What's the difference between of clk_get and of_clk_get? (linux) - linux-device-driver

Question

I ask it here to check if my guess is correct.
This page says
Currently we have devm_clk_get() which gives a managed-resource clk
(by name), or of_clk_get() which gives an unmanaged resource clk (by
id).
So I guess clk_get is selecting the clock using 'clock-names' (which is input to a clock consumer device) in the device tree, and of_clk_get is for selecting the clock using 'clock id' (which is the first number in the index-name pair of the clock input specifier.
And I see these lines in a driver drivers/tty/serial/bcm63xx_uart.c (linux 5.15.68).
clk = clk_get(&pdev->dev, "refclk"); // first try
if (IS_ERR(clk) && pdev->dev.of_node)
clk = of_clk_get(pdev->dev.of_node, 0); // second try
It looks like it first try to get the input clock from the name "refclk" and if it fails, it trys to get the clock from the clock speicifer, 0 meaning the first input clock. Is my understanding correct? Are both tries using device tree information?
I see in arch/arm64/boot/dts/broadcom/bcm4908/bcm4908.dtsi,
clocks {
periph_clk: periph_clk {
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <50000000>;
clock-output-names = "periph";
};
};
uart0: serial#640 {
compatible = "brcm,bcm6345-uart";
reg = <0x640 0x18>;
interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&periph_clk>;
clock-names = "refclk";
status = "okay";
};