This adds mandatory device tree binding documentation for the clock related IP found on Marvell Berlin2 (BG2, BG2CD, and BG2Q) SoCs. Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx> --- Cc: Mike Turquette <mturquette@xxxxxxxxxx> Cc: Rob Herring <robh+dt@xxxxxxxxxx> Cc: Pawel Moll <pawel.moll@xxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Ian Campbell <ijc+devicetree@xxxxxxxxxxxxxx> Cc: Kumar Gala <galak@xxxxxxxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx> Cc: Antoine Tenart <antoine.tenart@xxxxxxxxxxxxxxxxxx> Cc: devicetree@xxxxxxxxxxxxxxx Cc: linux-doc@xxxxxxxxxxxxxxx Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx --- .../devicetree/bindings/clock/berlin2-clock.txt | 169 +++++++++++++++++++++ 1 file changed, 169 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/berlin2-clock.txt diff --git a/Documentation/devicetree/bindings/clock/berlin2-clock.txt b/Documentation/devicetree/bindings/clock/berlin2-clock.txt new file mode 100644 index 000000000000..3da87a488402 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/berlin2-clock.txt @@ -0,0 +1,169 @@ +* Marvell Berlin2 clock bindings + +Marvell Berlin2 (BG2, BG2CD, BG2Q) share the same IP for PLLs and clocks, +with some minor differences in features and register layout. The below +describes the individual clock related IP: + +* Audio/Video PLL + +The Audio/Video PLL (AVPLL) is a dual-VCO PLL with 8 channels each. Each +of the VCOs can sythesize a single VCO frequency based on a single input +reference clock. Each of the 8 channels then, can derive an output clock +from that VCO frequency by various dividers/multipliers. + +Required properties: +- compatible: shall be "marvell,berlin2-avpll" +- reg: address and length of the corresponding AVPLL registers +- #clock-cells: shall be set to 2 +- clocks: single clock specifier referencing the AVPLL input clock + +To ease match-up with the desired AVPLL output clock, clock specifiers +referencing AVPLL clocks shall contain two cells. The first refers to +the VCO (0=AVPLL_A, 1=AVPLL_B) while the second refers to the corresponding +channel starting with 1. For example, to reference AVPLL_B3 the clock +specifier shall be: <&avpll 1 3>. + +Example: + +avpll: pll@ea0040 { + compatible = "marvell,berlin2-avpll"; + #clock-cells = <2>; + reg = <0xea0050 0x100>; + clocks = <&refclk>; +}; + +* Simple PLLs + +Simple PLLs are memory mapped PLLs that can sythesize a single output clock +based on a single input reference clock. + +Required properties: +- compatible: shall be one of the following: + "marvell,berlin2-pll" for Berlin BG2/BG2CD PLLs + "marvell,berlin2q-pll" for Berlin BG2Q PLLs +- reg: address and length of the corresponding PLL registers +- #clock-cells: shall be set to 0 +- clocks: single clock specifier referencing the PLL input clock + +Example: + +cpupll: pll@ea003c { + compatible = "marvell,berlin2-pll"; + #clock-cells = <0>; + reg = <0xea003c 0x14>; + clocks = <&refclk>; +}; + +* Single-register clock dividers + +Single-register clock dividers are complex divider cells, allowing +to divide a reference clock with a set of fixed dividers. Also they +comprise and input clock mux with bypass and an ouput clock gate. + +Required properties: +- compatible: shall be "marvell,berlin2-clk-div" +- reg: address and length of the corresponding DIV registers +- #clock-cells: shall be set to 0 +- clocks: clock specifiers referencing the DIV input clocks +- clock-names: array of strings describing the clock specifiers above. + Allowed clock-names are "mux_bypass" for the clock mux bypass selection + and "muxN" (N=0..7) for each of the 8 possible clock mux inputs. + +Example: + +gfx3dcore_clk: clock@ea022c { + compatible = "marvell,berlin2-clk-div"; + #clock-cells = <0>; + reg = <0xea0022c 0x4>; + clocks = <&syspll>, + <&avpll AVPLL_B 4>, <&avpll AVPLL_B 5>, + <&avpll AVPLL_B 6>, <&avpll AVPLL_B 7>; + clock-names = "mux_bypass", + "mux0", "mux1", "mux2", "mux3"; +}; + +* SoC-specific core clocks + +In addition to the above, there is a register set dealing with SoC +specific clock dividers, muxes, and gates. There is also the complex +divider cell used above, but instead of independent registers, they +share a common set of registers. The core clocks are represented by +a single DT node providing access to the remaining clocks. + +Required properties: +- compatible: shall be one of + "marvell,berlin2-core-clocks" for BG2/BG2CD SoCs + "marvell,berlin2q-core-clocks" for BG2Q SoCs +- reg: address and length of the corresponding clock registers +- #clock-cells: shall be set to 1 +- clocks: clock specifiers referencing the core clock input clocks +- clock-names: array of strings describing the clock specifiers above. + Allowed clock-names for the reference clocks are + "refclk", "syspll", "mempll", "cpupll" + also Audio/Video PLL clocks shall be named with + "avpll_VN" (V=0...1 for AVPLL_A and AVPLL_B, N=1..8 for the + corresponding reference input from AVPLL). + +Optional properties for BG2/BG2CD SoCs: +- clocks/clock-names: in addition to the allowed clock names above, + there is an external video clock input that shall be named "video_ext0". + +Clocks provided by core clocks shall be referenced by a clock specifier +indexing one of the provided clocks. A SoC-specific list of available clocks +is below the example. + +Example: +coreclk: clock@ea0150 { + compatible = "marvell,berlin2-core-clocks"; + #clock-cells = <1>; + reg = <0xea0150 0x1c>; + clocks = <&refclk>, <&syspll>, <&mempll>, <&cpupll>, + <&avpll 0 1>, <&avpll 0 2>, + <&avpll 0 3>, <&avpll 0 4>, + <&avpll 0 5>, <&avpll 0 6>, + <&avpll 0 7>, <&avpll 0 8>, + <&avpll 1 1>, <&avpll 1 2>, + <&avpll 1 3>, <&avpll 1 4>, + <&avpll 1 5>, <&avpll 1 6>, + <&avpll 1 7>, <&avpll 1 8>, + <&externalvideoclk>; + clock-names = "refclk", "syspll", "mempll", "cpupll", + "avpll_a1", "avpll_a2", "avpll_a3", "avpll_a4", + "avpll_a5", "avpll_a6", "avpll_a7", "avpll_a8", + "avpll_b1", "avpll_b2", "avpll_b3", "avpll_b4", + "avpll_b5", "avpll_b6", "avpll_b7", "avpll_b8", + "video_ext0"; +}; + +* BG2/BG2CD core clock indicies: +0 - SYS +1 - CPU +2 - DRMFIGO +3 - CFG +4 - GFX +5 - ZSP +6 - PERIF +7 - PCUBE +8 - VSCOPE +9 - NFC_ECC +10 - VPP +11 - APP +12 - AUDIO0 +23 - AUDIO2 +14 - AUDIO3 +15 - AUDIO1 +16 - GETH0 +17 - GETH1 +18 - SATA +19 - AHBAPB +20 - USB0 +21 - USB1 +22 - PBRIDGE +23 - SDIO0 +24 - SDIO1 +25 - NFC +26 - SMEMC +27 - AUDIOHD +28 - VIDEO0 +29 - VIDEO1 +30 - VIDEO2 -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html