serial: Pass port name/description as context attributes

Instead of overriding the context description that comes from the XML,
pass the serial port name and description as context attributes, and
keep the context description as-is.

Fixes #926.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>

serial.c

@@ -105,26 +105,6 @@ static int serial_get_version(const struct iio_context *ctx,
 			major, minor, git_tag);
 }
 
-static char * serial_get_description(struct sp_port *port)
-{
-	char *description, *name, *desc;
-	size_t desc_len;
-
-	name = sp_get_port_name(port);
-	desc = sp_get_port_description(port);
-
-	desc_len = sizeof(": \0") + strlen(name) + strlen(desc);
-	description = malloc(desc_len);
-	if (!description) {
-		errno = ENOMEM;
-		return NULL;
-	}
-
-	iio_snprintf(description, desc_len, "%s: %s", name, desc);
-
-	return description;
-}
-
 static int serial_open(const struct iio_device *dev,
 		size_t samples_count, bool cyclic)
 {
@@ -421,7 +401,7 @@ static struct iio_context * serial_create_context(const char *port_name,
 	struct sp_port *port;
 	struct iio_context_pdata *pdata;
 	struct iio_context *ctx;
-	char *description, *uri, buf[16];
+	char *uri, buf[16];
 	size_t uri_len;
 	unsigned int i;
 	int ret;
@@ -466,14 +446,10 @@ static struct iio_context * serial_create_context(const char *port_name,
 		}
 	} while (ret);
 
-	description = serial_get_description(port);
-	if (!description)
-		goto err_close_port;
-
 	pdata = zalloc(sizeof(*pdata));
 	if (!pdata) {
 		errno = ENOMEM;
-		goto err_free_description;
+		goto err_close_port;
 	}
 
 	pdata->port = port;
@@ -490,7 +466,6 @@ static struct iio_context * serial_create_context(const char *port_name,
 	ctx->name = "serial";
 	ctx->ops = &serial_ops;
 	ctx->pdata = pdata;
-	ctx->description = description;
 
 	for (i = 0; i < iio_context_get_devices_count(ctx); i++) {
 		struct iio_device *dev = iio_context_get_device(ctx, i);
@@ -510,6 +485,15 @@ static struct iio_context * serial_create_context(const char *port_name,
 		goto err_context_destroy;
 	free(uri);
 
+	ret = iio_context_add_attr(ctx, "serial,port", sp_get_port_name(port));
+	if (ret < 0)
+		goto err_context_destroy;
+
+	ret = iio_context_add_attr(ctx, "serial,description",
+				   sp_get_port_description(port));
+	if (ret < 0)
+		goto err_context_destroy;
+
 	return ctx;
 
 err_context_destroy:
@@ -522,8 +506,6 @@ static struct iio_context * serial_create_context(const char *port_name,
 	iiod_client_destroy(pdata->iiod_client);
 err_free_pdata:
 	free(pdata);
-err_free_description:
-	free(description);
 err_close_port:
 	sp_close(port);
 err_free_port: