Re: [PATCH 1/2] dt-bindings: soc: mediatek: Add document for mmdvfs driver

From: Chun-Kuang Hu
Date: Wed Apr 15 2020 - 12:31:04 EST

Hi, Anthony:

Anthony Huang <anthony.huang@xxxxxxxxxxxx> æ 2020å4æ15æ éä äå7:19åéï
>
> This document describes the properties what mtk mmdvfs
> device node support.
>
> Signed-off-by: Anthony Huang <anthony.huang@xxxxxxxxxxxx>
> ---
> .../devicetree/bindings/soc/mediatek/mmdvfs.yaml | 198 ++++++++++++++++++++
> 1 file changed, 198 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/soc/mediatek/mmdvfs.yaml
>
> diff --git a/Documentation/devicetree/bindings/soc/mediatek/mmdvfs.yaml b/Documentation/devicetree/bindings/soc/mediatek/mmdvfs.yaml
> new file mode 100644
> index 0000000..9ef1833
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/mediatek/mmdvfs.yaml
> @@ -0,0 +1,198 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/soc/mediatek/mmdvfs.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Mediatek MMDVFS driver binding
> +
> +maintainers:
> + - Rob Herring <robh+dt@xxxxxxxxxx>
> + - Mark Rutland <mark.rutland@xxxxxxx>
> +
> +description: |
> + The Mediatek MMDVFS(Multimedia Dynamic Voltage and Frequency Scaling) driver
> + is used to set clk for Mediatek multimedia hardwares, such as display,
> + camera, mdp and video codec. MMDVFS driver reads which clock muxes and clock
> + sources are used on this platform from DTS, and sets current clock according
> + to current voltage informed by regulator callback.
> +
> +properties:
> + compatible:
> + items:
> + - const: mediatek,mmdvfs
> +
> + operating-points-v2:
> + description:
> + Contains any one of opp tables for multimedia modules.
> + MMDVFS uses it to get voltage setting on this platform.
> +
> + mediatek,support_mux:
> + description: A list of clock mux names defined in clock-names.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/string-array
> +
> + clocks:
> + description:
> + A list of phandles of clock muxes and clock sources for
> + multimedia hardwares.
> +
> + clock-names:
> + description:
> + A list of name strings of clock muxes and clock sources for
> + multimedia hardwares.
> +
> + # If the platform needs frequency hopping for some clock sources, these
> + # following properties should be set.
> +
> + mediatek,support_hopping:
> + description: a list of clock names supporting frequency hopping.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/string-array
> +
> + mediatek,action:
> + description:
> + A cell with one entry.
> + It represents the action taken when setting clocks.
> + 0 means not setting frequency hopping and just set clock mux.
> + 1 means setting frequency hopping first if the voltage is increasing, but
> + setting clock mux first if the voltage is decreasing.
> + allOf:
> + - $ref: "/schemas/types.yaml#/definitions/uint32"
> + - enum: [0, 1]
> + maxItems: 1
> +
> +patternProperties:
> + "^mediatek,mux_+$":
> + description:
> + A series of properties with "mediatek,mux_" prefix.
> + Each property represents one clock mux, and its value is a list of all
> + the clock sources for it. The postfix and every item in the property
> + must be from the clock-names.
> +
> + "^mediatek,hopping_+$":
> + description:
> + A cell with the same size as opp numbers of an opp table for any MM module
> + and each entry represents the clock rate for each opp. For example, the
> + first entry is the clock rate set in opp-0, and the second entry is the
> + clock rate set in opp-1.
> +
> +required:
> + - compatible
> + - operating-points-v2
> + - mediatek,support_mux
> + - clock
> + - clock-names
> +
> +examples:
> + - |
> + #include <dt-bindings/clock/mt6779-clk.h>
> +
> + opp_table_mm: opp-table-mm {
> + compatible = "operating-points-v2";
> +
> + opp-0 {
> + opp-hz = /bits/ 64 <315000000>;
> + opp-microvolt = <650000>;
> + };
> + opp-1 {
> + opp-hz = /bits/ 64 <450000000>;
> + opp-microvolt = <725000>;
> + };
> + opp-2 {
> + opp-hz = /bits/ 64 <606000000>;
> + opp-microvolt = <825000>;
> + };
> + };
> +
> + opp_table_cam: opp-table-cam {
> + compatible = "operating-points-v2";
> +
> + opp-0 {
> + opp-hz = /bits/ 64 <315000000>;
> + opp-microvolt = <650000>;
> + };
> + opp-1 {
> + opp-hz = /bits/ 64 <416000000>;
> + opp-microvolt = <725000>;
> + };
> + opp-2 {
> + opp-hz = /bits/ 64 <560000000>;
> + opp-microvolt = <825000>;
> + };
> + };
> +
> + /* Other opp tables for multimedia modules */
> +
> + mmdvfs {
> + compatible = "mediatek,mmdvfs";
> +
> + operating-points-v2 = <&opp_table_mm>;
> +
> + mediatek,support_mux = "mm", "cam", "img", "ipe",
> + "venc", "vdec", "dpe", "ccu";
> +
> + mediatek,mux_mm = "clk_mmpll_d5_d2",
> + "clk_mmpll_d7", "clk_tvdpll_mainpll_d2_ck";
> + mediatek,mux_cam = "clk_mmpll_d5_d2",
> + "clk_univpll_d3", "clk_adsppll_d5";
> + mediatek,mux_img = "clk_mmpll_d5_d2",
> + "clk_univpll_d3", "clk_tvdpll_mainpll_d2_ck";
> + mediatek,mux_ipe = "clk_mmpll_d5_d2",
> + "clk_univpll_d3", "clk_mainpll_d2";
> + mediatek,mux_venc = "clk_mainpll_d3",
> + "clk_mmpll_d7", "clk_mmpll_d5";
> + mediatek,mux_vdec = "clk_univpll_d2_d2",
> + "clk_univpll_d3", "clk_univpll_d2";
> + mediatek,mux_dpe = "clk_mainpll_d3",
> + "clk_mmpll_d7", "clk_mainpll_d2";
> + mediatek,mux_ccu = "clk_mmpll_d5_d2",
> + "clk_univpll_d3", "clk_adsppll_d5";
> +
> + mediatek,support_hopping = "clk_mmpll_ck";
> + mediatek,hopping_clk_mmpll_ck = <630000000 630000000 650000000>;
> + mediatek,action = <1>;
> +
> +
> + clocks = <&topckgen CLK_TOP_MM>,
> + <&topckgen CLK_TOP_CAM>,
> + <&topckgen CLK_TOP_IMG>,
> + <&topckgen CLK_TOP_IPE>,
> + <&topckgen CLK_TOP_VENC>,
> + <&topckgen CLK_TOP_VDEC>,
> + <&topckgen CLK_TOP_DPE>,
> + <&topckgen CLK_TOP_CCU>,
> + <&topckgen CLK_TOP_MMPLL_D5>,
> + <&topckgen CLK_TOP_UNIVPLL_D2>,
> + <&topckgen CLK_TOP_TVDPLL_MAINPLL_D2_CK>,
> + <&topckgen CLK_TOP_ADSPPLL_D5>,
> + <&topckgen CLK_TOP_MAINPLL_D2>,
> + <&topckgen CLK_TOP_MMPLL_D6>,
> + <&topckgen CLK_TOP_MMPLL_D7>,
> + <&topckgen CLK_TOP_UNIVPLL_D3>,
> + <&topckgen CLK_TOP_MAINPLL_D3>,
> + <&topckgen CLK_TOP_MMPLL_D5_D2>,
> + <&topckgen CLK_TOP_UNIVPLL_D2_D2>,
> + <&topckgen CLK_TOP_MMPLL_CK>;
> + clock-names = "mm",
> + "cam",
> + "img",
> + "ipe",
> + "venc",
> + "vdec",
> + "dpe",
> + "ccu",
> + "clk_mmpll_d5",
> + "clk_univpll_d2",
> + "clk_tvdpll_mainpll_d2_ck",
> + "clk_adsppll_d5",
> + "clk_mainpll_d2",
> + "clk_mmpll_d6",
> + "clk_mmpll_d7",
> + "clk_univpll_d3",
> + "clk_mainpll_d3",
> + "clk_mmpll_d5_d2",
> + "clk_univpll_d2_d2",
> + "clk_mmpll_ck";
> + };

We do not like a virtual device which does not map to a real hardware
because device tree is used to describe hardware. All mmdvfs driver do
is to controll the clock, so I think you should move the driver into
drivers/clk/mediatek, move opp_table into driver, and forget anything
in device tree.

Regards,
Chun-Kuang.

> +...
> --
> 1.7.9.5
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