1c66ec88fSEmmanuel Vadot* NXP LPC1850 CREG clocks 2c66ec88fSEmmanuel Vadot 3c66ec88fSEmmanuel VadotThe NXP LPC18xx/43xx CREG (Configuration Registers) block contains 4c66ec88fSEmmanuel Vadotcontrol registers for two low speed clocks. One of the clocks is a 5c66ec88fSEmmanuel Vadot32 kHz oscillator driver with power up/down and clock gating. Next 6c66ec88fSEmmanuel Vadotis a fixed divider that creates a 1 kHz clock from the 32 kHz osc. 7c66ec88fSEmmanuel Vadot 8*aa1a8ff2SEmmanuel VadotThese clocks are used by the RTC and the Event Router peripherals. 9*aa1a8ff2SEmmanuel VadotThe 32 kHz can also be routed to other peripherals to enable low 10c66ec88fSEmmanuel Vadotpower modes. 11c66ec88fSEmmanuel Vadot 12c66ec88fSEmmanuel VadotThis binding uses the common clock binding: 13c66ec88fSEmmanuel Vadot Documentation/devicetree/bindings/clock/clock-bindings.txt 14c66ec88fSEmmanuel Vadot 15c66ec88fSEmmanuel VadotRequired properties: 16c66ec88fSEmmanuel Vadot- compatible: 17c66ec88fSEmmanuel Vadot Should be "nxp,lpc1850-creg-clk" 18c66ec88fSEmmanuel Vadot- #clock-cells: 19c66ec88fSEmmanuel Vadot Shall have value <1>. 20c66ec88fSEmmanuel Vadot- clocks: 21c66ec88fSEmmanuel Vadot Shall contain a phandle to the fixed 32 kHz crystal. 22c66ec88fSEmmanuel Vadot 23c66ec88fSEmmanuel VadotThe creg-clk node must be a child of the creg syscon node. 24c66ec88fSEmmanuel Vadot 25c66ec88fSEmmanuel VadotThe following clocks are available from the clock node. 26c66ec88fSEmmanuel Vadot 27c66ec88fSEmmanuel VadotClock ID Name 28c66ec88fSEmmanuel Vadot 0 1 kHz clock 29c66ec88fSEmmanuel Vadot 1 32 kHz Oscillator 30c66ec88fSEmmanuel Vadot 31c66ec88fSEmmanuel VadotExample: 32c66ec88fSEmmanuel Vadotsoc { 33c66ec88fSEmmanuel Vadot creg: syscon@40043000 { 34c66ec88fSEmmanuel Vadot compatible = "nxp,lpc1850-creg", "syscon", "simple-mfd"; 35c66ec88fSEmmanuel Vadot reg = <0x40043000 0x1000>; 36c66ec88fSEmmanuel Vadot 37c66ec88fSEmmanuel Vadot creg_clk: clock-controller { 38c66ec88fSEmmanuel Vadot compatible = "nxp,lpc1850-creg-clk"; 39c66ec88fSEmmanuel Vadot clocks = <&xtal32>; 40c66ec88fSEmmanuel Vadot #clock-cells = <1>; 41c66ec88fSEmmanuel Vadot }; 42c66ec88fSEmmanuel Vadot 43c66ec88fSEmmanuel Vadot ... 44c66ec88fSEmmanuel Vadot }; 45c66ec88fSEmmanuel Vadot 46c66ec88fSEmmanuel Vadot rtc: rtc@40046000 { 47c66ec88fSEmmanuel Vadot ... 48c66ec88fSEmmanuel Vadot clocks = <&creg_clk 0>, <&ccu1 CLK_CPU_BUS>; 49c66ec88fSEmmanuel Vadot clock-names = "rtc", "reg"; 50c66ec88fSEmmanuel Vadot ... 51c66ec88fSEmmanuel Vadot }; 52c66ec88fSEmmanuel Vadot}; 53