[PATCH 6/8] PCI: al: Add support for DW based driver type

From: Jonathan Chocron
Date: Thu Jul 11 2019 - 10:57:14 EST


This driver is DT based and utilizes the DesignWare APIs.
It allows using a smaller ECAM range for a larger bus range -
usually an entire bus uses 1MB of address space, but the driver
can use it for a larger number of buses.

All link initializations are handled by the boot FW.

Signed-off-by: Jonathan Chocron <jonnyc@xxxxxxxxxx>
---
drivers/pci/controller/dwc/Kconfig | 11 +
drivers/pci/controller/dwc/pcie-al.c | 397 +++++++++++++++++++++++++++
2 files changed, 408 insertions(+)

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index a6ce1ee51b4c..51da9cb219aa 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -230,4 +230,15 @@ config PCIE_UNIPHIER
Say Y here if you want PCIe controller support on UniPhier SoCs.
This driver supports LD20 and PXs3 SoCs.

+config PCIE_AL
+ bool "Amazon Annapurna Labs PCIe controller"
+ depends on OF && (ARM64 || COMPILE_TEST)
+ depends on PCI_MSI_IRQ_DOMAIN
+ select PCIE_DW_HOST
+ help
+ Say Y here to enable support of the Annapurna Labs PCIe controller IP
+ on Amazon SoCs.
+ The PCIe controller uses the DesignWare core plus
+ Amazon-specific hardware wrappers.
+
endmenu
diff --git a/drivers/pci/controller/dwc/pcie-al.c b/drivers/pci/controller/dwc/pcie-al.c
index 3ab58f0584a8..2742a0895aab 100644
--- a/drivers/pci/controller/dwc/pcie-al.c
+++ b/drivers/pci/controller/dwc/pcie-al.c
@@ -91,3 +91,400 @@ struct pci_ecam_ops al_pcie_ops = {
};

#endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */
+
+#ifdef CONFIG_PCIE_AL
+
+#include <linux/of_pci.h>
+#include "pcie-designware.h"
+
+#define AL_PCIE_REV_ID_2 2
+#define AL_PCIE_REV_ID_3 3
+#define AL_PCIE_REV_ID_4 4
+
+/* The AXI regs are always at the beginning of the PCIE controller reg space. */
+#define AXI_BASE_OFFSET 0x0
+
+#define DEVICE_ID_OFFSET 0x16c
+
+#define DEVICE_REV_ID 0x0
+#define DEVICE_REV_ID_DEV_ID_MASK 0xFFFF0000
+#define DEVICE_REV_ID_DEV_ID_SHIFT 16
+
+#define DEVICE_REV_ID_DEV_ID_X4 (0 << DEVICE_REV_ID_DEV_ID_SHIFT)
+#define DEVICE_REV_ID_DEV_ID_X8 (2 << DEVICE_REV_ID_DEV_ID_SHIFT)
+#define DEVICE_REV_ID_DEV_ID_X16 (4 << DEVICE_REV_ID_DEV_ID_SHIFT)
+
+/* The ob_ctrl offset inside the axi regs is different between revisions.
+ */
+#define OB_CTRL_REV1_2_OFFSET 0x0040
+#define OB_CTRL_REV3_5_OFFSET 0x0030
+
+#define CFG_TARGET_BUS 0x0
+#define CFG_TARGET_BUS_MASK_SHIFT 0
+#define CFG_TARGET_BUS_BUSNUM_SHIFT 8
+
+#define CFG_CONTROL 0x4
+#define CFG_CONTROL_SUBBUS_MASK 0x0000FF00
+#define CFG_CONTROL_SUBBUS_SHIFT 8
+#define CFG_CONTROL_SEC_BUS_MASK 0x00FF0000
+#define CFG_CONTROL_SEC_BUS_SHIFT 16
+
+struct al_pcie_reg_offsets {
+ unsigned int ob_ctrl;
+};
+
+struct al_pcie_target_bus_cfg {
+ u8 reg_val;
+ u8 reg_mask;
+ u8 ecam_mask;
+};
+
+struct al_pcie {
+ struct dw_pcie *pci;
+ void __iomem *controller_base; /* base of PCIe unit (not DW core) */
+ void __iomem *dbi_base;
+ resource_size_t ecam_size;
+ struct device *dev;
+ unsigned int controller_rev_id;
+ struct al_pcie_reg_offsets reg_offsets;
+ struct al_pcie_target_bus_cfg target_bus_cfg;
+};
+
+#define PCIE_ECAM_DEVFN(x) (((x) & 0xff) << 12)
+
+#define to_al_pcie(x) dev_get_drvdata((x)->dev)
+
+static int al_pcie_rev_id_get(struct al_pcie *pcie, unsigned int *rev_id)
+{
+ void __iomem *dev_rev_id_addr;
+ u32 dev_rev_id;
+
+ dev_rev_id_addr = (void __iomem *)((uintptr_t)pcie->controller_base +
+ AXI_BASE_OFFSET + DEVICE_ID_OFFSET + DEVICE_REV_ID);
+
+ dev_rev_id = readl(dev_rev_id_addr) & DEVICE_REV_ID_DEV_ID_MASK;
+
+ switch (dev_rev_id) {
+ case DEVICE_REV_ID_DEV_ID_X4:
+ *rev_id = AL_PCIE_REV_ID_2;
+ break;
+ case DEVICE_REV_ID_DEV_ID_X8:
+ *rev_id = AL_PCIE_REV_ID_3;
+ break;
+ case DEVICE_REV_ID_DEV_ID_X16:
+ *rev_id = AL_PCIE_REV_ID_4;
+ break;
+ default:
+ dev_err(pcie->dev, "Unsupported dev_rev_id (0x%08x)\n",
+ dev_rev_id);
+ return -EINVAL;
+ }
+
+ dev_dbg(pcie->dev, "dev_rev_id: 0x%08x\n", dev_rev_id);
+
+ return 0;
+}
+
+static int al_pcie_reg_offsets_set(struct al_pcie *pcie)
+{
+ switch (pcie->controller_rev_id) {
+ case AL_PCIE_REV_ID_2:
+ pcie->reg_offsets.ob_ctrl = OB_CTRL_REV1_2_OFFSET;
+ break;
+ case AL_PCIE_REV_ID_3:
+ case AL_PCIE_REV_ID_4:
+ pcie->reg_offsets.ob_ctrl = OB_CTRL_REV3_5_OFFSET;
+ break;
+ default:
+ dev_err(pcie->dev, "Unsupported controller rev_id: 0x%x\n",
+ pcie->controller_rev_id);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static inline void al_pcie_target_bus_set(struct al_pcie *pcie,
+ u8 target_bus,
+ u8 mask_target_bus)
+{
+ void __iomem *cfg_control_addr;
+ u32 reg = (target_bus << CFG_TARGET_BUS_BUSNUM_SHIFT) |
+ mask_target_bus;
+
+ cfg_control_addr = (void __iomem *)((uintptr_t)pcie->controller_base +
+ AXI_BASE_OFFSET + pcie->reg_offsets.ob_ctrl +
+ CFG_TARGET_BUS);
+
+ writel(reg, cfg_control_addr);
+}
+
+static void __iomem *al_pcie_conf_addr_map(struct al_pcie *pcie,
+ unsigned int busnr,
+ unsigned int devfn)
+{
+ void __iomem *pci_base_addr;
+ struct pcie_port *pp = &pcie->pci->pp;
+ struct al_pcie_target_bus_cfg *target_bus_cfg = &pcie->target_bus_cfg;
+ unsigned int busnr_ecam = busnr & target_bus_cfg->ecam_mask;
+ unsigned int busnr_reg = busnr & target_bus_cfg->reg_mask;
+
+ pci_base_addr = (void __iomem *)((uintptr_t)pp->va_cfg0_base +
+ (busnr_ecam << 20) +
+ PCIE_ECAM_DEVFN(devfn));
+
+ if (busnr_reg != target_bus_cfg->reg_val) {
+ dev_dbg(pcie->pci->dev, "Changing target bus busnum val from %d to %d\n",
+ target_bus_cfg->reg_val, busnr_reg);
+ target_bus_cfg->reg_val = busnr_reg;
+ al_pcie_target_bus_set(pcie,
+ target_bus_cfg->reg_val,
+ target_bus_cfg->reg_mask);
+ }
+
+ return pci_base_addr;
+}
+
+static int al_pcie_rd_other_conf(struct pcie_port *pp,
+ struct pci_bus *bus,
+ unsigned int devfn,
+ int where,
+ int size,
+ u32 *val)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+ struct al_pcie *pcie = to_al_pcie(pci);
+ unsigned int busnr = bus->number;
+ void __iomem *pci_addr;
+ int rc;
+
+ pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
+
+ rc = dw_pcie_read(pci_addr + where, size, val);
+
+ dev_dbg(pci->dev, "%d-byte config read from %04x:%02x:%02x.%d offset %#x (pci_addr: 0x%p) - val:0x%x\n",
+ size, pci_domain_nr(bus), bus->number,
+ PCI_SLOT(devfn), PCI_FUNC(devfn), where,
+ (pci_addr + where), *val);
+
+ return rc;
+}
+
+static int al_pcie_wr_other_conf(struct pcie_port *pp,
+ struct pci_bus *bus,
+ unsigned int devfn,
+ int where,
+ int size,
+ u32 val)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+ struct al_pcie *pcie = to_al_pcie(pci);
+ unsigned int busnr = bus->number;
+ void __iomem *pci_addr;
+ int rc;
+
+ pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);
+
+ rc = dw_pcie_write(pci_addr + where, size, val);
+
+ dev_dbg(pci->dev, "%d-byte config write to %04x:%02x:%02x.%d offset %#x (pci_addr: 0x%p) - val:0x%x\n",
+ size, pci_domain_nr(bus), bus->number,
+ PCI_SLOT(devfn), PCI_FUNC(devfn), where,
+ (pci_addr + where), val);
+
+ return rc;
+}
+
+static int al_pcie_config_prepare(struct al_pcie *pcie)
+{
+ struct al_pcie_target_bus_cfg *target_bus_cfg;
+ struct pcie_port *pp = &pcie->pci->pp;
+ unsigned int ecam_bus_mask;
+ u8 secondary_bus;
+ u8 subordinate_bus;
+ void __iomem *cfg_control_addr;
+ u32 cfg_control;
+ u32 reg = 0;
+
+ target_bus_cfg = &pcie->target_bus_cfg;
+
+ ecam_bus_mask = (pcie->ecam_size >> 20) - 1;
+ if (ecam_bus_mask > 255) {
+ dev_warn(pcie->dev, "ECAM window size is larger than 256MB. Cutting off at 256\n");
+ ecam_bus_mask = 255;
+ }
+
+ /* This portion is taken from the transaction address */
+ target_bus_cfg->ecam_mask = ecam_bus_mask;
+ /* This portion is taken from the cfg_target_bus reg */
+ target_bus_cfg->reg_mask = ~target_bus_cfg->ecam_mask;
+ target_bus_cfg->reg_val = pp->busn->start & target_bus_cfg->reg_mask;
+
+ al_pcie_target_bus_set(pcie,
+ target_bus_cfg->reg_val,
+ target_bus_cfg->reg_mask);
+
+ secondary_bus = pp->busn->start + 1;
+ subordinate_bus = pp->busn->end;
+
+ /* Set the valid values of secondary and subordinate buses */
+ cfg_control_addr = pcie->controller_base +
+ AXI_BASE_OFFSET + pcie->reg_offsets.ob_ctrl + CFG_CONTROL;
+
+ cfg_control = readl(cfg_control_addr);
+
+ reg = (cfg_control & ~CFG_CONTROL_SEC_BUS_MASK) |
+ (secondary_bus << CFG_CONTROL_SEC_BUS_SHIFT);
+ reg = (reg & ~CFG_CONTROL_SUBBUS_MASK) |
+ (subordinate_bus << CFG_CONTROL_SUBBUS_SHIFT);
+
+ writel(reg, cfg_control_addr);
+
+ return 0;
+}
+
+static int al_pcie_host_init(struct pcie_port *pp)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+ struct al_pcie *pcie = to_al_pcie(pci);
+ int link_up = 0;
+ u32 reg = 0;
+ int rc;
+
+ reg = dw_pcie_readb_dbi(pci, PCI_HEADER_TYPE);
+ if (reg != PCI_HEADER_TYPE_BRIDGE) {
+ dev_err(pci->dev, "PCIe controller is not set to bridge type (%d)!\n",
+ reg);
+ return -EIO;
+ }
+
+ link_up = dw_pcie_link_up(pci);
+ if (!link_up) {
+ dev_err(pci->dev, "link in not up!\n");
+ return -ENOLINK;
+ }
+
+ dev_info(pci->dev, "link is up\n");
+
+ rc = al_pcie_rev_id_get(pcie, &pcie->controller_rev_id);
+ if (rc)
+ return rc;
+
+ rc = al_pcie_reg_offsets_set(pcie);
+ if (rc)
+ return rc;
+
+ rc = al_pcie_config_prepare(pcie);
+ if (rc)
+ return rc;
+
+ return 0;
+}
+
+static const struct dw_pcie_host_ops al_pcie_host_ops = {
+ .rd_other_conf = al_pcie_rd_other_conf,
+ .wr_other_conf = al_pcie_wr_other_conf,
+ .host_init = al_pcie_host_init,
+};
+
+static int al_add_pcie_port(struct pcie_port *pp,
+ struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ pp->ops = &al_pcie_host_ops;
+
+ ret = dw_pcie_host_init(pp);
+ if (ret) {
+ dev_err(dev, "failed to initialize host\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+};
+
+static int al_pcie_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct al_pcie *al_pcie;
+ struct dw_pcie *pci;
+ struct resource *dbi_res;
+ struct resource *controller_res;
+ struct resource *ecam_res;
+ int ret;
+
+ al_pcie = devm_kzalloc(dev, sizeof(*al_pcie), GFP_KERNEL);
+ if (!al_pcie)
+ return -ENOMEM;
+
+ pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
+ if (!pci)
+ return -ENOMEM;
+
+ pci->dev = dev;
+ pci->ops = &dw_pcie_ops;
+
+ al_pcie->pci = pci;
+ al_pcie->dev = dev;
+
+ dbi_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+ pci->dbi_base = devm_pci_remap_cfg_resource(dev, dbi_res);
+ if (IS_ERR(pci->dbi_base)) {
+ dev_err(dev, "couldn't remap dbi base %p\n", dbi_res);
+ return PTR_ERR(pci->dbi_base);
+ }
+
+ ecam_res = platform_get_resource_byname(pdev,
+ IORESOURCE_MEM,
+ "config");
+ if (!ecam_res) {
+ dev_err(dev, "couldn't find 'config' reg in DT\n");
+ return -ENOENT;
+ }
+ al_pcie->ecam_size = resource_size(ecam_res);
+
+ controller_res = platform_get_resource_byname(pdev,
+ IORESOURCE_MEM,
+ "controller");
+ al_pcie->controller_base = devm_ioremap_resource(dev,
+ controller_res);
+ if (IS_ERR(al_pcie->controller_base)) {
+ dev_err(dev, "couldn't remap controller base %p\n",
+ controller_res);
+ return PTR_ERR(al_pcie->controller_base);
+ }
+
+ dev_dbg(dev, "From DT: dbi_base: 0x%llx, controller_base: 0x%llx\n",
+ dbi_res->start, controller_res->start);
+
+ platform_set_drvdata(pdev, al_pcie);
+
+ ret = al_add_pcie_port(&pci->pp, pdev);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static const struct of_device_id al_pcie_of_match[] = {
+ { .compatible = "amazon,al-pcie",
+ .data = NULL,
+ },
+ {},
+};
+
+static struct platform_driver al_pcie_driver = {
+ .driver = {
+ .name = "al-pcie",
+ .of_match_table = al_pcie_of_match,
+ .suppress_bind_attrs = true,
+ },
+ .probe = al_pcie_probe,
+};
+builtin_platform_driver(al_pcie_driver);
+
+#endif /* CONFIG_PCIE_AL*/
--
2.17.1