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From: Shawn Guo <shawnguo@kernel.org>
To: Richard Zhu <hongxing.zhu@nxp.com>
Cc: l.stach@pengutronix.de, bhelgaas@google.com,
	lorenzo.pieralisi@arm.com, linux-pci@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, kernel@pengutronix.de,
	linux-imx@nxp.com
Subject: Re: [PATCH v2 1/2] ARM: dts: imx6qp-sabresd: Enable PCIe support
Date: Sun, 13 Feb 2022 12:32:00 +0800	[thread overview]
Message-ID: <20220213043143.GN4909@dragon> (raw)
In-Reply-To: <1644564779-8448-1-git-send-email-hongxing.zhu@nxp.com>

On Fri, Feb 11, 2022 at 03:32:58PM +0800, Richard Zhu wrote:
> In the i.MX6QP sabresd board(sch-28857) design, one external oscillator
> is used as the PCIe reference clock source by the endpoint device.
> 
> If RC uses this oscillator as reference clock too, PLL6(ENET PLL) would
> has to be in bypass mode, and ENET clocks would be messed up.
> 
> To keep things simple, let RC use the internal PLL as reference clock
> and always enable the external oscillator for endpoint device on
> i.MX6QP sabresd board.
> 
> NOTE: This reference clock setup is used to pass the GEN2 TX compliance
> tests, and isn't recommended as a setup in the end-user design.

I do not quite follow.  The commit log is all talking about external
oscillator reference clock, while code is playing 'vgen3' regulator.

Shawn

> 
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> ---
>  arch/arm/boot/dts/imx6qp-sabresd.dts | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/imx6qp-sabresd.dts b/arch/arm/boot/dts/imx6qp-sabresd.dts
> index 480e73183f6b..083cf90bcab5 100644
> --- a/arch/arm/boot/dts/imx6qp-sabresd.dts
> +++ b/arch/arm/boot/dts/imx6qp-sabresd.dts
> @@ -50,8 +50,14 @@ MX6QDL_PAD_SD3_DAT7__SD3_DATA7		0x17059
>  	};
>  };
>  
> +&vgen3_reg {
> +	regulator-min-microvolt = <1800000>;
> +	regulator-max-microvolt = <3300000>;
> +	regulator-always-on;
> +};
> +
>  &pcie {
> -	status = "disabled";
> +	status = "okay";
>  };
>  
>  &sata {
> -- 
> 2.25.1
> 

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  parent reply	other threads:[~2022-02-13  4:33 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-11  7:32 [PATCH v2 1/2] ARM: dts: imx6qp-sabresd: Enable PCIe support Richard Zhu
2022-02-11  7:32 ` [PATCH v2 2/2] PCI: imx6: Enable i.MX6QP PCIe power management support Richard Zhu
2022-02-13  4:32 ` Shawn Guo [this message]
2022-02-14  1:18   ` [PATCH v2 1/2] ARM: dts: imx6qp-sabresd: Enable PCIe support Hongxing Zhu
2022-02-15  5:50     ` Hongxing Zhu

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