saleae-logic16: Implemented acquisition.

configure.ac

@@ -457,6 +457,7 @@ fi
 AC_CHECK_HEADERS([fcntl.h sys/time.h termios.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
+AC_C_BIGENDIAN
 AC_C_INLINE
 AC_TYPE_INT8_T
 AC_TYPE_INT16_T

hardware/saleae-logic16/api.c

@@ -34,6 +34,7 @@
 #define FX2_FIRMWARE		FIRMWARE_DIR "/saleae-logic16-fx2.fw"
 
 #define MAX_RENUM_DELAY_MS	3000
+#define NUM_SIMUL_TRANSFERS	32
 
 
 SR_PRIV struct sr_dev_driver saleae_logic16_driver_info;
@@ -45,6 +46,23 @@ static const char *probe_names[NUM_PROBES + 1] = {
 	NULL,
 };
 
+static const uint64_t samplerates[] = {
+	SR_KHZ(500),
+	SR_MHZ(1),
+	SR_MHZ(2),
+	SR_MHZ(4),
+	SR_MHZ(5),
+	SR_MHZ(8),
+	SR_MHZ(10),
+	SR_KHZ(12500),
+	SR_MHZ(16),
+	SR_MHZ(25),
+	SR_MHZ(32),
+	SR_MHZ(40),
+	SR_MHZ(80),
+	SR_MHZ(100),
+};
+
 static int init(struct sr_context *sr_ctx)
 {
 	return std_init(sr_ctx, di, LOG_PREFIX);
@@ -357,7 +375,7 @@ static int dev_open(struct sr_dev_inst *sdi)
 
 	if (devc->cur_samplerate == 0) {
 		/* Samplerate hasn't been set; default to the slowest one. */
-		devc->cur_samplerate = 500000;
+		devc->cur_samplerate = samplerates[0];
 	}
 
 	return SR_OK;
@@ -399,6 +417,7 @@ static int cleanup(void)
 
 static int config_get(int key, GVariant **data, const struct sr_dev_inst *sdi)
 {
+	struct dev_context *devc;
 	int ret;
 
 	(void)sdi;
@@ -406,7 +425,12 @@ static int config_get(int key, GVariant **data, const struct sr_dev_inst *sdi)
 
 	ret = SR_OK;
 	switch (key) {
-	/* TODO */
+	case SR_CONF_SAMPLERATE:
+		if (!sdi)
+			return SR_ERR;
+		devc = sdi->priv;
+		*data = g_variant_new_uint64(devc->cur_samplerate);
+		break;
 	default:
 		return SR_ERR_NA;
 	}
@@ -416,16 +440,22 @@ static int config_get(int key, GVariant **data, const struct sr_dev_inst *sdi)
 
 static int config_set(int key, GVariant *data, const struct sr_dev_inst *sdi)
 {
+	struct dev_context *devc;
 	int ret;
 
-	(void)data;
-
 	if (sdi->status != SR_ST_ACTIVE)
 		return SR_ERR_DEV_CLOSED;
 
+	devc = sdi->priv;
+
 	ret = SR_OK;
 	switch (key) {
-	/* TODO */
+	case SR_CONF_SAMPLERATE:
+		devc->cur_samplerate = g_variant_get_uint64(data);
+		break;
+	case SR_CONF_LIMIT_SAMPLES:
+		devc->limit_samples = g_variant_get_uint64(data);
+		break;
 	default:
 		ret = SR_ERR_NA;
 	}
@@ -435,14 +465,21 @@ static int config_set(int key, GVariant *data, const struct sr_dev_inst *sdi)
 
 static int config_list(int key, GVariant **data, const struct sr_dev_inst *sdi)
 {
+	GVariant *gvar;
+	GVariantBuilder gvb;
 	int ret;
 
 	(void)sdi;
-	(void)data;
 
 	ret = SR_OK;
 	switch (key) {
-	/* TODO */
+	case SR_CONF_SAMPLERATE:
+		g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
+		gvar = g_variant_new_fixed_array(G_VARIANT_TYPE("t"), samplerates,
+				ARRAY_SIZE(samplerates), sizeof(uint64_t));
+		g_variant_builder_add(&gvb, "{sv}", "samplerates", gvar);
+		*data = g_variant_builder_end(&gvb);
+		break;
 	default:
 		return SR_ERR_NA;
 	}
@@ -450,31 +487,244 @@ static int config_list(int key, GVariant **data, const struct sr_dev_inst *sdi)
 	return ret;
 }
 
+static void abort_acquisition(struct dev_context *devc)
+{
+	int i;
+
+	devc->num_samples = -1;
+
+	for (i = devc->num_transfers - 1; i >= 0; i--) {
+		if (devc->transfers[i])
+			libusb_cancel_transfer(devc->transfers[i]);
+	}
+}
+
+static unsigned int bytes_per_ms(struct dev_context *devc)
+{
+	return devc->cur_samplerate * devc->num_channels / 8000;
+}
+
+static size_t get_buffer_size(struct dev_context *devc)
+{
+	size_t s;
+
+	/*
+	 * The buffer should be large enough to hold 10ms of data and
+	 * a multiple of 512.
+	 */
+	s = 10 * bytes_per_ms(devc);
+	return (s + 511) & ~511;
+}
+
+static unsigned int get_number_of_transfers(struct dev_context *devc)
+{
+	unsigned int n;
+
+	/* Total buffer size should be able to hold about 500ms of data. */
+	n = 500 * bytes_per_ms(devc) / get_buffer_size(devc);
+
+	if (n > NUM_SIMUL_TRANSFERS)
+		return NUM_SIMUL_TRANSFERS;
+
+	return n;
+}
+
+static unsigned int get_timeout(struct dev_context *devc)
+{
+	size_t total_size;
+	unsigned int timeout;
+
+	total_size = get_buffer_size(devc) * get_number_of_transfers(devc);
+	timeout = total_size / bytes_per_ms(devc);
+	return timeout + timeout / 4; /* Leave a headroom of 25% percent. */
+}
+
+static int configure_probes(const struct sr_dev_inst *sdi)
+{
+	struct dev_context *devc;
+	struct sr_probe *probe;
+	GSList *l;
+	uint16_t probe_bit;
+
+	devc = sdi->priv;
+
+	devc->cur_channels = 0;
+	devc->num_channels = 0;
+	for (l = sdi->probes; l; l = l->next) {
+		probe = (struct sr_probe *)l->data;
+		if (probe->enabled == FALSE)
+			continue;
+
+		probe_bit = 1 << (probe->index);
+
+		devc->cur_channels |= probe_bit;
+
+#ifdef WORDS_BIGENDIAN
+		/* Output logic data should be stored in little endian
+		   format.  To speed things up during conversion, do the
+		   switcharoo here instead. */
+
+		probe_bit = 1 << (probe->index ^ 8);
+#endif
+
+		devc->channel_masks[devc->num_channels ++] = probe_bit;
+	}
+
+	return SR_OK;
+}
+
+static int receive_data(int fd, int revents, void *cb_data)
+{
+	struct timeval tv;
+	struct dev_context *devc;
+	struct drv_context *drvc;
+	const struct sr_dev_inst *sdi;
+
+	(void)fd;
+	(void)revents;
+
+	sdi = cb_data;
+	drvc = di->priv;
+	devc = sdi->priv;
+
+	tv.tv_sec = tv.tv_usec = 0;
+	libusb_handle_events_timeout(drvc->sr_ctx->libusb_ctx, &tv);
+
+	if (devc->num_samples == -2) {
+		saleae_logic16_abort_acquisition(sdi);
+		abort_acquisition(devc);
+	}
+
+	return TRUE;
+}
+
 static int dev_acquisition_start(const struct sr_dev_inst *sdi,
 				 void *cb_data)
 {
-	(void)sdi;
+	struct dev_context *devc;
-	(void)cb_data;
+	struct drv_context *drvc;
+	struct sr_usb_dev_inst *usb;
+	struct libusb_transfer *transfer;
+	const struct libusb_pollfd **lupfd;
+	unsigned int i, timeout, num_transfers;
+	int ret;
+	unsigned char *buf;
+	size_t size, convsize;
 
 	if (sdi->status != SR_ST_ACTIVE)
 		return SR_ERR_DEV_CLOSED;
 
-	/* TODO: configure hardware, reset acquisition state, set up
+	drvc = di->priv;
-	 * callbacks and send header packet. */
+	devc = sdi->priv;
+	usb = sdi->conn;
+
+	/* Configures devc->cur_channels */
+	if (configure_probes(sdi) != SR_OK) {
+		sr_err("Failed to configure probes.");
+		return SR_ERR;
+	}
+
+	devc->cb_data = cb_data;
+	devc->num_samples = 0;
+	devc->empty_transfer_count = 0;
+	devc->cur_channel = 0;
+	memset(devc->channel_data, 0, sizeof(devc->channel_data));
+
+	timeout = get_timeout(devc);
+	num_transfers = get_number_of_transfers(devc);
+	size = get_buffer_size(devc);
+	convsize = (size / devc->num_channels + 2) * 16;
+	devc->submitted_transfers = 0;
+	devc->usbfd = NULL;
+
+	devc->convbuffer_size = convsize;
+	if (!(devc->convbuffer = g_try_malloc(convsize))) {
+		sr_err("Conversion buffer malloc failed.");
+		return SR_ERR_MALLOC;
+	}
+
+	devc->transfers = g_try_malloc0(sizeof(*devc->transfers) * num_transfers);
+	if (!devc->transfers) {
+		sr_err("USB transfers malloc failed.");
+		g_free(devc->convbuffer);
+		return SR_ERR_MALLOC;
+	}
+
+	if ((ret = saleae_logic16_setup_acquisition(sdi, devc->cur_samplerate,
+						    devc->cur_channels)) != SR_OK) {
+		g_free(devc->transfers);
+		g_free(devc->convbuffer);
+		return ret;
+	}
+
+	devc->num_transfers = num_transfers;
+	for (i = 0; i < num_transfers; i++) {
+		if (!(buf = g_try_malloc(size))) {
+			sr_err("USB transfer buffer malloc failed.");
+			if (devc->submitted_transfers)
+				abort_acquisition(devc);
+			else {
+				g_free(devc->transfers);
+				g_free(devc->convbuffer);
+			}
+			return SR_ERR_MALLOC;
+		}
+		transfer = libusb_alloc_transfer(0);
+		libusb_fill_bulk_transfer(transfer, usb->devhdl,
+				2 | LIBUSB_ENDPOINT_IN, buf, size,
+				saleae_logic16_receive_transfer, devc, timeout);
+		if ((ret = libusb_submit_transfer(transfer)) != 0) {
+			sr_err("Failed to submit transfer: %s.",
+			       libusb_error_name(ret));
+			libusb_free_transfer(transfer);
+			g_free(buf);
+			abort_acquisition(devc);
+			return SR_ERR;
+		}
+		devc->transfers[i] = transfer;
+		devc->submitted_transfers++;
+	}
+
+	lupfd = libusb_get_pollfds(drvc->sr_ctx->libusb_ctx);
+	for (i = 0; lupfd[i]; i++);
+	if (!(devc->usbfd = g_try_malloc(sizeof(struct libusb_pollfd) * (i + 1)))) {
+		abort_acquisition(devc);
+		free(lupfd);
+		return SR_ERR;
+	}
+	for (i = 0; lupfd[i]; i++) {
+		sr_source_add(lupfd[i]->fd, lupfd[i]->events,
+			      timeout, receive_data, (void *)sdi);
+		devc->usbfd[i] = lupfd[i]->fd;
+	}
+	devc->usbfd[i] = -1;
+	free(lupfd);
+
+	/* Send header packet to the session bus. */
+	std_session_send_df_header(cb_data, LOG_PREFIX);
+
+	if ((ret = saleae_logic16_start_acquisition(sdi)) != SR_OK) {
+		abort_acquisition(devc);
+		return ret;
+	}
 
 	return SR_OK;
 }
 
 static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 {
+	int ret;
+
 	(void)cb_data;
 
 	if (sdi->status != SR_ST_ACTIVE)
 		return SR_ERR_DEV_CLOSED;
 
-	/* TODO: stop acquisition. */
+	ret = saleae_logic16_abort_acquisition(sdi);
 
-	return SR_OK;
+	abort_acquisition(sdi->priv);
+
+	return ret;
 }
 
 SR_PRIV struct sr_dev_driver saleae_logic16_driver_info = {

hardware/saleae-logic16/protocol.c

@@ -32,6 +32,16 @@
 #define FPGA_FIRMWARE_18	FIRMWARE_DIR"/saleae-logic16-fpga-18.bitstream"
 #define FPGA_FIRMWARE_33	FIRMWARE_DIR"/saleae-logic16-fpga-33.bitstream"
 
+#define MAX_SAMPLE_RATE		SR_MHZ(100)
+#define MAX_4CH_SAMPLE_RATE	SR_MHZ(50)
+#define MAX_7CH_SAMPLE_RATE	SR_MHZ(40)
+#define MAX_8CH_SAMPLE_RATE	SR_MHZ(32)
+#define MAX_10CH_SAMPLE_RATE	SR_MHZ(25)
+#define MAX_13CH_SAMPLE_RATE	SR_MHZ(16)
+
+#define BASE_CLOCK_0_FREQ	SR_MHZ(100)
+#define BASE_CLOCK_1_FREQ	SR_MHZ(160)
+
 #define COMMAND_START_ACQUISITION	1
 #define COMMAND_ABORT_ACQUISITION_ASYNC	2
 #define COMMAND_WRITE_EEPROM		6
@@ -52,6 +62,8 @@
 #define READ_EEPROM_COOKIE2		0x81
 #define ABORT_ACQUISITION_SYNC_PATTERN	0x55
 
+#define MAX_EMPTY_TRANSFERS		64
+
 
 static void encrypt(uint8_t *dest, const uint8_t *src, uint8_t cnt)
 {
@@ -384,15 +396,11 @@ static int upload_fpga_bitstream(const struct sr_dev_inst *sdi,
 	if ((ret = configure_led(sdi)) != SR_OK)
 		return ret;
 
-	/* XXX */
-	if ((ret = configure_led(sdi)) != SR_OK)
-		return ret;
-
 	devc->cur_voltage_range = vrange;
 	return SR_OK;
 }
 
-SR_PRIV int saleae_logic16_abort_acquisition(const struct sr_dev_inst *sdi)
+static int abort_acquisition_sync(const struct sr_dev_inst *sdi)
 {
 	static const uint8_t command[2] = {
 		COMMAND_ABORT_ACQUISITION_SYNC,
@@ -414,6 +422,137 @@ SR_PRIV int saleae_logic16_abort_acquisition(const struct sr_dev_inst *sdi)
 	return SR_OK;
 }
 
+SR_PRIV int saleae_logic16_setup_acquisition(const struct sr_dev_inst *sdi,
+					     uint64_t samplerate,
+					     uint16_t channels)
+{
+	uint8_t clock_select, reg1, reg10;
+	uint64_t div;
+	int i, ret, nchan = 0;
+
+	if (samplerate == 0 || samplerate > MAX_SAMPLE_RATE) {
+		sr_err("Unable to sample at %" PRIu64 "Hz.", samplerate);
+		return SR_ERR;
+	}
+
+	if (BASE_CLOCK_0_FREQ % samplerate == 0 &&
+	    (div = BASE_CLOCK_0_FREQ / samplerate) <= 256) {
+		clock_select = 0;
+	} else if (BASE_CLOCK_1_FREQ % samplerate == 0 &&
+		   (div = BASE_CLOCK_1_FREQ / samplerate) <= 256) {
+		clock_select = 1;
+	} else {
+		sr_err("Unable to sample at %" PRIu64 "Hz.", samplerate);
+		return SR_ERR;
+	}
+
+	for (i=0; i<16; i++)
+		if (channels & (1U<<i))
+			nchan++;
+
+	if ((nchan >= 13 && samplerate > MAX_13CH_SAMPLE_RATE) ||
+	    (nchan >= 10 && samplerate > MAX_10CH_SAMPLE_RATE) ||
+	    (nchan >= 8  && samplerate > MAX_8CH_SAMPLE_RATE) ||
+	    (nchan >= 7  && samplerate > MAX_7CH_SAMPLE_RATE) ||
+	    (nchan >= 4  && samplerate > MAX_4CH_SAMPLE_RATE)) {
+		sr_err("Unable to sample at %" PRIu64 "Hz "
+		       "with this many channels.", samplerate);
+		return SR_ERR;
+	}
+
+	if ((ret = read_fpga_register(sdi, 1, &reg1)) != SR_OK)
+		return ret;
+
+	if (reg1 != 0x08) {
+		sr_dbg("Invalid state at acquisition setup: 0x%02x != 0x08", reg1);
+		return SR_ERR;
+	}
+
+	if ((ret = write_fpga_register(sdi, 1, 0x40)) != SR_OK)
+		return ret;
+
+	if ((ret = write_fpga_register(sdi, 10, clock_select)) != SR_OK)
+		return ret;
+
+	if ((ret = write_fpga_register(sdi, 4, (uint8_t)(div-1))) != SR_OK)
+		return ret;
+
+	if ((ret = write_fpga_register(sdi, 2, (uint8_t)(channels & 0xff))) != SR_OK)
+		return ret;
+
+	if ((ret = write_fpga_register(sdi, 3, (uint8_t)(channels >> 8))) != SR_OK)
+		return ret;
+
+	if ((ret = write_fpga_register(sdi, 1, 0x42)) != SR_OK)
+		return ret;
+
+	if ((ret = write_fpga_register(sdi, 1, 0x40)) != SR_OK)
+		return ret;
+
+	if ((ret = read_fpga_register(sdi, 1, &reg1)) != SR_OK)
+		return ret;
+
+	if (reg1 != 0x48) {
+		sr_dbg("Invalid state at acquisition setup: 0x%02x != 0x48", reg1);
+		return SR_ERR;
+	}
+
+	if ((ret = read_fpga_register(sdi, 10, &reg10)) != SR_OK)
+		return ret;
+
+	if (reg10 != clock_select) {
+		sr_dbg("Invalid state at acquisition setup: 0x%02x != 0x%02x",
+		       reg10, (unsigned)clock_select);
+		return SR_ERR;
+	}
+
+	return SR_OK;
+}
+
+SR_PRIV int saleae_logic16_start_acquisition(const struct sr_dev_inst *sdi)
+{
+	static const uint8_t command[1] = {
+		COMMAND_START_ACQUISITION,
+	};
+	int ret;
+
+	if ((ret = do_ep1_command(sdi, command, 1, NULL, 0)) != SR_OK)
+		return ret;
+
+	return write_fpga_register(sdi, 1, 0x41);
+}
+
+SR_PRIV int saleae_logic16_abort_acquisition(const struct sr_dev_inst *sdi)
+{
+	static const uint8_t command[1] = {
+		COMMAND_ABORT_ACQUISITION_ASYNC,
+	};
+	int ret;
+	uint8_t reg1, reg8, reg9;
+
+	if ((ret = do_ep1_command(sdi, command, 1, NULL, 0)) != SR_OK)
+		return ret;
+
+	if ((ret = write_fpga_register(sdi, 1, 0x00)) != SR_OK)
+		return ret;
+
+	if ((ret = read_fpga_register(sdi, 1, &reg1)) != SR_OK)
+		return ret;
+
+	if (reg1 != 0x08) {
+		sr_dbg("Invalid state at acquisition stop: 0x%02x != 0x08", reg1);
+		return SR_ERR;
+	}
+
+	if ((ret = read_fpga_register(sdi, 8, &reg8)) != SR_OK)
+		return ret;
+
+	if ((ret = read_fpga_register(sdi, 9, &reg9)) != SR_OK)
+		return ret;
+
+	return SR_OK;
+}
+
 SR_PRIV int saleae_logic16_init_device(const struct sr_dev_inst *sdi)
 {
 	struct dev_context *devc;
@@ -423,7 +562,7 @@ SR_PRIV int saleae_logic16_init_device(const struct sr_dev_inst *sdi)
 
 	devc->cur_voltage_range = VOLTAGE_RANGE_UNKNOWN;
 
-	if ((ret = saleae_logic16_abort_acquisition(sdi)) != SR_OK)
+	if ((ret = abort_acquisition_sync(sdi)) != SR_OK)
 		return ret;
 
 	if ((ret = read_eeprom(sdi, 8, 8, devc->eeprom_data)) != SR_OK)
@@ -435,22 +574,188 @@ SR_PRIV int saleae_logic16_init_device(const struct sr_dev_inst *sdi)
 	return SR_OK;
 }
 
-SR_PRIV int saleae_logic16_receive_data(int fd, int revents, void *cb_data)
+static void finish_acquisition(struct dev_context *devc)
 {
-	(void)fd;
+	struct sr_datafeed_packet packet;
+	int i;
 
-	const struct sr_dev_inst *sdi;
+	/* Terminate session. */
+	packet.type = SR_DF_END;
+	sr_session_send(devc->cb_data, &packet);
+
+	/* Remove fds from polling. */
+	if (devc->usbfd != NULL) {
+		for (i = 0; devc->usbfd[i] != -1; i++)
+			sr_source_remove(devc->usbfd[i]);
+		g_free(devc->usbfd);
+	}
+
+	devc->num_transfers = 0;
+	g_free(devc->transfers);
+	g_free(devc->convbuffer);
+}
+
+static void free_transfer(struct libusb_transfer *transfer)
+{
 	struct dev_context *devc;
+	unsigned int i;
 
-	if (!(sdi = cb_data))
+	devc = transfer->user_data;
-		return TRUE;
 
-	if (!(devc = sdi->priv))
+	g_free(transfer->buffer);
-		return TRUE;
+	transfer->buffer = NULL;
+	libusb_free_transfer(transfer);
 
-	if (revents == G_IO_IN) {
+	for (i = 0; i < devc->num_transfers; i++) {
-		/* TODO */
+		if (devc->transfers[i] == transfer) {
+			devc->transfers[i] = NULL;
+			break;
+		}
 	}
 
-	return TRUE;
+	devc->submitted_transfers--;
+	if (devc->submitted_transfers == 0)
+		finish_acquisition(devc);
+}
+
+static void resubmit_transfer(struct libusb_transfer *transfer)
+{
+	int ret;
+
+	if ((ret = libusb_submit_transfer(transfer)) == LIBUSB_SUCCESS)
+		return;
+
+	free_transfer(transfer);
+	/* TODO: Stop session? */
+
+	sr_err("%s: %s", __func__, libusb_error_name(ret));
+}
+
+static size_t convert_sample_data(struct dev_context *devc,
+				  uint8_t *dest, size_t destcnt,
+				  const uint8_t *src, size_t srccnt)
+{
+	uint16_t *channel_data;
+	int i, cur_channel;
+	size_t ret = 0;
+
+	srccnt /= 2;
+
+	channel_data = devc->channel_data;
+	cur_channel = devc->cur_channel;
+
+	while(srccnt--) {
+		uint16_t sample, channel_mask;
+
+		sample = src[0] | (src[1] << 8);
+		src += 2;
+
+		channel_mask = devc->channel_masks[cur_channel];
+
+		for (i=15; i>=0; --i, sample >>= 1)
+			if (sample & 1)
+				channel_data[i] |= channel_mask;
+
+		if (++cur_channel == devc->num_channels) {
+			cur_channel = 0;
+			if (destcnt < 16*2) {
+				sr_err("Conversion buffer too small!");
+				break;
+			}
+			memcpy(dest, channel_data, 16*2);
+			memset(channel_data, 0, 16*2);
+			dest += 16*2;
+			ret += 16*2;
+			destcnt -= 16*2;
+		}
+	}
+
+	devc->cur_channel = cur_channel;
+
+	return ret;
+}
+
+SR_PRIV void saleae_logic16_receive_transfer(struct libusb_transfer *transfer)
+{
+	gboolean packet_has_error = FALSE;
+	struct sr_datafeed_packet packet;
+	struct sr_datafeed_logic logic;
+	struct dev_context *devc;
+	size_t converted_length;
+
+	devc = transfer->user_data;
+
+	/*
+	 * If acquisition has already ended, just free any queued up
+	 * transfer that come in.
+	 */
+	if (devc->num_samples < 0) {
+		free_transfer(transfer);
+		return;
+	}
+
+	sr_info("receive_transfer(): status %d received %d bytes.",
+		transfer->status, transfer->actual_length);
+
+	switch (transfer->status) {
+	case LIBUSB_TRANSFER_NO_DEVICE:
+		devc->num_samples = -2;
+		free_transfer(transfer);
+		return;
+	case LIBUSB_TRANSFER_COMPLETED:
+	case LIBUSB_TRANSFER_TIMED_OUT: /* We may have received some data though. */
+		break;
+	default:
+		packet_has_error = TRUE;
+		break;
+	}
+
+	if (transfer->actual_length & 1) {
+		sr_err("Got an odd number of bytes from the device.  This should not happen.");
+		/* Bail out right away */
+		packet_has_error = TRUE;
+		devc->empty_transfer_count = MAX_EMPTY_TRANSFERS;
+	}
+
+	if (transfer->actual_length == 0 || packet_has_error) {
+		devc->empty_transfer_count++;
+		if (devc->empty_transfer_count > MAX_EMPTY_TRANSFERS) {
+			/*
+			 * The FX2 gave up. End the acquisition, the frontend
+			 * will work out that the samplecount is short.
+			 */
+			devc->num_samples = -2;
+			free_transfer(transfer);
+		} else {
+			resubmit_transfer(transfer);
+		}
+		return;
+	} else {
+		devc->empty_transfer_count = 0;
+	}
+
+	converted_length =
+		convert_sample_data(devc,
+				    devc->convbuffer, devc->convbuffer_size,
+				    transfer->buffer, transfer->actual_length);
+
+	if (converted_length > 0) {
+		/* Send the incoming transfer to the session bus. */
+		packet.type = SR_DF_LOGIC;
+		packet.payload = &logic;
+		logic.length = converted_length;
+		logic.unitsize = 2;
+		logic.data = devc->convbuffer;
+		sr_session_send(devc->cb_data, &packet);
+
+		devc->num_samples += converted_length / 2;
+		if (devc->limit_samples &&
+		    (uint64_t)devc->num_samples > devc->limit_samples) {
+			devc->num_samples = -2;
+			free_transfer(transfer);
+			return;
+		}
+	}
+
+	resubmit_transfer(transfer);
 }

hardware/saleae-logic16/protocol.h

@@ -53,17 +53,41 @@ struct dev_context {
 	/** The currently configured samplerate of the device. */
 	uint64_t cur_samplerate;
 
+	/** Maximum number of samples to capture, if nonzero */
+	uint64_t limit_samples;
+
 	/** The currently configured input voltage of the device */
 	enum voltage_range cur_voltage_range;
 
+	/** Channels to use */
+	uint16_t cur_channels;
+
 	/*
 	 * EEPROM data from address 8
 	 */
 	uint8_t eeprom_data[8];
+
+	int64_t num_samples;
+	int submitted_transfers;
+	int empty_transfer_count;
+	int num_channels, cur_channel;
+	uint16_t channel_masks[16];
+	uint16_t channel_data[16];
+	uint8_t *convbuffer;
+	size_t convbuffer_size;
+
+	void *cb_data;
+	unsigned int num_transfers;
+	struct libusb_transfer **transfers;
+	int *usbfd;
 };
 
+SR_PRIV int saleae_logic16_setup_acquisition(const struct sr_dev_inst *sdi,
+					     uint64_t samplerate,
+					     uint16_t channels);
+SR_PRIV int saleae_logic16_start_acquisition(const struct sr_dev_inst *sdi);
 SR_PRIV int saleae_logic16_abort_acquisition(const struct sr_dev_inst *sdi);
 SR_PRIV int saleae_logic16_init_device(const struct sr_dev_inst *sdi);
-SR_PRIV int saleae_logic16_receive_data(int fd, int revents, void *cb_data);
+SR_PRIV void saleae_logic16_receive_transfer(struct libusb_transfer *transfer);
 
 #endif