xref: /openbmc/qemu/hw/display/bcm2835_fb.c (revision 64552b6b)
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 "qemu/log.h"
34 #include "qemu/module.h"
35 
36 #define DEFAULT_VCRAM_SIZE 0x4000000
37 #define BCM2835_FB_OFFSET  0x00100000
38 
39 /* Maximum permitted framebuffer size; experimentally determined on an rpi2 */
40 #define XRES_MAX 3840
41 #define YRES_MAX 2560
42 /* Framebuffer size used if guest requests zero size */
43 #define XRES_SMALL 592
44 #define YRES_SMALL 488
45 
46 static void fb_invalidate_display(void *opaque)
47 {
48     BCM2835FBState *s = BCM2835_FB(opaque);
49 
50     s->invalidate = true;
51 }
52 
53 static void draw_line_src16(void *opaque, uint8_t *dst, const uint8_t *src,
54                             int width, int deststep)
55 {
56     BCM2835FBState *s = opaque;
57     uint16_t rgb565;
58     uint32_t rgb888;
59     uint8_t r, g, b;
60     DisplaySurface *surface = qemu_console_surface(s->con);
61     int bpp = surface_bits_per_pixel(surface);
62 
63     while (width--) {
64         switch (s->config.bpp) {
65         case 8:
66             /* lookup palette starting at video ram base
67              * TODO: cache translation, rather than doing this each time!
68              */
69             rgb888 = ldl_le_phys(&s->dma_as, s->vcram_base + (*src << 2));
70             r = (rgb888 >> 0) & 0xff;
71             g = (rgb888 >> 8) & 0xff;
72             b = (rgb888 >> 16) & 0xff;
73             src++;
74             break;
75         case 16:
76             rgb565 = lduw_le_p(src);
77             r = ((rgb565 >> 11) & 0x1f) << 3;
78             g = ((rgb565 >>  5) & 0x3f) << 2;
79             b = ((rgb565 >>  0) & 0x1f) << 3;
80             src += 2;
81             break;
82         case 24:
83             rgb888 = ldl_le_p(src);
84             r = (rgb888 >> 0) & 0xff;
85             g = (rgb888 >> 8) & 0xff;
86             b = (rgb888 >> 16) & 0xff;
87             src += 3;
88             break;
89         case 32:
90             rgb888 = ldl_le_p(src);
91             r = (rgb888 >> 0) & 0xff;
92             g = (rgb888 >> 8) & 0xff;
93             b = (rgb888 >> 16) & 0xff;
94             src += 4;
95             break;
96         default:
97             r = 0;
98             g = 0;
99             b = 0;
100             break;
101         }
102 
103         if (s->config.pixo == 0) {
104             /* swap to BGR pixel format */
105             uint8_t tmp = r;
106             r = b;
107             b = tmp;
108         }
109 
110         switch (bpp) {
111         case 8:
112             *dst++ = rgb_to_pixel8(r, g, b);
113             break;
114         case 15:
115             *(uint16_t *)dst = rgb_to_pixel15(r, g, b);
116             dst += 2;
117             break;
118         case 16:
119             *(uint16_t *)dst = rgb_to_pixel16(r, g, b);
120             dst += 2;
121             break;
122         case 24:
123             rgb888 = rgb_to_pixel24(r, g, b);
124             *dst++ = rgb888 & 0xff;
125             *dst++ = (rgb888 >> 8) & 0xff;
126             *dst++ = (rgb888 >> 16) & 0xff;
127             break;
128         case 32:
129             *(uint32_t *)dst = rgb_to_pixel32(r, g, b);
130             dst += 4;
131             break;
132         default:
133             return;
134         }
135     }
136 }
137 
138 static bool fb_use_offsets(BCM2835FBConfig *config)
139 {
140     /*
141      * Return true if we should use the viewport offsets.
142      * Experimentally, the hardware seems to do this only if the
143      * viewport size is larger than the physical screen. (It doesn't
144      * prevent the guest setting this silly viewport setting, though...)
145      */
146     return config->xres_virtual > config->xres &&
147         config->yres_virtual > config->yres;
148 }
149 
150 static void fb_update_display(void *opaque)
151 {
152     BCM2835FBState *s = opaque;
153     DisplaySurface *surface = qemu_console_surface(s->con);
154     int first = 0;
155     int last = 0;
156     int src_width = 0;
157     int dest_width = 0;
158     uint32_t xoff = 0, yoff = 0;
159 
160     if (s->lock || !s->config.xres) {
161         return;
162     }
163 
164     src_width = bcm2835_fb_get_pitch(&s->config);
165     if (fb_use_offsets(&s->config)) {
166         xoff = s->config.xoffset;
167         yoff = s->config.yoffset;
168     }
169 
170     dest_width = s->config.xres;
171 
172     switch (surface_bits_per_pixel(surface)) {
173     case 0:
174         return;
175     case 8:
176         break;
177     case 15:
178         dest_width *= 2;
179         break;
180     case 16:
181         dest_width *= 2;
182         break;
183     case 24:
184         dest_width *= 3;
185         break;
186     case 32:
187         dest_width *= 4;
188         break;
189     default:
190         hw_error("bcm2835_fb: bad color depth\n");
191         break;
192     }
193 
194     if (s->invalidate) {
195         hwaddr base = s->config.base + xoff + (hwaddr)yoff * src_width;
196         framebuffer_update_memory_section(&s->fbsection, s->dma_mr,
197                                           base,
198                                           s->config.yres, src_width);
199     }
200 
201     framebuffer_update_display(surface, &s->fbsection,
202                                s->config.xres, s->config.yres,
203                                src_width, dest_width, 0, s->invalidate,
204                                draw_line_src16, s, &first, &last);
205 
206     if (first >= 0) {
207         dpy_gfx_update(s->con, 0, first, s->config.xres,
208                        last - first + 1);
209     }
210 
211     s->invalidate = false;
212 }
213 
214 void bcm2835_fb_validate_config(BCM2835FBConfig *config)
215 {
216     /*
217      * Validate the config, and clip any bogus values into range,
218      * as the hardware does. Note that fb_update_display() relies on
219      * this happening to prevent it from performing out-of-range
220      * accesses on redraw.
221      */
222     config->xres = MIN(config->xres, XRES_MAX);
223     config->xres_virtual = MIN(config->xres_virtual, XRES_MAX);
224     config->yres = MIN(config->yres, YRES_MAX);
225     config->yres_virtual = MIN(config->yres_virtual, YRES_MAX);
226 
227     /*
228      * These are not minima: a 40x40 framebuffer will be accepted.
229      * They're only used as defaults if the guest asks for zero size.
230      */
231     if (config->xres == 0) {
232         config->xres = XRES_SMALL;
233     }
234     if (config->yres == 0) {
235         config->yres = YRES_SMALL;
236     }
237     if (config->xres_virtual == 0) {
238         config->xres_virtual = config->xres;
239     }
240     if (config->yres_virtual == 0) {
241         config->yres_virtual = config->yres;
242     }
243 
244     if (fb_use_offsets(config)) {
245         /* Clip the offsets so the viewport is within the physical screen */
246         config->xoffset = MIN(config->xoffset,
247                               config->xres_virtual - config->xres);
248         config->yoffset = MIN(config->yoffset,
249                               config->yres_virtual - config->yres);
250     }
251 }
252 
253 void bcm2835_fb_reconfigure(BCM2835FBState *s, BCM2835FBConfig *newconfig)
254 {
255     s->lock = true;
256 
257     s->config = *newconfig;
258 
259     s->invalidate = true;
260     qemu_console_resize(s->con, s->config.xres, s->config.yres);
261     s->lock = false;
262 }
263 
264 static void bcm2835_fb_mbox_push(BCM2835FBState *s, uint32_t value)
265 {
266     uint32_t pitch;
267     uint32_t size;
268     BCM2835FBConfig newconf;
269 
270     value &= ~0xf;
271 
272     newconf.xres = ldl_le_phys(&s->dma_as, value);
273     newconf.yres = ldl_le_phys(&s->dma_as, value + 4);
274     newconf.xres_virtual = ldl_le_phys(&s->dma_as, value + 8);
275     newconf.yres_virtual = ldl_le_phys(&s->dma_as, value + 12);
276     newconf.bpp = ldl_le_phys(&s->dma_as, value + 20);
277     newconf.xoffset = ldl_le_phys(&s->dma_as, value + 24);
278     newconf.yoffset = ldl_le_phys(&s->dma_as, value + 28);
279 
280     newconf.base = s->vcram_base | (value & 0xc0000000);
281     newconf.base += BCM2835_FB_OFFSET;
282 
283     bcm2835_fb_validate_config(&newconf);
284 
285     pitch = bcm2835_fb_get_pitch(&newconf);
286     size = bcm2835_fb_get_size(&newconf);
287 
288     stl_le_phys(&s->dma_as, value + 16, pitch);
289     stl_le_phys(&s->dma_as, value + 32, newconf.base);
290     stl_le_phys(&s->dma_as, value + 36, size);
291 
292     bcm2835_fb_reconfigure(s, &newconf);
293 }
294 
295 static uint64_t bcm2835_fb_read(void *opaque, hwaddr offset, unsigned size)
296 {
297     BCM2835FBState *s = opaque;
298     uint32_t res = 0;
299 
300     switch (offset) {
301     case MBOX_AS_DATA:
302         res = MBOX_CHAN_FB;
303         s->pending = false;
304         qemu_set_irq(s->mbox_irq, 0);
305         break;
306 
307     case MBOX_AS_PENDING:
308         res = s->pending;
309         break;
310 
311     default:
312         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
313                       __func__, offset);
314         return 0;
315     }
316 
317     return res;
318 }
319 
320 static void bcm2835_fb_write(void *opaque, hwaddr offset, uint64_t value,
321                              unsigned size)
322 {
323     BCM2835FBState *s = opaque;
324 
325     switch (offset) {
326     case MBOX_AS_DATA:
327         /* bcm2835_mbox should check our pending status before pushing */
328         assert(!s->pending);
329         s->pending = true;
330         bcm2835_fb_mbox_push(s, value);
331         qemu_set_irq(s->mbox_irq, 1);
332         break;
333 
334     default:
335         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
336                       __func__, offset);
337         return;
338     }
339 }
340 
341 static const MemoryRegionOps bcm2835_fb_ops = {
342     .read = bcm2835_fb_read,
343     .write = bcm2835_fb_write,
344     .endianness = DEVICE_NATIVE_ENDIAN,
345     .valid.min_access_size = 4,
346     .valid.max_access_size = 4,
347 };
348 
349 static const VMStateDescription vmstate_bcm2835_fb = {
350     .name = TYPE_BCM2835_FB,
351     .version_id = 1,
352     .minimum_version_id = 1,
353     .fields = (VMStateField[]) {
354         VMSTATE_BOOL(lock, BCM2835FBState),
355         VMSTATE_BOOL(invalidate, BCM2835FBState),
356         VMSTATE_BOOL(pending, BCM2835FBState),
357         VMSTATE_UINT32(config.xres, BCM2835FBState),
358         VMSTATE_UINT32(config.yres, BCM2835FBState),
359         VMSTATE_UINT32(config.xres_virtual, BCM2835FBState),
360         VMSTATE_UINT32(config.yres_virtual, BCM2835FBState),
361         VMSTATE_UINT32(config.xoffset, BCM2835FBState),
362         VMSTATE_UINT32(config.yoffset, BCM2835FBState),
363         VMSTATE_UINT32(config.bpp, BCM2835FBState),
364         VMSTATE_UINT32(config.base, BCM2835FBState),
365         VMSTATE_UNUSED(8), /* Was pitch and size */
366         VMSTATE_UINT32(config.pixo, BCM2835FBState),
367         VMSTATE_UINT32(config.alpha, BCM2835FBState),
368         VMSTATE_END_OF_LIST()
369     }
370 };
371 
372 static const GraphicHwOps vgafb_ops = {
373     .invalidate  = fb_invalidate_display,
374     .gfx_update  = fb_update_display,
375 };
376 
377 static void bcm2835_fb_init(Object *obj)
378 {
379     BCM2835FBState *s = BCM2835_FB(obj);
380 
381     memory_region_init_io(&s->iomem, obj, &bcm2835_fb_ops, s, TYPE_BCM2835_FB,
382                           0x10);
383     sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
384     sysbus_init_irq(SYS_BUS_DEVICE(s), &s->mbox_irq);
385 }
386 
387 static void bcm2835_fb_reset(DeviceState *dev)
388 {
389     BCM2835FBState *s = BCM2835_FB(dev);
390 
391     s->pending = false;
392 
393     s->config = s->initial_config;
394 
395     s->invalidate = true;
396     s->lock = false;
397 }
398 
399 static void bcm2835_fb_realize(DeviceState *dev, Error **errp)
400 {
401     BCM2835FBState *s = BCM2835_FB(dev);
402     Error *err = NULL;
403     Object *obj;
404 
405     if (s->vcram_base == 0) {
406         error_setg(errp, "%s: required vcram-base property not set", __func__);
407         return;
408     }
409 
410     obj = object_property_get_link(OBJECT(dev), "dma-mr", &err);
411     if (obj == NULL) {
412         error_setg(errp, "%s: required dma-mr link not found: %s",
413                    __func__, error_get_pretty(err));
414         return;
415     }
416 
417     /* Fill in the parts of initial_config that are not set by QOM properties */
418     s->initial_config.xres_virtual = s->initial_config.xres;
419     s->initial_config.yres_virtual = s->initial_config.yres;
420     s->initial_config.xoffset = 0;
421     s->initial_config.yoffset = 0;
422     s->initial_config.base = s->vcram_base + BCM2835_FB_OFFSET;
423 
424     s->dma_mr = MEMORY_REGION(obj);
425     address_space_init(&s->dma_as, s->dma_mr, NULL);
426 
427     bcm2835_fb_reset(dev);
428 
429     s->con = graphic_console_init(dev, 0, &vgafb_ops, s);
430     qemu_console_resize(s->con, s->config.xres, s->config.yres);
431 }
432 
433 static Property bcm2835_fb_props[] = {
434     DEFINE_PROP_UINT32("vcram-base", BCM2835FBState, vcram_base, 0),/*required*/
435     DEFINE_PROP_UINT32("vcram-size", BCM2835FBState, vcram_size,
436                        DEFAULT_VCRAM_SIZE),
437     DEFINE_PROP_UINT32("xres", BCM2835FBState, initial_config.xres, 640),
438     DEFINE_PROP_UINT32("yres", BCM2835FBState, initial_config.yres, 480),
439     DEFINE_PROP_UINT32("bpp", BCM2835FBState, initial_config.bpp, 16),
440     DEFINE_PROP_UINT32("pixo", BCM2835FBState,
441                        initial_config.pixo, 1), /* 1=RGB, 0=BGR */
442     DEFINE_PROP_UINT32("alpha", BCM2835FBState,
443                        initial_config.alpha, 2), /* alpha ignored */
444     DEFINE_PROP_END_OF_LIST()
445 };
446 
447 static void bcm2835_fb_class_init(ObjectClass *klass, void *data)
448 {
449     DeviceClass *dc = DEVICE_CLASS(klass);
450 
451     dc->props = bcm2835_fb_props;
452     dc->realize = bcm2835_fb_realize;
453     dc->reset = bcm2835_fb_reset;
454     dc->vmsd = &vmstate_bcm2835_fb;
455 }
456 
457 static TypeInfo bcm2835_fb_info = {
458     .name          = TYPE_BCM2835_FB,
459     .parent        = TYPE_SYS_BUS_DEVICE,
460     .instance_size = sizeof(BCM2835FBState),
461     .class_init    = bcm2835_fb_class_init,
462     .instance_init = bcm2835_fb_init,
463 };
464 
465 static void bcm2835_fb_register_types(void)
466 {
467     type_register_static(&bcm2835_fb_info);
468 }
469 
470 type_init(bcm2835_fb_register_types)
471