1 /* $NetBSD: tegra_cpufreq.c,v 1.5 2017/04/22 23:53:24 jmcneill Exp $ */
2
3 /*-
4 * Copyright (c) 2015 Jared D. McNeill <jmcneill@invisible.ca>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include "locators.h"
30
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: tegra_cpufreq.c,v 1.5 2017/04/22 23:53:24 jmcneill Exp $");
33
34 #include <sys/param.h>
35 #include <sys/bus.h>
36 #include <sys/device.h>
37 #include <sys/intr.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/atomic.h>
41 #include <sys/kmem.h>
42 #include <sys/sysctl.h>
43
44 #include <arm/nvidia/tegra_var.h>
45
46 static u_int cpufreq_busy;
47 static struct sysctllog *cpufreq_log;
48 static int cpufreq_node_target, cpufreq_node_current, cpufreq_node_available;
49
50 static const struct tegra_cpufreq_func *cpufreq_func = NULL;
51
52 static int tegra_cpufreq_freq_helper(SYSCTLFN_PROTO);
53 static char tegra_cpufreq_available[TEGRA_CPUFREQ_MAX * 5];
54
55 #define cpufreq_set_rate cpufreq_func->set_rate
56 #define cpufreq_get_rate cpufreq_func->get_rate
57 #define cpufreq_get_available cpufreq_func->get_available
58
59 void
tegra_cpufreq_register(const struct tegra_cpufreq_func * cf)60 tegra_cpufreq_register(const struct tegra_cpufreq_func *cf)
61 {
62 const struct sysctlnode *node, *cpunode, *freqnode;
63 u_int availfreq[TEGRA_CPUFREQ_MAX];
64 size_t nfreq;
65 int error;
66
67 KASSERT(cpufreq_func == NULL);
68 cpufreq_func = cf;
69
70 nfreq = cpufreq_get_available(availfreq, TEGRA_CPUFREQ_MAX);
71 if (nfreq == 0)
72 return;
73
74 KASSERT(nfreq <= TEGRA_CPUFREQ_MAX);
75
76 for (int i = 0; i < nfreq; i++) {
77 char buf[6];
78 snprintf(buf, sizeof(buf), i ? " %u" : "%u", availfreq[i]);
79 strcat(tegra_cpufreq_available, buf);
80 }
81
82 error = sysctl_createv(&cpufreq_log, 0, NULL, &node,
83 CTLFLAG_PERMANENT, CTLTYPE_NODE, "machdep", NULL,
84 NULL, 0, NULL, 0, CTL_MACHDEP, CTL_EOL);
85 if (error)
86 goto sysctl_failed;
87 error = sysctl_createv(&cpufreq_log, 0, &node, &cpunode,
88 0, CTLTYPE_NODE, "cpu", NULL,
89 NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL);
90 if (error)
91 goto sysctl_failed;
92 error = sysctl_createv(&cpufreq_log, 0, &cpunode, &freqnode,
93 0, CTLTYPE_NODE, "frequency", NULL,
94 NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL);
95 if (error)
96 goto sysctl_failed;
97
98 error = sysctl_createv(&cpufreq_log, 0, &freqnode, &node,
99 CTLFLAG_READWRITE, CTLTYPE_INT, "target", NULL,
100 tegra_cpufreq_freq_helper, 0, NULL, 0,
101 CTL_CREATE, CTL_EOL);
102 if (error)
103 goto sysctl_failed;
104 cpufreq_node_target = node->sysctl_num;
105
106 error = sysctl_createv(&cpufreq_log, 0, &freqnode, &node,
107 CTLFLAG_READWRITE, CTLTYPE_INT, "current", NULL,
108 tegra_cpufreq_freq_helper, 0, NULL, 0,
109 CTL_CREATE, CTL_EOL);
110 if (error)
111 goto sysctl_failed;
112 cpufreq_node_current = node->sysctl_num;
113
114 error = sysctl_createv(&cpufreq_log, 0, &freqnode, &node,
115 0, CTLTYPE_STRING, "available", NULL,
116 NULL, 0, tegra_cpufreq_available, 0,
117 CTL_CREATE, CTL_EOL);
118 if (error)
119 goto sysctl_failed;
120 cpufreq_node_available = node->sysctl_num;
121
122 device_printf(curcpu()->ci_dev,
123 "setting speed to %d MHz\n", availfreq[0]);
124 cpufreq_set_rate(availfreq[0]);
125
126 return;
127
128 sysctl_failed:
129 aprint_error("cpufreq: couldn't create sysctl nodes (%d)\n", error);
130 sysctl_teardown(&cpufreq_log);
131 }
132
133 static int
tegra_cpufreq_freq_helper(SYSCTLFN_ARGS)134 tegra_cpufreq_freq_helper(SYSCTLFN_ARGS)
135 {
136 struct sysctlnode node;
137 int fq, oldfq = 0, error;
138
139 node = *rnode;
140 node.sysctl_data = &fq;
141
142 fq = cpufreq_get_rate();
143 if (rnode->sysctl_num == cpufreq_node_target)
144 oldfq = fq;
145
146 error = sysctl_lookup(SYSCTLFN_CALL(&node));
147 if (error || newp == NULL)
148 return error;
149
150 if (fq == oldfq || rnode->sysctl_num != cpufreq_node_target)
151 return 0;
152
153 if (atomic_cas_uint(&cpufreq_busy, 0, 1) != 0)
154 return EBUSY;
155
156 error = cpufreq_set_rate(fq);
157 if (error == 0) {
158 pmf_event_inject(NULL, PMFE_SPEED_CHANGED);
159 }
160
161 atomic_dec_uint(&cpufreq_busy);
162
163 return error;
164 }
165