RE: [PATCH v1 6/7] i2c-mlxbf.c: support BlueField-3 SoC

[Asmaa Mnebhi]

Thank you for your feedback. I will address them shortly in v2.

-----Original Message-----
From: Rob Herring <robh@xxxxxxxxxx> 
Sent: Thursday, August 18, 2022 11:12 AM
To: Asmaa Mnebhi <asmaa@xxxxxxxxxx>
Cc: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>; linux-i2c@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Khalil Blaiech <kblaiech@xxxxxxxxxx>
Subject: Re: [PATCH v1 6/7] i2c-mlxbf.c: support BlueField-3 SoC

On Tue, Aug 16, 2022 at 06:54:11PM -0400, Asmaa Mnebhi wrote:
> BlueField-3 SoC has the same I2C IP logic as previous
> BlueField-1 and 2 SoCs but it has different registers' addresses.
> This is an effort to keep this driver generic accross all BlueField 
> generations.
> This patch breaks down the "smbus" resource into 3 separate resources 
> to enable us to use common registers' offsets for all BlueField SoCs:
> struct mlxbf_i2c_resource *timer;
> struct mlxbf_i2c_resource *mst;
> struct mlxbf_i2c_resource *slv;
> 
> Of course, all offsets had to be adjusted accordingly, and we took 
> this chance to reorganize the macros depending on the register block 
> they target.
> 
> There are only 2 registers' offsets that do not fit within this schema 
> so their offsets are passed as SoC-specific parameters:
> smbus_master_rs_bytes_off
> smbus_master_fsm_off
> 
> Reviewed-by: Khalil Blaiech <kblaiech@xxxxxxxxxx>
> Signed-off-by: Asmaa Mnebhi <asmaa@xxxxxxxxxx>
> ---
>  .../bindings/i2c/mellanox,i2c-mlxbf.yaml      |  30 +-

Bindings go in a separate patch.

>  MAINTAINERS                                   |   1 +
>  drivers/i2c/busses/i2c-mlxbf.c                | 397 ++++++++++--------
>  3 files changed, 258 insertions(+), 170 deletions(-)
> 
> diff --git 
> a/Documentation/devicetree/bindings/i2c/mellanox,i2c-mlxbf.yaml 
> b/Documentation/devicetree/bindings/i2c/mellanox,i2c-mlxbf.yaml
> index 93198d5d43a6..cb3a012914e0 100644
> --- a/Documentation/devicetree/bindings/i2c/mellanox,i2c-mlxbf.yaml
> +++ b/Documentation/devicetree/bindings/i2c/mellanox,i2c-mlxbf.yaml
> @@ -8,6 +8,7 @@ title: Mellanox I2C SMBus on BlueField SoCs
>  
>  maintainers:
>    - Khalil Blaiech <kblaiech@xxxxxxxxxx>
> +  - Asmaa Mnebhi <asmaa@xxxxxxxxxx>
>  
>  allOf:
>    - $ref: /schemas/i2c/i2c-controller.yaml# @@ -17,11 +18,15 @@ 
> properties:
>      enum:
>        - mellanox,i2c-mlxbf1
>        - mellanox,i2c-mlxbf2
> +      - mellanox,i2c-mlxbf3
>  
>    reg:
> -    minItems: 3
> +    minItems: 5

You just broke platforms with 3 entries.

> +    maxItems: 6
>      items:
> -      - description: Smbus block registers
> +      - description: Smbus timer registers
> +      - description: Smbus master registers
> +      - description: Smbus slave registers

You can't add new registers at the beginning of the list for existing users.

Either add to the end or it has to be conditional (if/then schema).

>        - description: Cause master registers
>        - description: Cause slave registers
>        - description: Cause coalesce registers @@ -58,7 +63,9 @@ 
> examples:
>    - |
>      i2c@2804000 {
>          compatible = "mellanox,i2c-mlxbf1";
> -        reg = <0x02804000 0x800>,
> +        reg = <0x02804000 0x40>,
> +              <0x02804200 0x200>,
> +              <0x02804400 0x200>,
>                <0x02801200 0x020>,
>                <0x02801260 0x020>;
>          interrupts = <57>;
> @@ -68,10 +75,25 @@ examples:
>    - |
>      i2c@2808800 {
>          compatible = "mellanox,i2c-mlxbf2";
> -        reg = <0x02808800 0x600>,
> +        reg = <0x02808800 0x40>,
> +              <0x02808a00 0x200>,
> +              <0x02808c00 0x200>,
>                <0x02808e00 0x020>,
>                <0x02808e20 0x020>,
>                <0x02808e40 0x010>;
>          interrupts = <57>;
>          clock-frequency = <400000>;
>      };
> +
> +  - |
> +    i2c@2808800 {
> +        compatible = "mellanox,i2c-mlxbf3";
> +        reg = <0x13404480 0x40>,
> +              <0x13404200 0x200>,
> +              <0x13404000 0x200>,
> +              <0x13404400 0x020>,
> +              <0x13404420 0x020>,
> +              <0x13404440 0x010>;
> +        interrupts = <35>;
> +        clock-frequency = <400000>;
> +    };