1/*
  2 * Generic PCI host driver common code
  3 *
  4 * This program is free software; you can redistribute it and/or modify
  5 * it under the terms of the GNU General Public License version 2 as
  6 * published by the Free Software Foundation.
  7 *
  8 * This program is distributed in the hope that it will be useful,
  9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 11 * GNU General Public License for more details.
 12 *
 13 * You should have received a copy of the GNU General Public License
 14 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 15 *
 16 * Copyright (C) 2014 ARM Limited
 17 *
 18 * Author: Will Deacon <will.deacon@arm.com>
 19 */
 20
 21#include <linux/kernel.h>
 22#include <linux/of_address.h>
 23#include <linux/of_pci.h>
 24#include <linux/pci-ecam.h>
 25#include <linux/platform_device.h>
 26
 27static int gen_pci_parse_request_of_pci_ranges(struct device *dev,
 28		       struct list_head *resources, struct resource **bus_range)
 29{
 30	int err, res_valid = 0;
 31	struct device_node *np = dev->of_node;
 32	resource_size_t iobase;
 33	struct resource_entry *win, *tmp;
 34
 35	err = of_pci_get_host_bridge_resources(np, 0, 0xff, resources, &iobase);
 36	if (err)
 37		return err;
 38
 39	err = devm_request_pci_bus_resources(dev, resources);
 40	if (err)
 41		return err;
 42
 43	resource_list_for_each_entry_safe(win, tmp, resources) {
 44		struct resource *res = win->res;
 45
 46		switch (resource_type(res)) {
 47		case IORESOURCE_IO:
 48			err = pci_remap_iospace(res, iobase);
 49			if (err) {
 50				dev_warn(dev, "error %d: failed to map resource %pR\n",
 51					 err, res);
 52				resource_list_destroy_entry(win);
 53			}
 54			break;
 55		case IORESOURCE_MEM:
 56			res_valid |= !(res->flags & IORESOURCE_PREFETCH);
 57			break;
 58		case IORESOURCE_BUS:
 59			*bus_range = res;
 60			break;
 61		}
 62	}
 63
 64	if (res_valid)
 65		return 0;
 66
 67	dev_err(dev, "non-prefetchable memory resource required\n");
 68	return -EINVAL;
 69}
 70
 71static void gen_pci_unmap_cfg(void *ptr)
 72{
 73	pci_ecam_free((struct pci_config_window *)ptr);
 74}
 75
 76static struct pci_config_window *gen_pci_init(struct device *dev,
 77		struct list_head *resources, struct pci_ecam_ops *ops)
 78{
 79	int err;
 80	struct resource cfgres;
 81	struct resource *bus_range = NULL;
 82	struct pci_config_window *cfg;
 83
 84	/* Parse our PCI ranges and request their resources */
 85	err = gen_pci_parse_request_of_pci_ranges(dev, resources, &bus_range);
 86	if (err)
 87		goto err_out;
 88
 89	err = of_address_to_resource(dev->of_node, 0, &cfgres);
 90	if (err) {
 91		dev_err(dev, "missing \"reg\" property\n");
 92		goto err_out;
 93	}
 94
 95	cfg = pci_ecam_create(dev, &cfgres, bus_range, ops);
 96	if (IS_ERR(cfg)) {
 97		err = PTR_ERR(cfg);
 98		goto err_out;
 99	}
100
101	err = devm_add_action(dev, gen_pci_unmap_cfg, cfg);
102	if (err) {
103		gen_pci_unmap_cfg(cfg);
104		goto err_out;
105	}
106	return cfg;
107
108err_out:
109	pci_free_resource_list(resources);
110	return ERR_PTR(err);
111}
112
113int pci_host_common_probe(struct platform_device *pdev,
114			  struct pci_ecam_ops *ops)
115{
116	const char *type;
117	struct device *dev = &pdev->dev;
118	struct device_node *np = dev->of_node;
119	struct pci_bus *bus, *child;
120	struct pci_config_window *cfg;
121	struct list_head resources;
122
123	type = of_get_property(np, "device_type", NULL);
124	if (!type || strcmp(type, "pci")) {
125		dev_err(dev, "invalid \"device_type\" %s\n", type);
126		return -EINVAL;
127	}
128
129	of_pci_check_probe_only();
130
131	/* Parse and map our Configuration Space windows */
132	INIT_LIST_HEAD(&resources);
133	cfg = gen_pci_init(dev, &resources, ops);
134	if (IS_ERR(cfg))
135		return PTR_ERR(cfg);
136
137	/* Do not reassign resources if probe only */
138	if (!pci_has_flag(PCI_PROBE_ONLY))
139		pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
140
141	bus = pci_scan_root_bus(dev, cfg->busr.start, &ops->pci_ops, cfg,
142				&resources);
143	if (!bus) {
144		dev_err(dev, "Scanning rootbus failed");
145		return -ENODEV;
146	}
147
148	pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
149
150	/*
151	 * We insert PCI resources into the iomem_resource and
152	 * ioport_resource trees in either pci_bus_claim_resources()
153	 * or pci_bus_assign_resources().
154	 */
155	if (pci_has_flag(PCI_PROBE_ONLY)) {
156		pci_bus_claim_resources(bus);
157	} else {
158		pci_bus_size_bridges(bus);
159		pci_bus_assign_resources(bus);
160
161		list_for_each_entry(child, &bus->children, node)
162			pcie_bus_configure_settings(child);
163	}
164
165	pci_bus_add_devices(bus);
166	return 0;
167}