DRM应用程序进阶 （atomic-crtc）

转载：DRM应用程序进阶 （atomic-crtc）

https://github.com/dvdhrm/docs/blob/master/drm-howto/modeset-atomic.c
上面那个编译成功，但是运行异常，没有采用。

#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <time.h>
#include <unistd.h>
#include <xf86drm.h>
#include <xf86drmMode.h>

struct buffer_object {
	uint32_t width;
	uint32_t height;
	uint32_t pitch;
	uint32_t handle;
	uint32_t size;
	uint8_t *vaddr;
	uint32_t fb_id;
};

struct buffer_object buf;

static int modeset_create_fb(int fd, struct buffer_object *bo)
{
	struct drm_mode_create_dumb create = {};
 	struct drm_mode_map_dumb map = {};

	create.width = bo->width;
	create.height = bo->height;
	create.bpp = 32;
	drmIoctl(fd, DRM_IOCTL_MODE_CREATE_DUMB, &create);

	bo->pitch = create.pitch;
	bo->size = create.size;
	bo->handle = create.handle;
	drmModeAddFB(fd, bo->width, bo->height, 24, 32, bo->pitch,
			   bo->handle, &bo->fb_id);

	map.handle = create.handle;
	drmIoctl(fd, DRM_IOCTL_MODE_MAP_DUMB, &map);

	bo->vaddr = static_cast<uint8_t *>(mmap(0, create.size, PROT_READ | PROT_WRITE,
			MAP_SHARED, fd, map.offset));

	memset(bo->vaddr, 0xff, bo->size);

	return 0;
}

static void modeset_destroy_fb(int fd, struct buffer_object *bo)
{
	struct drm_mode_destroy_dumb destroy = {};

	drmModeRmFB(fd, bo->fb_id);

	munmap(bo->vaddr, bo->size);

	destroy.handle = bo->handle;
	drmIoctl(fd, DRM_IOCTL_MODE_DESTROY_DUMB, &destroy);
}

static uint32_t get_property_id(int fd, drmModeObjectProperties *props,
				const char *name)
{
	drmModePropertyPtr property;
	uint32_t i, id = 0;

	/* find property according to the name */
	for (i = 0; i < props->count_props; i++) {
		property = drmModeGetProperty(fd, props->props[i]);
		if (!strcmp(property->name, name))
			id = property->prop_id;
		drmModeFreeProperty(property);

		if (id)
			break;
	}

	return id;
}

int main()
{
	int fd;
	drmModeConnector *conn;
	drmModeRes *res;
	drmModePlaneRes *plane_res;
	drmModeObjectProperties *props;
	drmModeAtomicReq *req;
	uint32_t conn_id;
	uint32_t crtc_id;
	uint32_t plane_id;
	uint32_t blob_id;
	uint32_t property_crtc_id;
	uint32_t property_mode_id;
	uint32_t property_active;

	fd = open("/dev/dri/card2", O_RDWR | O_CLOEXEC);

	res = drmModeGetResources(fd);
	crtc_id = res->crtcs[0];
	conn_id = res->connectors[0];

	drmSetClientCap(fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
	plane_res = drmModeGetPlaneResources(fd);
	plane_id = plane_res->planes[0];

	conn = drmModeGetConnector(fd, conn_id);
	buf.width = conn->modes[0].hdisplay;
	buf.height = conn->modes[0].vdisplay;

	modeset_create_fb(fd, &buf);

	drmSetClientCap(fd, DRM_CLIENT_CAP_ATOMIC, 1);

	/* get connector properties */
	props = drmModeObjectGetProperties(fd, conn_id,	DRM_MODE_OBJECT_CONNECTOR);
	property_crtc_id = get_property_id(fd, props, "CRTC_ID");
	drmModeFreeObjectProperties(props);

	/* get crtc properties */
	props = drmModeObjectGetProperties(fd, crtc_id, DRM_MODE_OBJECT_CRTC);
	property_active = get_property_id(fd, props, "ACTIVE");
	property_mode_id = get_property_id(fd, props, "MODE_ID");
	drmModeFreeObjectProperties(props);

	/* create blob to store current mode, and retun the blob id */
	drmModeCreatePropertyBlob(fd, &conn->modes[0],
				sizeof(conn->modes[0]), &blob_id);

	/* start modeseting */
	req = drmModeAtomicAlloc();
	drmModeAtomicAddProperty(req, crtc_id, property_active, 1);
	drmModeAtomicAddProperty(req, crtc_id, property_mode_id, blob_id);
	drmModeAtomicAddProperty(req, conn_id, property_crtc_id, crtc_id);
	drmModeAtomicCommit(fd, req, DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
	drmModeAtomicFree(req);

	printf("drmModeAtomicCommit SetCrtcn");
	getchar();

	drmModeSetPlane(fd, plane_id, crtc_id, buf.fb_id, 0,
			50, 50, 320, 320,
			0, 0, 320 << 16, 320 << 16);

	printf("drmModeSetPlanen");
	getchar();

	modeset_destroy_fb(fd, &buf);

	drmModeFreeConnector(conn);
	drmModeFreePlaneResources(plane_res);
	drmModeFreeResources(res);

	close(fd);

	return 0;
}

文章汇总：DRM 学习简介

最后

以上就是伶俐音响为你收集整理的DRM应用程序进阶 （atomic-crtc）DRM应用程序进阶 （atomic-crtc）的全部内容，希望文章能够帮你解决DRM应用程序进阶 （atomic-crtc）DRM应用程序进阶 （atomic-crtc）所遇到的程序开发问题。

如果觉得靠谱客网站的内容还不错，欢迎将靠谱客网站推荐给程序员好友。