* the Free Software Foundation.
*/
+/* Made up value to limit allocation sizes */
+#include <string.h>
+#include <stdlib.h>
+
+#define IIO_MAX_NAME_LENGTH 30
+
#define IIO_EVENT_CODE_RING_50_FULL 200
#define IIO_EVENT_CODE_RING_75_FULL 201
#define IIO_EVENT_CODE_RING_100_FULL 202
+const char *iio_dir = "/sys/bus/iio/devices/";
+
struct iio_event_data {
int id;
__s64 timestamp;
};
-
-inline char *find_ring_subelement(const char *directory, const char *subelement)
-{
- DIR *dp;
- const struct dirent *ent;
- int pos;
- char temp[100];
- char *returnstring;
- dp = opendir(directory);
- if (dp == NULL) {
- printf("could not directory: %s\n", directory);
- return NULL;
- }
- while (ent = readdir(dp), ent != NULL) {
- if (strcmp(ent->d_name, ".") != 0 &&
- strcmp(ent->d_name, "..") != 0) {
- if (strncmp(ent->d_name, subelement, strlen(subelement)) == 0) {
- int length = sprintf(temp, "%s%s%s", directory, ent->d_name, "/");
- returnstring = malloc(length+1);
- strncpy(returnstring, temp, length+1);
- return returnstring;
-
- }
- }
- }
- return 0;
-}
-
-
-char *find_type_by_name(const char *name, const char *type)
+/**
+ * find_type_by_name() - function to match top level types by name
+ * @name: top level type instance name
+ * @type: the type of top level instance being sort
+ *
+ * Typical types this is used for are device and trigger.
+ **/
+inline int find_type_by_name(const char *name, const char *type)
{
- const char *iio_dir = "/sys/bus/iio/devices/";
const struct dirent *ent;
- int cnt, pos, pos2;
+ int number, numstrlen;
FILE *nameFile;
DIR *dp;
- char thisname[100];
- char temp[100];
-
- char *returnstring = NULL;
+ char thisname[IIO_MAX_NAME_LENGTH];
+ char *filename;
struct stat Stat;
- pos = sprintf(temp, "%s", iio_dir);
+
dp = opendir(iio_dir);
if (dp == NULL) {
printf("No industrialio devices available");
- return NULL;
+ return -ENODEV;
}
+
while (ent = readdir(dp), ent != NULL) {
- cnt++;
- /*reject . and .. */
if (strcmp(ent->d_name, ".") != 0 &&
- strcmp(ent->d_name, "..") != 0) {
- /*make sure it isn't a trigger!*/
- if (strncmp(ent->d_name, type, strlen(type)) == 0) {
- /* build full path to new file */
- pos2 = pos + sprintf(temp + pos, "%s/", ent->d_name);
- sprintf(temp + pos2, "name");
- printf("search location %s\n", temp);
- nameFile = fopen(temp, "r");
- if (!nameFile) {
- sprintf(temp + pos2, "modalias", ent->d_name);
- nameFile = fopen(temp, "r");
- if (!nameFile) {
- printf("Failed to find a name for device\n");
- return NULL;
- }
- }
+ strcmp(ent->d_name, "..") != 0 &&
+ strlen(ent->d_name) > strlen(type) &&
+ strncmp(ent->d_name, type, strlen(type)) == 0) {
+ numstrlen = sscanf(ent->d_name + strlen(type),
+ "%d",
+ &number);
+ /* verify the next character is not a colon */
+ if (strncmp(ent->d_name + strlen(type) + numstrlen,
+ ":",
+ 1) != 0) {
+ filename = malloc(strlen(iio_dir)
+ + strlen(type)
+ + 1
+ + numstrlen
+ + 1);
+ if (filename == NULL)
+ return -ENOMEM;
+ sprintf(filename, "%s%s%d/name",
+ iio_dir,
+ type,
+ number);
+ nameFile = fopen(filename, "r");
+ if (!nameFile)
+ continue;
+ free(filename);
fscanf(nameFile, "%s", thisname);
- if (strcmp(name, thisname) == 0) {
- returnstring = malloc(strlen(temp) + 1);
- sprintf(temp + pos2, "");
- strcpy(returnstring, temp);
- return returnstring;
- }
+ if (strcmp(name, thisname) == 0)
+ return number;
fclose(nameFile);
-
}
}
}
+ return -ENODEV;
}
-int write_sysfs_int(char *filename, char *basedir, int val)
+inline int _write_sysfs_int(char *filename, char *basedir, int val, int verify)
{
int ret;
- FILE *sysfsfp;
- char temp[100];
- sprintf(temp, "%s%s", basedir, filename);
+ FILE *sysfsfp;
+ int test;
+ char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
+ if (temp == NULL)
+ return -ENOMEM;
+ sprintf(temp, "%s/%s", basedir, filename);
sysfsfp = fopen(temp, "w");
- if (sysfsfp == NULL)
- return -1;
+ if (sysfsfp == NULL) {
+ printf("failed to open %s\n", temp);
+ ret = -errno;
+ goto error_free;
+ }
fprintf(sysfsfp, "%d", val);
fclose(sysfsfp);
- return 0;
+ if (verify) {
+ sysfsfp = fopen(temp, "r");
+ if (sysfsfp == NULL) {
+ printf("failed to open %s\n", temp);
+ ret = -errno;
+ goto error_free;
+ }
+ fscanf(sysfsfp, "%d", &test);
+ if (test != val) {
+ printf("Possible failure in int write %d to %s%s\n",
+ val,
+ basedir,
+ filename);
+ ret = -1;
+ }
+ }
+error_free:
+ free(temp);
+ return ret;
+}
+
+int write_sysfs_int(char *filename, char *basedir, int val)
+{
+ return _write_sysfs_int(filename, basedir, val, 0);
}
int write_sysfs_int_and_verify(char *filename, char *basedir, int val)
+{
+ return _write_sysfs_int(filename, basedir, val, 1);
+}
+
+int _write_sysfs_string(char *filename, char *basedir, char *val, int verify)
{
int ret;
FILE *sysfsfp;
- char temp[100];
- int test;
-
- sprintf(temp, "%s%s", basedir, filename);
+ char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
+ if (temp == NULL) {
+ printf("Memory allocation failed\n");
+ return -ENOMEM;
+ }
+ sprintf(temp, "%s/%s", basedir, filename);
sysfsfp = fopen(temp, "w");
- if (sysfsfp == NULL)
- return -1;
- fprintf(sysfsfp, "%d", val);
+ if (sysfsfp == NULL) {
+ printf("Could not open %s\n", temp);
+ ret = -errno;
+ goto error_free;
+ }
+ fprintf(sysfsfp, "%s", val);
fclose(sysfsfp);
-
- sysfsfp = fopen(temp, "r");
- if (sysfsfp == NULL)
- return -1;
- fscanf(sysfsfp, "%d", &test);
- if (test != val) {
- printf("Possible failure in int write %d to %s%s\n",
- val,
- basedir,
- filename);
- return -1;
+ if (verify) {
+ sysfsfp = fopen(temp, "r");
+ if (sysfsfp == NULL) {
+ ret = -errno;
+ goto error_free;
+ }
+ fscanf(sysfsfp, "%s", temp);
+ if (strcmp(temp, val) != 0) {
+ printf("Possible failure in string write of %s "
+ "Should be %s "
+ "writen to %s\%s\n",
+ temp,
+ val,
+ basedir,
+ filename);
+ ret = -1;
+ }
}
+error_free:
+ free(temp);
- return 0;
+ return ret;
}
-
/**
* write_sysfs_string_and_verify() - string write, readback and verify
* @filename: name of file to write to
**/
int write_sysfs_string_and_verify(char *filename, char *basedir, char *val)
{
- int ret;
- FILE *sysfsfp;
- char temp[100];
- sprintf(temp, "%s%s", basedir, filename);
- sysfsfp = fopen(temp, "w");
- if (sysfsfp == NULL)
- return -1;
- fprintf(sysfsfp, "%s", val);
- fclose(sysfsfp);
+ return _write_sysfs_string(filename, basedir, val, 1);
+}
- sysfsfp = fopen(temp, "r");
- if (sysfsfp == NULL)
- return -1;
- fscanf(sysfsfp, "%s", temp);
- if (strcmp(temp, val) != 0) {
- printf("Possible failure in string write %s to %s%s \n",
- val,
- basedir,
- filename);
- return -1;
- }
- return 0;
+int write_sysfs_string(char *filename, char *basedir, char *val)
+{
+ return _write_sysfs_string(filename, basedir, val, 0);
}
int read_sysfs_posint(char *filename, char *basedir)
{
int ret;
FILE *sysfsfp;
- char temp[100];
- sprintf(temp, "%s%s", basedir, filename);
+ char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
+ if (temp == NULL) {
+ printf("Memory allocation failed");
+ return -ENOMEM;
+ }
+ sprintf(temp, "%s/%s", basedir, filename);
sysfsfp = fopen(temp, "r");
- if (sysfsfp == NULL)
- return -1;
+ if (sysfsfp == NULL) {
+ ret = -errno;
+ goto error_free;
+ }
fscanf(sysfsfp, "%d\n", &ret);
fclose(sysfsfp);
+error_free:
+ free(temp);
+ return ret;
+}
+
+int read_sysfs_float(char *filename, char *basedir, float *val)
+{
+ float ret = 0;
+ FILE *sysfsfp;
+ char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
+ if (temp == NULL) {
+ printf("Memory allocation failed");
+ return -ENOMEM;
+ }
+ sprintf(temp, "%s/%s", basedir, filename);
+ sysfsfp = fopen(temp, "r");
+ if (sysfsfp == NULL) {
+ ret = -errno;
+ goto error_free;
+ }
+ fscanf(sysfsfp, "%f\n", val);
+ fclose(sysfsfp);
+error_free:
+ free(temp);
return ret;
}
-/* Industrialio test ring buffer with a lis3l02dq acceleromter
+/* Industrialio ring buffer with a lis3l02dq accelerometer
*
* Copyright (c) 2008 Jonathan Cameron
*
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
- * Assumes suitable udev rules are used to create the dev nodes as named here.
+ * This program is primarily intended as an example application.
*/
#include <dirent.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
-#include <stdint.h>
-#include <sys/types.h>
#include <sys/stat.h>
#include <sys/dir.h>
-
#include <linux/types.h>
#include "iio_utils.h"
-static const char *ring_access = "/dev/iio/lis3l02dq_ring_access";
-static const char *ring_event = "/dev/iio/lis3l02dq_ring_event";
-static const char *device_name = "lis3l02dq";
-static const char *trigger_name = "lis3l02dq-dev0";
-static int NumVals = 3;
-static int scan_ts = 1;
-static int RingLength = 128;
+const char *device_name = "lis3l02dq";
+const char *trigger_name_base = "lis3l02dq-dev";
+const int num_vals = 3;
+const int scan_ts = 1;
+const int buf_len = 128;
+const int num_loops = 10;
/*
* Could get this from ring bps, but only after starting the ring
- * which is a bit late for it to be useful
+ * which is a bit late for it to be useful.
+ *
+ * Todo: replace with much more generic version based on scan_elements
+ * directory.
*/
-int size_from_scanmode(int numVals, int timestamp)
+int size_from_scanmode(int num_vals, int timestamp)
{
- if (numVals && timestamp)
+ if (num_vals && timestamp)
return 16;
else if (timestamp)
return 8;
else
- return numVals*2;
+ return num_vals*2;
}
int main(int argc, char **argv)
{
+ int ret;
int i, j, k, toread;
FILE *fp_ev;
int fp;
+
+ char *trigger_name, *dev_dir_name, *buf_dir_name;
char *data;
size_t read_size;
struct iio_event_data dat;
+ int dev_num, trig_num;
+
+ char *buffer_access, *buffer_event;
+ const char *iio_dir = "/sys/bus/iio/devices/";
+ int scan_size;
+ float gain = 1;
- char *BaseDirectoryName,
- *TriggerDirectoryName,
- *RingBufferDirectoryName;
- BaseDirectoryName = find_type_by_name(device_name, "device");
- if (BaseDirectoryName == NULL) {
- printf("Failed to find the %s \n", device_name);
- return -1;
+ /* Find out which iio device is the accelerometer. */
+ 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;
}
- TriggerDirectoryName = find_type_by_name(trigger_name, "trigger");
- if (TriggerDirectoryName == NULL) {
+ printf("iio device number being used is %d\n", dev_num);
+ asprintf(&dev_dir_name, "%sdevice%d", iio_dir, dev_num);
+
+ /*
+ * Build the trigger name.
+ * In this case we want the lis3l02dq's data ready trigger
+ * for this lis3l02dq. The naming is lis3l02dq_dev[n], where
+ * n matches the device number found above.
+ */
+ ret = asprintf(&trigger_name, "%s%d", trigger_name_base, dev_num);
+ if (ret < 0) {
+ ret = -ENOMEM;
+ goto error_free_dev_dir_name;
+ }
+
+ /*
+ * Find the trigger by name.
+ * This is techically unecessary here as we only need to
+ * refer to the trigger by name and that name is already
+ * known.
+ */
+ trig_num = find_type_by_name(trigger_name, "trigger");
+ if (trig_num < 0) {
printf("Failed to find the %s\n", trigger_name);
- return -1;
+ ret = -ENODEV;
+ goto error_free_triggername;
}
- RingBufferDirectoryName = find_ring_subelement(BaseDirectoryName,
- "ring_buffer");
- if (RingBufferDirectoryName == NULL) {
- printf("Failed to find ring buffer\n");
- return -1;
+ printf("iio trigger number being used is %d\n", trig_num);
+
+ /*
+ * Read in the scale value - in a more generic case, first
+ * check for accel_scale, then the indivual channel scales
+ */
+ ret = read_sysfs_float("accel_scale", dev_dir_name, &gain);
+ if (ret)
+ 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;
}
-
- if (write_sysfs_string_and_verify("trigger/current_trigger",
- BaseDirectoryName,
- (char *)trigger_name) < 0) {
- printf("Failed to write current_trigger file \n");
- return -1;
+ /* 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 */
- if (write_sysfs_int("length", RingBufferDirectoryName,
- RingLength) < 0) {
- printf("Failed to open the ring buffer length file \n");
- return -1;
- }
+ ret = write_sysfs_int("length", buf_dir_name, buf_len);
+ if (ret < 0)
+ goto error_free_buf_dir_name;
- /* Enable the ring buffer */
- if (write_sysfs_int("ring_enable", RingBufferDirectoryName, 1) < 0) {
- printf("Failed to open the ring buffer control file \n");
- return -1;
- };
+ /* Enable the buffer */
+ ret = write_sysfs_int("ring_enable", buf_dir_name, 1);
+ if (ret < 0)
+ goto error_free_buf_dir_name;
- data = malloc(size_from_scanmode(NumVals, scan_ts)*RingLength);
+ data = malloc(size_from_scanmode(num_vals, scan_ts)*buf_len);
if (!data) {
- printf("Could not allocate space for usespace data store\n");
- return -1;
+ 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_data;
+ }
/* Attempt to open non blocking the access dev */
- fp = open(ring_access, O_RDONLY | O_NONBLOCK);
+ 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", ring_access);
- return -1;
+ 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(ring_event, "rb");
+ fp_ev = fopen(buffer_event, "rb");
if (fp_ev == NULL) {
- printf("Failed to open %s\n", ring_event);
- return -1;
+ printf("Failed to open %s\n", buffer_event);
+ ret = -errno;
+ goto error_close_buffer_access;
}
/* Wait for events 10 times */
- for (j = 0; j < 10; j++) {
+ 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 = RingLength;
+ toread = buf_len;
break;
case IIO_EVENT_CODE_RING_75_FULL:
- toread = RingLength*3/4;
+ toread = buf_len*3/4;
break;
case IIO_EVENT_CODE_RING_50_FULL:
- toread = RingLength/2;
+ toread = buf_len/2;
break;
default:
printf("Unexpecteded event code\n");
}
read_size = read(fp,
data,
- toread*size_from_scanmode(NumVals, scan_ts));
+ toread*size_from_scanmode(num_vals, scan_ts));
if (read_size == -EAGAIN) {
- printf("nothing available \n");
+ printf("nothing available\n");
continue;
}
-
- for (i = 0;
- i < read_size/size_from_scanmode(NumVals, scan_ts);
- i++) {
- for (k = 0; k < NumVals; k++) {
- __s16 val = *(__s16 *)(&data[i*size_from_scanmode(NumVals, scan_ts)
+ scan_size = size_from_scanmode(num_vals, scan_ts);
+ for (i = 0; i < read_size/scan_size; i++) {
+ for (k = 0; k < num_vals; k++) {
+ __s16 val = *(__s16 *)(&data[i*scan_size
+ (k)*2]);
- printf("%05d ", val);
+ printf("%05f ", (float)val*gain);
}
printf(" %lld\n",
- *(__s64 *)(&data[(i+1)*size_from_scanmode(NumVals, scan_ts)
+ *(__s64 *)(&data[(i + 1)
+ *size_from_scanmode(num_vals,
+ scan_ts)
- sizeof(__s64)]));
}
}
/* Stop the ring buffer */
- if (write_sysfs_int("ring_enable", RingBufferDirectoryName, 0) < 0) {
- printf("Failed to open the ring buffer control file \n");
- return -1;
- };
-
- /* Disconnect from the trigger - writing something that doesn't exist.*/
- write_sysfs_string_and_verify("trigger/current_trigger",
- BaseDirectoryName, "NULL");
- free(BaseDirectoryName);
- free(TriggerDirectoryName);
- free(RingBufferDirectoryName);
+ ret = write_sysfs_int("ring_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);
-
- return 0;
+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:
+ free(trigger_name);
+error_free_dev_dir_name:
+ free(dev_dir_name);
+error_ret:
+ return ret;
}