1/*
2 * leon_pci.c: LEON Host PCI support
3 *
4 * Copyright (C) 2011 Aeroflex Gaisler AB, Daniel Hellstrom
5 *
6 * Code is partially derived from pcic.c
7 */
8
9#include <linux/of_device.h>
10#include <linux/kernel.h>
11#include <linux/pci.h>
12#include <linux/export.h>
13#include <asm/leon.h>
14#include <asm/leon_pci.h>
15
16/* The LEON architecture does not rely on a BIOS or bootloader to setup
17 * PCI for us. The Linux generic routines are used to setup resources,
18 * reset values of configuration-space register settings are preserved.
19 *
20 * PCI Memory and Prefetchable Memory is direct-mapped. However I/O Space is
21 * accessed through a Window which is translated to low 64KB in PCI space, the
22 * first 4KB is not used so 60KB is available.
23 */
24void leon_pci_init(struct platform_device *ofdev, struct leon_pci_info *info)
25{
26	LIST_HEAD(resources);
27	struct pci_bus *root_bus;
28
29	pci_add_resource_offset(&resources, &info->io_space,
30				info->io_space.start - 0x1000);
31	pci_add_resource(&resources, &info->mem_space);
32	info->busn.flags = IORESOURCE_BUS;
33	pci_add_resource(&resources, &info->busn);
34
35	root_bus = pci_scan_root_bus(&ofdev->dev, 0, info->ops, info,
36				     &resources);
37	if (!root_bus) {
38		pci_free_resource_list(&resources);
39		return;
40	}
41
42	/* Setup IRQs of all devices using custom routines */
43	pci_fixup_irqs(pci_common_swizzle, info->map_irq);
44
45	/* Assign devices with resources */
46	pci_assign_unassigned_resources();
47	pci_bus_add_devices(root_bus);
48}
49
50void pcibios_fixup_bus(struct pci_bus *pbus)
51{
52	struct pci_dev *dev;
53	int i, has_io, has_mem;
54	u16 cmd;
55
56	list_for_each_entry(dev, &pbus->devices, bus_list) {
57		/*
58		 * We can not rely on that the bootloader has enabled I/O
59		 * or memory access to PCI devices. Instead we enable it here
60		 * if the device has BARs of respective type.
61		 */
62		has_io = has_mem = 0;
63		for (i = 0; i < PCI_ROM_RESOURCE; i++) {
64			unsigned long f = dev->resource[i].flags;
65			if (f & IORESOURCE_IO)
66				has_io = 1;
67			else if (f & IORESOURCE_MEM)
68				has_mem = 1;
69		}
70		/* ROM BARs are mapped into 32-bit memory space */
71		if (dev->resource[PCI_ROM_RESOURCE].end != 0) {
72			dev->resource[PCI_ROM_RESOURCE].flags |=
73							IORESOURCE_ROM_ENABLE;
74			has_mem = 1;
75		}
76		pci_bus_read_config_word(pbus, dev->devfn, PCI_COMMAND, &cmd);
77		if (has_io && !(cmd & PCI_COMMAND_IO)) {
78#ifdef CONFIG_PCI_DEBUG
79			printk(KERN_INFO "LEONPCI: Enabling I/O for dev %s\n",
80					 pci_name(dev));
81#endif
82			cmd |= PCI_COMMAND_IO;
83			pci_bus_write_config_word(pbus, dev->devfn, PCI_COMMAND,
84									cmd);
85		}
86		if (has_mem && !(cmd & PCI_COMMAND_MEMORY)) {
87#ifdef CONFIG_PCI_DEBUG
88			printk(KERN_INFO "LEONPCI: Enabling MEMORY for dev"
89					 "%s\n", pci_name(dev));
90#endif
91			cmd |= PCI_COMMAND_MEMORY;
92			pci_bus_write_config_word(pbus, dev->devfn, PCI_COMMAND,
93									cmd);
94		}
95	}
96}
97
98resource_size_t pcibios_align_resource(void *data, const struct resource *res,
99				resource_size_t size, resource_size_t align)
100{
101	return res->start;
102}
103