]> sigrok.org Git - libsigrok.git/blobdiff - src/hardware/kingst-la2016/api.c
kingst-la2016: rename logic channels to match product's labels
[libsigrok.git] / src / hardware / kingst-la2016 / api.c
index c6f18c8f6610bf7e17393de83840b14f0a98a34f..45262c1eb48bae88475e352df40499da9a7f26d6 100644 (file)
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/* mostly stolen from src/hardware/saleae-logic16/ */
+/*
+ * This driver implementation initially was derived from the
+ * src/hardware/saleae-logic16/ source code.
+ */
 
 #include <config.h>
-#include <glib.h>
-#include <libusb.h>
-#include <stdlib.h>
-#include <string.h>
-#include <math.h>
+
 #include <libsigrok/libsigrok.h>
+#include <string.h>
+
 #include "libsigrok-internal.h"
 #include "protocol.h"
 
@@ -60,11 +61,11 @@ static const int32_t trigger_matches[] = {
 };
 
 static const char *channel_names[] = {
-       "0", "1", "2", "3", "4", "5", "6", "7",
-       "8", "9", "10", "11", "12", "13", "14", "15",
+       "CH0", "CH1", "CH2", "CH3", "CH4", "CH5", "CH6", "CH7",
+       "CH8", "CH9", "CH10", "CH11", "CH12", "CH13", "CH14", "CH15",
 };
 
-static const uint64_t samplerates[] = {
+static const uint64_t samplerates_la2016[] = {
        SR_KHZ(20),
        SR_KHZ(50),
        SR_KHZ(100),
@@ -82,6 +83,23 @@ static const uint64_t samplerates[] = {
        SR_MHZ(200),
 };
 
+static const uint64_t samplerates_la1016[] = {
+       SR_KHZ(20),
+       SR_KHZ(50),
+       SR_KHZ(100),
+       SR_KHZ(200),
+       SR_KHZ(500),
+       SR_MHZ(1),
+       SR_MHZ(2),
+       SR_MHZ(4),
+       SR_MHZ(5),
+       SR_MHZ(8),
+       SR_MHZ(10),
+       SR_MHZ(20),
+       SR_MHZ(50),
+       SR_MHZ(100),
+};
+
 static const float logic_threshold_value[] = {
        1.58,
        2.5,
@@ -107,11 +125,12 @@ static const char *logic_threshold[] = {
        "USER",
 };
 
-#define MAX_NUM_LOGIC_THRESHOLD_ENTRIES ARRAY_SIZE(logic_threshold)
+#define LOGIC_THRESHOLD_IDX_USER       (ARRAY_SIZE(logic_threshold) - 1)
 
 static GSList *scan(struct sr_dev_driver *di, GSList *options)
 {
        struct drv_context *drvc;
+       struct sr_context *ctx;
        struct dev_context *devc;
        struct sr_dev_inst *sdi;
        struct sr_usb_dev_inst *usb;
@@ -120,14 +139,16 @@ static GSList *scan(struct sr_dev_driver *di, GSList *options)
        GSList *devices;
        GSList *conn_devices;
        struct libusb_device_descriptor des;
-       libusb_device **devlist;
-       unsigned int i, j;
+       libusb_device **devlist, *dev;
+       size_t dev_count, dev_idx, ch_idx;
+       uint8_t bus, addr;
        const char *conn;
-       char connection_id[64];
-       int64_t fw_updated;
-       unsigned int dev_addr;
+       char conn_id[64];
+       uint64_t fw_uploaded;
+       int ret;
 
        drvc = di->context;
+       ctx = drvc->sr_ctx;;
 
        conn = NULL;
        for (l = options; l; l = l->next) {
@@ -139,78 +160,88 @@ static GSList *scan(struct sr_dev_driver *di, GSList *options)
                }
        }
        if (conn)
-               conn_devices = sr_usb_find(drvc->sr_ctx->libusb_ctx, conn);
+               conn_devices = sr_usb_find(ctx->libusb_ctx, conn);
        else
                conn_devices = NULL;
 
-       /* Find all LA2016 devices and upload firmware to them. */
+       /* Find all LA2016 devices, optionally upload firmware to them. */
        devices = NULL;
-       libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
-       for (i = 0; devlist[i]; i++) {
+       ret = libusb_get_device_list(ctx->libusb_ctx, &devlist);
+       if (ret < 0) {
+               sr_err("Cannot get device list: %s.", libusb_error_name(ret));
+               return devices;
+       }
+       dev_count = ret;
+       for (dev_idx = 0; dev_idx < dev_count; dev_idx++) {
+               dev = devlist[dev_idx];
+               bus = libusb_get_bus_number(dev);
+               addr = libusb_get_device_address(dev);
                if (conn) {
                        usb = NULL;
                        for (l = conn_devices; l; l = l->next) {
                                usb = l->data;
-                               if (usb->bus == libusb_get_bus_number(devlist[i]) &&
-                                   usb->address == libusb_get_device_address(devlist[i]))
+                               if (usb->bus == bus && usb->address == addr)
                                        break;
                        }
                        if (!l) {
-                               /* This device matched none of the ones that
-                                * matched the conn specification. */
+                               /*
+                                * A connection parameter was specified and
+                                * this device does not match the filter.
+                                */
                                continue;
                        }
                }
 
-               libusb_get_device_descriptor(devlist[i], &des);
-
-               if (usb_get_port_path(devlist[i], connection_id, sizeof(connection_id)) < 0)
+               libusb_get_device_descriptor(dev, &des);
+               ret = usb_get_port_path(dev, conn_id, sizeof(conn_id));
+               if (ret < 0)
                        continue;
-
                if (des.idVendor != LA2016_VID || des.idProduct != LA2016_PID)
                        continue;
 
-               /* Already has the firmware */
-               sr_dbg("Found a LA2016 device.");
-               sdi = g_malloc0(sizeof(struct sr_dev_inst));
+               /* USB identification matches, a device was found. */
+               sr_dbg("Found a device (USB identification).");
+               sdi = g_malloc0(sizeof(*sdi));
                sdi->status = SR_ST_INITIALIZING;
-               sdi->connection_id = g_strdup(connection_id);
+               sdi->connection_id = g_strdup(conn_id);
 
-               fw_updated = 0;
-               dev_addr = libusb_get_device_address(devlist[i]);
-               if (des.iProduct != 2) {
-                       sr_info("device at '%s' has no firmware loaded!", connection_id);
+               fw_uploaded = 0;
+               if (des.iProduct != LA2016_IPRODUCT_INDEX) {
+                       sr_info("Device at '%s' has no firmware loaded.",
+                               conn_id);
 
-                       if (la2016_upload_firmware(drvc->sr_ctx, devlist[i], des.idProduct) != SR_OK) {
-                               sr_err("uC firmware upload failed!");
+                       ret = la2016_upload_firmware(ctx, dev, des.idProduct);
+                       if (ret != SR_OK) {
+                               sr_err("MCU firmware upload failed.");
                                g_free(sdi->connection_id);
                                g_free(sdi);
                                continue;
                        }
-                       fw_updated = g_get_monotonic_time();
-                       dev_addr = 0xff; /* to mark that we don't know address yet... ugly */
+                       fw_uploaded = g_get_monotonic_time();
+                       /* Will re-enumerate. Mark as "unknown address yet". */
+                       addr = 0xff;
                }
 
                sdi->vendor = g_strdup("Kingst");
                sdi->model = g_strdup("LA2016");
 
-               for (j = 0; j < ARRAY_SIZE(channel_names); j++)
-                       sr_channel_new(sdi, j, SR_CHANNEL_LOGIC, TRUE, channel_names[j]);
+               for (ch_idx = 0; ch_idx < ARRAY_SIZE(channel_names); ch_idx++) {
+                       sr_channel_new(sdi, ch_idx, SR_CHANNEL_LOGIC,
+                               TRUE, channel_names[ch_idx]);
+               }
 
                devices = g_slist_append(devices, sdi);
 
-               devc = g_malloc0(sizeof(struct dev_context));
+               devc = g_malloc0(sizeof(*devc));
                sdi->priv = devc;
-               devc->fw_updated = fw_updated;
+               devc->fw_uploaded = fw_uploaded;
                devc->threshold_voltage_idx = 0;
                devc->threshold_voltage = logic_threshold_value[devc->threshold_voltage_idx];
 
                sdi->status = SR_ST_INACTIVE;
                sdi->inst_type = SR_INST_USB;
 
-               sdi->conn = sr_usb_dev_inst_new(
-                       libusb_get_bus_number(devlist[i]),
-                       dev_addr, NULL);
+               sdi->conn = sr_usb_dev_inst_new(bus, addr, NULL);
        }
        libusb_free_device_list(devlist, 1);
        g_slist_free_full(conn_devices, (GDestroyNotify)sr_usb_dev_inst_free);
@@ -221,59 +252,73 @@ static GSList *scan(struct sr_dev_driver *di, GSList *options)
 static int la2016_dev_open(struct sr_dev_inst *sdi)
 {
        struct sr_dev_driver *di;
-       libusb_device **devlist;
+       struct drv_context *drvc;
+       struct sr_context *ctx;
+       libusb_device **devlist, *dev;
        struct sr_usb_dev_inst *usb;
        struct libusb_device_descriptor des;
-       struct drv_context *drvc;
-       int ret, i, device_count;
-       char connection_id[64];
+       int ret;
+       size_t device_count, dev_idx;
+       gboolean check_conn;
+       char conn_id[64];
 
        di = sdi->driver;
        drvc = di->context;
+       ctx = drvc->sr_ctx;;
        usb = sdi->conn;
        ret = SR_ERR;
 
-       device_count = libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
-       if (device_count < 0) {
-               sr_err("Failed to get device list: %s.", libusb_error_name(device_count));
+       ret = libusb_get_device_list(ctx->libusb_ctx, &devlist);
+       if (ret < 0) {
+               sr_err("Cannot get device list: %s.", libusb_error_name(ret));
                return SR_ERR;
        }
+       device_count = ret;
+       if (!device_count) {
+               sr_warn("Device list is empty. Cannot open.");
+               return SR_ERR;
+       }
+       for (dev_idx = 0; dev_idx < device_count; dev_idx++) {
+               dev = devlist[dev_idx];
+               libusb_get_device_descriptor(dev, &des);
 
-       for (i = 0; i < device_count; i++) {
-               libusb_get_device_descriptor(devlist[i], &des);
-
-               if (des.idVendor != LA2016_VID || des.idProduct != LA2016_PID || des.iProduct != 2)
+               if (des.idVendor != LA2016_VID || des.idProduct != LA2016_PID)
+                       continue;
+               if (des.iProduct != LA2016_IPRODUCT_INDEX)
                        continue;
 
-               if ((sdi->status == SR_ST_INITIALIZING) || (sdi->status == SR_ST_INACTIVE)) {
-                       /*
-                        * Check device by its physical USB bus/port address.
-                        */
-                       if (usb_get_port_path(devlist[i], connection_id, sizeof(connection_id)) < 0)
+               check_conn = sdi->status == SR_ST_INITIALIZING;
+               check_conn |= sdi->status == SR_ST_INACTIVE;
+               if (check_conn) {
+                       /* Check physical USB bus/port address. */
+                       ret = usb_get_port_path(dev, conn_id, sizeof(conn_id));
+                       if (ret < 0)
                                continue;
-
-                       if (strcmp(sdi->connection_id, connection_id))
-                               /* This is not the one. */
+                       if (strcmp(sdi->connection_id, conn_id) != 0) {
+                               /* Not the device we looked up before. */
                                continue;
+                       }
                }
 
-               if (!(ret = libusb_open(devlist[i], &usb->devhdl))) {
-                       if (usb->address == 0xff)
-                               /*
-                                * First time we touch this device after FW
-                                * upload, so we don't know the address yet.
-                                */
-                               usb->address = libusb_get_device_address(devlist[i]);
-               } else {
-                       sr_err("Failed to open device: %s.", libusb_error_name(ret));
-                       ret = SR_ERR;
+               ret = libusb_open(dev, &usb->devhdl);
+               if (ret != 0) {
+                       sr_err("Cannot open device: %s.",
+                               libusb_error_name(ret));
+                       ret = SR_ERR_IO;
                        break;
                }
 
+               if (usb->address == 0xff) {
+                       /*
+                        * First encounter after firmware upload.
+                        * Grab current address after enumeration.
+                        */
+                       usb->address = libusb_get_device_address(dev);
+               }
+
                ret = libusb_claim_interface(usb->devhdl, USB_INTERFACE);
                if (ret == LIBUSB_ERROR_BUSY) {
-                       sr_err("Unable to claim USB interface. Another "
-                              "program or driver has already claimed it.");
+                       sr_err("Cannot claim USB interface. Another program or driver using it?");
                        ret = SR_ERR;
                        break;
                } else if (ret == LIBUSB_ERROR_NO_DEVICE) {
@@ -281,24 +326,22 @@ static int la2016_dev_open(struct sr_dev_inst *sdi)
                        ret = SR_ERR;
                        break;
                } else if (ret != 0) {
-                       sr_err("Unable to claim interface: %s.", libusb_error_name(ret));
+                       sr_err("Cannot claim USB interface: %s.",
+                               libusb_error_name(ret));
                        ret = SR_ERR;
                        break;
                }
 
                if ((ret = la2016_init_device(sdi)) != SR_OK) {
-                       sr_err("Failed to init device.");
+                       sr_err("Cannot initialize device.");
                        break;
                }
 
                sr_info("Opened device on %d.%d (logical) / %s (physical), interface %d.",
                        usb->bus, usb->address, sdi->connection_id, USB_INTERFACE);
-
                ret = SR_OK;
-
                break;
        }
-
        libusb_free_device_list(devlist, 1);
 
        if (ret != SR_OK) {
@@ -307,7 +350,7 @@ static int la2016_dev_open(struct sr_dev_inst *sdi)
                        libusb_close(usb->devhdl);
                        usb->devhdl = NULL;
                }
-               return SR_ERR;
+               return ret;
        }
 
        return SR_OK;
@@ -316,48 +359,49 @@ static int la2016_dev_open(struct sr_dev_inst *sdi)
 static int dev_open(struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
-       int64_t timediff_us, timediff_ms;
-       uint64_t reset_done;
-       uint64_t now;
+       uint64_t reset_done, now, elapsed_ms;
        int ret;
 
        devc = sdi->priv;
 
        /*
-        * If the firmware was recently uploaded, wait up to MAX_RENUM_DELAY_MS
-        * milliseconds for the FX2 to renumerate.
+        * When the sigrok driver recently has uploaded MCU firmware,
+        * then wait for the FX2 to re-enumerate. Allow the USB device
+        * to vanish before it reappears. Timeouts are rough estimates
+        * after all, the imprecise time of the last check (potentially
+        * executes after the total check period) simplifies code paths
+        * with optional diagnostics. And increases the probability of
+        * successfully detecting "late/slow" devices.
         */
-       ret = SR_ERR;
-       if (devc->fw_updated > 0) {
+       if (devc->fw_uploaded) {
                sr_info("Waiting for device to reset after firmware upload.");
-               /* Takes >= 2000ms for the uC to be gone from the USB bus. */
-               reset_done = devc->fw_updated + 18 * (uint64_t)1e5; /* 1.8 seconds */
                now = g_get_monotonic_time();
-               if (reset_done > now)
+               reset_done = devc->fw_uploaded + RENUM_GONE_DELAY_MS * 1000;
+               if (now < reset_done)
                        g_usleep(reset_done - now);
-               timediff_ms = 0;
-               while (timediff_ms < MAX_RENUM_DELAY_MS) {
-                       g_usleep(200 * 1000);
-
-                       timediff_us = g_get_monotonic_time() - devc->fw_updated;
-                       timediff_ms = timediff_us / 1000;
-
-                       if ((ret = la2016_dev_open(sdi)) == SR_OK)
+               do {
+                       now = g_get_monotonic_time();
+                       elapsed_ms = (now - devc->fw_uploaded) / 1000;
+                       sr_spew("Waited %" PRIu64 "ms.", elapsed_ms);
+                       ret = la2016_dev_open(sdi);
+                       if (ret == SR_OK) {
+                               devc->fw_uploaded = 0;
                                break;
-                       sr_spew("Waited %" PRIi64 "ms.", timediff_ms);
-               }
+                       }
+                       g_usleep(RENUM_POLL_INTERVAL_MS * 1000);
+               } while (elapsed_ms < RENUM_CHECK_PERIOD_MS);
                if (ret != SR_OK) {
                        sr_err("Device failed to re-enumerate.");
-                       return SR_ERR;
+                       return ret;
                }
-               sr_info("Device came back after %" PRIi64 "ms.", timediff_ms);
+               sr_info("Device came back after %" PRIi64 "ms.", elapsed_ms);
        } else {
                ret = la2016_dev_open(sdi);
        }
 
        if (ret != SR_OK) {
-               sr_err("Unable to open device.");
-               return SR_ERR;
+               sr_err("Cannot open device.");
+               return ret;
        }
 
        return SR_OK;
@@ -389,6 +433,7 @@ static int config_get(uint32_t key, GVariant **data,
        struct dev_context *devc;
        struct sr_usb_dev_inst *usb;
        double rounded;
+       const char *label;
 
        (void)cg;
 
@@ -401,9 +446,11 @@ static int config_get(uint32_t key, GVariant **data,
                if (!sdi->conn)
                        return SR_ERR_ARG;
                usb = sdi->conn;
-               if (usb->address == 255) {
-                       /* Device still needs to re-enumerate after firmware
-                        * upload, so we don't know its (future) address. */
+               if (usb->address == 0xff) {
+                       /*
+                        * Device still needs to re-enumerate after firmware
+                        * upload, so we don't know its (future) address.
+                        */
                        return SR_ERR;
                }
                *data = g_variant_new_printf("%d.%d", usb->bus, usb->address);
@@ -422,7 +469,8 @@ static int config_get(uint32_t key, GVariant **data,
                *data = std_gvar_tuple_double(rounded, rounded + 0.1);
                return SR_OK;
        case SR_CONF_LOGIC_THRESHOLD:
-               *data = g_variant_new_string(logic_threshold[devc->threshold_voltage_idx]);
+               label = logic_threshold[devc->threshold_voltage_idx];
+               *data = g_variant_new_string(label);
                break;
        case SR_CONF_LOGIC_THRESHOLD_CUSTOM:
                *data = g_variant_new_double(devc->threshold_voltage);
@@ -459,14 +507,13 @@ static int config_set(uint32_t key, GVariant *data,
        case SR_CONF_VOLTAGE_THRESHOLD:
                g_variant_get(data, "(dd)", &low, &high);
                devc->threshold_voltage = (low + high) / 2.0;
-               devc->threshold_voltage_idx = MAX_NUM_LOGIC_THRESHOLD_ENTRIES - 1; /* USER */
+               devc->threshold_voltage_idx = LOGIC_THRESHOLD_IDX_USER;
                break;
        case SR_CONF_LOGIC_THRESHOLD: {
-               if ((idx = std_str_idx(data, logic_threshold, MAX_NUM_LOGIC_THRESHOLD_ENTRIES)) < 0)
+               idx = std_str_idx(data, ARRAY_AND_SIZE(logic_threshold));
+               if (idx < 0)
                        return SR_ERR_ARG;
-               if (idx == MAX_NUM_LOGIC_THRESHOLD_ENTRIES - 1) {
-                       /* user threshold */
-               } else {
+               if (idx != LOGIC_THRESHOLD_IDX_USER) {
                        devc->threshold_voltage = logic_threshold_value[idx];
                }
                devc->threshold_voltage_idx = idx;
@@ -485,15 +532,26 @@ static int config_set(uint32_t key, GVariant *data,
 static int config_list(uint32_t key, GVariant **data,
        const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
 {
+       struct dev_context *devc;
+
        switch (key) {
        case SR_CONF_SCAN_OPTIONS:
        case SR_CONF_DEVICE_OPTIONS:
-               return STD_CONFIG_LIST(key, data, sdi, cg, scanopts, drvopts, devopts);
+               return STD_CONFIG_LIST(key, data, sdi, cg,
+                       scanopts, drvopts, devopts);
        case SR_CONF_SAMPLERATE:
-               *data = std_gvar_samplerates(ARRAY_AND_SIZE(samplerates));
+               if (!sdi)
+                       return SR_ERR_ARG;
+               devc = sdi->priv;
+               if (devc->max_samplerate == SR_MHZ(200)) {
+                       *data = std_gvar_samplerates(ARRAY_AND_SIZE(samplerates_la2016));
+               } else {
+                       *data = std_gvar_samplerates(ARRAY_AND_SIZE(samplerates_la1016));
+               }
                break;
        case SR_CONF_LIMIT_SAMPLES:
-               *data = std_gvar_tuple_u64(LA2016_NUM_SAMPLES_MIN, LA2016_NUM_SAMPLES_MAX);
+               *data = std_gvar_tuple_u64(LA2016_NUM_SAMPLES_MIN,
+                       LA2016_NUM_SAMPLES_MAX);
                break;
        case SR_CONF_VOLTAGE_THRESHOLD:
                *data = std_gvar_min_max_step_thresholds(
@@ -504,7 +562,7 @@ static int config_list(uint32_t key, GVariant **data,
                *data = std_gvar_array_i32(ARRAY_AND_SIZE(trigger_matches));
                break;
        case SR_CONF_LOGIC_THRESHOLD:
-               *data = g_variant_new_strv(logic_threshold, MAX_NUM_LOGIC_THRESHOLD_ENTRIES);
+               *data = g_variant_new_strv(ARRAY_AND_SIZE(logic_threshold));
                break;
        default:
                return SR_ERR_NA;
@@ -513,200 +571,20 @@ static int config_list(uint32_t key, GVariant **data,
        return SR_OK;
 }
 
-static void send_chunk(struct sr_dev_inst *sdi,
-       const uint8_t *packets, unsigned int num_tfers)
-{
-       struct dev_context *devc;
-       struct sr_datafeed_logic logic;
-       struct sr_datafeed_packet sr_packet;
-       unsigned int max_samples, n_samples, total_samples, free_n_samples;
-       unsigned int i, j, k;
-       int do_signal_trigger;
-       uint16_t *wp;
-       const uint8_t *rp;
-       uint16_t state;
-       uint8_t repetitions;
-
-       devc = sdi->priv;
-
-       logic.unitsize = 2;
-       logic.data = devc->convbuffer;
-
-       sr_packet.type = SR_DF_LOGIC;
-       sr_packet.payload = &logic;
-
-       max_samples = devc->convbuffer_size / 2;
-       n_samples = 0;
-       wp = (uint16_t *)devc->convbuffer;
-       total_samples = 0;
-       do_signal_trigger = 0;
-
-       if (devc->had_triggers_configured && devc->reading_behind_trigger == 0 && devc->info.n_rep_packets_before_trigger == 0) {
-               std_session_send_df_trigger(sdi);
-               devc->reading_behind_trigger = 1;
-       }
-
-       rp = packets;
-       for (i = 0; i < num_tfers; i++) {
-               for (k = 0; k < NUM_PACKETS_IN_CHUNK; k++) {
-                       free_n_samples = max_samples - n_samples;
-                       if (free_n_samples < 256 || do_signal_trigger) {
-                               logic.length = n_samples * 2;
-                               sr_session_send(sdi, &sr_packet);
-                               n_samples = 0;
-                               wp = (uint16_t *)devc->convbuffer;
-                               if (do_signal_trigger) {
-                                       std_session_send_df_trigger(sdi);
-                                       do_signal_trigger = 0;
-                               }
-                       }
-
-                       state = read_u16le_inc(&rp);
-                       repetitions = read_u8_inc(&rp);
-                       for (j = 0; j < repetitions; j++)
-                               *wp++ = state;
-
-                       n_samples += repetitions;
-                       total_samples += repetitions;
-                       devc->total_samples += repetitions;
-                       if (!devc->reading_behind_trigger) {
-                               devc->n_reps_until_trigger--;
-                               if (devc->n_reps_until_trigger == 0) {
-                                       devc->reading_behind_trigger = 1;
-                                       do_signal_trigger = 1;
-                                       sr_dbg("  here is trigger position after %" PRIu64 " samples, %.6fms",
-                                              devc->total_samples,
-                                              (double)devc->total_samples / devc->cur_samplerate * 1e3);
-                               }
-                       }
-               }
-               (void)read_u8_inc(&rp); /* Skip sequence number. */
-       }
-       if (n_samples) {
-               logic.length = n_samples * 2;
-               sr_session_send(sdi, &sr_packet);
-               if (do_signal_trigger) {
-                       std_session_send_df_trigger(sdi);
-               }
-       }
-       sr_dbg("send_chunk done after %d samples", total_samples);
-}
-
-static void LIBUSB_CALL receive_transfer(struct libusb_transfer *transfer)
-{
-       struct sr_dev_inst *sdi;
-       struct dev_context *devc;
-       struct sr_usb_dev_inst *usb;
-       int ret;
-
-       sdi = transfer->user_data;
-       devc = sdi->priv;
-       usb = sdi->conn;
-
-       sr_dbg("receive_transfer(): status %s received %d bytes.",
-              libusb_error_name(transfer->status), transfer->actual_length);
-
-       if (transfer->status == LIBUSB_TRANSFER_TIMED_OUT) {
-               sr_err("bulk transfer timeout!");
-               devc->transfer_finished = 1;
-       }
-       send_chunk(sdi, transfer->buffer, transfer->actual_length / TRANSFER_PACKET_LENGTH);
-
-       devc->n_bytes_to_read -= transfer->actual_length;
-       if (devc->n_bytes_to_read) {
-               uint32_t to_read = devc->n_bytes_to_read;
-               if (to_read > LA2016_BULK_MAX)
-                       to_read = LA2016_BULK_MAX;
-               libusb_fill_bulk_transfer(
-                       transfer, usb->devhdl,
-                       0x86, transfer->buffer, to_read,
-                       receive_transfer, (void *)sdi, DEFAULT_TIMEOUT_MS);
-
-               if ((ret = libusb_submit_transfer(transfer)) == 0)
-                       return;
-               sr_err("Failed to submit further transfer: %s.", libusb_error_name(ret));
-       }
-
-       g_free(transfer->buffer);
-       libusb_free_transfer(transfer);
-       devc->transfer_finished = 1;
-}
-
-static int handle_event(int fd, int revents, void *cb_data)
-{
-       const struct sr_dev_inst *sdi;
-       struct dev_context *devc;
-       struct drv_context *drvc;
-       struct timeval tv;
-
-       (void)fd;
-       (void)revents;
-
-       sdi = cb_data;
-       devc = sdi->priv;
-       drvc = sdi->driver->context;
-
-       if (devc->have_trigger == 0) {
-               if (la2016_has_triggered(sdi) == 0) {
-                       sr_dbg("not yet ready for download...");
-                       return TRUE;
-               }
-               devc->have_trigger = 1;
-               devc->transfer_finished = 0;
-               devc->reading_behind_trigger = 0;
-               devc->total_samples = 0;
-               /* we can start retrieving data! */
-               if (la2016_start_retrieval(sdi, receive_transfer) != SR_OK) {
-                       sr_err("failed to start retrieval!");
-                       return FALSE;
-               }
-               sr_dbg("retrieval is started...");
-               std_session_send_df_frame_begin(sdi);
-
-               return TRUE;
-       }
-
-       tv.tv_sec = tv.tv_usec = 0;
-       libusb_handle_events_timeout(drvc->sr_ctx->libusb_ctx, &tv);
-
-       if (devc->transfer_finished) {
-               sr_dbg("transfer is finished!");
-               std_session_send_df_frame_end(sdi);
-
-               usb_source_remove(sdi->session, drvc->sr_ctx);
-               std_session_send_df_end(sdi);
-
-               la2016_stop_acquisition(sdi);
-
-               g_free(devc->convbuffer);
-               devc->convbuffer = NULL;
-
-               sr_dbg("transfer is now finished");
-       }
-
-       return TRUE;
-}
-
-static void abort_acquisition(struct dev_context *devc)
-{
-       if (devc->transfer)
-               libusb_cancel_transfer(devc->transfer);
-}
-
 static int configure_channels(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
+       GSList *l;
+       struct sr_channel *ch;
 
        devc = sdi->priv;
-       devc->cur_channels = 0;
-       devc->num_channels = 0;
 
-       for (GSList *l = sdi->channels; l; l = l->next) {
-               struct sr_channel *ch = (struct sr_channel*)l->data;
-               if (ch->enabled == FALSE)
+       devc->cur_channels = 0;
+       for (l = sdi->channels; l; l = l->next) {
+               ch = l->data;
+               if (!ch->enabled)
                        continue;
-               devc->cur_channels |= 1 << ch->index;
-               devc->num_channels++;
+               devc->cur_channels |= 1UL << ch->index;
        }
 
        return SR_OK;
@@ -716,39 +594,45 @@ static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 {
        struct sr_dev_driver *di;
        struct drv_context *drvc;
+       struct sr_context *ctx;
        struct dev_context *devc;
        int ret;
 
        di = sdi->driver;
        drvc = di->context;
+       ctx = drvc->sr_ctx;;
        devc = sdi->priv;
 
        if (configure_channels(sdi) != SR_OK) {
-               sr_err("Failed to configure channels.");
+               sr_err("Cannot configure channels.");
                return SR_ERR;
        }
 
-       devc->convbuffer_size = 4 * 1024 * 1024;
-       if (!(devc->convbuffer = g_try_malloc(devc->convbuffer_size))) {
-               sr_err("Conversion buffer malloc failed.");
+       devc->convbuffer_size = LA2016_CONVBUFFER_SIZE;
+       devc->convbuffer = g_try_malloc(devc->convbuffer_size);
+       if (!devc->convbuffer) {
+               sr_err("Cannot allocate conversion buffer.");
                return SR_ERR_MALLOC;
        }
 
-       if ((ret = la2016_setup_acquisition(sdi)) != SR_OK) {
+       ret = la2016_setup_acquisition(sdi);
+       if (ret != SR_OK) {
                g_free(devc->convbuffer);
                devc->convbuffer = NULL;
                return ret;
        }
 
-       devc->ctx = drvc->sr_ctx;
-
-       if ((ret = la2016_start_acquisition(sdi)) != SR_OK) {
-               abort_acquisition(devc);
+       ret = la2016_start_acquisition(sdi);
+       if (ret != SR_OK) {
+               la2016_abort_acquisition(sdi);
+               g_free(devc->convbuffer);
+               devc->convbuffer = NULL;
                return ret;
        }
 
-       devc->have_trigger = 0;
-       usb_source_add(sdi->session, drvc->sr_ctx, 50, handle_event, (void *)sdi);
+       devc->completion_seen = FALSE;
+       usb_source_add(sdi->session, ctx, 50,
+               la2016_receive_data, (void *)sdi);
 
        std_session_send_df_header(sdi);
 
@@ -760,7 +644,6 @@ static int dev_acquisition_stop(struct sr_dev_inst *sdi)
        int ret;
 
        ret = la2016_abort_acquisition(sdi);
-       abort_acquisition(sdi->priv);
 
        return ret;
 }