From ddfb157444e3cdb6da18ea759730b4b4af65d3d9 Mon Sep 17 00:00:00 2001 From: Joachim Eastwood Date: Thu, 28 May 2015 22:31:46 +0200 Subject: [PATCH] doc: dt: add documentation for lpc1850-ccu clk driver Add DT binding documentation for lpc1850-ccu clk driver. Signed-off-by: Joachim Eastwood Signed-off-by: Michael Turquette --- .../devicetree/bindings/clock/lpc1850-ccu.txt | 77 +++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/lpc1850-ccu.txt diff --git a/Documentation/devicetree/bindings/clock/lpc1850-ccu.txt b/Documentation/devicetree/bindings/clock/lpc1850-ccu.txt new file mode 100644 index 000000000000..fa97c12014ac --- /dev/null +++ b/Documentation/devicetree/bindings/clock/lpc1850-ccu.txt @@ -0,0 +1,77 @@ +* NXP LPC1850 Clock Control Unit (CCU) + +Each CGU base clock has several clock branches which can be turned on +or off independently by the Clock Control Units CCU1 or CCU2. The +branch clocks are distributed between CCU1 and CCU2. + + - Above text taken from NXP LPC1850 User Manual. + +This binding uses the common clock binding: + Documentation/devicetree/bindings/clock/clock-bindings.txt + +Required properties: +- compatible: + Should be "nxp,lpc1850-ccu" +- reg: + Shall define the base and range of the address space + containing clock control registers +- #clock-cells: + Shall have value <1>. The permitted clock-specifier values + are the branch clock names defined in table below. +- clocks: + Shall contain a list of phandles for the base clocks routed + from the CGU to the specific CCU. See mapping of base clocks + and CCU in table below. +- clock-names: + Shall contain a list of names for the base clock routed + from the CGU to the specific CCU. Valid CCU clock names: + "base_usb0_clk", "base_periph_clk", "base_usb1_clk", + "base_cpu_clk", "base_spifi_clk", "base_spi_clk", + "base_apb1_clk", "base_apb3_clk", "base_adchs_clk", + "base_sdio_clk", "base_ssp0_clk", "base_ssp1_clk", + "base_uart0_clk", "base_uart1_clk", "base_uart2_clk", + "base_uart3_clk", "base_audio_clk" + +Which branch clocks that are available on the CCU depends on the +specific LPC part. Check the user manual for your specific part. + +A list of CCU clocks can be found in dt-bindings/clock/lpc18xx-ccu.h. + +Example board file: + +soc { + ccu1: clock-controller@40051000 { + compatible = "nxp,lpc1850-ccu"; + reg = <0x40051000 0x1000>; + #clock-cells = <1>; + clocks = <&cgu BASE_APB3_CLK>, <&cgu BASE_APB1_CLK>, + <&cgu BASE_SPIFI_CLK>, <&cgu BASE_CPU_CLK>, + <&cgu BASE_PERIPH_CLK>, <&cgu BASE_USB0_CLK>, + <&cgu BASE_USB1_CLK>, <&cgu BASE_SPI_CLK>; + clock-names = "base_apb3_clk", "base_apb1_clk", + "base_spifi_clk", "base_cpu_clk", + "base_periph_clk", "base_usb0_clk", + "base_usb1_clk", "base_spi_clk"; + }; + + ccu2: clock-controller@40052000 { + compatible = "nxp,lpc1850-ccu"; + reg = <0x40052000 0x1000>; + #clock-cells = <1>; + clocks = <&cgu BASE_AUDIO_CLK>, <&cgu BASE_UART3_CLK>, + <&cgu BASE_UART2_CLK>, <&cgu BASE_UART1_CLK>, + <&cgu BASE_UART0_CLK>, <&cgu BASE_SSP1_CLK>, + <&cgu BASE_SSP0_CLK>, <&cgu BASE_SDIO_CLK>; + clock-names = "base_audio_clk", "base_uart3_clk", + "base_uart2_clk", "base_uart1_clk", + "base_uart0_clk", "base_ssp1_clk", + "base_ssp0_clk", "base_sdio_clk"; + }; + + /* A user of CCU brach clocks */ + uart1: serial@40082000 { + ... + clocks = <&ccu2 CLK_APB0_UART1>, <&ccu1 CLK_CPU_UART1>; + ... + }; +}; -- 2.20.1