On Fri, Feb 10, 2023 at 7:49 AM Yoshihiro Shimoda
<yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
>
> Add R-Car Gen4 PCIe Host support. This controller is based on
> Synopsys DesignWare PCIe.
>
> This controller doesn't support MSI-X interrupt. So, introduce
> no_msix flag in struct dw_pcie_host_ops to clear MSI_FLAG_PCI_MSIX
> from dw_pcie_msi_domain_info.
>
> Note that this controller on R-Car S4-8 has an unexpected register
> value on the dbi+0x97b register. So, add a new capability flag
> which would force the unrolled eDMA mapping for the problematic
> device, as suggested by Serge Semin.
>
> 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-designware-host.c | 3 +
> drivers/pci/controller/dwc/pcie-designware.c | 8 +-
> drivers/pci/controller/dwc/pcie-designware.h | 6 +-
> .../pci/controller/dwc/pcie-rcar-gen4-host.c | 165 +++++++++++++++++
> drivers/pci/controller/dwc/pcie-rcar-gen4.c | 166 ++++++++++++++++++
> drivers/pci/controller/dwc/pcie-rcar-gen4.h | 63 +++++++
> 8 files changed, 419 insertions(+), 3 deletions(-)
> 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 434f6a4f4041..94805ec31a8f 100644
> --- a/drivers/pci/controller/dwc/Kconfig
> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -414,4 +414,13 @@ config PCIE_FU740
> Say Y here if you want PCIe controller support for the SiFive
> FU740.
>
> +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-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 9952057c8819..5aefeec15c9b 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -242,6 +242,9 @@ int dw_pcie_allocate_domains(struct dw_pcie_rp *pp)
>
> irq_domain_update_bus_token(pp->irq_domain, DOMAIN_BUS_NEXUS);
>
> + if (pp->no_msix)
> + dw_pcie_msi_domain_info.flags &= ~MSI_FLAG_PCI_MSIX;
> +
> pp->msi_domain = pci_msi_create_irq_domain(fwnode,
> &dw_pcie_msi_domain_info,
> pp->irq_domain);
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index b4315cf84340..7d649ba387f8 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -847,8 +847,14 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
> * Indirect eDMA CSRs access has been completely removed since v5.40a
> * thus no space is now reserved for the eDMA channels viewport and
> * former DMA CTRL register is no longer fixed to FFs.
> + *
> + * Note some devices for unknown reason may have zeros in the eDMA CTRL
> + * register even though the HW-manual explicitly states there must FFs
> + * if the unrolled mapping is enabled. For such cases the low-level
> + * drivers are supposed to manually activate the unrolled mapping to
> + * bypass the auto-detection procedure.
> */
> - if (dw_pcie_ver_is_ge(pci, 540A))
> + if (dw_pcie_ver_is_ge(pci, 540A) || dw_pcie_cap_is(pci, EDMA_UNROLL))
> val = 0xFFFFFFFF;
> else
> val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index 1a6e7e9489ee..1b1af514b849 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -51,8 +51,9 @@
>
> /* DWC PCIe controller capabilities */
> #define DW_PCIE_CAP_REQ_RES 0
> -#define DW_PCIE_CAP_IATU_UNROLL 1
> -#define DW_PCIE_CAP_CDM_CHECK 2
> +#define DW_PCIE_CAP_EDMA_UNROLL 1
> +#define DW_PCIE_CAP_IATU_UNROLL 2
> +#define DW_PCIE_CAP_CDM_CHECK 3
>
> #define dw_pcie_cap_is(_pci, _cap) \
> test_bit(DW_PCIE_CAP_ ## _cap, &(_pci)->caps)
> @@ -303,6 +304,7 @@ struct dw_pcie_host_ops {
> struct dw_pcie_rp {
> bool has_msi_ctrl:1;
> bool cfg0_io_shared:1;
> + bool no_msix:1;
> u64 cfg0_base;
> void __iomem *va_cfg0_base;
> u32 cfg0_size;
> 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..d60f4895ffe9
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4-host.c
> @@ -0,0 +1,165 @@
> +// 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/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;
> +
> + ret = rcar_gen4_pcie_set_device_type(rcar, true, dw->num_lanes);
> + if (ret < 0)
> + return ret;
> +
> + dw_pcie_dbi_ro_wr_en(dw);
> +
> + rcar_gen4_pcie_disable_bar(dw, BAR0MASKF);
> + rcar_gen4_pcie_disable_bar(dw, BAR1MASKF);
> +
> + 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);
> + }
> +
> + gpiod_set_value_cansleep(dw->pe_rst, 0);
> +
> + dw_pcie_setup_rc(pp);
> +
> + dw_pcie_dbi_ro_wr_en(dw);
> + rcar_gen4_pcie_set_max_link_width(dw, dw->num_lanes);
> + dw_pcie_dbi_ro_wr_dis(dw);
> +
> + if (!dw_pcie_link_up(dw)) {
> + ret = dw->ops->start_link(dw);
The DW core code does this for you.
> + if (ret)
> + return ret;
> + }
> +
> + /* Ignore errors, the link may come up later */
> + if (dw_pcie_wait_for_link(dw))
> + dev_info(dw->dev, "PCIe link down\n");
Same here.
> +
> + 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;
> + int ret;
> +
> + pp->ops = &rcar_gen4_pcie_host_ops;
> + pp->no_msix = true;
> + dw_pcie_cap_set(dw, REQ_RES);
> +
> + ret = dw_pcie_host_init(pp);
> + if (ret) {
> + dev_err(&pdev->dev, "Failed to initialize host\n");
If this failed, dw_pcie_host_init() should have printed an error. No
reason for every caller to print something.
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +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_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 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;
> +
> + err = rcar_gen4_add_dw_pcie_rp(rcar, pdev);
> + if (err < 0)
> + goto err_add;
If you didn't add it, then you shouldn't remove it. You are calling
remove on both failed and successful 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 = 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..a6a29d6125c8
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> @@ -0,0 +1,166 @@
> +// 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/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)
> +
> +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 int rcar_gen4_pcie_link_up(struct dw_pcie *dw)
> +{
> + struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
> + u32 val, mask;
> +
> + 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 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);
> +}
> +
> +void rcar_gen4_pcie_disable_bar(struct dw_pcie *dw, u32 bar_mask_reg)
> +{
> + dw_pcie_writel_dbi(dw, SHADOW_REG(bar_mask_reg), 0x0);
> +}
> +
> +void rcar_gen4_pcie_set_max_link_width(struct dw_pcie *dw, int num_lanes)
> +{
> + u32 val = dw_pcie_readl_dbi(dw, EXPCAP(PCI_EXP_LNKCAP));
> +
> + val &= ~PCI_EXP_LNKCAP_MLW;
> + switch (num_lanes) {
> + case 1:
> + val |= PCI_EXP_LNKCAP_MLW_X1;
> + break;
> + case 2:
> + val |= PCI_EXP_LNKCAP_MLW_X2;
> + break;
> + case 4:
> + val |= PCI_EXP_LNKCAP_MLW_X4;
> + break;
> + default:
> + dev_info(dw->dev, "Invalid num-lanes %d\n", num_lanes);
> + val |= PCI_EXP_LNKCAP_MLW_X1;
> + break;
The register field is just the number of lanes, why not do a macro
that just uses directly instead of essentially a lookup table:
val |= PCI_EXP_LNKCAP_MLW(num_lanes);
You shouldn't need to validate 'num_lanes' here except for a max
value. Though dtschema does that (or should). If you want to validate
it further in the kernel, do that somewhere common so everyone
benefits.
Or better yet, refactor this to be common. We already have Tegra194
doing the same thing.
> + }
> + dw_pcie_writel_dbi(dw, EXPCAP(PCI_EXP_LNKCAP), val);
> +}
> +
> +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);
> +}
> +
> +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;
> +}
> +
> +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..1cdce0cf7dac
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.h
> @@ -0,0 +1,63 @@
> +/* 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"
> +
> +/* PCI Express capability */
> +#define EXPCAP(x) (0x0070 + (x))
This offset is discoverable, don't hardcode it.
> +/* ASPM L1 PM Substates */
> +#define L1PSCAP(x) (0x01bc + (x))
> +/* PCI Shadow offset */
> +#define SHADOW_REG(x) (0x2000 + (x))
> +/* BAR Mask registers */
> +#define BAR0MASKF 0x0010
> +#define BAR1MASKF 0x0014
> +#define BAR2MASKF 0x0018
> +#define BAR3MASKF 0x001c
> +#define BAR4MASKF 0x0020
> +#define BAR5MASKF 0x0024
> +
> +/* 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;
> +};
> +#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);
> +int rcar_gen4_pcie_set_device_type(struct rcar_gen4_pcie *rcar, bool rc,
> + int num_lanes);
> +void rcar_gen4_pcie_disable_bar(struct dw_pcie *dw, u32 bar_mask_reg);
> +void rcar_gen4_pcie_set_max_link_width(struct dw_pcie *pci, 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_devm_reset_get(struct rcar_gen4_pcie *pcie,
> + struct device *dev);
> +struct rcar_gen4_pcie *rcar_gen4_pcie_devm_alloc(struct device *dev);
> +
> +#endif /* _PCIE_RCAR_GEN4_H_ */
> --
> 2.25.1
>
