Re: [PATCH V3 4/4] PCI: exynos: support the using PHY generic framework

From: Bjorn Helgaas
Date: Wed Feb 15 2017 - 16:04:08 EST


On Mon, Feb 13, 2017 at 05:26:13PM +0900, Jaehoon Chung wrote:
> Switch the pci-exynos driver to generic PHY framework. At the same time
> backward compatibility is preserved: Warning will be printed for old
> DTB.
>
> Refer to the binding file:
> - Documentation/devictree/bindings/pci/samsung,exynos5440-pcie.txt
>
> Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
> Acked-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> Acked-by: Jingoo Han <jingoohan1@xxxxxxxxx>
> Reviewed-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
> Reviewed-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>

Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

> ---
> Changelog on V3:
> - Changes the commit-message
> - Fixes the merge conflict
>
> 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 | 54 +++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 50 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c
> index 758906b..f6a8b6e 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 {
> @@ -126,6 +131,10 @@ static int exynos5440_pcie_get_mem_resources(struct platform_device *pdev,
> struct resource *res;
> struct device *dev = ep->pp.dev;
>
> + /* If using the PHY framework, doesn't need to get other resource */
> + if (ep->using_phy)
> + return 0;
> +
> ep->mem_res = devm_kzalloc(dev, sizeof(*ep->mem_res), GFP_KERNEL);
> if (!ep->mem_res)
> return -ENOMEM;
> @@ -396,10 +405,28 @@ static int exynos_pcie_establish_link(struct exynos_pcie *ep)
> }
>
> exynos_pcie_assert_core_reset(ep);
> - exynos_pcie_assert_phy_reset(ep);
> - exynos_pcie_deassert_phy_reset(ep);
> - exynos_pcie_power_on_phy(ep);
> - exynos_pcie_init_phy(ep);
> +
> + if (ep->using_phy) {
> + phy_reset(ep->phy);
> +
> + exynos_pcie_writel(ep->mem_res->elbi_base, 1,
> + PCIE_PWR_RESET);
> +
> + phy_power_on(ep->phy);
> + phy_init(ep->phy);
> + } else {
> + exynos_pcie_assert_phy_reset(ep);
> + exynos_pcie_deassert_phy_reset(ep);
> + exynos_pcie_power_on_phy(ep);
> + exynos_pcie_init_phy(ep);
> +
> + /* pulse for common reset */
> + exynos_pcie_writel(ep->mem_res->block_base, 1,
> + PCIE_PHY_COMMON_RESET);
> + udelay(500);
> + exynos_pcie_writel(ep->mem_res->block_base, 0,
> + PCIE_PHY_COMMON_RESET);
> + }
>
> /* pulse for common reset */
> exynos_pcie_writel(ep->mem_res->block_base, 1, PCIE_PHY_COMMON_RESET);
> @@ -418,6 +445,11 @@ static int exynos_pcie_establish_link(struct exynos_pcie *ep)
> if (!dw_pcie_wait_for_link(pp))
> return 0;
>
> + if (ep->using_phy) {
> + phy_power_off(ep->phy);
> + return -ETIMEDOUT;
> + }
> +
> while (exynos_pcie_readl(ep->mem_res->phy_base,
> PCIE_PHY_PLL_LOCKED) == 0) {
> val = exynos_pcie_readl(ep->mem_res->block_base,
> @@ -624,6 +656,17 @@ static int __init exynos_pcie_probe(struct platform_device *pdev)
>
> ep->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0);
>
> + /* Assume that controller doesn't use the PHY framework */
> + ep->using_phy = false;
> +
> + ep->phy = devm_of_phy_get(dev, np, NULL);
> + if (IS_ERR(ep->phy)) {
> + if (PTR_ERR(ep->phy) == -EPROBE_DEFER)
> + return PTR_ERR(ep->phy);
> + dev_warn(dev, "Use the 'phy' property. Current DT of pci-exynos was deprecated!!\n");
> + } else
> + ep->using_phy = true;
> +
> if (ep->ops && ep->ops->get_mem_resources) {
> ret = ep->ops->get_mem_resources(pdev, ep);
> if (ret)
> @@ -647,6 +690,9 @@ static int __init exynos_pcie_probe(struct platform_device *pdev)
> return 0;
>
> fail_probe:
> + if (ep->using_phy)
> + phy_exit(ep->phy);
> +
> if (ep->ops && ep->ops->deinit_clk_resources)
> ep->ops->deinit_clk_resources(ep);
> return ret;
> --
> 2.10.2
>