xref: /openbmc/linux/arch/powerpc/sysdev/dcr.c (revision f42b3800)
1 /*
2  * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
3  *                    <benh@kernel.crashing.org>
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 
20 #undef DEBUG
21 
22 #include <linux/kernel.h>
23 #include <asm/prom.h>
24 #include <asm/dcr.h>
25 
26 unsigned int dcr_resource_start(struct device_node *np, unsigned int index)
27 {
28 	unsigned int ds;
29 	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
30 
31 	if (dr == NULL || ds & 1 || index >= (ds / 8))
32 		return 0;
33 
34 	return dr[index * 2];
35 }
36 EXPORT_SYMBOL_GPL(dcr_resource_start);
37 
38 unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
39 {
40 	unsigned int ds;
41 	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
42 
43 	if (dr == NULL || ds & 1 || index >= (ds / 8))
44 		return 0;
45 
46 	return dr[index * 2 + 1];
47 }
48 EXPORT_SYMBOL_GPL(dcr_resource_len);
49 
50 #ifndef CONFIG_PPC_DCR_NATIVE
51 
52 static struct device_node * find_dcr_parent(struct device_node * node)
53 {
54 	struct device_node *par, *tmp;
55 	const u32 *p;
56 
57 	for (par = of_node_get(node); par;) {
58 		if (of_get_property(par, "dcr-controller", NULL))
59 			break;
60 		p = of_get_property(par, "dcr-parent", NULL);
61 		tmp = par;
62 		if (p == NULL)
63 			par = of_get_parent(par);
64 		else
65 			par = of_find_node_by_phandle(*p);
66 		of_node_put(tmp);
67 	}
68 	return par;
69 }
70 
71 u64 of_translate_dcr_address(struct device_node *dev,
72 			     unsigned int dcr_n,
73 			     unsigned int *out_stride)
74 {
75 	struct device_node *dp;
76 	const u32 *p;
77 	unsigned int stride;
78 	u64 ret;
79 
80 	dp = find_dcr_parent(dev);
81 	if (dp == NULL)
82 		return OF_BAD_ADDR;
83 
84 	/* Stride is not properly defined yet, default to 0x10 for Axon */
85 	p = of_get_property(dp, "dcr-mmio-stride", NULL);
86 	stride = (p == NULL) ? 0x10 : *p;
87 
88 	/* XXX FIXME: Which property name is to use of the 2 following ? */
89 	p = of_get_property(dp, "dcr-mmio-range", NULL);
90 	if (p == NULL)
91 		p = of_get_property(dp, "dcr-mmio-space", NULL);
92 	if (p == NULL)
93 		return OF_BAD_ADDR;
94 
95 	/* Maybe could do some better range checking here */
96 	ret = of_translate_address(dp, p);
97 	if (ret != OF_BAD_ADDR)
98 		ret += (u64)(stride) * (u64)dcr_n;
99 	if (out_stride)
100 		*out_stride = stride;
101 	return ret;
102 }
103 
104 dcr_host_t dcr_map(struct device_node *dev, unsigned int dcr_n,
105 		   unsigned int dcr_c)
106 {
107 	dcr_host_t ret = { .token = NULL, .stride = 0, .base = dcr_n };
108 	u64 addr;
109 
110 	pr_debug("dcr_map(%s, 0x%x, 0x%x)\n",
111 		 dev->full_name, dcr_n, dcr_c);
112 
113 	addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
114 	pr_debug("translates to addr: 0x%lx, stride: 0x%x\n",
115 		 addr, ret.stride);
116 	if (addr == OF_BAD_ADDR)
117 		return ret;
118 	pr_debug("mapping 0x%x bytes\n", dcr_c * ret.stride);
119 	ret.token = ioremap(addr, dcr_c * ret.stride);
120 	if (ret.token == NULL)
121 		return ret;
122 	pr_debug("mapped at 0x%p -> base is 0x%p\n",
123 		 ret.token, ret.token - dcr_n * ret.stride);
124 	ret.token -= dcr_n * ret.stride;
125 	return ret;
126 }
127 EXPORT_SYMBOL_GPL(dcr_map);
128 
129 void dcr_unmap(dcr_host_t host, unsigned int dcr_c)
130 {
131 	dcr_host_t h = host;
132 
133 	if (h.token == NULL)
134 		return;
135 	h.token += host.base * h.stride;
136 	iounmap(h.token);
137 	h.token = NULL;
138 }
139 EXPORT_SYMBOL_GPL(dcr_unmap);
140 #else	/* defined(CONFIG_PPC_DCR_NATIVE) */
141 DEFINE_SPINLOCK(dcr_ind_lock);
142 #endif	/* !defined(CONFIG_PPC_DCR_NATIVE) */
143