kernel/Documentation/devicetree/bindings/clock/xlnx,zynqmp-clk.txt

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2024-07-22 17:22:30 +08:00
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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.
-------
Example
-------
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";
};
};
};