xref: /device/soc/rockchip/common/sdk_linux/include/drm/drm_crtc.h

/*
 * Copyright © 2006 Keith Packard
 * Copyright © 2007-2008 Dave Airlie
 * Copyright © 2007-2008 Intel Corporation
 *   Jesse Barnes <jesse.barnes@intel.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
#ifndef __DRM_CRTC_H__
#define __DRM_CRTC_H__

#include <linux/i2c.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/fb.h>
#include <linux/hdmi.h>
#include <linux/media-bus-format.h>
#include <uapi/drm/drm_mode.h>
#include <uapi/drm/drm_fourcc.h>
#include <drm/drm_modeset_lock.h>
#include <drm/drm_rect.h>
#include <drm/drm_mode_object.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_modes.h>
#include <drm/drm_connector.h>
#include <drm/drm_device.h>
#include <drm/drm_property.h>
#include <drm/drm_edid.h>
#include <drm/drm_plane.h>
#include <drm/drm_blend.h>
#include <drm/drm_color_mgmt.h>
#include <drm/drm_debugfs_crc.h>
#include <drm/drm_mode_config.h>

struct drm_device;
struct drm_mode_set;
struct drm_file;
struct drm_clip_rect;
struct drm_printer;
struct drm_self_refresh_data;
struct device_node;
struct dma_fence;
struct edid;

static inline int64_t U642I64(uint64_t val)
{
    return (int64_t) * ((int64_t *)&val);
}
static inline uint64_t I642U64(int64_t val)
{
    return (uint64_t) * ((uint64_t *)&val);
}

struct drm_crtc;
struct drm_pending_vblank_event;
struct drm_plane;
struct drm_bridge;
struct drm_atomic_state;

struct drm_crtc_helper_funcs;
struct drm_plane_helper_funcs;

/**
 * struct drm_crtc_state - mutable CRTC state
 *
 * Note that the distinction between @enable and @active is rather subtle:
 * Flipping @active while @enable is set without changing anything else may
 * never return in a failure from the &drm_mode_config_funcs.atomic_check
 * callback. Userspace assumes that a DPMS On will always succeed. In other
 * words: @enable controls resource assignment, @active controls the actual
 * hardware state.
 *
 * The three booleans active_changed, connectors_changed and mode_changed are
 * intended to indicate whether a full modeset is needed, rather than strictly
 * describing what has changed in a commit. See also:
 * drm_atomic_crtc_needs_modeset()
 *
 * WARNING: Transitional helpers (like drm_helper_crtc_mode_set() or
 * drm_helper_crtc_mode_set_base()) do not maintain many of the derived control
 * state like @plane_mask so drivers not converted over to atomic helpers should
 * not rely on these being accurate!
 */
struct drm_crtc_state {
    /** @crtc: backpointer to the CRTC */
    struct drm_crtc *crtc;

    /**
     * @enable: Whether the CRTC should be enabled, gates all other state.
     * This controls reservations of shared resources. Actual hardware state
     * is controlled by @active.
     */
    bool enable;

    /**
     * @active: Whether the CRTC is actively displaying (used for DPMS).
     * Implies that @enable is set. The driver must not release any shared
     * resources if @active is set to false but @enable still true, because
     * userspace expects that a DPMS ON always succeeds.
     *
     * Hence drivers must not consult @active in their various
     * &drm_mode_config_funcs.atomic_check callback to reject an atomic
     * commit. They can consult it to aid in the computation of derived
     * hardware state, since even in the DPMS OFF state the display hardware
     * should be as much powered down as when the CRTC is completely
     * disabled through setting @enable to false.
     */
    bool active;

    /**
     * @planes_changed: Planes on this crtc are updated. Used by the atomic
     * helpers and drivers to steer the atomic commit control flow.
     */
    bool planes_changed : 1;

    /**
     * @mode_changed: @mode or @enable has been changed. Used by the atomic
     * helpers and drivers to steer the atomic commit control flow. See also
     * drm_atomic_crtc_needs_modeset().
     *
     * Drivers are supposed to set this for any CRTC state changes that
     * require a full modeset. They can also reset it to false if e.g. a
     * @mode change can be done without a full modeset by only changing
     * scaler settings.
     */
    bool mode_changed : 1;

    /**
     * @active_changed: @active has been toggled. Used by the atomic
     * helpers and drivers to steer the atomic commit control flow. See also
     * drm_atomic_crtc_needs_modeset().
     */
    bool active_changed : 1;

    /**
     * @connectors_changed: Connectors to this crtc have been updated,
     * either in their state or routing. Used by the atomic
     * helpers and drivers to steer the atomic commit control flow. See also
     * drm_atomic_crtc_needs_modeset().
     *
     * Drivers are supposed to set this as-needed from their own atomic
     * check code, e.g. from &drm_encoder_helper_funcs.atomic_check
     */
    bool connectors_changed : 1;
    /**
     * @zpos_changed: zpos values of planes on this crtc have been updated.
     * Used by the atomic helpers and drivers to steer the atomic commit
     * control flow.
     */
    bool zpos_changed : 1;
    /**
     * @color_mgmt_changed: Color management properties have changed
     * (@gamma_lut, @degamma_lut or @ctm). Used by the atomic helpers and
     * drivers to steer the atomic commit control flow.
     */
    bool color_mgmt_changed : 1;

    /**
     * @no_vblank:
     *
     * Reflects the ability of a CRTC to send VBLANK events. This state
     * usually depends on the pipeline configuration. If set to true, DRM
     * atomic helpers will send out a fake VBLANK event during display
     * updates after all hardware changes have been committed. This is
     * implemented in drm_atomic_helper_fake_vblank().
     *
     * One usage is for drivers and/or hardware without support for VBLANK
     * interrupts. Such drivers typically do not initialize vblanking
     * (i.e., call drm_vblank_init() with the number of CRTCs). For CRTCs
     * without initialized vblanking, this field is set to true in
     * drm_atomic_helper_check_modeset(), and a fake VBLANK event will be
     * send out on each update of the display pipeline by
     * drm_atomic_helper_fake_vblank().
     *
     * Another usage is CRTCs feeding a writeback connector operating in
     * oneshot mode. In this case the fake VBLANK event is only generated
     * when a job is queued to the writeback connector, and we want the
     * core to fake VBLANK events when this part of the pipeline hasn't
     * changed but others had or when the CRTC and connectors are being
     * disabled.
     *
     * __drm_atomic_helper_crtc_duplicate_state() will not reset the value
     * from the current state, the CRTC driver is then responsible for
     * updating this field when needed.
     *
     * Note that the combination of &drm_crtc_state.event == NULL and
     * &drm_crtc_state.no_blank == true is valid and usually used when the
     * writeback connector attached to the CRTC has a new job queued. In
     * this case the driver will send the VBLANK event on its own when the
     * writeback job is complete.
     */
    bool no_vblank : 1;

    /**
     * @plane_mask: Bitmask of drm_plane_mask(plane) of planes attached to
     * this CRTC.
     */
    u32 plane_mask;

    /**
     * @connector_mask: Bitmask of drm_connector_mask(connector) of
     * connectors attached to this CRTC.
     */
    u32 connector_mask;

    /**
     * @encoder_mask: Bitmask of drm_encoder_mask(encoder) of encoders
     * attached to this CRTC.
     */
    u32 encoder_mask;

    /**
     * @adjusted_mode:
     *
     * Internal display timings which can be used by the driver to handle
     * differences between the mode requested by userspace in @mode and what
     * is actually programmed into the hardware.
     *
     * For drivers using &drm_bridge, this stores hardware display timings
     * used between the CRTC and the first bridge. For other drivers, the
     * meaning of the adjusted_mode field is purely driver implementation
     * defined information, and will usually be used to store the hardware
     * display timings used between the CRTC and encoder blocks.
     */
    struct drm_display_mode adjusted_mode;

    /**
     * @mode:
     *
     * Display timings requested by userspace. The driver should try to
     * match the refresh rate as close as possible (but note that it's
     * undefined what exactly is close enough, e.g. some of the HDMI modes
     * only differ in less than 1% of the refresh rate). The active width
     * and height as observed by userspace for positioning planes must match
     * exactly.
     *
     * For external connectors where the sink isn't fixed (like with a
     * built-in panel), this mode here should match the physical mode on the
     * wire to the last details (i.e. including sync polarities and
     * everything).
     */
    struct drm_display_mode mode;

    /**
     * @mode_blob: &drm_property_blob for @mode, for exposing the mode to
     * atomic userspace.
     */
    struct drm_property_blob *mode_blob;

    /**
     * @degamma_lut:
     *
     * Lookup table for converting framebuffer pixel data before apply the
     * color conversion matrix @ctm. See drm_crtc_enable_color_mgmt(). The
     * blob (if not NULL) is an array of &struct drm_color_lut.
     */
    struct drm_property_blob *degamma_lut;

    /**
     * @ctm:
     *
     * Color transformation matrix. See drm_crtc_enable_color_mgmt(). The
     * blob (if not NULL) is a &struct drm_color_ctm.
     */
    struct drm_property_blob *ctm;

    /**
     * @gamma_lut:
     *
     * Lookup table for converting pixel data after the color conversion
     * matrix @ctm.  See drm_crtc_enable_color_mgmt(). The blob (if not
     * NULL) is an array of &struct drm_color_lut.
     */
    struct drm_property_blob *gamma_lut;
#if defined(CONFIG_ROCKCHIP_DRM_CUBIC_LUT)
	/**
	 * @cubic_lut:
	 *
	 * Cubic Lookup table for converting pixel data. See
	 * drm_crtc_enable_color_mgmt(). The blob (if not NULL) is a 3D array
	 * of &struct drm_color_lut.
	 */
    struct drm_property_blob *cubic_lut;
#endif
	/**
     * @target_vblank:
     *
     * Target vertical blank period when a page flip
     * should take effect.
     */
    u32 target_vblank;

    /**
     * @async_flip:
     *
     * This is set when DRM_MODE_PAGE_FLIP_ASYNC is set in the legacy
     * PAGE_FLIP IOCTL. It's not wired up for the atomic IOCTL itself yet.
     */
    bool async_flip;

    /**
     * @vrr_enabled:
     *
     * Indicates if variable refresh rate should be enabled for the CRTC.
     * Support for the requested vrr state will depend on driver and
     * hardware capabiltiy - lacking support is not treated as failure.
     */
    bool vrr_enabled;

    /**
     * @self_refresh_active:
     *
     * Used by the self refresh helpers to denote when a self refresh
     * transition is occurring. This will be set on enable/disable callbacks
     * when self refresh is being enabled or disabled. In some cases, it may
     * not be desirable to fully shut off the crtc during self refresh.
     * CRTC's can inspect this flag and determine the best course of action.
     */
    bool self_refresh_active;

    /**
     * @event:
     *
     * Optional pointer to a DRM event to signal upon completion of the
     * state update. The driver must send out the event when the atomic
     * commit operation completes. There are two cases:
     *
     *  - The event is for a CRTC which is being disabled through this
     *    atomic commit. In that case the event can be send out any time
     *    after the hardware has stopped scanning out the current
     *    framebuffers. It should contain the timestamp and counter for the
     *    last vblank before the display pipeline was shut off. The simplest
     *    way to achieve that is calling drm_crtc_send_vblank_event()
     *    somewhen after drm_crtc_vblank_off() has been called.
     *
     *  - For a CRTC which is enabled at the end of the commit (even when it
     *    undergoes an full modeset) the vblank timestamp and counter must
     *    be for the vblank right before the first frame that scans out the
     *    new set of buffers. Again the event can only be sent out after the
     *    hardware has stopped scanning out the old buffers.
     *
     *  - Events for disabled CRTCs are not allowed, and drivers can ignore
     *    that case.
     *
     * For very simple hardware without VBLANK interrupt, enabling
     * &struct drm_crtc_state.no_vblank makes DRM's atomic commit helpers
     * send a fake VBLANK event at the end of the display update after all
     * hardware changes have been applied. See
     * drm_atomic_helper_fake_vblank().
     *
     * For more complex hardware this
     * can be handled by the drm_crtc_send_vblank_event() function,
     * which the driver should call on the provided event upon completion of
     * the atomic commit. Note that if the driver supports vblank signalling
     * and timestamping the vblank counters and timestamps must agree with
     * the ones returned from page flip events. With the current vblank
     * helper infrastructure this can be achieved by holding a vblank
     * reference while the page flip is pending, acquired through
     * drm_crtc_vblank_get() and released with drm_crtc_vblank_put().
     * Drivers are free to implement their own vblank counter and timestamp
     * tracking though, e.g. if they have accurate timestamp registers in
     * hardware.
     *
     * For hardware which supports some means to synchronize vblank
     * interrupt delivery with committing display state there's also
     * drm_crtc_arm_vblank_event(). See the documentation of that function
     * for a detailed discussion of the constraints it needs to be used
     * safely.
     *
     * If the device can't notify of flip completion in a race-free way
     * at all, then the event should be armed just after the page flip is
     * committed. In the worst case the driver will send the event to
     * userspace one frame too late. This doesn't allow for a real atomic
     * update, but it should avoid tearing.
     */
    struct drm_pending_vblank_event *event;

    /**
     * @commit:
     *
     * This tracks how the commit for this update proceeds through the
     * various phases. This is never cleared, except when we destroy the
     * state, so that subsequent commits can synchronize with previous ones.
     */
    struct drm_crtc_commit *commit;

    /** @state: backpointer to global drm_atomic_state */
    struct drm_atomic_state *state;
};

/**
 * struct drm_crtc_funcs - control CRTCs for a given device
 *
 * The drm_crtc_funcs structure is the central CRTC management structure
 * in the DRM.  Each CRTC controls one or more connectors (note that the name
 * CRTC is simply historical, a CRTC may control LVDS, VGA, DVI, TV out, etc.
 * connectors, not just CRTs).
 *
 * Each driver is responsible for filling out this structure at startup time,
 * in addition to providing other modesetting features, like i2c and DDC
 * bus accessors.
 */
struct drm_crtc_funcs {
    /**
     * @reset
     *
     * Reset CRTC hardware and software state to off. This function isn't
     * called by the core directly, only through drm_mode_config_reset().
     * It's not a helper hook only for historical reasons.
     *
     * Atomic drivers can use drm_atomic_helper_crtc_reset() to reset
     * atomic state using this hook.
     */
    void (*reset)(struct drm_crtc *crtc);

    /**
     * @cursor_set
     *
     * Update the cursor image. The cursor position is relative to the CRTC
     * and can be partially or fully outside of the visible area.
     *
     * Note that contrary to all other KMS functions the legacy cursor entry
     * points don't take a framebuffer object, but instead take directly a
     * raw buffer object id from the driver's buffer manager (which is
     * either GEM or TTM for current drivers).
     *
     * This entry point is deprecated, drivers should instead implement
     * universal plane support and register a proper cursor plane using
     * drm_crtc_init_with_planes().
     *
     * This callback is optional
     *
     * RETURNS
     *
     * 0 on success or a negative error code on failure.
     */
    int (*cursor_set)(struct drm_crtc *crtc, struct drm_file *file_priv, uint32_t handle, uint32_t width,
                      uint32_t height);

    /**
     * @cursor_set2
     *
     * Update the cursor image, including hotspot information. The hotspot
     * must not affect the cursor position in CRTC coordinates, but is only
     * meant as a hint for virtualized display hardware to coordinate the
     * guests and hosts cursor position. The cursor hotspot is relative to
     * the cursor image. Otherwise this works exactly like @cursor_set.
     *
     * This entry point is deprecated, drivers should instead implement
     * universal plane support and register a proper cursor plane using
     * drm_crtc_init_with_planes().
     *
     * This callback is optional.
     *
     * RETURNS
     *
     * 0 on success or a negative error code on failure.
     */
    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);

    /**
     * @cursor_move
     *
     * Update the cursor position. The cursor does not need to be visible
     * when this hook is called.
     *
     * This entry point is deprecated, drivers should instead implement
     * universal plane support and register a proper cursor plane using
     * drm_crtc_init_with_planes().
     *
     * This callback is optional.
     *
     * RETURNS
     *
     * 0 on success or a negative error code on failure.
     */
    int (*cursor_move)(struct drm_crtc *crtc, int x, int y);

    /**
     * @gamma_set
     *
     * Set gamma on the CRTC.
     *
     * This callback is optional.
     *
     * Atomic drivers who want to support gamma tables should implement the
     * atomic color management support, enabled by calling
     * drm_crtc_enable_color_mgmt(), which then supports the legacy gamma
     * interface through the drm_atomic_helper_legacy_gamma_set()
     * compatibility implementation.
     */
    int (*gamma_set)(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b, uint32_t size, struct drm_modeset_acquire_ctx *ctx);

    /**
     * @destroy
     *
     * Clean up CRTC resources. This is only called at driver unload time
     * through drm_mode_config_cleanup() since a CRTC cannot be hotplugged
     * in DRM.
     */
    void (*destroy)(struct drm_crtc *crtc);

    /**
     * @set_config
     *
     * This is the main legacy entry point to change the modeset state on a
     * CRTC. All the details of the desired configuration are passed in a
     * &struct drm_mode_set - see there for details.
     *
     * Drivers implementing atomic modeset should use
     * drm_atomic_helper_set_config() to implement this hook.
     *
     * RETURNS
     *
     * 0 on success or a negative error code on failure.
     */
    int (*set_config)(struct drm_mode_set *set, struct drm_modeset_acquire_ctx *ctx);

    /**
     * @page_flip
     *
     * Legacy entry point to schedule a flip to the given framebuffer.
     *
     * Page flipping is a synchronization mechanism that replaces the frame
     * buffer being scanned out by the CRTC with a new frame buffer during
     * vertical blanking, avoiding tearing (except when requested otherwise
     * through the DRM_MODE_PAGE_FLIP_ASYNC flag). When an application
     * requests a page flip the DRM core verifies that the new frame buffer
     * is large enough to be scanned out by the CRTC in the currently
     * configured mode and then calls this hook with a pointer to the new
     * frame buffer.
     *
     * The driver must wait for any pending rendering to the new framebuffer
     * to complete before executing the flip. It should also wait for any
     * pending rendering from other drivers if the underlying buffer is a
     * shared dma-buf.
     *
     * An application can request to be notified when the page flip has
     * completed. The drm core will supply a &struct drm_event in the event
     * parameter in this case. This can be handled by the
     * drm_crtc_send_vblank_event() function, which the driver should call on
     * the provided event upon completion of the flip. Note that if
     * the driver supports vblank signalling and timestamping the vblank
     * counters and timestamps must agree with the ones returned from page
     * flip events. With the current vblank helper infrastructure this can
     * be achieved by holding a vblank reference while the page flip is
     * pending, acquired through drm_crtc_vblank_get() and released with
     * drm_crtc_vblank_put(). Drivers are free to implement their own vblank
     * counter and timestamp tracking though, e.g. if they have accurate
     * timestamp registers in hardware.
     *
     * This callback is optional.
     *
     * NOTE
     *
     * Very early versions of the KMS ABI mandated that the driver must
     * block (but not reject) any rendering to the old framebuffer until the
     * flip operation has completed and the old framebuffer is no longer
     * visible. This requirement has been lifted, and userspace is instead
     * expected to request delivery of an event and wait with recycling old
     * buffers until such has been received.
     *
     * RETURNS
     *
     * 0 on success or a negative error code on failure. Note that if a
     * page flip operation is already pending the callback should return
     * -EBUSY. Pageflips on a disabled CRTC (either by setting a NULL mode
     * or just runtime disabled through DPMS respectively the new atomic
     * "ACTIVE" state) should result in an -EINVAL error code. Note that
     * drm_atomic_helper_page_flip() checks this already for atomic drivers.
     */
    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);

    /**
     * @page_flip_target
     *
     * Same as @page_flip but with an additional parameter specifying the
     * absolute target vertical blank period (as reported by
     * drm_crtc_vblank_count()) when the flip should take effect.
     *
     * Note that the core code calls drm_crtc_vblank_get before this entry
     * point, and will call drm_crtc_vblank_put if this entry point returns
     * any non-0 error code. It's the driver's responsibility to call
     * drm_crtc_vblank_put after this entry point returns 0, typically when
     * the flip completes.
     */
    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);

    /**
     * @set_property
     *
     * This is the legacy entry point to update a property attached to the
     * CRTC.
     *
     * This callback is optional if the driver does not support any legacy
     * driver-private properties. For atomic drivers it is not used because
     * property handling is done entirely in the DRM core.
     *
     * RETURNS
     *
     * 0 on success or a negative error code on failure.
     */
    int (*set_property)(struct drm_crtc *crtc, struct drm_property *property, uint64_t val);

    /**
     * @atomic_duplicate_state
     *
     * Duplicate the current atomic state for this CRTC and return it.
     * The core and helpers guarantee that any atomic state duplicated with
     * this hook and still owned by the caller (i.e. not transferred to the
     * driver by calling &drm_mode_config_funcs.atomic_commit) will be
     * cleaned up by calling the @atomic_destroy_state hook in this
     * structure.
     *
     * This callback is mandatory for atomic drivers.
     *
     * Atomic drivers which don't subclass &struct drm_crtc_state should use
     * drm_atomic_helper_crtc_duplicate_state(). Drivers that subclass the
     * state structure to extend it with driver-private state should use
     * __drm_atomic_helper_crtc_duplicate_state() to make sure shared state is
     * duplicated in a consistent fashion across drivers.
     *
     * It is an error to call this hook before &drm_crtc.state has been
     * initialized correctly.
     *
     * NOTE
     *
     * If the duplicate state references refcounted resources this hook must
     * acquire a reference for each of them. The driver must release these
     * references again in @atomic_destroy_state.
     *
     * RETURNS
     *
     * Duplicated atomic state or NULL when the allocation failed.
     */
    struct drm_crtc_state *(*atomic_duplicate_state)(struct drm_crtc *crtc);

    /**
     * @atomic_destroy_state
     *
     * Destroy a state duplicated with @atomic_duplicate_state and release
     * or unreference all resources it references
     *
     * This callback is mandatory for atomic drivers.
     */
    void (*atomic_destroy_state)(struct drm_crtc *crtc, struct drm_crtc_state *state);

    /**
     * @atomic_set_property
     *
     * Decode a driver-private property value and store the decoded value
     * into the passed-in state structure. Since the atomic core decodes all
     * standardized properties (even for extensions beyond the core set of
     * properties which might not be implemented by all drivers) this
     * requires drivers to subclass the state structure.
     *
     * Such driver-private properties should really only be implemented for
     * truly hardware/vendor specific state. Instead it is preferred to
     * standardize atomic extension and decode the properties used to expose
     * such an extension in the core.
     *
     * Do not call this function directly, use
     * drm_atomic_crtc_set_property() instead.
     *
     * This callback is optional if the driver does not support any
     * driver-private atomic properties.
     *
     * NOTE
     *
     * This function is called in the state assembly phase of atomic
     * modesets, which can be aborted for any reason (including on
     * userspace's request to just check whether a configuration would be
     * possible). Drivers MUST NOT touch any persistent state (hardware or
     * software) or data structures except the passed in @state parameter.
     *
     * Also since userspace controls in which order properties are set this
     * function must not do any input validation (since the state update is
     * incomplete and hence likely inconsistent). Instead any such input
     * validation must be done in the various atomic_check callbacks.
     *
     * RETURNS
     *
     * 0 if the property has been found, -EINVAL if the property isn't
     * implemented by the driver (which should never happen, the core only
     * asks for properties attached to this CRTC). No other validation is
     * allowed by the driver. The core already checks that the property
     * value is within the range (integer, valid enum value, ...) the driver
     * set when registering the property.
     */
    int (*atomic_set_property)(struct drm_crtc *crtc, struct drm_crtc_state *state, struct drm_property *property,
                               uint64_t val);
    /**
     * @atomic_get_property
     *
     * Reads out the decoded driver-private property. This is used to
     * implement the GETCRTC IOCTL.
     *
     * Do not call this function directly, use
     * drm_atomic_crtc_get_property() instead.
     *
     * This callback is optional if the driver does not support any
     * driver-private atomic properties.
     *
     * RETURNS
     *
     * 0 on success, -EINVAL if the property isn't implemented by the
     * driver (which should never happen, the core only asks for
     * properties attached to this CRTC).
     */
    int (*atomic_get_property)(struct drm_crtc *crtc, const struct drm_crtc_state *state, struct drm_property *property,
                               uint64_t *val);

    /**
     * @late_register
     *
     * This optional hook can be used to register additional userspace
     * interfaces attached to the crtc like debugfs interfaces.
     * It is called late in the driver load sequence from drm_dev_register().
     * Everything added from this callback should be unregistered in
     * the early_unregister callback.
     *
     * Returns
     *
     * 0 on success, or a negative error code on failure.
     */
    int (*late_register)(struct drm_crtc *crtc);

    /**
     * @early_unregister
     *
     * This optional hook should be used to unregister the additional
     * userspace interfaces attached to the crtc from
     * @late_register. It is called from drm_dev_unregister(),
     * early in the driver unload sequence to disable userspace access
     * before data structures are torndown.
     */
    void (*early_unregister)(struct drm_crtc *crtc);

    /**
     * @set_crc_source
     *
     * Changes the source of CRC checksums of frames at the request of
     * userspace, typically for testing purposes. The sources available are
     * specific of each driver and a %NULL value indicates that CRC
     * generation is to be switched off.
     *
     * When CRC generation is enabled, the driver should call
     * drm_crtc_add_crc_entry() at each frame, providing any information
     * that characterizes the frame contents in the crcN arguments, as
     * provided from the configured source. Drivers must accept an "auto"
     * source name that will select a default source for this CRTC.
     *
     * This may trigger an atomic modeset commit if necessary, to enable CRC
     * generation.
     *
     * Note that "auto" can depend upon the current modeset configuration,
     * e.g. it could pick an encoder or output specific CRC sampling point.
     *
     * This callback is optional if the driver does not support any CRC
     * generation functionality.
     *
     * RETURNS
     *
     * 0 on success or a negative error code on failure.
     */
    int (*set_crc_source)(struct drm_crtc *crtc, const char *source);

    /**
     * @verify_crc_source
     *
     * verifies the source of CRC checksums of frames before setting the
     * source for CRC and during crc open. Source parameter can be NULL
     * while disabling crc source.
     *
     * This callback is optional if the driver does not support any CRC
     * generation functionality.
     *
     * RETURNS
     *
     * 0 on success or a negative error code on failure.
     */
    int (*verify_crc_source)(struct drm_crtc *crtc, const char *source, size_t *values_cnt);
    /**
     * @get_crc_sources
     *
     * Driver callback for getting a list of all the available sources for
     * CRC generation. This callback depends upon verify_crc_source, So
     * verify_crc_source callback should be implemented before implementing
     * this. Driver can pass full list of available crc sources, this
     * callback does the verification on each crc-source before passing it
     * to userspace.
     *
     * This callback is optional if the driver does not support exporting of
     * possible CRC sources list.
     *
     * RETURNS
     *
     * a constant character pointer to the list of all the available CRC
     * sources. On failure driver should return NULL. count should be
     * updated with number of sources in list. if zero we don't process any
     * source from the list.
     */
    const char *const *(*get_crc_sources)(struct drm_crtc *crtc, size_t *count);

    /**
     * @atomic_print_state
     *
     * If driver subclasses &struct drm_crtc_state, it should implement
     * this optional hook for printing additional driver specific state.
     *
     * Do not call this directly, use drm_atomic_crtc_print_state()
     * instead.
     */
    void (*atomic_print_state)(struct drm_printer *p, const struct drm_crtc_state *state);

    /**
     * @get_vblank_counter
     *
     * Driver callback for fetching a raw hardware vblank counter for the
     * CRTC. It's meant to be used by new drivers as the replacement of
     * &drm_driver.get_vblank_counter hook.
     *
     * This callback is optional. If a device doesn't have a hardware
     * counter, the driver can simply leave the hook as NULL. The DRM core
     * will account for missed vblank events while interrupts where disabled
     * based on system timestamps.
     *
     * Wraparound handling and loss of events due to modesetting is dealt
     * with in the DRM core code, as long as drivers call
     * drm_crtc_vblank_off() and drm_crtc_vblank_on() when disabling or
     * enabling a CRTC.
     *
     * See also &drm_device.vblank_disable_immediate and
     * &drm_device.max_vblank_count.
     *
     * Returns
     *
     * Raw vblank counter value.
     */
    u32 (*get_vblank_counter)(struct drm_crtc *crtc);

    /**
     * @enable_vblank
     *
     * Enable vblank interrupts for the CRTC. It's meant to be used by
     * new drivers as the replacement of &drm_driver.enable_vblank hook.
     *
     * Returns
     *
     * Zero on success, appropriate errno if the vblank interrupt cannot
     * be enabled.
     */
    int (*enable_vblank)(struct drm_crtc *crtc);

    /**
     * @disable_vblank
     *
     * Disable vblank interrupts for the CRTC. It's meant to be used by
     * new drivers as the replacement of &drm_driver.disable_vblank hook.
     */
    void (*disable_vblank)(struct drm_crtc *crtc);

    /**
     * @get_vblank_timestamp
     *
     * Called by drm_get_last_vbltimestamp(). Should return a precise
     * timestamp when the most recent vblank interval ended or will end.
     *
     * Specifically, the timestamp in @vblank_time should correspond as
     * closely as possible to the time when the first video scanline of
     * the video frame after the end of vblank will start scanning out,
     * the time immediately after end of the vblank interval. If the
     * @crtc is currently inside vblank, this will be a time in the future.
     * If the @crtc is currently scanning out a frame, this will be the
     * past start time of the current scanout. This is meant to adhere
     * to the OpenML OML_sync_control extension specification.
     *
     * Parameters
     *
     * crtc:
     *     CRTC for which timestamp should be returned.
     * max_error:
     *     Maximum allowable timestamp error in nanoseconds.
     *     Implementation should strive to provide timestamp
     *     with an error of at most max_error nanoseconds.
     *     Returns true upper bound on error for timestamp.
     * vblank_time:
     *     Target location for returned vblank timestamp.
     * in_vblank_irq:
     *     True when called from drm_crtc_handle_vblank().  Some drivers
     *     need to apply some workarounds for gpu-specific vblank irq quirks
     *     if flag is set.
     *
     * Returns
     *
     * True on success, false on failure, which means the core should
     * fallback to a simple timestamp taken in drm_crtc_handle_vblank().
     */
    bool (*get_vblank_timestamp)(struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, bool in_vblank_irq);
};

/**
 * struct drm_crtc - central CRTC control structure
 *
 * Each CRTC may have one or more connectors associated with it.  This structure
 * allows the CRTC to be controlled.
 */
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_crtc_vblank_helper_get_vblank_timestamp().
     *
     * Note that atomic drivers should not use this, but instead use
     * &drm_crtc_state.adjusted_mode. And for high-precision timestamps
     * drm_crtc_vblank_helper_get_vblank_timestamp() 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;
};

/**
 * struct drm_mode_set - new values for a CRTC config change
 * @fb: framebuffer to use for new config
 * @crtc: CRTC whose configuration we're about to change
 * @mode: mode timings to use
 * @x: position of this CRTC relative to @fb
 * @y: position of this CRTC relative to @fb
 * @connectors: array of connectors to drive with this CRTC if possible
 * @num_connectors: size of @connectors array
 *
 * This represents a modeset configuration for the legacy SETCRTC ioctl and is
 * also used internally. Atomic drivers instead use &drm_atomic_state.
 */
struct drm_mode_set {
    struct drm_framebuffer *fb;
    struct drm_crtc *crtc;
    struct drm_display_mode *mode;

    uint32_t x;
    uint32_t y;

    struct drm_connector **connectors;
    size_t num_connectors;
};

#define obj_to_crtc(x) container_of(x, struct drm_crtc, base)

__printf(6, 7) 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, ...);
void drm_crtc_cleanup(struct drm_crtc *crtc);

/**
 * drm_crtc_index - find the index of a registered CRTC
 * @crtc: CRTC to find index for
 *
 * Given a registered CRTC, return the index of that CRTC within a DRM
 * device's list of CRTCs.
 */
static inline unsigned int drm_crtc_index(const struct drm_crtc *crtc)
{
    return crtc->index;
}

/**
 * drm_crtc_mask - find the mask of a registered CRTC
 * @crtc: CRTC to find mask for
 *
 * Given a registered CRTC, return the mask bit of that CRTC for the
 * &drm_encoder.possible_crtcs and &drm_plane.possible_crtcs fields.
 */
static inline uint32_t drm_crtc_mask(const struct drm_crtc *crtc)
{
    return 1 << drm_crtc_index(crtc);
}

int drm_mode_set_config_internal(struct drm_mode_set *set);
struct drm_crtc *drm_crtc_from_index(struct drm_device *dev, int idx);

/**
 * drm_crtc_find - look up a CRTC object from its ID
 * @dev: DRM device
 * @file_priv: drm file to check for lease against.
 * @id: &drm_mode_object ID
 *
 * This can be used to look up a CRTC from its userspace ID. Only used by
 * drivers for legacy IOCTLs and interface, nowadays extensions to the KMS
 * userspace interface should be done using &drm_property.
 */
static inline struct drm_crtc *drm_crtc_find(struct drm_device *dev, struct drm_file *file_priv, uint32_t id)
{
    struct drm_mode_object *mo;
    mo = drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_CRTC);
    return mo ? obj_to_crtc(mo) : NULL;
}

/**
 * drm_for_each_crtc - iterate over all CRTCs
 * @crtc: a &struct drm_crtc as the loop cursor
 * @dev: the &struct drm_device
 *
 * Iterate over all CRTCs of @dev.
 */
#define drm_for_each_crtc(crtc, dev) list_for_each_entry(crtc, &(dev)->mode_config.crtc_list, head)

#endif /* __DRM_CRTC_H__ */