1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2018 Emmanuel Vadot <manu@FreeBSD.org> 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 * $FreeBSD$ 28 */ 29 30 #include <sys/types.h> 31 #include <sys/ioctl.h> 32 #include <stdbool.h> 33 #include <sys/capsicum.h> 34 #include <dev/pwm/pwmc.h> 35 36 #include <err.h> 37 #include <errno.h> 38 #include <fcntl.h> 39 #include <limits.h> 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #include <unistd.h> 44 #include <capsicum_helpers.h> 45 46 #define PWM_ENABLE 0x0001 47 #define PWM_DISABLE 0x0002 48 #define PWM_SHOW_CONFIG 0x0004 49 #define PWM_PERIOD 0x0008 50 #define PWM_DUTY 0x0010 51 52 static char device_name[PATH_MAX] = "/dev/pwm/pwmc0.0"; 53 54 static void 55 set_device_name(const char *name) 56 { 57 58 if (name[0] == '/') 59 strlcpy(device_name, name, sizeof(device_name)); 60 else 61 snprintf(device_name, sizeof(device_name), "/dev/pwm/%s", name); 62 } 63 64 static void 65 usage(void) 66 { 67 fprintf(stderr, "Usage:\n"); 68 fprintf(stderr, "\tpwm [-f dev] -C\n"); 69 fprintf(stderr, "\tpwm [-f dev] [-D | -E] [-p period] [-d duty[%%]]\n"); 70 exit(1); 71 } 72 73 int 74 main(int argc, char *argv[]) 75 { 76 struct pwm_state state; 77 int fd; 78 int period, duty; 79 int action, ch; 80 cap_rights_t right_ioctl; 81 const unsigned long pwm_ioctls[] = {PWMGETSTATE, PWMSETSTATE}; 82 char *percent; 83 bool setname; 84 85 action = 0; 86 setname = false; 87 fd = -1; 88 period = duty = -1; 89 90 while ((ch = getopt(argc, argv, "f:EDCp:d:")) != -1) { 91 switch (ch) { 92 case 'E': 93 if (action & (PWM_DISABLE | PWM_SHOW_CONFIG)) 94 usage(); 95 action |= PWM_ENABLE; 96 break; 97 case 'D': 98 if (action & (PWM_ENABLE | PWM_SHOW_CONFIG)) 99 usage(); 100 action |= PWM_DISABLE; 101 break; 102 case 'C': 103 if (action) 104 usage(); 105 action = PWM_SHOW_CONFIG; 106 break; 107 case 'p': 108 if (action & PWM_SHOW_CONFIG) 109 usage(); 110 action |= PWM_PERIOD; 111 period = strtol(optarg, NULL, 10); 112 break; 113 case 'd': 114 if (action & PWM_SHOW_CONFIG) 115 usage(); 116 action |= PWM_DUTY; 117 duty = strtol(optarg, &percent, 10); 118 if (*percent == '%') { 119 if (duty < 0 || duty > 100) { 120 fprintf(stderr, 121 "Invalid duty percentage\n"); 122 usage(); 123 } 124 } else if (*percent != '\0') 125 usage(); 126 break; 127 case 'f': 128 setname = true; 129 set_device_name(optarg); 130 break; 131 case '?': 132 usage(); 133 break; 134 } 135 } 136 137 if (action == 0) 138 usage(); 139 140 if ((fd = open(device_name, O_RDWR)) == -1) { 141 fprintf(stderr, "pwm: cannot open %s: %s\n", 142 device_name, strerror(errno)); 143 if (setname) 144 exit(1); 145 else 146 usage(); 147 } 148 149 if (caph_limit_stdio() < 0) { 150 fprintf(stderr, "can't limit stdio rights"); 151 goto fail; 152 } 153 caph_cache_catpages(); 154 cap_rights_init(&right_ioctl, CAP_IOCTL); 155 if (caph_rights_limit(fd, &right_ioctl) < 0) { 156 fprintf(stderr, "cap_right_limit() failed\n"); 157 goto fail; 158 } 159 if (caph_ioctls_limit(fd, pwm_ioctls, nitems(pwm_ioctls)) < 0) { 160 fprintf(stderr, "caph_ioctls_limit() failed\n"); 161 goto fail; 162 } 163 if (caph_enter() < 0) { 164 fprintf(stderr, "failed to enter capability mode\n"); 165 goto fail; 166 } 167 168 /* Fill the common args */ 169 if (ioctl(fd, PWMGETSTATE, &state) == -1) { 170 fprintf(stderr, "Cannot get current state of the pwm controller\n"); 171 goto fail; 172 } 173 174 if (action == PWM_SHOW_CONFIG) { 175 printf("period: %u\nduty: %u\nenabled:%d\n", 176 state.period, 177 state.duty, 178 state.enable); 179 goto fail; 180 } else { 181 if (action & PWM_ENABLE) 182 state.enable = true; 183 if (action & PWM_DISABLE) 184 state.enable = false; 185 if (action & PWM_PERIOD) 186 state.period = period; 187 if (action & PWM_DUTY) { 188 if (*percent != '\0') 189 state.duty = state.period * duty / 100; 190 else 191 state.duty = duty; 192 } 193 194 if (ioctl(fd, PWMSETSTATE, &state) == -1) { 195 fprintf(stderr, 196 "Cannot configure the pwm controller\n"); 197 goto fail; 198 } 199 } 200 201 close(fd); 202 return (0); 203 204 fail: 205 close(fd); 206 return (1); 207 } 208