1/*
2 * PCI support for Xilinx plbv46_pci soft-core which can be used on
3 * Xilinx Virtex ML410 / ML510 boards.
4 *
5 * Copyright 2009 Roderick Colenbrander
6 * Copyright 2009 Secret Lab Technologies Ltd.
7 *
8 * The pci bridge fixup code was copied from ppc4xx_pci.c and was written
9 * by Benjamin Herrenschmidt.
10 * Copyright 2007 Ben. Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
11 *
12 * This file is licensed under the terms of the GNU General Public License
13 * version 2. This program is licensed "as is" without any warranty of any
14 * kind, whether express or implied.
15 */
16
17#include <linux/ioport.h>
18#include <linux/of.h>
19#include <linux/of_address.h>
20#include <linux/pci.h>
21#include <linux/io.h>
22
23#define XPLB_PCI_ADDR 0x10c
24#define XPLB_PCI_DATA 0x110
25#define XPLB_PCI_BUS  0x114
26
27#define PCI_HOST_ENABLE_CMD (PCI_COMMAND_SERR | PCI_COMMAND_PARITY | \
28				PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY)
29
30static struct of_device_id xilinx_pci_match[] = {
31	{ .compatible = "xlnx,plbv46-pci-1.03.a", },
32	{}
33};
34
35/**
36 * xilinx_pci_fixup_bridge - Block Xilinx PHB configuration.
37 */
38static void xilinx_pci_fixup_bridge(struct pci_dev *dev)
39{
40	struct pci_controller *hose;
41	int i;
42
43	if (dev->devfn || dev->bus->self)
44		return;
45
46	hose = pci_bus_to_host(dev->bus);
47	if (!hose)
48		return;
49
50	if (!of_match_node(xilinx_pci_match, hose->dn))
51		return;
52
53	/* Hide the PCI host BARs from the kernel as their content doesn't
54	 * fit well in the resource management
55	 */
56	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
57		dev->resource[i].start = 0;
58		dev->resource[i].end = 0;
59		dev->resource[i].flags = 0;
60	}
61
62	dev_info(&dev->dev, "Hiding Xilinx plb-pci host bridge resources %s\n",
63		 pci_name(dev));
64}
65DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, xilinx_pci_fixup_bridge);
66
67#ifdef DEBUG
68/**
69 * xilinx_pci_exclude_device - Don't do config access for non-root bus
70 *
71 * This is a hack.  Config access to any bus other than bus 0 does not
72 * currently work on the ML510 so we prevent it here.
73 */
74static int
75xilinx_pci_exclude_device(struct pci_controller *hose, u_char bus, u8 devfn)
76{
77	return (bus != 0);
78}
79
80/**
81 * xilinx_early_pci_scan - List pci config space for available devices
82 *
83 * List pci devices in very early phase.
84 */
85static void __init xilinx_early_pci_scan(struct pci_controller *hose)
86{
87	u32 bus = 0;
88	u32 val, dev, func, offset;
89
90	/* Currently we have only 2 device connected - up-to 32 devices */
91	for (dev = 0; dev < 2; dev++) {
92		/* List only first function number - up-to 8 functions */
93		for (func = 0; func < 1; func++) {
94			pr_info("%02x:%02x:%02x", bus, dev, func);
95			/* read the first 64 standardized bytes */
96			/* Up-to 192 bytes can be list of capabilities */
97			for (offset = 0; offset < 64; offset += 4) {
98				early_read_config_dword(hose, bus,
99					PCI_DEVFN(dev, func), offset, &val);
100				if (offset == 0 && val == 0xFFFFFFFF) {
101					pr_cont("\nABSENT");
102					break;
103				}
104				if (!(offset % 0x10))
105					pr_cont("\n%04x:    ", offset);
106
107				pr_cont("%08x  ", val);
108			}
109			pr_info("\n");
110		}
111	}
112}
113#else
114static void __init xilinx_early_pci_scan(struct pci_controller *hose)
115{
116}
117#endif
118
119/**
120 * xilinx_pci_init - Find and register a Xilinx PCI host bridge
121 */
122void __init xilinx_pci_init(void)
123{
124	struct pci_controller *hose;
125	struct resource r;
126	void __iomem *pci_reg;
127	struct device_node *pci_node;
128
129	pci_node = of_find_matching_node(NULL, xilinx_pci_match);
130	if (!pci_node)
131		return;
132
133	if (of_address_to_resource(pci_node, 0, &r)) {
134		pr_err("xilinx-pci: cannot resolve base address\n");
135		return;
136	}
137
138	hose = pcibios_alloc_controller(pci_node);
139	if (!hose) {
140		pr_err("xilinx-pci: pcibios_alloc_controller() failed\n");
141		return;
142	}
143
144	/* Setup config space */
145	setup_indirect_pci(hose, r.start + XPLB_PCI_ADDR,
146			   r.start + XPLB_PCI_DATA,
147			   INDIRECT_TYPE_SET_CFG_TYPE);
148
149	/* According to the xilinx plbv46_pci documentation the soft-core starts
150	 * a self-init when the bus master enable bit is set. Without this bit
151	 * set the pci bus can't be scanned.
152	 */
153	early_write_config_word(hose, 0, 0, PCI_COMMAND, PCI_HOST_ENABLE_CMD);
154
155	/* Set the max latency timer to 255 */
156	early_write_config_byte(hose, 0, 0, PCI_LATENCY_TIMER, 0xff);
157
158	/* Set the max bus number to 255, and bus/subbus no's to 0 */
159	pci_reg = of_iomap(pci_node, 0);
160	out_be32(pci_reg + XPLB_PCI_BUS, 0x000000ff);
161	iounmap(pci_reg);
162
163	/* Register the host bridge with the linux kernel! */
164	pci_process_bridge_OF_ranges(hose, pci_node,
165					INDIRECT_TYPE_SET_CFG_TYPE);
166
167	pr_info("xilinx-pci: Registered PCI host bridge\n");
168	xilinx_early_pci_scan(hose);
169}
170