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Diffstat (limited to 'include/drm/drm_modeset_helper_vtables.h')
| -rw-r--r-- | include/drm/drm_modeset_helper_vtables.h | 928 |
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diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h new file mode 100644 index 000000000000..a126a0d7aed4 --- /dev/null +++ b/include/drm/drm_modeset_helper_vtables.h @@ -0,0 +1,928 @@ +/* + * 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> + +/** + * 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 + * ->mode_fixup() functions. 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 connector's + * ->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 ->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 ->mode_valid() but also in ->mode_fixup() 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 @gamma_set functions from + * &drm_fb_helper_funcs. + * + * 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 ->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. + * + * 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 ->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() CRTCs' ->atomic_check() + * hooks are called after the ones for planes, which allows drivers to + * assign shared resources requested by planes in the CRTC 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&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_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_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); +}; + +/** + * 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; +} + +/** + * 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. + * 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 connector's + * ->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 ->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 ->mode_valid() but also in ->mode_fixup() 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. + */ + void (*mode_set)(struct drm_encoder *encoder, + struct drm_display_mode *mode, + struct drm_display_mode *adjusted_mode); + + /** + * @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 the CRTC's own ->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 + * the CRTC's own ->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; +} + +/** + * 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 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 @display_info, @width_mm and @height_mm fields of the + * struct #drm_connector 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(). + * + * RETURNS: + * + * The number of modes added by calling drm_mode_probed_add(). + */ + int (*get_modes)(struct drm_connector *connector); + + /** + * @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. + * + * RETURNS: + * + * Either 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. + * + * 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() and either + * this or @best_encoder is required. + * + * 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); +}; + +/** + * 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; +} + +/** + * 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 atomic_commit hook in &drm_mode_config_funcs. 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, + const 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, + const 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&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 ->atomic_begin() and + * ->atomic_flush() of &drm_crtc_helper_funcs. + * + * 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_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 ->atomic_begin() and + * ->atomic_flush() of &drm_crtc_helper_funcs. 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 + * ->disable() hook in &drm_crtc_helper_funcs. + * + * 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_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; +} + +#endif |