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From: Wolfram Sang <wsa@the-dreams.de>
To: Qii Wang <qii.wang@mediatek.com>
Cc: linux-i2c@vger.kernel.org, devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org,
	srv_heupstream@mediatek.com, leilk.liu@mediatek.com,
	matthias.bgg@gmail.com, robh+dt@kernel.org
Subject: Re: [PATCH 1/2] dt-bindings: i2c: Add MediaTek i2c AC timing binding
Date: Wed, 26 Jun 2019 15:39:41 +0200	[thread overview]
Message-ID: <20190626133941.GL801@ninjato> (raw)
In-Reply-To: <1560240715-22595-2-git-send-email-qii.wang@mediatek.com>

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Hi,

On Tue, Jun 11, 2019 at 04:11:54PM +0800, Qii Wang wrote:
> Add i2c AC timing binding to binding file. It can give the AC
> timing parameters to meet I2C specification at different speed.
> 
> Signed-off-by: Qii Wang <qii.wang@mediatek.com>

I think this is a too specific 1:1 mapping of your register set into DT
world. We already have these generic parameters:

- clock-frequency
        frequency of bus clock in Hz.

- i2c-scl-falling-time-ns
        Number of nanoseconds the SCL signal takes to fall; t(f) in the I2C
        specification.

- i2c-scl-internal-delay-ns
        Number of nanoseconds the IP core additionally needs to setup SCL.

- i2c-scl-rising-time-ns
        Number of nanoseconds the SCL signal takes to rise; t(r) in the I2C
        specification.

- i2c-sda-falling-time-ns
        Number of nanoseconds the SDA signal takes to fall; t(f) in the I2C
        specification.

(check Documentation/devicetree/bindings/i2c/i2c.txt)

Can't you use those to derive your values from that? Which ones are you missing
if not?

Regards,

   Wolfram

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WARNING: multiple messages have this Message-ID (diff)
From: Wolfram Sang <wsa@the-dreams.de>
To: Qii Wang <qii.wang@mediatek.com>
Cc: devicetree@vger.kernel.org, srv_heupstream@mediatek.com,
	leilk.liu@mediatek.com, linux-kernel@vger.kernel.org,
	robh+dt@kernel.org, linux-mediatek@lists.infradead.org,
	linux-i2c@vger.kernel.org, matthias.bgg@gmail.com,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/2] dt-bindings: i2c: Add MediaTek i2c AC timing binding
Date: Wed, 26 Jun 2019 15:39:41 +0200	[thread overview]
Message-ID: <20190626133941.GL801@ninjato> (raw)
In-Reply-To: <1560240715-22595-2-git-send-email-qii.wang@mediatek.com>


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Hi,

On Tue, Jun 11, 2019 at 04:11:54PM +0800, Qii Wang wrote:
> Add i2c AC timing binding to binding file. It can give the AC
> timing parameters to meet I2C specification at different speed.
> 
> Signed-off-by: Qii Wang <qii.wang@mediatek.com>

I think this is a too specific 1:1 mapping of your register set into DT
world. We already have these generic parameters:

- clock-frequency
        frequency of bus clock in Hz.

- i2c-scl-falling-time-ns
        Number of nanoseconds the SCL signal takes to fall; t(f) in the I2C
        specification.

- i2c-scl-internal-delay-ns
        Number of nanoseconds the IP core additionally needs to setup SCL.

- i2c-scl-rising-time-ns
        Number of nanoseconds the SCL signal takes to rise; t(r) in the I2C
        specification.

- i2c-sda-falling-time-ns
        Number of nanoseconds the SDA signal takes to fall; t(f) in the I2C
        specification.

(check Documentation/devicetree/bindings/i2c/i2c.txt)

Can't you use those to derive your values from that? Which ones are you missing
if not?

Regards,

   Wolfram

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  reply	other threads:[~2019-06-26 13:39 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-11  8:11 [PATCH 0/2] Add support for AC timing adjustment Qii Wang
2019-06-11  8:11 ` Qii Wang
2019-06-11  8:11 ` Qii Wang
2019-06-11  8:11 ` [PATCH 1/2] dt-bindings: i2c: Add MediaTek i2c AC timing binding Qii Wang
2019-06-11  8:11   ` Qii Wang
2019-06-11  8:11   ` Qii Wang
2019-06-26 13:39   ` Wolfram Sang [this message]
2019-06-26 13:39     ` Wolfram Sang
2019-07-17 12:55     ` Qii Wang
2019-07-17 12:55       ` Qii Wang
2019-07-17 12:55       ` Qii Wang
2019-07-17 13:29       ` Wolfram Sang
2019-07-17 13:29         ` Wolfram Sang
2019-06-11  8:11 ` [PATCH 2/2] i2c: mediatek: Add i2c AC timing adjust support Qii Wang
2019-06-11  8:11   ` Qii Wang
2019-06-11  8:11   ` Qii Wang

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