drm: add vblank hooks to struct drm_crtc_funcs

The vblank is mostly CRTC specific and implemented as part of CRTC
driver.  Let's keep the vblank hooks struct drm_driver for legacy
drivers, and add corresponding hooks in struct drm_crtc_funcs.  These
hooks take struct drm_crtc pointer as argument, and will be called by
core vblank handling code for DRIVER_MODESET drivers.

The new hooks get plugged into core by adding wrapper functions for
vblank handling code.  The .get_vblank_counter hook is effectively
optional, as we provide drm_vblank_no_hw_counter() as the default
fallback in the wrapper function.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1486458995-31018-2-git-send-email-shawnguo@kernel.org

1 files changed, 44 insertions, 0 deletions

diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index c38a572c16aa..bda9347554a1 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -608,6 +608,50 @@ struct drm_crtc_funcs {
 	 */
 	void (*atomic_print_state)(struct drm_printer *p,
 				   const struct drm_crtc_state *state);
+
+	/**
+	 * @get_vblank_counter:
+	 *
+	 * Driver callback for fetching a raw hardware vblank counter for the
+	 * CRTC. It's meant to be used by new drivers as the replacement of
+	 * &drm_driver.get_vblank_counter hook.
+	 *
+	 * This callback is optional. If a device doesn't have a hardware
+	 * counter, the driver can simply leave the hook as NULL. The DRM core
+	 * will account for missed vblank events while interrupts where disabled
+	 * based on system timestamps.
+	 *
+	 * Wraparound handling and loss of events due to modesetting is dealt
+	 * with in the DRM core code, as long as drivers call
+	 * drm_crtc_vblank_off() and drm_crtc_vblank_on() when disabling or
+	 * enabling a CRTC.
+	 *
+	 * Returns:
+	 *
+	 * Raw vblank counter value.
+	 */
+	u32 (*get_vblank_counter)(struct drm_crtc *crtc);
+
+	/**
+	 * @enable_vblank:
+	 *
+	 * Enable vblank interrupts for the CRTC. It's meant to be used by
+	 * new drivers as the replacement of &drm_driver.enable_vblank hook.
+	 *
+	 * Returns:
+	 *
+	 * Zero on success, appropriate errno if the vblank interrupt cannot
+	 * be enabled.
+	 */
+	int (*enable_vblank)(struct drm_crtc *crtc);
+
+	/**
+	 * @disable_vblank:
+	 *
+	 * Disable vblank interrupts for the CRTC. It's meant to be used by
+	 * new drivers as the replacement of &drm_driver.disable_vblank hook.
+	 */
+	void (*disable_vblank)(struct drm_crtc *crtc);
 };
 
 /**