xref: /openbmc/qemu/hw/display/bcm2835_fb.c (revision 979a8902)
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/hw.h"
30 #include "hw/irq.h"
31 #include "framebuffer.h"
32 #include "ui/pixel_ops.h"
33 #include "hw/misc/bcm2835_mbox_defs.h"
34 #include "hw/qdev-properties.h"
35 #include "migration/vmstate.h"
36 #include "qemu/log.h"
37 #include "qemu/module.h"
38 
39 #define DEFAULT_VCRAM_SIZE 0x4000000
40 #define BCM2835_FB_OFFSET  0x00100000
41 
42 /* Maximum permitted framebuffer size; experimentally determined on an rpi2 */
43 #define XRES_MAX 3840
44 #define YRES_MAX 2560
45 /* Framebuffer size used if guest requests zero size */
46 #define XRES_SMALL 592
47 #define YRES_SMALL 488
48 
49 static void fb_invalidate_display(void *opaque)
50 {
51     BCM2835FBState *s = BCM2835_FB(opaque);
52 
53     s->invalidate = true;
54 }
55 
56 static void draw_line_src16(void *opaque, uint8_t *dst, const uint8_t *src,
57                             int width, int deststep)
58 {
59     BCM2835FBState *s = opaque;
60     uint16_t rgb565;
61     uint32_t rgb888;
62     uint8_t r, g, b;
63     DisplaySurface *surface = qemu_console_surface(s->con);
64     int bpp = surface_bits_per_pixel(surface);
65 
66     while (width--) {
67         switch (s->config.bpp) {
68         case 8:
69             /* lookup palette starting at video ram base
70              * TODO: cache translation, rather than doing this each time!
71              */
72             rgb888 = ldl_le_phys(&s->dma_as, s->vcram_base + (*src << 2));
73             r = (rgb888 >> 0) & 0xff;
74             g = (rgb888 >> 8) & 0xff;
75             b = (rgb888 >> 16) & 0xff;
76             src++;
77             break;
78         case 16:
79             rgb565 = lduw_le_p(src);
80             r = ((rgb565 >> 11) & 0x1f) << 3;
81             g = ((rgb565 >>  5) & 0x3f) << 2;
82             b = ((rgb565 >>  0) & 0x1f) << 3;
83             src += 2;
84             break;
85         case 24:
86             rgb888 = ldl_le_p(src);
87             r = (rgb888 >> 0) & 0xff;
88             g = (rgb888 >> 8) & 0xff;
89             b = (rgb888 >> 16) & 0xff;
90             src += 3;
91             break;
92         case 32:
93             rgb888 = ldl_le_p(src);
94             r = (rgb888 >> 0) & 0xff;
95             g = (rgb888 >> 8) & 0xff;
96             b = (rgb888 >> 16) & 0xff;
97             src += 4;
98             break;
99         default:
100             r = 0;
101             g = 0;
102             b = 0;
103             break;
104         }
105 
106         if (s->config.pixo == 0) {
107             /* swap to BGR pixel format */
108             uint8_t tmp = r;
109             r = b;
110             b = tmp;
111         }
112 
113         switch (bpp) {
114         case 8:
115             *dst++ = rgb_to_pixel8(r, g, b);
116             break;
117         case 15:
118             *(uint16_t *)dst = rgb_to_pixel15(r, g, b);
119             dst += 2;
120             break;
121         case 16:
122             *(uint16_t *)dst = rgb_to_pixel16(r, g, b);
123             dst += 2;
124             break;
125         case 24:
126             rgb888 = rgb_to_pixel24(r, g, b);
127             *dst++ = rgb888 & 0xff;
128             *dst++ = (rgb888 >> 8) & 0xff;
129             *dst++ = (rgb888 >> 16) & 0xff;
130             break;
131         case 32:
132             *(uint32_t *)dst = rgb_to_pixel32(r, g, b);
133             dst += 4;
134             break;
135         default:
136             return;
137         }
138     }
139 }
140 
141 static bool fb_use_offsets(BCM2835FBConfig *config)
142 {
143     /*
144      * Return true if we should use the viewport offsets.
145      * Experimentally, the hardware seems to do this only if the
146      * viewport size is larger than the physical screen. (It doesn't
147      * prevent the guest setting this silly viewport setting, though...)
148      */
149     return config->xres_virtual > config->xres &&
150         config->yres_virtual > config->yres;
151 }
152 
153 static void fb_update_display(void *opaque)
154 {
155     BCM2835FBState *s = opaque;
156     DisplaySurface *surface = qemu_console_surface(s->con);
157     int first = 0;
158     int last = 0;
159     int src_width = 0;
160     int dest_width = 0;
161     uint32_t xoff = 0, yoff = 0;
162 
163     if (s->lock || !s->config.xres) {
164         return;
165     }
166 
167     src_width = bcm2835_fb_get_pitch(&s->config);
168     if (fb_use_offsets(&s->config)) {
169         xoff = s->config.xoffset;
170         yoff = s->config.yoffset;
171     }
172 
173     dest_width = s->config.xres;
174 
175     switch (surface_bits_per_pixel(surface)) {
176     case 0:
177         return;
178     case 8:
179         break;
180     case 15:
181         dest_width *= 2;
182         break;
183     case 16:
184         dest_width *= 2;
185         break;
186     case 24:
187         dest_width *= 3;
188         break;
189     case 32:
190         dest_width *= 4;
191         break;
192     default:
193         hw_error("bcm2835_fb: bad color depth\n");
194         break;
195     }
196 
197     if (s->invalidate) {
198         hwaddr base = s->config.base + xoff + (hwaddr)yoff * src_width;
199         framebuffer_update_memory_section(&s->fbsection, s->dma_mr,
200                                           base,
201                                           s->config.yres, src_width);
202     }
203 
204     framebuffer_update_display(surface, &s->fbsection,
205                                s->config.xres, s->config.yres,
206                                src_width, dest_width, 0, s->invalidate,
207                                draw_line_src16, s, &first, &last);
208 
209     if (first >= 0) {
210         dpy_gfx_update(s->con, 0, first, s->config.xres,
211                        last - first + 1);
212     }
213 
214     s->invalidate = false;
215 }
216 
217 void bcm2835_fb_validate_config(BCM2835FBConfig *config)
218 {
219     /*
220      * Validate the config, and clip any bogus values into range,
221      * as the hardware does. Note that fb_update_display() relies on
222      * this happening to prevent it from performing out-of-range
223      * accesses on redraw.
224      */
225     config->xres = MIN(config->xres, XRES_MAX);
226     config->xres_virtual = MIN(config->xres_virtual, XRES_MAX);
227     config->yres = MIN(config->yres, YRES_MAX);
228     config->yres_virtual = MIN(config->yres_virtual, YRES_MAX);
229 
230     /*
231      * These are not minima: a 40x40 framebuffer will be accepted.
232      * They're only used as defaults if the guest asks for zero size.
233      */
234     if (config->xres == 0) {
235         config->xres = XRES_SMALL;
236     }
237     if (config->yres == 0) {
238         config->yres = YRES_SMALL;
239     }
240     if (config->xres_virtual == 0) {
241         config->xres_virtual = config->xres;
242     }
243     if (config->yres_virtual == 0) {
244         config->yres_virtual = config->yres;
245     }
246 
247     if (fb_use_offsets(config)) {
248         /* Clip the offsets so the viewport is within the physical screen */
249         config->xoffset = MIN(config->xoffset,
250                               config->xres_virtual - config->xres);
251         config->yoffset = MIN(config->yoffset,
252                               config->yres_virtual - config->yres);
253     }
254 }
255 
256 void bcm2835_fb_reconfigure(BCM2835FBState *s, BCM2835FBConfig *newconfig)
257 {
258     s->lock = true;
259 
260     s->config = *newconfig;
261 
262     s->invalidate = true;
263     qemu_console_resize(s->con, s->config.xres, s->config.yres);
264     s->lock = false;
265 }
266 
267 static void bcm2835_fb_mbox_push(BCM2835FBState *s, uint32_t value)
268 {
269     uint32_t pitch;
270     uint32_t size;
271     BCM2835FBConfig newconf;
272 
273     value &= ~0xf;
274 
275     newconf.xres = ldl_le_phys(&s->dma_as, value);
276     newconf.yres = ldl_le_phys(&s->dma_as, value + 4);
277     newconf.xres_virtual = ldl_le_phys(&s->dma_as, value + 8);
278     newconf.yres_virtual = ldl_le_phys(&s->dma_as, value + 12);
279     newconf.bpp = ldl_le_phys(&s->dma_as, value + 20);
280     newconf.xoffset = ldl_le_phys(&s->dma_as, value + 24);
281     newconf.yoffset = ldl_le_phys(&s->dma_as, value + 28);
282 
283     newconf.base = s->vcram_base | (value & 0xc0000000);
284     newconf.base += BCM2835_FB_OFFSET;
285 
286     bcm2835_fb_validate_config(&newconf);
287 
288     pitch = bcm2835_fb_get_pitch(&newconf);
289     size = bcm2835_fb_get_size(&newconf);
290 
291     stl_le_phys(&s->dma_as, value + 16, pitch);
292     stl_le_phys(&s->dma_as, value + 32, newconf.base);
293     stl_le_phys(&s->dma_as, value + 36, size);
294 
295     bcm2835_fb_reconfigure(s, &newconf);
296 }
297 
298 static uint64_t bcm2835_fb_read(void *opaque, hwaddr offset, unsigned size)
299 {
300     BCM2835FBState *s = opaque;
301     uint32_t res = 0;
302 
303     switch (offset) {
304     case MBOX_AS_DATA:
305         res = MBOX_CHAN_FB;
306         s->pending = false;
307         qemu_set_irq(s->mbox_irq, 0);
308         break;
309 
310     case MBOX_AS_PENDING:
311         res = s->pending;
312         break;
313 
314     default:
315         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
316                       __func__, offset);
317         return 0;
318     }
319 
320     return res;
321 }
322 
323 static void bcm2835_fb_write(void *opaque, hwaddr offset, uint64_t value,
324                              unsigned size)
325 {
326     BCM2835FBState *s = opaque;
327 
328     switch (offset) {
329     case MBOX_AS_DATA:
330         /* bcm2835_mbox should check our pending status before pushing */
331         assert(!s->pending);
332         s->pending = true;
333         bcm2835_fb_mbox_push(s, value);
334         qemu_set_irq(s->mbox_irq, 1);
335         break;
336 
337     default:
338         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
339                       __func__, offset);
340         return;
341     }
342 }
343 
344 static const MemoryRegionOps bcm2835_fb_ops = {
345     .read = bcm2835_fb_read,
346     .write = bcm2835_fb_write,
347     .endianness = DEVICE_NATIVE_ENDIAN,
348     .valid.min_access_size = 4,
349     .valid.max_access_size = 4,
350 };
351 
352 static const VMStateDescription vmstate_bcm2835_fb = {
353     .name = TYPE_BCM2835_FB,
354     .version_id = 1,
355     .minimum_version_id = 1,
356     .fields = (VMStateField[]) {
357         VMSTATE_BOOL(lock, BCM2835FBState),
358         VMSTATE_BOOL(invalidate, BCM2835FBState),
359         VMSTATE_BOOL(pending, BCM2835FBState),
360         VMSTATE_UINT32(config.xres, BCM2835FBState),
361         VMSTATE_UINT32(config.yres, BCM2835FBState),
362         VMSTATE_UINT32(config.xres_virtual, BCM2835FBState),
363         VMSTATE_UINT32(config.yres_virtual, BCM2835FBState),
364         VMSTATE_UINT32(config.xoffset, BCM2835FBState),
365         VMSTATE_UINT32(config.yoffset, BCM2835FBState),
366         VMSTATE_UINT32(config.bpp, BCM2835FBState),
367         VMSTATE_UINT32(config.base, BCM2835FBState),
368         VMSTATE_UNUSED(8), /* Was pitch and size */
369         VMSTATE_UINT32(config.pixo, BCM2835FBState),
370         VMSTATE_UINT32(config.alpha, BCM2835FBState),
371         VMSTATE_END_OF_LIST()
372     }
373 };
374 
375 static const GraphicHwOps vgafb_ops = {
376     .invalidate  = fb_invalidate_display,
377     .gfx_update  = fb_update_display,
378 };
379 
380 static void bcm2835_fb_init(Object *obj)
381 {
382     BCM2835FBState *s = BCM2835_FB(obj);
383 
384     memory_region_init_io(&s->iomem, obj, &bcm2835_fb_ops, s, TYPE_BCM2835_FB,
385                           0x10);
386     sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
387     sysbus_init_irq(SYS_BUS_DEVICE(s), &s->mbox_irq);
388 }
389 
390 static void bcm2835_fb_reset(DeviceState *dev)
391 {
392     BCM2835FBState *s = BCM2835_FB(dev);
393 
394     s->pending = false;
395 
396     s->config = s->initial_config;
397 
398     s->invalidate = true;
399     s->lock = false;
400 }
401 
402 static void bcm2835_fb_realize(DeviceState *dev, Error **errp)
403 {
404     BCM2835FBState *s = BCM2835_FB(dev);
405     Error *err = NULL;
406     Object *obj;
407 
408     if (s->vcram_base == 0) {
409         error_setg(errp, "%s: required vcram-base property not set", __func__);
410         return;
411     }
412 
413     obj = object_property_get_link(OBJECT(dev), "dma-mr", &err);
414     if (obj == NULL) {
415         error_setg(errp, "%s: required dma-mr link not found: %s",
416                    __func__, error_get_pretty(err));
417         return;
418     }
419 
420     /* Fill in the parts of initial_config that are not set by QOM properties */
421     s->initial_config.xres_virtual = s->initial_config.xres;
422     s->initial_config.yres_virtual = s->initial_config.yres;
423     s->initial_config.xoffset = 0;
424     s->initial_config.yoffset = 0;
425     s->initial_config.base = s->vcram_base + BCM2835_FB_OFFSET;
426 
427     s->dma_mr = MEMORY_REGION(obj);
428     address_space_init(&s->dma_as, s->dma_mr, TYPE_BCM2835_FB "-memory");
429 
430     bcm2835_fb_reset(dev);
431 
432     s->con = graphic_console_init(dev, 0, &vgafb_ops, s);
433     qemu_console_resize(s->con, s->config.xres, s->config.yres);
434 }
435 
436 static Property bcm2835_fb_props[] = {
437     DEFINE_PROP_UINT32("vcram-base", BCM2835FBState, vcram_base, 0),/*required*/
438     DEFINE_PROP_UINT32("vcram-size", BCM2835FBState, vcram_size,
439                        DEFAULT_VCRAM_SIZE),
440     DEFINE_PROP_UINT32("xres", BCM2835FBState, initial_config.xres, 640),
441     DEFINE_PROP_UINT32("yres", BCM2835FBState, initial_config.yres, 480),
442     DEFINE_PROP_UINT32("bpp", BCM2835FBState, initial_config.bpp, 16),
443     DEFINE_PROP_UINT32("pixo", BCM2835FBState,
444                        initial_config.pixo, 1), /* 1=RGB, 0=BGR */
445     DEFINE_PROP_UINT32("alpha", BCM2835FBState,
446                        initial_config.alpha, 2), /* alpha ignored */
447     DEFINE_PROP_END_OF_LIST()
448 };
449 
450 static void bcm2835_fb_class_init(ObjectClass *klass, void *data)
451 {
452     DeviceClass *dc = DEVICE_CLASS(klass);
453 
454     device_class_set_props(dc, bcm2835_fb_props);
455     dc->realize = bcm2835_fb_realize;
456     dc->reset = bcm2835_fb_reset;
457     dc->vmsd = &vmstate_bcm2835_fb;
458 }
459 
460 static TypeInfo bcm2835_fb_info = {
461     .name          = TYPE_BCM2835_FB,
462     .parent        = TYPE_SYS_BUS_DEVICE,
463     .instance_size = sizeof(BCM2835FBState),
464     .class_init    = bcm2835_fb_class_init,
465     .instance_init = bcm2835_fb_init,
466 };
467 
468 static void bcm2835_fb_register_types(void)
469 {
470     type_register_static(&bcm2835_fb_info);
471 }
472 
473 type_init(bcm2835_fb_register_types)
474