[RESEND v4 11/14] PCI: imx6: Add i.MX PCIe EP mode support

Richard Zhu
2022-10-24T08:29:17Z

i.MX PCIe is one dual mode PCIe controller.

Add i.MX PCIe EP mode support here, and split the PCIe modes to the Root
Complex mode and Endpoint mode.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
drivers/pci/controller/dwc/Kconfig | 23 ++++-
drivers/pci/controller/dwc/pci-imx6.c | 128 +++++++++++++++++++++++---
2 files changed, 137 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 62ce3abf0f19..83580c92d216 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -92,10 +92,31 @@ config PCI_EXYNOS
functions to implement the driver.

config PCI_IMX6
- bool "Freescale i.MX6/7/8 PCIe controller"
+ bool
+
+config PCI_IMX6_HOST
+ bool "Freescale i.MX6/7/8 PCIe controller host mode"
depends on ARCH_MXC || COMPILE_TEST
depends on PCI_MSI_IRQ_DOMAIN
select PCIE_DW_HOST
+ select PCI_IMX6
+ help
+ Enables support for the PCIe controller in the i.MX SoCs to
+ work in Root Complex mode. The PCI controller on i.MX is based
+ on DesignWare hardware and therefore the driver re-uses the
+ DesignWare core functions to implement the driver.
+
+config PCI_IMX6_EP
+ bool "Freescale i.MX6/7/8 PCIe controller endpoint mode"
+ depends on ARCH_MXC || COMPILE_TEST
+ depends on PCI_ENDPOINT
+ select PCIE_DW_EP
+ select PCI_IMX6
+ help
+ Enables support for the PCIe controller in the i.MX SoCs to
+ work in endpoint mode. The PCI controller on i.MX is based
+ on DesignWare hardware and therefore the driver re-uses the
+ DesignWare core functions to implement the driver.

config PCIE_SPEAR13XX
bool "STMicroelectronics SPEAr PCIe controller"
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 2616585ca5f8..31467a31128a 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -60,6 +60,7 @@ enum imx6_pcie_variants {

struct imx6_pcie_drvdata {
enum imx6_pcie_variants variant;
+ enum dw_pcie_device_mode mode;
u32 flags;
int dbi_length;
const char *gpr;
@@ -159,17 +160,20 @@ static unsigned int imx6_pcie_grp_offset(const struct imx6_pcie *imx6_pcie)

static void imx6_pcie_configure_type(struct imx6_pcie *imx6_pcie)
{
- unsigned int mask, val;
+ unsigned int mask, val, mode;
+
+ if (imx6_pcie->drvdata->mode == DW_PCIE_EP_TYPE)
+ mode = PCI_EXP_TYPE_ENDPOINT;
+ else
+ mode = PCI_EXP_TYPE_ROOT_PORT;

if (imx6_pcie->drvdata->variant == IMX8MQ &&
imx6_pcie->controller_id == 1) {
mask = IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE;
- val = FIELD_PREP(IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE,
- PCI_EXP_TYPE_ROOT_PORT);
+ val = FIELD_PREP(IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE, mode);
} else {
mask = IMX6Q_GPR12_DEVICE_TYPE;
- val = FIELD_PREP(IMX6Q_GPR12_DEVICE_TYPE,
- PCI_EXP_TYPE_ROOT_PORT);
+ val = FIELD_PREP(IMX6Q_GPR12_DEVICE_TYPE, mode);
}

regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, mask, val);
@@ -1002,8 +1006,99 @@ static const struct dw_pcie_host_ops imx6_pcie_host_ops = {

static const struct dw_pcie_ops dw_pcie_ops = {
.start_link = imx6_pcie_start_link,
+ .stop_link = imx6_pcie_stop_link,
+};
+
+static void imx6_pcie_ep_init(struct dw_pcie_ep *ep)
+{
+ enum pci_barno bar;
+ struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+ for (bar = BAR_0; bar <= BAR_5; bar++)
+ dw_pcie_ep_reset_bar(pci, bar);
+}
+
+static int imx6_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
+ enum pci_epc_irq_type type,
+ u16 interrupt_num)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+ switch (type) {
+ case PCI_EPC_IRQ_LEGACY:
+ return dw_pcie_ep_raise_legacy_irq(ep, func_no);
+ case PCI_EPC_IRQ_MSI:
+ return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
+ case PCI_EPC_IRQ_MSIX:
+ return dw_pcie_ep_raise_msix_irq(ep, func_no, interrupt_num);
+ default:
+ dev_err(pci->dev, "UNKNOWN IRQ type\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static const struct pci_epc_features imx8m_pcie_epc_features = {
+ .linkup_notifier = false,
+ .msi_capable = true,
+ .msix_capable = false,
+ .reserved_bar = 1 << BAR_1 | 1 << BAR_3,
+ .align = SZ_64K,
+};
+
+static const struct pci_epc_features*
+imx6_pcie_ep_get_features(struct dw_pcie_ep *ep)
+{
+ return &imx8m_pcie_epc_features;
+}
+
+static const struct dw_pcie_ep_ops pcie_ep_ops = {
+ .ep_init = imx6_pcie_ep_init,
+ .raise_irq = imx6_pcie_ep_raise_irq,
+ .get_features = imx6_pcie_ep_get_features,
};

+static int imx6_add_pcie_ep(struct imx6_pcie *imx6_pcie,
+ struct platform_device *pdev)
+{
+ int ret;
+ unsigned int pcie_dbi2_offset;
+ struct dw_pcie_ep *ep;
+ struct resource *res;
+ struct dw_pcie *pci = imx6_pcie->pci;
+ struct dw_pcie_rp *pp = &pci->pp;
+ struct device *dev = pci->dev;
+
+ imx6_pcie_host_init(pp);
+ ep = &pci->ep;
+ ep->ops = &pcie_ep_ops;
+
+ switch (imx6_pcie->drvdata->variant) {
+ default:
+ pcie_dbi2_offset = SZ_4K;
+ break;
+ }
+ pci->dbi_base2 = pci->dbi_base + pcie_dbi2_offset;
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space");
+ if (!res)
+ return -EINVAL;
+
+ ep->phys_base = res->start;
+ ep->addr_size = resource_size(res);
+ ep->page_size = SZ_64K;
+
+ ret = dw_pcie_ep_init(ep);
+ if (ret) {
+ dev_err(dev, "failed to initialize endpoint\n");
+ return ret;
+ }
+ /* Start LTSSM. */
+ imx6_pcie_ltssm_enable(dev);
+
+ return 0;
+}
+
static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
{
struct device *dev = imx6_pcie->pci->dev;
@@ -1278,15 +1373,22 @@ static int imx6_pcie_probe(struct platform_device *pdev)
if (ret)
return ret;

- ret = dw_pcie_host_init(&pci->pp);
- if (ret < 0)
- return ret;
+ if (imx6_pcie->drvdata->mode == DW_PCIE_EP_TYPE) {
+ ret = imx6_add_pcie_ep(imx6_pcie, pdev);
+ if (ret < 0)
+ return ret;
+ } else {
+ ret = dw_pcie_host_init(&pci->pp);
+ if (ret < 0)
+ return ret;
+
+ if (pci_msi_enabled()) {
+ u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);

- if (pci_msi_enabled()) {
- u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
- val = dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS);
- val |= PCI_MSI_FLAGS_ENABLE;
- dw_pcie_writew_dbi(pci, offset + PCI_MSI_FLAGS, val);
+ val = dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS);
+ val |= PCI_MSI_FLAGS_ENABLE;
+ dw_pcie_writew_dbi(pci, offset + PCI_MSI_FLAGS, val);
+ }
}

return 0;
--
2.25.1