drm/vkms: Add vblank events simulated by hrtimers

This commit adds regular vblank events simulated through hrtimers, which
is a feature required by VKMS to mimic real hardware. Additionally, all
the vblank event send after pageflip is kept in the atomic_flush
function.

Changes since V1:
 - Compute the vblank timer interval per interruption
 Ville Syrjälä and Daniel Vetter:
 - Removes hardcoded vblank interval to get it from user space

Changes since V2:
 Chris Wilson
 - Removes unnecessary algorithm to compute the next period
 Daniel Vetter:
 - Uses drm_calc_timestamping_constants to get the vblank interval
   instead of calculating it manually
 - Adds disable_vblank helper that turns of crtc
 - Simplifies implementation by using drm_crtc_arm_vblank_event
 - Replaces the code in atomic_begin to atomic_flush
 - Removes unnecessary field in vkms_output

Changes since V3:
 Daniel Vetter:
 - Squash "drm/vkms: Add atomic helpers functions" into the commit that
   handling vblank events simulated by hrtimers

Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/7709bba40782ec06332d57fff337797b272581fc.1531359228.git.rodrigosiqueiramelo@gmail.com

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
index 823693235545..a1448fb56893 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.c
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -54,6 +54,7 @@ static struct drm_driver vkms_driver = {
 	.dumb_map_offset	= vkms_dumb_map,
 	.gem_vm_ops		= &vkms_gem_vm_ops,
 	.gem_free_object_unlocked = vkms_gem_free_object,
+	.get_vblank_timestamp	= vkms_get_vblank_timestamp,
 
 	.name			= DRIVER_NAME,
 	.desc			= DRIVER_DESC,
@@ -100,6 +101,14 @@ static int __init vkms_init(void)
 		goto out_fini;
 	}
 
+	vkms_device->drm.irq_enabled = true;
+
+	ret = drm_vblank_init(&vkms_device->drm, 1);
+	if (ret) {
+		DRM_ERROR("Failed to vblank\n");
+		goto out_fini;
+	}
+
 	ret = vkms_modeset_init(vkms_device);
 	if (ret)
 		goto out_unregister;