diff options
Diffstat (limited to 'include/drm/drm_device.h')
| -rw-r--r-- | include/drm/drm_device.h | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h index 6ea54a578cda..e2f894f1b90a 100644 --- a/include/drm/drm_device.h +++ b/include/drm/drm_device.h @@ -65,6 +65,28 @@ struct drm_device { struct device *dev; /** + * @dma_dev: + * + * Device for DMA operations. Only required if the device @dev + * cannot perform DMA by itself. Should be NULL otherwise. Call + * drm_dev_dma_dev() to get the DMA device instead of using this + * field directly. Call drm_dev_set_dma_dev() to set this field. + * + * DRM devices are sometimes bound to virtual devices that cannot + * perform DMA by themselves. Drivers should set this field to the + * respective DMA controller. + * + * Devices on USB and other peripheral busses also cannot perform + * DMA by themselves. The @dma_dev field should point the bus + * controller that does DMA on behalve of such a device. Required + * for importing buffers via dma-buf. + * + * If set, the DRM core automatically releases the reference on the + * device. + */ + struct device *dma_dev; + + /** * @managed: * * Managed resources linked to the lifetime of this &drm_device as @@ -327,4 +349,23 @@ struct drm_device { struct dentry *debugfs_root; }; +void drm_dev_set_dma_dev(struct drm_device *dev, struct device *dma_dev); + +/** + * drm_dev_dma_dev - returns the DMA device for a DRM device + * @dev: DRM device + * + * Returns the DMA device of the given DRM device. By default, this + * the DRM device's parent. See drm_dev_set_dma_dev(). + * + * Returns: + * A DMA-capable device for the DRM device. + */ +static inline struct device *drm_dev_dma_dev(struct drm_device *dev) +{ + if (dev->dma_dev) + return dev->dma_dev; + return dev->dev; +} + #endif |