From: Uwe Hermann <redacted>
Date: Tue, 4 Jun 2013 13:32:20 +0000 (+0200)
Subject: ikalogic-scanaplus: Initial driver implementation.
X-Git-Tag: libsigrok-0.2.1~36
X-Git-Url: https://sigrok.org/gitweb/?p=libsigrok.git;a=commitdiff_plain;h=ab4bb6eb7c6d7ab2eb212088a764fb696726c8dc

ikalogic-scanaplus: Initial driver implementation.
---

diff --git a/hardware/ikalogic-scanaplus/api.c b/hardware/ikalogic-scanaplus/api.c
index 2a1df8c1..7f1109a8 100644
--- a/hardware/ikalogic-scanaplus/api.c
+++ b/hardware/ikalogic-scanaplus/api.c
@@ -20,26 +20,146 @@
 
 #include "protocol.h"
 
+#define USB_VENDOR_ID			0x0403
+#define USB_DEVICE_ID			0x6014
+#define USB_VENDOR_NAME			"Ikalogic"
+#define USB_MODEL_NAME			"ScanaPLUS"
+#define USB_IPRODUCT			"SCANAPLUS"
+
+#define SAMPLE_BUF_SIZE			(8 * 1024 * 1024)
+
+static const int32_t hwcaps[] = {
+	SR_CONF_LOGIC_ANALYZER,
+	SR_CONF_SAMPLERATE,
+	SR_CONF_LIMIT_MSEC,
+	SR_CONF_LIMIT_SAMPLES,
+	SR_CONF_CONTINUOUS, // TODO?
+};
+
+/* Probes are numbered 1-9. */
+static const char *probe_names[] = {
+	"1", "2", "3", "4", "5", "6", "7", "8", "9",
+	NULL,
+};
+
+/* Note: The Ikalogic ScanaPLUS always samples at 100MHz. */
+static uint64_t samplerates[1] = { SR_MHZ(100) };
+
 SR_PRIV struct sr_dev_driver ikalogic_scanaplus_driver_info;
 static struct sr_dev_driver *di = &ikalogic_scanaplus_driver_info;
 
+static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data);
+
+static void clear_helper(void *priv)
+{
+	struct dev_context *devc;
+
+	devc = priv;
+
+	ftdi_free(devc->ftdic);
+	g_free(devc->compressed_buf);
+	g_free(devc->sample_buf);
+}
+
+static int dev_clear(void)
+{
+	return std_dev_clear(di, clear_helper);
+}
+
 static int init(struct sr_context *sr_ctx)
 {
-	return std_hw_init(sr_ctx, di, LOG_PREFIX);
+	return std_init(sr_ctx, di, LOG_PREFIX);
 }
 
 static GSList *scan(GSList *options)
 {
+	struct sr_dev_inst *sdi;
+	struct sr_probe *probe;
 	struct drv_context *drvc;
+	struct dev_context *devc;
 	GSList *devices;
+	unsigned int i;
+	int ret;
 
 	(void)options;
 
-	devices = NULL;
 	drvc = di->priv;
-	drvc->instances = NULL;
+
+	devices = NULL;
+
+	/* Allocate memory for our private device context. */
+	if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) {
+		sr_err("Device context malloc failed.");
+		goto err_free_nothing;
+	}
+
+	/* Allocate memory for the incoming compressed samples. */
+	if (!(devc->compressed_buf = g_try_malloc0(COMPRESSED_BUF_SIZE))) {
+		sr_err("compressed_buf malloc failed.");
+		goto err_free_devc;
+	}
+
+	/* Allocate memory for the uncompressed samples. */
+	if (!(devc->sample_buf = g_try_malloc0(SAMPLE_BUF_SIZE))) {
+		sr_err("sample_buf malloc failed.");
+		goto err_free_compressed_buf;
+	}
+
+	/* Allocate memory for the FTDI context (ftdic) and initialize it. */
+	if (!(devc->ftdic = ftdi_new())) {
+		sr_err("Failed to initialize libftdi.");
+		goto err_free_sample_buf;
+	}
+
+	/* Check for the device and temporarily open it. */
+	ret = ftdi_usb_open_desc(devc->ftdic, USB_VENDOR_ID, USB_DEVICE_ID,
+				 USB_IPRODUCT, NULL);
+	if (ret < 0) {
+		/* Log errors, except for -3 ("device not found"). */
+		if (ret != -3)
+			sr_err("Failed to open device (%d): %s", ret,
+			       ftdi_get_error_string(devc->ftdic));
+		goto err_free_ftdic;
+	}
+
+	/* Register the device with libsigrok. */
+	sdi = sr_dev_inst_new(0, SR_ST_INITIALIZING,
+			USB_VENDOR_NAME, USB_MODEL_NAME, NULL);
+	if (!sdi) {
+		sr_err("Failed to create device instance.");
+		goto err_close_ftdic;
+	}
+	sdi->driver = di;
+	sdi->priv = devc;
+
+	for (i = 0; probe_names[i]; i++) {
+		if (!(probe = sr_probe_new(i, SR_PROBE_LOGIC, TRUE,
+					   probe_names[i])))
+			return NULL;
+		sdi->probes = g_slist_append(sdi->probes, probe);
+	}
+
+	devices = g_slist_append(devices, sdi);
+	drvc->instances = g_slist_append(drvc->instances, sdi);
+
+	/* Close device. We'll reopen it again when we need it. */
+	scanaplus_close(devc);
 
 	return devices;
+
+err_close_ftdic:
+	scanaplus_close(devc);
+err_free_ftdic:
+	ftdi_free(devc->ftdic); /* NOT free() or g_free()! */
+err_free_sample_buf:
+	g_free(devc->sample_buf);
+err_free_compressed_buf:
+	g_free(devc->compressed_buf);
+err_free_devc:
+	g_free(devc);
+err_free_nothing:
+
+	return NULL;
 }
 
 static GSList *dev_list(void)
@@ -47,27 +167,111 @@ static GSList *dev_list(void)
 	return ((struct drv_context *)(di->priv))->instances;
 }
 
-static int dev_clear(void)
-{
-	return std_dev_clear(di, NULL);
-}
-
 static int dev_open(struct sr_dev_inst *sdi)
 {
-	(void)sdi;
+	struct dev_context *devc;
+	int ret;
+
+	devc = sdi->priv;
+
+	/* Select interface A, otherwise communication will fail. */
+	ret = ftdi_set_interface(devc->ftdic, INTERFACE_A);
+	if (ret < 0) {
+		sr_err("Failed to set FTDI interface A (%d): %s", ret,
+		       ftdi_get_error_string(devc->ftdic));
+		return SR_ERR;
+	}
+	sr_dbg("FTDI chip interface A set successfully.");
+
+	/* Open the device. */
+	ret = ftdi_usb_open_desc(devc->ftdic, USB_VENDOR_ID, USB_DEVICE_ID,
+				 USB_IPRODUCT, NULL);
+	if (ret < 0) {
+		sr_err("Failed to open device (%d): %s", ret,
+		       ftdi_get_error_string(devc->ftdic));
+		return SR_ERR;
+	}
+	sr_dbg("FTDI device opened successfully.");
+
+	/* Purge RX/TX buffers in the FTDI chip. */
+	if ((ret = ftdi_usb_purge_buffers(devc->ftdic)) < 0) {
+		sr_err("Failed to purge FTDI RX/TX buffers (%d): %s.",
+		       ret, ftdi_get_error_string(devc->ftdic));
+		goto err_dev_open_close_ftdic;
+	}
+	sr_dbg("FTDI chip buffers purged successfully.");
+
+	/* Reset the FTDI bitmode. */
+	ret = ftdi_set_bitmode(devc->ftdic, 0xff, BITMODE_RESET);
+	if (ret < 0) {
+		sr_err("Failed to reset the FTDI chip bitmode (%d): %s.",
+		       ret, ftdi_get_error_string(devc->ftdic));
+		goto err_dev_open_close_ftdic;
+	}
+	sr_dbg("FTDI chip bitmode reset successfully.");
+
+	/* Set FTDI bitmode to "sync FIFO". */
+	ret = ftdi_set_bitmode(devc->ftdic, 0xff, BITMODE_SYNCFF);
+	if (ret < 0) {
+		sr_err("Failed to put FTDI chip into sync FIFO mode (%d): %s.",
+		       ret, ftdi_get_error_string(devc->ftdic));
+		goto err_dev_open_close_ftdic;
+	}
+	sr_dbg("FTDI chip sync FIFO mode entered successfully.");
+
+	/* Set the FTDI latency timer to 2. */
+	ret = ftdi_set_latency_timer(devc->ftdic, 2);
+	if (ret < 0) {
+		sr_err("Failed to set FTDI latency timer (%d): %s.",
+		       ret, ftdi_get_error_string(devc->ftdic));
+		goto err_dev_open_close_ftdic;
+	}
+	sr_dbg("FTDI chip latency timer set successfully.");
+
+	/* Set the FTDI read data chunk size to 64kB. */
+	ret = ftdi_read_data_set_chunksize(devc->ftdic, 64 * 1024);
+	if (ret < 0) {
+		sr_err("Failed to set FTDI read data chunk size (%d): %s.",
+		       ret, ftdi_get_error_string(devc->ftdic));
+		goto err_dev_open_close_ftdic;
+	}
+	sr_dbg("FTDI chip read data chunk size set successfully.");
+
+	/* Get the ScanaPLUS device ID from the FTDI EEPROM. */
+	if ((ret = scanaplus_get_device_id(devc)) < 0) {
+		sr_err("Failed to get ScanaPLUS device ID: %d.", ret);
+		goto err_dev_open_close_ftdic;
+	}
+	sr_dbg("Received ScanaPLUS device ID successfully: %02x %02x %02x.",
+	       devc->devid[0], devc->devid[1], devc->devid[2]);
 
 	sdi->status = SR_ST_ACTIVE;
 
 	return SR_OK;
+
+err_dev_open_close_ftdic:
+	scanaplus_close(devc);
+	return SR_ERR;
 }
 
 static int dev_close(struct sr_dev_inst *sdi)
 {
-	(void)sdi;
+	int ret;
+	struct dev_context *devc;
+
+	ret = SR_OK;
+	devc = sdi->priv;
+
+	if (sdi->status == SR_ST_ACTIVE) {
+		sr_dbg("Status ACTIVE, closing device.");
+		ret = scanaplus_close(devc);
+	} else {
+		sr_spew("Status not ACTIVE, nothing to do.");
+	}
 
 	sdi->status = SR_ST_INACTIVE;
 
-	return SR_OK;
+	return ret;
 }
 
 static int cleanup(void)
@@ -75,73 +279,134 @@ static int cleanup(void)
 	return dev_clear();
 }
 
-static int config_get(int key, GVariant **data, const struct sr_dev_inst *sdi)
+static int config_get(int id, GVariant **data, const struct sr_dev_inst *sdi)
 {
-	int ret;
-
 	(void)sdi;
-	(void)data;
 
-	ret = SR_OK;
-	switch (key) {
+	switch (id) {
+	case SR_CONF_SAMPLERATE:
+		/* The ScanaPLUS samplerate is 100MHz and can't be changed. */
+		*data = g_variant_new_uint64(SR_MHZ(100));
+		break;
 	default:
 		return SR_ERR_NA;
 	}
 
-	return ret;
+	return SR_OK;
 }
 
-static int config_set(int key, GVariant *data, const struct sr_dev_inst *sdi)
+static int config_set(int id, GVariant *data, const struct sr_dev_inst *sdi)
 {
-	int ret;
-
-	(void)data;
+	struct dev_context *devc;
 
 	if (sdi->status != SR_ST_ACTIVE)
 		return SR_ERR_DEV_CLOSED;
 
-	ret = SR_OK;
-	switch (key) {
+	devc = sdi->priv;
+
+	switch (id) {
+	case SR_CONF_SAMPLERATE:
+		if (g_variant_get_uint64(data) != SR_MHZ(100)) {
+			sr_err("ScanaPLUS only supports samplerate = 100MHz.");
+			return SR_ERR_ARG;
+		}
+		/* Nothing to do, the ScanaPLUS samplerate is always 100MHz. */
+		break;
+	case SR_CONF_LIMIT_MSEC:
+		if (g_variant_get_uint64(data) == 0)
+			return SR_ERR_ARG;
+		devc->limit_msec = g_variant_get_uint64(data);
+		break;
+	case SR_CONF_LIMIT_SAMPLES:
+		if (g_variant_get_uint64(data) == 0)
+			return SR_ERR_ARG;
+		devc->limit_samples = g_variant_get_uint64(data);
+		break;
 	default:
-		ret = SR_ERR_NA;
+		return SR_ERR_NA;
 	}
 
-	return ret;
+	return SR_OK;
 }
 
 static int config_list(int key, GVariant **data, const struct sr_dev_inst *sdi)
 {
-	int ret;
+	GVariant *gvar;
+	GVariantBuilder gvb;
 
 	(void)sdi;
-	(void)data;
 
-	ret = SR_OK;
 	switch (key) {
+	case SR_CONF_DEVICE_OPTIONS:
+		*data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
+				hwcaps, ARRAY_SIZE(hwcaps), sizeof(int32_t));
+		break;
+	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;
 	}
 
-	return ret;
+	return SR_OK;
 }
 
 static int dev_acquisition_start(const struct sr_dev_inst *sdi, void *cb_data)
 {
-	(void)sdi;
-	(void)cb_data;
+	int ret;
+	struct dev_context *devc;
 
 	if (sdi->status != SR_ST_ACTIVE)
 		return SR_ERR_DEV_CLOSED;
 
+	if (!(devc = sdi->priv))
+		return SR_ERR_BUG;
+
+	if (!devc->ftdic)
+		return SR_ERR_BUG;
+
+	/* TODO: Configure probes later (thresholds etc.). */
+
+	devc->cb_data = cb_data;
+
+	/* Properly reset internal variables before every new acquisition. */
+	devc->compressed_bytes_ignored = 0;
+	devc->samples_sent = 0;
+	devc->bytes_received = 0;
+
+	if ((ret = scanaplus_init(devc)) < 0)
+		return ret;
+
+	if ((ret = scanaplus_start_acquisition(devc)) < 0)
+		return ret;
+
+	/* Send header packet to the session bus. */
+	std_session_send_df_header(cb_data, LOG_PREFIX);
+
+	/* Hook up a dummy handler to receive data from the device. */
+	sr_source_add(-1, G_IO_IN, 0, scanaplus_receive_data, (void *)sdi);
+
 	return SR_OK;
 }
 
 static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 {
-	(void)cb_data;
+	struct sr_datafeed_packet packet;
 
-	if (sdi->status != SR_ST_ACTIVE)
-		return SR_ERR_DEV_CLOSED;
+	(void)sdi;
+
+	sr_dbg("Stopping acquisition.");
+	sr_source_remove(-1);
+
+	/* Send end packet to the session bus. */
+	sr_dbg("Sending SR_DF_END.");
+	packet.type = SR_DF_END;
+	sr_session_send(cb_data, &packet);
 
 	return SR_OK;
 }
diff --git a/hardware/ikalogic-scanaplus/protocol.c b/hardware/ikalogic-scanaplus/protocol.c
index 2513153d..86597850 100644
--- a/hardware/ikalogic-scanaplus/protocol.c
+++ b/hardware/ikalogic-scanaplus/protocol.c
@@ -20,12 +20,286 @@
 
 #include "protocol.h"
 
-SR_PRIV int ikalogic_scanaplus_receive_data(int fd, int revents, void *cb_data)
+/*
+ * Logic level thresholds.
+ *
+ * For each of the two channel groups (1-4 and 5-9), the logic level
+ * threshold can be set independently.
+ *
+ * The threshold can be set to values that are usable for systems with
+ * different voltage levels, e.g. for 1.8V or 3.3V systems.
+ *
+ * The actual threshold value is always the middle of the values below.
+ * E.g. for a system voltage level of 1.8V, the threshold is at 0.9V. That
+ * means that values <= 0.9V are considered to be a logic 0/low, and
+ * values > 0.9V are considered to be a logic 1/high.
+ *
+ *  - 1.2V system: threshold = 0.6V
+ *  - 1.5V system: threshold = 0.75V
+ *  - 1.8V system: threshold = 0.9V
+ *  - 2.8V system: threshold = 1.4V
+ *  - 3.3V system: threshold = 1.65V
+ */
+#define THRESHOLD_1_2V_SYSTEM 0x2e
+#define THRESHOLD_1_5V_SYSTEM 0x39
+#define THRESHOLD_1_8V_SYSTEM 0x45
+#define THRESHOLD_2_8V_SYSTEM 0x6c
+#define THRESHOLD_3_3V_SYSTEM 0x7f
+
+static int scanaplus_write(struct dev_context *devc, uint8_t *buf, int size)
+{
+	int i, bytes_written;
+	GString *s;
+
+	/* Note: Caller checks devc, devc->ftdic, buf, size. */
+
+	s = g_string_sized_new(100);
+	g_string_printf(s, "Writing %d bytes: ", size);
+	for (i = 0; i < size; i++)
+		g_string_append_printf(s, "0x%02x ", buf[i]);
+	sr_spew("%s", s->str);
+	g_string_free(s, TRUE);
+
+	bytes_written = ftdi_write_data(devc->ftdic, buf, size);
+	if (bytes_written < 0) {
+		sr_err("Failed to write FTDI data (%d): %s.",
+		       bytes_written, ftdi_get_error_string(devc->ftdic));
+	} else if (bytes_written != size) {
+		sr_err("FTDI write error, only %d/%d bytes written: %s.",
+		       bytes_written, size, ftdi_get_error_string(devc->ftdic));
+	}
+
+	return bytes_written;
+}
+
+SR_PRIV int scanaplus_close(struct dev_context *devc)
+{
+	int ret;
+
+	/* Note: Caller checks devc and devc->ftdic. */
+
+	if ((ret = ftdi_usb_close(devc->ftdic)) < 0) {
+		sr_err("Failed to close FTDI device (%d): %s.",
+		       ret, ftdi_get_error_string(devc->ftdic));
+		return SR_ERR;
+	}
+
+	return SR_OK;
+}
+
+static void scanaplus_uncompress_block(struct dev_context *devc,
+				       uint64_t num_bytes)
 {
-	const struct sr_dev_inst *sdi;
+	uint64_t i, j;
+	uint8_t num_samples, low, high;
+
+	for (i = 0; i < num_bytes; i += 2) {
+		num_samples = devc->compressed_buf[i + 0] >> 1;
+
+		low = devc->compressed_buf[i + 0] & (1 << 0);
+		high = devc->compressed_buf[i + 1];
+
+		for (j = 0; j < num_samples; j++) {
+			devc->sample_buf[devc->bytes_received++] = high;
+			devc->sample_buf[devc->bytes_received++] = low;
+		}
+	}
+}
+
+static void send_samples(struct dev_context *devc, uint64_t samples_to_send)
+{
+	struct sr_datafeed_packet packet;
+	struct sr_datafeed_logic logic;
+
+	sr_spew("Sending %" PRIu64 " samples.", samples_to_send);
+
+	packet.type = SR_DF_LOGIC;
+	packet.payload = &logic;
+	logic.length = samples_to_send * 2;
+	logic.unitsize = 2; /* We need 2 bytes for 9 probes. */
+	logic.data = devc->sample_buf;
+	sr_session_send(devc->cb_data, &packet);
+
+	devc->samples_sent += samples_to_send;
+	devc->bytes_received -= samples_to_send * 2;
+}
+
+SR_PRIV int scanaplus_get_device_id(struct dev_context *devc)
+{
+	int ret;
+	uint16_t val1, val2;
+
+	/* FTDI EEPROM indices 16+17 contain the 3 device ID bytes. */
+	if ((ret = ftdi_read_eeprom_location(devc->ftdic, 16, &val1)) < 0) {
+		sr_err("Failed to read EEPROM index 16 (%d): %s.",
+		       ret, ftdi_get_error_string(devc->ftdic));
+		return SR_ERR;
+	}
+	if ((ret = ftdi_read_eeprom_location(devc->ftdic, 17, &val2)) < 0) {
+		sr_err("Failed to read EEPROM index 17 (%d): %s.",
+		       ret, ftdi_get_error_string(devc->ftdic));
+		return SR_ERR;
+	}
+
+	/*
+	 * Note: Bit 7 of the three bytes must not be used, apparently.
+	 *
+	 * Even though the three bits can be either 0 or 1 (we've seen both
+	 * in actual ScanaPLUS devices), the device ID as sent to the FPGA
+	 * has bit 7 of each byte zero'd out.
+	 *
+	 * It is unknown whether bit 7 of these bytes has any meaning,
+	 * whether it's used somewhere, or whether it can be simply ignored.
+	 */
+	devc->devid[0] = ((val1 >> 0) & 0xff) & ~(1 << 7);
+	devc->devid[1] = ((val1 >> 8) & 0xff) & ~(1 << 7);
+	devc->devid[2] = ((val2 >> 0) & 0xff) & ~(1 << 7);
+
+	return SR_OK;
+}
+
+static int scanaplus_clear_device_id(struct dev_context *devc)
+{
+	uint8_t buf[2];
+
+	buf[0] = 0x8c;
+	buf[1] = 0x00;
+	if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+		return SR_ERR;
+
+	buf[0] = 0x8e;
+	buf[1] = 0x00;
+	if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+		return SR_ERR;
+
+	buf[0] = 0x8f;
+	buf[1] = 0x00;
+	if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+		return SR_ERR;
+
+	return SR_OK;
+}
+
+static int scanaplus_send_device_id(struct dev_context *devc)
+{
+	uint8_t buf[2];
+
+	buf[0] = 0x8c;
+	buf[1] = devc->devid[0];
+	if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+		return SR_ERR;
+
+	buf[0] = 0x8e;
+	buf[1] = devc->devid[1];
+	if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+		return SR_ERR;
+
+	buf[0] = 0x8f;
+	buf[1] = devc->devid[2];
+	if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+		return SR_ERR;
+
+	return SR_OK;
+}
+
+SR_PRIV int scanaplus_init(struct dev_context *devc)
+{
+	int i;
+	uint8_t buf[8];
+
+	buf[0] = 0x88;
+	buf[1] = 0x41;
+	if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+		return SR_ERR;
+
+	buf[0] = 0x89;
+	buf[1] = 0x64;
+	buf[2] = 0x8a;
+	buf[3] = 0x64;
+	if (scanaplus_write(devc, (uint8_t *)&buf, 4) < 0)
+		return SR_ERR;
+
+	buf[0] = 0x88;
+	buf[1] = 0x41;
+	if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+		return SR_ERR;
+
+	buf[0] = 0x88;
+	buf[1] = 0x40;
+	if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+		return SR_ERR;
+
+	buf[0] = 0x8d;
+	buf[1] = 0x01;
+	buf[2] = 0x8d;
+	buf[3] = 0x05;
+	buf[4] = 0x8d;
+	buf[5] = 0x01;
+	buf[6] = 0x8d;
+	buf[7] = 0x02;
+	if (scanaplus_write(devc, (uint8_t *)&buf, 8) < 0)
+		return SR_ERR;
+
+	for (i = 0; i < 57; i++) {
+		buf[0] = 0x8d;
+		buf[1] = 0x06;
+		if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+			return SR_ERR;
+
+		buf[0] = 0x8d;
+		buf[1] = 0x02;
+		if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+			return SR_ERR;
+	}
+
+	if (scanaplus_send_device_id(devc) < 0)
+		return SR_ERR;
+
+	buf[0] = 0x88;
+	buf[1] = 0x40;
+	if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+		return SR_ERR;
+
+	return SR_OK;
+}
+
+SR_PRIV int scanaplus_start_acquisition(struct dev_context *devc)
+{
+	uint8_t buf[4];
+
+	/* Threshold and differential probe settings not yet implemented. */
+
+	buf[0] = 0x89;
+	buf[1] = 0x7f; /* Logic level threshold for probes 1-4. */
+	buf[2] = 0x8a;
+	buf[3] = 0x7f; /* Logic level threshold for probes 5-9. */
+	if (scanaplus_write(devc, (uint8_t *)&buf, 4) < 0)
+		return SR_ERR;
+
+	buf[0] = 0x88;
+	buf[1] = 0x40; /* Special config of probes 5/6 and 7/8. */
+	/* 0x40: normal, 0x50: ch56 diff, 0x48: ch78 diff, 0x58: ch5678 diff */
+	if (scanaplus_write(devc, (uint8_t *)&buf, 2) < 0)
+		return SR_ERR;
+
+	if (scanaplus_clear_device_id(devc) < 0)
+		return SR_ERR;
+
+	if (scanaplus_send_device_id(devc) < 0)
+		return SR_ERR;
+
+	return SR_OK;
+}
+
+SR_PRIV int scanaplus_receive_data(int fd, int revents, void *cb_data)
+{
+	int bytes_read;
+	struct sr_dev_inst *sdi;
 	struct dev_context *devc;
+	uint64_t max, n;
 
 	(void)fd;
+	(void)revents;
 
 	if (!(sdi = cb_data))
 		return TRUE;
@@ -33,8 +307,63 @@ SR_PRIV int ikalogic_scanaplus_receive_data(int fd, int revents, void *cb_data)
 	if (!(devc = sdi->priv))
 		return TRUE;
 
-	if (revents == G_IO_IN) {
-		/* TODO */
+	if (!devc->ftdic)
+		return TRUE;
+
+	/* Get a block of data. */
+	bytes_read = ftdi_read_data(devc->ftdic, devc->compressed_buf,
+				    COMPRESSED_BUF_SIZE);
+	if (bytes_read < 0) {
+		sr_err("Failed to read FTDI data (%d): %s.",
+		       bytes_read, ftdi_get_error_string(devc->ftdic));
+		sdi->driver->dev_acquisition_stop(sdi, sdi);
+		return FALSE;
+	}
+	if (bytes_read == 0) {
+		sr_spew("Received 0 bytes, nothing to do.");
+		return TRUE;
+	}
+
+	/*
+	 * After a ScanaPLUS acquisition starts, a bunch of samples will be
+	 * returned as all-zero, no matter which signals are actually present
+	 * on the probes. This is probably due to the FPGA reconfiguring some
+	 * of its internal state/config during this time.
+	 *
+	 * As far as we know there is apparently no way for the PC-side to
+	 * know when this "reconfiguration" starts or ends. The FTDI chip
+	 * will return all-zero "dummy" samples during this time, which is
+	 * indistinguishable from actual all-zero samples.
+	 *
+	 * We currently simply ignore the first 64kB of data after an
+	 * acquisition starts. Empirical tests have shown that the
+	 * "reconfigure" time is a lot less than that usually.
+	 */
+	if (devc->compressed_bytes_ignored < COMPRESSED_BUF_SIZE) {
+		/* Ignore the first 64kB of data of every acquisition. */
+		sr_spew("Ignoring first 64kB chunk of data.");
+		devc->compressed_bytes_ignored += COMPRESSED_BUF_SIZE;
+		return TRUE;
+	}
+
+	/* TODO: Handle bytes_read which is not a multiple of 2? */
+	scanaplus_uncompress_block(devc, bytes_read);
+
+	n = devc->samples_sent + (devc->bytes_received / 2);
+	max = (SR_MHZ(100) / 1000) * devc->limit_msec;
+
+	if (devc->limit_samples && (n >= devc->limit_samples)) {
+		send_samples(devc, devc->limit_samples - devc->samples_sent);
+		sr_info("Requested number of samples reached.");
+		sdi->driver->dev_acquisition_stop(sdi, cb_data);
+		return TRUE;
+	} else if (devc->limit_msec && (n >= max)) {
+		send_samples(devc, max - devc->samples_sent);
+		sr_info("Requested time limit reached.");
+		sdi->driver->dev_acquisition_stop(sdi, cb_data);
+		return TRUE;
+	} else {
+		send_samples(devc, devc->bytes_received / 2);
 	}
 
 	return TRUE;
diff --git a/hardware/ikalogic-scanaplus/protocol.h b/hardware/ikalogic-scanaplus/protocol.h
index 578a0110..e736f838 100644
--- a/hardware/ikalogic-scanaplus/protocol.h
+++ b/hardware/ikalogic-scanaplus/protocol.h
@@ -22,12 +22,14 @@
 #define LIBSIGROK_HARDWARE_IKALOGIC_SCANAPLUS_PROTOCOL_H
 
 #include <stdint.h>
+#include <string.h>
 #include <glib.h>
+#include <ftdi.h>
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
 /* Message logging helpers with subsystem-specific prefix string. */
-#define LOG_PREFIX "ikalogic-scanaplus: "
+#define LOG_PREFIX "scanaplus: "
 #define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
 #define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
 #define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
@@ -35,10 +37,35 @@
 #define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
 #define sr_err(s, args...) sr_err(LOG_PREFIX s, ## args)
 
-/** Private, per-device-instance driver context. */
+#define COMPRESSED_BUF_SIZE		(64 * 1024)
+
+/* Private, per-device-instance driver context. */
 struct dev_context {
+	/** FTDI device context (used by libftdi). */
+	struct ftdi_context *ftdic;
+
+	/** The current sampling limit (in ms). */
+	uint64_t limit_msec;
+
+	/** The current sampling limit (in number of samples). */
+	uint64_t limit_samples;
+
+	void *cb_data;
+
+	uint8_t *compressed_buf;
+	uint64_t compressed_bytes_ignored;
+	uint8_t *sample_buf;
+	uint64_t bytes_received;
+	uint64_t samples_sent;
+
+	/** ScanaPLUS unique device ID (3 bytes). */
+	uint8_t devid[3];
 };
 
-SR_PRIV int ikalogic_scanaplus_receive_data(int fd, int revents, void *cb_data);
+SR_PRIV int scanaplus_close(struct dev_context *devc);
+SR_PRIV int scanaplus_get_device_id(struct dev_context *devc);
+SR_PRIV int scanaplus_init(struct dev_context *devc);
+SR_PRIV int scanaplus_start_acquisition(struct dev_context *devc);
+SR_PRIV int scanaplus_receive_data(int fd, int revents, void *cb_data);
 
 #endif