1 /*
2  * Copyright (C) 2006 PA Semi, Inc
3  *
4  * Authors: Kip Walker, PA Semi
5  *	    Olof Johansson, PA Semi
6  *
7  * Maintained by: Olof Johansson <olof@lixom.net>
8  *
9  * Based on arch/powerpc/platforms/maple/pci.c
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
23  */
24 
25 
26 #include <linux/kernel.h>
27 #include <linux/pci.h>
28 
29 #include <asm/pci-bridge.h>
30 #include <asm/machdep.h>
31 
32 #include <asm/ppc-pci.h>
33 
34 #define PA_PXP_CFA(bus, devfn, off) (((bus) << 20) | ((devfn) << 12) | (off))
35 
36 static inline int pa_pxp_offset_valid(u8 bus, u8 devfn, int offset)
37 {
38 	/* Device 0 Function 0 is special: It's config space spans function 1 as
39 	 * well, so allow larger offset. It's really a two-function device but the
40 	 * second function does not probe.
41 	 */
42 	if (bus == 0 && devfn == 0)
43 		return offset < 8192;
44 	else
45 		return offset < 4096;
46 }
47 
48 static void volatile __iomem *pa_pxp_cfg_addr(struct pci_controller *hose,
49 				       u8 bus, u8 devfn, int offset)
50 {
51 	return hose->cfg_data + PA_PXP_CFA(bus, devfn, offset);
52 }
53 
54 static int pa_pxp_read_config(struct pci_bus *bus, unsigned int devfn,
55 			      int offset, int len, u32 *val)
56 {
57 	struct pci_controller *hose;
58 	void volatile __iomem *addr;
59 
60 	hose = pci_bus_to_host(bus);
61 	if (!hose)
62 		return PCIBIOS_DEVICE_NOT_FOUND;
63 
64 	if (!pa_pxp_offset_valid(bus->number, devfn, offset))
65 		return PCIBIOS_BAD_REGISTER_NUMBER;
66 
67 	addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset);
68 
69 	/*
70 	 * Note: the caller has already checked that offset is
71 	 * suitably aligned and that len is 1, 2 or 4.
72 	 */
73 	switch (len) {
74 	case 1:
75 		*val = in_8(addr);
76 		break;
77 	case 2:
78 		*val = in_le16(addr);
79 		break;
80 	default:
81 		*val = in_le32(addr);
82 		break;
83 	}
84 
85 	return PCIBIOS_SUCCESSFUL;
86 }
87 
88 static int pa_pxp_write_config(struct pci_bus *bus, unsigned int devfn,
89 			       int offset, int len, u32 val)
90 {
91 	struct pci_controller *hose;
92 	void volatile __iomem *addr;
93 
94 	hose = pci_bus_to_host(bus);
95 	if (!hose)
96 		return PCIBIOS_DEVICE_NOT_FOUND;
97 
98 	if (!pa_pxp_offset_valid(bus->number, devfn, offset))
99 		return PCIBIOS_BAD_REGISTER_NUMBER;
100 
101 	addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset);
102 
103 	/*
104 	 * Note: the caller has already checked that offset is
105 	 * suitably aligned and that len is 1, 2 or 4.
106 	 */
107 	switch (len) {
108 	case 1:
109 		out_8(addr, val);
110 		(void) in_8(addr);
111 		break;
112 	case 2:
113 		out_le16(addr, val);
114 		(void) in_le16(addr);
115 		break;
116 	default:
117 		out_le32(addr, val);
118 		(void) in_le32(addr);
119 		break;
120 	}
121 	return PCIBIOS_SUCCESSFUL;
122 }
123 
124 static struct pci_ops pa_pxp_ops = {
125 	pa_pxp_read_config,
126 	pa_pxp_write_config,
127 };
128 
129 static void __init setup_pa_pxp(struct pci_controller *hose)
130 {
131 	hose->ops = &pa_pxp_ops;
132 	hose->cfg_data = ioremap(0xe0000000, 0x10000000);
133 }
134 
135 static int __init pas_add_bridge(struct device_node *dev)
136 {
137 	struct pci_controller *hose;
138 
139 	pr_debug("Adding PCI host bridge %s\n", dev->full_name);
140 
141 	hose = pcibios_alloc_controller(dev);
142 	if (!hose)
143 		return -ENOMEM;
144 
145 	hose->first_busno = 0;
146 	hose->last_busno = 0xff;
147 
148 	setup_pa_pxp(hose);
149 
150 	printk(KERN_INFO "Found PA-PXP PCI host bridge.\n");
151 
152 	/* Interpret the "ranges" property */
153 	pci_process_bridge_OF_ranges(hose, dev, 1);
154 
155 	return 0;
156 }
157 
158 void __init pas_pci_init(void)
159 {
160 	struct device_node *np, *root;
161 
162 	root = of_find_node_by_path("/");
163 	if (!root) {
164 		printk(KERN_CRIT "pas_pci_init: can't find root "
165 			"of device tree\n");
166 		return;
167 	}
168 
169 	for (np = NULL; (np = of_get_next_child(root, np)) != NULL;)
170 		if (np->name && !strcmp(np->name, "pxp") && !pas_add_bridge(np))
171 			of_node_get(np);
172 
173 	of_node_put(root);
174 
175 	/* Setup the linkage between OF nodes and PHBs */
176 	pci_devs_phb_init();
177 
178 	/* Use the common resource allocation mechanism */
179 	pci_probe_only = 1;
180 }
181