dts/bindings/clock/nuvoton,npcm-pcc.yaml

# Copyright (c) 2024 Nuvoton Technology Corporation.
# SPDX-License-Identifier: Apache-2.0

description: |
  Nuvoton, NPCM PCC (Power and Clock Controller) node.
  Besides power management, this node is also in charge of configuring the
  Oscillator Frequency Multiplier Clock (OFMCLK), which is derived from
  High-Frequency Clock Generator (HFCG), is the source clock of Cortex-M4 core
  and most of NPCM hardware modules.

  Here is an example of configuring OFMCLK and the other clock sources derived
  from it in board dts file.
  &pcc {
      clock-frequency = <DT_FREQ_M(96)>; /* OFMCLK runs at 96MHz */
      core-prescaler = <1>; /* CORE_CLK runs at 96MHz */
      apb1-prescaler = <8>; /* APB1_CLK runs at 12MHz */
      apb2-prescaler = <1>; /* APB2_CLK runs at 96MHz */
      apb3-prescaler = <1>; /* APB3_CLK runs at 96MHz */
      apb6-prescaler = <1>; /* APB6_CLK runs at 96MHz */
      fiu-prescaler = <1>; /* FIU_CLK runs at 96MHz */
      i3c-prescaler = <1>; /* I3C_CLK runs at 96MHz */
  };

compatible: "nuvoton,npcm-pcc"

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

properties:
  reg:
    required: true

  clock-frequency:
    required: true
    type: int
    description: |
      Default frequency in Hz for HFCG output clock (OFMCLK). Currently,
      only the following values are allowed:
        100000000, 100 MHz
        96000000, 96 MHz
        80000000, 80 MHz
        66000000, 66 MHz
        50000000, 50 MHz
        48000000, 48 MHz
        40000000, 40 MHz
        33000000, 33 MHz
    enum:
      - 100000000
      - 96000000
      - 80000000
      - 66000000
      - 50000000
      - 48000000
      - 40000000
      - 33000000

  core-prescaler:
    type: int
    required: true
    description: |
      Core clock prescaler (FPRED). It sets the Core frequency, CORE_CLK, by
      dividing OFMCLK(MCLK) and needs to meet the following requirements.
      - The maximum CLK frequency is either the MCLK frequency divided by 1 or 100 MHz.
      - Only the following values are allowed:
        1, CORE_CLK = OFMCLK
        2, CORE_CLK = OFMCLK / 2
        3, CORE_CLK = OFMCLK / 3
        4, CORE_CLK = OFMCLK / 4
        5, CORE_CLK = OFMCLK / 5
        6, CORE_CLK = OFMCLK / 6
        7, CORE_CLK = OFMCLK / 7
        8, CORE_CLK = OFMCLK / 8
        9, CORE_CLK = OFMCLK / 9
        10, CORE_CLK = OFMCLK / 10
    enum:
      - 1
      - 2
      - 3
      - 4
      - 5
      - 6
      - 7
      - 8
      - 9
      - 10

  apb1-prescaler:
    type: int
    required: true
    description: |
      APB1 prescaler. It sets the APB1 bus frequency, APB1_CLK, by dividing
      OFMCLK(MCLK) and needs to meet the following requirements.
      - The maximum APB1_CLK frequency is either the MCLK frequency divided by 1 or 100 MHz.
      - Only the following values are allowed:
        1, APB1_CLK = OFMCLK
        2, APB1_CLK = OFMCLK / 2
        3, APB1_CLK = OFMCLK / 3
        4, APB1_CLK = OFMCLK / 4
        5, APB1_CLK = OFMCLK / 5
        6, APB1_CLK = OFMCLK / 6
        7, APB1_CLK = OFMCLK / 7
        8, APB1_CLK = OFMCLK / 8
        9, APB1_CLK = OFMCLK / 9
        10, APB1_CLK = OFMCLK / 10
    enum:
      - 1
      - 2
      - 3
      - 4
      - 5
      - 6
      - 7
      - 8
      - 9
      - 10

  apb2-prescaler:
    type: int
    required: true
    description: |
      APB2 prescaler. It sets the APB2 bus frequency, APB2_CLK, by dividing
      OFMCLK(MCLK) and needs to meet the following requirements.
      - The maximum APB2_CLK frequency is either the MCLK frequency divided by 1 or 100 MHz.
      - Only the following values are allowed:
        1, APB2_CLK = OFMCLK
        2, APB2_CLK = OFMCLK / 2
        3, APB2_CLK = OFMCLK / 3
        4, APB2_CLK = OFMCLK / 4
        5, APB2_CLK = OFMCLK / 5
        6, APB2_CLK = OFMCLK / 6
        7, APB2_CLK = OFMCLK / 7
        8, APB2_CLK = OFMCLK / 8
        9, APB2_CLK = OFMCLK / 9
        10, APB2_CLK = OFMCLK / 10
    enum:
      - 1
      - 2
      - 3
      - 4
      - 5
      - 6
      - 7
      - 8
      - 9
      - 10

  apb3-prescaler:
    type: int
    required: true
    description: |
      APB3 prescaler. It sets the APB3 bus frequency, APB3_CLK, by dividing
      OFMCLK(MCLK) and needs to meet the following requirements.
      - The maximum APB3_CLK frequency is either the MCLK frequency divided by 1 or 100 MHz.
      - Only the following values are allowed:
        1, APB3_CLK = OFMCLK
        2, APB3_CLK = OFMCLK / 2
        3, APB3_CLK = OFMCLK / 3
        4, APB3_CLK = OFMCLK / 4
        5, APB3_CLK = OFMCLK / 5
        6, APB3_CLK = OFMCLK / 6
        7, APB3_CLK = OFMCLK / 7
        8, APB3_CLK = OFMCLK / 8
        9, APB3_CLK = OFMCLK / 9
        10, APB3_CLK = OFMCLK / 10
    enum:
      - 1
      - 2
      - 3
      - 4
      - 5
      - 6
      - 7
      - 8
      - 9
      - 10

  ahb6-prescaler:
    type: int
    required: true
    description: |
      AHB6 prescaler. The AHB6 bus clock (AHB6_CLK) is derived from the Core clock (CLK) via a
      programmable divider controlled by the AHB6DIV field in HFCGP register.
      Its frequency must be set according to the following rules:
      - The maximum AHB6_CLK frequency is either the CLK frequency divided by 1 or 100 MHz.
      - Only the following values are allowed:
        1, AHB6_CLK = CORE_CLK
        2, AHB6_CLK = CORE_CLK / 2
        4, AHB6_CLK = CORE_CLK / 4
    enum:
      - 1
      - 2
      - 4

  fiu-prescaler:
    type: int
    required: true
    description: |
      FIU prescaler. The FIU clock (FIUCLK) is derived from the Core clock (CLK) via a
      programmable divider controlled by the FIUDIV field in HFCBCD1 register.
      Its frequency must be set according to the following rules:
      - The maximum FIUCLK frequency is either the CLK frequency divided by 1 or 100MHz.
      - Only the following values are allowed:
        1, FIU_CLK = CORE_CLK
        2, FIU_CLK = CORE_CLK / 2
        4, FIU_CLK = CORE_CLK / 4
    enum:
      - 1
      - 2
      - 4

  i3c-prescaler:
    type: int
    required: true
    description: |
      I3C prescaler. It sets the I3C clk_slow_tc frequency, by dividing
      APB3_CLK and it can be up to 100 MHz.
    enum:
      - 1
      - 2
      - 4

clock-cells:
  - clk_id