X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=include%2Fsound%2Fcontrol.h;h=112374dc0c5873b550bebc9d1700de189698b455;hb=98ca3964fe8da0d742331af80952443af5cff464;hp=4721b4bba0538360cd808db6c6cc0f13db9a3c7a;hpb=d3bd67cdbb5d12f30dfd1b627fd95bd6dcc7ff1e;p=safe%2Fjmp%2Flinux-2.6

diff --git a/include/sound/control.h b/include/sound/control.h
index 4721b4b..112374d 100644
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -56,7 +56,6 @@ struct snd_kcontrol_new {
 
 struct snd_kcontrol_volatile {
 	struct snd_ctl_file *owner;	/* locked */
-	pid_t owner_pid;
 	unsigned int access;	/* access rights */
 };
 
@@ -87,10 +86,12 @@ struct snd_kctl_event {
 
 #define snd_kctl_event(n) list_entry(n, struct snd_kctl_event, list)
 
+struct pid;
+
 struct snd_ctl_file {
 	struct list_head list;		/* list of all control files */
 	struct snd_card *card;
-	pid_t pid;
+	struct pid *pid;
 	int prefer_pcm_subdevice;
 	int prefer_rawmidi_subdevice;
 	wait_queue_head_t change_sleep;
@@ -171,6 +172,54 @@ int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
  */
 struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
 						 const unsigned int *tlv);
-int snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave);
-		      
+int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
+		       unsigned int flags);
+/* optional flags for slave */
+#define SND_CTL_SLAVE_NEED_UPDATE	(1 << 0)
+
+/**
+ * snd_ctl_add_slave - Add a virtual slave control
+ * @master: vmaster element
+ * @slave: slave element to add
+ *
+ * Add a virtual slave control to the given master element created via
+ * snd_ctl_create_virtual_master() beforehand.
+ * Returns zero if successful or a negative error code.
+ *
+ * All slaves must be the same type (returning the same information
+ * via info callback).  The fucntion doesn't check it, so it's your
+ * responsibility.
+ *
+ * Also, some additional limitations:
+ * at most two channels,
+ * logarithmic volume control (dB level) thus no linear volume,
+ * master can only attenuate the volume without gain
+ */
+static inline int
+snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave)
+{
+	return _snd_ctl_add_slave(master, slave, 0);
+}
+
+/**
+ * snd_ctl_add_slave_uncached - Add a virtual slave control
+ * @master: vmaster element
+ * @slave: slave element to add
+ *
+ * Add a virtual slave control to the given master.
+ * Unlike snd_ctl_add_slave(), the element added via this function
+ * is supposed to have volatile values, and get callback is called
+ * at each time quried from the master.
+ *
+ * When the control peeks the hardware values directly and the value
+ * can be changed by other means than the put callback of the element,
+ * this function should be used to keep the value always up-to-date.
+ */
+static inline int
+snd_ctl_add_slave_uncached(struct snd_kcontrol *master,
+			   struct snd_kcontrol *slave)
+{
+	return _snd_ctl_add_slave(master, slave, SND_CTL_SLAVE_NEED_UPDATE);
+}
+
 #endif	/* __SOUND_CONTROL_H */