This driver is required to work around several hardware bugs in the PCIe controller.
NB: Revision 1 does not support legacy interrupts, or IO space. Signed-off-by: Marc Gonzalez <marc_gonza...@sigmadesigns.com> --- Documentation/devicetree/bindings/pci/tango-pcie.txt | 32 ++++++++ drivers/pci/host/Kconfig | 8 ++ drivers/pci/host/Makefile | 1 + drivers/pci/host/pcie-tango.c | 161 +++++++++++++++++++++++++++++++++++++++ include/linux/pci_ids.h | 2 + 5 files changed, 204 insertions(+) diff --git a/Documentation/devicetree/bindings/pci/tango-pcie.txt b/Documentation/devicetree/bindings/pci/tango-pcie.txt new file mode 100644 index 000000000000..3353b4e77309 --- /dev/null +++ b/Documentation/devicetree/bindings/pci/tango-pcie.txt @@ -0,0 +1,32 @@ +Sigma Designs Tango PCIe controller + +Required properties: + +- compatible: "sigma,smp8759-pcie" +- reg: address/size of PCI configuration space, address/size of register area +- device_type: "pci" +- #size-cells: <2> +- #address-cells: <3> +- #interrupt-cells: <1> +- ranges: translation from system to bus addresses +- interrupts: spec for misc interrupts, spec for MSI +- msi-controller + +http://elinux.org/Device_Tree_Usage#PCI_Address_Translation +http://elinux.org/Device_Tree_Usage#Advanced_Interrupt_Mapping + +Example: + + pcie@2e000 { + compatible = "sigma,smp8759-pcie"; + reg = <0x50000000 SZ_4M>, <0x2e000 0x100>; + device_type = "pci"; + #size-cells = <2>; + #address-cells = <3>; + #interrupt-cells = <1>; + ranges = <0x02000000 0x0 0x00400000 0x50400000 0x0 SZ_60M>; + msi-controller; + interrupts = + <54 IRQ_TYPE_LEVEL_HIGH>, /* misc interrupts */ + <55 IRQ_TYPE_LEVEL_HIGH>; /* MSI */ + }; diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig index d7e7c0a827c3..5183d9095c3a 100644 --- a/drivers/pci/host/Kconfig +++ b/drivers/pci/host/Kconfig @@ -285,6 +285,14 @@ config PCIE_ROCKCHIP There is 1 internal PCIe port available to support GEN2 with 4 slots. +config PCIE_TANGO + bool "Tango PCIe controller" + depends on ARCH_TANGO && PCI_MSI && OF + select PCI_HOST_COMMON + help + Say Y here to enable PCIe controller support for Sigma Designs + Tango systems, such as SMP8759 and later chips. + config VMD depends on PCI_MSI && X86_64 tristate "Intel Volume Management Device Driver" diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile index 084cb4983645..fc7ea90196f3 100644 --- a/drivers/pci/host/Makefile +++ b/drivers/pci/host/Makefile @@ -32,4 +32,5 @@ obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o obj-$(CONFIG_PCIE_ROCKCHIP) += pcie-rockchip.o +obj-$(CONFIG_PCIE_TANGO) += pcie-tango.o obj-$(CONFIG_VMD) += vmd.o diff --git a/drivers/pci/host/pcie-tango.c b/drivers/pci/host/pcie-tango.c index ada8d35066ab..7eb74e82d325 100644 --- a/drivers/pci/host/pcie-tango.c +++ b/drivers/pci/host/pcie-tango.c @@ -230,3 +230,164 @@ static int tango_msi_probe(struct platform_device *pdev, struct tango_pcie *pcie return 0; } + +/*** HOST BRIDGE SUPPORT ***/ + +static int smp8759_config_read(struct pci_bus *bus, + unsigned int devfn, int where, int size, u32 *val) +{ + int ret; + struct pci_config_window *cfg = bus->sysdata; + struct tango_pcie *pcie = dev_get_drvdata(cfg->parent); + + /* + * QUIRK #1 + * Reads in configuration space outside devfn 0 return garbage. + */ + if (devfn != 0) + return PCIBIOS_FUNC_NOT_SUPPORTED; + + /* + * QUIRK #2 + * Unfortunately, config and mem spaces are muxed. + * Linux does not support such a setting, since drivers are free + * to access mem space directly, at any time. + * Therefore, we can only PRAY that config and mem space accesses + * NEVER occur concurrently. + */ + writel_relaxed(1, pcie->mux); + ret = pci_generic_config_read(bus, devfn, where, size, val); + writel_relaxed(0, pcie->mux); + + return ret; +} + +static int smp8759_config_write(struct pci_bus *bus, + unsigned int devfn, int where, int size, u32 val) +{ + int ret; + struct pci_config_window *cfg = bus->sysdata; + struct tango_pcie *pcie = dev_get_drvdata(cfg->parent); + + writel_relaxed(1, pcie->mux); + ret = pci_generic_config_write(bus, devfn, where, size, val); + writel_relaxed(0, pcie->mux); + + return ret; +} + +static struct pci_ecam_ops smp8759_ecam_ops = { + .bus_shift = 20, + .pci_ops = { + .map_bus = pci_ecam_map_bus, + .read = smp8759_config_read, + .write = smp8759_config_write, + } +}; + +static const struct of_device_id tango_pcie_ids[] = { + { .compatible = "sigma,smp8759-pcie" }, + { /* sentinel */ }, +}; + +static int tango_check_pcie_link(void __iomem *test_out) +{ + int i; + + writel_relaxed(16, test_out); + for (i = 0; i < 10; ++i) { + u32 ltssm_state = readl_relaxed(test_out) >> 8; + if ((ltssm_state & 0x1f) == 0xf) /* L0 */ + return 0; + usleep_range(3000, 4000); + } + + return -ENODEV; +} + +static int smp8759_init(struct tango_pcie *pcie, void __iomem *base) +{ + pcie->mux = base + 0x48; + pcie->msi_status = base + 0x80; + pcie->msi_enable = base + 0xa0; + pcie->msi_doorbell = 0xa0000000 + 0x2e07c; + + return tango_check_pcie_link(base + 0x74); +} + +static int tango_pcie_probe(struct platform_device *pdev) +{ + int ret = 0; + void __iomem *base; + struct resource *res; + struct tango_pcie *pcie; + struct device *dev = &pdev->dev; + + pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL); + if (!pcie) + return -ENOMEM; + + platform_set_drvdata(pdev, pcie); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + if (of_device_is_compatible(dev->of_node, "sigma,smp8759-pcie")) + ret = smp8759_init(pcie, base); + + if (ret) + return ret; + + ret = tango_msi_probe(pdev, pcie); + if (ret) + return ret; + + return pci_host_common_probe(pdev, &smp8759_ecam_ops); +} + +static int tango_pcie_remove(struct platform_device *pdev) +{ + return tango_msi_remove(pdev); +} + +static struct platform_driver tango_pcie_driver = { + .probe = tango_pcie_probe, + .remove = tango_pcie_remove, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = tango_pcie_ids, + }, +}; + +builtin_platform_driver(tango_pcie_driver); + +/* + * QUIRK #3 + * The root complex advertizes the wrong device class. + * Header Type 1 is for PCI-to-PCI bridges. + */ +static void tango_fixup_class(struct pci_dev *dev) +{ + dev->class = PCI_CLASS_BRIDGE_PCI << 8; +} +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x24, tango_fixup_class); +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x28, tango_fixup_class); + +/* + * QUIRK #4 + * The root complex exposes a "fake" BAR, which is used to filter + * bus-to-system accesses. Only accesses within the range defined + * by this BAR are forwarded to the host, others are ignored. + * + * By default, the DMA framework expects an identity mapping, + * and DRAM0 is mapped at 0x80000000. + */ +static void tango_fixup_bar(struct pci_dev *dev) +{ + dev->non_compliant_bars = true; + pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, 0x80000000); +} +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x24, tango_fixup_bar); +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x28, tango_fixup_bar); diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h index f020ab4079d3..b577dbe46f8f 100644 --- a/include/linux/pci_ids.h +++ b/include/linux/pci_ids.h @@ -1369,6 +1369,8 @@ #define PCI_DEVICE_ID_TTI_HPT374 0x0008 #define PCI_DEVICE_ID_TTI_HPT372N 0x0009 /* apparently a 372N variant? */ +#define PCI_VENDOR_ID_SIGMA 0x1105 + #define PCI_VENDOR_ID_VIA 0x1106 #define PCI_DEVICE_ID_VIA_8763_0 0x0198 #define PCI_DEVICE_ID_VIA_8380_0 0x0204 -- 2.11.0
