Add R-Car Gen4 PCIe controller support for host mode. This controller is based on Synopsys DesignWare PCIe. However, this particular controller has a number of vendor-specific registers, and as such, requires initialization code like mode setting and retraining and so on. [kwilczynski: commit log] Link: https://lore.kernel.org/linux-pci/20230825093219.2685912-17-yoshihiro.shimoda.uh@xxxxxxxxxxx Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> Signed-off-by: Krzysztof Wilczyński <kwilczynski@xxxxxxxxxx> Reviewed-by: Serge Semin <fancer.lancer@xxxxxxxxx> --- drivers/pci/controller/dwc/Kconfig | 14 + drivers/pci/controller/dwc/Makefile | 1 + drivers/pci/controller/dwc/pcie-rcar-gen4.c | 381 ++++++++++++++++++++ 3 files changed, 396 insertions(+) create mode 100644 drivers/pci/controller/dwc/pcie-rcar-gen4.c diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig index ab96da43e0c2..bc69fcab2e2a 100644 --- a/drivers/pci/controller/dwc/Kconfig +++ b/drivers/pci/controller/dwc/Kconfig @@ -415,4 +415,18 @@ 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 + +config PCIE_RCAR_GEN4_HOST + tristate "Renesas R-Car Gen4 PCIe controller (host mode)" + depends on ARCH_RENESAS || COMPILE_TEST + depends on PCI_MSI + select PCIE_DW_HOST + select PCIE_RCAR_GEN4 + help + Say Y here if you want PCIe controller (host mode) on R-Car Gen4 SoCs. + To compile this driver as a module, choose M here: the module will be + called pcie-rcar-gen4.ko. This uses the DesignWare core. + endmenu diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile index bf5c311875a1..bac103faa523 100644 --- a/drivers/pci/controller/dwc/Makefile +++ b/drivers/pci/controller/dwc/Makefile @@ -26,6 +26,7 @@ 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 +obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4.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.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c new file mode 100644 index 000000000000..f6b3c3ef187c --- /dev/null +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c @@ -0,0 +1,381 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * PCIe 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/io.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/pci.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/reset.h> + +#include "../../pci.h" +#include "pcie-designware.h" + +/* Renesas-specific */ +/* PCIe Mode Setting Register 0 */ +#define PCIEMSR0 0x0000 +#define BIFUR_MOD_SET_ON BIT(0) +#define DEVICE_TYPE_EP 0 +#define DEVICE_TYPE_RC BIT(4) + +/* PCIe Interrupt Status 0 */ +#define PCIEINTSTS0 0x0084 + +/* PCIe Interrupt Status 0 Enable */ +#define PCIEINTSTS0EN 0x0310 +#define MSI_CTRL_INT BIT(26) +#define SMLH_LINK_UP BIT(7) +#define RDLH_LINK_UP BIT(6) + +/* PCIe DMA Interrupt Status Enable */ +#define PCIEDMAINTSTSEN 0x0314 +#define PCIEDMAINTSTSEN_INIT GENMASK(15, 0) + +/* PCIe Reset Control Register 1 */ +#define PCIERSTCTRL1 0x0014 +#define APP_HOLD_PHY_RST BIT(16) +#define APP_LTSSM_ENABLE BIT(0) + +#define RCAR_NUM_SPEED_CHANGE_RETRIES 10 +#define RCAR_MAX_LINK_SPEED 4 + +struct rcar_gen4_pcie { + struct dw_pcie dw; + void __iomem *base; + struct platform_device *pdev; + enum dw_pcie_device_mode mode; +}; +#define to_rcar_gen4_pcie(_dw) container_of(_dw, struct rcar_gen4_pcie, dw) + +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 { + /* + * Since the datasheet of R-Car doesn't mention how to assert + * the APP_HOLD_PHY_RST, don't assert it again. Otherwise, + * hang-up issue happened in the dw_edma_core_off() when + * the controller didn't detect a PCI device. + */ + val &= ~APP_LTSSM_ENABLE; + } + 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; +} + +/* + * Manually initiate the speed change. Return true if the change succeeded, + * false if the change didn't finish within certain periods. + */ +static int rcar_gen4_pcie_speed_change(struct dw_pcie *dw) +{ + u32 val; + int i; + + val = dw_pcie_readl_dbi(dw, PCIE_LINK_WIDTH_SPEED_CONTROL); + val &= ~PORT_LOGIC_SPEED_CHANGE; + dw_pcie_writel_dbi(dw, PCIE_LINK_WIDTH_SPEED_CONTROL, val); + + val = dw_pcie_readl_dbi(dw, PCIE_LINK_WIDTH_SPEED_CONTROL); + val |= PORT_LOGIC_SPEED_CHANGE; + dw_pcie_writel_dbi(dw, PCIE_LINK_WIDTH_SPEED_CONTROL, val); + + for (i = 0; i < RCAR_NUM_SPEED_CHANGE_RETRIES; i++) { + val = dw_pcie_readl_dbi(dw, PCIE_LINK_WIDTH_SPEED_CONTROL); + if (!(val & PORT_LOGIC_SPEED_CHANGE)) + return 0; + usleep_range(10000, 11000); + } + + return -ETIMEDOUT; +} + +/* + * Enable LTSSM of this controller and manually initiate the speed change. + * Always return 0. + */ +static int rcar_gen4_pcie_start_link(struct dw_pcie *dw) +{ + struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw); + int i, changes; + + rcar_gen4_pcie_ltssm_enable(rcar, true); + + /* + * Require direct speed change with retrying here if the link_gen is + * PCIe Gen2 or higher. + */ + changes = min_not_zero(dw->link_gen, RCAR_MAX_LINK_SPEED) - 1; + + /* + * Since dw_pcie_setup_rc() sets it once, PCIe Gen2 will be trained. + * So, this needs remaining times for up to PCIe Gen4 if RC mode. + */ + if (changes && rcar->mode == DW_PCIE_RC_TYPE) + changes--; + + for (i = 0; i < changes; i++) { + /* No error because possible disconnected here if EP mode */ + if (rcar_gen4_pcie_speed_change(dw)) + break; + } + + 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); +} + +static int rcar_gen4_pcie_common_init(struct rcar_gen4_pcie *rcar) +{ + struct dw_pcie *dw = &rcar->dw; + u32 val; + int ret; + + ret = clk_bulk_prepare_enable(DW_PCIE_NUM_CORE_CLKS, dw->core_clks); + if (ret) { + dev_err(dw->dev, "Failed to enable ref clocks\n"); + return ret; + } + + if (!reset_control_status(dw->core_rsts[DW_PCIE_PWR_RST].rstc)) + reset_control_assert(dw->core_rsts[DW_PCIE_PWR_RST].rstc); + + val = readl(rcar->base + PCIEMSR0); + if (rcar->mode == DW_PCIE_RC_TYPE) { + val |= DEVICE_TYPE_RC; + } else if (rcar->mode == DW_PCIE_EP_TYPE) { + val |= DEVICE_TYPE_EP; + } else { + ret = -EINVAL; + goto err_unprepare; + } + + if (dw->num_lanes < 4) + val |= BIFUR_MOD_SET_ON; + + writel(val, rcar->base + PCIEMSR0); + + ret = reset_control_deassert(dw->core_rsts[DW_PCIE_PWR_RST].rstc); + if (ret) + goto err_unprepare; + + return 0; + +err_unprepare: + clk_bulk_disable_unprepare(DW_PCIE_NUM_CORE_CLKS, dw->core_clks); + + return ret; +} + +static void rcar_gen4_pcie_common_deinit(struct rcar_gen4_pcie *rcar) +{ + struct dw_pcie *dw = &rcar->dw; + + reset_control_assert(dw->core_rsts[DW_PCIE_PWR_RST].rstc); + clk_bulk_disable_unprepare(DW_PCIE_NUM_CORE_CLKS, dw->core_clks); +} + +static 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; +} + +static void rcar_gen4_pcie_unprepare(struct rcar_gen4_pcie *rcar) +{ + struct device *dev = rcar->dw.dev; + + pm_runtime_put(dev); + pm_runtime_disable(dev); +} + +static int rcar_gen4_pcie_get_resources(struct rcar_gen4_pcie *rcar) +{ + /* Renesas-specific registers */ + rcar->base = devm_platform_ioremap_resource_byname(rcar->pdev, "app"); + + return PTR_ERR_OR_ZERO(rcar->base); +} + +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, +}; + +static struct +rcar_gen4_pcie *rcar_gen4_pcie_devm_alloc(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rcar_gen4_pcie *rcar; + + rcar = devm_kzalloc(dev, sizeof(*rcar), GFP_KERNEL); + if (!rcar) + return ERR_PTR(-ENOMEM); + + rcar->dw.ops = &dw_pcie_ops; + rcar->dw.dev = dev; + rcar->pdev = pdev; + dw_pcie_cap_set(&rcar->dw, EDMA_UNROLL); + dw_pcie_cap_set(&rcar->dw, REQ_RES); + platform_set_drvdata(pdev, rcar); + + return rcar; +} + +/* Host mode */ +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_common_init(rcar); + if (ret) + return ret; + + /* + * 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); + + /* Enable MSI interrupt signal */ + val = readl(rcar->base + PCIEINTSTS0EN); + val |= MSI_CTRL_INT; + writel(val, rcar->base + PCIEINTSTS0EN); + + msleep(PCIE_T_PVPERL_MS); /* pe_rst requires 100msec delay */ + + gpiod_set_value_cansleep(dw->pe_rst, 0); + + return 0; +} + +static void rcar_gen4_pcie_host_deinit(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); + + gpiod_set_value_cansleep(dw->pe_rst, 1); + rcar_gen4_pcie_common_deinit(rcar); +} + +static const struct dw_pcie_host_ops rcar_gen4_pcie_host_ops = { + .host_init = rcar_gen4_pcie_host_init, + .host_deinit = rcar_gen4_pcie_host_deinit, +}; + +static int rcar_gen4_add_dw_pcie_rp(struct rcar_gen4_pcie *rcar) +{ + struct dw_pcie_rp *pp = &rcar->dw.pp; + + pp->num_vectors = MAX_MSI_IRQS; + pp->ops = &rcar_gen4_pcie_host_ops; + rcar->mode = DW_PCIE_RC_TYPE; + + 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); +} + +static int rcar_gen4_pcie_probe(struct platform_device *pdev) +{ + struct rcar_gen4_pcie *rcar; + int err; + + rcar = rcar_gen4_pcie_devm_alloc(pdev); + if (IS_ERR(rcar)) + return PTR_ERR(rcar); + + err = rcar_gen4_pcie_get_resources(rcar); + if (err) + return err; + + err = rcar_gen4_pcie_prepare(rcar); + if (err) + return err; + + err = rcar_gen4_add_dw_pcie_rp(rcar); + if (err) + goto err_unprepare; + + return 0; + +err_unprepare: + rcar_gen4_pcie_unprepare(rcar); + + return err; +} + +static void 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); +} + +static const struct of_device_id rcar_gen4_pcie_of_match[] = { + { .compatible = "renesas,rcar-gen4-pcie", }, + {}, +}; +MODULE_DEVICE_TABLE(of, rcar_gen4_pcie_of_match); + +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_new = rcar_gen4_pcie_remove, +}; +module_platform_driver(rcar_gen4_pcie_driver); + +MODULE_DESCRIPTION("Renesas R-Car Gen4 PCIe controller driver"); +MODULE_LICENSE("GPL"); -- 2.25.1
