xref: /freebsd/sys/arm/broadcom/bcm2835/bcm2835_mbox.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@freebsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/kernel.h>
34 #include <sys/lock.h>
35 #include <sys/module.h>
36 #include <sys/mutex.h>
37 #include <sys/sx.h>
38 #include <sys/rman.h>
39 #include <machine/bus.h>
40 
41 #include <dev/ofw/ofw_bus.h>
42 #include <dev/ofw/ofw_bus_subr.h>
43 
44 #include <arm/broadcom/bcm2835/bcm2835_firmware.h>
45 #include <arm/broadcom/bcm2835/bcm2835_mbox.h>
46 #include <arm/broadcom/bcm2835/bcm2835_mbox_prop.h>
47 #include <arm/broadcom/bcm2835/bcm2835_vcbus.h>
48 
49 #include "mbox_if.h"
50 
51 #define	REG_READ	0x00
52 #define	REG_POL		0x10
53 #define	REG_SENDER	0x14
54 #define	REG_STATUS	0x18
55 #define		STATUS_FULL	0x80000000
56 #define		STATUS_EMPTY	0x40000000
57 #define	REG_CONFIG	0x1C
58 #define		CONFIG_DATA_IRQ	0x00000001
59 #define	REG_WRITE	0x20 /* This is Mailbox 1 address */
60 
61 #define	MBOX_MSG(chan, data)	(((data) & ~0xf) | ((chan) & 0xf))
62 #define	MBOX_CHAN(msg)		((msg) & 0xf)
63 #define	MBOX_DATA(msg)		((msg) & ~0xf)
64 
65 #define	MBOX_LOCK(sc)	do {	\
66 	mtx_lock(&(sc)->lock);	\
67 } while(0)
68 
69 #define	MBOX_UNLOCK(sc)	do {		\
70 	mtx_unlock(&(sc)->lock);	\
71 } while(0)
72 
73 #ifdef  DEBUG
74 #define dprintf(fmt, args...) printf(fmt, ##args)
75 #else
76 #define dprintf(fmt, args...)
77 #endif
78 
79 struct bcm_mbox_softc {
80 	struct mtx		lock;
81 	struct resource *	mem_res;
82 	struct resource *	irq_res;
83 	void*			intr_hl;
84 	bus_space_tag_t		bst;
85 	bus_space_handle_t	bsh;
86 	int			msg[BCM2835_MBOX_CHANS];
87 	int			have_message[BCM2835_MBOX_CHANS];
88 	struct sx		property_chan_lock;
89 };
90 
91 #define	mbox_read_4(sc, reg)		\
92     bus_space_read_4((sc)->bst, (sc)->bsh, reg)
93 #define	mbox_write_4(sc, reg, val)		\
94     bus_space_write_4((sc)->bst, (sc)->bsh, reg, val)
95 
96 static struct ofw_compat_data compat_data[] = {
97 	{"broadcom,bcm2835-mbox",	1},
98 	{"brcm,bcm2835-mbox",		1},
99 	{NULL,				0}
100 };
101 
102 static int
103 bcm_mbox_read_msg(struct bcm_mbox_softc *sc, int *ochan)
104 {
105 #ifdef DEBUG
106 	uint32_t data;
107 #endif
108 	uint32_t msg;
109 	int chan;
110 
111 	msg = mbox_read_4(sc, REG_READ);
112 	dprintf("bcm_mbox_intr: raw data %08x\n", msg);
113 	chan = MBOX_CHAN(msg);
114 #ifdef DEBUG
115 	data = MBOX_DATA(msg);
116 #endif
117 	if (sc->msg[chan]) {
118 		printf("bcm_mbox_intr: channel %d oveflow\n", chan);
119 		return (1);
120 	}
121 	dprintf("bcm_mbox_intr: chan %d, data %08x\n", chan, data);
122 	sc->msg[chan] = msg;
123 
124 	if (ochan != NULL)
125 		*ochan = chan;
126 
127 	return (0);
128 }
129 
130 static void
131 bcm_mbox_intr(void *arg)
132 {
133 	struct bcm_mbox_softc *sc = arg;
134 	int chan;
135 
136 	MBOX_LOCK(sc);
137 	while (!(mbox_read_4(sc, REG_STATUS) & STATUS_EMPTY))
138 		if (bcm_mbox_read_msg(sc, &chan) == 0) {
139 			sc->have_message[chan] = 1;
140 			wakeup(&sc->have_message[chan]);
141 		}
142 	MBOX_UNLOCK(sc);
143 }
144 
145 static int
146 bcm_mbox_probe(device_t dev)
147 {
148 
149 	if (!ofw_bus_status_okay(dev))
150 		return (ENXIO);
151 
152 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
153 		return (ENXIO);
154 
155 	device_set_desc(dev, "BCM2835 VideoCore Mailbox");
156 
157 	return (BUS_PROBE_DEFAULT);
158 }
159 
160 static int
161 bcm_mbox_attach(device_t dev)
162 {
163 	struct bcm_mbox_softc *sc = device_get_softc(dev);
164 	int i;
165 	int rid = 0;
166 
167 	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
168 	if (sc->mem_res == NULL) {
169 		device_printf(dev, "could not allocate memory resource\n");
170 		return (ENXIO);
171 	}
172 
173 	sc->bst = rman_get_bustag(sc->mem_res);
174 	sc->bsh = rman_get_bushandle(sc->mem_res);
175 
176 	rid = 0;
177 	sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE);
178 	if (sc->irq_res == NULL) {
179 		device_printf(dev, "could not allocate interrupt resource\n");
180 		return (ENXIO);
181 	}
182 
183 	/* Setup and enable the timer */
184 	if (bus_setup_intr(dev, sc->irq_res, INTR_MPSAFE | INTR_TYPE_MISC,
185 	    NULL, bcm_mbox_intr, sc, &sc->intr_hl) != 0) {
186 		bus_release_resource(dev, SYS_RES_IRQ, rid, sc->irq_res);
187 		device_printf(dev, "Unable to setup the clock irq handler.\n");
188 		return (ENXIO);
189 	}
190 
191 	mtx_init(&sc->lock, "vcio mbox", NULL, MTX_DEF);
192 	for (i = 0; i < BCM2835_MBOX_CHANS; i++) {
193 		sc->msg[i] = 0;
194 		sc->have_message[i] = 0;
195 	}
196 
197 	sx_init(&sc->property_chan_lock, "mboxprop");
198 
199 	/* Read all pending messages */
200 	while ((mbox_read_4(sc, REG_STATUS) & STATUS_EMPTY) == 0)
201 		(void)mbox_read_4(sc, REG_READ);
202 
203 	mbox_write_4(sc, REG_CONFIG, CONFIG_DATA_IRQ);
204 
205 	return (0);
206 }
207 
208 /*
209  * Mailbox API
210  */
211 static int
212 bcm_mbox_write(device_t dev, int chan, uint32_t data)
213 {
214 	int limit = 1000;
215 	struct bcm_mbox_softc *sc = device_get_softc(dev);
216 
217 	dprintf("bcm_mbox_write: chan %d, data %08x\n", chan, data);
218 	MBOX_LOCK(sc);
219 	sc->have_message[chan] = 0;
220 	while ((mbox_read_4(sc, REG_STATUS) & STATUS_FULL) && --limit)
221 		DELAY(5);
222 	if (limit == 0) {
223 		printf("bcm_mbox_write: STATUS_FULL stuck");
224 		MBOX_UNLOCK(sc);
225 		return (EAGAIN);
226 	}
227 	mbox_write_4(sc, REG_WRITE, MBOX_MSG(chan, data));
228 	MBOX_UNLOCK(sc);
229 
230 	return (0);
231 }
232 
233 static int
234 bcm_mbox_read(device_t dev, int chan, uint32_t *data)
235 {
236 	struct bcm_mbox_softc *sc = device_get_softc(dev);
237 	int err, read_chan;
238 
239 	dprintf("bcm_mbox_read: chan %d\n", chan);
240 
241 	err = 0;
242 	MBOX_LOCK(sc);
243 	if (!cold) {
244 		if (sc->have_message[chan] == 0) {
245 			if (mtx_sleep(&sc->have_message[chan], &sc->lock, 0,
246 			    "mbox", 10*hz) != 0) {
247 				device_printf(dev, "timeout waiting for message on chan %d\n", chan);
248 				err = ETIMEDOUT;
249 			}
250 		}
251 	} else {
252 		do {
253 			/* Wait for a message */
254 			while ((mbox_read_4(sc, REG_STATUS) & STATUS_EMPTY))
255 				;
256 			/* Read the message */
257 			if (bcm_mbox_read_msg(sc, &read_chan) != 0) {
258 				err = EINVAL;
259 				goto out;
260 			}
261 		} while (read_chan != chan);
262 	}
263 	/*
264 	 *  get data from intr handler, the same channel is never coming
265 	 *  because of holding sc lock.
266 	 */
267 	*data = MBOX_DATA(sc->msg[chan]);
268 	sc->msg[chan] = 0;
269 	sc->have_message[chan] = 0;
270 out:
271 	MBOX_UNLOCK(sc);
272 	dprintf("bcm_mbox_read: chan %d, data %08x\n", chan, *data);
273 
274 	return (err);
275 }
276 
277 static device_method_t bcm_mbox_methods[] = {
278 	DEVMETHOD(device_probe,		bcm_mbox_probe),
279 	DEVMETHOD(device_attach,	bcm_mbox_attach),
280 
281 	DEVMETHOD(mbox_read,		bcm_mbox_read),
282 	DEVMETHOD(mbox_write,		bcm_mbox_write),
283 
284 	DEVMETHOD_END
285 };
286 
287 static driver_t bcm_mbox_driver = {
288 	"mbox",
289 	bcm_mbox_methods,
290 	sizeof(struct bcm_mbox_softc),
291 };
292 
293 EARLY_DRIVER_MODULE(mbox, simplebus, bcm_mbox_driver, 0, 0,
294     BUS_PASS_INTERRUPT + BUS_PASS_ORDER_LAST);
295 
296 static void
297 bcm2835_mbox_dma_cb(void *arg, bus_dma_segment_t *segs, int nseg, int err)
298 {
299 	bus_addr_t *addr;
300 
301 	if (err)
302 		return;
303 	addr = (bus_addr_t *)arg;
304 	*addr = ARMC_TO_VCBUS(segs[0].ds_addr);
305 }
306 
307 static void *
308 bcm2835_mbox_init_dma(device_t dev, size_t len, bus_dma_tag_t *tag,
309     bus_dmamap_t *map, bus_addr_t *phys)
310 {
311 	void *buf;
312 	int err;
313 
314 	err = bus_dma_tag_create(bus_get_dma_tag(dev), 16, 0,
315 	    bcm283x_dmabus_peripheral_lowaddr(), BUS_SPACE_MAXADDR, NULL, NULL,
316 	    len, 1, len, 0, NULL, NULL, tag);
317 	if (err != 0) {
318 		device_printf(dev, "can't create DMA tag\n");
319 		return (NULL);
320 	}
321 
322 	err = bus_dmamem_alloc(*tag, &buf, 0, map);
323 	if (err != 0) {
324 		bus_dma_tag_destroy(*tag);
325 		device_printf(dev, "can't allocate dmamem\n");
326 		return (NULL);
327 	}
328 
329 	err = bus_dmamap_load(*tag, *map, buf, len, bcm2835_mbox_dma_cb,
330 	    phys, 0);
331 	if (err != 0) {
332 		bus_dmamem_free(*tag, buf, *map);
333 		bus_dma_tag_destroy(*tag);
334 		device_printf(dev, "can't load DMA map\n");
335 		return (NULL);
336 	}
337 
338 	return (buf);
339 }
340 
341 static int
342 bcm2835_mbox_err(device_t dev, bus_addr_t msg_phys, uint32_t resp_phys,
343 	struct bcm2835_mbox_hdr *msg, size_t len)
344 {
345 	int idx;
346 	struct bcm2835_mbox_tag_hdr *tag;
347 	uint8_t *last;
348 
349 	if ((uint32_t)msg_phys != resp_phys) {
350 		device_printf(dev, "response channel mismatch\n");
351 		return (EIO);
352 	}
353 	if (msg->code != BCM2835_MBOX_CODE_RESP_SUCCESS) {
354 		device_printf(dev, "mbox response error\n");
355 		return (EIO);
356 	}
357 
358 	/* Loop until the end tag. */
359 	tag = (struct bcm2835_mbox_tag_hdr *)(msg + 1);
360 	last = (uint8_t *)msg + len;
361 	for (idx = 0; tag->tag != 0; idx++) {
362 		/*
363 		 * When setting the GPIO config or state the firmware doesn't
364 		 * set tag->val_len correctly.
365 		 */
366 		if ((tag->tag == BCM2835_FIRMWARE_TAG_SET_GPIO_CONFIG ||
367 		     tag->tag == BCM2835_FIRMWARE_TAG_SET_GPIO_STATE) &&
368 		    tag->val_len == 0) {
369 			tag->val_len = BCM2835_MBOX_TAG_VAL_LEN_RESPONSE |
370 			    tag->val_buf_size;
371 		}
372 		if ((tag->val_len & BCM2835_MBOX_TAG_VAL_LEN_RESPONSE) == 0) {
373 			device_printf(dev, "tag %d response error\n", idx);
374 			return (EIO);
375 		}
376 		/* Clear the response bit. */
377 		tag->val_len &= ~BCM2835_MBOX_TAG_VAL_LEN_RESPONSE;
378 
379 		/* Next tag. */
380 		tag = (struct bcm2835_mbox_tag_hdr *)((uint8_t *)tag +
381 		    sizeof(*tag) + tag->val_buf_size);
382 
383 		if ((uint8_t *)tag > last) {
384 			device_printf(dev, "mbox buffer size error\n");
385 			return (EIO);
386 		}
387 	}
388 
389 	return (0);
390 }
391 
392 int
393 bcm2835_mbox_property(void *msg, size_t msg_size)
394 {
395 	struct bcm_mbox_softc *sc;
396 	bus_dma_tag_t msg_tag;
397 	bus_dmamap_t msg_map;
398 	bus_addr_t msg_phys;
399 	char *buf;
400 	uint32_t reg;
401 	device_t mbox;
402 	int err;
403 
404 	/* get mbox device */
405 	mbox = devclass_get_device(devclass_find("mbox"), 0);
406 	if (mbox == NULL)
407 		return (ENXIO);
408 
409 	sc = device_get_softc(mbox);
410 	sx_xlock(&sc->property_chan_lock);
411 
412 	/* Allocate memory for the message */
413 	buf = bcm2835_mbox_init_dma(mbox, msg_size, &msg_tag, &msg_map,
414 	    &msg_phys);
415 	if (buf == NULL) {
416 		err = ENOMEM;
417 		goto out;
418 	}
419 
420 	memcpy(buf, msg, msg_size);
421 
422 	bus_dmamap_sync(msg_tag, msg_map,
423 	    BUS_DMASYNC_PREWRITE);
424 
425 	MBOX_WRITE(mbox, BCM2835_MBOX_CHAN_PROP, (uint32_t)msg_phys);
426 	MBOX_READ(mbox, BCM2835_MBOX_CHAN_PROP, &reg);
427 
428 	bus_dmamap_sync(msg_tag, msg_map,
429 	    BUS_DMASYNC_PREREAD);
430 
431 	memcpy(msg, buf, msg_size);
432 
433 	err = bcm2835_mbox_err(mbox, msg_phys, reg,
434 	    (struct bcm2835_mbox_hdr *)msg, msg_size);
435 
436 	bus_dmamap_unload(msg_tag, msg_map);
437 	bus_dmamem_free(msg_tag, buf, msg_map);
438 	bus_dma_tag_destroy(msg_tag);
439 out:
440 	sx_xunlock(&sc->property_chan_lock);
441 	return (err);
442 }
443 
444 int
445 bcm2835_mbox_set_power_state(uint32_t device_id, boolean_t on)
446 {
447 	struct msg_set_power_state msg;
448 	int err;
449 
450 	memset(&msg, 0, sizeof(msg));
451 	msg.hdr.buf_size = sizeof(msg);
452 	msg.hdr.code = BCM2835_MBOX_CODE_REQ;
453 	msg.tag_hdr.tag = BCM2835_MBOX_TAG_SET_POWER_STATE;
454 	msg.tag_hdr.val_buf_size = sizeof(msg.body);
455 	msg.tag_hdr.val_len = sizeof(msg.body.req);
456 	msg.body.req.device_id = device_id;
457 	msg.body.req.state = (on ? BCM2835_MBOX_POWER_ON : 0) |
458 	    BCM2835_MBOX_POWER_WAIT;
459 	msg.end_tag = 0;
460 
461 	err = bcm2835_mbox_property(&msg, sizeof(msg));
462 
463 	return (err);
464 }
465 
466 int
467 bcm2835_mbox_notify_xhci_reset(uint32_t pci_dev_addr)
468 {
469 	struct msg_notify_xhci_reset msg;
470 	int err;
471 
472 	memset(&msg, 0, sizeof(msg));
473 	msg.hdr.buf_size = sizeof(msg);
474 	msg.hdr.code = BCM2835_MBOX_CODE_REQ;
475 	msg.tag_hdr.tag = BCM2835_MBOX_TAG_NOTIFY_XHCI_RESET;
476 	msg.tag_hdr.val_buf_size = sizeof(msg.body);
477 	msg.tag_hdr.val_len = sizeof(msg.body.req);
478 	msg.body.req.pci_device_addr = pci_dev_addr;
479 	msg.end_tag = 0;
480 
481 	err = bcm2835_mbox_property(&msg, sizeof(msg));
482 
483 	return (err);
484 }
485 
486 int
487 bcm2835_mbox_get_clock_rate(uint32_t clock_id, uint32_t *hz)
488 {
489 	struct msg_get_clock_rate msg;
490 	int err;
491 
492 	memset(&msg, 0, sizeof(msg));
493 	msg.hdr.buf_size = sizeof(msg);
494 	msg.hdr.code = BCM2835_MBOX_CODE_REQ;
495 	msg.tag_hdr.tag = BCM2835_MBOX_TAG_GET_CLOCK_RATE;
496 	msg.tag_hdr.val_buf_size = sizeof(msg.body);
497 	msg.tag_hdr.val_len = sizeof(msg.body.req);
498 	msg.body.req.clock_id = clock_id;
499 	msg.end_tag = 0;
500 
501 	err = bcm2835_mbox_property(&msg, sizeof(msg));
502 	*hz = msg.body.resp.rate_hz;
503 
504 	return (err);
505 }
506 
507 int
508 bcm2835_mbox_fb_get_w_h(struct bcm2835_fb_config *fb)
509 {
510 	int err;
511 	struct msg_fb_get_w_h msg;
512 
513 	memset(&msg, 0, sizeof(msg));
514 	msg.hdr.buf_size = sizeof(msg);
515 	msg.hdr.code = BCM2835_MBOX_CODE_REQ;
516 	BCM2835_MBOX_INIT_TAG(&msg.physical_w_h, GET_PHYSICAL_W_H);
517 	msg.physical_w_h.tag_hdr.val_len = 0;
518 	msg.end_tag = 0;
519 
520 	err = bcm2835_mbox_property(&msg, sizeof(msg));
521 	if (err == 0) {
522 		fb->xres = msg.physical_w_h.body.resp.width;
523 		fb->yres = msg.physical_w_h.body.resp.height;
524 	}
525 
526 	return (err);
527 }
528 
529 int
530 bcm2835_mbox_fb_get_bpp(struct bcm2835_fb_config *fb)
531 {
532 	int err;
533 	struct msg_fb_get_bpp msg;
534 
535 	memset(&msg, 0, sizeof(msg));
536 	msg.hdr.buf_size = sizeof(msg);
537 	msg.hdr.code = BCM2835_MBOX_CODE_REQ;
538 	BCM2835_MBOX_INIT_TAG(&msg.bpp, GET_DEPTH);
539 	msg.bpp.tag_hdr.val_len = 0;
540 	msg.end_tag = 0;
541 
542 	err = bcm2835_mbox_property(&msg, sizeof(msg));
543 	if (err == 0)
544 		fb->bpp = msg.bpp.body.resp.bpp;
545 
546 	return (err);
547 }
548 
549 int
550 bcm2835_mbox_fb_init(struct bcm2835_fb_config *fb)
551 {
552 	int err;
553 	struct msg_fb_setup msg;
554 
555 	memset(&msg, 0, sizeof(msg));
556 	msg.hdr.buf_size = sizeof(msg);
557 	msg.hdr.code = BCM2835_MBOX_CODE_REQ;
558 	BCM2835_MBOX_INIT_TAG(&msg.physical_w_h, SET_PHYSICAL_W_H);
559 	msg.physical_w_h.body.req.width = fb->xres;
560 	msg.physical_w_h.body.req.height = fb->yres;
561 	BCM2835_MBOX_INIT_TAG(&msg.virtual_w_h, SET_VIRTUAL_W_H);
562 	msg.virtual_w_h.body.req.width = fb->vxres;
563 	msg.virtual_w_h.body.req.height = fb->vyres;
564 	BCM2835_MBOX_INIT_TAG(&msg.offset, SET_VIRTUAL_OFFSET);
565 	msg.offset.body.req.x = fb->xoffset;
566 	msg.offset.body.req.y = fb->yoffset;
567 	BCM2835_MBOX_INIT_TAG(&msg.depth, SET_DEPTH);
568 	msg.depth.body.req.bpp = fb->bpp;
569 	BCM2835_MBOX_INIT_TAG(&msg.alpha, SET_ALPHA_MODE);
570 	msg.alpha.body.req.alpha = BCM2835_MBOX_ALPHA_MODE_IGNORED;
571 	BCM2835_MBOX_INIT_TAG(&msg.buffer, ALLOCATE_BUFFER);
572 	msg.buffer.body.req.alignment = PAGE_SIZE;
573 	BCM2835_MBOX_INIT_TAG(&msg.pitch, GET_PITCH);
574 	msg.end_tag = 0;
575 
576 	err = bcm2835_mbox_property(&msg, sizeof(msg));
577 	if (err == 0) {
578 		fb->xres = msg.physical_w_h.body.resp.width;
579 		fb->yres = msg.physical_w_h.body.resp.height;
580 		fb->vxres = msg.virtual_w_h.body.resp.width;
581 		fb->vyres = msg.virtual_w_h.body.resp.height;
582 		fb->xoffset = msg.offset.body.resp.x;
583 		fb->yoffset = msg.offset.body.resp.y;
584 		fb->pitch = msg.pitch.body.resp.pitch;
585 		fb->base = VCBUS_TO_ARMC(msg.buffer.body.resp.fb_address);
586 		fb->size = msg.buffer.body.resp.fb_size;
587 	}
588 
589 	return (err);
590 }
591