drm/atomic-helper: Add atomic_disable CRTC helper callback

Some display controllers need plane(s) to be disabled together with
the relevant CRTC, e.g., the IPUv3 display controller for imx-drm.
This patch adds atomic_disable CRTC helper callback so that
old_crtc_state(as a parameter of the callback) could be used
to get the active plane(s) of the old CRTC state for disable operation.

Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Liu Ying <gnuiyl@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1472196644-30563-2-git-send-email-gnuiyl@gmail.com

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 9abe0a242f96f3a531a63c07b6ba62d03d13e057..4828b9b860de47416da9996c182724e3405973a6 100644 (file)
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -749,6 +749,8 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
                /* Right function depends upon target state. */
                if (crtc->state->enable && funcs->prepare)
                        funcs->prepare(crtc);
+               else if (funcs->atomic_disable)
+                       funcs->atomic_disable(crtc, old_crtc_state);
                else if (funcs->disable)
                        funcs->disable(crtc);
                else

diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h
index 6c8d3dad66ec0f15bb1dbbc68d862042d63e2ae0..10e449c86dbd6bf26a7570a44da2b4b82dafa7c2 100644 (file)
--- a/include/drm/drm_modeset_helper_vtables.h
+++ b/include/drm/drm_modeset_helper_vtables.h
@@ -266,6 +266,8 @@ struct drm_crtc_helper_funcs {
         * 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 @enable for atomic drivers.
+        * Atomic drivers should consider to use @atomic_disable instead of
+        * this one.
         *
         * NOTE:
         *
@@ -391,6 +393,28 @@ struct drm_crtc_helper_funcs {
         */
        void (*atomic_flush)(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 ->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);
 };
 
 /**