--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the PCIe Controller in QiLai from Andes
+ *
+ * Copyright (C) 2026 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/pm_runtime.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)
+
+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;
+
+ val = readl(pcie->apb_base + PCIE_REGS_PCIE_SII_PM_STATE);
+
+ return FIELD_GET(SMLH_LINK_UP, val) && FIELD_GET(RDLH_LINK_UP, val);
+}
+
+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,
+};
+
+/*
+ * Set up 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);
+
+ val = dw_pcie_readl_dbi(pci, PCIE_LOGIC_COHERENCY_CONTROL3);
+ 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_writel_dbi(pci, PCIE_LOGIC_COHERENCY_CONTROL3, 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);
+}
+
+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 0;
+}
+
+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);
+
+ pm_runtime_set_active(dev);
+ pm_runtime_no_callbacks(dev);
+ devm_pm_runtime_enable(dev);
+
+ ret = dw_pcie_host_init(&pcie->pci.pp);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to initialize PCIe host\n");
+
+ 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");
projects / thirdparty / kernel / stable.git / commitdiff
