Re: [PATCH v2 11/13] dt-bindings: ipmi: Convert IPMI-SMIC bindings to json-schema

From: "André Przywara" <andre.przywara@arm.com>
To: Rob Herring <robh@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
	Maxime Ripard <mripard@kernel.org>,
	Robert Richter <rric@kernel.org>,
	soc@kernel.org, Jon Loeliger <jdl@jdl.com>,
	Mark Langsdorf <mlangsdo@redhat.com>,
	Eric Auger <eric.auger@redhat.com>, Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Corey Minyard <minyard@acm.org>,
	openipmi-developer@lists.sourceforge.net
Subject: Re: [PATCH v2 11/13] dt-bindings: ipmi: Convert IPMI-SMIC bindings to json-schema
Date: Fri, 28 Feb 2020 00:21:31 +0000	[thread overview]
Message-ID: <270389bf-3a6e-6e89-624f-006cace493ae@arm.com> (raw)
In-Reply-To: <20200227222145.GF26010@bogus>

On 27/02/2020 22:21, Rob Herring wrote:

Hi,

> On Thu, Feb 27, 2020 at 06:22:08PM +0000, Andre Przywara wrote:
>> Convert the generic IPMI controller bindings to DT schema format
>> using json-schema.
>>
>> I removed the formerly mandatory device-type property, since this
>> is deprecated in the DT spec, except for the legacy CPU and memory
>> nodes.
> 
> Yes, but it is still used by the ipmi driver to match on, so we should 
> keep it.

Oh, indeed, I missed that. Should we:
- Remove the .type field from the driver.
- Mark/comment this as deprecated in the bindings, but
- Keep in it in the DTs.
to limit proliferation of device_type usage?

> 
>> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
>> Cc: Corey Minyard <minyard@acm.org>
>> Cc: openipmi-developer@lists.sourceforge.net
>> ---
>>  .../devicetree/bindings/ipmi/ipmi-smic.txt    | 25 ---------
>>  .../devicetree/bindings/ipmi/ipmi-smic.yaml   | 56 +++++++++++++++++++
>>  2 files changed, 56 insertions(+), 25 deletions(-)
>>  delete mode 100644 Documentation/devicetree/bindings/ipmi/ipmi-smic.txt
>>  create mode 100644 Documentation/devicetree/bindings/ipmi/ipmi-smic.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/ipmi/ipmi-smic.txt b/Documentation/devicetree/bindings/ipmi/ipmi-smic.txt
>> deleted file mode 100644
>> index d5f1a877ed3e..000000000000
>> --- a/Documentation/devicetree/bindings/ipmi/ipmi-smic.txt
>> +++ /dev/null
>> @@ -1,25 +0,0 @@
>> -IPMI device
>> -
>> -Required properties:
>> -- compatible: should be one of ipmi-kcs, ipmi-smic, or ipmi-bt
>> -- device_type: should be ipmi
>> -- reg: Address and length of the register set for the device
>> -
>> -Optional properties:
>> -- interrupts: The interrupt for the device.  Without this the interface
>> -	is polled.
>> -- reg-size - The size of the register.  Defaults to 1
>> -- reg-spacing - The number of bytes between register starts.  Defaults to 1
>> -- reg-shift - The amount to shift the registers to the right to get the data
>> -	into bit zero.
>> -
>> -Example:
>> -
>> -smic@fff3a000 {
>> -	compatible = "ipmi-smic";
>> -	device_type = "ipmi";
>> -	reg = <0xfff3a000 0x1000>;
>> -	interrupts = <0 24 4>;
>> -	reg-size = <4>;
>> -	reg-spacing = <4>;
>> -};
>> diff --git a/Documentation/devicetree/bindings/ipmi/ipmi-smic.yaml b/Documentation/devicetree/bindings/ipmi/ipmi-smic.yaml
>> new file mode 100644
>> index 000000000000..c859e0e959b9
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/ipmi/ipmi-smic.yaml
>> @@ -0,0 +1,56 @@
>> +# SPDX-License-Identifier: GPL-2.0
> 
> Anything I wrote which should be most of the series, you can relicense 
> to:
> 
> (GPL-2.0-only OR BSD-2-Clause)

Oh, good point. I copied the header from some file I picked.

> 
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/ipmi/ipmi-smic.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: IPMI device bindings
>> +
>> +description: IPMI device bindings
>> +
>> +maintainers:
>> +  - Corey Minyard <cminyard@mvista.com>
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - ipmi-kcs
>> +      - ipmi-smic
>> +      - ipmi-bt
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  interrupts:
>> +    description: Interface is polled if this property is omitted.
>> +    maxItems: 1
>> +
>> +  reg-size:
>> +    description: The access width of the register in bytes. Defaults to 1.
>> +    allOf:
>> +      - $ref: /schemas/types.yaml#/definitions/uint32
>> +      - enum: [1, 2, 4, 8]
> 
> Does 8 really work?

The driver supports it, at least on architectures providing readq.

> 
>> +
>> +  reg-spacing:
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    description: The number of bytes between register starts. Defaults to 1.
>> +
>> +  reg-shift:
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    description: |
>> +      The amount of bits to shift the register content to the right to get
>> +      the data into bit zero.
> 
> either 24 or 56 would be the max, right?

True, will limit this to 56.

Thanks!
Andre

> 
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +
>> +examples:
>> +  - |
>> +    smic@fff3a000 {
>> +        compatible = "ipmi-smic";
>> +        reg = <0xfff3a000 0x1000>;
>> +        interrupts = <0 24 4>;
>> +        reg-size = <4>;
>> +        reg-spacing = <4>;
>> +    };
>> -- 
>> 2.17.1
>>