xref: /openbmc/linux/arch/arm64/kernel/pci.c (revision a06c488d)
1 /*
2  * Code borrowed from powerpc/kernel/pci-common.c
3  *
4  * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
5  * Copyright (C) 2014 ARM Ltd.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * version 2 as published by the Free Software Foundation.
10  *
11  */
12 
13 #include <linux/acpi.h>
14 #include <linux/init.h>
15 #include <linux/io.h>
16 #include <linux/kernel.h>
17 #include <linux/mm.h>
18 #include <linux/of_pci.h>
19 #include <linux/of_platform.h>
20 #include <linux/slab.h>
21 
22 #include <asm/pci-bridge.h>
23 
24 /*
25  * Called after each bus is probed, but before its children are examined
26  */
27 void pcibios_fixup_bus(struct pci_bus *bus)
28 {
29 	/* nothing to do, expected to be removed in the future */
30 }
31 
32 /*
33  * We don't have to worry about legacy ISA devices, so nothing to do here
34  */
35 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
36 				resource_size_t size, resource_size_t align)
37 {
38 	return res->start;
39 }
40 
41 /**
42  * pcibios_enable_device - Enable I/O and memory.
43  * @dev: PCI device to be enabled
44  * @mask: bitmask of BARs to enable
45  */
46 int pcibios_enable_device(struct pci_dev *dev, int mask)
47 {
48 	if (pci_has_flag(PCI_PROBE_ONLY))
49 		return 0;
50 
51 	return pci_enable_resources(dev, mask);
52 }
53 
54 /*
55  * Try to assign the IRQ number from DT when adding a new device
56  */
57 int pcibios_add_device(struct pci_dev *dev)
58 {
59 	dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
60 
61 	return 0;
62 }
63 
64 /*
65  * raw_pci_read/write - Platform-specific PCI config space access.
66  */
67 int raw_pci_read(unsigned int domain, unsigned int bus,
68 		  unsigned int devfn, int reg, int len, u32 *val)
69 {
70 	return -ENXIO;
71 }
72 
73 int raw_pci_write(unsigned int domain, unsigned int bus,
74 		unsigned int devfn, int reg, int len, u32 val)
75 {
76 	return -ENXIO;
77 }
78 
79 #ifdef CONFIG_ACPI
80 /* Root bridge scanning */
81 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
82 {
83 	/* TODO: Should be revisited when implementing PCI on ACPI */
84 	return NULL;
85 }
86 #endif
87