[PATCH v4 5/7] PCI: spacemit: introduce SpacemiT PCIe host driver

Alex Elder posted 7 patches 3 months, 1 week ago
There is a newer version of this series
[PATCH v4 5/7] PCI: spacemit: introduce SpacemiT PCIe host driver
Posted by Alex Elder 3 months, 1 week ago
Introduce a driver for the PCIe host controller found in the SpacemiT
K1 SoC.  The hardware is derived from the Synopsys DesignWare PCIe IP.
The driver supports three PCIe ports that operate at PCIe gen2 transfer
rates (5 GT/sec).  The first port uses a combo PHY, which may be
configured for use for USB 3 instead.

Signed-off-by: Alex Elder <elder@riscstar.com>
---
 drivers/pci/controller/dwc/Kconfig            |  11 +
 drivers/pci/controller/dwc/Makefile           |   1 +
 drivers/pci/controller/dwc/pcie-spacemit-k1.c | 349 ++++++++++++++++++
 3 files changed, 361 insertions(+)
 create mode 100644 drivers/pci/controller/dwc/pcie-spacemit-k1.c

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 349d4657393c9..d229260f0337e 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -509,6 +509,17 @@ config PCI_KEYSTONE_EP
 	  on DesignWare hardware and therefore the driver re-uses the
 	  DesignWare core functions to implement the driver.
 
+config PCIE_SPACEMIT_K1
+	tristate "SpacemiT K1 PCIe controller (host mode)"
+	depends on ARCH_SPACEMIT || COMPILE_TEST
+	depends on PCI && OF && HAS_IOMEM
+	select PCIE_DW_HOST
+	select PCI_PWRCTRL_SLOT
+	default ARCH_SPACEMIT
+	help
+	  Enables support for the PCIe controller in the K1 SoC operating
+	  in host mode.
+
 config PCIE_VISCONTI_HOST
 	bool "Toshiba Visconti PCIe controller"
 	depends on ARCH_VISCONTI || COMPILE_TEST
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index 7ae28f3b0fb39..662b0a219ddc4 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
 obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
 obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.o
 obj-$(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
 
diff --git a/drivers/pci/controller/dwc/pcie-spacemit-k1.c b/drivers/pci/controller/dwc/pcie-spacemit-k1.c
new file mode 100644
index 0000000000000..2efb92ef948f2
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-spacemit-k1.c
@@ -0,0 +1,349 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SpacemiT K1 PCIe host driver
+ *
+ * Copyright (C) 2025 by RISCstar Solutions Corporation.  All rights reserved.
+ * Copyright (c) 2023, spacemit Corporation.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mod_devicetable.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/types.h>
+
+#include "pcie-designware.h"
+
+#define PCI_VENDOR_ID_SPACEMIT		0x201f
+#define PCI_DEVICE_ID_SPACEMIT_K1	0x0001
+
+/* Offsets and field definitions for link management registers */
+#define K1_PHY_AHB_IRQ_EN			0x0000
+#define PCIE_INTERRUPT_EN		BIT(0)
+
+#define K1_PHY_AHB_LINK_STS			0x0004
+#define SMLH_LINK_UP			BIT(1)
+#define RDLH_LINK_UP			BIT(12)
+
+#define INTR_ENABLE				0x0014
+#define MSI_CTRL_INT			BIT(11)
+
+/* Some controls require APMU regmap access */
+#define SYSCON_APMU			"spacemit,apmu"
+
+/* Offsets and field definitions for APMU registers */
+#define PCIE_CLK_RESET_CONTROL			0x0000
+#define LTSSM_EN			BIT(6)
+#define PCIE_AUX_PWR_DET		BIT(9)
+#define PCIE_RC_PERST			BIT(12)	/* 1: assert PERST# */
+#define APP_HOLD_PHY_RST		BIT(30)
+#define DEVICE_TYPE_RC			BIT(31)	/* 0: endpoint; 1: RC */
+
+#define PCIE_CONTROL_LOGIC			0x0004
+#define PCIE_SOFT_RESET			BIT(0)
+
+struct k1_pcie {
+	struct dw_pcie pci;
+	struct phy *phy;
+	void __iomem *link;
+	struct regmap *pmu;	/* Errors ignored; MMIO-backed regmap */
+	u32 pmu_off;
+};
+
+#define to_k1_pcie(dw_pcie) \
+		platform_get_drvdata(to_platform_device((dw_pcie)->dev))
+
+static void k1_pcie_toggle_soft_reset(struct k1_pcie *k1)
+{
+	u32 offset;
+	u32 val;
+
+	/*
+	 * Write, then read back to guarantee it has reached the device
+	 * before we start the delay.
+	 */
+	offset = k1->pmu_off + PCIE_CONTROL_LOGIC;
+	regmap_set_bits(k1->pmu, offset, PCIE_SOFT_RESET);
+	regmap_read(k1->pmu, offset, &val);
+
+	mdelay(2);
+
+	regmap_clear_bits(k1->pmu, offset, PCIE_SOFT_RESET);
+}
+
+/* Enable app clocks, deassert resets */
+static int k1_pcie_enable_resources(struct k1_pcie *k1)
+{
+	struct dw_pcie *pci = &k1->pci;
+	int ret;
+
+	ret = clk_bulk_prepare_enable(ARRAY_SIZE(pci->app_clks), pci->app_clks);
+	if (ret)
+		return ret;
+
+	ret = reset_control_bulk_deassert(ARRAY_SIZE(pci->app_rsts),
+					  pci->app_rsts);
+	if (ret)
+		goto err_disable_clks;
+
+	return 0;
+
+err_disable_clks:
+	clk_bulk_disable_unprepare(ARRAY_SIZE(pci->app_clks), pci->app_clks);
+
+	return ret;
+}
+
+/* Assert resets, disable app clocks */
+static void k1_pcie_disable_resources(struct k1_pcie *k1)
+{
+	struct dw_pcie *pci = &k1->pci;
+
+	reset_control_bulk_assert(ARRAY_SIZE(pci->app_rsts), pci->app_rsts);
+	clk_bulk_disable_unprepare(ARRAY_SIZE(pci->app_clks), pci->app_clks);
+}
+
+static int k1_pcie_init(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct k1_pcie *k1 = to_k1_pcie(pci);
+	u32 offset;
+	u32 mask;
+	u32 val;
+	int ret;
+
+	k1_pcie_toggle_soft_reset(k1);
+
+	ret = k1_pcie_enable_resources(k1);
+	if (ret)
+		return ret;
+
+	ret = phy_init(k1->phy);
+	if (ret) {
+		k1_pcie_disable_resources(k1);
+
+		return ret;
+	}
+
+	/* Set the PCI vendor and device ID */
+	dw_pcie_dbi_ro_wr_en(pci);
+	dw_pcie_writew_dbi(pci, PCI_VENDOR_ID, PCI_VENDOR_ID_SPACEMIT);
+	dw_pcie_writew_dbi(pci, PCI_DEVICE_ID, PCI_DEVICE_ID_SPACEMIT_K1);
+	dw_pcie_dbi_ro_wr_dis(pci);
+
+	/*
+	 * Assert fundamental reset (drive PERST# low).  Put the controller
+	 * in root complex mode, and indicate that Vaux (3.3v) is present.
+	 */
+	mask = PCIE_RC_PERST;
+	mask |= DEVICE_TYPE_RC | PCIE_AUX_PWR_DET;
+
+	/*
+	 * Write, then read back to guarantee it has reached the device
+	 * before we start the delay.
+	 */
+	offset = k1->pmu_off + PCIE_CLK_RESET_CONTROL;
+	regmap_set_bits(k1->pmu, offset, mask);
+	regmap_read(k1->pmu, offset, &val);
+
+	mdelay(PCIE_T_PVPERL_MS);
+
+	/* Deassert fundamental reset (drive PERST# high) */
+	regmap_clear_bits(k1->pmu, offset, PCIE_RC_PERST);
+
+	return 0;
+}
+
+/* Disable ASPM L1 for now, until reported errors can be reproduced */
+static void k1_pcie_post_init(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	u8 offset;
+	u32 val;
+
+	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+
+	dw_pcie_dbi_ro_wr_en(pci);
+
+	/* Turn off ASPM L1 for the link */
+	val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP);
+	val &= ~PCI_EXP_LNKCAP_ASPM_L1;
+	writel(val, pci->dbi_base + offset + PCI_EXP_LNKCAP);
+
+	dw_pcie_dbi_ro_wr_dis(pci);
+}
+
+static void k1_pcie_deinit(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct k1_pcie *k1 = to_k1_pcie(pci);
+
+	/* Assert fundamental reset (drive PERST# low) */
+	regmap_set_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL,
+			PCIE_RC_PERST);
+
+	phy_exit(k1->phy);
+
+	k1_pcie_disable_resources(k1);
+}
+
+static const struct dw_pcie_host_ops k1_pcie_host_ops = {
+	.init		= k1_pcie_init,
+	.post_init	= k1_pcie_post_init,
+	.deinit		= k1_pcie_deinit,
+};
+
+static bool k1_pcie_link_up(struct dw_pcie *pci)
+{
+	struct k1_pcie *k1 = to_k1_pcie(pci);
+	u32 val;
+
+	val = readl_relaxed(k1->link + K1_PHY_AHB_LINK_STS);
+
+	return (val & RDLH_LINK_UP) && (val & SMLH_LINK_UP);
+}
+
+static int k1_pcie_start_link(struct dw_pcie *pci)
+{
+	struct k1_pcie *k1 = to_k1_pcie(pci);
+	u32 val;
+
+	/* Stop holding the PHY in reset, and enable link training */
+	regmap_update_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL,
+			   APP_HOLD_PHY_RST | LTSSM_EN, LTSSM_EN);
+
+	/* Enable the MSI interrupt */
+	writel_relaxed(MSI_CTRL_INT, k1->link + INTR_ENABLE);
+
+	/* Top-level interrupt enable */
+	val = readl_relaxed(k1->link + K1_PHY_AHB_IRQ_EN);
+	val |= PCIE_INTERRUPT_EN;
+	writel_relaxed(val, k1->link + K1_PHY_AHB_IRQ_EN);
+
+	return 0;
+}
+
+static void k1_pcie_stop_link(struct dw_pcie *pci)
+{
+	struct k1_pcie *k1 = to_k1_pcie(pci);
+	u32 val;
+
+	/* Disable interrupts */
+	val = readl_relaxed(k1->link + K1_PHY_AHB_IRQ_EN);
+	val &= ~PCIE_INTERRUPT_EN;
+	writel_relaxed(val, k1->link + K1_PHY_AHB_IRQ_EN);
+
+	writel_relaxed(0, k1->link + INTR_ENABLE);
+
+	/* Disable the link and hold the PHY in reset */
+	regmap_update_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL,
+			   APP_HOLD_PHY_RST | LTSSM_EN, APP_HOLD_PHY_RST);
+}
+
+static const struct dw_pcie_ops k1_pcie_ops = {
+	.link_up	= k1_pcie_link_up,
+	.start_link	= k1_pcie_start_link,
+	.stop_link	= k1_pcie_stop_link,
+};
+
+static int k1_pcie_parse_port(struct k1_pcie *k1)
+{
+	struct device *dev = k1->pci.dev;
+	struct device_node *root_port;
+	struct phy *phy;
+
+	/* We assume only one root port */
+	root_port = of_get_next_available_child(dev_of_node(dev), NULL);
+	if (!root_port)
+		return -EINVAL;
+
+	phy = devm_of_phy_get(dev, root_port, NULL);
+
+	of_node_put(root_port);
+
+	if (IS_ERR(phy))
+		return PTR_ERR(phy);
+
+	k1->phy = phy;
+
+	return 0;
+}
+
+static int k1_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct k1_pcie *k1;
+	int ret;
+
+	k1 = devm_kzalloc(dev, sizeof(*k1), GFP_KERNEL);
+	if (!k1)
+		return -ENOMEM;
+
+	k1->pmu = syscon_regmap_lookup_by_phandle_args(dev_of_node(dev),
+						       SYSCON_APMU, 1,
+						       &k1->pmu_off);
+	if (IS_ERR(k1->pmu))
+		return dev_err_probe(dev, PTR_ERR(k1->pmu),
+				     "failed to lookup PMU registers\n");
+
+	k1->link = devm_platform_ioremap_resource_byname(pdev, "link");
+	if (!k1->link)
+		return dev_err_probe(dev, -ENOMEM,
+				     "failed to map \"link\" registers\n");
+
+	k1->pci.dev = dev;
+	k1->pci.ops = &k1_pcie_ops;
+	dw_pcie_cap_set(&k1->pci, REQ_RES);
+
+	k1->pci.pp.ops = &k1_pcie_host_ops;
+
+	/* Hold the PHY in reset until we start the link */
+	regmap_set_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL,
+			APP_HOLD_PHY_RST);
+
+	pm_runtime_set_active(dev);
+	pm_runtime_no_callbacks(dev);
+	devm_pm_runtime_enable(dev);
+
+	platform_set_drvdata(pdev, k1);
+
+	ret = k1_pcie_parse_port(k1);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to parse root port\n");
+
+	ret = dw_pcie_host_init(&k1->pci.pp);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to initialize host\n");
+
+	return 0;
+}
+
+static void k1_pcie_remove(struct platform_device *pdev)
+{
+	struct k1_pcie *k1 = platform_get_drvdata(pdev);
+
+	dw_pcie_host_deinit(&k1->pci.pp);
+}
+
+static const struct of_device_id k1_pcie_of_match_table[] = {
+	{ .compatible = "spacemit,k1-pcie", },
+	{ },
+};
+
+static struct platform_driver k1_pcie_driver = {
+	.probe	= k1_pcie_probe,
+	.remove	= k1_pcie_remove,
+	.driver = {
+		.name			= "spacemit-k1-pcie",
+		.of_match_table		= k1_pcie_of_match_table,
+		.probe_type		= PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+module_platform_driver(k1_pcie_driver);
-- 
2.48.1
Re: [PATCH v4 5/7] PCI: spacemit: introduce SpacemiT PCIe host driver
Posted by Aurelien Jarno 3 months, 1 week ago
Hi Alex,

On 2025-10-30 17:02, Alex Elder wrote:
> +/* Disable ASPM L1 for now, until reported errors can be reproduced */

Thanks for adding this function.

> +static void k1_pcie_post_init(struct dw_pcie_rp *pp)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	u8 offset;
> +	u32 val;
> +
> +	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> +
> +	dw_pcie_dbi_ro_wr_en(pci);
> +
> +	/* Turn off ASPM L1 for the link */
> +	val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP);

Why not using dw_pcie_readl_dbi() instead?

> +	val &= ~PCI_EXP_LNKCAP_ASPM_L1;
> +	writel(val, pci->dbi_base + offset + PCI_EXP_LNKCAP);

And here dw_pcie_writel_dbi()?

> +
> +	dw_pcie_dbi_ro_wr_dis(pci);
> +}
> +
> +static void k1_pcie_deinit(struct dw_pcie_rp *pp)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	struct k1_pcie *k1 = to_k1_pcie(pci);
> +
> +	/* Assert fundamental reset (drive PERST# low) */
> +	regmap_set_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL,
> +			PCIE_RC_PERST);
> +
> +	phy_exit(k1->phy);
> +
> +	k1_pcie_disable_resources(k1);
> +}
> +
> +static const struct dw_pcie_host_ops k1_pcie_host_ops = {
> +	.init		= k1_pcie_init,
> +	.post_init	= k1_pcie_post_init,

Unfortunately, while I can see the effect of the change with for 
instance lspci -vvv, this happens way too late in the device scan 
process, i.e. after pcie_aspm_override_default_link_state() and causes 
L1 to still be enabled.

I have tried to move it earlier, in k1_pcie_init() after writing the 
vendor and device IDs. This works as long as "nvme scan" is run in 
U-Boot. But if I don't run this command, it seems that the change is 
ignored or lost (i.e. I can still see L1 enabled with lspci -vvv).

Moving it at the end of k1_pcie_init() works fine, like moving it at the 
beginning of k1_pcie_start_link(). But my knowledge is too limited to 
know where is the correct place.

Regards
Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                     http://aurel32.net
Re: [PATCH v4 5/7] PCI: spacemit: introduce SpacemiT PCIe host driver
Posted by Alex Elder 3 months, 1 week ago
On 10/31/25 5:31 PM, Aurelien Jarno wrote:
> Hi Alex,
> 
> On 2025-10-30 17:02, Alex Elder wrote:
>> +/* Disable ASPM L1 for now, until reported errors can be reproduced */
> 
> Thanks for adding this function.
> 
>> +static void k1_pcie_post_init(struct dw_pcie_rp *pp)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	u8 offset;
>> +	u32 val;
>> +
>> +	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
>> +
>> +	dw_pcie_dbi_ro_wr_en(pci);
>> +
>> +	/* Turn off ASPM L1 for the link */
>> +	val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP);
> 
> Why not using dw_pcie_readl_dbi() instead?
> 
>> +	val &= ~PCI_EXP_LNKCAP_ASPM_L1;
>> +	writel(val, pci->dbi_base + offset + PCI_EXP_LNKCAP);
> 
> And here dw_pcie_writel_dbi()?
> 
>> +
>> +	dw_pcie_dbi_ro_wr_dis(pci);
>> +}
>> +
>> +static void k1_pcie_deinit(struct dw_pcie_rp *pp)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	struct k1_pcie *k1 = to_k1_pcie(pci);
>> +
>> +	/* Assert fundamental reset (drive PERST# low) */
>> +	regmap_set_bits(k1->pmu, k1->pmu_off + PCIE_CLK_RESET_CONTROL,
>> +			PCIE_RC_PERST);
>> +
>> +	phy_exit(k1->phy);
>> +
>> +	k1_pcie_disable_resources(k1);
>> +}
>> +
>> +static const struct dw_pcie_host_ops k1_pcie_host_ops = {
>> +	.init		= k1_pcie_init,
>> +	.post_init	= k1_pcie_post_init,
> 
> Unfortunately, while I can see the effect of the change with for
> instance lspci -vvv, this happens way too late in the device scan
> process, i.e. after pcie_aspm_override_default_link_state() and causes
> L1 to still be enabled.

OK thanks for this information.  I am going to contact you
privately to get more information on your errors (and those
Johannes is reporting) so that I can try to resolve them
before I post the next version of this patch series.

					-Alex

> 
> I have tried to move it earlier, in k1_pcie_init() after writing the
> vendor and device IDs. This works as long as "nvme scan" is run in
> U-Boot. But if I don't run this command, it seems that the change is
> ignored or lost (i.e. I can still see L1 enabled with lspci -vvv).
> 
> Moving it at the end of k1_pcie_init() works fine, like moving it at the
> beginning of k1_pcie_start_link(). But my knowledge is too limited to
> know where is the correct place.
> 
> Regards
> Aurelien
>
Re: [PATCH v4 5/7] PCI: spacemit: introduce SpacemiT PCIe host driver
Posted by Bjorn Helgaas 3 months, 1 week ago
In subject, capitalize "introduce" to match history.  Or you could
just use "Add ...", which has the advantage of being shorter.

On Thu, Oct 30, 2025 at 05:02:56PM -0500, Alex Elder wrote:
> Introduce a driver for the PCIe host controller found in the SpacemiT
> K1 SoC.  The hardware is derived from the Synopsys DesignWare PCIe IP.
> The driver supports three PCIe ports that operate at PCIe gen2 transfer
> rates (5 GT/sec).  The first port uses a combo PHY, which may be
> configured for use for USB 3 instead.
> ...

I guess this doesn't support INTx interrupts at all?

> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -509,6 +509,17 @@ config PCI_KEYSTONE_EP
>  	  on DesignWare hardware and therefore the driver re-uses the
>  	  DesignWare core functions to implement the driver.
>  
> +config PCIE_SPACEMIT_K1
> +	tristate "SpacemiT K1 PCIe controller (host mode)"

Move this to keep the menu items alphabetized by vendor.

> +	depends on ARCH_SPACEMIT || COMPILE_TEST
> +	depends on PCI && OF && HAS_IOMEM

I don't think you need PCI or OF.

> +	select PCIE_DW_HOST
> +	select PCI_PWRCTRL_SLOT
> +	default ARCH_SPACEMIT
> +	help
> +	  Enables support for the PCIe controller in the K1 SoC operating
> +	  in host mode.

Most help text includes both the vendor and the product line names.
Re: [PATCH v4 5/7] PCI: spacemit: introduce SpacemiT PCIe host driver
Posted by Alex Elder 3 months, 1 week ago
On 10/30/25 6:08 PM, Bjorn Helgaas wrote:
> In subject, capitalize "introduce" to match history.  Or you could
> just use "Add ...", which has the advantage of being shorter.

OK.  I'll capitalize all of them in this series.

> On Thu, Oct 30, 2025 at 05:02:56PM -0500, Alex Elder wrote:
>> Introduce a driver for the PCIe host controller found in the SpacemiT
>> K1 SoC.  The hardware is derived from the Synopsys DesignWare PCIe IP.
>> The driver supports three PCIe ports that operate at PCIe gen2 transfer
>> rates (5 GT/sec).  The first port uses a combo PHY, which may be
>> configured for use for USB 3 instead.
>> ...
> 
> I guess this doesn't support INTx interrupts at all?

It can, but I removed that support first to simplify the task
of converting the original code, and second because I had no way
to test it.  I planned for it to be added at a future date.

>> +++ b/drivers/pci/controller/dwc/Kconfig
>> @@ -509,6 +509,17 @@ config PCI_KEYSTONE_EP
>>   	  on DesignWare hardware and therefore the driver re-uses the
>>   	  DesignWare core functions to implement the driver.
>>   
>> +config PCIE_SPACEMIT_K1
>> +	tristate "SpacemiT K1 PCIe controller (host mode)"
> 
> Move this to keep the menu items alphabetized by vendor.

OK.  I was going by Kconfig option name, but now I see
what you mean.

I'll put it between PCIE_SOPHGO_DW and PCIE_SPEAR13XX.

>> +	depends on ARCH_SPACEMIT || COMPILE_TEST
>> +	depends on PCI && OF && HAS_IOMEM
> 
> I don't think you need PCI or OF.

You're right.  PCI for sure, but it doesn't look like I make
an direct OF calls either.  I'll drop them both.

>> +	select PCIE_DW_HOST
>> +	select PCI_PWRCTRL_SLOT
>> +	default ARCH_SPACEMIT
>> +	help
>> +	  Enables support for the PCIe controller in the K1 SoC operating
>> +	  in host mode.
> 
> Most help text includes both the vendor and the product line names.
I guess I didn't include "SpacemiT".  I'll add that, and will try
to come up with a few more words in the description.

Thanks for your quick response.

					-Alex