--- /dev/null
+/* Industrialio buffer test code.
+ *
+ * Copyright (c) 2008 Jonathan Cameron
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is primarily intended as an example application.
+ * Reads the current buffer setup from sysfs and starts a short capture
+ * from the specified device, pretty printing the result after appropriate
+ * conversion.
+ *
+ * Command line parameters
+ * generic_buffer -n <device_name> -t <trigger_name>
+ * If trigger name is not specified the program assumes you want a dataready
+ * trigger associated with the device and goes looking for it.
+ *
+ */
+
+#include <unistd.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/dir.h>
+#include <linux/types.h>
+#include "iio_utils.h"
+
+const int buf_len = 128;
+const int num_loops = 2;
+
+/**
+ * size_from_channelarray() - calculate the storage size of a scan
+ * @channels: the channel info array
+ * @num_channels: size of the channel info array
+ *
+ * Has the side effect of filling the channels[i].location values used
+ * in processing the buffer output.
+ **/
+int size_from_channelarray(struct iio_channel_info *channels, int num_channels)
+{
+ int bytes = 0;
+ int i = 0;
+ while (i < num_channels) {
+ if (bytes % channels[i].bytes == 0)
+ channels[i].location = bytes;
+ else
+ channels[i].location = bytes - bytes%channels[i].bytes
+ + channels[i].bytes;
+ bytes = channels[i].location + channels[i].bytes;
+ i++;
+ }
+ return bytes;
+}
+
+/**
+ * process_scan() - print out the values in SI units
+ * @data: pointer to the start of the scan
+ * @infoarray: information about the channels. Note
+ * size_from_channelarray must have been called first to fill the
+ * location offsets.
+ * @num_channels: the number of active channels
+ **/
+void process_scan(char *data,
+ struct iio_channel_info *infoarray,
+ int num_channels)
+{
+ int k;
+ for (k = 0; k < num_channels; k++)
+ switch (infoarray[k].bytes) {
+ /* only a few cases implemented so far */
+ case 2:
+ if (infoarray[k].is_signed) {
+ int16_t val = *(int16_t *)
+ (data
+ + infoarray[k].location);
+ if ((val >> infoarray[k].bits_used) & 1)
+ val = (val & infoarray[k].mask) |
+ ~infoarray[k].mask;
+ printf("%05f ", ((float)val +
+ infoarray[k].offset)*
+ infoarray[k].scale);
+ } else {
+ uint16_t val = *(uint16_t *)
+ (data +
+ infoarray[k].location);
+ val = (val & infoarray[k].mask);
+ printf("%05f ", ((float)val +
+ infoarray[k].offset)*
+ infoarray[k].scale);
+ }
+ break;
+ case 8:
+ if (infoarray[k].is_signed) {
+ int64_t val = *(int64_t *)
+ (data +
+ infoarray[k].location);
+ if ((val >> infoarray[k].bits_used) & 1)
+ val = (val & infoarray[k].mask) |
+ ~infoarray[k].mask;
+ /* special case for timestamp */
+ if (infoarray[k].scale == 1.0f &&
+ infoarray[k].offset == 0.0f)
+ printf(" %lld", val);
+ else
+ printf("%05f ", ((float)val +
+ infoarray[k].offset)*
+ infoarray[k].scale);
+ }
+ break;
+ default:
+ break;
+ }
+ printf("\n");
+}
+
+int main(int argc, char **argv)
+{
+ int ret, c, i, j, toread;
+
+ FILE *fp_ev;
+ int fp;
+
+ int num_channels;
+ char *trigger_name = NULL, *device_name = NULL;
+ char *dev_dir_name, *buf_dir_name;
+
+ int datardytrigger = 1;
+ char *data;
+ size_t read_size;
+ struct iio_event_data dat;
+ int dev_num, trig_num;
+ char *buffer_access, *buffer_event;
+ int scan_size;
+
+ struct iio_channel_info *infoarray;
+
+ while ((c = getopt(argc, argv, "t:n:")) != -1) {
+ switch (c) {
+ case 'n':
+ device_name = optarg;
+ break;
+ case 't':
+ trigger_name = optarg;
+ datardytrigger = 0;
+ break;
+ case '?':
+ return -1;
+ }
+ }
+
+ /* Find the device requested */
+ dev_num = find_type_by_name(device_name, "device");
+ if (dev_num < 0) {
+ printf("Failed to find the %s\n", device_name);
+ ret = -ENODEV;
+ goto error_ret;
+ }
+ printf("iio device number being used is %d\n", dev_num);
+
+ asprintf(&dev_dir_name, "%sdevice%d", iio_dir, dev_num);
+ if (trigger_name == NULL) {
+ /*
+ * Build the trigger name. If it is device associated it's
+ * name is <device_name>_dev[n] where n matches the device
+ * number found above
+ */
+ ret = asprintf(&trigger_name,
+ "%s-dev%d", device_name, dev_num);
+ if (ret < 0) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+ }
+
+ /* Verify the trigger exists */
+ trig_num = find_type_by_name(trigger_name, "trigger");
+ if (trig_num < 0) {
+ printf("Failed to find the trigger %s\n", trigger_name);
+ ret = -ENODEV;
+ goto error_free_triggername;
+ }
+ printf("iio trigger number being used is %d\n", trig_num);
+
+ /*
+ * Parse the files in scan_elements to identify what channels are
+ * present
+ */
+ ret = build_channel_array(dev_dir_name, &infoarray, &num_channels);
+ if (ret) {
+ printf("Problem reading scan element information \n");
+ goto error_free_triggername;
+ }
+
+ /*
+ * Construct the directory name for the associated buffer.
+ * As we know that the lis3l02dq has only one buffer this may
+ * be built rather than found.
+ */
+ ret = asprintf(&buf_dir_name, "%sdevice%d:buffer0", iio_dir, dev_num);
+ if (ret < 0) {
+ ret = -ENOMEM;
+ goto error_free_triggername;
+ }
+ printf("%s %s\n", dev_dir_name, trigger_name);
+ /* Set the device trigger to be the data rdy trigger found above */
+ ret = write_sysfs_string_and_verify("trigger/current_trigger",
+ dev_dir_name,
+ trigger_name);
+ if (ret < 0) {
+ printf("Failed to write current_trigger file\n");
+ goto error_free_buf_dir_name;
+ }
+
+ /* Setup ring buffer parameters */
+ ret = write_sysfs_int("length", buf_dir_name, buf_len);
+ if (ret < 0)
+ goto error_free_buf_dir_name;
+
+ /* Enable the buffer */
+ ret = write_sysfs_int("enable", buf_dir_name, 1);
+ if (ret < 0)
+ goto error_free_buf_dir_name;
+ scan_size = size_from_channelarray(infoarray, num_channels);
+ data = malloc(scan_size*buf_len);
+ if (!data) {
+ ret = -ENOMEM;
+ goto error_free_buf_dir_name;
+ }
+
+ ret = asprintf(&buffer_access,
+ "/dev/device%d:buffer0:access0",
+ dev_num);
+ if (ret < 0) {
+ ret = -ENOMEM;
+ goto error_free_data;
+ }
+
+ ret = asprintf(&buffer_event, "/dev/device%d:buffer0:event0", dev_num);
+ if (ret < 0) {
+ ret = -ENOMEM;
+ goto error_free_buffer_access;
+ }
+ /* Attempt to open non blocking the access dev */
+ fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
+ if (fp == -1) { /*If it isn't there make the node */
+ printf("Failed to open %s\n", buffer_access);
+ ret = -errno;
+ goto error_free_buffer_event;
+ }
+ /* Attempt to open the event access dev (blocking this time) */
+ fp_ev = fopen(buffer_event, "rb");
+ if (fp_ev == NULL) {
+ printf("Failed to open %s\n", buffer_event);
+ ret = -errno;
+ goto error_close_buffer_access;
+ }
+
+ /* Wait for events 10 times */
+ for (j = 0; j < num_loops; j++) {
+ read_size = fread(&dat, 1, sizeof(struct iio_event_data),
+ fp_ev);
+ switch (dat.id) {
+ case IIO_EVENT_CODE_RING_100_FULL:
+ toread = buf_len;
+ break;
+ case IIO_EVENT_CODE_RING_75_FULL:
+ toread = buf_len*3/4;
+ break;
+ case IIO_EVENT_CODE_RING_50_FULL:
+ toread = buf_len/2;
+ break;
+ default:
+ printf("Unexpecteded event code\n");
+ continue;
+ }
+ read_size = read(fp,
+ data,
+ toread*scan_size);
+ if (read_size == -EAGAIN) {
+ printf("nothing available\n");
+ continue;
+ }
+ for (i = 0; i < read_size/scan_size; i++)
+ process_scan(data + scan_size*i,
+ infoarray,
+ num_channels);
+ }
+
+ /* Stop the ring buffer */
+ ret = write_sysfs_int("enable", buf_dir_name, 0);
+ if (ret < 0)
+ goto error_close_buffer_event;
+
+ /* Disconnect from the trigger - just write a dummy name.*/
+ write_sysfs_string("trigger/current_trigger",
+ dev_dir_name, "NULL");
+
+error_close_buffer_event:
+ fclose(fp_ev);
+error_close_buffer_access:
+ close(fp);
+error_free_data:
+ free(data);
+error_free_buffer_access:
+ free(buffer_access);
+error_free_buffer_event:
+ free(buffer_event);
+error_free_buf_dir_name:
+ free(buf_dir_name);
+error_free_triggername:
+ if (datardytrigger)
+ free(trigger_name);
+error_ret:
+ return ret;
+}
projects / mv-sheeva.git / blobdiff