PCI: tango: Add Sigma Designs Tango SMP8759 PCIe host bridge support (5e14e9fa) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/pci/host/Kconfig

+14 −0

Original line number	Diff line number	Diff line
		@@ -180,6 +180,20 @@ config PCIE_ROCKCHIP
		There is 1 internal PCIe port available to support GEN2 with
		4 slots.

		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"

drivers/pci/host/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@ obj-$(CONFIG_PCIE_IPROC_BCMA) += pcie-iproc-bcma.o
		obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o
		obj-$(CONFIG_PCIE_ALTERA_MSI) += pcie-altera-msi.o
		obj-$(CONFIG_PCIE_ROCKCHIP) += pcie-rockchip.o
		obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
		obj-$(CONFIG_VMD) += vmd.o

		# The following drivers are for devices that use the generic ACPI

drivers/pci/host/pcie-tango.c

0 → 100644

+141 −0

Original line number	Diff line number	Diff line
		#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);

include/linux/pci_ids.h

+2 −0

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		@@ -1373,6 +1373,8 @@
		#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