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22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/of_address.h>
25#include <linux/of_pci.h>
26#include <linux/platform_device.h>
27
28struct gen_pci_cfg_bus_ops {
29 u32 bus_shift;
30 void __iomem *(*map_bus)(struct pci_bus *, unsigned int, int);
31};
32
33struct gen_pci_cfg_windows {
34 struct resource res;
35 struct resource *bus_range;
36 void __iomem **win;
37
38 const struct gen_pci_cfg_bus_ops *ops;
39};
40
41
42
43
44
45
46
47struct gen_pci {
48#ifdef CONFIG_ARM
49 struct pci_sys_data sys;
50#endif
51 struct pci_host_bridge host;
52 struct gen_pci_cfg_windows cfg;
53 struct list_head resources;
54};
55
56static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
57 unsigned int devfn,
58 int where)
59{
60 struct gen_pci *pci = bus->sysdata;
61 resource_size_t idx = bus->number - pci->cfg.bus_range->start;
62
63 return pci->cfg.win[idx] + ((devfn << 8) | where);
64}
65
66static struct gen_pci_cfg_bus_ops gen_pci_cfg_cam_bus_ops = {
67 .bus_shift = 16,
68 .map_bus = gen_pci_map_cfg_bus_cam,
69};
70
71static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
72 unsigned int devfn,
73 int where)
74{
75 struct gen_pci *pci = bus->sysdata;
76 resource_size_t idx = bus->number - pci->cfg.bus_range->start;
77
78 return pci->cfg.win[idx] + ((devfn << 12) | where);
79}
80
81static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = {
82 .bus_shift = 20,
83 .map_bus = gen_pci_map_cfg_bus_ecam,
84};
85
86static struct pci_ops gen_pci_ops = {
87 .read = pci_generic_config_read,
88 .write = pci_generic_config_write,
89};
90
91static const struct of_device_id gen_pci_of_match[] = {
92 { .compatible = "pci-host-cam-generic",
93 .data = &gen_pci_cfg_cam_bus_ops },
94
95 { .compatible = "pci-host-ecam-generic",
96 .data = &gen_pci_cfg_ecam_bus_ops },
97
98 { },
99};
100MODULE_DEVICE_TABLE(of, gen_pci_of_match);
101
102static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
103{
104 pci_free_resource_list(&pci->resources);
105}
106
107static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
108{
109 int err, res_valid = 0;
110 struct device *dev = pci->host.dev.parent;
111 struct device_node *np = dev->of_node;
112 resource_size_t iobase;
113 struct resource_entry *win;
114
115 err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources,
116 &iobase);
117 if (err)
118 return err;
119
120 resource_list_for_each_entry(win, &pci->resources) {
121 struct resource *parent, *res = win->res;
122
123 switch (resource_type(res)) {
124 case IORESOURCE_IO:
125 parent = &ioport_resource;
126 err = pci_remap_iospace(res, iobase);
127 if (err) {
128 dev_warn(dev, "error %d: failed to map resource %pR\n",
129 err, res);
130 continue;
131 }
132 break;
133 case IORESOURCE_MEM:
134 parent = &iomem_resource;
135 res_valid |= !(res->flags & IORESOURCE_PREFETCH);
136 break;
137 case IORESOURCE_BUS:
138 pci->cfg.bus_range = res;
139 default:
140 continue;
141 }
142
143 err = devm_request_resource(dev, parent, res);
144 if (err)
145 goto out_release_res;
146 }
147
148 if (!res_valid) {
149 dev_err(dev, "non-prefetchable memory resource required\n");
150 err = -EINVAL;
151 goto out_release_res;
152 }
153
154 return 0;
155
156out_release_res:
157 gen_pci_release_of_pci_ranges(pci);
158 return err;
159}
160
161static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
162{
163 int err;
164 u8 bus_max;
165 resource_size_t busn;
166 struct resource *bus_range;
167 struct device *dev = pci->host.dev.parent;
168 struct device_node *np = dev->of_node;
169
170 err = of_address_to_resource(np, 0, &pci->cfg.res);
171 if (err) {
172 dev_err(dev, "missing \"reg\" property\n");
173 return err;
174 }
175
176
177 bus_max = pci->cfg.bus_range->start +
178 (resource_size(&pci->cfg.res) >> pci->cfg.ops->bus_shift) - 1;
179 pci->cfg.bus_range->end = min_t(resource_size_t,
180 pci->cfg.bus_range->end, bus_max);
181
182 pci->cfg.win = devm_kcalloc(dev, resource_size(pci->cfg.bus_range),
183 sizeof(*pci->cfg.win), GFP_KERNEL);
184 if (!pci->cfg.win)
185 return -ENOMEM;
186
187
188 if (!devm_request_mem_region(dev, pci->cfg.res.start,
189 resource_size(&pci->cfg.res),
190 "Configuration Space"))
191 return -ENOMEM;
192
193 bus_range = pci->cfg.bus_range;
194 for (busn = bus_range->start; busn <= bus_range->end; ++busn) {
195 u32 idx = busn - bus_range->start;
196 u32 sz = 1 << pci->cfg.ops->bus_shift;
197
198 pci->cfg.win[idx] = devm_ioremap(dev,
199 pci->cfg.res.start + busn * sz,
200 sz);
201 if (!pci->cfg.win[idx])
202 return -ENOMEM;
203 }
204
205 return 0;
206}
207
208static int gen_pci_probe(struct platform_device *pdev)
209{
210 int err;
211 const char *type;
212 const struct of_device_id *of_id;
213 const int *prop;
214 struct device *dev = &pdev->dev;
215 struct device_node *np = dev->of_node;
216 struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
217 struct pci_bus *bus, *child;
218
219 if (!pci)
220 return -ENOMEM;
221
222 type = of_get_property(np, "device_type", NULL);
223 if (!type || strcmp(type, "pci")) {
224 dev_err(dev, "invalid \"device_type\" %s\n", type);
225 return -EINVAL;
226 }
227
228 prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL);
229 if (prop) {
230 if (*prop)
231 pci_add_flags(PCI_PROBE_ONLY);
232 else
233 pci_clear_flags(PCI_PROBE_ONLY);
234 }
235
236 of_id = of_match_node(gen_pci_of_match, np);
237 pci->cfg.ops = of_id->data;
238 gen_pci_ops.map_bus = pci->cfg.ops->map_bus;
239 pci->host.dev.parent = dev;
240 INIT_LIST_HEAD(&pci->host.windows);
241 INIT_LIST_HEAD(&pci->resources);
242
243
244 err = gen_pci_parse_request_of_pci_ranges(pci);
245 if (err)
246 return err;
247
248
249 err = gen_pci_parse_map_cfg_windows(pci);
250 if (err) {
251 gen_pci_release_of_pci_ranges(pci);
252 return err;
253 }
254
255
256 if (!pci_has_flag(PCI_PROBE_ONLY))
257 pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
258
259 bus = pci_scan_root_bus(dev, 0, &gen_pci_ops, pci, &pci->resources);
260 if (!bus) {
261 dev_err(dev, "Scanning rootbus failed");
262 return -ENODEV;
263 }
264
265 pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
266
267 if (!pci_has_flag(PCI_PROBE_ONLY)) {
268 pci_bus_size_bridges(bus);
269 pci_bus_assign_resources(bus);
270
271 list_for_each_entry(child, &bus->children, node)
272 pcie_bus_configure_settings(child);
273 }
274
275 pci_bus_add_devices(bus);
276 return 0;
277}
278
279static struct platform_driver gen_pci_driver = {
280 .driver = {
281 .name = "pci-host-generic",
282 .of_match_table = gen_pci_of_match,
283 },
284 .probe = gen_pci_probe,
285};
286module_platform_driver(gen_pci_driver);
287
288MODULE_DESCRIPTION("Generic PCI host driver");
289MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
290MODULE_LICENSE("GPL v2");
291
