PCI: imx6: Factor out ref clock enable

[Christoph Fritz]

*ping*

On Mon, 2016-03-14 at 00:30 +0100, Christoph Fritz wrote:
> commit dfcc1a16e6954e8ca6cadfc9dd309db6b6ef46b2
> Author: Bjorn Helgaas <bhelgaas at google.com>
> Date: Fri, 11 Mar 2016 11:15:36 -0600
> 
> Factor out ref clock enable to make it cleaner to add imx6sx support.  No
> functional change intended.
> 
> Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
> Tested-by: Christoph Fritz <chf.fritz at googlemail.com>
> ---
>  drivers/pci/host/pci-imx6.c | 36 ++++++++++++++++++++++++------------
>  1 file changed, 24 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
> index bd3f7d0..4e0e47f 100644
> --- a/drivers/pci/host/pci-imx6.c
> +++ b/drivers/pci/host/pci-imx6.c
> @@ -264,6 +264,23 @@ static int imx6_pcie_assert_core_reset(struct pcie_port *pp)
>  	return 0;
>  }
>  
> +static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
> +{
> +	/* power up core phy and enable ref clock */
> +	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> +			IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
> +	/*
> +	 * the async reset input need ref clock to sync internally,
> +	 * when the ref clock comes after reset, internal synced
> +	 * reset time is too short, cannot meet the requirement.
> +	 * add one ~10us delay here.
> +	 */
> +	udelay(10);
> +	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> +			IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
> +	return 0;
> +}
> +
>  static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
>  {
>  	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
> @@ -287,18 +304,11 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
>  		goto err_pcie;
>  	}
>  
> -	/* power up core phy and enable ref clock */
> -	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> -			IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
> -	/*
> -	 * the async reset input need ref clock to sync internally,
> -	 * when the ref clock comes after reset, internal synced
> -	 * reset time is too short, cannot meet the requirement.
> -	 * add one ~10us delay here.
> -	 */
> -	udelay(10);
> -	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> -			IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
> +	ret = imx6_pcie_enable_ref_clk(imx6_pcie);
> +	if (ret) {
> +		dev_err(pp->dev, "unable to enable pcie ref clock\n");
> +		goto err_ref_clk;
> +	}
>  
>  	/* allow the clocks to stabilize */
>  	usleep_range(200, 500);
> @@ -311,6 +321,8 @@ static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
>  	}
>  	return 0;
>  
> +err_ref_clk:
> +	clk_disable_unprepare(imx6_pcie->pcie);
>  err_pcie:
>  	clk_disable_unprepare(imx6_pcie->pcie_bus);
>  err_pcie_bus: