xref: /freebsd/sys/dev/fdt/fdt_clock.c (revision 6b6d6c4437cbc8d580710bd030d3f7055105a38a)
1 /*-
2  * Copyright (c) 2014 Ian Lepore <ian@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/cdefs.h>
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/lock.h>
33 #include <sys/mutex.h>
34 #include <sys/queue.h>
35 
36 #include <dev/ofw/ofw_bus.h>
37 #include <dev/ofw/ofw_bus_subr.h>
38 
39 #include "fdt_clock_if.h"
40 #include <dev/fdt/fdt_clock.h>
41 
42 /*
43  * Loop through all the tuples in the clocks= property for a device, enabling or
44  * disabling each clock.
45  *
46  * Be liberal about errors for now: warn about a failure to enable but keep
47  * trying with any other clocks in the list.  Return ENXIO if any errors were
48  * found, and let the caller decide whether the problem is fatal.
49  */
50 static int
51 enable_disable_all(device_t consumer, boolean_t enable)
52 {
53 	phandle_t cnode;
54 	device_t clockdev;
55 	int clocknum, err, i, ncells;
56 	uint32_t *clks;
57 	boolean_t anyerrors;
58 
59 	cnode = ofw_bus_get_node(consumer);
60 	ncells = OF_getencprop_alloc(cnode, "clocks", sizeof(*clks),
61 	    (void **)&clks);
62 	if (enable && ncells < 2) {
63 		device_printf(consumer, "Warning: No clocks specified in fdt "
64 		    "data; device may not function.");
65 		return (ENXIO);
66 	}
67 	anyerrors = false;
68 	for (i = 0; i < ncells; i += 2) {
69 		clockdev = OF_device_from_xref(clks[i]);
70 		clocknum = clks[i + 1];
71 		if (clockdev == NULL) {
72 			if (enable)
73 				device_printf(consumer, "Warning: can not find "
74 				    "driver for clock number %u; device may not "
75 				    "function\n", clocknum);
76 			anyerrors = true;
77 			continue;
78 		}
79 		if (enable)
80 			err = FDT_CLOCK_ENABLE(clockdev, clocknum);
81 		else
82 			err = FDT_CLOCK_DISABLE(clockdev, clocknum);
83 		if (err != 0) {
84 			if (enable)
85 				device_printf(consumer, "Warning: failed to "
86 				    "enable clock number %u; device may not "
87 				    "function\n", clocknum);
88 			anyerrors = true;
89 		}
90 	}
91 	free(clks, M_OFWPROP);
92 	return (anyerrors ? ENXIO : 0);
93 }
94 
95 int
96 fdt_clock_get_info(device_t consumer, int n, struct fdt_clock_info *info)
97 {
98 	phandle_t cnode;
99 	device_t clockdev;
100 	int clocknum, err, ncells;
101 	uint32_t *clks;
102 
103 	cnode = ofw_bus_get_node(consumer);
104 	ncells = OF_getencprop_alloc(cnode, "clocks", sizeof(*clks),
105 	    (void **)&clks);
106 	if (ncells <= 0)
107 		return (ENXIO);
108 	n *= 2;
109 	if (ncells <= n)
110 		err = ENXIO;
111 	else {
112 		clockdev = OF_device_from_xref(clks[n]);
113 		if (clockdev == NULL)
114 			err = ENXIO;
115 		else  {
116 			/*
117 			 * Make struct contents minimally valid, then call
118 			 * provider to fill in what it knows (provider can
119 			 * override anything it wants to).
120 			 */
121 			clocknum = clks[n + 1];
122 			memset(info, 0, sizeof(*info));
123 			info->provider = clockdev;
124 			info->index = clocknum;
125 			info->name = "";
126 			err = FDT_CLOCK_GET_INFO(clockdev, clocknum, info);
127 		}
128 	}
129 	free(clks, M_OFWPROP);
130 	return (err);
131 }
132 
133 int
134 fdt_clock_enable_all(device_t consumer)
135 {
136 
137 	return (enable_disable_all(consumer, true));
138 }
139 
140 int
141 fdt_clock_disable_all(device_t consumer)
142 {
143 
144 	return (enable_disable_all(consumer, false));
145 }
146 
147 void
148 fdt_clock_register_provider(device_t provider)
149 {
150 
151 	OF_device_register_xref(OF_xref_from_node(provider), provider);
152 }
153 
154 void
155 fdt_clock_unregister_provider(device_t provider)
156 {
157 
158 	OF_device_register_xref(OF_xref_from_node(provider), NULL);
159 }
160 
161