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From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Marek Vasut <marex@denx.de>, Rob Herring <robh@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Lucas Stach <l.stach@pengutronix.de>,
	NXP Linux Team <linux-imx@nxp.com>,
	Paul Elder <paul.elder@ideasonboard.com>,
	Peng Fan <peng.fan@nxp.com>,
	devicetree@vger.kernel.org
Subject: Re: [PATCH] dt-bindings: soc: imx8mp-media-blk-ctrl: Add LDB into DT example
Date: Mon, 4 Jul 2022 10:00:17 +0200	[thread overview]
Message-ID: <eb8cede8-6493-c116-29eb-0303c1871239@linaro.org> (raw)
In-Reply-To: <cbb47a74-72ae-5db3-ca11-6c01a092fa98@denx.de>

On 01/07/2022 10:06, Marek Vasut wrote:
> In the local patch I have to imx8mp.dtsi , the simple-mfd had to be 
> added for the ldb bridge child node to bind.
> 
>> 'simple-mfd' is saying the child has 0 dependence on the parent. IMO,
>> 'syscon' contradicts that, but that's an all to common pattern. You are
>> saying all the clocks (or any other resources) in the parent can be off
>> and the LDB bridge is still functional.
> 
> The bridge itself should work even if the block control is clocked off. 
> The block controller apb (register) clock have to be enabled only when 
> accessing these two LDB registers, which should be handled by runtime 
> PM. Or what am I missing here ?

If I understand correctly, you need the device's APB clocks to be
enabled to use the child device? You have a dependency between child and
parent, so it is not a simple-mfd.

Best regards,
Krzysztof

WARNING: multiple messages have this Message-ID (diff)
From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Marek Vasut <marex@denx.de>, Rob Herring <robh@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Lucas Stach <l.stach@pengutronix.de>,
	NXP Linux Team <linux-imx@nxp.com>,
	Paul Elder <paul.elder@ideasonboard.com>,
	Peng Fan <peng.fan@nxp.com>,
	devicetree@vger.kernel.org
Subject: Re: [PATCH] dt-bindings: soc: imx8mp-media-blk-ctrl: Add LDB into DT example
Date: Mon, 4 Jul 2022 10:00:17 +0200	[thread overview]
Message-ID: <eb8cede8-6493-c116-29eb-0303c1871239@linaro.org> (raw)
In-Reply-To: <cbb47a74-72ae-5db3-ca11-6c01a092fa98@denx.de>

On 01/07/2022 10:06, Marek Vasut wrote:
> In the local patch I have to imx8mp.dtsi , the simple-mfd had to be 
> added for the ldb bridge child node to bind.
> 
>> 'simple-mfd' is saying the child has 0 dependence on the parent. IMO,
>> 'syscon' contradicts that, but that's an all to common pattern. You are
>> saying all the clocks (or any other resources) in the parent can be off
>> and the LDB bridge is still functional.
> 
> The bridge itself should work even if the block control is clocked off. 
> The block controller apb (register) clock have to be enabled only when 
> accessing these two LDB registers, which should be handled by runtime 
> PM. Or what am I missing here ?

If I understand correctly, you need the device's APB clocks to be
enabled to use the child device? You have a dependency between child and
parent, so it is not a simple-mfd.

Best regards,
Krzysztof

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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2022-07-04  8:00 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-30 17:39 [PATCH] dt-bindings: soc: imx8mp-media-blk-ctrl: Add LDB into DT example Marek Vasut
2022-06-30 17:39 ` Marek Vasut
2022-06-30 19:11 ` Krzysztof Kozlowski
2022-06-30 19:11   ` Krzysztof Kozlowski
2022-06-30 19:16   ` Marek Vasut
2022-06-30 19:16     ` Marek Vasut
2022-06-30 19:31     ` Krzysztof Kozlowski
2022-06-30 19:31       ` Krzysztof Kozlowski
2022-06-30 19:50       ` Marek Vasut
2022-06-30 19:50         ` Marek Vasut
2022-07-01  0:09         ` Rob Herring
2022-07-01  0:09           ` Rob Herring
2022-07-01  8:06           ` Marek Vasut
2022-07-01  8:06             ` Marek Vasut
2022-07-04  8:00             ` Krzysztof Kozlowski [this message]
2022-07-04  8:00               ` Krzysztof Kozlowski
2022-07-08 15:32               ` Marek Vasut
2022-07-08 15:32                 ` Marek Vasut
2022-07-11  9:22                 ` Krzysztof Kozlowski
2022-07-11  9:22                   ` Krzysztof Kozlowski
2022-06-30 23:28 ` Rob Herring
2022-06-30 23:28   ` Rob Herring

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