PCI: imx6: Add i.MX PCIe EP mode support

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.

Link: https://lore.kernel.org/r/1673847684-31893-12-git-send-email-hongxing.zhu@nxp.com
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index a0d2713..dffd7fb 100644 (file)
--- 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
        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 1dde5c5..572faa9 100644 (file)
--- 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);
@@ -1003,8 +1007,99 @@ 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;
@@ -1279,15 +1374,22 @@ 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;