xref: /qemu/hw/display/bcm2835_fb.c (revision a976ed3f) 
1 /*
2  * Raspberry Pi emulation (c) 2012 Gregory Estrade
3  * Refactoring for Pi2 Copyright (c) 2015, Microsoft. Written by Andrew Baumann.
4  *
5  * Heavily based on milkymist-vgafb.c, copyright terms below:
6  *  QEMU model of the Milkymist VGA framebuffer.
7  *
8  *  Copyright (c) 2010-2012 Michael Walle <michael@walle.cc>
9  *
10  * This library is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2 of the License, or (at your option) any later version.
14  *
15  * This library is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
22  *
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qapi/error.h"
27 #include "hw/display/bcm2835_fb.h"
28 #include "hw/hw.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 "hw/qdev-properties.h"
34 #include "migration/vmstate.h"
35 #include "qemu/log.h"
36 #include "qemu/module.h"
37 
38 #define DEFAULT_VCRAM_SIZE 0x4000000
39 #define BCM2835_FB_OFFSET  0x00100000
40 
41 /* Maximum permitted framebuffer size; experimentally determined on an rpi2 */
42 #define XRES_MAX 3840
43 #define YRES_MAX 2560
44 /* Framebuffer size used if guest requests zero size */
45 #define XRES_SMALL 592
46 #define YRES_SMALL 488
47 
48 static void fb_invalidate_display(void *opaque)
49 {
50     BCM2835FBState *s = BCM2835_FB(opaque);
51 
52     s->invalidate = true;
53 }
54 
55 static void draw_line_src16(void *opaque, uint8_t *dst, const uint8_t *src,
56                             int width, int deststep)
57 {
58     BCM2835FBState *s = opaque;
59     uint16_t rgb565;
60     uint32_t rgb888;
61     uint8_t r, g, b;
62     DisplaySurface *surface = qemu_console_surface(s->con);
63     int bpp = surface_bits_per_pixel(surface);
64 
65     while (width--) {
66         switch (s->config.bpp) {
67         case 8:
68             /* lookup palette starting at video ram base
69              * TODO: cache translation, rather than doing this each time!
70              */
71             rgb888 = ldl_le_phys(&s->dma_as, s->vcram_base + (*src << 2));
72             r = (rgb888 >> 0) & 0xff;
73             g = (rgb888 >> 8) & 0xff;
74             b = (rgb888 >> 16) & 0xff;
75             src++;
76             break;
77         case 16:
78             rgb565 = lduw_le_p(src);
79             r = ((rgb565 >> 11) & 0x1f) << 3;
80             g = ((rgb565 >>  5) & 0x3f) << 2;
81             b = ((rgb565 >>  0) & 0x1f) << 3;
82             src += 2;
83             break;
84         case 24:
85             rgb888 = ldl_le_p(src);
86             r = (rgb888 >> 0) & 0xff;
87             g = (rgb888 >> 8) & 0xff;
88             b = (rgb888 >> 16) & 0xff;
89             src += 3;
90             break;
91         case 32:
92             rgb888 = ldl_le_p(src);
93             r = (rgb888 >> 0) & 0xff;
94             g = (rgb888 >> 8) & 0xff;
95             b = (rgb888 >> 16) & 0xff;
96             src += 4;
97             break;
98         default:
99             r = 0;
100             g = 0;
101             b = 0;
102             break;
103         }
104 
105         if (s->config.pixo == 0) {
106             /* swap to BGR pixel format */
107             uint8_t tmp = r;
108             r = b;
109             b = tmp;
110         }
111 
112         switch (bpp) {
113         case 8:
114             *dst++ = rgb_to_pixel8(r, g, b);
115             break;
116         case 15:
117             *(uint16_t *)dst = rgb_to_pixel15(r, g, b);
118             dst += 2;
119             break;
120         case 16:
121             *(uint16_t *)dst = rgb_to_pixel16(r, g, b);
122             dst += 2;
123             break;
124         case 24:
125             rgb888 = rgb_to_pixel24(r, g, b);
126             *dst++ = rgb888 & 0xff;
127             *dst++ = (rgb888 >> 8) & 0xff;
128             *dst++ = (rgb888 >> 16) & 0xff;
129             break;
130         case 32:
131             *(uint32_t *)dst = rgb_to_pixel32(r, g, b);
132             dst += 4;
133             break;
134         default:
135             return;
136         }
137     }
138 }
139 
140 static bool fb_use_offsets(BCM2835FBConfig *config)
141 {
142     /*
143      * Return true if we should use the viewport offsets.
144      * Experimentally, the hardware seems to do this only if the
145      * viewport size is larger than the physical screen. (It doesn't
146      * prevent the guest setting this silly viewport setting, though...)
147      */
148     return config->xres_virtual > config->xres &&
149         config->yres_virtual > config->yres;
150 }
151 
152 static void fb_update_display(void *opaque)
153 {
154     BCM2835FBState *s = opaque;
155     DisplaySurface *surface = qemu_console_surface(s->con);
156     int first = 0;
157     int last = 0;
158     int src_width = 0;
159     int dest_width = 0;
160     uint32_t xoff = 0, yoff = 0;
161 
162     if (s->lock || !s->config.xres) {
163         return;
164     }
165 
166     src_width = bcm2835_fb_get_pitch(&s->config);
167     if (fb_use_offsets(&s->config)) {
168         xoff = s->config.xoffset;
169         yoff = s->config.yoffset;
170     }
171 
172     dest_width = s->config.xres;
173 
174     switch (surface_bits_per_pixel(surface)) {
175     case 0:
176         return;
177     case 8:
178         break;
179     case 15:
180         dest_width *= 2;
181         break;
182     case 16:
183         dest_width *= 2;
184         break;
185     case 24:
186         dest_width *= 3;
187         break;
188     case 32:
189         dest_width *= 4;
190         break;
191     default:
192         hw_error("bcm2835_fb: bad color depth\n");
193         break;
194     }
195 
196     if (s->invalidate) {
197         hwaddr base = s->config.base + xoff + (hwaddr)yoff * src_width;
198         framebuffer_update_memory_section(&s->fbsection, s->dma_mr,
199                                           base,
200                                           s->config.yres, src_width);
201     }
202 
203     framebuffer_update_display(surface, &s->fbsection,
204                                s->config.xres, s->config.yres,
205                                src_width, dest_width, 0, s->invalidate,
206                                draw_line_src16, s, &first, &last);
207 
208     if (first >= 0) {
209         dpy_gfx_update(s->con, 0, first, s->config.xres,
210                        last - first + 1);
211     }
212 
213     s->invalidate = false;
214 }
215 
216 void bcm2835_fb_validate_config(BCM2835FBConfig *config)
217 {
218     /*
219      * Validate the config, and clip any bogus values into range,
220      * as the hardware does. Note that fb_update_display() relies on
221      * this happening to prevent it from performing out-of-range
222      * accesses on redraw.
223      */
224     config->xres = MIN(config->xres, XRES_MAX);
225     config->xres_virtual = MIN(config->xres_virtual, XRES_MAX);
226     config->yres = MIN(config->yres, YRES_MAX);
227     config->yres_virtual = MIN(config->yres_virtual, YRES_MAX);
228 
229     /*
230      * These are not minima: a 40x40 framebuffer will be accepted.
231      * They're only used as defaults if the guest asks for zero size.
232      */
233     if (config->xres == 0) {
234         config->xres = XRES_SMALL;
235     }
236     if (config->yres == 0) {
237         config->yres = YRES_SMALL;
238     }
239     if (config->xres_virtual == 0) {
240         config->xres_virtual = config->xres;
241     }
242     if (config->yres_virtual == 0) {
243         config->yres_virtual = config->yres;
244     }
245 
246     if (fb_use_offsets(config)) {
247         /* Clip the offsets so the viewport is within the physical screen */
248         config->xoffset = MIN(config->xoffset,
249                               config->xres_virtual - config->xres);
250         config->yoffset = MIN(config->yoffset,
251                               config->yres_virtual - config->yres);
252     }
253 }
254 
255 void bcm2835_fb_reconfigure(BCM2835FBState *s, BCM2835FBConfig *newconfig)
256 {
257     s->lock = true;
258 
259     s->config = *newconfig;
260 
261     s->invalidate = true;
262     qemu_console_resize(s->con, s->config.xres, s->config.yres);
263     s->lock = false;
264 }
265 
266 static void bcm2835_fb_mbox_push(BCM2835FBState *s, uint32_t value)
267 {
268     uint32_t pitch;
269     uint32_t size;
270     BCM2835FBConfig newconf;
271 
272     value &= ~0xf;
273 
274     newconf.xres = ldl_le_phys(&s->dma_as, value);
275     newconf.yres = ldl_le_phys(&s->dma_as, value + 4);
276     newconf.xres_virtual = ldl_le_phys(&s->dma_as, value + 8);
277     newconf.yres_virtual = ldl_le_phys(&s->dma_as, value + 12);
278     newconf.bpp = ldl_le_phys(&s->dma_as, value + 20);
279     newconf.xoffset = ldl_le_phys(&s->dma_as, value + 24);
280     newconf.yoffset = ldl_le_phys(&s->dma_as, value + 28);
281 
282     newconf.base = s->vcram_base | (value & 0xc0000000);
283     newconf.base += BCM2835_FB_OFFSET;
284 
285     bcm2835_fb_validate_config(&newconf);
286 
287     pitch = bcm2835_fb_get_pitch(&newconf);
288     size = bcm2835_fb_get_size(&newconf);
289 
290     stl_le_phys(&s->dma_as, value + 16, pitch);
291     stl_le_phys(&s->dma_as, value + 32, newconf.base);
292     stl_le_phys(&s->dma_as, value + 36, size);
293 
294     bcm2835_fb_reconfigure(s, &newconf);
295 }
296 
297 static uint64_t bcm2835_fb_read(void *opaque, hwaddr offset, unsigned size)
298 {
299     BCM2835FBState *s = opaque;
300     uint32_t res = 0;
301 
302     switch (offset) {
303     case MBOX_AS_DATA:
304         res = MBOX_CHAN_FB;
305         s->pending = false;
306         qemu_set_irq(s->mbox_irq, 0);
307         break;
308 
309     case MBOX_AS_PENDING:
310         res = s->pending;
311         break;
312 
313     default:
314         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
315                       __func__, offset);
316         return 0;
317     }
318 
319     return res;
320 }
321 
322 static void bcm2835_fb_write(void *opaque, hwaddr offset, uint64_t value,
323                              unsigned size)
324 {
325     BCM2835FBState *s = opaque;
326 
327     switch (offset) {
328     case MBOX_AS_DATA:
329         /* bcm2835_mbox should check our pending status before pushing */
330         assert(!s->pending);
331         s->pending = true;
332         bcm2835_fb_mbox_push(s, value);
333         qemu_set_irq(s->mbox_irq, 1);
334         break;
335 
336     default:
337         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
338                       __func__, offset);
339         return;
340     }
341 }
342 
343 static const MemoryRegionOps bcm2835_fb_ops = {
344     .read = bcm2835_fb_read,
345     .write = bcm2835_fb_write,
346     .endianness = DEVICE_NATIVE_ENDIAN,
347     .valid.min_access_size = 4,
348     .valid.max_access_size = 4,
349 };
350 
351 static const VMStateDescription vmstate_bcm2835_fb = {
352     .name = TYPE_BCM2835_FB,
353     .version_id = 1,
354     .minimum_version_id = 1,
355     .fields = (VMStateField[]) {
356         VMSTATE_BOOL(lock, BCM2835FBState),
357         VMSTATE_BOOL(invalidate, BCM2835FBState),
358         VMSTATE_BOOL(pending, BCM2835FBState),
359         VMSTATE_UINT32(config.xres, BCM2835FBState),
360         VMSTATE_UINT32(config.yres, BCM2835FBState),
361         VMSTATE_UINT32(config.xres_virtual, BCM2835FBState),
362         VMSTATE_UINT32(config.yres_virtual, BCM2835FBState),
363         VMSTATE_UINT32(config.xoffset, BCM2835FBState),
364         VMSTATE_UINT32(config.yoffset, BCM2835FBState),
365         VMSTATE_UINT32(config.bpp, BCM2835FBState),
366         VMSTATE_UINT32(config.base, BCM2835FBState),
367         VMSTATE_UNUSED(8), /* Was pitch and size */
368         VMSTATE_UINT32(config.pixo, BCM2835FBState),
369         VMSTATE_UINT32(config.alpha, BCM2835FBState),
370         VMSTATE_END_OF_LIST()
371     }
372 };
373 
374 static const GraphicHwOps vgafb_ops = {
375     .invalidate  = fb_invalidate_display,
376     .gfx_update  = fb_update_display,
377 };
378 
379 static void bcm2835_fb_init(Object *obj)
380 {
381     BCM2835FBState *s = BCM2835_FB(obj);
382 
383     memory_region_init_io(&s->iomem, obj, &bcm2835_fb_ops, s, TYPE_BCM2835_FB,
384                           0x10);
385     sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
386     sysbus_init_irq(SYS_BUS_DEVICE(s), &s->mbox_irq);
387 }
388 
389 static void bcm2835_fb_reset(DeviceState *dev)
390 {
391     BCM2835FBState *s = BCM2835_FB(dev);
392 
393     s->pending = false;
394 
395     s->config = s->initial_config;
396 
397     s->invalidate = true;
398     s->lock = false;
399 }
400 
401 static void bcm2835_fb_realize(DeviceState *dev, Error **errp)
402 {
403     BCM2835FBState *s = BCM2835_FB(dev);
404     Error *err = NULL;
405     Object *obj;
406 
407     if (s->vcram_base == 0) {
408         error_setg(errp, "%s: required vcram-base property not set", __func__);
409         return;
410     }
411 
412     obj = object_property_get_link(OBJECT(dev), "dma-mr", &err);
413     if (obj == NULL) {
414         error_setg(errp, "%s: required dma-mr link not found: %s",
415                    __func__, error_get_pretty(err));
416         return;
417     }
418 
419     /* Fill in the parts of initial_config that are not set by QOM properties */
420     s->initial_config.xres_virtual = s->initial_config.xres;
421     s->initial_config.yres_virtual = s->initial_config.yres;
422     s->initial_config.xoffset = 0;
423     s->initial_config.yoffset = 0;
424     s->initial_config.base = s->vcram_base + BCM2835_FB_OFFSET;
425 
426     s->dma_mr = MEMORY_REGION(obj);
427     address_space_init(&s->dma_as, s->dma_mr, TYPE_BCM2835_FB "-memory");
428 
429     bcm2835_fb_reset(dev);
430 
431     s->con = graphic_console_init(dev, 0, &vgafb_ops, s);
432     qemu_console_resize(s->con, s->config.xres, s->config.yres);
433 }
434 
435 static Property bcm2835_fb_props[] = {
436     DEFINE_PROP_UINT32("vcram-base", BCM2835FBState, vcram_base, 0),/*required*/
437     DEFINE_PROP_UINT32("vcram-size", BCM2835FBState, vcram_size,
438                        DEFAULT_VCRAM_SIZE),
439     DEFINE_PROP_UINT32("xres", BCM2835FBState, initial_config.xres, 640),
440     DEFINE_PROP_UINT32("yres", BCM2835FBState, initial_config.yres, 480),
441     DEFINE_PROP_UINT32("bpp", BCM2835FBState, initial_config.bpp, 16),
442     DEFINE_PROP_UINT32("pixo", BCM2835FBState,
443                        initial_config.pixo, 1), /* 1=RGB, 0=BGR */
444     DEFINE_PROP_UINT32("alpha", BCM2835FBState,
445                        initial_config.alpha, 2), /* alpha ignored */
446     DEFINE_PROP_END_OF_LIST()
447 };
448 
449 static void bcm2835_fb_class_init(ObjectClass *klass, void *data)
450 {
451     DeviceClass *dc = DEVICE_CLASS(klass);
452 
453     device_class_set_props(dc, bcm2835_fb_props);
454     dc->realize = bcm2835_fb_realize;
455     dc->reset = bcm2835_fb_reset;
456     dc->vmsd = &vmstate_bcm2835_fb;
457 }
458 
459 static TypeInfo bcm2835_fb_info = {
460     .name          = TYPE_BCM2835_FB,
461     .parent        = TYPE_SYS_BUS_DEVICE,
462     .instance_size = sizeof(BCM2835FBState),
463     .class_init    = bcm2835_fb_class_init,
464     .instance_init = bcm2835_fb_init,
465 };
466 
467 static void bcm2835_fb_register_types(void)
468 {
469     type_register_static(&bcm2835_fb_info);
470 }
471 
472 type_init(bcm2835_fb_register_types)
473