aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/bcm27xx/patches-5.10/950-0042-Pulled-in-the-multi-frame-buffer-support-from-the-Pi.patch
blob: 884753f87246e0000ff56ec1a117aced5747e405 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
From 4ac7128970e15d83ef3c2a65e65ca9ee4096c9d1 Mon Sep 17 00:00:00 2001
From: James Hughes <james.hughes@raspberrypi.org>
Date: Thu, 14 Mar 2019 13:27:54 +0000
Subject: [PATCH] Pulled in the multi frame buffer support from the Pi3
 repo

---
 drivers/video/fbdev/bcm2708_fb.c           | 457 +++++++++++++++------
 include/soc/bcm2835/raspberrypi-firmware.h |  13 +
 2 files changed, 337 insertions(+), 133 deletions(-)

--- a/drivers/video/fbdev/bcm2708_fb.c
+++ b/drivers/video/fbdev/bcm2708_fb.c
@@ -2,6 +2,7 @@
  *  linux/drivers/video/bcm2708_fb.c
  *
  * Copyright (C) 2010 Broadcom
+ * Copyright (C) 2018 Raspberry Pi (Trading) Ltd
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file COPYING in the main directory of this archive
@@ -13,6 +14,7 @@
  * Copyright 1999-2001 Jeff Garzik <jgarzik@pobox.com>
  *
  */
+
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
@@ -33,6 +35,7 @@
 #include <linux/io.h>
 #include <linux/dma-mapping.h>
 #include <soc/bcm2835/raspberrypi-firmware.h>
+#include <linux/mutex.h>
 
 //#define BCM2708_FB_DEBUG
 #define MODULE_NAME "bcm2708_fb"
@@ -79,64 +82,150 @@ struct bcm2708_fb_stats {
 	u32 dma_irqs;
 };
 
+struct vc4_display_settings_t {
+	u32 display_num;
+	u32 width;
+	u32 height;
+	u32 depth;
+	u32 pitch;
+	u32 virtual_width;
+	u32 virtual_height;
+	u32 virtual_width_offset;
+	u32 virtual_height_offset;
+	unsigned long fb_bus_address;
+};
+
+struct bcm2708_fb_dev;
+
 struct bcm2708_fb {
 	struct fb_info fb;
 	struct platform_device *dev;
-	struct rpi_firmware *fw;
 	u32 cmap[16];
 	u32 gpu_cmap[256];
-	int dma_chan;
-	int dma_irq;
-	void __iomem *dma_chan_base;
-	void *cb_base;		/* DMA control blocks */
-	dma_addr_t cb_handle;
 	struct dentry *debugfs_dir;
-	wait_queue_head_t dma_waitq;
-	struct bcm2708_fb_stats stats;
+	struct dentry *debugfs_subdir;
 	unsigned long fb_bus_address;
-	bool disable_arm_alloc;
+	struct { u32 base, length; } gpu;
+	struct vc4_display_settings_t display_settings;
+	struct debugfs_regset32 screeninfo_regset;
+	struct bcm2708_fb_dev *fbdev;
 	unsigned int image_size;
 	dma_addr_t dma_addr;
 	void *cpuaddr;
 };
 
+#define MAX_FRAMEBUFFERS 3
+
+struct bcm2708_fb_dev {
+	int firmware_supports_multifb;
+	/* Protects the DMA system from multiple FB access */
+	struct mutex dma_mutex;
+	int dma_chan;
+	int dma_irq;
+	void __iomem *dma_chan_base;
+	wait_queue_head_t dma_waitq;
+	bool disable_arm_alloc;
+	struct bcm2708_fb_stats dma_stats;
+	void *cb_base;	/* DMA control blocks */
+	dma_addr_t cb_handle;
+	int instance_count;
+	int num_displays;
+	struct rpi_firmware *fw;
+	struct bcm2708_fb displays[MAX_FRAMEBUFFERS];
+};
+
 #define to_bcm2708(info)	container_of(info, struct bcm2708_fb, fb)
 
 static void bcm2708_fb_debugfs_deinit(struct bcm2708_fb *fb)
 {
-	debugfs_remove_recursive(fb->debugfs_dir);
-	fb->debugfs_dir = NULL;
+	debugfs_remove_recursive(fb->debugfs_subdir);
+	fb->debugfs_subdir = NULL;
+
+	fb->fbdev->instance_count--;
+
+	if (!fb->fbdev->instance_count) {
+		debugfs_remove_recursive(fb->debugfs_dir);
+		fb->debugfs_dir = NULL;
+	}
 }
 
 static int bcm2708_fb_debugfs_init(struct bcm2708_fb *fb)
 {
+	char buf[3];
+	struct bcm2708_fb_dev *fbdev = fb->fbdev;
+
 	static struct debugfs_reg32 stats_registers[] = {
-		{
-			"dma_copies",
-			offsetof(struct bcm2708_fb_stats, dma_copies)
-		},
-		{
-			"dma_irqs",
-			offsetof(struct bcm2708_fb_stats, dma_irqs)
-		},
+	{"dma_copies", offsetof(struct bcm2708_fb_stats, dma_copies)},
+	{"dma_irqs",   offsetof(struct bcm2708_fb_stats, dma_irqs)},
 	};
 
-	fb->debugfs_dir = debugfs_create_dir(DRIVER_NAME, NULL);
+	static struct debugfs_reg32 screeninfo[] = {
+	{"width",	 offsetof(struct fb_var_screeninfo, xres)},
+	{"height",	 offsetof(struct fb_var_screeninfo, yres)},
+	{"bpp",		 offsetof(struct fb_var_screeninfo, bits_per_pixel)},
+	{"xres_virtual", offsetof(struct fb_var_screeninfo, xres_virtual)},
+	{"yres_virtual", offsetof(struct fb_var_screeninfo, yres_virtual)},
+	{"xoffset",	 offsetof(struct fb_var_screeninfo, xoffset)},
+	{"yoffset",	 offsetof(struct fb_var_screeninfo, yoffset)},
+	};
+
+	fb->debugfs_dir = debugfs_lookup(DRIVER_NAME, NULL);
+
+	if (!fb->debugfs_dir)
+		fb->debugfs_dir = debugfs_create_dir(DRIVER_NAME, NULL);
+
 	if (!fb->debugfs_dir) {
-		pr_warn("%s: could not create debugfs entry\n",
-			__func__);
+		dev_warn(fb->fb.dev, "%s: could not create debugfs folder\n",
+			 __func__);
 		return -EFAULT;
 	}
 
-	fb->stats.regset.regs = stats_registers;
-	fb->stats.regset.nregs = ARRAY_SIZE(stats_registers);
-	fb->stats.regset.base = &fb->stats;
+	snprintf(buf, sizeof(buf), "%u", fb->display_settings.display_num);
+
+	fb->debugfs_subdir = debugfs_create_dir(buf, fb->debugfs_dir);
 
 	debugfs_create_regset32("stats", 0444, fb->debugfs_dir,
 				&fb->stats.regset);
+
+	if (!fb->debugfs_subdir) {
+		dev_warn(fb->fb.dev, "%s: could not create debugfs entry %u\n",
+			 __func__, fb->display_settings.display_num);
+		return -EFAULT;
+	}
+
+	fbdev->dma_stats.regset.regs = stats_registers;
+	fbdev->dma_stats.regset.nregs = ARRAY_SIZE(stats_registers);
+	fbdev->dma_stats.regset.base = &fbdev->dma_stats;
+
+	debugfs_create_regset32("dma_stats", 0444, fb->debugfs_subdir,
+				&fbdev->dma_stats.regset);
+
+	fb->screeninfo_regset.regs = screeninfo;
+	fb->screeninfo_regset.nregs = ARRAY_SIZE(screeninfo);
+	fb->screeninfo_regset.base = &fb->fb.var;
+
+	debugfs_create_regset32("screeninfo", 0444, fb->debugfs_subdir,
+				&fb->screeninfo_regset);
+
+	fbdev->instance_count++;
+
 	return 0;
 }
 
+static void set_display_num(struct bcm2708_fb *fb)
+{
+	if (fb && fb->fbdev && fb->fbdev->firmware_supports_multifb) {
+		u32 tmp = fb->display_settings.display_num;
+
+		if (rpi_firmware_property(fb->fbdev->fw,
+					  RPI_FIRMWARE_FRAMEBUFFER_SET_DISPLAY_NUM,
+					  &tmp,
+					  sizeof(tmp)))
+			dev_warn_once(fb->fb.dev,
+				      "Set display number call failed. Old GPU firmware?");
+	}
+}
+
 static int bcm2708_fb_set_bitfields(struct fb_var_screeninfo *var)
 {
 	int ret = 0;
@@ -214,11 +303,11 @@ static int bcm2708_fb_check_var(struct f
 				struct fb_info *info)
 {
 	/* info input, var output */
-	print_debug("%s(%p) %dx%d (%dx%d), %d, %d\n",
+	print_debug("%s(%p) %ux%u (%ux%u), %ul, %u\n",
 		    __func__, info, info->var.xres, info->var.yres,
 		    info->var.xres_virtual, info->var.yres_virtual,
-		    (int)info->screen_size, info->var.bits_per_pixel);
-	print_debug("%s(%p) %dx%d (%dx%d), %d\n", __func__, var, var->xres,
+		    info->screen_size, info->var.bits_per_pixel);
+	print_debug("%s(%p) %ux%u (%ux%u), %u\n", __func__, var, var->xres,
 		    var->yres, var->xres_virtual, var->yres_virtual,
 		    var->bits_per_pixel);
 
@@ -281,17 +370,24 @@ static int bcm2708_fb_set_par(struct fb_
 	};
 	int ret, image_size;
 
-
-	print_debug("%s(%p) %dx%d (%dx%d), %d, %d\n", __func__, info,
+	print_debug("%s(%p) %dx%d (%dx%d), %d, %d (display %d)\n", __func__,
+		    info,
 		    info->var.xres, info->var.yres, info->var.xres_virtual,
 		    info->var.yres_virtual, (int)info->screen_size,
-		    info->var.bits_per_pixel);
+		    info->var.bits_per_pixel, value);
+
+	/* Need to set the display number to act on first
+	 * Cannot do it in the tag list because on older firmware the call
+	 * will fail and stop the rest of the list being executed.
+	 * We can ignore this call failing as the default at other end is 0
+	 */
+	set_display_num(fb);
 
 	/* Try allocating our own buffer. We can specify all the parameters */
 	image_size = ((info->var.xres * info->var.yres) *
 		      info->var.bits_per_pixel) >> 3;
 
-	if (!fb->disable_arm_alloc &&
+	if (!fb->fbdev->disable_arm_alloc &&
 	    (image_size != fb->image_size || !fb->dma_addr)) {
 		if (fb->dma_addr) {
 			dma_free_coherent(info->device, fb->image_size,
@@ -306,7 +402,7 @@ static int bcm2708_fb_set_par(struct fb_
 
 		if (!fb->cpuaddr) {
 			fb->dma_addr = 0;
-			fb->disable_arm_alloc = true;
+			fb->fbdev->disable_arm_alloc = true;
 		} else {
 			fb->image_size = image_size;
 		}
@@ -317,7 +413,7 @@ static int bcm2708_fb_set_par(struct fb_
 		fbinfo.screen_size = image_size;
 		fbinfo.pitch = (info->var.xres * info->var.bits_per_pixel) >> 3;
 
-		ret = rpi_firmware_property_list(fb->fw, &fbinfo,
+		ret = rpi_firmware_property_list(fb->fbdev->fw, &fbinfo,
 						 sizeof(fbinfo));
 		if (ret || fbinfo.base != fb->dma_addr) {
 			/* Firmware either failed, or assigned a different base
@@ -330,7 +426,7 @@ static int bcm2708_fb_set_par(struct fb_
 			fb->image_size = 0;
 			fb->cpuaddr = NULL;
 			fb->dma_addr = 0;
-			fb->disable_arm_alloc = true;
+			fb->fbdev->disable_arm_alloc = true;
 		}
 	} else {
 		/* Our allocation failed - drop into the old scheme of
@@ -349,7 +445,7 @@ static int bcm2708_fb_set_par(struct fb_
 		fbinfo.tag6.tag = RPI_FIRMWARE_FRAMEBUFFER_GET_PITCH;
 		fbinfo.pitch = 0;
 
-		ret = rpi_firmware_property_list(fb->fw, &fbinfo,
+		ret = rpi_firmware_property_list(fb->fbdev->fw, &fbinfo,
 						 sizeof(fbinfo));
 		if (ret) {
 			dev_err(info->device,
@@ -439,7 +535,10 @@ static int bcm2708_fb_setcolreg(unsigned
 			packet->length = regno + 1;
 			memcpy(packet->cmap, fb->gpu_cmap,
 			       sizeof(packet->cmap));
-			ret = rpi_firmware_property(fb->fw,
+
+			set_display_num(fb);
+
+			ret = rpi_firmware_property(fb->fbdev->fw,
 						    RPI_FIRMWARE_FRAMEBUFFER_SET_PALETTE,
 						    packet,
 						    (2 + packet->length) * sizeof(u32));
@@ -478,8 +577,11 @@ static int bcm2708_fb_blank(int blank_mo
 		return -EINVAL;
 	}
 
-	ret = rpi_firmware_property(fb->fw, RPI_FIRMWARE_FRAMEBUFFER_BLANK,
+	set_display_num(fb);
+
+	ret = rpi_firmware_property(fb->fbdev->fw, RPI_FIRMWARE_FRAMEBUFFER_BLANK,
 				    &value, sizeof(value));
+
 	if (ret)
 		dev_err(info->device, "%s(%d) failed: %d\n", __func__,
 			blank_mode, ret);
@@ -496,12 +598,14 @@ static int bcm2708_fb_pan_display(struct
 	info->var.yoffset = var->yoffset;
 	result = bcm2708_fb_set_par(info);
 	if (result != 0)
-		pr_err("%s(%d,%d) returns=%d\n", __func__, var->xoffset,
+		pr_err("%s(%u,%u) returns=%d\n", __func__, var->xoffset,
 		       var->yoffset, result);
 	return result;
 }
 
 static int bcm2708_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
+static int bcm2708_ioctl(struct fb_info *info, unsigned int cmd,
+			 unsigned long arg)
 {
 	struct bcm2708_fb *fb = to_bcm2708(info);
 	u32 dummy = 0;
@@ -509,7 +613,9 @@ static int bcm2708_ioctl(struct fb_info
 
 	switch (cmd) {
 	case FBIO_WAITFORVSYNC:
-		ret = rpi_firmware_property(fb->fw,
+		set_display_num(fb);
+
+		ret = rpi_firmware_property(fb->fbdev->fw,
 					    RPI_FIRMWARE_FRAMEBUFFER_SET_VSYNC,
 					    &dummy, sizeof(dummy));
 		break;
@@ -526,23 +632,22 @@ static int bcm2708_ioctl(struct fb_info
 static void bcm2708_fb_fillrect(struct fb_info *info,
 				const struct fb_fillrect *rect)
 {
-	/* (is called) print_debug("bcm2708_fb_fillrect\n"); */
 	cfb_fillrect(info, rect);
 }
 
 /* A helper function for configuring dma control block */
 static void set_dma_cb(struct bcm2708_dma_cb *cb,
-		       int        burst_size,
-		       dma_addr_t dst,
-		       int        dst_stride,
-		       dma_addr_t src,
-		       int        src_stride,
-		       int        w,
-		       int        h)
+		int        burst_size,
+		dma_addr_t dst,
+		int        dst_stride,
+		dma_addr_t src,
+		int        src_stride,
+		int        w,
+		int        h)
 {
 	cb->info = BCM2708_DMA_BURST(burst_size) | BCM2708_DMA_S_WIDTH |
-		   BCM2708_DMA_S_INC | BCM2708_DMA_D_WIDTH |
-		   BCM2708_DMA_D_INC | BCM2708_DMA_TDMODE;
+		BCM2708_DMA_S_INC | BCM2708_DMA_D_WIDTH |
+		BCM2708_DMA_D_INC | BCM2708_DMA_TDMODE;
 	cb->dst = dst;
 	cb->src = src;
 	/*
@@ -560,15 +665,19 @@ static void bcm2708_fb_copyarea(struct f
 				const struct fb_copyarea *region)
 {
 	struct bcm2708_fb *fb = to_bcm2708(info);
-	struct bcm2708_dma_cb *cb = fb->cb_base;
+	struct bcm2708_fb_dev *fbdev = fb->fbdev;
+	struct bcm2708_dma_cb *cb = fbdev->cb_base;
 	int bytes_per_pixel = (info->var.bits_per_pixel + 7) >> 3;
 
 	/* Channel 0 supports larger bursts and is a bit faster */
-	int burst_size = (fb->dma_chan == 0) ? 8 : 2;
+	int burst_size = (fbdev->dma_chan == 0) ? 8 : 2;
 	int pixels = region->width * region->height;
 
-	/* Fallback to cfb_copyarea() if we don't like something */
-	if (bytes_per_pixel > 4 ||
+	/* If DMA is currently in use (ie being used on another FB), then
+	 * rather than wait for it to finish, just use the cfb_copyarea
+	 */
+	if (!mutex_trylock(&fbdev->dma_mutex) ||
+	    bytes_per_pixel > 4 ||
 	    info->var.xres * info->var.yres > 1920 * 1200 ||
 	    region->width <= 0 || region->width > info->var.xres ||
 	    region->height <= 0 || region->height > info->var.yres ||
@@ -595,8 +704,8 @@ static void bcm2708_fb_copyarea(struct f
 		 * 1920x1200 resolution at 32bpp pixel depth.
 		 */
 		int y;
-		dma_addr_t control_block_pa = fb->cb_handle;
-		dma_addr_t scratchbuf = fb->cb_handle + 16 * 1024;
+		dma_addr_t control_block_pa = fbdev->cb_handle;
+		dma_addr_t scratchbuf = fbdev->cb_handle + 16 * 1024;
 		int scanline_size = bytes_per_pixel * region->width;
 		int scanlines_per_cb = (64 * 1024 - 16 * 1024) / scanline_size;
 
@@ -646,10 +755,10 @@ static void bcm2708_fb_copyarea(struct f
 		}
 		set_dma_cb(cb, burst_size,
 			   fb->fb_bus_address + dy * fb->fb.fix.line_length +
-						   bytes_per_pixel * region->dx,
+			   bytes_per_pixel * region->dx,
 			   stride,
 			   fb->fb_bus_address + sy * fb->fb.fix.line_length +
-						   bytes_per_pixel * region->sx,
+			   bytes_per_pixel * region->sx,
 			   stride,
 			   region->width * bytes_per_pixel,
 			   region->height);
@@ -659,32 +768,33 @@ static void bcm2708_fb_copyarea(struct f
 	cb->next = 0;
 
 	if (pixels < dma_busy_wait_threshold) {
-		bcm_dma_start(fb->dma_chan_base, fb->cb_handle);
-		bcm_dma_wait_idle(fb->dma_chan_base);
+		bcm_dma_start(fbdev->dma_chan_base, fbdev->cb_handle);
+		bcm_dma_wait_idle(fbdev->dma_chan_base);
 	} else {
-		void __iomem *dma_chan = fb->dma_chan_base;
+		void __iomem *local_dma_chan = fbdev->dma_chan_base;
 
 		cb->info |= BCM2708_DMA_INT_EN;
-		bcm_dma_start(fb->dma_chan_base, fb->cb_handle);
-		while (bcm_dma_is_busy(dma_chan)) {
-			wait_event_interruptible(fb->dma_waitq,
-						 !bcm_dma_is_busy(dma_chan));
+		bcm_dma_start(fbdev->dma_chan_base, fbdev->cb_handle);
+		while (bcm_dma_is_busy(local_dma_chan)) {
+			wait_event_interruptible(fbdev->dma_waitq,
+						 !bcm_dma_is_busy(local_dma_chan));
 		}
-		fb->stats.dma_irqs++;
+		fbdev->dma_stats.dma_irqs++;
 	}
-	fb->stats.dma_copies++;
+	fbdev->dma_stats.dma_copies++;
+
+	mutex_unlock(&fbdev->dma_mutex);
 }
 
 static void bcm2708_fb_imageblit(struct fb_info *info,
 				 const struct fb_image *image)
 {
-	/* (is called) print_debug("bcm2708_fb_imageblit\n"); */
 	cfb_imageblit(info, image);
 }
 
 static irqreturn_t bcm2708_fb_dma_irq(int irq, void *cxt)
 {
-	struct bcm2708_fb *fb = cxt;
+	struct bcm2708_fb_dev *fbdev = cxt;
 
 	/* FIXME: should read status register to check if this is
 	 * actually interrupting us or not, in case this interrupt
@@ -694,9 +804,9 @@ static irqreturn_t bcm2708_fb_dma_irq(in
 	 */
 
 	/* acknowledge the interrupt */
-	writel(BCM2708_DMA_INT, fb->dma_chan_base + BCM2708_DMA_CS);
+	writel(BCM2708_DMA_INT, fbdev->dma_chan_base + BCM2708_DMA_CS);
 
-	wake_up(&fb->dma_waitq);
+	wake_up(&fbdev->dma_waitq);
 	return IRQ_HANDLED;
 }
 
@@ -729,11 +839,23 @@ static int bcm2708_fb_register(struct bc
 	fb->fb.fix.ywrapstep = 0;
 	fb->fb.fix.accel = FB_ACCEL_NONE;
 
-	fb->fb.var.xres = fbwidth;
-	fb->fb.var.yres = fbheight;
-	fb->fb.var.xres_virtual = fbwidth;
-	fb->fb.var.yres_virtual = fbheight;
-	fb->fb.var.bits_per_pixel = fbdepth;
+	/* If we have data from the VC4 on FB's, use that, otherwise use the
+	 * module parameters
+	 */
+	if (fb->display_settings.width) {
+		fb->fb.var.xres = fb->display_settings.width;
+		fb->fb.var.yres = fb->display_settings.height;
+		fb->fb.var.xres_virtual = fb->fb.var.xres;
+		fb->fb.var.yres_virtual = fb->fb.var.yres;
+		fb->fb.var.bits_per_pixel = fb->display_settings.depth;
+	} else {
+		fb->fb.var.xres = fbwidth;
+		fb->fb.var.yres = fbheight;
+		fb->fb.var.xres_virtual = fbwidth;
+		fb->fb.var.yres_virtual = fbheight;
+		fb->fb.var.bits_per_pixel = fbdepth;
+	}
+
 	fb->fb.var.vmode = FB_VMODE_NONINTERLACED;
 	fb->fb.var.activate = FB_ACTIVATE_NOW;
 	fb->fb.var.nonstd = 0;
@@ -749,26 +871,23 @@ static int bcm2708_fb_register(struct bc
 	fb->fb.monspecs.dclkmax = 100000000;
 
 	bcm2708_fb_set_bitfields(&fb->fb.var);
-	init_waitqueue_head(&fb->dma_waitq);
 
 	/*
 	 * Allocate colourmap.
 	 */
-
 	fb_set_var(&fb->fb, &fb->fb.var);
+
 	ret = bcm2708_fb_set_par(&fb->fb);
+
 	if (ret)
 		return ret;
 
-	print_debug("BCM2708FB: registering framebuffer (%dx%d@%d) (%d)\n",
-		    fbwidth, fbheight, fbdepth, fbswap);
-
 	ret = register_framebuffer(&fb->fb);
-	print_debug("BCM2708FB: register framebuffer (%d)\n", ret);
+
 	if (ret == 0)
 		goto out;
 
-	print_debug("BCM2708FB: cannot register framebuffer (%d)\n", ret);
+	dev_warn(fb->fb.dev, "Unable to register framebuffer (%d)\n", ret);
 out:
 	return ret;
 }
@@ -777,10 +896,18 @@ static int bcm2708_fb_probe(struct platf
 {
 	struct device_node *fw_np;
 	struct rpi_firmware *fw;
-	struct bcm2708_fb *fb;
-	int ret;
+	int ret, i;
+	u32 num_displays;
+	struct bcm2708_fb_dev *fbdev;
+	struct { u32 base, length; } gpu_mem;
+
+	fbdev = devm_kzalloc(&dev->dev, sizeof(*fbdev), GFP_KERNEL);
+
+	if (!fbdev)
+		return -ENOMEM;
 
 	fw_np = of_parse_phandle(dev->dev.of_node, "firmware", 0);
+
 /* Remove comment when booting without Device Tree is no longer supported
  *	if (!fw_np) {
  *		dev_err(&dev->dev, "Missing firmware node\n");
@@ -788,90 +915,154 @@ static int bcm2708_fb_probe(struct platf
  *	}
  */
 	fw = rpi_firmware_get(fw_np);
+	fbdev->fw = fw;
+
 	if (!fw)
 		return -EPROBE_DEFER;
 
-	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
-	if (!fb) {
-		ret = -ENOMEM;
-		goto free_region;
+	ret = rpi_firmware_property(fw,
+				    RPI_FIRMWARE_FRAMEBUFFER_GET_NUM_DISPLAYS,
+				    &num_displays, sizeof(u32));
+
+	/* If we fail to get the number of displays, or it returns 0, then
+	 * assume old firmware that doesn't have the mailbox call, so just
+	 * set one display
+	 */
+	if (ret || num_displays == 0) {
+		num_displays = 1;
+		dev_err(&dev->dev,
+			"Unable to determine number of FB's. Assuming 1\n");
+		ret = 0;
+	} else {
+		fbdev->firmware_supports_multifb = 1;
+	}
+
+	if (num_displays > MAX_FRAMEBUFFERS) {
+		dev_warn(&dev->dev,
+			 "More displays reported from firmware than supported in driver (%u vs %u)",
+			 num_displays, MAX_FRAMEBUFFERS);
+		num_displays = MAX_FRAMEBUFFERS;
 	}
 
-	fb->fw = fw;
-	bcm2708_fb_debugfs_init(fb);
+	dev_info(&dev->dev, "FB found %d display(s)\n", num_displays);
+
+	/* Set up the DMA information. Note we have just one set of DMA
+	 * parameters to work with all the FB's so requires synchronising when
+	 * being used
+	 */
+
+	mutex_init(&fbdev->dma_mutex);
 
-	fb->cb_base = dma_alloc_wc(&dev->dev, SZ_64K,
-					     &fb->cb_handle, GFP_KERNEL);
-	if (!fb->cb_base) {
+	fbdev->cb_base = dma_alloc_wc(&dev->dev, SZ_64K,
+						&fbdev->cb_handle,
+						GFP_KERNEL);
+	if (!fbdev->cb_base) {
 		dev_err(&dev->dev, "cannot allocate DMA CBs\n");
 		ret = -ENOMEM;
 		goto free_fb;
 	}
 
-	pr_info("BCM2708FB: allocated DMA memory %pad\n", &fb->cb_handle);
-
 	ret = bcm_dma_chan_alloc(BCM_DMA_FEATURE_BULK,
-				 &fb->dma_chan_base, &fb->dma_irq);
+				 &fbdev->dma_chan_base,
+				 &fbdev->dma_irq);
 	if (ret < 0) {
-		dev_err(&dev->dev, "couldn't allocate a DMA channel\n");
+		dev_err(&dev->dev, "Couldn't allocate a DMA channel\n");
 		goto free_cb;
 	}
-	fb->dma_chan = ret;
+	fbdev->dma_chan = ret;
 
-	ret = request_irq(fb->dma_irq, bcm2708_fb_dma_irq,
-			  0, "bcm2708_fb dma", fb);
+	ret = request_irq(fbdev->dma_irq, bcm2708_fb_dma_irq,
+			  0, "bcm2708_fb DMA", fbdev);
 	if (ret) {
-		pr_err("%s: failed to request DMA irq\n", __func__);
+		dev_err(&dev->dev,
+			"Failed to request DMA irq\n");
 		goto free_dma_chan;
 	}
 
-	pr_info("BCM2708FB: allocated DMA channel %d\n", fb->dma_chan);
+	rpi_firmware_property(fbdev->fw,
+			      RPI_FIRMWARE_GET_VC_MEMORY,
+			      &gpu_mem, sizeof(gpu_mem));
+
+	for (i = 0; i < num_displays; i++) {
+		struct bcm2708_fb *fb = &fbdev->displays[i];
+
+		fb->display_settings.display_num = i;
+		fb->dev = dev;
+		fb->fb.device = &dev->dev;
+		fb->fbdev = fbdev;
+
+		fb->gpu.base = gpu_mem.base;
+		fb->gpu.length = gpu_mem.length;
+
+		if (fbdev->firmware_supports_multifb) {
+			ret = rpi_firmware_property(fw,
+						    RPI_FIRMWARE_FRAMEBUFFER_GET_DISPLAY_SETTINGS,
+						    &fb->display_settings,
+						    GET_DISPLAY_SETTINGS_PAYLOAD_SIZE);
+		} else {
+			memset(&fb->display_settings, 0,
+			       sizeof(fb->display_settings));
+		}
 
-	fb->dev = dev;
-	fb->fb.device = &dev->dev;
+		ret = bcm2708_fb_register(fb);
 
-	/* failure here isn't fatal, but we'll fail in vc_mem_copy if
-	 * fb->gpu is not valid
-	 */
-	rpi_firmware_property(fb->fw, RPI_FIRMWARE_GET_VC_MEMORY, &fb->gpu,
-			      sizeof(fb->gpu));
+		if (ret == 0) {
+			bcm2708_fb_debugfs_init(fb);
 
-	ret = bcm2708_fb_register(fb);
-	if (ret == 0) {
-		platform_set_drvdata(dev, fb);
-		goto out;
+			fbdev->num_displays++;
+
+			dev_info(&dev->dev,
+				 "Registered framebuffer for display %u, size %ux%u\n",
+				 fb->display_settings.display_num,
+				 fb->fb.var.xres,
+				 fb->fb.var.yres);
+		} else {
+			// Use this to flag if this FB entry is in use.
+			fb->fbdev = NULL;
+		}
+	}
+
+	// Did we actually successfully create any FB's?
+	if (fbdev->num_displays) {
+		init_waitqueue_head(&fbdev->dma_waitq);
+		platform_set_drvdata(dev, fbdev);
+		return ret;
 	}
 
 free_dma_chan:
-	bcm_dma_chan_free(fb->dma_chan);
+	bcm_dma_chan_free(fbdev->dma_chan);
 free_cb:
-	dma_free_wc(&dev->dev, SZ_64K, fb->cb_base, fb->cb_handle);
+	dma_free_wc(&dev->dev, SZ_64K, fbdev->cb_base,
+			      fbdev->cb_handle);
 free_fb:
-	kfree(fb);
-free_region:
 	dev_err(&dev->dev, "probe failed, err %d\n", ret);
-out:
+
 	return ret;
 }
 
 static int bcm2708_fb_remove(struct platform_device *dev)
 {
-	struct bcm2708_fb *fb = platform_get_drvdata(dev);
+	struct bcm2708_fb_dev *fbdev = platform_get_drvdata(dev);
+	int i;
 
 	platform_set_drvdata(dev, NULL);
 
-	if (fb->fb.screen_base)
-		iounmap(fb->fb.screen_base);
-	unregister_framebuffer(&fb->fb);
-
-	dma_free_wc(&dev->dev, SZ_64K, fb->cb_base, fb->cb_handle);
-	bcm_dma_chan_free(fb->dma_chan);
-
-	bcm2708_fb_debugfs_deinit(fb);
+	for (i = 0; i < fbdev->num_displays; i++) {
+		if (fbdev->displays[i].fb.screen_base)
+			iounmap(fbdev->displays[i].fb.screen_base);
+
+		if (fbdev->displays[i].fbdev) {
+			unregister_framebuffer(&fbdev->displays[i].fb);
+			bcm2708_fb_debugfs_deinit(&fbdev->displays[i]);
+		}
+	}
 
-	free_irq(fb->dma_irq, fb);
+	dma_free_wc(&dev->dev, SZ_64K, fbdev->cb_base,
+			      fbdev->cb_handle);
+	bcm_dma_chan_free(fbdev->dma_chan);
+	free_irq(fbdev->dma_irq, fbdev);
 
-	kfree(fb);
+	mutex_destroy(&fbdev->dma_mutex);
 
 	return 0;
 }
@@ -886,10 +1077,10 @@ static struct platform_driver bcm2708_fb
 	.probe = bcm2708_fb_probe,
 	.remove = bcm2708_fb_remove,
 	.driver = {
-		   .name = DRIVER_NAME,
-		   .owner = THIS_MODULE,
-		   .of_match_table = bcm2708_fb_of_match_table,
-		   },
+		  .name = DRIVER_NAME,
+		  .owner = THIS_MODULE,
+		  .of_match_table = bcm2708_fb_of_match_table,
+		  },
 };
 
 static int __init bcm2708_fb_init(void)
--- a/include/soc/bcm2835/raspberrypi-firmware.h
+++ b/include/soc/bcm2835/raspberrypi-firmware.h
@@ -106,9 +106,15 @@ enum rpi_firmware_property_tag {
 	RPI_FIRMWARE_FRAMEBUFFER_GET_VIRTUAL_OFFSET =         0x00040009,
 	RPI_FIRMWARE_FRAMEBUFFER_GET_OVERSCAN =               0x0004000a,
 	RPI_FIRMWARE_FRAMEBUFFER_GET_PALETTE =                0x0004000b,
+	RPI_FIRMWARE_FRAMEBUFFER_GET_LAYER =                  0x0004000c,
+	RPI_FIRMWARE_FRAMEBUFFER_GET_TRANSFORM =              0x0004000d,
+	RPI_FIRMWARE_FRAMEBUFFER_GET_VSYNC =                  0x0004000e,
 	RPI_FIRMWARE_FRAMEBUFFER_GET_TOUCHBUF =               0x0004000f,
 	RPI_FIRMWARE_FRAMEBUFFER_GET_GPIOVIRTBUF =            0x00040010,
 	RPI_FIRMWARE_FRAMEBUFFER_RELEASE =                    0x00048001,
+	RPI_FIRMWARE_FRAMEBUFFER_SET_DISPLAY_NUM =            0x00048013,
+	RPI_FIRMWARE_FRAMEBUFFER_GET_NUM_DISPLAYS =           0x00040013,
+	RPI_FIRMWARE_FRAMEBUFFER_GET_DISPLAY_SETTINGS =       0x00040014,
 	RPI_FIRMWARE_FRAMEBUFFER_TEST_PHYSICAL_WIDTH_HEIGHT = 0x00044003,
 	RPI_FIRMWARE_FRAMEBUFFER_TEST_VIRTUAL_WIDTH_HEIGHT =  0x00044004,
 	RPI_FIRMWARE_FRAMEBUFFER_TEST_DEPTH =                 0x00044005,
@@ -117,6 +123,8 @@ enum rpi_firmware_property_tag {
 	RPI_FIRMWARE_FRAMEBUFFER_TEST_VIRTUAL_OFFSET =        0x00044009,
 	RPI_FIRMWARE_FRAMEBUFFER_TEST_OVERSCAN =              0x0004400a,
 	RPI_FIRMWARE_FRAMEBUFFER_TEST_PALETTE =               0x0004400b,
+	RPI_FIRMWARE_FRAMEBUFFER_TEST_LAYER =                 0x0004400c,
+	RPI_FIRMWARE_FRAMEBUFFER_TEST_TRANSFORM =             0x0004400d,
 	RPI_FIRMWARE_FRAMEBUFFER_TEST_VSYNC =                 0x0004400e,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_PHYSICAL_WIDTH_HEIGHT =  0x00048003,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_VIRTUAL_WIDTH_HEIGHT =   0x00048004,
@@ -127,9 +135,12 @@ enum rpi_firmware_property_tag {
 	RPI_FIRMWARE_FRAMEBUFFER_SET_VIRTUAL_OFFSET =         0x00048009,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_OVERSCAN =               0x0004800a,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_PALETTE =                0x0004800b,
+
 	RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF =               0x0004801f,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_GPIOVIRTBUF =            0x00048020,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_VSYNC =                  0x0004800e,
+	RPI_FIRMWARE_FRAMEBUFFER_SET_LAYER =                  0x0004800c,
+	RPI_FIRMWARE_FRAMEBUFFER_SET_TRANSFORM =              0x0004800d,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_BACKLIGHT =              0x0004800f,
 
 	RPI_FIRMWARE_VCHIQ_INIT =                             0x00048010,
@@ -138,6 +149,8 @@ enum rpi_firmware_property_tag {
 	RPI_FIRMWARE_GET_DMA_CHANNELS =                       0x00060001,
 };
 
+#define GET_DISPLAY_SETTINGS_PAYLOAD_SIZE 64
+
 #if IS_ENABLED(CONFIG_RASPBERRYPI_FIRMWARE)
 int rpi_firmware_property(struct rpi_firmware *fw,
 			  u32 tag, void *data, size_t len);