[PATCH v4 2/2] PCI: EIC7700: Add Eswin PCIe host controller driver

zhangsenchuan
2025-10-30T08:32:14Z

From: Senchuan Zhang <zhangsenchuan@eswincomputing.com>

Add driver for the Eswin EIC7700 PCIe host controller, which is based on
the DesignWare PCIe core, IP revision 6.00a. The PCIe Gen.3 controller
supports a data rate of 8 GT/s and 4 channels, support INTX and MSI
interrupts.

Signed-off-by: Yu Ning <ningyu@eswincomputing.com>
Signed-off-by: Yanghui Ou <ouyanghui@eswincomputing.com>
Signed-off-by: Senchuan Zhang <zhangsenchuan@eswincomputing.com>
---
drivers/pci/controller/dwc/Kconfig | 11 +
drivers/pci/controller/dwc/Makefile | 1 +
drivers/pci/controller/dwc/pcie-eic7700.c | 462 ++++++++++++++++++++++
3 files changed, 474 insertions(+)
create mode 100644 drivers/pci/controller/dwc/pcie-eic7700.c

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 349d4657393c..6a51978d3c49 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -93,6 +93,17 @@ config PCIE_BT1
Enables support for the PCIe controller in the Baikal-T1 SoC to work
in host mode. It's based on the Synopsys DWC PCIe v4.60a IP-core.

+config PCIE_EIC7700
+ bool "Eswin PCIe controller"
+ depends on ARCH_ESWIN || COMPILE_TEST
+ depends on PCI_MSI
+ select PCIE_DW_HOST
+ help
+ Say Y here if you want PCIe controller support for the Eswin.
+ The PCIe controller on Eswin is based on DesignWare hardware,
+ enables support for the PCIe controller in the Eswin SoC to
+ work in host mode.
+
config PCI_IMX6
bool

diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index 7ae28f3b0fb3..04f751c49eba 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -6,6 +6,7 @@ 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_BT1) += pcie-bt1.o
+obj-$(CONFIG_PCIE_EIC7700) += pcie-eic7700.o
obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
obj-$(CONFIG_PCIE_FU740) += pcie-fu740.o
diff --git a/drivers/pci/controller/dwc/pcie-eic7700.c b/drivers/pci/controller/dwc/pcie-eic7700.c
new file mode 100644
index 000000000000..0016dd0be743
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-eic7700.c
@@ -0,0 +1,462 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ESWIN PCIe root complex driver
+ *
+ * Copyright 2025, Beijing ESWIN Computing Technology Co., Ltd.
+ *
+ * Authors: Yu Ning <ningyu@eswincomputing.com>
+ * Senchuan Zhang <zhangsenchuan@eswincomputing.com>
+ * Yanghui Ou <ouyanghui@eswincomputing.com>
+ */
+
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/resource.h>
+#include <linux/reset.h>
+#include <linux/types.h>
+
+#include "pcie-designware.h"
+
+/* PCIe top csr registers */
+#define PCIEMGMT_CTRL0_OFFSET 0x0
+#define PCIEMGMT_STATUS0_OFFSET 0x100
+
+/* LTSSM register fields */
+#define PCIEMGMT_APP_LTSSM_ENABLE BIT(5)
+
+/* APP_HOLD_PHY_RST register fields */
+#define PCIEMGMT_APP_HOLD_PHY_RST BIT(6)
+
+/* PM_SEL_AUX_CLK register fields */
+#define PCIEMGMT_PM_SEL_AUX_CLK BIT(16)
+
+/* ROOT_PORT register fields */
+#define PCIEMGMT_CTRL0_ROOT_PORT_MASK GENMASK(3, 0)
+
+/* Vendor and device id value */
+#define PCI_VENDOR_ID_ESWIN 0x1fe1
+#define PCI_DEVICE_ID_ESWIN 0x2030
+
+struct eswin_pcie_data {
+ bool msix_cap;
+};
+
+struct eswin_pcie_port {
+ struct list_head list;
+ struct reset_control *perst;
+ int num_lanes;
+};
+
+struct eswin_pcie {
+ struct dw_pcie pci;
+ void __iomem *mgmt_base;
+ struct clk_bulk_data *clks;
+ struct reset_control *powerup_rst;
+ struct reset_control *cfg_rst;
+ struct list_head ports;
+ int num_clks;
+ bool msix_cap;
+ bool linked_up;
+};
+
+#define to_eswin_pcie(x) dev_get_drvdata((x)->dev)
+
+static int eswin_pcie_start_link(struct dw_pcie *pci)
+{
+ struct eswin_pcie *pcie = to_eswin_pcie(pci);
+ u32 val;
+
+ /* Enable LTSSM */
+ val = readl_relaxed(pcie->mgmt_base + PCIEMGMT_CTRL0_OFFSET);
+ val |= PCIEMGMT_APP_LTSSM_ENABLE;
+ writel_relaxed(val, pcie->mgmt_base + PCIEMGMT_CTRL0_OFFSET);
+
+ return 0;
+}
+
+static bool eswin_pcie_link_up(struct dw_pcie *pci)
+{
+ struct eswin_pcie *pcie = to_eswin_pcie(pci);
+
+ u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+ u16 val = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
+
+ if (val & PCI_EXP_LNKSTA_DLLLA)
+ pcie->linked_up = true;
+
+ return val & PCI_EXP_LNKSTA_DLLLA;
+}
+
+static enum dw_pcie_ltssm eswin_pcie_get_ltssm(struct dw_pcie *pci)
+{
+ dev_info(pci->dev, "LTSSM_L2 not supported\n");
+ /* Return 0 only ensure skip read_poll_timeout function check */
+ return 0;
+}
+
+static int eswin_pcie_deassert(struct eswin_pcie *pcie)
+{
+ int ret;
+
+ ret = reset_control_deassert(pcie->cfg_rst);
+ if (ret) {
+ dev_err(pcie->pci.dev, "Failed to deassert CFG#");
+ return ret;
+ }
+
+ ret = reset_control_deassert(pcie->powerup_rst);
+ if (ret) {
+ dev_err(pcie->pci.dev, "Failed to deassert POWERUP#");
+ goto err_powerup;
+ }
+
+ return 0;
+
+err_powerup:
+ reset_control_assert(pcie->cfg_rst);
+
+ return ret;
+}
+
+static void eswin_pcie_assert(struct eswin_pcie *pcie)
+{
+ reset_control_assert(pcie->powerup_rst);
+ reset_control_assert(pcie->cfg_rst);
+}
+
+static int eswin_pcie_perst_deassert(struct eswin_pcie_port *port,
+ struct eswin_pcie *pcie)
+{
+ int ret;
+
+ ret = reset_control_assert(port->perst);
+ if (ret) {
+ dev_err(pcie->pci.dev, "Failed to assert PERST#");
+ return ret;
+ }
+
+ /* Ensure that PERST has been asserted for at least 100 ms */
+ msleep(PCIE_T_PVPERL_MS);
+
+ ret = reset_control_deassert(port->perst);
+ if (ret) {
+ dev_err(pcie->pci.dev, "Failed to deassert PERST#");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int eswin_pcie_parse_port(struct eswin_pcie *pcie,
+ struct device_node *node)
+{
+ struct device *dev = pcie->pci.dev;
+ struct eswin_pcie_port *port;
+
+ port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
+ if (!port)
+ return -ENOMEM;
+
+ port->perst = of_reset_control_get(node, "perst");
+ if (IS_ERR(port->perst)) {
+ dev_err(dev, "Failed to get perst reset\n");
+ return PTR_ERR(port->perst);
+ }
+
+ /*
+ * Since the root port node is separated out by pcie devicetree, the
+ * DWC core initialization code cannot parse the num-lanes attribute
+ * in the root port. Before entering the DWC core initialization code,
+ * the platform driver code parses the root port node. The EIC7700 only
+ * supports one root port node, and the num-lanes attribute is suitable
+ * for the case of one root port.
+ */
+ of_property_read_u32(node, "num-lanes", &port->num_lanes);
+ pcie->pci.num_lanes = port->num_lanes;
+
+ INIT_LIST_HEAD(&port->list);
+ list_add_tail(&port->list, &pcie->ports);
+
+ return 0;
+}
+
+static int eswin_pcie_parse_ports(struct eswin_pcie *pcie)
+{
+ struct device *dev = pcie->pci.dev;
+ struct eswin_pcie_port *port, *tmp;
+ int ret;
+
+ for_each_available_child_of_node_scoped(dev->of_node, of_port) {
+ ret = eswin_pcie_parse_port(pcie, of_port);
+ if (ret)
+ goto err_port;
+ }
+
+ return 0;
+
+err_port:
+ list_for_each_entry_safe(port, tmp, &pcie->ports, list)
+ list_del(&port->list);
+
+ return ret;
+}
+
+static void eswin_pcie_hide_broken_msix_cap(struct dw_pcie *pci)
+{
+ u16 offset, val;
+
+ /*
+ * Hardware doesn't support MSI-X but it advertises MSI-X capability,
+ * to avoid this problem, the MSI-X capability in the PCIe capabilities
+ * linked-list needs to be disabled. Since the PCI Express capability
+ * structure's next pointer points to the MSI-X capability, and the
+ * MSI-X capability's next pointer is null (00H), so only the PCI
+ * Express capability structure's next pointer needs to be set 00H.
+ */
+ offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+ val = dw_pcie_readl_dbi(pci, offset);
+ val &= ~PCI_CAP_LIST_NEXT_MASK;
+ dw_pcie_writel_dbi(pci, offset, val);
+}
+
+static int eswin_pcie_host_init(struct dw_pcie_rp *pp)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+ struct eswin_pcie *pcie = to_eswin_pcie(pci);
+ struct eswin_pcie_port *port;
+ u8 msi_cap;
+ u32 val;
+ int ret;
+
+ pcie->num_clks = devm_clk_bulk_get_all_enabled(pci->dev, &pcie->clks);
+ if (pcie->num_clks < 0)
+ return dev_err_probe(pci->dev, pcie->num_clks,
+ "Failed to get pcie clocks\n");
+
+ ret = eswin_pcie_deassert(pcie);
+ if (ret)
+ return ret;
+
+ /* Configure root port type */
+ val = readl_relaxed(pcie->mgmt_base + PCIEMGMT_CTRL0_OFFSET);
+ val &= ~PCIEMGMT_CTRL0_ROOT_PORT_MASK;
+ writel_relaxed(val | PCI_EXP_TYPE_ROOT_PORT,
+ pcie->mgmt_base + PCIEMGMT_CTRL0_OFFSET);
+
+ list_for_each_entry(port, &pcie->ports, list) {
+ ret = eswin_pcie_perst_deassert(port, pcie);
+ if (ret)
+ goto err_perst;
+ }
+
+ /* Configure app_hold_phy_rst */
+ val = readl_relaxed(pcie->mgmt_base + PCIEMGMT_CTRL0_OFFSET);
+ val &= ~PCIEMGMT_APP_HOLD_PHY_RST;
+ writel_relaxed(val, pcie->mgmt_base + PCIEMGMT_CTRL0_OFFSET);
+
+ /* The maximum waiting time for the clock switch lock is 20ms */
+ ret = readl_poll_timeout(pcie->mgmt_base + PCIEMGMT_STATUS0_OFFSET,
+ val, !(val & PCIEMGMT_PM_SEL_AUX_CLK), 1000,
+ 20000);
+
+ if (ret) {
+ dev_err(pci->dev, "Timeout waiting for PM_SEL_AUX_CLK ready\n");
+ goto err_phy_init;
+ }
+
+ /*
+ * Configure ESWIN VID:DID for Root Port as the default values are
+ * invalid.
+ */
+ dw_pcie_writew_dbi(pci, PCI_VENDOR_ID, PCI_VENDOR_ID_ESWIN);
+ dw_pcie_writew_dbi(pci, PCI_DEVICE_ID, PCI_DEVICE_ID_ESWIN);
+
+ /* Configure support 32 MSI vectors */
+ msi_cap = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
+ val = dw_pcie_readw_dbi(pci, msi_cap + PCI_MSI_FLAGS);
+ val &= ~PCI_MSI_FLAGS_QMASK;
+ val |= FIELD_PREP(PCI_MSI_FLAGS_QMASK, 5);
+ dw_pcie_writew_dbi(pci, msi_cap + PCI_MSI_FLAGS, val);
+
+ /* Configure disable MSI-X cap */
+ if (!pcie->msix_cap)
+ eswin_pcie_hide_broken_msix_cap(pci);
+
+ return 0;
+
+err_phy_init:
+ list_for_each_entry(port, &pcie->ports, list)
+ reset_control_assert(port->perst);
+err_perst:
+ eswin_pcie_assert(pcie);
+
+ return ret;
+}
+
+static void eswin_pcie_host_exit(struct dw_pcie_rp *pp)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+ struct eswin_pcie *pcie = to_eswin_pcie(pci);
+ struct eswin_pcie_port *port;
+
+ /*
+ * For controllers with active devices, resources are retained and
+ * cannot be turned off, like NVMEe.
+ */
+ if (!dw_pcie_link_up(&pcie->pci)) {
+ list_for_each_entry(port, &pcie->ports, list)
+ reset_control_assert(port->perst);
+ eswin_pcie_assert(pcie);
+ clk_bulk_disable_unprepare(pcie->num_clks, pcie->clks);
+ }
+}
+
+static void eswin_pcie_pme_turn_off(struct dw_pcie_rp *pp)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+
+ /*
+ * Hardware doesn't support enter the D3code and L2/L3 states, send
+ * PME_TURN_OFF message, which will then cause Vmain to be removed and
+ * controller stop working.
+ */
+ dev_info(pci->dev, "Can't send PME_TURN_OFF message\n");
+}
+
+static const struct dw_pcie_host_ops eswin_pcie_host_ops = {
+ .init = eswin_pcie_host_init,
+ .deinit = eswin_pcie_host_exit,
+ .pme_turn_off = eswin_pcie_pme_turn_off,
+};
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+ .start_link = eswin_pcie_start_link,
+ .link_up = eswin_pcie_link_up,
+ .get_ltssm = eswin_pcie_get_ltssm,
+};
+
+static int eswin_pcie_probe(struct platform_device *pdev)
+{
+ const struct eswin_pcie_data *data;
+ struct eswin_pcie_port *port, *tmp;
+ struct device *dev = &pdev->dev;
+ struct eswin_pcie *pcie;
+ struct dw_pcie *pci;
+ int ret;
+
+ data = of_device_get_match_data(dev);
+ if (!data)
+ return dev_err_probe(dev, -EINVAL, "OF data missing\n");
+
+ pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+ if (!pcie)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&pcie->ports);
+
+ pci = &pcie->pci;
+ pci->dev = dev;
+ pci->ops = &dw_pcie_ops;
+ pci->pp.ops = &eswin_pcie_host_ops;
+ pcie->msix_cap = data->msix_cap;
+
+ pcie->mgmt_base = devm_platform_ioremap_resource_byname(pdev, "mgmt");
+ if (IS_ERR(pcie->mgmt_base))
+ return dev_err_probe(dev, PTR_ERR(pcie->mgmt_base),
+ "Failed to map mgmt registers\n");
+
+ pcie->powerup_rst = devm_reset_control_get(&pdev->dev, "powerup");
+ if (IS_ERR(pcie->powerup_rst))
+ return dev_err_probe(dev, PTR_ERR(pcie->powerup_rst),
+ "Failed to get powerup reset\n");
+
+ pcie->cfg_rst = devm_reset_control_get(&pdev->dev, "dbi");
+ if (IS_ERR(pcie->cfg_rst))
+ return dev_err_probe(dev, PTR_ERR(pcie->cfg_rst),
+ "Failed to get dbi reset\n");
+
+ ret = eswin_pcie_parse_ports(pcie);
+ if (ret)
+ return dev_err_probe(pci->dev, ret,
+ "Failed to parse Root Port: %d\n", ret);
+
+ platform_set_drvdata(pdev, pcie);
+
+ ret = dw_pcie_host_init(&pci->pp);
+ if (ret) {
+ dev_err(dev, "Failed to initialize host\n");
+ goto err_init;
+ }
+
+ return 0;
+
+err_init:
+ list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
+ list_del(&port->list);
+ reset_control_put(port->perst);
+ }
+
+ return ret;
+}
+
+static int eswin_pcie_suspend_noirq(struct device *dev)
+{
+ struct eswin_pcie *pcie = dev_get_drvdata(dev);
+
+ return dw_pcie_suspend_noirq(&pcie->pci);
+}
+
+static int eswin_pcie_resume_noirq(struct device *dev)
+{
+ struct eswin_pcie *pcie = dev_get_drvdata(dev);
+ int ret;
+
+ ret = dw_pcie_resume_noirq(&pcie->pci);
+ /*
+ * If the downstream device is not inserted, linkup will TIMEDOUT. At
+ * this time, when the resume function return, -ETIMEDOUT shouldn't be
+ * returned, which will raise "PM: failed to resume noirq: error -110".
+ * Only log message "Ignore errors, the link may come up later".
+ */
+ if (ret == -ETIMEDOUT && !pcie->linked_up) {
+ dev_info(dev, "Ignore errors, the link may come up later\n");
+ return 0;
+ }
+
+ return ret;
+}
+
+static const struct dev_pm_ops eswin_pcie_pm_ops = {
+ NOIRQ_SYSTEM_SLEEP_PM_OPS(eswin_pcie_suspend_noirq,
+ eswin_pcie_resume_noirq)
+};
+
+static const struct eswin_pcie_data eswin_7700_data = {
+ .msix_cap = false,
+};
+
+static const struct of_device_id eswin_pcie_of_match[] = {
+ { .compatible = "eswin,eic7700-pcie", .data = &eswin_7700_data },
+ {},
+};
+
+static struct platform_driver eswin_pcie_driver = {
+ .probe = eswin_pcie_probe,
+ .driver = {
+ .name = "eic7700-pcie",
+ .of_match_table = eswin_pcie_of_match,
+ .suppress_bind_attrs = true,
+ .pm = &eswin_pcie_pm_ops,
+ },
+};
+builtin_platform_driver(eswin_pcie_driver);
+
+MODULE_DESCRIPTION("PCIe host controller driver for EIC7700 SoCs");
+MODULE_AUTHOR("Yu Ning <ningyu@eswincomputing.com>");
+MODULE_AUTHOR("Senchuan Zhang <zhangsenchuan@eswincomputing.com>");
+MODULE_AUTHOR("Yanghui Ou <ouyanghui@eswincomputing.com>");
+MODULE_LICENSE("GPL");
--
2.25.1