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// SPDX-License-Identifier: MIT
#include <drm/drm_atomic.h>
#include <drm/drm_crtc.h>
#include <drm/drm_managed.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_print.h>
#include <drm/drm_vblank.h>
#include <drm/drm_vblank_helper.h>
/**
* DOC: overview
*
* The vblank helper library provides functions for supporting vertical
* blanking in DRM drivers.
*
* For vblank timers, several callback implementations are available.
* Drivers enable support for vblank timers by setting the vblank callbacks
* in struct &drm_crtc_funcs to the helpers provided by this library. The
* initializer macro DRM_CRTC_VBLANK_TIMER_FUNCS does this conveniently.
* The driver further has to send the VBLANK event from its atomic_flush
* callback and control vblank from the CRTC's atomic_enable and atomic_disable
* callbacks. The callbacks are located in struct &drm_crtc_helper_funcs.
* The vblank helper library provides implementations of these callbacks
* for drivers without further requirements. The initializer macro
* DRM_CRTC_HELPER_VBLANK_FUNCS sets them coveniently.
*
* Once the driver enables vblank support with drm_vblank_init(), each
* CRTC's vblank timer fires according to the programmed display mode. By
* default, the vblank timer invokes drm_crtc_handle_vblank(). Drivers with
* more specific requirements can set their own handler function in
* struct &drm_crtc_helper_funcs.handle_vblank_timeout.
*/
/*
* VBLANK helpers
*/
/**
* drm_crtc_vblank_atomic_flush -
* Implements struct &drm_crtc_helper_funcs.atomic_flush
* @crtc: The CRTC
* @state: The atomic state to apply
*
* The helper drm_crtc_vblank_atomic_flush() implements atomic_flush of
* struct drm_crtc_helper_funcs for CRTCs that only need to send out a
* VBLANK event.
*
* See also struct &drm_crtc_helper_funcs.atomic_flush.
*/
void drm_crtc_vblank_atomic_flush(struct drm_crtc *crtc,
struct drm_atomic_state *state)
{
struct drm_device *dev = crtc->dev;
struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
struct drm_pending_vblank_event *event;
spin_lock_irq(&dev->event_lock);
event = crtc_state->event;
crtc_state->event = NULL;
if (event) {
if (drm_crtc_vblank_get(crtc) == 0)
drm_crtc_arm_vblank_event(crtc, event);
else
drm_crtc_send_vblank_event(crtc, event);
}
spin_unlock_irq(&dev->event_lock);
}
EXPORT_SYMBOL(drm_crtc_vblank_atomic_flush);
/**
* drm_crtc_vblank_atomic_enable - Implements struct &drm_crtc_helper_funcs.atomic_enable
* @crtc: The CRTC
* @state: The atomic state
*
* The helper drm_crtc_vblank_atomic_enable() implements atomic_enable
* of struct drm_crtc_helper_funcs for CRTCs the only need to enable VBLANKs.
*
* See also struct &drm_crtc_helper_funcs.atomic_enable.
*/
void drm_crtc_vblank_atomic_enable(struct drm_crtc *crtc,
struct drm_atomic_state *state)
{
drm_crtc_vblank_on(crtc);
}
EXPORT_SYMBOL(drm_crtc_vblank_atomic_enable);
/**
* drm_crtc_vblank_atomic_disable - Implements struct &drm_crtc_helper_funcs.atomic_disable
* @crtc: The CRTC
* @state: The atomic state
*
* The helper drm_crtc_vblank_atomic_disable() implements atomic_disable
* of struct drm_crtc_helper_funcs for CRTCs the only need to disable VBLANKs.
*
* See also struct &drm_crtc_funcs.atomic_disable.
*/
void drm_crtc_vblank_atomic_disable(struct drm_crtc *crtc,
struct drm_atomic_state *state)
{
drm_crtc_vblank_off(crtc);
}
EXPORT_SYMBOL(drm_crtc_vblank_atomic_disable);
/*
* VBLANK timer
*/
/**
* drm_crtc_vblank_helper_enable_vblank_timer - Implements struct &drm_crtc_funcs.enable_vblank
* @crtc: The CRTC
*
* The helper drm_crtc_vblank_helper_enable_vblank_timer() implements
* enable_vblank of struct drm_crtc_helper_funcs for CRTCs that require
* a VBLANK timer. It sets up the timer on the first invocation. The
* started timer expires after the current frame duration. See struct
* &drm_vblank_crtc.framedur_ns.
*
* See also struct &drm_crtc_helper_funcs.enable_vblank.
*
* Returns:
* 0 on success, or a negative errno code otherwise.
*/
int drm_crtc_vblank_helper_enable_vblank_timer(struct drm_crtc *crtc)
{
return drm_crtc_vblank_start_timer(crtc);
}
EXPORT_SYMBOL(drm_crtc_vblank_helper_enable_vblank_timer);
/**
* drm_crtc_vblank_helper_disable_vblank_timer - Implements struct &drm_crtc_funcs.disable_vblank
* @crtc: The CRTC
*
* The helper drm_crtc_vblank_helper_disable_vblank_timer() implements
* disable_vblank of struct drm_crtc_funcs for CRTCs that require a
* VBLANK timer.
*
* See also struct &drm_crtc_helper_funcs.disable_vblank.
*/
void drm_crtc_vblank_helper_disable_vblank_timer(struct drm_crtc *crtc)
{
drm_crtc_vblank_cancel_timer(crtc);
}
EXPORT_SYMBOL(drm_crtc_vblank_helper_disable_vblank_timer);
/**
* drm_crtc_vblank_helper_get_vblank_timestamp_from_timer -
* Implements struct &drm_crtc_funcs.get_vblank_timestamp
* @crtc: The CRTC
* @max_error: Maximum acceptable error
* @vblank_time: Returns the next vblank timestamp
* @in_vblank_irq: True is called from drm_crtc_handle_vblank()
*
* The helper drm_crtc_helper_get_vblank_timestamp_from_timer() implements
* get_vblank_timestamp of struct drm_crtc_funcs for CRTCs that require a
* VBLANK timer. It returns the timestamp according to the timer's expiry
* time.
*
* See also struct &drm_crtc_funcs.get_vblank_timestamp.
*
* Returns:
* True on success, or false otherwise.
*/
bool drm_crtc_vblank_helper_get_vblank_timestamp_from_timer(struct drm_crtc *crtc,
int *max_error,
ktime_t *vblank_time,
bool in_vblank_irq)
{
drm_crtc_vblank_get_vblank_timeout(crtc, vblank_time);
return true;
}
EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp_from_timer);
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