/*
 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * Copyright (c) 2009-2010, Code Aurora Forum.
 * Copyright 2016 Intel Corp.
 *
 * 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 (including the next
 * paragraph) 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
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS 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_DRV_H_
#define _DRM_DRV_H_

#include <linux/list.h>
#include <linux/irqreturn.h>

#include <drm/drm_device.h>

struct drm_file;
struct drm_gem_object;
struct drm_master;
struct drm_minor;
struct dma_buf_attachment;
struct drm_display_mode;
struct drm_mode_create_dumb;
struct drm_printer;

/**
 * enum drm_driver_feature - feature flags
 *
 * See &drm_driver.driver_features, drm_device.driver_features and
 * drm_core_check_feature().
 */
enum drm_driver_feature {
        /**
         * @DRIVER_GEM:
         *
         * Driver use the GEM memory manager. This should be set for all modern
         * drivers.
         */
        DRIVER_GEM                      = BIT(0),
        /**
         * @DRIVER_MODESET:
         *
         * Driver supports mode setting interfaces (KMS).
         */
        DRIVER_MODESET                  = BIT(1),
        /**
         * @DRIVER_RENDER:
         *
         * Driver supports dedicated render nodes. See also the :ref:`section on
         * render nodes <drm_render_node>` for details.
         */
        DRIVER_RENDER                   = BIT(3),
        /**
         * @DRIVER_ATOMIC:
         *
         * Driver supports the full atomic modesetting userspace API. Drivers
         * which only use atomic internally, but do not the support the full
         * userspace API (e.g. not all properties converted to atomic, or
         * multi-plane updates are not guaranteed to be tear-free) should not
         * set this flag.
         */
        DRIVER_ATOMIC                   = BIT(4),
        /**
         * @DRIVER_SYNCOBJ:
         *
         * Driver supports &drm_syncobj for explicit synchronization of command
         * submission.
         */
        DRIVER_SYNCOBJ                  = BIT(5),
        /**
         * @DRIVER_SYNCOBJ_TIMELINE:
         *
         * Driver supports the timeline flavor of &drm_syncobj for explicit
         * synchronization of command submission.
         */
        DRIVER_SYNCOBJ_TIMELINE         = BIT(6),

        /* IMPORTANT: Below are all the legacy flags, add new ones above. */

        /**
         * @DRIVER_USE_AGP:
         *
         * Set up DRM AGP support, see drm_agp_init(), the DRM core will manage
         * AGP resources. New drivers don't need this.
         */
        DRIVER_USE_AGP                  = BIT(25),
        /**
         * @DRIVER_LEGACY:
         *
         * Denote a legacy driver using shadow attach. Do not use.
         */
        DRIVER_LEGACY                   = BIT(26),
        /**
         * @DRIVER_PCI_DMA:
         *
         * Driver is capable of PCI DMA, mapping of PCI DMA buffers to userspace
         * will be enabled. Only for legacy drivers. Do not use.
         */
        DRIVER_PCI_DMA                  = BIT(27),
        /**
         * @DRIVER_SG:
         *
         * Driver can perform scatter/gather DMA, allocation and mapping of
         * scatter/gather buffers will be enabled. Only for legacy drivers. Do
         * not use.
         */
        DRIVER_SG                       = BIT(28),

        /**
         * @DRIVER_HAVE_DMA:
         *
         * Driver supports DMA, the userspace DMA API will be supported. Only
         * for legacy drivers. Do not use.
         */
        DRIVER_HAVE_DMA                 = BIT(29),
        /**
         * @DRIVER_HAVE_IRQ:
         *
         * Legacy irq support. Only for legacy drivers. Do not use.
         *
         * New drivers can either use the drm_irq_install() and
         * drm_irq_uninstall() helper functions, or roll their own irq support
         * code by calling request_irq() directly.
         */
        DRIVER_HAVE_IRQ                 = BIT(30),
        /**
         * @DRIVER_KMS_LEGACY_CONTEXT:
         *
         * Used only by nouveau for backwards compatibility with existing
         * userspace.  Do not use.
         */
        DRIVER_KMS_LEGACY_CONTEXT       = BIT(31),
};

/**
 * struct drm_driver - DRM driver structure
 *
 * This structure represent the common code for a family of cards. There will be
 * one &struct drm_device for each card present in this family. It contains lots
 * of vfunc entries, and a pile of those probably should be moved to more
 * appropriate places like &drm_mode_config_funcs or into a new operations
 * structure for GEM drivers.
 */
struct drm_driver {
        /**
         * @load:
         *
         * Backward-compatible driver callback to complete
         * initialization steps after the driver is registered.  For
         * this reason, may suffer from race conditions and its use is
         * deprecated for new drivers.  It is therefore only supported
         * for existing drivers not yet converted to the new scheme.
         * See drm_dev_init() and drm_dev_register() for proper and
         * race-free way to set up a &struct drm_device.
         *
         * This is deprecated, do not use!
         *
         * Returns:
         *
         * Zero on success, non-zero value on failure.
         */
        int (*load) (struct drm_device *, unsigned long flags);

        /**
         * @open:
         *
         * Driver callback when a new &struct drm_file is opened. Useful for
         * setting up driver-private data structures like buffer allocators,
         * execution contexts or similar things. Such driver-private resources
         * must be released again in @postclose.
         *
         * Since the display/modeset side of DRM can only be owned by exactly
         * one &struct drm_file (see &drm_file.is_master and &drm_device.master)
         * there should never be a need to set up any modeset related resources
         * in this callback. Doing so would be a driver design bug.
         *
         * Returns:
         *
         * 0 on success, a negative error code on failure, which will be
         * promoted to userspace as the result of the open() system call.
         */
        int (*open) (struct drm_device *, struct drm_file *);

        /**
         * @postclose:
         *
         * One of the driver callbacks when a new &struct drm_file is closed.
         * Useful for tearing down driver-private data structures allocated in
         * @open like buffer allocators, execution contexts or similar things.
         *
         * Since the display/modeset side of DRM can only be owned by exactly
         * one &struct drm_file (see &drm_file.is_master and &drm_device.master)
         * there should never be a need to tear down any modeset related
         * resources in this callback. Doing so would be a driver design bug.
         */
        void (*postclose) (struct drm_device *, struct drm_file *);

        /**
         * @lastclose:
         *
         * Called when the last &struct drm_file has been closed and there's
         * currently no userspace client for the &struct drm_device.
         *
         * Modern drivers should only use this to force-restore the fbdev
         * framebuffer using drm_fb_helper_restore_fbdev_mode_unlocked().
         * Anything else would indicate there's something seriously wrong.
         * Modern drivers can also use this to execute delayed power switching
         * state changes, e.g. in conjunction with the :ref:`vga_switcheroo`
         * infrastructure.
         *
         * This is called after @postclose hook has been called.
         *
         * NOTE:
         *
         * All legacy drivers use this callback to de-initialize the hardware.
         * This is purely because of the shadow-attach model, where the DRM
         * kernel driver does not really own the hardware. Instead ownershipe is
         * handled with the help of userspace through an inheritedly racy dance
         * to set/unset the VT into raw mode.
         *
         * Legacy drivers initialize the hardware in the @firstopen callback,
         * which isn't even called for modern drivers.
         */
        void (*lastclose) (struct drm_device *);

        /**
         * @unload:
         *
         * Reverse the effects of the driver load callback.  Ideally,
         * the clean up performed by the driver should happen in the
         * reverse order of the initialization.  Similarly to the load
         * hook, this handler is deprecated and its usage should be
         * dropped in favor of an open-coded teardown function at the
         * driver layer.  See drm_dev_unregister() and drm_dev_put()
         * for the proper way to remove a &struct drm_device.
         *
         * The unload() hook is called right after unregistering
         * the device.
         *
         */
        void (*unload) (struct drm_device *);

        /**
         * @release:
         *
         * Optional callback for destroying device data after the final
         * reference is released, i.e. the device is being destroyed. Drivers
         * using this callback are responsible for calling drm_dev_fini()
         * to finalize the device and then freeing the struct themselves.
         */
        void (*release) (struct drm_device *);

        /**
         * @get_vblank_counter:
         *
         * Driver callback for fetching a raw hardware vblank counter for the
         * CRTC specified with the pipe argument.  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.
         *
         * This is deprecated and should not be used by new drivers.
         * Use &drm_crtc_funcs.get_vblank_counter instead.
         *
         * Returns:
         *
         * Raw vblank counter value.
         */
        u32 (*get_vblank_counter) (struct drm_device *dev, unsigned int pipe);

        /**
         * @enable_vblank:
         *
         * Enable vblank interrupts for the CRTC specified with the pipe
         * argument.
         *
         * This is deprecated and should not be used by new drivers.
         * Use &drm_crtc_funcs.enable_vblank instead.
         *
         * Returns:
         *
         * Zero on success, appropriate errno if the given @crtc's vblank
         * interrupt cannot be enabled.
         */
        int (*enable_vblank) (struct drm_device *dev, unsigned int pipe);

        /**
         * @disable_vblank:
         *
         * Disable vblank interrupts for the CRTC specified with the pipe
         * argument.
         *
         * This is deprecated and should not be used by new drivers.
         * Use &drm_crtc_funcs.disable_vblank instead.
         */
        void (*disable_vblank) (struct drm_device *dev, unsigned int pipe);

        /**
         * @get_scanout_position:
         *
         * Called by vblank timestamping code.
         *
         * Returns the current display scanout position from a crtc, and an
         * optional accurate ktime_get() timestamp of when position was
         * measured. Note that this is a helper callback which is only used if a
         * driver uses drm_calc_vbltimestamp_from_scanoutpos() for the
         * @get_vblank_timestamp callback.
         *
         * Parameters:
         *
         * dev:
         *     DRM device.
         * pipe:
         *     Id of the crtc to query.
         * 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.
         * vpos:
         *     Target location for current vertical scanout position.
         * hpos:
         *     Target location for current horizontal scanout position.
         * stime:
         *     Target location for timestamp taken immediately before
         *     scanout position query. Can be NULL to skip timestamp.
         * etime:
         *     Target location for timestamp taken immediately after
         *     scanout position query. Can be NULL to skip timestamp.
         * mode:
         *     Current display timings.
         *
         * Returns vpos as a positive number while in active scanout area.
         * Returns vpos as a negative number inside vblank, counting the number
         * of scanlines to go until end of vblank, e.g., -1 means "one scanline
         * until start of active scanout / end of vblank."
         *
         * Returns:
         *
         * True on success, false if a reliable scanout position counter could
         * not be read out.
         *
         * FIXME:
         *
         * Since this is a helper to implement @get_vblank_timestamp, we should
         * move it to &struct drm_crtc_helper_funcs, like all the other
         * helper-internal hooks.
         */
        bool (*get_scanout_position) (struct drm_device *dev, unsigned int pipe,
                                      bool in_vblank_irq, int *vpos, int *hpos,
                                      ktime_t *stime, ktime_t *etime,
                                      const struct drm_display_mode *mode);

        /**
         * @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.
         *
         * Paramters:
         *
         * dev:
         *     dev DRM device handle.
         * pipe:
         *     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().
         *
         * FIXME:
         *
         * We should move this hook to &struct drm_crtc_funcs like all the other
         * vblank hooks.
         */
        bool (*get_vblank_timestamp) (struct drm_device *dev, unsigned int pipe,
                                     int *max_error,
                                     ktime_t *vblank_time,
                                     bool in_vblank_irq);

        /**
         * @irq_handler:
         *
         * Interrupt handler called when using drm_irq_install(). Not used by
         * drivers which implement their own interrupt handling.
         */
        irqreturn_t(*irq_handler) (int irq, void *arg);

        /**
         * @irq_preinstall:
         *
         * Optional callback used by drm_irq_install() which is called before
         * the interrupt handler is registered. This should be used to clear out
         * any pending interrupts (from e.g. firmware based drives) and reset
         * the interrupt handling registers.
         */
        void (*irq_preinstall) (struct drm_device *dev);

        /**
         * @irq_postinstall:
         *
         * Optional callback used by drm_irq_install() which is called after
         * the interrupt handler is registered. This should be used to enable
         * interrupt generation in the hardware.
         */
        int (*irq_postinstall) (struct drm_device *dev);

        /**
         * @irq_uninstall:
         *
         * Optional callback used by drm_irq_uninstall() which is called before
         * the interrupt handler is unregistered. This should be used to disable
         * interrupt generation in the hardware.
         */
        void (*irq_uninstall) (struct drm_device *dev);

        /**
         * @master_create:
         *
         * Called whenever a new master is created. Only used by vmwgfx.
         */
        int (*master_create)(struct drm_device *dev, struct drm_master *master);

        /**
         * @master_destroy:
         *
         * Called whenever a master is destroyed. Only used by vmwgfx.
         */
        void (*master_destroy)(struct drm_device *dev, struct drm_master *master);

        /**
         * @master_set:
         *
         * Called whenever the minor master is set. Only used by vmwgfx.
         */
        int (*master_set)(struct drm_device *dev, struct drm_file *file_priv,
                          bool from_open);
        /**
         * @master_drop:
         *
         * Called whenever the minor master is dropped. Only used by vmwgfx.
         */
        void (*master_drop)(struct drm_device *dev, struct drm_file *file_priv);

        /**
         * @debugfs_init:
         *
         * Allows drivers to create driver-specific debugfs files.
         */
        int (*debugfs_init)(struct drm_minor *minor);

        /**
         * @gem_free_object: deconstructor for drm_gem_objects
         *
         * This is deprecated and should not be used by new drivers. Use
         * &drm_gem_object_funcs.free instead.
         */
        void (*gem_free_object) (struct drm_gem_object *obj);

        /**
         * @gem_free_object_unlocked: deconstructor for drm_gem_objects
         *
         * This is deprecated and should not be used by new drivers. Use
         * &drm_gem_object_funcs.free instead.
         * Compared to @gem_free_object this is not encumbered with
         * &drm_device.struct_mutex legacy locking schemes.
         */
        void (*gem_free_object_unlocked) (struct drm_gem_object *obj);

        /**
         * @gem_open_object:
         *
         * This callback is deprecated in favour of &drm_gem_object_funcs.open.
         *
         * Driver hook called upon gem handle creation
         */
        int (*gem_open_object) (struct drm_gem_object *, struct drm_file *);

        /**
         * @gem_close_object:
         *
         * This callback is deprecated in favour of &drm_gem_object_funcs.close.
         *
         * Driver hook called upon gem handle release
         */
        void (*gem_close_object) (struct drm_gem_object *, struct drm_file *);

        /**
         * @gem_print_info:
         *
         * This callback is deprecated in favour of
         * &drm_gem_object_funcs.print_info.
         *
         * If driver subclasses struct &drm_gem_object, it can implement this
         * optional hook for printing additional driver specific info.
         *
         * drm_printf_indent() should be used in the callback passing it the
         * indent argument.
         *
         * This callback is called from drm_gem_print_info().
         */
        void (*gem_print_info)(struct drm_printer *p, unsigned int indent,
                               const struct drm_gem_object *obj);

        /**
         * @gem_create_object: constructor for gem objects
         *
         * Hook for allocating the GEM object struct, for use by the CMA and
         * SHMEM GEM helpers.
         */
        struct drm_gem_object *(*gem_create_object)(struct drm_device *dev,
                                                    size_t size);
        /**
         * @prime_handle_to_fd:
         *
         * Main PRIME export function. Should be implemented with
         * drm_gem_prime_handle_to_fd() for GEM based drivers.
         *
         * For an in-depth discussion see :ref:`PRIME buffer sharing
         * documentation <prime_buffer_sharing>`.
         */
        int (*prime_handle_to_fd)(struct drm_device *dev, struct drm_file *file_priv,
                                uint32_t handle, uint32_t flags, int *prime_fd);
        /**
         * @prime_fd_to_handle:
         *
         * Main PRIME import function. Should be implemented with
         * drm_gem_prime_fd_to_handle() for GEM based drivers.
         *
         * For an in-depth discussion see :ref:`PRIME buffer sharing
         * documentation <prime_buffer_sharing>`.
         */
        int (*prime_fd_to_handle)(struct drm_device *dev, struct drm_file *file_priv,
                                int prime_fd, uint32_t *handle);
        /**
         * @gem_prime_export:
         *
         * Export hook for GEM drivers. Deprecated in favour of
         * &drm_gem_object_funcs.export.
         */
        struct dma_buf * (*gem_prime_export)(struct drm_gem_object *obj,
                                             int flags);
        /**
         * @gem_prime_import:
         *
         * Import hook for GEM drivers.
         *
         * This defaults to drm_gem_prime_import() if not set.
         */
        struct drm_gem_object * (*gem_prime_import)(struct drm_device *dev,
                                struct dma_buf *dma_buf);

        /**
         * @gem_prime_pin:
         *
         * Deprecated hook in favour of &drm_gem_object_funcs.pin.
         */
        int (*gem_prime_pin)(struct drm_gem_object *obj);

        /**
         * @gem_prime_unpin:
         *
         * Deprecated hook in favour of &drm_gem_object_funcs.unpin.
         */
        void (*gem_prime_unpin)(struct drm_gem_object *obj);


        /**
         * @gem_prime_get_sg_table:
         *
         * Deprecated hook in favour of &drm_gem_object_funcs.get_sg_table.
         */
        struct sg_table *(*gem_prime_get_sg_table)(struct drm_gem_object *obj);

        /**
         * @gem_prime_import_sg_table:
         *
         * Optional hook used by the PRIME helper functions
         * drm_gem_prime_import() respectively drm_gem_prime_import_dev().
         */
        struct drm_gem_object *(*gem_prime_import_sg_table)(
                                struct drm_device *dev,
                                struct dma_buf_attachment *attach,
                                struct sg_table *sgt);
        /**
         * @gem_prime_vmap:
         *
         * Deprecated vmap hook for GEM drivers. Please use
         * &drm_gem_object_funcs.vmap instead.
         */
        void *(*gem_prime_vmap)(struct drm_gem_object *obj);

        /**
         * @gem_prime_vunmap:
         *
         * Deprecated vunmap hook for GEM drivers. Please use
         * &drm_gem_object_funcs.vunmap instead.
         */
        void (*gem_prime_vunmap)(struct drm_gem_object *obj, void *vaddr);

        /**
         * @gem_prime_mmap:
         *
         * mmap hook for GEM drivers, used to implement dma-buf mmap in the
         * PRIME helpers.
         *
         * FIXME: There's way too much duplication going on here, and also moved
         * to &drm_gem_object_funcs.
         */
        int (*gem_prime_mmap)(struct drm_gem_object *obj,
                                struct vm_area_struct *vma);

        /**
         * @dumb_create:
         *
         * This creates a new dumb buffer in the driver's backing storage manager (GEM,
         * TTM or something else entirely) and returns the resulting buffer handle. This
         * handle can then be wrapped up into a framebuffer modeset object.
         *
         * Note that userspace is not allowed to use such objects for render
         * acceleration - drivers must create their own private ioctls for such a use
         * case.
         *
         * Width, height and depth are specified in the &drm_mode_create_dumb
         * argument. The callback needs to fill the handle, pitch and size for
         * the created buffer.
         *
         * Called by the user via ioctl.
         *
         * Returns:
         *
         * Zero on success, negative errno on failure.
         */
        int (*dumb_create)(struct drm_file *file_priv,
                           struct drm_device *dev,
                           struct drm_mode_create_dumb *args);
        /**
         * @dumb_map_offset:
         *
         * Allocate an offset in the drm device node's address space to be able to
         * memory map a dumb buffer.
         *
         * The default implementation is drm_gem_create_mmap_offset(). GEM based
         * drivers must not overwrite this.
         *
         * Called by the user via ioctl.
         *
         * Returns:
         *
         * Zero on success, negative errno on failure.
         */
        int (*dumb_map_offset)(struct drm_file *file_priv,
                               struct drm_device *dev, uint32_t handle,
                               uint64_t *offset);
        /**
         * @dumb_destroy:
         *
         * This destroys the userspace handle for the given dumb backing storage buffer.
         * Since buffer objects must be reference counted in the kernel a buffer object
         * won't be immediately freed if a framebuffer modeset object still uses it.
         *
         * Called by the user via ioctl.
         *
         * The default implementation is drm_gem_dumb_destroy(). GEM based drivers
         * must not overwrite this.
         *
         * Returns:
         *
         * Zero on success, negative errno on failure.
         */
        int (*dumb_destroy)(struct drm_file *file_priv,
                            struct drm_device *dev,
                            uint32_t handle);

        /**
         * @gem_vm_ops: Driver private ops for this object
         *
         * For GEM drivers this is deprecated in favour of
         * &drm_gem_object_funcs.vm_ops.
         */
        const struct vm_operations_struct *gem_vm_ops;

        /** @major: driver major number */
        int major;
        /** @minor: driver minor number */
        int minor;
        /** @patchlevel: driver patch level */
        int patchlevel;
        /** @name: driver name */
        char *name;
        /** @desc: driver description */
        char *desc;
        /** @date: driver date */
        char *date;

        /**
         * @driver_features:
         * Driver features, see &enum drm_driver_feature. Drivers can disable
         * some features on a per-instance basis using
         * &drm_device.driver_features.
         */
        u32 driver_features;

        /**
         * @ioctls:
         *
         * Array of driver-private IOCTL description entries. See the chapter on
         * :ref:`IOCTL support in the userland interfaces
         * chapter<drm_driver_ioctl>` for the full details.
         */

        const struct drm_ioctl_desc *ioctls;
        /** @num_ioctls: Number of entries in @ioctls. */
        int num_ioctls;

        /**
         * @fops:
         *
         * File operations for the DRM device node. See the discussion in
         * :ref:`file operations<drm_driver_fops>` for in-depth coverage and
         * some examples.
         */
        const struct file_operations *fops;

        /* Everything below here is for legacy driver, never use! */
        /* private: */

        /* List of devices hanging off this driver with stealth attach. */
        struct list_head legacy_dev_list;
        int (*firstopen) (struct drm_device *);
        void (*preclose) (struct drm_device *, struct drm_file *file_priv);
        int (*dma_ioctl) (struct drm_device *dev, void *data, struct drm_file *file_priv);
        int (*dma_quiescent) (struct drm_device *);
        int (*context_dtor) (struct drm_device *dev, int context);
        int dev_priv_size;
};

int drm_dev_init(struct drm_device *dev,
                 struct drm_driver *driver,
                 struct device *parent);
int devm_drm_dev_init(struct device *parent,
                      struct drm_device *dev,
                      struct drm_driver *driver);
void drm_dev_fini(struct drm_device *dev);

struct drm_device *drm_dev_alloc(struct drm_driver *driver,
                                 struct device *parent);
int drm_dev_register(struct drm_device *dev, unsigned long flags);
void drm_dev_unregister(struct drm_device *dev);

void drm_dev_get(struct drm_device *dev);
void drm_dev_put(struct drm_device *dev);
void drm_put_dev(struct drm_device *dev);
bool drm_dev_enter(struct drm_device *dev, int *idx);
void drm_dev_exit(int idx);
void drm_dev_unplug(struct drm_device *dev);

/**
 * drm_dev_is_unplugged - is a DRM device unplugged
 * @dev: DRM device
 *
 * This function can be called to check whether a hotpluggable is unplugged.
 * Unplugging itself is singalled through drm_dev_unplug(). If a device is
 * unplugged, these two functions guarantee that any store before calling
 * drm_dev_unplug() is visible to callers of this function after it completes
 *
 * WARNING: This function fundamentally races against drm_dev_unplug(). It is
 * recommended that drivers instead use the underlying drm_dev_enter() and
 * drm_dev_exit() function pairs.
 */
static inline bool drm_dev_is_unplugged(struct drm_device *dev)
{
        int idx;

        if (drm_dev_enter(dev, &idx)) {
                drm_dev_exit(idx);
                return false;
        }

        return true;
}

/**
 * drm_core_check_feature - check driver feature flags
 * @dev: DRM device to check
 * @feature: feature flag
 *
 * This checks @dev for driver features, see &drm_driver.driver_features,
 * &drm_device.driver_features, and the various &enum drm_driver_feature flags.
 *
 * Returns true if the @feature is supported, false otherwise.
 */
static inline bool drm_core_check_feature(const struct drm_device *dev, u32 feature)
{
        return dev->driver->driver_features & dev->driver_features & feature;
}

/**
 * drm_drv_uses_atomic_modeset - check if the driver implements
 * atomic_commit()
 * @dev: DRM device
 *
 * This check is useful if drivers do not have DRIVER_ATOMIC set but
 * have atomic modesetting internally implemented.
 */
static inline bool drm_drv_uses_atomic_modeset(struct drm_device *dev)
{
        return drm_core_check_feature(dev, DRIVER_ATOMIC) ||
                (dev->mode_config.funcs && dev->mode_config.funcs->atomic_commit != NULL);
}


int drm_dev_set_unique(struct drm_device *dev, const char *name);


#endif