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Release 4.12 include/drm/drm_modeset_helper_vtables.h

Directory: include/drm
/*
 * Copyright © 2006 Keith Packard
 * Copyright © 2007-2008 Dave Airlie
 * Copyright © 2007-2008 Intel Corporation
 *   Jesse Barnes <jesse.barnes@intel.com>
 * Copyright © 2011-2013 Intel Corporation
 * Copyright © 2015 Intel Corporation
 *   Daniel Vetter <daniel.vetter@ffwll.ch>
 *
 * 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_MODESET_HELPER_VTABLES_H__

#define __DRM_MODESET_HELPER_VTABLES_H__

#include <drm/drm_crtc.h>
#include <drm/drm_encoder.h>

/**
 * DOC: overview
 *
 * The DRM mode setting helper functions are common code for drivers to use if
 * they wish.  Drivers are not forced to use this code in their
 * implementations but it would be useful if the code they do use at least
 * provides a consistent interface and operation to userspace. Therefore it is
 * highly recommended to use the provided helpers as much as possible.
 *
 * Because there is only one pointer per modeset object to hold a vfunc table
 * for helper libraries they are by necessity shared among the different
 * helpers.
 *
 * To make this clear all the helper vtables are pulled together in this location here.
 */

enum mode_set_atomic;

/**
 * struct drm_crtc_helper_funcs - helper operations for CRTCs
 *
 * These hooks are used by the legacy CRTC helpers, the transitional plane
 * helpers and the new atomic modesetting helpers.
 */

struct drm_crtc_helper_funcs {
	/**
         * @dpms:
         *
         * Callback to control power levels on the CRTC.  If the mode passed in
         * is unsupported, the provider must use the next lowest power level.
         * This is used by the legacy CRTC helpers to implement DPMS
         * functionality in drm_helper_connector_dpms().
         *
         * This callback is also used to disable a CRTC by calling it with
         * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
         *
         * This callback is used by the legacy CRTC helpers.  Atomic helpers
         * also support using this hook for enabling and disabling a CRTC to
         * facilitate transitions to atomic, but it is deprecated. Instead
         * @enable and @disable should be used.
         */
	
void (*dpms)(struct drm_crtc *crtc, int mode);

	/**
         * @prepare:
         *
         * This callback should prepare the CRTC for a subsequent modeset, which
         * in practice means the driver should disable the CRTC if it is
         * running. Most drivers ended up implementing this by calling their
         * @dpms hook with DRM_MODE_DPMS_OFF.
         *
         * This callback is used by the legacy CRTC helpers.  Atomic helpers
         * also support using this hook for disabling a CRTC to facilitate
         * transitions to atomic, but it is deprecated. Instead @disable should
         * be used.
         */
	
void (*prepare)(struct drm_crtc *crtc);

	/**
         * @commit:
         *
         * This callback should commit the new mode on the CRTC after a modeset,
         * which in practice means the driver should enable the CRTC.  Most
         * drivers ended up implementing this by calling their @dpms hook with
         * DRM_MODE_DPMS_ON.
         *
         * This callback is used by the legacy CRTC helpers.  Atomic helpers
         * also support using this hook for enabling a CRTC to facilitate
         * transitions to atomic, but it is deprecated. Instead @enable should
         * be used.
         */
	
void (*commit)(struct drm_crtc *crtc);

	/**
         * @mode_fixup:
         *
         * This callback is used to validate a mode. The parameter mode is the
         * display mode that userspace requested, adjusted_mode is the mode the
         * encoders need to be fed with. Note that this is the inverse semantics
         * of the meaning for the &drm_encoder and &drm_bridge_funcs.mode_fixup
         * vfunc. If the CRTC cannot support the requested conversion from mode
         * to adjusted_mode it should reject the modeset.
         *
         * This function is used by both legacy CRTC helpers and atomic helpers.
         * With atomic helpers it is optional.
         *
         * NOTE:
         *
         * This function is called in the check 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). Atomic drivers
         * MUST NOT touch any persistent state (hardware or software) or data
         * structures except the passed in adjusted_mode parameter.
         *
         * This is in contrast to the legacy CRTC helpers where this was
         * allowed.
         *
         * Atomic drivers which need to inspect and adjust more state should
         * instead use the @atomic_check callback.
         *
         * Also beware that neither core nor helpers filter modes before
         * passing them to the driver: While the list of modes that is
         * advertised to userspace is filtered using the
         * &drm_connector.mode_valid callback, neither the core nor the helpers
         * do any filtering on modes passed in from userspace when setting a
         * mode. It is therefore possible for userspace to pass in a mode that
         * was previously filtered out using &drm_connector.mode_valid or add a
         * custom mode that wasn't probed from EDID or similar to begin with.
         * Even though this is an advanced feature and rarely used nowadays,
         * some users rely on being able to specify modes manually so drivers
         * must be prepared to deal with it. Specifically this means that all
         * drivers need not only validate modes in &drm_connector.mode_valid but
         * also in this or in the &drm_encoder_helper_funcs.mode_fixup callback
         * to make sure invalid modes passed in from userspace are rejected.
         *
         * RETURNS:
         *
         * True if an acceptable configuration is possible, false if the modeset
         * operation should be rejected.
         */
	
bool (*mode_fixup)(struct drm_crtc *crtc,
			   const struct drm_display_mode *mode,
			   struct drm_display_mode *adjusted_mode);

	/**
         * @mode_set:
         *
         * This callback is used by the legacy CRTC helpers to set a new mode,
         * position and framebuffer. Since it ties the primary plane to every
         * mode change it is incompatible with universal plane support. And
         * since it can't update other planes it's incompatible with atomic
         * modeset support.
         *
         * This callback is only used by CRTC helpers and deprecated.
         *
         * RETURNS:
         *
         * 0 on success or a negative error code on failure.
         */
	
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);

	/**
         * @mode_set_nofb:
         *
         * This callback is used to update the display mode of a CRTC without
         * changing anything of the primary plane configuration. This fits the
         * requirement of atomic and hence is used by the atomic helpers. It is
         * also used by the transitional plane helpers to implement a
         * @mode_set hook in drm_helper_crtc_mode_set().
         *
         * Note that the display pipe is completely off when this function is
         * called. Atomic drivers which need hardware to be running before they
         * program the new display mode (e.g. because they implement runtime PM)
         * should not use this hook. This is because the helper library calls
         * this hook only once per mode change and not every time the display
         * pipeline is suspended using either DPMS or the new "ACTIVE" property.
         * Which means register values set in this callback might get reset when
         * the CRTC is suspended, but not restored.  Such drivers should instead
         * move all their CRTC setup into the @enable callback.
         *
         * This callback is optional.
         */
	
void (*mode_set_nofb)(struct drm_crtc *crtc);

	/**
         * @mode_set_base:
         *
         * This callback is used by the legacy CRTC helpers to set a new
         * framebuffer and scanout position. It is optional and used as an
         * optimized fast-path instead of a full mode set operation with all the
         * resulting flickering. If it is not present
         * drm_crtc_helper_set_config() will fall back to a full modeset, using
         * the @mode_set callback. Since it can't update other planes it's
         * incompatible with atomic modeset support.
         *
         * This callback is only used by the CRTC helpers and deprecated.
         *
         * RETURNS:
         *
         * 0 on success or a negative error code on failure.
         */
	
int (*mode_set_base)(struct drm_crtc *crtc, int x, int y,
			     struct drm_framebuffer *old_fb);

	/**
         * @mode_set_base_atomic:
         *
         * This callback is used by the fbdev helpers to set a new framebuffer
         * and scanout without sleeping, i.e. from an atomic calling context. It
         * is only used to implement kgdb support.
         *
         * This callback is optional and only needed for kgdb support in the fbdev
         * helpers.
         *
         * RETURNS:
         *
         * 0 on success or a negative error code on failure.
         */
	
int (*mode_set_base_atomic)(struct drm_crtc *crtc,
				    struct drm_framebuffer *fb, int x, int y,
				    enum mode_set_atomic);

	/**
         * @load_lut:
         *
         * Load a LUT prepared with the &drm_fb_helper_funcs.gamma_set vfunc.
         *
         * This callback is optional and is only used by the fbdev emulation
         * helpers.
         *
         * FIXME:
         *
         * This callback is functionally redundant with the core gamma table
         * support and simply exists because the fbdev hasn't yet been
         * refactored to use the core gamma table interfaces.
         */
	
void (*load_lut)(struct drm_crtc *crtc);

	/**
         * @disable:
         *
         * This callback should be used to disable the CRTC. With the atomic
         * drivers it is called after all encoders connected to this CRTC have
         * been shut off already using their own
         * &drm_encoder_helper_funcs.disable hook. If that sequence is too
         * simple drivers can just add their own hooks and call it from this
         * CRTC callback here by looping over all encoders connected to it using
         * for_each_encoder_on_crtc().
         *
         * This hook is used both by legacy CRTC helpers and atomic helpers.
         * Atomic drivers don't need to implement it if there's no need to
         * disable anything at the CRTC level. To ensure that runtime PM
         * handling (using either DPMS or the new "ACTIVE" property) works
         * @disable must be the inverse of @enable for atomic drivers.
         * Atomic drivers should consider to use @atomic_disable instead of
         * this one.
         *
         * NOTE:
         *
         * With legacy CRTC helpers there's a big semantic difference between
         * @disable and other hooks (like @prepare or @dpms) used to shut down a
         * CRTC: @disable is only called when also logically disabling the
         * display pipeline and needs to release any resources acquired in
         * @mode_set (like shared PLLs, or again release pinned framebuffers).
         *
         * Therefore @disable must be the inverse of @mode_set plus @commit for
         * drivers still using legacy CRTC helpers, which is different from the
         * rules under atomic.
         */
	
void (*disable)(struct drm_crtc *crtc);

	/**
         * @enable:
         *
         * This callback should be used to enable the CRTC. With the atomic
         * drivers it is called before all encoders connected to this CRTC are
         * enabled through the encoder's own &drm_encoder_helper_funcs.enable
         * hook.  If that sequence is too simple drivers can just add their own
         * hooks and call it from this CRTC callback here by looping over all
         * encoders connected to it using for_each_encoder_on_crtc().
         *
         * This hook is used only by atomic helpers, for symmetry with @disable.
         * Atomic drivers don't need to implement it if there's no need to
         * enable anything at the CRTC level. To ensure that runtime PM handling
         * (using either DPMS or the new "ACTIVE" property) works
         * @enable must be the inverse of @disable for atomic drivers.
         */
	
void (*enable)(struct drm_crtc *crtc);

	/**
         * @atomic_check:
         *
         * Drivers should check plane-update related CRTC constraints in this
         * hook. They can also check mode related limitations but need to be
         * aware of the calling order, since this hook is used by
         * drm_atomic_helper_check_planes() whereas the preparations needed to
         * check output routing and the display mode is done in
         * drm_atomic_helper_check_modeset(). Therefore drivers that want to
         * check output routing and display mode constraints in this callback
         * must ensure that drm_atomic_helper_check_modeset() has been called
         * beforehand. This is calling order used by the default helper
         * implementation in drm_atomic_helper_check().
         *
         * When using drm_atomic_helper_check_planes() this hook is called
         * after the &drm_plane_helper_funcs.atomc_check hook for planes, which
         * allows drivers to assign shared resources requested by planes in this
         * callback here. For more complicated dependencies the driver can call
         * the provided check helpers multiple times until the computed state
         * has a final configuration and everything has been checked.
         *
         * This function is also allowed to inspect any other object's state and
         * can add more state objects to the atomic commit if needed. Care must
         * be taken though to ensure that state check and compute functions for
         * these added states are all called, and derived state in other objects
         * all updated. Again the recommendation is to just call check helpers
         * until a maximal configuration is reached.
         *
         * This callback is used by the atomic modeset helpers and by the
         * transitional plane helpers, but it is optional.
         *
         * NOTE:
         *
         * This function is called in the check phase of an atomic update. The
         * driver is not allowed to change anything outside of the free-standing
         * state objects passed-in or assembled in the overall &drm_atomic_state
         * update tracking structure.
         *
         * RETURNS:
         *
         * 0 on success, -EINVAL if the state or the transition can't be
         * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
         * attempt to obtain another state object ran into a &drm_modeset_lock
         * deadlock.
         */
	
int (*atomic_check)(struct drm_crtc *crtc,
			    struct drm_crtc_state *state);

	/**
         * @atomic_begin:
         *
         * Drivers should prepare for an atomic update of multiple planes on
         * a CRTC in this hook. Depending upon hardware this might be vblank
         * evasion, blocking updates by setting bits or doing preparatory work
         * for e.g. manual update display.
         *
         * This hook is called before any plane commit functions are called.
         *
         * Note that the power state of the display pipe when this function is
         * called depends upon the exact helpers and calling sequence the driver
         * has picked. See drm_atomic_helper_commit_planes() for a discussion of
         * the tradeoffs and variants of plane commit helpers.
         *
         * This callback is used by the atomic modeset helpers and by the
         * transitional plane helpers, but it is optional.
         */
	
void (*atomic_begin)(struct drm_crtc *crtc,
			     struct drm_crtc_state *old_crtc_state);
	/**
         * @atomic_flush:
         *
         * Drivers should finalize an atomic update of multiple planes on
         * a CRTC in this hook. Depending upon hardware this might include
         * checking that vblank evasion was successful, unblocking updates by
         * setting bits or setting the GO bit to flush out all updates.
         *
         * Simple hardware or hardware with special requirements can commit and
         * flush out all updates for all planes from this hook and forgo all the
         * other commit hooks for plane updates.
         *
         * This hook is called after any plane commit functions are called.
         *
         * Note that the power state of the display pipe when this function is
         * called depends upon the exact helpers and calling sequence the driver
         * has picked. See drm_atomic_helper_commit_planes() for a discussion of
         * the tradeoffs and variants of plane commit helpers.
         *
         * This callback is used by the atomic modeset helpers and by the
         * transitional plane helpers, but it is optional.
         */
	
void (*atomic_flush)(struct drm_crtc *crtc,
			     struct drm_crtc_state *old_crtc_state);

	/**
         * @atomic_disable:
         *
         * This callback should be used to disable the CRTC. With the atomic
         * drivers it is called after all encoders connected to this CRTC have
         * been shut off already using their own
         * &drm_encoder_helper_funcs.disable hook. If that sequence is too
         * simple drivers can just add their own hooks and call it from this
         * CRTC callback here by looping over all encoders connected to it using
         * for_each_encoder_on_crtc().
         *
         * This hook is used only by atomic helpers. Atomic drivers don't
         * need to implement it if there's no need to disable anything at the
         * CRTC level.
         *
         * Comparing to @disable, this one provides the additional input
         * parameter @old_crtc_state which could be used to access the old
         * state. Atomic drivers should consider to use this one instead
         * of @disable.
         */
	
void (*atomic_disable)(struct drm_crtc *crtc,
			       struct drm_crtc_state *old_crtc_state);
};

/**
 * drm_crtc_helper_add - sets the helper vtable for a crtc
 * @crtc: DRM CRTC
 * @funcs: helper vtable to set for @crtc
 */

static inline void drm_crtc_helper_add(struct drm_crtc *crtc, const struct drm_crtc_helper_funcs *funcs) { crtc->helper_private = funcs; }

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/** * struct drm_encoder_helper_funcs - helper operations for encoders * * These hooks are used by the legacy CRTC helpers, the transitional plane * helpers and the new atomic modesetting helpers. */ struct drm_encoder_helper_funcs { /** * @dpms: * * Callback to control power levels on the encoder. If the mode passed in * is unsupported, the provider must use the next lowest power level. * This is used by the legacy encoder helpers to implement DPMS * functionality in drm_helper_connector_dpms(). * * This callback is also used to disable an encoder by calling it with * DRM_MODE_DPMS_OFF if the @disable hook isn't used. * * This callback is used by the legacy CRTC helpers. Atomic helpers * also support using this hook for enabling and disabling an encoder to * facilitate transitions to atomic, but it is deprecated. Instead * @enable and @disable should be used. */ void (*dpms)(struct drm_encoder *encoder, int mode); /** * @mode_fixup: * * This callback is used to validate and adjust a mode. The parameter * mode is the display mode that should be fed to the next element in * the display chain, either the final &drm_connector or a &drm_bridge. * The parameter adjusted_mode is the input mode the encoder requires. It * can be modified by this callback and does not need to match mode. * * This function is used by both legacy CRTC helpers and atomic helpers. * This hook is optional. * * NOTE: * * This function is called in the check 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). Atomic drivers * MUST NOT touch any persistent state (hardware or software) or data * structures except the passed in adjusted_mode parameter. * * This is in contrast to the legacy CRTC helpers where this was * allowed. * * Atomic drivers which need to inspect and adjust more state should * instead use the @atomic_check callback. * * Also beware that neither core nor helpers filter modes before * passing them to the driver: While the list of modes that is * advertised to userspace is filtered using the connector's * &drm_connector_helper_funcs.mode_valid callback, neither the core nor * the helpers do any filtering on modes passed in from userspace when * setting a mode. It is therefore possible for userspace to pass in a * mode that was previously filtered out using * &drm_connector_helper_funcs.mode_valid or add a custom mode that * wasn't probed from EDID or similar to begin with. Even though this * is an advanced feature and rarely used nowadays, some users rely on * being able to specify modes manually so drivers must be prepared to * deal with it. Specifically this means that all drivers need not only * validate modes in &drm_connector.mode_valid but also in this or in * the &drm_crtc_helper_funcs.mode_fixup callback to make sure * invalid modes passed in from userspace are rejected. * * RETURNS: * * True if an acceptable configuration is possible, false if the modeset * operation should be rejected. */ bool (*mode_fixup)(struct drm_encoder *encoder, const struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode); /** * @prepare: * * This callback should prepare the encoder for a subsequent modeset, * which in practice means the driver should disable the encoder if it * is running. Most drivers ended up implementing this by calling their * @dpms hook with DRM_MODE_DPMS_OFF. * * This callback is used by the legacy CRTC helpers. Atomic helpers * also support using this hook for disabling an encoder to facilitate * transitions to atomic, but it is deprecated. Instead @disable should * be used. */ void (*prepare)(struct drm_encoder *encoder); /** * @commit: * * This callback should commit the new mode on the encoder after a modeset, * which in practice means the driver should enable the encoder. Most * drivers ended up implementing this by calling their @dpms hook with * DRM_MODE_DPMS_ON. * * This callback is used by the legacy CRTC helpers. Atomic helpers * also support using this hook for enabling an encoder to facilitate * transitions to atomic, but it is deprecated. Instead @enable should * be used. */ void (*commit)(struct drm_encoder *encoder); /** * @mode_set: * * This callback is used to update the display mode of an encoder. * * Note that the display pipe is completely off when this function is * called. Drivers which need hardware to be running before they program * the new display mode (because they implement runtime PM) should not * use this hook, because the helper library calls it only once and not * every time the display pipeline is suspend using either DPMS or the * new "ACTIVE" property. Such drivers should instead move all their * encoder setup into the @enable callback. * * This callback is used both by the legacy CRTC helpers and the atomic * modeset helpers. It is optional in the atomic helpers. * * NOTE: * * If the driver uses the atomic modeset helpers and needs to inspect * the connector state or connector display info during mode setting, * @atomic_mode_set can be used instead. */ void (*mode_set)(struct drm_encoder *encoder, struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode); /** * @atomic_mode_set: * * This callback is used to update the display mode of an encoder. * * Note that the display pipe is completely off when this function is * called. Drivers which need hardware to be running before they program * the new display mode (because they implement runtime PM) should not * use this hook, because the helper library calls it only once and not * every time the display pipeline is suspended using either DPMS or the * new "ACTIVE" property. Such drivers should instead move all their * encoder setup into the @enable callback. * * This callback is used by the atomic modeset helpers in place of the * @mode_set callback, if set by the driver. It is optional and should * be used instead of @mode_set if the driver needs to inspect the * connector state or display info, since there is no direct way to * go from the encoder to the current connector. */ void (*atomic_mode_set)(struct drm_encoder *encoder, struct drm_crtc_state *crtc_state, struct drm_connector_state *conn_state); /** * @get_crtc: * * This callback is used by the legacy CRTC helpers to work around * deficiencies in its own book-keeping. * * Do not use, use atomic helpers instead, which get the book keeping * right. * * FIXME: * * Currently only nouveau is using this, and as soon as nouveau is * atomic we can ditch this hook. */ struct drm_crtc *(*get_crtc)(struct drm_encoder *encoder); /** * @detect: * * This callback can be used by drivers who want to do detection on the * encoder object instead of in connector functions. * * It is not used by any helper and therefore has purely driver-specific * semantics. New drivers shouldn't use this and instead just implement * their own private callbacks. * * FIXME: * * This should just be converted into a pile of driver vfuncs. * Currently radeon, amdgpu and nouveau are using it. */ enum drm_connector_status (*detect)(struct drm_encoder *encoder, struct drm_connector *connector); /** * @disable: * * This callback should be used to disable the encoder. With the atomic * drivers it is called before this encoder's CRTC has been shut off * using their own &drm_crtc_helper_funcs.disable hook. If that * sequence is too simple drivers can just add their own driver private * encoder hooks and call them from CRTC's callback by looping over all * encoders connected to it using for_each_encoder_on_crtc(). * * This hook is used both by legacy CRTC helpers and atomic helpers. * Atomic drivers don't need to implement it if there's no need to * disable anything at the encoder level. To ensure that runtime PM * handling (using either DPMS or the new "ACTIVE" property) works * @disable must be the inverse of @enable for atomic drivers. * * NOTE: * * With legacy CRTC helpers there's a big semantic difference between * @disable and other hooks (like @prepare or @dpms) used to shut down a * encoder: @disable is only called when also logically disabling the * display pipeline and needs to release any resources acquired in * @mode_set (like shared PLLs, or again release pinned framebuffers). * * Therefore @disable must be the inverse of @mode_set plus @commit for * drivers still using legacy CRTC helpers, which is different from the * rules under atomic. */ void (*disable)(struct drm_encoder *encoder); /** * @enable: * * This callback should be used to enable the encoder. With the atomic * drivers it is called after this encoder's CRTC has been enabled using * their own &drm_crtc_helper_funcs.enable hook. If that sequence is * too simple drivers can just add their own driver private encoder * hooks and call them from CRTC's callback by looping over all encoders * connected to it using for_each_encoder_on_crtc(). * * This hook is used only by atomic helpers, for symmetry with @disable. * Atomic drivers don't need to implement it if there's no need to * enable anything at the encoder level. To ensure that runtime PM handling * (using either DPMS or the new "ACTIVE" property) works * @enable must be the inverse of @disable for atomic drivers. */ void (*enable)(struct drm_encoder *encoder); /** * @atomic_check: * * This callback is used to validate encoder state for atomic drivers. * Since the encoder is the object connecting the CRTC and connector it * gets passed both states, to be able to validate interactions and * update the CRTC to match what the encoder needs for the requested * connector. * * This function is used by the atomic helpers, but it is optional. * * NOTE: * * This function is called in the check phase of an atomic update. The * driver is not allowed to change anything outside of the free-standing * state objects passed-in or assembled in the overall &drm_atomic_state * update tracking structure. * * RETURNS: * * 0 on success, -EINVAL if the state or the transition can't be * supported, -ENOMEM on memory allocation failure and -EDEADLK if an * attempt to obtain another state object ran into a &drm_modeset_lock * deadlock. */ int (*atomic_check)(struct drm_encoder *encoder, struct drm_crtc_state *crtc_state, struct drm_connector_state *conn_state); }; /** * drm_encoder_helper_add - sets the helper vtable for an encoder * @encoder: DRM encoder * @funcs: helper vtable to set for @encoder */
static inline void drm_encoder_helper_add(struct drm_encoder *encoder, const struct drm_encoder_helper_funcs *funcs) { encoder->helper_private = funcs; }

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Total24100.00%1100.00%

/** * struct drm_connector_helper_funcs - helper operations for connectors * * These functions are used by the atomic and legacy modeset helpers and by the * probe helpers. */ struct drm_connector_helper_funcs { /** * @get_modes: * * This function should fill in all modes currently valid for the sink * into the &drm_connector.probed_modes list. It should also update the * EDID property by calling drm_mode_connector_update_edid_property(). * * The usual way to implement this is to cache the EDID retrieved in the * probe callback somewhere in the driver-private connector structure. * In this function drivers then parse the modes in the EDID and add * them by calling drm_add_edid_modes(). But connectors that driver a * fixed panel can also manually add specific modes using * drm_mode_probed_add(). Drivers which manually add modes should also * make sure that the &drm_connector.display_info, * &drm_connector.width_mm and &drm_connector.height_mm fields are * filled in. * * Virtual drivers that just want some standard VESA mode with a given * resolution can call drm_add_modes_noedid(), and mark the preferred * one using drm_set_preferred_mode(). * * Finally drivers that support audio probably want to update the ELD * data, too, using drm_edid_to_eld(). * * This function is only called after the @detect hook has indicated * that a sink is connected and when the EDID isn't overridden through * sysfs or the kernel commandline. * * This callback is used by the probe helpers in e.g. * drm_helper_probe_single_connector_modes(). * * To avoid races with concurrent connector state updates, the helper * libraries always call this with the &drm_mode_config.connection_mutex * held. Because of this it's safe to inspect &drm_connector->state. * * RETURNS: * * The number of modes added by calling drm_mode_probed_add(). */ int (*get_modes)(struct drm_connector *connector); /** * @detect_ctx: * * Check to see if anything is attached to the connector. The parameter * force is set to false whilst polling, true when checking the * connector due to a user request. force can be used by the driver to * avoid expensive, destructive operations during automated probing. * * This callback is optional, if not implemented the connector will be * considered as always being attached. * * This is the atomic version of &drm_connector_funcs.detect. * * To avoid races against concurrent connector state updates, the * helper libraries always call this with ctx set to a valid context, * and &drm_mode_config.connection_mutex will always be locked with * the ctx parameter set to this ctx. This allows taking additional * locks as required. * * RETURNS: * * &drm_connector_status indicating the connector's status, * or the error code returned by drm_modeset_lock(), -EDEADLK. */ int (*detect_ctx)(struct drm_connector *connector, struct drm_modeset_acquire_ctx *ctx, bool force); /** * @mode_valid: * * Callback to validate a mode for a connector, irrespective of the * specific display configuration. * * This callback is used by the probe helpers to filter the mode list * (which is usually derived from the EDID data block from the sink). * See e.g. drm_helper_probe_single_connector_modes(). * * NOTE: * * This only filters the mode list supplied to userspace in the * GETCONNECOTR IOCTL. Userspace is free to create modes of its own and * ask the kernel to use them. It this case the atomic helpers or legacy * CRTC helpers will not call this function. Drivers therefore must * still fully validate any mode passed in in a modeset request. * * To avoid races with concurrent connector state updates, the helper * libraries always call this with the &drm_mode_config.connection_mutex * held. Because of this it's safe to inspect &drm_connector->state. * * RETURNS: * * Either &drm_mode_status.MODE_OK or one of the failure reasons in &enum * drm_mode_status. */ enum drm_mode_status (*mode_valid)(struct drm_connector *connector, struct drm_display_mode *mode); /** * @best_encoder: * * This function should select the best encoder for the given connector. * * This function is used by both the atomic helpers (in the * drm_atomic_helper_check_modeset() function) and in the legacy CRTC * helpers. * * NOTE: * * In atomic drivers this function is called in the check phase of an * atomic update. The driver is not allowed to change or inspect * anything outside of arguments passed-in. Atomic drivers which need to * inspect dynamic configuration state should instead use * @atomic_best_encoder. * * You can leave this function to NULL if the connector is only * attached to a single encoder and you are using the atomic helpers. * In this case, the core will call drm_atomic_helper_best_encoder() * for you. * * RETURNS: * * Encoder that should be used for the given connector and connector * state, or NULL if no suitable encoder exists. Note that the helpers * will ensure that encoders aren't used twice, drivers should not check * for this. */ struct drm_encoder *(*best_encoder)(struct drm_connector *connector); /** * @atomic_best_encoder: * * This is the atomic version of @best_encoder for atomic drivers which * need to select the best encoder depending upon the desired * configuration and can't select it statically. * * This function is used by drm_atomic_helper_check_modeset(). * If it is not implemented, the core will fallback to @best_encoder * (or drm_atomic_helper_best_encoder() if @best_encoder is NULL). * * NOTE: * * This function is called in the check phase of an atomic update. The * driver is not allowed to change anything outside of the free-standing * state objects passed-in or assembled in the overall &drm_atomic_state * update tracking structure. * * RETURNS: * * Encoder that should be used for the given connector and connector * state, or NULL if no suitable encoder exists. Note that the helpers * will ensure that encoders aren't used twice, drivers should not check * for this. */ struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector, struct drm_connector_state *connector_state); /** * @atomic_check: * * This hook is used to validate connector state. This function is * called from &drm_atomic_helper_check_modeset, and is called when * a connector property is set, or a modeset on the crtc is forced. * * Because &drm_atomic_helper_check_modeset may be called multiple times, * this function should handle being called multiple times as well. * * This function is also allowed to inspect any other object's state and * can add more state objects to the atomic commit if needed. Care must * be taken though to ensure that state check and compute functions for * these added states are all called, and derived state in other objects * all updated. Again the recommendation is to just call check helpers * until a maximal configuration is reached. * * NOTE: * * This function is called in the check phase of an atomic update. The * driver is not allowed to change anything outside of the free-standing * state objects passed-in or assembled in the overall &drm_atomic_state * update tracking structure. * * RETURNS: * * 0 on success, -EINVAL if the state or the transition can't be * supported, -ENOMEM on memory allocation failure and -EDEADLK if an * attempt to obtain another state object ran into a &drm_modeset_lock * deadlock. */ int (*atomic_check)(struct drm_connector *connector, struct drm_connector_state *state); }; /** * drm_connector_helper_add - sets the helper vtable for a connector * @connector: DRM connector * @funcs: helper vtable to set for @connector */
static inline void drm_connector_helper_add(struct drm_connector *connector, const struct drm_connector_helper_funcs *funcs) { connector->helper_private = funcs; }

Contributors

PersonTokensPropCommitsCommitProp
Daniel Vetter24100.00%1100.00%
Total24100.00%1100.00%

/** * struct drm_plane_helper_funcs - helper operations for planes * * These functions are used by the atomic helpers and by the transitional plane * helpers. */ struct drm_plane_helper_funcs { /** * @prepare_fb: * * This hook is to prepare a framebuffer for scanout by e.g. pinning * it's backing storage or relocating it into a contiguous block of * VRAM. Other possible preparatory work includes flushing caches. * * This function must not block for outstanding rendering, since it is * called in the context of the atomic IOCTL even for async commits to * be able to return any errors to userspace. Instead the recommended * way is to fill out the fence member of the passed-in * &drm_plane_state. If the driver doesn't support native fences then * equivalent functionality should be implemented through private * members in the plane structure. * * The helpers will call @cleanup_fb with matching arguments for every * successful call to this hook. * * This callback is used by the atomic modeset helpers and by the * transitional plane helpers, but it is optional. * * RETURNS: * * 0 on success or one of the following negative error codes allowed by * the &drm_mode_config_funcs.atomic_commit vfunc. When using helpers * this callback is the only one which can fail an atomic commit, * everything else must complete successfully. */ int (*prepare_fb)(struct drm_plane *plane, struct drm_plane_state *new_state); /** * @cleanup_fb: * * This hook is called to clean up any resources allocated for the given * framebuffer and plane configuration in @prepare_fb. * * This callback is used by the atomic modeset helpers and by the * transitional plane helpers, but it is optional. */ void (*cleanup_fb)(struct drm_plane *plane, struct drm_plane_state *old_state); /** * @atomic_check: * * Drivers should check plane specific constraints in this hook. * * When using drm_atomic_helper_check_planes() plane's @atomic_check * hooks are called before the ones for CRTCs, which allows drivers to * request shared resources that the CRTC controls here. For more * complicated dependencies the driver can call the provided check helpers * multiple times until the computed state has a final configuration and * everything has been checked. * * This function is also allowed to inspect any other object's state and * can add more state objects to the atomic commit if needed. Care must * be taken though to ensure that state check and compute functions for * these added states are all called, and derived state in other objects * all updated. Again the recommendation is to just call check helpers * until a maximal configuration is reached. * * This callback is used by the atomic modeset helpers and by the * transitional plane helpers, but it is optional. * * NOTE: * * This function is called in the check phase of an atomic update. The * driver is not allowed to change anything outside of the free-standing * state objects passed-in or assembled in the overall &drm_atomic_state * update tracking structure. * * RETURNS: * * 0 on success, -EINVAL if the state or the transition can't be * supported, -ENOMEM on memory allocation failure and -EDEADLK if an * attempt to obtain another state object ran into a &drm_modeset_lock * deadlock. */ int (*atomic_check)(struct drm_plane *plane, struct drm_plane_state *state); /** * @atomic_update: * * Drivers should use this function to update the plane state. This * hook is called in-between the &drm_crtc_helper_funcs.atomic_begin and * drm_crtc_helper_funcs.atomic_flush callbacks. * * Note that the power state of the display pipe when this function is * called depends upon the exact helpers and calling sequence the driver * has picked. See drm_atomic_helper_commit_planes() for a discussion of * the tradeoffs and variants of plane commit helpers. * * This callback is used by the atomic modeset helpers and by the * transitional plane helpers, but it is optional. */ void (*atomic_update)(struct drm_plane *plane, struct drm_plane_state *old_state); /** * @atomic_disable: * * Drivers should use this function to unconditionally disable a plane. * This hook is called in-between the * &drm_crtc_helper_funcs.atomic_begin and * drm_crtc_helper_funcs.atomic_flush callbacks. It is an alternative to * @atomic_update, which will be called for disabling planes, too, if * the @atomic_disable hook isn't implemented. * * This hook is also useful to disable planes in preparation of a modeset, * by calling drm_atomic_helper_disable_planes_on_crtc() from the * &drm_crtc_helper_funcs.disable hook. * * Note that the power state of the display pipe when this function is * called depends upon the exact helpers and calling sequence the driver * has picked. See drm_atomic_helper_commit_planes() for a discussion of * the tradeoffs and variants of plane commit helpers. * * This callback is used by the atomic modeset helpers and by the * transitional plane helpers, but it is optional. */ void (*atomic_disable)(struct drm_plane *plane, struct drm_plane_state *old_state); }; /** * drm_plane_helper_add - sets the helper vtable for a plane * @plane: DRM plane * @funcs: helper vtable to set for @plane */
static inline void drm_plane_helper_add(struct drm_plane *plane, const struct drm_plane_helper_funcs *funcs) { plane->helper_private = funcs; }

Contributors

PersonTokensPropCommitsCommitProp
Daniel Vetter24100.00%1100.00%
Total24100.00%1100.00%

/** * struct drm_mode_config_helper_funcs - global modeset helper operations * * These helper functions are used by the atomic helpers. */ struct drm_mode_config_helper_funcs { /** * @atomic_commit_tail: * * This hook is used by the default atomic_commit() hook implemented in * drm_atomic_helper_commit() together with the nonblocking commit * helpers (see drm_atomic_helper_setup_commit() for a starting point) * to implement blocking and nonblocking commits easily. It is not used * by the atomic helpers * * This function is called when the new atomic state has already been * swapped into the various state pointers. The passed in state * therefore contains copies of the old/previous state. This hook should * commit the new state into hardware. Note that the helpers have * already waited for preceeding atomic commits and fences, but drivers * can add more waiting calls at the start of their implementation, e.g. * to wait for driver-internal request for implicit syncing, before * starting to commit the update to the hardware. * * After the atomic update is committed to the hardware this hook needs * to call drm_atomic_helper_commit_hw_done(). Then wait for the upate * to be executed by the hardware, for example using * drm_atomic_helper_wait_for_vblanks(), and then clean up the old * framebuffers using drm_atomic_helper_cleanup_planes(). * * When disabling a CRTC this hook _must_ stall for the commit to * complete. Vblank waits don't work on disabled CRTC, hence the core * can't take care of this. And it also can't rely on the vblank event, * since that can be signalled already when the screen shows black, * which can happen much earlier than the last hardware access needed to * shut off the display pipeline completely. * * This hook is optional, the default implementation is * drm_atomic_helper_commit_tail(). */ void (*atomic_commit_tail)(struct drm_atomic_state *state); }; #endif

Overall Contributors

PersonTokensPropCommitsCommitProp
Daniel Vetter74189.49%750.00%
Maarten Lankhorst414.95%214.29%
Philipp Zabel222.66%17.14%
Liu Ying172.05%17.14%
Laurent Pinchart30.36%17.14%
Stefan Agner20.24%17.14%
Boris Brezillon20.24%17.14%
Total828100.00%14100.00%
Directory: include/drm
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