[PATCH v8 4/5] PCI: andes: Add Andes QiLai SoC PCIe host driver support
From: Randolph Lin <randolph@andestech.com>
Date: 2025-10-14 12:04:22
Also in:
linux-pci, linux-riscv, lkml
Subsystem:
pci driver for andes qilai pcie, pci native host bridge and endpoint drivers, pci subsystem, the rest · Maintainers:
Randolph Lin, Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds
Add driver support for DesignWare based PCIe controller in Andes QiLai SoC. The driver only supports the Root Complex mode. Signed-off-by: Randolph Lin <randolph@andestech.com> --- drivers/pci/controller/dwc/Kconfig | 13 + drivers/pci/controller/dwc/Makefile | 1 + drivers/pci/controller/dwc/pcie-andes-qilai.c | 240 ++++++++++++++++++ 3 files changed, 254 insertions(+) create mode 100644 drivers/pci/controller/dwc/pcie-andes-qilai.c
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 349d4657393c..09ce40640e2f 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig@@ -61,6 +61,19 @@ config PCI_MESON and therefore the driver re-uses the DesignWare core functions to implement the driver. +config PCIE_ANDES_QILAI + tristate "Andes QiLai PCIe controller" + depends on ARCH_ANDES || COMPILE_TEST + depends on PCI_MSI + select PCIE_DW_HOST + help + Say Y here to enable PCIe controller support on Andes QiLai SoCs, + which operate in Root Complex mode. The Andes QiLai SoC PCIe + controller is based on DesignWare IP (5.97a version) and therefore + the driver re-uses the DesignWare core functions to implement the + driver. The Andes QiLai SoC features three Root Complexes, each + operating on PCIe 4.0. + config PCIE_ARTPEC6 bool
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index 7ae28f3b0fb3..5d3ec2d26275 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile@@ -5,6 +5,7 @@ obj-$(CONFIG_PCIE_DW_HOST) += pcie-designware-host.o obj-$(CONFIG_PCIE_DW_EP) += pcie-designware-ep.o obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o obj-$(CONFIG_PCIE_AMD_MDB) += pcie-amd-mdb.o +obj-$(CONFIG_PCIE_ANDES_QILAI) += pcie-andes-qilai.o obj-$(CONFIG_PCIE_BT1) += pcie-bt1.o obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
diff --git a/drivers/pci/controller/dwc/pcie-andes-qilai.c b/drivers/pci/controller/dwc/pcie-andes-qilai.c
new file mode 100644
index 000000000000..0b9f9604c0f7
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-andes-qilai.c@@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Driver for the PCIe Controller in QiLai from Andes + * + * Copyright (C) 2025 Andes Technology Corporation + */ + +#include <linux/bitfield.h> +#include <linux/bits.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/platform_device.h> +#include <linux/types.h> + +#include "pcie-designware.h" + +#define PCIE_INTR_CONTROL1 0x15c +#define PCIE_MSI_CTRL_INT_EN BIT(28) + +#define PCIE_LOGIC_COHERENCY_CONTROL3 0x8e8 + +/* + * Refer to Table A4-5 (Memory type encoding) in the + * AMBA AXI and ACE Protocol Specification. + * + * The selected value corresponds to the Memory type field: + * "Write-back, Read and Write-allocate". + * + * The last three rows in the table A4-5 in + * AMBA AXI and ACE Protocol Specification: + * ARCACHE AWCACHE Memory type + * ------------------------------------------------------------------ + * 1111 (0111) 0111 Write-back Read-allocate + * 1011 1111 (1011) Write-back Write-allocate + * 1111 1111 Write-back Read and Write-allocate (selected) + */ +#define IOCP_ARCACHE 0b1111 +#define IOCP_AWCACHE 0b1111 + +#define PCIE_CFG_MSTR_ARCACHE_MODE GENMASK(6, 3) +#define PCIE_CFG_MSTR_AWCACHE_MODE GENMASK(14, 11) +#define PCIE_CFG_MSTR_ARCACHE_VALUE GENMASK(22, 19) +#define PCIE_CFG_MSTR_AWCACHE_VALUE GENMASK(30, 27) + +#define PCIE_GEN_CONTROL2 0x54 +#define PCIE_CFG_LTSSM_EN BIT(0) + +#define PCIE_REGS_PCIE_SII_PM_STATE 0xc0 +#define SMLH_LINK_UP BIT(6) +#define RDLH_LINK_UP BIT(7) +#define PCIE_REGS_PCIE_SII_LINK_UP (SMLH_LINK_UP | RDLH_LINK_UP) + +struct qilai_pcie { + struct dw_pcie pci; + void __iomem *apb_base; +}; + +#define to_qilai_pcie(_pci) container_of(_pci, struct qilai_pcie, pci) + +static bool qilai_pcie_link_up(struct dw_pcie *pci) +{ + struct qilai_pcie *pcie = to_qilai_pcie(pci); + u32 val; + + /* Read smlh & rdlh link up by checking debug port */ + val = readl(pcie->apb_base + PCIE_REGS_PCIE_SII_PM_STATE); + + return (val & PCIE_REGS_PCIE_SII_LINK_UP) == PCIE_REGS_PCIE_SII_LINK_UP; +} + +static int qilai_pcie_start_link(struct dw_pcie *pci) +{ + struct qilai_pcie *pcie = to_qilai_pcie(pci); + u32 val; + + val = readl(pcie->apb_base + PCIE_GEN_CONTROL2); + val |= PCIE_CFG_LTSSM_EN; + writel(val, pcie->apb_base + PCIE_GEN_CONTROL2); + + return 0; +} + +static const struct dw_pcie_ops qilai_pcie_ops = { + .link_up = qilai_pcie_link_up, + .start_link = qilai_pcie_start_link, +}; + +/* + * Setup the Qilai PCIe IOCP (IO Coherence Port) Read/Write Behaviors to the + * Write-Back, Read and Write Allocate mode. + * + * The IOCP HW target is SoC last-level cache (L2 Cache), which serves as the + * system cache. The IOCP HW helps maintain cache monitoring, ensuring that + * the device can snoop data from/to the cache. + */ +static void qilai_pcie_iocp_cache_setup(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + u32 val; + + dw_pcie_dbi_ro_wr_en(pci); + + dw_pcie_read(pci->dbi_base + PCIE_LOGIC_COHERENCY_CONTROL3, + sizeof(val), &val); + FIELD_MODIFY(PCIE_CFG_MSTR_ARCACHE_MODE, &val, IOCP_ARCACHE); + FIELD_MODIFY(PCIE_CFG_MSTR_AWCACHE_MODE, &val, IOCP_AWCACHE); + FIELD_MODIFY(PCIE_CFG_MSTR_ARCACHE_VALUE, &val, IOCP_ARCACHE); + FIELD_MODIFY(PCIE_CFG_MSTR_AWCACHE_VALUE, &val, IOCP_AWCACHE); + dw_pcie_write(pci->dbi_base + PCIE_LOGIC_COHERENCY_CONTROL3, + sizeof(val), val); + + dw_pcie_dbi_ro_wr_dis(pci); +} + +static void qilai_pcie_enable_msi(struct qilai_pcie *pcie) +{ + u32 val; + + val = readl(pcie->apb_base + PCIE_INTR_CONTROL1); + val |= PCIE_MSI_CTRL_INT_EN; + writel(val, pcie->apb_base + PCIE_INTR_CONTROL1); +} + +/* + * The QiLai SoC PCIe controller's outbound iATU region supports + * a maximum size of SZ_4G - 1. To prevent programming failures, + * only consider bridge->windows with sizes within this limit. + * + * To ensure compatibility with most endpoint devices, at least + * one memory region must be mapped within the 32-bits address space. + */ +static int qilai_pcie_host_fix_ob_iatu_count(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct device *dev = pci->dev; + struct resource_entry *entry; + /* Reserved 1 ob iATU for config space */ + int count = 1; + bool ranges_32bits = false; + u64 pci_addr; + u64 size; + + resource_list_for_each_entry(entry, &pp->bridge->windows) { + if (resource_type(entry->res) != IORESOURCE_MEM) + continue; + + size = resource_size(entry->res); + if (size < SZ_4G) + count++; + + pci_addr = entry->res->start - entry->offset; + if (pci_addr < SZ_4G) + ranges_32bits = true; + } + + if (!ranges_32bits) { + dev_err(dev, "Bridge window must contain 32-bits address\n"); + return -EINVAL; + } + + pci->num_ob_windows = count; + + return 0; +} + +static int qilai_pcie_host_init(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct qilai_pcie *pcie = to_qilai_pcie(pci); + + qilai_pcie_enable_msi(pcie); + + return qilai_pcie_host_fix_ob_iatu_count(pp); +} + +static void qilai_pcie_host_post_init(struct dw_pcie_rp *pp) +{ + qilai_pcie_iocp_cache_setup(pp); +} + +static const struct dw_pcie_host_ops qilai_pcie_host_ops = { + .init = qilai_pcie_host_init, + .post_init = qilai_pcie_host_post_init, +}; + +static int qilai_pcie_probe(struct platform_device *pdev) +{ + struct qilai_pcie *pcie; + struct dw_pcie *pci; + struct device *dev = &pdev->dev; + int ret; + + pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL); + if (!pcie) + return -ENOMEM; + + platform_set_drvdata(pdev, pcie); + + pci = &pcie->pci; + pcie->pci.dev = dev; + pcie->pci.ops = &qilai_pcie_ops; + pcie->pci.pp.ops = &qilai_pcie_host_ops; + pci->use_parent_dt_ranges = true; + + dw_pcie_cap_set(&pcie->pci, REQ_RES); + + pcie->apb_base = devm_platform_ioremap_resource_byname(pdev, "apb"); + if (IS_ERR(pcie->apb_base)) + return PTR_ERR(pcie->apb_base); + + ret = dw_pcie_host_init(&pcie->pci.pp); + if (ret) { + dev_err_probe(dev, ret, "Failed to initialize PCIe host\n"); + return ret; + } + + return 0; +} + +static const struct of_device_id qilai_pcie_of_match[] = { + { .compatible = "andestech,qilai-pcie" }, + {}, +}; +MODULE_DEVICE_TABLE(of, qilai_pcie_of_match); + +static struct platform_driver qilai_pcie_driver = { + .probe = qilai_pcie_probe, + .driver = { + .name = "qilai-pcie", + .of_match_table = qilai_pcie_of_match, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, +}; + +builtin_platform_driver(qilai_pcie_driver); + +MODULE_AUTHOR("Randolph Lin <randolph@andestech.com>"); +MODULE_DESCRIPTION("Andes Qilai PCIe driver"); +MODULE_LICENSE("GPL");
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2.34.1