dts/bindings/clock/st,stm32u5-pll-clock.yaml

# Copyright (c) 2021, Linaro Limited
# SPDX-License-Identifier: Apache-2.0

description: |
  PLL node binding for STM32U5 devices

  It can be used to describe 3 different PLLs: PLL1, PLL2 and PLL3.

  These PLLs could take one of clk_hse, clk_hsi or clk_msis as input clock, with
  an input frequency from 4 to 16 MHz. PLLM factor is used to set the input
  clock in this acceptable range.

  Each PLL can have up to 3 output clocks and for each output clock, the
  frequency can be computed with the following formulae:

    f(PLL_P) = f(VCO clock) / PLLP
    f(PLL_Q) = f(VCO clock) / PLLQ
    f(PLL_R) = f(VCO clock) / PLLR

      with f(VCO clock) = f(PLL clock input) × (PLLN / PLLM)

  Note: To reduce the power consumption, it is recommended to configure the VCOx
        clock output to the lowest frequency.

  The PLL output frequency must not exceed 160 MHz.

compatible: "st,stm32u5-pll-clock"

include: [clock-controller.yaml, base.yaml]

properties:

    "#clock-cells":
      const: 0

    clocks:
      required: true

    div-m:
      type: int
      required: true
      description: |
          Prescaler for PLLx
          input clock
          Valid range: 1 - 16

    mul-n:
      type: int
      required: true
      description: |
          PLLx multiplication factor for VCO
          Valid range: 4 - 512

    div-p:
      type: int
      required: false
      description: |
          PLLx DIVP division factor
          Valid range: 1 - 128

    div-q:
      type: int
      required: false
      description: |
          PLLx DIVQ division factor
          Valid range: 1 - 128

    div-r:
      type: int
      required: true
      description: |
          PLLx DIVR division factor
          On PLL1, only division by 1 and even division values are allowed.
          No restrictions for PLL2 and PLL3
          Valid range: 1 - 128