xref: /openbmc/linux/arch/powerpc/sysdev/dcr.c (revision 545e4006)
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 #ifdef CONFIG_PPC_DCR_MMIO
27 static struct device_node *find_dcr_parent(struct device_node *node)
28 {
29 	struct device_node *par, *tmp;
30 	const u32 *p;
31 
32 	for (par = of_node_get(node); par;) {
33 		if (of_get_property(par, "dcr-controller", NULL))
34 			break;
35 		p = of_get_property(par, "dcr-parent", NULL);
36 		tmp = par;
37 		if (p == NULL)
38 			par = of_get_parent(par);
39 		else
40 			par = of_find_node_by_phandle(*p);
41 		of_node_put(tmp);
42 	}
43 	return par;
44 }
45 #endif
46 
47 #if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)
48 
49 bool dcr_map_ok_generic(dcr_host_t host)
50 {
51 	if (host.type == DCR_HOST_NATIVE)
52 		return dcr_map_ok_native(host.host.native);
53 	else if (host.type == DCR_HOST_MMIO)
54 		return dcr_map_ok_mmio(host.host.mmio);
55 	else
56 		return 0;
57 }
58 EXPORT_SYMBOL_GPL(dcr_map_ok_generic);
59 
60 dcr_host_t dcr_map_generic(struct device_node *dev,
61 			   unsigned int dcr_n,
62 			   unsigned int dcr_c)
63 {
64 	dcr_host_t host;
65 	struct device_node *dp;
66 	const char *prop;
67 
68 	host.type = DCR_HOST_INVALID;
69 
70 	dp = find_dcr_parent(dev);
71 	if (dp == NULL)
72 		return host;
73 
74 	prop = of_get_property(dp, "dcr-access-method", NULL);
75 
76 	pr_debug("dcr_map_generic(dcr-access-method = %s)\n", prop);
77 
78 	if (!strcmp(prop, "native")) {
79 		host.type = DCR_HOST_NATIVE;
80 		host.host.native = dcr_map_native(dev, dcr_n, dcr_c);
81 	} else if (!strcmp(prop, "mmio")) {
82 		host.type = DCR_HOST_MMIO;
83 		host.host.mmio = dcr_map_mmio(dev, dcr_n, dcr_c);
84 	}
85 
86 	of_node_put(dp);
87 	return host;
88 }
89 EXPORT_SYMBOL_GPL(dcr_map_generic);
90 
91 void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c)
92 {
93 	if (host.type == DCR_HOST_NATIVE)
94 		dcr_unmap_native(host.host.native, dcr_c);
95 	else if (host.type == DCR_HOST_MMIO)
96 		dcr_unmap_mmio(host.host.mmio, dcr_c);
97 	else /* host.type == DCR_HOST_INVALID */
98 		WARN_ON(true);
99 }
100 EXPORT_SYMBOL_GPL(dcr_unmap_generic);
101 
102 u32 dcr_read_generic(dcr_host_t host, unsigned int dcr_n)
103 {
104 	if (host.type == DCR_HOST_NATIVE)
105 		return dcr_read_native(host.host.native, dcr_n);
106 	else if (host.type == DCR_HOST_MMIO)
107 		return dcr_read_mmio(host.host.mmio, dcr_n);
108 	else /* host.type == DCR_HOST_INVALID */
109 		WARN_ON(true);
110 	return 0;
111 }
112 EXPORT_SYMBOL_GPL(dcr_read_generic);
113 
114 void dcr_write_generic(dcr_host_t host, unsigned int dcr_n, u32 value)
115 {
116 	if (host.type == DCR_HOST_NATIVE)
117 		dcr_write_native(host.host.native, dcr_n, value);
118 	else if (host.type == DCR_HOST_MMIO)
119 		dcr_write_mmio(host.host.mmio, dcr_n, value);
120 	else /* host.type == DCR_HOST_INVALID */
121 		WARN_ON(true);
122 }
123 EXPORT_SYMBOL_GPL(dcr_write_generic);
124 
125 #endif /* defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO) */
126 
127 unsigned int dcr_resource_start(struct device_node *np, unsigned int index)
128 {
129 	unsigned int ds;
130 	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
131 
132 	if (dr == NULL || ds & 1 || index >= (ds / 8))
133 		return 0;
134 
135 	return dr[index * 2];
136 }
137 EXPORT_SYMBOL_GPL(dcr_resource_start);
138 
139 unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
140 {
141 	unsigned int ds;
142 	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
143 
144 	if (dr == NULL || ds & 1 || index >= (ds / 8))
145 		return 0;
146 
147 	return dr[index * 2 + 1];
148 }
149 EXPORT_SYMBOL_GPL(dcr_resource_len);
150 
151 #ifdef CONFIG_PPC_DCR_MMIO
152 
153 u64 of_translate_dcr_address(struct device_node *dev,
154 			     unsigned int dcr_n,
155 			     unsigned int *out_stride)
156 {
157 	struct device_node *dp;
158 	const u32 *p;
159 	unsigned int stride;
160 	u64 ret = OF_BAD_ADDR;
161 
162 	dp = find_dcr_parent(dev);
163 	if (dp == NULL)
164 		return OF_BAD_ADDR;
165 
166 	/* Stride is not properly defined yet, default to 0x10 for Axon */
167 	p = of_get_property(dp, "dcr-mmio-stride", NULL);
168 	stride = (p == NULL) ? 0x10 : *p;
169 
170 	/* XXX FIXME: Which property name is to use of the 2 following ? */
171 	p = of_get_property(dp, "dcr-mmio-range", NULL);
172 	if (p == NULL)
173 		p = of_get_property(dp, "dcr-mmio-space", NULL);
174 	if (p == NULL)
175 		goto done;
176 
177 	/* Maybe could do some better range checking here */
178 	ret = of_translate_address(dp, p);
179 	if (ret != OF_BAD_ADDR)
180 		ret += (u64)(stride) * (u64)dcr_n;
181 	if (out_stride)
182 		*out_stride = stride;
183 
184  done:
185 	of_node_put(dp);
186 	return ret;
187 }
188 
189 dcr_host_mmio_t dcr_map_mmio(struct device_node *dev,
190 			     unsigned int dcr_n,
191 			     unsigned int dcr_c)
192 {
193 	dcr_host_mmio_t ret = { .token = NULL, .stride = 0, .base = dcr_n };
194 	u64 addr;
195 
196 	pr_debug("dcr_map(%s, 0x%x, 0x%x)\n",
197 		 dev->full_name, dcr_n, dcr_c);
198 
199 	addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
200 	pr_debug("translates to addr: 0x%llx, stride: 0x%x\n",
201 		 (unsigned long long) addr, ret.stride);
202 	if (addr == OF_BAD_ADDR)
203 		return ret;
204 	pr_debug("mapping 0x%x bytes\n", dcr_c * ret.stride);
205 	ret.token = ioremap(addr, dcr_c * ret.stride);
206 	if (ret.token == NULL)
207 		return ret;
208 	pr_debug("mapped at 0x%p -> base is 0x%p\n",
209 		 ret.token, ret.token - dcr_n * ret.stride);
210 	ret.token -= dcr_n * ret.stride;
211 	return ret;
212 }
213 EXPORT_SYMBOL_GPL(dcr_map_mmio);
214 
215 void dcr_unmap_mmio(dcr_host_mmio_t host, unsigned int dcr_c)
216 {
217 	dcr_host_mmio_t h = host;
218 
219 	if (h.token == NULL)
220 		return;
221 	h.token += host.base * h.stride;
222 	iounmap(h.token);
223 	h.token = NULL;
224 }
225 EXPORT_SYMBOL_GPL(dcr_unmap_mmio);
226 
227 #endif /* defined(CONFIG_PPC_DCR_MMIO) */
228 
229 #ifdef CONFIG_PPC_DCR_NATIVE
230 DEFINE_SPINLOCK(dcr_ind_lock);
231 #endif	/* defined(CONFIG_PPC_DCR_NATIVE) */
232 
233