+/**
+ * snd_jack_set_key - Set a key mapping on a jack
+ *
+ * @jack: The jack to configure
+ * @type: Jack report type for this key
+ * @keytype: Input layer key type to be reported
+ *
+ * Map a SND_JACK_BTN_ button type to an input layer key, allowing
+ * reporting of keys on accessories via the jack abstraction. If no
+ * mapping is provided but keys are enabled in the jack type then
+ * BTN_n numeric buttons will be reported.
+ *
+ * Note that this is intended to be use by simple devices with small
+ * numbers of keys that can be reported. It is also possible to
+ * access the input device directly - devices with complex input
+ * capabilities on accessories should consider doing this rather than
+ * using this abstraction.
+ *
+ * This function may only be called prior to registration of the jack.
+ */
+int snd_jack_set_key(struct snd_jack *jack, enum snd_jack_types type,
+ int keytype)
+{
+ int key = fls(SND_JACK_BTN_0) - fls(type);
+
+ WARN_ON(jack->registered);
+
+ if (!keytype || key >= ARRAY_SIZE(jack->key))
+ return -EINVAL;
+
+ jack->type |= type;
+ jack->key[key] = keytype;
+
+ return 0;
+}
+EXPORT_SYMBOL(snd_jack_set_key);
+