[libsigrok.git] / src / input / logicport.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2018 Gerhard Sittig <gerhard.sittig@gmx.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

/*
 * See the LA1034 vendor's http://www.pctestinstruments.com/ website.
 *
 * The hardware comes with (Windows only) software which uses the .lpf
 * ("LogicPort File") filename extension for project files, which hold
 * both the configuration as well as sample data (up to 2K samples). In
 * the absence of an attached logic analyzer, the software provides a
 * demo mode which generates random input signals. The software installs
 * example project files (with samples), too.
 *
 * The file format is "mostly text", is line oriented, though it uses
 * funny DC1 separator characters as well as line continuation by means
 * of a combination of DC1 and slashes. Fortunately the last text line
 * is terminated by means of CRLF.
 *
 * The software is rather complex and has features which don't easily
 * translate to sigrok semantics (like one signal being a member of
 * multiple groups, display format specs for groups' values).
 *
 * This input module implementation supports the following features:
 * - input format auto detection
 * - sample period to sample rate conversion
 * - wire names, acquisition filters ("enabled") and inversion flags
 * - decompression (repetition counters for sample data)
 * - strict '0' and '1' levels (as well as ignoring 'U' values)
 * - signal names (user assigned names, "aliases" for "wires")
 * - signal groups (no support for multiple assignments, no support for
 *   display format specs)
 * - "logic" channels (mere bits, no support for analog channels, also
 *   nothing analog "gets derived from" any signal groups) -- libsigrok
 *   using applications might provide such a feature if they want to
 */

#include <config.h>
#include <ctype.h>
#include <glib.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"

/* TODO: Move these helpers to some library API routine group. */
struct sr_channel_group *sr_channel_group_new(const char *name, void *priv);
void sr_channel_group_free(struct sr_channel_group *cg);

#define LOG_PREFIX      "input/logicport"

#define MAX_CHANNELS    34
#define CHUNK_SIZE      (4 * 1024 * 1024)

#define CRLF            "\r\n"
#define DC1_CHR         '\x11'
#define DC1_STR         "\x11"
#define CONT_OPEN       "/" DC1_STR
#define CONT_CLOSE      DC1_STR "/"

/*
 * This is some heuristics (read: a HACK). The current implementation
 * neither processes nor displays the user's notes, but takes their
 * presence as a hint that all relevant input was seen, and sample data
 * can get forwarded to the session bus.
 */
#define LAST_KEYWORD    "NotesString"

/*
 * The vendor software supports signal groups, and a single signal can
 * be a member in multiple groups at the same time. The sigrok project
 * does not support that configuration. Let's ignore the "All Signals"
 * group by default, thus reducing the probability of a conflict.
 */
#define SKIP_SIGNAL_GROUP       "All Signals"

struct signal_group_desc {
        char *name;
        uint64_t mask;
};

struct context {
        gboolean got_header;
        gboolean ch_feed_prep;
        gboolean header_sent;
        gboolean rate_sent;
        char *sw_version;
        size_t sw_build;
        GString *cont_buff;
        size_t channel_count;
        size_t sample_lines_total;
        size_t sample_lines_read;
        size_t sample_lines_fed;
        uint64_t samples_got_uncomp;
        enum {
                SAMPLEDATA_NONE,
                SAMPLEDATA_OPEN_BRACE,
                SAMPLEDATA_WIRES_COUNT,
                SAMPLEDATA_DATA_LINES,
                SAMPLEDATA_CLOSE_BRACE,
        } in_sample_data;
        struct sample_data_entry {
                uint64_t bits;
                size_t repeat;
        } *sample_data_queue;
        uint64_t sample_rate;
        uint64_t wires_all_mask;
        uint64_t wires_enabled;
        uint64_t wires_inverted;
        uint64_t wires_undefined;
        char *wire_names[MAX_CHANNELS];
        char *signal_names[MAX_CHANNELS];
        uint64_t wires_grouped;
        GSList *signal_groups;
        GSList *channels;
        size_t unitsize;
        size_t samples_per_chunk;
        size_t samples_in_buffer;
        uint8_t *feed_buffer;
};

static struct signal_group_desc *alloc_signal_group(const char *name)
{
        struct signal_group_desc *desc;

        desc = g_malloc0(sizeof(*desc));
        if (name)
                desc->name = g_strdup(name);

        return desc;
}

static void free_signal_group(struct signal_group_desc *desc)
{
        if (!desc)
                return;
        g_free(desc->name);
        g_free(desc);
}

struct sr_channel_group *sr_channel_group_new(const char *name, void *priv)
{
        struct sr_channel_group *cg;

        cg = g_malloc0(sizeof(*cg));
        if (name && *name)
                cg->name = g_strdup(name);
        cg->priv = priv;

        return cg;
}

void sr_channel_group_free(struct sr_channel_group *cg)
{
        if (!cg)
                return;
        g_free(cg->name);
        g_slist_free(cg->channels);
}

/* Wrapper for GDestroyNotify compatibility. */
static void sg_free(void *p)
{
        return free_signal_group(p);
}

static int check_vers_line(char *line, int need_key,
        gchar **version, gchar **build)
{
        static const char *keyword = "Version";
        static const char *caution = " CAUTION: Do not change the contents of this file.";
        char *read_ptr;
        const char *prev_ptr;

        read_ptr = line;
        if (version)
                *version = NULL;
        if (build)
                *build = NULL;

        /* Expect the 'Version' literal, followed by a DC1 separator. */
        if (need_key) {
                if (strncmp(read_ptr, keyword, strlen(keyword)) != 0)
                        return SR_ERR_DATA;
                read_ptr += strlen(keyword);
                if (*read_ptr != DC1_CHR)
                        return SR_ERR_DATA;
                read_ptr++;
        }

        /* Expect some "\d+\.\d+" style version string and DC1. */
        if (!*read_ptr)
                return SR_ERR_DATA;
        if (version)
                *version = read_ptr;
        prev_ptr = read_ptr;
        read_ptr += strspn(read_ptr, "0123456789.");
        if (read_ptr == prev_ptr)
                return SR_ERR_DATA;
        if (*read_ptr != DC1_CHR)
                return SR_ERR_DATA;
        *read_ptr++ = '\0';

        /* Expect some "\d+" style build number and DC1. */
        if (!*read_ptr)
                return SR_ERR_DATA;
        if (build)
                *build = read_ptr;
        prev_ptr = read_ptr;
        read_ptr += strspn(read_ptr, "0123456789");
        if (read_ptr == prev_ptr)
                return SR_ERR_DATA;
        if (*read_ptr != DC1_CHR)
                return SR_ERR_DATA;
        *read_ptr++ = '\0';

        /* Expect the 'CAUTION...' text (weak test, only part of the text). */
        if (strncmp(read_ptr, caution, strlen(caution)) != 0)
                return SR_ERR_DATA;
        read_ptr += strlen(caution);

        /* No check for CRLF, due to the weak CAUTION test. */
        return SR_OK;
}

static int process_wire_names(struct context *inc, char **names)
{
        size_t count, idx;

        /*
         * The 'names' array contains the *wire* names, plus a 'Count'
         * label for the last column.
         */
        count = g_strv_length(names);
        if (count != inc->channel_count + 1)
                return SR_ERR_DATA;
        if (strcmp(names[inc->channel_count], "Count") != 0)
                return SR_ERR_DATA;

        for (idx = 0; idx < inc->channel_count; idx++)
                inc->wire_names[idx] = g_strdup(names[idx]);

        return SR_OK;
}

static int process_signal_names(struct context *inc, char **names)
{
        size_t count, idx;

        /*
         * The 'names' array contains the *signal* names (and no other
         * entries, unlike the *wire* names).
         */
        count = g_strv_length(names);
        if (count != inc->channel_count)
                return SR_ERR_DATA;

        for (idx = 0; idx < inc->channel_count; idx++)
                inc->signal_names[idx] = g_strdup(names[idx]);

        return SR_OK;
}

static int process_signal_group(struct context *inc, char **args)
{
        char *name, *wires;
        struct signal_group_desc *desc;
        uint64_t bit_tmpl, bit_mask;
        char *p, *endp;
        size_t idx;

        /*
         * List of arguments that we receive:
         * - [0] group name
         * - [1] - [5] uncertain meaning, four integers and one boolean
         * - [6] comma separated list of wire indices (zero based)
         * - [7] - [9] uncertain meaning, a boolean, two integers
         * - [10] - [35] uncertain meaning, 26 empty columns
         */

        /* Check for the minimum amount of input data. */
        if (!args)
                return SR_ERR_DATA;
        if (g_strv_length(args) < 7)
                return SR_ERR_DATA;
        name = args[0];
        wires = args[6];

        /* Accept empty names and empty signal lists. Silently ignore. */
        if (!name || !*name)
                return SR_OK;
        if (!wires || !*wires)
                return SR_OK;
        /*
         * TODO: Introduce a user configurable "ignore" option? Skip the
         * "All Signals" group by default, and in addition whatever
         * the user specified?
         */
        if (strcmp(name, SKIP_SIGNAL_GROUP) == 0) {
                sr_info("Skipping signal group '%s'", name);
                return SR_OK;
        }

        /*
         * Create the descriptor here to store the member list to. We
         * cannot access signal names and sigrok channels yet, they
         * only become avilable at a later point in time.
         */
        desc = alloc_signal_group(name);
        if (!desc)
                return SR_ERR_MALLOC;
        inc->signal_groups = g_slist_append(inc->signal_groups, desc);

        /*
         * Determine the bit mask of the group's signals' indices.
         *
         * Implementation note: Use a "template" for a single bit, to
         * avoid portability issues with upper bits. Without this 64bit
         * intermediate variable, I would not know how to phrase e.g.
         * (1ULL << 33) in portable, robust, and easy to maintain ways
         * on all platforms that are supported by sigrok.
         */
        bit_tmpl = 1UL << 0;
        bit_mask = 0;
        p = wires;
        while (p && *p) {
                endp = NULL;
                idx = strtoul(p, &endp, 0);
                if (!endp || endp == p)
                        return SR_ERR_DATA;
                if (*endp && *endp != ',')
                        return SR_ERR_DATA;
                p = endp;
                if (*p == ',')
                        p++;
                if (idx >= MAX_CHANNELS)
                        return SR_ERR_DATA;
                bit_mask = bit_tmpl << idx;
                if (inc->wires_grouped & bit_mask) {
                        sr_warn("Not adding signal at index %zu to group %s (multiple assignments)",
                                idx, name);
                } else {
                        desc->mask |= bit_mask;
                        inc->wires_grouped |= bit_mask;
                }
        }
        sr_dbg("'Group' done, name '%s', mask 0x%" PRIx64 ".",
                desc->name, desc->mask);

        return SR_OK;
}

static int process_ungrouped_signals(struct context *inc)
{
        uint64_t bit_mask;
        struct signal_group_desc *desc;

        /*
         * Only create the "ungrouped" channel group if there are any
         * groups of other signals already.
         */
        if (!inc->signal_groups)
                return SR_OK;

        /*
         * Determine the bit mask of signals that are part of the
         * acquisition and are not a member of any other group.
         */
        bit_mask = inc->wires_all_mask;
        bit_mask &= inc->wires_enabled;
        bit_mask &= ~inc->wires_grouped;
        sr_dbg("'ungrouped' check: all 0x%" PRIx64 ", en 0x%" PRIx64 ", grp 0x%" PRIx64 " -> un 0x%" PRIx64 ".",
                inc->wires_all_mask, inc->wires_enabled,
                inc->wires_grouped, bit_mask);
        if (!bit_mask)
                return SR_OK;

        /* Create a sigrok channel group without a name. */
        desc = alloc_signal_group(NULL);
        if (!desc)
                return SR_ERR_MALLOC;
        inc->signal_groups = g_slist_append(inc->signal_groups, desc);
        desc->mask = bit_mask;

        return SR_OK;
}

static int process_enabled_channels(struct context *inc, char **flags)
{
        size_t count, idx;
        uint64_t bits, mask;

        /*
         * The 'flags' array contains (the textual representation of)
         * the "enabled" state of the acquisition device's channels.
         */
        count = g_strv_length(flags);
        if (count != inc->channel_count)
                return SR_ERR_DATA;
        bits = 0;
        mask = 1UL << 0;
        for (idx = 0; idx < inc->channel_count; idx++, mask <<= 1) {
                if (strcmp(flags[idx], "True") == 0)
                        bits |= mask;
        }
        inc->wires_enabled = bits;

        return SR_OK;
}

static int process_inverted_channels(struct context *inc, char **flags)
{
        size_t count, idx;
        uint64_t bits, mask;

        /*
         * The 'flags' array contains (the textual representation of)
         * the "inverted" state of the acquisition device's channels.
         */
        count = g_strv_length(flags);
        if (count != inc->channel_count)
                return SR_ERR_DATA;
        bits = 0;
        mask = 1UL << 0;
        for (idx = 0; idx < inc->channel_count; idx++, mask <<= 1) {
                if (strcmp(flags[idx], "True") == 0)
                        bits |= mask;
        }
        inc->wires_inverted = bits;

        return SR_OK;
}

static int process_sample_line(struct context *inc, char **values)
{
        size_t count, idx;
        struct sample_data_entry *entry;
        uint64_t mask;
        long conv_ret;
        int rc;

        /*
         * The 'values' array contains '0'/'1' text representation of
         * wire's values, as well as a (a textual representation of a)
         * repeat counter for that set of samples.
         */
        count = g_strv_length(values);
        if (count != inc->channel_count + 1)
                return SR_ERR_DATA;
        entry = &inc->sample_data_queue[inc->sample_lines_read];
        entry->bits = 0;
        mask = 1UL << 0;
        for (idx = 0; idx < inc->channel_count; idx++, mask <<= 1) {
                if (strcmp(values[idx], "1") == 0)
                        entry->bits |= mask;
                if (strcmp(values[idx], "U") == 0)
                        inc->wires_undefined |= mask;
        }
        rc = sr_atol(values[inc->channel_count], &conv_ret);
        if (rc != SR_OK)
                return rc;
        entry->repeat = conv_ret;
        inc->samples_got_uncomp += entry->repeat;

        return SR_OK;
}

static int process_keyvalue_line(struct context *inc, char *line)
{
        char *sep, *key, *arg;
        char **args;
        int rc;
        char *version, *build;
        long build_num;
        int wires, samples;
        size_t alloc_size;
        double period, dbl_rate;
        uint64_t int_rate;

        /*
         * Process lines of the 'SampleData' block. Inspection of the
         * block got started below in the "regular keyword line" section.
         * The code here handles the remaining number of lines: Opening
         * and closing braces, wire names, and sample data sets. Note
         * that the wire names and sample values are separated by comma,
         * not by DC1 like other key/value pairs and argument lists.
         */
        switch (inc->in_sample_data) {
        case SAMPLEDATA_OPEN_BRACE:
                if (strcmp(line, "{") != 0)
                        return SR_ERR_DATA;
                inc->in_sample_data++;
                return SR_OK;
        case SAMPLEDATA_WIRES_COUNT:
                while (isspace(*line))
                        line++;
                args = g_strsplit(line, ",", 0);
                rc = process_wire_names(inc, args);
                g_strfreev(args);
                if (rc)
                        return rc;
                inc->in_sample_data++;
                inc->sample_lines_read = 0;
                return SR_OK;
        case SAMPLEDATA_DATA_LINES:
                while (isspace(*line))
                        line++;
                args = g_strsplit(line, ",", 0);
                rc = process_sample_line(inc, args);
                g_strfreev(args);
                if (rc)
                        return rc;
                inc->sample_lines_read++;
                if (inc->sample_lines_read == inc->sample_lines_total)
                        inc->in_sample_data++;
                return SR_OK;
        case SAMPLEDATA_CLOSE_BRACE:
                if (strcmp(line, "}") != 0)
                        return SR_ERR_DATA;
                sr_dbg("'SampleData' done: samples count %" PRIu64 ".",
                        inc->samples_got_uncomp);
                inc->sample_lines_fed = 0;
                inc->in_sample_data = SAMPLEDATA_NONE;
                return SR_OK;
        case SAMPLEDATA_NONE:
                /* EMPTY */ /* Fall through to regular keyword-line logic. */
                break;
        }

        /* Process regular key/value lines separated by DC1. */
        key = line;
        sep = strchr(line, DC1_CHR);
        if (!sep)
                return SR_ERR_DATA;
        *sep++ = '\0';
        arg = sep;
        if (strcmp(key, "Version") == 0) {
                rc = check_vers_line(arg, 0, &version, &build);
                if (rc == SR_OK) {
                        inc->sw_version = g_strdup(version ? version : "?");
                        rc = sr_atol(build, &build_num);
                        inc->sw_build = build_num;
                }
                sr_dbg("'Version' line: version %s, build %zu.",
                        inc->sw_version, inc->sw_build);
                return rc;
        }
        if (strcmp(key, "AcquiredSamplePeriod") == 0) {
                rc = sr_atod(arg, &period);
                if (rc != SR_OK)
                        return rc;
                /*
                 * Implementation detail: The vendor's software provides
                 * 1/2/5 choices in the 1kHz - 500MHz range. Unfortunately
                 * the choice of saving the sample _period_ as a floating
                 * point number in the text file yields inaccurate results
                 * for naive implementations of the conversion (0.1 is an
                 * "odd number" in the computer's internal representation).
                 * The below logic of rounding to integer and then rounding
                 * to full kHz works for the samplerate value's range.
                 * "Simplifying" the implementation will introduce errors.
                 */
                dbl_rate = 1.0 / period;
                int_rate = (uint64_t)(dbl_rate + 0.5);
                int_rate += 500;
                int_rate /= 1000;
                int_rate *= 1000;
                inc->sample_rate = int_rate;
                if (!inc->sample_rate)
                        return SR_ERR_DATA;
                sr_dbg("Sample rate: %" PRIu64 ".", inc->sample_rate);
                return SR_OK;
        }
        if (strcmp(key, "AcquiredChannelList") == 0) {
                args = g_strsplit(arg, DC1_STR, 0);
                rc = process_enabled_channels(inc, args);
                g_strfreev(args);
                if (rc)
                        return rc;
                sr_dbg("Enabled channels: 0x%" PRIx64 ".",
                        inc->wires_enabled);
                return SR_OK;
        }
        if (strcmp(key, "InvertedChannelList") == 0) {
                args = g_strsplit(arg, DC1_STR, 0);
                rc = process_inverted_channels(inc, args);
                g_strfreev(args);
                sr_dbg("Inverted channels: 0x%" PRIx64 ".",
                        inc->wires_inverted);
                return SR_OK;
        }
        if (strcmp(key, "Signals") == 0) {
                args = g_strsplit(arg, DC1_STR, 0);
                rc = process_signal_names(inc, args);
                g_strfreev(args);
                if (rc)
                        return rc;
                sr_dbg("Got signal names.");
                return SR_OK;
        }
        if (strcmp(key, "SampleData") == 0) {
                args = g_strsplit(arg, DC1_STR, 3);
                if (!args || !args[0] || !args[1]) {
                        g_strfreev(args);
                        return SR_ERR_DATA;
                }
                rc = sr_atoi(args[0], &wires);
                if (rc) {
                        g_strfreev(args);
                        return SR_ERR_DATA;
                }
                rc = sr_atoi(args[1], &samples);
                if (rc) {
                        g_strfreev(args);
                        return SR_ERR_DATA;
                }
                g_strfreev(args);
                if (!wires || !samples)
                        return SR_ERR_DATA;
                inc->channel_count = wires;
                inc->sample_lines_total = samples;
                sr_dbg("'SampleData' start: wires %zu, sample lines %zu.",
                        inc->channel_count, inc->sample_lines_total);
                if (inc->channel_count > MAX_CHANNELS)
                        return SR_ERR_DATA;
                inc->in_sample_data = SAMPLEDATA_OPEN_BRACE;
                alloc_size = sizeof(inc->sample_data_queue[0]);
                alloc_size *= inc->sample_lines_total;
                inc->sample_data_queue = g_malloc0(alloc_size);
                if (!inc->sample_data_queue)
                        return SR_ERR_DATA;
                inc->sample_lines_fed = 0;
                return SR_OK;
        }
        if (strcmp(key, "Group") == 0) {
                args = g_strsplit(arg, DC1_STR, 0);
                rc = process_signal_group(inc, args);
                g_strfreev(args);
                if (rc)
                        return rc;
                return SR_OK;
        }
        if (strcmp(key, LAST_KEYWORD) == 0) {
                sr_dbg("'" LAST_KEYWORD "' seen, assuming \"header done\".");
                inc->got_header = TRUE;
                return SR_OK;
        }

        /* Unsupported keyword, silently ignore the line. */
        return SR_OK;
}

/* Check for, and isolate another line of text input. */
static int have_text_line(struct sr_input *in, char **line, char **next)
{
        char *sol_ptr, *eol_ptr;

        if (!in || !in->buf || !in->buf->str)
                return 0;
        sol_ptr = in->buf->str;
        eol_ptr = strstr(sol_ptr, CRLF);
        if (!eol_ptr)
                return 0;
        if (line)
                *line = sol_ptr;
        *eol_ptr = '\0';
        eol_ptr += strlen(CRLF);
        if (next)
                *next = eol_ptr;

        return 1;
}

/* Handle line continuation. Have logical lines processed. */
static int process_text_line(struct context *inc, char *line)
{
        char *p;
        int is_cont_end;
        int rc;

        /*
         * Handle line continuation in the input stream. Notice that
         * continued lines can start and end on the same input line.
         * The text between the markers can be empty, too.
         *
         * Make the result look like a regular line. Put a DC1 delimiter
         * between the keyword and the right hand side. Strip the /<DC1>
         * and <DC1>/ "braces". Put CRLF between all continued parts,
         * this makes the data appear "most intuitive and natural"
         * should we e.g. pass on user's notes in a future version.
         */
        is_cont_end = 0;
        if (!inc->cont_buff) {
                p = strstr(line, CONT_OPEN);
                if (p) {
                        /* Start of continuation. */
                        inc->cont_buff = g_string_new_len(line, p - line + 1);
                        inc->cont_buff->str[inc->cont_buff->len - 1] = DC1_CHR;
                        line = p + strlen(CONT_OPEN);
                }
                /* Regular line, fall through to below regular logic. */
        }
        if (inc->cont_buff) {
                p = strstr(line, CONT_CLOSE);
                is_cont_end = p != NULL;
                if (is_cont_end)
                        *p = '\0';
                g_string_append_len(inc->cont_buff, line, strlen(line));
                if (!is_cont_end) {
                        /* Keep accumulating. */
                        g_string_append_len(inc->cont_buff, CRLF, strlen(CRLF));
                        return SR_OK;
                }
                /* End of continuation. */
                line = inc->cont_buff->str;
        }

        /*
         * Process a logical line of input. It either was received from
         * the caller, or is the result of accumulating continued lines.
         */
        rc = process_keyvalue_line(inc, line);

        /* Release the accumulation buffer when a continuation ended. */
        if (is_cont_end) {
                g_string_free(inc->cont_buff, TRUE);
                inc->cont_buff = NULL;
        }

        return rc;
}

/* Tell whether received data is sufficient for session feed preparation. */
static int have_header(GString *buf)
{
        const char *assumed_last_key = CRLF LAST_KEYWORD CONT_OPEN;

        if (strstr(buf->str, assumed_last_key))
                return TRUE;

        return FALSE;
}

/* Process/inspect previously received input data. Get header parameters. */
static int parse_header(struct sr_input *in)
{
        struct context *inc;
        char *line, *next;
        int rc;

        inc = in->priv;
        while (have_text_line(in, &line, &next)) {
                rc = process_text_line(inc, line);
                g_string_erase(in->buf, 0, next - line);
                if (rc)
                        return rc;
        }

        return SR_OK;
}

/* Create sigrok channels and groups. Allocate the session feed buffer. */
static int create_channels_groups_buffer(struct sr_input *in)
{
        struct context *inc;
        uint64_t mask;
        size_t idx;
        const char *name;
        gboolean enabled;
        struct sr_channel *ch;
        struct sr_dev_inst *sdi;
        GSList *l;
        struct signal_group_desc *desc;
        struct sr_channel_group *cg;

        inc = in->priv;

        mask = 1UL << 0;
        for (idx = 0; idx < inc->channel_count; idx++, mask <<= 1) {
                name = inc->signal_names[idx];
                if (!name || !*name)
                        name = inc->wire_names[idx];
                enabled = (inc->wires_enabled & mask) ? TRUE : FALSE;
                ch = sr_channel_new(in->sdi, idx,
                        SR_CHANNEL_LOGIC, enabled, name);
                if (!ch)
                        return SR_ERR_MALLOC;
                inc->channels = g_slist_append(inc->channels, ch);
        }

        sdi = in->sdi;
        for (l = inc->signal_groups; l; l = l->next) {
                desc = l->data;
                cg = sr_channel_group_new(desc->name, NULL);
                if (!cg)
                        return SR_ERR_MALLOC;
                sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);
                mask = 1UL << 0;
                for (idx = 0; idx < inc->channel_count; idx++, mask <<= 1) {
                        if (!(desc->mask & mask))
                                continue;
                        ch = g_slist_nth_data(inc->channels, idx);
                        if (!ch)
                                return SR_ERR_DATA;
                        cg->channels = g_slist_append(cg->channels, ch);
                }
        }

        inc->unitsize = (inc->channel_count + 7) / 8;
        inc->samples_per_chunk = CHUNK_SIZE / inc->unitsize;
        inc->samples_in_buffer = 0;
        inc->feed_buffer = g_malloc0(inc->samples_per_chunk * inc->unitsize);
        if (!inc->feed_buffer)
                return SR_ERR_MALLOC;

        return SR_OK;
}

/* Send all accumulated sample data values to the session. */
static int send_buffer(struct sr_input *in)
{
        struct context *inc;
        struct sr_datafeed_packet packet;
        struct sr_datafeed_meta meta;
        struct sr_config *src;
        struct sr_datafeed_logic logic;
        int rc;

        inc = in->priv;
        if (!inc->samples_in_buffer)
                return SR_OK;

        if (!inc->header_sent) {
                rc = std_session_send_df_header(in->sdi);
                if (rc)
                        return rc;
                inc->header_sent = TRUE;
        }

        if (inc->sample_rate && !inc->rate_sent) {
                packet.type = SR_DF_META;
                packet.payload = &meta;
                src = sr_config_new(SR_CONF_SAMPLERATE,
                        g_variant_new_uint64(inc->sample_rate));
                meta.config = g_slist_append(NULL, src);
                rc = sr_session_send(in->sdi, &packet);
                g_slist_free(meta.config);
                sr_config_free(src);
                if (rc)
                        return rc;
                inc->rate_sent = TRUE;
        }

        packet.type = SR_DF_LOGIC;
        packet.payload = &logic;
        logic.unitsize = inc->unitsize;
        logic.data = inc->feed_buffer;
        logic.length = inc->unitsize * inc->samples_in_buffer;
        rc = sr_session_send(in->sdi, &packet);

        inc->samples_in_buffer = 0;

        if (rc)
                return rc;

        return SR_OK;
}

/*
 * Add N copies of the current sample to the buffer. Send the buffer to
 * the session feed when a maximum amount of data was collected.
 */
static int add_samples(struct sr_input *in, uint64_t samples, size_t count)
{
        struct context *inc;
        uint8_t sample_buffer[sizeof(uint64_t)];
        size_t idx;
        size_t copy_count;
        uint8_t *p;
        int rc;

        inc = in->priv;
        for (idx = 0; idx < inc->unitsize; idx++) {
                sample_buffer[idx] = samples & 0xff;
                samples >>= 8;
        }
        while (count) {
                copy_count = inc->samples_per_chunk - inc->samples_in_buffer;
                if (copy_count > count)
                        copy_count = count;
                count -= copy_count;

                p = inc->feed_buffer + inc->samples_in_buffer * inc->unitsize;
                while (copy_count-- > 0) {
                        memcpy(p, sample_buffer, inc->unitsize);
                        p += inc->unitsize;
                        inc->samples_in_buffer++;
                }

                if (inc->samples_in_buffer == inc->samples_per_chunk) {
                        rc = send_buffer(in);
                        if (rc)
                                return rc;
                }
        }

        return SR_OK;
}

/* Pass on previously received samples to the session. */
static int process_queued_samples(struct sr_input *in)
{
        struct context *inc;
        struct sample_data_entry *entry;
        uint64_t sample_bits;
        int rc;

        inc = in->priv;
        while (inc->sample_lines_fed < inc->sample_lines_total) {
                entry = &inc->sample_data_queue[inc->sample_lines_fed++];
                sample_bits = entry->bits;
                sample_bits ^= inc->wires_inverted;
                sample_bits &= inc->wires_enabled;
                rc = add_samples(in, sample_bits, entry->repeat);
                if (rc)
                        return rc;
        }

        return SR_OK;
}

/*
 * Create required resources between having read the input file and
 * sending sample data to the session. Send initial packets before
 * sample data follows.
 */
static int prepare_session_feed(struct sr_input *in)
{
        struct context *inc;
        int rc;

        inc = in->priv;
        if (inc->ch_feed_prep)
                return SR_OK;

        /* Got channel names? At least fallbacks? */
        if (!inc->wire_names[0] || !inc->wire_names[0][0])
                return SR_ERR_DATA;
        /* Samples seen? Seen them all? */
        if (!inc->channel_count)
                return SR_ERR_DATA;
        if (!inc->sample_lines_total)
                return SR_ERR_DATA;
        if (inc->in_sample_data)
                return SR_ERR_DATA;
        if (!inc->sample_data_queue)
                return SR_ERR_DATA;
        inc->sample_lines_fed = 0;

        /*
         * Normalize some variants of input data.
         * - Let's create a mask for the maximum possible
         *   bit positions, it will be useful to avoid garbage
         *   in other code paths, too.
         * - Input files _might_ specify which channels were
         *   enabled during acquisition. _Or_ not specify the
         *   enabled channels, but provide 'U' values in some
         *   columns. When neither was seen, assume that all
         *   channels are enabled.
         * - If there are any signal groups, put all signals into
         *   an anonymous group that are not part of another group.
         */
        inc->wires_all_mask = 1UL << 0;
        inc->wires_all_mask <<= inc->channel_count;
        inc->wires_all_mask--;
        sr_dbg("all wires mask: 0x%" PRIx64 ".", inc->wires_all_mask);
        if (!inc->wires_enabled) {
                inc->wires_enabled = ~inc->wires_undefined;
                inc->wires_enabled &= ~inc->wires_all_mask;
                sr_dbg("enabled from undefined: 0x%" PRIx64 ".",
                        inc->wires_enabled);
        }
        if (!inc->wires_enabled) {
                inc->wires_enabled = inc->wires_all_mask;
                sr_dbg("enabled from total mask: 0x%" PRIx64 ".",
                        inc->wires_enabled);
        }
        sr_dbg("enabled mask: 0x%" PRIx64 ".",
                inc->wires_enabled);
        rc = process_ungrouped_signals(inc);
        if (rc)
                return rc;

        /*
         * "Start" the session: Create channels, send the DF
         * header to the session. Optionally send the sample
         * rate before sample data will be sent.
         */
        rc = create_channels_groups_buffer(in);
        if (rc)
                return rc;

        inc->ch_feed_prep = TRUE;

        return SR_OK;
}

static int format_match(GHashTable *metadata, unsigned int *confidence)
{
        GString *buf, *tmpbuf;
        int rc;
        gchar *version, *build;

        /* Get a copy of the start of the file's content. */
        buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
        if (!buf || !buf->str)
                return SR_ERR_ARG;
        tmpbuf = g_string_new_len(buf->str, buf->len);
        if (!tmpbuf || !tmpbuf->str)
                return SR_ERR_MALLOC;

        /* See if we can spot a typical first LPF line. */
        rc = check_vers_line(tmpbuf->str, 1, &version, &build);
        if (rc == SR_OK && version && build) {
                sr_dbg("Looks like a LogicProbe project, version %s, build %s.",
                        version, build);
                *confidence = 1;
        }
        g_string_free(tmpbuf, TRUE);

        return rc;
}

static int init(struct sr_input *in, GHashTable *options)
{
        struct context *inc;

        (void)options;

        in->sdi = g_malloc0(sizeof(*in->sdi));
        inc = g_malloc0(sizeof(*inc));
        in->priv = inc;

        return SR_OK;
}

static int receive(struct sr_input *in, GString *buf)
{
        struct context *inc;
        int rc;

        /* Accumulate another chunk of input data. */
        g_string_append_len(in->buf, buf->str, buf->len);

        /*
         * Wait for the full header's availability, then process it in a
         * single call, and set the "ready" flag. Make sure sample data
         * and the header get processed in disjoint calls to receive(),
         * the backend requires those separate phases.
         */
        inc = in->priv;
        if (!inc->got_header) {
                if (!have_header(in->buf))
                        return SR_OK;
                rc = parse_header(in);
                if (rc)
                        return rc;
                rc = prepare_session_feed(in);
                if (rc)
                        return rc;
                in->sdi_ready = TRUE;
                return SR_OK;
        }

        /* Process sample data, after the header got processed. */
        rc = process_queued_samples(in);

        return rc;
}

static int end(struct sr_input *in)
{
        struct context *inc;
        int rc;

        /* Nothing to do here if we never started feeding the session. */
        if (!in->sdi_ready)
                return SR_OK;

        /*
         * Process sample data that may not have been forwarded before.
         * Flush any potentially queued samples.
         */
        rc = process_queued_samples(in);
        if (rc)
                return rc;
        rc = send_buffer(in);
        if (rc)
                return rc;

        /* End the session feed if one was started. */
        inc = in->priv;
        if (inc->header_sent) {
                rc = std_session_send_df_end(in->sdi);
                inc->header_sent = FALSE;
        }

        return rc;
}

static void cleanup(struct sr_input *in)
{
        struct context *inc;
        size_t idx;

        if (!in)
                return;

        inc = in->priv;
        if (!inc)
                return;

        /*
         * Release potentially allocated resources. Void all references
         * and scalars, so that re-runs start out fresh again.
         */
        g_free(inc->sw_version);
        g_string_free(inc->cont_buff, TRUE);
        g_free(inc->sample_data_queue);
        for (idx = 0; idx < inc->channel_count; idx++)
                g_free(inc->wire_names[idx]);
        for (idx = 0; idx < inc->channel_count; idx++)
                g_free(inc->signal_names[idx]);
        g_slist_free_full(inc->signal_groups, sg_free);
        g_slist_free_full(inc->channels, g_free);
        g_free(inc->feed_buffer);
        memset(inc, 0, sizeof(*inc));
}

static int reset(struct sr_input *in)
{
        struct context *inc;

        inc = in->priv;
        cleanup(in);
        inc->ch_feed_prep = FALSE;
        inc->header_sent = FALSE;
        inc->rate_sent = FALSE;
        g_string_truncate(in->buf, 0);

        return SR_OK;
}

static struct sr_option options[] = {
        ALL_ZERO,
};

static const struct sr_option *get_options(void)
{
        return options;
}

SR_PRIV struct sr_input_module input_logicport = {
        .id = "logicport",
        .name = "LogicPort File",
        .desc = "Intronix LA1034 LogicPort project",
        .exts = (const char *[]){ "lpf", NULL },
        .metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
        .options = get_options,
        .format_match = format_match,
        .init = init,
        .receive = receive,
        .end = end,
        .cleanup = cleanup,
        .reset = reset,
};