xref: /freebsd-14.2/sys/dev/extres/syscon/syscon.c (revision eca005d8)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2017 Kyle Evans <[email protected]>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 /*
29  * This is a generic syscon driver, whose purpose is to provide access to
30  * various unrelated bits packed in a single register space. It is usually used
31  * as a fallback to more specific driver, but works well enough for simple
32  * access.
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 #include "opt_platform.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/bus.h>
42 #include <sys/kernel.h>
43 #include <sys/kobj.h>
44 #include <sys/lock.h>
45 #include <sys/malloc.h>
46 #include <sys/module.h>
47 #include <sys/rman.h>
48 #include <sys/sx.h>
49 #include <sys/queue.h>
50 
51 #include <machine/bus.h>
52 
53 #ifdef FDT
54 #include <dev/ofw/ofw_bus.h>
55 #include <dev/ofw/ofw_bus_subr.h>
56 #endif
57 
58 #include "syscon_if.h"
59 #include "syscon.h"
60 
61 /*
62  * Syscon interface details
63  */
64 typedef TAILQ_HEAD(syscon_list, syscon) syscon_list_t;
65 
66 /*
67  * Declarations
68  */
69 static int syscon_method_init(struct syscon *syscon);
70 static int syscon_method_uninit(struct syscon *syscon);
71 static uint32_t syscon_method_read_4(struct syscon *syscon, bus_size_t offset);
72 static int syscon_method_write_4(struct syscon *syscon, bus_size_t offset,
73     uint32_t val);
74 static int syscon_method_modify_4(struct syscon *syscon, bus_size_t offset,
75     uint32_t clear_bits, uint32_t set_bits);
76 
77 
78 MALLOC_DEFINE(M_SYSCON, "syscon", "Syscon driver");
79 
80 static syscon_list_t syscon_list = TAILQ_HEAD_INITIALIZER(syscon_list);
81 static struct sx		syscon_topo_lock;
82 SX_SYSINIT(syscon_topology, &syscon_topo_lock, "Syscon topology lock");
83 
84 /*
85  * Syscon methods.
86  */
87 static syscon_method_t syscon_methods[] = {
88 	SYSCONMETHOD(syscon_init,	syscon_method_init),
89 	SYSCONMETHOD(syscon_uninit,	syscon_method_uninit),
90 	SYSCONMETHOD(syscon_read_4,	syscon_method_read_4),
91 	SYSCONMETHOD(syscon_write_4,	syscon_method_write_4),
92 	SYSCONMETHOD(syscon_modify_4,	syscon_method_modify_4),
93 
94 	SYSCONMETHOD_END
95 };
96 DEFINE_CLASS_0(syscon, syscon_class, syscon_methods, 0);
97 
98 #define SYSCON_TOPO_SLOCK()	sx_slock(&syscon_topo_lock)
99 #define SYSCON_TOPO_XLOCK()	sx_xlock(&syscon_topo_lock)
100 #define SYSCON_TOPO_UNLOCK()	sx_unlock(&syscon_topo_lock)
101 #define SYSCON_TOPO_ASSERT()	sx_assert(&syscon_topo_lock, SA_LOCKED)
102 #define SYSCON_TOPO_XASSERT()	sx_assert(&syscon_topo_lock, SA_XLOCKED)
103 
104 /*
105  * Default syscon methods for base class.
106  */
107 static int
108 syscon_method_init(struct syscon *syscon)
109 {
110 
111 	return (0);
112 };
113 
114 static int
115 syscon_method_uninit(struct syscon *syscon)
116 {
117 
118 	return (0);
119 };
120 
121 void *
122 syscon_get_softc(struct syscon *syscon)
123 {
124 
125 	return (syscon->softc);
126 };
127 
128 static uint32_t
129 syscon_method_read_4(struct syscon *syscon, bus_size_t offset)
130 {
131 	uint32_t val;
132 
133 	SYSCON_DEVICE_LOCK(syscon->pdev);
134 	val = SYSCON_UNLOCKED_READ_4(syscon, offset);
135 	SYSCON_DEVICE_UNLOCK(syscon->pdev);
136 	return(val);
137 }
138 
139 static int
140 syscon_method_write_4(struct syscon *syscon, bus_size_t offset, uint32_t val)
141 {
142 	int	rv;
143 
144 	SYSCON_DEVICE_LOCK(syscon->pdev);
145 	rv = SYSCON_UNLOCKED_WRITE_4(syscon, offset, val);
146 	SYSCON_DEVICE_UNLOCK(syscon->pdev);
147 	return(rv);
148 }
149 
150 static int
151 syscon_method_modify_4(struct syscon *syscon, bus_size_t offset,
152     uint32_t clear_bits, uint32_t set_bits)
153 {
154 	int	rv;
155 
156 	SYSCON_DEVICE_LOCK(syscon->pdev);
157 	rv = SYSCON_UNLOCKED_MODIFY_4(syscon, offset, clear_bits, set_bits);
158 	SYSCON_DEVICE_UNLOCK(syscon->pdev);
159 	return(rv);
160 }
161 /*
162  * Create and initialize syscon object, but do not register it.
163  */
164 struct syscon *
165 syscon_create(device_t pdev, syscon_class_t syscon_class)
166 {
167 	struct syscon *syscon;
168 
169 	/* Create object and initialize it. */
170 	syscon = malloc(sizeof(struct syscon), M_SYSCON,
171 	    M_WAITOK | M_ZERO);
172 	kobj_init((kobj_t)syscon, (kobj_class_t)syscon_class);
173 
174 	/* Allocate softc if required. */
175 	if (syscon_class->size > 0)
176 		syscon->softc = malloc(syscon_class->size, M_SYSCON,
177 		    M_WAITOK | M_ZERO);
178 
179 	/* Rest of init. */
180 	syscon->pdev = pdev;
181 	return (syscon);
182 }
183 
184 /* Register syscon object. */
185 struct syscon *
186 syscon_register(struct syscon *syscon)
187 {
188 	int rv;
189 
190 #ifdef FDT
191 	if (syscon->ofw_node <= 0)
192 		syscon->ofw_node = ofw_bus_get_node(syscon->pdev);
193 	if (syscon->ofw_node <= 0)
194 		return (NULL);
195 #endif
196 
197 	rv = SYSCON_INIT(syscon);
198 	if (rv != 0) {
199 		printf("SYSCON_INIT failed: %d\n", rv);
200 		return (NULL);
201 	}
202 
203 #ifdef FDT
204 	OF_device_register_xref(OF_xref_from_node(syscon->ofw_node),
205 	    syscon->pdev);
206 #endif
207 	SYSCON_TOPO_XLOCK();
208 	TAILQ_INSERT_TAIL(&syscon_list, syscon, syscon_link);
209 	SYSCON_TOPO_UNLOCK();
210 	return (syscon);
211 }
212 
213 int
214 syscon_unregister(struct syscon *syscon)
215 {
216 
217 	SYSCON_TOPO_XLOCK();
218 	TAILQ_REMOVE(&syscon_list, syscon, syscon_link);
219 	SYSCON_TOPO_UNLOCK();
220 #ifdef FDT
221 	OF_device_register_xref(OF_xref_from_node(syscon->ofw_node), NULL);
222 #endif
223 	return (SYSCON_UNINIT(syscon));
224 }
225 
226 /**
227  * Provider methods
228  */
229 #ifdef FDT
230 static struct syscon *
231 syscon_find_by_ofw_node(phandle_t node)
232 {
233 	struct syscon *entry;
234 
235 	SYSCON_TOPO_ASSERT();
236 
237 	TAILQ_FOREACH(entry, &syscon_list, syscon_link) {
238 		if (entry->ofw_node == node)
239 			return (entry);
240 	}
241 
242 	return (NULL);
243 }
244 
245 struct syscon *
246 syscon_create_ofw_node(device_t pdev, syscon_class_t syscon_class,
247     phandle_t node)
248 {
249 	struct syscon *syscon;
250 
251 	syscon = syscon_create(pdev, syscon_class);
252 	if (syscon == NULL)
253 		return (NULL);
254 	syscon->ofw_node = node;
255 	if (syscon_register(syscon) == NULL)
256 		return (NULL);
257 	return (syscon);
258 }
259 
260 phandle_t
261 syscon_get_ofw_node(struct syscon *syscon)
262 {
263 
264 	return (syscon->ofw_node);
265 }
266 
267 int
268 syscon_get_by_ofw_node(device_t cdev, phandle_t node, struct syscon **syscon)
269 {
270 
271 	SYSCON_TOPO_SLOCK();
272 	*syscon = syscon_find_by_ofw_node(node);
273 	if (*syscon == NULL) {
274 		SYSCON_TOPO_UNLOCK();
275 		device_printf(cdev, "Failed to find syscon node\n");
276 		return (ENODEV);
277 	}
278 	SYSCON_TOPO_UNLOCK();
279 	return (0);
280 }
281 
282 int
283 syscon_get_by_ofw_property(device_t cdev, phandle_t cnode, char *name,
284     struct syscon **syscon)
285 {
286 	pcell_t *cells;
287 	int ncells;
288 
289 	if (cnode <= 0)
290 		cnode = ofw_bus_get_node(cdev);
291 	if (cnode <= 0) {
292 		device_printf(cdev,
293 		    "%s called on not ofw based device\n", __func__);
294 		return (ENXIO);
295 	}
296 	ncells = OF_getencprop_alloc_multi(cnode, name, sizeof(pcell_t),
297 	    (void **)&cells);
298 	if (ncells < 1)
299 		return (ENOENT);
300 
301 	/* Translate to syscon node. */
302 	SYSCON_TOPO_SLOCK();
303 	*syscon = syscon_find_by_ofw_node(OF_node_from_xref(cells[0]));
304 	if (*syscon == NULL) {
305 		SYSCON_TOPO_UNLOCK();
306 		device_printf(cdev, "Failed to find syscon node\n");
307 		OF_prop_free(cells);
308 		return (ENODEV);
309 	}
310 	SYSCON_TOPO_UNLOCK();
311 	OF_prop_free(cells);
312 	return (0);
313 }
314 #endif
315