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 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 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