From: Adrian Fiergolski <adrian.fiergolski@fastree3d.com>
To: Mark Brown <broonie@kernel.org>,
Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Lukas Wunner <lukas@wunner.de>, kernel test robot <lkp@intel.com>,
Rob Herring <robh+dt@kernel.org>,
linux-spi <linux-spi@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/2] spi: Add the SPI daisy chain support.
Date: Tue, 7 Jul 2020 13:06:01 +0200 [thread overview]
Message-ID: <2ed68c34-9b25-30a8-525b-aa469c9dd4d1@fastree3d.com> (raw)
In-Reply-To: <20200707102511.GE4870@sirena.org.uk>
On 07.07.2020 12:25, Mark Brown wrote:
> On Mon, Jul 06, 2020 at 09:57:53PM +0200, Geert Uytterhoeven wrote:
>> On Mon, Jul 6, 2020 at 6:18 PM Mark Brown <broonie@kernel.org> wrote:
>>> It would really help to have an example of how a client device will use
>>> this, right now it's a bit hard to follow. Overall it feels like this
>>> should be better abstracted, right now there's lots of ifdefs throughout
>>> the code which make things unclear and also seem like they're going to
>>> be fragile long term since realistically very few systems will be using
>>> this.
>> Can't the ifdefs be avoided by implementing this as a new SPI controller?
>> I.e. the daisy chain driver will operate as a slave of the parent SPI
>> controller,
>> but will expose a new SPI bus to the daisy-chained slaves.
> Yes, that might work. I do worry about locking issues with having a SPI
> controller connected via SPI but we mostly only lock at the controller
> level so it's probably fine. Not sure how this would perform either.
I see your point here. I could evaluate how complicated it would be to
abstract the spi-daisy_chain driver as an SPI controller for its nodes.
Regards,
Adrian
next prev parent reply other threads:[~2020-07-07 11:06 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-03 14:12 [PATCH 1/2] spi: Add the SPI daisy chain support Adrian Fiergolski
2020-07-03 14:12 ` [PATCH 2/2] dt-bindings: Add documentation for SPI daisy chain driver Adrian Fiergolski
2020-07-03 22:32 ` [PATCH 1/2] spi: Add the SPI daisy chain support kernel test robot
2020-07-03 22:32 ` kernel test robot
2020-07-04 0:18 ` kernel test robot
2020-07-04 0:18 ` kernel test robot
2020-07-06 9:22 ` [PATCH v2 " Adrian Fiergolski
2020-07-06 9:22 ` [PATCH v2 2/2] dt-bindings: Add documentation for SPI daisy chain driver Adrian Fiergolski
2020-07-06 15:10 ` Geert Uytterhoeven
2020-07-06 15:19 ` Adrian Fiergolski
2020-07-06 15:32 ` Geert Uytterhoeven
2020-07-06 16:22 ` Mark Brown
2020-07-07 9:55 ` Adrian Fiergolski
2020-07-06 16:18 ` [PATCH v2 1/2] spi: Add the SPI daisy chain support Mark Brown
2020-07-06 19:57 ` Geert Uytterhoeven
2020-07-07 10:25 ` Mark Brown
2020-07-07 11:06 ` Adrian Fiergolski [this message]
2020-07-07 10:53 ` Adrian Fiergolski
2020-07-07 11:21 ` Mark Brown
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