xref: /openbmc/qemu/hw/display/bcm2835_fb.c (revision d4842052100a3b44167e34ebdce0e7b3bf7512cf)
1 /*
2  * Raspberry Pi emulation (c) 2012 Gregory Estrade
3  * Refactoring for Pi2 Copyright (c) 2015, Microsoft. Written by Andrew Baumann.
4  * This code is licensed under the GNU GPLv2 and later.
5  *
6  * Heavily based on milkymist-vgafb.c, copyright terms below:
7  *  QEMU model of the Milkymist VGA framebuffer.
8  *
9  *  Copyright (c) 2010-2012 Michael Walle <michael@walle.cc>
10  *
11  * This library is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU Lesser General Public
13  * License as published by the Free Software Foundation; either
14  * version 2 of the License, or (at your option) any later version.
15  *
16  * This library is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * Lesser General Public License for more details.
20  *
21  * You should have received a copy of the GNU Lesser General Public
22  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
23  *
24  */
25 
26 #include "qemu/osdep.h"
27 #include "qapi/error.h"
28 #include "hw/display/bcm2835_fb.h"
29 #include "hw/irq.h"
30 #include "framebuffer.h"
31 #include "ui/pixel_ops.h"
32 #include "hw/misc/bcm2835_mbox_defs.h"
33 #include "migration/vmstate.h"
34 #include "qemu/log.h"
35 #include "qemu/module.h"
36 
37 #define DEFAULT_VCRAM_SIZE 0x4000000
38 #define BCM2835_FB_OFFSET  0x00100000
39 
40 /* Maximum permitted framebuffer size; experimentally determined on an rpi2 */
41 #define XRES_MAX 3840
42 #define YRES_MAX 2560
43 /* Framebuffer size used if guest requests zero size */
44 #define XRES_SMALL 592
45 #define YRES_SMALL 488
46 
47 static void fb_invalidate_display(void *opaque)
48 {
49     BCM2835FBState *s = BCM2835_FB(opaque);
50 
51     s->invalidate = true;
52 }
53 
54 static void draw_line_src16(void *opaque, uint8_t *dst, const uint8_t *src,
55                             int width, int deststep)
56 {
57     BCM2835FBState *s = opaque;
58     uint16_t rgb565;
59     uint32_t rgb888;
60     uint8_t r, g, b;
61     DisplaySurface *surface = qemu_console_surface(s->con);
62     int bpp = surface_bits_per_pixel(surface);
63 
64     while (width--) {
65         switch (s->config.bpp) {
66         case 8:
67             /* lookup palette starting at video ram base
68              * TODO: cache translation, rather than doing this each time!
69              */
70             rgb888 = ldl_le_phys(&s->dma_as, s->vcram_base + (*src << 2));
71             r = (rgb888 >> 0) & 0xff;
72             g = (rgb888 >> 8) & 0xff;
73             b = (rgb888 >> 16) & 0xff;
74             src++;
75             break;
76         case 16:
77             rgb565 = lduw_le_p(src);
78             r = ((rgb565 >> 11) & 0x1f) << 3;
79             g = ((rgb565 >>  5) & 0x3f) << 2;
80             b = ((rgb565 >>  0) & 0x1f) << 3;
81             src += 2;
82             break;
83         case 24:
84             rgb888 = ldl_le_p(src);
85             r = (rgb888 >> 0) & 0xff;
86             g = (rgb888 >> 8) & 0xff;
87             b = (rgb888 >> 16) & 0xff;
88             src += 3;
89             break;
90         case 32:
91             rgb888 = ldl_le_p(src);
92             r = (rgb888 >> 0) & 0xff;
93             g = (rgb888 >> 8) & 0xff;
94             b = (rgb888 >> 16) & 0xff;
95             src += 4;
96             break;
97         default:
98             r = 0;
99             g = 0;
100             b = 0;
101             break;
102         }
103 
104         if (s->config.pixo == 0) {
105             /* swap to BGR pixel format */
106             uint8_t tmp = r;
107             r = b;
108             b = tmp;
109         }
110 
111         switch (bpp) {
112         case 8:
113             *dst++ = rgb_to_pixel8(r, g, b);
114             break;
115         case 15:
116             *(uint16_t *)dst = rgb_to_pixel15(r, g, b);
117             dst += 2;
118             break;
119         case 16:
120             *(uint16_t *)dst = rgb_to_pixel16(r, g, b);
121             dst += 2;
122             break;
123         case 24:
124             rgb888 = rgb_to_pixel24(r, g, b);
125             *dst++ = rgb888 & 0xff;
126             *dst++ = (rgb888 >> 8) & 0xff;
127             *dst++ = (rgb888 >> 16) & 0xff;
128             break;
129         case 32:
130             *(uint32_t *)dst = rgb_to_pixel32(r, g, b);
131             dst += 4;
132             break;
133         default:
134             return;
135         }
136     }
137 }
138 
139 static bool fb_use_offsets(BCM2835FBConfig *config)
140 {
141     /*
142      * Return true if we should use the viewport offsets.
143      * Experimentally, the hardware seems to do this only if the
144      * viewport size is larger than the physical screen. (It doesn't
145      * prevent the guest setting this silly viewport setting, though...)
146      */
147     return config->xres_virtual > config->xres &&
148         config->yres_virtual > config->yres;
149 }
150 
151 static void fb_update_display(void *opaque)
152 {
153     BCM2835FBState *s = opaque;
154     DisplaySurface *surface = qemu_console_surface(s->con);
155     int first = 0;
156     int last = 0;
157     int src_width = 0;
158     int dest_width = 0;
159     uint32_t xoff = 0, yoff = 0;
160 
161     if (s->lock || !s->config.xres) {
162         return;
163     }
164 
165     src_width = bcm2835_fb_get_pitch(&s->config);
166     if (fb_use_offsets(&s->config)) {
167         xoff = s->config.xoffset;
168         yoff = s->config.yoffset;
169     }
170 
171     dest_width = s->config.xres;
172 
173     switch (surface_bits_per_pixel(surface)) {
174     case 0:
175         return;
176     case 8:
177         break;
178     case 15:
179         dest_width *= 2;
180         break;
181     case 16:
182         dest_width *= 2;
183         break;
184     case 24:
185         dest_width *= 3;
186         break;
187     case 32:
188         dest_width *= 4;
189         break;
190     default:
191         hw_error("bcm2835_fb: bad color depth\n");
192         break;
193     }
194 
195     if (s->invalidate) {
196         hwaddr base = s->config.base + xoff + (hwaddr)yoff * src_width;
197         framebuffer_update_memory_section(&s->fbsection, s->dma_mr,
198                                           base,
199                                           s->config.yres, src_width);
200     }
201 
202     framebuffer_update_display(surface, &s->fbsection,
203                                s->config.xres, s->config.yres,
204                                src_width, dest_width, 0, s->invalidate,
205                                draw_line_src16, s, &first, &last);
206 
207     if (first >= 0) {
208         dpy_gfx_update(s->con, 0, first, s->config.xres,
209                        last - first + 1);
210     }
211 
212     s->invalidate = false;
213 }
214 
215 void bcm2835_fb_validate_config(BCM2835FBConfig *config)
216 {
217     /*
218      * Validate the config, and clip any bogus values into range,
219      * as the hardware does. Note that fb_update_display() relies on
220      * this happening to prevent it from performing out-of-range
221      * accesses on redraw.
222      */
223     config->xres = MIN(config->xres, XRES_MAX);
224     config->xres_virtual = MIN(config->xres_virtual, XRES_MAX);
225     config->yres = MIN(config->yres, YRES_MAX);
226     config->yres_virtual = MIN(config->yres_virtual, YRES_MAX);
227 
228     /*
229      * These are not minima: a 40x40 framebuffer will be accepted.
230      * They're only used as defaults if the guest asks for zero size.
231      */
232     if (config->xres == 0) {
233         config->xres = XRES_SMALL;
234     }
235     if (config->yres == 0) {
236         config->yres = YRES_SMALL;
237     }
238     if (config->xres_virtual == 0) {
239         config->xres_virtual = config->xres;
240     }
241     if (config->yres_virtual == 0) {
242         config->yres_virtual = config->yres;
243     }
244 
245     if (fb_use_offsets(config)) {
246         /* Clip the offsets so the viewport is within the physical screen */
247         config->xoffset = MIN(config->xoffset,
248                               config->xres_virtual - config->xres);
249         config->yoffset = MIN(config->yoffset,
250                               config->yres_virtual - config->yres);
251     }
252 }
253 
254 void bcm2835_fb_reconfigure(BCM2835FBState *s, BCM2835FBConfig *newconfig)
255 {
256     s->lock = true;
257 
258     s->config = *newconfig;
259 
260     s->invalidate = true;
261     qemu_console_resize(s->con, s->config.xres, s->config.yres);
262     s->lock = false;
263 }
264 
265 static void bcm2835_fb_mbox_push(BCM2835FBState *s, uint32_t value)
266 {
267     uint32_t pitch;
268     uint32_t size;
269     BCM2835FBConfig newconf;
270 
271     value &= ~0xf;
272 
273     newconf.xres = ldl_le_phys(&s->dma_as, value);
274     newconf.yres = ldl_le_phys(&s->dma_as, value + 4);
275     newconf.xres_virtual = ldl_le_phys(&s->dma_as, value + 8);
276     newconf.yres_virtual = ldl_le_phys(&s->dma_as, value + 12);
277     newconf.bpp = ldl_le_phys(&s->dma_as, value + 20);
278     newconf.xoffset = ldl_le_phys(&s->dma_as, value + 24);
279     newconf.yoffset = ldl_le_phys(&s->dma_as, value + 28);
280 
281     newconf.base = s->vcram_base | (value & 0xc0000000);
282     newconf.base += BCM2835_FB_OFFSET;
283 
284     bcm2835_fb_validate_config(&newconf);
285 
286     pitch = bcm2835_fb_get_pitch(&newconf);
287     size = bcm2835_fb_get_size(&newconf);
288 
289     stl_le_phys(&s->dma_as, value + 16, pitch);
290     stl_le_phys(&s->dma_as, value + 32, newconf.base);
291     stl_le_phys(&s->dma_as, value + 36, size);
292 
293     bcm2835_fb_reconfigure(s, &newconf);
294 }
295 
296 static uint64_t bcm2835_fb_read(void *opaque, hwaddr offset, unsigned size)
297 {
298     BCM2835FBState *s = opaque;
299     uint32_t res = 0;
300 
301     switch (offset) {
302     case MBOX_AS_DATA:
303         res = MBOX_CHAN_FB;
304         s->pending = false;
305         qemu_set_irq(s->mbox_irq, 0);
306         break;
307 
308     case MBOX_AS_PENDING:
309         res = s->pending;
310         break;
311 
312     default:
313         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
314                       __func__, offset);
315         return 0;
316     }
317 
318     return res;
319 }
320 
321 static void bcm2835_fb_write(void *opaque, hwaddr offset, uint64_t value,
322                              unsigned size)
323 {
324     BCM2835FBState *s = opaque;
325 
326     switch (offset) {
327     case MBOX_AS_DATA:
328         /* bcm2835_mbox should check our pending status before pushing */
329         assert(!s->pending);
330         s->pending = true;
331         bcm2835_fb_mbox_push(s, value);
332         qemu_set_irq(s->mbox_irq, 1);
333         break;
334 
335     default:
336         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
337                       __func__, offset);
338         return;
339     }
340 }
341 
342 static const MemoryRegionOps bcm2835_fb_ops = {
343     .read = bcm2835_fb_read,
344     .write = bcm2835_fb_write,
345     .endianness = DEVICE_NATIVE_ENDIAN,
346     .valid.min_access_size = 4,
347     .valid.max_access_size = 4,
348 };
349 
350 static const VMStateDescription vmstate_bcm2835_fb = {
351     .name = TYPE_BCM2835_FB,
352     .version_id = 1,
353     .minimum_version_id = 1,
354     .fields = (VMStateField[]) {
355         VMSTATE_BOOL(lock, BCM2835FBState),
356         VMSTATE_BOOL(invalidate, BCM2835FBState),
357         VMSTATE_BOOL(pending, BCM2835FBState),
358         VMSTATE_UINT32(config.xres, BCM2835FBState),
359         VMSTATE_UINT32(config.yres, BCM2835FBState),
360         VMSTATE_UINT32(config.xres_virtual, BCM2835FBState),
361         VMSTATE_UINT32(config.yres_virtual, BCM2835FBState),
362         VMSTATE_UINT32(config.xoffset, BCM2835FBState),
363         VMSTATE_UINT32(config.yoffset, BCM2835FBState),
364         VMSTATE_UINT32(config.bpp, BCM2835FBState),
365         VMSTATE_UINT32(config.base, BCM2835FBState),
366         VMSTATE_UNUSED(8), /* Was pitch and size */
367         VMSTATE_UINT32(config.pixo, BCM2835FBState),
368         VMSTATE_UINT32(config.alpha, BCM2835FBState),
369         VMSTATE_END_OF_LIST()
370     }
371 };
372 
373 static const GraphicHwOps vgafb_ops = {
374     .invalidate  = fb_invalidate_display,
375     .gfx_update  = fb_update_display,
376 };
377 
378 static void bcm2835_fb_init(Object *obj)
379 {
380     BCM2835FBState *s = BCM2835_FB(obj);
381 
382     memory_region_init_io(&s->iomem, obj, &bcm2835_fb_ops, s, TYPE_BCM2835_FB,
383                           0x10);
384     sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
385     sysbus_init_irq(SYS_BUS_DEVICE(s), &s->mbox_irq);
386 }
387 
388 static void bcm2835_fb_reset(DeviceState *dev)
389 {
390     BCM2835FBState *s = BCM2835_FB(dev);
391 
392     s->pending = false;
393 
394     s->config = s->initial_config;
395 
396     s->invalidate = true;
397     s->lock = false;
398 }
399 
400 static void bcm2835_fb_realize(DeviceState *dev, Error **errp)
401 {
402     BCM2835FBState *s = BCM2835_FB(dev);
403     Error *err = NULL;
404     Object *obj;
405 
406     if (s->vcram_base == 0) {
407         error_setg(errp, "%s: required vcram-base property not set", __func__);
408         return;
409     }
410 
411     obj = object_property_get_link(OBJECT(dev), "dma-mr", &err);
412     if (obj == NULL) {
413         error_setg(errp, "%s: required dma-mr link not found: %s",
414                    __func__, error_get_pretty(err));
415         return;
416     }
417 
418     /* Fill in the parts of initial_config that are not set by QOM properties */
419     s->initial_config.xres_virtual = s->initial_config.xres;
420     s->initial_config.yres_virtual = s->initial_config.yres;
421     s->initial_config.xoffset = 0;
422     s->initial_config.yoffset = 0;
423     s->initial_config.base = s->vcram_base + BCM2835_FB_OFFSET;
424 
425     s->dma_mr = MEMORY_REGION(obj);
426     address_space_init(&s->dma_as, s->dma_mr, NULL);
427 
428     bcm2835_fb_reset(dev);
429 
430     s->con = graphic_console_init(dev, 0, &vgafb_ops, s);
431     qemu_console_resize(s->con, s->config.xres, s->config.yres);
432 }
433 
434 static Property bcm2835_fb_props[] = {
435     DEFINE_PROP_UINT32("vcram-base", BCM2835FBState, vcram_base, 0),/*required*/
436     DEFINE_PROP_UINT32("vcram-size", BCM2835FBState, vcram_size,
437                        DEFAULT_VCRAM_SIZE),
438     DEFINE_PROP_UINT32("xres", BCM2835FBState, initial_config.xres, 640),
439     DEFINE_PROP_UINT32("yres", BCM2835FBState, initial_config.yres, 480),
440     DEFINE_PROP_UINT32("bpp", BCM2835FBState, initial_config.bpp, 16),
441     DEFINE_PROP_UINT32("pixo", BCM2835FBState,
442                        initial_config.pixo, 1), /* 1=RGB, 0=BGR */
443     DEFINE_PROP_UINT32("alpha", BCM2835FBState,
444                        initial_config.alpha, 2), /* alpha ignored */
445     DEFINE_PROP_END_OF_LIST()
446 };
447 
448 static void bcm2835_fb_class_init(ObjectClass *klass, void *data)
449 {
450     DeviceClass *dc = DEVICE_CLASS(klass);
451 
452     dc->props = bcm2835_fb_props;
453     dc->realize = bcm2835_fb_realize;
454     dc->reset = bcm2835_fb_reset;
455     dc->vmsd = &vmstate_bcm2835_fb;
456 }
457 
458 static TypeInfo bcm2835_fb_info = {
459     .name          = TYPE_BCM2835_FB,
460     .parent        = TYPE_SYS_BUS_DEVICE,
461     .instance_size = sizeof(BCM2835FBState),
462     .class_init    = bcm2835_fb_class_init,
463     .instance_init = bcm2835_fb_init,
464 };
465 
466 static void bcm2835_fb_register_types(void)
467 {
468     type_register_static(&bcm2835_fb_info);
469 }
470 
471 type_init(bcm2835_fb_register_types)
472