1 // SPDX-License-Identifier: GPL-2.0
3 * leon_pci.c: LEON Host PCI support
5 * Copyright (C) 2011 Aeroflex Gaisler AB, Daniel Hellstrom
7 * Code is partially derived from pcic.c
10 #include <linux/of_device.h>
11 #include <linux/kernel.h>
12 #include <linux/pci.h>
13 #include <linux/export.h>
15 #include <asm/leon_pci.h>
17 /* The LEON architecture does not rely on a BIOS or bootloader to setup
18 * PCI for us. The Linux generic routines are used to setup resources,
19 * reset values of configuration-space register settings are preserved.
21 * PCI Memory and Prefetchable Memory is direct-mapped. However I/O Space is
22 * accessed through a Window which is translated to low 64KB in PCI space, the
23 * first 4KB is not used so 60KB is available.
25 void leon_pci_init(struct platform_device *ofdev, struct leon_pci_info *info)
28 struct pci_bus *root_bus;
29 struct pci_host_bridge *bridge;
32 bridge = pci_alloc_host_bridge(0);
36 pci_add_resource_offset(&resources, &info->io_space,
37 info->io_space.start - 0x1000);
38 pci_add_resource(&resources, &info->mem_space);
39 info->busn.flags = IORESOURCE_BUS;
40 pci_add_resource(&resources, &info->busn);
42 list_splice_init(&resources, &bridge->windows);
43 bridge->dev.parent = &ofdev->dev;
44 bridge->sysdata = info;
46 bridge->ops = info->ops;
47 bridge->swizzle_irq = pci_common_swizzle;
48 bridge->map_irq = info->map_irq;
50 ret = pci_scan_root_bus_bridge(bridge);
52 pci_free_host_bridge(bridge);
56 root_bus = bridge->bus;
58 /* Assign devices with resources */
59 pci_assign_unassigned_resources();
60 pci_bus_add_devices(root_bus);
63 int pcibios_enable_device(struct pci_dev *dev, int mask)
68 pci_read_config_word(dev, PCI_COMMAND, &cmd);
71 for (i = 0; i < PCI_NUM_RESOURCES; i++) {
72 struct resource *res = &dev->resource[i];
74 /* Only set up the requested stuff */
78 if (res->flags & IORESOURCE_IO)
79 cmd |= PCI_COMMAND_IO;
80 if (res->flags & IORESOURCE_MEM)
81 cmd |= PCI_COMMAND_MEMORY;
85 pci_info(dev, "enabling device (%04x -> %04x)\n", oldcmd, cmd);
86 pci_write_config_word(dev, PCI_COMMAND, cmd);