static int data_read_async(void *dst, struct a4l_calibration_subdev *s,
unsigned int nb_samples, int speriod, int irange)
{
int i, len, err;
a4l_cmd_t cmd;
unsigned int chan_descs[] = {
PACK(CR_ALT_SOURCE|CR_ALT_FILTER, irange, AREF_DIFF)
};
memset(&cmd, 0, sizeof(cmd));
cmd.scan_begin_src = TRIG_TIMER;
cmd.scan_end_src = TRIG_COUNT;
cmd.convert_src = TRIG_TIMER;
cmd.stop_src = TRIG_COUNT;
cmd.start_src = TRIG_NOW;
cmd.scan_end_arg = 1;
cmd.convert_arg = 0;
cmd.nb_chan = 1;
cmd.scan_begin_arg = speriod;
cmd.chan_descs = chan_descs;
cmd.idx_subd = s->idx;
cmd.stop_arg = nb_samples;
cmd.flags = A4L_CMD_SIMUL;
SET_BIT(3, &cmd.valid_simul_stages);
/* get driver specific info into the command structure */
for (i = 0; i< 4; i++)
a4l_snd_command(&descriptor, &cmd);
/* send the real command */
cmd.flags = 0;
err = a4l_snd_command(&descriptor, &cmd);
if (err)
error(EXIT, 0, "a4l_snd_command (%d)", err);
len = nb_samples * ai_subd.slen;
for (;;) {
err = a4l_async_read(&descriptor, dst, len, A4L_INFINITE);
if (err <0)
error(EXIT, 0, "a4l_async_read (%d)", err);
if (err < len) {
dst = dst + err;
len = len - err;
} else
break;
}
a4l_snd_cancel(&descriptor, ai_subd.idx);
return 0;
}
int main(int argc, char *argv[])
{
int ret = 0, len, ofs;
unsigned int i, scan_size = 0, cnt = 0;
unsigned long buf_size;
void *map = NULL;
a4l_desc_t dsc = { .sbdata = NULL };
int (*dump_function) (a4l_desc_t *, a4l_cmd_t*, unsigned char *, int) =
dump_text;
/* Compute arguments */
while ((ret = getopt_long(argc,
argv,
"vrd:s:S:c:mwk:h",
cmd_read_opts, NULL)) >= 0) {
switch (ret) {
case 'v':
verbose = 1;
break;
case 'r':
real_time = 1;
break;
case 'd':
filename = optarg;
break;
case 's':
cmd.idx_subd = strtoul(optarg, NULL, 0);
break;
case 'S':
cmd.stop_arg = strtoul(optarg, NULL, 0);
break;
case 'c':
str_chans = optarg;
break;
case 'm':
use_mmap = 1;
break;
case 'w':
dump_function = dump_raw;
break;
case 'k':
wake_count = strtoul(optarg, NULL, 0);
break;
case 'h':
default:
do_print_usage();
return 0;
}
}
if (isatty(STDOUT_FILENO) && dump_function == dump_raw) {
fprintf(stderr,
"cmd_read: cannot dump raw data on a terminal\n\n");
return -EINVAL;
}
/* Recover the channels to compute */
do {
cmd.nb_chan++;
len = strlen(str_chans);
ofs = strcspn(str_chans, ",");
if (sscanf(str_chans, "%u", &chans[cmd.nb_chan - 1]) == 0) {
fprintf(stderr, "cmd_read: bad channel argument\n");
return -EINVAL;
}
str_chans += ofs + 1;
} while (len != ofs);
/* Update the command structure */
cmd.scan_end_arg = cmd.nb_chan;
cmd.stop_src = cmd.stop_arg != 0 ? TRIG_COUNT : TRIG_NONE;
if (real_time != 0) {
if (verbose != 0)
printf("cmd_read: switching to real-time mode\n");
/* Prevent any memory-swapping for this program */
ret = mlockall(MCL_CURRENT | MCL_FUTURE);
if (ret < 0) {
ret = errno;
fprintf(stderr, "cmd_read: mlockall failed (ret=%d)\n",
ret);
goto out_main;
}
/* Turn the current process into an RT task */
ret = rt_task_shadow(&rt_task_desc, NULL, 1, 0);
if (ret < 0) {
fprintf(stderr,
"cmd_read: rt_task_shadow failed (ret=%d)\n",
ret);
goto out_main;
}
}
/* Open the device */
ret = a4l_open(&dsc, filename);
if (ret < 0) {
fprintf(stderr, "cmd_read: a4l_open %s failed (ret=%d)\n",
filename, ret);
return ret;
}
if (verbose != 0) {
printf("cmd_read: device %s opened (fd=%d)\n",
filename, dsc.fd);
printf("cmd_read: basic descriptor retrieved\n");
printf("\t subdevices count = %d\n", dsc.nb_subd);
printf("\t read subdevice index = %d\n", dsc.idx_read_subd);
printf("\t write subdevice index = %d\n", dsc.idx_write_subd);
}
/* Allocate a buffer so as to get more info (subd, chan, rng) */
dsc.sbdata = malloc(dsc.sbsize);
if (dsc.sbdata == NULL) {
fprintf(stderr, "cmd_read: malloc failed \n");
return -ENOMEM;
}
/* Get this data */
ret = a4l_fill_desc(&dsc);
if (ret < 0) {
fprintf(stderr,
"cmd_read: a4l_fill_desc failed (ret=%d)\n", ret);
goto out_main;
}
if (verbose != 0)
printf("cmd_read: complex descriptor retrieved\n");
/* Get the size of a single acquisition */
for (i = 0; i < cmd.nb_chan; i++) {
a4l_chinfo_t *info;
ret = a4l_get_chinfo(&dsc,
cmd.idx_subd, cmd.chan_descs[i], &info);
if (ret < 0) {
fprintf(stderr,
"cmd_read: a4l_get_chinfo failed (ret=%d)\n",
ret);
goto out_main;
}
if (verbose != 0) {
printf("cmd_read: channel %x\n", cmd.chan_descs[i]);
printf("\t ranges count = %d\n", info->nb_rng);
printf("\t bit width = %d (bits)\n", info->nb_bits);
}
scan_size += a4l_sizeof_chan(info);
}
if (verbose != 0) {
printf("cmd_read: scan size = %u\n", scan_size);
if (cmd.stop_arg != 0)
printf("cmd_read: size to read = %u\n",
scan_size * cmd.stop_arg);
}
/* Cancel any former command which might be in progress */
a4l_snd_cancel(&dsc, cmd.idx_subd);
if (use_mmap != 0) {
/* Get the buffer size to map */
ret = a4l_get_bufsize(&dsc, cmd.idx_subd, &buf_size);
if (ret < 0) {
fprintf(stderr,
"cmd_read: a4l_get_bufsize() failed (ret=%d)\n",
ret);
goto out_main;
}
if (verbose != 0)
printf("cmd_read: buffer size = %lu bytes\n", buf_size);
/* Map the analog input subdevice buffer */
ret = a4l_mmap(&dsc, cmd.idx_subd, buf_size, &map);
if (ret < 0) {
fprintf(stderr,
"cmd_read: a4l_mmap() failed (ret=%d)\n",
ret);
goto out_main;
}
if (verbose != 0)
printf
("cmd_read: mmap performed successfully (map=0x%p)\n",
map);
}
ret = a4l_set_wakesize(&dsc, wake_count);
if (ret < 0) {
fprintf(stderr,
"cmd_read: a4l_set_wakesize failed (ret=%d)\n", ret);
goto out_main;
}
if (verbose != 0)
printf("cmd_read: wake size successfully set (%lu)\n",
wake_count);
/* Send the command to the input device */
ret = a4l_snd_command(&dsc, &cmd);
if (ret < 0) {
fprintf(stderr,
"cmd_read: a4l_snd_command failed (ret=%d)\n", ret);
goto out_main;
}
if (verbose != 0)
printf("cmd_read: command successfully sent\n");
if (use_mmap == 0) {
/* Fetch data */
do {
/* Perform the read operation */
ret = a4l_async_read(&dsc, buf, BUF_SIZE, A4L_INFINITE);
if (ret < 0) {
fprintf(stderr,
"cmd_read: a4l_read failed (ret=%d)\n",
ret);
goto out_main;
}
/* Display the results */
if (dump_function(&dsc, &cmd, buf, ret) < 0) {
ret = -EIO;
goto out_main;
}
/* Update the counter */
cnt += ret;
} while (ret > 0);
} else {
unsigned long front = 0;
/* Fetch data without any memcpy */
do {
/* Retrieve and update the buffer's state
(In input case, we recover how many bytes are available
to read) */
ret = a4l_mark_bufrw(&dsc, cmd.idx_subd, front, &front);
if (ret == -ENOENT)
break;
else if (ret < 0) {
fprintf(stderr,
"cmd_read: a4l_mark_bufrw() failed (ret=%d)\n",
ret);
goto out_main;
}
/* If there is nothing to read, wait for an event
(Note that a4l_poll() also retrieves the data amount
to read; in our case it is useless as we have to update
the data read counter) */
if (front == 0) {
ret = a4l_poll(&dsc, cmd.idx_subd, A4L_INFINITE);
if (ret == 0)
break;
else if (ret < 0) {
fprintf(stderr,
"cmd_read: a4l_poll() failed (ret=%d)\n",
ret);
goto out_main;
}
}
/* Display the results */
if (dump_function(&dsc,
&cmd,
&((unsigned char *)map)[cnt % buf_size],
front) < 0) {
ret = -EIO;
goto out_main;
}
/* Update the counter */
cnt += front;
} while (1);
}
if (verbose != 0)
printf("cmd_read: %d bytes successfully received\n", cnt);
ret = 0;
out_main:
if (use_mmap != 0)
/* Clean the pages table */
munmap(map, buf_size);
/* Free the buffer used as device descriptor */
if (dsc.sbdata != NULL)
free(dsc.sbdata);
/* Release the file descriptor */
a4l_close(&dsc);
return ret;
}