xref: /freebsd/sys/dev/fdt/fdt_clock.c (revision bc96366c864c07ef352edb92017357917c75b36c)
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 #include <sys/systm.h>
36 
37 #include <dev/ofw/ofw_bus.h>
38 #include <dev/ofw/ofw_bus_subr.h>
39 
40 #include "fdt_clock_if.h"
41 #include <dev/fdt/fdt_clock.h>
42 
43 /*
44  * Loop through all the tuples in the clocks= property for a device, enabling or
45  * disabling each clock.
46  *
47  * Be liberal about errors for now: warn about a failure to enable but keep
48  * trying with any other clocks in the list.  Return ENXIO if any errors were
49  * found, and let the caller decide whether the problem is fatal.
50  */
51 static int
52 enable_disable_all(device_t consumer, boolean_t enable)
53 {
54 	phandle_t cnode;
55 	device_t clockdev;
56 	int clocknum, err, i, ncells;
57 	uint32_t *clks;
58 	boolean_t anyerrors;
59 
60 	cnode = ofw_bus_get_node(consumer);
61 	ncells = OF_getencprop_alloc(cnode, "clocks", sizeof(*clks),
62 	    (void **)&clks);
63 	if (enable && ncells < 2) {
64 		device_printf(consumer, "Warning: No clocks specified in fdt "
65 		    "data; device may not function.");
66 		return (ENXIO);
67 	}
68 	anyerrors = false;
69 	for (i = 0; i < ncells; i += 2) {
70 		clockdev = OF_device_from_xref(clks[i]);
71 		clocknum = clks[i + 1];
72 		if (clockdev == NULL) {
73 			if (enable)
74 				device_printf(consumer, "Warning: can not find "
75 				    "driver for clock number %u; device may not "
76 				    "function\n", clocknum);
77 			anyerrors = true;
78 			continue;
79 		}
80 		if (enable)
81 			err = FDT_CLOCK_ENABLE(clockdev, clocknum);
82 		else
83 			err = FDT_CLOCK_DISABLE(clockdev, clocknum);
84 		if (err != 0) {
85 			if (enable)
86 				device_printf(consumer, "Warning: failed to "
87 				    "enable clock number %u; device may not "
88 				    "function\n", clocknum);
89 			anyerrors = true;
90 		}
91 	}
92 	free(clks, M_OFWPROP);
93 	return (anyerrors ? ENXIO : 0);
94 }
95 
96 int
97 fdt_clock_get_info(device_t consumer, int n, struct fdt_clock_info *info)
98 {
99 	phandle_t cnode;
100 	device_t clockdev;
101 	int clocknum, err, ncells;
102 	uint32_t *clks;
103 
104 	cnode = ofw_bus_get_node(consumer);
105 	ncells = OF_getencprop_alloc(cnode, "clocks", sizeof(*clks),
106 	    (void **)&clks);
107 	if (ncells <= 0)
108 		return (ENXIO);
109 	n *= 2;
110 	if (ncells <= n)
111 		err = ENXIO;
112 	else {
113 		clockdev = OF_device_from_xref(clks[n]);
114 		if (clockdev == NULL)
115 			err = ENXIO;
116 		else  {
117 			/*
118 			 * Make struct contents minimally valid, then call
119 			 * provider to fill in what it knows (provider can
120 			 * override anything it wants to).
121 			 */
122 			clocknum = clks[n + 1];
123 			bzero(info, sizeof(*info));
124 			info->provider = clockdev;
125 			info->index = clocknum;
126 			info->name = "";
127 			err = FDT_CLOCK_GET_INFO(clockdev, clocknum, info);
128 		}
129 	}
130 	free(clks, M_OFWPROP);
131 	return (err);
132 }
133 
134 int
135 fdt_clock_enable_all(device_t consumer)
136 {
137 
138 	return (enable_disable_all(consumer, true));
139 }
140 
141 int
142 fdt_clock_disable_all(device_t consumer)
143 {
144 
145 	return (enable_disable_all(consumer, false));
146 }
147 
148 void
149 fdt_clock_register_provider(device_t provider)
150 {
151 
152 	OF_device_register_xref(OF_xref_from_device(provider), provider);
153 }
154 
155 void
156 fdt_clock_unregister_provider(device_t provider)
157 {
158 
159 	OF_device_register_xref(OF_xref_from_device(provider), NULL);
160 }
161 
162