It may come as a surprise, but until very recently requesting a reasonable accommodation for a disability or religious belief was not "protected activity" that would give rise to a retaliation claim under the California Fair Employment and Housing Act ("FEHA"). The California Second District Court of Appeal had ruled in Rope v. Auto-Chlor System of Washington, Inc., (2013) 220 Cal.App.4th 635 that requests for accommodation were not "protected activity" because such requests did not "oppose" an unlawful practice as defined in Cal. Gov. Code section 12940(h). This decision conflicted with longstanding federal religious and disability discrimination laws that protect an employee's right to request an accommodation.
Fortunately for California employees, on July 16, 2015 Governor Brown signed AB 987, bringing the FEHA into conformity with well established federal law. AB 987 amends Cal Gov. Code section 12940(l) & (m) and clarifies that employers may not retaliate or otherwise discriminate against employees who make reasonable accommodation requests for their disability or religion.
AB 987 can be found here.