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/pci.h>
20 #include <mm/mmu_decl.h>
21 #include <asm/io.h>
22 #include <asm/xilinx_pci.h>
23
24 #define XPLB_PCI_ADDR 0x10c
25 #define XPLB_PCI_DATA 0x110
26 #define XPLB_PCI_BUS 0x114
27
28 #define PCI_HOST_ENABLE_CMD PCI_COMMAND_SERR | PCI_COMMAND_PARITY | PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY
29
30 static const 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 /**
68 * xilinx_pci_exclude_device - Don't do config access for non-root bus
69 *
70 * This is a hack. Config access to any bus other than bus 0 does not
71 * currently work on the ML510 so we prevent it here.
72 */
73 static int
xilinx_pci_exclude_device(struct pci_controller * hose,u_char bus,u8 devfn)74 xilinx_pci_exclude_device(struct pci_controller *hose, u_char bus, u8 devfn)
75 {
76 return (bus != 0);
77 }
78
79 /**
80 * xilinx_pci_init - Find and register a Xilinx PCI host bridge
81 */
xilinx_pci_init(void)82 void __init xilinx_pci_init(void)
83 {
84 struct pci_controller *hose;
85 struct resource r;
86 void __iomem *pci_reg;
87 struct device_node *pci_node;
88
89 pci_node = of_find_matching_node(NULL, xilinx_pci_match);
90 if(!pci_node)
91 return;
92
93 if (of_address_to_resource(pci_node, 0, &r)) {
94 pr_err("xilinx-pci: cannot resolve base address\n");
95 return;
96 }
97
98 hose = pcibios_alloc_controller(pci_node);
99 if (!hose) {
100 pr_err("xilinx-pci: pcibios_alloc_controller() failed\n");
101 return;
102 }
103
104 /* Setup config space */
105 setup_indirect_pci(hose, r.start + XPLB_PCI_ADDR,
106 r.start + XPLB_PCI_DATA,
107 PPC_INDIRECT_TYPE_SET_CFG_TYPE);
108
109 /* According to the xilinx plbv46_pci documentation the soft-core starts
110 * a self-init when the bus master enable bit is set. Without this bit
111 * set the pci bus can't be scanned.
112 */
113 early_write_config_word(hose, 0, 0, PCI_COMMAND, PCI_HOST_ENABLE_CMD);
114
115 /* Set the max latency timer to 255 */
116 early_write_config_byte(hose, 0, 0, PCI_LATENCY_TIMER, 0xff);
117
118 /* Set the max bus number to 255 */
119 pci_reg = of_iomap(pci_node, 0);
120 out_8(pci_reg + XPLB_PCI_BUS, 0xff);
121 iounmap(pci_reg);
122
123 /* Nothing past the root bridge is working right now. By default
124 * exclude config access to anything except bus 0 */
125 if (!ppc_md.pci_exclude_device)
126 ppc_md.pci_exclude_device = xilinx_pci_exclude_device;
127
128 /* Register the host bridge with the linux kernel! */
129 pci_process_bridge_OF_ranges(hose, pci_node, 1);
130
131 pr_info("xilinx-pci: Registered PCI host bridge\n");
132 }
133