
410 *         should be increased after each access or
411 *         BCM_DMA_SAME_ADDR if address should remain
412 *         the same
413 *     width - size of read operation, BCM_DMA_32BIT
414 *         for 32bit bursts, BCM_DMA_128BIT for 128 bits
415 *
416 * Returns 0 on success, -1 otherwise
417 */
418int
419bcm_dma_setup_src(int ch, int dreq, int inc_addr, int width)
420{
421	struct bcm_dma_softc *sc = bcm_dma_sc;
422	uint32_t info;
423
424	if (ch < 0 || ch >= BCM_DMA_CH_MAX)
425		return (-1);
426
427	if (!(sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED))
428		return (-1);
429
430	info = sc->sc_dma_ch[ch].cb->info;
431	info &= ~INFO_PERMAP_MASK;
432	info |= (dreq << INFO_PERMAP_SHIFT) & INFO_PERMAP_MASK;
433
434	if (dreq)
435		info |= INFO_S_DREQ;
436	else
437		info &= ~INFO_S_DREQ;
438
439	if (width == BCM_DMA_128BIT)
440		info |= INFO_S_WIDTH;
441	else
442		info &= ~INFO_S_WIDTH;
443
444	if (inc_addr == BCM_DMA_INC_ADDR)
445		info |= INFO_S_INC;
446	else
447		info &= ~INFO_S_INC;
448
449	sc->sc_dma_ch[ch].cb->info = info;
450
451	return (0);
452}
453
454/*
455 * Setup DMA destination parameters
456 *     ch - channel number
457 *     dreq - hardware DREQ # or BCM_DMA_DREQ_NONE if
458 *         destination is physical memory
459 *     inc_addr - BCM_DMA_INC_ADDR if source address
460 *         should be increased after each access or
461 *         BCM_DMA_SAME_ADDR if address should remain
462 *         the same
463 *     width - size of write operation, BCM_DMA_32BIT
464 *         for 32bit bursts, BCM_DMA_128BIT for 128 bits
465 *
466 * Returns 0 on success, -1 otherwise
467 */
468int
469bcm_dma_setup_dst(int ch, int dreq, int inc_addr, int width)
470{
471	struct bcm_dma_softc *sc = bcm_dma_sc;
472	uint32_t info;
473
474	if (ch < 0 || ch >= BCM_DMA_CH_MAX)
475		return (-1);
476
477	if (!(sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED))
478		return (-1);
479
480	info = sc->sc_dma_ch[ch].cb->info;
481	info &= ~INFO_PERMAP_MASK;
482	info |= (dreq << INFO_PERMAP_SHIFT) & INFO_PERMAP_MASK;
483
484	if (dreq)
485		info |= INFO_D_DREQ;
486	else
487		info &= ~INFO_D_DREQ;
488
489	if (width == BCM_DMA_128BIT)
490		info |= INFO_D_WIDTH;
491	else
492		info &= ~INFO_D_WIDTH;
493
494	if (inc_addr == BCM_DMA_INC_ADDR)
495		info |= INFO_D_INC;
496	else
497		info &= ~INFO_D_INC;
498
499	sc->sc_dma_ch[ch].cb->info = info;
500
501	return (0);
502}
503
504#ifdef DEBUG
505void
506bcm_dma_cb_dump(struct bcm_dma_cb *cb)
507{
508
509	printf("DMA CB ");
510	printf("INFO: %8.8x ", cb->info);
511	printf("SRC: %8.8x ", cb->src);
512	printf("DST: %8.8x ", cb->dst);
513	printf("LEN: %8.8x ", cb->len);
514	printf("\n");
515	printf("STRIDE: %8.8x ", cb->stride);
516	printf("NEXT: %8.8x ", cb->next);
517	printf("RSVD1: %8.8x ", cb->rsvd1);
518	printf("RSVD2: %8.8x ", cb->rsvd2);
519	printf("\n");
520}
521
522void
523bcm_dma_reg_dump(int ch)
524{
525	struct bcm_dma_softc *sc = bcm_dma_sc;
526	int i;
527	uint32_t reg;
528
529	if (ch < 0 || ch >= BCM_DMA_CH_MAX)
530		return;
531
532	printf("DMA%d: ", ch);
533	for (i = 0; i < MAX_REG; i++) {
534		reg = bus_read_4(sc->sc_mem, BCM_DMA_CH(ch) + i*4);
535		printf("%8.8x ", reg);
536	}
537	printf("\n");
538}
539#endif
540
541/*
542 * Start DMA transaction
543 *     ch - channel number
544 *     src, dst - source and destination address in
545 *         ARM physical memory address space.
546 *     len - amount of bytes to be transferred
547 *
548 * Returns 0 on success, -1 otherwise
549 */
550int
551bcm_dma_start(int ch, vm_paddr_t src, vm_paddr_t dst, int len)
552{
553	struct bcm_dma_softc *sc = bcm_dma_sc;
554	struct bcm_dma_cb *cb;
555
556	if (ch < 0 || ch >= BCM_DMA_CH_MAX)
557		return (-1);
558
559	if (!(sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED))
560		return (-1);
561
562	cb = sc->sc_dma_ch[ch].cb;
563	if (BCM2835_ARM_IS_IO(src))
564		cb->src = IO_TO_VCBUS(src);
565	else
566		cb->src = PHYS_TO_VCBUS(src);
567	if (BCM2835_ARM_IS_IO(dst))
568		cb->dst = IO_TO_VCBUS(dst);
569	else
570		cb->dst = PHYS_TO_VCBUS(dst);
571	cb->len = len;
572
573	bus_dmamap_sync(sc->sc_dma_tag,
574	    sc->sc_dma_ch[ch].dma_map, BUS_DMASYNC_PREWRITE);
575
576	bus_write_4(sc->sc_mem, BCM_DMA_CBADDR(ch),
577	    sc->sc_dma_ch[ch].vc_cb);
578	bus_write_4(sc->sc_mem, BCM_DMA_CS(ch), CS_ACTIVE);
579
580#ifdef DEBUG
581	bcm_dma_cb_dump(sc->sc_dma_ch[ch].cb);
582	bcm_dma_reg_dump(ch);
583#endif
584
585	return (0);
586}
587
588/*
589 * Get length requested for DMA transaction
590 *     ch - channel number
591 *
592 * Returns size of transaction, 0 if channel is invalid
593 */
594uint32_t
595bcm_dma_length(int ch)
596{
597	struct bcm_dma_softc *sc = bcm_dma_sc;
598	struct bcm_dma_cb *cb;
599
600	if (ch < 0 || ch >= BCM_DMA_CH_MAX)
601		return (0);
602
603	if (!(sc->sc_dma_ch[ch].flags & BCM_DMA_CH_USED))
604		return (0);
605
606	cb = sc->sc_dma_ch[ch].cb;
607
608	return (cb->len);
609}
610
611static void
612bcm_dma_intr(void *arg)
613{
614	struct bcm_dma_softc *sc = bcm_dma_sc;
615	struct bcm_dma_ch *ch = (struct bcm_dma_ch *)arg;
616	uint32_t cs, debug;
617
618	/* my interrupt? */
619	cs = bus_read_4(sc->sc_mem, BCM_DMA_CS(ch->ch));
620
621	if (!(cs & (CS_INT | CS_ERR))) {
622		device_printf(sc->sc_dev,
623		    "unexpected DMA intr CH=%d, CS=%x\n", ch->ch, cs);
624		return;
625	}
626
627	/* running? */
628	if (!(ch->flags & BCM_DMA_CH_USED)) {
629		device_printf(sc->sc_dev,
630		    "unused DMA intr CH=%d, CS=%x\n", ch->ch, cs);
631		return;
632	}
633
634	if (cs & CS_ERR) {
635		debug = bus_read_4(sc->sc_mem, BCM_DMA_DEBUG(ch->ch));
636		device_printf(sc->sc_dev, "DMA error %d on CH%d\n",
637			debug & DEBUG_ERROR_MASK, ch->ch);
638		bus_write_4(sc->sc_mem, BCM_DMA_DEBUG(ch->ch),
639		    debug & DEBUG_ERROR_MASK);
640		bcm_dma_reset(sc->sc_dev, ch->ch);
641	}
642
643	if (cs & CS_INT) {
644		/* acknowledge interrupt */
645		bus_write_4(sc->sc_mem, BCM_DMA_CS(ch->ch),
646		    CS_INT | CS_END);
647
648		/* Prepare for possible access to len field */
649		bus_dmamap_sync(sc->sc_dma_tag, ch->dma_map,
650		    BUS_DMASYNC_POSTWRITE);
651
652		/* save callback function and argument */
653		if (ch->intr_func)
654			ch->intr_func(ch->ch, ch->intr_arg);
655	}
656}
657
658static int
659bcm_dma_probe(device_t dev)
660{
661
662	if (!ofw_bus_status_okay(dev))
663		return (ENXIO);
664
665	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
666		return (ENXIO);
667
668	device_set_desc(dev, "BCM2835 DMA Controller");
669	return (BUS_PROBE_DEFAULT);
670}
671
672static int
673bcm_dma_attach(device_t dev)
674{
675	struct bcm_dma_softc *sc = device_get_softc(dev);
676	phandle_t node;
677	int rid, err = 0;
678	int i;
679
680	sc->sc_dev = dev;
681
682	if (bcm_dma_sc)
683		return (ENXIO);
684
685	for (i = 0; i < BCM_DMA_CH_MAX; i++) {
686		sc->sc_irq[i] = NULL;
687		sc->sc_intrhand[i] = NULL;
688	}
689
690	/* Get DMA channel mask. */
691	node = ofw_bus_get_node(sc->sc_dev);
692	if (OF_getencprop(node, "brcm,dma-channel-mask", &bcm_dma_channel_mask,
693	    sizeof(bcm_dma_channel_mask)) == -1 &&
694	    OF_getencprop(node, "broadcom,channels", &bcm_dma_channel_mask,
695	    sizeof(bcm_dma_channel_mask)) == -1) {
696		device_printf(dev, "could not get channel mask property\n");
697		return (ENXIO);
698	}
699
700	/* Mask out channels used by GPU. */
701	bcm_dma_channel_mask &= ~BCM_DMA_CH_GPU_MASK;
702
703	/* DMA0 - DMA14 */
704	rid = 0;
705	sc->sc_mem = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
706	if (sc->sc_mem == NULL) {
707		device_printf(dev, "could not allocate memory resource\n");
708		return (ENXIO);
709	}
710
711	/* IRQ DMA0 - DMA11 XXX NOT USE DMA12(spurious?) */
712	for (rid = 0; rid < BCM_DMA_CH_MAX; rid++) {
713		if ((bcm_dma_channel_mask & (1 << rid)) == 0)
714			continue;
715
716		sc->sc_irq[rid] = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
717						       RF_ACTIVE);
718		if (sc->sc_irq[rid] == NULL) {
719			device_printf(dev, "cannot allocate interrupt\n");
720			err = ENXIO;
721			goto fail;
722		}
723		if (bus_setup_intr(dev, sc->sc_irq[rid], INTR_TYPE_MISC | INTR_MPSAFE,
724				   NULL, bcm_dma_intr, &sc->sc_dma_ch[rid],
725				   &sc->sc_intrhand[rid])) {
726			device_printf(dev, "cannot setup interrupt handler\n");
727			err = ENXIO;
728			goto fail;
729		}
730	}
731
732	mtx_init(&sc->sc_mtx, "bcmdma", "bcmdma", MTX_DEF);
733	bcm_dma_sc = sc;
734
735	err = bcm_dma_init(dev);
736	if (err)
737		goto fail;
738
739	return (err);
740
741fail:
742	if (sc->sc_mem)
743		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem);
744
745	for (i = 0; i < BCM_DMA_CH_MAX; i++) {
746		if (sc->sc_intrhand[i])
747			bus_teardown_intr(dev, sc->sc_irq[i], sc->sc_intrhand[i]);
748		if (sc->sc_irq[i])
749			bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq[i]);
750	}
751
752	return (err);
753}
754
755static device_method_t bcm_dma_methods[] = {
756	DEVMETHOD(device_probe,		bcm_dma_probe),
757	DEVMETHOD(device_attach,	bcm_dma_attach),
758	{ 0, 0 }
759};
760
761static driver_t bcm_dma_driver = {
762	"bcm_dma",
763	bcm_dma_methods,
764	sizeof(struct bcm_dma_softc),
765};
766
767static devclass_t bcm_dma_devclass;
768
769DRIVER_MODULE(bcm_dma, simplebus, bcm_dma_driver, bcm_dma_devclass, 0, 0);
770MODULE_VERSION(bcm_dma, 1);
771