fbdev: don't clear more than needed
[libpicofe.git] / linux / fbdev.c
... / ...
CommitLineData
1/*
2 * (C) GraÅžvydas "notaz" Ignotas, 2009-2010
3 *
4 * This work is licensed under the terms of any of these licenses
5 * (at your option):
6 * - GNU GPL, version 2 or later.
7 * - GNU LGPL, version 2.1 or later.
8 * - MAME license.
9 * See the COPYING file in the top-level directory.
10 */
11
12#include <stdio.h>
13#include <stdlib.h>
14#include <string.h>
15#include <sys/types.h>
16#include <sys/stat.h>
17#include <fcntl.h>
18#include <sys/ioctl.h>
19#include <sys/mman.h>
20#include <unistd.h>
21#include <linux/fb.h>
22#include <linux/matroxfb.h>
23
24#include "fbdev.h"
25
26#define PFX "fbdev: "
27
28struct vout_fbdev {
29 int fd;
30 void *mem;
31 size_t mem_size;
32 struct fb_var_screeninfo fbvar_old;
33 struct fb_var_screeninfo fbvar_new;
34 int buffer_write;
35 int fb_size;
36 int buffer_count;
37 int top_border, bottom_border;
38 void *mem_saved;
39 size_t mem_saved_size;
40};
41
42void *vout_fbdev_flip(struct vout_fbdev *fbdev)
43{
44 int draw_buf;
45
46 if (fbdev->buffer_count < 2)
47 return fbdev->mem;
48
49 draw_buf = fbdev->buffer_write;
50 fbdev->buffer_write++;
51 if (fbdev->buffer_write >= fbdev->buffer_count)
52 fbdev->buffer_write = 0;
53
54 fbdev->fbvar_new.yoffset =
55 (fbdev->top_border + fbdev->fbvar_new.yres + fbdev->bottom_border) * draw_buf +
56 fbdev->top_border;
57
58 ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
59
60 return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
61}
62
63void vout_fbdev_wait_vsync(struct vout_fbdev *fbdev)
64{
65 int arg = 0;
66 ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &arg);
67}
68
69/* it is recommended to call vout_fbdev_clear() before this */
70void *vout_fbdev_resize(struct vout_fbdev *fbdev, int w, int h, int bpp,
71 int left_border, int right_border, int top_border, int bottom_border, int buffer_cnt)
72{
73 int w_total = left_border + w + right_border;
74 int h_total = top_border + h + bottom_border;
75 size_t mem_size;
76 int ret;
77
78 // unblank to be sure the mode is really accepted
79 ioctl(fbdev->fd, FBIOBLANK, FB_BLANK_UNBLANK);
80
81 if (fbdev->fbvar_new.bits_per_pixel != bpp ||
82 fbdev->fbvar_new.xres != w ||
83 fbdev->fbvar_new.yres != h ||
84 fbdev->fbvar_new.xres_virtual != w_total||
85 fbdev->fbvar_new.yres_virtual < h_total ||
86 fbdev->fbvar_new.xoffset != left_border ||
87 fbdev->buffer_count != buffer_cnt)
88 {
89 if (fbdev->fbvar_new.bits_per_pixel != bpp ||
90 w != fbdev->fbvar_new.xres || h != fbdev->fbvar_new.yres)
91 printf(PFX "switching to %dx%d@%d\n", w, h, bpp);
92
93 fbdev->fbvar_new.xres = w;
94 fbdev->fbvar_new.yres = h;
95 fbdev->fbvar_new.xres_virtual = w_total;
96 fbdev->fbvar_new.yres_virtual = h_total * buffer_cnt;
97 fbdev->fbvar_new.xoffset = left_border;
98 fbdev->fbvar_new.yoffset = top_border;
99 fbdev->fbvar_new.bits_per_pixel = bpp;
100 fbdev->fbvar_new.nonstd = 0; // can set YUV here on omapfb
101 fbdev->buffer_count = buffer_cnt;
102 fbdev->buffer_write = buffer_cnt > 1 ? 1 : 0;
103
104 // seems to help a bit to avoid glitches
105 vout_fbdev_wait_vsync(fbdev);
106
107 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
108 if (ret == -1) {
109 // retry with no multibuffering
110 fbdev->fbvar_new.yres_virtual = h_total;
111 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
112 if (ret == -1) {
113 perror(PFX "FBIOPUT_VSCREENINFO ioctl");
114 return NULL;
115 }
116 fbdev->buffer_count = 1;
117 fbdev->buffer_write = 0;
118 fprintf(stderr, PFX "Warning: failed to increase virtual resolution, "
119 "multibuffering disabled\n");
120 }
121
122 }
123
124 fbdev->fb_size = w_total * h_total * bpp / 8;
125 fbdev->top_border = top_border;
126 fbdev->bottom_border = bottom_border;
127
128 mem_size = fbdev->fb_size * fbdev->buffer_count;
129 if (fbdev->mem_size >= mem_size)
130 goto out;
131
132 if (fbdev->mem != NULL)
133 munmap(fbdev->mem, fbdev->mem_size);
134
135 fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
136 if (fbdev->mem == MAP_FAILED && fbdev->buffer_count > 1) {
137 fprintf(stderr, PFX "Warning: can't map %zd bytes, doublebuffering disabled\n", mem_size);
138 fbdev->buffer_count = 1;
139 fbdev->buffer_write = 0;
140 mem_size = fbdev->fb_size;
141 fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
142 }
143 if (fbdev->mem == MAP_FAILED) {
144 fbdev->mem = NULL;
145 fbdev->mem_size = 0;
146 perror(PFX "mmap framebuffer");
147 return NULL;
148 }
149
150 fbdev->mem_size = mem_size;
151
152out:
153 return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
154}
155
156void vout_fbdev_clear(struct vout_fbdev *fbdev)
157{
158 if (fbdev->mem)
159 memset(fbdev->mem, 0, fbdev->fb_size * fbdev->buffer_count);
160}
161
162void vout_fbdev_clear_lines(struct vout_fbdev *fbdev, int y, int count)
163{
164 int stride = fbdev->fbvar_new.xres_virtual * fbdev->fbvar_new.bits_per_pixel / 8;
165 int i;
166
167 if (y + count > fbdev->top_border + fbdev->fbvar_new.yres)
168 count = fbdev->top_border + fbdev->fbvar_new.yres - y;
169
170 if (y >= 0 && count > 0)
171 for (i = 0; i < fbdev->buffer_count; i++)
172 memset((char *)fbdev->mem + fbdev->fb_size * i + y * stride, 0, stride * count);
173}
174
175int vout_fbdev_get_fd(struct vout_fbdev *fbdev)
176{
177 return fbdev->fd;
178}
179
180struct vout_fbdev *vout_fbdev_init(const char *fbdev_name, int *w, int *h, int bpp, int buffer_cnt)
181{
182 struct vout_fbdev *fbdev;
183 int req_w, req_h;
184 void *pret;
185 int ret;
186
187 fbdev = calloc(1, sizeof(*fbdev));
188 if (fbdev == NULL)
189 return NULL;
190
191 fbdev->fd = open(fbdev_name, O_RDWR);
192 if (fbdev->fd == -1) {
193 fprintf(stderr, PFX "%s: ", fbdev_name);
194 perror("open");
195 goto fail_open;
196 }
197
198 ret = ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->fbvar_old);
199 if (ret == -1) {
200 perror(PFX "FBIOGET_VSCREENINFO ioctl");
201 goto fail;
202 }
203
204 fbdev->fbvar_new = fbdev->fbvar_old;
205
206 req_w = fbdev->fbvar_new.xres;
207 if (*w != 0)
208 req_w = *w;
209 req_h = fbdev->fbvar_new.yres;
210 if (*h != 0)
211 req_h = *h;
212
213 pret = vout_fbdev_resize(fbdev, req_w, req_h, bpp, 0, 0, 0, 0, buffer_cnt);
214 if (pret == NULL)
215 goto fail;
216
217 printf(PFX "%s: %ix%i@%d\n", fbdev_name, fbdev->fbvar_new.xres,
218 fbdev->fbvar_new.yres, fbdev->fbvar_new.bits_per_pixel);
219 *w = fbdev->fbvar_new.xres;
220 *h = fbdev->fbvar_new.yres;
221
222 memset(fbdev->mem, 0, fbdev->mem_size);
223
224 // some checks
225 ret = 0;
226 ret = ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &ret);
227 if (ret != 0)
228 fprintf(stderr, PFX "Warning: vsync doesn't seem to be supported\n");
229
230 if (fbdev->buffer_count > 1) {
231 fbdev->buffer_write = 0;
232 fbdev->fbvar_new.yoffset = fbdev->fbvar_new.yres * (fbdev->buffer_count - 1);
233 ret = ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
234 if (ret != 0) {
235 fbdev->buffer_count = 1;
236 fprintf(stderr, PFX "Warning: can't pan display, doublebuffering disabled\n");
237 }
238 }
239
240 printf("fbdev initialized.\n");
241 return fbdev;
242
243fail:
244 close(fbdev->fd);
245fail_open:
246 free(fbdev);
247 return NULL;
248}
249
250static void vout_fbdev_release(struct vout_fbdev *fbdev)
251{
252 ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_old);
253 if (fbdev->mem != MAP_FAILED)
254 munmap(fbdev->mem, fbdev->mem_size);
255 fbdev->mem = NULL;
256}
257
258int vout_fbdev_save(struct vout_fbdev *fbdev)
259{
260 void *tmp;
261
262 if (fbdev == NULL || fbdev->mem == NULL || fbdev->mem == MAP_FAILED) {
263 fprintf(stderr, PFX "bad args for save\n");
264 return -1;
265 }
266
267 if (fbdev->mem_saved_size < fbdev->mem_size) {
268 tmp = realloc(fbdev->mem_saved, fbdev->mem_size);
269 if (tmp == NULL)
270 return -1;
271 fbdev->mem_saved = tmp;
272 }
273 memcpy(fbdev->mem_saved, fbdev->mem, fbdev->mem_size);
274 fbdev->mem_saved_size = fbdev->mem_size;
275
276 vout_fbdev_release(fbdev);
277 return 0;
278}
279
280int vout_fbdev_restore(struct vout_fbdev *fbdev)
281{
282 int ret;
283
284 if (fbdev == NULL || fbdev->mem != NULL) {
285 fprintf(stderr, PFX "bad args/state for restore\n");
286 return -1;
287 }
288
289 fbdev->mem = mmap(0, fbdev->mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
290 if (fbdev->mem == MAP_FAILED) {
291 perror(PFX "restore: memory restore failed");
292 return -1;
293 }
294 memcpy(fbdev->mem, fbdev->mem_saved, fbdev->mem_size);
295
296 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
297 if (ret == -1) {
298 perror(PFX "restore: FBIOPUT_VSCREENINFO");
299 return -1;
300 }
301
302 return 0;
303}
304
305void vout_fbdev_finish(struct vout_fbdev *fbdev)
306{
307 vout_fbdev_release(fbdev);
308 if (fbdev->fd >= 0)
309 close(fbdev->fd);
310 fbdev->fd = -1;
311 free(fbdev);
312}
313