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
30 static 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 */
xilinx_pci_fixup_bridge(struct pci_dev * dev)38 static 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 }
65 DECLARE_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 */
74 static int
xilinx_pci_exclude_device(struct pci_controller * hose,u_char bus,u8 devfn)75 xilinx_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 */
xilinx_early_pci_scan(struct pci_controller * hose)85 static 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
xilinx_early_pci_scan(struct pci_controller * hose)114 static 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 */
xilinx_pci_init(void)122 void __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 WARN_ON(!pci_reg);
161 out_be32(pci_reg + XPLB_PCI_BUS, 0x000000ff);
162 iounmap(pci_reg);
163
164 /* Register the host bridge with the linux kernel! */
165 pci_process_bridge_OF_ranges(hose, pci_node,
166 INDIRECT_TYPE_SET_CFG_TYPE);
167
168 pr_info("xilinx-pci: Registered PCI host bridge\n");
169 xilinx_early_pci_scan(hose);
170 }
171