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From: Rob Herring <robh+dt@kernel.org>
To: Simon Xue <xxm@rock-chips.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	PCI <linux-pci@vger.kernel.org>,
	"open list:ARM/Rockchip SoC..."
	<linux-rockchip@lists.infradead.org>,
	devicetree@vger.kernel.org, Johan Jonker <jbx6244@gmail.com>,
	Heiko Stuebner <heiko@sntech.de>,
	Shawn Lin <shawn.lin@rock-chips.com>
Subject: Re: [PATCH v6] PCI: rockchip: Add Rockchip RK356X host controller driver
Date: Tue, 13 Apr 2021 13:28:11 -0500	[thread overview]
Message-ID: <CAL_JsqKxP_i7U57UrG641ArD1symHfxvjWBxf_3gt3kVBBsp9Q@mail.gmail.com> (raw)
In-Reply-To: <20210325010413.3618261-1-xxm@rock-chips.com>

On Wed, Mar 24, 2021 at 8:04 PM Simon Xue <xxm@rock-chips.com> 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.
>
> Signed-off-by: Simon Xue <xxm@rock-chips.com>
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> ---
>  drivers/pci/controller/dwc/Kconfig            |  10 +
>  drivers/pci/controller/dwc/Makefile           |   1 +
>  drivers/pci/controller/dwc/pcie-dw-rockchip.c | 291 ++++++++++++++++++
>  3 files changed, 302 insertions(+)
>  create mode 100644 drivers/pci/controller/dwc/pcie-dw-rockchip.c
>
> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> index 22c5529e9a65..159791775cc6 100644
> --- a/drivers/pci/controller/dwc/Kconfig
> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -214,6 +214,16 @@ config PCIE_ARTPEC6_EP
>           Enables support for the PCIe controller in the ARTPEC-6 SoC to work in
>           endpoint mode. This uses the DesignWare core.
>
> +config PCIE_ROCKCHIP_DW_HOST
> +       bool "Rockchip DesignWare PCIe controller"
> +       select PCIE_DW
> +       select PCIE_DW_HOST
> +       depends on ARCH_ROCKCHIP || COMPILE_TEST
> +       depends on OF
> +       help
> +         Enables support for the DesignWare PCIe controller in the
> +         Rockchip SoC except RK3399.
> +
>  config PCIE_INTEL_GW
>         bool "Intel Gateway PCIe host controller support"
>         depends on OF && (X86 || COMPILE_TEST)
> diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
> index a751553fa0db..30eef8e9ee8a 100644
> --- a/drivers/pci/controller/dwc/Makefile
> +++ b/drivers/pci/controller/dwc/Makefile
> @@ -13,6 +13,7 @@ obj-$(CONFIG_PCI_LAYERSCAPE_EP) += pci-layerscape-ep.o
>  obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
>  obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
>  obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
> +obj-$(CONFIG_PCIE_ROCKCHIP_DW_HOST) += pcie-dw-rockchip.o
>  obj-$(CONFIG_PCIE_INTEL_GW) += pcie-intel-gw.o
>  obj-$(CONFIG_PCIE_KIRIN) += pcie-kirin.o
>  obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
> diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> new file mode 100644
> index 000000000000..6d003353d030
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> @@ -0,0 +1,291 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * PCIe host controller driver for Rockchip SoCs.
> + *
> + * Copyright (C) 2021 Rockchip Electronics Co., Ltd.
> + *             http://www.rock-chips.com
> + *
> + * Author: Simon Xue <xxm@rock-chips.com>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +
> +#include "pcie-designware.h"
> +
> +/*
> + * The upper 16 bits of PCIE_CLIENT_CONFIG are a write
> + * mask for the lower 16 bits.
> + */
> +#define HIWORD_UPDATE(mask, val) (((mask) << 16) | (val))
> +#define HIWORD_UPDATE_BIT(val) HIWORD_UPDATE(val, val)
> +
> +#define to_rockchip_pcie(x) dev_get_drvdata((x)->dev)
> +
> +#define PCIE_CLIENT_RC_MODE            HIWORD_UPDATE_BIT(0x40)
> +#define PCIE_CLIENT_ENABLE_LTSSM       HIWORD_UPDATE_BIT(0xc)
> +#define PCIE_SMLH_LINKUP               BIT(16)
> +#define PCIE_RDLH_LINKUP               BIT(17)
> +#define PCIE_LINKUP                    (PCIE_SMLH_LINKUP | PCIE_RDLH_LINKUP)
> +#define PCIE_L0S_ENTRY                 0x11
> +#define PCIE_CLIENT_GENERAL_CONTROL    0x0
> +#define PCIE_CLIENT_GENERAL_DEBUG      0x104
> +#define PCIE_CLIENT_HOT_RESET_CTRL      0x180
> +#define PCIE_CLIENT_LTSSM_STATUS       0x300
> +#define PCIE_LTSSM_ENABLE_ENHANCE       BIT(4)
> +
> +struct rockchip_pcie {
> +       struct dw_pcie                  pci;
> +       void __iomem                    *apb_base;
> +       struct phy                      *phy;
> +       struct clk_bulk_data            *clks;
> +       unsigned int                    clk_cnt;
> +       struct reset_control            *rst;
> +       struct gpio_desc                *rst_gpio;
> +       struct regulator                *vpcie3v3;
> +};
> +
> +static int rockchip_pcie_readl_apb(struct rockchip_pcie *rockchip,
> +                                            u32 reg)
> +{
> +       return readl(rockchip->apb_base + reg);
> +}
> +
> +static void rockchip_pcie_writel_apb(struct rockchip_pcie *rockchip,
> +                                               u32 val, u32 reg)
> +{
> +       writel(val, rockchip->apb_base + reg);
> +}
> +
> +static void rockchip_pcie_enable_ltssm(struct rockchip_pcie *rockchip)
> +{
> +       rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_ENABLE_LTSSM,
> +                                PCIE_CLIENT_GENERAL_CONTROL);
> +}
> +
> +static int rockchip_pcie_link_up(struct dw_pcie *pci)
> +{
> +       struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
> +       u32 val = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_LTSSM_STATUS);
> +
> +       if ((val & (PCIE_RDLH_LINKUP | PCIE_SMLH_LINKUP)) == PCIE_LINKUP &&
> +           (val & GENMASK(5, 0)) == PCIE_L0S_ENTRY)
> +               return 1;
> +
> +       return 0;
> +}
> +
> +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 a little more extra time as before, rather than setting just

1000x more is not 'a little more'.

> +        * 100us as we don't know how long should the device need to reset.
> +        */
> +       msleep(100);
> +       gpiod_set_value_cansleep(rockchip->rst_gpio, 1);
> +
> +       return 0;
> +}
> +
> +static void rockchip_pcie_fast_link_setup(struct rockchip_pcie *rockchip)
> +{
> +       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);
> +}
> +
> +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);
> +
> +       rockchip_pcie_fast_link_setup(rockchip);

This is the only caller, just move the function contents here.

> +
> +       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->rst),
> +                                       "failed to get vpcie3v3 regulator\n");
> +               rockchip->vpcie3v3 = NULL;

devm_regulator_get_optional should do all this for you. IOW, -ENODEV
is changed to a NULL return.

> +       }
> +
> +       if (rockchip->vpcie3v3) {

Don't need this.

> +               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);

This:
> +       if (ret)
> +               goto deinit_clk;
> +
> +       return 0;

can be:

if (!ret)
  return 0;

> +
> +deinit_clk:
> +       clk_bulk_disable_unprepare(rockchip->clk_cnt, rockchip->clks);
> +deinit_phy:
> +       rockchip_pcie_phy_deinit(rockchip);
> +disable_regulator:
> +       if (rockchip->vpcie3v3)

Don't need this check.

> +               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
>
>
>

      parent reply	other threads:[~2021-04-13 18:28 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-25  1:04 Simon Xue
2021-04-12  7:22 ` xxm
2021-04-13 18:28 ` Rob Herring [this message]

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