[PATCH 4/4] PCI: dwc: Add UltraRISC DP1000 PCIe rc driver
Bjorn Helgaas
helgaas at kernel.org
Mon Mar 16 13:49:58 PDT 2026
In subject, s/dwc/ultrarisc/ or whatever tag we're going to use for
this driver, e.g.,
PCI: ultrarisc: Add UltraRISC DP1000 PCIe Root Complex driver
On Mon, Mar 16, 2026 at 03:07:00PM +0800, Jia Wang via B4 Relay wrote:
> From: Xincheng Zhang <zhangxincheng at ultrarisc.com>
>
> Add DP1000 soc PCIe rc driver.
s/soc/SoC/
s/rc/RC/ or Root Complex (also in subject)
> Signed-off-by: Xincheng Zhang <zhangxincheng at ultrarisc.com>
> Signed-off-by: Jia Wang <wangjia at ultrarisc.com>
> ---
> drivers/pci/controller/dwc/Kconfig | 15 ++
> drivers/pci/controller/dwc/Makefile | 1 +
> drivers/pci/controller/dwc/pcie-designware.h | 22 +++
> drivers/pci/controller/dwc/pcie-ultrarisc.c | 202 +++++++++++++++++++++++++++
> 4 files changed, 240 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> index d0aa031397fa..0a33891bf7ef 100644
> --- a/drivers/pci/controller/dwc/Kconfig
> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -548,4 +548,19 @@ 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
> + bool "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. When selected, it automatically
> + enables both `PCIE_DW_HOST` and `PCI_MSI`, ensuring proper support
> + for MSI-based interrupt handling in the PCIe controller.
I don't think the PCIE_DW_HOST and PCI_MSI explanation is relevant for
Kconfig help.
> + By default, this symbol is enabled when `ARCH_ULTRARISC` is active,
> + requiring no further configuration on that platform.
> +
> +
Remove spurious blank line.
> 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..8f2ed86cb5c5 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.
Wrap to fit in 80 columns like the rest of the file.
> + * 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(n) FIELD_PREP(PORT_FLT_SF_MASK, n)
> +#define PORT_FLT_SF_1024 PORT_FLT_SF(0x0)
> +#define PORT_FLT_SF_256 PORT_FLT_SF(0x1)
> +#define PORT_FLT_SF_64 PORT_FLT_SF(0x2)
> +#define PORT_FLT_SF_16 PORT_FLT_SF(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..64cbf16d3ff7
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-ultrarisc.c
> @@ -0,0 +1,202 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * DWC PCIe RC driver for UltraRISC DP1000 SoC
> + *
> + * Copyright (C) 2023 UltraRISC
> + *
Remove spurious blank line. Maybe you want "(C) 2026"?
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/of_device.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/resource.h>
> +#include <linux/types.h>
> +#include <linux/regmap.h>
Order alphabetically.
> +#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;
s/dw_pcie /dw_pcie / (single space to match irq_mask below)
> + u32 irq_mask[MAX_MSI_CTRLS];
> +};
> +
> +static const struct of_device_id ultrarisc_pcie_of_match[];
This declaration looks unnecessary.
> +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,
I guess this hardware has the defect that it can only do 32-bit
writes?
> +};
> +
> +static int ultrarisc_pcie_host_init(struct dw_pcie_rp *pp)
> +{
> + struct pci_host_bridge *bridge = pp->bridge;
> +
> + /* Set the bus ops */
Drop spurious comment.
> + bridge->ops = &ultrarisc_pci_ops;
> +
> + return 0;
> +}
> +
> +static const struct dw_pcie_host_ops ultrarisc_pcie_host_ops = {
> + .init = ultrarisc_pcie_host_init,
> +};
> +
> +static int ultrarisc_pcie_establish_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);
> + val &= ~PORT_FLT_SF_MASK;
> + val |= PORT_FLT_SF_64;
FIELD_MODIFY() here and below.
> + 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);
> + val &= ~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);
> + val &= ~PORT_LINK_NUM_MASK;
> + dw_pcie_writel_dbi(pci, PCIE_PORT_FORCE, val);
> +
> + val = dw_pcie_readl_dbi(pci, cap_exp + PCI_EXP_DEVCTL2);
> + val &= ~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_establish_link,
s/ultrarisc_pcie_establish_link/ultrarisc_pcie_start_link/
to match member name and other drivers.
> +};
> +
> +static int ultrarisc_pcie_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct ultrarisc_pcie *ultrarisc_pcie;
"ultrarisc_pcie" is a pretty long name that will be used for
parameters when you add more functionality. Several drivers just use
"pcie", some use the equivalent of "ultrarisc", etc.
> + struct dw_pcie *pci;
> + struct dw_pcie_rp *pp;
> + int ret;
> +
> + ultrarisc_pcie = devm_kzalloc(dev, sizeof(*ultrarisc_pcie), GFP_KERNEL);
> + if (!ultrarisc_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;
> +
> + ultrarisc_pcie->pci = pci;
> +
> + pp = &pci->pp;
> +
> + platform_set_drvdata(pdev, ultrarisc_pcie);
> +
> + pp->irq = platform_get_irq(pdev, 1);
> + if (pp->irq < 0)
> + return pp->irq;
> +
> + pp->num_vectors = MAX_MSI_IRQS;
> + 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(struct platform_device *pdev, pm_message_t state)
If you use generic power management, this will be:
static int ultrarisc_pcie_suspend(struct device *dev)
> +{
> + struct ultrarisc_pcie *ultrarisc_pcie = platform_get_drvdata(pdev);
> + struct dw_pcie *pci = ultrarisc_pcie->pci;
> + struct dw_pcie_rp *pp = &pci->pp;
> + int num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
> + unsigned long flags;
> + int ctrl;
> +
> + raw_spin_lock_irqsave(&pp->lock, flags);
> +
> + for (ctrl = 0; ctrl < num_ctrls; ctrl++)
> + ultrarisc_pcie->irq_mask[ctrl] = pp->irq_mask[ctrl];
> +
> + raw_spin_unlock_irqrestore(&pp->lock, flags);
> +
> + return 0;
> +}
> +
> +static int ultrarisc_pcie_resume(struct platform_device *pdev)
> +{
> + struct ultrarisc_pcie *ultrarisc_pcie = platform_get_drvdata(pdev);
> + struct dw_pcie *pci = ultrarisc_pcie->pci;
> + struct dw_pcie_rp *pp = &pci->pp;
> + int num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
> + unsigned long flags;
> + int ctrl;
> +
> + raw_spin_lock_irqsave(&pp->lock, flags);
> +
> + for (ctrl = 0; ctrl < num_ctrls; ctrl++) {
> + pp->irq_mask[ctrl] = ultrarisc_pcie->irq_mask[ctrl];
> + dw_pcie_writel_dbi(pci,
> + PCIE_MSI_INTR0_MASK +
> + ctrl * MSI_REG_CTRL_BLOCK_SIZE,
> + pp->irq_mask[ctrl]);
> + }
> +
> + raw_spin_unlock_irqrestore(&pp->lock, flags);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id ultrarisc_pcie_of_match[] = {
> + {
> + .compatible = "ultrarisc,dp1000-pcie",
> + },
> + {},
> +};
> +
> +static struct platform_driver ultrarisc_pcie_driver = {
> + .driver = {
> + .name = "ultrarisc-pcie",
> + .of_match_table = ultrarisc_pcie_of_match,
> + .suppress_bind_attrs = true,
> + },
> + .probe = ultrarisc_pcie_probe,
> + .suspend = ultrarisc_pcie_suspend,
> + .resume = ultrarisc_pcie_resume,
Use generic driver PM instead of the platform_driver.suspend/resume.
> +};
> +builtin_platform_driver(ultrarisc_pcie_driver);
>
> --
> 2.34.1
>
>
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