Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 31 Mar 2023 09:42:08 +0200
From:   Herve Codina <herve.codina@bootlin.com>
To:     Lee Jones <lee@kernel.org>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, alsa-devel@alsa-project.org,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: Re: [PATCH v5 2/5] mfd: Add support for the Lantiq PEF2256 framer
Message-ID: <20230331094208.41ab4420@bootlin.com>
In-Reply-To: <20230330160510.GB489249@google.com>
References: <20230328092645.634375-1-herve.codina@bootlin.com>
        <20230328092645.634375-3-herve.codina@bootlin.com>
        <20230330160510.GB489249@google.com>
Organization: Bootlin
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

Hi Lee,

On Thu, 30 Mar 2023 17:05:10 +0100
Lee Jones <lee@kernel.org> wrote:

> On Tue, 28 Mar 2023, Herve Codina wrote:
> 
> > The Lantiq PEF2256 is a framer and line interface component designed to
> > fulfill all required interfacing between an analog E1/T1/J1 line and the
> > digital PCM system highway/H.100 bus.  
> 
> My goodness!
> 
> It's been a long time since I've seen anything quite like this.

Yes, old things but working on recent kernel.

> 
> My suggestion to you:
> 
> * Split this up into components that fit functional subsystems

It is done. The audio part is present in ASoC subsystem (path 5 in this
series). pinctrl function is implemented in this driver and, as I don't
want to share registers, I would prefer to keep this function inside this
driver.

Also, I sent a RFC related to HDLC and PHY. In this RFC, the pef2256 is
considered as a PHY and handled in the PHY subsystem.
  https://lore.kernel.org/linux-kernel/20230323103154.264546-1-herve.codina@bootlin.com/

> * Run checkpatch.pl

I did.

> * Remove all of the debug prints

I can do that in the next iteration if really needed.

> * Move all of the defines out to a header file

These defines are related to registers. As I don't want to share these
registers, is it really necessary to use a header file for them ?

> * Be more verbose in your documentation / comments

I can improve the API documentation present in include/mfd/pef2256.h.
Do you thing that is necessary ? Only a few devices will use this API.

> * Consider using simple-mfd to probe child devices.

I did.
The driver has (and needs to have) a compatible string.
Having this compatible string, sub-nodes are not automatically populated
in the device tree. In order to have them populated and probed, the pef2256
probe function ends calling devm_of_platform_populate().

Best regards,
Hervé

> 
> > Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> > ---
> >  drivers/mfd/Kconfig         |   17 +
> >  drivers/mfd/Makefile        |    1 +
> >  drivers/mfd/pef2256.c       | 1355 +++++++++++++++++++++++++++++++++++
> >  include/linux/mfd/pef2256.h |   28 +
> >  4 files changed, 1401 insertions(+)
> >  create mode 100644 drivers/mfd/pef2256.c
> >  create mode 100644 include/linux/mfd/pef2256.h  
> 
> --
> Lee Jones [李琼斯]