tekpower-dmm: Cosmetics.

hardware/tekpower-dmm/api.c

@@ -94,73 +94,86 @@ static int hw_init(void)
 typedef gboolean (*packet_valid_t)(const uint8_t *buf);
 
 /**
- * Try to find a valid packet in a serial data stream
+ * Try to find a valid packet in a serial data stream.
  *
- * @param fd File descriptor of the serial port.
+ * @param serial Previously initialized serial port structure.
  * @param buf Buffer containing the bytes to write.
  * @param count Size of the buffer.
- * @param packet_size Size, in bytes, of a valid packet
+ * @param packet_size Size, in bytes, of a valid packet.
- * @param is_valid callback that assesses whether the packet is valid or not
+ * @param is_valid Callback that assesses whether the packet is valid or not.
- * @param timeout_ms the timeout after which, if no packet is detected, to abort
+ * @param timeout_ms The timeout after which, if no packet is detected, to
- *                   scanning.
+ *                   abort scanning.
- * @param baudrate the baudrate of the serial port. This parameter is not
+ * @param baudrate The baudrate of the serial port. This parameter is not
  *                 critical, but it helps fine tune the serial port polling
- *                 delay
+ *                 delay.
  *
- * @return SR_OK if a valid packet is found within he given timeout,
+ * @return SR_OK if a valid packet is found within the given timeout,
  *         SR_ERR upon failure.
  */
 static int serial_stream_detect(struct sr_serial_dev_inst *serial,
 				uint8_t *buf, size_t *buflen,
-				const size_t packet_size,
+				size_t packet_size, packet_valid_t is_valid,
-				packet_valid_t is_valid,
 				uint64_t timeout_ms, int baudrate)
 {
-	uint64_t start;
+	uint64_t start, time, byte_delay_us;
-	uint64_t time;
+	size_t ibuf, i, maxlen;
-	uint64_t byte_delay_us;
-	size_t ibuf, i;
 	int len;
-	const size_t maxlen = *buflen;
 
-	if(maxlen < (packet_size << 1) ) {
+	maxlen = *buflen;
-		sr_err("Buffer size must be at least twice the packet size");
+
+	sr_dbg("Detecting packets on FD %d (timeout = %" PRIu64
+	       "ms, baudrate = %d).", serial->fd, timeout_ms, baudrate);
+
+	if (maxlen < (packet_size / 2) ) {
+		sr_err("Buffer size must be at least twice the packet size.");
 		return SR_ERR;
 	}
 
 	timeout_ms *= 1000;
-	/* Assume 8n1 transmission. That is 10 bits for every byte */
+
-	byte_delay_us = 10000000 / baudrate;
+	/* Assume 8n1 transmission. That is 10 bits for every byte. */
+	byte_delay_us = 10 * (1000000 / baudrate);
 	start = g_get_monotonic_time();
 
 	i = ibuf = len = 0;
 	while (ibuf < maxlen) {
 		len = serial_read(serial, &buf[ibuf], 1);
-		if (len > 0)
+		if (len > 0) {
-			ibuf+= len;
+			ibuf += len;
+		} else if (len == 0) {
+			sr_spew("Error: Only read 0 bytes.");
+		} else {
+			/* Error reading byte, but continuing anyway. */
+		}
 		if ((ibuf - i) >= packet_size) {
-			/* We have at least a packet's worth of data */
+			/* We have at least a packet's worth of data. */
 			if (is_valid(&buf[i])) {
-				time = g_get_monotonic_time()-start;
+				time = g_get_monotonic_time() - start;
 				time /= 1000;
-				sr_spew("Serial detection took %li ms", time);
+				sr_spew("Found valid %d-byte packet after "
+					"%" PRIu64 "ms.", (ibuf - i), time);
 				*buflen = ibuf;
 				return SR_OK;
+			} else {
+				sr_spew("Got %d bytes, but not a valid "
+					"packet.", (ibuf - i));
 			}
-			/* Not a valid packet; continue searching */
+			/* Not a valid packet. Continue searching. */
 			i++;
 		}
 		if (g_get_monotonic_time() - start > timeout_ms) {
 			/* Timeout */
-			sr_warn("Serial detection timeout");
+			sr_dbg("Detection timed out after %dms.", timeout_ms);
 			break;
 		}
 		g_usleep(byte_delay_us);
 	}
 
 	*buflen = ibuf;
-	return SR_ERR;
 
+	sr_err("Didn't find a valid packet (read %d bytes).", *buflen);
+
+	return SR_ERR;
 }
 
 static GSList *lcd14_scan(const char *conn, const char *serialcomm)
@@ -178,7 +191,7 @@ static GSList *lcd14_scan(const char *conn, const char *serialcomm)
 	if (!(serial = sr_serial_dev_inst_new(conn, serialcomm)))
 		return NULL;
 
-	if (serial_open(serial, O_RDONLY|O_NONBLOCK) != SR_OK)
+	if (serial_open(serial, O_RDONLY | O_NONBLOCK) != SR_OK)
 		return NULL;
 
 	sr_info("Probing port %s readonly.", conn);
@@ -209,16 +222,15 @@ static GSList *lcd14_scan(const char *conn, const char *serialcomm)
 	 * the serial port or USB to serial adapter.
 	 */
 	dropped = len - FS9721_PACKET_SIZE;
-	if (dropped > 2 * FS9721_PACKET_SIZE) {
+	if (dropped > 2 * FS9721_PACKET_SIZE)
-
+		sr_warn("Had to drop too much data.");
-		sr_warn("Had to drop too much data");
-	}
 
 	sr_info("Found device on port %s.", conn);
 
 	if (!(sdi = sr_dev_inst_new(0, SR_ST_INACTIVE, "TekPower",
 				    "TP4000ZC", "")))
 		goto scan_cleanup;
+
 	if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) {
 		sr_err("Device context malloc failed.");
 		goto scan_cleanup;

hardware/tekpower-dmm/protocol.c

@@ -29,6 +29,14 @@
 /* User-defined FS9721_LP3 flag 'c2c1_10' means temperature on this DMM. */
 #define is_temperature info.is_c2c1_10
 
+static void log_dmm_packet(const uint8_t *buf)
+{
+	sr_dbg("DMM packet: %02x %02x %02x %02x %02x %02x %02x"
+	       " %02x %02x %02x %02x %02x %02x %02x",
+	       buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6],
+	       buf[7], buf[8], buf[9], buf[10], buf[11], buf[12], buf[13]);
+}
+
 /* Now see what the value means, and pass that on. */
 static void fs9721_serial_handle_packet(const uint8_t *buf,
 					struct dev_context *devc)
@@ -38,6 +46,8 @@ static void fs9721_serial_handle_packet(const uint8_t *buf,
 	struct sr_datafeed_analog *analog;
 	struct fs9721_info info;
 
+	log_dmm_packet(buf);
+
 	if (!(analog = g_try_malloc0(sizeof(struct sr_datafeed_analog)))) {
 		sr_err("Analog packet malloc failed.");
 		return;
@@ -121,6 +131,7 @@ SR_PRIV int tekpower_dmm_receive_data(int fd, int revents, void *cb_data)
 	}
 
 	if (devc->num_samples >= devc->limit_samples) {
+		sr_info("Requested number of samples reached, stopping.");
 		sdi->driver->dev_acquisition_stop(sdi, cb_data);
 		return TRUE;
 	}