1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2004 Koninklijke Philips Electronics NV
4  *
5  * Conversion to platform driver and DT:
6  * Copyright 2014 Linaro Ltd.
7  *
8  * 14/04/2005 Initial version, colin.king@philips.com
9  */
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/of_address.h>
13 #include <linux/of_pci.h>
14 #include <linux/of_platform.h>
15 #include <linux/pci.h>
16 #include <linux/platform_device.h>
17 
18 #include "../pci.h"
19 
20 static void __iomem *versatile_pci_base;
21 static void __iomem *versatile_cfg_base[2];
22 
23 #define PCI_IMAP(m)		(versatile_pci_base + ((m) * 4))
24 #define PCI_SMAP(m)		(versatile_pci_base + 0x14 + ((m) * 4))
25 #define PCI_SELFID		(versatile_pci_base + 0xc)
26 
27 #define VP_PCI_DEVICE_ID		0x030010ee
28 #define VP_PCI_CLASS_ID			0x0b400000
29 
30 static u32 pci_slot_ignore;
31 
32 static int __init versatile_pci_slot_ignore(char *str)
33 {
34 	int slot;
35 
36 	while (get_option(&str, &slot)) {
37 		if ((slot < 0) || (slot > 31))
38 			pr_err("Illegal slot value: %d\n", slot);
39 		else
40 			pci_slot_ignore |= (1 << slot);
41 	}
42 	return 1;
43 }
44 __setup("pci_slot_ignore=", versatile_pci_slot_ignore);
45 
46 
47 static void __iomem *versatile_map_bus(struct pci_bus *bus,
48 				       unsigned int devfn, int offset)
49 {
50 	unsigned int busnr = bus->number;
51 
52 	if (pci_slot_ignore & (1 << PCI_SLOT(devfn)))
53 		return NULL;
54 
55 	return versatile_cfg_base[1] + ((busnr << 16) | (devfn << 8) | offset);
56 }
57 
58 static struct pci_ops pci_versatile_ops = {
59 	.map_bus = versatile_map_bus,
60 	.read	= pci_generic_config_read32,
61 	.write	= pci_generic_config_write,
62 };
63 
64 static int versatile_pci_probe(struct platform_device *pdev)
65 {
66 	struct device *dev = &pdev->dev;
67 	struct resource *res;
68 	struct resource_entry *entry;
69 	int i, myslot = -1, mem = 1;
70 	u32 val;
71 	void __iomem *local_pci_cfg_base;
72 	struct pci_host_bridge *bridge;
73 
74 	bridge = devm_pci_alloc_host_bridge(dev, 0);
75 	if (!bridge)
76 		return -ENOMEM;
77 
78 	versatile_pci_base = devm_platform_ioremap_resource(pdev, 0);
79 	if (IS_ERR(versatile_pci_base))
80 		return PTR_ERR(versatile_pci_base);
81 
82 	versatile_cfg_base[0] = devm_platform_ioremap_resource(pdev, 1);
83 	if (IS_ERR(versatile_cfg_base[0]))
84 		return PTR_ERR(versatile_cfg_base[0]);
85 
86 	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
87 	versatile_cfg_base[1] = devm_pci_remap_cfg_resource(dev, res);
88 	if (IS_ERR(versatile_cfg_base[1]))
89 		return PTR_ERR(versatile_cfg_base[1]);
90 
91 	resource_list_for_each_entry(entry, &bridge->windows) {
92 		if (resource_type(entry->res) == IORESOURCE_MEM) {
93 			writel(entry->res->start >> 28, PCI_IMAP(mem));
94 			writel(__pa(PAGE_OFFSET) >> 28, PCI_SMAP(mem));
95 			mem++;
96 		}
97 	}
98 
99 	/*
100 	 * We need to discover the PCI core first to configure itself
101 	 * before the main PCI probing is performed
102 	 */
103 	for (i = 0; i < 32; i++) {
104 		if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) &&
105 		    (readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) {
106 			myslot = i;
107 			break;
108 		}
109 	}
110 	if (myslot == -1) {
111 		dev_err(dev, "Cannot find PCI core!\n");
112 		return -EIO;
113 	}
114 	/*
115 	 * Do not to map Versatile FPGA PCI device into memory space
116 	 */
117 	pci_slot_ignore |= (1 << myslot);
118 
119 	dev_info(dev, "PCI core found (slot %d)\n", myslot);
120 
121 	writel(myslot, PCI_SELFID);
122 	local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11);
123 
124 	val = readl(local_pci_cfg_base + PCI_COMMAND);
125 	val |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE;
126 	writel(val, local_pci_cfg_base + PCI_COMMAND);
127 
128 	/*
129 	 * Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM
130 	 */
131 	writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_0);
132 	writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_1);
133 	writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_2);
134 
135 	/*
136 	 * For many years the kernel and QEMU were symbiotically buggy
137 	 * in that they both assumed the same broken IRQ mapping.
138 	 * QEMU therefore attempts to auto-detect old broken kernels
139 	 * so that they still work on newer QEMU as they did on old
140 	 * QEMU. Since we now use the correct (ie matching-hardware)
141 	 * IRQ mapping we write a definitely different value to a
142 	 * PCI_INTERRUPT_LINE register to tell QEMU that we expect
143 	 * real hardware behaviour and it need not be backwards
144 	 * compatible for us. This write is harmless on real hardware.
145 	 */
146 	writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE);
147 
148 	pci_add_flags(PCI_REASSIGN_ALL_BUS);
149 
150 	bridge->ops = &pci_versatile_ops;
151 
152 	return pci_host_probe(bridge);
153 }
154 
155 static const struct of_device_id versatile_pci_of_match[] = {
156 	{ .compatible = "arm,versatile-pci", },
157 	{ },
158 };
159 MODULE_DEVICE_TABLE(of, versatile_pci_of_match);
160 
161 static struct platform_driver versatile_pci_driver = {
162 	.driver = {
163 		.name = "versatile-pci",
164 		.of_match_table = versatile_pci_of_match,
165 		.suppress_bind_attrs = true,
166 	},
167 	.probe = versatile_pci_probe,
168 };
169 module_platform_driver(versatile_pci_driver);
170 
171 MODULE_DESCRIPTION("Versatile PCI driver");
172 MODULE_LICENSE("GPL v2");
173