Hi Everyone, This email contains a test application showing DMABUF sharing between DRM/KMS display and camera capture node. It show simple camera preview on LCD display. The similar application showing DMABUF sharing between two V4L devices is available at link:
http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/43793...
The program is written in C99 and it was tested using Exynos/DRM and FIMC capture for M5MOLS and S5K6AAFX sensors on UniversalC210 board.
This application shows how buffer sharing between V4L2/DRM may look like. Please let me know if/where I use DRM/V4L2 incorrectly.
The application was tested against 3.3-rc5 kernel with patches: http://thread.gmane.org/gmane.linux.kernel.cross-arch/12819 [redesign of DMA mapping] http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/43793... [support for dma_get_pages, PoC generic API for transforming DMA object into list of pages] http://thread.gmane.org/gmane.comp.video.dri.devel/65583/focus=65703 [DRM prime support] http://git.infradead.org/users/kmpark/linux-samsung/shortlog/refs/heads/exyn... [DRM prime support for Exynos DRM] http://thread.gmane.org/gmane.comp.video.dri.devel/65992 [fix to DRM prime in Exynos DRM] http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/42966... [support for DMABUF importing in V4L2] http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/45394 [integrate V4L2 with DMABUF]
Regards, Tomasz Stanislawski
--- #include <errno.h> #include <fcntl.h> #include <linux/videodev2.h> #include <math.h> #include <poll.h> #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <sys/ioctl.h> #include <sys/mman.h> #include <sys/stat.h> #include <sys/types.h> #include <unistd.h>
#include <xf86drm.h> #include <xf86drmMode.h> #include <exynos_drm.h>
#define ERRSTR strerror(errno)
#define BYE_ON(cond, ...) \ do { \ if (cond) { \ int errsv = errno; \ fprintf(stderr, "ERROR(%s:%d) : ", \ __FILE__, __LINE__); \ errno = errsv; \ fprintf(stderr, __VA_ARGS__); \ abort(); \ } \ } while(0)
static inline int warn(const char *file, int line, const char *fmt, ...) { int errsv = errno; va_list va; va_start(va, fmt); fprintf(stderr, "WARN(%s:%d): ", file, line); vfprintf(stderr, fmt, va); va_end(va); errno = errsv; return 1; }
#define WARN_ON(cond, ...) \ ((cond) ? warn(__FILE__, __LINE__, __VA_ARGS__) : 0)
struct setup { char module[32]; uint32_t conId; uint32_t crtId; char modestr[32]; char video[32]; unsigned int w, h; unsigned int use_wh : 1; unsigned int in_fourcc; unsigned int out_fourcc; unsigned int buffer_count; unsigned int use_crop : 1; unsigned int use_compose : 1; struct v4l2_rect crop; struct v4l2_rect compose; };
struct buffer { unsigned int bo_handle; unsigned int fb_handle; int dbuf_fd; };
struct stream { int v4lfd; int current_buffer; int buffer_count; struct buffer *buffer; } stream;
static void usage(char *name) { fprintf(stderr, "usage: %s [-Moisth]\n", name); fprintf(stderr, "\t-M <drm-module>\tset DRM module\n"); fprintf(stderr, "\t-o <connector_id>:<crtc_id>:<mode>\tset a mode\n"); fprintf(stderr, "\t-i <video-node>\tset video node like /dev/video*\n"); fprintf(stderr, "\t-S <width,height>\tset input resolution\n"); fprintf(stderr, "\t-f <fourcc>\tset input format using 4cc\n"); fprintf(stderr, "\t-F <fourcc>\tset output format using 4cc\n"); fprintf(stderr, "\t-s <width,height>@<left,top>\tset crop area\n"); fprintf(stderr, "\t-t <width,height>@<left,top>\tset compose area\n"); fprintf(stderr, "\t-b buffer_count\tset number of buffers\n"); fprintf(stderr, "\t-h\tshow this help\n"); fprintf(stderr, "\n\tDefault is to dump all info.\n"); }
static inline int parse_rect(char *s, struct v4l2_rect *r) { return sscanf(s, "%d,%d@%d,%d", &r->width, &r->height, &r->top, &r->left) != 4; }
static int parse_args(int argc, char *argv[], struct setup *s) { if (argc <= 1) usage(argv[0]);
int c, ret; memset(s, 0, sizeof(*s));
while ((c = getopt(argc, argv, "M:o:i:S:f:F:s:t:b:h")) != -1) { switch (c) { case 'M': strncpy(s->module, optarg, 31); break; case 'o': ret = sscanf(optarg, "%u:%u:%31s", &s->conId, &s->crtId, s->modestr); if (WARN_ON(ret != 3, "incorrect mode description\n")) return -1; break; case 'i': strncpy(s->video, optarg, 31); break; case 'S': ret = sscanf(optarg, "%u,%u", &s->w, &s->h); if (WARN_ON(ret != 2, "incorrect input size\n")) return -1; s->use_wh = 1; break; case 'f': if (WARN_ON(strlen(optarg) != 4, "invalid fourcc\n")) return -1; s->in_fourcc = ((unsigned)optarg[0] << 0) | ((unsigned)optarg[1] << 8) | ((unsigned)optarg[2] << 16) | ((unsigned)optarg[3] << 24); break; case 'F': if (WARN_ON(strlen(optarg) != 4, "invalid fourcc\n")) return -1; s->out_fourcc = ((unsigned)optarg[0] << 0) | ((unsigned)optarg[1] << 8) | ((unsigned)optarg[2] << 16) | ((unsigned)optarg[3] << 24); break; case 's': ret = parse_rect(optarg, &s->crop); if (WARN_ON(ret, "incorrect crop area\n")) return -1; s->use_crop = 1; break; case 't': ret = parse_rect(optarg, &s->compose); if (WARN_ON(ret, "incorrect compose area\n")) return -1; s->use_compose = 1; break; case 'b': ret = sscanf(optarg, "%u", &s->buffer_count); if (WARN_ON(ret != 1, "incorrect buffer count\n")) return -1; break; case '?': case 'h': usage(argv[0]); return -1; } }
return 0; }
static int buffer_create(struct buffer *b, int drmfd, struct setup *s, uint64_t size, uint32_t pitch) { int ret = strncmp(s->module, "exynos", 6); if (WARN_ON(ret, "drm: only exynos GEM is supported\n")) return -1;
struct drm_exynos_gem_create gem; struct drm_gem_close gem_close;
memset(&gem, 0, sizeof gem); gem.size = size; ret = ioctl(drmfd, DRM_IOCTL_EXYNOS_GEM_CREATE, &gem); if (WARN_ON(ret, "EXYNOS_GEM_CREATE failed: %s\n", ERRSTR)) return -1; b->bo_handle = gem.handle;
struct drm_prime_handle prime; memset(&prime, 0, sizeof prime); prime.handle = b->bo_handle;
ret = ioctl(drmfd, DRM_IOCTL_PRIME_HANDLE_TO_FD, &prime); if (WARN_ON(ret, "PRIME_HANDLE_TO_FD failed: %s\n", ERRSTR)) goto fail_gem; printf("dbuf_fd = %d\n", prime.fd); b->dbuf_fd = prime.fd;
uint32_t offsets[4] = { 0 }; uint32_t pitches[4] = { pitch }; uint32_t bo_handles[4] = { b->bo_handle }; unsigned int fourcc = s->out_fourcc; if (!fourcc) fourcc = s->in_fourcc; ret = drmModeAddFB2(drmfd, s->w, s->h, fourcc, bo_handles, pitches, offsets, &b->fb_handle, 0); if (WARN_ON(ret, "drmModeAddFB2 failed: %s\n", ERRSTR)) goto fail_prime;
return 0;
fail_prime: close(b->dbuf_fd);
fail_gem: memset(&gem_close, 0, sizeof gem_close); gem_close.handle = b->bo_handle, ret = ioctl(drmfd, DRM_IOCTL_GEM_CLOSE, gem_close); WARN_ON(ret, "GEM_CLOSE failed: %s\n", ERRSTR);
return -1; }
static int find_mode(drmModeModeInfo *m, int drmfd, struct setup *s, uint32_t *con) { int ret = -1; drmModeRes *res = drmModeGetResources(drmfd); if (WARN_ON(!res, "drmModeGetResources failed: %s\n", ERRSTR)) return -1;
if (WARN_ON(res->count_crtcs <= 0, "drm: no crts\n")) goto fail_res;
if (WARN_ON(res->count_connectors <= 0, "drm: no connectors\n")) goto fail_res;
if (WARN_ON(s->conId >= res->count_connectors, "connector %d " "is not supported\n", s->conId)) goto fail_res;
drmModeConnector *c; c = drmModeGetConnector(drmfd, res->connectors[s->conId]);
if (WARN_ON(!c, "drmModeGetConnector failed: %s\n", ERRSTR)) goto fail_res;
if (WARN_ON(!c->count_modes, "connector supports no mode\n")) goto fail_conn;
drmModeModeInfo *found = NULL; for (int i = 0; i < c->count_modes; ++i) if (strcmp(c->modes[i].name, s->modestr) == 0) found = &c->modes[i];
if (WARN_ON(!found, "mode %s not supported\n", s->modestr)) { fprintf(stderr, "Valid modes:"); for (int i = 0; i < c->count_modes; ++i) fprintf(stderr, " %s", c->modes[i].name); fprintf(stderr, "\n"); goto fail_conn; }
memcpy(m, found, sizeof *found); if (con) *con = c->connector_id; ret = 0;
fail_conn: drmModeFreeConnector(c);
fail_res: drmModeFreeResources(res);
return ret; }
static void page_flip_handler(int fd, unsigned int frame, unsigned int sec, unsigned int usec, void *data) { int index = stream.current_buffer; struct v4l2_buffer buf; struct v4l2_plane plane; int ret;
stream.current_buffer = (int)data; if (index < 0) return;
memset(&buf, 0, sizeof buf); memset(&plane, 0, sizeof plane); buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE; buf.memory = V4L2_MEMORY_DMABUF; buf.index = index; buf.m.planes = &plane; buf.length = 1; plane.m.fd = stream.buffer[index].dbuf_fd;
ret = ioctl(stream.v4lfd, VIDIOC_QBUF, &buf); BYE_ON(ret, "VIDIOC_QBUF(index = %d) failed: %s\n", index, ERRSTR); }
int main(int argc, char *argv[]) { int ret; struct setup s;
ret = parse_args(argc, argv, &s); BYE_ON(ret, "failed to parse arguments\n"); BYE_ON(s.module[0] == 0, "DRM module is missing\n"); BYE_ON(s.video[0] == 0, "video node is missing\n");
int drmfd = drmOpen(s.module, NULL); BYE_ON(drmfd < 0, "drmOpen(%s) failed: %s\n", s.module, ERRSTR);
int v4lfd = open(s.video, O_RDWR); BYE_ON(v4lfd < 0, "failed to open %s: %s\n", s.video, ERRSTR);
struct v4l2_capability caps; memset(&caps, 0, sizeof caps);
ret = ioctl(v4lfd, VIDIOC_QUERYCAP, &caps); BYE_ON(ret, "VIDIOC_QUERYCAP failed: %s\n", ERRSTR);
/* TODO: add single plane support */ BYE_ON(~caps.capabilities & V4L2_CAP_VIDEO_CAPTURE_MPLANE, "video: multiplanar capture is not supported\n");
struct v4l2_format fmt; memset(&fmt, 0, sizeof fmt); fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
ret = ioctl(v4lfd, VIDIOC_G_FMT, &fmt); BYE_ON(ret < 0, "VIDIOC_G_FMT failed: %s\n", ERRSTR); printf("G_FMT(start): width = %u, height = %u, 4cc = %.4s\n", fmt.fmt.pix_mp.width, fmt.fmt.pix_mp.height, (char*)&fmt.fmt.pix_mp.pixelformat);
if (s.use_wh) { fmt.fmt.pix_mp.width = s.w; fmt.fmt.pix_mp.height = s.h; } if (s.in_fourcc) fmt.fmt.pix_mp.pixelformat = s.in_fourcc;
ret = ioctl(v4lfd, VIDIOC_S_FMT, &fmt); BYE_ON(ret < 0, "VIDIOC_S_FMT failed: %s\n", ERRSTR);
ret = ioctl(v4lfd, VIDIOC_G_FMT, &fmt); BYE_ON(ret < 0, "VIDIOC_G_FMT failed: %s\n", ERRSTR); printf("G_FMT(final): width = %u, height = %u, 4cc = %.4s\n", fmt.fmt.pix_mp.width, fmt.fmt.pix_mp.height, (char*)&fmt.fmt.pix_mp.pixelformat);
BYE_ON(fmt.fmt.pix_mp.num_planes > 1, "multiplanar formats are not supported\n");
struct v4l2_requestbuffers rqbufs; memset(&rqbufs, 0, sizeof(rqbufs)); rqbufs.count = s.buffer_count; rqbufs.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE; rqbufs.memory = V4L2_MEMORY_DMABUF;
ret = ioctl(v4lfd, VIDIOC_REQBUFS, &rqbufs); BYE_ON(ret < 0, "VIDIOC_REQBUFS failed: %s\n", ERRSTR); BYE_ON(rqbufs.count < s.buffer_count, "video node allocated only " "%u of %u buffers\n", rqbufs.count, s.buffer_count);
s.in_fourcc = fmt.fmt.pix_mp.pixelformat; s.w = fmt.fmt.pix_mp.width; s.h = fmt.fmt.pix_mp.height;
/* TODO: add support for multiplanar formats */ struct buffer buffer[s.buffer_count]; uint64_t size = fmt.fmt.pix_mp.plane_fmt[0].sizeimage; uint32_t pitch = fmt.fmt.pix_mp.plane_fmt[0].bytesperline; printf("size = %llu pitch = %u\n", size, pitch); for (int i = 0; i < s.buffer_count; ++i) { ret = buffer_create(&buffer[i], drmfd, &s, size, pitch); BYE_ON(ret, "failed to create buffer%d\n", i); } printf("buffers ready\n");
drmModeModeInfo drmmode; uint32_t con; ret = find_mode(&drmmode, drmfd, &s, &con); BYE_ON(ret, "failed to find valid mode\n");
ret = drmModeSetCrtc(drmfd, s.crtId, buffer[0].fb_handle, 0, 0, &con, 1, &drmmode); BYE_ON(ret, "drmModeSetCrtc failed: %s\n", ERRSTR);
/* enqueueing first buffer to DRM */ ret = drmModePageFlip(drmfd, s.crtId, buffer[0].fb_handle, DRM_MODE_PAGE_FLIP_EVENT, 0); BYE_ON(ret, "drmModePageFlip failed: %s\n", ERRSTR);
for (int i = 1; i < s.buffer_count; ++i) { struct v4l2_plane plane; memset(&plane, 0, sizeof plane); struct v4l2_buffer buf; memset(&buf, 0, sizeof buf);
buf.index = i; buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE; buf.memory = V4L2_MEMORY_DMABUF; buf.m.planes = &plane; buf.length = 1; plane.m.fd = buffer[i].dbuf_fd; ret = ioctl(v4lfd, VIDIOC_QBUF, &buf); BYE_ON(ret < 0, "VIDIOC_QBUF for buffer %d failed: %s\n", buf.index, ERRSTR); }
int type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE; ret = ioctl(v4lfd, VIDIOC_STREAMON, &type); BYE_ON(ret < 0, "STREAMON failed: %s\n", ERRSTR);
struct pollfd fds[] = { { .fd = v4lfd, .events = POLLIN }, { .fd = drmfd, .events = POLLIN }, };
/* buffer currently used by drm */ stream.v4lfd = v4lfd; stream.current_buffer = -1; stream.buffer = buffer;
while ((ret = poll(fds, 2, 5000)) > 0) { if (fds[0].revents & POLLIN) { struct v4l2_buffer buf; memset(&buf, 0, sizeof buf); /* dequeue buffer */ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE; buf.memory = V4L2_MEMORY_DMABUF; ret = ioctl(v4lfd, VIDIOC_DQBUF, &buf); BYE_ON(ret, "VIDIOC_DQBUF failed: %s\n", ERRSTR);
ret = drmModePageFlip(drmfd, s.crtId, buffer[buf.index].fb_handle, DRM_MODE_PAGE_FLIP_EVENT, (void*)buf.index); BYE_ON(ret, "drmModePageFlip failed: %s\n", ERRSTR);
} if (fds[1].revents & POLLIN) { drmEventContext evctx; memset(&evctx, 0, sizeof evctx); evctx.version = DRM_EVENT_CONTEXT_VERSION; evctx.page_flip_handler = page_flip_handler;
ret = drmHandleEvent(drmfd, &evctx); BYE_ON(ret, "drmHandleEvent failed: %s\n", ERRSTR); } }
return 0; }