]> sigrok.org Git - libsigrok.git/blobdiff - src/input/logicport.c
input/logicport: introduce input module for LogicPort File (*.lpf)
[libsigrok.git] / src / input / logicport.c
diff --git a/src/input/logicport.c b/src/input/logicport.c
new file mode 100644 (file)
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--- /dev/null
@@ -0,0 +1,1209 @@
+/*
+ * 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 (!desc)
+               return NULL;
+       if (name) {
+               desc->name = g_strdup(name);
+               if (!desc->name) {
+                       g_free(desc);
+                       return NULL;
+               }
+       }
+
+       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 (!cg)
+               return NULL;
+       if (name && *name) {
+               cg->name = g_strdup(name);
+               if (!cg->name) {
+                       g_free(cg);
+                       return NULL;
+               }
+       }
+       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)
+{
+       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);
+       }
+       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));
+       if (!inc)
+               return SR_ERR_MALLOC;
+       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,
+};