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  • [PATCH 01/12] mmc: dt-bindings: update Mediatek MMC bindings

    From Yingjoe Chen@21:1/5 to Chaotian Jing on Mon Oct 2 12:50:02 2017
    On Fri, 2017-09-29 at 09:56 +0800, Chaotian Jing wrote:
    On Wed, 2017-09-27 at 09:18 +0800, Chaotian Jing wrote:
    On Wed, 2017-09-27 at 00:33 +0200, Ulf Hansson wrote:
    On 14 September 2017 at 04:10, Chaotian Jing <chaotian.jing@mediatek.com> wrote:
    On Wed, 2017-09-13 at 09:10 -0500, Rob Herring wrote:
    On Tue, Sep 12, 2017 at 05:07:41PM +0800, Chaotian Jing wrote:
    Change the comptiable for support of multi-platform
    Add description for reg
    Add description for source_cg
    Add description for mediatek,latch-ck

    This is at least the 3rd patch with exactly the same vague subject.
    Please make the subject somewhat unique.

    Thx, will change the subject at next version

    Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
    ---
    Documentation/devicetree/bindings/mmc/mtk-sd.txt | 13 ++++++++++--- >> > 1 file changed, 10 insertions(+), 3 deletions(-)

    diff --git a/Documentation/devicetree/bindings/mmc/mtk-sd.txt b/Documentation/devicetree/bindings/mmc/mtk-sd.txt
    index 4182ea3..405cd06 100644
    --- a/Documentation/devicetree/bindings/mmc/mtk-sd.txt
    +++ b/Documentation/devicetree/bindings/mmc/mtk-sd.txt
    @@ -7,10 +7,15 @@ This file documents differences between the core properties in mmc.txt
    and the properties used by the msdc driver.

    Required properties:
    -- compatible: Should be "mediatek,mt8173-mmc","mediatek,mt8135-mmc" >> > +- compatible: value should be either of the following.
    + "mediatek,mt8135-mmc": for mmc host ip compatible with mt8135
    + "mediatek,mt8173-mmc": for mmc host ip compatible with mt8173
    + "mediatek,mt2701-mmc": for mmc host ip compatible with mt2701
    + "mediatek,mt2712-mmc": for mmc host ip compatible with mt2712
    +- reg: physical base address of the controller and length
    - interrupts: Should contain MSDC interrupt number
    -- clocks: MSDC source clock, HCLK
    -- clock-names: "source", "hclk"
    +- clocks: MSDC source clock, HCLK, source_cg
    +- clock-names: "source", "hclk", "source_cg"

    All chips support source_cg? That's not backwards compatible for
    existing compatible strings if the driver requires it.
    Not all chips support source_cg, for chips which do not support source_cg, no need source_cg here, and the driver will parse it
    to know if current chip support it.

    In such case you must not add add a required binding for it. I think
    that is what Rob is trying to point out for you.

    [...]

    Kind regards
    Uffe
    The source_cg is required(MUST) at MT2712 and future SoCs, but not required(do not have it) at previous SoCs, so that put it at required properties, let the driver to handle it.

    Any other comments about it ? still must not add a required binding for
    it ? if add a optional binding for it, how to add it ? as cannot
    duplicate "clocks" & "clock-names" in one node.


    Chaotian,

    You can follow examples of scpsys [1]:

    - clock, clock-names: clocks according to the common clock binding.
    These are clocks which hardware needs to be
    enabled before enabling certain power domains.
    Required clocks for MT2701: "mm", "mfg", "ethif"
    Required clocks for MT6797: "mm", "mfg", "vdec"
    Required clocks for MT8173: "mm", "mfg", "venc", "venc_lt"

    [1]: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/tree/Documentation/devicetree/bindings/soc/mediatek/scpsys.txt?h=v4.13.4

    Joe.C

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