Milwaukee-based Johnson Controls Inc. has purchased stock in the Donnelly Corp., another automotive systems manufacturer. Donnelly is a Michigan supplier of automotive rearview-mirror systems, modular window systems, and handle products. The 1.54 million shares purchased represent about 3.3% of the voting power of Donnelly, and 15.1% of its common shares outstanding. Johnson Controls, a $17.2 billion company, said it already has a positive relationship with Donnelly and that it has no other plans with respect to the company. In the automotive market, Johnson Controls is a major supplier of seating, interior systems, and batteries. For nonresidential facilities, Johnson Controls provides building control systems and services, energy management, and integrated facility management.