Re: [PATCH v8 4/6] PCI: tegra: Add Tegra264 support
Manikanta Maddireddy <[email protected]> Fri, 24 Jul 2026 13:58:15 +0530
| Newsgroups | org.kernel.vger.linux-tegra,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel,org.kernel.vger.linux-pci |
|---|---|
| Message-ID | <[email protected]> |
On 16/07/26 10:37 pm, Thierry Reding wrote: > From: Thierry Reding <[email protected]> > > Add a driver for the PCIe controller found on NVIDIA Tegra264 SoCs. The > driver is very small, with its main purpose being to set up the address > translation registers and then creating a standard PCI host using ECAM. > > Signed-off-by: Manikanta Maddireddy <[email protected]> > Signed-off-by: Thierry Reding <[email protected]> > --- > Changes in v8: > - remove controller deinitialization, firmware does this already > - separately track hotplug support and link up state for clarity > - select pinctrl sleep state on suspend for symmetry with resume > - fail probe if the link is down and not hotplug-capable > - remove WAKE# IRQ support > - add err_ prefix to gotos > > Changes in v7: > - select PCI_ECAM to satisfy the build dependency (Jonathan Hunter) > - remove pre-silicon support patch to avoid extra build dependency > > Changes in v6: > - remove unneeded pm_runtime_disable() call (Sashiko) > - do not use noirq suspend/resume callbacks (Sashiko) > - wrap PM ops in pm_ptr() macro (Sashiko) > - use standard wait times with msleep() (Lukas Wunner) > - properly check errors for wake IRQs > - fix build failures /o\ > > Changes in v5: > - make PCIE_TEGRA264 symbol tristate > - drop dependency on PCI_MSI > - reorganize tegra264_pcie struct > - use standard wake-gpios property > - rename tegra264_pcie_bpmp_set_rp_state() to tegra264_pcie_power_off() > - use dev_err() instead of dev_info() for some error messages > - add clarifying comment as to why bandwidth requests aren't fatal > - address some compiler warnings on 32-bit physical address platforms > - drop needless comments > - explicitly deinitialize controller on suspend > - use devm_pm_runtime_active_enabled() > - rename "free" label to "free_ecam" > - use dev_err_probe() in more places > - reselect default pin state during resume, not probe > - return early on absence of wake GPIO > - simplify BW value calculation > > Changes in v2: > - specify generations applicable for PCI_TEGRA driver to avoid confusion > - drop SPDX-FileCopyrightText tag > - rename link_state to link_up to clarify meaning > - replace memset() by an empty initializer > - sanity-check only enable BAR regions > - bring PCI link out of reset in case firmware didn't > - use common wait times instead of defining our own > - use core helpers to parse and print PCI link speed > - fix multi-line comment > - use dev_err_probe() more ubiquitously > - fix probe sequence and error cleanup > - use DEFINE_NOIRQ_DEV_PM_OPS() to avoid warnings for !PM_SUSPEND > - reuse more standard registers and remove unused register definitions > - use %pe and ERR_PTR() to print symbolic errors > - add signed-off-by from Manikanta as the original author > - add myself as author after significantly modifying the driver > --- > drivers/pci/controller/Kconfig | 10 +- > drivers/pci/controller/Makefile | 1 + > drivers/pci/controller/pcie-tegra264.c | 485 +++++++++++++++++++++++++++++++++ > 3 files changed, 495 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig > index 2247709ef6d6..3045c8aecc7e 100644 > --- a/drivers/pci/controller/Kconfig > +++ b/drivers/pci/controller/Kconfig > @@ -255,7 +255,15 @@ config PCI_TEGRA > select IRQ_MSI_LIB > help > Say Y here if you want support for the PCIe host controller found > - on NVIDIA Tegra SoCs. > + on NVIDIA Tegra SoCs (Tegra20 through Tegra186). > + > +config PCIE_TEGRA264 > + tristate "NVIDIA Tegra264 PCIe controller" > + depends on ARCH_TEGRA || COMPILE_TEST > + select PCI_ECAM > + help > + Say Y here if you want support for the PCIe host controller found > + on NVIDIA Tegra264 SoCs. > > config PCIE_RCAR_HOST > bool "Renesas R-Car PCIe controller (host mode)" > diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile > index ac8db283f0fe..d478743b5142 100644 > --- a/drivers/pci/controller/Makefile > +++ b/drivers/pci/controller/Makefile > @@ -7,6 +7,7 @@ obj-$(CONFIG_PCI_HYPERV_INTERFACE) += pci-hyperv-intf.o > obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o > obj-$(CONFIG_PCI_AARDVARK) += pci-aardvark.o > obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o > +obj-$(CONFIG_PCIE_TEGRA264) += pcie-tegra264.o > obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o > obj-$(CONFIG_PCIE_RCAR_HOST) += pcie-rcar.o pcie-rcar-host.o > obj-$(CONFIG_PCIE_RCAR_EP) += pcie-rcar.o pcie-rcar-ep.o > diff --git a/drivers/pci/controller/pcie-tegra264.c b/drivers/pci/controller/pcie-tegra264.c > new file mode 100644 > index 000000000000..7071f4b3b97b > --- /dev/null > +++ b/drivers/pci/controller/pcie-tegra264.c > @@ -0,0 +1,485 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * PCIe host controller driver for Tegra264 SoC > + * > + * Copyright (c) 2022-2026, NVIDIA CORPORATION. All rights reserved. > + */ > + > +#include <linux/delay.h> > +#include <linux/gpio/consumer.h> GPIO header can be removed since WAKE gpio feature is removed. > +#include <linux/init.h> > +#include <linux/interconnect.h> > +#include <linux/interrupt.h> Interrupt header file can be removed. > +#include <linux/iopoll.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of_address.h> > +#include <linux/of_device.h> > +#include <linux/of.h> > +#include <linux/of_pci.h> > +#include <linux/of_platform.h> > +#include <linux/pci-ecam.h> > +#include <linux/pci.h> > +#include <linux/pinctrl/consumer.h> > +#include <linux/platform_device.h> > +#include <linux/pm_runtime.h> > + > +#include <soc/tegra/bpmp.h> > +#include <soc/tegra/bpmp-abi.h> > +#include <soc/tegra/fuse.h> > + > +#include "../pci.h" > + > +/* XAL registers */ > +#define XAL_RC_ECAM_BASE_HI 0x00 > +#define XAL_RC_ECAM_BASE_LO 0x04 > +#define XAL_RC_ECAM_BUSMASK 0x08 > +#define XAL_RC_IO_BASE_HI 0x0c > +#define XAL_RC_IO_BASE_LO 0x10 > +#define XAL_RC_IO_LIMIT_HI 0x14 > +#define XAL_RC_IO_LIMIT_LO 0x18 > +#define XAL_RC_MEM_32BIT_BASE_HI 0x1c > +#define XAL_RC_MEM_32BIT_BASE_LO 0x20 > +#define XAL_RC_MEM_32BIT_LIMIT_HI 0x24 > +#define XAL_RC_MEM_32BIT_LIMIT_LO 0x28 > +#define XAL_RC_MEM_64BIT_BASE_HI 0x2c > +#define XAL_RC_MEM_64BIT_BASE_LO 0x30 > +#define XAL_RC_MEM_64BIT_LIMIT_HI 0x34 > +#define XAL_RC_MEM_64BIT_LIMIT_LO 0x38 > +#define XAL_RC_BAR_CNTL_STANDARD 0x40 > +#define XAL_RC_BAR_CNTL_STANDARD_IOBAR_EN BIT(0) > +#define XAL_RC_BAR_CNTL_STANDARD_32B_BAR_EN BIT(1) > +#define XAL_RC_BAR_CNTL_STANDARD_64B_BAR_EN BIT(2) > + > +/* XTL registers */ > +#define XTL_RC_PCIE_CFG_LINK_STATUS 0x5a > + > +#define XTL_RC_MGMT_PERST_CONTROL 0x218 > +#define XTL_RC_MGMT_PERST_CONTROL_PERST_O_N BIT(0) > + > +#define XTL_RC_MGMT_CLOCK_CONTROL 0x47c > +#define XTL_RC_MGMT_CLOCK_CONTROL_PEX_CLKREQ_I_N_PIN_USE_CONV_TO_PRSNT BIT(9) > + > +struct tegra264_pcie { > + struct device *dev; > + > + /* I/O memory */ > + void __iomem *xal; > + void __iomem *xtl; > + void __iomem *ecam; > + > + /* bridge configuration */ > + struct pci_config_window *cfg; > + struct pci_host_bridge *bridge; > + > + /* BPMP and bandwidth management */ > + struct icc_path *icc_path; > + struct tegra_bpmp *bpmp; > + u32 ctl_id; > + > + bool supports_hotplug; > + bool link_up; > +}; > + > +static void tegra264_pcie_power_off(struct tegra264_pcie *pcie) > +{ > + struct tegra_bpmp_message msg = {}; > + struct mrq_pcie_request req = {}; > + int err; > + > + req.cmd = CMD_PCIE_RP_CONTROLLER_OFF; > + req.rp_ctrlr_off.rp_controller = pcie->ctl_id; > + > + msg.mrq = MRQ_PCIE; > + msg.tx.data = &req; > + msg.tx.size = sizeof(req); > + > + err = tegra_bpmp_transfer(pcie->bpmp, &msg); > + if (err) > + dev_err(pcie->dev, "failed to turn off PCIe #%u: %pe\n", > + pcie->ctl_id, ERR_PTR(err)); > + > + if (msg.rx.ret) > + dev_err(pcie->dev, "failed to turn off PCIe #%u: %d\n", > + pcie->ctl_id, msg.rx.ret); > +} > + > +static void tegra264_pcie_icc_set(struct tegra264_pcie *pcie) > +{ > + u32 value, speed, width; > + int err; > + > + value = readw(pcie->ecam + XTL_RC_PCIE_CFG_LINK_STATUS); > + speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, value); > + width = FIELD_GET(PCI_EXP_LNKSTA_NLW, value); > + > + value = Mbps_to_icc(width * PCIE_SPEED2MBS_ENC(pcie_link_speed[speed])); > + > + /* > + * We don't want to error out here because a boot-critical device > + * could be connected to this root port. Failure to set the bandwidth > + * request may have an adverse impact on performance, but it is not > + * generally fatal, so we opt to continue regardless so that users > + * get a chance to fix things. > + */ > + err = icc_set_bw(pcie->icc_path, value, value); > + if (err < 0) > + dev_err(pcie->dev, > + "failed to request bandwidth (%u MBps): %pe\n", > + value, ERR_PTR(err)); > +} > + > +/* > + * The various memory regions used by the controller (I/O, memory, ECAM) are > + * set up during early boot and have hardware-level protections in place. If > + * the DT ranges don't match what's been setup, the controller won't be able > + * to write the address endpoints properly, so make sure to validate that DT > + * and firmware programming agree on these ranges. > + */ > +static bool tegra264_pcie_check_ranges(struct platform_device *pdev) > +{ > + struct tegra264_pcie *pcie = platform_get_drvdata(pdev); > + struct device_node *np = pcie->dev->of_node; > + struct of_pci_range_parser parser; > + phys_addr_t phys, limit, hi, lo; > + struct of_pci_range range; > + struct resource *res; > + bool status = true; > + u32 value; > + int err; > + > + err = of_pci_range_parser_init(&parser, np); > + if (err < 0) > + return false; > + > + for_each_of_pci_range(&parser, &range) { > + unsigned int addr_hi, addr_lo, limit_hi, limit_lo, enable; > + unsigned long type = range.flags & IORESOURCE_TYPE_BITS; > + phys_addr_t start, end, mask; > + const char *region = NULL; > + > + end = range.cpu_addr + range.size - 1; > + start = range.cpu_addr; > + > + switch (type) { > + case IORESOURCE_IO: > + addr_hi = XAL_RC_IO_BASE_HI; > + addr_lo = XAL_RC_IO_BASE_LO; > + limit_hi = XAL_RC_IO_LIMIT_HI; > + limit_lo = XAL_RC_IO_LIMIT_LO; > + enable = XAL_RC_BAR_CNTL_STANDARD_IOBAR_EN; > + mask = SZ_64K - 1; > + region = "I/O"; > + break; > + > + case IORESOURCE_MEM: > + if (range.flags & IORESOURCE_PREFETCH) { > + addr_hi = XAL_RC_MEM_64BIT_BASE_HI; > + addr_lo = XAL_RC_MEM_64BIT_BASE_LO; > + limit_hi = XAL_RC_MEM_64BIT_LIMIT_HI; > + limit_lo = XAL_RC_MEM_64BIT_LIMIT_LO; > + enable = XAL_RC_BAR_CNTL_STANDARD_64B_BAR_EN; > + region = "prefetchable memory"; > + } else { > + addr_hi = XAL_RC_MEM_32BIT_BASE_HI; > + addr_lo = XAL_RC_MEM_32BIT_BASE_LO; > + limit_hi = XAL_RC_MEM_32BIT_LIMIT_HI; > + limit_lo = XAL_RC_MEM_32BIT_LIMIT_LO; > + enable = XAL_RC_BAR_CNTL_STANDARD_32B_BAR_EN; > + region = "memory"; > + } > + > + mask = SZ_1M - 1; > + break; > + } > + > + /* not interested in anything that's not I/O or memory */ > + if (!region) > + continue; > + > + /* don't check regions that haven't been enabled */ > + value = readl(pcie->xal + XAL_RC_BAR_CNTL_STANDARD); > + if ((value & enable) == 0) > + continue; > + > + hi = readl(pcie->xal + addr_hi); > + lo = readl(pcie->xal + addr_lo); > + phys = ((hi << 16) << 16) | lo; > + > + hi = readl(pcie->xal + limit_hi); > + lo = readl(pcie->xal + limit_lo); > + limit = ((hi << 16) << 16) | lo | mask; > + > + if (phys != start || limit != end) { > + dev_err(pcie->dev, > + "%s region mismatch: %pap-%pap -> %pap-%pap\n", > + region, &phys, &limit, &start, &end); > + status = false; > + } > + } > + > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ecam"); > + if (!res) > + return false; > + > + hi = readl(pcie->xal + XAL_RC_ECAM_BASE_HI); > + lo = readl(pcie->xal + XAL_RC_ECAM_BASE_LO); > + phys = ((hi << 16) << 16) | lo; > + > + value = readl(pcie->xal + XAL_RC_ECAM_BUSMASK); > + limit = phys + ((value + 1) << 20) - 1; > + > + if (phys != res->start || limit != res->end) { > + dev_err(pcie->dev, > + "ECAM region mismatch: %pap-%pap -> %pap-%pap\n", > + &phys, &limit, &res->start, &res->end); > + status = false; > + } > + > + return status; > +} > + > +static bool tegra264_pcie_supports_hotplug(struct tegra264_pcie *pcie) > +{ > + u32 value = readl(pcie->xtl + XTL_RC_MGMT_CLOCK_CONTROL); > + > + return (value & XTL_RC_MGMT_CLOCK_CONTROL_PEX_CLKREQ_I_N_PIN_USE_CONV_TO_PRSNT) != 0; > +} > + > +static bool tegra264_pcie_link_up(struct tegra264_pcie *pcie, > + enum pci_bus_speed *speed) > +{ > + u16 value = readw(pcie->ecam + XTL_RC_PCIE_CFG_LINK_STATUS); > + > + if (value & PCI_EXP_LNKSTA_DLLLA) { > + if (speed) > + *speed = pcie_link_speed[FIELD_GET(PCI_EXP_LNKSTA_CLS, > + value)]; > + > + return true; > + } > + > + return false; > +} > + > +static void tegra264_pcie_init(struct tegra264_pcie *pcie) > +{ > + enum pci_bus_speed speed; > + unsigned int i; > + u32 value; > + > + /* bring the endpoint out of reset */ > + value = readl(pcie->xtl + XTL_RC_MGMT_PERST_CONTROL); > + value |= XTL_RC_MGMT_PERST_CONTROL_PERST_O_N; > + writel(value, pcie->xtl + XTL_RC_MGMT_PERST_CONTROL); > + > + for (i = 0; i < PCIE_LINK_WAIT_MAX_RETRIES; i++) { > + if (tegra264_pcie_link_up(pcie, NULL)) > + break; > + > + msleep(PCIE_LINK_WAIT_SLEEP_MS); > + } > + > + pcie->supports_hotplug = tegra264_pcie_supports_hotplug(pcie); > + pcie->link_up = tegra264_pcie_link_up(pcie, &speed); > + > + if (pcie->link_up) { > + msleep(PCIE_RESET_CONFIG_WAIT_MS); > + dev_info(pcie->dev, "PCIe #%u link is up (speed: %s)\n", > + pcie->ctl_id, pci_speed_string(speed)); > + tegra264_pcie_icc_set(pcie); > + } else { > + dev_info(pcie->dev, "PCIe #%u link is down\n", pcie->ctl_id); > + > + /* > + * Make sure to reset the bandwidth requirements if the link > + * is down but hotplug-capable. > + */ > + if (pcie->supports_hotplug) > + tegra264_pcie_icc_set(pcie); > + } > +} > + > +static int tegra264_pcie_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct pci_host_bridge *bridge; > + struct tegra264_pcie *pcie; > + struct resource_entry *bus; > + struct resource *res; > + int err; > + > + bridge = devm_pci_alloc_host_bridge(dev, sizeof(struct tegra264_pcie)); > + if (!bridge) > + return dev_err_probe(dev, -ENOMEM, > + "failed to allocate host bridge\n"); > + > + pcie = pci_host_bridge_priv(bridge); > + platform_set_drvdata(pdev, pcie); > + pcie->bridge = bridge; > + pcie->dev = dev; > + > + pcie->xal = devm_platform_ioremap_resource_byname(pdev, "xal"); > + if (IS_ERR(pcie->xal)) > + return dev_err_probe(dev, PTR_ERR(pcie->xal), > + "failed to map XAL memory\n"); > + > + pcie->xtl = devm_platform_ioremap_resource_byname(pdev, "xtl-pri"); > + if (IS_ERR(pcie->xtl)) > + return dev_err_probe(dev, PTR_ERR(pcie->xtl), > + "failed to map XTL-PRI memory\n"); > + > + bus = resource_list_first_type(&bridge->windows, IORESOURCE_BUS); > + if (!bus) > + return dev_err_probe(dev, -ENODEV, > + "failed to get bus resources\n"); > + > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ecam"); > + if (!res) > + return dev_err_probe(dev, -ENXIO, > + "failed to get ECAM resource\n"); > + > + pcie->icc_path = devm_of_icc_get(dev, "write"); > + if (IS_ERR(pcie->icc_path)) > + return dev_err_probe(dev, PTR_ERR(pcie->icc_path), > + "failed to get ICC\n"); > + > + pcie->bpmp = tegra_bpmp_get_with_id(dev, &pcie->ctl_id); > + if (IS_ERR(pcie->bpmp)) > + return dev_err_probe(dev, PTR_ERR(pcie->bpmp), > + "failed to get BPMP\n"); > + > + err = devm_pm_runtime_set_active_enabled(dev); > + if (err < 0) { > + dev_err_probe(dev, err, "failed to enable runtime PM\n"); > + goto err_put_bpmp; > + } > + > + err = pm_runtime_get_sync(dev); > + if (err < 0) { > + dev_err_probe(dev, err, "failed to power on device\n"); > + goto err_put_bpmp; > + } pm_runtime_get_sync() increments the runtime-PM usage counter even when its resume operation returns an error. The failure path does not call pm_runtime_put_noidle() and bypasses err_put_pm. Prefer pm_runtime_resume_and_get(), whose failure semantics avoid the usage-counter imbalance, or explicitly balance the failed pm_runtime_get_sync(). > + > + /* sanity check that programmed ranges match what's in DT */ > + if (!tegra264_pcie_check_ranges(pdev)) { > + err = -EINVAL; > + goto err_put_pm; > + } > + > + pcie->cfg = pci_ecam_create(dev, res, bus->res, &pci_generic_ecam_ops); > + if (IS_ERR(pcie->cfg)) { > + err = dev_err_probe(dev, PTR_ERR(pcie->cfg), > + "failed to create ECAM\n"); > + goto err_put_pm; > + } > + > + bridge->ops = (struct pci_ops *)&pci_generic_ecam_ops.pci_ops; > + bridge->sysdata = pcie->cfg; > + pcie->ecam = pcie->cfg->win; > + > + tegra264_pcie_init(pcie); > + > + /* > + * Fail if the link isn't up and doesn't support hotplug, no device > + * will ever be able to be added on this bus. > + */ > + if (!pcie->link_up && !pcie->supports_hotplug) { > + err = dev_err_probe(pcie->dev, -ENODEV, > + "PCIe #%u link is down and not hotplug-capable, turning off\n", > + pcie->ctl_id); > + tegra264_pcie_power_off(pcie); > + goto err_free_ecam; > + } > + > + err = pci_host_probe(bridge); > + if (err < 0) { > + dev_err_probe(dev, err, "failed to register host\n"); > + goto err_free_ecam; > + } > + > + return 0; > + > +err_free_ecam: > + pci_ecam_free(pcie->cfg); > +err_put_pm: > + pm_runtime_put_sync(dev); > +err_put_bpmp: > + tegra_bpmp_put(pcie->bpmp); > + > + return err; > +} > + > +static void tegra264_pcie_remove(struct platform_device *pdev) > +{ > + struct tegra264_pcie *pcie = platform_get_drvdata(pdev); > + > + /* > + * If we undo tegra264_pcie_init() then link goes down and need > + * controller reset to bring up the link again. Remove intention is > + * to clean up the root bridge and re-enumerate during bind. > + */ > + pci_lock_rescan_remove(); > + pci_stop_root_bus(pcie->bridge->bus); > + pci_remove_root_bus(pcie->bridge->bus); > + pci_unlock_rescan_remove(); > + > + pm_runtime_put_sync(&pdev->dev); > + tegra_bpmp_put(pcie->bpmp); > + pci_ecam_free(pcie->cfg); > +} > + > +static int tegra264_pcie_suspend(struct device *dev) > +{ > + /* > + * No need to do anything device-specific here, BPMP handles the > + * details of taking the link into L2. > + */ > + > + return pinctrl_pm_select_sleep_state(dev); > +} > + > +static int tegra264_pcie_resume(struct device *dev) > +{ > + struct tegra264_pcie *pcie = dev_get_drvdata(dev); > + int err; > + > + err = pinctrl_pm_select_default_state(dev); > + if (err < 0) { > + dev_err(dev, "failed to configure sideband pins: %pe\n", > + ERR_PTR(err)); > + return err; > + } > + > + tegra264_pcie_init(pcie); > + > + return 0; > +} > + > +static DEFINE_SIMPLE_DEV_PM_OPS(tegra264_pcie_pm_ops, > + tegra264_pcie_suspend, > + tegra264_pcie_resume); PCI subsystem registered pm_noirq callbacks. So, controller should also register to pm_noirq callbacks. > + > +static const struct of_device_id tegra264_pcie_of_match[] = { > + { > + .compatible = "nvidia,tegra264-pcie", > + }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, tegra264_pcie_of_match); > + > +static struct platform_driver tegra264_pcie_driver = { > + .probe = tegra264_pcie_probe, > + .remove = tegra264_pcie_remove, > + .driver = { > + .name = "tegra264-pcie", > + .pm = pm_ptr(&tegra264_pcie_pm_ops), > + .of_match_table = tegra264_pcie_of_match, > + }, > +}; > +module_platform_driver(tegra264_pcie_driver); > + > +MODULE_AUTHOR("Manikanta Maddireddy <[email protected]>"); > +MODULE_AUTHOR("Thierry Reding <[email protected]>"); > +MODULE_DESCRIPTION("NVIDIA Tegra264 PCIe host controller driver"); > +MODULE_LICENSE("GPL"); > Thanks, Manikanta -- nvpublic