xref: /openbmc/linux/arch/powerpc/sysdev/dcr.c (revision 827634ad)
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 <linux/export.h>
24 #include <asm/prom.h>
25 #include <asm/dcr.h>
26 
27 #ifdef CONFIG_PPC_DCR_MMIO
28 static struct device_node *find_dcr_parent(struct device_node *node)
29 {
30 	struct device_node *par, *tmp;
31 	const u32 *p;
32 
33 	for (par = of_node_get(node); par;) {
34 		if (of_get_property(par, "dcr-controller", NULL))
35 			break;
36 		p = of_get_property(par, "dcr-parent", NULL);
37 		tmp = par;
38 		if (p == NULL)
39 			par = of_get_parent(par);
40 		else
41 			par = of_find_node_by_phandle(*p);
42 		of_node_put(tmp);
43 	}
44 	return par;
45 }
46 #endif
47 
48 #if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)
49 
50 bool dcr_map_ok_generic(dcr_host_t host)
51 {
52 	if (host.type == DCR_HOST_NATIVE)
53 		return dcr_map_ok_native(host.host.native);
54 	else if (host.type == DCR_HOST_MMIO)
55 		return dcr_map_ok_mmio(host.host.mmio);
56 	else
57 		return false;
58 }
59 EXPORT_SYMBOL_GPL(dcr_map_ok_generic);
60 
61 dcr_host_t dcr_map_generic(struct device_node *dev,
62 			   unsigned int dcr_n,
63 			   unsigned int dcr_c)
64 {
65 	dcr_host_t host;
66 	struct device_node *dp;
67 	const char *prop;
68 
69 	host.type = DCR_HOST_INVALID;
70 
71 	dp = find_dcr_parent(dev);
72 	if (dp == NULL)
73 		return host;
74 
75 	prop = of_get_property(dp, "dcr-access-method", NULL);
76 
77 	pr_debug("dcr_map_generic(dcr-access-method = %s)\n", prop);
78 
79 	if (!strcmp(prop, "native")) {
80 		host.type = DCR_HOST_NATIVE;
81 		host.host.native = dcr_map_native(dev, dcr_n, dcr_c);
82 	} else if (!strcmp(prop, "mmio")) {
83 		host.type = DCR_HOST_MMIO;
84 		host.host.mmio = dcr_map_mmio(dev, dcr_n, dcr_c);
85 	}
86 
87 	of_node_put(dp);
88 	return host;
89 }
90 EXPORT_SYMBOL_GPL(dcr_map_generic);
91 
92 void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c)
93 {
94 	if (host.type == DCR_HOST_NATIVE)
95 		dcr_unmap_native(host.host.native, dcr_c);
96 	else if (host.type == DCR_HOST_MMIO)
97 		dcr_unmap_mmio(host.host.mmio, dcr_c);
98 	else /* host.type == DCR_HOST_INVALID */
99 		WARN_ON(true);
100 }
101 EXPORT_SYMBOL_GPL(dcr_unmap_generic);
102 
103 u32 dcr_read_generic(dcr_host_t host, unsigned int dcr_n)
104 {
105 	if (host.type == DCR_HOST_NATIVE)
106 		return dcr_read_native(host.host.native, dcr_n);
107 	else if (host.type == DCR_HOST_MMIO)
108 		return dcr_read_mmio(host.host.mmio, dcr_n);
109 	else /* host.type == DCR_HOST_INVALID */
110 		WARN_ON(true);
111 	return 0;
112 }
113 EXPORT_SYMBOL_GPL(dcr_read_generic);
114 
115 void dcr_write_generic(dcr_host_t host, unsigned int dcr_n, u32 value)
116 {
117 	if (host.type == DCR_HOST_NATIVE)
118 		dcr_write_native(host.host.native, dcr_n, value);
119 	else if (host.type == DCR_HOST_MMIO)
120 		dcr_write_mmio(host.host.mmio, dcr_n, value);
121 	else /* host.type == DCR_HOST_INVALID */
122 		WARN_ON(true);
123 }
124 EXPORT_SYMBOL_GPL(dcr_write_generic);
125 
126 #endif /* defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO) */
127 
128 unsigned int dcr_resource_start(const struct device_node *np,
129 				unsigned int index)
130 {
131 	unsigned int ds;
132 	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
133 
134 	if (dr == NULL || ds & 1 || index >= (ds / 8))
135 		return 0;
136 
137 	return dr[index * 2];
138 }
139 EXPORT_SYMBOL_GPL(dcr_resource_start);
140 
141 unsigned int dcr_resource_len(const struct device_node *np, unsigned int index)
142 {
143 	unsigned int ds;
144 	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
145 
146 	if (dr == NULL || ds & 1 || index >= (ds / 8))
147 		return 0;
148 
149 	return dr[index * 2 + 1];
150 }
151 EXPORT_SYMBOL_GPL(dcr_resource_len);
152 
153 #ifdef CONFIG_PPC_DCR_MMIO
154 
155 static u64 of_translate_dcr_address(struct device_node *dev,
156 				    unsigned int dcr_n,
157 				    unsigned int *out_stride)
158 {
159 	struct device_node *dp;
160 	const u32 *p;
161 	unsigned int stride;
162 	u64 ret = OF_BAD_ADDR;
163 
164 	dp = find_dcr_parent(dev);
165 	if (dp == NULL)
166 		return OF_BAD_ADDR;
167 
168 	/* Stride is not properly defined yet, default to 0x10 for Axon */
169 	p = of_get_property(dp, "dcr-mmio-stride", NULL);
170 	stride = (p == NULL) ? 0x10 : *p;
171 
172 	/* XXX FIXME: Which property name is to use of the 2 following ? */
173 	p = of_get_property(dp, "dcr-mmio-range", NULL);
174 	if (p == NULL)
175 		p = of_get_property(dp, "dcr-mmio-space", NULL);
176 	if (p == NULL)
177 		goto done;
178 
179 	/* Maybe could do some better range checking here */
180 	ret = of_translate_address(dp, p);
181 	if (ret != OF_BAD_ADDR)
182 		ret += (u64)(stride) * (u64)dcr_n;
183 	if (out_stride)
184 		*out_stride = stride;
185 
186  done:
187 	of_node_put(dp);
188 	return ret;
189 }
190 
191 dcr_host_mmio_t dcr_map_mmio(struct device_node *dev,
192 			     unsigned int dcr_n,
193 			     unsigned int dcr_c)
194 {
195 	dcr_host_mmio_t ret = { .token = NULL, .stride = 0, .base = dcr_n };
196 	u64 addr;
197 
198 	pr_debug("dcr_map(%s, 0x%x, 0x%x)\n",
199 		 dev->full_name, dcr_n, dcr_c);
200 
201 	addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
202 	pr_debug("translates to addr: 0x%llx, stride: 0x%x\n",
203 		 (unsigned long long) addr, ret.stride);
204 	if (addr == OF_BAD_ADDR)
205 		return ret;
206 	pr_debug("mapping 0x%x bytes\n", dcr_c * ret.stride);
207 	ret.token = ioremap(addr, dcr_c * ret.stride);
208 	if (ret.token == NULL)
209 		return ret;
210 	pr_debug("mapped at 0x%p -> base is 0x%p\n",
211 		 ret.token, ret.token - dcr_n * ret.stride);
212 	ret.token -= dcr_n * ret.stride;
213 	return ret;
214 }
215 EXPORT_SYMBOL_GPL(dcr_map_mmio);
216 
217 void dcr_unmap_mmio(dcr_host_mmio_t host, unsigned int dcr_c)
218 {
219 	dcr_host_mmio_t h = host;
220 
221 	if (h.token == NULL)
222 		return;
223 	h.token += host.base * h.stride;
224 	iounmap(h.token);
225 	h.token = NULL;
226 }
227 EXPORT_SYMBOL_GPL(dcr_unmap_mmio);
228 
229 #endif /* defined(CONFIG_PPC_DCR_MMIO) */
230 
231 #ifdef CONFIG_PPC_DCR_NATIVE
232 DEFINE_SPINLOCK(dcr_ind_lock);
233 EXPORT_SYMBOL_GPL(dcr_ind_lock);
234 #endif	/* defined(CONFIG_PPC_DCR_NATIVE) */
235 
236