tekpower-dmm: Cosmetics.

[libsigrok.git] / hardware / tekpower-dmm / api.c

diff --git a/hardware/tekpower-dmm/api.c b/hardware/tekpower-dmm/api.c
index 8f78ca51e254f94a14953cde828ef5b2bda61ca1..bd6cb9402137957bd31edecca545970e3629bd74 100644 (file)
--- a/hardware/tekpower-dmm/api.c
+++ b/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 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
- *                   scanning.
- * @param baudrate the baudrate of the serial port. This parameter is not
+ * @param packet_size Size, in bytes, of a valid packet.
+ * @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 scanning.
+ * @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,
-                               packet_valid_t is_valid,
+                               size_t packet_size, packet_valid_t is_valid,
                                uint64_t timeout_ms, int baudrate)
 {
-       uint64_t start;
-       uint64_t time;
-       uint64_t byte_delay_us;
-       size_t ibuf, i;
+       uint64_t start, time, byte_delay_us;
+       size_t ibuf, i, maxlen;
        int len;
-       const size_t maxlen = *buflen;
 
-       if(maxlen < (packet_size << 1) ) {
-               sr_err("Buffer size must be at least twice the packet size");
+       maxlen = *buflen;
+
+       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)
-                       ibuf+= len;
+               if (len > 0) {
+                       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) {
-
-               sr_warn("Had to drop too much data");
-       }
+       if (dropped > 2 * FS9721_PACKET_SIZE)
+               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;