diff options
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/host/Kconfig | 14 | ||||
| -rw-r--r-- | drivers/pci/host/Makefile | 1 | ||||
| -rw-r--r-- | drivers/pci/host/pcie-tango.c | 141 |
3 files changed, 156 insertions, 0 deletions
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig index 0cd5b30dccb1..89d61c2cbfaa 100644 --- a/drivers/pci/host/Kconfig +++ b/drivers/pci/host/Kconfig @@ -191,6 +191,20 @@ config PCIE_MEDIATEK MT7623 series SoCs. There is one single root complex with 3 root ports available. Each port supports Gen2 lane x1. +config PCIE_TANGO_SMP8759 + bool "Tango SMP8759 PCIe controller (DANGEROUS)" + depends on ARCH_TANGO && PCI_MSI && OF + depends on BROKEN + select PCI_HOST_COMMON + help + Say Y here to enable PCIe controller support for Sigma Designs + Tango SMP8759-based systems. + + Note: The SMP8759 controller multiplexes PCI config and MMIO + accesses, and Linux doesn't provide a way to serialize them. + This can lead to data corruption if drivers perform concurrent + config and MMIO accesses. + config VMD depends on PCI_MSI && X86_64 && SRCU tristate "Intel Volume Management Device Driver" diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile index b10d104c85fd..12382785e02a 100644 --- a/drivers/pci/host/Makefile +++ b/drivers/pci/host/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o obj-$(CONFIG_PCIE_ALTERA_MSI) += pcie-altera-msi.o obj-$(CONFIG_PCIE_ROCKCHIP) += pcie-rockchip.o obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o +obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o obj-$(CONFIG_VMD) += vmd.o # The following drivers are for devices that use the generic ACPI diff --git a/drivers/pci/host/pcie-tango.c b/drivers/pci/host/pcie-tango.c new file mode 100644 index 000000000000..6bbb81f06a53 --- /dev/null +++ b/drivers/pci/host/pcie-tango.c @@ -0,0 +1,141 @@ +#include <linux/pci-ecam.h> +#include <linux/delay.h> +#include <linux/of.h> + +#define SMP8759_MUX 0x48 +#define SMP8759_TEST_OUT 0x74 + +struct tango_pcie { + void __iomem *base; +}; + +static int smp8759_config_read(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *val) +{ + struct pci_config_window *cfg = bus->sysdata; + struct tango_pcie *pcie = dev_get_drvdata(cfg->parent); + int ret; + + /* Reads in configuration space outside devfn 0 return garbage */ + if (devfn != 0) + return PCIBIOS_FUNC_NOT_SUPPORTED; + + /* + * PCI config and MMIO accesses are muxed. Linux doesn't have a + * mutual exclusion mechanism for config vs. MMIO accesses, so + * concurrent accesses may cause corruption. + */ + writel_relaxed(1, pcie->base + SMP8759_MUX); + ret = pci_generic_config_read(bus, devfn, where, size, val); + writel_relaxed(0, pcie->base + SMP8759_MUX); + + return ret; +} + +static int smp8759_config_write(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val) +{ + struct pci_config_window *cfg = bus->sysdata; + struct tango_pcie *pcie = dev_get_drvdata(cfg->parent); + int ret; + + writel_relaxed(1, pcie->base + SMP8759_MUX); + ret = pci_generic_config_write(bus, devfn, where, size, val); + writel_relaxed(0, pcie->base + SMP8759_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 int tango_pcie_link_up(struct tango_pcie *pcie) +{ + void __iomem *test_out = pcie->base + SMP8759_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 1; + usleep_range(3000, 4000); + } + + return 0; +} + +static int tango_pcie_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct tango_pcie *pcie; + struct resource *res; + int ret; + + dev_warn(dev, "simultaneous PCI config and MMIO accesses may cause data corruption\n"); + add_taint(TAINT_CRAP, LOCKDEP_STILL_OK); + + pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL); + if (!pcie) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + pcie->base = devm_ioremap_resource(dev, res); + if (IS_ERR(pcie->base)) + return PTR_ERR(pcie->base); + + platform_set_drvdata(pdev, pcie); + + if (!tango_pcie_link_up(pcie)) + return -ENODEV; + + return pci_host_common_probe(pdev, &smp8759_ecam_ops); +} + +static const struct of_device_id tango_pcie_ids[] = { + { .compatible = "sigma,smp8759-pcie" }, + { }, +}; + +static struct platform_driver tango_pcie_driver = { + .probe = tango_pcie_probe, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = tango_pcie_ids, + .suppress_bind_attrs = true, + }, +}; +builtin_platform_driver(tango_pcie_driver); + +/* + * The root complex advertises 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, 0x0024, tango_fixup_class); +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x0028, tango_fixup_class); + +/* + * 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, 0x0024, tango_fixup_bar); +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x0028, tango_fixup_bar); |