[v2,01/11] dt-bindings: i2c: nomadik: add mobileye,eyeq5-i2c bindings and example

Add EyeQ5 bindings to the existing Nomadik I2C dt-bindings. Add the
EyeQ5-specific property behind a conditional. Add an example for this
compatible.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
 .../devicetree/bindings/i2c/st,nomadik-i2c.yaml    | 48 ++++++++++++++++++++--
 1 file changed, 44 insertions(+), 4 deletions(-)

On Thu, 29 Feb 2024 19:10:49 +0100, Théo Lebrun wrote:
> Add EyeQ5 bindings to the existing Nomadik I2C dt-bindings. Add the
> EyeQ5-specific property behind a conditional. Add an example for this
> compatible.
> 
> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
> ---
>  .../devicetree/bindings/i2c/st,nomadik-i2c.yaml    | 48 ++++++++++++++++++++--
>  1 file changed, 44 insertions(+), 4 deletions(-)
> 

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/i2c/st,nomadik-i2c.example.dtb: i2c@300000: 'mobileye,olb' does not match any of the regexes: '^#.*', '^(at25|bm|devbus|dmacap|dsa|exynos|fsi[ab]|gpio-fan|gpio-key|gpio|gpmc|hdmi|i2c-gpio),.*', '^(keypad|m25p|max8952|max8997|max8998|mpmc),.*', '^(pinctrl-single|#pinctrl-single|PowerPC),.*', '^(pl022|pxa-mmc|rcar_sound|rotary-encoder|s5m8767|sdhci),.*', '^(simple-audio-card|st-plgpio|st-spics|ts),.*', '^100ask,.*', '^70mai,.*', '^8dev,.*', '^GEFanuc,.*', '^ORCL,.*', '^SUNW,.*', '^[a-zA-Z0-9#_][a-zA-Z0-9+\\-._@]{0,63}$', '^[a-zA-Z0-9+\\-._]*@[0-9a-zA-Z,]*$', '^abb,.*', '^abilis,.*', '^abracon,.*', '^abt,.*', '^acbel,.*', '^acer,.*', '^acme,.*', '^actions,.*', '^active-semi,.*', '^ad,.*', '^adafruit,.*', '^adapteva,.*', '^adaptrum,.*', '^adh,.*', '^adi,.*', '^adieng,.*', '^advantech,.*', '^aeroflexgaisler,.*', '^aesop,.*', '^airoha,.*', '^al,.*', '^alcatel,.*', '^aldec,.*', '^alfa-network,.*', '^allegro,.*', '^allie
 dvision,.*', '^allo,.*', '^allwinner,.*', '^alphascale,.*', '^alps,.*', '^alt,.*', '^altr,.*', '^amarula,.*', '^amazon,.*', '^amcc,.*', '^amd,.*', '^amediatech,.*', '^amlogic,.*', '^ampere,.*', '^ampire,.*', '^ams,.*', '^amstaos,.*', '^analogix,.*', '^anbernic,.*', '^andestech,.*', '^anvo,.*', '^aosong,.*', '^apm,.*', '^apple,.*', '^aptina,.*', '^arasan,.*', '^archermind,.*', '^arcom,.*', '^arctic,.*', '^arcx,.*', '^aries,.*', '^arm,.*', '^armadeus,.*', '^arrow,.*', '^artesyn,.*', '^asahi-kasei,.*', '^asc,.*', '^asix,.*', '^aspeed,.*', '^asrock,.*', '^asus,.*', '^atheros,.*', '^atlas,.*', '^atmel,.*', '^auo,.*', '^auvidea,.*', '^avago,.*', '^avia,.*', '^avic,.*', '^avnet,.*', '^awinic,.*', '^axentia,.*', '^axis,.*', '^azoteq,.*', '^azw,.*', '^baikal,.*', '^bananapi,.*', '^beacon,.*', '^beagle,.*', '^belling,.*', '^bhf,.*', '^bigtreetech,.*', '^bitmain,.*', '^blutek,.*', '^boe,.*', '^bosch,.*', '^boundary,.*', '^brcm,.*', '^broadmobi,.*', '^bsh,.*', '^bticino,.*', '^buffalo,.*', '^bu
 r,.*', '^bytedance,.*', '^calamp,.*', '^calaosystems,.*', '^calxeda,.*', '^canaan,.*', '^caninos,.*', '^capella,.*', '^cascoda,.*', '^catalyst,.*', '^cavium,.*', '^cdns,.*', '^cdtech,.*', '^cellwise,.*', '^ceva,.*', '^chargebyte,.*', '^checkpoint,.*', '^chefree,.*', '^chipidea,.*', '^chipone,.*', '^chipspark,.*', '^chongzhou,.*', '^chrontel,.*', '^chrp,.*', '^chunghwa,.*', '^chuwi,.*', '^ciaa,.*', '^cirrus,.*', '^cisco,.*', '^clockwork,.*', '^cloos,.*', '^cloudengines,.*', '^cnm,.*', '^cnxt,.*', '^colorfly,.*', '^compulab,.*', '^congatec,.*', '^coolpi,.*', '^coreriver,.*', '^corpro,.*', '^cortina,.*', '^cosmic,.*', '^crane,.*', '^creative,.*', '^crystalfontz,.*', '^csky,.*', '^csq,.*', '^ctera,.*', '^ctu,.*', '^cubietech,.*', '^cui,.*', '^cypress,.*', '^cyx,.*', '^cznic,.*', '^dallas,.*', '^dataimage,.*', '^davicom,.*', '^dell,.*', '^delta,.*', '^densitron,.*', '^denx,.*', '^devantech,.*', '^dfi,.*', '^dh,.*', '^difrnce,.*', '^digi,.*', '^digilent,.*', '^dimonoff,.*', '^diodes,.*', 
 '^dioo,.*', '^dlc,.*', '^dlg,.*', '^dlink,.*', '^dmo,.*', '^domintech,.*', '^dongwoon,.*', '^dptechnics,.*', '^dragino,.*', '^ds,.*', '^dserve,.*', '^dynaimage,.*', '^ea,.*', '^ebang,.*', '^ebbg,.*', '^ebs-systart,.*', '^ebv,.*', '^eckelmann,.*', '^edgeble,.*', '^edimax,.*', '^edt,.*', '^ees,.*', '^eeti,.*', '^einfochips,.*', '^eink,.*', '^elan,.*', '^element14,.*', '^elgin,.*', '^elida,.*', '^elimo,.*', '^elpida,.*', '^embedfire,.*', '^embest,.*', '^emlid,.*', '^emmicro,.*', '^empire-electronix,.*', '^emtrion,.*', '^enclustra,.*', '^endless,.*', '^ene,.*', '^energymicro,.*', '^engicam,.*', '^engleder,.*', '^epcos,.*', '^epfl,.*', '^epson,.*', '^esp,.*', '^est,.*', '^ettus,.*', '^eukrea,.*', '^everest,.*', '^everspin,.*', '^evervision,.*', '^exar,.*', '^excito,.*', '^exegin,.*', '^ezchip,.*', '^facebook,.*', '^fairphone,.*', '^faraday,.*', '^fascontek,.*', '^fastrax,.*', '^fcs,.*', '^feixin,.*', '^feiyang,.*', '^fii,.*', '^firefly,.*', '^focaltech,.*', '^forlinx,.*', '^freecom,.*', 
 '^frida,.*', '^friendlyarm,.*', '^fsl,.*', '^fujitsu,.*', '^fxtec,.*', '^galaxycore,.*', '^gardena,.*', '^gateway,.*', '^gateworks,.*', '^gcw,.*', '^ge,.*', '^geekbuying,.*', '^gef,.*', '^gemei,.*', '^gemtek,.*', '^genesys,.*', '^geniatech,.*', '^giantec,.*', '^giantplus,.*', '^globalscale,.*', '^globaltop,.*', '^gmt,.*', '^goldelico,.*', '^goodix,.*', '^google,.*', '^goramo,.*', '^gplus,.*', '^grinn,.*', '^grmn,.*', '^gumstix,.*', '^gw,.*', '^hannstar,.*', '^haochuangyi,.*', '^haoyu,.*', '^hardkernel,.*', '^hechuang,.*', '^hideep,.*', '^himax,.*', '^hirschmann,.*', '^hisi,.*', '^hisilicon,.*', '^hit,.*', '^hitex,.*', '^holt,.*', '^holtek,.*', '^honestar,.*', '^honeywell,.*', '^hoperun,.*', '^hp,.*', '^hpe,.*', '^hsg,.*', '^htc,.*', '^huawei,.*', '^hugsun,.*', '^hwacom,.*', '^hxt,.*', '^hycon,.*', '^hydis,.*', '^hynitron,.*', '^hynix,.*', '^hyundai,.*', '^i2se,.*', '^ibm,.*', '^icplus,.*', '^idt,.*', '^ifi,.*', '^ilitek,.*', '^imagis,.*', '^img,.*', '^imi,.*', '^inanbo,.*', '^incirc
 uit,.*', '^indiedroid,.*', '^inet-tek,.*', '^infineon,.*', '^inforce,.*', '^ingenic,.*', '^ingrasys,.*', '^injoinic,.*', '^innocomm,.*', '^innolux,.*', '^inside-secure,.*', '^insignal,.*', '^inspur,.*', '^intel,.*', '^intercontrol,.*', '^invensense,.*', '^inventec,.*', '^inversepath,.*', '^iom,.*', '^irondevice,.*', '^isee,.*', '^isil,.*', '^issi,.*', '^ite,.*', '^itead,.*', '^itian,.*', '^ivo,.*', '^iwave,.*', '^jadard,.*', '^jasonic,.*', '^jdi,.*', '^jedec,.*', '^jesurun,.*', '^jethome,.*', '^jianda,.*', '^joz,.*', '^kam,.*', '^karo,.*', '^keithkoep,.*', '^keymile,.*', '^khadas,.*', '^kiebackpeter,.*', '^kinetic,.*', '^kingdisplay,.*', '^kingnovel,.*', '^kionix,.*', '^kobo,.*', '^kobol,.*', '^koe,.*', '^kontron,.*', '^kosagi,.*', '^kvg,.*', '^kyo,.*', '^lacie,.*', '^laird,.*', '^lamobo,.*', '^lantiq,.*', '^lattice,.*', '^lctech,.*', '^leadtek,.*', '^leez,.*', '^lego,.*', '^lemaker,.*', '^lenovo,.*', '^lg,.*', '^lgphilips,.*', '^libretech,.*', '^licheepi,.*', '^linaro,.*', '^linear
 technology,.*', '^linksprite,.*', '^linksys,.*', '^linutronix,.*', '^linux,.*', '^linx,.*', '^liteon,.*', '^litex,.*', '^lltc,.*', '^logicpd,.*', '^logictechno,.*', '^longcheer,.*', '^lontium,.*', '^loongmasses,.*', '^loongson,.*', '^lsi,.*', '^lunzn,.*', '^lwn,.*', '^lxa,.*', '^m5stack,.*', '^macnica,.*', '^mantix,.*', '^mapleboard,.*', '^marantec,.*', '^marvell,.*', '^maxbotix,.*', '^maxim,.*', '^maxlinear,.*', '^mbvl,.*', '^mcube,.*', '^meas,.*', '^mecer,.*', '^mediatek,.*', '^megachips,.*', '^mele,.*', '^melexis,.*', '^melfas,.*', '^mellanox,.*', '^memsensing,.*', '^memsic,.*', '^menlo,.*', '^mentor,.*', '^meraki,.*', '^merrii,.*', '^methode,.*', '^micrel,.*', '^microchip,.*', '^microcrystal,.*', '^micron,.*', '^microsoft,.*', '^microsys,.*', '^mikroe,.*', '^mikrotik,.*', '^milkv,.*', '^miniand,.*', '^minix,.*', '^miramems,.*', '^mitsubishi,.*', '^mitsumi,.*', '^mixel,.*', '^miyoo,.*', '^mntre,.*', '^modtronix,.*', '^moortec,.*', '^mosaixtech,.*', '^motorcomm,.*', '^motorola,.*'
 , '^moxa,.*', '^mpl,.*', '^mps,.*', '^mqmaker,.*', '^mrvl,.*', '^mscc,.*', '^msi,.*', '^mstar,.*', '^mti,.*', '^multi-inno,.*', '^mundoreader,.*', '^murata,.*', '^mxic,.*', '^mxicy,.*', '^myir,.*', '^national,.*', '^nec,.*', '^neonode,.*', '^netgear,.*', '^netlogic,.*', '^netron-dy,.*', '^netronix,.*', '^netxeon,.*', '^neweast,.*', '^newhaven,.*', '^newvision,.*', '^nexbox,.*', '^nextthing,.*', '^ni,.*', '^nintendo,.*', '^nlt,.*', '^nokia,.*', '^nordic,.*', '^novatek,.*', '^novtech,.*', '^nutsboard,.*', '^nuvoton,.*', '^nvd,.*', '^nvidia,.*', '^nxp,.*', '^oceanic,.*', '^ocs,.*', '^oct,.*', '^okaya,.*', '^oki,.*', '^olimex,.*', '^olpc,.*', '^oneplus,.*', '^onie,.*', '^onion,.*', '^onnn,.*', '^ontat,.*', '^opalkelly,.*', '^openailab,.*', '^opencores,.*', '^openembed,.*', '^openpandora,.*', '^openrisc,.*', '^option,.*', '^oranth,.*', '^orisetech,.*', '^ortustech,.*', '^osddisplays,.*', '^osmc,.*', '^ouya,.*', '^overkiz,.*', '^ovti,.*', '^oxsemi,.*', '^ozzmaker,.*', '^panasonic,.*', '^p
 arade,.*', '^parallax,.*', '^pda,.*', '^pericom,.*', '^pervasive,.*', '^phicomm,.*', '^phytec,.*', '^picochip,.*', '^pine64,.*', '^pineriver,.*', '^pixcir,.*', '^plantower,.*', '^plathome,.*', '^plda,.*', '^plx,.*', '^ply,.*', '^pni,.*', '^pocketbook,.*', '^polaroid,.*', '^polyhex,.*', '^portwell,.*', '^poslab,.*', '^pov,.*', '^powertip,.*', '^powervr,.*', '^powkiddy,.*', '^primux,.*', '^probox2,.*', '^prt,.*', '^pulsedlight,.*', '^purism,.*', '^qca,.*', '^qcom,.*', '^qemu,.*', '^qi,.*', '^qiaodian,.*', '^qihua,.*', '^qishenglong,.*', '^qnap,.*', '^quanta,.*', '^radxa,.*', '^raidsonic,.*', '^ralink,.*', '^ramtron,.*', '^raspberrypi,.*', '^raydium,.*', '^rda,.*', '^realtek,.*', '^remarkable,.*', '^renesas,.*', '^rervision,.*', '^revotics,.*', '^rex,.*', '^richtek,.*', '^ricoh,.*', '^rikomagic,.*', '^riot,.*', '^riscv,.*', '^rockchip,.*', '^rocktech,.*', '^rohm,.*', '^ronbo,.*', '^roofull,.*', '^roseapplepi,.*', '^rve,.*', '^saef,.*', '^samsung,.*', '^samtec,.*', '^sancloud,.*', '^san
 disk,.*', '^satoz,.*', '^sbs,.*', '^schindler,.*', '^seagate,.*', '^seeed,.*', '^seirobotics,.*', '^semtech,.*', '^senseair,.*', '^sensirion,.*', '^sensortek,.*', '^sercomm,.*', '^sff,.*', '^sgd,.*', '^sgmicro,.*', '^sgx,.*', '^sharp,.*', '^shift,.*', '^shimafuji,.*', '^shineworld,.*', '^shiratech,.*', '^si-en,.*', '^si-linux,.*', '^siemens,.*', '^sifive,.*', '^sigma,.*', '^sii,.*', '^sil,.*', '^silabs,.*', '^silan,.*', '^silead,.*', '^silergy,.*', '^silex-insight,.*', '^siliconfile,.*', '^siliconmitus,.*', '^silvaco,.*', '^simtek,.*', '^sinlinx,.*', '^sinovoip,.*', '^sinowealth,.*', '^sipeed,.*', '^sirf,.*', '^sis,.*', '^sitronix,.*', '^skov,.*', '^skyworks,.*', '^smartlabs,.*', '^smi,.*', '^smsc,.*', '^snps,.*', '^sochip,.*', '^socionext,.*', '^solidrun,.*', '^solomon,.*', '^sony,.*', '^sophgo,.*', '^sourceparts,.*', '^spansion,.*', '^sparkfun,.*', '^spinalhdl,.*', '^sprd,.*', '^square,.*', '^ssi,.*', '^sst,.*', '^sstar,.*', '^st,.*', '^st-ericsson,.*', '^starfive,.*', '^starry,.*
 ', '^startek,.*', '^starterkit,.*', '^ste,.*', '^stericsson,.*', '^storlink,.*', '^storm,.*', '^storopack,.*', '^summit,.*', '^sunchip,.*', '^sundance,.*', '^sunplus,.*', '^supermicro,.*', '^swir,.*', '^syna,.*', '^synology,.*', '^synopsys,.*', '^tbs,.*', '^tbs-biometrics,.*', '^tcg,.*', '^tcl,.*', '^tcs,.*', '^tdo,.*', '^team-source-display,.*', '^technexion,.*', '^technologic,.*', '^techstar,.*', '^techwell,.*', '^teejet,.*', '^teltonika,.*', '^tempo,.*', '^terasic,.*', '^tesla,.*', '^tfc,.*', '^thead,.*', '^thine,.*', '^thingyjp,.*', '^thundercomm,.*', '^thwc,.*', '^ti,.*', '^tianma,.*', '^tlm,.*', '^tmt,.*', '^topeet,.*', '^topic,.*', '^toppoly,.*', '^topwise,.*', '^toradex,.*', '^toshiba,.*', '^toumaz,.*', '^tpk,.*', '^tplink,.*', '^tpo,.*', '^tq,.*', '^transpeed,.*', '^traverse,.*', '^tronfy,.*', '^tronsmart,.*', '^truly,.*', '^tsd,.*', '^turing,.*', '^tyan,.*', '^u-blox,.*', '^u-boot,.*', '^ubnt,.*', '^ucrobotics,.*', '^udoo,.*', '^ufispace,.*', '^ugoos,.*', '^uniwest,.*', '^
 upisemi,.*', '^urt,.*', '^usi,.*', '^usr,.*', '^utoo,.*', '^v3,.*', '^vaisala,.*', '^vamrs,.*', '^variscite,.*', '^vdl,.*', '^vertexcom,.*', '^via,.*', '^vialab,.*', '^vicor,.*', '^videostrong,.*', '^virtio,.*', '^virtual,.*', '^vishay,.*', '^visionox,.*', '^vitesse,.*', '^vivante,.*', '^vivax,.*', '^vocore,.*', '^voipac,.*', '^vot,.*', '^vxt,.*', '^wanchanglong,.*', '^wand,.*', '^waveshare,.*', '^wd,.*', '^we,.*', '^welltech,.*', '^wetek,.*', '^wexler,.*', '^whwave,.*', '^wi2wi,.*', '^widora,.*', '^wiligear,.*', '^willsemi,.*', '^winbond,.*', '^wingtech,.*', '^winlink,.*', '^winstar,.*', '^wirelesstag,.*', '^wits,.*', '^wlf,.*', '^wm,.*', '^wobo,.*', '^x-powers,.*', '^xen,.*', '^xes,.*', '^xiaomi,.*', '^xillybus,.*', '^xingbangda,.*', '^xinpeng,.*', '^xiphera,.*', '^xlnx,.*', '^xnano,.*', '^xunlong,.*', '^xylon,.*', '^yadro,.*', '^yamaha,.*', '^yes-optoelectronics,.*', '^yic,.*', '^yiming,.*', '^ylm,.*', '^yna,.*', '^yones-toptech,.*', '^ys,.*', '^ysoft,.*', '^zarlink,.*', '^zealz,
 .*', '^zeitec,.*', '^zidoo,.*', '^zii,.*', '^zinitix,.*', '^zkmagic,.*', '^zte,.*', '^zyxel,.*', 'pinctrl-[0-9]+'
	from schema $id: http://devicetree.org/schemas/vendor-prefixes.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20240229-mbly-i2c-v2-1-b32ed18c098c@bootlin.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

On Thu, Feb 29, 2024 at 07:10:49PM +0100, Théo Lebrun wrote:
> Add EyeQ5 bindings to the existing Nomadik I2C dt-bindings. Add the
> EyeQ5-specific property behind a conditional. Add an example for this
> compatible.
> 
> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
> ---
>  .../devicetree/bindings/i2c/st,nomadik-i2c.yaml    | 48 ++++++++++++++++++++--
>  1 file changed, 44 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/st,nomadik-i2c.yaml b/Documentation/devicetree/bindings/i2c/st,nomadik-i2c.yaml
> index 16024415a4a7..2d9d5b276762 100644
> --- a/Documentation/devicetree/bindings/i2c/st,nomadik-i2c.yaml
> +++ b/Documentation/devicetree/bindings/i2c/st,nomadik-i2c.yaml
> @@ -14,9 +14,6 @@ description: The Nomadik I2C host controller began its life in the ST
>  maintainers:
>    - Linus Walleij <linus.walleij@linaro.org>
>  
> -allOf:
> -  - $ref: /schemas/i2c/i2c-controller.yaml#
> -
>  # Need a custom select here or 'arm,primecell' will match on lots of nodes
>  select:
>    properties:
> @@ -24,6 +21,7 @@ select:
>        contains:
>          enum:
>            - st,nomadik-i2c
> +          - mobileye,eyeq5-i2c
>    required:
>      - compatible
>  
> @@ -39,6 +37,10 @@ properties:
>            - const: stericsson,db8500-i2c
>            - const: st,nomadik-i2c
>            - const: arm,primecell
> +      # The variant found on Mobileye EyeQ5

Kind of obvious from the compatible string, but maybe you are keeping 
the existing style...

> +      - items:
> +          - const: mobileye,eyeq5-i2c
> +          - const: arm,primecell
>  
>    reg:
>      maxItems: 1
> @@ -55,7 +57,7 @@ properties:
>        - items:
>            - const: mclk
>            - const: apb_pclk
> -      # Clock name in DB8500
> +      # Clock name in DB8500 or EyeQ5
>        - items:
>            - const: i2cclk
>            - const: apb_pclk
> @@ -70,6 +72,16 @@ properties:
>      minimum: 1
>      maximum: 400000
>  
> +  mobileye,olb:
> +    $ref: /schemas/types.yaml#/definitions/phandle-array
> +    items:
> +      - items:
> +          - description: Phandle to OLB system controller node.
> +          - description: Platform-wide controller ID (integer starting from zero).

Rather than a made up ID, just store the shift value you ultimately 
need.

These properties are fragile because they break if anything that's not 
defined in DT changes whether that's register offset, bit offset, 
bitfield size or values. Or also if there are additional fields to 
access. 

Rob

Hello,

On Fri Mar 1, 2024 at 4:11 PM CET, Rob Herring wrote:
> On Thu, Feb 29, 2024 at 07:10:49PM +0100, Théo Lebrun wrote:
> > Add EyeQ5 bindings to the existing Nomadik I2C dt-bindings. Add the
> > EyeQ5-specific property behind a conditional. Add an example for this
> > compatible.
> > 
> > Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
> > ---
> >  .../devicetree/bindings/i2c/st,nomadik-i2c.yaml    | 48 ++++++++++++++++++++--
> >  1 file changed, 44 insertions(+), 4 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/i2c/st,nomadik-i2c.yaml b/Documentation/devicetree/bindings/i2c/st,nomadik-i2c.yaml
> > index 16024415a4a7..2d9d5b276762 100644
> > --- a/Documentation/devicetree/bindings/i2c/st,nomadik-i2c.yaml
> > +++ b/Documentation/devicetree/bindings/i2c/st,nomadik-i2c.yaml
> > @@ -14,9 +14,6 @@ description: The Nomadik I2C host controller began its life in the ST
> >  maintainers:
> >    - Linus Walleij <linus.walleij@linaro.org>
> >  
> > -allOf:
> > -  - $ref: /schemas/i2c/i2c-controller.yaml#
> > -
> >  # Need a custom select here or 'arm,primecell' will match on lots of nodes
> >  select:
> >    properties:
> > @@ -24,6 +21,7 @@ select:
> >        contains:
> >          enum:
> >            - st,nomadik-i2c
> > +          - mobileye,eyeq5-i2c
> >    required:
> >      - compatible
> >  
> > @@ -39,6 +37,10 @@ properties:
> >            - const: stericsson,db8500-i2c
> >            - const: st,nomadik-i2c
> >            - const: arm,primecell
> > +      # The variant found on Mobileye EyeQ5
>
> Kind of obvious from the compatible string, but maybe you are keeping 
> the existing style...

I indeed kept the existing style.
Ping me if you want this removed!

> > +      - items:
> > +          - const: mobileye,eyeq5-i2c
> > +          - const: arm,primecell
> >  
> >    reg:
> >      maxItems: 1
> > @@ -55,7 +57,7 @@ properties:
> >        - items:
> >            - const: mclk
> >            - const: apb_pclk
> > -      # Clock name in DB8500
> > +      # Clock name in DB8500 or EyeQ5
> >        - items:
> >            - const: i2cclk
> >            - const: apb_pclk
> > @@ -70,6 +72,16 @@ properties:
> >      minimum: 1
> >      maximum: 400000
> >  
> > +  mobileye,olb:
> > +    $ref: /schemas/types.yaml#/definitions/phandle-array
> > +    items:
> > +      - items:
> > +          - description: Phandle to OLB system controller node.
> > +          - description: Platform-wide controller ID (integer starting from zero).
>
> Rather than a made up ID, just store the shift value you ultimately 
> need.

Issue with storing the shift value is that you also need to know what
value to put in that field. It's an enum mapping the I2C speed which
isn't found in DT.

> These properties are fragile because they break if anything that's not 
> defined in DT changes whether that's register offset, bit offset, 
> bitfield size or values. Or also if there are additional fields to 
> access.

My take is that it is better to have it all either in DT or in driver.
Having a mix of both is a mess when debugging. If something breaks it
is a driver bug; such bugs get fixed in driver code. That way DT
doesn't know about it and doesn't have to be changed.

Putting shifts in DT is an abstraction that ends up being unhelpful. You
split hardware knowledge half in DT (register offset and/or mask), half
in driver (value to put in the field). We'd rather have it all in
driver code.

Next hardware revision will be more complex with potentially fields
split across registers. A shift value wouldn't cut it. A new
compatible + made up ID allows accomodating for that. That way we have
homogeneity across compatibles.

Have a nice day,

--
Théo Lebrun, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com