]> sigrok.org Git - libsigrok.git/blobdiff - hardware/brymen-dmm/protocol.c
brymen-dmm: Use std_hw_init().
[libsigrok.git] / hardware / brymen-dmm / protocol.c
index cf59ee25e6be17bf1ac87d7156c4269d43fc23b2..41bcd4c528163939a4924042f2813a2c3a76d988 100644 (file)
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <stdlib.h>
-#include <glib.h>
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 #include "protocol.h"
 
+#include <string.h>
+
+/* --- parser.c --- */
+SR_PRIV int sr_brymen_parse(const uint8_t *buf, float *floatval,
+                           struct sr_datafeed_analog *analog, void *info);
+
+
+static void handle_packet(const uint8_t *buf, struct sr_dev_inst *sdi)
+{
+       float floatval;
+       struct dev_context *devc;
+       struct sr_datafeed_packet packet;
+       struct sr_datafeed_analog analog;
+
+       devc = sdi->priv;
+       
+       analog.num_samples = 1;
+       analog.mq = -1;
+
+       sr_brymen_parse(buf, &floatval, &analog, NULL);
+       analog.data = &floatval;
+
+       analog.probes = sdi->probes;
+
+       if (analog.mq != -1) {
+               /* Got a measurement. */
+               packet.type = SR_DF_ANALOG;
+               packet.payload = &analog;
+               sr_session_send(devc->cb_data, &packet);
+               devc->num_samples++;
+       }
+}
+
+static void handle_new_data(struct sr_dev_inst *sdi)
+{
+       struct dev_context *devc;
+       int len, status, offset = 0;
+
+       devc = sdi->priv;
+
+       /* Try to get as much data as the buffer can hold. */
+       len = DMM_BUFSIZE - devc->buflen;
+       len = serial_read(devc->serial, devc->buf + devc->buflen, len);
+       if (len < 1) {
+               sr_err("Serial port read error: %d.", len);
+               return;
+       }
+       devc->buflen += len;
+       status = PACKET_INVALID_HEADER;
+
+       /* Now look for packets in that data. */
+       while (status != PACKET_NEED_MORE_DATA) {
+               /* We don't have a header, look for one */
+               if (devc->next_packet_len == 0) {
+                       len = devc->buflen - offset;
+                       status = brymen_packet_length(devc->buf + offset, &len);
+                       if (status == PACKET_HEADER_OK) {
+                               /* We know how large the packet will be */
+                               devc->next_packet_len = len;
+                       } else if (status == PACKET_NEED_MORE_DATA) {
+                               /* We did not yet receive the complete header */
+                               devc->next_packet_len = 0;
+                               break;
+                       } else {
+                               /* Invalid header. Move on */
+                               devc->next_packet_len = 0;
+                               offset++;
+                               continue;
+                       }
+               }
+
+               /* We know how the packet size, but did we receive all of it? */
+               if (devc->buflen - offset < devc->next_packet_len)
+                       break;
+
+               /* We should have a full packet here, so we can check it */
+               if (brymen_packet_is_valid(devc->buf + offset)) {
+                       handle_packet(devc->buf + offset, sdi);
+                       offset += devc->next_packet_len;
+               } else {
+                       offset++;
+               }
+               /* We are done with this packet. Look for a new one. */
+               devc->next_packet_len = 0;
+       }
+
+       /* If we have any data left, move it to the beginning of our buffer. */
+       memmove(devc->buf, devc->buf + offset, devc->buflen - offset);
+       devc->buflen -= offset;
+}
+
 SR_PRIV int brymen_dmm_receive_data(int fd, int revents, void *cb_data)
 {
-       const struct sr_dev_inst *sdi;
+       struct sr_dev_inst *sdi;
        struct dev_context *devc;
+       int ret;
+       int64_t time;
+
+       (void)fd;
 
        if (!(sdi = cb_data))
                return TRUE;
@@ -35,8 +128,134 @@ SR_PRIV int brymen_dmm_receive_data(int fd, int revents, void *cb_data)
                return TRUE;
 
        if (revents == G_IO_IN) {
-               /* TODO */
+               /* Serial data arrived. */
+               handle_new_data(sdi);
+       } else {
+               /* Timeout, send another packet request. */
+               ret = brymen_packet_request(devc->serial);
+               if (ret < 0) {
+                       sr_err("Failed to request packet: %d.", ret);
+                       return FALSE;
+               }
+       }
+
+       if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
+               sr_info("Requested number of samples reached, stopping.");
+               sdi->driver->dev_acquisition_stop(sdi, cb_data);
+               return TRUE;
+       }
+
+       if (devc->limit_msec) {
+               time = (g_get_monotonic_time() - devc->starttime) / 1000;
+               if (time > (int64_t)devc->limit_msec) {
+                       sr_info("Requested time limit reached, stopping.");
+                       sdi->driver->dev_acquisition_stop(sdi, cb_data);
+                       return TRUE;
+               }
        }
 
        return TRUE;
 }
+
+/**
+ * Try to find a valid packet in a serial data stream.
+ *
+ * @param serial Previously initialized serial port structure.
+ * @param buf Buffer containing the bytes to write.
+ * @param buflen Size of the buffer.
+ * @param packet_size Callback that assesses the size of the incoming 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.
+ *
+ * @return SR_OK if a valid packet is found within the given timeout,
+ *         SR_ERR upon failure.
+ */
+SR_PRIV int brymen_stream_detect(struct sr_serial_dev_inst *serial,
+                               uint8_t *buf, size_t *buflen,
+                               packet_length_t get_packet_size,
+                               packet_valid_t is_valid,
+                               uint64_t timeout_ms, int baudrate)
+{
+       int64_t start, time, byte_delay_us;
+       size_t ibuf, i, maxlen;
+       int status, len, packet_len, stream_len;
+
+       maxlen = *buflen;
+
+       sr_dbg("Detecting packets on FD %d (timeout = %" PRIu64
+       "ms, baudrate = %d).", serial->fd, timeout_ms, baudrate);
+
+       /* Assume 8n1 transmission. That is 10 bits for every byte. */
+       byte_delay_us = 10 * (1000000 / baudrate);
+       start = g_get_monotonic_time();
+
+       packet_len = i = ibuf = len = 0;
+       while (ibuf < maxlen) {
+               len = serial_read(serial, &buf[ibuf], maxlen - ibuf);
+               if (len > 0) {
+                       ibuf += len;
+                       sr_spew("Read %d bytes", len);
+               }
+
+               time = g_get_monotonic_time() - start;
+               time /= 1000;
+
+               stream_len = ibuf - i;
+               if (stream_len > 0 && packet_len == 0) {
+                       /* How large of a packet are we expecting? */
+                       packet_len = stream_len;
+                       status = get_packet_size(&buf[i], &packet_len);
+                       switch(status) {
+                       case PACKET_HEADER_OK:
+                               /* We know how much data we need to wait for */
+                               break;
+                       case PACKET_NEED_MORE_DATA:
+                               /* We did not receive the full header */
+                               packet_len = 0;
+                               break;
+                       case PACKET_INVALID_HEADER:
+                       default:
+                               /*
+                                * We had enough data, but here was an error in
+                                * parsing the header. Restart parsing from the
+                                * next byte
+                                */
+                               packet_len = 0;
+                               i++;
+                               break;
+                       }
+               }
+
+               if ( (stream_len >= packet_len) && (packet_len != 0) ) {
+                       /* We have at least a packet's worth of data. */
+                       if (is_valid(&buf[i])) {
+                               sr_spew("Found valid %d-byte packet after "
+                               "%" PRIu64 "ms.", packet_len, time);
+                               *buflen = ibuf;
+                               return SR_OK;
+                       } else {
+                               sr_spew("Got %d bytes, but not a valid "
+                               "packet.", packet_len);
+
+                       }
+                       /* Not a valid packet. Continue searching. */
+                       i++;
+                       packet_len = 0;
+               }
+               if (time >= (int64_t)timeout_ms) {
+                       /* Timeout */
+                       sr_dbg("Detection timed out after %dms.", time);
+                       break;
+               }
+               g_usleep(byte_delay_us);
+       }
+
+       *buflen = ibuf;
+       sr_err("Didn't find a valid packet (read %d bytes).", ibuf);
+
+       return SR_ERR;
+}