drm/vkms: Add kerneldoc entry

Add an initial kerneldoc entry for vkms with a todo list.
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
[danvet: Keep the todo.rst entry to point at the vkms docs instead.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907174136.GA2648@haneenDRM

Documentation/gpu/drivers.rst

@@ -13,6 +13,7 @@ GPU Driver Documentation
    tve200
    v3d
    vc4
+   vkms
    bridge/dw-hdmi
    xen-front
 

Documentation/gpu/todo.rst

@@ -360,6 +360,13 @@ converting things over. For modeset tests we also first need a bit of
 infrastructure to use dumb buffers for untiled buffers, to be able to run all
 the non-i915 specific modeset tests.
 
+Extend virtual test driver (VKMS)
+---------------------------------
+
+See the documentation of :ref:`VKMS <vkms>` for more details. This is an ideal
+internship task, since it only requires a virtual machine and can be sized to
+fit the available time.
+
 Contact: Daniel Vetter
 
 Driver Specific

Documentation/gpu/vkms.rst

+.. _vkms:
+
+==========================================
+ drm/vkms Virtual Kernel Modesetting
+==========================================
+
+.. kernel-doc:: drivers/gpu/drm/vkms/vkms_drv.c
+   :doc: vkms (Virtual Kernel Modesetting)
+
+TODO
+====
+
+CRC API
+-------
+
+- Optimize CRC computation ``compute_crc()`` and plane blending ``blend()``
+
+- Use the alpha value to blend vaddr_src with vaddr_dst instead of
+  overwriting it in ``blend()``.
+
+- Add igt test to check cleared alpha value for XRGB plane format.
+
+- Add igt test to check extreme alpha values i.e. fully opaque and fully
+  transparent (intermediate values are affected by hw-specific rounding modes).

drivers/gpu/drm/vkms/vkms_drv.c

@@ -5,6 +5,15 @@
  * (at your option) any later version.
  */
 
+/**
+ * DOC: vkms (Virtual Kernel Modesetting)
+ *
+ * vkms is a software-only model of a kms driver that is useful for testing,
+ * or for running X (or similar) on headless machines and be able to still
+ * use the GPU. vkms aims to enable a virtual display without the need for
+ * a hardware display capability.
+ */
+
 #include <linux/module.h>
 #include <drm/drm_gem.h>
 #include <drm/drm_crtc_helper.h>