[+Pali]
On Thu, May 06, 2021 at 10:35:44AM +0800, Simon Xue wrote:
> Add a driver for the DesignWare-based PCIe controller found on
> RK356X. The existing pcie-rockchip-host driver is only used for
> the Rockchip-designed IP found on RK3399.
>
> Tested-by: Peter Geis <pgwipeout@xxxxxxxxx>
> Reviewed-by: Kever Yang <kever.yang@xxxxxxxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
I will remove this tag - it does not make sense on a patch adding
a new driver.
[...]
> +static int rockchip_pcie_start_link(struct dw_pcie *pci)
> +{
> + struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
> +
> + /* Reset device */
> + gpiod_set_value_cansleep(rockchip->rst_gpio, 0);
> +
> + rockchip_pcie_enable_ltssm(rockchip);
> +
> + /*
> + * PCIe requires the refclk to be stable for 100µs prior to releasing
> + * PERST. See table 2-4 in section 2.6.2 AC Specifications of the PCI
> + * Express Card Electromechanical Specification, 1.1. However, we don't
> + * know if the refclk is coming from RC's PHY or external OSC. If it's
> + * from RC, so enabling LTSSM is the just right place to release #PERST.
> + * We need more extra time as before, rather than setting just
> + * 100us as we don't know how long should the device need to reset.
> + */
> + msleep(100);
Any rationale behind the time chosen ?
Ongoing discussion:
https://lore.kernel.org/linux-pci/20210531090540.2663171-1-luca@xxxxxxxxxxxxxxxx
Lorenzo
> + gpiod_set_value_cansleep(rockchip->rst_gpio, 1);
> +
> + return 0;
> +}
> +
> +static int rockchip_pcie_host_init(struct pcie_port *pp)
> +{
> + struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> + struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
> + u32 val;
> +
> + /* LTSSM enable control mode */
> + val = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_HOT_RESET_CTRL);
> + val |= PCIE_LTSSM_ENABLE_ENHANCE | (PCIE_LTSSM_ENABLE_ENHANCE << 16);
> + rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL);
> +
> + rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_RC_MODE,
> + PCIE_CLIENT_GENERAL_CONTROL);
> +
> + return 0;
> +}
> +
> +static const struct dw_pcie_host_ops rockchip_pcie_host_ops = {
> + .host_init = rockchip_pcie_host_init,
> +};
> +
> +static int rockchip_pcie_clk_init(struct rockchip_pcie *rockchip)
> +{
> + struct device *dev = rockchip->pci.dev;
> + int ret;
> +
> + ret = devm_clk_bulk_get_all(dev, &rockchip->clks);
> + if (ret < 0)
> + return ret;
> +
> + rockchip->clk_cnt = ret;
> +
> + return clk_bulk_prepare_enable(rockchip->clk_cnt, rockchip->clks);
> +}
> +
> +static int rockchip_pcie_resource_get(struct platform_device *pdev,
> + struct rockchip_pcie *rockchip)
> +{
> + rockchip->apb_base = devm_platform_ioremap_resource_byname(pdev, "apb");
> + if (IS_ERR(rockchip->apb_base))
> + return PTR_ERR(rockchip->apb_base);
> +
> + rockchip->rst_gpio = devm_gpiod_get_optional(&pdev->dev, "reset",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(rockchip->rst_gpio))
> + return PTR_ERR(rockchip->rst_gpio);
> +
> + return 0;
> +}
> +
> +static int rockchip_pcie_phy_init(struct rockchip_pcie *rockchip)
> +{
> + struct device *dev = rockchip->pci.dev;
> + int ret;
> +
> + rockchip->phy = devm_phy_get(dev, "pcie-phy");
> + if (IS_ERR(rockchip->phy))
> + return dev_err_probe(dev, PTR_ERR(rockchip->phy),
> + "missing PHY\n");
> +
> + ret = phy_init(rockchip->phy);
> + if (ret < 0)
> + return ret;
> +
> + ret = phy_power_on(rockchip->phy);
> + if (ret)
> + phy_exit(rockchip->phy);
> +
> + return ret;
> +}
> +
> +static void rockchip_pcie_phy_deinit(struct rockchip_pcie *rockchip)
> +{
> + phy_exit(rockchip->phy);
> + phy_power_off(rockchip->phy);
> +}
> +
> +static int rockchip_pcie_reset_control_release(struct rockchip_pcie *rockchip)
> +{
> + struct device *dev = rockchip->pci.dev;
> +
> + rockchip->rst = devm_reset_control_array_get_exclusive(dev);
> + if (IS_ERR(rockchip->rst))
> + return dev_err_probe(dev, PTR_ERR(rockchip->rst),
> + "failed to get reset lines\n");
> +
> + return reset_control_deassert(rockchip->rst);
> +}
> +
> +static const struct dw_pcie_ops dw_pcie_ops = {
> + .link_up = rockchip_pcie_link_up,
> + .start_link = rockchip_pcie_start_link,
> +};
> +
> +static int rockchip_pcie_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct rockchip_pcie *rockchip;
> + struct pcie_port *pp;
> + int ret;
> +
> + rockchip = devm_kzalloc(dev, sizeof(*rockchip), GFP_KERNEL);
> + if (!rockchip)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, rockchip);
> +
> + rockchip->pci.dev = dev;
> + rockchip->pci.ops = &dw_pcie_ops;
> +
> + pp = &rockchip->pci.pp;
> + pp->ops = &rockchip_pcie_host_ops;
> +
> + ret = rockchip_pcie_resource_get(pdev, rockchip);
> + if (ret)
> + return ret;
> +
> + /* DON'T MOVE ME: must be enable before PHY init */
> + rockchip->vpcie3v3 = devm_regulator_get_optional(dev, "vpcie3v3");
> + if (IS_ERR(rockchip->vpcie3v3))
> + if (PTR_ERR(rockchip->vpcie3v3) != -ENODEV)
> + return dev_err_probe(dev, PTR_ERR(rockchip->vpcie3v3),
> + "failed to get vpcie3v3 regulator\n");
> +
> + ret = regulator_enable(rockchip->vpcie3v3);
> + if (ret) {
> + dev_err(dev, "failed to enable vpcie3v3 regulator\n");
> + return ret;
> + }
> +
> + ret = rockchip_pcie_phy_init(rockchip);
> + if (ret)
> + goto disable_regulator;
> +
> + ret = rockchip_pcie_reset_control_release(rockchip);
> + if (ret)
> + goto deinit_phy;
> +
> + ret = rockchip_pcie_clk_init(rockchip);
> + if (ret)
> + goto deinit_phy;
> +
> + ret = dw_pcie_host_init(pp);
> + if (!ret)
> + return 0;
> +
> + clk_bulk_disable_unprepare(rockchip->clk_cnt, rockchip->clks);
> +deinit_phy:
> + rockchip_pcie_phy_deinit(rockchip);
> +disable_regulator:
> + regulator_disable(rockchip->vpcie3v3);
> +
> + return ret;
> +}
> +
> +static const struct of_device_id rockchip_pcie_of_match[] = {
> + { .compatible = "rockchip,rk3568-pcie", },
> + {},
> +};
> +
> +static struct platform_driver rockchip_pcie_driver = {
> + .driver = {
> + .name = "rockchip-dw-pcie",
> + .of_match_table = rockchip_pcie_of_match,
> + .suppress_bind_attrs = true,
> + },
> + .probe = rockchip_pcie_probe,
> +};
> +builtin_platform_driver(rockchip_pcie_driver);
> --
> 2.25.1
>
>
>
