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 struct pci_host_bridge host;
43 struct gen_pci_cfg_windows cfg;
44 struct list_head resources;
47 static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
51 struct pci_sys_data *sys = bus->sysdata;
52 struct gen_pci *pci = sys->private_data;
53 resource_size_t idx = bus->number - pci->cfg.bus_range->start;
55 return pci->cfg.win[idx] + ((devfn << 8) | where);
58 static struct gen_pci_cfg_bus_ops gen_pci_cfg_cam_bus_ops = {
60 .map_bus = gen_pci_map_cfg_bus_cam,
63 static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
67 struct pci_sys_data *sys = bus->sysdata;
68 struct gen_pci *pci = sys->private_data;
69 resource_size_t idx = bus->number - pci->cfg.bus_range->start;
71 return pci->cfg.win[idx] + ((devfn << 12) | where);
74 static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = {
76 .map_bus = gen_pci_map_cfg_bus_ecam,
79 static struct pci_ops gen_pci_ops = {
80 .read = pci_generic_config_read,
81 .write = pci_generic_config_write,
84 static const struct of_device_id gen_pci_of_match[] = {
85 { .compatible = "pci-host-cam-generic",
86 .data = &gen_pci_cfg_cam_bus_ops },
88 { .compatible = "pci-host-ecam-generic",
89 .data = &gen_pci_cfg_ecam_bus_ops },
93 MODULE_DEVICE_TABLE(of, gen_pci_of_match);
95 static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
97 pci_free_resource_list(&pci->resources);
100 static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
102 int err, res_valid = 0;
103 struct device *dev = pci->host.dev.parent;
104 struct device_node *np = dev->of_node;
105 resource_size_t iobase;
106 struct resource_entry *win;
108 err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources,
113 resource_list_for_each_entry(win, &pci->resources) {
114 struct resource *parent, *res = win->res;
116 switch (resource_type(res)) {
118 parent = &ioport_resource;
119 err = pci_remap_iospace(res, iobase);
121 dev_warn(dev, "error %d: failed to map resource %pR\n",
127 parent = &iomem_resource;
128 res_valid |= !(res->flags & IORESOURCE_PREFETCH);
131 pci->cfg.bus_range = res;
136 err = devm_request_resource(dev, parent, res);
138 goto out_release_res;
142 dev_err(dev, "non-prefetchable memory resource required\n");
144 goto out_release_res;
150 gen_pci_release_of_pci_ranges(pci);
154 static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
158 resource_size_t busn;
159 struct resource *bus_range;
160 struct device *dev = pci->host.dev.parent;
161 struct device_node *np = dev->of_node;
163 err = of_address_to_resource(np, 0, &pci->cfg.res);
165 dev_err(dev, "missing \"reg\" property\n");
169 /* Limit the bus-range to fit within reg */
170 bus_max = pci->cfg.bus_range->start +
171 (resource_size(&pci->cfg.res) >> pci->cfg.ops->bus_shift) - 1;
172 pci->cfg.bus_range->end = min_t(resource_size_t,
173 pci->cfg.bus_range->end, bus_max);
175 pci->cfg.win = devm_kcalloc(dev, resource_size(pci->cfg.bus_range),
176 sizeof(*pci->cfg.win), GFP_KERNEL);
180 /* Map our Configuration Space windows */
181 if (!devm_request_mem_region(dev, pci->cfg.res.start,
182 resource_size(&pci->cfg.res),
183 "Configuration Space"))
186 bus_range = pci->cfg.bus_range;
187 for (busn = bus_range->start; busn <= bus_range->end; ++busn) {
188 u32 idx = busn - bus_range->start;
189 u32 sz = 1 << pci->cfg.ops->bus_shift;
191 pci->cfg.win[idx] = devm_ioremap(dev,
192 pci->cfg.res.start + busn * sz,
194 if (!pci->cfg.win[idx])
201 static int gen_pci_setup(int nr, struct pci_sys_data *sys)
203 struct gen_pci *pci = sys->private_data;
204 list_splice_init(&pci->resources, &sys->resources);
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);
219 .private_data = (void **)&pci,
220 .setup = gen_pci_setup,
221 .map_irq = of_irq_parse_and_map_pci,
228 type = of_get_property(np, "device_type", NULL);
229 if (!type || strcmp(type, "pci")) {
230 dev_err(dev, "invalid \"device_type\" %s\n", type);
234 prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL);
237 pci_add_flags(PCI_PROBE_ONLY);
239 pci_clear_flags(PCI_PROBE_ONLY);
242 of_id = of_match_node(gen_pci_of_match, np);
243 pci->cfg.ops = of_id->data;
244 gen_pci_ops.map_bus = pci->cfg.ops->map_bus;
245 pci->host.dev.parent = dev;
246 INIT_LIST_HEAD(&pci->host.windows);
247 INIT_LIST_HEAD(&pci->resources);
249 /* Parse our PCI ranges and request their resources */
250 err = gen_pci_parse_request_of_pci_ranges(pci);
254 /* Parse and map our Configuration Space windows */
255 err = gen_pci_parse_map_cfg_windows(pci);
257 gen_pci_release_of_pci_ranges(pci);
261 pci_common_init_dev(dev, &hw);
265 static struct platform_driver gen_pci_driver = {
267 .name = "pci-host-generic",
268 .of_match_table = gen_pci_of_match,
270 .probe = gen_pci_probe,
272 module_platform_driver(gen_pci_driver);
274 MODULE_DESCRIPTION("Generic PCI host driver");
275 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
276 MODULE_LICENSE("GPL v2");