From dd93276bf6b7537b65cab270f66666bf23fbc585 Mon Sep 17 00:00:00 2001
From: Uwe Hermann <uwe@hermann-uwe.de>
Date: Thu, 10 May 2012 09:34:13 +0200
Subject: [PATCH] srd: Support for one or more optional probes.

In the protocol decoder you always get all required probes, then _all_
optional probes in the list of probes in the decode() call.

Example:

 (r1, r2, r3, o1, o2, o3, o4) = pins

In this case r1-r3 are required probes, o1-o4 are optional probes.
However, the value of valid/used/specified probes will be 0 or 1,
whereas the value of probes that were not specified/assigned by the user
will be (at the moment) 42.

The PD can check for a valid probe like this:

  if p in (0, 1):
    ...

Or check for an invalid probe:

  if (p > 1):
    ...

The value of 42 could change to be -1 or None later.
---
 controller.c | 20 ++++++++++++++++++--
 decoder.c    | 15 +++++++++++++++
 type_logic.c | 17 ++++++++++++++++-
 3 files changed, 49 insertions(+), 3 deletions(-)

diff --git a/controller.c b/controller.c
index 0d914c9..995ddd7 100644
--- a/controller.c
+++ b/controller.c
@@ -344,6 +344,7 @@ SRD_API int srd_inst_probe_set_all(struct srd_decoder_inst *di,
 	struct srd_probe *p;
 	int *new_probemap, new_probenum;
 	char *probe_id, *probenum_str;
+	int i, num_required_probes;
 
 	srd_dbg("set probes called for instance %s with list of %d probes",
 		di->inst_id, g_hash_table_size(new_probes));
@@ -366,6 +367,13 @@ SRD_API int srd_inst_probe_set_all(struct srd_decoder_inst *di,
 		return SRD_ERR_MALLOC;
 	}
 
+	/*
+	 * For now, map all indexes to probe -1 (can be overridden later).
+	 * This -1 is interpreted as an unspecified probe later.
+	 */
+	for (i = 0; i < di->dec_num_probes; i++)
+		new_probemap[i] = -1;
+
 	for (l = g_hash_table_get_keys(new_probes); l; l = l->next) {
 		probe_id = l->data;
 		probenum_str = g_hash_table_lookup(new_probes, probe_id);
@@ -390,9 +398,17 @@ SRD_API int srd_inst_probe_set_all(struct srd_decoder_inst *di,
 		}
 		p = sl->data;
 		new_probemap[p->order] = new_probenum;
-		srd_dbg("setting probe mapping for %d = probe %d", p->order,
-			new_probenum);
+		srd_dbg("Setting probe mapping: %s (index %d) = probe %d.",
+			p->id, p->order, new_probenum);
 	}
+
+	srd_dbg("Final probe map:");
+	num_required_probes = g_slist_length(di->decoder->probes);
+	for (i = 0; i < di->dec_num_probes; i++) {
+		srd_dbg(" - index %d = probe %d (%s)", i, new_probemap[i],
+		        (i < num_required_probes) ? "required" : "optional");
+	}
+
 	g_free(di->dec_probemap);
 	di->dec_probemap = new_probemap;
 
diff --git a/decoder.c b/decoder.c
index 4cf4197..6dfeeca 100644
--- a/decoder.c
+++ b/decoder.c
@@ -134,6 +134,8 @@ SRD_API int srd_decoder_load(const char *module_name)
 	struct srd_decoder *d;
 	int alen, ret, i;
 	char **ann;
+	struct srd_probe *p;
+	GSList *l;
 
 	srd_dbg("Loading protocol decoder '%s'.", module_name);
 
@@ -222,6 +224,19 @@ SRD_API int srd_decoder_load(const char *module_name)
 	if (get_probes(d, "optional_probes", &d->opt_probes) != SRD_OK)
 		goto err_out;
 
+	/*
+	 * Fix order numbers for the optional probes.
+	 *
+	 * Example:
+	 * Required probes: r1, r2, r3. Optional: o1, o2, o3, o4.
+	 * 'order' fields in the d->probes list = 0, 1, 2.
+	 * 'order' fields in the d->opt_probes list = 3, 4, 5, 6.
+	 */
+	for (l = d->opt_probes; l; l = l->next) {
+		p = l->data;
+		p->order += g_slist_length(d->probes);
+	}
+
 	/* Store required fields in newly allocated strings. */
 	if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK)
 		goto err_out;
diff --git a/type_logic.c b/type_logic.c
index b284ebf..098e34d 100644
--- a/type_logic.c
+++ b/type_logic.c
@@ -45,11 +45,26 @@ static PyObject *srd_logic_iternext(PyObject *self)
 	 * Convert the bit-packed sample to an array of bytes, with only 0x01
 	 * and 0x00 values, so the PD doesn't need to do any bitshifting.
 	 */
+
+	/* Get probe bits into the 'sample' variable. */
 	memcpy(&sample,
 	       logic->inbuf + logic->itercnt * logic->di->data_unitsize,
 	       logic->di->data_unitsize);
-	for (i = 0; i < logic->di->dec_num_probes; i++)
+
+	/* All probe values (required + optional) are pre-set to 42. */
+	memset(probe_samples, 42, logic->di->dec_num_probes);
+	/* TODO: None or -1 in Python would be better. */
+
+	/*
+	 * Set probe values of specified/used probes to their resp. values.
+	 * Unused probe values (those not specified by the user) remain at 42.
+	 */
+	for (i = 0; i < logic->di->dec_num_probes; i++) {
+		/* A probemap value of -1 means "unused optional probe". */
+		if (logic->di->dec_probemap[i] == -1)
+			continue;
 		probe_samples[i] = sample & (1 << logic->di->dec_probemap[i]) ? 1 : 0;
+	}
 
 	/* Prepare the next samplenum/sample list in this iteration. */
 	py_samplenum =
-- 
2.30.2