Opengl quad tesselation, I need it to be more regular. I need it to be image on left, rather than that on right

Question

I am trying to tesselate a quad to have a regular grid pattern as shown in quad on the left of the image. But what I am getting from the opengl tesselation is irregular pattern as you can see on the quad on right of image. Is there a way that I can output regular grid from tesselation just as that of quad on left of image?