]> sigrok.org Git - libsigrok.git/blobdiff - src/hardware/kingst-la2016/protocol.c
output/csv: use intermediate time_t var, silence compiler warning
[libsigrok.git] / src / hardware / kingst-la2016 / protocol.c
index c3e51722c4156522cd5429373dbbbc889f587943..dd806eaa5e065acd0f9623c450045f58bebefdf7 100644 (file)
@@ -1,6 +1,7 @@
 /*
  * This file is part of the libsigrok project.
  *
+ * Copyright (C) 2022 Gerhard Sittig <gerhard.sittig@gmx.net>
  * Copyright (C) 2020 Florian Schmidt <schmidt_florian@gmx.de>
  * Copyright (C) 2013 Marcus Comstedt <marcus@mc.pp.se>
  * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
 
 #include <config.h>
 
-#include <errno.h>
-#include <glib.h>
-#include <glib/gstdio.h>
-#include <inttypes.h>
 #include <libsigrok/libsigrok.h>
-#include <math.h>
-#include <stdint.h>
-#include <stdio.h>
 #include <string.h>
 
 #include "libsigrok-internal.h"
 #include "protocol.h"
 
-#define UC_FIRMWARE    "kingst-la-%04x.fw"
-#define FPGA_FW_LA2016 "kingst-la2016-fpga.bitstream"
-#define FPGA_FW_LA2016A        "kingst-la2016a1-fpga.bitstream"
-#define FPGA_FW_LA1016 "kingst-la1016-fpga.bitstream"
-#define FPGA_FW_LA1016A        "kingst-la1016a1-fpga.bitstream"
+/* USB PID dependent MCU firmware. Model dependent FPGA bitstream. */
+#define MCU_FWFILE_FMT "kingst-la-%04x.fw"
+#define FPGA_FWFILE_FMT        "kingst-%s-fpga.bitstream"
 
-#define MAX_SAMPLE_RATE_LA2016 SR_MHZ(200)
-#define MAX_SAMPLE_RATE_LA1016 SR_MHZ(100)
-#define MAX_SAMPLE_DEPTH 10e9
-#define MAX_PWM_FREQ     SR_MHZ(20)
-#define PWM_CLOCK        SR_MHZ(200)   /* this is 200MHz for both the LA2016 and LA1016 */
-
-/* usb vendor class control requests to the cypress FX2 microcontroller */
+/*
+ * List of known devices and their features. See @ref kingst_model
+ * for the fields' type and meaning. Table is sorted by EEPROM magic.
+ * More specific items need to go first (additional byte[2/6]). Not
+ * all devices are covered by this driver implementation, but telling
+ * users what was detected is considered useful.
+ *
+ * TODO Verify the identification of models that were not tested before.
+ */
+static const struct kingst_model models[] = {
+       { 0x02, 0x01, "LA2016", "la2016a1", SR_MHZ(200), 16, 1, 0, },
+       { 0x02, 0x00, "LA2016", "la2016",   SR_MHZ(200), 16, 1, 0, },
+       { 0x03, 0x01, "LA1016", "la1016a1", SR_MHZ(100), 16, 1, 0, },
+       { 0x03, 0x00, "LA1016", "la1016",   SR_MHZ(100), 16, 1, 0, },
+       { 0x04, 0x00, "LA1010", "la1010a0", SR_MHZ(100), 16, 0, SR_MHZ(800), },
+       { 0x05, 0x00, "LA5016", "la5016a1", SR_MHZ(500), 16, 2, SR_MHZ(800), },
+       { 0x06, 0x00, "LA5032", "la5032a0", SR_MHZ(500), 32, 4, SR_MHZ(800), },
+       { 0x07, 0x00, "LA1010", "la1010a1", SR_MHZ(100), 16, 0, SR_MHZ(800), },
+       { 0x08, 0x00, "LA2016", "la2016a1", SR_MHZ(200), 16, 1, 0, },
+       { 0x09, 0x00, "LA1016", "la1016a1", SR_MHZ(100), 16, 1, 0, },
+       { 0x0a, 0x00, "LA1010", "la1010a2", SR_MHZ(100), 16, 0, SR_MHZ(800), },
+       { 0x0b, 0x10, "LA2016", "la2016a2", SR_MHZ(200), 16, 1, 0, },
+       { 0x0c, 0x10, "LA5016", "la5016a2", SR_MHZ(500), 16, 2, SR_MHZ(800), },
+       { 0x0c, 0x00, "LA5016", "la5016a2", SR_MHZ(500), 16, 2, SR_MHZ(800), },
+       { 0x41, 0x00, "LA5016", "la5016a1", SR_MHZ(500), 16, 2, SR_MHZ(800), },
+};
+
+/* USB vendor class control requests, executed by the Cypress FX2 MCU. */
 #define CMD_FPGA_ENABLE        0x10
-#define CMD_FPGA_SPI   0x20    /* access registers in the FPGA over SPI bus, ctrl_in reads, ctrl_out writes */
-#define CMD_BULK_START 0x30    /* begin transfer of capture data via usb endpoint 6 IN */
-#define CMD_BULK_RESET 0x38    /* flush FX2 usb endpoint 6 IN fifos */
-#define CMD_FPGA_INIT  0x50    /* used before and after FPGA bitstream loading */
-#define CMD_KAUTH      0x60    /* communicate with authentication ic U10, not used */
-#define CMD_EEPROM     0xa2    /* ctrl_in reads, ctrl_out writes */
+#define CMD_FPGA_SPI   0x20    /* R/W access to FPGA registers via SPI. */
+#define CMD_BULK_START 0x30    /* Start sample data download via USB EP6 IN. */
+#define CMD_BULK_RESET 0x38    /* Flush FIFO of FX2 USB EP6 IN. */
+#define CMD_FPGA_INIT  0x50    /* Used before and after FPGA bitstream upload. */
+#define CMD_KAUTH      0x60    /* Communicate to auth IC (U10). Not used. */
+#define CMD_EEPROM     0xa2    /* R/W access to EEPROM content. */
 
 /*
- * fpga spi register addresses for control request CMD_FPGA_SPI:
- * There are around 60 byte-wide registers within the fpga and
- * these are the base addresses used for accessing them.
- * On the spi bus, the msb of the address byte is set for read
- * and cleared for write, but that is handled by the fx2 mcu
- * as appropriate. In this driver code just use IN transactions
- * to read, OUT to write.
+ * FPGA register addresses (base addresses when registers span multiple
+ * bytes, in that case data is kept in little endian format). Passed to
+ * CMD_FPGA_SPI requests. The FX2 MCU transparently handles the detail
+ * of SPI transfers encoding the read (1) or write (0) direction in the
+ * MSB of the address field. There are some 60 byte-wide FPGA registers.
+ *
+ * Unfortunately the FPGA registers change their meaning between the
+ * read and write directions of access, or exclusively provide one of
+ * these directions and not the other. This is an arbitrary vendor's
+ * choice, there is nothing which the sigrok driver could do about it.
+ * Values written to registers typically cannot get read back, neither
+ * verified after writing a configuration, nor queried upon startup for
+ * automatic detection of the current configuration. Neither appear to
+ * be there echo registers for presence and communication checks, nor
+ * version identifying registers, as far as we know.
  */
-#define REG_RUN                0x00    /* read capture status, write capture start */
-#define REG_PWM_EN     0x02    /* user pwm channels on/off */
-#define REG_CAPT_MODE  0x03    /* set to 0x00 for capture to sdram, 0x01 bypass sdram for streaming */
-#define REG_BULK       0x08    /* write start address and number of bytes for capture data bulk upload */
-#define REG_SAMPLING   0x10    /* write capture config, read capture data location in sdram */
-#define REG_TRIGGER    0x20    /* write level and edge trigger config */
-#define REG_THRESHOLD  0x68    /* write two pwm configs to control input threshold dac */
-#define REG_PWM1       0x70    /* write config for user pwm1 */
-#define REG_PWM2       0x78    /* write config for user pwm2 */
+#define REG_RUN                0x00    /* Read capture status, write start capture. */
+#define REG_PWM_EN     0x02    /* User PWM channels on/off. */
+#define REG_CAPT_MODE  0x03    /* Write 0x00 capture to SDRAM, 0x01 streaming. */
+#define REG_PIN_STATE  0x04    /* Read current pin state (real time display). */
+#define REG_BULK       0x08    /* Write start addr, byte count to download samples. */
+#define REG_SAMPLING   0x10    /* Write capture config, read capture SDRAM location. */
+#define REG_TRIGGER    0x20    /* Write level and edge trigger config. */
+#define REG_UNKNOWN_30 0x30
+#define REG_THRESHOLD  0x68    /* Write PWM config to setup input threshold DAC. */
+#define REG_PWM1       0x70    /* Write config for user PWM1. */
+#define REG_PWM2       0x78    /* Write config for user PWM2. */
+
+/* Bit patterns to write to REG_CAPT_MODE. */
+#define CAPTMODE_TO_RAM        0x00
+#define CAPTMODE_STREAM        0x01
+
+/* Bit patterns to write to REG_RUN, setup run mode. */
+#define RUNMODE_HALT   0x00
+#define RUNMODE_RUN    0x03
+
+/* Bit patterns when reading from REG_RUN, get run state. */
+#define RUNSTATE_IDLE_BIT      (1UL << 0)
+#define RUNSTATE_DRAM_BIT      (1UL << 1)
+#define RUNSTATE_TRGD_BIT      (1UL << 2)
+#define RUNSTATE_POST_BIT      (1UL << 3)
 
 static int ctrl_in(const struct sr_dev_inst *sdi,
-                  uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
-                  void *data, uint16_t wLength)
+       uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
+       void *data, uint16_t wLength)
 {
        struct sr_usb_dev_inst *usb;
        int ret;
 
        usb = sdi->conn;
 
-       if ((ret = libusb_control_transfer(
-                    usb->devhdl, LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN,
-                    bRequest, wValue, wIndex, (unsigned char *)data, wLength,
-                    DEFAULT_TIMEOUT_MS)) != wLength) {
-               sr_err("failed to read %d bytes via ctrl-in %d %#x, %d: %s.",
-                      wLength, bRequest, wValue, wIndex,
-                      libusb_error_name(ret));
-               return SR_ERR;
+       ret = libusb_control_transfer(usb->devhdl,
+               LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN,
+               bRequest, wValue, wIndex, data, wLength,
+               DEFAULT_TIMEOUT_MS);
+       if (ret != wLength) {
+               sr_dbg("USB ctrl in: %d bytes, req %d val %#x idx %d: %s.",
+                       wLength, bRequest, wValue, wIndex,
+                       libusb_error_name(ret));
+               sr_err("Cannot read %d bytes from USB: %s.",
+                       wLength, libusb_error_name(ret));
+               return SR_ERR_IO;
        }
 
        return SR_OK;
 }
 
 static int ctrl_out(const struct sr_dev_inst *sdi,
-                   uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
-                   void *data, uint16_t wLength)
+       uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
+       void *data, uint16_t wLength)
 {
        struct sr_usb_dev_inst *usb;
        int ret;
 
        usb = sdi->conn;
 
-       if ((ret = libusb_control_transfer(
-                    usb->devhdl, LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_OUT,
-                    bRequest, wValue, wIndex, (unsigned char*)data, wLength,
-                    DEFAULT_TIMEOUT_MS)) != wLength) {
-               sr_err("failed to write %d bytes via ctrl-out %d %#x, %d: %s.",
-                      wLength, bRequest, wValue, wIndex,
-                      libusb_error_name(ret));
-               return SR_ERR;
+       ret = libusb_control_transfer(usb->devhdl,
+               LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_OUT,
+               bRequest, wValue, wIndex, data, wLength,
+               DEFAULT_TIMEOUT_MS);
+       if (ret != wLength) {
+               sr_dbg("USB ctrl out: %d bytes, req %d val %#x idx %d: %s.",
+                       wLength, bRequest, wValue, wIndex,
+                       libusb_error_name(ret));
+               sr_err("Cannot write %d bytes to USB: %s.",
+                       wLength, libusb_error_name(ret));
+               return SR_ERR_IO;
        }
 
        return SR_OK;
 }
 
-static int upload_fpga_bitstream(const struct sr_dev_inst *sdi, const char *bitstream_fname)
+/* HACK Experiment to spot FPGA registers of interest. */
+static void la2016_dump_fpga_registers(const struct sr_dev_inst *sdi,
+       const char *caption, size_t reg_lower, size_t reg_upper)
+{
+       static const size_t dump_chunk_len = 16;
+
+       size_t rdlen;
+       uint8_t rdbuf[0x80 - 0x00];     /* Span all FPGA registers. */
+       const uint8_t *rdptr;
+       int ret;
+       size_t dump_addr, indent, dump_len;
+       GString *txt;
+
+       if (sr_log_loglevel_get() < SR_LOG_SPEW)
+               return;
+
+       if (!reg_lower && !reg_upper) {
+               reg_lower = 0;
+               reg_upper = sizeof(rdbuf);
+       }
+       if (reg_upper - reg_lower > sizeof(rdbuf))
+               reg_upper = sizeof(rdbuf) - reg_lower;
+
+       rdlen = reg_upper - reg_lower;
+       ret = ctrl_in(sdi, CMD_FPGA_SPI, reg_lower, 0, rdbuf, rdlen);
+       if (ret != SR_OK) {
+               sr_err("Cannot get registers space.");
+               return;
+       }
+       rdptr = rdbuf;
+
+       sr_spew("FPGA registers dump: %s", caption ? : "for fun");
+       dump_addr = reg_lower;
+       while (rdlen) {
+               dump_len = rdlen;
+               indent = dump_addr % dump_chunk_len;
+               if (dump_len > dump_chunk_len)
+                       dump_len = dump_chunk_len;
+               if (dump_len + indent > dump_chunk_len)
+                       dump_len = dump_chunk_len - indent;
+               txt = sr_hexdump_new(rdptr, dump_len);
+               sr_spew("  %04zx  %*s%s",
+                       dump_addr, (int)(3 * indent), "", txt->str);
+               sr_hexdump_free(txt);
+               dump_addr += dump_len;
+               rdptr += dump_len;
+               rdlen -= dump_len;
+       }
+}
+
+/*
+ * Check the necessity for FPGA bitstream upload, because another upload
+ * would take some 600ms which is undesirable after program startup. Try
+ * to access some FPGA registers and check the values' plausibility. The
+ * check should fail on the safe side, request another upload when in
+ * doubt. A positive response (the request to continue operation with the
+ * currently active bitstream) should be conservative. Accessing multiple
+ * registers is considered cheap compared to the cost of bitstream upload.
+ *
+ * It helps though that both the vendor software and the sigrok driver
+ * use the same bundle of MCU firmware and FPGA bitstream for any of the
+ * supported models. We don't expect to successfully communicate to the
+ * device yet disagree on its protocol. Ideally we would access version
+ * identifying registers for improved robustness, but are not aware of
+ * any. A bitstream reload can always be forced by a power cycle.
+ */
+static int check_fpga_bitstream(const struct sr_dev_inst *sdi)
+{
+       uint8_t init_rsp;
+       uint8_t buff[REG_PWM_EN - REG_RUN]; /* Larger of REG_RUN, REG_PWM_EN. */
+       int ret;
+       uint16_t run_state;
+       uint8_t pwm_en;
+       size_t read_len;
+       const uint8_t *rdptr;
+
+       sr_dbg("Checking operation of the FPGA bitstream.");
+       la2016_dump_fpga_registers(sdi, "bitstream check", 0, 0);
+
+       init_rsp = ~0;
+       ret = ctrl_in(sdi, CMD_FPGA_INIT, 0x00, 0, &init_rsp, sizeof(init_rsp));
+       if (ret != SR_OK || init_rsp != 0) {
+               sr_dbg("FPGA init query failed, or unexpected response.");
+               return SR_ERR_IO;
+       }
+
+       read_len = sizeof(run_state);
+       ret = ctrl_in(sdi, CMD_FPGA_SPI, REG_RUN, 0, buff, read_len);
+       if (ret != SR_OK) {
+               sr_dbg("FPGA register access failed (run state).");
+               return SR_ERR_IO;
+       }
+       rdptr = buff;
+       run_state = read_u16le_inc(&rdptr);
+       sr_spew("FPGA register: run state 0x%04x.", run_state);
+       if (run_state && (run_state & 0x3) != 0x1) {
+               sr_dbg("Unexpected FPGA register content (run state).");
+               return SR_ERR_DATA;
+       }
+       if (run_state && (run_state & ~0xf) != 0x85e0) {
+               sr_dbg("Unexpected FPGA register content (run state).");
+               return SR_ERR_DATA;
+       }
+
+       read_len = sizeof(pwm_en);
+       ret = ctrl_in(sdi, CMD_FPGA_SPI, REG_PWM_EN, 0, buff, read_len);
+       if (ret != SR_OK) {
+               sr_dbg("FPGA register access failed (PWM enable).");
+               return SR_ERR_IO;
+       }
+       rdptr = buff;
+       pwm_en = read_u8_inc(&rdptr);
+       sr_spew("FPGA register: PWM enable 0x%02x.", pwm_en);
+       if ((pwm_en & 0x3) != 0x0) {
+               sr_dbg("Unexpected FPGA register content (PWM enable).");
+               return SR_ERR_DATA;
+       }
+
+       sr_info("Could re-use current FPGA bitstream. No upload required.");
+       return SR_OK;
+}
+
+static int upload_fpga_bitstream(const struct sr_dev_inst *sdi,
+       const char *bitstream_fname)
 {
-       struct dev_context *devc;
        struct drv_context *drvc;
        struct sr_usb_dev_inst *usb;
        struct sr_resource bitstream;
+       uint32_t bitstream_size;
        uint8_t buffer[sizeof(uint32_t)];
        uint8_t *wrptr;
-       uint8_t cmd_resp;
        uint8_t block[4096];
        int len, act_len;
        unsigned int pos;
        int ret;
-       unsigned int zero_pad_to = 0x2c000;
+       unsigned int zero_pad_to;
 
-       devc = sdi->priv;
        drvc = sdi->driver->context;
        usb = sdi->conn;
 
        sr_info("Uploading FPGA bitstream '%s'.", bitstream_fname);
 
-       ret = sr_resource_open(drvc->sr_ctx, &bitstream, SR_RESOURCE_FIRMWARE, bitstream_fname);
+       ret = sr_resource_open(drvc->sr_ctx, &bitstream,
+               SR_RESOURCE_FIRMWARE, bitstream_fname);
        if (ret != SR_OK) {
-               sr_err("could not find fpga firmware %s!", bitstream_fname);
+               sr_err("Cannot find FPGA bitstream %s.", bitstream_fname);
                return ret;
        }
 
-       devc->bitstream_size = (uint32_t)bitstream.size;
+       bitstream_size = (uint32_t)bitstream.size;
        wrptr = buffer;
-       write_u32le_inc(&wrptr, devc->bitstream_size);
-       if ((ret = ctrl_out(sdi, CMD_FPGA_INIT, 0x00, 0, buffer, wrptr - buffer)) != SR_OK) {
-               sr_err("failed to give upload init command");
+       write_u32le_inc(&wrptr, bitstream_size);
+       ret = ctrl_out(sdi, CMD_FPGA_INIT, 0x00, 0, buffer, wrptr - buffer);
+       if (ret != SR_OK) {
+               sr_err("Cannot initiate FPGA bitstream upload.");
                sr_resource_close(drvc->sr_ctx, &bitstream);
                return ret;
        }
+       zero_pad_to = bitstream_size;
+       zero_pad_to += LA2016_EP2_PADDING - 1;
+       zero_pad_to /= LA2016_EP2_PADDING;
+       zero_pad_to *= LA2016_EP2_PADDING;
 
        pos = 0;
        while (1) {
                if (pos < bitstream.size) {
-                       len = (int)sr_resource_read(drvc->sr_ctx, &bitstream, &block, sizeof(block));
+                       len = (int)sr_resource_read(drvc->sr_ctx, &bitstream,
+                               block, sizeof(block));
                        if (len < 0) {
-                               sr_err("failed to read from fpga bitstream!");
+                               sr_err("Cannot read FPGA bitstream.");
                                sr_resource_close(drvc->sr_ctx, &bitstream);
-                               return SR_ERR;
+                               return SR_ERR_IO;
                        }
                } else {
-                       // fill with zero's until zero_pad_to
+                       /*  Zero-pad until 'zero_pad_to'. */
                        len = zero_pad_to - pos;
                        if ((unsigned)len > sizeof(block))
                                len = sizeof(block);
@@ -174,101 +345,103 @@ static int upload_fpga_bitstream(const struct sr_dev_inst *sdi, const char *bits
                if (len == 0)
                        break;
 
-               ret = libusb_bulk_transfer(usb->devhdl, 2, (unsigned char*)&block[0], len, &act_len, DEFAULT_TIMEOUT_MS);
+               ret = libusb_bulk_transfer(usb->devhdl, USB_EP_FPGA_BITSTREAM,
+                       &block[0], len, &act_len, DEFAULT_TIMEOUT_MS);
                if (ret != 0) {
-                       sr_dbg("failed to write fpga bitstream block at %#x len %d: %s.", pos, (int)len, libusb_error_name(ret));
-                       ret = SR_ERR;
+                       sr_dbg("Cannot write FPGA bitstream, block %#x len %d: %s.",
+                               pos, (int)len, libusb_error_name(ret));
+                       ret = SR_ERR_IO;
                        break;
                }
                if (act_len != len) {
-                       sr_dbg("failed to write fpga bitstream block at %#x len %d: act_len is %d.", pos, (int)len, act_len);
-                       ret = SR_ERR;
+                       sr_dbg("Short write for FPGA bitstream, block %#x len %d: got %d.",
+                               pos, (int)len, act_len);
+                       ret = SR_ERR_IO;
                        break;
                }
                pos += len;
        }
        sr_resource_close(drvc->sr_ctx, &bitstream);
-       if (ret != 0)
+       if (ret != SR_OK)
                return ret;
-       sr_info("FPGA bitstream upload (%" PRIu64 " bytes) done.", bitstream.size);
+       sr_info("FPGA bitstream upload (%" PRIu64 " bytes) done.",
+               bitstream.size);
+
+       return SR_OK;
+}
+
+static int enable_fpga_bitstream(const struct sr_dev_inst *sdi)
+{
+       int ret;
+       uint8_t resp;
 
-       if ((ret = ctrl_in(sdi, CMD_FPGA_INIT, 0x00, 0, &cmd_resp, sizeof(cmd_resp))) != SR_OK) {
-               sr_err("failed to read response after FPGA bitstream upload");
+       ret = ctrl_in(sdi, CMD_FPGA_INIT, 0x00, 0, &resp, sizeof(resp));
+       if (ret != SR_OK) {
+               sr_err("Cannot read response after FPGA bitstream upload.");
                return ret;
        }
-       if (cmd_resp != 0) {
-               sr_err("after fpga bitstream upload command response is 0x%02x, expect 0!", cmd_resp);
-               return SR_ERR;
+       if (resp != 0) {
+               sr_err("Unexpected FPGA bitstream upload response, got 0x%02x, want 0.",
+                       resp);
+               return SR_ERR_DATA;
        }
+       g_usleep(30 * 1000);
 
-       g_usleep(30000);
-
-       if ((ret = ctrl_out(sdi, CMD_FPGA_ENABLE, 0x01, 0, NULL, 0)) != SR_OK) {
-               sr_err("failed enable fpga");
+       ret = ctrl_out(sdi, CMD_FPGA_ENABLE, 0x01, 0, NULL, 0);
+       if (ret != SR_OK) {
+               sr_err("Cannot enable FPGA after bitstream upload.");
                return ret;
        }
+       g_usleep(40 * 1000);
 
-       g_usleep(40000);
        return SR_OK;
 }
 
 static int set_threshold_voltage(const struct sr_dev_inst *sdi, float voltage)
 {
-       struct dev_context *devc;
        int ret;
-
-       devc = sdi->priv;
-
-       uint16_t duty_R79,duty_R56;
-       uint8_t buf[2 * sizeof(uint16_t)];
+       uint16_t duty_R79, duty_R56;
+       uint8_t buf[REG_PWM1 - REG_THRESHOLD]; /* Width of REG_THRESHOLD. */
        uint8_t *wrptr;
 
-       /* clamp threshold setting within valid range for LA2016 */
-       if (voltage > 4.0) {
-               voltage = 4.0;
-       }
-       else if (voltage < -4.0) {
-               voltage = -4.0;
+       /* Clamp threshold setting to valid range for LA2016. */
+       if (voltage > LA2016_THR_VOLTAGE_MAX) {
+               voltage = LA2016_THR_VOLTAGE_MAX;
+       } else if (voltage < -LA2016_THR_VOLTAGE_MAX) {
+               voltage = -LA2016_THR_VOLTAGE_MAX;
        }
 
        /*
-        * The fpga has two programmable pwm outputs which feed a dac that
-        * is used to adjust input offset. The dac changes the input
-        * swing around the fixed fpga input threshold.
-        * The two pwm outputs can be seen on R79 and R56 respectvely.
-        * Frequency is fixed at 100kHz and duty is varied.
-        * The R79 pwm uses just three settings.
-        * The R56 pwm varies with required threshold and its behaviour
-        * also changes depending on the setting of R79 PWM.
-        */
-
-       /*
-        * calculate required pwm duty register values from requested threshold voltage
-        * see last page of schematic (on wiki) for an explanation of these numbers
+        * Two PWM output channels feed one DAC which generates a bias
+        * voltage, which offsets the input probe's voltage level, and
+        * in combination with the FPGA pins' fixed threshold result in
+        * a programmable input threshold from the user's perspective.
+        * The PWM outputs can be seen on R79 and R56 respectively, the
+        * frequency is 100kHz and the duty cycle varies. The R79 PWM
+        * uses three discrete settings. The R56 PWM varies with desired
+        * thresholds and depends on the R79 PWM configuration. See the
+        * schematics comments which discuss the formulae.
         */
        if (voltage >= 2.9) {
-               duty_R79 = 0;           /* this pwm is off (0V)*/
+               duty_R79 = 0;           /* PWM off (0V). */
                duty_R56 = (uint16_t)(302 * voltage - 363);
-       }
-       else if (voltage <= -0.4) {
-               duty_R79 = 0x02D7;      /* 72% duty */
-               duty_R56 = (uint16_t)(302 * voltage + 1090);
-       }
-       else {
-               duty_R79 = 0x00f2;      /* 25% duty */
+       } else if (voltage > -0.4) {
+               duty_R79 = 0x00f2;      /* 25% duty cycle. */
                duty_R56 = (uint16_t)(302 * voltage + 121);
+       } else {
+               duty_R79 = 0x02d7;      /* 72% duty cycle. */
+               duty_R56 = (uint16_t)(302 * voltage + 1090);
        }
 
-       /* clamp duty register values at sensible limits */
+       /* Clamp duty register values to sensible limits. */
        if (duty_R56 < 10) {
                duty_R56 = 10;
-       }
-       else if (duty_R56 > 1100) {
+       } else if (duty_R56 > 1100) {
                duty_R56 = 1100;
        }
 
-       sr_dbg("set threshold voltage %.2fV", voltage);
-       sr_dbg("duty_R56=0x%04x, duty_R79=0x%04x", duty_R56, duty_R79);
+       sr_dbg("Set threshold voltage %.2fV.", voltage);
+       sr_dbg("Duty cycle values: R56 0x%04x, R79 0x%04x.", duty_R56, duty_R79);
 
        wrptr = buf;
        write_u16le_inc(&wrptr, duty_R56);
@@ -276,149 +449,190 @@ static int set_threshold_voltage(const struct sr_dev_inst *sdi, float voltage)
 
        ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_THRESHOLD, 0, buf, wrptr - buf);
        if (ret != SR_OK) {
-               sr_err("error setting new threshold voltage of %.2fV", voltage);
+               sr_err("Cannot set threshold voltage %.2fV.", voltage);
                return ret;
        }
-       devc->threshold_voltage = voltage;
 
        return SR_OK;
 }
 
-static int enable_pwm(const struct sr_dev_inst *sdi, uint8_t p1, uint8_t p2)
+/*
+ * Communicates a channel's configuration to the device after the
+ * parameters may have changed. Configuration of one channel may
+ * interfere with other channels since they share FPGA registers.
+ */
+static int set_pwm_config(const struct sr_dev_inst *sdi, size_t idx)
 {
+       static uint8_t reg_bases[] = { REG_PWM1, REG_PWM2, };
+
        struct dev_context *devc;
-       uint8_t cfg;
+       struct pwm_setting *params;
+       uint8_t reg_base;
+       double val_f;
+       uint32_t val_u;
+       uint32_t period, duty;
+       size_t ch;
        int ret;
+       uint8_t enable_all, enable_cfg, reg_val;
+       uint8_t buf[REG_PWM2 - REG_PWM1]; /* Width of one REG_PWMx. */
+       uint8_t *wrptr;
 
        devc = sdi->priv;
-       cfg = 0;
+       if (idx >= ARRAY_SIZE(devc->pwm_setting))
+               return SR_ERR_ARG;
+       params = &devc->pwm_setting[idx];
+       if (idx >= ARRAY_SIZE(reg_bases))
+               return SR_ERR_ARG;
+       reg_base = reg_bases[idx];
 
-       if (p1) cfg |= 1 << 0;
-       if (p2) cfg |= 1 << 1;
+       /*
+        * Map application's specs to hardware register values. Do math
+        * in floating point initially, but convert to u32 eventually.
+        */
+       sr_dbg("PWM config, app spec, ch %zu, en %d, freq %.1f, duty %.1f.",
+               idx, params->enabled ? 1 : 0, params->freq, params->duty);
+       val_f = PWM_CLOCK;
+       val_f /= params->freq;
+       val_u = val_f;
+       period = val_u;
+       val_f = period;
+       val_f *= params->duty;
+       val_f /= 100.0;
+       val_f += 0.5;
+       val_u = val_f;
+       duty = val_u;
+       sr_dbg("PWM config, reg 0x%04x, freq %u, duty %u.",
+               (unsigned)reg_base, (unsigned)period, (unsigned)duty);
+
+       /* Get the "enabled" state of all supported PWM channels. */
+       enable_all = 0;
+       for (ch = 0; ch < ARRAY_SIZE(devc->pwm_setting); ch++) {
+               if (!devc->pwm_setting[ch].enabled)
+                       continue;
+               enable_all |= 1U << ch;
+       }
+       enable_cfg = 1U << idx;
+       sr_spew("PWM config, enable all 0x%02hhx, cfg 0x%02hhx.",
+               enable_all, enable_cfg);
 
-       sr_dbg("set pwm enable %d %d", p1, p2);
-       ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_PWM_EN, 0, &cfg, sizeof(cfg));
+       /*
+        * Disable the to-get-configured channel before its parameters
+        * will change. Or disable and exit when the channel is supposed
+        * to get turned off.
+        */
+       sr_spew("PWM config, disabling before param change.");
+       reg_val = enable_all & ~enable_cfg;
+       ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_PWM_EN, 0,
+               &reg_val, sizeof(reg_val));
        if (ret != SR_OK) {
-               sr_err("error setting new pwm enable 0x%02x", cfg);
+               sr_err("Cannot adjust PWM enabled state.");
                return ret;
        }
-       devc->pwm_setting[0].enabled = (p1) ? 1 : 0;
-       devc->pwm_setting[1].enabled = (p2) ? 1 : 0;
-
-       return SR_OK;
-}
-
-static int set_pwm(const struct sr_dev_inst *sdi, uint8_t which, float freq, float duty)
-{
-       int CTRL_PWM[] = { REG_PWM1, REG_PWM2 };
-       struct dev_context *devc;
-       pwm_setting_dev_t cfg;
-       pwm_setting_t *setting;
-       int ret;
-       uint8_t buf[2 * sizeof(uint32_t)];
-       uint8_t *wrptr;
+       if (!params->enabled)
+               return SR_OK;
 
-       devc = sdi->priv;
-
-       if (which < 1 || which > 2) {
-               sr_err("invalid pwm channel: %d", which);
-               return SR_ERR;
-       }
-       if (freq > MAX_PWM_FREQ) {
-               sr_err("pwm frequency too high: %.1f", freq);
-               return SR_ERR;
-       }
-       if (duty > 100 || duty < 0) {
-               sr_err("invalid pwm percentage: %f", duty);
-               return SR_ERR;
+       /* Write register values to device. */
+       sr_spew("PWM config, sending new parameters.");
+       wrptr = buf;
+       write_u32le_inc(&wrptr, period);
+       write_u32le_inc(&wrptr, duty);
+       ret = ctrl_out(sdi, CMD_FPGA_SPI, reg_base, 0, buf, wrptr - buf);
+       if (ret != SR_OK) {
+               sr_err("Cannot change PWM parameters.");
+               return ret;
        }
 
-       cfg.period = (uint32_t)(PWM_CLOCK / freq);
-       cfg.duty = (uint32_t)(0.5f + (cfg.period * duty / 100.));
-       sr_dbg("set pwm%d period %d, duty %d", which, cfg.period, cfg.duty);
-
-       wrptr = buf;
-       write_u32le_inc(&wrptr, cfg.period);
-       write_u32le_inc(&wrptr, cfg.duty);
-       ret = ctrl_out(sdi, CMD_FPGA_SPI, CTRL_PWM[which - 1], 0, buf, wrptr - buf);
+       /* Enable configured channel after write completion. */
+       sr_spew("PWM config, enabling after param change.");
+       reg_val = enable_all | enable_cfg;
+       ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_PWM_EN, 0,
+               &reg_val, sizeof(reg_val));
        if (ret != SR_OK) {
-               sr_err("error setting new pwm%d config %d %d", which, cfg.period, cfg.duty);
+               sr_err("Cannot adjust PWM enabled state.");
                return ret;
        }
-       setting = &devc->pwm_setting[which - 1];
-       setting->freq = freq;
-       setting->duty = duty;
 
        return SR_OK;
 }
 
-static int set_defaults(const struct sr_dev_inst *sdi)
+/*
+ * Determine the number of enabled channels as well as their bitmask
+ * representation. Derive data here which later simplifies processing
+ * of raw capture data memory content in streaming mode.
+ */
+static void la2016_prepare_stream(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
-       int ret;
+       struct stream_state_t *stream;
+       size_t channel_mask;
+       GSList *l;
+       struct sr_channel *ch;
 
        devc = sdi->priv;
-
-       devc->capture_ratio = 5; /* percent */
-       devc->cur_channels = 0xffff;
-       devc->limit_samples = 5000000;
-       devc->cur_samplerate = SR_MHZ(100);
-
-       ret = set_threshold_voltage(sdi, devc->threshold_voltage);
-       if (ret)
-               return ret;
-
-       ret = enable_pwm(sdi, 0, 0);
-       if (ret)
-               return ret;
-
-       ret = set_pwm(sdi, 1, 1e3, 50);
-       if (ret)
-               return ret;
-
-       ret = set_pwm(sdi, 2, 100e3, 50);
-       if (ret)
-               return ret;
-
-       ret = enable_pwm(sdi, 1, 1);
-       if (ret)
-               return ret;
-
-       return SR_OK;
+       stream = &devc->stream;
+       memset(stream, 0, sizeof(*stream));
+
+       stream->enabled_count = 0;
+       for (l = sdi->channels; l; l = l->next) {
+               ch = l->data;
+               if (ch->type != SR_CHANNEL_LOGIC)
+                       continue;
+               if (!ch->enabled)
+                       continue;
+               channel_mask = 1UL << ch->index;
+               stream->enabled_mask |= channel_mask;
+               stream->channel_masks[stream->enabled_count++] = channel_mask;
+       }
+       stream->channel_index = 0;
 }
 
+/*
+ * This routine configures the set of enabled channels, as well as the
+ * trigger condition (if one was specified). Also prepares the capture
+ * data processing in stream mode, where the memory layout dramatically
+ * differs from normal mode.
+ */
 static int set_trigger_config(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
        struct sr_trigger *trigger;
-       trigger_cfg_t cfg;
+       struct trigger_cfg {
+               uint32_t channels;      /* Actually: Enabled channels? */
+               uint32_t enabled;       /* Actually: Triggering channels? */
+               uint32_t level;
+               uint32_t high_or_falling;
+       } cfg;
        GSList *stages;
        GSList *channel;
        struct sr_trigger_stage *stage1;
        struct sr_trigger_match *match;
-       uint16_t ch_mask;
+       uint32_t ch_mask;
        int ret;
-       uint8_t buf[4 * sizeof(uint32_t)];
+       uint8_t buf[REG_UNKNOWN_30 - REG_TRIGGER]; /* Width of REG_TRIGGER. */
        uint8_t *wrptr;
 
        devc = sdi->priv;
-       trigger = sr_session_trigger_get(sdi->session);
-
-       memset(&cfg, 0, sizeof(cfg));
 
-       cfg.channels = devc->cur_channels;
+       la2016_prepare_stream(sdi);
 
+       memset(&cfg, 0, sizeof(cfg));
+       cfg.channels = devc->stream.enabled_mask;
+       if (!cfg.channels) {
+               sr_err("Need at least one enabled logic channel.");
+               return SR_ERR_ARG;
+       }
+       trigger = sr_session_trigger_get(sdi->session);
        if (trigger && trigger->stages) {
                stages = trigger->stages;
                stage1 = stages->data;
                if (stages->next) {
                        sr_err("Only one trigger stage supported for now.");
-                       return SR_ERR;
+                       return SR_ERR_ARG;
                }
                channel = stage1->matches;
                while (channel) {
                        match = channel->data;
-                       ch_mask = 1 << match->channel->index;
+                       ch_mask = 1UL << match->channel->index;
 
                        switch (match->match) {
                        case SR_TRIGGER_ZERO:
@@ -431,162 +645,318 @@ static int set_trigger_config(const struct sr_dev_inst *sdi)
                                break;
                        case SR_TRIGGER_RISING:
                                if ((cfg.enabled & ~cfg.level)) {
-                                       sr_err("Only one trigger signal with falling-/rising-edge allowed.");
-                                       return SR_ERR;
+                                       sr_err("Device only supports one edge trigger.");
+                                       return SR_ERR_ARG;
                                }
                                cfg.level &= ~ch_mask;
                                cfg.high_or_falling &= ~ch_mask;
                                break;
                        case SR_TRIGGER_FALLING:
                                if ((cfg.enabled & ~cfg.level)) {
-                                       sr_err("Only one trigger signal with falling-/rising-edge allowed.");
-                                       return SR_ERR;
+                                       sr_err("Device only supports one edge trigger.");
+                                       return SR_ERR_ARG;
                                }
                                cfg.level &= ~ch_mask;
                                cfg.high_or_falling |= ch_mask;
                                break;
                        default:
-                               sr_err("Unknown trigger value.");
-                               return SR_ERR;
+                               sr_err("Unknown trigger condition.");
+                               return SR_ERR_ARG;
                        }
                        cfg.enabled |= ch_mask;
                        channel = channel->next;
                }
        }
-       sr_dbg("set trigger configuration channels: 0x%04x, "
-              "trigger-enabled 0x%04x, level-triggered 0x%04x, "
-              "high/falling 0x%04x", cfg.channels, cfg.enabled, cfg.level,
-              cfg.high_or_falling);
+       sr_dbg("Set trigger config: "
+               "enabled-channels 0x%04x, triggering-channels 0x%04x, "
+               "level-triggered 0x%04x, high/falling 0x%04x.",
+               cfg.channels, cfg.enabled, cfg.level, cfg.high_or_falling);
 
-       devc->had_triggers_configured = cfg.enabled != 0;
+       /*
+        * Don't configure hardware trigger parameters in streaming mode
+        * or when the device lacks local memory. Yet the above dump of
+        * derived parameters from user specs is considered valueable.
+        *
+        * TODO Add support for soft triggers when hardware triggers in
+        * the device are not used or are not available at all.
+        */
+       if (!devc->model->memory_bits || devc->continuous) {
+               if (!devc->model->memory_bits)
+                       sr_dbg("Device without memory. No hardware triggers.");
+               else if (devc->continuous)
+                       sr_dbg("Streaming mode. No hardware triggers.");
+               cfg.enabled = 0;
+               cfg.level = 0;
+               cfg.high_or_falling = 0;
+       }
+
+       devc->trigger_involved = cfg.enabled != 0;
 
        wrptr = buf;
        write_u32le_inc(&wrptr, cfg.channels);
        write_u32le_inc(&wrptr, cfg.enabled);
        write_u32le_inc(&wrptr, cfg.level);
        write_u32le_inc(&wrptr, cfg.high_or_falling);
+       /* TODO
+        * Comment on this literal 16. Origin, meaning? Cannot be the
+        * register offset, nor the transfer length. Is it a channels
+        * count that is relevant for 16 and 32 channel models? Is it
+        * an obsolete experiment?
+        */
        ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_TRIGGER, 16, buf, wrptr - buf);
        if (ret != SR_OK) {
-               sr_err("error setting trigger config!");
+               sr_err("Cannot setup trigger configuration.");
                return ret;
        }
 
        return SR_OK;
 }
 
+/*
+ * This routine communicates the sample configuration to the device:
+ * Total samples count and samplerate, pre-trigger configuration.
+ */
 static int set_sample_config(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
-       double clock_divisor;
-       uint64_t total;
-       int ret;
-       uint16_t divisor;
-       uint8_t buf[2 * sizeof(uint32_t) + 48 / 8 + sizeof(uint16_t)];
+       uint64_t baseclock;
+       uint64_t min_samplerate, eff_samplerate;
+       uint64_t stream_bandwidth;
+       uint16_t divider_u16;
+       uint64_t limit_samples;
+       uint64_t pre_trigger_samples;
+       uint64_t pre_trigger_memory;
+       uint8_t buf[REG_TRIGGER - REG_SAMPLING]; /* Width of REG_SAMPLING. */
        uint8_t *wrptr;
+       int ret;
 
        devc = sdi->priv;
-       total = 128 * 1024 * 1024;
 
-       if (devc->cur_samplerate > devc->max_samplerate) {
-               sr_err("too high sample rate: %" PRIu64, devc->cur_samplerate);
-               return SR_ERR;
+       /*
+        * The base clock need not be identical to the maximum samplerate,
+        * and differs between models. The 500MHz devices even use a base
+        * clock of 800MHz, and communicate divider 1 to the hardware to
+        * configure the 500MHz samplerate. This allows them to operate at
+        * a 200MHz samplerate which uses divider 4.
+        */
+       if (devc->samplerate > devc->model->samplerate) {
+               sr_err("Too high a sample rate: %" PRIu64 ".",
+                       devc->samplerate);
+               return SR_ERR_ARG;
        }
-
-       clock_divisor = devc->max_samplerate / (double)devc->cur_samplerate;
-       if (clock_divisor > 0xffff)
-               clock_divisor = 0xffff;
-       divisor = (uint16_t)(clock_divisor + 0.5);
-       devc->cur_samplerate = devc->max_samplerate / divisor;
-
-       if (devc->limit_samples > MAX_SAMPLE_DEPTH) {
-               sr_err("too high sample depth: %" PRIu64, devc->limit_samples);
-               return SR_ERR;
+       baseclock = devc->model->baseclock;
+       if (!baseclock)
+               baseclock = devc->model->samplerate;
+       min_samplerate = baseclock;
+       min_samplerate /= 65536;
+       if (devc->samplerate < min_samplerate) {
+               sr_err("Too low a sample rate: %" PRIu64 ".",
+                       devc->samplerate);
+               return SR_ERR_ARG;
        }
+       divider_u16 = baseclock / devc->samplerate;
+       eff_samplerate = baseclock / divider_u16;
+       if (eff_samplerate > devc->model->samplerate)
+               eff_samplerate = devc->model->samplerate;
 
-       devc->pre_trigger_size = (devc->capture_ratio * devc->limit_samples) / 100;
+       ret = sr_sw_limits_get_remain(&devc->sw_limits,
+               &limit_samples, NULL, NULL, NULL);
+       if (ret != SR_OK) {
+               sr_err("Cannot get acquisition limits.");
+               return ret;
+       }
+       if (limit_samples > LA2016_NUM_SAMPLES_MAX) {
+               sr_warn("Too high a sample depth: %" PRIu64 ", capping.",
+                       limit_samples);
+               limit_samples = LA2016_NUM_SAMPLES_MAX;
+       }
+       if (limit_samples == 0) {
+               limit_samples = LA2016_NUM_SAMPLES_MAX;
+               sr_dbg("Passing %" PRIu64 " to HW for unlimited samples.",
+                       limit_samples);
+       }
 
-       sr_dbg("set sampling configuration %.0fkHz, %d samples, trigger-pos %d%%",
-              devc->cur_samplerate / 1e3, (unsigned int)devc->limit_samples, (unsigned int)devc->capture_ratio);
+       /*
+        * The acquisition configuration communicates "pre-trigger"
+        * specs in several formats. sigrok users provide a percentage
+        * (0-100%), which translates to a pre-trigger samples count
+        * (assuming that a total samples count limit was specified).
+        * The device supports hardware compression, which depends on
+        * slowly changing input data to be effective. Fast changing
+        * input data may occupy more space in sample memory than its
+        * uncompressed form would. This is why a third parameter can
+        * limit the amount of sample memory to use for pre-trigger
+        * data. Only the upper 24 bits of that memory size spec get
+        * communicated to the device (written to its FPGA register).
+        */
+       if (!devc->model->memory_bits) {
+               sr_dbg("Memory-less device, skipping pre-trigger config.");
+               pre_trigger_samples = 0;
+               pre_trigger_memory = 0;
+       } else if (devc->trigger_involved) {
+               pre_trigger_samples = limit_samples;
+               pre_trigger_samples *= devc->capture_ratio;
+               pre_trigger_samples /= 100;
+               pre_trigger_memory = devc->model->memory_bits;
+               pre_trigger_memory *= UINT64_C(1024 * 1024 * 1024);
+               pre_trigger_memory /= 8; /* devc->model->channel_count ? */
+               pre_trigger_memory *= devc->capture_ratio;
+               pre_trigger_memory /= 100;
+       } else {
+               sr_dbg("No trigger setup, skipping pre-trigger config.");
+               pre_trigger_samples = 0;
+               pre_trigger_memory = 0;
+       }
+       /* Ensure non-zero value after LSB shift out in HW reg. */
+       if (pre_trigger_memory < 0x100)
+               pre_trigger_memory = 0x100;
+
+       sr_dbg("Set sample config: %" PRIu64 "kHz (div %" PRIu16 "), %" PRIu64 " samples.",
+               eff_samplerate / SR_KHZ(1), divider_u16, limit_samples);
+       sr_dbg("Capture ratio %" PRIu64 "%%, count %" PRIu64 ", mem %" PRIu64 ".",
+               devc->capture_ratio, pre_trigger_samples, pre_trigger_memory);
+
+       if (devc->continuous) {
+               stream_bandwidth = eff_samplerate;
+               stream_bandwidth *= devc->stream.enabled_count;
+               sr_dbg("Streaming: channel count %zu, product %" PRIu64 ".",
+                       devc->stream.enabled_count, stream_bandwidth);
+               stream_bandwidth /= 1000 * 1000;
+               if (stream_bandwidth >= LA2016_STREAM_MBPS_MAX) {
+                       sr_warn("High USB stream bandwidth: %" PRIu64 "Mbps.",
+                               stream_bandwidth);
+               }
+               if (stream_bandwidth < LA2016_STREAM_PUSH_THR) {
+                       sr_dbg("Streaming: low Mbps, suggest periodic flush.");
+                       devc->stream.flush_period_ms = LA2016_STREAM_PUSH_IVAL;
+               }
+       }
 
+       /*
+        * The acquisition configuration occupies a total of 16 bytes:
+        * - A 34bit total samples count limit (up to 10 billions) that
+        *   is kept in a 40bit register.
+        * - A 34bit pre-trigger samples count limit (up to 10 billions)
+        *   in another 40bit register.
+        * - A 32bit pre-trigger memory space limit (in bytes) of which
+        *   the upper 24bits are kept in an FPGA register.
+        * - A 16bit clock divider which gets applied to the maximum
+        *   samplerate of the device.
+        * - An 8bit register of unknown meaning. Currently always 0.
+        */
        wrptr = buf;
-       write_u32le_inc(&wrptr, devc->limit_samples);
+       write_u40le_inc(&wrptr, limit_samples);
+       write_u40le_inc(&wrptr, pre_trigger_samples);
+       write_u24le_inc(&wrptr, pre_trigger_memory >> 8);
+       write_u16le_inc(&wrptr, divider_u16);
        write_u8_inc(&wrptr, 0);
-       write_u32le_inc(&wrptr, devc->pre_trigger_size);
-       write_u32le_inc(&wrptr, ((total * devc->capture_ratio) / 100) & 0xFFFFFF00);
-       write_u16le_inc(&wrptr, divisor);
-       write_u8_inc(&wrptr, 0);
-
        ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_SAMPLING, 0, buf, wrptr - buf);
        if (ret != SR_OK) {
-               sr_err("error setting sample config!");
+               sr_err("Cannot setup acquisition configuration.");
                return ret;
        }
 
        return SR_OK;
 }
 
-/* The run state is read from FPGA registers 1[hi-byte] and 0[lo-byte]
- * and the bits are interpreted as follows:
- *
- * register 0:
- *     bit0 1= idle
- *     bit1 1= writing to sdram
- *     bit2 0= waiting_for_trigger 1=been_triggered
- *     bit3 0= pretrigger_sampling 1=posttrigger_sampling
- *     ...unknown...
- * register 1:
- *     meaning of bits unknown (but vendor software reads this, so just do the same)
+/*
+ * FPGA register REG_RUN holds the run state (u16le format). Bit fields
+ * of interest:
+ *   bit 0: value 1 = idle
+ *   bit 1: value 1 = writing to SDRAM
+ *   bit 2: value 0 = waiting for trigger, 1 = trigger seen
+ *   bit 3: value 0 = pretrigger sampling, 1 = posttrigger sampling
+ * The meaning of other bit fields is unknown.
  *
- * The run state values occur in this order:
- * 0x85E2: pre-sampling (for samples before trigger position, capture ratio > 0%)
- * 0x85EA: pre-sampling complete, now waiting for trigger (whilst sampling continuously)
- * 0x85EE: running
- * 0x85ED: idle
+ * Typical values in order of appearance during execution:
+ *   0x85e1: idle, no acquisition pending
+ *     IDLE set, TRGD don't care, POST don't care; DRAM don't care
+ *     "In idle state." Takes precedence over all others.
+ *   0x85e2: pre-sampling, samples before the trigger position,
+ *     when capture ratio > 0%
+ *     IDLE clear, TRGD clear, POST clear; DRAM don't care
+ *     "Not idle any more, no post yet, not triggered yet."
+ *   0x85ea: pre-sampling complete, now waiting for the trigger
+ *     (whilst sampling continuously)
+ *     IDLE clear, TRGD clear, POST set; DRAM don't care
+ *     "Post set thus after pre, not triggered yet"
+ *   0x85ee: trigger seen, capturing post-trigger samples, running
+ *     IDLE clear, TRGD set, POST set; DRAM don't care
+ *     "Triggered and in post, not idle yet."
+ *   0x85ed: idle
+ *     IDLE set, TRGD don't care, POST don't care; DRAM don't care
+ *     "In idle state." TRGD/POST don't care, same meaning as above.
  */
+static const uint16_t runstate_mask_idle = RUNSTATE_IDLE_BIT;
+static const uint16_t runstate_patt_idle = RUNSTATE_IDLE_BIT;
+static const uint16_t runstate_mask_step =
+       RUNSTATE_IDLE_BIT | RUNSTATE_TRGD_BIT | RUNSTATE_POST_BIT;
+static const uint16_t runstate_patt_pre_trig = 0;
+static const uint16_t runstate_patt_wait_trig = RUNSTATE_POST_BIT;
+static const uint16_t runstate_patt_post_trig =
+       RUNSTATE_TRGD_BIT | RUNSTATE_POST_BIT;
+
 static uint16_t run_state(const struct sr_dev_inst *sdi)
 {
-       uint16_t state;
-       static uint16_t previous_state = 0;
+       static uint16_t previous_state;
+
        int ret;
+       uint16_t state;
+       uint8_t buff[REG_PWM_EN - REG_RUN]; /* Width of REG_RUN. */
+       const uint8_t *rdptr;
+       const char *label;
 
-       if ((ret = ctrl_in(sdi, CMD_FPGA_SPI, REG_RUN, 0, &state, sizeof(state))) != SR_OK) {
-               sr_err("failed to read run state!");
+       ret = ctrl_in(sdi, CMD_FPGA_SPI, REG_RUN, 0, buff, sizeof(state));
+       if (ret != SR_OK) {
+               sr_err("Cannot read run state.");
                return ret;
        }
+       rdptr = buff;
+       state = read_u16le_inc(&rdptr);
 
-       /* This function is called about every 50ms.
-        * To avoid filling the log file with redundant information during long captures,
-        * just print a log message if status has changed.
+       /*
+        * Avoid flooding the log, only dump values as they change.
+        * The routine is called about every 50ms.
         */
-
-       if (state != previous_state) {
-               previous_state = state;
-               if ((state & 0x0003) == 0x01) {
-                       sr_dbg("run_state: 0x%04x (%s)", state, "idle");
-               }
-               else if ((state & 0x000f) == 0x02) {
-                       sr_dbg("run_state: 0x%04x (%s)", state, "pre-trigger sampling");
-               }
-               else if ((state & 0x000f) == 0x0a) {
-                       sr_dbg("run_state: 0x%04x (%s)", state, "sampling, waiting for trigger");
-               }
-               else if ((state & 0x000f) == 0x0e) {
-                       sr_dbg("run_state: 0x%04x (%s)", state, "post-trigger sampling");
-               }
-               else {
-                       sr_dbg("run_state: 0x%04x", state);
-               }
-       }
+       if (state == previous_state)
+               return state;
+
+       previous_state = state;
+       label = NULL;
+       if ((state & runstate_mask_idle) == runstate_patt_idle)
+               label = "idle";
+       if ((state & runstate_mask_step) == runstate_patt_pre_trig)
+               label = "pre-trigger sampling";
+       if ((state & runstate_mask_step) == runstate_patt_wait_trig)
+               label = "sampling, waiting for trigger";
+       if ((state & runstate_mask_step) == runstate_patt_post_trig)
+               label = "post-trigger sampling";
+       if (label && *label)
+               sr_dbg("Run state: 0x%04x (%s).", state, label);
+       else
+               sr_dbg("Run state: 0x%04x.", state);
 
        return state;
 }
 
-static int set_run_mode(const struct sr_dev_inst *sdi, uint8_t fast_blinking)
+static gboolean la2016_is_idle(const struct sr_dev_inst *sdi)
+{
+       uint16_t state;
+
+       state = run_state(sdi);
+       if ((state & runstate_mask_idle) == runstate_patt_idle)
+               return TRUE;
+
+       return FALSE;
+}
+
+static int set_run_mode(const struct sr_dev_inst *sdi, uint8_t mode)
 {
        int ret;
 
-       if ((ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_RUN, 0, &fast_blinking, sizeof(fast_blinking))) != SR_OK) {
-               sr_err("failed to send set-run-mode command %d", fast_blinking);
+       ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_RUN, 0, &mode, sizeof(mode));
+       if (ret != SR_OK) {
+               sr_err("Cannot configure run mode %d.", mode);
                return ret;
        }
 
@@ -597,13 +967,14 @@ static int get_capture_info(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
        int ret;
-       uint8_t buf[3 * sizeof(uint32_t)];
+       uint8_t buf[REG_TRIGGER - REG_SAMPLING]; /* Width of REG_SAMPLING. */
        const uint8_t *rdptr;
 
        devc = sdi->priv;
 
-       if ((ret = ctrl_in(sdi, CMD_FPGA_SPI, REG_SAMPLING, 0, buf, sizeof(buf))) != SR_OK) {
-               sr_err("failed to read capture info!");
+       ret = ctrl_in(sdi, CMD_FPGA_SPI, REG_SAMPLING, 0, buf, sizeof(buf));
+       if (ret != SR_OK) {
+               sr_err("Cannot read capture info.");
                return ret;
        }
 
@@ -612,25 +983,199 @@ static int get_capture_info(const struct sr_dev_inst *sdi)
        devc->info.n_rep_packets_before_trigger = read_u32le_inc(&rdptr);
        devc->info.write_pos = read_u32le_inc(&rdptr);
 
-       sr_dbg("capture info: n_rep_packets: 0x%08x/%d, before_trigger: 0x%08x/%d, write_pos: 0x%08x%d",
-              devc->info.n_rep_packets, devc->info.n_rep_packets,
-              devc->info.n_rep_packets_before_trigger, devc->info.n_rep_packets_before_trigger,
-              devc->info.write_pos, devc->info.write_pos);
+       sr_dbg("Capture info: n_rep_packets: 0x%08x/%d, before_trigger: 0x%08x/%d, write_pos: 0x%08x/%d.",
+               devc->info.n_rep_packets, devc->info.n_rep_packets,
+               devc->info.n_rep_packets_before_trigger,
+               devc->info.n_rep_packets_before_trigger,
+               devc->info.write_pos, devc->info.write_pos);
+
+       if (devc->info.n_rep_packets % devc->packets_per_chunk) {
+               sr_warn("Unexpected packets count %lu, not a multiple of %lu.",
+                       (unsigned long)devc->info.n_rep_packets,
+                       (unsigned long)devc->packets_per_chunk);
+       }
+
+       return SR_OK;
+}
+
+SR_PRIV int la2016_upload_firmware(const struct sr_dev_inst *sdi,
+       struct sr_context *sr_ctx, libusb_device *dev, gboolean skip_upload)
+{
+       struct dev_context *devc;
+       uint16_t pid;
+       char *fw;
+       int ret;
 
-       if (devc->info.n_rep_packets % 5)
-               sr_warn("number of packets is not as expected multiples of 5: %d", devc->info.n_rep_packets);
+       devc = sdi ? sdi->priv : NULL;
+       if (!devc || !devc->usb_pid)
+               return SR_ERR_ARG;
+       pid = devc->usb_pid;
+
+       fw = g_strdup_printf(MCU_FWFILE_FMT, pid);
+       sr_info("USB PID %04hx, MCU firmware '%s'.", pid, fw);
+       devc->mcu_firmware = g_strdup(fw);
+
+       if (skip_upload)
+               ret = SR_OK;
+       else
+               ret = ezusb_upload_firmware(sr_ctx, dev, USB_CONFIGURATION, fw);
+       g_free(fw);
+       if (ret != SR_OK)
+               return ret;
 
        return SR_OK;
 }
 
-SR_PRIV int la2016_upload_firmware(struct sr_context *sr_ctx, libusb_device *dev, uint16_t product_id)
+static void LIBUSB_CALL receive_transfer(struct libusb_transfer *xfer);
+
+static void la2016_usbxfer_release_cb(gpointer p)
+{
+       struct libusb_transfer *xfer;
+
+       xfer = p;
+       g_free(xfer->buffer);
+       libusb_free_transfer(xfer);
+}
+
+static int la2016_usbxfer_release(const struct sr_dev_inst *sdi)
 {
-       char fw_file[1024];
-       snprintf(fw_file, sizeof(fw_file) - 1, UC_FIRMWARE, product_id);
-       return ezusb_upload_firmware(sr_ctx, dev, USB_CONFIGURATION, fw_file);
+       struct dev_context *devc;
+
+       devc = sdi ? sdi->priv : NULL;
+       if (!devc)
+               return SR_ERR_ARG;
+
+       /* Release all USB transfers. */
+       g_slist_free_full(devc->transfers, la2016_usbxfer_release_cb);
+       devc->transfers = NULL;
+
+       return SR_OK;
 }
 
-SR_PRIV int la2016_setup_acquisition(const struct sr_dev_inst *sdi)
+static int la2016_usbxfer_allocate(const struct sr_dev_inst *sdi)
+{
+       struct dev_context *devc;
+       size_t bufsize, xfercount;
+       uint8_t *buffer;
+       struct libusb_transfer *xfer;
+
+       devc = sdi ? sdi->priv : NULL;
+       if (!devc)
+               return SR_ERR_ARG;
+
+       /* Transfers were already allocated before? */
+       if (devc->transfers)
+               return SR_OK;
+
+       /*
+        * Allocate all USB transfers and their buffers. Arrange for a
+        * buffer size which is within the device's capabilities, and
+        * is a multiple of the USB endpoint's size, to make use of the
+        * RAW_IO performance feature.
+        *
+        * Implementation detail: The LA2016_USB_BUFSZ value happens
+        * to match all those constraints. No additional arithmetics is
+        * required in this location.
+        */
+       bufsize = LA2016_USB_BUFSZ;
+       xfercount = LA2016_USB_XFER_COUNT;
+       while (xfercount--) {
+               buffer = g_try_malloc(bufsize);
+               if (!buffer) {
+                       sr_err("Cannot allocate USB transfer buffer.");
+                       return SR_ERR_MALLOC;
+               }
+               xfer = libusb_alloc_transfer(0);
+               if (!xfer) {
+                       sr_err("Cannot allocate USB transfer.");
+                       g_free(buffer);
+                       return SR_ERR_MALLOC;
+               }
+               xfer->buffer = buffer;
+               devc->transfers = g_slist_append(devc->transfers, xfer);
+       }
+       devc->transfer_bufsize = bufsize;
+
+       return SR_OK;
+}
+
+static int la2016_usbxfer_cancel_all(const struct sr_dev_inst *sdi)
+{
+       struct dev_context *devc;
+       GSList *l;
+       struct libusb_transfer *xfer;
+
+       devc = sdi ? sdi->priv : NULL;
+       if (!devc)
+               return SR_ERR_ARG;
+
+       /* Unconditionally cancel the transfer. Ignore errors. */
+       for (l = devc->transfers; l; l = l->next) {
+               xfer = l->data;
+               if (!xfer)
+                       continue;
+               libusb_cancel_transfer(xfer);
+       }
+
+       return SR_OK;
+}
+
+static int la2016_usbxfer_resubmit(const struct sr_dev_inst *sdi,
+       struct libusb_transfer *xfer)
+{
+       struct dev_context *devc;
+       struct sr_usb_dev_inst *usb;
+       libusb_transfer_cb_fn cb;
+       int ret;
+
+       devc = sdi ? sdi->priv : NULL;
+       usb = sdi ? sdi->conn : NULL;
+       if (!devc || !usb)
+               return SR_ERR_ARG;
+
+       if (!xfer)
+               return SR_ERR_ARG;
+
+       cb = receive_transfer;
+       libusb_fill_bulk_transfer(xfer, usb->devhdl,
+               USB_EP_CAPTURE_DATA | LIBUSB_ENDPOINT_IN,
+               xfer->buffer, devc->transfer_bufsize,
+               cb, (void *)sdi, CAPTURE_TIMEOUT_MS);
+       ret = libusb_submit_transfer(xfer);
+       if (ret != 0) {
+               sr_err("Cannot submit USB transfer: %s.",
+                       libusb_error_name(ret));
+               return SR_ERR_IO;
+       }
+
+       return SR_OK;
+}
+
+static int la2016_usbxfer_submit_all(const struct sr_dev_inst *sdi)
+{
+       struct dev_context *devc;
+       GSList *l;
+       struct libusb_transfer *xfer;
+       int ret;
+
+       devc = sdi ? sdi->priv : NULL;
+       if (!devc)
+               return SR_ERR_ARG;
+
+       for (l = devc->transfers; l; l = l->next) {
+               xfer = l->data;
+               if (!xfer)
+                       return SR_ERR_ARG;
+               ret = la2016_usbxfer_resubmit(sdi, xfer);
+               if (ret != SR_OK)
+                       return ret;
+       }
+
+       return SR_OK;
+}
+
+SR_PRIV int la2016_setup_acquisition(const struct sr_dev_inst *sdi,
+       double voltage)
 {
        struct dev_context *devc;
        int ret;
@@ -638,13 +1183,14 @@ SR_PRIV int la2016_setup_acquisition(const struct sr_dev_inst *sdi)
 
        devc = sdi->priv;
 
-       ret = set_threshold_voltage(sdi, devc->threshold_voltage);
+       ret = set_threshold_voltage(sdi, voltage);
        if (ret != SR_OK)
                return ret;
 
-       cmd = 0;
-       if ((ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_CAPT_MODE, 0, &cmd, sizeof(cmd))) != SR_OK) {
-               sr_err("failed to send stop sampling command");
+       cmd = devc->continuous ? CAPTMODE_STREAM : CAPTMODE_TO_RAM;
+       ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_CAPT_MODE, 0, &cmd, sizeof(cmd));
+       if (ret != SR_OK) {
+               sr_err("Cannot send command to stop sampling.");
                return ret;
        }
 
@@ -661,241 +1207,382 @@ SR_PRIV int la2016_setup_acquisition(const struct sr_dev_inst *sdi)
 
 SR_PRIV int la2016_start_acquisition(const struct sr_dev_inst *sdi)
 {
+       struct dev_context *devc;
        int ret;
 
-       ret = set_run_mode(sdi, 3);
+       devc = sdi->priv;
+
+       ret = la2016_usbxfer_allocate(sdi);
        if (ret != SR_OK)
                return ret;
 
+       if (devc->continuous) {
+               ret = ctrl_out(sdi, CMD_BULK_RESET, 0x00, 0, NULL, 0);
+               if (ret != SR_OK)
+                       return ret;
+
+               ret = la2016_usbxfer_submit_all(sdi);
+               if (ret != SR_OK)
+                       return ret;
+
+               /*
+                * Periodic receive callback will set runmode. This
+                * activity MUST be close to data reception, a pause
+                * between these steps breaks the stream's operation.
+                */
+       } else {
+               ret = set_run_mode(sdi, RUNMODE_RUN);
+               if (ret != SR_OK)
+                       return ret;
+       }
+
        return SR_OK;
 }
 
 static int la2016_stop_acquisition(const struct sr_dev_inst *sdi)
 {
+       struct dev_context *devc;
        int ret;
 
-       ret = set_run_mode(sdi, 0);
+       ret = set_run_mode(sdi, RUNMODE_HALT);
        if (ret != SR_OK)
                return ret;
 
+       devc = sdi->priv;
+       if (devc->continuous)
+               devc->download_finished = TRUE;
+
        return SR_OK;
 }
 
 SR_PRIV int la2016_abort_acquisition(const struct sr_dev_inst *sdi)
 {
        int ret;
-       struct dev_context *devc;
 
        ret = la2016_stop_acquisition(sdi);
        if (ret != SR_OK)
                return ret;
 
-       devc = sdi ? sdi->priv : NULL;
-       if (devc && devc->transfer)
-               libusb_cancel_transfer(devc->transfer);
+       (void)la2016_usbxfer_cancel_all(sdi);
 
        return SR_OK;
 }
 
-static int la2016_has_triggered(const struct sr_dev_inst *sdi)
-{
-       uint16_t state;
-
-       state = run_state(sdi);
-
-       return (state & 0x3) == 1;
-}
-
-static int la2016_start_retrieval(const struct sr_dev_inst *sdi, libusb_transfer_cb_fn cb)
+static int la2016_start_download(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
-       struct sr_usb_dev_inst *usb;
        int ret;
-       uint8_t wrbuf[2 * sizeof(uint32_t)];
+       uint8_t wrbuf[REG_SAMPLING - REG_BULK]; /* Width of REG_BULK. */
        uint8_t *wrptr;
-       uint32_t to_read;
-       uint8_t *buffer;
 
        devc = sdi->priv;
-       usb = sdi->conn;
 
-       if ((ret = get_capture_info(sdi)) != SR_OK)
+       ret = get_capture_info(sdi);
+       if (ret != SR_OK)
                return ret;
 
-       devc->n_transfer_packets_to_read = devc->info.n_rep_packets / NUM_PACKETS_IN_CHUNK;
-       devc->n_bytes_to_read = devc->n_transfer_packets_to_read * TRANSFER_PACKET_LENGTH;
+       devc->n_transfer_packets_to_read = devc->info.n_rep_packets;
+       devc->n_transfer_packets_to_read /= devc->packets_per_chunk;
+       devc->n_bytes_to_read = devc->n_transfer_packets_to_read;
+       devc->n_bytes_to_read *= devc->transfer_size;
        devc->read_pos = devc->info.write_pos - devc->n_bytes_to_read;
        devc->n_reps_until_trigger = devc->info.n_rep_packets_before_trigger;
 
-       sr_dbg("want to read %d tfer-packets starting from pos %d",
-              devc->n_transfer_packets_to_read, devc->read_pos);
+       sr_dbg("Want to read %u xfer-packets starting from pos %" PRIu32 ".",
+               devc->n_transfer_packets_to_read, devc->read_pos);
 
-       if ((ret = ctrl_out(sdi, CMD_BULK_RESET, 0x00, 0, NULL, 0)) != SR_OK) {
-               sr_err("failed to reset bulk state");
+       ret = ctrl_out(sdi, CMD_BULK_RESET, 0x00, 0, NULL, 0);
+       if (ret != SR_OK) {
+               sr_err("Cannot reset USB bulk state.");
                return ret;
        }
-       sr_dbg("will read from 0x%08x, 0x%08x bytes", devc->read_pos, devc->n_bytes_to_read);
+       sr_dbg("Will read from 0x%08lx, 0x%08x bytes.",
+               (unsigned long)devc->read_pos, devc->n_bytes_to_read);
        wrptr = wrbuf;
        write_u32le_inc(&wrptr, devc->read_pos);
        write_u32le_inc(&wrptr, devc->n_bytes_to_read);
-       if ((ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_BULK, 0, wrbuf, wrptr - wrbuf)) != SR_OK) {
-               sr_err("failed to send bulk config");
-               return ret;
-       }
-       if ((ret = ctrl_out(sdi, CMD_BULK_START, 0x00, 0, NULL, 0)) != SR_OK) {
-               sr_err("failed to unblock bulk transfers");
+       ret = ctrl_out(sdi, CMD_FPGA_SPI, REG_BULK, 0, wrbuf, wrptr - wrbuf);
+       if (ret != SR_OK) {
+               sr_err("Cannot send USB bulk config.");
                return ret;
        }
 
-       to_read = devc->n_bytes_to_read;
-       /* choose a buffer size for all of the usb transfers */
-       if (to_read >= LA2016_USB_BUFSZ)
-               to_read = LA2016_USB_BUFSZ; /* multiple transfers */
-       else /* one transfer, make buffer size some multiple of LA2016_EP6_PKTSZ */
-               to_read = (to_read + (LA2016_EP6_PKTSZ-1)) & ~(LA2016_EP6_PKTSZ-1);
-       buffer = g_try_malloc(to_read);
-       if (!buffer) {
-               sr_err("Failed to allocate %d bytes for bulk transfer", to_read);
-               return SR_ERR_MALLOC;
+       ret = la2016_usbxfer_submit_all(sdi);
+       if (ret != SR_OK) {
+               sr_err("Cannot submit USB bulk transfers.");
+               return ret;
        }
 
-       devc->transfer = libusb_alloc_transfer(0);
-       libusb_fill_bulk_transfer(
-               devc->transfer, usb->devhdl,
-               0x86, buffer, to_read,
-               cb, (void *)sdi, DEFAULT_TIMEOUT_MS);
-
-       if ((ret = libusb_submit_transfer(devc->transfer)) != 0) {
-               sr_err("Failed to submit transfer: %s.", libusb_error_name(ret));
-               libusb_free_transfer(devc->transfer);
-               devc->transfer = NULL;
-               g_free(buffer);
-               return SR_ERR;
+       ret = ctrl_out(sdi, CMD_BULK_START, 0x00, 0, NULL, 0);
+       if (ret != SR_OK) {
+               sr_err("Cannot start USB bulk transfers.");
+               return ret;
        }
 
        return SR_OK;
 }
 
+/*
+ * A chunk of sample memory was received via USB. These chunks contain
+ * transfers of 16 or 32 bytes each (model dependent size and layout).
+ * Transfers contain a number of packets (5 or 6 per transfer), which
+ * contain a number of samples (16 or 32 sampled pin values, and an
+ * 8bit repeat count for these sampled pin values). A sequence number
+ * follows the packets within the transfer, allows to detect missing or
+ * out of order reception.
+ *
+ * Memory layout for 16-channel models:
+ * - 16 bytes per transfer
+ * - 5x (u16 pins, and u8 count)
+ * - 1x u8 sequence number
+ *
+ * Memory layout for 32-channel models:
+ * - 32 bytes per transfer
+ * - 6x (u32 pins, and u8 count)
+ * - 2x u8 sequence number (inverted, and normal)
+ *
+ * This implementation silently ignores the (weak) sequence number.
+ */
 static void send_chunk(struct sr_dev_inst *sdi,
-       const uint8_t *packets, unsigned int num_tfers)
+       const uint8_t *data_buffer, size_t data_length)
 {
        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;
+       size_t num_xfers, num_pkts, num_seqs;
        const uint8_t *rp;
-       uint16_t state;
-       uint8_t repetitions;
+       uint32_t sample_value;
+       size_t repetitions;
+       uint8_t sample_buff[sizeof(sample_value)];
 
        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;
-                               }
-                       }
+       /* Ignore incoming USB data after complete sample data download. */
+       if (devc->download_finished)
+               return;
+
+       if (devc->trigger_involved && !devc->trigger_marked && devc->info.n_rep_packets_before_trigger == 0) {
+               feed_queue_logic_send_trigger(devc->feed_queue);
+               devc->trigger_marked = TRUE;
+       }
 
-                       state = read_u16le_inc(&rp);
+       /*
+        * Adjust the number of remaining bytes to read from the device
+        * before the processing of the currently received chunk affects
+        * the variable which holds the number of received bytes.
+        */
+       if (data_length > devc->n_bytes_to_read)
+               devc->n_bytes_to_read = 0;
+       else
+               devc->n_bytes_to_read -= data_length;
+
+       /* Process the received chunk of capture data. */
+       sample_value = 0;
+       rp = data_buffer;
+       num_xfers = data_length / devc->transfer_size;
+       while (num_xfers--) {
+               num_pkts = devc->packets_per_chunk;
+               while (num_pkts--) {
+
+                       if (devc->model->channel_count == 32)
+                               sample_value = read_u32le_inc(&rp);
+                       else if (devc->model->channel_count == 16)
+                               sample_value = 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);
+
+                       write_u32le(sample_buff, sample_value);
+                       feed_queue_logic_submit_one(devc->feed_queue,
+                               sample_buff, repetitions);
+                       sr_sw_limits_update_samples_read(&devc->sw_limits,
+                               repetitions);
+
+                       if (devc->trigger_involved && !devc->trigger_marked) {
+                               if (!--devc->n_reps_until_trigger) {
+                                       feed_queue_logic_send_trigger(devc->feed_queue);
+                                       devc->trigger_marked = TRUE;
+                                       sr_dbg("Trigger position after %" PRIu64 " samples, %.6fms.",
+                                               devc->total_samples,
+                                               (double)devc->total_samples / devc->samplerate * 1e3);
                                }
                        }
                }
-               (void)read_u8_inc(&rp); /* Skip sequence number. */
+               /* Skip the sequence number bytes. */
+               num_seqs = devc->sequence_size;
+               while (num_seqs--)
+                       (void)read_u8_inc(&rp);
+       }
+
+       /*
+        * Check for several conditions which shall terminate the
+        * capture data download: When the amount of capture data in
+        * the device is exhausted. When the user specified samples
+        * count limit is reached.
+        */
+       if (!devc->n_bytes_to_read) {
+               devc->download_finished = TRUE;
+       } else {
+               sr_dbg("%" PRIu32 " more bytes to download from the device.",
+                       devc->n_bytes_to_read);
+       }
+       if (!devc->download_finished && sr_sw_limits_check(&devc->sw_limits)) {
+               sr_dbg("Acquisition limit reached.");
+               devc->download_finished = TRUE;
+       }
+       if (devc->download_finished) {
+               sr_dbg("Download finished, flushing session feed queue.");
+               feed_queue_logic_flush(devc->feed_queue);
        }
-       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("Total samples after chunk: %" PRIu64 ".", devc->total_samples);
+}
+
+/*
+ * Process a chunk of capture data in streaming mode. The memory layout
+ * is rather different from "normal mode" (see the send_chunk() routine
+ * above). In streaming mode data is not compressed, and memory cells
+ * neither contain raw sampled pin values at a given point in time. The
+ * memory content needs transformation.
+ *
+ * All enabled channels get iterated over. Disabled channels will not
+ * occupy space in the streamed sample data. Per channel chunk there is
+ * one 16bit entity which carries samples that were taken at different
+ * times. The least significant bit was sampled first, higher bits were
+ * sampled later. After all 16bit entities for all enabled channels
+ * were seen, the first enabled channel's next chunk follows.
+ *
+ * Implementor's note: This routine is inspired by convert_sample_data()
+ * in the https://github.com/AlexUg/sigrok implementation. Which in turn
+ * appears to have been derived from the saleae-logic16 sigrok driver.
+ * The code is phrased conservatively to verify the layout as discussed
+ * above, performance was not a priority. Operation was verified with an
+ * LA2016 device. The LA5032 reportedly shares the 16 samples per channel
+ * layout, just round-robins through a potentially larger set of enabled
+ * channels before returning to the first of the channels.
+ */
+static void stream_data(struct sr_dev_inst *sdi,
+       const uint8_t *data_buffer, size_t data_length)
+{
+       struct dev_context *devc;
+       struct stream_state_t *stream;
+       size_t bit_count;
+       const uint8_t *rp;
+       uint32_t sample_value;
+       uint8_t sample_buff[sizeof(sample_value)];
+       size_t bit_idx;
+       uint32_t ch_mask;
+
+       devc = sdi->priv;
+       stream = &devc->stream;
+
+       /* Ignore incoming USB data after complete sample data download. */
+       if (devc->download_finished)
+               return;
+       sr_dbg("Stream mode, got another chunk: %p, length %zu.",
+               data_buffer, data_length);
+
+       /* TODO Add soft trigger support when in stream mode? */
+
+       /* All channels' chunks carry 16 samples for one channel. */
+       bit_count = 16;
+       data_length /= sizeof(uint16_t);
+
+       rp = data_buffer;
+       sample_value = 0;
+       while (data_length--) {
+               /* Get another entity. */
+               sample_value = read_u16le_inc(&rp);
+
+               /* Map the entity's bits to a channel's samples. */
+               ch_mask = stream->channel_masks[stream->channel_index];
+               for (bit_idx = 0; bit_idx < bit_count; bit_idx++) {
+                       if (sample_value & (1UL << bit_idx))
+                               stream->sample_data[bit_idx] |= ch_mask;
+               }
+
+               /*
+                * Advance to the next channel. Submit a block of
+                * samples when all channels' data was seen.
+                */
+               stream->channel_index++;
+               if (stream->channel_index != stream->enabled_count)
+                       continue;
+               for (bit_idx = 0; bit_idx < bit_count; bit_idx++) {
+                       sample_value = stream->sample_data[bit_idx];
+                       write_u32le(sample_buff, sample_value);
+                       feed_queue_logic_submit_one(devc->feed_queue,
+                               sample_buff, 1);
                }
+               sr_sw_limits_update_samples_read(&devc->sw_limits, bit_count);
+               devc->total_samples += bit_count;
+               memset(stream->sample_data, 0, sizeof(stream->sample_data));
+               stream->channel_index = 0;
        }
-       sr_dbg("send_chunk done after %d samples", total_samples);
+
+       /*
+        * Need we count empty or failed USB transfers? This version
+        * doesn't, assumes that timeouts are perfectly legal because
+        * transfers are started early, and slow samplerates or trigger
+        * support in hardware are plausible causes for empty transfers.
+        *
+        * TODO Maybe a good condition would be (rather large) a timeout
+        * after a previous capture data chunk was seen? So that stalled
+        * streaming gets detected which _is_ an exceptional condition.
+        * We have observed these when "runmode" is set early but bulk
+        * transfers start late with a pause after setting the runmode.
+        */
+       if (sr_sw_limits_check(&devc->sw_limits)) {
+               sr_dbg("Acquisition end reached (sw limits).");
+               devc->download_finished = TRUE;
+       }
+       if (devc->download_finished) {
+               sr_dbg("Stream receive done, flushing session feed queue.");
+               feed_queue_logic_flush(devc->feed_queue);
+       }
+       sr_dbg("Total samples after chunk: %" PRIu64 ".", devc->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;
+       gboolean was_cancelled, device_gone;
        int ret;
 
        sdi = transfer->user_data;
        devc = sdi->priv;
-       usb = sdi->conn;
 
+       was_cancelled = transfer->status == LIBUSB_TRANSFER_CANCELLED;
+       device_gone = transfer->status == LIBUSB_TRANSFER_NO_DEVICE;
        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;
-               /* determine read size for the next usb transfer */
-               if (to_read >= LA2016_USB_BUFSZ)
-                       to_read = LA2016_USB_BUFSZ;
-               else /* last transfer, make read size some multiple of LA2016_EP6_PKTSZ */
-                       to_read = (to_read + (LA2016_EP6_PKTSZ-1)) & ~(LA2016_EP6_PKTSZ-1);
-               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));
+               libusb_error_name(transfer->status), transfer->actual_length);
+       if (device_gone) {
+               sr_warn("Lost communication to USB device.");
+               devc->download_finished = TRUE;
+               return;
        }
 
-       g_free(transfer->buffer);
-       libusb_free_transfer(transfer);
-       devc->transfer_finished = 1;
+       /*
+        * Implementation detail: A USB transfer timeout is not fatal
+        * here. We just process whatever was received, empty input is
+        * perfectly acceptable. Reaching (or exceeding) the sw limits
+        * or exhausting the device's captured data will complete the
+        * sample data download.
+        */
+       if (devc->continuous)
+               stream_data(sdi, transfer->buffer, transfer->actual_length);
+       else
+               send_chunk(sdi, transfer->buffer, transfer->actual_length);
+
+       /*
+        * Re-submit completed transfers (regardless of timeout or
+        * data reception), unless the transfer was cancelled when
+        * the acquisition was terminated or has completed.
+        */
+       if (!was_cancelled && !devc->download_finished) {
+               ret = la2016_usbxfer_resubmit(sdi, transfer);
+               if (ret == SR_OK)
+                       return;
+               devc->download_finished = TRUE;
+       }
 }
 
 SR_PRIV int la2016_receive_data(int fd, int revents, void *cb_data)
@@ -904,6 +1591,7 @@ SR_PRIV int la2016_receive_data(int fd, int revents, void *cb_data)
        struct dev_context *devc;
        struct drv_context *drvc;
        struct timeval tv;
+       int ret;
 
        (void)fd;
        (void)revents;
@@ -912,176 +1600,330 @@ SR_PRIV int la2016_receive_data(int fd, int revents, void *cb_data)
        devc = sdi->priv;
        drvc = sdi->driver->context;
 
-       if (devc->have_trigger == 0) {
-               if (la2016_has_triggered(sdi) == 0) {
-                       /* not yet ready for download */
+       /* Arrange for the start of stream mode when requested. */
+       if (devc->continuous && !devc->frame_begin_sent) {
+               sr_dbg("First receive callback in stream mode.");
+               devc->download_finished = FALSE;
+               devc->trigger_marked = FALSE;
+               devc->total_samples = 0;
+
+               std_session_send_df_frame_begin(sdi);
+               devc->frame_begin_sent = TRUE;
+
+               ret = set_run_mode(sdi, RUNMODE_RUN);
+               if (ret != SR_OK) {
+                       sr_err("Cannot set 'runmode' to 'run'.");
+                       return FALSE;
+               }
+
+               ret = ctrl_out(sdi, CMD_BULK_START, 0x00, 0, NULL, 0);
+               if (ret != SR_OK) {
+                       sr_err("Cannot start USB bulk transfers.");
+                       return FALSE;
+               }
+               sr_dbg("Stream data reception initiated.");
+       }
+
+       /*
+        * Wait for the acquisition to complete in hardware.
+        * Periodically check a potentially configured msecs timeout.
+        */
+       if (!devc->continuous && !devc->completion_seen) {
+               if (!la2016_is_idle(sdi)) {
+                       if (sr_sw_limits_check(&devc->sw_limits)) {
+                               devc->sw_limits.limit_msec = 0;
+                               sr_dbg("Limit reached. Stopping acquisition.");
+                               la2016_stop_acquisition(sdi);
+                       }
+                       /* Not yet ready for sample data download. */
                        return TRUE;
                }
-               devc->have_trigger = 1;
-               devc->transfer_finished = 0;
-               devc->reading_behind_trigger = 0;
+               sr_dbg("Acquisition completion seen (hardware).");
+               devc->sw_limits.limit_msec = 0;
+               devc->completion_seen = TRUE;
+               devc->download_finished = FALSE;
+               devc->trigger_marked = FALSE;
                devc->total_samples = 0;
-               /* we can start retrieving data! */
-               if (la2016_start_retrieval(sdi, receive_transfer) != SR_OK) {
-                       sr_err("failed to start retrieval!");
+
+               la2016_dump_fpga_registers(sdi, "acquisition complete", 0, 0);
+
+               /* Initiate the download of acquired sample data. */
+               std_session_send_df_frame_begin(sdi);
+               devc->frame_begin_sent = TRUE;
+               ret = la2016_start_download(sdi);
+               if (ret != SR_OK) {
+                       sr_err("Cannot start acquisition data download.");
                        return FALSE;
                }
-               sr_dbg("retrieval is started...");
-               std_session_send_df_frame_begin(sdi);
+               sr_dbg("Acquisition data download started.");
 
                return TRUE;
        }
 
-       tv.tv_sec = tv.tv_usec = 0;
+       /* Handle USB reception. Drives sample data download. */
+       memset(&tv, 0, sizeof(tv));
        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);
+       /*
+        * Periodically flush acquisition data in streaming mode.
+        * Without this nudge, previously received and accumulated data
+        * keeps sitting in queues and is not seen by applications.
+        */
+       if (devc->continuous && devc->stream.flush_period_ms) {
+               uint64_t now, elapsed;
+               now = g_get_monotonic_time();
+               if (!devc->stream.last_flushed)
+                       devc->stream.last_flushed = now;
+               elapsed = now - devc->stream.last_flushed;
+               elapsed /= 1000;
+               if (elapsed >= devc->stream.flush_period_ms) {
+                       sr_dbg("Stream mode, flushing.");
+                       feed_queue_logic_flush(devc->feed_queue);
+                       devc->stream.last_flushed = now;
+               }
+       }
 
-               usb_source_remove(sdi->session, drvc->sr_ctx);
-               std_session_send_df_end(sdi);
+       /* Postprocess completion of sample data download. */
+       if (devc->download_finished) {
+               sr_dbg("Download finished, post processing.");
 
                la2016_stop_acquisition(sdi);
+               usb_source_remove(sdi->session, drvc->sr_ctx);
 
-               g_free(devc->convbuffer);
-               devc->convbuffer = NULL;
+               la2016_usbxfer_cancel_all(sdi);
+               memset(&tv, 0, sizeof(tv));
+               libusb_handle_events_timeout(drvc->sr_ctx->libusb_ctx, &tv);
 
-               devc->transfer = NULL;
+               feed_queue_logic_flush(devc->feed_queue);
+               feed_queue_logic_free(devc->feed_queue);
+               devc->feed_queue = NULL;
+               if (devc->frame_begin_sent) {
+                       std_session_send_df_frame_end(sdi);
+                       devc->frame_begin_sent = FALSE;
+               }
+               std_session_send_df_end(sdi);
 
-               sr_dbg("transfer is now finished");
+               sr_dbg("Download finished, done post processing.");
        }
 
        return TRUE;
 }
 
-SR_PRIV int la2016_init_device(const struct sr_dev_inst *sdi)
+SR_PRIV int la2016_identify_device(const struct sr_dev_inst *sdi,
+       gboolean show_message)
 {
        struct dev_context *devc;
-       uint16_t state;
-       uint8_t buf[8];
-       int16_t purchase_date_bcd[2];
-       uint8_t magic;
+       uint8_t buf[8]; /* Larger size of manuf date and device type magic. */
+       size_t rdoff, rdlen;
+       const uint8_t *rdptr;
+       uint8_t date_yy, date_mm;
+       uint8_t dinv_yy, dinv_mm;
+       uint8_t magic, magic2;
+       size_t model_idx;
+       const struct kingst_model *model;
        int ret;
 
        devc = sdi->priv;
 
-       /* Four bytes of eeprom at 0x20 are purchase year & month in BCD format, with 16bit
-        * complemented checksum; e.g. 2004DFFB = 2020-April.
-        * This helps to identify the age of devices if unknown magic numbers occur.
+       /*
+        * Four EEPROM bytes at offset 0x20 are the manufacturing date,
+        * year and month in BCD format, followed by inverted values for
+        * consistency checks. For example bytes 20 04 df fb translate
+        * to 2020-04. This information can help identify the vintage of
+        * devices when unknown magic numbers are seen.
         */
-       if ((ret = ctrl_in(sdi, CMD_EEPROM, 0x20, 0, purchase_date_bcd, sizeof(purchase_date_bcd))) != SR_OK) {
-               sr_err("failed to read eeprom purchase_date_bcd");
-       }
-       else {
-               sr_dbg("purchase date: 20%02hx-%02hx", (purchase_date_bcd[0]) & 0x00ff, (purchase_date_bcd[0] >> 8) & 0x00ff);
-               if (purchase_date_bcd[0] != (0x0ffff & ~purchase_date_bcd[1])) {
-                       sr_err("purchase date: checksum failure");
+       rdoff = 0x20;
+       rdlen = 4 * sizeof(uint8_t);
+       ret = ctrl_in(sdi, CMD_EEPROM, rdoff, 0, buf, rdlen);
+       if (ret != SR_OK && !show_message) {
+               /* Non-fatal weak attempt during probe. Not worth logging. */
+               sr_dbg("Cannot access EEPROM.");
+               return SR_ERR_IO;
+       } else if (ret != SR_OK) {
+               /* Failed attempt in regular use. Non-fatal. Worth logging. */
+               sr_err("Cannot read manufacture date in EEPROM.");
+       } else {
+               if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
+                       GString *txt;
+                       txt = sr_hexdump_new(buf, rdlen);
+                       sr_spew("Manufacture date bytes %s.", txt->str);
+                       sr_hexdump_free(txt);
                }
+               rdptr = &buf[0];
+               date_yy = read_u8_inc(&rdptr);
+               date_mm = read_u8_inc(&rdptr);
+               dinv_yy = read_u8_inc(&rdptr);
+               dinv_mm = read_u8_inc(&rdptr);
+               sr_info("Manufacture date: 20%02hx-%02hx.", date_yy, date_mm);
+               if ((date_mm ^ dinv_mm) != 0xff || (date_yy ^ dinv_yy) != 0xff)
+                       sr_warn("Manufacture date fails checksum test.");
        }
 
        /*
-        * There are four known kingst logic analyser devices which use this same usb vid and pid:
-        * LA2016, LA1016 and the older revision of each of these. They all use the same hardware
-        * and the same FX2 mcu firmware but each requires a different fpga bitstream. They are
-        * differentiated by a 'magic' byte within the 8 bytes of EEPROM from address 0x08.
-        * For example;
+        * Several Kingst logic analyzer devices share the same USB VID
+        * and PID. The product ID determines which MCU firmware to load.
+        * The MCU firmware provides access to EEPROM content which then
+        * allows to identify the device model. Which in turn determines
+        * which FPGA bitstream to load. Eight bytes at offset 0x08 are
+        * to get inspected.
         *
-        * magic=0x08
-        *  | ~magic=0xf7
-        *  | |
-        * 08F7000008F710EF
-        *          | |
-        *          | ~magic-backup
-        *          magic-backup
+        * EEPROM content for model identification is kept redundantly
+        * in memory. The values are stored in verbatim and in inverted
+        * form, multiple copies are kept at different offsets. Example
+        * data:
         *
-        * It seems that only these magic bytes are used, other bytes shown above are 'don't care'.
-        * Changing the magic byte on newer device to older magic causes OEM software to load
-        * the older fpga bitstream. The device then functions but has channels out of order.
-        * It's likely the bitstreams were changed to move input channel pins due to PCB changes.
+        *   magic 0x08
+        *    | ~magic 0xf7
+        *    | |
+        *   08f7000008f710ef
+        *            | |
+        *            | ~magic backup
+        *            magic backup
         *
-        * magic 9 == LA1016a using "kingst-la1016a1-fpga.bitstream" (latest v1.3.0 PCB, perhaps others)
-        * magic 8 == LA2016a using "kingst-la2016a1-fpga.bitstream" (latest v1.3.0 PCB, perhaps others)
-        * magic 3 == LA1016 using "kingst-la1016-fpga.bitstream"
-        * magic 2 == LA2016 using "kingst-la2016-fpga.bitstream"
+        * Exclusively inspecting the magic byte appears to be sufficient,
+        * other fields seem to be 'don't care'.
         *
-        * This was all determined by altering the eeprom contents of an LA2016 and LA1016 and observing
-        * the vendor software actions, either raising errors or loading specific bitstreams.
+        *   magic 2 == LA2016 using "kingst-la2016-fpga.bitstream"
+        *   magic 3 == LA1016 using "kingst-la1016-fpga.bitstream"
+        *   magic 8 == LA2016a using "kingst-la2016a1-fpga.bitstream"
+        *              (latest v1.3.0 PCB, perhaps others)
+        *   magic 9 == LA1016a using "kingst-la1016a1-fpga.bitstream"
+        *              (latest v1.3.0 PCB, perhaps others)
         *
-        * Note:
-        * An LA1016 cannot be converted to an LA2016 by changing the magic number - the bitstream
-        * will not authenticate with ic U10, which has different security coding for each device type.
+        * When EEPROM content does not match the hardware configuration
+        * (the board layout), the software may load but yield incorrect
+        * results (like swapped channels). The FPGA bitstream itself
+        * will authenticate with IC U10 and fail when its capabilities
+        * do not match the hardware model. An LA1016 won't become a
+        * LA2016 by faking its EEPROM content.
         */
-
-       if ((ret = ctrl_in(sdi, CMD_EEPROM, 0x08, 0, &buf, sizeof(buf))) != SR_OK) {
-               sr_err("failed to read eeprom device identifier bytes");
+       devc->identify_magic = 0;
+       rdoff = 0x08;
+       rdlen = 8 * sizeof(uint8_t);
+       ret = ctrl_in(sdi, CMD_EEPROM, rdoff, 0, &buf, rdlen);
+       if (ret != SR_OK) {
+               sr_err("Cannot read EEPROM device identifier bytes.");
                return ret;
        }
-
+       if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
+               GString *txt;
+               txt = sr_hexdump_new(buf, rdlen);
+               sr_spew("EEPROM magic bytes %s.", txt->str);
+               sr_hexdump_free(txt);
+       }
        magic = 0;
-       if (buf[0] == (0x0ff & ~buf[1])) {
-               /* primary copy of magic passes complement check */
+       magic2 = 0;
+       if ((buf[0] ^ buf[1]) == 0xff && (buf[2] ^ buf[3]) == 0xff) {
+               /* Primary copy of magic passes complement check (4 bytes). */
                magic = buf[0];
-       }
-       else if (buf[4] == (0x0ff & ~buf[5])) {
-               /* backup copy of magic passes complement check */
-               sr_dbg("device_type: using backup copy of magic number");
+               magic2 = buf[2];
+               sr_dbg("Using primary magic 0x%hhx (0x%hhx).", magic, magic2);
+       } else if ((buf[4] ^ buf[5]) == 0xff && (buf[6] ^ buf[7]) == 0xff) {
+               /* Backup copy of magic passes complement check (4 bytes). */
+               magic = buf[4];
+               magic2 = buf[6];
+               sr_dbg("Using secondary magic 0x%hhx (0x%hhx).", magic, magic2);
+       } else if ((buf[0] ^ buf[1]) == 0xff) {
+               /* Primary copy of magic passes complement check (2 bytes). */
+               magic = buf[0];
+               sr_dbg("Using primary magic 0x%hhx.", magic);
+       } else if ((buf[4] ^ buf[5]) == 0xff) {
+               /* Backup copy of magic passes complement check (2 bytes). */
                magic = buf[4];
+               sr_dbg("Using secondary magic 0x%hhx.", magic);
+       } else {
+               sr_err("Cannot find consistent device type identification.");
        }
-
-       sr_dbg("device_type: magic number is %hhu", magic);
-
-       /* select the correct fpga bitstream for this device */
-       switch (magic) {
-       case 2:
-               ret = upload_fpga_bitstream(sdi, FPGA_FW_LA2016);
-               devc->max_samplerate = MAX_SAMPLE_RATE_LA2016;
-               break;
-       case 3:
-               ret = upload_fpga_bitstream(sdi, FPGA_FW_LA1016);
-               devc->max_samplerate = MAX_SAMPLE_RATE_LA1016;
-               break;
-       case 8:
-               ret = upload_fpga_bitstream(sdi, FPGA_FW_LA2016A);
-               devc->max_samplerate = MAX_SAMPLE_RATE_LA2016;
-               break;
-       case 9:
-               ret = upload_fpga_bitstream(sdi, FPGA_FW_LA1016A);
-               devc->max_samplerate = MAX_SAMPLE_RATE_LA1016;
+       devc->identify_magic = magic;
+       devc->identify_magic2 = magic2;
+
+       devc->model = NULL;
+       for (model_idx = 0; model_idx < ARRAY_SIZE(models); model_idx++) {
+               model = &models[model_idx];
+               if (model->magic != magic)
+                       continue;
+               if (model->magic2 && model->magic2 != magic2)
+                       continue;
+               devc->model = model;
+               sr_info("Model '%s', %zu channels, max %" PRIu64 "MHz.",
+                       model->name, model->channel_count,
+                       model->samplerate / SR_MHZ(1));
+               devc->fpga_bitstream = g_strdup_printf(FPGA_FWFILE_FMT,
+                       model->fpga_stem);
+               sr_info("FPGA bitstream file '%s'.", devc->fpga_bitstream);
+               if (!model->channel_count) {
+                       sr_warn("Device lacks logic channels. Not supported.");
+                       devc->model = NULL;
+               }
                break;
-       default:
-               sr_err("device_type: device not supported; magic number indicates this is not a LA2016 or LA1016");
-               return SR_ERR;
        }
+       if (!devc->model) {
+               sr_err("Cannot identify as one of the supported models.");
+               return SR_ERR_DATA;
+       }
+
+       return SR_OK;
+}
+
+SR_PRIV int la2016_init_hardware(const struct sr_dev_inst *sdi)
+{
+       struct dev_context *devc;
+       const char *bitstream_fn;
+       int ret;
+       uint16_t state;
+
+       devc = sdi->priv;
+       bitstream_fn = devc ? devc->fpga_bitstream : "";
 
+       ret = check_fpga_bitstream(sdi);
        if (ret != SR_OK) {
-               sr_err("failed to upload fpga bitstream");
+               ret = upload_fpga_bitstream(sdi, bitstream_fn);
+               if (ret != SR_OK) {
+                       sr_err("Cannot upload FPGA bitstream.");
+                       return ret;
+               }
+       }
+       ret = enable_fpga_bitstream(sdi);
+       if (ret != SR_OK) {
+               sr_err("Cannot enable FPGA bitstream after upload.");
                return ret;
        }
 
        state = run_state(sdi);
-       if (state != 0x85e9) {
-               sr_warn("expect run state to be 0x85e9, but it reads 0x%04x", state);
+       if ((state & 0xfff0) != 0x85e0) {
+               sr_warn("Unexpected run state, want 0x85eX, got 0x%04x.", state);
        }
 
-       if ((ret = ctrl_out(sdi, CMD_BULK_RESET, 0x00, 0, NULL, 0)) != SR_OK) {
-               sr_err("failed to send CMD_BULK_RESET");
+       ret = ctrl_out(sdi, CMD_BULK_RESET, 0x00, 0, NULL, 0);
+       if (ret != SR_OK) {
+               sr_err("Cannot reset USB bulk transfer.");
                return ret;
        }
 
-       sr_dbg("device should be initialized");
+       sr_dbg("Device should be initialized.");
 
-       return set_defaults(sdi);
+       return SR_OK;
 }
 
-SR_PRIV int la2016_deinit_device(const struct sr_dev_inst *sdi)
+SR_PRIV int la2016_deinit_hardware(const struct sr_dev_inst *sdi)
 {
        int ret;
 
-       if ((ret = ctrl_out(sdi, CMD_FPGA_ENABLE, 0x00, 0, NULL, 0)) != SR_OK) {
-               sr_err("failed to send deinit command");
+       ret = ctrl_out(sdi, CMD_FPGA_ENABLE, 0x00, 0, NULL, 0);
+       if (ret != SR_OK) {
+               sr_err("Cannot deinitialize device's FPGA.");
                return ret;
        }
 
        return SR_OK;
 }
+
+SR_PRIV void la2016_release_resources(const struct sr_dev_inst *sdi)
+{
+       (void)la2016_usbxfer_release(sdi);
+}
+
+SR_PRIV int la2016_write_pwm_config(const struct sr_dev_inst *sdi, size_t idx)
+{
+       return set_pwm_config(sdi, idx);
+}