struct channel_priv {
int ch_type;
+ int fd;
+ float val;
struct channel_group_priv *probe;
};
*/
fd = g_fopen(path->str, "w");
if (!fd) {
- sr_err("Error opening %s: %s", path->str, strerror(errno));
+ sr_err("Error opening %s: %s", path->str, g_strerror(errno));
ret = SR_ERR_IO;
goto out;
}
gboolean off)
{
struct channel_group_priv *cgp;
+ int val;
cgp = cg->priv;
return SR_ERR_ARG;
}
- sr_gpio_setval_export(pws_gpios[cgp->index], off ? 0 : 1);
+ val = sr_gpio_setval_export(pws_gpios[cgp->index], off ? 0 : 1);
+ if (val < 0) {
+ sr_err("Error setting power-off state: gpio: %d",
+ pws_gpios[cgp->index]);
+ return SR_ERR_IO;
+ }
return SR_OK;
}
static float read_sample(struct sr_channel *ch)
{
struct channel_priv *chp;
- char path[64], *file, buf[16];
+ char buf[16];
ssize_t len;
int fd;
+ chp = ch->priv;
+ fd = chp->fd;
+
+ lseek(fd, 0, SEEK_SET);
+
+ len = read(fd, buf, sizeof(buf));
+ if (len < 0) {
+ sr_err("Error reading from channel %s (hwmon: %d): %s",
+ ch->name, chp->probe->hwmon_num, g_strerror(errno));
+ ch->enabled = FALSE;
+ return -1.0;
+ }
+
+ return adjust_data(strtol(buf, NULL, 10), chp->ch_type);
+}
+
+SR_PRIV int bl_acme_open_channel(struct sr_channel *ch)
+{
+ struct channel_priv *chp;
+ char path[64], *file;
+ int fd;
+
chp = ch->priv;
switch (chp->ch_type) {
case TEMP_OUT: file = "temp2_input"; break;
default:
sr_err("Invalid channel type: %d.", chp->ch_type);
- return -1.0;
+ return SR_ERR;
}
snprintf(path, sizeof(path), "/sys/class/hwmon/hwmon%d/%s",
chp->probe->hwmon_num, file);
+
fd = open(path, O_RDONLY);
if (fd < 0) {
- sr_err("Error opening %s: %s", path, strerror(errno));
+ sr_err("Error opening %s: %s", path, g_strerror(errno));
ch->enabled = FALSE;
- return -1.0;
+ return SR_ERR;
}
- len = read(fd, buf, sizeof(buf));
- close(fd);
- if (len < 0) {
- sr_err("Error reading from %s: %s", path, strerror(errno));
- ch->enabled = FALSE;
- return -1.0;
- }
+ chp->fd = fd;
- return adjust_data(strtol(buf, NULL, 10), chp->ch_type);
+ return 0;
+}
+
+SR_PRIV void bl_acme_close_channel(struct sr_channel *ch)
+{
+ struct channel_priv *chp;
+
+ chp = ch->priv;
+ close(chp->fd);
+ chp->fd = -1;
}
SR_PRIV int bl_acme_receive_data(int fd, int revents, void *cb_data)
{
- uint32_t cur_time, elapsed_time, diff_time;
- int64_t time_to_sleep;
+ uint32_t cur_time, elapsed_time;
+ uint64_t nrexpiration;
struct sr_datafeed_packet packet, framep;
struct sr_datafeed_analog analog;
struct sr_dev_inst *sdi;
struct sr_channel *ch;
+ struct channel_priv *chp;
struct dev_context *devc;
GSList *chl, chonly;
- float valf;
+ unsigned i;
(void)fd;
(void)revents;
packet.type = SR_DF_ANALOG;
packet.payload = &analog;
memset(&analog, 0, sizeof(struct sr_datafeed_analog));
- analog.data = &valf;
- /*
- * Reading from sysfs takes some time - try to keep up with samplerate.
- */
- if (devc->samples_read) {
- cur_time = g_get_monotonic_time();
- diff_time = cur_time - devc->last_sample_fin;
- time_to_sleep = G_USEC_PER_SEC / devc->samplerate - diff_time;
- if (time_to_sleep > 0)
- g_usleep(time_to_sleep);
+ if (read(devc->timer_fd, &nrexpiration, sizeof(nrexpiration)) < 0) {
+ sr_warn("Failed to read timer information");
+ return TRUE;
}
- framep.type = SR_DF_FRAME_BEGIN;
- sr_session_send(cb_data, &framep);
+ /*
+ * We were not able to process the previous timer expiration, we are
+ * overloaded.
+ */
+ if (nrexpiration > 1)
+ devc->samples_missed += nrexpiration - 1;
/*
- * Due to different units used in each channel we're sending
- * samples one-by-one.
+ * XXX This is a nasty workaround...
+ *
+ * At high sampling rates and maximum channels we are not able to
+ * acquire samples fast enough, even though frontends still think
+ * that samples arrive on time. This causes shifts in frontend
+ * plots.
+ *
+ * To compensate for the delay we check if any clock events were
+ * missed and - if so - don't really read the next value, but send
+ * the same sample as fast as possible. We do it until we are back
+ * on schedule.
+ *
+ * At high sampling rate this doesn't seem to visibly reduce the
+ * accuracy.
*/
- for (chl = sdi->channels; chl; chl = chl->next) {
- ch = chl->data;
- if (!ch->enabled)
- continue;
- chonly.next = NULL;
- chonly.data = ch;
- analog.channels = &chonly;
- analog.num_samples = 1;
- analog.mq = channel_to_mq(chl->data);
- analog.unit = channel_to_unit(ch);
-
- valf = read_sample(ch);
-
- sr_session_send(cb_data, &packet);
- }
+ for (i = 0; i < nrexpiration; i++) {
+ framep.type = SR_DF_FRAME_BEGIN;
+ sr_session_send(cb_data, &framep);
+
+ /*
+ * Due to different units used in each channel we're sending
+ * samples one-by-one.
+ */
+ for (chl = sdi->channels; chl; chl = chl->next) {
+ ch = chl->data;
+ chp = ch->priv;
+
+ if (!ch->enabled)
+ continue;
+ chonly.next = NULL;
+ chonly.data = ch;
+ analog.channels = &chonly;
+ analog.num_samples = 1;
+ analog.mq = channel_to_mq(chl->data);
+ analog.unit = channel_to_unit(ch);
+
+ if (i < 1)
+ chp->val = read_sample(ch);
+
+ analog.data = &chp->val;
+ sr_session_send(cb_data, &packet);
+ }
- framep.type = SR_DF_FRAME_END;
- sr_session_send(cb_data, &framep);
+ framep.type = SR_DF_FRAME_END;
+ sr_session_send(cb_data, &framep);
+ }
devc->samples_read++;
if (devc->limit_samples > 0 &&
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