]> sigrok.org Git - libsigrok.git/blobdiff - src/hardware/uni-t-ut32x/protocol.c
uni-t-ut32x: improve robustness of packet parser, more diagnostics
[libsigrok.git] / src / hardware / uni-t-ut32x / protocol.c
index 14e70cf221ed13f9d41adf1082098ce215f8648e..7d69091eab77eba1cc2ce839b91952aa0b7f744b 100644 (file)
 #include <math.h>
 #include "protocol.h"
 
-extern struct sr_dev_driver uni_t_ut32x_driver_info;
+#define SEP    "\r\n"
+#define BLANK  ':'
+#define NEG    ';'
 
+/*
+ * Get a temperature value from a four-character buffer. The value is
+ * encoded in ASCII and the unit is deci-degrees (tenths of degrees).
+ */
 static float parse_temperature(unsigned char *buf)
 {
        float temp;
@@ -33,23 +39,22 @@ static float parse_temperature(unsigned char *buf)
        negative = FALSE;
        temp = 0.0;
        for (i = 0; i < 4; i++) {
-               if (buf[i] == 0x3a)
+               if (buf[i] == BLANK)
                        continue;
-               if (buf[i] == 0x3b) {
+               if (buf[i] == NEG) {
                        if (negative) {
                                sr_dbg("Double negative sign!");
                                return NAN;
-                       } else {
-                               negative = TRUE;
-                               continue;
                        }
+                       negative = TRUE;
+                       continue;
                }
-               if (buf[i] < 0x30 || buf[i] > 0x39) {
+               if (buf[i] < '0' || buf[i] > '9') {
                        sr_dbg("Invalid digit '%.2x'!", buf[i]);
                        return NAN;
                }
                temp *= 10;
-               temp += (buf[i] - 0x30);
+               temp += buf[i] - '0';
        }
        temp /= 10;
        if (negative)
@@ -58,92 +63,97 @@ static float parse_temperature(unsigned char *buf)
        return temp;
 }
 
-static void process_packet(struct sr_dev_inst *sdi)
+static void process_packet(struct sr_dev_inst *sdi, uint8_t *pkt, size_t len)
 {
        struct dev_context *devc;
        struct sr_datafeed_packet packet;
-       struct sr_datafeed_analog_old analog;
+       struct sr_datafeed_analog analog;
+       struct sr_analog_encoding encoding;
+       struct sr_analog_meaning meaning;
+       struct sr_analog_spec spec;
        GString *spew;
        float temp;
-       int i;
        gboolean is_valid;
 
-       devc = sdi->priv;
-       sr_dbg("Received full 19-byte packet.");
        if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
-               spew = g_string_sized_new(60);
-               for (i = 0; i < devc->packet_len; i++)
-                       g_string_append_printf(spew, "%.2x ", devc->packet[i]);
-               sr_spew("%s", spew->str);
-               g_string_free(spew, TRUE);
+               spew = sr_hexdump_new(pkt, len);
+               sr_spew("Got a packet, len %zu, bytes%s", len, spew->str);
+               sr_hexdump_free(spew);
        }
+       if (len != PACKET_SIZE)
+               return;
+       if (pkt[17] != SEP[0] || pkt[18] != SEP[1])
+               return;
+       if (pkt[8] != '0' || pkt[16] != '1')
+               return;
+       sr_dbg("Processing 19-byte packet.");
 
        is_valid = TRUE;
-       if (devc->packet[1] == 0x3b && devc->packet[2] == 0x3b
-                       && devc->packet[3] == 0x3b && devc->packet[4] == 0x3b)
+       if (pkt[1] == NEG && pkt[2] == NEG && pkt[3] == NEG && pkt[4] == NEG)
                /* No measurement: missing channel, empty storage location, ... */
                is_valid = FALSE;
 
-       temp = parse_temperature(devc->packet + 1);
+       temp = parse_temperature(&pkt[1]);
        if (isnan(temp))
                is_valid = FALSE;
 
        if (is_valid) {
-               memset(&analog, 0, sizeof(struct sr_datafeed_analog_old));
-               analog.mq = SR_MQ_TEMPERATURE;
-               analog.mqflags = 0;
-               switch (devc->packet[5] - 0x30) {
+               memset(&packet, 0, sizeof(packet));
+               sr_analog_init(&analog, &encoding, &meaning, &spec, 1);
+               analog.meaning->mq = SR_MQ_TEMPERATURE;
+               analog.meaning->mqflags = 0;
+               switch (pkt[5] - '0') {
                case 1:
-                       analog.unit = SR_UNIT_CELSIUS;
+                       analog.meaning->unit = SR_UNIT_CELSIUS;
                        break;
                case 2:
-                       analog.unit = SR_UNIT_FAHRENHEIT;
+                       analog.meaning->unit = SR_UNIT_FAHRENHEIT;
                        break;
                case 3:
-                       analog.unit = SR_UNIT_KELVIN;
+                       analog.meaning->unit = SR_UNIT_KELVIN;
                        break;
                default:
                        /* We can still pass on the measurement, whatever it is. */
-                       sr_dbg("Unknown unit 0x%.2x.", devc->packet[5]);
+                       sr_dbg("Unknown unit 0x%.2x.", pkt[5]);
                }
-               switch (devc->packet[13] - 0x30) {
+               switch (pkt[13] - '0') {
                case 0:
                        /* Channel T1. */
-                       analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 0));
+                       analog.meaning->channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 0));
                        break;
                case 1:
                        /* Channel T2. */
-                       analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 1));
+                       analog.meaning->channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 1));
                        break;
                case 2:
                case 3:
                        /* Channel T1-T2. */
-                       analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 2));
-                       analog.mqflags |= SR_MQFLAG_RELATIVE;
+                       analog.meaning->channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 2));
+                       analog.meaning->mqflags |= SR_MQFLAG_RELATIVE;
                        break;
                default:
-                       sr_err("Unknown channel 0x%.2x.", devc->packet[13]);
+                       sr_err("Unknown channel 0x%.2x.", pkt[13]);
                        is_valid = FALSE;
                }
                if (is_valid) {
                        analog.num_samples = 1;
                        analog.data = &temp;
-                       packet.type = SR_DF_ANALOG_OLD;
+                       packet.type = SR_DF_ANALOG;
                        packet.payload = &analog;
-                       sr_session_send(devc->cb_data, &packet);
-                       g_slist_free(analog.channels);
+                       sr_session_send(sdi, &packet);
+                       g_slist_free(analog.meaning->channels);
                }
        }
 
-       /* We count packets even if the temperature was invalid. This way
-        * a sample limit on "Memory" data source still works: unused
-        * memory slots come through as "----" measurements. */
-       devc->num_samples++;
-       if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
-               sdi->driver->dev_acquisition_stop((struct sr_dev_inst *)sdi,
-                               devc->cb_data);
-       }
-
+       /*
+        * We count packets even if the measurement was invalid. This way
+        * a sample limit on "Memory" data source still works: Unused
+        * memory slots come through as "----" measurements.
+        */
+       devc = sdi->priv;
+       sr_sw_limits_update_samples_read(&devc->limits, 1);
+       if (sr_sw_limits_check(&devc->limits))
+               sr_dev_acquisition_stop(sdi);
 }
 
 SR_PRIV void LIBUSB_CALL uni_t_ut32x_receive_transfer(struct libusb_transfer *transfer)
@@ -162,17 +172,16 @@ SR_PRIV void LIBUSB_CALL uni_t_ut32x_receive_transfer(struct libusb_transfer *tr
                                hid_payload_len);
                devc->packet_len += hid_payload_len;
                if (devc->packet_len >= 2
-                               && devc->packet[devc->packet_len - 2] == 0x0d
-                               && devc->packet[devc->packet_len - 1] == 0x0a) {
-                       /* Got end of packet, but do we have a complete packet? */
-                       if (devc->packet_len == 19)
-                               process_packet(sdi);
-                       /* Either way, done with it. */
+                               && devc->packet[devc->packet_len - 2] == SEP[0]
+                               && devc->packet[devc->packet_len - 1] == SEP[1]) {
+                       /* Got end of packet. */
+                       process_packet(sdi, devc->packet, devc->packet_len);
                        devc->packet_len = 0;
-               } else if (devc->packet_len > 19) {
+               } else if (devc->packet_len > PACKET_SIZE) {
                        /* Guard against garbage from the device overrunning
                         * our packet buffer. */
                        sr_dbg("Buffer overrun!");
+                       process_packet(sdi, devc->packet, devc->packet_len);
                        devc->packet_len = 0;
                }
        }
@@ -218,7 +227,7 @@ SR_PRIV int uni_t_ut32x_handle_events(int fd, int revents, void *cb_data)
 
        if (sdi->status == SR_ST_STOPPING) {
                usb_source_remove(sdi->session, drvc->sr_ctx);
-               std_session_send_df_header(cb_data, LOG_PREFIX);
+               std_session_send_df_end(sdi);
 
                /* Tell the device to stop sending USB packets. */
                usb = sdi->conn;