mips: octeon: Add Octeon PCIe host controller driver

This patch adds the PCIe host controller driver for MIPS Octeon II/III.
The driver mainly consist of the PCI config functions, as all of the
complex serdes related port / lane setup, is done in the serdes / pcie
code available in the "arch/mips/mach-octeon" directory.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Aaron Williams <awilliams@marvell.com>
Cc: Chandrakala Chavva <cchavva@marvell.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

drivers/pci/Kconfig

@@ -158,6 +158,12 @@ config PCI_OCTEONTX
 	  These controllers provide PCI configuration access to all on-board
 	  peripherals so it should only be disabled for testing purposes
 
+config PCIE_OCTEON
+	bool "MIPS Octeon PCIe support"
+	depends on ARCH_OCTEON
+	help
+	  Enable support for the MIPS Octeon SoC family PCIe controllers.
+
 config PCI_XILINX
 	bool "Xilinx AXI Bridge for PCI Express"
 	depends on DM_PCI

drivers/pci/Makefile

@@ -53,3 +53,4 @@ obj-$(CONFIG_PCIE_DW_ROCKCHIP) += pcie_dw_rockchip.o
 obj-$(CONFIG_PCIE_DW_MESON) += pcie_dw_meson.o
 obj-$(CONFIG_PCI_BRCMSTB) += pcie_brcmstb.o
 obj-$(CONFIG_PCI_OCTEONTX) += pci_octeontx.o
+obj-$(CONFIG_PCIE_OCTEON) += pcie_octeon.o

drivers/pci/pcie_octeon.c

@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Stefan Roese <sr@denx.de>
+ */
+
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <log.h>
+#include <pci.h>
+#include <linux/delay.h>
+
+#include <mach/octeon-model.h>
+#include <mach/octeon_pci.h>
+#include <mach/cvmx-regs.h>
+#include <mach/cvmx-pcie.h>
+#include <mach/cvmx-pemx-defs.h>
+
+struct octeon_pcie {
+	void *base;
+	int first_busno;
+	u32 port;
+	struct udevice *dev;
+	int pcie_port;
+};
+
+static bool octeon_bdf_invalid(pci_dev_t bdf, int first_busno)
+{
+	/*
+	 * In PCIe only a single device (0) can exist on the local bus.
+	 * Beyound the local bus, there might be a switch and everything
+	 * is possible.
+	 */
+	if ((PCI_BUS(bdf) == first_busno) && (PCI_DEV(bdf) > 0))
+		return true;
+
+	return false;
+}
+
+static int pcie_octeon_write_config(struct udevice *bus, pci_dev_t bdf,
+				    uint offset, ulong value,
+				    enum pci_size_t size)
+{
+	struct octeon_pcie *pcie = dev_get_priv(bus);
+	struct pci_controller *hose = dev_get_uclass_priv(bus);
+	int busno;
+	int port;
+
+	debug("PCIE CFG write: (b,d,f)=(%2d,%2d,%2d) ",
+	      PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
+	debug("(addr,size,val)=(0x%04x, %d, 0x%08lx)\n", offset, size, value);
+
+	port = pcie->pcie_port;
+	busno = PCI_BUS(bdf) - hose->first_busno + 1;
+
+	switch (size) {
+	case PCI_SIZE_8:
+		cvmx_pcie_config_write8(port, busno, PCI_DEV(bdf),
+					PCI_FUNC(bdf), offset, value);
+		break;
+	case PCI_SIZE_16:
+		cvmx_pcie_config_write16(port, busno, PCI_DEV(bdf),
+					 PCI_FUNC(bdf), offset, value);
+		break;
+	case PCI_SIZE_32:
+		cvmx_pcie_config_write32(port, busno, PCI_DEV(bdf),
+					 PCI_FUNC(bdf), offset, value);
+		break;
+	default:
+		printf("Invalid size\n");
+	};
+
+	return 0;
+}
+
+static int pcie_octeon_read_config(const struct udevice *bus, pci_dev_t bdf,
+				   uint offset, ulong *valuep,
+				   enum pci_size_t size)
+{
+	struct octeon_pcie *pcie = dev_get_priv(bus);
+	struct pci_controller *hose = dev_get_uclass_priv(bus);
+	int busno;
+	int port;
+
+	port = pcie->pcie_port;
+	busno = PCI_BUS(bdf) - hose->first_busno + 1;
+	if (octeon_bdf_invalid(bdf, pcie->first_busno)) {
+		*valuep = pci_get_ff(size);
+		return 0;
+	}
+
+	switch (size) {
+	case PCI_SIZE_8:
+		*valuep = cvmx_pcie_config_read8(port, busno, PCI_DEV(bdf),
+						 PCI_FUNC(bdf), offset);
+		break;
+	case PCI_SIZE_16:
+		*valuep = cvmx_pcie_config_read16(port, busno, PCI_DEV(bdf),
+						  PCI_FUNC(bdf), offset);
+		break;
+	case PCI_SIZE_32:
+		*valuep = cvmx_pcie_config_read32(port, busno, PCI_DEV(bdf),
+						  PCI_FUNC(bdf), offset);
+		break;
+	default:
+		printf("Invalid size\n");
+	};
+
+	debug("%02x.%02x.%02x: u%d %x -> %lx\n",
+	      PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf), size, offset, *valuep);
+
+	return 0;
+}
+
+static int pcie_octeon_probe(struct udevice *dev)
+{
+	struct octeon_pcie *pcie = dev_get_priv(dev);
+	int node = cvmx_get_node_num();
+	int pcie_port;
+	int ret = 0;
+
+	/* Get port number, lane number and memory target / attr */
+	if (ofnode_read_u32(dev_ofnode(dev), "marvell,pcie-port",
+			    &pcie->port)) {
+		ret = -ENODEV;
+		goto err;
+	}
+
+	pcie->first_busno = dev_seq(dev);
+	pcie_port = ((node << 4) | pcie->port);
+	ret = cvmx_pcie_rc_initialize(pcie_port);
+	if (ret != 0)
+		return ret;
+
+	return 0;
+
+err:
+	return ret;
+}
+
+static const struct dm_pci_ops pcie_octeon_ops = {
+	.read_config = pcie_octeon_read_config,
+	.write_config = pcie_octeon_write_config,
+};
+
+static const struct udevice_id pcie_octeon_ids[] = {
+	{ .compatible = "marvell,pcie-host-octeon" },
+	{ }
+};
+
+U_BOOT_DRIVER(pcie_octeon) = {
+	.name		= "pcie_octeon",
+	.id		= UCLASS_PCI,
+	.of_match	= pcie_octeon_ids,
+	.ops		= &pcie_octeon_ops,
+	.probe		= pcie_octeon_probe,
+	.priv_auto	= sizeof(struct octeon_pcie),
+	.flags		= DM_FLAG_PRE_RELOC,
+};