[PATCH v3] PCI: imx6: Add PHY reference clock source support

[Richard Zhu]

Best Regards
hongxing zhu
Linux BSP team
Office: 86-21-28937189
Email: hongxing.zhu at nxp.com


> -----Original Message-----
> From: Ilya Ledvich [mailto:ilya at compulab.co.il]
> Sent: Thursday, January 04, 2018 9:53 PM
> To: Richard Zhu <hongxing.zhu at nxp.com>; Lucas Stach
> <l.stach at pengutronix.de>
> Cc: Bjorn Helgaas <bhelgaas at google.com>; Rob Herring
> <robh+dt at kernel.org>; linux-pci at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org; linux-kernel at vger.kernel.org;
> devicetree at vger.kernel.org; Ilya Ledvich <ilya at compulab.co.il>
> Subject: [PATCH v3] PCI: imx6: Add PHY reference clock source support
> 
> i.MX7D variant of the IP can use either Crystal Oscillator input or internal
> clock input as a Reference Clock input for PCIe PHY.
> Add support for an optional property 'fsl,pcie-phy-refclk-internal'.
> If present then an internal clock input is used as PCIe PHY reference clock
> source. By default an external oscillator input is still used.
> 
> Verified on Compulab SBC-iMX7 Single Board Computer.
> 
> Signed-off-by: Ilya Ledvich <ilya at compulab.co.il>
Acked-by: Richard Zhu <hongxing.zhu at nxp.com >

Thanks.
Best Regards
Richard

> ---
> changes since V2:
> 	add a vendor prefix 'fsl' to a new property
> 
>  Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt | 5 +++++
>  drivers/pci/dwc/pci-imx6.c                               | 8 +++++++-
>  2 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> index 7b1e48b..1591a6a 100644
> --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
> @@ -50,6 +50,11 @@ Additional required properties for imx7d-pcie:
>  	       - "pciephy"
>  	       - "apps"
> 
> +Additional optional properties for imx7d-pcie:
> +- fsl,pcie-phy-refclk-internal: If present then an internal PLL input
> +is used
> +  as PCIe PHY reference clock source. By default an external oscillator
> +input
> +  is used.
> +
>  Example:
> 
>  	pcie at 0x01000000 {
> diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c index
> b734835..36812d3 100644
> --- a/drivers/pci/dwc/pci-imx6.c
> +++ b/drivers/pci/dwc/pci-imx6.c
> @@ -61,6 +61,7 @@ struct imx6_pcie {
>  	u32			tx_swing_low;
>  	int			link_gen;
>  	struct regulator	*vpcie;
> +	bool			pciephy_refclk_sel;
>  };
> 
>  /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */ @@ -
> 474,7 +475,9 @@ static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
>  	switch (imx6_pcie->variant) {
>  	case IMX7D:
>  		regmap_update_bits(imx6_pcie->iomuxc_gpr,
> IOMUXC_GPR12,
> -				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
> +				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
> +				   imx6_pcie->pciephy_refclk_sel ?
> +				   IMX7D_GPR12_PCIE_PHY_REFCLK_SEL : 0);
>  		break;
>  	case IMX6SX:
>  		regmap_update_bits(imx6_pcie->iomuxc_gpr,
> IOMUXC_GPR12, @@ -840,6 +843,9 @@ static int imx6_pcie_probe(struct
> platform_device *pdev)
>  		imx6_pcie->vpcie = NULL;
>  	}
> 
> +	imx6_pcie->pciephy_refclk_sel =
> +		of_property_read_bool(node, "fsl,pcie-phy-refclk-internal");
> +
>  	platform_set_drvdata(pdev, imx6_pcie);
> 
>  	ret = imx6_add_pcie_port(imx6_pcie, pdev);
> --
> 1.9.1