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| -rw-r--r-- | include/drm/drm_modeset_helper_vtables.h | 1252 |
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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 000000000..0eb3372d0 --- /dev/null +++ b/include/drm/drm_modeset_helper_vtables.h @@ -0,0 +1,1252 @@ +/* + * 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 + * @atomic_enable and @atomic_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 @atomic_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 @atomic_enable + * should be used. + */ + void (*commit)(struct drm_crtc *crtc); + + /** + * @mode_valid: + * + * This callback is used to check if a specific mode is valid in this + * crtc. This should be implemented if the crtc has some sort of + * restriction in the modes it can display. For example, a given crtc + * may be responsible to set a clock value. If the clock can not + * produce all the values for the available modes then this callback + * can be used to restrict the number of modes to only the ones that + * can be displayed. + * + * This hook is used by the probe helpers to filter the mode list in + * drm_helper_probe_single_connector_modes(), and it is used by the + * atomic helpers to validate modes supplied by userspace in + * drm_atomic_helper_check_modeset(). + * + * This function is optional. + * + * NOTE: + * + * Since this function is both called from the check phase of an atomic + * commit, and the mode validation in the probe paths it is not allowed + * to look at anything else but the passed-in mode, and validate it + * against configuration-invariant hardward constraints. Any further + * limits which depend upon the configuration can only be checked in + * @mode_fixup or @atomic_check. + * + * RETURNS: + * + * drm_mode_status Enum + */ + enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc, + const struct drm_display_mode *mode); + + /** + * @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. See also + * &drm_crtc_state.adjusted_mode for more details. + * + * 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, but note that they're not + * perfectly equivalent: @mode_valid is called from + * drm_atomic_helper_check_modeset(), but @atomic_check is called from + * drm_atomic_helper_check_planes(), because originally it was meant for + * plane update checks only. + * + * Also beware that userspace can request its own custom modes, neither + * core nor helpers filter modes to the list of probe modes reported by + * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure + * that modes are filtered consistently put any CRTC constraints and + * limits checks into @mode_valid. + * + * 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 @atomic_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); + + /** + * @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 @atomic_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); + + /** + * @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.atomic_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. + * + * Also beware that userspace can request its own custom modes, neither + * core nor helpers filter modes to the list of probe modes reported by + * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure + * that modes are filtered consistently put any CRTC constraints and + * limits checks into @mode_valid. + * + * 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_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 + * @atomic_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 + * @atomic_enable must be the inverse of @atomic_disable for atomic + * drivers. + * + * Drivers can use the @old_crtc_state input parameter if the operations + * needed to enable the CRTC don't depend solely on the new state but + * also on the transition between the old state and the new state. + */ + void (*atomic_enable)(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; +} + +/** + * 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_valid: + * + * This callback is used to check if a specific mode is valid in this + * encoder. This should be implemented if the encoder has some sort + * of restriction in the modes it can display. For example, a given + * encoder may be responsible to set a clock value. If the clock can + * not produce all the values for the available modes then this callback + * can be used to restrict the number of modes to only the ones that + * can be displayed. + * + * This hook is used by the probe helpers to filter the mode list in + * drm_helper_probe_single_connector_modes(), and it is used by the + * atomic helpers to validate modes supplied by userspace in + * drm_atomic_helper_check_modeset(). + * + * This function is optional. + * + * NOTE: + * + * Since this function is both called from the check phase of an atomic + * commit, and the mode validation in the probe paths it is not allowed + * to look at anything else but the passed-in mode, and validate it + * against configuration-invariant hardward constraints. Any further + * limits which depend upon the configuration can only be checked in + * @mode_fixup or @atomic_check. + * + * RETURNS: + * + * drm_mode_status Enum + */ + enum drm_mode_status (*mode_valid)(struct drm_encoder *crtc, + const struct drm_display_mode *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. See + * also &drm_crtc_state.adjusted_mode for more details. + * + * 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. If @atomic_check is used, + * this hook isn't called since @atomic_check allows a strict superset + * of the functionality of @mode_fixup. + * + * Also beware that userspace can request its own custom modes, neither + * core nor helpers filter modes to the list of probe modes reported by + * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure + * that modes are filtered consistently put any encoder constraints and + * limits checks into @mode_valid. + * + * 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. + * + * Since this provides a strict superset of the functionality of + * @mode_fixup (the requested and adjusted modes are both available + * through the passed in &struct drm_crtc_state) @mode_fixup is not + * called when @atomic_check is implemented. + * + * 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. + * + * Also beware that userspace can request its own custom modes, neither + * core nor helpers filter modes to the list of probe modes reported by + * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure + * that modes are filtered consistently put any encoder constraints and + * limits checks into @mode_valid. + * + * 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 &drm_connector.probed_modes list. It should also update the + * EDID property by calling drm_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(). + * + * 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(). + * + * This function is optional. + * + * NOTE: + * + * This only filters the mode list supplied to userspace in the + * GETCONNECTOR IOCTL. Compared to &drm_encoder_helper_funcs.mode_valid, + * &drm_crtc_helper_funcs.mode_valid and &drm_bridge_funcs.mode_valid, + * which are also called by the atomic helpers from + * drm_atomic_helper_check_modeset(). This allows userspace to force and + * ignore sink constraint (like the pixel clock limits in the screen's + * EDID), which is useful for e.g. testing, or working around a broken + * EDID. Any source hardware constraint (which always need to be + * enforced) therefore should be checked in one of the above callbacks, + * and not this one here. + * + * 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); + + /** + * @atomic_commit: + * + * This hook is to be used by drivers implementing writeback connectors + * that need a point when to commit the writeback job to the hardware. + * The writeback_job to commit is available in + * &drm_connector_state.writeback_job. + * + * This hook is optional. + * + * This callback is used by the atomic modeset helpers. + */ + void (*atomic_commit)(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; +} + +/** + * 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 &drm_plane_state.fence 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. + * + * Drivers which always have their buffers pinned should use + * drm_gem_fb_prepare_fb() for this hook. + * + * 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); + + /** + * @atomic_async_check: + * + * Drivers should set this function pointer to check if the plane state + * can be updated in a async fashion. Here async means "not vblank + * synchronized". + * + * This hook is called by drm_atomic_async_check() to establish if a + * given update can be committed asynchronously, that is, if it can + * jump ahead of the state currently queued for update. + * + * RETURNS: + * + * Return 0 on success and any error returned indicates that the update + * can not be applied in asynchronous manner. + */ + int (*atomic_async_check)(struct drm_plane *plane, + struct drm_plane_state *state); + + /** + * @atomic_async_update: + * + * Drivers should set this function pointer to perform asynchronous + * updates of planes, that is, jump ahead of the currently queued + * state and update the plane. Here async means "not vblank + * synchronized". + * + * This hook is called by drm_atomic_helper_async_commit(). + * + * An async update will happen on legacy cursor updates. An async + * update won't happen if there is an outstanding commit modifying + * the same plane. + * + * Note that unlike &drm_plane_helper_funcs.atomic_update this hook + * takes the new &drm_plane_state as parameter. When doing async_update + * drivers shouldn't replace the &drm_plane_state but update the + * current one with the new plane configurations in the new + * plane_state. + * + * Drivers should also swap the framebuffers between current plane + * state (&drm_plane.state) and new_state. + * This is required since cleanup for async commits is performed on + * the new state, rather than old state like for traditional commits. + * Since we want to give up the reference on the current (old) fb + * instead of our brand new one, swap them in the driver during the + * async commit. + * + * FIXME: + * - It only works for single plane updates + * - Async Pageflips are not supported yet + * - Some hw might still scan out the old buffer until the next + * vblank, however we let go of the fb references as soon as + * we run this hook. For now drivers must implement their own workers + * for deferring if needed, until a common solution is created. + */ + void (*atomic_async_update)(struct drm_plane *plane, + struct drm_plane_state *new_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; +} + +/** + * 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() or + * drm_atomic_helper_wait_for_flip_done(), 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 |