X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=src%2Fhardware%2Fbaylibre-acme%2Fprotocol.c;h=d9131cb09c9f3fe097366b85f3f2b178c2ebe652;hb=6ec6c43b4738dbc7091f4a49a4ec80ea6102cb52;hp=66a22ad4ffe0e93b4f2f0bcd9017dc3c80e0a7f9;hpb=391e23a97fe5b919f7f0716702bd1b151c601f66;p=libsigrok.git

diff --git a/src/hardware/baylibre-acme/protocol.c b/src/hardware/baylibre-acme/protocol.c
index 66a22ad4..d9131cb0 100644
--- a/src/hardware/baylibre-acme/protocol.c
+++ b/src/hardware/baylibre-acme/protocol.c
@@ -17,6 +17,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <config.h>
 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>
@@ -33,6 +34,8 @@ struct channel_group_priv {
 
 struct channel_priv {
 	int ch_type;
+	int fd;
+	float val;
 	struct channel_group_priv *probe;
 };
 
@@ -201,13 +204,12 @@ static void append_channel(struct sr_dev_inst *sdi, struct sr_channel_group *cg,
 	cp->ch_type = type;
 	cp->probe = cg->priv;
 
-	ch = sr_channel_new(devc->num_channels++,
+	ch = sr_channel_new(sdi, devc->num_channels++,
 			    SR_CHANNEL_ANALOG, TRUE, name);
 	g_free(name);
 
 	ch->priv = cp;
 	cg->channels = g_slist_append(cg->channels, ch);
-	sdi->channels = g_slist_append(sdi->channels, ch);
 }
 
 SR_PRIV gboolean bl_acme_register_probe(struct sr_dev_inst *sdi, int type,
@@ -246,6 +248,20 @@ SR_PRIV gboolean bl_acme_register_probe(struct sr_dev_inst *sdi, int type,
 	return TRUE;
 }
 
+SR_PRIV int bl_acme_get_probe_type(const struct sr_channel_group *cg)
+{
+	struct channel_group_priv *cgp = cg->priv;
+
+	return cgp->probe_type;
+}
+
+SR_PRIV int bl_acme_probe_has_pws(const struct sr_channel_group *cg)
+{
+	struct channel_group_priv *cgp = cg->priv;
+
+	return sr_gpio_getval_export(pws_info_gpios[cgp->index]);
+}
+
 /*
  * Sets path to the hwmon attribute if this channel group
  * supports shunt resistance setting. The caller has to supply
@@ -282,6 +298,43 @@ static int get_shunt_path(const struct sr_channel_group *cg, GString *path)
 	return ret;
 }
 
+/*
+ * Try setting the update_interval sysfs attribute for each probe according
+ * to samplerate.
+ */
+SR_PRIV void bl_acme_maybe_set_update_interval(const struct sr_dev_inst *sdi,
+					       uint64_t samplerate)
+{
+	struct sr_channel_group *cg;
+	struct channel_group_priv *cgp;
+	GString *hwmon;
+	GSList *l;
+	FILE *fd;
+
+	for (l = sdi->channel_groups; l != NULL; l = l->next) {
+		cg = l->data;
+		cgp = cg->priv;
+
+		hwmon = g_string_sized_new(64);
+		g_string_append_printf(hwmon,
+				"/sys/class/hwmon/hwmon%d/update_interval",
+				cgp->hwmon_num);
+
+		if (g_file_test(hwmon->str, G_FILE_TEST_EXISTS)) {
+			fd = g_fopen(hwmon->str, "w");
+			if (!fd) {
+				g_string_free(hwmon, TRUE);
+				continue;
+			}
+
+			g_fprintf(fd, "%" PRIu64 "\n", 1000 / samplerate);
+			fclose(fd);
+		}
+
+		g_string_free(hwmon, TRUE);
+	}
+}
+
 SR_PRIV int bl_acme_get_shunt(const struct sr_channel_group *cg,
 			      uint64_t *shunt)
 {
@@ -328,17 +381,12 @@ SR_PRIV int bl_acme_set_shunt(const struct sr_channel_group *cg, uint64_t shunt)
 	 */
 	fd = g_fopen(path->str, "w");
 	if (!fd) {
-		sr_err("Error opening %s: %s", path->str, strerror(errno));
-		g_string_free(path, TRUE);
-		return SR_ERR_IO;
+		sr_err("Error opening %s: %s", path->str, g_strerror(errno));
+		ret = SR_ERR_IO;
+		goto out;
 	}
 
-	g_string_free(path, TRUE);
-	g_fprintf(fd, "%llu\n", MOHM_TO_UOHM(shunt));
-	/*
-	 * XXX There's no g_fclose() in GLib. This seems to work,
-	 * but is it safe?
-	 */
+	g_fprintf(fd, "%" PRIu64 "\n", MOHM_TO_UOHM(shunt));
 	fclose(fd);
 
 out:
@@ -354,8 +402,7 @@ SR_PRIV int bl_acme_read_power_state(const struct sr_channel_group *cg,
 
 	cgp = cg->priv;
 
-	val = sr_gpio_getval_export(pws_info_gpios[cgp->index]);
-	if (val != 1) {
+	if (!bl_acme_probe_has_pws(cg)) {
 		sr_err("Probe has no power-switch");
 		return SR_ERR_ARG;
 	}
@@ -374,13 +421,17 @@ SR_PRIV int bl_acme_set_power_off(const struct sr_channel_group *cg,
 
 	cgp = cg->priv;
 
-	val = sr_gpio_getval_export(pws_info_gpios[cgp->index]);
-	if (val != 1) {
+	if (!bl_acme_probe_has_pws(cg)) {
 		sr_err("Probe has no power-switch");
 		return SR_ERR_ARG;
 	}
 
 	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;
 }
@@ -446,10 +497,32 @@ static float adjust_data(int val, int type)
 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) {
@@ -460,40 +533,45 @@ static float read_sample(struct sr_channel *ch)
 	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;
@@ -508,45 +586,67 @@ SR_PRIV int bl_acme_receive_data(int fd, int revents, void *cb_data)
 
 	packet.type = SR_DF_ANALOG;
 	packet.payload = &analog;
-	memset(&analog, 0, sizeof(analog));
-	analog.data = &valf;
+	memset(&analog, 0, sizeof(struct sr_datafeed_analog));
 
-	/*
-	 * 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);
 
-	framep.type = SR_DF_FRAME_END;
-	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);
+	}
 
 	devc->samples_read++;
 	if (devc->limit_samples > 0 &&