diff options
Diffstat (limited to 'drivers/staging/iio/Documentation/lis3l02dqbuffersimple.c')
| -rw-r--r-- | drivers/staging/iio/Documentation/lis3l02dqbuffersimple.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/staging/iio/Documentation/lis3l02dqbuffersimple.c b/drivers/staging/iio/Documentation/lis3l02dqbuffersimple.c new file mode 100644 index 000000000000..2b5cfc58d78d --- /dev/null +++ b/drivers/staging/iio/Documentation/lis3l02dqbuffersimple.c @@ -0,0 +1,171 @@ +/* Industrialio test ring buffer with a lis3l02dq acceleromter + * + * 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. + * + * Assumes suitable udev rules are used to create the dev nodes as named here. + */ + +#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 <dirent.h> +#include "iio_util.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; + +/* + * Could get this from ring bps, but only after starting the ring + * which is a bit late for it to be useful + */ +int size_from_scanmode(int numVals, int timestamp) +{ + if (numVals && timestamp) + return 16; + else if (timestamp) + return 8; + else + return numVals*2; +} + +int main(int argc, char **argv) +{ + int i, j, k, toread; + FILE *fp_ev; + int fp; + char *data; + size_t read_size; + struct iio_event_data dat; + + 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; + } + TriggerDirectoryName = find_type_by_name(trigger_name, "trigger"); + if (TriggerDirectoryName == NULL) { + printf("Failed to find the %s\n", trigger_name); + return -1; + } + RingBufferDirectoryName = find_ring_subelement(BaseDirectoryName, + "ring_buffer"); + if (RingBufferDirectoryName == NULL) { + printf("Failed to find ring buffer\n"); + return -1; + } + + if (write_sysfs_string_and_verify("trigger/current_trigger", + BaseDirectoryName, + (char *)trigger_name) < 0) { + printf("Failed to write current_trigger file \n"); + return -1; + } + + /* Setup ring buffer parameters */ + if (write_sysfs_int("length", RingBufferDirectoryName, + RingLength) < 0) { + printf("Failed to open the ring buffer length file \n"); + return -1; + } + + /* 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; + }; + + data = malloc(size_from_scanmode(NumVals, scan_ts)*RingLength); + if (!data) { + printf("Could not allocate space for usespace data store\n"); + return -1; + } + + /* Attempt to open non blocking the access dev */ + fp = open(ring_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; + } + /* Attempt to open the event access dev (blocking this time) */ + fp_ev = fopen(ring_event, "rb"); + if (fp_ev == NULL) { + printf("Failed to open %s\n", ring_event); + return -1; + } + + /* Wait for events 10 times */ + for (j = 0; j < 10; 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; + break; + case IIO_EVENT_CODE_RING_75_FULL: + toread = RingLength*3/4; + break; + case IIO_EVENT_CODE_RING_50_FULL: + toread = RingLength/2; + break; + default: + printf("Unexpecteded event code\n"); + continue; + } + read_size = read(fp, + data, + toread*size_from_scanmode(NumVals, scan_ts)); + if (read_size == -EAGAIN) { + 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) + + (k)*2]); + printf("%05d ", val); + } + printf(" %lld\n", + *(__s64 *)(&data[(i+1)*size_from_scanmode(NumVals, 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); + free(data); + + return 0; +} |