xref: /kernel/linux/linux-5.10/Documentation/devicetree/bindings/clock/xlnx,zynqmp-clk.txt (revision 8c2ecf20)

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Device Tree Clock bindings for the Zynq Ultrascale+ MPSoC controlled using
Zynq MPSoC firmware interface
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The clock controller is a h/w block of Zynq Ultrascale+ MPSoC clock
tree. It reads required input clock frequencies from the devicetree and acts
as clock provider for all clock consumers of PS clocks.

See clock_bindings.txt for more information on the generic clock bindings.

Required properties:
 - #clock-cells:	Must be 1
 - compatible:		Must contain:	"xlnx,zynqmp-clk"
 - clocks:		List of clock specifiers which are external input
			clocks to the given clock controller. Please refer
			the next section to find the input clocks for a
			given controller.
 - clock-names:		List of clock names which are exteral input clocks
			to the given clock controller. Please refer to the
			clock bindings for more details.

Input clocks for zynqmp Ultrascale+ clock controller:

The Zynq UltraScale+ MPSoC has one primary and four alternative reference clock
inputs. These required clock inputs are:
 - pss_ref_clk (PS reference clock)
 - video_clk (reference clock for video system )
 - pss_alt_ref_clk (alternative PS reference clock)
 - aux_ref_clk
 - gt_crx_ref_clk (transceiver reference clock)

The following strings are optional parameters to the 'clock-names' property in
order to provide an optional (E)MIO clock source:
 - swdt0_ext_clk
 - swdt1_ext_clk
 - gem0_emio_clk
 - gem1_emio_clk
 - gem2_emio_clk
 - gem3_emio_clk
 - mio_clk_XX		# with XX = 00..77
 - mio_clk_50_or_51	#for the mux clock to gem tsu from 50 or 51


Output clocks are registered based on clock information received
from firmware. Output clocks indexes are mentioned in
include/dt-bindings/clock/xlnx-zynqmp-clk.h.

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Example
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firmware {
	zynqmp_firmware: zynqmp-firmware {
		compatible = "xlnx,zynqmp-firmware";
		method = "smc";
		zynqmp_clk: clock-controller {
			#clock-cells = <1>;
			compatible = "xlnx,zynqmp-clk";
			clocks = <&pss_ref_clk>, <&video_clk>, <&pss_alt_ref_clk>, <&aux_ref_clk>, <&gt_crx_ref_clk>;
			clock-names = "pss_ref_clk", "video_clk", "pss_alt_ref_clk","aux_ref_clk", "gt_crx_ref_clk";
		};
	};
};