On Wed, Apr 26, 2023 at 01:55:54PM +0900, Yoshihiro Shimoda wrote:
> Add R-Car Gen4 PCIe Host support. This controller is based on
> Synopsys DesignWare PCIe, but this controller has vendor-specific
> registers so that requires initialization code like mode setting
> and retraining and so on.
>
> To reduce code delta, adds some helper functions which are used by
> both the host driver and the endpoint driver (whitch is added
s/whitch/which
> immediately afterwards) into a separate file.
>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/Kconfig | 9 +
> drivers/pci/controller/dwc/Makefile | 2 +
> .../pci/controller/dwc/pcie-rcar-gen4-host.c | 141 +++++++++++++
> drivers/pci/controller/dwc/pcie-rcar-gen4.c | 187 ++++++++++++++++++
> drivers/pci/controller/dwc/pcie-rcar-gen4.h | 48 +++++
> 5 files changed, 387 insertions(+)
> create mode 100644 drivers/pci/controller/dwc/pcie-rcar-gen4-host.c
> create mode 100644 drivers/pci/controller/dwc/pcie-rcar-gen4.c
> create mode 100644 drivers/pci/controller/dwc/pcie-rcar-gen4.h
>
> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> index ab96da43e0c2..64d4d37bc891 100644
> --- a/drivers/pci/controller/dwc/Kconfig
> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -415,4 +415,13 @@ config PCIE_VISCONTI_HOST
> Say Y here if you want PCIe controller support on Toshiba Visconti SoC.
> This driver supports TMPV7708 SoC.
>
> +config PCIE_RCAR_GEN4
> + tristate "Renesas R-Car Gen4 PCIe Host controller"
> + depends on ARCH_RENESAS || COMPILE_TEST
> + depends on PCI_MSI
> + select PCIE_DW_HOST
> + help
> + Say Y here if you want PCIe host controller support on R-Car Gen4 SoCs.
> + This uses the DesignWare core.
> +
> endmenu
> diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
> index bf5c311875a1..486cf706b53d 100644
> --- a/drivers/pci/controller/dwc/Makefile
> +++ b/drivers/pci/controller/dwc/Makefile
> @@ -26,6 +26,8 @@ obj-$(CONFIG_PCIE_TEGRA194) += pcie-tegra194.o
> obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
> obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
> obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.o
> +pcie-rcar-gen4-host-drv-objs := pcie-rcar-gen4.o pcie-rcar-gen4-host.o
> +obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4-host-drv.o
>
> # The following drivers are for devices that use the generic ACPI
> # pci_root.c driver but don't support standard ECAM config access.
> diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4-host.c b/drivers/pci/controller/dwc/pcie-rcar-gen4-host.c
> new file mode 100644
> index 000000000000..df7d80f1874f
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4-host.c
> @@ -0,0 +1,141 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * PCIe host controller driver for Renesas R-Car Gen4 Series SoCs
> + * Copyright (C) 2022-2023 Renesas Electronics Corporation
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +
> +#include "pcie-rcar-gen4.h"
> +#include "pcie-designware.h"
> +
> +static int rcar_gen4_pcie_host_init(struct dw_pcie_rp *pp)
> +{
> + struct dw_pcie *dw = to_dw_pcie_from_pp(pp);
> + struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
> + int ret;
> + u32 val;
> +
> + gpiod_set_value_cansleep(dw->pe_rst, 1);
> +
> + ret = rcar_gen4_pcie_set_device_type(rcar, true, dw->num_lanes);
> + if (ret < 0)
> + return ret;
> +
> + dw_pcie_dbi_ro_wr_en(dw);
> +
> + /*
> + * According to the section 3.5.7.2 "RC Mode" in DWC PCIe Dual Mode
> + * Rev.5.20a, we should disable two BARs to avoid unnecessary memory
> + * assignment during device enumeration.
> + */
> + dw_pcie_writel_dbi2(dw, PCI_BASE_ADDRESS_0, 0x0);
> + dw_pcie_writel_dbi2(dw, PCI_BASE_ADDRESS_1, 0x0);
> +
> + dw_pcie_dbi_ro_wr_dis(dw);
> +
> + if (IS_ENABLED(CONFIG_PCI_MSI)) {
> + /* Enable MSI interrupt signal */
> + val = readl(rcar->base + PCIEINTSTS0EN);
> + val |= MSI_CTRL_INT;
> + writel(val, rcar->base + PCIEINTSTS0EN);
> + }
> +
> + msleep(100); /* pe_rst requires 100msec delay */
> +
> + gpiod_set_value_cansleep(dw->pe_rst, 0);
> +
> + return 0;
> +}
> +
> +static const struct dw_pcie_host_ops rcar_gen4_pcie_host_ops = {
> + .host_init = rcar_gen4_pcie_host_init,
> +};
> +
> +static int rcar_gen4_add_dw_pcie_rp(struct rcar_gen4_pcie *rcar,
> + struct platform_device *pdev)
> +{
> + struct dw_pcie *dw = &rcar->dw;
> + struct dw_pcie_rp *pp = &dw->pp;
> +
> + pp->num_vectors = MAX_MSI_IRQS;
> + pp->ops = &rcar_gen4_pcie_host_ops;
> + dw_pcie_cap_set(dw, REQ_RES);
> +
> + return dw_pcie_host_init(pp);
> +}
> +
> +static void rcar_gen4_remove_dw_pcie_rp(struct rcar_gen4_pcie *rcar)
> +{
> + dw_pcie_host_deinit(&rcar->dw.pp);
> + gpiod_set_value_cansleep(rcar->dw.pe_rst, 1);
> +}
> +
> +static int rcar_gen4_pcie_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct rcar_gen4_pcie *rcar;
> + int err;
> +
> + rcar = rcar_gen4_pcie_devm_alloc(dev);
> + if (!rcar)
> + return -ENOMEM;
> +
> + err = rcar_gen4_pcie_get_resources(rcar, pdev);
> + if (err < 0) {
> + dev_err(dev, "Failed to request resource: %d\n", err);
> + return err;
> + }
> +
> + platform_set_drvdata(pdev, rcar);
> +
> + err = rcar_gen4_pcie_prepare(rcar);
> + if (err < 0)
> + return err;
> +
> + rcar->needs_retrain = true;
> + err = rcar_gen4_add_dw_pcie_rp(rcar, pdev);
> + if (err < 0)
> + goto err_add;
> +
> + return 0;
> +
> +err_add:
> + rcar_gen4_pcie_unprepare(rcar);
> +
> + return err;
> +}
> +
> +static int rcar_gen4_pcie_remove(struct platform_device *pdev)
> +{
> + struct rcar_gen4_pcie *rcar = platform_get_drvdata(pdev);
> +
> + rcar_gen4_remove_dw_pcie_rp(rcar);
> + rcar_gen4_pcie_unprepare(rcar);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id rcar_gen4_pcie_of_match[] = {
> + { .compatible = "renesas,rcar-gen4-pcie", },
> + {},
> +};
> +
> +static struct platform_driver rcar_gen4_pcie_driver = {
> + .driver = {
> + .name = "pcie-rcar-gen4",
> + .of_match_table = rcar_gen4_pcie_of_match,
> + .probe_type = PROBE_PREFER_ASYNCHRONOUS,
> + },
> + .probe = rcar_gen4_pcie_probe,
> + .remove = rcar_gen4_pcie_remove,
> +};
> +module_platform_driver(rcar_gen4_pcie_driver);
> +
> +MODULE_DESCRIPTION("Renesas R-Car Gen4 PCIe host controller driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> new file mode 100644
> index 000000000000..ee916a149708
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> @@ -0,0 +1,187 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * PCIe host/endpoint controller driver for Renesas R-Car Gen4 Series SoCs
> + * Copyright (C) 2022-2023 Renesas Electronics Corporation
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/of_device.h>
> +#include <linux/pci.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/reset.h>
> +
> +#include "pcie-rcar-gen4.h"
> +#include "pcie-designware.h"
> +
> +/* Renesas-specific */
> +#define PCIERSTCTRL1 0x0014
> +#define APP_HOLD_PHY_RST BIT(16)
> +#define APP_LTSSM_ENABLE BIT(0)
> +
> +#define RETRAIN_MAX_RETRY 10
> +
> +static void rcar_gen4_pcie_ltssm_enable(struct rcar_gen4_pcie *rcar,
> + bool enable)
> +{
> + u32 val;
> +
> + val = readl(rcar->base + PCIERSTCTRL1);
> + if (enable) {
> + val |= APP_LTSSM_ENABLE;
> + val &= ~APP_HOLD_PHY_RST;
> + } else {
> + val &= ~APP_LTSSM_ENABLE;
> + val |= APP_HOLD_PHY_RST;
> + }
> + writel(val, rcar->base + PCIERSTCTRL1);
> +}
> +
> +static bool rcar_gen4_pcie_check_retrain_link(struct dw_pcie *dw)
> +{
> + u8 offset = dw_pcie_find_capability(dw, PCI_CAP_ID_EXP);
> + u32 lnkcap = dw_pcie_readl_dbi(dw, offset + PCI_EXP_LNKCAP);
> + u32 lnkctl = dw_pcie_readl_dbi(dw, offset + PCI_EXP_LNKCTL);
> + u16 lnksta = dw_pcie_readw_dbi(dw, offset + PCI_EXP_LNKSTA);
> + int i;
> +
> + if ((lnksta & PCI_EXP_LNKSTA_CLS) == (lnkcap & PCI_EXP_LNKCAP_SLS))
> + return true;
> +
> + lnkctl |= PCI_EXP_LNKCTL_RL;
> + dw_pcie_writel_dbi(dw, offset + PCI_EXP_LNKCTL, lnkctl);
> +
> + for (i = 0; i < RETRAIN_MAX_RETRY; i++) {
> + lnksta = dw_pcie_readw_dbi(dw, offset + PCI_EXP_LNKSTA);
> + if (lnksta & PCI_EXP_LNKSTA_LT)
> + return true;
> + usleep_range(1000, 1100);
> + }
> +
> + return false;
> +}
> +
> +static int rcar_gen4_pcie_link_up(struct dw_pcie *dw)
> +{
> + struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
> + u32 val, mask;
> +
> + /*
> + * Require retraining here. Otherwise RDLH_LINK_UP of PCIEINTSTS0 which
> + * is this controller specific register may not be set.
> + */
> + if (rcar->needs_retrain && !rcar_gen4_pcie_check_retrain_link(dw))
> + return 0;
Retraining the link on each link-up test doesn't seem right. What
about moving the PCI_EXP_LNKCTL.PCI_EXP_LNKCTL_RL field update to the
start_link() callback? Will that be enough to make sure that the link
will be established afterwards?
* Note on Baikal-T1 PCIe we also have had a problem with establishing
* the higher gen link. (It's Gen3 in our case.) But instead of
* re-training the link all over we get to set the
* GEN2_CTRL_OFF.DIRECT_SPEED_CHANGE flag which causes the higher gen
* link establishment right away. Please see
* pcie-bt1.c:bt1_pcie_start_link() function for reference.
> +
> + val = readl(rcar->base + PCIEINTSTS0);
> + mask = RDLH_LINK_UP | SMLH_LINK_UP;
> +
> + return (val & mask) == mask;
> +}
> +
> +static int rcar_gen4_pcie_start_link(struct dw_pcie *dw)
> +{
> + struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
> +
> + rcar_gen4_pcie_ltssm_enable(rcar, true);
> +
> + return 0;
> +}
> +
> +static void rcar_gen4_pcie_stop_link(struct dw_pcie *dw)
> +{
> + struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
> +
> + rcar_gen4_pcie_ltssm_enable(rcar, false);
> +}
> +
> +int rcar_gen4_pcie_set_device_type(struct rcar_gen4_pcie *rcar, bool rc,
> + int num_lanes)
> +{
> + u32 val;
> +
> + /* Note: Assume the rcar->rst which is Cold-reset is asserted here */
> + val = readl(rcar->base + PCIEMSR0);
> + if (rc)
> + val |= DEVICE_TYPE_RC;
> + else
> + val |= DEVICE_TYPE_EP;
> +
> + if (num_lanes < 4)
> + val |= BIFUR_MOD_SET_ON;
> +
> + writel(val, rcar->base + PCIEMSR0);
> +
> + return reset_control_deassert(rcar->rst);
> +}
> +
> +int rcar_gen4_pcie_prepare(struct rcar_gen4_pcie *rcar)
> +{
> + struct device *dev = rcar->dw.dev;
> + int err;
> +
> + pm_runtime_enable(dev);
> + err = pm_runtime_resume_and_get(dev);
> + if (err < 0) {
> + dev_err(dev, "Failed to resume/get Runtime PM\n");
> + pm_runtime_disable(dev);
> + }
> +
> + return err;
> +}
> +
> +void rcar_gen4_pcie_unprepare(struct rcar_gen4_pcie *rcar)
> +{
> + struct device *dev = rcar->dw.dev;
> +
> + if (!reset_control_status(rcar->rst))
> + reset_control_assert(rcar->rst);
> + pm_runtime_put(dev);
> + pm_runtime_disable(dev);
> +}
> +
> +static int rcar_gen4_pcie_devm_reset_get(struct rcar_gen4_pcie *rcar,
> + struct device *dev)
> +{
> + rcar->rst = devm_reset_control_get(dev, NULL);
> + if (IS_ERR(rcar->rst)) {
> + dev_err(dev, "Failed to get Cold-reset\n");
> + return PTR_ERR(rcar->rst);
> + }
> +
> + return 0;
> +}
Since v9 this method has been no longer globally defined. What about
moving its content to rcar_gen4_pcie_get_resources()? Thus the later
will still look coherent meanwhile we'll be able to drop an
excessive function definition with no harm to the code readability.
> +
> +int rcar_gen4_pcie_get_resources(struct rcar_gen4_pcie *rcar,
> + struct platform_device *pdev)
> +{
> + struct dw_pcie *dw = &rcar->dw;
> +
> + /* Renesas-specific registers */
> + rcar->base = devm_platform_ioremap_resource_byname(pdev, "app");
> + if (IS_ERR(rcar->base))
> + return PTR_ERR(rcar->base);
> +
> + return rcar_gen4_pcie_devm_reset_get(rcar, dw->dev);
> +}
> +
> +static const struct dw_pcie_ops dw_pcie_ops = {
> + .start_link = rcar_gen4_pcie_start_link,
> + .stop_link = rcar_gen4_pcie_stop_link,
> + .link_up = rcar_gen4_pcie_link_up,
> +};
> +
> +struct rcar_gen4_pcie *rcar_gen4_pcie_devm_alloc(struct device *dev)
> +{
> + struct rcar_gen4_pcie *rcar;
> +
> + rcar = devm_kzalloc(dev, sizeof(*rcar), GFP_KERNEL);
> + if (!rcar)
> + return NULL;
> +
> + rcar->dw.dev = dev;
> + rcar->dw.ops = &dw_pcie_ops;
> + dw_pcie_cap_set(&rcar->dw, EDMA_UNROLL);
> +
> + return rcar;
> +}
> diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.h b/drivers/pci/controller/dwc/pcie-rcar-gen4.h
> new file mode 100644
> index 000000000000..7c765c2d79b9
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.h
> @@ -0,0 +1,48 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * PCIe host/endpoint controller driver for Renesas R-Car Gen4 Series SoCs
> + * Copyright (C) 2022-2023 Renesas Electronics Corporation
> + */
> +
> +#ifndef _PCIE_RCAR_GEN4_H_
> +#define _PCIE_RCAR_GEN4_H_
> +
> +#include <linux/io.h>
> +#include <linux/pci.h>
> +#include <linux/reset.h>
> +
> +#include "pcie-designware.h"
> +
> +/* Renesas-specific */
> +#define PCIEMSR0 0x0000
> +#define BIFUR_MOD_SET_ON BIT(0)
> +#define DEVICE_TYPE_EP 0
> +#define DEVICE_TYPE_RC BIT(4)
> +
> +#define PCIEINTSTS0 0x0084
> +#define PCIEINTSTS0EN 0x0310
> +#define MSI_CTRL_INT BIT(26)
> +#define SMLH_LINK_UP BIT(7)
> +#define RDLH_LINK_UP BIT(6)
> +#define PCIEDMAINTSTSEN 0x0314
> +#define PCIEDMAINTSTSEN_INIT GENMASK(15, 0)
> +
> +struct rcar_gen4_pcie {
> + struct dw_pcie dw;
> + void __iomem *base;
> + struct reset_control *rst;
> + bool needs_retrain;
> +};
> +#define to_rcar_gen4_pcie(x) dev_get_drvdata((x)->dev)
> +
> +u32 rcar_gen4_pcie_readl(struct rcar_gen4_pcie *pcie, u32 reg);
> +void rcar_gen4_pcie_writel(struct rcar_gen4_pcie *pcie, u32 reg, u32 val);
I don't see these methods being defined here.
-Serge(y)
> +int rcar_gen4_pcie_set_device_type(struct rcar_gen4_pcie *rcar, bool rc,
> + int num_lanes);
> +int rcar_gen4_pcie_prepare(struct rcar_gen4_pcie *pcie);
> +void rcar_gen4_pcie_unprepare(struct rcar_gen4_pcie *pcie);
> +int rcar_gen4_pcie_get_resources(struct rcar_gen4_pcie *rcar,
> + struct platform_device *pdev);
> +struct rcar_gen4_pcie *rcar_gen4_pcie_devm_alloc(struct device *dev);
> +
> +#endif /* _PCIE_RCAR_GEN4_H_ */
> --
> 2.25.1
>
