Jonathan Cameron | e58537c | 2010-10-08 12:14:14 +0100 | [diff] [blame^] | 1 | /* Industrialio buffer test code. |
| 2 | * |
| 3 | * Copyright (c) 2008 Jonathan Cameron |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 as published by |
| 7 | * the Free Software Foundation. |
| 8 | * |
| 9 | * This program is primarily intended as an example application. |
| 10 | * Reads the current buffer setup from sysfs and starts a short capture |
| 11 | * from the specified device, pretty printing the result after appropriate |
| 12 | * conversion. |
| 13 | * |
| 14 | * Command line parameters |
| 15 | * generic_buffer -n <device_name> -t <trigger_name> |
| 16 | * If trigger name is not specified the program assumes you want a dataready |
| 17 | * trigger associated with the device and goes looking for it. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #include <unistd.h> |
| 22 | #include <dirent.h> |
| 23 | #include <fcntl.h> |
| 24 | #include <stdio.h> |
| 25 | #include <errno.h> |
| 26 | #include <sys/stat.h> |
| 27 | #include <sys/dir.h> |
| 28 | #include <linux/types.h> |
| 29 | #include "iio_utils.h" |
| 30 | |
| 31 | const int buf_len = 128; |
| 32 | const int num_loops = 2; |
| 33 | |
| 34 | /** |
| 35 | * size_from_channelarray() - calculate the storage size of a scan |
| 36 | * @channels: the channel info array |
| 37 | * @num_channels: size of the channel info array |
| 38 | * |
| 39 | * Has the side effect of filling the channels[i].location values used |
| 40 | * in processing the buffer output. |
| 41 | **/ |
| 42 | int size_from_channelarray(struct iio_channel_info *channels, int num_channels) |
| 43 | { |
| 44 | int bytes = 0; |
| 45 | int i = 0; |
| 46 | while (i < num_channels) { |
| 47 | if (bytes % channels[i].bytes == 0) |
| 48 | channels[i].location = bytes; |
| 49 | else |
| 50 | channels[i].location = bytes - bytes%channels[i].bytes |
| 51 | + channels[i].bytes; |
| 52 | bytes = channels[i].location + channels[i].bytes; |
| 53 | i++; |
| 54 | } |
| 55 | return bytes; |
| 56 | } |
| 57 | |
| 58 | /** |
| 59 | * process_scan() - print out the values in SI units |
| 60 | * @data: pointer to the start of the scan |
| 61 | * @infoarray: information about the channels. Note |
| 62 | * size_from_channelarray must have been called first to fill the |
| 63 | * location offsets. |
| 64 | * @num_channels: the number of active channels |
| 65 | **/ |
| 66 | void process_scan(char *data, |
| 67 | struct iio_channel_info *infoarray, |
| 68 | int num_channels) |
| 69 | { |
| 70 | int k; |
| 71 | for (k = 0; k < num_channels; k++) |
| 72 | switch (infoarray[k].bytes) { |
| 73 | /* only a few cases implemented so far */ |
| 74 | case 2: |
| 75 | if (infoarray[k].is_signed) { |
| 76 | int16_t val = *(int16_t *) |
| 77 | (data |
| 78 | + infoarray[k].location); |
| 79 | if ((val >> infoarray[k].bits_used) & 1) |
| 80 | val = (val & infoarray[k].mask) | |
| 81 | ~infoarray[k].mask; |
| 82 | printf("%05f ", ((float)val + |
| 83 | infoarray[k].offset)* |
| 84 | infoarray[k].scale); |
| 85 | } else { |
| 86 | uint16_t val = *(uint16_t *) |
| 87 | (data + |
| 88 | infoarray[k].location); |
| 89 | val = (val & infoarray[k].mask); |
| 90 | printf("%05f ", ((float)val + |
| 91 | infoarray[k].offset)* |
| 92 | infoarray[k].scale); |
| 93 | } |
| 94 | break; |
| 95 | case 8: |
| 96 | if (infoarray[k].is_signed) { |
| 97 | int64_t val = *(int64_t *) |
| 98 | (data + |
| 99 | infoarray[k].location); |
| 100 | if ((val >> infoarray[k].bits_used) & 1) |
| 101 | val = (val & infoarray[k].mask) | |
| 102 | ~infoarray[k].mask; |
| 103 | /* special case for timestamp */ |
| 104 | if (infoarray[k].scale == 1.0f && |
| 105 | infoarray[k].offset == 0.0f) |
| 106 | printf(" %lld", val); |
| 107 | else |
| 108 | printf("%05f ", ((float)val + |
| 109 | infoarray[k].offset)* |
| 110 | infoarray[k].scale); |
| 111 | } |
| 112 | break; |
| 113 | default: |
| 114 | break; |
| 115 | } |
| 116 | printf("\n"); |
| 117 | } |
| 118 | |
| 119 | int main(int argc, char **argv) |
| 120 | { |
| 121 | int ret, c, i, j, toread; |
| 122 | |
| 123 | FILE *fp_ev; |
| 124 | int fp; |
| 125 | |
| 126 | int num_channels; |
| 127 | char *trigger_name = NULL, *device_name = NULL; |
| 128 | char *dev_dir_name, *buf_dir_name; |
| 129 | |
| 130 | int datardytrigger = 1; |
| 131 | char *data; |
| 132 | size_t read_size; |
| 133 | struct iio_event_data dat; |
| 134 | int dev_num, trig_num; |
| 135 | char *buffer_access, *buffer_event; |
| 136 | int scan_size; |
| 137 | |
| 138 | struct iio_channel_info *infoarray; |
| 139 | |
| 140 | while ((c = getopt(argc, argv, "t:n:")) != -1) { |
| 141 | switch (c) { |
| 142 | case 'n': |
| 143 | device_name = optarg; |
| 144 | break; |
| 145 | case 't': |
| 146 | trigger_name = optarg; |
| 147 | datardytrigger = 0; |
| 148 | break; |
| 149 | case '?': |
| 150 | return -1; |
| 151 | } |
| 152 | } |
| 153 | |
| 154 | /* Find the device requested */ |
| 155 | dev_num = find_type_by_name(device_name, "device"); |
| 156 | if (dev_num < 0) { |
| 157 | printf("Failed to find the %s\n", device_name); |
| 158 | ret = -ENODEV; |
| 159 | goto error_ret; |
| 160 | } |
| 161 | printf("iio device number being used is %d\n", dev_num); |
| 162 | |
| 163 | asprintf(&dev_dir_name, "%sdevice%d", iio_dir, dev_num); |
| 164 | if (trigger_name == NULL) { |
| 165 | /* |
| 166 | * Build the trigger name. If it is device associated it's |
| 167 | * name is <device_name>_dev[n] where n matches the device |
| 168 | * number found above |
| 169 | */ |
| 170 | ret = asprintf(&trigger_name, |
| 171 | "%s-dev%d", device_name, dev_num); |
| 172 | if (ret < 0) { |
| 173 | ret = -ENOMEM; |
| 174 | goto error_ret; |
| 175 | } |
| 176 | } |
| 177 | |
| 178 | /* Verify the trigger exists */ |
| 179 | trig_num = find_type_by_name(trigger_name, "trigger"); |
| 180 | if (trig_num < 0) { |
| 181 | printf("Failed to find the trigger %s\n", trigger_name); |
| 182 | ret = -ENODEV; |
| 183 | goto error_free_triggername; |
| 184 | } |
| 185 | printf("iio trigger number being used is %d\n", trig_num); |
| 186 | |
| 187 | /* |
| 188 | * Parse the files in scan_elements to identify what channels are |
| 189 | * present |
| 190 | */ |
| 191 | ret = build_channel_array(dev_dir_name, &infoarray, &num_channels); |
| 192 | if (ret) { |
| 193 | printf("Problem reading scan element information \n"); |
| 194 | goto error_free_triggername; |
| 195 | } |
| 196 | |
| 197 | /* |
| 198 | * Construct the directory name for the associated buffer. |
| 199 | * As we know that the lis3l02dq has only one buffer this may |
| 200 | * be built rather than found. |
| 201 | */ |
| 202 | ret = asprintf(&buf_dir_name, "%sdevice%d:buffer0", iio_dir, dev_num); |
| 203 | if (ret < 0) { |
| 204 | ret = -ENOMEM; |
| 205 | goto error_free_triggername; |
| 206 | } |
| 207 | printf("%s %s\n", dev_dir_name, trigger_name); |
| 208 | /* Set the device trigger to be the data rdy trigger found above */ |
| 209 | ret = write_sysfs_string_and_verify("trigger/current_trigger", |
| 210 | dev_dir_name, |
| 211 | trigger_name); |
| 212 | if (ret < 0) { |
| 213 | printf("Failed to write current_trigger file\n"); |
| 214 | goto error_free_buf_dir_name; |
| 215 | } |
| 216 | |
| 217 | /* Setup ring buffer parameters */ |
| 218 | ret = write_sysfs_int("length", buf_dir_name, buf_len); |
| 219 | if (ret < 0) |
| 220 | goto error_free_buf_dir_name; |
| 221 | |
| 222 | /* Enable the buffer */ |
| 223 | ret = write_sysfs_int("enable", buf_dir_name, 1); |
| 224 | if (ret < 0) |
| 225 | goto error_free_buf_dir_name; |
| 226 | scan_size = size_from_channelarray(infoarray, num_channels); |
| 227 | data = malloc(scan_size*buf_len); |
| 228 | if (!data) { |
| 229 | ret = -ENOMEM; |
| 230 | goto error_free_buf_dir_name; |
| 231 | } |
| 232 | |
| 233 | ret = asprintf(&buffer_access, |
| 234 | "/dev/device%d:buffer0:access0", |
| 235 | dev_num); |
| 236 | if (ret < 0) { |
| 237 | ret = -ENOMEM; |
| 238 | goto error_free_data; |
| 239 | } |
| 240 | |
| 241 | ret = asprintf(&buffer_event, "/dev/device%d:buffer0:event0", dev_num); |
| 242 | if (ret < 0) { |
| 243 | ret = -ENOMEM; |
| 244 | goto error_free_buffer_access; |
| 245 | } |
| 246 | /* Attempt to open non blocking the access dev */ |
| 247 | fp = open(buffer_access, O_RDONLY | O_NONBLOCK); |
| 248 | if (fp == -1) { /*If it isn't there make the node */ |
| 249 | printf("Failed to open %s\n", buffer_access); |
| 250 | ret = -errno; |
| 251 | goto error_free_buffer_event; |
| 252 | } |
| 253 | /* Attempt to open the event access dev (blocking this time) */ |
| 254 | fp_ev = fopen(buffer_event, "rb"); |
| 255 | if (fp_ev == NULL) { |
| 256 | printf("Failed to open %s\n", buffer_event); |
| 257 | ret = -errno; |
| 258 | goto error_close_buffer_access; |
| 259 | } |
| 260 | |
| 261 | /* Wait for events 10 times */ |
| 262 | for (j = 0; j < num_loops; j++) { |
| 263 | read_size = fread(&dat, 1, sizeof(struct iio_event_data), |
| 264 | fp_ev); |
| 265 | switch (dat.id) { |
| 266 | case IIO_EVENT_CODE_RING_100_FULL: |
| 267 | toread = buf_len; |
| 268 | break; |
| 269 | case IIO_EVENT_CODE_RING_75_FULL: |
| 270 | toread = buf_len*3/4; |
| 271 | break; |
| 272 | case IIO_EVENT_CODE_RING_50_FULL: |
| 273 | toread = buf_len/2; |
| 274 | break; |
| 275 | default: |
| 276 | printf("Unexpecteded event code\n"); |
| 277 | continue; |
| 278 | } |
| 279 | read_size = read(fp, |
| 280 | data, |
| 281 | toread*scan_size); |
| 282 | if (read_size == -EAGAIN) { |
| 283 | printf("nothing available\n"); |
| 284 | continue; |
| 285 | } |
| 286 | for (i = 0; i < read_size/scan_size; i++) |
| 287 | process_scan(data + scan_size*i, |
| 288 | infoarray, |
| 289 | num_channels); |
| 290 | } |
| 291 | |
| 292 | /* Stop the ring buffer */ |
| 293 | ret = write_sysfs_int("enable", buf_dir_name, 0); |
| 294 | if (ret < 0) |
| 295 | goto error_close_buffer_event; |
| 296 | |
| 297 | /* Disconnect from the trigger - just write a dummy name.*/ |
| 298 | write_sysfs_string("trigger/current_trigger", |
| 299 | dev_dir_name, "NULL"); |
| 300 | |
| 301 | error_close_buffer_event: |
| 302 | fclose(fp_ev); |
| 303 | error_close_buffer_access: |
| 304 | close(fp); |
| 305 | error_free_data: |
| 306 | free(data); |
| 307 | error_free_buffer_access: |
| 308 | free(buffer_access); |
| 309 | error_free_buffer_event: |
| 310 | free(buffer_event); |
| 311 | error_free_buf_dir_name: |
| 312 | free(buf_dir_name); |
| 313 | error_free_triggername: |
| 314 | if (datardytrigger) |
| 315 | free(trigger_name); |
| 316 | error_ret: |
| 317 | return ret; |
| 318 | } |