plane代码分析 ===================== struct drm_plane结构体 ------------------------ :: struct drm_plane { /** @dev: DRM device this plane belongs to */ struct drm_device *dev; struct list_head head; char *name; struct drm_modeset_lock mutex; /** @base: base mode object */ struct drm_mode_object base; //plane绑定的crtc uint32_t possible_crtcs; //plane支持的fb像素format类型数组，format类型如DRM_FORMAT_ARGB8888 uint32_t *format_types; //plane支持的fb像素format类型数组大小 unsigned int format_count; bool format_default; //modifier数组，其存放的值DRM_FORMAT_MOD_LINEAR/DRM_FORMAT_MOD_X_TILED uint64_t *modifiers; //modifier数组大小 unsigned int modifier_count; //d当前绑定的crtc struct drm_crtc *crtc; //no-atomic drivers用来标识当前绑定的fb struct drm_framebuffer *fb; //对于no-atomic drivers, old_fb用于在modeset操作时跟踪老的fb struct drm_framebuffer *old_fb; /** @funcs: plane control functions */ const struct drm_plane_funcs *funcs; /** @properties: property tracking for this plane */ struct drm_object_properties properties; /** @type: Type of plane, see &enum drm_plane_type for details. */ enum drm_plane_type type; /** * @index: Position inside the mode_config.list, can be used as an array * index. It is invariant over the lifetime of the plane. */ unsigned index; /** @helper_private: mid-layer private data */ const struct drm_plane_helper_funcs *helper_private; //表示plane的各种状态，如其绑定的crtc/fb等，用于atomic操作 struct drm_plane_state *state; /** * @alpha_property: * Optional alpha property for this plane. See * drm_plane_create_alpha_property(). */ struct drm_property *alpha_property; /** * @zpos_property: * Optional zpos property for this plane. See * drm_plane_create_zpos_property(). */ struct drm_property *zpos_property; /** * @rotation_property: * Optional rotation property for this plane. See * drm_plane_create_rotation_property(). */ struct drm_property *rotation_property; /** * @blend_mode_property: * Optional "pixel blend mode" enum property for this plane. * Blend mode property represents the alpha blending equation selection, * describing how the pixels from the current plane are composited with * the background. */ struct drm_property *blend_mode_property; /** * @color_encoding_property: * * Optional "COLOR_ENCODING" enum property for specifying * color encoding for non RGB formats. * See drm_plane_create_color_properties(). */ struct drm_property *color_encoding_property; /** * @color_range_property: * * Optional "COLOR_RANGE" enum property for specifying * color range for non RGB formats. * See drm_plane_create_color_properties(). */ struct drm_property *color_range_property; }; drm_universal_plane_init ---------------------------- :: int drm_universal_plane_init(struct drm_device *dev, struct drm_plane *plane, uint32_t possible_crtcs, const struct drm_plane_funcs *funcs, const uint32_t *formats, unsigned int format_count, const uint64_t *format_modifiers, enum drm_plane_type type, const char *name, ...) { struct drm_mode_config *config = &dev->mode_config; unsigned int format_modifier_count = 0; int ret; /* plane index is used with 32bit bitmasks */ if (WARN_ON(config->num_total_plane >= 32)) return -EINVAL; WARN_ON(drm_drv_uses_atomic_modeset(dev) && (!funcs->atomic_destroy_state || !funcs->atomic_duplicate_state)); //创建一个类型为DRM_MODE_OBJECT_PLANE的 ret = drm_mode_object_add(dev, &plane->base, DRM_MODE_OBJECT_PLANE); if (ret) return ret; drm_modeset_lock_init(&plane->mutex); plane->base.properties = &plane->properties; plane->dev = dev; plane->funcs = funcs; plane->format_types = kmalloc_array(format_count, sizeof(uint32_t), GFP_KERNEL); if (!plane->format_types) { DRM_DEBUG_KMS("out of memory when allocating plane\n"); drm_mode_object_unregister(dev, &plane->base); return -ENOMEM; } /* * First driver to need more than 64 formats needs to fix this. Each * format is encoded as a bit and the current code only supports a u64. */ if (WARN_ON(format_count > 64)) return -EINVAL; if (format_modifiers) { const uint64_t *temp_modifiers = format_modifiers; while (*temp_modifiers++ != DRM_FORMAT_MOD_INVALID) format_modifier_count++; } if (format_modifier_count) config->allow_fb_modifiers = true; plane->modifier_count = format_modifier_count; plane->modifiers = kmalloc_array(format_modifier_count, sizeof(format_modifiers[0]), GFP_KERNEL); if (format_modifier_count && !plane->modifiers) { DRM_DEBUG_KMS("out of memory when allocating plane\n"); kfree(plane->format_types); drm_mode_object_unregister(dev, &plane->base); return -ENOMEM; } if (name) { va_list ap; va_start(ap, name); plane->name = kvasprintf(GFP_KERNEL, name, ap); va_end(ap); } else { plane->name = kasprintf(GFP_KERNEL, "plane-%d", drm_num_planes(dev)); } if (!plane->name) { kfree(plane->format_types); kfree(plane->modifiers); drm_mode_object_unregister(dev, &plane->base); return -ENOMEM; } memcpy(plane->format_types, formats, format_count * sizeof(uint32_t)); plane->format_count = format_count; memcpy(plane->modifiers, format_modifiers, format_modifier_count * sizeof(format_modifiers[0])); plane->possible_crtcs = possible_crtcs; plane->type = type; list_add_tail(&plane->head, &config->plane_list); plane->index = config->num_total_plane++; drm_object_attach_property(&plane->base, config->plane_type_property, plane->type); if (drm_core_check_feature(dev, DRIVER_ATOMIC)) { drm_object_attach_property(&plane->base, config->prop_fb_id, 0); drm_object_attach_property(&plane->base, config->prop_in_fence_fd, -1); drm_object_attach_property(&plane->base, config->prop_crtc_id, 0); drm_object_attach_property(&plane->base, config->prop_crtc_x, 0); drm_object_attach_property(&plane->base, config->prop_crtc_y, 0); drm_object_attach_property(&plane->base, config->prop_crtc_w, 0); drm_object_attach_property(&plane->base, config->prop_crtc_h, 0); drm_object_attach_property(&plane->base, config->prop_src_x, 0); drm_object_attach_property(&plane->base, config->prop_src_y, 0); drm_object_attach_property(&plane->base, config->prop_src_w, 0); drm_object_attach_property(&plane->base, config->prop_src_h, 0); } if (config->allow_fb_modifiers) create_in_format_blob(dev, plane); return 0; } func ---------- - struct drm_plane_funcs :: /** * struct drm_plane_funcs - driver plane control functions */ struct drm_plane_funcs { /*使能配置plane的crtc和framebuffer.src_x/src_y/src_w/src_h指定fb的源区域 *crtc_x/crtc_y/crtc_w/crtc_h指定其显示在crtc上的目标区域 *atomic操作使用drm_atomic_helper_update_plane实现 */ int (*update_plane)(struct drm_plane *plane, struct drm_crtc *crtc, struct drm_framebuffer *fb, int crtc_x, int crtc_y, unsigned int crtc_w, unsigned int crtc_h, uint32_t src_x, uint32_t src_y, uint32_t src_w, uint32_t src_h, struct drm_modeset_acquire_ctx *ctx); /*DRM_IOCTL_MODE_SETPLANE IOCTL调用时，fb id参数，如果为0，就会调用该接口 *关闭plane， atomic modeset使用drm_atomic_helper_disable_plane()实现该hook */ int (*disable_plane)(struct drm_plane *plane, struct drm_modeset_acquire_ctx *ctx); //该接口仅在driver卸载的时候通过drm_mode_config_cleanup()调用来清空plane资源 void (*destroy)(struct drm_plane *plane); /*reset plane的软硬件状态， 通过drm_mode_config_reset接口调用 *atomic drivers 使用drm_atomic_helper_plane_reset()实现该hook*/ void (*reset)(struct drm_plane *plane); /*设置属性的legacy入口， atomic drivers不使用*/ int (*set_property)(struct drm_plane *plane, struct drm_property *property, uint64_t val); /*复制plane state, atomic driver必须要有该接口 *drm_atomic_get_plane_state会调用到该hook*/ struct drm_plane_state *(*atomic_duplicate_state)(struct drm_plane *plane); //销毁plane state void (*atomic_destroy_state)(struct drm_plane *plane, struct drm_plane_state *state); /*设置驱动自定义的属性， 通过drm_atomic_plane_set_property调用*/ int (*atomic_set_property)(struct drm_plane *plane, struct drm_plane_state *state, struct drm_property *property, uint64_t val); //获取驱动自定义的属性， 通过drm_atomic_plane_get_property调用 int (*atomic_get_property)(struct drm_plane *plane, const struct drm_plane_state *state, struct drm_property *property, uint64_t *val); //drm_dev_register接口调用后，调用该hook注册额外的用户接口 int (*late_register)(struct drm_plane *plane); //drm_dev_unregister()前调用，unregister用户空间接口 void (*early_unregister)(struct drm_plane *plane); //打印plane state, drm_atomic_plane_print_state()会调用 void (*atomic_print_state)(struct drm_printer *p, const struct drm_plane_state *state); //检查format和modifier是否有效 bool (*format_mod_supported)(struct drm_plane *plane, uint32_t format, uint64_t modifier); }; - struct drm_plane_helper_funcs :: struct drm_plane_helper_funcs { //准备fb，主要包括设置fb fence, 映射fb虚拟地址等 int (*prepare_fb)(struct drm_plane *plane, struct drm_plane_state *new_state); //和prepare_fb是相反的操作，比如解除fb虚拟地址的映射 void (*cleanup_fb)(struct drm_plane *plane, struct drm_plane_state *old_state); //可选的检查plane属性的约束项 int (*atomic_check)(struct drm_plane *plane, struct drm_atomic_state *state); /*更新plane的属性状态到软硬件中， 这个接口才是真正更新参数*/ void (*atomic_update)(struct drm_plane *plane, struct drm_atomic_state *state); //disable plane 非必需，不做介绍 void (*atomic_disable)(struct drm_plane *plane, struct drm_atomic_state *state); //异步检查 后续了解 int (*atomic_async_check)(struct drm_plane *plane, struct drm_atomic_state *state); //异步更新，后续了解 void (*atomic_async_update)(struct drm_plane *plane, struct drm_atomic_state *state); };