crtc代码分析 ================ struct drm_crtc结构体 ------------------------- :: struct drm_crtc { /** @dev: parent DRM device */ struct drm_device *dev; /** @port: OF node used by drm_of_find_possible_crtcs(). */ struct device_node *port; /** * @head: * * List of all CRTCs on @dev, linked from &drm_mode_config.crtc_list. * Invariant over the lifetime of @dev and therefore does not need * locking. */ struct list_head head; /** @name: human readable name, can be overwritten by the driver */ char *name; /** * @mutex: * * This provides a read lock for the overall CRTC state (mode, dpms * state, ...) and a write lock for everything which can be update * without a full modeset (fb, cursor data, CRTC properties ...). A full * modeset also need to grab &drm_mode_config.connection_mutex. * * For atomic drivers specifically this protects @state. */ struct drm_modeset_lock mutex; /** @base: base KMS object for ID tracking etc. */ struct drm_mode_object base; /** * @primary: * Primary plane for this CRTC. Note that this is only * relevant for legacy IOCTL, it specifies the plane implicitly used by * the SETCRTC and PAGE_FLIP IOCTLs. It does not have any significance * beyond that. */ struct drm_plane *primary; /** * @cursor: * Cursor plane for this CRTC. Note that this is only relevant for * legacy IOCTL, it specifies the plane implicitly used by the SETCURSOR * and SETCURSOR2 IOCTLs. It does not have any significance * beyond that. */ struct drm_plane *cursor; /** * @index: Position inside the mode_config.list, can be used as an array * index. It is invariant over the lifetime of the CRTC. */ unsigned index; /** * @cursor_x: Current x position of the cursor, used for universal * cursor planes because the SETCURSOR IOCTL only can update the * framebuffer without supplying the coordinates. Drivers should not use * this directly, atomic drivers should look at &drm_plane_state.crtc_x * of the cursor plane instead. */ int cursor_x; /** * @cursor_y: Current y position of the cursor, used for universal * cursor planes because the SETCURSOR IOCTL only can update the * framebuffer without supplying the coordinates. Drivers should not use * this directly, atomic drivers should look at &drm_plane_state.crtc_y * of the cursor plane instead. */ int cursor_y; /** * @enabled: * * Is this CRTC enabled? Should only be used by legacy drivers, atomic * drivers should instead consult &drm_crtc_state.enable and * &drm_crtc_state.active. Atomic drivers can update this by calling * drm_atomic_helper_update_legacy_modeset_state(). */ bool enabled; /** * @mode: * * Current mode timings. Should only be used by legacy drivers, atomic * drivers should instead consult &drm_crtc_state.mode. Atomic drivers * can update this by calling * drm_atomic_helper_update_legacy_modeset_state(). */ struct drm_display_mode mode; /** * @hwmode: * * Programmed mode in hw, after adjustments for encoders, crtc, panel * scaling etc. Should only be used by legacy drivers, for high * precision vblank timestamps in * drm_calc_vbltimestamp_from_scanoutpos(). * * Note that atomic drivers should not use this, but instead use * &drm_crtc_state.adjusted_mode. And for high-precision timestamps * drm_calc_vbltimestamp_from_scanoutpos() used &drm_vblank_crtc.hwmode, * which is filled out by calling drm_calc_timestamping_constants(). */ struct drm_display_mode hwmode; /** * @x: * x position on screen. Should only be used by legacy drivers, atomic * drivers should look at &drm_plane_state.crtc_x of the primary plane * instead. Updated by calling * drm_atomic_helper_update_legacy_modeset_state(). */ int x; /** * @y: * y position on screen. Should only be used by legacy drivers, atomic * drivers should look at &drm_plane_state.crtc_y of the primary plane * instead. Updated by calling * drm_atomic_helper_update_legacy_modeset_state(). */ int y; /** @funcs: CRTC control functions */ const struct drm_crtc_funcs *funcs; /** * @gamma_size: Size of legacy gamma ramp reported to userspace. Set up * by calling drm_mode_crtc_set_gamma_size(). */ uint32_t gamma_size; /** * @gamma_store: Gamma ramp values used by the legacy SETGAMMA and * GETGAMMA IOCTls. Set up by calling drm_mode_crtc_set_gamma_size(). */ uint16_t *gamma_store; /** @helper_private: mid-layer private data */ const struct drm_crtc_helper_funcs *helper_private; /** @properties: property tracking for this CRTC */ struct drm_object_properties properties; /** * @state: * * Current atomic state for this CRTC. * * This is protected by @mutex. Note that nonblocking atomic commits * access the current CRTC state without taking locks. Either by going * through the &struct drm_atomic_state pointers, see * for_each_oldnew_crtc_in_state(), for_each_old_crtc_in_state() and * for_each_new_crtc_in_state(). Or through careful ordering of atomic * commit operations as implemented in the atomic helpers, see * &struct drm_crtc_commit. */ struct drm_crtc_state *state; /** * @commit_list: * * List of &drm_crtc_commit structures tracking pending commits. * Protected by @commit_lock. This list holds its own full reference, * as does the ongoing commit. * * "Note that the commit for a state change is also tracked in * &drm_crtc_state.commit. For accessing the immediately preceding * commit in an atomic update it is recommended to just use that * pointer in the old CRTC state, since accessing that doesn't need * any locking or list-walking. @commit_list should only be used to * stall for framebuffer cleanup that's signalled through * &drm_crtc_commit.cleanup_done." */ struct list_head commit_list; /** * @commit_lock: * * Spinlock to protect @commit_list. */ spinlock_t commit_lock; #ifdef CONFIG_DEBUG_FS /** * @debugfs_entry: * * Debugfs directory for this CRTC. */ struct dentry *debugfs_entry; #endif /** * @crc: * * Configuration settings of CRC capture. */ struct drm_crtc_crc crc; /** * @fence_context: * * timeline context used for fence operations. */ unsigned int fence_context; /** * @fence_lock: * * spinlock to protect the fences in the fence_context. */ spinlock_t fence_lock; /** * @fence_seqno: * * Seqno variable used as monotonic counter for the fences * created on the CRTC's timeline. */ unsigned long fence_seqno; /** * @timeline_name: * * The name of the CRTC's fence timeline. */ char timeline_name[32]; /** * @self_refresh_data: Holds the state for the self refresh helpers * * Initialized via drm_self_refresh_helper_init(). */ struct drm_self_refresh_data *self_refresh_data; }; crtc相关的API ----------------- - drm_crtc_init_with_planes :: int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc, struct drm_plane *primary, struct drm_plane *cursor, const struct drm_crtc_funcs *funcs, const char *name, ...) { struct drm_mode_config *config = &dev->mode_config; int ret; WARN_ON(primary && primary->type != DRM_PLANE_TYPE_PRIMARY); WARN_ON(cursor && cursor->type != DRM_PLANE_TYPE_CURSOR); /* crtc index is used with 32bit bitmasks */ if (WARN_ON(config->num_crtc >= 32)) return -EINVAL; WARN_ON(drm_drv_uses_atomic_modeset(dev) && (!funcs->atomic_destroy_state || !funcs->atomic_duplicate_state)); crtc->dev = dev; crtc->funcs = funcs; INIT_LIST_HEAD(&crtc->commit_list); spin_lock_init(&crtc->commit_lock); drm_modeset_lock_init(&crtc->mutex); //创建类型为DRM_MODE_OBJECT_CRTC的struct drm_mode_object结构体 ret = drm_mode_object_add(dev, &crtc->base, DRM_MODE_OBJECT_CRTC); if (ret) return ret; //设置名称 if (name) { va_list ap; va_start(ap, name); crtc->name = kvasprintf(GFP_KERNEL, name, ap); va_end(ap); } else { crtc->name = kasprintf(GFP_KERNEL, "crtc-%d", drm_num_crtcs(dev)); } if (!crtc->name) { drm_mode_object_unregister(dev, &crtc->base); return -ENOMEM; } crtc->fence_context = dma_fence_context_alloc(1); spin_lock_init(&crtc->fence_lock); snprintf(crtc->timeline_name, sizeof(crtc->timeline_name), "CRTC:%d-%s", crtc->base.id, crtc->name); //初始化properties crtc->base.properties = &crtc->properties; list_add_tail(&crtc->head, &config->crtc_list); crtc->index = config->num_crtc++; /初始化primary plane, cursor plane crtc->primary = primary; crtc->cursor = cursor; if (primary && !primary->possible_crtcs) primary->possible_crtcs = drm_crtc_mask(crtc); if (cursor && !cursor->possible_crtcs) cursor->possible_crtcs = drm_crtc_mask(crtc); //调试相关的初始化 ret = drm_crtc_crc_init(crtc); if (ret) { drm_mode_object_unregister(dev, &crtc->base); return ret; } //attach一些properties变量 if (drm_core_check_feature(dev, DRIVER_ATOMIC)) { drm_object_attach_property(&crtc->base, config->prop_active, 0); drm_object_attach_property(&crtc->base, config->prop_mode_id, 0); drm_object_attach_property(&crtc->base, config->prop_out_fence_ptr, 0); drm_object_attach_property(&crtc->base, config->prop_vrr_enabled, 0); } return 0; } - drm_mode_setcrtc :: int drm_mode_setcrtc(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_mode_config *config = &dev->mode_config; struct drm_mode_crtc *crtc_req = data; struct drm_crtc *crtc; struct drm_plane *plane; struct drm_connector **connector_set = NULL, *connector; struct drm_framebuffer *fb = NULL; struct drm_display_mode *mode = NULL; struct drm_mode_set set; uint32_t __user *set_connectors_ptr; struct drm_modeset_acquire_ctx ctx; int ret; int i; if (!drm_core_check_feature(dev, DRIVER_MODESET)) return -EOPNOTSUPP; /* * Universal plane src offsets are only 16.16, prevent havoc for * drivers using universal plane code internally. */ if (crtc_req->x & 0xffff0000 || crtc_req->y & 0xffff0000) return -ERANGE; //找到需要的crtc实体 crtc = drm_crtc_find(dev, file_priv, crtc_req->crtc_id); if (!crtc) { DRM_DEBUG_KMS("Unknown CRTC ID %d\n", crtc_req->crtc_id); return -ENOENT; } DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name); plane = crtc->primary; /* allow disabling with the primary plane leased */ if (crtc_req->mode_valid && !drm_lease_held(file_priv, plane->base.id)) return -EACCES; mutex_lock(&crtc->dev->mode_config.mutex); DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE, ret); //得到或者生成primary plane的framebuffer if (crtc_req->mode_valid) { /* If we have a mode we need a framebuffer. */ /* If we pass -1, set the mode with the currently bound fb */ if (crtc_req->fb_id == -1) { struct drm_framebuffer *old_fb; if (plane->state) old_fb = plane->state->fb; else old_fb = plane->fb; if (!old_fb) { DRM_DEBUG_KMS("CRTC doesn't have current FB\n"); ret = -EINVAL; goto out; } fb = old_fb; /* Make refcounting symmetric with the lookup path. */ drm_framebuffer_get(fb); } else { fb = drm_framebuffer_lookup(dev, file_priv, crtc_req->fb_id); if (!fb) { DRM_DEBUG_KMS("Unknown FB ID%d\n", crtc_req->fb_id); ret = -ENOENT; goto out; } } //创建struct drm_display_mode结构体，并把应用层传递下来的参数赋值给结构体 mode = drm_mode_create(dev); if (!mode) { ret = -ENOMEM; goto out; } if (!file_priv->aspect_ratio_allowed && (crtc_req->mode.flags & DRM_MODE_FLAG_PIC_AR_MASK) != DRM_MODE_FLAG_PIC_AR_NONE) { DRM_DEBUG_KMS("Unexpected aspect-ratio flag bits\n"); ret = -EINVAL; goto out; } //赋值操作 ret = drm_mode_convert_umode(dev, mode, &crtc_req->mode); if (ret) { DRM_DEBUG_KMS("Invalid mode (ret=%d, status=%s)\n", ret, drm_get_mode_status_name(mode->status)); drm_mode_debug_printmodeline(mode); goto out; } /* * Check whether the primary plane supports the fb pixel format. * Drivers not implementing the universal planes API use a * default formats list provided by the DRM core which doesn't * match real hardware capabilities. Skip the check in that * case. */ if (!plane->format_default) { //检查pixel format是否支持 ret = drm_plane_check_pixel_format(plane, fb->format->format, fb->modifier); if (ret) { struct drm_format_name_buf format_name; DRM_DEBUG_KMS("Invalid pixel format %s, modifier 0x%llx\n", drm_get_format_name(fb->format->format, &format_name), fb->modifier); goto out; } } //检查framebuffer是否足够大，能否满足crtc viewport ret = drm_crtc_check_viewport(crtc, crtc_req->x, crtc_req->y, mode, fb); if (ret) goto out; } if (crtc_req->count_connectors == 0 && mode) { DRM_DEBUG_KMS("Count connectors is 0 but mode set\n"); ret = -EINVAL; goto out; } if (crtc_req->count_connectors > 0 && (!mode || !fb)) { DRM_DEBUG_KMS("Count connectors is %d but no mode or fb set\n", crtc_req->count_connectors); ret = -EINVAL; goto out; } if (crtc_req->count_connectors > 0) { u32 out_id; /* Avoid unbounded kernel memory allocation */ if (crtc_req->count_connectors > config->num_connector) { ret = -EINVAL; goto out; } connector_set = kmalloc_array(crtc_req->count_connectors, sizeof(struct drm_connector *), GFP_KERNEL); if (!connector_set) { ret = -ENOMEM; goto out; } for (i = 0; i < crtc_req->count_connectors; i++) { connector_set[i] = NULL; set_connectors_ptr = (uint32_t __user *)(unsigned long)crtc_req->set_connectors_ptr; if (get_user(out_id, &set_connectors_ptr[i])) { ret = -EFAULT; goto out; } //找到crtc绑定链接的connector connector = drm_connector_lookup(dev, file_priv, out_id); if (!connector) { DRM_DEBUG_KMS("Connector id %d unknown\n", out_id); ret = -ENOENT; goto out; } DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, connector->name); connector_set[i] = connector; } } set.crtc = crtc; set.x = crtc_req->x; set.y = crtc_req->y; set.mode = mode; set.connectors = connector_set; set.num_connectors = crtc_req->count_connectors; set.fb = fb; //设置struct drm_mode_set结构体 if (drm_drv_uses_atomic_modeset(dev)) ret = crtc->funcs->set_config(&set, &ctx); else ret = __drm_mode_set_config_internal(&set, &ctx); out: if (fb) drm_framebuffer_put(fb); if (connector_set) { for (i = 0; i < crtc_req->count_connectors; i++) { if (connector_set[i]) drm_connector_put(connector_set[i]); } } kfree(connector_set); drm_mode_destroy(dev, mode); /* In case we need to retry... */ connector_set = NULL; fb = NULL; mode = NULL; DRM_MODESET_LOCK_ALL_END(ctx, ret); mutex_unlock(&crtc->dev->mode_config.mutex); return ret; } func的一些介绍 ------------------- :: //crtc控制接口，一般填写helper函数 struct drm_crtc_funcs { //重置软硬件state, 由drm_mode_config_reset调用，一般赋值为 //drm_atomic_helper_crtc_reset void (*reset)(struct drm_crtc *crtc); //设置鼠标图片，width/height应该是鼠标的宽高，handle是鼠标图片buf(drm_gem_obj //该接口已经废弃，使用鼠标层代替 int (*cursor_set)(struct drm_crtc *crtc, struct drm_file *file_priv, uint32_t handle, uint32_t width, uint32_t height); //同上，多了hot_x, hot_y int (*cursor_set2)(struct drm_crtc *crtc, struct drm_file *file_priv, uint32_t handle, uint32_t width, uint32_t height, int32_t hot_x, int32_t hot_y); //移动鼠标操作 int (*cursor_move)(struct drm_crtc *crtc, int x, int y); //gamma设置 int (*gamma_set)(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b, uint32_t size, struct drm_modeset_acquire_ctx *ctx); //drm_mode_config_cleanup调用该接口 void (*destroy)(struct drm_crtc *crtc); //设置crtc的fb/connector/mode的属性，对应用户态drmModeSetCrtc接口atomic modeset操作 //使用drm_atomic_helper_set_config接口赋值 int (*set_config)(struct drm_mode_set *set, struct drm_modeset_acquire_ctx *ctx); //page翻转接口，vsync同步的 int (*page_flip)(struct drm_crtc *crtc, struct drm_framebuffer *fb, struct drm_pending_vblank_event *event, uint32_t flags, struct drm_modeset_acquire_ctx *ctx); //和page_flip类似，但该接口会等待特定的vbank int (*page_flip_target)(struct drm_crtc *crtc, struct drm_framebuffer *fb, struct drm_pending_vblank_event *event, uint32_t flags, uint32_t target, struct drm_modeset_acquire_ctx *ctx); //设置属性 int (*set_property)(struct drm_crtc *crtc, struct drm_property *property, uint64_t val); //拷贝crtc的drm_crtc_state对象，一般赋值为drm_atomic_helper_crtc_duplicate_state struct drm_crtc_state *(*atomic_duplicate_state)(struct drm_crtc *crtc); void (*atomic_destroy_state)(struct drm_crtc *crtc, struct drm_crtc_state *state); //atomic操作中设置特定属性到state中，该接口一般可由drm_atomic_set_property调用 int (*atomic_set_property)(struct drm_crtc *crtc, struct drm_crtc_state *state, struct drm_property *property, uint64_t val); //获取atomic属性 int (*atomic_get_property)(struct drm_crtc *crtc, const struct drm_crtc_state *state, struct drm_property *property, uint64_t *val); //drm_dev_register之后，调用该接口进行额外的crtc操作 int (*late_register)(struct drm_crtc *crtc); //与late接口相反 void (*early_unregister)(struct drm_crtc *crtc); //以下接口与crc相关 int (*set_crc_source)(struct drm_crtc *crtc, const char *source); int (*verify_crc_source)(struct drm_crtc *crtc, const char *source, size_t *values_cnt); const char *const *(*get_crc_sources)(struct drm_crtc *crtc, size_t *count); //打印crtc的atomic state属性，一般由drm_atomic_print_state调用 void (*atomic_print_state)(struct drm_printer *p, const struct drm_crtc_state *state); //获取硬件vblank counter计数 u32 (*get_vblank_counter)(struct drm_crtc *crtc); //使能vblank中断 int (*enable_vblank)(struct drm_crtc *crtc); void (*disable_vblank)(struct drm_crtc *crtc); }; - struct drm_crtc_helper_funcs :: struct drm_crtc_helper_funcs { //电源管理接口，一般由drm_helper_connector_dpms调用 void (*dpms)(struct drm_crtc *crtc, int mode); //为modeset做准备，一般就是调用dpms接口关闭crtc(DRM_MODE_DPMS_OFF) void (*prepare)(struct drm_crtc *crtc); //与prepare接口对应，在modeset完成后，调用该接口来enable crtc void (*commit)(struct drm_crtc *crtc); //检查显示mode的有效性 enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc, const struct drm_display_mode *mode); //验证并修正mode,由drm_atomic_helper_check_modeset调用 bool (*mode_fixup)(struct drm_crtc *crtc, const struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode); //设置display mode, crtc_set_mode会调用该接口 int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode, int x, int y, struct drm_framebuffer *old_fb); //更新crtc的display mode, 但不会修改其primary plane配置 void (*mode_set_nofb)(struct drm_crtc *crtc); //设置fb和显示位置，drm_crtc_helper_set_config会调用该接口 int (*mode_set_base)(struct drm_crtc *crtc, int x, int y, struct drm_framebuffer *old_fb); int (*mode_set_base_atomic)(struct drm_crtc *crtc, struct drm_framebuffer *fb, int x, int y, enum mode_set_atomic); //关闭crtc void (*disable)(struct drm_crtc *crtc); //检查待更新的drm_crtc_state int (*atomic_check)(struct drm_crtc *crtc, struct drm_crtc_state *state); //多plane的atomic update之前需要调用该接口 void (*atomic_begin)(struct drm_crtc *crtc, struct drm_crtc_state *old_crtc_state); //多plane的atomic update之后需要调用该接口 void (*atomic_flush)(struct drm_crtc *crtc, struct drm_crtc_state *old_crtc_state); //atomic enable crtc void (*atomic_enable)(struct drm_crtc *crtc, struct drm_crtc_state *old_crtc_state); void (*atomic_disable)(struct drm_crtc *crtc, struct drm_crtc_state *old_crtc_state); }; rcar_du_crtc_create ------------------------ :: rcar_du_crtc_create drm_crtc_init_with_planes drm_crtc_helper_add drm_crtc_vblank_off rcar_du_crtc_crc_init :: static const struct drm_crtc_helper_funcs crtc_helper_funcs = { .atomic_check = rcar_du_crtc_atomic_check, .atomic_begin = rcar_du_crtc_atomic_begin, .atomic_flush = rcar_du_crtc_atomic_flush, .atomic_enable = rcar_du_crtc_atomic_enable, .atomic_disable = rcar_du_crtc_atomic_disable, .mode_valid = rcar_du_crtc_mode_valid, };