2 * Simple, generic PCI host controller driver targetting firmware-initialised
3 * systems and virtual machines (e.g. the PCI emulation provided by kvmtool).
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 * Copyright (C) 2014 ARM Limited
19 * Author: Will Deacon <will.deacon@arm.com>
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>
28 struct gen_pci_cfg_bus_ops {
30 void __iomem *(*map_bus)(struct pci_bus *, unsigned int, int);
33 struct gen_pci_cfg_windows {
35 struct resource *bus_range;
38 const struct gen_pci_cfg_bus_ops *ops;
42 * ARM pcibios functions expect the ARM struct pci_sys_data as the PCI
43 * sysdata. Add pci_sys_data as the first element in struct gen_pci so
44 * that when we use a gen_pci pointer as sysdata, it is also a pointer to
45 * a struct pci_sys_data.
49 struct pci_sys_data sys;
51 struct pci_host_bridge host;
52 struct gen_pci_cfg_windows cfg;
53 struct list_head resources;
56 static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
60 struct gen_pci *pci = bus->sysdata;
61 resource_size_t idx = bus->number - pci->cfg.bus_range->start;
63 return pci->cfg.win[idx] + ((devfn << 8) | where);
66 static struct gen_pci_cfg_bus_ops gen_pci_cfg_cam_bus_ops = {
68 .map_bus = gen_pci_map_cfg_bus_cam,
71 static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
75 struct gen_pci *pci = bus->sysdata;
76 resource_size_t idx = bus->number - pci->cfg.bus_range->start;
78 return pci->cfg.win[idx] + ((devfn << 12) | where);
81 static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = {
83 .map_bus = gen_pci_map_cfg_bus_ecam,
86 static struct pci_ops gen_pci_ops = {
87 .read = pci_generic_config_read,
88 .write = pci_generic_config_write,
91 static const struct of_device_id gen_pci_of_match[] = {
92 { .compatible = "pci-host-cam-generic",
93 .data = &gen_pci_cfg_cam_bus_ops },
95 { .compatible = "pci-host-ecam-generic",
96 .data = &gen_pci_cfg_ecam_bus_ops },
100 MODULE_DEVICE_TABLE(of, gen_pci_of_match);
102 static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
104 pci_free_resource_list(&pci->resources);
107 static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
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;
115 err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources,
120 resource_list_for_each_entry(win, &pci->resources) {
121 struct resource *parent, *res = win->res;
123 switch (resource_type(res)) {
125 parent = &ioport_resource;
126 err = pci_remap_iospace(res, iobase);
128 dev_warn(dev, "error %d: failed to map resource %pR\n",
134 parent = &iomem_resource;
135 res_valid |= !(res->flags & IORESOURCE_PREFETCH);
138 pci->cfg.bus_range = res;
143 err = devm_request_resource(dev, parent, res);
145 goto out_release_res;
149 dev_err(dev, "non-prefetchable memory resource required\n");
151 goto out_release_res;
157 gen_pci_release_of_pci_ranges(pci);
161 static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
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;
170 err = of_address_to_resource(np, 0, &pci->cfg.res);
172 dev_err(dev, "missing \"reg\" property\n");
176 /* Limit the bus-range to fit within reg */
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);
182 pci->cfg.win = devm_kcalloc(dev, resource_size(pci->cfg.bus_range),
183 sizeof(*pci->cfg.win), GFP_KERNEL);
187 /* Map our Configuration Space windows */
188 if (!devm_request_mem_region(dev, pci->cfg.res.start,
189 resource_size(&pci->cfg.res),
190 "Configuration Space"))
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;
198 pci->cfg.win[idx] = devm_ioremap(dev,
199 pci->cfg.res.start + busn * sz,
201 if (!pci->cfg.win[idx])
208 static int gen_pci_probe(struct platform_device *pdev)
212 const struct of_device_id *of_id;
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;
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);
228 prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL);
231 pci_add_flags(PCI_PROBE_ONLY);
233 pci_clear_flags(PCI_PROBE_ONLY);
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);
243 /* Parse our PCI ranges and request their resources */
244 err = gen_pci_parse_request_of_pci_ranges(pci);
248 /* Parse and map our Configuration Space windows */
249 err = gen_pci_parse_map_cfg_windows(pci);
251 gen_pci_release_of_pci_ranges(pci);
255 /* Do not reassign resources if probe only */
256 if (!pci_has_flag(PCI_PROBE_ONLY))
257 pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
259 bus = pci_scan_root_bus(dev, 0, &gen_pci_ops, pci, &pci->resources);
261 dev_err(dev, "Scanning rootbus failed");
265 pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
267 if (!pci_has_flag(PCI_PROBE_ONLY)) {
268 pci_bus_size_bridges(bus);
269 pci_bus_assign_resources(bus);
271 list_for_each_entry(child, &bus->children, node)
272 pcie_bus_configure_settings(child);
275 pci_bus_add_devices(bus);
279 static struct platform_driver gen_pci_driver = {
281 .name = "pci-host-generic",
282 .of_match_table = gen_pci_of_match,
284 .probe = gen_pci_probe,
286 module_platform_driver(gen_pci_driver);
288 MODULE_DESCRIPTION("Generic PCI host driver");
289 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
290 MODULE_LICENSE("GPL v2");