From: Roger Quadros <rogerq@kernel.org>
To: Miquel Raynal <miquel.raynal@bootlin.com>,
Grygorii Strashko <grygorii.strashko@ti.com>
Cc: tony@atomide.com, robh+dt@kernel.org, nm@ti.com,
lokeshvutla@ti.com, nsekhar@ti.com,
krzysztof.kozlowski@canonical.com, devicetree@vger.kernel.org,
linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 5/8] dt-bindings: mtd: ti,gpmc-nand: Convert to yaml
Date: Tue, 7 Sep 2021 19:57:16 +0300 [thread overview]
Message-ID: <2c6491c2-dae8-c8b3-9f8c-14a7583720f1@kernel.org> (raw)
In-Reply-To: <20210907183545.3e281b7d@xps13>
Hi Miquel,
On 07/09/2021 19:35, Miquel Raynal wrote:
> Hi Grygorii,
>
>>>
>>>> +
>>>> + nand-bus-width:
>>>> + description:
>>>> + Bus width to the NAND chip
>>>> + $ref: /schemas/types.yaml#/definitions/uint32
>>>> + enum: [8, 16]
>>>> + default: 8
>>>
>>> This is part of nand-controller.yaml binding and should not be there.
>>>
>>>> +
>>>> +allOf:
>>>> + - $ref: "../memory-controllers/ti,gpmc-child.yaml"
>>>
>>> Maybe you need to reference the nand controller bindings as well
>>>
>>
>> This will not work out of the box :( as nand-controller.yaml defines both
>> nand controller and nand memory. It potentially might work if it will be possible to split
>> nand memory definition (or nand memory properties) out of and-controller.yaml, similarly to
>> ti,gpmc-child.yaml from this series.
>
> What you think would be the issue?
The issue is that dt_binding checks will fail if I reference nand-controller.yaml
as we currently represent the controller as follows
memory-controller { /* GPMC controller */
memory-controller-props;
nand-chip {
/* @chip select 0 */
nand-controller-props;
memory-controller-timing-props;
chip-props;
}
nand-chip {
/* @chip select 1 */
nand-controller-props;
memory-controller-timing-props;
chip-props;
}
nor-chip {
/* @chip select 2 */
memory-controller-timing-props;
chip-props;
}
}
The NAND controller IO registers are at different addresses for different
chip select regions. Also, this is one way we can specify GPMC settings/timings
for different chip selects.
>
> I am not opposed to split nand-controller.yaml into
> nand-controller.yaml and nand-chip.yaml if it simplifies the
> description of controllers but I don't get why it would be needed. In
> particular since we expect all drivers to support the
>
> nand-controller {
> controller-props;
> nand-chip {
> chip-props;
> }
> }
Changing to this format will cause a lot of churn in DT files, which I'm not sure
if it gives enough benefit.
TI platforms will never have 2 NAND chips in the same chip select region.
>
> organization which has been enforced since at least 2018. Having a
> controller vs. chip representation is fundamentally right. But here I
> see how "legacy" are these bindings with so much unneeded specific "ti,"
> properties... On one side it would be good to verify that the driver
> supports this representation (which I believe is true) and on the other
> side maybe it's time to advertise "better" bindings as well.
Yes, I'm OK to mark ti specific properties deprecated and use standard NAND chip
bindings.
cheers,
-roger
next prev parent reply other threads:[~2021-09-07 16:57 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-07 11:32 [PATCH v3 0/8] dt-bindings: memory-controllers: ti,gpmc: Convert to yaml Roger Quadros
2021-09-07 11:32 ` [PATCH v3 1/8] ARM: dts: omap: Fixup GPMC child nodes Roger Quadros
2021-09-07 12:44 ` Krzysztof Kozlowski
2021-09-15 8:53 ` Roger Quadros
2021-09-07 11:32 ` [PATCH v3 2/8] dt-bindings: mtd: Remove gpmc-nor.txt Roger Quadros
2021-09-07 11:32 ` [PATCH v3 3/8] dt-bindings: net: Remove gpmc-eth.txt Roger Quadros
2021-09-07 11:32 ` [PATCH v3 4/8] dt-bindings: memory-controllers: Introduce ti,gpmc-child Roger Quadros
2021-09-07 11:32 ` [PATCH v3 5/8] dt-bindings: mtd: ti,gpmc-nand: Convert to yaml Roger Quadros
2021-09-07 14:03 ` Miquel Raynal
2021-09-07 15:27 ` Grygorii Strashko
2021-09-07 16:35 ` Miquel Raynal
2021-09-07 16:57 ` Roger Quadros [this message]
2021-09-07 22:24 ` Rob Herring
2021-09-08 6:55 ` Roger Quadros
2021-09-07 17:01 ` Rob Herring
2021-09-08 11:14 ` Roger Quadros
2021-09-08 12:46 ` Rob Herring
2021-09-07 11:32 ` [PATCH v3 6/8] dt-bindings: mtd: ti,gpmc-onenand: " Roger Quadros
2021-09-07 11:32 ` [PATCH v3 7/8] dt-bindings: memory-controllers: ti,gpmc: " Roger Quadros
2021-09-07 11:32 ` [PATCH v3 8/8] memory: gpmc-omap: "gpmc,device-width" DT property is optional Roger Quadros
2021-09-07 12:36 ` Krzysztof Kozlowski
2021-09-15 9:11 ` Roger Quadros
2021-09-16 10:48 ` Krzysztof Kozlowski
2021-09-17 7:17 ` Roger Quadros
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