then:
               properties:
                 groups:
-                  enum: [pcie_clk, pcie_wake, pcie_pereset]
+                  items:
+                    enum: [pcie_clk, pcie_wake, pcie_pereset]
+                  maxItems: 3
           - if:
               properties:
                 function:
             then:
               properties:
                 groups:
-                  enum: [pwm0, pwm1_0, pwm1_1]
+                  items:
+                    enum: [pwm0, pwm1_0, pwm1_1]
+                  maxItems: 2
           - if:
               properties:
                 function:
             then:
               properties:
                 groups:
-                  enum: [spi0, spi0_wp_hold, spi1_0, spi1_1, spi1_2, spi1_3]
+                  items:
+                    enum: [spi0, spi0_wp_hold, spi1_0, spi1_1, spi1_2, spi1_3]
+                  maxItems: 2
           - if:
               properties:
                 function: