Cal. Const. art. XI, § 5

(a) It shall be competent in any city charter to provide that the city governed thereunder may make and enforce all ordinances and regulations in respect to municipal affairs, subject only to restrictions and limitations provided in their several charters and in respect to other matters they shall be subject to general laws. City charters adopted pursuant to this Constitution shall supersede any existing charter, and with respect to municipal affairs shall supersede all laws inconsistent therewith.

(b) It shall be competent in all city charters to provide, in addition to those provisions allowable by this Constitution, and by the laws of the State for: (1) the constitution, regulation, and government of the city police force (2) subgovernment in all or part of a city (3) conduct of city elections and (4) plenary authority is hereby granted, subject only to the restrictions of this article, to provide therein or by amendment thereto, the manner in which, the method by which, the times at which, and the terms for which the several municipal officers and employees whose compensation is paid by the city shall be elected or appointed, and for their removal, and for their compensation, and for the number of deputies, clerks and other employees that each shall have, and for the compensation, method of appointment, qualifications, tenure of office and removal of such deputies, clerks and other employees.