Files
rockchip-kernel/Documentation/devicetree/bindings/clock/rockchip,clk-out.yaml
Sugar Zhang b3cfac5e37 clk: rockchip: Add support for clk input / output switch
This patch add support switch for clk-bidirection which located
at GRF, such as SAIx_MCLK_{IN OUT} which share the same pin.
and these config maybe located in many pieces of GRF,
which hard to addressed in one single clk driver. so, we add
this simple helper driver to address this situation.

In order to simplify implement and usage, and also for safety
clk usage (avoid high freq glitch), we set all clk out as disabled
(which means Input default for clk-bidrection) in the pre-stage,
such boot-loader or init by HW default. And then set a safety freq
before enable clk-out, such as "assign-clock-rates" or clk_set_rate
in drivers.

e.g.

1. mclk{out,in}_sai0 define:

  mclkin_sai0: mclkin-sai0 {
      compatible = "fixed-clock";
      #clock-cells = <0>;
      clock-frequency = <12288000>;
      clock-output-names = "mclk_sai0_from_io";
  };

  mclkout_sai0: mclkout-sai0@ff040070 {
      compatible = "rockchip,clk-out";
      reg = <0 0xff040070 0 0x4>;
      clocks = <&cru MCLK_SAI0_OUT2IO>;
      #clock-cells = <0>;
      clock-output-names = "mclk_sai0_to_io";
      rockchip,bit-shift = <4>;
      //example with PD if reg access needed
      power-domains = <&power RK3562_PD_VO>;
  };

Note:

clock-output-names of mclkin_sai0 should equal to strings in drivers. such as:

drivers/clk/rockchip/clk-rk3562.c:
PNAME(clk_sai0_p) = { "clk_sai0_src", "clk_sai0_frac", "xin_osc0_half", "mclk_sai0_from_io" };

2. mclkout_sai0 usage:

  &ext_codec {
      clocks = <&mclkout_sai0>;
      clock-names = "mclk";
      assigned-clocks = <&mclkout_sai0>;
      assigned-clock-rates = <12288000>;
      pinctrl-names = "default";
      pinctrl-0 = <&i2s0m0_mclk>;
  };

  clk_summary on sai0 work:

  cat /sys/kernel/debug/clk/clk_summary | egrep "pll|sai0"

  clk_sai0_src                1        1        0  1188000000          0     0  50000
    clk_sai0_frac             1        1        0    12288000          0     0  50000
      clk_sai0                1        1        0    12288000          0     0  50000
        mclk_sai0             1        1        0    12288000          0     0  50000
          mclk_sai0_out2io    1        1        0    12288000          0     0  50000
            mclk_sai0_to_io   1        1        0    12288000          0     0  50000

  example with PD if reg access needed:

  * PD status when mclk_sai0_to_io on:

  cat /sys/kernel/debug/pm_genpd/pm_genpd_summary

  domain                          status          children
    /device                                                runtime status
  ----------------------------------------------------------------------
  ...

  vo                              on
    /devices/platform/clocks/ff040070.mclkout-sai0         active
  ...

  * PD status when mclk_sai0_to_io off:

  cat /sys/kernel/debug/pm_genpd/pm_genpd_summary

  domain                          status          children
    /device                                                runtime status
  ----------------------------------------------------------------------
  ...

  vo                              off-0
    /devices/platform/clocks/ff040070.mclkout-sai0         suspended
  ...

3. mclkin_sai0 usage:

  please override freq of mclkin as the real external clkin, such as:

  &mclkin_sai0 {
      clock-frequency = <24576000>;
  }

  &ext_codec {
      clocks = <&mclkin_sai0>;
      clock-names = "mclk";
      assigned-clocks = <&cru CLK_SAI0>;
      assigned-clock-parents = <&mclkin_sai0>;
      pinctrl-names = "default";
      pinctrl-0 = <&i2s0m0_mclk>;
  };

  clk_summary on sai0 work:

  cat /sys/kernel/debug/clk/clk_summary | egrep "pll|sai0"

  mclk_sai0_from_io          1        1        0    12288000          0     0  50000
    clk_sai0                 1        1        0    12288000          0     0  50000
      mclk_sai0              1        1        0    12288000          0     0  50000
        mclk_sai0_out2io     0        0        0    12288000          0     0  50000
          mclk_sai0_to_io    0        0        0    12288000          0     0  50000

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Change-Id: Ibe8286bb98ea1fc3bc6421c30f6e46fc0b1b0d88
2023-02-21 09:50:13 +08:00

108 lines
2.8 KiB
YAML

# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
%YAML 1.2
---
$id: http://devicetree.org/schemas/clock/rockchip,clk-out.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Rockchip Clock Out Control Module Binding
maintainers:
- Sugar Zhang <sugar.zhang@rock-chips.com>
description: |
This add support switch for clk-bidirection which located
at GRF, such as SAIx_MCLK_{IN OUT} which share the same pin.
and these config maybe located in many pieces of GRF,
which hard to addressed in one single clk driver. so, we add
this simple helper driver to address this situation.
In order to simplify implement and usage, and also for safety
clk usage (avoid high freq glitch), we set all clk out as disabled
(which means Input default for clk-bidrection) in the pre-stage,
such boot-loader or init by HW default. And then set a safety freq
before enable clk-out, such as "assign-clock-rates" or clk_set_rate
in drivers.
properties:
compatible:
enum:
- rockchip,clk-out
reg:
maxItems: 1
"#clock-cells":
const: 1
clocks:
maxItems: 1
description: parent clocks.
power-domains:
maxItems: 1
clock-output-names:
maxItems: 1
rockchip,bit-shift:
$ref: /schemas/types.yaml#/definitions/uint32
description: Defines the bit shift of clk out enable.
rockchip,bit-set-to-disable:
type: boolean
description: |
By default this clock sets the bit at bit-shift to enable the clock.
Setting this property does the opposite: setting the bit disable
the clock and clearing it enables the clock.
required:
- compatible
- reg
- clocks
- "#clock-cells"
- clock-output-names
- rockchip,bit-shift
additionalProperties: false
examples:
# Clock Provider node:
- |
mclkin_sai0: mclkin-sai0 {
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <12288000>;
clock-output-names = "mclk_sai0_from_io";
};
mclkout_sai0: mclkout-sai0@ff040070 {
compatible = "rockchip,clk-out";
reg = <0 0xff040070 0 0x4>;
clocks = <&cru MCLK_SAI0_OUT2IO>;
#clock-cells = <0>;
clock-output-names = "mclk_sai0_to_io";
rockchip,bit-shift = <4>;
};
# Clock mclkout Consumer node:
- |
ext_codec {
clocks = <&mclkout_sai0>;
clock-names = "mclk";
assigned-clocks = <&mclkout_sai0>;
assigned-clock-rates = <12288000>;
pinctrl-names = "default";
pinctrl-0 = <&i2s0m0_mclk>;
};
# Clock mclkin Consumer node:
- |
ext_codec {
clocks = <&mclkin_sai0>;
clock-names = "mclk";
assigned-clocks = <&cru CLK_SAI0>;
assigned-clock-parents = <&mclkin_sai0>;
pinctrl-names = "default";
pinctrl-0 = <&i2s0m0_mclk>;
};