linux/drivers/pci/host/pci-host-common.c

170 lines
4.2 KiB
C

/*
* Generic PCI host driver common code
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright (C) 2014 ARM Limited
*
* Author: Will Deacon <will.deacon@arm.com>
*/
#include <linux/kernel.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/pci-ecam.h>
#include <linux/platform_device.h>
static int gen_pci_parse_request_of_pci_ranges(struct device *dev,
struct list_head *resources, struct resource **bus_range)
{
int err, res_valid = 0;
struct device_node *np = dev->of_node;
resource_size_t iobase;
struct resource_entry *win, *tmp;
err = of_pci_get_host_bridge_resources(np, 0, 0xff, resources, &iobase);
if (err)
return err;
err = devm_request_pci_bus_resources(dev, resources);
if (err)
return err;
resource_list_for_each_entry_safe(win, tmp, resources) {
struct resource *res = win->res;
switch (resource_type(res)) {
case IORESOURCE_IO:
err = pci_remap_iospace(res, iobase);
if (err) {
dev_warn(dev, "error %d: failed to map resource %pR\n",
err, res);
resource_list_destroy_entry(win);
}
break;
case IORESOURCE_MEM:
res_valid |= !(res->flags & IORESOURCE_PREFETCH);
break;
case IORESOURCE_BUS:
*bus_range = res;
break;
}
}
if (res_valid)
return 0;
dev_err(dev, "non-prefetchable memory resource required\n");
return -EINVAL;
}
static void gen_pci_unmap_cfg(void *ptr)
{
pci_ecam_free((struct pci_config_window *)ptr);
}
static struct pci_config_window *gen_pci_init(struct device *dev,
struct list_head *resources, struct pci_ecam_ops *ops)
{
int err;
struct resource cfgres;
struct resource *bus_range = NULL;
struct pci_config_window *cfg;
/* Parse our PCI ranges and request their resources */
err = gen_pci_parse_request_of_pci_ranges(dev, resources, &bus_range);
if (err)
goto err_out;
err = of_address_to_resource(dev->of_node, 0, &cfgres);
if (err) {
dev_err(dev, "missing \"reg\" property\n");
goto err_out;
}
cfg = pci_ecam_create(dev, &cfgres, bus_range, ops);
if (IS_ERR(cfg)) {
err = PTR_ERR(cfg);
goto err_out;
}
err = devm_add_action(dev, gen_pci_unmap_cfg, cfg);
if (err) {
gen_pci_unmap_cfg(cfg);
goto err_out;
}
return cfg;
err_out:
pci_free_resource_list(resources);
return ERR_PTR(err);
}
int pci_host_common_probe(struct platform_device *pdev,
struct pci_ecam_ops *ops)
{
const char *type;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct pci_bus *bus, *child;
struct pci_config_window *cfg;
struct list_head resources;
type = of_get_property(np, "device_type", NULL);
if (!type || strcmp(type, "pci")) {
dev_err(dev, "invalid \"device_type\" %s\n", type);
return -EINVAL;
}
of_pci_check_probe_only();
/* Parse and map our Configuration Space windows */
INIT_LIST_HEAD(&resources);
cfg = gen_pci_init(dev, &resources, ops);
if (IS_ERR(cfg))
return PTR_ERR(cfg);
/* Do not reassign resources if probe only */
if (!pci_has_flag(PCI_PROBE_ONLY))
pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
bus = pci_scan_root_bus(dev, cfg->busr.start, &ops->pci_ops, cfg,
&resources);
if (!bus) {
dev_err(dev, "Scanning rootbus failed");
return -ENODEV;
}
#ifdef CONFIG_ARM
pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
#endif
/*
* We insert PCI resources into the iomem_resource and
* ioport_resource trees in either pci_bus_claim_resources()
* or pci_bus_assign_resources().
*/
if (pci_has_flag(PCI_PROBE_ONLY)) {
pci_bus_claim_resources(bus);
} else {
pci_bus_size_bridges(bus);
pci_bus_assign_resources(bus);
list_for_each_entry(child, &bus->children, node)
pcie_bus_configure_settings(child);
}
pci_bus_add_devices(bus);
return 0;
}