diff options
Diffstat (limited to 'drivers/gpu/drm/drm_ioctl.c')
| -rw-r--r-- | drivers/gpu/drm/drm_ioctl.c | 54 |
1 files changed, 52 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index a7c61c23685a..865e3ee4d743 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -28,6 +28,7 @@ * OTHER DEALINGS IN THE SOFTWARE. */ +#include <drm/drm_ioctl.h> #include <drm/drmP.h> #include <drm/drm_auth.h> #include "drm_legacy.h" @@ -285,6 +286,9 @@ static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_ case DRM_CAP_ADDFB2_MODIFIERS: req->value = dev->mode_config.allow_fb_modifiers; break; + case DRM_CAP_CRTC_IN_VBLANK_EVENT: + req->value = 1; + break; default: return -EINVAL; } @@ -646,13 +650,59 @@ static const struct drm_ioctl_desc drm_ioctls[] = { #define DRM_CORE_IOCTL_COUNT ARRAY_SIZE( drm_ioctls ) /** + * DOC: driver specific ioctls + * + * First things first, driver private IOCTLs should only be needed for drivers + * supporting rendering. Kernel modesetting is all standardized, and extended + * through properties. There are a few exceptions in some existing drivers, + * which define IOCTL for use by the display DRM master, but they all predate + * properties. + * + * Now if you do have a render driver you always have to support it through + * driver private properties. There's a few steps needed to wire all the things + * up. + * + * First you need to define the structure for your IOCTL in your driver private + * UAPI header in ``include/uapi/drm/my_driver_drm.h``:: + * + * struct my_driver_operation { + * u32 some_thing; + * u32 another_thing; + * }; + * + * Please make sure that you follow all the best practices from + * ``Documentation/ioctl/botching-up-ioctls.txt``. Note that drm_ioctl() + * automatically zero-extends structures, hence make sure you can add more stuff + * at the end, i.e. don't put a variable sized array there. + * + * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(), + * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix:: + * + * ##define DRM_IOCTL_MY_DRIVER_OPERATION \ + * DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation) + * + * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to + * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire + * up the handlers and set the access rights: + * + * static const struct drm_ioctl_desc my_driver_ioctls[] = { + * DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation, + * DRM_AUTH|DRM_RENDER_ALLOW), + * }; + * + * And then assign this to the &drm_driver.ioctls field in your driver + * structure. + */ + +/** * drm_ioctl - ioctl callback implementation for DRM drivers * @filp: file this ioctl is called on * @cmd: ioctl cmd number * @arg: user argument * - * Looks up the ioctl function in the ::ioctls table, checking for root - * previleges if so required, and dispatches to the respective function. + * Looks up the ioctl function in the DRM core and the driver dispatch table, + * stored in &drm_driver.ioctls. It checks for necessary permission by calling + * drm_ioctl_permit(), and dispatches to the respective function. * * Returns: * Zero on success, negative error code on failure. |