[PATCH v3] ucm: add existence checks to geti calls

[cujomalainey at chromium.org]

From: Curtis Malainey <cujomalainey at chromium.org>

Right now in snd_use_case_geti you cannot tell if the item being queried
exists or not when being checked. This also means the only way to check
for the existence of something in the client of the library is to
iterate over the list of mods/devs even if we know exactly the name we
are looking for. We have functions that do exactly this internally so
lets return this information in a logical fashion through geti.

Also clean up some trailing white space nearby.

Signed-off-by: Curtis Malainey <cujomalainey at chromium.org>
---
 src/ucm/main.c | 83 ++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 67 insertions(+), 16 deletions(-)

diff --git a/src/ucm/main.c b/src/ucm/main.c
index 2ff4d3f3..55867012 100644
--- a/src/ucm/main.c
+++ b/src/ucm/main.c
@@ -2414,12 +2414,73 @@ int snd_use_case_get(snd_use_case_mgr_t *uc_mgr,
 	return err;
 }
 
+/**
+ * \brief check device status and existance
+ * \param uc_mgr Use case manager
+ * \param str device identifier
+ * \param value Value pointer
+ * \return Zero if success, otherwise a negative error code
+ */
+static long check_device(snd_use_case_mgr_t *uc_mgr,
+		      const char *str,
+		      long *value)
+{
+	struct use_case_device *dev;
+	int err;
+
+	if (!str) {
+		return -EINVAL;
+	}
+	err = device_status(uc_mgr, str);
+	if (err > 0) {
+		*value = err;
+		err = 0;
+	} else if (err < 0) {
+		return err;
+	}
+	dev = find_device(uc_mgr, uc_mgr->active_verb, str, 0);
+	if (!dev) {
+		return -ENOENT;
+	}
+	return 0;
+}
+
+/**
+ * \brief check modifier status and existance
+ * \param uc_mgr Use case manager
+ * \param str modifier identifier
+ * \param value Value pointer
+ * \return Zero if success, otherwise a negative error code
+ */
+static long check_modifier(snd_use_case_mgr_t *uc_mgr,
+		      const char *str,
+		      long *value)
+{
+	struct use_case_modifier *mod;
+	long err;
+
+	if (!str) {
+		return -EINVAL;
+	}
+	err = modifier_status(uc_mgr, str);
+	if (err > 0) {
+		*value = err;
+		return 0;
+	} else if (err < 0) {
+		return err;
+	}
+	mod = find_modifier(uc_mgr, uc_mgr->active_verb, str, 0);
+	if (!mod) {
+		return -ENOENT;
+	}
+	return 0;
+}
 
 /**
  * \brief Get current - integer
  * \param uc_mgr Use case manager
- * \param identifier 
- * \return Value if success, otherwise a negative error code 
+ * \param identifier
+ * \return Value if success, otherwise a negative error code
  */
 int snd_use_case_geti(snd_use_case_mgr_t *uc_mgr,
 		      const char *identifier,
@@ -2443,25 +2504,15 @@ int snd_use_case_geti(snd_use_case_mgr_t *uc_mgr,
 			str = NULL;
 		}
 		if (check_identifier(identifier, "_devstatus")) {
-			if (!str) {
-				err = -EINVAL;
+			err = check_device(uc_mgr, str, value);
+			if (err < 0) {
 				goto __end;
 			}
-			err = device_status(uc_mgr, str);
-			if (err >= 0) {
-				*value = err;
-				err = 0;
-			}
 		} else if (check_identifier(identifier, "_modstatus")) {
-			if (!str) {
-				err = -EINVAL;
+			err = check_modifier(uc_mgr, str, value);
+			if (err < 0) {
 				goto __end;
 			}
-			err = modifier_status(uc_mgr, str);
-			if (err >= 0) {
-				*value = err;
-				err = 0;
-			}
 #if 0
 		/*
 		 * enable this block if the else clause below is expanded to query
-- 
2.39.0.314.g84b9a713c41-goog