linux-kernel - Re: [PATCH 3/3] arm64: dts: qcom: sm7225-fp4: Revert "arm64: dts: qcom: sm7225-fairphone-fp4: Add AW8695 haptics"

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <CV3ZCVK29BLY.D7Y8AEEOYLO3@otso>
Date:   Mon, 28 Aug 2023 08:56:25 +0200
From:   "Luca Weiss" <luca.weiss@...rphone.com>
To:     "Krzysztof Kozlowski" <krzysztof.kozlowski@...aro.org>,
        "Andy Gross" <agross@...nel.org>,
        "Bjorn Andersson" <andersson@...nel.org>,
        "Konrad Dybcio" <konrad.dybcio@...aro.org>,
        "Rob Herring" <robh+dt@...nel.org>,
        "Krzysztof Kozlowski" <krzysztof.kozlowski+dt@...aro.org>,
        "Conor Dooley" <conor+dt@...nel.org>,
        <linux-arm-msm@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 3/3] arm64: dts: qcom: sm7225-fp4: Revert "arm64: dts:
 qcom: sm7225-fairphone-fp4: Add AW8695 haptics"

Hi Krzysztof,

On Sun Aug 27, 2023 at 2:28 PM CEST, Krzysztof Kozlowski wrote:
> This reverts commit 413821b7777d062b57f8dc66ab088ed390cbc3ec because it
> was never reviewed, was buggy (report from kernel test robot:
> https://lore.kernel.org/all/202204090333.QZXMI2tu-lkp@intel.com/) and

(I wouldn't say this part is accurate, the robot just didn't use a tree
with the i2c10 node already present, it was sent in an earlier patch
IIRC, but whatever)

> used undocumented, broken bindings.  Half of the properties in this
> device are questioned, thus adding DTS node causes only errors and does
> not make the device usable without the bindings and driver part:
>
>   sm7225-fairphone-fp4.dtb: haptics@5a: failed to match any schema with compatible: ['awinic,aw8695']
>   sm7225-fairphone-fp4.dtb: haptics@5a: awinic,tset: b'\x12' is not of type 'object', 'array', 'boolean', 'null'
>   sm7225-fairphone-fp4.dtb: haptics@5a: awinic,r-spare: b'h' is not of type 'object', 'array', 'boolean', 'null'
>
> Since bindings were abandoned (4 months since review), revert the commit
> to avoid false sense of supporting something which is not supported.

I've been avoiding touching this topic again since I'm really not sure
how to resolve.

There's a bunch of magic registers being written to in the downstream
driver, I don't have any documentation for that so I'm not exactly sure
what I can do to make nice bindings with proper properties.

Would you recommend just hardcoding some of these properties in the
driver, assuming they're constant for every AW8695, even though the
downstream driver has these properties in devicetree? Because of that I
assumed these properties could differ per implementation / usage of the
AW8695 in different devices.

Or do you have any other suggestion?

In any case:

Acked-by: Luca Weiss <luca.weiss@...rphone.com>

Regards
Luca

>
> Cc: Luca Weiss <luca.weiss@...rphone.com>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
> ---
>  .../boot/dts/qcom/sm7225-fairphone-fp4.dts    | 28 +------------------
>  1 file changed, 1 insertion(+), 27 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/qcom/sm7225-fairphone-fp4.dts b/arch/arm64/boot/dts/qcom/sm7225-fairphone-fp4.dts
> index 18171c5d8a38..568165f4f9e4 100644
> --- a/arch/arm64/boot/dts/qcom/sm7225-fairphone-fp4.dts
> +++ b/arch/arm64/boot/dts/qcom/sm7225-fairphone-fp4.dts
> @@ -386,36 +386,10 @@ &i2c8 {
>  };
>  
>  &i2c10 {
> -	clock-frequency = <400000>;
> -	status = "okay";
> -
>  	/* PM8008 PMIC @ 8 and 9 */
>  	/* PX8618 @ 26 */
>  	/* SMB1395 PMIC @ 34 */
> -
> -	haptics@5a {
> -		compatible = "awinic,aw8695";
> -		reg = <0x5a>;
> -		interrupts-extended = <&tlmm 85 IRQ_TYPE_EDGE_FALLING>;
> -		reset-gpios = <&tlmm 90 GPIO_ACTIVE_HIGH>;
> -
> -		awinic,f0-preset = <2350>;
> -		awinic,f0-coefficient = <260>;
> -		awinic,f0-calibration-percent = <7>;
> -		awinic,drive-level = <125>;
> -
> -		awinic,f0-detection-play-time = <5>;
> -		awinic,f0-detection-wait-time = <3>;
> -		awinic,f0-detection-repeat = <2>;
> -		awinic,f0-detection-trace = <15>;
> -
> -		awinic,boost-debug = /bits/ 8 <0x30 0xeb 0xd4>;
> -		awinic,tset = /bits/ 8 <0x12>;
> -		awinic,r-spare = /bits/ 8 <0x68>;
> -
> -		awinic,bemf-upper-threshold = <4104>;
> -		awinic,bemf-lower-threshold = <1016>;
> -	};
> +	/* awinic,aw8695 @ 5a */
>  };
>  
>  &ipa {