From: Xincheng Zhang <zhangxincheng@ultrarisc.com>

Add DP1000 SoC PCIe Root Complex driver.

Signed-off-by: Xincheng Zhang <zhangxincheng@ultrarisc.com>
Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
---
 drivers/pci/controller/dwc/Kconfig           |  12 ++
 drivers/pci/controller/dwc/Makefile          |   1 +
 drivers/pci/controller/dwc/pcie-designware.h |  22 ++++
 drivers/pci/controller/dwc/pcie-ultrarisc.c  | 188 +++++++++++++++++++++++++++
 4 files changed, 223 insertions(+)

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index d0aa031397fa..06f7d98259cd 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -548,4 +548,16 @@ config PCIE_VISCONTI_HOST
 	  Say Y here if you want PCIe controller support on Toshiba Visconti SoC.
 	  This driver supports TMPV7708 SoC.
 
+config PCIE_ULTRARISC
+	tristate "UltraRISC PCIe host controller"
+	depends on ARCH_ULTRARISC || COMPILE_TEST
+	select PCIE_DW_HOST
+	select PCI_MSI
+	default y if ARCH_ULTRARISC
+	help
+	  Enables support for the PCIe controller in the UltraRISC SoC.
+	  This driver supports UR-DP1000 SoC.
+	  By default, this symbol is enabled when ARCH_ULTRARISC is active,
+	  requiring no further configuration on that platform.
+
 endmenu
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index 67ba59c02038..884c46b78e01 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4.o
 obj-$(CONFIG_PCIE_SPACEMIT_K1) += pcie-spacemit-k1.o
 obj-$(CONFIG_PCIE_STM32_HOST) += pcie-stm32.o
 obj-$(CONFIG_PCIE_STM32_EP) += pcie-stm32-ep.o
+obj-$(CONFIG_PCIE_ULTRARISC) += pcie-ultrarisc.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-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index ae6389dd9caa..88dcb0e7943a 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -69,6 +69,8 @@
 
 /* Synopsys-specific PCIe configuration registers */
 #define PCIE_PORT_FORCE			0x708
+/* Bit[7:0] LINK_NUM: Link Number. Not used for endpoint */
+#define PORT_LINK_NUM_MASK		GENMASK(7, 0)
 #define PORT_FORCE_DO_DESKEW_FOR_SRIS	BIT(23)
 
 #define PCIE_PORT_AFR			0x70C
@@ -96,6 +98,26 @@
 #define PCIE_PORT_LANE_SKEW		0x714
 #define PORT_LANE_SKEW_INSERT_MASK	GENMASK(23, 0)
 
+/*
+ * PCIE_TIMER_CTRL_MAX_FUNC_NUM: Timer Control and Max Function Number
+ * Register.
+ * This register holds the ack frequency, latency, replay, fast link
+ * scaling timers, and max function number values.
+ * Bit[30:29] FAST_LINK_SCALING_FACTOR: Fast Link Timer Scaling Factor.
+ *   0x0 (SF_1024):Scaling Factor is 1024 (1ms is 1us).
+ *     When the LTSSM is in Config or L12 Entry State, 1ms
+ *     timer is 2us, 2ms timer is 4us and 3ms timer is 6us.
+ *   0x1 (SF_256): Scaling Factor is 256 (1ms is 4us)
+ *   0x2 (SF_64): Scaling Factor is 64 (1ms is 16us)
+ *   0x3 (SF_16): Scaling Factor is 16 (1ms is 64us)
+ */
+#define PCIE_TIMER_CTRL_MAX_FUNC_NUM	0x718
+#define PORT_FLT_SF_MASK	GENMASK(30, 29)
+#define PORT_FLT_SF_VAL_1024	0x0
+#define PORT_FLT_SF_VAL_256	0x1
+#define PORT_FLT_SF_VAL_64	0x2
+#define PORT_FLT_SF_VAL_16	0x3
+
 #define PCIE_PORT_DEBUG0		0x728
 #define PORT_LOGIC_LTSSM_STATE_MASK	0x3f
 #define PORT_LOGIC_LTSSM_STATE_L0	0x11
diff --git a/drivers/pci/controller/dwc/pcie-ultrarisc.c b/drivers/pci/controller/dwc/pcie-ultrarisc.c
new file mode 100644
index 000000000000..0da37efa8680
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-ultrarisc.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DWC PCIe RC driver for UltraRISC DP1000 SoC
+ *
+ * Copyright (C) 2026 UltraRISC Technology (Shanghai) Co., Ltd.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/resource.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#include "pcie-designware.h"
+
+#define PCIE_CUS_CORE          0x400000
+
+#define LTSSM_ENABLE           BIT(7)
+#define FAST_LINK_MODE         BIT(12)
+#define HOLD_PHY_RST           BIT(14)
+#define L1SUB_DISABLE          BIT(15)
+
+struct ultrarisc_pcie {
+	struct dw_pcie *pci;
+	u32 irq_mask[MAX_MSI_CTRLS];
+};
+
+static struct pci_ops ultrarisc_pci_ops = {
+	.map_bus = dw_pcie_own_conf_map_bus,
+	.read = pci_generic_config_read32,
+	.write = pci_generic_config_write32,
+};
+
+static int ultrarisc_pcie_host_init(struct dw_pcie_rp *pp)
+{
+	struct pci_host_bridge *bridge = pp->bridge;
+
+	bridge->ops = &ultrarisc_pci_ops;
+
+	return 0;
+}
+
+static void ultrarisc_pcie_pme_turn_off(struct dw_pcie_rp *pp)
+{
+	/*
+	 * DP1000 does not support sending PME_Turn_Off from the RC.
+	 * Keep this callback empty to skip the generic MSG TLP path.
+	 */
+}
+
+static const struct dw_pcie_host_ops ultrarisc_pcie_host_ops = {
+	.init = ultrarisc_pcie_host_init,
+	.pme_turn_off = ultrarisc_pcie_pme_turn_off,
+};
+
+static int ultrarisc_pcie_start_link(struct dw_pcie *pci)
+{
+	u32 val;
+	u8 cap_exp;
+
+	val = dw_pcie_readl_dbi(pci, PCIE_CUS_CORE);
+	val &= ~FAST_LINK_MODE;
+	dw_pcie_writel_dbi(pci, PCIE_CUS_CORE, val);
+
+	val = dw_pcie_readl_dbi(pci, PCIE_TIMER_CTRL_MAX_FUNC_NUM);
+	FIELD_MODIFY(PORT_FLT_SF_MASK, &val, PORT_FLT_SF_VAL_64);
+	dw_pcie_writel_dbi(pci, PCIE_TIMER_CTRL_MAX_FUNC_NUM, val);
+
+	cap_exp = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	val = dw_pcie_readl_dbi(pci, cap_exp + PCI_EXP_LNKCTL2);
+	FIELD_MODIFY(PCI_EXP_LNKCTL2_TLS, &val, PCI_EXP_LNKCTL2_TLS_16_0GT);
+	dw_pcie_writel_dbi(pci, cap_exp + PCI_EXP_LNKCTL2, val);
+
+	val = dw_pcie_readl_dbi(pci, PCIE_PORT_FORCE);
+	FIELD_MODIFY(PORT_LINK_NUM_MASK, &val, 0);
+	dw_pcie_writel_dbi(pci, PCIE_PORT_FORCE, val);
+
+	val = dw_pcie_readl_dbi(pci, cap_exp + PCI_EXP_DEVCTL2);
+	FIELD_MODIFY(PCI_EXP_DEVCTL2_COMP_TIMEOUT, &val, 0x6);
+	dw_pcie_writel_dbi(pci, cap_exp + PCI_EXP_DEVCTL2, val);
+
+	val = dw_pcie_readl_dbi(pci, PCIE_CUS_CORE);
+	val &= ~(HOLD_PHY_RST | L1SUB_DISABLE);
+	val |= LTSSM_ENABLE;
+	dw_pcie_writel_dbi(pci, PCIE_CUS_CORE, val);
+
+	return 0;
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+	.start_link = ultrarisc_pcie_start_link,
+};
+
+static int ultrarisc_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ultrarisc_pcie *pcie;
+	struct dw_pcie *pci;
+	struct dw_pcie_rp *pp;
+	int ret;
+
+	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
+	if (!pci)
+		return -ENOMEM;
+
+	pci->dev = dev;
+	pci->ops = &dw_pcie_ops;
+
+	/* Set a default value suitable for at most 16 in and 16 out windows */
+	pci->atu_size = SZ_8K;
+
+	pcie->pci = pci;
+
+	pp = &pci->pp;
+
+	platform_set_drvdata(pdev, pcie);
+
+	pp->irq = platform_get_irq(pdev, 1);
+	if (pp->irq < 0)
+		return pp->irq;
+
+	pp->num_vectors = MAX_MSI_IRQS;
+	/* No L2/L3 Ready indication is available on this platform. */
+	pp->skip_l23_ready = true;
+	pp->ops = &ultrarisc_pcie_host_ops;
+
+	ret = dw_pcie_host_init(pp);
+	if (ret) {
+		dev_err(dev, "Failed to initialize host\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ultrarisc_pcie_suspend_noirq(struct device *dev)
+{
+	struct ultrarisc_pcie *pcie = dev_get_drvdata(dev);
+	struct dw_pcie *pci = pcie->pci;
+
+	return dw_pcie_suspend_noirq(pci);
+}
+
+static int ultrarisc_pcie_resume_noirq(struct device *dev)
+{
+	struct ultrarisc_pcie *pcie = dev_get_drvdata(dev);
+	struct dw_pcie *pci = pcie->pci;
+
+	return dw_pcie_resume_noirq(pci);
+}
+
+static const struct dev_pm_ops ultrarisc_pcie_pm_ops = {
+	NOIRQ_SYSTEM_SLEEP_PM_OPS(ultrarisc_pcie_suspend_noirq,
+				  ultrarisc_pcie_resume_noirq)
+};
+
+static const struct of_device_id ultrarisc_pcie_of_match[] = {
+	{
+		.compatible = "ultrarisc,dp1000-pcie",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, ultrarisc_pcie_of_match);
+
+static struct platform_driver ultrarisc_pcie_driver = {
+	.driver = {
+		.name	= "ultrarisc-pcie",
+		.of_match_table = ultrarisc_pcie_of_match,
+		.suppress_bind_attrs = true,
+		.pm = &ultrarisc_pcie_pm_ops,
+	},
+	.probe = ultrarisc_pcie_probe,
+};
+module_platform_driver(ultrarisc_pcie_driver);
+
+MODULE_DESCRIPTION("UltraRISC DP1000 DWC PCIe host controller");
+MODULE_LICENSE("GPL");

-- 
2.34.1