ump_msg: Add a new helper snd_ump_get_byte()

For making it easier to extract a byte from the UMP packet no matter which endian is used, introduce a new helper function snd_ump_get_byte(). It'll be useful for retrieving SysEx byte or a name string. Signed-off-by: Takashi Iwai <[email protected]>
thesofproject · Jul 28, 2024 · 28948f2 · 28948f2
1 parent 530e2f8
commit 28948f2
Showing 1 changed file with 12 additions and 0 deletions.
diff --git a/include/ump_msg.h b/include/ump_msg.h
@@ -1001,6 +1001,18 @@ static inline uint8_t snd_ump_sysex_msg_length(const uint32_t *ump)
 	return (*ump >> 16) & 0xf;
 }
 
+/**
+ * \brief extract one byte from a UMP packet
+ */
+static inline uint8_t snd_ump_get_byte(const uint32_t *ump, unsigned int offset)
+{
+#ifdef SNDRV_BIG_ENDIAN
+	return ((const uint8_t *)ump)[offset];
+#else
+	return ((const uint8_t *)ump)[(offset & ~3) | (3 - (offset & 3))];
+#endif
+}
+
 int snd_ump_msg_sysex_expand(const uint32_t *ump, uint8_t *buf, size_t maxlen,
 			     size_t *filled);
 int snd_ump_packet_length(unsigned int type);