Merge tag 'lsk-v4.4-17.03-android' of git://git.linaro.org/kernel/linux-linaro-stable.git
[firefly-linux-kernel-4.4.55.git] / drivers / gpu / drm / drm_atomic_helper.c
index ea443fafb9340001b2ce6c331cd94086c91a5033..40a67eb373fa071639fcd626413899e67fe845e7 100644 (file)
@@ -909,9 +909,23 @@ static void wait_for_fences(struct drm_device *dev,
        }
 }
 
-static bool framebuffer_changed(struct drm_device *dev,
-                               struct drm_atomic_state *old_state,
-                               struct drm_crtc *crtc)
+/**
+ * drm_atomic_helper_framebuffer_changed - check if framebuffer has changed
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ * @crtc: DRM crtc
+ *
+ * Checks whether the framebuffer used for this CRTC changes as a result of
+ * the atomic update.  This is useful for drivers which cannot use
+ * drm_atomic_helper_wait_for_vblanks() and need to reimplement its
+ * functionality.
+ *
+ * Returns:
+ * true if the framebuffer changed.
+ */
+bool drm_atomic_helper_framebuffer_changed(struct drm_device *dev,
+                                          struct drm_atomic_state *old_state,
+                                          struct drm_crtc *crtc)
 {
        struct drm_plane *plane;
        struct drm_plane_state *old_plane_state;
@@ -928,6 +942,7 @@ static bool framebuffer_changed(struct drm_device *dev,
 
        return false;
 }
+EXPORT_SYMBOL(drm_atomic_helper_framebuffer_changed);
 
 /**
  * drm_atomic_helper_wait_for_vblanks - wait for vblank on crtcs
@@ -962,7 +977,8 @@ drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
                if (old_state->legacy_cursor_update)
                        continue;
 
-               if (!framebuffer_changed(dev, old_state, crtc))
+               if (!drm_atomic_helper_framebuffer_changed(dev,
+                               old_state, crtc))
                        continue;
 
                ret = drm_crtc_vblank_get(crtc);
@@ -1813,6 +1829,161 @@ commit:
        return 0;
 }
 
+/**
+ * drm_atomic_helper_disable_all - disable all currently active outputs
+ * @dev: DRM device
+ * @ctx: lock acquisition context
+ *
+ * Loops through all connectors, finding those that aren't turned off and then
+ * turns them off by setting their DPMS mode to OFF and deactivating the CRTC
+ * that they are connected to.
+ *
+ * This is used for example in suspend/resume to disable all currently active
+ * functions when suspending.
+ *
+ * Note that if callers haven't already acquired all modeset locks this might
+ * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ *
+ * See also:
+ * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
+ */
+int drm_atomic_helper_disable_all(struct drm_device *dev,
+                                 struct drm_modeset_acquire_ctx *ctx)
+{
+       struct drm_atomic_state *state;
+       struct drm_connector *conn;
+       int err;
+
+       state = drm_atomic_state_alloc(dev);
+       if (!state)
+               return -ENOMEM;
+
+       state->acquire_ctx = ctx;
+
+       drm_for_each_connector(conn, dev) {
+               struct drm_crtc *crtc = conn->state->crtc;
+               struct drm_crtc_state *crtc_state;
+
+               if (!crtc || conn->dpms != DRM_MODE_DPMS_ON)
+                       continue;
+
+               crtc_state = drm_atomic_get_crtc_state(state, crtc);
+               if (IS_ERR(crtc_state)) {
+                       err = PTR_ERR(crtc_state);
+                       goto free;
+               }
+
+               crtc_state->active = false;
+       }
+
+       err = drm_atomic_commit(state);
+
+free:
+       if (err < 0)
+               drm_atomic_state_free(state);
+
+       return err;
+}
+EXPORT_SYMBOL(drm_atomic_helper_disable_all);
+
+/**
+ * drm_atomic_helper_suspend - subsystem-level suspend helper
+ * @dev: DRM device
+ *
+ * Duplicates the current atomic state, disables all active outputs and then
+ * returns a pointer to the original atomic state to the caller. Drivers can
+ * pass this pointer to the drm_atomic_helper_resume() helper upon resume to
+ * restore the output configuration that was active at the time the system
+ * entered suspend.
+ *
+ * Note that it is potentially unsafe to use this. The atomic state object
+ * returned by this function is assumed to be persistent. Drivers must ensure
+ * that this holds true. Before calling this function, drivers must make sure
+ * to suspend fbdev emulation so that nothing can be using the device.
+ *
+ * Returns:
+ * A pointer to a copy of the state before suspend on success or an ERR_PTR()-
+ * encoded error code on failure. Drivers should store the returned atomic
+ * state object and pass it to the drm_atomic_helper_resume() helper upon
+ * resume.
+ *
+ * See also:
+ * drm_atomic_helper_duplicate_state(), drm_atomic_helper_disable_all(),
+ * drm_atomic_helper_resume()
+ */
+struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev)
+{
+       struct drm_modeset_acquire_ctx ctx;
+       struct drm_atomic_state *state;
+       int err;
+
+       drm_modeset_acquire_init(&ctx, 0);
+
+retry:
+       err = drm_modeset_lock_all_ctx(dev, &ctx);
+       if (err < 0) {
+               state = ERR_PTR(err);
+               goto unlock;
+       }
+
+       state = drm_atomic_helper_duplicate_state(dev, &ctx);
+       if (IS_ERR(state))
+               goto unlock;
+
+       err = drm_atomic_helper_disable_all(dev, &ctx);
+       if (err < 0) {
+               drm_atomic_state_free(state);
+               state = ERR_PTR(err);
+               goto unlock;
+       }
+
+unlock:
+       if (PTR_ERR(state) == -EDEADLK) {
+               drm_modeset_backoff(&ctx);
+               goto retry;
+       }
+
+       drm_modeset_drop_locks(&ctx);
+       drm_modeset_acquire_fini(&ctx);
+       return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_suspend);
+
+/**
+ * drm_atomic_helper_resume - subsystem-level resume helper
+ * @dev: DRM device
+ * @state: atomic state to resume to
+ *
+ * Calls drm_mode_config_reset() to synchronize hardware and software states,
+ * grabs all modeset locks and commits the atomic state object. This can be
+ * used in conjunction with the drm_atomic_helper_suspend() helper to
+ * implement suspend/resume for drivers that support atomic mode-setting.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ *
+ * See also:
+ * drm_atomic_helper_suspend()
+ */
+int drm_atomic_helper_resume(struct drm_device *dev,
+                            struct drm_atomic_state *state)
+{
+       struct drm_mode_config *config = &dev->mode_config;
+       int err;
+
+       drm_mode_config_reset(dev);
+       drm_modeset_lock_all(dev);
+       state->acquire_ctx = config->acquire_ctx;
+       err = drm_atomic_commit(state);
+       drm_modeset_unlock_all(dev);
+
+       return err;
+}
+EXPORT_SYMBOL(drm_atomic_helper_resume);
+
 /**
  * drm_atomic_helper_crtc_set_property - helper for crtc properties
  * @crtc: DRM crtc
@@ -2426,7 +2597,9 @@ EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);
  * @ctx: lock acquisition context
  *
  * Makes a copy of the current atomic state by looping over all objects and
- * duplicating their respective states.
+ * duplicating their respective states. This is used for example by suspend/
+ * resume support code to save the state prior to suspend such that it can
+ * be restored upon resume.
  *
  * Note that this treats atomic state as persistent between save and restore.
  * Drivers must make sure that this is possible and won't result in confusion
@@ -2438,6 +2611,9 @@ EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);
  * Returns:
  * A pointer to the copy of the atomic state object on success or an
  * ERR_PTR()-encoded error code on failure.
+ *
+ * See also:
+ * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
  */
 struct drm_atomic_state *
 drm_atomic_helper_duplicate_state(struct drm_device *dev,