From f1e2b6371c12aec5e772e5fdedaa4455c20a787f Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Thu, 23 Jan 2020 14:59:23 +0100 Subject: drm: Add get_scanout_position() to struct drm_crtc_helper_funcs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The new callback get_scanout_position() reads the current location of the scanout process. The operation is currently located in struct drm_driver, but really belongs to the CRTC. Drivers will be converted in separate patches. To help with the conversion, the timestamp calculation has been moved from drm_calc_vbltimestamp_from_scanoutpos() to drm_crtc_vblank_helper_get_vblank_timestamp_internal(). The helper function supports the new and old interface of get_scanout_position(). drm_calc_vbltimestamp_from_scanoutpos() remains as a wrapper around the new function. Callback functions return the scanout position from the CRTC. The legacy version of the interface receives the device and pipe index, the modern version receives a pointer to the CRTC. We keep the legacy version until all drivers have been converted. v4: * 80-character line fixes v3: * refactor drm_calc_vbltimestamp_from_scanoutpos() to minimize code duplication * define types for get_scanout_position() callbacks v2: * fix logical op in drm_calc_vbltimestamp_from_scanoutpos() Signed-off-by: Thomas Zimmermann Tested-by: Yannick Fertré Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200123135943.24140-3-tzimmermann@suse.de --- include/drm/drm_modeset_helper_vtables.h | 47 ++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) (limited to 'include/drm/drm_modeset_helper_vtables.h') diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index 5a87f1bd7a3f..e398512bfd5f 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -450,6 +450,53 @@ struct drm_crtc_helper_funcs { */ void (*atomic_disable)(struct drm_crtc *crtc, struct drm_crtc_state *old_crtc_state); + + /** + * @get_scanout_position: + * + * Called by vblank timestamping code. + * + * Returns the current display scanout position from a CRTC and an + * optional accurate ktime_get() timestamp of when the position was + * measured. Note that this is a helper callback which is only used + * if a driver uses drm_calc_vbltimestamp_from_scanoutpos() for the + * @drm_driver.get_vblank_timestamp callback. + * + * Parameters: + * + * crtc: + * The CRTC. + * in_vblank_irq: + * True when called from drm_crtc_handle_vblank(). Some drivers + * need to apply some workarounds for gpu-specific vblank irq + * quirks if the flag is set. + * vpos: + * Target location for current vertical scanout position. + * hpos: + * Target location for current horizontal scanout position. + * stime: + * Target location for timestamp taken immediately before + * scanout position query. Can be NULL to skip timestamp. + * etime: + * Target location for timestamp taken immediately after + * scanout position query. Can be NULL to skip timestamp. + * mode: + * Current display timings. + * + * Returns vpos as a positive number while in active scanout area. + * Returns vpos as a negative number inside vblank, counting the number + * of scanlines to go until end of vblank, e.g., -1 means "one scanline + * until start of active scanout / end of vblank." + * + * Returns: + * + * True on success, false if a reliable scanout position counter could + * not be read out. + */ + bool (*get_scanout_position)(struct drm_crtc *crtc, + bool in_vblank_irq, int *vpos, int *hpos, + ktime_t *stime, ktime_t *etime, + const struct drm_display_mode *mode); }; /** -- cgit v1.2.3