Move link parsing from main.c to media.c, making it part of libmediactl

This makes it possible to benefit from the link parsing code anywhere the
library is being used.

dprintf macro will later be replaced with proper debug support.

Also fix a case where -1 was returned on error and the user was expected to
check the value of errno. Negative error codes are now returned
consistently.

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

3 files changed, 212 insertions, 151 deletions

diff --git a/src/main.c b/src/main.c
index 55a6e2d..02cdecd 100644
--- a/src/main.c
+++ b/src/main.c
@@ -335,137 +335,6 @@ void media_print_topology(struct media_device *media, int dot)
 }
 
 /* -----------------------------------------------------------------------------
- * Links setup
- */
-
-static struct media_pad *parse_pad(struct media_device *media, const char *p, char **endp)
-{
-	unsigned int entity_id, pad;
-	struct media_entity *entity;
-	char *end;
-
-	for (; isspace(*p); ++p);
-
-	if (*p == '"') {
-		for (end = (char *)p + 1; *end && *end != '"'; ++end);
-		if (*end != '"')
-			return NULL;
-
-		entity = media_get_entity_by_name(media, p + 1, end - p - 1);
-		if (entity == NULL)
-			return NULL;
-
-		++end;
-	} else {
-		entity_id = strtoul(p, &end, 10);
-		entity = media_get_entity_by_id(media, entity_id);
-		if (entity == NULL)
-			return NULL;
-	}
-	for (; isspace(*end); ++end);
-
-	if (*end != ':')
-		return NULL;
-	for (p = end + 1; isspace(*p); ++p);
-
-	pad = strtoul(p, &end, 10);
-	for (p = end; isspace(*p); ++p);
-
-	if (pad >= entity->info.pads)
-		return NULL;
-
-	for (p = end; isspace(*p); ++p);
-	if (endp)
-		*endp = (char *)p;
-
-	return &entity->pads[pad];
-}
-
-static struct media_link *parse_link(struct media_device *media, const char *p, char **endp)
-{
-	struct media_link *link;
-	struct media_pad *source;
-	struct media_pad *sink;
-	unsigned int i;
-	char *end;
-
-	source = parse_pad(media, p, &end);
-	if (source == NULL)
-		return NULL;
-
-	if (end[0] != '-' || end[1] != '>')
-		return NULL;
-	p = end + 2;
-
-	sink = parse_pad(media, p, &end);
-	if (sink == NULL)
-		return NULL;
-
-	*endp = end;
-
-	for (i = 0; i < source->entity->num_links; i++) {
-		link = &source->entity->links[i];
-
-		if (link->source == source && link->sink == sink)
-			return link;
-	}
-
-	return NULL;
-}
-
-static int setup_link(struct media_device *media, const char *p, char **endp)
-{
-	struct media_link *link;
-	__u32 flags;
-	char *end;
-
-	link = parse_link(media, p, &end);
-	if (link == NULL) {
-		printf("Unable to parse link\n");
-		return -EINVAL;
-	}
-
-	p = end;
-	if (*p++ != '[') {
-		printf("Unable to parse link flags\n");
-		return -EINVAL;
-	}
-
-	flags = strtoul(p, &end, 10);
-	for (p = end; isspace(*p); p++);
-	if (*p++ != ']') {
-		printf("Unable to parse link flags\n");
-		return -EINVAL;
-	}
-
-	for (; isspace(*p); p++);
-	*endp = (char *)p;
-
-	printf("Setting up link %u:%u -> %u:%u [%u]\n",
-		link->source->entity->info.id, link->source->index,
-		link->sink->entity->info.id, link->sink->index,
-		flags);
-
-	return media_setup_link(media, link->source, link->sink, flags);
-}
-
-static int setup_links(struct media_device *media, const char *p)
-{
-	char *end;
-	int ret;
-
-	do {
-		ret = setup_link(media, p, &end);
-		if (ret < 0)
-			return ret;
-
-		p = end + 1;
-	} while (*end == ',');
-
-	return *end ? -EINVAL : 0;
-}
-
-/* -----------------------------------------------------------------------------
  * Formats setup
  */
 
@@ -558,7 +427,7 @@ static struct media_pad *parse_pad_format(struct media_device *media,
 
 	for (; isspace(*p); ++p);
 
-	pad = parse_pad(media, p, &end);
+	pad = media_parse_pad(media, p, &end);
 	if (pad == NULL)
 		return NULL;
 
@@ -775,7 +644,7 @@ int main(int argc, char **argv)
 	if (media_opts.pad) {
 		struct media_pad *pad;
 
-		pad = parse_pad(media, media_opts.pad, NULL);
+		pad = media_parse_pad(media, media_opts.pad, NULL);
 		if (pad == NULL) {
 			printf("Pad '%s' not found\n", media_opts.pad);
 			goto out;
@@ -797,7 +666,7 @@ int main(int argc, char **argv)
 	}
 
 	if (media_opts.links)
-		setup_links(media, media_opts.links);
+		media_parse_setup_links(media, media_opts.links);
 
 	if (media_opts.formats)
 		setup_formats(media, media_opts.formats);
@@ -814,7 +683,7 @@ int main(int argc, char **argv)
 			if (buffer[0] == '\n')
 				break;
 
-			setup_link(media, buffer, &end);
+			media_parse_setup_link(media, buffer, &end);
 		}
 	}
 
diff --git a/src/mediactl.c b/src/mediactl.c
index 8f7d0a9..7c3adbe 100644
--- a/src/mediactl.c
+++ b/src/mediactl.c
@@ -36,6 +36,12 @@
 #include "mediactl.h"
 #include "tools.h"
 
+#ifdef DEBUG
+#define dprintf(...) printf(__VA_ARGS__)
+#else
+#define dprintf(...)
+#endif
+
 struct media_pad *media_entity_remote_source(struct media_pad *pad)
 {
 	unsigned int i;
@@ -107,8 +113,8 @@ int media_setup_link(struct media_device *media,
 	}
 
 	if (i == source->entity->num_links) {
-		printf("%s: Link not found\n", __func__);
-		return -EINVAL;
+		dprintf("%s: Link not found\n", __func__);
+		return -ENOENT;
 	}
 
 	/* source pad */
@@ -124,10 +130,10 @@ int media_setup_link(struct media_device *media,
 	ulink.flags = flags | (link->flags & MEDIA_LNK_FL_IMMUTABLE);
 
 	ret = ioctl(media->fd, MEDIA_IOC_SETUP_LINK, &ulink);
-	if (ret < 0) {
-		printf("%s: Unable to setup link (%s)\n", __func__,
+	if (ret == -1) {
+		dprintf("%s: Unable to setup link (%s)\n", __func__,
 			strerror(errno));
-		return ret;
+		return -errno;
 	}
 
 	link->flags = ulink.flags;
@@ -196,7 +202,7 @@ static int media_enum_links(struct media_device *media)
 		links.links = malloc(entity->info.links * sizeof(struct media_link_desc));
 
 		if (ioctl(media->fd, MEDIA_IOC_ENUM_LINKS, &links) < 0) {
-			printf("%s: Unable to enumerate pads and links (%s).\n",
+			dprintf("%s: Unable to enumerate pads and links (%s).\n",
 				__func__, strerror(errno));
 			free(links.pads);
 			free(links.links);
@@ -220,7 +226,7 @@ static int media_enum_links(struct media_device *media)
 			sink = media_get_entity_by_id(media, link->sink.entity);
 
 			if (source == NULL || sink == NULL) {
-				printf("WARNING entity %u link %u from %u/%u to %u/%u is invalid!\n",
+				dprintf("WARNING entity %u link %u from %u/%u to %u/%u is invalid!\n",
 					id, i, link->source.entity, link->source.index,
 					link->sink.entity, link->sink.index);
 				ret = -EINVAL;
@@ -412,39 +418,40 @@ struct media_device *media_open(const char *name, int verbose)
 
 	media = calloc(1, sizeof(*media));
 	if (media == NULL) {
-		printf("%s: unable to allocate memory\n", __func__);
+		dprintf("%s: unable to allocate memory\n", __func__);
 		return NULL;
 	}
 
 	if (verbose)
-		printf("Opening media device %s\n", name);
+		dprintf("Opening media device %s\n", name);
+
 	media->fd = open(name, O_RDWR);
 	if (media->fd < 0) {
 		media_close(media);
-		printf("%s: Can't open media device %s\n", __func__, name);
+		dprintf("%s: Can't open media device %s\n", __func__, name);
 		return NULL;
 	}
 
 	if (verbose)
-		printf("Enumerating entities\n");
+		dprintf("Enumerating entities\n");
 
 	ret = media_enum_entities(media, verbose);
 
 	if (ret < 0) {
-		printf("%s: Unable to enumerate entities for device %s (%s)\n",
+		dprintf("%s: Unable to enumerate entities for device %s (%s)\n",
 			__func__, name, strerror(-ret));
 		media_close(media);
 		return NULL;
 	}
 
 	if (verbose) {
-		printf("Found %u entities\n", media->entities_count);
-		printf("Enumerating pads and links\n");
+		dprintf("Found %u entities\n", media->entities_count);
+		dprintf("Enumerating pads and links\n");
 	}
 
 	ret = media_enum_links(media);
 	if (ret < 0) {
-		printf("%s: Unable to enumerate pads and linksfor device %s\n",
+		dprintf("%s: Unable to enumerate pads and linksfor device %s\n",
 			__func__, name);
 		media_close(media);
 		return NULL;
@@ -472,3 +479,133 @@ void media_close(struct media_device *media)
 	free(media->entities);
 	free(media);
 }
+
+struct media_pad *media_parse_pad(struct media_device *media,
+				  const char *p, char **endp)
+{
+	unsigned int entity_id, pad;
+	struct media_entity *entity;
+	char *end;
+
+	for (; isspace(*p); ++p);
+
+	if (*p == '"') {
+		for (end = (char *)p + 1; *end && *end != '"'; ++end);
+		if (*end != '"')
+			return NULL;
+
+		entity = media_get_entity_by_name(media, p + 1, end - p - 1);
+		if (entity == NULL)
+			return NULL;
+
+		++end;
+	} else {
+		entity_id = strtoul(p, &end, 10);
+		entity = media_get_entity_by_id(media, entity_id);
+		if (entity == NULL)
+			return NULL;
+	}
+	for (; isspace(*end); ++end);
+
+	if (*end != ':')
+		return NULL;
+	for (p = end + 1; isspace(*p); ++p);
+
+	pad = strtoul(p, &end, 10);
+	for (p = end; isspace(*p); ++p);
+
+	if (pad >= entity->info.pads)
+		return NULL;
+
+	for (p = end; isspace(*p); ++p);
+	if (endp)
+		*endp = (char *)p;
+
+	return &entity->pads[pad];
+}
+
+struct media_link *media_parse_link(struct media_device *media,
+				    const char *p, char **endp)
+{
+	struct media_link *link;
+	struct media_pad *source;
+	struct media_pad *sink;
+	unsigned int i;
+	char *end;
+
+	source = media_parse_pad(media, p, &end);
+	if (source == NULL)
+		return NULL;
+
+	if (end[0] != '-' || end[1] != '>')
+		return NULL;
+	p = end + 2;
+
+	sink = media_parse_pad(media, p, &end);
+	if (sink == NULL)
+		return NULL;
+
+	*endp = end;
+
+	for (i = 0; i < source->entity->num_links; i++) {
+		link = &source->entity->links[i];
+
+		if (link->source == source && link->sink == sink)
+			return link;
+	}
+
+	return NULL;
+}
+
+int media_parse_setup_link(struct media_device *media,
+			   const char *p, char **endp)
+{
+	struct media_link *link;
+	__u32 flags;
+	char *end;
+
+	link = media_parse_link(media, p, &end);
+	if (link == NULL) {
+		dprintf("Unable to parse link\n");
+		return -EINVAL;
+	}
+
+	p = end;
+	if (*p++ != '[') {
+		dprintf("Unable to parse link flags\n");
+		return -EINVAL;
+	}
+
+	flags = strtoul(p, &end, 10);
+	for (p = end; isspace(*p); p++);
+	if (*p++ != ']') {
+		dprintf("Unable to parse link flags\n");
+		return -EINVAL;
+	}
+
+	for (; isspace(*p); p++);
+	*endp = (char *)p;
+
+	dprintf("Setting up link %u:%u -> %u:%u [%u]\n",
+		link->source->entity->info.id, link->source->index,
+		link->sink->entity->info.id, link->sink->index,
+		flags);
+
+	return media_setup_link(media, link->source, link->sink, flags);
+}
+
+int media_parse_setup_links(struct media_device *media, const char *p)
+{
+	char *end;
+	int ret;
+
+	do {
+		ret = media_parse_setup_link(media, p, &end);
+		if (ret < 0)
+			return ret;
+
+		p = end + 1;
+	} while (*end == ',');
+
+	return *end ? -EINVAL : 0;
+}
diff --git a/src/mediactl.h b/src/mediactl.h
index b53b9cc..937b918 100644
--- a/src/mediactl.h
+++ b/src/mediactl.h
@@ -140,7 +140,9 @@ struct media_entity *media_get_entity_by_id(struct media_device *media,
  *
  * Only the MEDIA_LINK_FLAG_ENABLED flag is writable.
  *
- * @return 0 on success, or a negative error code on failure.
+ * @return 0 on success, -1 on failure:
+ *	   -ENOENT: link not found
+ *	   - other error codes returned by MEDIA_IOC_SETUP_LINK
  */
 int media_setup_link(struct media_device *media,
 	struct media_pad *source, struct media_pad *sink,
@@ -157,4 +159,57 @@ int media_setup_link(struct media_device *media,
  */
 int media_reset_links(struct media_device *media);
 
+/**
+ * @brief Parse string to a pad on the media device.
+ * @param media - media device.
+ * @param p - input string
+ * @param endp - pointer to string where parsing ended
+ *
+ * Parse NULL terminated string describing a pad and return its struct
+ * media_pad instance.
+ *
+ * @return Pointer to struct media_pad on success, NULL on failure.
+ */
+struct media_pad *media_parse_pad(struct media_device *media,
+				  const char *p, char **endp);
+
+/**
+ * @brief Parse string to a link on the media device.
+ * @param media - media device.
+ * @param p - input string
+ * @param endp - pointer to p where parsing ended
+ *
+ * Parse NULL terminated string p describing a link and return its struct
+ * media_link instance.
+ *
+ * @return Pointer to struct media_link on success, NULL on failure.
+ */
+struct media_link *media_parse_link(struct media_device *media,
+				    const char *p, char **endp);
+
+/**
+ * @brief Parse string to a link on the media device and set it up.
+ * @param media - media device.
+ * @param p - input string
+ *
+ * Parse NULL terminated string p describing a link and its configuration
+ * and configure the link.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+int media_parse_setup_link(struct media_device *media,
+			   const char *p, char **endp);
+
+/**
+ * @brief Parse string to link(s) on the media device and set it up.
+ * @param media - media device.
+ * @param p - input string
+ *
+ * Parse NULL terminated string p describing link(s) separated by
+ * commas (,) and configure the link(s).
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+int media_parse_setup_links(struct media_device *media, const char *p);
+
 #endif