staging:iio:Documentation generic_buffer.c update to new abi for buffers + misc fixes

Trivial space before newline fix incorporated.

Additional fixes related to handling of sign extension and shifted
data.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>

squash into buffer handling update.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Jonathan Cameron 2011-05-18 14:41:19 +01:00 committed by Greg Kroah-Hartman
parent d96d1337e3
commit 52615d4783
2 changed files with 39 additions and 74 deletions

View File

@ -27,6 +27,7 @@
#include <sys/dir.h>
#include <linux/types.h>
#include <string.h>
#include <poll.h>
#include "iio_utils.h"
/**
@ -53,6 +54,24 @@ int size_from_channelarray(struct iio_channel_info *channels, int num_channels)
return bytes;
}
void print2byte(int input, struct iio_channel_info *info)
{
/* shift before conversion to avoid sign extension
of left aligned data */
input = input >> info->shift;
if (info->is_signed) {
int16_t val = input;
val &= (1 << info->bits_used) - 1;
val = (int16_t)(val << (16 - info->bits_used)) >>
(16 - info->bits_used);
printf("%05f ", val,
(float)(val + info->offset)*info->scale);
} else {
uint16_t val = input;
val &= (1 << info->bits_used) - 1;
printf("%05f ", ((float)val + info->offset)*info->scale);
}
}
/**
* process_scan() - print out the values in SI units
* @data: pointer to the start of the scan
@ -70,25 +89,8 @@ void process_scan(char *data,
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);
}
print2byte(*(uint16_t *)(data + infoarray[k].location),
&infoarray[k]);
break;
case 8:
if (infoarray[k].is_signed) {
@ -133,9 +135,8 @@ int main(int argc, char **argv)
int datardytrigger = 1;
char *data;
ssize_t read_size;
struct iio_event_data dat;
int dev_num, trig_num;
char *buffer_access, *buffer_event;
char *buffer_access;
int scan_size;
int noevents = 0;
char *dummy;
@ -210,7 +211,7 @@ int main(int argc, char **argv)
*/
ret = build_channel_array(dev_dir_name, &infoarray, &num_channels);
if (ret) {
printf("Problem reading scan element information \n");
printf("Problem reading scan element information\n");
goto error_free_triggername;
}
@ -251,54 +252,32 @@ int main(int argc, char **argv)
}
ret = asprintf(&buffer_access,
"/dev/device%d:buffer0:access0",
"/dev/device%d:buffer0",
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;
goto error_free_buffer_access;
}
/* Wait for events 10 times */
for (j = 0; j < num_loops; j++) {
if (!noevents) {
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;
}
struct pollfd pfd = {
.fd = fp,
.events = POLLIN,
};
poll(&pfd, 1, -1);
toread = buf_len;
} else {
usleep(timedelay);
toread = 64;
@ -320,22 +299,18 @@ int main(int argc, char **argv)
/* Stop the ring buffer */
ret = write_sysfs_int("enable", buf_dir_name, 0);
if (ret < 0)
goto error_close_buffer_event;
goto error_close_buffer_access;
/* 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:

View File

@ -16,25 +16,11 @@
#define IIO_MAX_NAME_LENGTH 30
#define IIO_EV_CLASS_BUFFER 0
#define IIO_BUFFER_EVENT_CODE(code) \
(IIO_EV_CLASS_BUFFER | (code << 8))
#define IIO_EVENT_CODE_RING_50_FULL IIO_BUFFER_EVENT_CODE(0)
#define IIO_EVENT_CODE_RING_75_FULL IIO_BUFFER_EVENT_CODE(1)
#define IIO_EVENT_CODE_RING_100_FULL IIO_BUFFER_EVENT_CODE(2)
#define FORMAT_SCAN_ELEMENTS_DIR "%s:buffer0/scan_elements"
#define FORMAT_TYPE_FILE "%s_type"
const char *iio_dir = "/sys/bus/iio/devices/";
struct iio_event_data {
int id;
__s64 timestamp;
};
/**
* iioutils_break_up_name() - extract generic name from full channel name
* @full_name: the full channel name
@ -85,6 +71,7 @@ struct iio_channel_info {
unsigned index;
unsigned bytes;
unsigned bits_used;
unsigned shift;
uint64_t mask;
unsigned is_signed;
unsigned enabled;
@ -103,6 +90,7 @@ struct iio_channel_info {
inline int iioutils_get_type(unsigned *is_signed,
unsigned *bytes,
unsigned *bits_used,
unsigned *shift,
uint64_t *mask,
const char *device_dir,
const char *name,
@ -157,7 +145,8 @@ inline int iioutils_get_type(unsigned *is_signed,
goto error_free_filename;
}
fscanf(sysfsfp,
"%c%u/%u", &signchar, bits_used, &padint);
"%c%u/%u>>%u", &signchar, bits_used,
&padint, shift);
*bytes = padint / 8;
if (*bits_used == 64)
*mask = ~0;
@ -395,6 +384,7 @@ inline int build_channel_array(const char *device_dir,
ret = iioutils_get_type(&current->is_signed,
&current->bytes,
&current->bits_used,
&current->shift,
&current->mask,
device_dir,
current->name,