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Diffstat (limited to 'include/drm/drm_bridge.h')
| -rw-r--r-- | include/drm/drm_bridge.h | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h new file mode 100644 index 000000000..bd850747c --- /dev/null +++ b/include/drm/drm_bridge.h @@ -0,0 +1,327 @@ +/* + * Copyright (c) 2016 Intel Corporation + * + * Permission to use, copy, modify, distribute, and sell this software and its + * documentation for any purpose is hereby granted without fee, provided that + * the above copyright notice appear in all copies and that both that copyright + * notice and this permission notice appear in supporting documentation, and + * that the name of the copyright holders not be used in advertising or + * publicity pertaining to distribution of the software without specific, + * written prior permission. The copyright holders make no representations + * about the suitability of this software for any purpose. It is provided "as + * is" without express or implied warranty. + * + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE + * OF THIS SOFTWARE. + */ + +#ifndef __DRM_BRIDGE_H__ +#define __DRM_BRIDGE_H__ + +#include <linux/list.h> +#include <linux/ctype.h> +#include <drm/drm_mode_object.h> +#include <drm/drm_modes.h> + +struct drm_bridge; +struct drm_bridge_timings; +struct drm_panel; + +/** + * struct drm_bridge_funcs - drm_bridge control functions + */ +struct drm_bridge_funcs { + /** + * @attach: + * + * This callback is invoked whenever our bridge is being attached to a + * &drm_encoder. + * + * The attach callback is optional. + * + * RETURNS: + * + * Zero on success, error code on failure. + */ + int (*attach)(struct drm_bridge *bridge); + + /** + * @detach: + * + * This callback is invoked whenever our bridge is being detached from a + * &drm_encoder. + * + * The detach callback is optional. + */ + void (*detach)(struct drm_bridge *bridge); + + /** + * @mode_valid: + * + * This callback is used to check if a specific mode is valid in this + * bridge. This should be implemented if the bridge has some sort of + * restriction in the modes it can display. For example, a given bridge + * 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. + * + * RETURNS: + * + * drm_mode_status Enum + */ + enum drm_mode_status (*mode_valid)(struct drm_bridge *bridge, + 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 the next + * &drm_bridge. The parameter adjusted_mode is the input mode the bridge + * 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 is the only hook that allows a bridge to reject a modeset. If + * this function passes all other callbacks must succeed for this + * configuration. + * + * The mode_fixup callback 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). Drivers MUST + * NOT touch any persistent state (hardware or software) or data + * structures except the passed in @state parameter. + * + * 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 bridge 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_bridge *bridge, + const struct drm_display_mode *mode, + struct drm_display_mode *adjusted_mode); + /** + * @disable: + * + * This callback should disable the bridge. It is called right before + * the preceding element in the display pipe is disabled. If the + * preceding element is a bridge this means it's called before that + * bridge's @disable vfunc. If the preceding element is a &drm_encoder + * it's called right before the &drm_encoder_helper_funcs.disable, + * &drm_encoder_helper_funcs.prepare or &drm_encoder_helper_funcs.dpms + * hook. + * + * The bridge can assume that the display pipe (i.e. clocks and timing + * signals) feeding it is still running when this callback is called. + * + * The disable callback is optional. + */ + void (*disable)(struct drm_bridge *bridge); + + /** + * @post_disable: + * + * This callback should disable the bridge. It is called right after the + * preceding element in the display pipe is disabled. If the preceding + * element is a bridge this means it's called after that bridge's + * @post_disable function. If the preceding element is a &drm_encoder + * it's called right after the encoder's + * &drm_encoder_helper_funcs.disable, &drm_encoder_helper_funcs.prepare + * or &drm_encoder_helper_funcs.dpms hook. + * + * The bridge must assume that the display pipe (i.e. clocks and timing + * singals) feeding it is no longer running when this callback is + * called. + * + * The post_disable callback is optional. + */ + void (*post_disable)(struct drm_bridge *bridge); + + /** + * @mode_set: + * + * This callback should set the given mode on the bridge. It is called + * after the @mode_set callback for the preceding element in the display + * pipeline has been called already. If the bridge is the first element + * then this would be &drm_encoder_helper_funcs.mode_set. The display + * pipe (i.e. clocks and timing signals) is off when this function is + * called. + * + * The adjusted_mode parameter is the mode output by the CRTC for the + * first bridge in the chain. It can be different from the mode + * parameter that contains the desired mode for the connector at the end + * of the bridges chain, for instance when the first bridge in the chain + * performs scaling. The adjusted mode is mostly useful for the first + * bridge in the chain and is likely irrelevant for the other bridges. + * + * For atomic drivers the adjusted_mode is the mode stored in + * &drm_crtc_state.adjusted_mode. + * + * NOTE: + * + * If a need arises to store and access modes adjusted for other + * locations than the connection between the CRTC and the first bridge, + * the DRM framework will have to be extended with DRM bridge states. + */ + void (*mode_set)(struct drm_bridge *bridge, + struct drm_display_mode *mode, + struct drm_display_mode *adjusted_mode); + /** + * @pre_enable: + * + * This callback should enable the bridge. It is called right before + * the preceding element in the display pipe is enabled. If the + * preceding element is a bridge this means it's called before that + * bridge's @pre_enable function. If the preceding element is a + * &drm_encoder it's called right before the encoder's + * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or + * &drm_encoder_helper_funcs.dpms hook. + * + * The display pipe (i.e. clocks and timing signals) feeding this bridge + * will not yet be running when this callback is called. The bridge must + * not enable the display link feeding the next bridge in the chain (if + * there is one) when this callback is called. + * + * The pre_enable callback is optional. + */ + void (*pre_enable)(struct drm_bridge *bridge); + + /** + * @enable: + * + * This callback should enable the bridge. It is called right after + * the preceding element in the display pipe is enabled. If the + * preceding element is a bridge this means it's called after that + * bridge's @enable function. If the preceding element is a + * &drm_encoder it's called right after the encoder's + * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or + * &drm_encoder_helper_funcs.dpms hook. + * + * The bridge can assume that the display pipe (i.e. clocks and timing + * signals) feeding it is running when this callback is called. This + * callback must enable the display link feeding the next bridge in the + * chain if there is one. + * + * The enable callback is optional. + */ + void (*enable)(struct drm_bridge *bridge); +}; + +/** + * struct drm_bridge_timings - timing information for the bridge + */ +struct drm_bridge_timings { + /** + * @sampling_edge: + * + * Tells whether the bridge samples the digital input signal + * from the display engine on the positive or negative edge of the + * clock, this should reuse the DRM_BUS_FLAG_PIXDATA_[POS|NEG]EDGE + * bitwise flags from the DRM connector (bit 2 and 3 valid). + */ + u32 sampling_edge; + /** + * @setup_time_ps: + * + * Defines the time in picoseconds the input data lines must be + * stable before the clock edge. + */ + u32 setup_time_ps; + /** + * @hold_time_ps: + * + * Defines the time in picoseconds taken for the bridge to sample the + * input signal after the clock edge. + */ + u32 hold_time_ps; +}; + +/** + * struct drm_bridge - central DRM bridge control structure + */ +struct drm_bridge { + /** @dev: DRM device this bridge belongs to */ + struct drm_device *dev; + /** @encoder: encoder to which this bridge is connected */ + struct drm_encoder *encoder; + /** @next: the next bridge in the encoder chain */ + struct drm_bridge *next; +#ifdef CONFIG_OF + /** @of_node: device node pointer to the bridge */ + struct device_node *of_node; +#endif + /** @list: to keep track of all added bridges */ + struct list_head list; + /** + * @timings: + * + * the timing specification for the bridge, if any (may be NULL) + */ + const struct drm_bridge_timings *timings; + /** @funcs: control functions */ + const struct drm_bridge_funcs *funcs; + /** @driver_private: pointer to the bridge driver's internal context */ + void *driver_private; +}; + +void drm_bridge_add(struct drm_bridge *bridge); +void drm_bridge_remove(struct drm_bridge *bridge); +struct drm_bridge *of_drm_find_bridge(struct device_node *np); +int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, + struct drm_bridge *previous); + +bool drm_bridge_mode_fixup(struct drm_bridge *bridge, + const struct drm_display_mode *mode, + struct drm_display_mode *adjusted_mode); +enum drm_mode_status drm_bridge_mode_valid(struct drm_bridge *bridge, + const struct drm_display_mode *mode); +void drm_bridge_disable(struct drm_bridge *bridge); +void drm_bridge_post_disable(struct drm_bridge *bridge); +void drm_bridge_mode_set(struct drm_bridge *bridge, + struct drm_display_mode *mode, + struct drm_display_mode *adjusted_mode); +void drm_bridge_pre_enable(struct drm_bridge *bridge); +void drm_bridge_enable(struct drm_bridge *bridge); + +#ifdef CONFIG_DRM_PANEL_BRIDGE +struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel, + u32 connector_type); +void drm_panel_bridge_remove(struct drm_bridge *bridge); +struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev, + struct drm_panel *panel, + u32 connector_type); +#endif + +#endif |