linux-kernel - Re: [PATCH V2 4/5] PCI: exynos: support the using PHY generic framework

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Message-id: <e7c19900-0e9f-a3aa-240f-cba4244a8ef9@samsung.com>
Date:   Mon, 09 Jan 2017 19:09:18 +0530
From:   Alim Akhtar <alim.akhtar@...sung.com>
To:     Jaehoon Chung <jh80.chung@...sung.com>, linux-pci@...r.kernel.org
Cc:     devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-samsung-soc@...r.kernel.org, bhelgaas@...gle.com,
        robh+dt@...nel.org, mark.rutland@....com, kgene@...nel.org,
        krzk@...nel.org, kishon@...com, jingoohan1@...il.com,
        vivek.gautam@...eaurora.org, pankaj.dubey@...sung.com,
        cpgs@...sung.com
Subject: Re: [PATCH V2 4/5] PCI: exynos: support the using PHY generic framework

Hi Jaehoon,

On 01/04/2017 06:04 PM, Jaehoon Chung wrote:
> This patch is for using PHY generic framework.
> To maintain backward compatibility, check whether phy is supported or
> not with 'using_phy'.
>
> And if someone use the old dt-file, display the "deprecated" message.
> But it's still working fine with it.
>
> Signed-off-by: Jaehoon Chung <jh80.chung@...sung.com>
> ---

Reviewed-by: Alim Akhtar <alim.akhtar@...sung.com>


> Changelog on V2:
> - This patch is split from previous PATCH[1/4]
> - Maintain the backward compatibility
> - Adds 'using_phy' for cheching whether phy framework is used or not
> - Adds 'DEPRECATED' message for old dt-binding way
>
>  drivers/pci/host/pci-exynos.c | 61 +++++++++++++++++++++++++++++++++++--------
>  1 file changed, 50 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c
> index feed0fd..34f2eed 100644
> --- a/drivers/pci/host/pci-exynos.c
> +++ b/drivers/pci/host/pci-exynos.c
> @@ -21,6 +21,7 @@
>  #include <linux/of_gpio.h>
>  #include <linux/pci.h>
>  #include <linux/platform_device.h>
> +#include <linux/phy/phy.h>
>  #include <linux/resource.h>
>  #include <linux/signal.h>
>  #include <linux/types.h>
> @@ -110,6 +111,10 @@ struct exynos_pcie {
>  	struct exynos_pcie_clk_res	*clk_res;
>  	const struct exynos_pcie_ops	*ops;
>  	int				reset_gpio;
> +
> +	/* For Generic PHY Framework */
> +	bool				using_phy;
> +	struct phy			*phy;
>  };
>
>  struct exynos_pcie_ops {
> @@ -135,6 +140,10 @@ static int exynos5440_pcie_get_mem_resources(struct platform_device *pdev,
>  	if (IS_ERR(ep->mem_res->elbi_base))
>  		return PTR_ERR(ep->mem_res->elbi_base);
>
> +	/* If using the PHY framework, doesn't need to get other resource */
> +	if (ep->using_phy)
> +		return 0;
> +
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>  	ep->mem_res->phy_base = devm_ioremap_resource(dev, res);
>  	if (IS_ERR(ep->mem_res->phy_base))
> @@ -396,17 +405,28 @@ static int exynos_pcie_establish_link(struct exynos_pcie *exynos_pcie)
>  	}
>
>  	exynos_pcie_assert_core_reset(exynos_pcie);
> -	exynos_pcie_assert_phy_reset(exynos_pcie);
> -	exynos_pcie_deassert_phy_reset(exynos_pcie);
> -	exynos_pcie_power_on_phy(exynos_pcie);
> -	exynos_pcie_init_phy(exynos_pcie);
> -
> -	/* pulse for common reset */
> -	exynos_pcie_writel(exynos_pcie->mem_res->block_base, 1,
> -				PCIE_PHY_COMMON_RESET);
> -	udelay(500);
> -	exynos_pcie_writel(exynos_pcie->mem_res->block_base, 0,
> -				PCIE_PHY_COMMON_RESET);
> +
> +	if (exynos_pcie->using_phy) {
> +		phy_reset(exynos_pcie->phy);
> +
> +		exynos_pcie_writel(exynos_pcie->mem_res->elbi_base, 1,
> +				PCIE_PWR_RESET);
> +
> +		phy_power_on(exynos_pcie->phy);
> +		phy_init(exynos_pcie->phy);
> +	} else {
> +		exynos_pcie_assert_phy_reset(exynos_pcie);
> +		exynos_pcie_deassert_phy_reset(exynos_pcie);
> +		exynos_pcie_power_on_phy(exynos_pcie);
> +		exynos_pcie_init_phy(exynos_pcie);
> +
> +		/* pulse for common reset */
> +		exynos_pcie_writel(exynos_pcie->mem_res->block_base, 1,
> +					PCIE_PHY_COMMON_RESET);
> +		udelay(500);
> +		exynos_pcie_writel(exynos_pcie->mem_res->block_base, 0,
> +					PCIE_PHY_COMMON_RESET);
> +	}
>
>  	exynos_pcie_deassert_core_reset(exynos_pcie);
>  	dw_pcie_setup_rc(pp);
> @@ -420,6 +440,11 @@ static int exynos_pcie_establish_link(struct exynos_pcie *exynos_pcie)
>  	if (!dw_pcie_wait_for_link(pp))
>  		return 0;
>
> +	if (exynos_pcie->using_phy) {
> +		phy_power_off(exynos_pcie->phy);
> +		return -ETIMEDOUT;
> +	}
> +
>  	while (exynos_pcie_readl(exynos_pcie->mem_res->phy_base,
>  				PCIE_PHY_PLL_LOCKED) == 0) {
>  		val = exynos_pcie_readl(exynos_pcie->mem_res->block_base,
> @@ -633,6 +658,17 @@ static int __init exynos_pcie_probe(struct platform_device *pdev)
>
>  	exynos_pcie->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0);
>
> +	/* Assume that controller doesn't use the PHY framework */
> +	exynos_pcie->using_phy = false;
> +
> +	exynos_pcie->phy = devm_of_phy_get(dev, np, NULL);
> +	if (IS_ERR(exynos_pcie->phy)) {
> +		if (PTR_ERR(exynos_pcie->phy) == -EPROBE_DEFER)
> +			return PTR_ERR(exynos_pcie->phy);
> +		dev_warn(dev, "Use the 'phy' property. Current DT of pci-exynos was deprecated!!\n");
> +	} else
> +		exynos_pcie->using_phy = true;
> +
>  	if (exynos_pcie->ops && exynos_pcie->ops->get_mem_resources) {
>  		ret = exynos_pcie->ops->get_mem_resources(pdev, exynos_pcie);
>  		if (ret)
> @@ -657,6 +693,9 @@ static int __init exynos_pcie_probe(struct platform_device *pdev)
>  	return 0;
>
>  fail_probe:
> +	if (exynos_pcie->using_phy)
> +		phy_exit(exynos_pcie->phy);
> +
>  	if (exynos_pcie->ops && exynos_pcie->ops->deinit_clk_resources)
>  		exynos_pcie->ops->deinit_clk_resources(exynos_pcie);
>  	return ret;
>