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 retval;
35 	int slot;
36 
37 	while ((retval = get_option(&str, &slot))) {
38 		if ((slot < 0) || (slot > 31))
39 			pr_err("Illegal slot value: %d\n", slot);
40 		else
41 			pci_slot_ignore |= (1 << slot);
42 	}
43 	return 1;
44 }
45 __setup("pci_slot_ignore=", versatile_pci_slot_ignore);
46 
47 
48 static void __iomem *versatile_map_bus(struct pci_bus *bus,
49 				       unsigned int devfn, int offset)
50 {
51 	unsigned int busnr = bus->number;
52 
53 	if (pci_slot_ignore & (1 << PCI_SLOT(devfn)))
54 		return NULL;
55 
56 	return versatile_cfg_base[1] + ((busnr << 16) | (devfn << 8) | offset);
57 }
58 
59 static struct pci_ops pci_versatile_ops = {
60 	.map_bus = versatile_map_bus,
61 	.read	= pci_generic_config_read32,
62 	.write	= pci_generic_config_write,
63 };
64 
65 static int versatile_pci_probe(struct platform_device *pdev)
66 {
67 	struct device *dev = &pdev->dev;
68 	struct resource *res;
69 	struct resource_entry *entry;
70 	int ret, i, myslot = -1, mem = 1;
71 	u32 val;
72 	void __iomem *local_pci_cfg_base;
73 	struct pci_bus *bus, *child;
74 	struct pci_host_bridge *bridge;
75 
76 	bridge = devm_pci_alloc_host_bridge(dev, 0);
77 	if (!bridge)
78 		return -ENOMEM;
79 
80 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
81 	versatile_pci_base = devm_ioremap_resource(dev, res);
82 	if (IS_ERR(versatile_pci_base))
83 		return PTR_ERR(versatile_pci_base);
84 
85 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
86 	versatile_cfg_base[0] = devm_ioremap_resource(dev, res);
87 	if (IS_ERR(versatile_cfg_base[0]))
88 		return PTR_ERR(versatile_cfg_base[0]);
89 
90 	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
91 	versatile_cfg_base[1] = devm_pci_remap_cfg_resource(dev, res);
92 	if (IS_ERR(versatile_cfg_base[1]))
93 		return PTR_ERR(versatile_cfg_base[1]);
94 
95 	ret = pci_parse_request_of_pci_ranges(dev, &bridge->windows,
96 					      NULL, NULL);
97 	if (ret)
98 		return ret;
99 
100 	resource_list_for_each_entry(entry, &bridge->windows) {
101 		if (resource_type(entry->res) == IORESOURCE_MEM) {
102 			writel(entry->res->start >> 28, PCI_IMAP(mem));
103 			writel(__pa(PAGE_OFFSET) >> 28, PCI_SMAP(mem));
104 			mem++;
105 		}
106 	}
107 
108 	/*
109 	 * We need to discover the PCI core first to configure itself
110 	 * before the main PCI probing is performed
111 	 */
112 	for (i = 0; i < 32; i++) {
113 		if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) &&
114 		    (readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) {
115 			myslot = i;
116 			break;
117 		}
118 	}
119 	if (myslot == -1) {
120 		dev_err(dev, "Cannot find PCI core!\n");
121 		return -EIO;
122 	}
123 	/*
124 	 * Do not to map Versatile FPGA PCI device into memory space
125 	 */
126 	pci_slot_ignore |= (1 << myslot);
127 
128 	dev_info(dev, "PCI core found (slot %d)\n", myslot);
129 
130 	writel(myslot, PCI_SELFID);
131 	local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11);
132 
133 	val = readl(local_pci_cfg_base + PCI_COMMAND);
134 	val |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE;
135 	writel(val, local_pci_cfg_base + PCI_COMMAND);
136 
137 	/*
138 	 * Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM
139 	 */
140 	writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_0);
141 	writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_1);
142 	writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_2);
143 
144 	/*
145 	 * For many years the kernel and QEMU were symbiotically buggy
146 	 * in that they both assumed the same broken IRQ mapping.
147 	 * QEMU therefore attempts to auto-detect old broken kernels
148 	 * so that they still work on newer QEMU as they did on old
149 	 * QEMU. Since we now use the correct (ie matching-hardware)
150 	 * IRQ mapping we write a definitely different value to a
151 	 * PCI_INTERRUPT_LINE register to tell QEMU that we expect
152 	 * real hardware behaviour and it need not be backwards
153 	 * compatible for us. This write is harmless on real hardware.
154 	 */
155 	writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE);
156 
157 	pci_add_flags(PCI_ENABLE_PROC_DOMAINS);
158 	pci_add_flags(PCI_REASSIGN_ALL_BUS);
159 
160 	bridge->dev.parent = dev;
161 	bridge->sysdata = NULL;
162 	bridge->busnr = 0;
163 	bridge->ops = &pci_versatile_ops;
164 	bridge->map_irq = of_irq_parse_and_map_pci;
165 	bridge->swizzle_irq = pci_common_swizzle;
166 
167 	ret = pci_scan_root_bus_bridge(bridge);
168 	if (ret < 0)
169 		return ret;
170 
171 	bus = bridge->bus;
172 
173 	pci_assign_unassigned_bus_resources(bus);
174 	list_for_each_entry(child, &bus->children, node)
175 		pcie_bus_configure_settings(child);
176 	pci_bus_add_devices(bus);
177 
178 	return 0;
179 }
180 
181 static const struct of_device_id versatile_pci_of_match[] = {
182 	{ .compatible = "arm,versatile-pci", },
183 	{ },
184 };
185 MODULE_DEVICE_TABLE(of, versatile_pci_of_match);
186 
187 static struct platform_driver versatile_pci_driver = {
188 	.driver = {
189 		.name = "versatile-pci",
190 		.of_match_table = versatile_pci_of_match,
191 		.suppress_bind_attrs = true,
192 	},
193 	.probe = versatile_pci_probe,
194 };
195 module_platform_driver(versatile_pci_driver);
196 
197 MODULE_DESCRIPTION("Versatile PCI driver");
198 MODULE_LICENSE("GPL v2");
199