Re: [PATCH v4 08/10] PCI: qcom: Add ipq8064 rev2 variant and set tx term offset

[Rob Herring <robh@kernel.org>]

On Thu, May 14, 2020 at 10:07:09PM +0200, Ansuel Smith wrote:
> Add tx term offset support to pcie qcom driver need in some revision of
> the ipq806x SoC. Ipq8064 have tx term offset set to 7. Ipq8064-v2 revision
> and ipq8065 have the tx term offset set to 0.

Seems like this should be 2 patches or why isn't 'Ipq8064 have tx term 
offset set to 7' done in the prior patch? One tweak is needed for 
stable, but this isn't?

> 
> Signed-off-by: Sham Muthayyan <smuthayy@codeaurora.org>
> Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> ---
>  drivers/pci/controller/dwc/pcie-qcom.c | 18 ++++++++++++++++--
>  1 file changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index f5398b0d270c..ab6f1bdd24c3 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -45,6 +45,9 @@
>  #define PCIE_CAP_CPL_TIMEOUT_DISABLE		0x10
>  
>  #define PCIE20_PARF_PHY_CTRL			0x40
> +#define PHY_CTRL_PHY_TX0_TERM_OFFSET_MASK	GENMASK(20, 16)
> +#define PHY_CTRL_PHY_TX0_TERM_OFFSET(x)		((x) << 16)
> +
>  #define PCIE20_PARF_PHY_REFCLK			0x4C
>  #define PHY_REFCLK_SSP_EN			BIT(16)
>  #define PHY_REFCLK_USE_PAD			BIT(12)
> @@ -363,7 +366,8 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie)
>  	val &= ~BIT(0);
>  	writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
>  
> -	if (of_device_is_compatible(node, "qcom,pcie-ipq8064")) {
> +	if (of_device_is_compatible(node, "qcom,pcie-ipq8064") |
> +	    of_device_is_compatible(node, "qcom,pcie-ipq8064-v2")) {
>  		writel(PCS_DEEMPH_TX_DEEMPH_GEN1(24) |
>  			       PCS_DEEMPH_TX_DEEMPH_GEN2_3_5DB(24) |
>  			       PCS_DEEMPH_TX_DEEMPH_GEN2_6DB(34),
> @@ -374,9 +378,18 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie)
>  		writel(PHY_RX0_EQ(4), pcie->parf + PCIE20_PARF_CONFIG_BITS);
>  	}
>  
> +	if (of_device_is_compatible(node, "qcom,pcie-ipq8064")) {
> +		/* set TX termination offset */
> +		val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
> +		val &= ~PHY_CTRL_PHY_TX0_TERM_OFFSET_MASK;
> +		val |= PHY_CTRL_PHY_TX0_TERM_OFFSET(7);
> +		writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
> +	}
> +
>  	/* enable external reference clock */
>  	val = readl(pcie->parf + PCIE20_PARF_PHY_REFCLK);
> -	val |= BIT(16);
> +	val &= ~PHY_REFCLK_USE_PAD;
> +	val |= PHY_REFCLK_SSP_EN;
>  	writel(val, pcie->parf + PCIE20_PARF_PHY_REFCLK);
>  
>  	/* wait for clock acquisition */
> @@ -1452,6 +1465,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  static const struct of_device_id qcom_pcie_match[] = {
>  	{ .compatible = "qcom,pcie-apq8084", .data = &ops_1_0_0 },
>  	{ .compatible = "qcom,pcie-ipq8064", .data = &ops_2_1_0 },
> +	{ .compatible = "qcom,pcie-ipq8064-v2", .data = &ops_2_1_0 },
>  	{ .compatible = "qcom,pcie-apq8064", .data = &ops_2_1_0 },
>  	{ .compatible = "qcom,pcie-msm8996", .data = &ops_2_3_2 },
>  	{ .compatible = "qcom,pcie-ipq8074", .data = &ops_2_3_3 },
> -- 
> 2.25.1
>