+static void samples_generator(uint8_t *buf, uint64_t size, void *data)
+{
+ struct databag *mydata = data;
+ uint64_t p, i;
+#ifdef DEMO_ANALOG
+ /*
+ * We will simulate a device with 8 logic probes and 1 analog probe.
+ * This fictional device sends the data packed: 8 bits for 8 logic
+ * probes and 16 bits for the analog probe, in this order.
+ * Total of 24 bits.
+ * I could just generate a properly formatted DF_ANALOG packet here,
+ * but I will leave the formatting to receive_data() to make its code
+ * more like a real hardware driver.
+ */
+ memset(buf, 0, size * 3);
+
+ switch (mydata->sample_generator) {
+ default:
+ case GENMODE_DEFAULT:
+ case GENMODE_SINE:
+ for (i = 0; i < size * 3; i += 3) {
+ *(buf + i) = i / 3;
+ *(uint16_t *) (buf + i + 1) =
+ (uint16_t) (sin(i / 3) * 256 * 30);
+ }
+ break;
+ case GENMODE_RANDOM:
+ for (i = 0; i < size * 3; i += 3) {
+ *(buf + i) = (uint8_t)(rand() & 0xff);
+ *(uint16_t *) (buf + i + 1) = (uint16_t)(rand() & 0xffff);
+ }
+ break;
+ case GENMODE_INC:
+ for (i = 0; i < size * 3; i += 3) {
+ *(buf + i) = i / 3;
+ *(uint16_t *)(buf + i + 1) = i / 3 * 256 * 10;
+ }
+ break;
+ }
+#else
+
+ memset(buf, 0, size);
+
+ switch (mydata->sample_generator) {
+ case GENMODE_DEFAULT:
+ p = 0;
+ for (i = 0; i < size; i++) {
+ *(buf + i) = ~(genmode_default[p] >> 1);
+ if (++p == 64)
+ p = 0;
+ }
+ break;
+ case GENMODE_RANDOM: /* Random */
+ for (i = 0; i < size; i++)
+ *(buf + i) = (uint8_t)(rand() & 0xff);
+ break;
+ case GENMODE_INC: /* Simple increment */
+ for (i = 0; i < size; i++)
+ *(buf + i) = i;
+ break;
+ }
+#endif
+}
+
+/* Thread function */
+static void thread_func(void *data)
+{
+ struct databag *mydata = data;
+ uint8_t buf[BUFSIZE];
+ uint64_t nb_to_send = 0;
+ int bytes_written;
+
+ double time_cur, time_last, time_diff;
+
+ time_last = g_timer_elapsed(mydata->timer, NULL);
+
+ while (thread_running) {
+ /* Rate control */
+ time_cur = g_timer_elapsed(mydata->timer, NULL);
+
+ time_diff = time_cur - time_last;
+ time_last = time_cur;
+
+ nb_to_send = cur_samplerate * time_diff;
+
+ if (limit_samples)
+ nb_to_send = MIN(nb_to_send,
+ limit_samples - mydata->samples_counter);
+
+ /* Make sure we don't overflow. */
+#ifdef DEMO_ANALOG
+ nb_to_send = MIN(nb_to_send, BUFSIZE / 3);
+#else
+ nb_to_send = MIN(nb_to_send, BUFSIZE);
+#endif
+
+ if (nb_to_send) {
+ samples_generator(buf, nb_to_send, data);
+ mydata->samples_counter += nb_to_send;
+#ifdef DEMO_ANALOG
+ g_io_channel_write_chars(channels[1], (gchar *) &buf,
+ nb_to_send * 3, (gsize *) &bytes_written, NULL);
+#else
+ g_io_channel_write_chars(channels[1], (gchar *) &buf,
+ nb_to_send, (gsize *) &bytes_written, NULL);
+#endif
+ }
+
+ /* Check if we're done. */
+ if ((limit_msec && time_cur * 1000 > limit_msec) ||
+ (limit_samples && mydata->samples_counter >= limit_samples))
+ {
+ close(mydata->pipe_fds[1]);
+ thread_running = 0;
+ }
+
+ g_usleep(10);
+ }
+}
+
+/* Callback handling data */
+static int receive_data(int fd, int revents, void *user_data)
+{
+ struct datafeed_packet packet;
+ char c[BUFSIZE];
+ uint64_t z;
+#ifdef DEMO_ANALOG
+ struct analog_sample *sample;
+ unsigned int i, x;
+ int sample_size = sizeof(struct analog_sample) +
+ (NUM_PROBES * sizeof(struct analog_probe));
+ char *buf;
+#endif
+
+ /* Avoid compiler warnings. */
+ fd = fd;
+ revents = revents;
+
+ do {
+ g_io_channel_read_chars(channels[0],
+ (gchar *) &c, BUFSIZE, (gsize *) &z, NULL);
+
+ if (z > 0) {
+#ifdef DEMO_ANALOG
+ packet.type = DF_ANALOG;
+
+ packet.length = (z / 3) * sample_size;
+ packet.unitsize = sample_size;
+
+ buf = malloc(sample_size * packet.length);
+ if (!buf)
+ return FALSE;
+
+ /* Craft our packet. */
+ for (i = 0; i < z / 3; i++) {
+ sample = (struct analog_sample *) (buf + (i * sample_size));
+ sample->num_probes = NUM_PROBES;
+
+ /* 8 Logic probes */
+ for (x = 0; x < NUM_PROBES - 1; x++) {
+ sample->probes[x].val =
+ (c[i * 3] >> x) & 1;
+ sample->probes[x].res = 1;
+ }
+
+ /* 1 Analog probe, 16 bit adc */
+ for (; x < NUM_PROBES; x++) {
+ sample->probes[x].val =
+ *(uint16_t *) (c + i * 3 + 1);
+ sample->probes[x].val &= ((1 << 16) - 1);
+ sample->probes[x].res = 16;
+ }
+
+ }
+
+ packet.payload = buf;
+ session_bus(user_data, &packet);
+ free(buf);
+#else
+ packet.type = DF_LOGIC;
+ packet.length = z;
+ packet.unitsize = 1;
+ packet.payload = c;
+ session_bus(user_data, &packet);
+#endif
+ }
+ } while (z > 0);
+
+ if (!thread_running && z <= 0)
+ {
+ /* Make sure we don't receive more packets */
+ g_io_channel_close(channels[0]);
+
+ /* Send last packet. */
+ packet.type = DF_END;
+ session_bus(user_data, &packet);
+
+ return FALSE;
+ }
+
+ return TRUE;
+}
+