ALSA: hda - add DP mst verb support

Add snd_hda_get_dev_select() and snd_hda_set_dev_select() functions
for DP MST audio support.

Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Libin Yang <libin.yang@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1484208294-8637-2-git-send-email-libin.yang@intel.com

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 9913be8..9dc847d 100644 (file)
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -311,9 +311,15 @@ int snd_hda_get_conn_index(struct hda_codec *codec, hda_nid_t mux,
 }
 EXPORT_SYMBOL_GPL(snd_hda_get_conn_index);
 
-
-/* return DEVLIST_LEN parameter of the given widget */
-static unsigned int get_num_devices(struct hda_codec *codec, hda_nid_t nid)
+/**
+ * snd_hda_get_num_devices - get DEVLIST_LEN parameter of the given widget
+ *  @codec: the HDA codec
+ *  @nid: NID of the pin to parse
+ *
+ * Get the device entry number on the given widget. This is a feature of
+ * DP MST audio. Each pin can have several device entries in it.
+ */
+unsigned int snd_hda_get_num_devices(struct hda_codec *codec, hda_nid_t nid)
 {
        unsigned int wcaps = get_wcaps(codec, nid);
        unsigned int parm;
@@ -327,6 +333,7 @@ static unsigned int get_num_devices(struct hda_codec *codec, hda_nid_t nid)
                parm = 0;
        return parm & AC_DEV_LIST_LEN_MASK;
 }
+EXPORT_SYMBOL_GPL(snd_hda_get_num_devices);
 
 /**
  * snd_hda_get_devices - copy device list without cache
@@ -344,7 +351,7 @@ int snd_hda_get_devices(struct hda_codec *codec, hda_nid_t nid,
        unsigned int parm;
        int i, dev_len, devices;
 
-       parm = get_num_devices(codec, nid);
+       parm = snd_hda_get_num_devices(codec, nid);
        if (!parm)      /* not multi-stream capable */
                return 0;
 
@@ -368,6 +375,63 @@ int snd_hda_get_devices(struct hda_codec *codec, hda_nid_t nid,
        return devices;
 }
 
+/**
+ * snd_hda_get_dev_select - get device entry select on the pin
+ * @codec: the HDA codec
+ * @nid: NID of the pin to get device entry select
+ *
+ * Get the devcie entry select on the pin. Return the device entry
+ * id selected on the pin. Return 0 means the first device entry
+ * is selected or MST is not supported.
+ */
+int snd_hda_get_dev_select(struct hda_codec *codec, hda_nid_t nid)
+{
+       /* not support dp_mst will always return 0, using first dev_entry */
+       if (!codec->dp_mst)
+               return 0;
+
+       return snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_DEVICE_SEL, 0);
+}
+EXPORT_SYMBOL_GPL(snd_hda_get_dev_select);
+
+/**
+ * snd_hda_set_dev_select - set device entry select on the pin
+ * @codec: the HDA codec
+ * @nid: NID of the pin to set device entry select
+ * @dev_id: device entry id to be set
+ *
+ * Set the device entry select on the pin nid.
+ */
+int snd_hda_set_dev_select(struct hda_codec *codec, hda_nid_t nid, int dev_id)
+{
+       int ret, num_devices;
+
+       /* not support dp_mst will always return 0, using first dev_entry */
+       if (!codec->dp_mst)
+               return 0;
+
+       /* AC_PAR_DEVLIST_LEN is 0 based. */
+       num_devices = snd_hda_get_num_devices(codec, nid) + 1;
+       /* If Device List Length is 0 (num_device = 1),
+        * the pin is not multi stream capable.
+        * Do nothing in this case.
+        */
+       if (num_devices == 1)
+               return 0;
+
+       /* Behavior of setting index being equal to or greater than
+        * Device List Length is not predictable
+        */
+       if (num_devices <= dev_id)
+               return -EINVAL;
+
+       ret = snd_hda_codec_write(codec, nid, 0,
+                       AC_VERB_SET_DEVICE_SEL, dev_id);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(snd_hda_set_dev_select);
+
 /*
  * read widget caps for each widget and store in cache
  */

diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h
index 373fcad..f17f252 100644 (file)
--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -347,8 +347,11 @@ int snd_hda_override_conn_list(struct hda_codec *codec, hda_nid_t nid, int nums,
                          const hda_nid_t *list);
 int snd_hda_get_conn_index(struct hda_codec *codec, hda_nid_t mux,
                           hda_nid_t nid, int recursive);
+unsigned int snd_hda_get_num_devices(struct hda_codec *codec, hda_nid_t nid);
 int snd_hda_get_devices(struct hda_codec *codec, hda_nid_t nid,
                        u8 *dev_list, int max_devices);
+int snd_hda_get_dev_select(struct hda_codec *codec, hda_nid_t nid);
+int snd_hda_set_dev_select(struct hda_codec *codec, hda_nid_t nid, int dev_id);
 
 struct hda_verb {
        hda_nid_t nid;