+/**
+ * drm_vblank_count - retrieve "cooked" vblank counter value
+ * @dev: DRM device
+ * @crtc: which counter to retrieve
+ *
+ * Fetches the "cooked" vblank count value that represents the number of
+ * vblank events since the system was booted, including lost events due to
+ * modesetting activity.
+ */
+u32 drm_vblank_count(struct drm_device *dev, int crtc)
+{
+ return atomic_read(&dev->_vblank_count[crtc]) +
+ dev->vblank_offset[crtc];
+}
+EXPORT_SYMBOL(drm_vblank_count);
+
+/**
+ * drm_update_vblank_count - update the master vblank counter
+ * @dev: DRM device
+ * @crtc: counter to update
+ *
+ * Call back into the driver to update the appropriate vblank counter
+ * (specified by @crtc). Deal with wraparound, if it occurred, and
+ * update the last read value so we can deal with wraparound on the next
+ * call if necessary.
+ */
+void drm_update_vblank_count(struct drm_device *dev, int crtc)
+{
+ unsigned long irqflags;
+ u32 cur_vblank, diff;
+
+ /*
+ * Interrupts were disabled prior to this call, so deal with counter
+ * wrap if needed.
+ * NOTE! It's possible we lost a full dev->max_vblank_count events
+ * here if the register is small or we had vblank interrupts off for
+ * a long time.
+ */
+ cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ if (cur_vblank < dev->last_vblank[crtc]) {
+ diff = dev->max_vblank_count -
+ dev->last_vblank[crtc];
+ diff += cur_vblank;
+ } else {
+ diff = cur_vblank - dev->last_vblank[crtc];
+ }
+ dev->last_vblank[crtc] = cur_vblank;
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+
+ atomic_add(diff, &dev->_vblank_count[crtc]);
+}
+EXPORT_SYMBOL(drm_update_vblank_count);
+
+/**
+ * drm_vblank_get - get a reference count on vblank events
+ * @dev: DRM device
+ * @crtc: which CRTC to own
+ *
+ * Acquire a reference count on vblank events to avoid having them disabled
+ * while in use. Note callers will probably want to update the master counter
+ * using drm_update_vblank_count() above before calling this routine so that
+ * wakeups occur on the right vblank event.
+ *
+ * RETURNS
+ * Zero on success, nonzero on failure.
+ */
+int drm_vblank_get(struct drm_device *dev, int crtc)
+{
+ unsigned long irqflags;
+ int ret = 0;
+
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ /* Going from 0->1 means we have to enable interrupts again */
+ if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1 &&
+ !dev->vblank_enabled[crtc]) {
+ ret = dev->driver->enable_vblank(dev, crtc);
+ if (ret)
+ atomic_dec(&dev->vblank_refcount[crtc]);
+ else
+ dev->vblank_enabled[crtc] = 1;
+ }
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_vblank_get);
+
+/**
+ * drm_vblank_put - give up ownership of vblank events
+ * @dev: DRM device
+ * @crtc: which counter to give up
+ *
+ * Release ownership of a given vblank counter, turning off interrupts
+ * if possible.
+ */
+void drm_vblank_put(struct drm_device *dev, int crtc)
+{
+ /* Last user schedules interrupt disable */
+ if (atomic_dec_and_test(&dev->vblank_refcount[crtc]))
+ mod_timer(&dev->vblank_disable_timer, jiffies + 5*DRM_HZ);
+}
+EXPORT_SYMBOL(drm_vblank_put);
+
+/**
+ * drm_modeset_ctl - handle vblank event counter changes across mode switch
+ * @DRM_IOCTL_ARGS: standard ioctl arguments
+ *
+ * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
+ * ioctls around modesetting so that any lost vblank events are accounted for.
+ */
+int drm_modeset_ctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct drm_modeset_ctl *modeset = data;
+ int crtc, ret = 0;
+ u32 new;
+
+ crtc = modeset->arg;
+ if (crtc >= dev->num_crtcs) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ switch (modeset->cmd) {
+ case _DRM_PRE_MODESET:
+ dev->vblank_premodeset[crtc] =
+ dev->driver->get_vblank_counter(dev, crtc);
+ break;
+ case _DRM_POST_MODESET:
+ new = dev->driver->get_vblank_counter(dev, crtc);
+ dev->vblank_offset[crtc] = dev->vblank_premodeset[crtc] - new;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+out:
+ return ret;
+}
+
projects / linux-2.6-omap-h63xx.git / commitdiff